表面微深孔对高副接触零件减磨效应研究

发布时间：2018-04-25 04:02

本文选题：耐磨性 + 微深孔　；参考：《扬州大学》2012年硕士论文

【摘要】：随着越来越多的高速、重载传动机构的出现,零件的工作条件愈来愈苛刻,零件的使用寿命越来越短。因此,提高零件的使用寿命是现代工程中面临的一个重要难题,另外,在以节能减排为主题的当今社会中,提高零件的使用寿命对全球经济的可持续发展具有重要的影响。提高零件的使用寿命,其中最有效的一种方法就是降低零件接触表面的磨损。目前,提高零件表面耐磨性能常用的方法主要有：改变材料的化学成份与组织结构、改变热处理工艺以及材料的表面改性技术等。在此,本文提出了一种提高零件耐磨性的方法——在零件表面制造很多排列有序的微深孔；由于零件表面在重载情况下,接触面会产生变形,使接触区的微深孔容积变小,可以在接触区产生挤油现象,从而增加了接触区的油膜厚度,已达到减磨效果。本文主要介绍了利用激光加工技术在零件表面制造微深孔的方法,阐述了激光加工过程中影响微深孔加工的因素,以及应用HGL-LCY300激光加工设备在圆柱滚轮表面加工出直径为0.2～0.4mm左右,孔深为1.5～2.0mm左右的众多排列有序的微深孔。在经典弹流动力润滑理论的基础上推导出零件表面具有微深孔时的弹流动力润滑方程组；利用数值分析的方法,对润滑方程组进行数值求解。将计算结果与光滑零件表面在相同条件下求得的数值结果作比较,得出了零件表面在有微深孔时能增大接触区的油膜厚度,也能降低接触区的油膜压力。并且分析了节点数目、载荷、速度和微深孔流量的变化对润滑油膜的压力和油膜厚度的影响,得出了以下结论：(1)计算区域的节点数划分对数值结果有一点的影响,节点数越多,弹流润滑油膜的最大压力不断下降,而最小油膜厚度不断上升,但数值变化不大,同时获得数值结果越慢。(2)在相同条件下,随着载荷的增加,油膜的最大压力和最小厚度都在增大,但是,零件表面所具有的微深孔的最小油膜厚度要比光滑表面的最小油膜厚度要大,而最大油膜压力相对要小。(3)在相同条件下,流体的速度在不断增大,对最大油膜压力影响不是太明显,相反,随着速度在不断增大,最小油膜膜厚变化明显。(4)微深孔流量发生变化,最小油膜厚度变化不怎么明显,但是比光滑零件表面的油膜厚度变化要大,而最大油膜压力在不断减小,同时也给出了微深孔总流量的一个合理变化范围。本文还介绍了减磨润滑的对比试验的设计,并在有限的实验条件下进行零件耐磨性的对比试验,进一步验证了零件表面具有微深孔时具有良好的耐磨性,提高了零件的使用寿命。
[Abstract]:With more and more high speed and heavy load transmission mechanism, the working conditions of parts are becoming more and more harsh, and the service life of parts is becoming shorter and shorter. Therefore, increasing the service life of parts is an important problem in modern engineering. In addition, in today's society with the theme of energy saving and emission reduction, increasing the service life of parts has an important impact on the sustainable development of global economy. One of the most effective ways to improve the service life of parts is to reduce the wear of contact surfaces. At present, the main methods to improve the wear resistance of the parts are: changing the chemical composition and structure of the material, changing the heat treatment process and the surface modification technology of the material, etc. In this paper, a method to improve the wear resistance of the parts is proposed, which makes many ordered micro-deep holes on the surface of the parts. Because the contact surface of the parts will be deformed under heavy load, the volume of the micro-deep holes in the contact area will become smaller. Oil squeezing can be produced in the contact area, thus increasing the thickness of the oil film in the contact area and achieving the effect of reducing wear. This paper mainly introduces the method of making micro deep holes on the surface of parts by using laser machining technology, and expounds the factors that affect the processing of micro deep holes in the process of laser processing. And the HGL-LCY300 laser machining equipment is used to fabricate many well-arranged micro-deep holes with diameter of 0.2~0.4mm or so and hole depth of 1.5~2.0mm on the surface of cylindrical roller. Based on the classical elastohydrodynamic lubrication theory, the elastohydrodynamic lubrication equations with micro-deep holes on the surface of parts are derived, and the equations of lubrication are solved numerically by the method of numerical analysis. By comparing the calculated results with the numerical results obtained from the smooth parts under the same conditions, it is concluded that the oil film thickness of the contact area can be increased and the oil film pressure of the contact area can be reduced when the surface of the part has a micro-deep hole. The effect of the number of nodes, load, velocity and flow rate on the pressure and thickness of lubricating oil film is analyzed. The following conclusion is drawn: 1) the number of nodes in the calculated area has a little effect on the numerical results, and the more the nodes are, the more the number of nodes is. The maximum pressure of elastohydrodynamic lubricating oil film is decreasing, while the minimum film thickness is increasing, but the numerical value is not changed much, and the numerical results are obtained slowly. 2) under the same conditions, with the increase of load, The maximum pressure and the minimum thickness of the oil film are both increasing, but the minimum oil film thickness of the micro-deep hole on the surface of the part is larger than the minimum oil film thickness of the smooth surface, and the maximum oil film pressure is relatively small under the same conditions. As the velocity of the fluid increases, the effect on the maximum oil film pressure is not obvious. On the contrary, with the increasing of the velocity, the minimum film thickness changes obviously. But the thickness of the oil film is larger than that of the smooth surface, and the maximum oil film pressure is decreasing continuously. At the same time, a reasonable range of the total flow rate of the micro-deep hole is given. This paper also introduces the design of the contrast test of reducing wear and lubrication, and carries on the contrast test of the wear resistance of the parts under the limited experimental conditions. It is further proved that the surface of the parts has good wear resistance when the surface has micro-deep holes. The service life of the parts is increased.
【学位授予单位】：扬州大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH117;TG665

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