drive shaft
The drive shaft is a component of automotive engineering . It is used to transmit power between the gearbox and the driven wheel and is part of the drive train .
In order to be able to follow the deflection movements and the steering angle, there are joints, which is why the generic term cardan shaft is used. However, special homokinetic cardan shafts are used for steered wheels .
To protect the joints, sleeves made of rubber and, increasingly, made of TPE are pulled over the joints and filled with grease .
construction
A typical design consists of a wheel-side axle journal on which a constant velocity joint is located. Above all, this joint must allow the wheel to be turned on the steered axle and is one of the components that can limit the turning circle (only when the front axle is driven). The joint on the transmission side usually also absorbs axial displacements that occur during compression. The wheel-side joint is usually designed as a fixed joint, which only compensates for changes in angle but not changes in length.
In order to do justice to the limited space in the engine compartment, it is often no longer possible to install the drive shafts stretched out on the front axle, even if this would mean the best efficiency (~ 100%, as there is no movement in the joints of the stretched drive shaft). In practice, the PTO shaft must therefore compensate for the offset between the gear output and the wheel; the greater this offset, the more difficult it is to achieve a small turning circle.
Typical failure
In normal cars, drive shafts are designed for the service life of the vehicle and are the predetermined breaking points in the drive train in the crack start test . Damage occurs when the cuffs have been damaged. The typical damage pattern shows traces of grease on the front vehicle doors in particular, which are ejected by the torn sleeve when the steering is fully turned. Penetrating water emulsifies with the fat; dirt also causes wear on the sliding surfaces of the joint. Cracking noises during load changes can also be signs of incipient damage .
A visual inspection of the cuffs as regular maintenance work is prescribed by the manufacturer. Porous cuffs should be replaced soon. Axle drives can only rarely break off while driving and cause major damage to the vehicle.
literature
- Hans-Hermann Braess, Ulrich Seiffert: Vieweg manual automotive technology. 2nd edition, Friedrich Vieweg & Sohn Verlagsgesellschaft mbH, Braunschweig / Wiesbaden, 2001, ISBN 3-528-13114-4
See also
- Big start : test for cardan shafts in the vehicle
- homokinetic cardan shaft : drive shaft preferably used to drive steered wheels
- Cardan shaft : non-homokinetic cardan shaft
- Damper weight : Preventive measure against damage caused by vibrations
