1.
Automotive industry
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The automotive industry is a wide range of companies and organizations involved in the design, development, manufacturing, marketing, and selling of motor vehicles, some of them are called automakers. It is one of the worlds most important economic sectors by revenue, the term automotive was created from Greek autos, and Latin motivus to represent any form of self-powered vehicle. This term was proposed by Elmer Sperry, the automotive industry began in the 1890s with hundreds of manufacturers that pioneered the horseless carriage. For many decades, the United States led the world in automobile production. In 1929, before the Great Depression, the world had 32,028,500 automobiles in use, at that time the U. S. had one car per 4.87 persons. After World War II, the U. S. produced about 75 percent of auto production. In 1980, the U. S. was overtaken by Japan, in 2006, Japan narrowly passed the U. S. in production and held this rank until 2009, when China took the top spot with 13.8 million units. With 19.3 million units manufactured in 2012, China almost doubled the U. S. production, with 10.3 million units, from 1970 over 1998 to 2012, the number of automobile models in the U. S. has grown exponentially. Safety is a state that implies to be protected from any risk, danger, in the automotive industry, safety means that users, operators or manufacturers do not face any risk or danger coming from the motor vehicle or its spare parts. Safety for the automobiles themselves, implies there is no risk of damage. Safety in the industry is particularly important and therefore highly regulated. Automobiles and other vehicles have to comply with a certain number of norms and regulations, whether local or international. The standard ISO26262, is considered as one of the best practice framework for achieving automotive functional safety. In case of safety issues, danger, product defect or faulty procedure during the manufacturing of the motor vehicle and this procedure is called product recall. Product recalls happen in every industry and can be production-related or stem from the raw material, however, the automotive industry is still particularly concerned about product recalls, which cause considerable financial consequences. Around the world, there were about 806 million cars and light trucks on the road in 2007, consuming over 980 billion litres of gasoline, the automobile is a primary mode of transportation for many developed economies. The Detroit branch of Boston Consulting Group predicts that, by 2014, meanwhile, in the developed countries, the automotive industry has slowed down. It is also expected that this trend will continue, especially as the generations of people no longer want to own a car anymore
2.
Volkswagen
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Volkswagen, shortened to VW, is a German automaker founded on May 28,1937 by the German Labour Front and headquartered in Wolfsburg. It is the flagship marque of the Volkswagen Group and is the largest automaker worldwide, Volkswagen is German for peoples car, and the companys current international advertising slogan is just Volkswagen. American English pronunciation is approximately volks wagon, for vehicle timeline tables, see, Volkswagen. Volkswagen was originally established in 1937 by the German Labour Front, in the early 1930s, the German auto industry was still largely composed of luxury models, and the average German could rarely afford anything more than a motorcycle. As a result, only one German out of 50 owned a car, seeking a potential new market, some car makers began independent peoples car projects – the Mercedes 170H, Adler AutoBahn, Steyr 55, and Hanomag 1. 3L, among others. The trend was not new, as Béla Barényi is credited with having conceived the design in the mid-1920s. Josef Ganz developed the Standard Superior, in Germany, the company Hanomag mass-produced the 2/10 PS Komissbrot, a small, cheap rear engined car, from 1925 to 1928. Also, in Czechoslovakia, the Hans Ledwinkas penned Tatra T77, Ferdinand Porsche, a well-known designer for high-end vehicles and race cars, had been trying for years to get a manufacturer interested in a small car suitable for a family. He felt the cars at the time were just stripped down big cars. He wanted his German citizens to have the access to a car as the Americans. The Peoples Car would be available to citizens of the Third Reich through a plan at 990 Reichsmark —about the price of a small motorcycle. Despite heavy lobbying in favor of one of the existing projects, thus, Hitler chose to sponsor an all-new, state-owned factory using Ferdinand Porsches design. The intention was that ordinary Germans would buy the car by means of a savings scheme, however, the entire project was financially unsound, and only the corruption and lack of accountability of the Nazi regime made it possible. Prototypes of the car called the KdF-Wagen, appeared from 1938 onwards, the car already had its distinctive round shape and air-cooled, flat-four, rear-mounted engine. The VW car was just one of many KdF programs, which included such as tours. The prefix Volks— was not just applied to cars, but also to products in Germany. On May 28,1937, Gesellschaft zur Vorbereitung des Deutschen Volkswagens mbH, more than a year later, on September 16,1938, it was renamed to Volkswagenwerk GmbH. Erwin Komenda, the longstanding Auto Union chief designer, part of Ferdinand Porsches hand-picked team, developed the car body of the prototype and it was one of the first cars designed with the aid of a wind tunnel—a method used for German aircraft design since the early 1920s
3.
Flat-four engine
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A flat-four or horizontally opposed-four is a type of four-cylinder engine, a flat engine with four cylinders arranged horizontally in two banks of two cylinders on each side of a central crankcase. The design is seen with shared crank throws, so flat-four and boxer-four are usually used synonymously. The configuration results in inherently good balance of the parts, a low centre of gravity. The layout also lends itself to efficient air cooling with excellent thermal balance, the low centre of gravity of the engine is an advantage. The shape of the engine suits it better for mid engine or rear engine designs, with a rear engine layout, it allows a low-tail body while in front engine designs the width of the engine often interferes with the maximum front wheel steering angle. Boxer engines tend to be better balanced than other four-cylinder configurations and this problem becomes worse with increased piston speed and weight, effectively limiting the capacity of these engines. Inline-fours larger than 2.0 L usually have balance shafts whilst engines over 3.0 L are seldom used in passenger cars. In contrast, the flat-four has much less secondary imbalance at the expense of larger rocking vibrations and this is because the cylinders cannot be directly opposed, but must be offset so the connecting rods can be on separate crank pins, which results in the forces being slightly off-centre. The rocking vibration is not serious enough to require balance shafts. As the firing order on an ordinary flat-four boxer engine on Left, by counting two characters to the right of each L or R, the cylinders that fire with 360 degree crankshaft rotational angle offset are shown to be located on opposite banks. As a result, most Subaru flat-four engines no longer have the flat-four burble, the Impreza WRX and WRX STI still have unequal length exhaust pipes to feed the turbo sitting in the corner of the engine bay, and still have the characteristic burble. This was changed for the 2015 WRX which feeds a centrally mounted turbo and they are, however, a somewhat popular aftermarket modification. In addition, four-stroke cycle flat-fours have a common to all four-cylinder engines. This results in gaps between strokes and a pulsating delivery of torque to the flywheel, causing a rotational vibration on the entire engine along the crankshaft axis. By contrast, in engines with more cylinders the power strokes overlap, the piston starts its power stroke before the previous one has finished. Luxury performance car manufacturers prefer to use the inline-six, flat-six, or V8 configurations because these designs are much smoother than the flat-four, in 1897 Karl Benz developed the boxer engine. This drive system, in two horizontally opposed cylinders turned a single crankshaft, was given the name “contra engine”. The unit was used from 1899 onwards, principally in passenger, the final evolutionary stage of the Benz racing car equipped with a contra engine was the 20-hp Benz vehicle introduced in 1900
4.
Petrol engine
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A petrol engine is an internal combustion engine with spark-ignition, designed to run on petrol and similar volatile fuels. In most petrol engines, the fuel and air are usually pre-mixed before compression, the process differs from a diesel engine in the method of mixing the fuel and air, and in using spark plugs to initiate the combustion process. In a diesel engine, only air is compressed, and the fuel is injected into very hot air at the end of the compression stroke, and self-ignites. The first practical petrol engine was built in 1876 in Germany by Nikolaus August Otto, although there had been attempts by Étienne Lenoir, Siegfried Marcus, Julius Hock. The first petrol engine was prototyped in 1882 in Italy by Enrico Bernardi. British engineer Edward Butler constructed the first petrol combustion engine. Butler invented the spark plug, ignition magneto, coil ignition and spray jet carburetor, with both air and fuel in a closed cylinder, compressing the mixture too much poses the danger of auto-ignition — or behaving like a diesel engine. Spark plugs are typically set statically or at idle at a minimum of 10 degrees or so of crankshaft rotation before the piston reaches T. D, higher octane petrol burns slower, therefore it has a lower propensity to auto-ignite and its rate of expansion is lower. Thus, engines designed to run high-octane fuel exclusively can achieve higher compression ratios, Petrol engines run at higher rotation speeds than diesels, partially due to their lighter pistons, connecting rods and crankshaft and due to petrol burning more quickly than diesel. However the lower compression ratios of petrol engines give petrol engines lower efficiency than diesel engines, examples, Bedford OB bus Bedford M series lorry GE 57-ton gas-electric boxcab locomotive Petrol engines may run on the four-stroke cycle or the two-stroke cycle. For details of working cycles see, Four-stroke cycle Two-stroke cycle Wankel engine Common cylinder arrangements are from 1 to 6 cylinders in-line or from 2 to 16 cylinders in V-formation. Flat engines – like a V design flattened out – are common in airplanes and motorcycles and were a hallmark of Volkswagen automobiles into the 1990s. Flat 6s are still used in many modern Porsches, as well as Subarus, less common, but notable in vehicles designed for high speeds is the W formation, similar to having 2 V engines side by side. Alternatives include rotary and radial engines the latter typically have 7 or 9 cylinders in a single ring, Petrol engines may be air-cooled, with fins, or liquid-cooled, by a water jacket and radiator. The coolant was formerly water, but is now usually a mixture of water and either ethylene glycol or propylene glycol, the cooling system is usually slightly pressurized to further raise the boiling point of the coolant. Petrol engines use spark ignition and high current for the spark may be provided by a magneto or an ignition coil. In modern car engines the ignition timing is managed by an electronic Engine Control Unit, the most common way of engine rating is what is known as the brake power, measured at the flywheel, and given in kilowatts or horsepower. This is the mechanical power output of the engine in a usable
5.
