Abstract:
Lubrication efficiency is a key factor affecting the service performance of rolling bearings. For oil and gas lubrication or oil injection lubrication, analysis shows that when the lubricating oil is injected into the bearing cavity by high pressure, it is difficult to directly inject into the contact area between the rolling element and the ring due to the influence of high speed air flow inside the bearing cavity, which leads to the reduction of bearing lubrication efficiency. In this regard, scholars have confirmed the influence of high-speed air curtain phenomenon on bearing lubrication efficiency through visualization experiments and simulation of bearing internal flow field. In order to improve the utilization efficiency of the lubricating oil in the bearing cavity at high speed, the Qingdao University of Technology team added guiding fibers on the basis of traditional side nozzles to improve the utilization rate of lubricating oil. On the basis of the optimal design of the nozzle, engineers try to further improve the lubrication performance of the bearing by changing the oil supply position, such as the oil supply unit installed in the inner ring, the outer ring and other different positions, in order to weaken the influence of the air curtain phenomenon on the flow of lubricating oil. By optimizing the nozzle structure and changing the oil supply position, the lubrication efficiency of the bearing has been significantly improved, but it also leads to new problems. In recent years, the team from Xi 'an Jiaotong University has made use of the guiding effect of groove structure on fluid flow, and proposed to add axial groove in the non-contact area of the surface of the bearing rotating ring. In view of this emerging technology direction, the team discussed the action mechanism of grooves on lubricating oil flow guidance, and discussed the drainage effect of grooves under different working conditions. The above work mainly carried out the analysis of the flow and temperature rise inside the grooved bearing based on CFD method. Affected by the complexity of the internal component structure and relative movement of the rolling bearing, the research on the flow field distribution inside the bearing and the overall temperature rise of the bearing analyzed the change law of the bearing performance from a macro level. However, due to the lack of grooves for in-depth analysis of the flow process of the lubricating medium on the bearing ring surface, it was not yet possible to understand the flow law of grooves on bearing surface lubrication media, which was not enough to guide the groove optimization design in engineering applications, and it was not possible to evaluate the effect of different groove structures on the bearing lubrication performance. In this regard, this paper compared the flow behavior of lubricating oil on the surface of smooth bearing inner ring and grooved inner ring through visual simulation and experimental technology, and evaluated the guiding effect of groove structure on lubricating oil based on the flow rate of lubricating oil in the raceway of the inner ring, and provided theoretical support for groove design and engineering application oriented to bearing lubrication efficiency. Aiming at the research on the guiding mechanism and influence rule of the grooves on the lubricating oil flow on the surface of the high-speed rotating ring, this paper monitored and compared the flow behavior of lubricating oil on the surface of the smooth bearing inner ring and the grooved inner ring through visual simulation and experimental research, and evaluated the guiding effect of the groove structure on the lubricating oil based on the flow rate of lubricating oil in the raceway of the inner ring. Finally, the rationality of the analysis results was verified by the temperature rise experiment under the condition of bearing spent oil. The results showed that, compared with smooth inner rings, the inner rings with different groove structure might enhance/weaken the lubrication medium flow, and reasonable/unreasonable groove design might improve/reduce the bearing lubrication efficiency.