Dampers: Shocks" Unless a dampening structure is present, a car spring will extend and release the energy it absorbs from a bump at an uncontrolled rate. The spring will continue to bounce at its natural frequency until all of the energy originally put into it is used up. A suspension built on springs alone would make for an extremely bouncy ride and, depending on the terrain, an uncontrollable car. Enter the shock absorber, or snubber, a device that controls unwanted spring motion through a process known as dampening. Shock absorbers slow down and reduce the magnitude of vibratory motions by turning the kinetic energy of suspension movement into heat energy that can be dissipated through hydraulic fluid. To understand how this works, it's best to look inside a shock absorber to see its structure and function. A shock absorber is basically an oil pump placed between the frame of the car and the wheels. Shock absorbers work in two cycles -- the compression cycle and the extension cycle.
Top 10 Everyday Car Technologies that Came from Racing" Most drivers in the United States use automatic transmissions, which makes cruising around town worlds apart from a hard-shifting lap on a Formula One track. But, the purpose of a transmission in a race car and a road car are the same: it translates the engine's power to the car's wheels. While an automatic transmission shifts gears with no input from the driver (other than the initial selection of Drive), a manual transmission lets the driver control the flow of power from the engine to the wheels. Race car drivers want the control of a manual transmission, but the manual process can be too slow and prone to human error. Enter Direct-Shift Gearboxes (DSG) and clutchless manual transmissions. DSGs actually work like two transmissions: one dials in the odd numbered gears and one dials in the even numbered gears. Running late?
Camber angle From the front of the car, a right wheel with a negative camber angle The 1960 Milliken MX1 Camber Car showing a large negative camber. Camber angle alters the handling qualities of a particular suspension design; in particular, negative camber improves grip when cornering. On the other hand, for maximum straight-line acceleration, the greatest traction will be attained when the camber angle is zero and the tread is flat on the road. Off-road vehicles such as agricultural tractors generally use positive camber. See also[edit] References[edit] External links[edit] How the Ariel Atom Works" The Atom features a double-wishbone suspension front and rear, which consists of a short upper control arm and a longer lower control arm that hold the wheel to the frame. The control arms operate much like a hinge, allowing the wheel to move up and down. Rubber bushings at the inboard end of the control arms allow the wheel to pivot. The bushings also help to absorb road shock and reduce noise entering the vehicle. Overall, the double-wishbone suspension allows for more control over the camber angle of the wheels. Camber angle describes the degree to which the wheels tilt in and out. Koni-manufactured dampers at each wishbone provide additional adjustability. The braking system of the Atom offers another opportunity to fine-tune the driving experience. Next, we'll take a look at the origins of the Atom.
Caster angle θ is the caster angle, the red line is the pivot line, and the grey area is the tire. Bikes[edit] In the context of bicycles and motorcycles, caster is more commonly referred to as "rake and trail", especially in American English. British English still predominantly uses the term caster. Front end alignment[edit] When a vehicle's front suspension is aligned, caster is adjusted to achieve the self-centering action of steering, which affects the vehicle's straight-line stability. Positive caster angle[edit] The pivot points of the steering are angled such that a line drawn through them intersects the road surface slightly ahead of the contact patch of the tire on the pavement. Trail or trailing[edit] History[edit] See also[edit] References[edit] Jump up ^ "Merriam Webster Dictionary". External links[edit]
How Car Steering Works" Rack-and-pinion steering is quickly becoming the most common type of steering on cars, small trucks and SUVs. It is actually a pretty simple mechanism. A rack-and-pinion gearset is enclosed in a metal tube, with each end of the rack protruding from the tube. The pinion gear is attached to the steering shaft. The rack-and-pinion gearset does two things: It converts the rotational motion of the steering wheel into the linear motion needed to turn the wheels.It provides a gear reduction, making it easier to turn the wheels. On most cars, it takes three to four complete revolutions of the steering wheel to make the wheels turn from lock to lock (from far left to far right). The steering ratio is the ratio of how far you turn the steering wheel to how far the wheels turn. Generally, lighter, sportier cars have lower steering ratios than larger cars and trucks. Power Rack-and-pinion When the rack-and-pinion is in a power-steering system, the rack has a slightly different design.
