基于光弹性原理的弹流润滑实验装置研制

Development of Photoelastic Experimental Device for Elastohydrodynamic Lubrication Analysis

基于目前弹流油膜压力测量实验方法的优缺点,提出用光弹法测量弹流油膜压力,并讨论了相应的测量原理.研制了新型光弹性弹流润滑压力实验装置,该装置由体视显微镜、偏振片、LED光源、加载机构等组成.上试样为透明聚碳酸酯圆盘,下试样为由直流电机通过同步带驱动的GCr15轴承钢制成的转轴,上下试样构成了线接触摩擦副.安装在体视显微镜上的摄像机可拍摄到放大40倍的弹流接触区及其上的聚碳酸酯圆盘上的光弹图像,光弹图像的条纹级次反映了接触区油膜压力和摩擦表面下内部应力的变化.用该装置拍摄了聚碳酸酯和轴承钢滚动摩擦配副在施加载荷为2～50 N,滚动线速度为24、44、63 mm/s时的弹流润滑压力光弹照片.实验结果表明,该装置利用光弹法测量弹流油膜压力与摩擦表面下内部应力是可行的和有效的.

By taking into consideration the advantages and disadvantages of the existing measurement methods of elastohydrodynamic lubrication （EHL） pressure, a novel measurement method based on the photoelastie theory is proposed, and the corresponding mechanism is discussed. Then, an experimental deviee consisting of a stereo- microscope, a polarizer, a LED light source and a loading mechanism is developed. The linear-contact fiction pairs of the device consist of an upper polycarbonate disk and a lower cylinder made of GCrl5 bearing steel and driven by a DC motor through a synchronous belt. By using a camera mounted on the stereomicroseope, the photoelastic ima- ges of the EHL contact region and the polycarbonate disk, which are enlarged 40 times, can be captured, with their fringe grades well reflecting the variations of the lubricant film pressure in the contact region and the inner stress beneath the friction surface. Finally, some experiments are carried out under the load varying from 2 to 50N and at the friction-pair rolling speed of 24, 44 and 63 mm/s. The results show that the proposed method is feasible and effective in measuring the lubricant film pressure and the inner stress.