The Lancia Aurelia is a car produced by Italian manufacturer Lancia from 1950 to the summer of 1958. It is noted for using the first series-production V6 engine. Several body styles were offered: 4-door saloon, 2-door GT coupé, 2-door spider/convertible, a chassis to be custom bodied by external coachbuilders. Establishing a post-war Lancia tradition, the car was named after a Roman road: the Via Aurelia, leading from Rome to Pisa. An Aurelia-based car is now produced by Thornley Kelham; the Aurelia was designed under the direction of engineer Vittorio Jano. Its engine, the first production V6 engine, a 60° design developed by Francesco de Virgilio, between 1943 and 1948 a Lancia engineer, who worked under Jano. During production, capacity grew from 1.8 l to 2.5 l. Prototype engines used a bore and stroke of 68 mm x 72 mm for 1,569 cc, it was an all-alloy pushrod design with a single camshaft between the cylinder banks. A hemispherical combustion chamber and in-line valves were used. A single Solex or Weber carburettor completed the engine.
Some uprated 1,991 cc models were fitted with twin carburettors. At the rear was an innovative combination transaxle with the gearbox, clutch and inboard-mounted drum brakes; the front suspension was a sliding pillar design, with rear semi-trailing arms replaced by a de Dion tube in the Fourth series. The Aurelia was first car to be fitted with radial tires as standard equipment. 165SR400 Michelin X and on the sports models fitted with 165HR400 Pirelli Cinturato. B21 engine technical specificationsBore: 72.00 mm. Stroke: 81.50 mm. Displacement: 1991 cc. Dry weight: 150 kg. Firing order: 1L-4R-3L-6R-5L-2R. Carburetors: Solex 30 AAI, 23 and 24mm venturis. Power: 75 Gross HP @4500RPM; the first Aurelias were the B10 berlinas. They used a 1754 cc version of the V6; the B21 was released in 1951 with a larger 1991 cc 70 hp engine. A 2-door B20 GT coupé appeared that same year, it had a Ghia-designed, Pininfarina-built body. The same 1991 cc engine produced 75 hp in the B20. In all, 500 first series Aurelias were produced.
The second series Aurelia coupé pushed power up to 80 hp from the 1991 cc V6 with a higher compression ratio and repositioned valves. Other changes included better brakes and minor styling tweaks, such as chromed bumpers instead of the aluminium ones used in the earlier car. A new dashboard featured two larger instrument gauges; the suspension was unchanged from the first series. A new B22 sedan was released in 1952 with a hotter camshaft for 90 hp; the third series appeared in 1953 with a larger 2451 cc version of the engine. The rear of the car lost the tail fins of the earlier series; the fourth series introduced the new de Dion tube rear suspension. The engine was changed from white metal bearings to shell bearings. An open car, the B24 Spider, was well received, it was similar to the B20 coupé mechanically, with an 8-inch shorter wheelbase than the coupé. The fourth series cars were the first Aurelias to be available in left-hand drive; this model was immortalized by Dino Risi's 1962 movie Il Sorpasso, starring Vittorio Gassman.
The actual car used for shooting was not destroyed during the accident scene sealing the end of the story: an Alfa Romeo Giulietta Spider was used as replacement. The fifth series coupé, appearing in 1956, was more luxury-oriented, it had a different transaxle, more robust and similar to that used in the Flaminias. The driveshaft was revised to reduce vibration. Alongside the fifth series coupés was the B24 convertible; this differed from the earlier B24 Spider, having roll-up windows, better seating position, a windscreen with vent windows. In mechanical aspects, the B24 convertible was similar to the coupé of the same series. Power was down to 112 hp for the 1957 sixth series, with increased torque to offset the greater weight of the car; the sixth series coupés had vent windows, a chrome strip down the bonnet. They were the most touring oriented of the B20 series; the sixth series B24 convertible was similar to the fifth series, with some minor differences in trim. Most notably, the fuel tank was in the boot, not behind the seats as it was in the fourth and fifth series open cars.
