Tripod Joint

grabcad

The inboard end of car driveshafts features joints with a three-pointed yoke attached to the shaft; these sport barrel-shaped roller bearings at their ends, which fit into a cup with three corresponding grooves connected to the differential. The simple arrangement works effectively due to minimal movement in one axis. Additionally, it allows axial 'plunge' movement of the shaft, preventing preloading of bearings caused by engine rocking and other effects. However, this joint is not a constant velocity joint as its medium plane remains perpendicular to the drive shaft's axis, not bisecting the angle between input and output shafts. Furthermore, it has limited angular range compared to other joint types but is often chosen for rear-wheel drive vehicle configurations or front-wheel drive vehicles' inboard side due to lower cost requirements and reduced necessary motion range. Note that dimensions are approximate, making this demonstrative only. Higher quality animations can be viewed here: http://imgur.com/a/NLCos.