The drive shaft in a motor vehicle connects the transmission to the rear differential. A drive shaft can be of longitudinal or side-shaft configuration. Unlike a fixed-shaft structure, a drive shaft cannot be a solid connection. As a result, there is no precise relationship between the angular velocities of the two shafts, and the drive shaft may experience distortion and vibration. This can be a severe problem, especially if the driven member has an angle of over 3 degrees.
The present invention aims at producing a drive shaft of the type indicated initially. In this respect, the invention consists of an input shaft that fits into a large steel star gear and an enveloping outer shell. The input shaft and the inner shell are inserted into a cage with six openings around the perimeter. These openings are guided in the cage using the centering cage surfaces. Each cage opening accommodates one spherical driving ball.
The cage has an axial clamping bushing part shrunk over annular flanges on the yoke halves. A lid is also provided, which seals off the hollow shaft section. The lid prevents the homocentric joint’s inner hub from penetrating the hollow shaft section. There is also a sealing disk between the accommodation part and the outer hub.
Constant velocity joints keep the drive shaft’s rotation angle from increasing when the driven member is displaced. Steering joint For example, if the driveshaft is displaced by a car accident, high axial forces will act on the drive shaft. The constant velocity joint may be destroyed when these forces exceed the design limit. The joint should be optimized for crash behavior.
Drive shafts with constant velocity joints are suitable for use in longitudinal and side-shaft systems in motor vehicles. These joints are typically used in rear-wheel drive vehicles. However, they can be used in front-wheel drive applications, as well. Generally, it is preferable to have a constant velocity joint on the side shaft, where the maximal deflection required is usually higher than for the longitudinal shaft.
Constant velocity joints can be classified into three different types. The first type is the Cardan joint. Initially, the first Cardan joint was a set of two Cardan joints offset by 90 degrees. Later, Gerolamo Cardano introduced the Polhem knot, a variant of the universal joint. After this, several new joints have been developed.
Another type of joint is the Tripod joint. This joint is typically found on the inboard side of a front-wheel drive vehicle; besides the three-pointed yoke attached to the shaft, the joint features barrel-shaped roller bearings at the ends. An advantage of the Tripod joint is its ability to move the shaft axially “plunge” inward and outward.
U-joints are another type of joint. The yoke has one side that is bolted into the yoke of the other shaft. If the yoke is worn or has a thread gap, the u-joint may not make a tight connection with the driveshaft. Therefore, a u-bolt kit is often used to attach the yoke to the drive shaft.