Comprehensive theoretical and experimental study on the transient slip behaviors of the roller and cage within the radial loaded cylindrical roller bearing

The widespread occurrence of slippage resulting from relative sliding between rolling elements and raceways within rolling bearings poses a significant risk to their internal heating and lifespan, previous research has predominantly focused on the overall slip behavior of the bearing's internal cage, with relatively little attention given to the local slip behavior of the rolling elements inside the bearings. To gain deeper insights into the relations between the localized slip of the roller and the macroscopic slip of the cage for a cylindrical roller bearing, a comprehensive theoretical and experimental analysis on slip characteristics of both the roller slip and cage are presented. Firstly, a complete transient dynamic model is proposed, which meticulously considers the intricate interactions among multiple components within the bearing. Based on this, the mechanisms and effects of both local roller slip and overall cage slope within the bearing are discussed. Secondly, an experimental rig for the slip testing of cylindrical roller bearing is designed utilizing non-contact electromagnetic that leverages high-temperature resistant radial magnets embedded at the roller's ends, and then the slip characteristics of the local roller and cage are tested and analyzed for the cylindrical roller bearing operating under different external loads and rotational speeds. The research results indicate that the experimental results of roller and cage slip align with the theoretical analysis trend, demonstrating periodic fluctuations in the roller slip rate. Notably, a sudden surge in the slip rate is observed during the roller's transition from the non-loading area to the loading area, referred to as the “bite-in” movement. Furthermore, even when the slip rate of the cage remains exceptionally low, the transient slip rate of the local roller may exhibit notable fluctuations as it switches between the loading and unloading areas.