加工及装配误差对气体轴承运动状态的影响规律  

Effects of Machining and Assembly Errors on the Motion State of a Hybrid Bearing

作　　者：李勇德 何永熹[1] 刘检华[1] LI Yongde;HE Yongxi;LIU Jianhua(School of Mechanical Engineering,Beijing Institute of Technology,Beijing 100081,China)

机构地区：[1]北京理工大学机械与车辆学院,北京100081

出　　处：《润滑与密封》2021年第11期19-26,共8页Lubrication Engineering

基　　金：国家自然科学基金项目(51935003);国防基础科研项目(JCKY2016204B201;JCKY2019203B031).

摘　　要：以螺旋槽动静压气体轴承气膜为研究对象,基于计算流体力学与六自由度耦合方法,模拟支撑气膜的流动以及刚体转子的运动,通过分析轴心轨迹及其频谱特征,研究定子轴线偏移、倾斜、定子尺寸误差以及粗糙度等加工及装配特征对动静压气体轴承运动状态的影响规律。结果表明:装配误差对轴承稳定性影响较大,当转速达到30000 r/min,定子轴线偏移误差以及定子轴线倾斜误差分别达到2μm以及2°时,转子振幅明显增加,轴承运动状态均为极限环运动,处于临界稳定状态,因此为保证气体轴承运动稳定性,应确保气体轴承的轴线装配精度;而在轴承对中稳定情况下,加工误差对轴承稳定性影响不大。研究结果为球面螺旋槽动静压气体轴承的加工及装配工艺提供了理论参考。The gas film of a hybrid bearing with spherical spiral grooves was taken as the research object,based on a computational⁃fluid⁃dynamics and six⁃degree⁃of⁃freedom coupled method,a dynamics model was developed to simulate the fluid flow in the gas film and the motion of gas⁃supported rigid rotor.By analyzing the axis orbit and spectrum characteris⁃tics,the effect of machining and assembly errors,such as axis position and direction,structure dimension,and wall rough⁃ness,on the motion state of the rotor was studied.The results show that the assembly error has a great impact on the stability of the rotor,specifically when the revolving speed reaches 30000 r/min,the position and direction errors of the axis reach 2μm and 2°,respectively,the rotor amplitude is increased obviously and the bearing is in a limit cycle motion state,which is in a critical steady⁃state.Therefore,in order to ensure the movement stability of the hybrid bearing,the assembly preci⁃sion of the axis should be ensured.When the bearing alignment is stable,the machining error has little effect on the bearing stability.

关 键 词：气体轴承 计算流体力学 六自由度 装配误差 稳定性 

分 类 号：TH122[机械工程—机械设计及理论]