Relationship between Supplied Oil Flow Rates and Oil Film Thicknesses under Starved Elastohydrodynamic Lubrication

Taisuke Maruyama,Tsuyoshi Saitoh

doi:10.3390/lubricants3020365

Abstract

Many studies have already considered starved lubrication. However, there have been no reports on the oil film thicknesses under steady starved EHL (elastohydrodynamic lubrication), where the ultra-low volume of oil supplied per unit time is uniform. The present study examined the relationship between the supplied oil flow rate and oil film thickness under steady starved lubrication. A ball-on-disk testing machine was used in experiments to measure the oil film thickness by means of optical interferometry. A microsyringe pump was used to accurately control the supplied oil flow rate. The supplied oil flow rate was kept constant, and the minimum oil film thickness was measured for 1 h after the start of the tests to determine the relationship between the supplied oil flow rate and oil film thickness.

Highlights

Rolling bearings are used in load support [1] and power transmission of various machines
The transition of oil film thickness without oil resupply was measured to find the experimental conditions of starved lubrication in this study
The ultra-low volume of oil supplied per unit time was assumed to be constant, and the relationship between the supplied oil flow rate and oil film thickness under steady starved lubrication was investigated

Summary

Introduction

Rolling bearings are used in load support [1] and power transmission of various machines. The supplied oil flow rate is an important parameter that affects the bearing life and friction torque. In order to keep the bearing life long, the supplied oil flow rate must be high enough to form an oil film thicker than the surface roughness of raceway. An excessive supplied oil flow rate increases the bearing torque. Bearings should ideally be lubricated at the minimum supplied oil flow. Minimizing the amount of waste oil can contribute to solving several problems, such as churning heating effect and ensuing emissions, side leakage out of contact, spillage, cost, conservation of environment, and so on

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Results

Discussion

Conclusion