This change, did not apply for the first 150 sixth series cars, which were like the fifth series. The sixth series convertibles featured different seats than either both earlier cars. Produced only in 1954-1955, 240 cars were built. Panoramic front windscreen, distinctive 2 part chrome bumpers, removable side screens, soft top and Pinin Farina styling. 181 LHD cars with B24S designation. All were equipped with 2451 cc engines; the dashboard features one prominent and two small dials. In 2014, RM Auctions sold a "barn find" 1955 Aurelia Spider at auction for £500,000. In 2014, Gooding and Company Auctions sold a restored 1955 Aurelia Spider for $1,815,000. Produced from 1956, second series with many small alterations to the Aurelia Spider. One part chrome wider bonnet air-scoop. Cars from this series no longer now have fixed quarter-lights. 521 cars were built. All had 2,451cc engines. Dashboard features 2 big dials; the first prototype of the B50 cabriolet was shown at the 1950 Turin Auto Show. Produced in small numbers, around 265 cars, by cabriolet-specialist Pinin Farina, the B50 Cabriolet was a four-seat comfortable cruiser
The Mercedes-Benz W125 was a Grand Prix racing car designed by Rudolf Uhlenhaut to race during the 1937 Grand Prix season. The car was used by Rudolf Caracciola to win the 1937 European Championship and W125 drivers finished in the second and fourth positions in the championship; the supercharged engine, with 8 cylinders in line and 5,662.85 cc, attained an output of up to 595 horse power in race trim. The highest test bed power measured was 637 BHP at 5,800 rpm, it gave 245 BHP at a mere 2,000 rpm. In 1938, the engine capacity of supercharged Grand Prix cars was limited to 3000cc, the W125 was replaced by the Mercedes-Benz W154; the W125 was considered the most powerful race car for about 3 decades, until large capacity American-built V8 engines in CanAm sportcars reached similar power in the mid 1960s. In Grand Prix racing itself, the figure was not exceeded until the early 1980s, with the appearance of turbo-charged engines in Formula One; the W125 reached race speeds of well over 300 km/h in 1937 on the AVUS in Berlin, equipped with a streamlined body.
In land speed record runs, a Mercedes-Benz W125 Rekordwagen was clocked at 432.7 km/h over a mile and a kilometer. This car was fitted with a DAB V12 engine of 5,576.75 cc with a power of 726 BHP at 5,800 rpm. The weight of this engine caused the car to weigh over the 750 kg maximum limit, so it never appeared in Grand Prix.. Due to the uncompetitiveness of their W25 car, Mercedes pulled out of the 1936 Grand Prix Season midway through the year in order to concentrate on designing a car that would see them return to the top of the rankings. A new racing department was set up within Mercedes-Benz. Rudolf Uhlenhaut a production car engineer for the company, was selected to lead the design team in late 1936. Uhlenhaut had not designed a racing car, but had significant experience testing road cars on the Nürburgring race track, experience which allowed him to adapt his knowledge easily to race cars; when testing the old W25 car, Uhlenhaut remarked that the suspension was too stiff, preventing the wheels from following the road.
During the test session, a wheel came off the car, yet Uhlenhaut continued to drive the car as if nothing had happened. This stiffness caused the chassis to the rear axle to bend by up to 7 -- 10 cm under braking; the brief for the new car included a stiffer chassis and more travel on the suspension to avoid the problems experienced in the 1936 car. The W125 had a much stiffer tubular frame construction compared to the previous W25 model; this was achieved using oval tubes made of nickel-chrome molybdenum steel which flexed less than the frame used in the W25. The bodywork of the W125 was aluminium metal, which like its predecessor was left unpainted in its bare silver colour; this brought Mercedes' cars during this period the nickname of Silver Arrows, the racing colours of Germany being silver. With no regulations limiting engine size, other than the 750 kg total car weight limit, Mercedes designed a 5.6 litre engine configured with eight inline cylinders and double overhead camshaft for the W125.
Named the M125, the engine was fitted with a Roots type supercharger producing 632 lb⋅ft of torque at the start of the season. The engines built varied in power, attaining an output between 640 horse power at 5800 rpm. Fuel used was a custom mix of 40% methyl alcohol, 32% benzene, 24% ethyl alcohol and 4% gasoline light; the engine weighed 222 kg - 30% of the total weight of the car, was mounted in the front of the car. Like its W25 predecessor, the W125 used a 4-speed manual transmission; the gearbox design was changed to a constant mesh type, which provided better reliability compared to the sliding mesh transmission of the M25. In a constant mesh gearbox, the transmission gears are always in mesh and rotating, but the gears are not rigidly connected to the shafts on which they rotate. Instead, the gears can rotate or be locked to the shaft on which they are carried; the previous sliding mesh transmission required the gears to be spinning at the same speed when engaged. The W125 made its first competitive outing in May at the 1937 Tripoli Grand Prix with Mercedes-Benz entering four cars.
