
A trailing-arm suspension, also referred to as trailing-link, is a form of
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.
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
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
A wheel is a rotating component (typically circular in shape) that is intended to turn on an axle Bearing (mechanical), bearing. The wheel is one of the key components of the wheel and axle which is one of the Simple machine, six simple machin ...
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
Landing gear is the undercarriage of an aircraft or spacecraft that is used for taxiing, takeoff or landing. For aircraft, it is generally needed for all three of these. It was also formerly called ''alighting gear'' by some manufacturers, s ...
, 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.
Semi-trailing arm
A semi-trailing arm suspension is a supple
independent rear suspension system for
automobile
A car, or an automobile, is a motor vehicle with wheels. Most definitions of cars state that they run primarily on roads, Car seat, seat one to eight people, have four wheels, and mainly transport private transport#Personal transport, peopl ...
s where each
wheel
A wheel is a rotating component (typically circular in shape) that is intended to turn on an axle Bearing (mechanical), bearing. The wheel is one of the key components of the wheel and axle which is one of the Simple machine, six simple machin ...
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
In geometry, two geometric objects are perpendicular if they intersect at right angles, i.e. at an angle of 90 degrees or π/2 radians. The condition of perpendicularity may be represented graphically using the '' perpendicular symbol'', � ...
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
Front-wheel drive (FWD) is a form of internal combustion engine, engine and transmission (mechanics), transmission layout used in motor vehicles, in which the engine drives the front wheels only. Most modern front-wheel-drive vehicles feature ...
vehicles feature a
MacPherson strut
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 ...
front suspension and trailing-arm rear axle.
See also
*
List of auto parts
This is a list of auto parts, which are manufactured components of automobiles. This list reflects both fossil-fueled cars (using internal combustion engine
An internal combustion engine (ICE or IC engine) is a heat engine in which the c ...
*
Swingarm
A swingarm ( or swinging arm), originally known as a swing fork or pivoted fork, is a single or double sided mechanical device which attaches the rear wheel of a motorcycle to its body, allowing it to pivot vertically. The main component of the ...
– the predominant type of motorcycle rear suspension, which is basically a trailing arm
*
Weissach axle – a variant of semi-trailing arm suspension
References
{{DEFAULTSORT:Trailing Arm
Automotive suspension technologies
Aircraft components