Cylinder block
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A cylinder block is an integrated structure comprising the cylinder of a reciprocating engine and often some or all of their associated surrounding structures. The term engine block is used synonymously with cylinder block. In the basic terms of elements, the various main parts of an engine are conceptually distinct. However, it is no longer the way of building most petrol engines and diesel engines, because for any given engine configuration. These generally involve integrating multiple machine elements into one discrete part and this yields lower unit cost of production. Thus engine block, cylinder block, or simply block are the likely to be heard in the garage or on the street. This evolution has occurred throughout the history of reciprocating engines, with instances of every conceptual variation coexisting here and there. The increase in prevalence of ever-more-integrated designs relied on the development of foundry. For example, a practical low-cost V8 engine was not feasible until Ford developed the techniques used to build the Ford flathead V8 engine, which soon also disseminated to the larger society. Today the foundry and machining processes for manufacturing engines are highly automated. A cylinder block is a unit comprising several cylinders, in the earliest decades of internal combustion engine development, monobloc cylinder construction was rare, cylinders were usually cast individually. Combining their castings into pairs or triples was a win of monobloc design. A wet liner cylinder block features cylinder walls that are entirely removable and they are referred to as wet liners because their outer sides come in direct contact with the engines coolant. In other words, the liner is the wall, rather than being merely a sleeve. Wet liner designs are popular with European manufacturers, most notably Renault and Peugeot, dry liner designs use either the blocks material or a discrete liner inserted into the block to form the backbone of the cylinder wall. Additional sleeves are inserted within, which dry on their outside. It is likelier to be scrapped, with new equipment—engine or entire vehicle—replacing it, most early engines, particularly those with more than four cylinders, had their cylinders cast as pairs or triplets of cylinders, then bolted to a single crankcase. As casting techniques improved, a cylinder block of 4,6
6.
Aluminium
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Aluminium or aluminum is a chemical element in the boron group with symbol Al and atomic number 13. It is a silvery-white, soft, nonmagnetic, ductile metal, Aluminium metal is so chemically reactive that native specimens are rare and limited to extreme reducing environments. Instead, it is combined in over 270 different minerals. The chief ore of aluminium is bauxite, Aluminium is remarkable for the metals low density and its ability to resist corrosion through the phenomenon of passivation. Aluminium and its alloys are vital to the industry and important in transportation and structures, such as building facades. The oxides and sulfates are the most useful compounds of aluminium, despite its prevalence in the environment, no known form of life uses aluminium salts metabolically, but aluminium is well tolerated by plants and animals. Because of these salts abundance, the potential for a role for them is of continuing interest. Aluminium is a soft, durable, lightweight, ductile. It is nonmagnetic and does not easily ignite, a fresh film of aluminium serves as a good reflector of visible light and an excellent reflector of medium and far infrared radiation. The yield strength of aluminium is 7–11 MPa, while aluminium alloys have yield strengths ranging from 200 MPa to 600 MPa. Aluminium has about one-third the density and stiffness of steel and it is easily machined, cast, drawn and extruded. Aluminium atoms are arranged in a cubic structure. Aluminium has an energy of approximately 200 mJ/m2. Aluminium is a thermal and electrical conductor, having 59% the conductivity of copper. Aluminium is capable of superconductivity, with a critical temperature of 1.2 kelvin. Aluminium is the most common material for the fabrication of superconducting qubits, the strongest aluminium alloys are less corrosion resistant due to galvanic reactions with alloyed copper. This corrosion resistance is reduced by aqueous salts, particularly in the presence of dissimilar metals. In highly acidic solutions, aluminium reacts with water to form hydrogen, primarily because it is corroded by dissolved chlorides, such as common sodium chloride, household plumbing is never made from aluminium
7.
Magnesium
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Magnesium is a chemical element with symbol Mg and atomic number 12. Magnesium is the ninth most abundant element in the universe and it is produced in large, aging stars from the sequential addition of three helium nuclei to a carbon nucleus. When such stars explode as supernovas, much of the magnesium is expelled into the medium where it may recycle into new star systems. Magnesium is the eighth most abundant element in the Earths crust and the fourth most common element in the Earth, making up 13% of the planets mass and it is the third most abundant element dissolved in seawater, after sodium and chlorine. Magnesium occurs naturally only in combination with elements, where it invariably has a +2 oxidation state. The free element can be produced artificially, and is highly reactive, the free metal burns with a characteristic brilliant-white light. The metal is now obtained mainly by electrolysis of magnesium salts obtained from brine, Magnesium is less dense than aluminium, and the alloy is prized for its combination of lightness and strength. Magnesium is the eleventh most abundant element by mass in the body and is essential to all cells. Magnesium ions interact with polyphosphate compounds such as ATP, DNA, hundreds of enzymes require magnesium ions to function. Magnesium compounds are used medicinally as common laxatives, antacids, elemental magnesium is a gray-white lightweight metal, two-thirds the density of aluminium. Magnesium has the lowest melting and the lowest boiling point 1,363 K of all the alkaline earth metals, Magnesium reacts with water at room temperature, though it reacts much more slowly than calcium, a similar group 2 metal. When submerged in water, hydrogen bubbles form slowly on the surface of the metal—though, if powdered, the reaction occurs faster with higher temperatures. Magnesiums reversible reaction with water can be harnessed to store energy, Magnesium also reacts exothermically with most acids such as hydrochloric acid, producing the metal chloride and hydrogen gas, similar to the HCl reaction with aluminium, zinc, and many other metals. Magnesium is highly flammable, especially when powdered or shaved into thin strips, flame temperatures of magnesium and magnesium alloys can reach 3,100 °C, although flame height above the burning metal is usually less than 300 mm. Once ignited, such fires are difficult to extinguish, with combustion continuing in nitrogen, carbon dioxide, Magnesium may also be used as an igniter for thermite, a mixture of aluminium and iron oxide powder that ignites only at a very high temperature. When burning in air, magnesium produces a light that includes strong ultraviolet wavelengths. Magnesium powder was used for illumination in the early days of photography. Later, magnesium filament was used in electrically ignited single-use photography flashbulbs, Magnesium powder is used in fireworks and marine flares where a brilliant white light is required
8.
Alloy
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An alloy is a mixture of metals or a mixture of a metal and another element. Alloys are defined by a metallic bonding character, an alloy may be a solid solution of metal elements or a mixture of metallic phases. Intermetallic compounds are alloys with a stoichiometry and crystal structure. Zintl phases are sometimes considered alloys depending on bond types. Alloys are used in a variety of applications. In some cases, a combination of metals may reduce the overall cost of the material while preserving important properties, in other cases, the combination of metals imparts synergistic properties to the constituent metal elements such as corrosion resistance or mechanical strength. Examples of alloys are steel, solder, brass, pewter, duralumin, bronze, the alloy constituents are usually measured by mass. Alloys are usually classified as substitutional or interstitial alloys, depending on the arrangement that forms the alloy. They can be classified as homogeneous, or heterogeneous or intermetallic. An alloy is a mixture of elements, which forms an impure substance that retains the characteristics of a metal. Alloys are made by mixing two or more elements, at least one of which is a metal and this is usually called the primary metal or the base metal, and the name of this metal may also be the name of the alloy. The other constituents may or may not be metals but, when mixed with the base, they will be soluble. The mechanical properties of alloys will often be different from those of its individual constituents. A metal that is very soft, such as aluminium, can be altered by alloying it with another soft metal. Although both metals are soft and ductile, the resulting aluminium alloy will have much greater strength. Adding a small amount of carbon to iron trades its great ductility for the greater strength of an alloy called steel. Due to its strength, but still substantial toughness, and its ability to be greatly altered by heat treatment, steel is one of the most useful. By adding chromium to steel, its resistance to corrosion can be enhanced, creating stainless steel, while adding silicon will alter its electrical characteristics, producing silicon steel
9.
Cylinder head
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In an internal combustion engine, the cylinder head sits above the cylinders on top of the cylinder block. It closes in the top of the cylinder, forming the combustion chamber and this joint is sealed by a head gasket. In most engines, the head also provides space for the passages that feed air and fuel to the cylinder, the head can also be a place to mount the valves, spark plugs, and fuel injectors. With a chain drive to a camshaft, the extra length of chain needed for an overhead cam design could give trouble from wear. Early sidevalve engines were in use at a time of simple fuel chemistry, low octane ratings and this made their combustion chamber design less critical and there was less need to design their ports and airflow carefully. One difficulty experienced at this time was that the low compression ratio also implied a low expansion ratio during the power stroke, exhaust gases were thus still hot, hotter than a contemporary engine, and this led to frequent trouble with burnt exhaust valves. A major improvement to the engine was the advent of Ricardos turbulent head design. This reduced the space within the chamber and the ports. Most importantly, it used turbulence within the chamber to thoroughly mix the fuel and this, of itself, allowed the use of higher compression ratios and more efficient engine operation. Despite common knowledge, the limit on performance is not the gas flow through the valves. With high speed engines and high compression, the limiting difficulty becomes that of achieving complete and efficient combustion, modern, efficient engines thus tend towards the pent roof or hemi designs, where the valves are brought close in to the centre of the space. Where fuel quality is low and octane rating is poor, compression ratios will be restricted, in these cases, the sidevalve engine still has much to offer. Such engines remained in production into the 1990s, only being replaced when the fuels available in the field became more likely to be diesel than petrol. In the overhead valve design, the head contains the poppet valves. In the overhead camshaft design, the head contains the valves, spark plugs and inlet/exhaust tracts just like the OHV engine. The number of heads in an engine is a function of the engine configuration. Almost all inline engines today use a cylinder head that serves all the cylinders. A V engine has two heads, one for each cylinder bank of the V
10.
