Trailing-arm suspension

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Trailing-arm (or link) landing gear leg on a Cessna 404 aircraft Oleo trailing link main landing gear.JPG
Trailing-arm (or link) landing gear leg on a Cessna 404 aircraft

A trailing-arm suspension, also referred to as trailing-link, is a form of vehicle vehicle suspension. In a motor vehicle it places one or more horizontal arms (or "links") perpendicular to and forward of the axle on the chassis or unibody, which are connected to the axle or wheels with pivot joint(s) . These are typically used on the rear axle or wheels of vehicles, but also found in both front and main landing gear of aircraft.

Contents

A "semi trailing-arm" (or semi trailing-link) is a common form of independent rear suspension on automobiles, particularly those with front wheel drive (where it allows a flatter rear floor pan).

Leading arms are similar horizontal arms, perpendicular to the axle, but connecting the wheels to the vehicle structure via pivot joints to the rear of them. These are typically used on the front axle or wheels, as on the Citroën 2CV and its derivatives, and on the Citroën DS, as well as on the M422 Mighty Mite jeep.

Types

Axle - Trailing arm 42.gif
Trailing arm rear suspension of FF cars
Axle - Trailing arm 41.gif
Rear suspension of Renault 4 and Renault 5
Axle - Semi trailing-arm 23.gif
Semi-trailing arm suspension

Trailing-arm

Trailing-arm designs in live axle setups often use just two or three links and a Panhard rod to locate the wheel laterally. A trailing arm design can also be used in an independent suspension arrangement. Each wheel hub is located only by a large, roughly triangular arm that pivots at one point, ahead of the wheel. Seen from the side, this arm is roughly parallel to the ground, with the angle changing based on road irregularities. A twist-beam rear suspension is very similar except that the arms are connected by a beam, used to locate the wheels and which twists and has an anti-roll effect.

Some aircraft also use trailing arms in their landing gear, with oleo struts for shock absorption. A trailing arm landing gear results in smoother landings and a better ride when taxiing compared to other types of landing gear. [1]

Semi-trailing arm

A semi-trailing arm suspension is a supple independent rear suspension system for automobiles where each wheel hub is located only by a large, roughly triangular arm that pivots at two points. Viewed from the top, the line formed by the two pivots is somewhere between parallel and perpendicular to the car's longitudinal axis; it is generally parallel to the ground. Trailing-arm and multilink suspension designs are much more commonly used for the rear wheels of a vehicle where they can allow for a flatter floor and more cargo room. Many small, front-wheel drive vehicles feature a MacPherson strut front suspension and trailing-arm rear axle.

See also

Related Research Articles

<span class="mw-page-title-main">Axle</span> Central shaft for a rotating wheel or gear

An axle or axletree is a central shaft for a rotating wheel or gear. On wheeled vehicles, the axle may be fixed to the wheels, rotating with them, or fixed to the vehicle, with the wheels rotating around the axle. In the former case, bearings or bushings are provided at the mounting points where the axle is supported. In the latter case, a bearing or bushing sits inside a central hole in the wheel to allow the wheel or gear to rotate around the axle. Sometimes, especially on bicycles, the latter type of axle is referred to as a spindle.

<span class="mw-page-title-main">MacPherson strut</span> Type of automotive suspension design

The MacPherson strut is a type of automotive suspension system that uses the top of a telescopic damper as the upper steering pivot. It is widely used in the front suspension of modern vehicles. The name comes from American automotive engineer Earle S. MacPherson, who invented and developed the design.

<span class="mw-page-title-main">Steering</span> System of components that allows vehicles to follow the desired course

Steering is a system of components, linkages, and other parts that allows a driver to control the direction of a vehicle.

<span class="mw-page-title-main">Strut</span> Structural component designed to resist longitudinal compression

A strut is a structural component commonly found in engineering, aeronautics, architecture and anatomy. Struts generally work by resisting longitudinal compression, but they may also serve in tension.

<span class="mw-page-title-main">Torsion bar suspension</span> Vehicle suspension that uses a torsion bar

A torsion bar suspension, also known as a torsion spring suspension, is any vehicle suspension that uses a torsion bar as its main weight-bearing spring. One end of a long metal bar is attached firmly to the vehicle chassis; the opposite end terminates in a lever, the torsion key, mounted perpendicular to the bar, that is attached to a suspension arm, a spindle, or the axle. Vertical motion of the wheel causes the bar to twist around its axis and is resisted by the bar's torsion resistance. The effective spring rate of the bar is determined by its length, cross section, shape, material, and manufacturing process.

<span class="mw-page-title-main">Car suspension</span> Suspension system for a vehicle

Suspension is the system of tires, tire air, springs, 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 also 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.

<span class="mw-page-title-main">Independent suspension</span> Vehicle suspension in which each wheel is suspended independently

Independent suspension is any automobile suspension system that allows each wheel on the same axle to move vertically independently of the others. This is contrasted with a beam axle or deDion axle system in which the wheels are linked. "Independent" refers to the motion or path of movement of the wheels or suspension. It is common for the left and right sides of the suspension to be connected with anti-roll bars or other such mechanisms. The anti-roll bar ties the left and right suspension spring rates together but does not tie their motion together.

