多自由度电机中的气体静压球轴承特性分析

Characteristic analysis of air bearing for multi-degree-of-freedom motor

针对多自由度电机采用传统关节轴承在三维运动时存在摩擦力高,且易产生机械碰撞的问题,提出了一种利用气体静压球轴承代替传统关节轴承作为支撑的多自由度电机。在对不同气体静压球轴承的特性进行了对比的基础上,选定了多孔气体静压球轴承;建立了气体静压球轴承的数学模型及COMSOL三维仿真模型;通过仿真计算,验证了解析法算法的准确性,并进一步分析了各类参数对轴承的承载能力、耗气量和静态刚度的影响。研究结果表明:节流孔数目、包角角度及供气压力,对气体静压球轴承性能都有直接影响,其节流孔最优分布角度为32°;该结果为气体静压球轴承的设计以及在多自由度电机中的应用提供了参考。

Aiming at the problem of high friction and easy mechanical collision of multi-degree-of-freedom motors using traditional joint bearings in three-dimensional motion,a multi-degree-of-freedom motor with a gas static pressure ball bearing instead of a conventional joint bearing was proposed.Comparing the characteristics of different gas static pressure ball bearings,porous gas static pressure ball bearings were selected.The mathematical model of the gas hydrostatic ball bearing and the COMSOL 3D simulation model were established.The accuracy of the analytical algorithm was verified by simulation calculation,and the influence of various parameters on the bearing capacity,air consumption and static stiffness of the bearing was further analyzed.The results indicate that the number of orifices,wrap angle and supply pressure have a direct impact on the performance of gas static ball bearings.The optimum distribution angle for the orifice is 32°.It provides a reference for the design of gas static pressure ball bearings and the application of multi-degree-of-freedom motors.