摘要
针对高速旋转微电机中典型的转子轴衬摩擦磨损问题,以半球形轴衬为研究对象,提出了1种描述其磨损过程的线性滑动磨损模型,建立了半球形轴衬-极板接触有限元模型,分析微转子轴衬的磨损特性和轴衬-极板接触副的接触动力学特性,研究接触副几何结构参数和操作参数对微转子系统磨损特性的影响.结果表明:在MEMS微转子系统中,微转子轴衬偏心距离和转子轴衬半径影响线磨损率,以两者减至最小为较理想,但须注意设计中轴承半径的限制,并使轴衬偏心距离大于轴承内半径;在转子加工制造许可的范围内,可以通过调整转子轴衬的半径和偏心距离来减少摩擦磨损对微电机的影响,随着转子所承受载荷和转子旋转速度的增加,其磨损严重;接触区的应力分布不同于经典Hertz解,这是由于应力集中出现在不连续的曲率线上,且接触区的接触压力呈现轴对称抛物线状分布.该模型可用于预测微转子轴衬的磨损与接触状况,分析微转子系统的磨损特性.
A linear sliding wear to describe the wear process for model of the contact between hemispherical bushing and ground plane is presented the issues of typical friction and wear of the rotor bushings in high-speed rotating micro-motors. A hemispherical-bushing-on-ground-plane configuration finite element model （FEM） was set up to investigate the wear characteristics of the micro-rotor bushings and the contact characteristics of the bushing-on-ground-plane elements. Effects of geometry parameters and applied operating conditions on the wear were investigated. Results indicate that radial distance of the bushing from the rotor center and the radius of the hemispherical bushing significantly affect wear rate, and minimzing both two values will result in lowest wear for micro-rotor systems in MEMS. However, it is noted that the bearing radius sets a lower limit on the hemispherical bushing radius since the bushings are located beyond the rotor inner radius. It is desirable to reduce their effects on friction and wear on micro-rotors by regulating the radius of the bushing and the radial distance of the bushing from the rotor center within permissive range of micro-fabrication. Severe wear exists with increasing applied load and rotating speed of the rotor. Stress distributions in the contact region are different from Hertz solutions due to the convergence stresses apearing on the uncontinuous curvature line and the contact pressures display symmetrical parabola in the contact region. This model can be used to predict wear of rotor bushing, to solve contact problem, and to analyze wear characteristics of the micro-rotor system.
出处
《摩擦学学报》
EI
CAS
CSCD
北大核心
2006年第2期155-158,共4页
Tribology
基金
国家杰出青年基金资助项目(10325209)
