A tire or tyre is a ring-shaped vehicle component that covers the wheels rim to protect it and enable better vehicle performance. Most tires, such as those for automobiles and bicycles, provide traction between the vehicle and the road providing a flexible cushion that absorbs shock. The materials of modern tires are synthetic rubber, natural rubber and wire, along with carbon black. They consist of a tread and a body, the tread provides traction while the body provides containment for a quantity of compressed air. Before rubber was developed, the first versions of tires were bands of metal fitted around wooden wheels to prevent wear and tear. Pneumatic tires are used on many types of vehicles, including cars, motorcycles, trucks, heavy equipment, and aircraft. Metal tires are used on locomotives and railcars, and solid rubber tires are still used in various non-automotive applications, such as some casters, lawnmowers. The etymology of tire is that the word is a form of attire. The spelling tyre does not appear until the 1840s when the English began shrink fitting railway car wheels with malleable iron, traditional publishers continued using tire.
The Times newspaper in Britain was still using tire as late as 1905, the spelling tyre began to be commonly used in the 19th century for pneumatic tires in the UK. However, over the course of the 20th century, tyre became established as the standard British spelling, the earliest tires were bands of leather, placed on wooden wheels, used on carts and wagons. The tire would be heated in a fire, placed over the wheel and quenched, causing the metal to contract. A skilled worker, known as a wheelwright, carried out this work, the outer ring served to tie the wheel segments together for use, providing a wear-resistant surface to the perimeter of the wheel. The word tire thus emerged as a variant spelling to refer to the bands used to tie wheels. The first patent for what appears to be a standard pneumatic tire appeared in 1847 lodged by the Scottish inventor Robert William Thomson, this never went into production. The first practical pneumatic tire was made in 1888 on May Street, Belfast, by Scots-born John Boyd Dunlop and it was an effort to prevent the headaches of his 10-year-old son Johnnie, while riding his tricycle on rough pavements.
His doctor, Sir John Fagan, had prescribed cycling as an exercise for the boy, Fagan participated in designing the first pneumatic tires. In Dunlops tire patent specification dated 31 October 1888, his interest is only in its use in cycles, in September 1890, he was made aware of an earlier development but the company kept the information to itself
In the automobile industry, weight transfer customarily refers to the change in load borne by different wheels during acceleration. This article uses this latter pair of definitions, in wheeled vehicles, load transfer is the measurable change of load borne by different wheels during acceleration. No motion of the center of mass relative to the wheels is necessary, load transfer is a crucial concept in understanding vehicle dynamics. The same is true in bikes, though only longitudinally, the major forces that accelerate a vehicle occur at the tires contact patches. It is these moments that cause variation in the load distributed between the tires, often this is interpreted by the casual observer as a pitching or rolling motion of the vehicles body. A perfectly rigid vehicle without suspension that would not exhibit pitching or rolling of the body still undergoes load transfer. e, contact patch displacement relative to wheel. Lowering the CoM towards the ground is one method of reducing load transfer, as a result load transfer is reduced in both the longitudinal and lateral directions.
Another method of reducing load transfer is by increasing the wheel spacings, increasing the vehicles wheelbase reduces longitudinal load transfer while increasing the vehicles track reduces lateral load transfer. Most high performance automobiles are designed to sit as low as possible and usually have an extended wheelbase, weight transfer occurs as the vehicles CoM shifts during automotive maneuvers. Acceleration causes the mass to rotate about a geometric axis resulting in relocation of the CoM. Liquids, such as fuel, readily flow within their containers, as fuel is consumed, not only does the position of the CoM change, but the total weight of the vehicle is reduced. By way of example, when a vehicle accelerates, a weight transfer toward the wheels can occur. An outside observer might witness this as the vehicle visibly leans to the back, under braking, weight transfer toward the front of the car can occur. Under hard braking it might be visible even from inside the vehicle as the nose dives toward the ground.