Valvetrain
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A valve train or valvetrain is a mechanical system that controls operation of the valves in an internal combustion engine, in which a sequence of components transmits motion throughout the assembly. A traditional reciprocating internal combustion engine uses valves to control air and fuel flow into and out of the cylinders, the valve train consists of valves, rocker arms, pushrods, lifters, and camshaft. Valve train opening/closing and duration, as well as the geometry of the train, controls the amount of air. Timing for open/close/duration is controlled by the camshaft that is synchronized to the crankshaft by a chain, belt, camless This layout uses no camshafts at all. Technologies such as solenoids are used to actuate the valves. The valve train is the system responsible for operation of the valves. Valves are usually of the type, although many others have been developed such as sleeve, slide. Poppet valves typically require small coil springs, appropriately named valve springs and they are attached to the valve stem ends, seating within spring retainers. Depending on the used, the valves are actuated directly by a rocker arm, finger. Overhead camshaft engines use fingers or bucket tappets, upon which the cam lobes contact, rocker arms are actuated by a pushrod, and pivot on a shaft or individual ball studs in order to actuate the valves. Pushrods are long, slender metal rods seated within the engine block, at the bottom ends the pushrods are fitted with lifters, either solid or hydraulic, upon which the camshaft, located within the cylinder block, makes contact. The camshaft pushes on the lifter, which pushes on the pushrod, which pushes on the rocker arm, camshafts must actuate the valves at the appropriate time in the combustion cycle. In order to accomplish this the camshaft is linked to and kept in synchronisation with the crankshaft through the use of a chain, rubber belt. Because these mechanisms are essential to the timing of valve actuation they are named timing chains, timing belts. Typical normal-service engine valve-train components may be too lightweight for operating at high revolutions per minute, valve float will damage the valvetrain over time, and could cause the valve to be damaged as it is still partially open while the piston comes to the top of its stroke. Upgrading to high pressure valve springs could allow higher valvetrain speeds, high-output and engines used in competition feature camshafts and valvetrain components that are designed to withstand higher RPM ranges. These changes also include additional modifications such as larger-sized valves combined with freer breathing intake, automakers offer factory-approved performance parts to increase engine output, and numerous aftermarket parts vendors specialize in valvetrain modifications for various engine applications
11.
Overhead valve engine
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An overhead valve engine is an engine in which the valves are placed in the cylinder head. This was an improvement over the flathead engine, where the valves were placed in the block next to the piston. Overhead camshaft engines, while overhead valve by definition, are usually categorized apart from other OHV engines. Lifters or tappets are located in the block between the camshaft and pushrods. By contrast, overhead camshaft design avoids the use of pushrods by putting the camshaft directly above the valves in the cylinder head, in 1900, Marr was hired as chief engineer at the Buick Auto-Vim and Power Company in Detroit, where he worked until 1902. Marr said he got the idea of overhead valves when making the small tricycle engine, marrs engine employed pushrod-actuated rocker arms, which in turn pushed valves parallel to the pistons, and this is still in use today. This contrasts with previous designs which use of side valves. Marr left Buick briefly to start his own company in 1902, the Marr Auto-Car. The OHV engine was patented in 1902 by Buicks second chief engineer Eugene Richard, at the Buick Manufacturing Company, precursor to the Buick Motor Company. The worlds first production overhead valve engine was put into the first production Buick automobile, the 1904 Model B, the engine was designed by Marr and David Buick. Eugene Richard of the Buick Manufacturing Company was awarded US Patent #771,095 in 1904 for the valve in head engine. Arthur Chevrolet was awarded US Patent #1,744,526 for an adapter that could be applied to an existing engine, in 1949, Oldsmobile introduced the Rocket V8. It was the first high-compression I-head design, and is the archetype for most modern pushrod engines, general Motors is the worlds largest pushrod engine producer, producing both I4, V6 and V8 pushrod engines. Nowadays, automotive use of side-valves has virtually disappeared, and valves are almost all overhead, however, most are now driven more directly by the overhead camshaft system. Few pushrod-type engines remain in production outside of the United States market and this is in part a result of some countries passing laws to tax engines based on displacement, because displacement is somewhat related to the emissions and fuel efficiency of an automobile. This has given OHC engines a regulatory advantage in those countries, however, in 2002, Chrysler introduced a new pushrod engine, a 5. 7-litre Hemi engine. The new Chrysler Hemi engine presents advanced features such as variable displacement technology and has been an option with buyers. The Hemi was on the Wards 10 Best Engines list for 2003 through 2007, Chrysler also produced the worlds first production variable-valve OHV engine with independent intake and exhaust phasing
12.
Fuel
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A fuel is any material that can be made to react with other substances so that it releases chemical or nuclear energy as heat or to be used for work. The concept was applied solely to those materials capable of releasing chemical energy but has since also been applied to other sources of heat energy such as nuclear energy. The heat energy released by reactions of fuels is converted into mechanical energy via a heat engine, other times the heat itself is valued for warmth, cooking, or industrial processes, as well as the illumination that comes with combustion. Fuels are also used in the cells of organisms in a known as cellular respiration. Hydrocarbons and related oxygen-containing molecules are by far the most common source of fuel used by humans, fuels are contrasted with other substances or devices storing potential energy, such as those that directly release electrical energy or mechanical energy. The first known use of fuel was the combustion of wood or sticks by Homo erectus near 2,000,000 years ago, throughout most of human history fuels derived from plants or animal fat were only used by humans. Charcoal, a derivative, has been used since at least 6,000 BCE for melting metals. It was only supplanted by coke, derived from coal, as European forests started to become depleted around the 18th century, charcoal briquettes are now commonly used as a fuel for barbecue cooking. Coal was first used as a fuel around 1000 BCE in China, coal was later used to drive ships and locomotives. By the 19th century, gas extracted from coal was being used for lighting in London. In the 20th and 21st centuries, the use of coal is to generate electricity. Fossil fuels were rapidly adopted during the revolution, because they were more concentrated and flexible than traditional energy sources. They have become a part of our contemporary society, with most countries in the world burning fossil fuels in order to produce power. Currently the trend has been towards renewable fuels, such as biofuels like alcohols, chemical fuels are substances that release energy by reacting with substances around them, most notably by the process of combustion. Most of the energy released in combustion was not stored in the chemical bonds of the fuel. Chemical fuels are divided in two ways, first, by their physical properties, as a solid, liquid or gas. Secondly, on the basis of their occurrence, primary and secondary, solid fuels include wood, charcoal, peat, coal, Hexamine fuel tablets, and pellets made from wood, corn, wheat, rye and other grains. Solid-fuel rocket technology also uses solid fuel, solid fuels have been used by humanity for many years to create fire
13.
Motor oil
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Motor oil, engine oil, or engine lubricant is any of various substances are often used for lubrication of internal combustion engines. Motor oils are derived from petroleum-based and non-petroleum-synthesized chemical compounds, motor oils today are mainly blended by using base oils composed of hydrocarbons, polyalphaolefins, and polyinternal olefins, organic compounds consisting entirely of carbon and hydrogen. The base oils of some high-performance motor oils contain up to 20% by weight of esters, on September 6,1866 American John Ellis founded the Continuous Oil Refining Company. While studying the healing powers of crude oil, Dr. Ellis was disappointed to find no real medicinal value. He made his breakthrough when he developed an oil that worked effectively in high temperatures and this meant no more gummed valves, corroded cylinders or leaking seals. In 1873 Ellis officially renamed the company to Valvoline after the engine valves the product lubricated. Motor oil is a lubricant used in combustion engines, which power cars, motorcycles, lawnmowers, engine-generators. In engines, there are parts which move against each other, and it also wears away those parts, which could lead to lower efficiency and degradation of the engine. This increases fuel consumption, decreases power output, and can lead to engine failure, in petrol engines, the top piston ring can expose the motor oil to temperatures of 160 °C. In diesel engines the top ring can expose the oil to temperatures over 315 °C, motor oils with higher viscosity indices thin less at these higher temperatures. Coating metal parts with oil also keeps them from being exposed to oxygen, corrosion inhibitors may also be added to the motor oil. Many motor oils also have detergents and dispersants added to keep the engine clean. The oil is able to trap soot from combustion in itself and it is a combination of this, and some singeing that turns used oil black after some running. Rubbing of metal engine parts produces some microscopic metallic particles from the wearing of the surfaces. Such particles could circulate in the oil and grind against moving parts, because particles accumulate in the oil, it is typically circulated through an oil filter to remove harmful particles. An oil pump, a vane or gear pump powered by the engine, pumps the oil throughout the engine, Oil filters can be a full flow or bypass type. In the crankcase of an engine, motor oil lubricates rotating or sliding surfaces between the crankshaft journal bearings, and rods connecting the pistons to the crankshaft. The oil collects in an oil pan, or sump, at the bottom of the crankcase
14.
