轮毂轴承润滑脂失效的流变学分析

摘要

Rheology properties of five hub greases were measured by Physica MCR301 rheometer,and the results were discussed combined with these grease fieldwork data.The influences of the parameters such as base oil viscosity and type, tackifier,the type and concentration of thicker on the rheological properties under different temperatures were studied,and the mechanism was discussed.The results show that the greases,with elastic modulus value of exceeding 80 kPa,strain am-plitude of approximate 4%,apparent viscosity of more than 20 Pa·s at 120 ℃,have the perfect high temperature perform-ance in hub bearing.The primary cause of hub bearing grease failure is the marked change of grease rheology parameters due to the temperature rising of hub bearing.By adding the content of grease thickener and choosing lithium complex to en-hance the elastic module,increasing base oil viscosity to enlarge grease strain amplitude,adding special polymer in grease formula to boost grease apparent viscosity,the high temperature performance of the hub bearing greases can be improved.%用Physica MCR301旋转流变仪对5种轮毂润滑脂流变特性进行测试，并结合行车试验结果进行讨论，分析基础油黏度和类型、增黏剂、稠化剂类型和浓度等参数在不同温度条件下对润滑脂流变性能的影响，并对产生的机制进行探讨。结果表明：120℃下弹性模量超过80 kPa、应变幅度接近4％、表观黏度大于20 Pa·s的润滑脂在轮毂轴承中表现出了优异的高温使用性能。轮毂温度升高引起轴承内润滑脂的流变学参数发生显著变化是润滑脂失效的主要原因，通过提高稠化剂含量、选用复合稠化剂来增加高温下的弹性模量，提高基础油黏度来增大高温下应变幅度，加入特种高分子增黏剂来提高表观黏度，可以提高轮毂轴承润滑脂在高温下的性能。