Hot Finish Rolling of Injection-Molded Plastic Helical Gears. Process of Reversing Gear Rotation.

The present paper describes hot finish rolling of injection-molded helical gears with a process of reversing the gear rotation. The finished work gear has a pressure angle error on its tooth profile. This is due to a sliding between die and work tooth flanks, so that the reversed process added to the ordinary one should be useful for reducing the pressure angle error. Thus, some experiments are performed under several operating conditions to reveal the effect of the combinations of rolling time and applied load for rolling in the ordinary and the reversed processes on finished tooth profiles. As a result, given lower applied load and shorter rolling time in the reversed process than in the ordinary one, the pressure angle error can be reduced and a more accurate tooth profile of the finished work gear can be obtained.