ISSN   1004-0595

CN  62-1224/O4

高级检索

基于推力球轴承结构的润滑油回填特性试验观察

Experimental Observation of the Lubricant Replenishment Using Trust-Ball-Bearing-Structured Device

  • 摘要: 采用基于推力球轴承结构的润滑油膜与摩擦力测量仪,试验观察了回填时间、供油量和黏度等对润滑油回填特性及润滑状态的影响,其中,回填时间由滚动体数量及排布方式决定. 结果表明:增加回填时间可改善入口区供油状态和接触区润滑状态,并使摩擦系数整体下降,其诱因是玻璃盘表面润滑剂自发回填量的增加;存在最佳供油量使摩擦系数达到最小值;轴承接触几何特征和保持架对润滑剂的再分布是钢球表面润滑剂回填主导机制,该机制使接触区入口维持一定量润滑剂,同时削弱了润滑剂自发回填对黏度的依赖性,使乏油条件下较高黏度对润滑油膜的建立仍起到促进作用.

     

    Abstract:
    The lubricant is displaced to both sides of the rolling track under over rolling of the rolling element. Basically, the displaced lubricant will replenish to the rolling track to maintain an available amount and lubrication safety. However, due to successive motion of the rolling elements, the replenishment interval is too short for efficient replenishment of the lubricant, resulting in insufficient supply and subsequent kinematic starvation. To investigate both starvation and replenishment mechanisms, a simple ball-on-disc configuration is commonly employed. By understanding these mechanisms, measures are developed to regulate replenishment and enhance lubrication efficiency. Even when operating under starvation conditions, the rolling bearing demonstrates a prolonged service life compared to the duration of model tests, suggesting that certain inherent features of the bearing contribute to lubricant replenishment. This is primarily due to the oversimplification of the conventional ball-on-disc single contact configuration, which overlooks crucial bearing features such as contact geometry, cage design, and bearing kinematics and dynamics. As a result, it becomes challenging to extrapolate the obtained results to complete bearing performance.
    Alternatively, a thrust rolling bearing test device with a comprehensive bearing structure is employed, wherein the upper race of the rolling bearing can be directly replaced by the transparent disc. Using this test device, experiments can be conducted to explore the various factors that affect replenishment such as replenishment time, speed, lubricant supply amount, and lubricant viscosity. In this study, the influence of replenishment interval on the lubricant state was quantitively observed by regulating the numbers of the rolling elements and arrangement. The findings demonstrated that an increase in the replenishment interval leaded to improvements in both the supply of inlet lubricant and lubrication states, resulting in a reduction in friction coefficient. The investigation revealed the existence of an optimal lubricant supply amount that minimized the friction coefficient while maintaining an acceptable film thickness for effective separation of the bounding surfaces. Additionally, the presence of a cage significantly contributed to the replenishment of lubricant on the ball surface. This was primarily due to the fact that as the lubricant passed through the clearance between the ball and cage, it caused a squeezing effect on the lubricant at sidebands, redirecting it back onto the rolling track. The replenishment mechanisms under mechanical action mitigated the impact of lubricant viscosity on replenishment, resulting in a positive correlation between higher viscosity and increased film thickness. From the investigations, it was evident that the inherent bearing features had potential contributions to the lubricant replenishment and improvement to the film formation. This study was beneficial to understand the negative and positive factors that impact the lubricant replenishment, which was helpful to regulate lubrication state through bearing design.

     

/

返回文章
返回