Abstract: The hobbing machine can hob components such as gears and worm gears with 5 grade accuracy and high accuracy SG-71 worm gearing, if it is provided with the correcting mechanism to compensate its transmission error. We have measured the composition error of the generating gearing chain on the Y3180 hobbing machine, have used FFT program to obtain the frequency spectrum figure, have found out sourc.es of several errors and magnitude of their effects.And then according to these factors we have designed the correcting mechanism, which consists of the correcting cam, the swing arm of the cam and the correcting eccentric gear unit,by using CAD technology.
This results in the reduction of lowfrequency error and short-period error.This method can be applied to design the cam of the relieving mechanism of SG-71 worm, so that the inlet relieving and the outlet relieving can be ground in one operation, the production rate can be raised. The short-period error can be compensated and the working stability of SG-71 worm gearing can be increased, if the correcting eccentric gear unit is used.