 Gasfilled Shock absorber. A shock absorber in common parlance (or damper in technical use) is a mechanical device designed to smooth out or damp a sudden shock impulse and dissipate kinetic energy. It is analogous to a resistor in an electric RLC circuit. Image File history File links Gas_damper_mov. ...
Image File history File links Gas_damper_mov. ...
Damping is any effect, either deliberately engendered or inherent to a system, that tends to reduce the amplitude of oscillations of an oscillatory system. ...
In mechanics, a shock is a sudden acceleration or deceleration caused, for example, by impact or explosion. ...
The kinetic energy of an object is the extra energy which it possesses due to its motion. ...
Resistor symbols (non-European) Resistor symbols (Europe, IEC) A pack of resistors A resistor is a two-terminal electrical or electronic component that resists an electric current by producing a voltage drop between its terminals in accordance with Ohms law. ...
An RLC circuit (also known as a resonant circuit or a tuned circuit) is an electrical circuit consisting of a resistor (R), an inductor (L), and a capacitor (C), connected in series or in parallel. ...
Explanation Shock absorbers must absorb or dissipate energy. One design consideration, when designing or choosing a shock absorber is where that energy will go. In most dashpots, energy is converted to heat inside the viscous fluid. In hydraulic cylinders, the hydraulic fluid will heat up. In air cylinders, the hot air is usually exhausted to the atmosphere. In other types of dashpots, such as electromagnetic ones, the dissipated energy can be stored and used later. A dashpot is a mechanical device, a damper which resists motion via viscous friction. ...
Hydraulics is a branch of science and engineering concerned with the use of liquids to perform mechanical tasks. ...
Look up cylinder in Wiktionary, the free dictionary. ...
A fluid is defined as a substance that continually deforms (flows) under an applied shear stress regardless of the magnitude of the applied stress. ...
Electromagnetism is the physics of the electromagnetic field: a field, encompassing all of space, composed of the electric field and the magnetic field. ...
Description Pneumatic and hydraulic shock absorbers commonly take the form of a cylinder with a sliding piston inside. The cylinder is filled with a fluid, such as hydraulic fluid or air. This fluid filled piston/cylinder combination is a dashpot. Pneumatics, from the Greek πνευματικός (pneumatikos, coming from the wind) is the use of pressurized air in science and technology. ...
piston + connecting rod Components of a typical, four stroke cycle, DOHC piston engine. ...
A dashpot is a mechanical device, a damper which resists motion via viscous friction. ...
Applications Shock absorbers are an important part of automobile and motorcycle suspensions, aircraft landing gear, and the supports for many industrial machines. Large shock absorbers have also been used in structural engineering to reduce the susceptibility of structures to earthquake damage and resonance. Karl Benzs Velo (vélo means bicycle in French) model (1894) - entered into the first automobile race 2005 MINI Cooper S. An automobile (also motor car or simply car) is a wheeled passenger vehicle that carries its own motor. ...
Motorcyclists take a break from the road A motorcycle or motorbike is a single-track, two-wheeled motor vehicle powered by an engine. ...
The front suspension components of a Ford Model T. Suspension is the term given to the system of springs, shock absorbers and linkages that connects a vehicle to its wheels. ...
Look up aircraft in Wiktionary, the free dictionary. ...
Main and nosewheel undercarriage of a Qatar Airways Airbus A330 The undercarriage or landing gear is equipment which supports an aircraft when it is not flying. ...
Wind turbines The scientific definition of a machine is any device that transmits or modifies energy. ...
Taipei 101, the worlds tallest building as of 2004. ...
An earthquake is the result from the sudden release of stored energy in the Earths crust that creates seismic waves. ...
This article is about resonance in physics. ...
 Rear shock absorber and spring of a BMW R75/5 motorcycle Image File history File links No higher resolution available. ...
Image File history File links No higher resolution available. ...
Vehicles suspension In a vehicle, it reduces the effect of traveling over rough ground, leading to improved ride quality. Without shock absorbers, the vehicle would have a bouncing ride, as energy is stored in the spring and then released to the vehicle, possibly exceeding the allowed range of suspension movement. Control of excessive suspension movement without shock absorption requires stiffer (higher rate) springs, which would in turn give a harsh ride. Shock absorbers allow the use of soft (lower rate) springs while controlling the rate of suspension movement in response to bumps. They also, along with hysteresis in the tire itself, damp the motion of the unsprung weight up and down on the springiness of the tire. Since the tire is not as soft as the springs, effective wheel bounce damping may require stiffer shocks than would be ideal for the vehicle motion alone. Ride quality refers to the degree of protection offered vehicle occupants from uneven elements in the road surface, or the terrain if driving off-road. ...
The front suspension components of a Ford Model T. Suspension is the term given to the system of springs, shock absorbers and linkages that connects a vehicle to its wheels. ...