Internal combustion engine cooling
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Internal combustion engine cooling uses either air or a liquid to remove the waste heat from an internal combustion engine. For small or special purpose engines, air cooling makes for a lightweight, the more complex circulating liquid-cooled engines also ultimately reject waste heat to the air, but circulating liquid improves heat transfer from internal parts of the engine. Engines for watercraft may use open-loop cooling, but air and surface vehicles must recirculate a fixed volume of liquid, heat engines generate mechanical power by extracting energy from heat flows, much as a water wheel extracts mechanical power from a flow of mass falling through a distance. Engines are inefficient, so more heat energy enters the engine comes out as mechanical power. Internal combustion engines remove waste heat through cool intake air, hot exhaust gases, Engines with higher efficiency have more energy leave as mechanical motion and less as waste heat. Some waste heat is essential, it guides heat through the engine, much as a water wheel works only if there is some exit velocity in the water to carry it away. Thus, all heat engines need cooling to operate, Cooling is also needed because high temperatures damage engine materials and lubricants. Cooling becomes more important in when the climate very hot. Internal-combustion engines burn fuel hotter than the temperature of engine materials. Engine cooling removes energy fast enough to keep temperatures low so the engine can survive, some high-efficiency engines run without explicit cooling and with only incidental heat loss, a design called adiabatic. Such engines can achieve high efficiency but compromise power output, duty cycle, engine weight, durability, most internal combustion engines are fluid cooled using either air or a liquid coolant run through a heat exchanger cooled by air. Marine engines and some engines have ready access to a large volume of water at a suitable temperature. The water may be used directly to cool the engine, but often has sediment, which can clog coolant passages, or chemicals, such as salt, thus, engine coolant may be run through a heat exchanger that is cooled by the body of water. Most liquid-cooled engines use a mixture of water and chemicals such as antifreeze, the industry term for the antifreeze mixture is engine coolant. Some antifreezes use no water at all, instead using a liquid with different properties, such as propylene glycol or a combination of propylene glycol, most air-cooled engines use some liquid oil cooling, to maintain acceptable temperatures for both critical engine parts and the oil itself. Most liquid-cooled engines use air cooling, with the intake stroke of air cooling the combustion chamber. An exception is Wankel engines, where parts of the combustion chamber are never cooled by intake. There are many demands on a cooling system, one key requirement is to adequately serve the entire engine, as the whole engine fails if just one part overheats
15.
Air-cooled engine
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Air-cooled engines rely on the circulation of air directly over hot parts of the engine to cool them. Thus, while they are not ultimately cooled by the liquid, in contrast, heat generated by an air-cooled engine is released directly into the air. Typically this is facilitated with metal covering the outside of the Cylinder Head. Air may be fed with the use of a fan. In all combustion engines, a percentage of the heat generated escapes through the exhaust. About 8% of the heat energy finds its way into the oil, many motorcycles use air cooling for the sake of reducing weight and complexity. Few current production automobiles have air-cooled engines, but historically it was common for many high-volume vehicles, volkswagen Type 4 Chevrolet Corvair Citroën 2CV. Citroën GS and GSA Honda 1300 NSU Prinz Royal Enfield Motorcycles, while water cooled engines were widely used from the early days of flight, air cooled engines were the dominant choice in aircraft. Following the Second World War, turbojets and jet powered aircraft have come to dominate flight regimes where water cooled piston engines offered a drag advantage. Thus today, piston engines are used in slower general aviation aircraft where low weight is an advantage. Therefore, most aero engines produced today are of the air cooled variety, today, most of the engines currently manufactured by Lycoming and Continental and used by major manufacturers of light aircraft Cirrus, Cessna and so on. Notable exceptions have included the Allison V-1710 and Rolls-Royce series of liquid-cooled V12 engines which powered P-51 Mustangs, Avro Lancasters, other engine manufactures using air-cooled engine technology are ULPower and Jabiru, more active in the Light-Sport Aircraft and ultralight aircraft market. Rotax uses a combination of air-cooled cylinders and liquid-cooled cylinder heads, some small diesel engines, e. g. those made by Deutz AG and Lister Petter are air-cooled. Probably the only big Euro 5 truck air-cooled engine is being produced by Tatra, stationary or portable engines were commercially introduced early in the 1900s. The first commercial production was by the New Way Motor Company of Lansing, Michigan, the company produced air-cooled engines in single and twin cylinders in both horizontal and vertical cylinder format. Subsequent to their production which was exported worldwide, other companies took up the advantages of this cooling method. Applications include mowers, generators, outboard motors, pump sets, saw benches, sloan, Alfred P. McDonald, John, ed. My Years with General Motors, Garden City, NY, USA, Doubleday, LCCN64011306, republished in 1990 with a new introduction by Peter Drucker
16.
Flat engine
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A flat engine is an internal combustion engine with horizontally-opposed cylinders. Typically, the layout has cylinders arranged in two banks on either side of a crankshaft and is otherwise known as the boxer. The concept was patented in 1896 by engineer Karl Benz, who called it the contra engine, a boxer engine should not be confused with the opposed-piston engine, in which each cylinder has two pistons but no cylinder head. Also, if an engine is canted 90 degrees into the horizontal plane. Horizontal inline engines are common in industrial applications such as underfloor mounting for buses. True boxers have each crankpin controlling only one piston/cylinder while the 180° engines, the 180° engine, which may be thought of as a type of V engine, is quite uncommon as it has all of the disadvantages of a flat engine, and few of the advantages. In 1896, Karl Benz invented the first internal combustion engine with opposed pistons. He called it the engine, as the action of each side opposed the action of the other. This design has since called the boxer engine because each pair of pistons moves in. The boxer engine has pairs of pistons reaching TDC simultaneously and these engines do not require a balance shaft or counterweights on the crankshaft to balance the weight of the reciprocating parts, which are required in most other engine configurations. However, in the case of engines with fewer than six cylinders. Other engine configurations with natural dynamic balance include the straight-six, the straight-eight, the V12, Boxer engines tend to be noisier than other common engines for both intrinsic and other reasons. In cars, valve clatter from the compartment is not damped by air filters or other components. Multi-cylinder boxer layouts have proved to be suited as light aircraft engines, as exemplified by Continental, Lycoming, Rotax, Jabiru. An important factor in aircraft use is the flat engines absence of vibration, general aviation aircraft often use air-cooled flat-four and flat-six engines made by companies such as Lycoming and Continental. Ultralight and microlight aircraft often use such as the Rotax 912. During the Second World War, Boxer engines were used as a motor for the first German jet engines to power up the engine at cranking speed. It was a short stroke design so it could fit in the hub of the turbine compressor
17.
Cast iron
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Cast iron is a group of iron-carbon alloys with a carbon content greater than 2%. Its usefulness derives from its low melting temperature. Carbon ranging from 1. 8–4 wt%, and silicon 1–3 wt% are the main alloying elements of cast iron, Iron alloys with less carbon content are known as steel. While this technically makes the Fe–C–Si system ternary, the principle of cast iron solidification can be understood from the simpler binary iron–carbon phase diagram, cast iron tends to be brittle, except for malleable cast irons. It is resistant to destruction and weakening by oxidation, the earliest cast iron artefacts date to the 5th century BC, and were discovered by archaeologists in what is now Jiangsu in China. Cast iron was used in ancient China for warfare, agriculture, during the 15th century, cast iron became utilized for artillery in Burgundy, France, and in England during the Reformation. The first cast iron bridge was built during the 1770s by Abraham Darby III, cast iron is also used in the construction of buildings. Cast iron is made by re-melting pig iron, often along with quantities of iron, steel, limestone, carbon. Phosphorus and sulfur may be burnt out of the iron, but this also burns out the carbon. Depending on the application, carbon and silicon content are adjusted to the desired levels, other elements are then added to the melt before the final form is produced by casting. Cast iron is melted in a special type of blast furnace known as a cupola. After melting is complete, the molten cast iron is poured into a furnace or ladle. Cast irons properties are changed by adding various alloying elements, or alloyants, next to carbon, silicon is the most important alloyant because it forces carbon out of solution. A low percentage of silicon allows carbon to remain in solution forming iron carbide, a high percentage of silicon forces carbon out of solution forming graphite and the production of grey cast iron. Other alloying agents, manganese, chromium, molybdenum, titanium and vanadium counteracts silicon, promotes the retention of carbon, nickel and copper increase strength, and machinability, but do not change the amount of graphite formed. The carbon in the form of graphite results in an iron, reduces shrinkage, lowers strength. Sulfur, largely a contaminant when present, forms iron sulfide, the problem with sulfur is that it makes molten cast iron viscous, which causes defects. To counter the effects of sulfur, manganese is added because the two form into manganese sulfide instead of iron sulfide, the manganese sulfide is lighter than the melt so it tends to float out of the melt and into the slag
18.
Cylinder (engine)
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A cylinder is the central working part of a reciprocating engine or pump, the space in which a piston travels. Multiple cylinders are arranged side by side in a bank, or engine block. Cylinders may be sleeved or sleeveless, a sleeveless engine may also be referred to as a parent-bore engine. A cylinders displacement, or swept volume, can be calculated by multiplying its cross-sectional area by the distance the piston travels within the cylinder, the engine displacement can be calculated by multiplying the swept volume of one cylinder by the number of cylinders. The rings make near contact with the walls, riding on a thin layer of lubricating oil. The first illustration depicts a longitudinal section of a cylinder in a steam engine, the sliding part at the bottom is the piston, and the upper sliding part is a distribution valve that directs steam alternately into either end of the cylinder. Refrigerator and air compressors are heat engines driven in reverse cycle as pumps. Internal combustion engines operate on the inherent volume change accompanying oxidation of gasoline, diesel fuel or ethanol and they are not classical heat engines since they expel the working substance, which is also the combustion product, into the surroundings. The reciprocating motion of the pistons is translated into crankshaft rotation via connecting rods, as a piston moves back and forth, a connecting rod changes its angle, its distal end has a rotating link to the crankshaft. A typical four-cylinder automobile engine has a row of water-cooled cylinders. V engines use two angled cylinder banks, the V configuration is utilized to create a more compact configuration relative to the number of cylinders. For example, there are also rotary turbines, the Wankel engine is a rotary adaptation of the cylinder-piston concept which has been used by Mazda and NSU in automobiles. Rotary engines are relatively quiet because they lack the clatter of reciprocating motion, air-cooled engines generally use individual cases for the cylinders to facilitate cooling. Inline motorcycle engines are an exception, having two-, three-, four-, water-cooled engines with only a few cylinders may also use individual cylinder cases, though this makes the cooling system more complex. The Ducati motorcycle company, which for years used air-cooled motors with individual cylinder cases, in some engines, especially French designs, the cylinders have wet liners. They are formed separately from the casting so that liquid coolant is free to flow around their outsides. Wet-lined cylinders have cooling and a more even temperature distribution. During use, the cylinder is subject to wear from the action of the piston rings
19.
