Ultra-high speed factors influencing deep groove ball bearing design and optimization

Ultra-high speed deep groove ball bearing 2021 - design factors and optimization 02 - 04 with the high-speed development of hybrid and electric vehicles, the requirements of environmental protection is smaller and lighter. Motor size smaller, its output power also decreased, but to ensure that with the current engine has the same or higher output power, will need to use higher rotational speed of motor. The following motor in deep groove ball bearings in order to be able to withstand more than 30, 000 r/min speed ( 1 is currently used bearing limit speed. 5 times) , carries on the analysis and optimization. Influence factors analysis of 1) Lubrication oil lubrication is. Due to the high speed rotation of the rolling element and cage, a large number of lubricating oil will be under the action of centrifugal force to bearing outside diameter direction, between inner ring and rolling body or between the rolling element and cage lubrication inadequate. Insufficient lubrication can cause bearing internal components of the adhesive, lead to bearing jammed. Add lubricating oil solution will cause oil mixing of resistance increase, increase torque. Under the high speed bearing the internal state of 2) Friction on the surface of the ball and the channel friction deep groove ball bearing rotates, the ball and the channel surface sliding friction between the proportional to the speed of the bearing. Normal speed down the influence of kinetic friction is negligible. But under the condition of the ultra-high speed control of the ball and friction on the surface of the channel is very important, because of the rapid increase of friction heat output can lead to increased. Friction between the ball and cage deep groove ball bearings are commonly used stamping steel ribbon cage and plastic crown retainers. Stamping steel cage is made up of two and a half wave shape is the ball pocket pore structure of a half cage riveting; Plastic crown cage made by resin containing glass fiber reinforced nylon. Both cage spherical pocket has a lock at the mouth of the hole; Will produce friction between the ball and cage pocket hole. Under the normal speed, the forces acting on the ball and keep on the shelf is very small, cage pocket hole of the friction force and the friction between the ball and bearing ring, are negligible. But in 30, 000 r/min ultra-high speed of operation conditions, the circumference of the ball speed can reach 40 m/s or more, stress increased between the ball and cage. Plastic cage has a self lubrication and lighter weight, so its more than stamping steel cage is suitable for high-speed operation. If insufficient lubrication bearing ultra-high speed run, the friction between the ball and cage pocket hole will increase the pocket hole on the surface of the wear and tear, even cage is likely to emerge from the bearing. 3) Maintains a strength to choose plastic crown retainers. Plastic crown retainers when rotating at high speed, under the action of centrifugal force, the outer surface of the cage deformation will happen, then keep frame will be in contact with the bearing outer ring. When maintains contact with the bearing outer ring and bearing temperature increase. In addition, there have been large deformation of cage pocket hole will occur due to pocket hole circumferential surface stress fracture, the need to develop enhanced cage structure, can withstand the deformation and failure caused by centrifugal force to maintain, can increase the cage wall thickness to improve the strength of the cage, but not increase the width of the bearing. Optimize the 1) Install cover cover control oil flow by installing cover to avoid oil overflow to the bearing face, can make the bearing internal lubrication, fully solve the high-speed operation under the action of centrifugal force the problem of insufficient internal bearing lubrication. 2) Reduce friction by optimizing the groove diameter size and ball diameter to reduce the sliding between the ball and bearing ring. By improving the pocket hole surface lubricity and reduce the impact between the ball and cage to effectively avoid pocket holes on the surface of the wear and tear. Install weather cover add lubricating oil flow; By adjusting the clearance between the ball and cage pocket hole and the outer diameter of inner ring and maintain internal clearance, to reduce the impact and abrasion between the ball and cage. 3) Existing cage cage strength increased wall thickness, the increase of the stiffness in the cage, reduce the deformation of the cage under high-speed operation, to avoid cage pocket hole surface produces too much stress, leading to fracture. The latest development of bearing section below. Optimization design of bearing section optimization design of bearing, through temperature rise test, high speed endurance test can meet the demand of 30 000 r/min ultra-high speed of operation. Source: Motion & amp; Control translation: Zhang Haoyang proofreading: Xu Haili finishing: bearing magazine