Predicting Fatigue Life for Finite Line Contact under Starved Elastohydrodynamic Lubrication Condition

Haofeng Ku,Mingyong Liu,Peidong Xu,Chenhui Wu,Jinxi Zhang

doi:10.1155/2020/5928621

Haofeng Ku, Mingyong Liu + Show 3 more

Open Access

https://doi.org/10.1155/2020/5928621

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Abstract

Surface contact fatigue is the main failure mode in many mechanical components, such as gears, bearings, and cam-followers. A fatigue life prediction model is proposed for finite line contact under starved thermal elastohydrodynamic lubrication (TEHL) condition in this paper. Then, the effects of inlet oil-supply thickness, slide-to-roll ratio (SRR), and operating conditions on the lubrication performance and fatigue life are investigated. The results show that the lubrication characteristics and fatigue life of finite line contact are obviously different from those of fully flooded situation by introducing the starved lubrication condition. For example, the severe starved conditions lead to a significant increase in friction coefficient and decreased fatigue life. The variation of SRR has an important influence on the fatigue life. With the increase of SRR, the fatigue life decreases firstly and then increases. The stress concentration occurs near the surface when speed is low. In addition, under the low-speed situation, rotation speed variation has little effect on the fatigue life.

Highlights

With the development of engineering machinery to high speed and heavy load, the starved situation widely exists in many mechanical components
Yin et al [5] developed a starved thermal EHL model in elliptical contact based on the multigrid technique and analyzed the influence of ellipticity ratio, thickness of oil-supply layer, slide-to-roll ratio (SRR), and so forth on the lubrication behaviour
In order to reveal the information on lubrication of finite line contact under the starvation condition, a starved thermal EHL model of finite line contact has been established in the paper. e effects of working conditions and inlet oil-supply condition on the lubrication characteristics and pitting life are discussed

Summary

Introduction

With the development of engineering machinery to high speed and heavy load, the starved situation widely exists in many mechanical components. Mihailidis et al [8] discussed the effect of working conditions and end shape modification on lubrication performance for the non-Newtonian starved thermal EHL of a finite line contact. Torabi et al [12] proposed a mixed EHL model of a finite length cam and follower mechanism considering surface roughness and studied the influence of thermal effects, end leakage, and roughness on the friction performance. Liu et al [13] established a mixed EHL model of a finite line contact by using realistic surface roughness and predicted the influence of working conditions and lubrication parameters on the fatigue life. Liu et al [14, 15] developed a starved EHL model for a spur gear pair and discussed the influence of working condition parameters on the friction coefficient and mechanical power loss. In order to reveal the information on lubrication of finite line contact under the starvation condition, a starved thermal EHL model of finite line contact has been established in the paper. e effects of working conditions and inlet oil-supply condition on the lubrication characteristics and pitting life are discussed

Model Formulations

Results and Discussion

Findings

Conclusions