German Hermann Lang won his first Grand Prix motor race to give the W125 a victory on its début and provide Mercedes with their first victory over rivals Auto Union since May 1936. The next race was held at the AVUS motor-racing circuit in Germany, a 12-mile long circuit consisting of two long straights of 6 miles length joined at either end by a curve; as such, it was possible for a car to reach its top speed. Mercedes entered two W125 cars, a streamliner, modified from the original design to increase its top speed on the straights and a standard car driven by Richard Seaman in case of problems with the streamliner; the streamliner had a top speed 25 km/h faster than the regular car. On lap three of the race, the streamliner retired. Seaman's regular W125 finished in fifth position. At the Eifelrennen held at the Nürburgring circuit, Mercedes entered five W125's, including one driven by Christian Kautz fitted with the new suction carburettor supercharger system. Kautz finished in ninth, while teammates Rudolf Caracciola and Manfred von Brauchitsch finished in
The Hotchkiss drive is a shaft drive form of power transmission. It was the dominant means for rear-wheel drive layout cars in the 20th century; the name comes from the French automobile manufacturer Hotchkiss, although other makers, such as Peerless, used similar systems before Hotchkiss. During the early part of the 20th century chain-drive power transmission was the main direct drive competitor of the Hotchkiss system, with the torque tube popular until the 1950s. Most shaft-drive systems consist of a drive shaft extending from the transmission in front to the differential in the rear; the differentiating characteristic of the Hotchkiss drive is the fact that the axle housing is attached to the leaf springs to transfer the axle torque through them to the car body. It uses universal joints at both ends of the driveshaft, not enclosed; the use of two universal joints, properly phased and with parallel alignment of the drive and driven shafts, allows the use of simple cross-type universals. In contrast, a torque tube arrangement uses only a single universal at the end of the transmission tailshaft a constant velocity joint.
In the Hotchkiss drive, slip-splines or a plunge-type eliminate thrust transmitted back up the driveshaft from the axle, allowing simple rear-axle positioning using parallel leaf springs. In the torque-tube type this thrust is taken by the torque tube to the transmission and thence to the transmission and motor mounts to the frame. While the torque-tube type, when combined with rear coil springs, requires additional locating elements, such as a Panhard rod, this is not needed with a torque tube/leaf spring combination; some Hotchkiss driveshafts are made in two pieces with another universal joint in the center for greater flexibility in trucks and specialty vehicles built on firetruck frames. Some installations use rubber mounts to isolate vibration; the 1984–1987 RWD Toyota Corolla coupe is another example of a car that uses a 2-part Hotchkiss driveshaft with a rubber-mounted center bearing. This design was the main form of power transmission for most cars from the 1920s through the 1970s; as of 2016 it remains common in pick-up trucks, sport utility vehicles.
There is no connection between The Hotchkiss drive and the modern suspension-modification company Hotchkis. Automobile Engineering: A General Reference Work
Ford Ranger EV
The Ford Ranger EV is a battery electric vehicle, produced by Ford. It is no longer in production, it is built upon a light truck chassis used in the Ford Ranger. A few vehicles with lead-acid batteries were sold. A few persistent and interested private parties were able to obtain leases over a period of three to five years. All leases were terminated in 2003-04, the vehicles were recalled; the above the line cost of this vehicle was $52,720.00. Ford Motor Credit supported a generous 3-year lease program; the Lawrence Livermore/Berkeley Labs in eco-friendly Northern California signed on for 20 units from Ford Motor Credit, with a total lease cost to the Labs of $0 over the 3-year lease term. Thanks to overwhelming financial support from Government funded Clean Cities programs and AQMD Grants, when applied towards an APP version of the RangerEV commercial lease the resulting lease became Paid In Full; the Ranger EV qualifies for a California White Clean Air Vehicle decal, enabling access to carpool lanes for single-occupant vehicles.
