Wednesday, October 10, 2012

Multi Link : Derivation and Brief History

Multi-link is known as the best and most practical independent suspension . As independent suspension, multi-link wide used and applied by car manufactured for rear suspension. Why it is called multi-link ? By looking at the design of multi-link suspension, there are about three or more lateral arms and one or more longitudinal arm. Thus, multi – link suspension also called multi - arm suspension.

Multi - Link Suspension

Multi link can have 3- link but it also can have as much as 5-link. It is all depend on the theory and practical uses of the car’s demand.

According to US Patent and Trademark Office, the multi-link rear suspension assembly under patern no. 6945547, the inventor  is Robert J. Ackley and Ryan J.  Suhre under Delphi Technologies, Inc.

Drawing of Multi - Link rear suspension
Since the late 80s, multi link suspension has been popular choice when its come to rear suspension. Among the earlier car that applied multi-link suspension are Nissan 200SX, Infiniti Q45, Mercedes S-Class and BMW 3-Series.

Different approach has been applied when using multi link suspension. Thus, different derivative giving different geometry and different characteristic. An example, BMW multilink system giving Z shape. Thus, it is called Z-Axle. In addition, Audi A4 ‘s Quadralink front suspension has 4 link . Its look alike double wishbone but eliminate torque steer.

For now, the development of multi – link suspension still under gradual progress by research company. In example, an Italian company majored in auto electronics component, Magneti Marelli under significant time to produce cost-effective multi-link system for small cars. In its design it induce flexible link.

Magnet Marelli logo

Double Wishbone : Derivation and History

Double Wishbone widely used by car manufacture and among one of the popular choice for suspension. What is Double Wishbone actually? Basically, Double wishbone is a Double A-Arm suspension but famously called Double Wishbone. Where are the word ‘Wishbone’ come from? Wishbone is a derived from Christmas turkey’s bone that have V-shape which when rotates similar like A, so Double A-Arm reknown as Double Wishbone Suspension.

Turkey V-shape bone

There are no true story who pioneering double wishbone but it is believe that double wishbone technology is applied as early as 1930s. Among first automobile maker who applied the double wishbone technology is Packard Automaker, based on Detroit City, USA and the technology was advertised as safety feature. Packard was an American luxury type automobile manufactured for Packard Motor Car Company. The first automobile produced was 1899 and last car built on 1958.  Many American car popular with double wishbone technology rather than Europe because Europe car can not accommodate space – engaging suspension.

Packard advertising pamphlet

Packard logo

Nowadays, many car manufacturer opted to use double wishbone technology as front suspension especially in FI arena. F1 racing team choose  double wishbone technology as their front suspension. Usually the opted carbon fiber to make the suspension because aerodynamic and lightweight are important factor in racing.

Racing car with double wishbone suspension                     

Between double wishbone and Macpherson strut which on exist first? According to history the double wishbone exist large scale on 1935. During that time Macpherson still in the area of aviation technology and derived from aircraft landing mechanism. Later on, during 1949, Ford Company use Macpherson strut suspension on Ford Vedette. So, double wishbone applied early in automobiles history and there are no genetic relationship between Macpherson strut suspension and double wishbone suspension.

Macpherson strut with A-Arm and double wishbone suspension 

Because double wishbone considered having superior dynamic characteristic as well as load handling capabilities , many car manufactured opted for double wishbone suspension. Cars like higher performance car, Alfa Romeo, Honda, and Mercedes Benz.  Short Long Arm suspension, ones of derivative of double wishbone technology used by Honda Accord, Peugeot 407, and Mazda Atenza while all racing car and sport car, a double wishbone suspension is a must.