Similarly, during changes in direction, weight transfer to the outside of the direction of the turn can occur, weight transfer is generally of far less practical importance than load transfer, for cars and SUVs at least. Total available grip will drop by around 6% as a result of load transfer. 01%. Load transfer causes the available traction at all four wheels to vary as the car brakes and this bias to one pair of tires doing more work than the other pair results in a net loss of total available traction. The net loss can be attributed to the known as tire load sensitivity
A spring is an elastic object used to store mechanical energy. Springs are usually out of spring steel. There are a number of spring designs, in everyday usage the term often refers to coil springs. When a spring is compressed or stretched from its resting position, the rate or spring constant of a spring is the change in the force it exerts, divided by the change in deflection of the spring. That is, it is the gradient of the force versus deflection curve, an extension or compression springs rate is expressed in units of force divided by distance, for example lbf/in or N/m. A torsion spring is a spring that works by twisting, when it is twisted about its axis by an angle, a torsion springs rate is in units of torque divided by angle, such as N·m/rad or ft·lbf/degree. The inverse of spring rate is compliance, that is, if a spring has a rate of 10 N/mm, the stiffness of springs in parallel is additive, as is the compliance of springs in series. Springs are made from a variety of materials, the most common being spring steel.
Small springs can be wound from pre-hardened stock, while larger ones are made from annealed steel, some non-ferrous metals are used including phosphor bronze and titanium for parts requiring corrosion resistance and beryllium copper for springs carrying electrical current. Simple non-coiled springs were used throughout history, e. g. the bow. In the Bronze Age more sophisticated spring devices were used, as shown by the spread of tweezers in many cultures, coiled springs appeared early in the 15th century, in door locks. The first spring powered-clocks appeared in that century and evolved into the first large watches by the 16th century, in 1676 British physicist Robert Hooke discovered Hookes law which states that the force a spring exerts is proportional to its extension. Compression spring – is designed to operate with a compression load, flat spring – this type is made of a flat spring steel. Machined spring – this type of spring is manufactured by machining bar stock with a lathe and/or milling operation rather than a coiling operation, since it is machined, the spring may incorporate features in addition to the elastic element.
Machined springs can be made in the load cases of compression/extension, torsion. Serpentine spring - a zig-zag of thick wire - often used in modern upholstery/furniture, the most common types of spring are, Cantilever spring – a spring which is fixed only at one end. Coil spring or helical spring – a spring is of two types, Tension or extension springs are designed to become longer under load and their turns are normally touching in the unloaded position, and they have a hook, eye or some other means of attachment at each end. Compression springs are designed to become shorter when loaded and their turns are not touching in the unloaded position, and they need no attachment points
Other means to store energy include pressurized fluid in hydraulic hybrids. Early prototype motorcycles in the late 19th century used the same principle, most motorized bicycles, mopeds are of this type. In a series hybrid bicycle the user pedals a generator, charging a battery or feeding the motor and they are commercially available, being simple in theory and manufacturing. The first published prototype of an SHB is by Augustus Kinzel in 1975, in 1994 Bernie Macdonalds conceived the Electrilite SHB with power electronics allowing regenerative braking and pedaling while stationary. In 1995 Thomas Muller designed and built a Fahrrad mit elektromagnetischem Antrieb for his 1995 diploma thesis, in 1996 Jürg Blatter and Andreas Fuchs of Berne University of Applied Sciences built an SHB and in 1998 modified a Leitra tricycle. Until 2005 they built several prototype SH tricycles and quadricycles, in 1999 Harald Kutzke described an active bicycle, the aim is to approach the ideal bicycle weighing nothing and having no drag by electronic compensation. A series hybrid bicycle is powered by pedals, batteries.
Active cooling keeps plastic parts from softening, the prototype uses a regular electric bicycle charge port. Hybrid power trains use diesel-electric or turbo-electric to power railway locomotives, heavy vehicles, mobile hydraulic machinery. A diesel/turbine engine drives a generator or hydraulic pump, which powers electric/hydraulic motor - strictly an electric/hydraulic transmission. Both series and parallel setups were used in WW2 submarines, europe The new Autorail à grande capacité built by the Canadian company Bombardier for service in France is diesel/electric motors, using 1500 or 25000 V on different rail systems. It was tested in Rotterdam, the Netherlands with Railfeeding, a Genesse, China The First Hybrid Evaluating locomotive was designed by rail research center MATRAI in 1999 and built in 2000. It was a G12 locomotive upgraded with batteries, a 200 kW diesel generator and 4 AC motors, Japan Japans first hybrid train with significant energy storage is the KiHa E200, with roof-mounted lithium ion batteries.