The Ranger EV was a Ford Ranger XL 4X2 Regular Cab featuring an electric vehicle powertrain instead of the Ranger XL's standard I4 engine. The only difference between a Ranger XL and a Ranger EV was that the Ranger EV had no engine, so the tachometer, on the Ranger XL was replaced by a battery range gauge on the Ranger EV. Other than this minor difference, the Ranger EV included the standard features that the Ranger XL 4X2 Regular Cab included as standard: an AM and FM radio, two speakers, fifteen-inch steelwheels, a bench seat or bucket seats trimmed in vinyl, air conditioning and a heater, an automatic transmission, two SRS airbags, seating for either two or three passengers, a passenger airbag on/off switch activated by the vehicle's ignition and door key, vinyl flooring. Additional options, such as fifteen-inch alloy wheels, a spare tire, a cassette and/or CD player, two additional speakers behind the front seats, power windows and door locks, keyless entry were available for all Ranger EV's.
All Ranger. The principal identifiers of an electric Ranger are the appearance of the front charging door in a grille location, open on ICE Rangers, the missing tailpipe, the visibility of the EV's unique rear suspension and the traction motor from behind the vehicle. From the side, the vehicle is indistinguishable from the ICE Ranger except for a modest script Electric on the side. Only the slight projection of the battery trays below the frame rails is noticeable at a distance. Vehicle height is close to that of four-wheel drive vehicles; the front underhood compartment contains the charger, an electric air conditioner, the power steering mechanism, the power brake unit, a radiator for the air conditioner, a vacuum pump and reservoir for the power brakes and a reservoir for the windshield washer. Charger and battery liquid cooling service is performed here but is not an owner-operator service item. To the rear of the rear axle is the AC motor controller; the spare tire could be carried at a station within the truck bed.
The spare tire is poorly located within the bed relative to its inefficient use of bed space. Many operators did not carry the spare. To improve aerodynamics, the bed is covered by a vinyl snap on cover supported by aluminum bows. Snap receivers slide within aluminum channels. A rear bow allows the tailgate to be opened without removing the cover; the cover can be quite difficult to re-snap under cold conditions due to shrinkage and stiffness of the vinyl material. As the bed was a carryover from the standard Ford Ranger body, some owners opted for after-market tonneau covers, such as hard fiberglass or roll-top. From left to right, the instruments are: A charge indicator in the lower left corner, in the place of the normal fuel gauge. With underperforming batteries, cannot be relied upon owing to its tendency to decline from a full charge to about 3/4 and suddenly drop to empty within a mile or two. A rate indicator in the upper left corner, showing energy recovery. A miles to go indicator; this indicator is accurate only when the battery system is performing to specification, otherwise it may mislead the driver.
The usual speedometer and odometer. At the upper right corner, an off-run electric gauge will come up to the run position in a few seconds after Start is commanded by a keyswitch turn; this does not indicate the pack voltage. The vehicle's main contacts will not close. At the lower right corner, a temperature gauge monitors the liquid coolant temperature. Various indicator lights are included, one of which indicates that the truck is plugged in for charging; this is interlocked with the start circuit. Ford attempted to make the driving and operating experience as similar as possible to that experienced in an ICE vehicle with an automatic transmission. A selector operates similar to that for an automatic transmission with the following positions: Park Reverse Neutral Drive EconomyThe economy position reduces the maximum speed, the throttle response, engages energy recovery, so it is usefu
Ferrari 250 Testa Rossa
The Ferrari 250 Testa Rossa, or 250 TR, is a racing sports car built by Ferrari from 1957 to 1961. It was introduced at the end of the 1957 racing season in response to rule changes that enforced a maximum engine displacement of 3 liters for the 24 Hours of Le Mans and World Sports Car Championship races; the 250 TR was related to earlier Ferrari sports cars, sharing many key components with other 250 models and the 500 TR. The 250 TR achieved many racing successes, with variations winning 10 World Sports Car Championship races including the 24 Hours of Le Mans in 1958, 1960, 1961, the 12 Hours of Sebring in 1958, 1959 and 1961, the Targa Florio in 1958, the 1000 Km Buenos Aires in 1958 and 1960 and the Pescara 4 Hours in 1961; these results led to World Sports Car Championship constructor's titles for Ferrari in 1958, 1960 and 1961. The 250 Testa Rossa was developed to compete in the 1957 World Sports Car Championship racing season, in response to rule changes planned for the upcoming 1958 season that would enforce a maximum engine displacement of 3 liters.
