Development of Conical Involute Gears (Beveloids) for Vehicle Transmissions

Conical involute gears (beveloids) are used in transmissions with intersecting or skew axes and for backlash-free transmissions with parallel axes. Conical gears are spur or helical gears with variable addendum modification (tooth thickness) across the face width. They can mesh with all gears made with the same tool. The geometry of such gears is generally known, but applications in power transmissions are more or less exceptional. ZF applications so far include marine transmissions with inclined output shafts and low backlash robot transmissions. The latest development has been realized for the AWD version of a six-speed automatic transmission. Here, the torque must be transmitted from a center differential to a front-axle bevel gear. By means of conical spur gears, it has been possible to realize an inclined drive shaft which offers considerable advantages in terms of installation space. This lecture deals with the development of conical gears for vehicle transmissions: basic geometry, design, production and testing.Copyright © 2003 by ASME