Cylindrical Gears with Contact Areas Distributed Along the Arc Teeth Length

Abstract

The issue of increasing the reliability of high-load machine drives is related to ensuring the performance ability of cylindrical gears in the presence of meshing teeth twist angles caused by gear manufacture and assembly errors as well as by ductility of their elements and body parts. An effective way to solve the problem is a transition from plain spur gears and helical gears to arc teeth gears. In comparison with straight or helical teeth, the bending strength of arc teeth is 20…30 % higher. The processes of shaping the arc teeth surfaces allow to obtain a linear, locally linear and point contacts in their meshing, and to provide an optimal law of load distribution over the contact area. The paper considers the features of compensation for the misalignment of the teeth in meshing by movement (self-adjustment) of a pinion or arc teeth wheel along the axis. It has been shown that the self-adjustment of the wheels occurs only for a constant torque and a non-changing twist angle. To compensate for a random twist angle under conditions of varying torque, an adaptive arc teeth cylindrical gear has been proposed, in meshing of which there are two contact areas distributed along the length. The gear wheel consists of two semi-wheels separated by an elastic gasket. The axial forces arising in the contact areas balance each other and provide self-adjustment of the semi-wheels under the twist angle variation. Cutting arc teeth on both half-wheels is carried out simultaneously, so the labor intensity of manufacturing an adaptive arc teeth gear does not change. For the semi-rolled variant of forming arc teeth surfaces of the adaptive cylindrical gear, the results of calculating the position of the working lines in meshing and dimensions of arc teeth surface contact brake zones are presented.