【作者】 张开飞；

【导师】 任成祖；

【作者基本信息】 天津大学 ， 机械制造及其自动化， 2013， 博士

【摘要】 球轴承的套圈沟道是滚动轴承的基本工作面，该沟道除了要求具有特殊的材料及热处理性能外，还应具有良好的几何精度及加工精度，而沟道加工质量的好坏将直接影响到轴承的旋转精度和寿命。ELID（Electrolytic in-process dressing）磨削是以电化学加工及电解磨削的原理为基础发展起来的一项磨削新技术，该技术具有加工精度高、加工表面质量好、砂轮廓形保持性好等优点，同时由于采用该技术进行磨削时砂轮锋利且不易堵塞，非常适用于硬脆材料的磨削。本文将ELID技术应用于套圈沟道的超精加工，系统研究了基于工件阴极和氧化膜状态主动控制的ELID磨削机理、圆弧砂轮修整及ELID成形磨削的砂轮耐用度等关键科学问题。在提高沟道的几何精度、改善沟道的表面质量的基础上，旨意降低轴承噪音，提高轴承的承载能力和寿命，本文主要研究的内容有以下几个方面。数控改造现有磨床，开发了球轴承套圈沟道的ELID成形磨削系统。该系统包括砂轮整形、砂轮修锐、氧化膜状态的监测和控制及磨削力的监测等四个子系统。推导获得了两个沿支承方向的单向力与法向和切向磨削力之间的关系式，提出了内圆磨削磨削力的法向力和切向力的监测方法。试验研究指出，该检测方法性能稳定且可靠。采用基于工件阴极和氧化膜状态主动控制的ELID磨削方法，开展了内圆磨削试验研究。主要考察了磨削参数和电解参数对磨削力、材料去除率、加工表面粗糙度和波纹度的影响规律。研究结果表明，随着轴向进给量和电解电流的增加，磨削力增大；随着磨粒粒度的增加，磨削力下降；随着电解电流的增加，材料去除率增大；随着电解电流和磨粒粒度的增加，加工表面粗糙度和波纹度降低。在分析ELID成形磨削中砂轮廓形变化规律的基础上，提出了工件的沟形偏差可良好衡量砂轮廓形变化程度这一重要结论。以该结论为基础，研究了进给速度对砂轮耐用度的影响规律，结果表明随着进给速度的增加，砂轮耐用度降低。此外，研究了磨削用量对表面粗糙度和波纹度的影响规律。结果表明，随着砂轮转速和工件转速的增加，表面粗糙度减小，波纹度增大；随着进给速度的增加，表面粗糙度和波纹度均增大。更多还原

【Abstract】 The ball bearing raceway is a fundamental area of rolling bearing. Aiming for themachining of ring raceway of ball bearing, it not only has a need for materials andheat treatment, but also has a need for geometrical precision and machining precision.So the machining quality of ring raceway of ball bearing will directly affect rotaryprecision and the life of bearing. ELID (electrolytic in-process dressing) is a newgrinding technology based on principles of electrochemical etching and electrolyticgrinding. It not only has high precision, sound quality, and high shaping precision, butalso has wheel sharpness and high resistance to block. Thus, it is used in the grindingprocess of hard brittle material. This dissertation investigated critical scientific issuesduring a grinding principle of shaping machining based on a state control of oxidelayer without an electrode, wheel life, and forming wheel dressing. And it canimprove geometrical precision and machining precision for the machining quality ofring raceway of ball bearing with ELID grinding technology to reduce noise, improveload capacity and life of the ball bearing. The specific contents are as follows.Based on a numerical control machine tools, a grinding system for studyingforming machining a ring raceway of ball bearing with ELID process was developed.This system consists of wheel truing, wheel dressing, monitoring and controlling foroxide layer state, and monitoring for grinding force.In order to more easily research ELID internal cylindrical grinding process, aforce measurement device with two unidirectional force sensors was developed. Andtwo unidirectional force sensors have been used to detect the grinding forces in thegrinding process to analyze a relationship between normal and tangential grindingforce and force of two one-way. Based on the above analysis, the theoretical formulasof grinding force were derived. The results demonstrate that the system was reliableand stable.The ELID grinding strategy based on the state control of oxide layer which awork piece acting as the dressing electrode was developed, avoiding the destruction ofthe quality of the machined surface in the grinding process caused by dulled wheel.The influences of the grinding and electrical parameters on force characteristics,material removal rate, surface roughness and surface waviness of internal machiningof bearing steel were investigated in detail. The experimental results show that thegrinding forces increase with increasing feed rate and dressing current, and the normal and tangential forces increase with decrease of wheel grit size. The material removalrate increases as the dressing current increases. Surface roughness and surfacewaviness increase as the dressing current increases. The experimental results alsoshow that surface roughness and surface waviness increase with increasing wheel gritsize.According to a change rule of wheel shape in ELID grinding process,groove-shaped deviation of workpiece was used to be an index for wheel wear. Anexperiment of the shape accuracy of a machined workpiece was carried out on anELID CNC grinding machine, The experimental results show that grinding wheeldurability decreases as feed rate increases. Furthermore, the influences of the grindingparameters on surface roughness and surface waviness were investigated in detail.The test results show that surface roughness decreases with increasing grinding wheelspeed and workpiece speed, and increases with increasing feed rate. And surfacewaviness increases with increasing grinding wheel speed, workpiece speed, and feedrate.更多还原