变工况下滚动轴承保持架碰撞接触动力学特性分析

Dynamic analysis of impact contact characteristics of the cage of a rolling bearing under variable working conditions

滚动轴承保持架在运动过程中始终会与滚动体产生碰撞,尤其在变工况条件下更易表现出复杂的动态接触特性,对轴承使用性能和寿命产生重要影响。该研究以深沟球轴承6309为研究对象,考虑滚动体与内外圈、保持架之间动态接触关系,建立了滚动轴承耦合动力学模型,分别讨论了匀、加、减速及不同转速波动工况下滚动体与保持架间碰撞力幅值、次数及分布情况等接触特性变化。研究结果表明:变速工况下滚动体与保持架间碰撞次数增多;加速工况下滚动体与保持架兜孔前端碰撞力幅值明显小于后端碰撞力幅值,且承载区内滚动体主要与兜孔前端发生频繁碰撞,非承载内则主要与后端发生碰撞,减速工况则相反;相较于稳定工况,转速波动工况下滚动体与保持架间碰撞作用力要大得多,碰撞程度从小到大依次为三角波动工况、简谐波动工况、矩形波动工况。该研究结果可为保持架的设计和失效分析提供理论依据。

The cage of rolling bearing always collides with the rolling element in the process of movement, especially under the condition of variable working conditions. It is easier to show complex dynamic contact characteristics, which has an important impact on the service performance and life of the rolling bearing. Taking deep groove ball bearing 6309 as the research object, considering the dynamic contact relationship between rolling element, inner and outer ring and cage, a coupling dynamic model of the rolling element bearing was established. The change of contact characteristics such as amplitude, times and distribution of contact force between rolling element and cage under the conditions of uniform, acceleration, deceleration and different speed fluctuation were discussed, respectively. Results show that the number of collision between the rolling element and the cage increases under the condition of variable speed. Moreover, the impact force amplitude between the rolling element and the front end of the cage pocket is obviously smaller than that of the rear end under the acceleration condition, and the rolling element in the bearing area mainly collides with the front end of the pocket frequently. The rolling element in the non bearing area mainly collides with the rear end, while the deceleration condition is on the contrary. In addition, compared with the uniform speed condition, the impact force between the rolling element and cage is much larger under the speed fluctuation condition, and the collision degree from small to large is triangular fluctuation condition, simple harmonic fluctuation condition and rectangular fluctuation condition, which provides theoretical guidance for the selection of rolling bearing working conditions and cage structure design.