A fatigue model for spiral bevel gears under mixed elastohydrodynamic lubrication conditions

Abstract

Many contributions have focused on the pitting analysis in gear transmissions. However, studies on pitting fatigue in spiral bevel gears are limited due to the complexity of tooth contact and lubrication analysis. This paper is to present a reasonable methodology to simulate the pitting crack nucleation of spiral bevel gears considering the real three‐dimensional (3D) rough surface contact where the intermittent asperity stress concentrations is prominent. The proposed model includes a loaded tooth contact analysis model, a mixed elastohydrodynamic lubrication model proposed previously, 3D stress filed formulation, and multi‐axial fatigue criterions. In order to determine an appropriate multi‐axial fatigue criterion for spiral bevel gear, a characteristic plane approach and a conventional critical plane approach are employed in this study. The predicted micro‐pitting lives are compared to published micro‐pitting investigations to assess the reliability of two fatigue criterions in simulation of the micro‐pitting failure. It is observed that the characteristic plane approach is better to reveal the failure mechanism in spiral bevel gears.