CT机双列角接触球转盘轴承建模与振动特性分析  

Modeling and Vibration Characteristics Analysis of Double-row Angular Contact Ball Turntable Bearings in CT Machine

作　　者：袁峰[1] 刘凌仲 秦东晨[1] 陈江义[1] 谢兴会 YUAN Feng;LIU Lingzhong;QIN Dongchen;CHEN Jiangyi;XIE Xinghui(School of Mechanical and Power Engineering,Zhengzhou University,Zhengzhou 450001,China;Luoyang LYC Bearing Co.,Ltd.,Luoyang 471039,China)

机构地区：[1]郑州大学机械与动力工程学院,河南郑州450001 [2]洛阳LYC轴承有限公司,河南洛阳471039

出　　处：《郑州大学学报（工学版）》2024年第5期23-29,共7页Journal of Zhengzhou University（Engineering Science）

基　　金：国家重点研发计划项目(2018YFB20005-01);河南省重大科技专项(221100220100)。

摘　　要：为了提高CT机主轴承的运转特性,确保CT机医学成像的稳定性,以洛阳LYC轴承有限公司研制的双列角接触球转盘轴承为研究对象进行建模与振动特性分析。首先,基于Hertz接触理论建立轴承在承受复合载荷作用下的力学模型;其次,结合Newton运动定律确立轴承外圈3自由度非线性动力学微分方程;最后,采用4阶Runge-Kutta法对微分方程组进行求解,获得轴承外圈的振动特性。在此基础上,通过分析影响轴承振动特性的因素如轴承内、外圈沟曲率半径系数、滚动体数量、游隙、预紧力等,从而确定满足CT机主轴承低振动下的最优结构参数。结果表明:轴承振动幅值随着内、外圈沟曲率半径系数的增加呈现出先减小后增大的趋势,将其分别控制在0.515~0.525、0.510~0.525更有利于降低轴承的振动;随着滚动体数量的增加,轴承的振动幅值也随之增加,但变化平稳,故在满足设计条件的前提下减少滚动体的数量可以降低轴承振动;随着轴承游隙的增加,轴承的振动幅值先减小后急剧增大,在18μm处振动达到最小;合适的轴向载荷可以有效降低轴承的振动幅值。In order to improve the running characteristics of the main bearing of the CT machine and ensure the stability of the medical imaging of the CT machine,the double-row angular contact ball turntable bearing developed by Luoyang LYC Bearing Co.,Ltd.was used as the research object for modeling and vibration characteristic analysis.Firstly,based on Hertz′s contact theory,the mechanical model of the bearing with the action of composite load was established.Then the nonlinear dynamic differential equation of the bearing outer ring with 3 degrees of freedom was established in combination with Newton′s law of motion.Finally the differential equation system was solved by the fourth-order Runge-Kutta method to obtain the vibration characteristics of the bearing outer ring.On this basis,by analyzing the factors affecting the vibration characteristics of the bearing,such as the radius coefficient of curvature of the groove in the inner and outer rings of the bearing,the number of rolling elements,the clearance,the preload,etc.,the optimal structural parameters to meet the low vibration of the main bearing of the CT machine were determined.The results show that the vibration amplitude of the bearing decreases first and then increases with the increase of the radius coefficient of curvature of the inner and outer ring grooves,which were controlled at 0.515 to 0.525,respectively.The range of 0.510 to 0.525 was more conducive to reducing the vibration of the bearing.With the increase of the number of rolling elements,the vibration amplitude of the bearing also increases,but the change was stable,so the vibration of the bearing can be reduced by reducing the number of rolling elements under the premise of satisfying the design conditions.With the increase of the bearing clearance,the vibration amplitude of the bearing decreases first and then increases sharply,and the vibration reaches the minimum at 18μm.Appropriate axial load can effectively reduce the vibration amplitude of the bearing.

关 键 词：CT机 力学模型 振动模型 结构参数 振动加速度 

分 类 号：TH133.3[机械工程—机械制造及自动化] TH113.1