轴承滚动面的几何误差对微振动的激励机理研究

Mechanism of micro-vibration excited by bearing rolling face geometrical errors

高速旋转的飞轮转子在输出姿控力矩的同时伴随输出宽频微幅振动,为了分析飞轮微振动的来源并估计其幅值,首先结合轴承零件间的相对运动关系将轴承滚动面的几何误差展开成Fourier级数的形式;其次,基于滚动体和沟道间的点接触本质,运用Hertz接触理论,研究了预紧轴承的滚动面几何误差所导致的预紧力波动量,并建立了轴承组件的动力学模型;最后,进行了试验和仿真结果的对比研究,结果表明:在频率点上吻合良好,在幅值的趋势上保持一致。从而验证了轴承滚动面的几何误差和点接触的非线性是轴承微振动的主要根源,同时也验证了低频激励的幅值是转速的二次函数,为飞轮振源定位奠定理论基础。

High-frequency micro vibrations associated with the high-speed rotation of the flywheel affect negatively the perform-ances of precision instruments on the spacecraft. In order to analyze the sources of the micro vibration of the flywheel and esti-mate its amplitudes？ the relative movement of angular contact ball bearing parts is analyzed firstly in this issue？ and the geo-metrical errors of bearings working face are expanded in Fourier series. Secondly？ the amount of force deviation excited by the errors of preloaded bearing is derived from the Hertz contact theory in conjunction with the point contact essence between its balls and races. Thirdly？ a concept on the equivalent geometrical error is defined and the rotting speed is introduced into the calculation of micro-vibration caused by bearing in the aspect of curve fitting. Finally, the micro-vibration of some kind fly-wheel is tested while numerical simulation is performed using same structural parameters. Furthermore, the comparison and a-nalysis between simulation results and experimental results are presented,which show their frequency points are coincident and their amplitudes trends are accordant.