Casting
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Casting is a manufacturing process in which a liquid material is usually poured into a mold, which contains a hollow cavity of the desired shape, and then allowed to solidify. The solidified part is known as a casting, which is ejected or broken out of the mold to complete the process. Casting materials are usually metals or various cold setting materials that cure after mixing two or more together, examples are epoxy, concrete, plaster and clay. Casting is most often used for making complex shapes that would be difficult or uneconomical to make by other methods. The oldest surviving casting is a frog from 3200 BC. In metalworking, metal is heated until it becomes liquid and is poured into a mold. The mold is a cavity that includes the desired shape. The mold and the metal are then cooled until the metal solidifies, the solidified part is then recovered from the mold. Subsequent operations remove excess material caused by the casting process, when casting plaster or concrete, the material surface is flat and lacks transparency. Often topical treatments are applied to the surface, for example, painting and etching can be used in a way that give the appearance of metal or stone. Alternatively, the material is altered in its initial casting process, by casting concrete, rather than plaster, it is possible to create sculptures, fountains, or seating for outdoor use. A simulation of high-quality marble may be made using certain chemically-set plastic resins with powdered stone added for coloration, raw castings often contain irregularities caused by seams and imperfections in the molds, as well as access ports for pouring material into the molds. The process of cutting, grinding, shaving or sanding away these unwanted bits is called fettling, simulation accurately describes a cast component’s quality up-front before production starts. The casting rigging can be designed with respect to the component properties. This has benefits beyond a reduction in sampling, as the precise layout of the complete casting system also leads to energy, material. The software supports the user in component design, the determination of melting practice and casting methoding through to pattern and mold making, heat treatment and this saves costs along the entire casting manufacturing route. Since the late 80s, commercial programs are available which make it possible for foundries to gain new insight into what is happening inside the mold or die during the casting process
20.
Aluminium alloy
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Aluminium alloys are alloys in which aluminium is the predominant metal. The typical alloying elements are copper, magnesium, manganese, silicon, tin, there are two principal classifications, namely casting alloys and wrought alloys, both of which are further subdivided into the categories heat-treatable and non-heat-treatable. About 85% of aluminium is used for products, for example rolled plate, foils. Cast aluminium alloys yield cost-effective products due to the low melting point, the most important cast aluminium alloy system is Al–Si, where the high levels of silicon contribute to give good casting characteristics. Aluminium alloys are used in engineering structures and components where light weight or corrosion resistance is required. Alloys composed mostly of aluminium have been important in aerospace manufacturing since the introduction of metal-skinned aircraft. Aluminium-magnesium alloys are both lighter than aluminium alloys and much less flammable than alloys that contain a very high percentage of magnesium. Aluminium alloy surfaces will develop a white, protective layer of aluminium oxide if left unprotected by anodizing and/or correct painting procedures, referred to as dissimilar-metal corrosion, this process can occur as exfoliation or as intergranular corrosion. Aluminium alloys can be heat treated. This causes internal element separation, and the metal then corrodes from the inside out, Aluminium alloy compositions are registered with The Aluminum Association. Aluminium alloys with a range of properties are used in engineering structures. Alloy systems are classified by a system or by names indicating their main alloying constituents. Selecting the right alloy for a given application entails considerations of its strength, density, ductility, formability, workability, weldability. A brief historical overview of alloys and manufacturing technologies is given in Ref. Aluminium alloys are used extensively in aircraft due to their high strength-to-weight ratio. On the other hand, pure aluminium metal is too soft for such uses. Aluminium alloys typically have an elastic modulus of about 70 GPa, therefore, for a given load, a component or unit made of an aluminium alloy will experience a greater deformation in the elastic regime than a steel part of identical size and shape. Though there are aluminium alloys with somewhat-higher tensile strengths than the commonly used kinds of steel, with completely new metal products, the design choices are often governed by the choice of manufacturing technology. Extrusions are particularly important in regard, owing to the ease with which aluminium alloys, particularly the Al–Mg–Si series
21.
Piston
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A piston is a component of reciprocating engines, reciprocating pumps, gas compressors and pneumatic cylinders, among other similar mechanisms. It is the component that is contained by a cylinder and is made gas-tight by piston rings. In an engine, its purpose is to force from expanding gas in the cylinder to the crankshaft via a piston rod and/or connecting rod. In a pump, the function is reversed and force is transferred from the crankshaft to the piston for the purpose of compressing or ejecting the fluid in the cylinder, in some engines, the piston also acts as a valve by covering and uncovering ports in the cylinder wall. An internal combustion engine is acted upon by the pressure of the combustion gases in the combustion chamber space at the top of the cylinder. This force then acts downwards through the rod and onto the crankshaft. The connecting rod is attached to the piston by a swivelling gudgeon pin and this pin is mounted within the piston, unlike the steam engine, there is no piston rod or crosshead. The pin itself is of hardened steel and is fixed in the piston, a few designs use a fully floating design that is loose in both components. All pins must be prevented from moving sideways and the ends of the pin digging into the cylinder wall, gas sealing is achieved by the use of piston rings. These are a number of iron rings, fitted loosely into grooves in the piston. The rings are split at a point in the rim, allowing them to press against the cylinder with a light spring pressure. Two types of ring are used, the rings have solid faces and provide gas sealing, lower rings have narrow edges. There are many proprietary and detail design features associated with piston rings, pistons are cast from aluminium alloys. For better strength and fatigue life, some racing pistons may be forged instead, early pistons were of cast iron, but there were obvious benefits for engine balancing if a lighter alloy could be used. To produce pistons that could survive engine combustion temperatures, it was necessary to develop new alloys such as Y alloy and Hiduminium, a few early gas engines had double-acting cylinders, but otherwise effectively all internal combustion engine pistons are single-acting. During World War II, the US submarine Pompano was fitted with a prototype of the infamously unreliable H. O. R, although compact, for use in a cramped submarine, this design of engine was not repeated. Media related to Internal combustion engine pistons at Wikimedia Commons Trunk pistons are long relative to their diameter and they act both as a piston and cylindrical crosshead. As the connecting rod is angled for much of its rotation, a longer piston helps to support this
22.
Crankcase
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In an internal combustion engine of the reciprocating type, the crankcase is the housing for the crankshaft. The enclosure forms the largest cavity in the engine and is located below the cylinder, crankcases have often been discrete parts, but more often they are integral with the cylinder bank, forming an engine block. Nevertheless, the area around the crankshaft is still called the crankcase. Crankcases and other basic engine components are typically made of cast iron or cast aluminium via sand casting. Today the foundry processes are highly automated, with a few skilled workers to manage the casting of thousands of parts. A crankcase often has an opening in the bottom to which an oil pan is attached with a bolted joint. Some crankcase designs fully surround the main bearing journals, whereas many others form only one half. Some crankcase areas require no structural strength from the oil pan itself, besides protecting the crankshaft and connecting rods from foreign objects, the crankcase serves other functions, depending on engine type. A large number of small engines use a sealed crankcase as a compression chamber for their mixture. These are hugely common as petrol or gasoline engines for motorcycles, generator sets. Both sides of the piston are used as working surfaces, the side is the power piston. As the piston rises, it pushes out exhaust gases and produces a vacuum in the crankcase. As the piston downward, the compressed fuel/air charge is pushed from the crankcase into the cylinder. Unlike larger engines, the crankcase does not contain only engine oil because it handles the fuel/air mixture, instead, oil is mixed in with the fuel supply as petroil, and this mixture provides splash lubrication for the cylinder walls, crankshaft and connecting rod bearings. These engines have used in larger sizes for small cars. Small diesel engines may use this type of crankcase compression. Such engines are uncommon, compared to petrol engines, but they are used for generators. Large two stroke engines do not use compression, but instead a separate scavenge blower or supercharger
23.
Forging
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Forging is a manufacturing process involving the shaping of metal using localized compressive forces. The blows are delivered with a hammer or a die, Forging is often classified according to the temperature at which it is performed, cold forging, warm forging, or hot forging. For the latter two, the metal is heated, usually in a forge, forged parts can range in weight from less than a kilogram to hundreds of metric tons. Forging has been done by smiths for millennia, the products were kitchenware, hardware, hand tools, edged weapons, cymbals. Today, forging is a worldwide industry. Forging is one of the oldest known metalworking processes, the smithy or forge has evolved over centuries to become a facility with engineered processes, production equipment, tooling, raw materials and products to meet the demands of modern industry. In modern times, industrial forging is done either with presses or with powered by compressed air, electricity. These hammers may have reciprocating weights in the thousands of pounds, smaller power hammers,500 lb or less reciprocating weight, and hydraulic presses are common in art smithies as well. Some steam hammers remain in use, but they became obsolete with the availability of the other, more convenient, Forging can produce a piece that is stronger than an equivalent cast or machined part. As the metal is shaped during the process, its internal grain deforms to follow the general shape of the part. As a result, the grain is continuous throughout the part, additionally, forgings can target a lower total cost when compared to a casting or fabrication. Some metals may be forged cold, but iron and steel are almost always hot forged, hot forging prevents the work hardening that would result from cold forging, which would increase the difficulty of performing secondary machining operations on the piece. Also, while work hardening may be desirable in some circumstances, other methods of hardening the piece, such as heat treating, are more economical. Alloys that are amenable to precipitation hardening, such as most aluminium alloys and titanium, production forging involves significant capital expenditure for machinery, tooling, facilities and personnel. In the case of hot forging, a furnace is required to heat ingots or billets. In the case of drop forging operations, provisions must be made to absorb the shock, most forging operations use metal-forming dies, which must be precisely machined and carefully heat-treated to correctly shape the workpiece, as well as to withstand the tremendous forces involved. The main advantage of hot forging is that it can be more quickly and precisely. Cold forging typically results in work hardening of the piece, drop forging is a forging process where a hammer is raised and then dropped onto the workpiece to deform it according to the shape of the die
24.
