Microstress cycle and contact fatigue of spiral bevel gears by rolling-sliding of asperity contact

Abstract

The rolling contact fatigue (RCF) model is commonly used to predict the contact fatigue life when the sliding is insignificant in contact surfaces. However, many studies reveal that the sliding, compared to the rolling state, can lead to a considerable reduction of the fatigue life and an excessive increase of the pitting area, which result from the microscopic stress cycle growth caused by the sliding of the asperity contact. This suggests that fatigue life in the rolling-sliding condition can be overestimated based only on the RCF model. The rubbing surfaces of spiral bevel gears are subject to typical rolling-sliding motion. This paper aims to study the mechanism of the micro stress cycle along the meshing path and provide a reasonable method for predicting the fatigue life in spiral bevel gears. The microscopic stress cycle equation is derived with the consideration of gear meshing parameters. The combination of the RCF model and asperity stress cycle is developed to calculate the fatigue life in spiral bevel gears. We find that the contact fatigue life decreases significantly compared with that obtained from the RCF model. There is strong evidence that the microscopic stress cycle is remarkably increased by the rolling-sliding motion of the asperity contact, which is consistent with the experimental data in previous literature. In addition, the fatigue life under different assembling misalignments are investigated and the results demonstrate the important role of misalignments on fatigue life.

A traction coefficient formula for EHL line contacts operating in the linear isothermal region

“…Chong et al [8], Cheng et al [9] investigated the effect of roughness on friction in EHL point contacts operating in the mixed lubrication regime in the PE region under pure sliding motion. Wei et al [10] and Xiu-jiang et al [11] developed a 3D mixed lubrication model for rolling point and line contacts operating in the piezoviscous elastic region (PE), in order to investigate friction and temperature development in gears. Orgeldinger et al [12], investigated the friction losses for the time-dependent cam-follower in two-dimensional line contact in the isoviscous elastic (IE) region by using a numerical model.…”

Application of Similarity Theory and Dimensional Analysis for Helical Gear Fatigue Model Test

“…However, helical gears are easily failure under dynamic loads. Many studies show that fatigue damage is the main cause of helical gear failures [2][3][4]. In order to ensure the developed helical gears have required reliability and safety, we must do the experimental fatigue test on bench test systems [5] .…”

Determination of the optimal coverage for heavy-duty-axle gears in shot peening

“…Spiral bevel gears mounted on the drive axle are key transmission parts for heavy-duty vehicles. The meshing gear pair suffers from percussive load, high torque and harsh running conditions, thus initial pitting and wear failures often occur on the gear tooth flanks [1,2]. Shot peening is a cold working process, wherein a lot of shots with high hardness and high speed strike the surface of the workpiece and induce compressive residual stress for the improvement of the anti-fatigue performance of the workpiece [3].…”