Abstract: Transmission errors and contact pattern have determinative effects on the gearing performances of a gear drive, so a new approach for design of spiral bevel gears is proposed, based on a predesigned parabolic function of transmission errors with limited magnitude of maximal transmission errors and a predesigned linear function of contact path. This approach is based on three meshing points. By controlling their magnitudes of transmission errors and the positions on the tooth surface, the allover control of engagement quality is realized. The advan-tages of the function-oriented active tooth surface design are the reduction of level of noise and the obtaining of favorable shape and dimensions of contact pattern, and moreover, the gearing performance in whole tooth contact could be controlled directly in design. The goals are achieved by application of local syn-thesis algorithm, local conjugate theory and machining princi-ple of spiral bevel gears. Function-oriented active tooth surface design provides an innovative designing approach for the spiral bevel gears and is quite important for the gears in high speed, heavy duty or with special requirements.

Key words: Contact pattern, Function-oriented design, Spiral bevel gears, Transmission errors