Lubrication Behavior Analysis Of Cageless Ball Bearing With Recuded-collision Raceway

As the backup bearing of magnetic bearing,cage free ball bearing plays the role of supporting the main shaft when the magnetic bearing stops working.However,due to the lack of cage isolation,cage free ball bearing is prone to collision between rolling elements,resulting in increased wear.For this reason,the research group has carried out the research on the design of local recuded-collision raceway on the outer ring raceway of the bearing to make the rolling bodies uniformly distributed.This paper is to carry out the research on the lubrication behavior of cageless ball bearings with recuded-collision raceway,analyze the ability of the recuded-collision raceway structure to store lubricating oil,and the impact of the dynamic characteristics of the rolling body when rolling through the recuded-collision raceway on the flow of lubricating oil,and conduct the research through theoretical modeling,numerical simulation analysis and experimental verification.Firstly,the factors affecting the lubrication effect of ball bearing without cage with anti-collision raceway are analyzed,including the structural parameters of anti-collision raceway,the speed of rolling body and the deformation of contact surface.The volume equation of the initial oil volume,the velocity equation of the lubricating oil inlet area and the deformation equation of the contact surface are established respectively.The analysis of the three influencing factors provides a theoretical basis for the subsequent solution of the lubricating oil flow model of the ball bearing without cage with anti-collision raceway.Secondly,combined with the structural parameters of the anti-collision raceway,the speed of the rolling body and the deformation of the contact surface,through the analysis of the Navier-Stokes equation(N-S equation),the lubricating oil flow model and the elastohydrodynamic lubrication equations of the ball bearing without cage with the anti-collision raceway are established and solved numerically,and the oil film pressure between the rolling body and the conventional raceway and the anti-collision raceway is obtained when the lubrication is sufficient under the working conditions of different rotational speeds The distribution of oil film thickness and oil film flow velocity;Thus,the relationship between the amount of oil required for elastohydrodynamic lubrication of ball bearing without cage with anti-collision raceway and the depth of anti-collision raceway is analyzed,and the distribution law of the oil film thickness between each rolling body and raceway is obtained when the lubrication is sufficient under the working conditions of different rotational speeds,and the value range of the optimal depth of anti-collision raceway is determined.Finally,the simulation model and test specimen of ball bearing without cage with anti-collision raceway are determined based on the range of the best anti-collision raceway depth.Through simulation analysis,it is verified that the lubricating oil in the anti-collision raceway can play a role in lubrication.Then,high-speed photography test and vibration analysis test were carried out on the ball bearing without cage in the anti-collision raceway to further verify that the lubricating oil in the anti-collision raceway can play a lubricating role.By comparing and analyzing the high-speed photography results at different speeds and the vibration results of bearing lubrication and non-lubrication,it can be seen that the operation stability of the ball bearing without cage in the anti-collision raceway after lubrication is better,And the initial lubricating oil required by the bearing increases with the increase of the speed,which is consistent with the theoretical analysis.Through the analysis of the lubrication behavior of cageless ball bearing with recuded-collision raceway,this paper determines the influence of the depth,number and placement position of the recuded-collision raceway on the lubrication effect of the bearing.This research has important guiding significance for the design and application of cageless ball bearing with recuded-collision raceway.