Hypoid drive
The hypoid drive (also hypoid gear ) is a modification of the bevel gear . In contrast to the normal bevel gear drive, the axes of the drive and ring gear are offset, so they do not intersect.
As a result of the offset, the pinion that is usually driving, the pinion - with the size of the usually driven ring gear unchanged - becomes larger or smaller, depending on whether the offset is positive or negative. A positive axial offset not only results in an increase in the diameter of the pinion, but also in an increase in the spiral angle and the jump overlap. This increases the smoothness and resilience while saving space at the same time. For these reasons, the hypoid drive is particularly suitable as an axle drive in the differential gear for all motor vehicles in which the axle is driven via a cardan shaft (longitudinal shaft), including above all vehicles with front-engine and rear-axle drive (almost all trucks , some cars ). Due to the offset, the entire cardan shaft is lowered. This lowers the center of gravity of the vehicle slightly, and there is more space in the area of the underbody to e.g. B. to make the transmission tunnel flatter or to use the space for the exhaust system.
In addition to the rolling movement of the teeth, a sliding movement that is undesirable for gears also arises as a result of the axial offset. This places increased demands on material quality and usually requires gear oil with special additives ( hypoid oils ) for lubrication. In contrast to other gears, the ring gear is not straight or helical, but spiral-toothed, which makes production more expensive.
See also
Web links
- To test the wheels ( Research Center for Gear Wheels and Gear Construction ): [1] (last accessed: October 12, 2011)