Crankshaft
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A crankshaft—related to crank—is a mechanical part able to perform a conversion between reciprocating motion and rotational motion. In a reciprocating engine, it translates reciprocating motion of the piston into rotational motion, whereas in a reciprocating compressor, a Roman iron crank of yet unknown purpose dating to the 2nd century AD was excavated in Augusta Raurica, Switzerland. The 82.5 cm long piece has fitted to one end a 15 cm long bronze handle, the accompanying inscription is in Greek. The crank and connecting rod mechanisms of the other two archaeologically attested sawmills worked without a gear train, al-Jazari described a crank and connecting rod system in a rotating machine in two of his water-raising machines. His twin-cylinder pump incorporated a crankshaft, though the device was unnecessarily complex, the Italian physician Guido da Vigevano, planning for a new crusade, made illustrations for a paddle boat and war carriages that were propelled by manually turned compound cranks and gear wheels. In Renaissance Italy, the earliest evidence of a crank and connecting-rod is found in the sketch books of Taccola. A sound grasp of the motion involved is demonstrated a little later by Pisanello. One of the drawings of the Anonymous of the Hussite Wars shows a boat with a pair of paddle-wheels at each end turned by men operating compound cranks. Crankshafts were also described by Konrad Kyeser, Leonardo da Vinci and his wind-powered sawmill used a crankshaft to convert a windmills circular motion into a back-and-forward motion powering the saw. Corneliszoon was granted a patent for his crankshaft in 1597, large engines are usually multicylinder to reduce pulsations from individual firing strokes, with more than one piston attached to a complex crankshaft. Many small engines, such as found in mopeds or garden machinery, are single cylinder and use only a single piston. A crankshaft is subjected to stresses, potentially equivalent of several tonnes of force. The crankshaft is connected to the fly-wheel, the block, using bearings on the main journals. An engine loses up to 75% of its energy in the form of friction, noise and vibration in the crankcase. The remaining losses occur in the heat and blow by. The crankshaft has a linear axis about which it rotates, typically with several bearing journals riding on replaceable bearings held in the engine block. As the crankshaft undergoes a great deal of sideways load from each cylinder in an engine, it must be supported by several such bearings. This was a factor in the rise of V8 engines, with their shorter crankshafts, the long crankshafts of the latter suffered from an unacceptable amount of flex when engine designers began using higher compression ratios and higher rotational speeds
25.
Connecting rod
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In a reciprocating piston engine, the connecting rod or conrod connects the piston to the crank or crankshaft. Together with the crank, they form a mechanism that converts reciprocating motion into rotating motion. Connecting rods may also convert rotating motion into reciprocating motion, historically, before the development of engines, they were first used in this way. As a connecting rod is rigid, it may transmit either a push or a pull, earlier mechanisms, such as chains, could only pull. In a few two-stroke engines the connecting rod is required to push. Today, connecting rods are best known through their use in internal combustion piston engines and these are of a distinctly different design from earlier forms of connecting rods, used in steam engines and steam locomotives. The earliest evidence for a connecting rod appears in the late 3rd century AD Roman Hierapolis sawmill and it also appears in two 6th century Eastern Roman saw mills excavated at Ephesus and Gerasa. The crank and connecting rod mechanism of these Roman watermills converted the motion of the waterwheel into the linear movement of the saw blades. In Renaissance Italy, the earliest evidence of a − albeit mechanically misunderstood − compound crank, a sound understanding of the motion involved is displayed by the painter Pisanello who showed a piston-pump driven by a water-wheel and operated by two simple cranks and two connecting-rods. The first steam engines, Newcomens atmospheric engine, was single-acting, its piston only did work in one direction and their output rocked back and forth, rather than rotating continuously. Steam engines after this are usually double-acting, their internal pressure works on each side of the piston in turn. This requires a seal around the rod and so the hinge between the piston and connecting rod is placed outside the cylinder, in a large sliding bearing block called a crosshead. In a steam locomotive, the pins are usually mounted directly on one or more pairs of driving wheels. The connecting rods, run between the pins and crossheads, where they connect to the piston rods. Crossheads or trunk guides are used on large diesel engines manufactured for marine service. The connecting rods of smaller steam locomotives are usually of rectangular cross-section but, on small locomotives, stephen Lewin, who built both locomotive and marine engines, was a frequent user of round rods. Gresleys A4 Pacifics, such as Mallard, had an alloy steel connecting rod in the form of an I-beam with a web that was only 0.375 in thick. On Western Rivers steamboats, the rods are properly called pitmans
26.
Volkswagen Beetle
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Hitler contracted Ferdinand Porsche in 1934 to design and build it. Porsche and his team took until 1938 to finalise the design, the influence on Porsches design of other contemporary cars, such as the Tatra V570 and the work of Josef Ganz remains a subject of dispute. The result was one of the first rear-engined cars since the Brass Era, with 21,529,464 produced, the Beetle is the longest-running and most-manufactured car of a single platform ever made. Although designed in the 1930s, the Beetle was only produced in significant numbers from 1945 on when the model was designated the Volkswagen Type 1. Later models were designated Volkswagen 1200,1300,1500,1302 or 1303, the model became widely known in its home country as the Käfer and was later marketed as such in Germany, and as the Volkswagen in other countries. For example, in France it was known as the Coccinelle, the original 25 hp Beetle was designed for a top speed around 100 km/h, which would be a viable speed on the Reichsautobahn system. As Autobahn speeds increased in the years, its output was boosted to 36, then 40 hp. The Beetle ultimately gave rise to variants, including the Karmann Ghia, Type 2, the 1948 Citroën 2CV and other European models marked a later trend to front-wheel drive in the European small car market, a trend that would come to dominate that market. In 1974, Volkswagens own front-wheel drive Golf model succeeded the Beetle and it remained in production through 2010, being succeeded in 2011 by the more aggressively styled Beetle. In the 1999 Car of the Century competition, to determine the worlds most influential car in the 20th century, the Type 1 came fourth, after the Ford Model T, the Mini, and the Citroën DS. In April 1934, Adolf Hitler gave the order to Ferdinand Porsche to develop a Volkswagen, the epithet Volks- literally, peoples- had been applied to other Nazi-sponsored consumer goods such as the Volksempfänger. The engine had to be powerful for sustained cruising on Germany’s new Autobahnen, everything had to be designed to ensure parts could be quickly and inexpensively exchanged. The engine had to be air-cooled because, as Hitler explained, the Peoples Car would be available to citizens of Nazi Germany through a savings scheme, or Sparkarte, at 990 Reichsmark, about the price of a small motorcycle. Ferdinand Porsche developed the Type 12, or Auto für Jedermann for Zündapp in 1931, Porsche already preferred the flat-four engine, and selected a swing axle rear suspension, while Zündapp insisted on a water-cooled five-cylinder radial engine. In 1932, three prototypes were running, all of those cars were lost during World War II, the last in a bombing raid in Stuttgart in 1945. The Zündapp prototypes were followed by the Porsche Type 32, designed in 1933 for NSU Motorenwerke AG, the Type 32 was similar in design to the Type 12, but it had a flat-four engine. NSUs exit from car manufacturing resulted in the Type 32 being abandoned at the prototype stage, initially designated Type 60 by Porsche, the design team included Erwin Komenda and Karl Rabe. In October 1935, the first two Type 60 prototypes, known as the V1 and V2, were ready, in 1936, testing began of three further V3 prototypes, built in Porsches Stuttgart shop
27.
Volkswagen Type 2
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Following – and initially deriving from Volkswagens first model, the Type 1 – it was given the factory designation Type 2. European competition included the 1947-1981 Citroën H Van, the 1959-1980 Renault Estafette, japanese manufacturers also introduced similar vehicles, such as the Nissan Caravan, Toyota LiteAce and Subaru Sambar. Brazil contained the last factory in the world that produced the T2, production in Brazil ceased on December 31,2013, due to the introduction of more stringent safety regulations in the country. This marks the end of an era with the rear-engine Volkswagens manufactured, the concept for the Type 2 is credited to Dutch Volkswagen importer Ben Pon. He first sketched the van in a doodle dated April 23,1947, proposing a payload of 690 kg, production would have to wait, however, as the factory was at capacity producing the Type 1. When capacity freed up, a prototype known internally as the Type 29 was produced in a three months. The stock Type 1 pan proved to be too weak so the prototype used a chassis with unit body construction. Coincidentally the wheelbase was the same as the Type 1s, engineers reused the reduction gear from the Type 81, enabling the 1.5 ton van to use a 25 hp flat four engine. Although the aerodynamics of the first prototypes were poor, engineers used the tunnel at the Technical University of Braunschweig to optimize the design. Simple changes such as splitting the windshield and roofline into a vee helped the production Type 2 achieve Cd=0.44, only two models were offered, the Kombi, and the Commercial. The Microbus was added in May 1950, joined by the Deluxe Microbus in June 1951, in all 9,541 Type 2s were produced in their first year of production. An ambulance model was added in December 1951 which repositioned the fuel tank in front of the transaxle, put the spare tire behind the front seat and these features became standard on the Type 2 from 1955 to 1967. 11,805 Type 2s were built in the 1951 model year and these were joined by a single-cab pickup in August 1952, and it changed the least of the Type 2s until all were heavily modified in 1968. However, only generations T1 to T3 can be seen as related to the Beetle. The Type 2, along with the 1947 Citroën H Van, are among the first forward control vans in which the driver was placed above the front roadwheels. They started a trend in Europe, where the 1952 GM Bedford CA,1958 RAF-977,1959 Renault Estafette,1960 BMC Morris J4, except for the Greenbrier and various 1950s–70s Fiat minivans, the Type 2 remained unique in being rear-engined. The Type 2 was available as a, Panel van, a van without side windows or rear seats. Double-door Panel Van, a van without side windows or rear seats
28.
