On a possible way of size and weight reduction of a car transmission

摘要

This study is focused on some features of the geometry and kinematics of gear hobbing operations. The principal goal is to determine the minimal hob idle distance that is required for complete generation of the gear teeth. This task is important in many aspects, especially for reducing the axial size of a hobbed shoulder-gear. Reduction of the axial size of a hobbed shoulder-gear leads to reduction of size and weight of the shoulder-gear itself and of the gear train housing. Developed by E. Buckingham, methods of analytical mechanics of gears are applied to determine an exact minimal allowed length of the gear hob idle distance. The results reported in the paper are applicable for manufacturing of spur and helical involute gears. Applying the results allows one to reduce the axial size and weight of a gear train and its housing. The consideration below is focused on hobbing of involute gears. Slightly modified results obtained are applicable for hobbing of splines, sprockets, ratchets and other form tooth profiles. The results obtained are important for the application of multi-start hobs of small diameter.