The objective was to improve on the existing 4-cylinder 2.0L 500 TR/500 TRC Testa Rossa by integrating the more powerful Colombo-designed 3.0L V12 as used in 250 GT series. Along with the new engine, Ferrari improved bodywork; as with other Ferrari racing cars, Enzo Ferrari demanded absolute reliability from all components, resulting in a somewhat conservative design approach that aimed for endurance racing success through durability rather than overall speed. Carlo Chiti was the chief designer during 250 TR development and his continual experimentation counterbalanced Mr. Ferrari's conservatism and led to the many revisions that kept the car competitive through 1962. Other Ferrari engineers had major contributions to the 250 TR, notably Giotto Bizzarrini, who helped with aerodynamic improvements for the 1961 season, Andrea Fraschetti, who helped developed the first 250 TR prototype before his 1957 death during a test drive; the 250 TR was raced and continually developed by Scuderia Ferrari from 1957 through 1962.
In total, 33 250 TRs of all types were built between 1957 and 1962. Included in this total are 19 "customer versions" of the 250 TR sold to independent racing teams, replacing the 500 TRC for this market. All customer cars had left hand live rear axles, they did not benefit from the continual improvements to Scuderia Ferrari cars, although many independent teams modified their 250 TRs or purchased ex-Scuderia Ferrari cars in order to stay competitive. The 250 Testa Rossa engine was based on Colombo-designed 3.0L V12 used in 250 GT road and racing cars. Carlo Chiti and other Ferrari engineers made several modifications to increase the performance of this proven engine; the starting point was a 1953-style cylinder block with an overall capacity of 2953 cc, a 73mm bore and 58.8 mm stroke. Six two-barrel Weber 38 DCN carburetors fed the engine, increased from the 3 carburetors typical for 250 GT engines; the cylinder heads used single overhead cams, 2 valves per cylinder and helical double-coil valve springs.
The helical valve springs were much smaller than used torsion springs, allowing the cylinder heads to be strengthened and secured with 24 studs rather than 18 in previous 250 engines. This increased the overall reliability of the engine by improving head gasket sealing. One spark plug was used per cylinder and the position was changed from earlier 250 designs, now located outside the engine vee between exhaust ports; this allowed for a more efficient combustion. Piston connecting rods were now machined from steel billet, rather than forged, which resulted in more stress-resistance at higher RPMs; the cam covers were painted bright red, the source of the name "Testa Rossa". This tradition and name originated with the 500 TR; the resulting engine was generated 300 hp at 7000 rpm. The power/displacement ratio of 100 hp/liter was a particular point of pride for Ferrari, as it demonstrated how Ferrari's engineering prowess could create a competitive engine under rules restricting displacement; the engineering team improved a well understood, proven design by incorporating new technology and strengthening known weak points.
They created a massive benefit in endurance racing. Other Ferrari racing cars achieved racing success with the same basic engine well into the 1960s, years after the 250 TR chassis was obsolete. 1957-1958 250 TRs used a 4-speed transmission, followed by a 5-speed transmission in 1959. Customer cars were equipped with a 250 GT-style transmission positioned directly behind the engine, while Scuderia Ferrari team cars sometimes used rear-mounted transaxles for better weight distribution; the 250 Testa Rossa used a tubular steel spaceframe chassis, similar to that used in the 500 TR. Compared to the 500 TR, the wheelbase was extended by 10 cm to 2.35 meters. The chassis gained a reputation for durability, as it was designed according to Enzo Ferrari's desire for absolute reliability at the expense of excess weight. All 250 TRs used independent front suspension with coil springs. All customer cars had live rear axles. Pre-1960 factory team cars used either live or de Dion rear axles while the 1960 250 TRI60 and 1961 250 TRI61 used independent rear suspension.1957 and 1958 250 TRs were equipped with drum brakes on all four wheels.
Enzo Ferrari insisted on the use of drum brakes in the early 250 TRs as he believed they were more reliable and predictable in how they faded compared to more powerful but new disc brakes. Drum brakes were unpopular with drivers as they required tremendous physical exertion to operate, due to
This article is about four-wheeled vehicle suspension. For information on two wheeled vehicles' suspensions see Suspension, Motorcycle fork, Bicycle suspension, Bicycle fork. Suspension is the system of tires, tire air, shock absorbers and linkages that connects a vehicle to its wheels and allows relative motion between the two. Suspension systems must support both road holding/handling and ride quality, which are at odds with each other; the tuning of suspensions involves finding the right compromise. It is important for the suspension to keep the road wheel in contact with the road surface as much as possible, because all the road or ground forces acting on the vehicle do so through the contact patches of the tires; the suspension protects the vehicle itself and any cargo or luggage from damage and wear. The design of front and rear suspension of a car may be different. An early form of suspension on ox-drawn carts had the platform swing on iron chains attached to the wheeled frame of the carriage.
