The cage strength is a critical factor that constrains performance of high-speed deep groove ball bearing (DGBB) used in the drive motor of new energy vehicles. This paper presents a rigid-flexible coupling dynamic model for high-speed DGBBs, based on interactions dynamic of the flexible crown cage, balls, and rings. This study systematically analyzed the cage weaknesses in strength, and explored how factors such as the pocket clearance, claw length, modification radius and bottom thickness influence cage strength. In addition, an improved design aimed at enhancing cage strength was proposed. The results indicate that the cage strength is more sensitive to the inner-ring speed. Particularly, both the maximum stress and deformation in the radial direction increase sharply when the speed exceeds a threshold of 18,000 r/min. Additionally, an increase in the bearing rotational acceleration leads to a 45.7% rise in the cage stress. Furthermore, the sensitivity of the cage strength to temperature also escalates with bearing speed; the maximum stress and deformation increase by 5% to 16% at 80 °C compared to that obtained at 25 °C. Based on the structural influence on the cage strength, a structural improvement is proposed. With a pocket clearance of 0.23 mm, a claw length of 2.3 mm, a bottom thickness of 2.4 mm, and a shaping radius of 7.0 mm, the strength of the cage was evaluated both before and after the improvements. The results indicated that the enhanced cage exhibited superior strength.

With the advancement of industries such as high-speed railways, new energy vehicles, and wind power, bearings are frequently exposed to various electric field environments, leading to the need for lubricating oil films of bearings to withstand voltage. One of the major issues caused by the breakdown discharge process of the lubricating oil film in bearings is the generation of local instantaneous high temperatures. This temperature rise is a key factor contributing to problems such as high operating temperature of bearings, surface damage in the contact area, and degradation of lubrication performance. This research article focuses on the comprehensive influence of bearing friction and electrical factors. It establishes a heat source calculation model and a temperature field simulation model specifically for current-carrying bearings. This study analyzes both the overall temperature rise of bearings and the local temperature rise resulting from breakdown discharge. Furthermore, the accuracy of the simulation analysis is verified through experiments. The temperature field simulation and experimental results consistently indicate that electrical environmental factors can cause an increase in the overall temperature rise of a bearing. Additionally, the breakdown and discharge of the lubricating oil film generate local instantaneous high temperatures in the contact area of the bearing.

The traction motor is a crucial component of high-speed electric multiple units, and its operational reliability is directly impacted by the temperature increase in the bearings. To accurately predict and simulate the temperature change process of traction motor bearings during operation, a fluid–solid–thermal simulation analysis model of grease-lubricated deep groove ball bearings was constructed. This model aimed to simulate the temperature rise of the bearing and the grease flow process, which was validated through experiments. The results from the simulation analysis and tests indicate that the temperature in the contact zone between the bearing rolling element and the raceway, as well as the ring temperature, initially increases to a peak and then gradually decreases, eventually stabilizing once the bearing’s heat generation power and heat transfer power reach equilibrium. Furthermore, the established fluid–solid–thermal coupling simulation analysis model can accurately predict the amount of grease required for effective lubrication in the bearing cavity, which stabilizes along with the bearing temperature. The findings of this research can serve as a theoretical foundation and technical support for monitoring the health status of high-speed EMU traction motor bearings.

The dynamics model of cylindrical roller bearing (CRB) in aeroengine main shaft was promoted and solved by Hilber–Hughes–Taylor (HHT) integer algorithm with variable step in combination with symmetric multiprocessing (SMP) parallel solving technology, and a finite element model of roller to cage contact was built. The dynamic characteristics of CRB at the stage of start-up and stop were analyzed firstly, and then, the collision forces between rollers and cage were used as the boundary conditions of the finite element model to discuss the influences of working conditions, structural parameters, and materials on the stress distribution and safety characteristic of cage at the stage of start-up and stop. The findings will provide the theoretical basis for the designing of CRB in aeroengine main shaft.