
A bushing or rubber bushing is a type of
vibration isolator. It provides an interface between two parts, damping the energy transmitted through the bushing. A common application is in
vehicle suspension
Suspension is the system of tires, tire air, spring (device), springs, shock absorbers and Linkage (mechanical), linkages that connects a vehicle to its wheels and allows relative motion between the two. Suspension systems must support b ...
systems, where a bushing made of
rubber
Rubber, also called India rubber, latex, Amazonian rubber, ''caucho'', or ''caoutchouc'', as initially produced, consists of polymers of the organic compound isoprene, with minor impurities of other organic compounds.
Types of polyisoprene ...
(or, more often,
synthetic rubber
A synthetic rubber is an artificial elastomer. They are polymers synthesized from petroleum byproducts. About of rubber is produced annually in the United States, and of that amount two thirds are synthetic. Synthetic rubber, just like natural ru ...
or
polyurethane
Polyurethane (; often abbreviated PUR and PU) is a class of polymers composed of organic chemistry, organic units joined by carbamate (urethane) links. In contrast to other common polymers such as polyethylene and polystyrene, polyurethane term ...
) separates the faces of two metal objects while allowing a certain amount of movement. This movement allows the suspension parts to move freely, for example, when traveling over a large bump, while minimizing transmission of noise and small vibrations through to the chassis of the vehicle. A rubber bushing may also be described as a flexible mounting or antivibration mounting.
These bushings often take the form of an annular cylinder of flexible material inside a metallic casing or outer tube. They might also feature an internal ''crush tube'' which protects the bushing from being crushed by the fixings which hold it onto a threaded
spigot. Many different types of bushing designs exist. An important difference compared with
plain bearing
file:NYC 100-driving-axle-friction-bearing.jpg, Plain bearing on a 1906 S-Motor locomotive showing the axle, bearing, oil supply and oiling pad
file:Linear-table with detail numbered.png, A sliding table with four cylindrical bearings
file:GWR Spo ...
s is that the relative motion between the two connected parts is accommodated by strain in the rubber, rather than by shear or friction at the interface. Some rubber bushings, such as the D block for a
sway bar
An anti-roll bar (roll bar, anti-sway bar, sway bar, stabilizer bar) is an automobile suspension part that helps reduce the body roll of a vehicle during fast cornering or over road irregularities. It links opposite front or rear wheels to a to ...
, do allow sliding at the interface between one part and the rubber.
History
Charles E. Sorensen credits
Walter Chrysler
Walter Percy Chrysler (April 2, 1875 – August 18, 1940) was an American industrial pioneer in the automotive industry, automotive industry executive, and the founder and namesake of American Chrysler, Chrysler Corporation.
Childhood
Chrysler ...
as being a leader in encouraging the adoption of rubber vibration-isolating mounts. In his memoir (1956), he says that, on March 10, 1932, Chrysler called at Ford headquarters to show off a new
Plymouth
Plymouth ( ) is a port city status in the United Kingdom, city and unitary authority in Devon, South West England. It is located on Devon's south coast between the rivers River Plym, Plym and River Tamar, Tamar, about southwest of Exeter and ...
model.
:"The most radical feature of his car was the novel suspension of its six-cylinder engine so as to cut down vibration. The engine was supported on three points and rested on rubber mounts. Noise and vibration were much less. There was still a lot of movement of the engine when idling, but under a load it settled down. Although it was a great success in the Plymouth,
Henry Ford
Henry Ford (July 30, 1863 – April 7, 1947) was an American Technological and industrial history of the United States, industrialist and business magnate. As the founder of the Ford Motor Company, he is credited as a pioneer in making automob ...
did not like it. For no given reason, he just didn't like it, and that was that. I told Walter that I felt it was a step in the right direction, that it would smooth out all noises and would adapt itself to axles and springs and steering-gear mounts, which would stop the transfer of road noises into the body. Today rubber mounts are used on all cars. They are also found on electric-motor mounts, in refrigerators, radios, television sets—wherever mechanical noises are apparent, rubber is used to eliminate them. We can thank Walter Chrysler for a quieter way of life. Mr. Ford could have installed this new mount at once in
the V-8, but he missed the value of it. Later
Edsel
Edsel is a discontinued division and brand of automobiles that was produced by the Ford Motor Company in the 1958 to 1960 model years. Deriving its name from Edsel Ford, son of company founder Henry Ford, Edsels were developed in an effort to ...
and I persuaded him. Rubber mounts are now found also in doors, hinges, windshields, fenders, spring hangers, shackles, and lamps—all with the idea of eliminating squeaks and rattles."
[
.]
Lee Iacocca
Lido Anthony "Lee" Iacocca ( ; October 15, 1924 – July 2, 2019) was an American automobile executive who developed the Ford Mustang, Lincoln Continental Mark III, and Ford Pinto cars while at the Ford Motor Company in the 1960s, and then reviv ...
credits Chrysler's chief of engineering during that era,
Frederick Zeder, with leading the effort.
[.] Iacocca said that Zeder "was the first man to figure out how to get the vibrations out of cars. His solution? He mounted their engines on a rubber base."
In Vehicles
A bushing is a type of bearing that is used in the suspension system of a vehicle. It is typically used to connect moving parts such as control arms and sway bars to the frame of the vehicle, and also to isolate these parts from each other and from the frame. The main function of a bushing is to reduce the transmission of vibrations and shocks from the road to the rest of the vehicle, which helps to improve the overall ride comfort and reduce noise and harshness inside the vehicle.
See also
*
Shock mount
A shock mount or isolation mount is a mechanical fastener that connects two parts elastically to provide shock (mechanics), shock and vibration isolation.
Isolation mounts allow equipment to be securely mounted to a foundation and/or frame and, ...
References
Bibliography
*
*
* DeSilva, C. W., "Vibration and Shock Handbook", CRC, 2005,
* Harris, C. M., and Peirsol, A. G. "Shock and Vibration Handbook", 2001, McGraw Hill, {{ISBN, 0-07-137081-1
Hardware (mechanical)
Mechanical engineering
Mechanical vibrations
Skateboarding equipment