航天器驱动机构轴系摩擦力矩建模与分析研究

Friction Torque Modeling of Spacecraft Driving Mechanism Shafting

基于接触力学、摩擦学及角接触轴承拟静力学理论,建立了固体润滑角接触轴承摩擦力矩理论计算模型,并在航天器驱动机构的边界条件下,研究了航天器驱动机构轴系摩擦力矩与预紧力之间的关系,从理论上分析了轴系预紧力对轴系摩擦力矩的影响并进行了试验验证。研究表明,固体润滑角接触轴承摩擦力矩随着轴向载荷的增大而增大,当轴系拧紧力矩达到临界值后,摩擦力矩随着拧紧力矩的增大而增大;且理论分析值和试验值的趋势一致,数值接近;说明基于拟静力学建立的摩擦力矩计算模型能较好地实现低速下的固体润滑轴承和轴系摩擦力矩预测。

Based on the contact mechanics, tribology and the pseudo static theory of angular contact bearing, the theoretical computational formulae of the friction torque of solid lubrication angular contact ball bearings are obtained. Based on this, the relationship between the friction torque of spacecraft driving mechanism shafting is studied and the theoretical analysis and experimental verification for the friction torque are presented after fully considering the boundary conditions on the shafting. The result shows that the friction torque of the angular contact coated solid lubricating film increases with the increase of axial preload and the friction torque of shafting increases with the increase of tightening torque after it reaches the critical value. Furthermore the theoretical and experimental values keep consistent. So theoretical computational formulae of friction torque based on pseudo static theory is suitable for the solid lubrication angular contact bearing and spacecraft driving mechanism shafting at low speed.