径向磁气组合轴承系统的动态性能

为探究磁轴承失效时能否减轻转子跌落带来的损害，将人字槽径向动压气体轴承引入磁轴承转子系统，研究磁气组合轴承对系统动态性能的影响和动压气体轴承的支承特性。采用有限差分法和小扰动法求解气膜厚度方程和雷诺方程，研究动压气体轴承的静动态特性。对磁轴承电磁力进行了分析，采用磁轴承不完全微分PID（比例-积分-微分）控制策略，对系统进行了理论模态分析和试验模态分析，完成了系统高速旋转试验，测试了动压气体轴承在不同偏心率和转速下的承载力。结果表明，引入动压气体轴承可提高系统的动态性能，在磁轴承失效造成高速转子跌落瞬间，偏心率趋近于1，两个径向动压气体轴承能够产生较大承载力，减轻转子跌落造成的损害。 

Dynamic performance of radial magnetic-gas bearing system

In order to explore whether the damage caused by rotor drop can be reduced in case of the failure of magnetic bearing，the herringbone groove radial dynamic pressure gas bearing was introduced into the magnetic bearing rotor system，and the influence of the magnetic-gas bearing on the dynamic performance of the system and the support characteristics of the dynamic pressure gas bearing were studied.The finite difference method and small disturbance method were used to solve the film thickness equation and Reynolds equation，and the static and dynamic characteristics of the dynamic pressure gas bearing were studied.The electromagnetic force of the magnetic bearing was analyzed.The incomplete differential PID （proportion integration differentiation） control strategy of the magnetic bearing was used.The theoretical and test modal analysis of the system was performed.The high-speed rotation test of the system was completed.The bearing capacity of dynamic pressure gas bearing under different eccentricity and rotating speed was tested.Results showed that introduction of dynamic pressure gas bearings can improve the dynamic performance of the system.At the moment when the high-speed rotor dropped due to the failure of the magnetic bearing，the eccentricity was close to 1.The two radial dynamic pressure gas bearings can produce larger bearing capacity and reduce the drop caused by the rotor damage.