Lundberg对数滚子的热弹流特性及其凸度量的修正

Study on Thermal EHL Performance of Lundberg Profile Rollers and the Modification of its Crowning Value

研究了Lundberg对数轮廓滚子的弹流特性,并探讨了不同凸度量对压力分布和膜厚分布的影响.结果表明:在弹流状态下Lundberg对数滚子端部仍略有压力集中,且端部膜厚过薄,应适当增大凸度量;而随着凸度量增大,压力逐渐沿滚子轴线向中部集中而导致载荷分配不均.设计凸度量时应综合考虑润滑油成膜性能与压力分布两方面因素的影响,凸度量存在1个最优取值区间,其上、下限分别由压力分布和膜厚分布所决定.提出的凸度量最佳取值区间比以往相关文献中提出的最佳凸度量更合理并便于工程应用.

Rolling contact friction pairs, such as rolling beatings, gears are widely in mechanical engineering, and crowning design should be applied to increase their working performance and service life. Crowning design is currently still mainly based on elastostatic theory, although the effect of applied load was considered, the effects of the velocity and lubricants were ignored. Moreover, the pressure in elastostatic and EHL states is quite different. The EHL performance of Lundberg profile was discovered, and the effect of the crowning value on the pressure as well as film thickness distributions were discussed. Although the pressure ＂edge effect＂ could be considerably avoided, the film thickness ＂edge effect＂ appeared, and satisfactory lubrication state can not constructed. Therefore, the Lundberg profile crowning value was insufficient in EHL state. However, with increase of crowning value, the pressure shifts to the center in axial direction though the film thickness remains thick enough at the edge. The pressure and film thickness distribution should be considered at the same time in designing suitable crowning. There is an optimum range of the crowning value for a particular working condition. The lower bound of the optimum range is mainly decided by the film thickness, while the upper limit of it is mainly decided by the pressure distribution. Compared with the ＂optimum crowning value＂ proposed in former researches, the ＂optimum range of the crowning value＂ proposed currently is more reasonable and convenient to be applied in industry.