【作者】 汤科锋；

【导师】 袁巨龙；

【作者基本信息】 浙江工业大学 ， 机械电子工程， 2010， 硕士

【摘要】 精密机械的运转常使用轴承,而轴承球、陶瓷球是轴承的主要元件之一,精密球在精密工程领域发挥着重要作用。然而,成球机理不完善、加工效率低的传统研磨方式越来越不能适应当代科技发展需求。为克服上述不利因素,本研究中心独创性提出双自转研磨方式,它继承了自转角主动控制研磨方式的研磨均匀性优点,使研磨轨迹点在球上分布均匀。为定量评价双自转研磨方式的研磨均匀性,对球坯和研磨盘接触点上的基本材料去除率进行了研究,即单位接触面积,单位力作用,单位相对速度条件下的材料去除量。运用有限元法计算得到轴承钢球和上研磨盘之间的接触应力,由接触应力分别设计了不同加工载荷和转速的轴承钢平面研磨实验,得出材料的基本去除率,作为仿真中球和盘接触点上的材料去除率,为定量评价双自转研磨方式的均匀性奠定了前提条件。本文还对几种不同类型的研磨方式进行了力学特性的分析,得出了双自转研磨方式下的球坯运动方程,根据球坯的运动方程,计算出研磨轨迹,并用计算机仿真精密球球面研磨轨迹的分布。为了进一步对研磨均匀性做定量化分析,提出了对精密球进行网格划分的评价方式,将平面研磨实验得出的轴承钢材料去除规则应用到仿真中,分析双自转研磨方式的研磨均匀性。最后从研磨均匀性角度比较了新型研磨方式和传统研磨方式的区别,并分析了影响研磨均匀性的一些机构参数。为验证双自转研磨方式的研磨均匀性,选取仿真后几组工艺参数组合,在磨球机上进行了研磨均匀性试验研究。在试验过程中,以研磨后的球形偏差为评价指标,验证以上几组组合条件下的研磨均匀性。仿真结果和试验结果表明,在双自转研磨方式下,球坯表面能均匀研磨,且研磨盘转速和加工载荷都对球度有较大影响。最后通过建立研磨过程中单球球形误差修正过程、球坯滑动和碰撞等模型,对研磨成球过程中成球机理及影响因素进行了分析。并探讨了材料去除、设备精度、研磨盘端跳等因素对研磨成球的影响。更多还原

【Abstract】 Bearing is widely used in precision mechanism, and the bearing balls and ceramic balls are one of its major components. The precise bearing balls play the important role in precision engineering. Because of the limitation of sphere generation mechanism, low finishing efficiency and high cost, the traditional lapping technique of precise bearing balls can hardly meet the requirements of modern science and technology. To overcome limitations in traditional lapping process, a new type of high efficiency lapping method for high precision ball, Rotated Dual-Plates (RDP) lapping, is developed by our research center, which inherits the advantage of spin angle control lapping, so the lapping trace can be evenly distributed on the ball.In orde to quantificationally analyze the lapping uniform of RDP, the basic material removal rate of ball-plates’contact point is researched. Firstly the contact stress between the upper grinding plate and presion ball is calculated by finite element method, and the plane grinding experiments of bearing steel and Si3N4 materials are designed according to the contact stress. At last, the rules of two typical materials are obtained by the array of single factor grinding experiment, which provides the basis for lapping uniformity of simulation.In this thesis, the kinematics of the other lapping method is also analysised, and the motion equations of RDP lapping mode is obtained, according to the equations of motion equations of RDP lapping mode, the lapping trace is calculated, and the distribution of lapping trace on the ball is simulated by computer simulation. At last, for further quantificationally analyzing lapping uniform, the estimation methods of grid division on precision bearing ball are put forward, and the plane grinding experiments of bearing steel material removal rules is also applied to the simulation, so the lapping uniformity of balls can be well analysised. At last, the difference of RDP lapping mode and traditional v-grooves lapping method are compared, and some parameters of device which influence the lapping uniformity are also analysed.In order to verify the lapping uniform of the RDP lapping devices, the lapping uniform experiment of RDP lapping devices is done based on the sphericity of simulation. During the experiment, the material removal rate and sphericity are selected as the target of the evaluation, so the abave of grinding combination can be verified. It is shown that the precision ball can be lapped uniformly in RDP mode, and rotational speed and load are the chief influence factors on the lapping uniformity.By establishing of mechanisms of sphere error correction, ball sliding against plates and impaction between balls mode, the ball’s mechanism of the RDP lapping mode and influence factors in the lapping are analysised in the end. The influence of material remova, the presion of device and lapping tools on sphere-shaping process is also discussed with theory analysis.更多还原