考虑油膜润滑的轮毂轴承弯曲疲劳寿命预测与分析

Prediction and Analysis of Bending Fatigue Life of Hub Bearing Considering Oil Film Lubrication

为精确分析预测某型轿车轮毂轴承的弯曲疲劳寿命,考虑轴承工作状态下游隙与油膜厚度的关系,以及温度对游隙和油膜厚度的影响,结合点接触弹流油膜厚度计算方法,精确计算其最小油膜厚度值;根据ISO提供的对Lundberg-Palmgren寿命模型修正方法,计算油膜参数和润滑剂黏度比,从而确定修正系数,建立改进的寿命模型。为了验证改进模型的正确性,使用旋转弯曲疲劳寿命试验机进行疲劳试验,试验结果在误差合理区间内,证明研究模型的可靠性。建立轮毂轴承载荷分布分析模型,讨论中心距对最大滚动体载荷的影响,研究轮毂轴承的疲劳寿命在不同纯弯矩载荷和不同车速下随中心距的变化规律。结果表明:弯矩载荷是影响疲劳寿命的主要因素,增加中心距可以延长轴承寿命;轴承润滑条件与轴承转速有关,在一定范围内,转速越高,其内部润滑越充分,使用寿命越长。

In order to accurately analyze and predict the bending fatigue life of a car hub bearing,considering the relationship between clearance and oil film thickness,as well as the influence of temperature on clearance and oil film thickness under the operating condition of the bearing,the minimum oil film thickness value was accurately calculated by combining the calculation method of point contact elastomeric oil film thickness.According to the correction method provided by ISO for Lundberg-Palmgren life model,the correction coefficient was determined and the improved life model was established.In order to verify the correctness of the improved model,a fatigue test was conducted using a rotating bending fatigue life tester,and the test results were within a reasonable error range,which proved the reliability of the research model.A hub bearing load distribution analysis model was established to discuss the effect of center distance on the maximum rolling body load.The variation law of fatigue life of hub bearings with the center distance under different pure bending moment loads and different vehicle speeds was studied.The results show that the moment load is the main factor affecting the fatigue life,and the bearing life can be extended by increasing the center distance.Bearing lubrication conditions are related to the bearing speed,and within a certain range,the higher the speed,the more adequate its internal lubrication and the longer the service life.