润滑油水污染对齿轮热弹流润滑特性的影响研究

Study on the effect of water pollution in lubricants on gear thermal elastohydrodynamic lubrication characteristics

以渐开线直齿圆柱齿轮为研究对象,考虑热效应和时变效应,建立油水两相流模型和齿轮的热弹流润滑模型,探究润滑油中含水率对油水两相流体的黏度及齿面润滑特性的影响。研究结果表明:润滑油中混入冷却水后,当含水率不超过5%时,随着含水率的增加,油水两相流体的黏度不断增大;含水率为5%时,油水两相流体的黏度达到其峰值,之后随着含水率的增加,油水两相流体的黏度不断减小。适当增加含水率可改善齿面的润滑特性,但考虑油膜温升及对设备的腐蚀磨损,应将含水率控制在5%以内。

Taking the involute spur gear as the research object and considering the thermal effect and time-varying effect,the oil-water two-phase flow model and the thermal elastohydrodynamic lubrication model of the gear system were established to explore the influence of water content in lubricating oil on the viscosity of the oil-water two-phase fluid and the lubrication characteristics of the tooth surface.The results showed that when the water content in lubricating oil was less than 5%,the viscosity of oil-water two-phase fluid increased with the increment of water content.When the water content was 5%,the viscosity of oil-water two-phase fluid reached its peak value,and then decreased with the increment of water content.Appropriate increase of water content can improve the lubrication characteristics of tooth surface,but considering oil film temperature rise and corrosion wear of equipment,the water content should be controlled within 5%.