This system remained the basis for all suspension systems until the turn of the 19th century, although the iron chains were replaced with the use of leather straps by the 17th century. No modern automobiles use the'strap suspension' system. Automobiles were developed as self-propelled versions of horse-drawn vehicles. However, horse-drawn vehicles had been designed for slow speeds, their suspension was not well suited to the higher speeds permitted by the internal combustion engine; the first workable spring-suspension required advanced metallurgical knowledge and skill, only became possible with the advent of industrialisation. Obadiah Elliott registered the first patent for a spring-suspension vehicle. Within a decade, most British horse carriages were equipped with springs; these were made of low-carbon steel and took the form of multiple layer leaf springs. Leaf springs have been around since the early Egyptians. Ancient military engineers used leaf springs in the form of bows to power their siege engines, with little success at first.
The use of leaf springs in catapults was refined and made to work years later. Springs were not only made of metal. Horse-drawn carriages and the Ford Model T used this system, it is still used today in larger vehicles mounted in the rear suspension. Leaf springs were the first modern suspension system and, along with advances in the construction of roads, heralded the single greatest improvement in road transport until the advent of the automobile; the British steel springs were not well-suited for use on America's rough roads of the time, so the Abbot-Downing Company of Concord, New Hampshire re-introduced leather strap suspension, which gave a swinging motion instead of the jolting up and down of a spring suspension. In 1901 Mors of Paris first fitted an automobile with shock absorbers. With the advantage of a damped suspension system on his'Mors Machine', Henri Fournier won the prestigious Paris-to-Berlin race on 20 June 1901. Fournier's superior time was 11 hrs 46 min 10 sec, while the best competitor was Léonce Girardot in a Panhard with a time of 12 hrs 15 min 40 sec.
Coil springs first appeared on a production vehicle in 1906 in the Brush Runabout made by the Brush Motor Company. Today, coil springs are used in most cars. In 1920, Leyland Motors used torsion bars in a suspension system. In 1922, independent front suspension was pioneered on the Lancia Lambda and became more common in mass market cars from 1932. Today, most cars have independent suspension on all four wheels. In 2002, a new passive suspension component was invented by Malcolm C. Smith, the inerter; this has the ability to increase the effective inertia of a wheel suspension using a geared flywheel, but without adding significant mass. It was employed in Formula One in secrecy but has since spread to other motorsport. Any four wheel vehicle needs suspension for both the front wheels and the rear suspension, but in two wheel drive vehicles there can be a different configuration. For front-wheel drive cars, rear suspension has few constraints and a variety of beam axles and independent suspensions are used.
For rear-wheel drive cars, rear suspension has many constraints and the development of the superior but more expensive independent suspension layout has been difficult. Four-wheel drive has suspensions that are similar for both the front and rear wheels. Henry Ford's Model T used a torque tube to restrain this force, for his differential was attached to the chassis by a lateral leaf spring and two narrow rods; the torque tube surrounded the true driveshaft and exerted the force to its ball joint at the extreme rear of the transmission, attached to the engine. A similar method was used in the late 1930s by Buick and by Hudson's bathtub car in 1948, which used helical springs which could not take fore-and-aft thrust; the Hotchkiss drive, invented by Albert Hotchkiss, was the most popular rear suspension system used in American cars from the 1930s to the 1970s. The system uses longitudinal leaf springs attached both forward and behind the differential of the live axle; these springs transmit the torque to the frame.
