目的 增强钢/橡胶摩擦副的润滑性能,为提高混合润滑状态下水润滑轴承的性能提供参考.方法 建立水润滑条件下钢/橡胶摩擦副的热混合润滑模型,讨论热效应对润滑性能的影响,并在此基础上进一步研究表面粗糙度、水基润滑剂黏度和供水压力对水润滑增强调控的作用.结果 与等温解相比,热效应使Stribeck曲线发生了右移,摩擦因数和载荷比增大,膜厚比降低.最高水膜温度随着转速的增加而升高,热效应对混合润滑性能的影响显著.减小摩擦副表面粗糙度,Stribeck曲线向左移动.在相同转速下,载荷比随着表面粗糙度的减小而降低,膜厚比反之.表面粗糙度越大,水膜温度越高,最高温度位于出口区,且钢的表面温度低于水膜和橡胶的表面温度.当水基润滑剂的黏度增大时,膜厚比增大,载荷比和最高水膜温度降低,Stribeck曲线发生左移.增加供水压力可以改善水膜压力分布,使水膜承载区增大、压力减小,粗糙峰接触压力和承载区减小,导致载荷比减小、膜厚比增加,Stribeck曲线向左偏移,水膜最高温度降低.当接触区由边界润滑向混合润滑过渡时,水膜最高温度出现拐点,且水膜最高温度拐点随着供水压力的增加而左移.结论 热效应会降低摩擦副的混合润滑性能,因此在混合润滑中不能忽略.考虑热效应时,通过减小表面粗糙度,或增加水基润滑剂黏度和供水压力,均有利于增强钢/橡胶接触表面水润滑的混合润滑性能.
Due to the low viscosity of water,the water-lubricated bearing is prone to friction and wear.In order to guide the design of water-lubricated bearings under mixed lubrication,it is necessary to enhance the lubrication performance of steel/rubber friction pairs with water as the lubricant.For this goal,a thermal mixed lubrication model of steel/rubber friction pairs under water lubrication was established,and the thermal effects on lubrication performance were discussed by a comparative study.On this basis,the effects of surface roughness,viscosity of water-based lubricant and water supply pressure on the regulation of water lubrication enhancement were further studied with consideration of the Stribeck curve.The results showed that,when the friction coefficient for thermal solution was the same as that of isothermal solution,the rotational speed of thermal solution was greater than that of isothermal solution,which made the Stribeck curve shift to the right.Different from the isothermal solution,the thermal effect increased the friction coefficient and the load ratio,and decreased the film thickness ratio for the same rotational speed.The maximum water film temperature increased with the increase of the rotating speed,and the thermal effect had a significant impact on the mixed lubrication performance.For the thermal mixed lubrication of steel/rubber pairs,when the surface roughness of the friction pair reduced,the Stribeck curve moved to the left.At the same rotational speed,the load ratio decreased,while the film thickness ratio increased with the decrease of surface roughness;In addition,the larger the surface roughness,the higher the temperature of the water film and steel/rubber friction pair.The highest temperature was located in the outlet of the contact region,and the surface temperature of the steel was lower than that of the water film and the rubber.When the rotational speed was constant for different viscosity of water-based lubricant,increasing the viscosity could increase the film thickness ratio,and reduce the load ratio and the maximum water film temperature.When the friction coefficient was the same,the higher the viscosity,the lower the rotational speed,therefore,the Stribeck curve shifted to the left.As the water supply pressure increased,the water film pressure distribution was improved,resulting in an increase in the water film bearing area,a decrease in the water film pressure,and a decrease in the rough peak contact pressure and its bearing area,so that the load ratio decreased,the film thickness ratio increased,the Stribeck curve shifted to the left,and the maximum temperature of the water film decreased.Moreover,the maximum temperature of the water film increased firstly and then decreased with the increase of the rotating speed,and the maximum temperature of the water film appearred an inflection point,and the inflection point moved to the left with the increase of the water supply pressure.The reason was that the speed at the inflection point was correspondingly the transition of the lubrication state from boundary lubrication to mixed lubrication.It can be concluded that the thermal effects will weaken the mixed lubrication performance of the friction pair and cannot be negligible in the mixed lubrication.When considering the thermal effect,reducing the surface roughness,increasing the viscosity of water-based lubricant and water supply pressure are beneficial to enhance the mixed lubrication performance of water lubrication on the steel/rubber contact surface.
李群;刘晓玲;郭峰;周家傲;张政
青岛理工大学 机械与汽车工程学院,山东 青岛 266520
机械工程
水润滑;热混合润滑;粗糙度;水基润滑剂;供水压力;Stribeck曲线
water lubrication;thermal mixed lubrication;roughness;water-based lubricant;water supply pressure;Stribeck curve
《表面技术》 2024 (003)
142-151,178 / 11
国家自然科学基金(51475250);泰山学者人才工程(TS20190943)National Natural Science Foundation of China(51475250);The Taishan Scholars Talent Project(TS20190943)
10.16490/j.cnki.issn.1001-3660.2024.03.014
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