India Indian railway launched one of its kind CNG-Diesel hybrid trains in January 2015, the train has a 1400 hp engine which uses fumigation technology. The first of these train is set to run on the 81 km long Rewari-Rohtak route, CNG is less-polluting alternative for diesel and petrol and is popular as an alternative fuel in India. North America In the US, General Electric made a locomotive with sodium - nickel chloride battery storage, no fuel is wasted for idling — ~60–85% of the time for these type locomotives. It is unclear if regenerative braking is used, but in principle it is easily utilized, since these engines typically need extra weight for traction purposes anyway the battery packs weight is a negligible penalty. The diesel generator and batteries are normally built on an existing retired yard locomotives frame, the existing motors and running gear are all rebuilt and reused
A beam axle, rigid axle or solid axle is a dependent suspension design, in which a set of wheels is connected laterally by a single beam or shaft. Beam axles were commonly used at the rear wheels of a vehicle. In most automobiles, beam axles have been replaced by front, with a beam axle the camber angle between the wheels is the same no matter where it is in the travel of the suspension. A beam axles fore and aft location is constrained by either, trailing arms, semi-trailing arms, radius rods, the lateral location is constrained by either, a Panhard rod, a Scott Russell linkage or a Watts linkage. While shock absorbers and either leaf springs, coil springs, or air bags are used to control vertical movement. A live axle is a type of beam axle in which the shaft transmits power to the wheels, while typically used in vehicles with Hotchkiss drive, this suspension system can be used with other types of power transmission. The principal advantage of the axle is its simplicity. This simplicity makes it very space-efficient and relatively cheap to manufacture and they are nearly universally used in buses and heavy-duty trucks.
Most light and medium duty trucks, SUVs, and vans use a beam axle. Beam axles have an important advantage for off-road applications, as they provide better vehicle articulation and this simplicity makes it relatively easy to lift a vehicle. Also the cornering ability is typically worse than other designs because the wheels have zero camber angle gain during body roll. Front beam axle suspension is sensitive to any lack of concentricity in the hub. This is addressed on some vehicles with steering dampers although removal and careful refitting of the front wheels often cures the problem
Diesel engines work by compressing only the air. This increases the air temperature inside the cylinder to such a degree that it ignites atomised diesel fuel that is injected into the combustion chamber. This contrasts with spark-ignition engines such as an engine or gas engine. In diesel engines, glow plugs may be used to aid starting in cold weather, or when the engine uses a lower compression-ratio, the original diesel engine operates on the constant pressure cycle of gradual combustion and produces no audible knock. Low-speed diesel engines can have an efficiency that exceeds 50%. Diesel engines may be designed as either two-stroke or four-stroke cycles and they were originally used as a more efficient replacement for stationary steam engines. Since the 1910s they have used in submarines and ships. Use in locomotives, heavy equipment and electricity generation plants followed later, in the 1930s, they slowly began to be used in a few automobiles. Since the 1970s, the use of engines in larger on-road and off-road vehicles in the US increased.
According to the British Society of Motor Manufacturing and Traders, the EU average for diesel cars accounts for 50% of the total sold, including 70% in France and 38% in the UK. The worlds largest diesel engine is currently a Wärtsilä-Sulzer RTA96-C Common Rail marine diesel, the definition of a Diesel engine to many has become an engine that uses compression ignition. To some it may be an engine that uses heavy fuel oil, to others an engine that does not use spark ignition. However the original cycle proposed by Rudolf Diesel in 1892 was a constant temperature cycle which would require higher compression than what is needed for compression ignition. Diesels idea was to compress the air so tightly that the temperature of the air would exceed that of combustion, to make this more clear, let it be assumed that the subsequent combustion shall take place at a temperature of 700°. Then in that case the pressure must be sixty-four atmospheres, or for 800° centigrade the pressure must be ninety atmospheres.
In years Diesel realized his original cycle would not work, Diesel describes the cycle in his 1895 patent application. Notice that there is no longer a mention of compression temperatures exceeding the temperature of combustion, now all that is mentioned is the compression must be high enough for ignition. In 1806 Claude and Nicéphore Niépce developed the first known internal combustion engine, the Pyréolophore fuel system used a blast of air provided by a bellows to atomize Lycopodium
De Dion tube
A de Dion tube is an automobile suspension technology. It is a form of non-independent suspension and is a considerable improvement over the swing axle, Hotchkiss drive. Because it plays no part in transmitting power to the drive wheels, De Dion suspension uses universal joints at both the wheel hubs and differential, and uses a solid tubular beam to hold the opposite wheels in parallel. Unlike an anti-roll bar, a de Dion tube is not directly connected to the chassis nor is it intended to flex, in suspension geometry it is a beam axle suspension. The de Dion tube was named after Comte Jules-Albert de Dion, the tube, was invented around 1894 by co-founder Charles Trépardoux for use on the companys steam tricycles. Advantages, Reduced unsprung weight compared to the Hotchkiss drive, since the differential, unlike most fully independent suspension there are no camber changes on axle loading and unloading. Fixing the camber of both wheels at 0° assists in obtaining good traction from wide tires and tends to reduce wheel hop under high power operations compared to an independent suspension, the choice of shock absorbers and springs is made easier.