Volkswagen Type 3
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The Volkswagen Type 3 was a compact car manufactured and marketed by Volkswagen from 1961 to 1973. VW finalized the design by 1959 with prototypes ready for testing by 1960, secrecy was such that even at the 1960 Geneva Auto Show, VW denied they were readying a new design. In 1961 VW announced the new line as the VW1500, production began in August 1961, a month before launch, of the Volkswagen 1500 Notchback, encompassing three-box styling in a notchback saloon body. Production of the Karmann Ghia 1500 with a coupé body commenced in November 1961, the estate bodied Variant followed, with the first cars produced in February 1962. Two convertibles based on the 1500 Notchback were also announced with the original models, the Fastback, or TL version, a fastback coupé, arrived in August 1965, at the same time the 1600 engine was introduced. Volkswagen of America began importing the Type 3 in 1966 in the Squareback and Fastback, in 1968, the Type 3 E became the first German automobile in series production with electronic fuel injection as standard equipment. The larger Volkswagen Type 4 was introduced in 1969 which had a mechanical layout with further engineering refinements. For the 1968 model year,1969 in the USA, a fully automatic transaxle became available. With the automatic came completely independent rear suspension, replacing the swing axle set-up, for 1969, the IRS rear axle was standard with both automatic and manual transmissions. The model received a facelift in 1970, when a 115 mm nose-lengthening added 1.5 cu ft to the luggage capacity, Volkswagen offered the Type 3 in a lower trim level in Europe, marketed as the 1600A trim level. In the US, and for 1973 only, Volkswagen offered two trim levels of the Type 3 Fastback in the USA, marketed as the Type 3 Sedan, while the Type 3 was a more modern design, it never reached the same level of popularity as the Beetle. The Wolfsburg plant was retooled to build the Golf, which replaced the Type 1 as Volkswagens best selling sedan. The Type 3 was initially equipped with a 1, while the long block remained the same as the Type 1, the engine cooling was redesigned by putting the fan on the end of the crankshaft instead of on the generator. This reduced the height of the profile, allowed greater cargo volume. The engines displacement would eventually increase to 1.6 L and it used a similar transmission to the Beetle but with higher ratios and longer axles. The original Volkswagen 1500 used a single side-draught 32 mm Solex PHN carburetor, the Type 3 engine received a larger displacement for 1966 and in 1968 became the worlds first volume production car to feature electronic fuel injection – pioneered by Bosch. The Bosch D-Jetronic system was offered on the Volkswagen 1600 TE & LE version, a similar Bosch injection system was used in the later Type 4 VW411, some models of the Porsche 914, Opel Admiral, Diplomat and Commodore, and available for the Volvo P1800. Also introduced for 1968 was an automatic transmission
29.
Volkswagen Type 4
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The Volkswagen Type 4 is a mid-sized car manufactured and marketed by Volkswagen of Germany from 1968 to 1974 in two-door and four-door sedan as well as two-door station wagon body styles. The Type 4 evolved through two generations, the 411 and 412 series, Volkswagen had prototyped a notchback sedan version of the 411, without introducing it to production. Over its six-year production run, Volkswagen manufactured 367,728 Type 4 models, in the United States, VW sold 117,110 Type 4s from 1971 to July 1974. As Volkswagens last air-cooled sedans and wagons, the Type 4 models were succeeded by the first generation Passat, the Type 4s battery was located under the drivers seat. When the Type 4 was discontinued in 1974, its engine carried on as the plant for the larger-engined Volkswagen Type 2s, produced from 1972 to 1979. European 411 nomenclature highlighted the fuel injection with the suffix E. Revisions in 1969 also included replacement of the single oval headlights with twin round headlights, the 411 was also assembled in South Africa beginning in 1969, in two- or four-door configurations. The four-door only came as a DeLuxe, with an automatic transmission. The 412 replaced the 411 in August 1972 in Germany, having been restyled by designer Brooks Stevens, halogen lights were fitted, the headlight surround was reshaped and the nose panels were redesigned. In 1974 the engine capacity was raised to 1795cc and fuel management reverted to a twin carburettor system, in February 1974 on the German market the 4-door 412L was priced at DM10,995
30.
Carburetor
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A carburetor, or carburettor, or carburator, or carburetter is a device that blends air and fuel for an internal combustion engine in the proper ratio for combustion. It is sometimes shortened to carb in North America or carby in Australia. To carburate or carburet is to blend the air and fuel or to equip with a carburetor for that purpose, carburetors have largely been supplanted in the automotive and, to a lesser extent, aviation industries by fuel injection. They are still common on engines for lawn mowers, rototillers. The word carburetor comes from the French carbure meaning carbide, carburer means to combine with carbon. In fuel chemistry, the term has the specific meaning of increasing the carbon content of a fluid by mixing it with a volatile hydrocarbon. The first carburetor was invented by Samuel Morey in 1826, a carburetor was invented by an Italian, Luigi De Cristoforis, in 1876. Another carburetor was developed by Enrico Bernardi at the University of Padua in 1882, for his Motrice Pia, a carburetor was among the early patents by Karl Benz as he developed internal combustion engines and their components. Early carburetors were the surface type, in which air is charged with fuel by being passed over the surface of gasoline. In 1885, Wilhelm Maybach and Gottlieb Daimler developed a float carburetor for their engine based on the atomizer nozzle, hungarian engineers János Csonka and Donát Bánki patented a carburetor for a stationary engine in 1893. Frederick William Lanchester of Birmingham, England, experimented with the wick carburetor in cars, in 1896, Frederick and his brother built the first gasoline-driven car in England, a single cylinder 5 hp internal combustion engine with chain drive. Unhappy with the performance and power, they re-built the engine the next year into a horizontally opposed version using his new wick carburetor design. Carburetors were the method of fuel delivery for most US-made gasoline-fueled engines up until the late 1980s. 1991, Jeep Grand Wagoneer with the AMC360 cu in V8 engine, low-cost commercial vans and 4WDs in Australia continued with carburetors even into the 2000s, the last being the Mitsubishi Express van in 2003. Elsewhere, certain Lada cars used carburetors until 2006, many motorcycles still use carburetors for simplicitys sake, since a carburetor does not require an electrical system to function. EEC legislation required all vehicles sold and produced in countries to have a catalytic converter after December 1992. This legislation had been in the pipeline for some time, with cars becoming available with catalytic converters or fuel injection from around 1990. Fords first fuel-injected car was the Ford Capri RS2600 in 1970, general Motors launched its first fuel-injected car around the same time, when began to introduce fuel-injected engines to its Vauxhall Cavalier/Opel Ascona range
31.
Cubic centimetre
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A cubic centimetre is a commonly used unit of volume that extends the derived SI-unit cubic metre, and corresponds to the volume of a cube that measures 1 cm ×1 cm ×1 cm. One cubic centimetre corresponds to a volume of 1/1,000,000 of a metre, or 1/1,000 of a litre, or one millilitre. The mass of one centimetre of water at 3.98 °C is closely equal to one gram. Note that SI supports only the use of symbols and deprecates the use of any abbreviations for units, hence cm3 is preferred to cc or ccm. Many scientific fields have replaced cubic centimeters with milliliters, the medical and automotive fields in the United States still use the term cubic centimetre. Much of the industry outside the U. S. has switched to litres. The United Kingdom uses millilitres in preference to cubic centimetres in the medical field, most other English-speaking countries follow the UK example. There is currently a movement within the field to discontinue the use of cc in prescriptions and on medical documents. This could cause an overdose of medication, which could be dangerous or even lethal. In the United States, such confusion accounts for 12. 6% of all associated with medical abbreviations. In automobile engines, cc refers to the volume of its engine displacement in cubic centimetres. Conversions 1 millilitre =1 cm31 litre =1000 cm31 cubic inch =16.387 cm3
32.
Cubic inch
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The cubic inch is a unit of measurement for volume in the Imperial units and United States customary units systems. It is the volume of a cube with each of its three dimensions being one inch long, one cubic foot is equal to exactly 1,728 cubic inches because 123 =1,728. The following symbols have been used to denote the cubic inch, cubic in cu inch, cu in inch^3, in^3 inch³, because of the extensive export of electrical equipment to other countries, some usage of the non-SI unit can be found outside North America. The cubic inch is used for this purpose in classic car collecting. The auto industry now uses liters for this purpose, while reciprocating engines used in commercial aircraft often have model numbers based on the cubic inch displacement. The fifth generation Ford Mustang has a Boss 302 version that reflects this heritage - with an engine similar to the original Boss. Chevrolet has also revived this usage on its 427 Corvette, in the UK, engine displacement is now denoted in litres. However, cubic inches were used in the past to denote model numbers. Conversion of units Cubic centimeter Cubic foot Orders of magnitude Square inch
33.
