A Study on the Design of Thin-Shaped Straight Bevel Gears : 2nd Report, Numerical Analyses of the Effects of Rim-Web Configuration upon the Root Stress Distribution along the Tooth Trace

Abstract

Various configurations of thin-shaped bevel gears are widely used such as in the main reduction gear of helicopters and hovercraft. But a reasonable and concise design guide for these bevel gears has to be obtained, since the tooth of the bevel gear has a complex from. The purpose of this study is to establish a design guide and to propose the desirable configuration for thin-shaped straight bevel gears. In this report, the desirable configuration is examined numerically using the finite element method. The results are summarized as follows : (1) As a desirable configuration of a thin shaped bevel gear, it is recommended from the viewpoint of root stress that the rim is supported by a web at the center of its width. (2) When the rim is supported at the center of its width, a flat web, a cone-shaped web, a web composed of cone-shaped and and flat plates and a web composed of root stress. (3) For practical use, it is recommended that the bevel gear has a flat web at the center of rim width and a rim whose thickness varies in direct proportion to the change of tooth height.