The two wheels may be aligned, allowing for independent camber and track alignment. Disadvantages, A pair of CV or universal joints is required for each wheel, adding complexity and weight. If coil springs are used, a location link is required, plus additional torque links on each side or a combination of lower trailing links. None of these links are required if leaf springs are used. The torque links are not required if the setup uses inboard brakes, like in the Pegaso 1502, Rover P6, sympathetic camber changes on opposite wheels are seen on single-wheel suspension compression, just as in a Hotchkiss drive or live axle. This is not important for operation on improved surfaces but is critical for rough road or off road use. Alfa Romeo is probably the most famous adopter of technology, using it on the Alfa Romeo Alfetta, GT, GTV, GTV6, Alfa 6,90, 75/Milano. A recent vehicle to use this suspension coupled with leaf springs was the Ford Ranger EV, the American built MV-1 van by VPG uses this suspension in the rear with leaf springs and is just starting production in spring 2010.
4WD variants of the Honda Fit use a De Dion style suspension in lieu of a torsion bar, benefits include simplicity, compactness and a relatively low liftover height for the cargo bed. Forged steel axles were used instead of tubes, setright, L. J. K. De Dion axle, The First Step to Independence, in Ward, executive editor. World of Automobiles, Volume 5, pp. 515–516
A leaf spring is a simple form of spring commonly used for the suspension in wheeled vehicles. Originally called a laminated or carriage spring, and sometimes referred to as a spring or cart spring. A leaf spring takes the form of a slender arc-shaped length of spring steel of rectangular cross-section, in the most common configuration, the center of the arc provides location for the axle, while tie holes are provided at either end for attaching to the vehicle body. For very heavy vehicles, a spring can be made from several leaves stacked on top of each other in several layers. Leaf springs can serve locating and to some extent damping as well as springing functions, while the interleaf friction provides a damping action, it is not well controlled and results in stiction in the motion of the suspension. For this reason some manufacturers have used mono-leaf springs, a leaf spring can either be attached directly to the frame at both ends or attached directly at one end, usually the front, with the other end attached through a shackle, a short swinging arm.
The shackle takes up the tendency of the spring to elongate when compressed. Some springs terminated in an end, called a spoon end. There were a variety of springs, usually employing the word elliptical. Elliptical or full elliptical leaf springs referred to two circular arcs linked at their tips and this was joined to the frame at the top center of the upper arc, the bottom center was joined to the live suspension components, such as a solid front axle. Additional suspension components, such as trailing arms, would usually be needed for this design and that employed the lower arc, hence its name. As an example of leaf springs, the Ford Model T had multiple leaf springs over its differential that were curved in the shape of a yoke. As a substitute for dampers, some manufacturers laid non-metallic sheets in between the leaves, such as wood. Today leaf springs are used in heavy commercial vehicles such as vans and trucks, SUVs. For heavy vehicles, they have the advantage of spreading the load more widely over the vehicles chassis, whereas coil springs transfer it to a single point.
Unlike coil springs, leaf springs locate the axle, eliminating the need for trailing arms. A further advantage of a leaf spring over a spring is that the end of the leaf spring may be guided along a definite path. A more modern implementation is the leaf spring
Steering is the collection of components, etc. which allows any vehicle to follow the desired course. An exception is the case of transport by which rail tracks combined together with railroad switches provide the steering function. The primary purpose of the system is to allow the driver to guide the vehicle. Other arrangements are found on different types of vehicles, for example. The basic aim of steering is to ensure that the wheels are pointing in the desired directions and this is typically achieved by a series of linkages, rods and gears. The angle the wheels make with the plane influences steering dynamics as do the tires. The rack and pinion design has the advantages of a degree of feedback. A disadvantage is that it is not adjustable, so that when it does wear and develop lash, BMW began to use rack and pinion steering systems in the 1930s, and many other European manufacturers adopted the technology. American automakers adopted rack and pinion steering beginning with the 1974 Ford Pinto, older designs use two main principles, the worm and sector design and the screw and nut.