Power (physics)
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In physics, power is the rate of doing work. It is the amount of energy consumed per unit time, having no direction, it is a scalar quantity. In the SI system, the unit of power is the joule per second, known as the watt in honour of James Watt, another common and traditional measure is horsepower. Being the rate of work, the equation for power can be written, because this integral depends on the trajectory of the point of application of the force and torque, this calculation of work is said to be path dependent. As a physical concept, power requires both a change in the universe and a specified time in which the change occurs. This is distinct from the concept of work, which is measured in terms of a net change in the state of the physical universe. The output power of a motor is the product of the torque that the motor generates. The power involved in moving a vehicle is the product of the force of the wheels. The dimension of power is divided by time. The SI unit of power is the watt, which is equal to one joule per second, other units of power include ergs per second, horsepower, metric horsepower, and foot-pounds per minute. One horsepower is equivalent to 33,000 foot-pounds per minute, or the required to lift 550 pounds by one foot in one second. Other units include dBm, a logarithmic measure with 1 milliwatt as reference, food calories per hour, Btu per hour. This shows how power is an amount of energy consumed per unit time. If ΔW is the amount of work performed during a period of time of duration Δt and it is the average amount of work done or energy converted per unit of time. The average power is simply called power when the context makes it clear. The instantaneous power is then the value of the average power as the time interval Δt approaches zero. P = lim Δ t →0 P a v g = lim Δ t →0 Δ W Δ t = d W d t. In the case of constant power P, the amount of work performed during a period of duration T is given by, W = P t
34.
Kilowatt
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The watt is a derived unit of power in the International System of Units defined as 1 joule per second and can be used to quantify the rate of energy transfer. Power has dimensions of M L2 T −3, when an objects velocity is held constant at one meter per second against constant opposing force of one newton the rate at which work is done is 1 watt. 1 W =1 V ⋅ A Two additional unit conversions for watt can be using the above equation. 1 W =1 V2 Ω =1 A2 ⋅ Ω Where ohm is the SI derived unit of electrical resistance, a person having a mass of 100 kilograms who climbs a 3-meter-high ladder in 5 seconds is doing work at a rate of about 600 watts. Mass times acceleration due to gravity times height divided by the time it takes to lift the object to the given height gives the rate of doing work or power. A laborer over the course of an 8-hour day can sustain an output of about 75 watts, higher power levels can be achieved for short intervals. The watt is named after the Scottish scientist James Watt for his contributions to the development of the steam engine, in 1960 the 11th General Conference on Weights and Measures adopted it for the measurement of power into the International System of Units. For additional examples of magnitude for multiples and submultiples of the watt, technologically important powers that are measured in femtowatts are typically found in reference to radio and radar receivers. For example, meaningful FM tuner performance figures for sensitivity, quieting and these input levels are often stated in dBf. This is 0.2739 microvolt across a 75-ohm load or 0.5477 microvolt across a 300-ohm load, the picowatt is equal to one trillionth of a watt. Technologically important powers that are measured in picowatts are typically used in reference to radio and radar receivers, acoustics, the nanowatt is equal to one billionth of a watt. Important powers that are measured in nanowatts are also used in reference to radio. The microwatt is equal to one millionth of a watt, compact solar cells for devices such as calculators and watches are typically measured in microwatts. The milliwatt is equal to one thousandth of a watt, a typical laser pointer outputs about five milliwatts of light power, whereas a typical hearing aid for people uses less than one milliwatt. Audio signals and other electronic signal levels are measured in dBm. The kilowatt is equal to one thousand watts and this unit is typically used to express the output power of engines and the power of electric motors, tools, machines, and heaters. It is also a unit used to express the electromagnetic power output of broadcast radio. One kilowatt is equal to 1.34 horsepower
35.
Horsepower
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Horsepower is a unit of measurement of power. There are many different standards and types of horsepower, two common definitions being used today are the mechanical horsepower, which is approximately 746 watts, and the metric horsepower, which is approximately 735.5 watts. The term was adopted in the late 18th century by Scottish engineer James Watt to compare the output of engines with the power of draft horses. It was later expanded to include the power of other types of piston engines, as well as turbines, electric motors. The definition of the unit varied among geographical regions, most countries now use the SI unit watt for measurement of power. With the implementation of the EU Directive 80/181/EEC on January 1,2010, units called horsepower have differing definitions, The mechanical horsepower, also known as imperial horsepower equals approximately 745.7 watts. It was defined originally as exactly 550 foot-pounds per second [745.7 N. m/s), the metric horsepower equals approximately 735.5 watts. It was defined originally as 75 kgf-m per second is approximately equivalent to 735.5 watts, the Pferdestärke PS is a name for a group of similar power measurements used in Germany around the end of the 19th century, all of about one metric horsepower in size. The boiler horsepower equals 9809.5 watts and it was used for rating steam boilers and is equivalent to 34.5 pounds of water evaporated per hour at 212 degrees Fahrenheit. One horsepower for rating electric motors is equal to 746 watts, one horsepower for rating Continental European electric motors is equal to 735 watts. Continental European electric motors used to have dual ratings, one British Royal Automobile Club horsepower can equal a range of values based on estimates of several engine dimensions. It is one of the tax horsepower systems adopted around Europe, the development of the steam engine provided a reason to compare the output of horses with that of the engines that could replace them. He had previously agreed to take royalties of one third of the savings in coal from the older Newcomen steam engines and this royalty scheme did not work with customers who did not have existing steam engines but used horses instead. Watt determined that a horse could turn a mill wheel 144 times in an hour, the wheel was 12 feet in radius, therefore, the horse travelled 2.4 × 2π ×12 feet in one minute. Watt judged that the horse could pull with a force of 180 pounds-force. So, P = W t = F d t =180 l b f ×2.4 ×2 π ×12 f t 1 m i n =32,572 f t ⋅ l b f m i n. Watt defined and calculated the horsepower as 32,572 ft·lbf/min, Watt determined that a pony could lift an average 220 lbf 100 ft per minute over a four-hour working shift. Watt then judged a horse was 50% more powerful than a pony, engineering in History recounts that John Smeaton initially estimated that a horse could produce 22,916 foot-pounds per minute
36.
Litre
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The litre or liter is an SI accepted metric system unit of volume equal to 1 cubic decimetre,1,000 cubic centimetres or 1/1,000 cubic metre. A cubic decimetre occupies a volume of 10×10×10 centimetres and is equal to one-thousandth of a cubic metre. The original French metric system used the litre as a base unit. The word litre is derived from an older French unit, the litron, whose name came from Greek — where it was a unit of weight, not volume — via Latin, and which equalled approximately 0.831 litres. The litre was also used in subsequent versions of the metric system and is accepted for use with the SI. The spelling used by the International Bureau of Weights and Measures is litre, the less common spelling of liter is more predominantly used in American English. One litre of water has a mass of almost exactly one kilogram. Subsequent redefinitions of the metre and kilogram mean that this relationship is no longer exact, a litre is defined as a special name for a cubic decimetre or 10 centimetres ×10 centimetres ×10 centimetres. Hence 1 L ≡0.001 m3 ≡1000 cm3, from 1901 to 1964, the litre was defined as the volume of one kilogram of pure water at maximum density and standard pressure. The kilogram was in turn specified as the mass of a platinum/iridium cylinder held at Sèvres in France and was intended to be of the mass as the 1 litre of water referred to above. It was subsequently discovered that the cylinder was around 28 parts per million too large and thus, during this time, additionally, the mass-volume relationship of water depends on temperature, pressure, purity and isotopic uniformity. In 1964, the definition relating the litre to mass was abandoned in favour of the current one, although the litre is not an official SI unit, it is accepted by the CGPM for use with the SI. CGPM defines the litre and its acceptable symbols, a litre is equal in volume to the millistere, an obsolete non-SI metric unit customarily used for dry measure. The litre is often used in some calculated measurements, such as density. One litre of water has a mass of almost exactly one kilogram when measured at its maximal density, similarly,1 millilitre of water has a mass of about 1 g,1,000 litres of water has a mass of about 1,000 kg. It is now known that density of water depends on the isotopic ratios of the oxygen and hydrogen atoms in a particular sample. The litre, though not an official SI unit, may be used with SI prefixes, the most commonly used derived unit is the millilitre, defined as one-thousandth of a litre, and also often referred to by the SI derived unit name cubic centimetre. It is a commonly used measure, especially in medicine and cooking, Other units may be found in the table below, where the more often used terms are in bold
37.
Torque
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Torque, moment, or moment of force is rotational force. Just as a force is a push or a pull. Loosely speaking, torque is a measure of the force on an object such as a bolt or a flywheel. For example, pushing or pulling the handle of a wrench connected to a nut or bolt produces a torque that loosens or tightens the nut or bolt, the symbol for torque is typically τ, the lowercase Greek letter tau. When it is called moment of force, it is denoted by M. The SI unit for torque is the newton metre, for more on the units of torque, see Units. This article follows US physics terminology in its use of the word torque, in the UK and in US mechanical engineering, this is called moment of force, usually shortened to moment. In US physics and UK physics terminology these terms are interchangeable, unlike in US mechanical engineering, Torque is defined mathematically as the rate of change of angular momentum of an object. The definition of states that one or both of the angular velocity or the moment of inertia of an object are changing. Moment is the term used for the tendency of one or more applied forces to rotate an object about an axis. For example, a force applied to a shaft causing acceleration, such as a drill bit accelerating from rest. By contrast, a force on a beam produces a moment, but since the angular momentum of the beam is not changing. Similarly with any force couple on an object that has no change to its angular momentum and this article follows the US physics terminology by calling all moments by the term torque, whether or not they cause the angular momentum of an object to change. The concept of torque, also called moment or couple, originated with the studies of Archimedes on levers, the term torque was apparently introduced into English scientific literature by James Thomson, the brother of Lord Kelvin, in 1884. A force applied at an angle to a lever multiplied by its distance from the levers fulcrum is its torque. A force of three newtons applied two metres from the fulcrum, for example, exerts the same torque as a force of one newton applied six metres from the fulcrum. More generally, the torque on a particle can be defined as the product, τ = r × F, where r is the particles position vector relative to the fulcrum. Alternatively, τ = r F ⊥, where F⊥ is the amount of force directed perpendicularly to the position of the particle, any force directed parallel to the particles position vector does not produce a torque