Ackermann steering geometry Ackermann geometry Ackermann steering geometry is a geometric arrangement of linkages in the steering of a car or other vehicle designed to solve the problem of wheels on the inside and outside of a turn needing to trace out circles of different radius. It was invented by the German carriage builder Georg Lankensperger in Munich in 1817, then patented by his agent in England, Rudolph Ackermann (1764–1834) in 1818 for horse-drawn carriages. Erasmus Darwin may have a prior claim as the inventor dating from 1758.[1] Advantages[edit] The intention of Ackermann geometry is to avoid the need for tyres to slip sideways when following the path around a curve.[2] The geometrical solution to this is for all wheels to have their axles arranged as radii of a circle with a common centre point. Rather than the preceding "turntable" steering, where both front wheels turned around a common pivot, each wheel gained its own pivot, close to its own hub. Design and choice of geometry[edit] References[edit]
How Car Steering Works" Recirculating-ball steering is used on many trucks and SUVs today. The linkage that turns the wheels is slightly different than on a rack-and-pinion system. The recirculating-ball steering gear contains a worm gear. You can image the gear in two parts. The first part is a block of metal with a threaded hole in it. Instead of the bolt directly engaging the threads in the block, all of the threads are filled with ball bearings that recirculate through the gear as it turns. Power steering in a recirculating-ball system works similarly to a rack-and-pinion system. Now let's take a look at the other components that make up a power-steering system.
Strut bar mounted strut bar front strut bar Combined strut bar and overflow container in an mk2 Saab Sonett. A strut bar is designed to reduce this strut tower flex by tying two parallel strut towers together. On versions of the Saab Sonett, the overflow container for the cooling system doubles as a strut bar. Many manufacturers have fitted strut braces to performance models as standard or optional equipment, including the Acura CL Type-S, Acura TSX, BMW M3, BMW 3-Series, Ford Mustang Bullitt, Holden VY II Commodore, Honda Crosstour, Honda Integra Type R, Hyundai Genesis Coupe, Mazda Protege 5, Mazda RX-8, Mitsubishi Colt Ralliart, Mitsubishi Lancer Evolution, Mitsubishi Outlander, Nissan Skyline, Nissan 350Z, Pontiac GTO, Pontiac Bonneville GXP, Saab 900 NG, Toyota MR2, Toyota Solara, Toyota Camry SE, Volvo S60 and the Subaru Legacy GM vehicles[edit] See also[edit] Lower tie bar External links[edit] Strut Tower Bar Theory
How Car Steering Works" There are a couple of key components in power steering in addition to the rack-and-pinion or recirculating-ball mechanism. Pump The hydraulic power for the steering is provided by a rotary-vane pump (see diagram below). This pump is driven by the car's engine via a belt and pulley. As the vanes spin, they pull hydraulic fluid from the return line at low pressure and force it into the outlet at high pressure. The pump contains a pressure-relief valve to make sure that the pressure does not get too high, especially at high engine speeds when so much fluid is being pumped. Rotary Valve A power-steering system should assist the driver only when he is exerting force on the steering wheel (such as when starting a turn). The key to the rotary valve is a torsion bar. The input from the steering shaft forms the inner part of a spool-valve assembly. Animation showing what happens inside the rotary valve when you first start to turn the steering wheel
Torsion bar suspension A torsion bar with no load applied. A torsion bar with a load applied. Usage[edit] Torsion bar suspensions are used on combat vehicles or tanks like the T-72, Leopard 1, Leopard 2, M18 Hellcat, and Abrams (many tanks from late in World War II used this suspension), and on trucks and SUVs from Ford, Dodge, GM, Mitsubishi, Mazda, Nissan, Isuzu and Toyota. Manufacturers change the torsion bar or key to adjust the ride height, usually to compensate for heavier or lighter engines. Advantages and disadvantages[edit] The main advantages of a torsion bar suspension are durability, easy adjustability of ride height, and small profile along the width of the vehicle. Leveling[edit] Some vehicles use torsion bars to provide automatic levelling, using a motor to pre-stress the bars to provide greater resistance to load and, in some cases (depending on the speed with which the motors can act), to respond to changes in road conditions. History[edit] Variations[edit] Other uses[edit] References[edit]
How Car Steering Works" Since the power-steering pump on most cars today runs constantly, pumping fluid all the time, it wastes horsepower. This wasted power translates into wasted fuel. You can expect to see several innovations that will improve fuel economy. One of the coolest ideas on the drawing board is the "steer-by-wire" or "drive-by-wire" system. General Motors has introduced a concept car, the Hy-wire, that features this type of driving system. In the past fifty years, car steering systems haven't changed much. For more information on steering systems and related topics, check out the links on the next page.
Independent suspension A multi-link type rear independent suspension on an AWD car. The anti-roll bar has some yellow paint on it. Most modern vehicles have independent front suspension (IFS). Independent suspension typically offers better ride quality and handling characteristics, due to lower unsprung weight and the ability of each wheel to address the road undisturbed by activities of the other wheel on the vehicle. The relative movement between the wheels and the differential is achieved through the use of swinging driveshafts connected via universal (U) joints, analogous to the constant-velocity (CV) joints used in front wheel drive vehicles. Independent suspension[edit] Suspension[edit] Suspension is the only component that separates the driver and/or passenger from the ground. Advantages[edit] This system provides many advantages over other suspension systems. Types[edit] MacPherson strut[edit] This is the most common, widely used front suspension system in cars of European origin. References[edit]