<span class="mw-page-title-main">Double wishbone suspension</span> Automotive independent suspension design

A double wishbone suspension is an independent suspension design for automobiles using two wishbone-shaped arms to locate the wheel. Each wishbone or arm has two mounting points to the chassis and one joint at the knuckle. The shock absorber and coil spring mount to the wishbones to control vertical movement. Double wishbone designs allow the engineer to carefully control the motion of the wheel throughout suspension travel, controlling such parameters as camber angle, caster angle, toe pattern, roll center height, scrub radius, scuff and more.

A swing axle is a simple type of independent suspension designed and patented by Edmund Rumpler in 1903. This was a revolutionary invention in automotive suspension, allowing driven (powered) wheels to follow uneven road surfaces independently, thus enabling the vehicle's wheels to maintain better road contact and holding; plus each wheel's reduced unsprung weight means their movements have less impact on the vehicle as a whole. The first automotive application was the Rumpler Tropfenwagen, later followed by the Mercedes 130H/150H/170H, the Standard Superior, the Volkswagen Beetle and its derivatives, the Chevrolet Corvair, and the roll-over prone M151 jeep amongst others.

<span class="mw-page-title-main">De Dion tube</span>

A de Dion tube is a form of non-independent automobile suspension. It is a considerable improvement over the swing axle, Hotchkiss drive, or live axle. Because it plays no part in transmitting power to the drive wheels, it is sometimes called a "dead axle".

<span class="mw-page-title-main">Anti-roll bar</span> Device that reduces the body roll of a vehicle

An anti-roll bar is a part of many automobile suspensions that helps reduce the body roll of a vehicle during fast cornering or over road irregularities. It connects opposite (left/right) wheels together through short lever arms linked by a torsion spring. An anti-roll bar increases the suspension's roll stiffness—its resistance to roll in turns—independent of its spring rate in the vertical direction. The first stabilizer bar patent was awarded to Canadian inventor Stephen Coleman of Fredericton, New Brunswick on April 22, 1919.

<span class="mw-page-title-main">Control arm</span>

In automotive suspension, a control arm, also known as an A-arm, is a hinged suspension link between the chassis and the suspension upright or hub that carries the wheel. In simple terms, it governs a wheel's vertical travel, allowing it to move up or down when driving over bumps, into potholes, or otherwise reacting to the irregularities of a road surface. Most control arms form the lower link of a suspension. Control arms play a crucial role in the suspension system of a vehicle. They help to keep the wheels aligned and maintain proper tire contact with the road, which is essential for safety and stability.

Torque steer is the unintended influence of engine torque on the steering, especially in front-wheel-drive vehicles. For example, during heavy acceleration, the steering may pull to one side, which may be disturbing to the driver. The effect is manifested either as a tugging sensation in the steering wheel, or a veering of the vehicle from the intended path. Torque steer is directly related to differences in the forces in the contact patches of the left and right drive wheels. The effect becomes more evident when high torques are applied to the drive wheels because of a high overall reduction ratio between the engine and wheels, high engine torque, or some combination of the two. Torque steer is distinct from steering kickback.

<span class="mw-page-title-main">Beam axle</span> Automobile mechanism

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 once commonly used at the rear wheels of a vehicle, but historically they have also been used as front axles in four-wheel-drive vehicles. In most automobiles, beam axles have been replaced with front and rear independent suspensions.

<span class="mw-page-title-main">Ball joint</span> Spherical bearing most commonly used in automobile steering mechanisms

In an automobile, ball joints are spherical bearings that connect the control arms to the steering knuckles, and are used on virtually every automobile made. They bionically resemble the ball-and-socket joints found in most tetrapod animals.

The following outline is provided as an overview of and topical guide to automobiles:

<span class="mw-page-title-main">Twist-beam rear suspension</span>

The twist-beam rear suspension is a type of automobile suspension based on a large H or C-shaped member. The front of the H attaches to the body via rubber bushings, and the rear of the H carries each stub-axle assembly, on each side of the car. The cross beam of the H holds the two trailing arms together, and provides the roll stiffness of the suspension, by twisting as the two trailing arms move vertically, relative to each other.

<span class="mw-page-title-main">Jaguar independent rear suspension</span> Common component of a number of Jaguar production cars since 1961

Jaguar's independent rear suspension (IRS) unit has been a common component of a number of Jaguar production cars since 1961, passing through two major changes of configuration up to 2006 and last used in the Jaguar XK8 and Aston Martin DB7. This article concentrates on the first generation Jaguar IRS, which firmly established the marque's reputation for suspension sophistication, combining as it did smooth ride with excellent roadholding and low levels of noise, vibration, and harshness (NVH). The two generations overlap in time due to their being used in both full size and sports models that were updated at different times.

<span class="mw-page-title-main">Macfie monoplane</span> Type of aircraft

The Macfie monoplane was a British shoulder wing, tractor monoplane. The aircraft was powered by a 35 hp (26 kW) J.A.P. V8 engine fixed at the front of an open-frame 'fuselage', at the rear end of which a tailplane and vertical rudder were mounted.

<span class="mw-page-title-main">Platform chassis</span>

A platform chassis is a form of vehicle frame / automobile chassis, constructed as a flat plate or platform, sometimes integrating a backbone or frame-structure with a vehicle's floor-pan.

References

  1. Cook, Mark E (November 2004). "Revere the Gear: Good landings are more than ego-boosters; they're kind to your airplane's landing gear". Flight Training. Frederick, Maryland: Aircraft Owners and Pilots Association . Retrieved 19 February 2014.