微型轴承内滚道超声辅助超精研磨系统的设计

Design of ultrasonic assisted superfinishing grinding system for inner raceway of miniature bearing

为了提高5G基站中微型轴承的精度和使用寿命,基于微型轴承外套圈结构特征提出一种超声振动辅助研磨轴承外圈滚道的加工工艺。通过坐标变换及运动合成,获得了振动研磨轴承外圈滚道的工作面轨迹特点,阐明了振动高效研磨的本质特征;之后,分别采用等效电路法和有限分析法,建立了振动系统的等效电路图与频率方程,分析了该系统模型的固有模态与谐响应特性;最后,通过对自行研制的超声辅助研磨系统分别进行振动特性测试和加工效果测试。结果表明,加工系统振动频率相对设计频率的误差率为10‰,超声振幅为12.95m,加工轴承滚道的粗糙度和轮廓度较传统研磨加工分别降低了27.17%和24.1%。

In order to improve the accuracy and service life of mini-bearing in 5G communication base station,an ultrasonic vibration assisted traditional grinding process of the bearing outer ring raceway is proposed based on the structural characteristics of mini-bearing outer ring.Through the coordinate transformation and motion synthesis,the working surface trajectory characteristics of outer ring raceway of vibration grinding bearing are obtained,and the essential characteristics of vibration high-efficiency grinding are clarified.Then,the equivalent circuit diagram and frequency equation of the vibration system are established by using the equivalent circuit method,and the natural mode and harmonic response characteristics of the vibration system are analyzed by the finite element method.At last,the vibration characteristics test shows that the error rate of vibration frequency relative to the design frequency is 10‰,and the ultrasonic amplitude is 12.95m,and the processing effect test shows that the roughness and profile tolerance of the machined bearing raceway is 27.17%and 24.1%lower than that of traditional grinding.