双列角接触球轴承动刚度特性分析

为研究双列角接触球轴承动刚度特性,在双列角接触球轴承动力学分析基础上,建立双列角接触球轴承动刚度仿真分析模型。采用精细积分法和预估-校正Adams-Bashforth-Moulton多步法相结合的算法对双列角接触球轴承动刚度模型进行求解,分析轴承结构参数和工况参数对轴承动刚度的影响。分析结果表明:沟曲率半径系数对轴承动刚度影响较小,随着内、外沟曲率半径系数的增加,径向刚度略有增大,轴向刚度和角刚度相对减小;增加钢球数有利于提高轴承动刚度;轴向预紧量较大时轴承动刚度较高,但过大的轴向预紧会使轴承寿命降低,应合理确定轴向预紧量;随转速的增大,轴承动刚度先减小后增大,且转速较低时可近似以接触刚度代替轴承动刚度,转速较高时应综合接触刚度和油膜刚度求得轴承动刚度;外载荷对轴承动刚度有较大影响,加大径向载荷和轴向载荷有利于提高轴承动刚度,随着力矩载荷的增大,轴承动刚度变化较为复杂,但整体上,呈现先减小后增大的趋势。

Analysis of Dynamic Stiffness Characteristics of Double-row Angular Contact Ball Bearings

A simulation and analysis model is established to describe the dynamic stiffness of double-row angular contact ball bearings based on the dynamics analysis. Fine integral method and predict-correct Adams-Bashforth-Moulton multi-step method are used to solve the dynamic stiffness model. The influences of bearing structural parameters and operating conditions on the dynamic stiffness are investigated. The research provides theoretical basis to analyze the dynamic stiffness and optimize the geometry parameters of double-row angular contact ball bearings. The results show that the groove radius of curvature has a small effect on the bearing dynamic stiffness. With the increase in inner and outer groove radii of curvature, the radial stiffness increases slightly, while the axial stiffness and angular stiffness decrease. The dynamic stiffness can be improved by increasing the number of balls. A big axial preload contributes to higher dynamic stiffness, while excess preload makes the bearing life decrease, so the axial preload should be selected properly. With the increase in rotating speed, the dynamic stiffness decreases first and then increases. The bearing dynamic stiffness can be replaced by the contact stiffness approximately when the bearing works at a low speed, while at a high speed, the bearing dynamic stiffness should be calculated by combining the contact stiffness with the film stiffness. External loads have an obvious effect on the dynamic stiffness, which gains greatly with the increase in radial and axial loads. The dynamic stiffness changes complexly with the increase in tilting moment, and decreases first and then increases trend on the whole.