Both types were enhanced by reducing the friction, for screw and nut it is the ball mechanism. The steering column turns a large screw which meshes with nut by recirculating balls and this design is still in use in trucks and other large vehicles, where rapidity of steering and direct feel are less important than robustness and mechanical advantage. The worm and sector was a design, used for example in Willys and Chrysler vehicles. To reduce friction the sector is replaced by a roller or rotating pins on the rocker shaft arm, other systems for steering exist, but are uncommon on road vehicles. Power steering helps the driver of a vehicle to steer by directing some of its power to assist in swiveling the steered road wheels about their steering axes. To alleviate this auto makers have developed power steering systems, or more correctly power-assisted steering, there are two types of power steering systems and electric/electronic. A hydraulic-electric hybrid system is possible, a hydraulic power steering uses hydraulic pressure supplied by an engine-driven pump to assist the motion of turning the steering wheel.
In EPS, the amount of assistance is easily tunable to the type, road speed. An added benefit is the elimination of environmental hazard posed by leakage, an outgrowth of power steering is speed sensitive steering, where the steering is heavily assisted at low speed and lightly assisted at high speed
A car is a wheeled, self-powered motor vehicle used for transportation and a product of the automotive industry. The year 1886 is regarded as the year of the modern car. In that year, German inventor Karl Benz built the Benz Patent-Motorwagen, cars did not become widely available until the early 20th century. One of the first cars that was accessible to the masses was the 1908 Model T, an American car manufactured by the Ford Motor Company. Cars were rapidly adopted in the United States of America, where they replaced animal-drawn carriages and carts, cars are equipped with controls used for driving, passenger comfort and safety, and controlling a variety of lights. Over the decades, additional features and controls have been added to vehicles, examples include rear reversing cameras, air conditioning, navigation systems, and in car entertainment. Most cars in use in the 2010s are propelled by a combustion engine. Both fuels cause air pollution and are blamed for contributing to climate change.
Vehicles using alternative fuels such as ethanol flexible-fuel vehicles and natural gas vehicles are gaining popularity in some countries, electric cars, which were invented early in the history of the car, began to become commercially available in 2008. There are costs and benefits to car use, the costs of car usage include the cost of, acquiring the vehicle, interest payments and auto maintenance, depreciation, driving time, parking fees and insurance. The costs to society of car use include, maintaining roads, land use, road congestion, air pollution, public health, health care, road traffic accidents are the largest cause of injury-related deaths worldwide. The benefits may include transportation, independence. The ability for humans to move flexibly from place to place has far-reaching implications for the nature of societies and it was estimated in 2010 that the number of cars had risen to over 1 billion vehicles, up from the 500 million of 1986. The numbers are increasing rapidly, especially in China, the word car is believed to originate from the Latin word carrus or carrum, or the Middle English word carre.
In turn, these originated from the Gaulish word karros, the Gaulish language was a branch of the Brythoic language which used the word Karr, the Brythonig language evolved into Welsh where Car llusg and car rhyfel still survive. It originally referred to any wheeled vehicle, such as a cart, carriage. Motor car is attested from 1895, and is the formal name for cars in British English. Autocar is a variant that is attested from 1895
They are made of an elastic material formed into the shape of a helix which returns to its natural length when unloaded. Under tension or compression, the material of a coil spring undergoes torsion, the spring characteristics therefore depend on the shear modulus, not Youngs Modulus. A coil spring may be used as a torsion spring, the material of the spring is thereby subjected to a bending moment, either reducing or increasing the helical radius. In this mode, it is the Youngs Modulus of the material determines the spring characteristics. Metal coil springs are made by winding a wire around a shaped former - a cylinder is used to form cylindrical coil springs, types of coil spring are, Tension/extension coil springs, designed to resist stretching. They usually have a hook or eye form at each end for attachment, compression coil springs, designed to resist being compressed. A typical use for compression coil springs is in car suspension systems, volute springs are used as heavy load compression springs. A strip of plate is rolled into the shape of both a helix and a spiral, when compressed, the strip is stiffer edge-on than a wire coil, but the spiral arrangement allows the turns to overlap rather than bottoming out on each other.
Torsion springs, designed to resist twisting actions, often associated to clothes pegs or up-and-over garage doors. Spring Helical Spring by Sándor Kabai at The Wolfram Demonstrations Project, Institute of Spring Technology Spring Manufacturers Institute, tutorial by Dave Silberstein. You Spring From Morning To Night, April 1949, Popular Science article on the basics of steel coil springs manufacturing