This does not cite its references or sources. ...
Spring-based shock absorbers commonly use coil springs or leaf springs, though torsion bars can be used in torsional shocks as well. Ideal springs alone, however, are not shock absorbers as springs only store and do not dissipate or absorb energy. Vehicles typically employ both springs or torsion bars as well as hydraulic shock absorbers. In this combination, "shock absorber" is reserved specifically for the hydraulic piston that absorbs and dissipates vibration. Helical or coil springs designed for tension A spring is a flexible elastic object used to store mechanical energy. ...
A compression coil spring A tension coil spring A selection of conical coil springs A Coil spring, also known as a helical spring, is a mechanical device, which is typically used to store energy and subsequently release it, to absorb shock, or to maintain a force between contacting surfaces. ...
A traditional leaf spring arrangement. ...
A torsion spring is a ribbon, bar, or coil that reacts against twisting motion. ...
Look up torsion in Wiktionary, the free dictionary. ...
Structures Applied to a structure such as a building or bridge it may be part of a seismic retrofit or as part of new, earthquake resistant construction. In this application it allows yet restrains motion and absorbs resonant energy, which can cause excessive motion and eventual structural failure. For other uses, see Building (disambiguation). ...
A log bridge in the French Alps near Vallorcine. ...
Seismic retrofitting is the modification of existing structures to make them more resistant to seismic activity, ground motion, or soil failure due to earthquakes. ...
An earthquake is the result from the sudden release of stored energy in the Earths crust that creates seismic waves. ...
This article is about resonance in physics. ...
Structural failure refers to loss of the load-carying capacity of a component or member within the structure or of the structure itself. ...
Types of shock absorbers There are several commonly-used approaches to shock absorption: - Hysteresis of structural material, for example the compression of rubber disks, stretching of rubber bands and cords, bending of steel springs, or twisting of torsion bars. Hysteresis is the tendency for otherwise elastic materials to rebound with less force than was required to deform them. Simple vehicles with no separate shock absorbers are damped, to some extent, by the hysteresis of their springs and frames.
- Dry friction as used in wheel brakes, by using disks (classically made of leather) at the pivot of a lever, with friction forced by springs. Used in early automobiles such as the Ford Model T, up through some British cars of the 1940s. Although now considered obsolete, an advantage of this system is its mechanical simplicity; the degree of damping can be easily adjusted by tightening or loosening the screw clamping the disks, and it can be easily rebuilt with simple hand tools. A disadvantage is that the damping force tends not to increase with the speed of the vertical motion.
- Solid state, tapered chain shock absorbers, using one or more tapered, axial alignment(s) of granular spheres, typically made of metals such as nitinol, in a casing. [1],[2]
- Fluid friction, for example the flow of fluid through a narrow orifice (hydraulics), constitute the vast majority of automotive shock absorbers. An advantage of this type is that using special internal valving the absorber may be made relatively soft to compression (allowing a soft response to a bump) and relatively stiff to extension, controlling "jounce", which is the vehicle response to energy stored in the springs; similarly, a series of valves controlled by springs can change the degree of stiffness according to the velocity of the impact or rebound. Specialized shock absorbers for racing purposes may allow the front end of a dragster to rise with minimal resistance under acceleration, then strongly resist letting it settle, thereby maintaining a desirable rearward weight distribution for enhanced traction. Some shock absorbers allow tuning of the ride via control of the valve by a manual adjustment provided at the shock absorber. In more expensive vehicles the valves may be remotely adjustable, offering the driver control of the ride at will while the vehicle is operated. The ultimate control is provided by dynamic valve control via computer in response to sensors, giving both a smooth ride and a firm suspension when needed. Many shock absorbers contain compressed nitrogen, to reduce the tendency for the oil to foam under heavy use. Foaming temporarily reduces the damping ability of the unit. In very heavy duty units used for racing and/or off-road use, there may even be a secondary cylinder connected to the shock absorber to act as a reservoir for the oil and pressurized gas.
- Compression of a gas, for example pneumatic shock absorbers, which can act like springs as the air pressure is building to resist the force on it. Once the air pressure reaches the necessary maximum, air dashpots will act like hydraulic dashpots. In aircraft landing gear air dashpots may be combined with hydraulic damping to reduce bounce. Such struts are called oleo struts (combining oil and air) [3].
- Magnetic effects. Eddy current dampers are dashpots that are constructed out of a large magnet inside of a non-magnetic, electrically conductive tube. Furthermore, many modern hybrid automobiles have regenerative braking, which uses a reversed electric motor to damp and eventually stop the motion of the car.
- Inertial resistance to acceleration, for example the Citroën 2CV has an additional pair of rear shock absorbers that damp wheel bounce with no external moving parts. The energy is absorbed by hydraulic fluid friction, but their operation depends on the inertia of an internal weight. These are essentially small versions of the tuned mass dampers used on tall buildings
- Composite hydropneumatic devices which combine in a single device spring action, shock absorption, and often also ride-height control, as in some models of the Citroën automobile.