Although scorned by many European car makers of the time, it was accepted by American car makers because it was inexpensive to manufacture. The dynamic defects of this design were suppressed by the enormous weight of US passenger vehicles before implementation of the Corporate Average Fuel Economy
A shock absorber is a mechanical or hydraulic device designed to absorb and damp shock impulses. It does this by converting the kinetic energy of the shock into another form of energy, dissipated. Most shock absorbers are a form of dashpot. Pneumatic and hydraulic shock absorbers are used in conjunction with springs. An automobile shock absorber contains spring-loaded check valves and orifices to control the flow of oil through an internal piston. One design consideration, when designing or choosing a shock absorber, is. In most shock absorbers, energy is converted to heat inside the viscous fluid. In hydraulic cylinders, the hydraulic fluid heats up, while in air cylinders, the hot air is exhausted to the atmosphere. In other types of shock absorbers, such as electromagnetic types, the dissipated energy can be stored and used later. In general terms, shock absorbers help cushion vehicles on uneven roads. In a vehicle, shock absorbers reduce the effect of traveling over rough ground, leading to improved ride quality and vehicle handling.
While shock absorbers serve the purpose of limiting excessive suspension movement, their intended sole purpose is to damp spring oscillations. Shock absorbers use gasses to absorb excess energy from the springs. Spring rates are chosen by the manufacturer based on the weight of the vehicle and unloaded; some people use shocks to modify spring rates but this is not the correct use. Along with hysteresis in the tire itself, they damp the energy stored in the motion of the unsprung weight up and down. Effective wheel bounce damping may require tuning shocks to an optimal resistance. Spring-based shock absorbers use coil springs or leaf springs, though torsion bars are used in torsional shocks as well. Ideal springs alone, are not shock absorbers, as springs only store and do not dissipate or absorb energy. Vehicles employ both hydraulic shock absorbers and springs or torsion bars. In this combination, "shock absorber" refers to the hydraulic piston that absorbs and dissipates vibration. Now, composite suspension system are used in 2 wheelers and leaf spring are made up of composite material in 4 wheelers.
In common with carriages and railway locomotives, most early motor vehicles used leaf springs. One of the features of these springs was that the friction between the leaves offered a degree of damping, in a 1912 review of vehicle suspension, the lack of this characteristic in helical springs was the reason it was "impossible" to use them as main springs; however the amount of damping provided by leaf spring friction was limited and variable according to the conditions of the springs, whether wet or dry. It operated in both directions. Motorcycle front suspension adopted coil sprung Druid forks from about 1906, similar designs added rotary friction dampers, which damped both ways - but they were adjustable; these friction disk shock absorbers were fitted to many cars. One of the problems with motor cars was the large variation in sprung weight between loaded and loaded for the rear springs; when loaded the springs could bottom out, apart from fitting rubber'bump stops', there were attempts to use heavy main springs with auxiliary springs to smooth the ride when loaded, which were called'shock absorbers'.
Realising that the spring and vehicle combination bounced with a characteristic frequency, these auxiliary springs were designed with a different period, but were not a solution to the problem that the spring rebound after striking a bump could throw you out of your seat. What was called for was damping that operated on the rebound. Although C. L. Horock came up with a design in 1901 that had hydraulic damping, it worked in one direction only, it does not seem to have gone into production right away, whereas mechanical dampers such as the Gabriel Snubber started being fitted in the late 1900s. These used a belt coiled inside a device such that it wound in under the action of a coiled spring, but met friction when drawn out. Gabriel Snubbers were fitted to an 11.9HP Arrol-Johnston car which broke the 6 hour Class B record at Brooklands in late 1912, the Automotor journal noted that this snubber might have a great future for racing due to its light weight and easy fitment. One of the earliest hydraulic dampers to go into production was the Telesco Shock Absorber, exhibited at the 1912 Olympia Motor Show and marketed by Polyrhoe Carburettors Ltd.
This contained a spring inside the telescopic unit like the pure spring type'shock absorbers' mentioned above, but oil and an internal valve so that the oil damped in the rebound direction. The Telesco unit was fitted at the rear end of the leaf spring, in place of the rear spring to chassis mount, so that it formed part of the springing system, albeit a hydraulically damped part; this layout was selected as it was easy to apply to existing vehicles, but it meant the hydraulic damping was not applied to the action of the main leaf spring, but only to the action of the auxiliary spring in the unit itself. The first production hydraulic dampers to act on the main leaf spring movement were those based on an original concept by Maurice Houdaille patented in 1908 and 1909; these used a lever arm. The main advantage over the friction disk dampers was that it would resist sudden movement but allow slow movement, whereas the rotary friction dampers tended to stick and offer the same resistance regardless of speed of movement.
There appears t