【作者】 林瑞华；

【导师】 江亲瑜；

【作者基本信息】 大连铁道学院 ， 机械制造及自动化， 2003， 硕士

【摘要】 在铁路机车车辆中应用的圆柱滚子轴承，对其滚子外圆表面的质量要求非常高，因此常采用贯穿式无心外圆超精方法加工。在传统的设计方法中轴承滚子的母线都是采用直母线，工作过程中整个有效长度都受力，虽然在大部分接触区域上的接触应力分布较为均匀，但在端部会引起严重的边缘效应，导致此处产生较平均应力大数倍的应力峰，常造成该处轴承内、外圈滚道及滚子发生早期疲劳剥落，运用实践表明这种型线的零件已不能满足铁路运输高速重载的要求，主要症结在于没有设计出合理的母线形状。目前在国内外为了克服这种不利因素，已对滚子母线形状进行了各种修形，如采用带弧坡滚子、修正线形滚子和全凸度滚子等，而在我国轴承厂家还是采用弧坡滚子，设有一道工序加工两端的弧坡，不仅生产率低，而且表面粗糙度较高，更主要的是无法以此工序产生理想的对数母线。常规的无心超精磨削加工是难以同时满足上述要求的，已有一些文献对油石超精加工各参数对超精加工效果的影响作了论述，但对于各参数改变时滚子表面形貌的变化，缺乏详细、直观的理论论述和图形描述。本文从这两方面出发，首先根据不同零件、不同母线形状的圆柱体，从设计原理、材质选取原则、机加工工艺等方面进行系统研究，解决圆柱体零件连续支撑送料导辊的型面设计和制造的问题，加工出最佳母线的滚子即对数滚子，获得高精度的加工表面，提高滚子的接触疲劳强度和使用寿命，从根本上解决接触应力分布不合理的问题。其次，建立了油石超精加工的运动模型和切削模型，对滚子表面形貌进行三维模拟，并计算出油石超精加工的切削量，获得最优加工工艺参数和条件。同时直观地表示出滚子转动的圆周线速度、油石振动频率、油石振动振幅等因素对滚子外圆表面形貌和油石切削量的影响。通过计算机仿真为油石超精加工技术提供了理论依据，获得了达到较好表面加工质量的切削因素和条件，拓展了油石超精加工技术的应用前景。更多还原

【Abstract】 Short cylindrical roller bearings widely used in railway locomotives demand extremely high quality. Through centerless superfinishing technique is often adopted in the process of machining the roller surface. The roller generant adopts straight one in traditional design and during the running the whole effective length is all under load. Although the contact stress distribution is even on most of the contact zone, serious edge effect is arisen at the two ends and results in the stress peaks several times higher than the mean stress, and earlier fatigue failure often occurs in the inner and outer of the rollaway and the roller itself. Application practice shows that rollers of straight generant can’t meet the requirements of thigh speed and heavy load in railway transportation, and the roller design of appropriate generant is needed. At present in order to overcome this disadvantage factor, the roller generant shape has to be amended, such as adopting the bowtype roller, amendatory linetype and convexity ratio roller, whereas Chinese bearing factories adopt bowtype roller which is machined on two ends in one process .Not only is the low productivity, but also the surface roughness is very high, and what is more the ideal logarithm generant can’t be produced in this process. The regular centerless grinding is unable to meet the above requirements simultaneously. There have been some literatures expounded all kinds of parameters of abrasive stone superfinishing and the influence of superfinishing effects, but short of detailed, direct theoretical and graphic description. From the above two aspects, firstly based on different rollers, different generant shape, the studies are systematically done from design principle ,material-choosing principle ,heat treatment criterion and machining process and so on., and the problems of the supporting rollerdesign and its manufacturing are solved and the optimal generantroller-----logarithm roller is made. The machining surfaces of highprecision is acquired, and the contact fatigue strength and operating life of the bearings are raised, and the irrational problems of the contact stress distribution are thoroughly solved. Secondly, a motion and a cutting model of abrasive stone superfinishing are built respectively, and optimal process parameters and conditions are acquired. At the same time it is clearly shown that the topography of the roller surface and abrasive stone cutting quantity are affected by the rotational speed of the roller, the vibration frequency and altitude of the abrasive stone and so on. The theory proof is provided for abrasive stone superfinishing technique through computer simulation, and cutting factors and conditions of better surface machining quality are obtained, and the application prospect of the abrasive stone superfinishing technique is expanded.更多还原