- Conventional shock absorbers combined with composite pneumatic springs with which allow ride height adjustment or even ride height control, seen in some large trucks and luxury sedans such as certain Lincoln and most Land Rover automobiles. Ride height control is especially desirable in highway vehicles intended for occasional rough road use, as a means of improving handling and reducing aerodynamic drag by lowering the vehicle when operating on improved high speed roads.
- The effect of a shock absorber at high (sound) frequencies is usually limited by using a compressible gas as the working fluid and/or mounting it with rubber bushings.
Hysteresis is a property of systems (usually physical systems) that do not instantly follow the forces applied to them, but react slowly, or do not return completely to their original state: that is, systems whose states depend on their immediate history. ...
Physical compression is the result of the subjection of a material to compressive stress, resulting in reduction of volume. ...
Latex being collected from a tapped rubber tree Rubber is an elastic hydrocarbon polymer which occurs as a milky colloidal suspension (known as latex) in the sap of several varieties of plants. ...
An actively stretching Siberian tiger Cat stretching in utterly relaxed rest Stretching is the activity of gradually applying tensile force to lengthen, strengthen, and lubricate muscles, often performed in anticipation of physical exertion and to increase the range of motion within a joint. ...
Figure 1. ...
The steel cable of a colliery winding tower. ...
Helical or coil springs designed for tension A spring is a flexible elastic object used to store mechanical energy. ...
This article or section does not adequately cite its references or sources. ...
Elasticity has meanings in two different fields: In physics and mechanical engineering, the theory of elasticity describes how a solid object moves and deforms in response to external stress. ...
Friction is the force that opposes the relative motion or tendency toward such motion of two surfaces in contact. ...
A brake is a device for slowing or stopping the motion of a machine or vehicle, and to keep it from starting to move again. ...
Modern leather-working tools Leather is a material created through the tanning of hides and skins of animals, primarily cattlehide. ...
The Ford Model T (colloquially known as the Tin Lizzie and the Flivver) was an automobile produced by Henry Fords Ford Motor Company from 1908 through 1927. ...
When something is granular, it is made up of minute semi-fine particals like sand or granulated sugar. ...
A shape memory alloy (SMA) (also known as memory metal or smart wire) is a metal that remembers its geometry. ...
A fluid is defined as a substance that continually deforms (flows) under an applied shear stress regardless of the magnitude of the applied stress. ...
Hydraulics is a branch of science and engineering concerned with the use of liquids to perform mechanical tasks. ...
Drag racing is a form of auto racing in which cars attempt to complete a fairly short, straight and level course in the shortest amount of time. ...
General Name, Symbol, Number nitrogen, N, 7 Chemical series nonmetals Group, Period, Block 15, 2, p Appearance colorless gas Standard atomic weight 14. ...
Sea foam on the beach. ...
Pneumatics, from the Greek πνευματικός (pneumatikos, coming from the wind) is the use of pressurized air in science and technology. ...
Look up aircraft in Wiktionary, the free dictionary. ...
It has been suggested that this article or section be merged with Magnetism. ...
As the circular plate moves down through a small region of constant magnetic field directed into the page, eddy currents are induced in the plate. ...
A dashpot is a mechanical device, a damper which resists motion via viscous friction. ...
Regenerative braking is any technology which allows a vehicle to recapture and store part of the kinetic energy that would otherwise be lost to heat when braking. ...
The principle of inertia is one of the fundamental laws of classical physics which are used to describe the motion of matter and how it is affected by applied forces. ...
First generation Ripple Bonnet Citroën 2CV built from 1948 to 1960 The Citroën 2CV (French: deux chevaux, literally two horses, from the tax horsepower rating) was an economy car produced by the French automaker Citroën from 1948 to 1990. ...
A tuned mass damper is a device mounted in structures to prevent discomfort, damage or outright structural failure by vibration. ...
Hydropneumatic is the name given to a suspension system invented by Citroën and fitted to Citroën cars, as well as being adapted by other car manufacturers, notably Rolls-Royce, Mercedes-Benz and Peugeot. ...
Citroën is a French automobile manufacturer, founded in 1919 by André Citroën. ...
Lincoln is an American luxury automobile brand, operated under the Ford Motor Company. ...
Car handling and vehicle handling is a description of the way wheeled vehicles perform transverse to their direction of motion, particularly during cornering and swerving. ...
See also A strut is a structural component designed to resist longitudinal compression. ...
Front Strut Bar mounted strut bar A strut bar or strut brace is a mostly aftermarket car suspension accessory used in conjunction with MacPherson struts on monocoque or unibody chassis to provide extra strength between the strut towers. ...
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