Yan Zhaobin, Fan Shuangjiao, Xu Wenpeng, Zhang Zhixin, Pang Guibing
College of Mechanical Engineering and Automation, Dalian Polytechnic University, Dalian 116034, China.
Micromachines (Basel). 2022 Dec 26;14(1):63. doi: 10.3390/mi14010063.
Roundness is one of the most important evaluation indexes of rotary parts. The formation and change of roundness in the machining of parts is essentially the formation and genetic process of profile. Centerless positioning machining is one of the main surface finishing methods of rotary parts. The rounding mechanism of centerless positioning machining determines its unique roundness profile formation and genetic characteristics. How to eliminate the roundness error of centerless positioning machining has become one of the important issues in the research of high-precision rotary part machining. This paper explores the influence of process parameters on the roundness error from the perspective of profile evolution during centerless grinding and electrochemical mechanical machining, with the aim of providing a cross-process collaboration strategy for improving bearing raceway accuracy. Through an experiment of centerless grinding, the influence law and mechanism of process parameters on the profile are discussed. On this basis, electrochemical mechanical machining experiments are designed to explore the variation rules and mechanisms of different profile shapes in the machining process. The cross-process collaboration strategy is studied, and reasonable parameters of centerless grinding and electrochemical mechanical machining are determined. The results show that in the centerless grinding stage, increasing the support plate angle can form a multiple-lobe profile with high frequency within a wide range of process parameters. Electrochemical mechanical machining can effectively smooth the high-frequency profile and appropriately expanding the cathode coverage can improve the roundness error and reduce the requirement of initial accuracy of a multiple-lobe profile workpiece to a certain extent. Therefore, the combined machining technology of "centerless grinding + electrochemical mechanical machining" provides an efficient technical means to realize the precision machining of rotary parts such as bearing raceways.
圆度是回转零件最重要的评价指标之一。零件加工过程中圆度的形成与变化，本质上是轮廓的形成与遗传过程。无心定位加工是回转零件主要的表面光整加工方法之一。无心定位加工的圆整机理决定了其独特的圆度轮廓形成及遗传特性。如何消除无心定位加工的圆度误差，已成为高精度回转零件加工研究中的重要问题之一。本文从无心磨削和电化学机械加工过程中轮廓演变的角度，探讨工艺参数对圆度误差的影响，旨在为提高轴承滚道精度提供跨工艺协同策略。通过无心磨削实验，探讨工艺参数对轮廓的影响规律及机理。在此基础上，设计电化学机械加工实验，探究加工过程中不同轮廓形状的变化规律及机理。研究跨工艺协同策略，确定无心磨削和电化学机械加工的合理参数。结果表明，在无心磨削阶段，增大支承板角度可在较宽工艺参数范围内形成高频多叶轮廓。电化学机械加工可有效平滑高频轮廓，适当扩大阴极覆盖范围可改善圆度误差，并在一定程度上降低多叶轮廓工件的初始精度要求。因此，“无心磨削 + 电化学机械加工”的复合加工技术为实现轴承滚道等回转零件的精密加工提供了一种高效的技术手段。
