What impact does preloading have on the service life of ball splines

Proper preloading to extend service life
Uniform force: It can make the force on the ball in the raceway more uniform, avoiding excessive local force. During the transmission process, each ball can effectively share the load, reduce the fatigue wear of individual balls, and thus extend the overall service life of the ball spline. For example, in the joint transmission of industrial robots, appropriately preloaded ball splines can evenly load each ball and reduce failures caused by excessive wear of individual balls.
Improve rigidity: Enhance the rigidity of the ball spline, making it deform less when subjected to loads. Smaller deformation helps to maintain good contact between the ball and the raceway, reduce additional friction and wear caused by deformation, and thus extend the service life. For example, in the feed system of CNC machine tools, high rigidity ball splines can better resist deformation, maintain accuracy and wear resistance during frequent feed movements.
Reduce vibration and impact: Helps reduce the impact of vibration and impact on ball splines. During the operation of the equipment, vibration and impact may cause instantaneous high stress and collision between the ball and the raceway, and appropriate preloading can buffer these external forces and reduce their damage to the ball spline. In conveyor equipment on automated production lines, pre pressing appropriate ball splines can effectively resist the vibration and impact generated during material transportation.
Improper preloading shortens the service life
Excessive preloading: will cause excessive contact stress between the ball and the raceway, increasing friction and wear. Excessive wear can lead to premature fatigue and peeling of the surface materials of the ball and raceway, shortening the service life of the ball spline. For example, if excessive preload is applied in the transmission of precision instruments under light loads, it will intensify the wear of ball splines and reduce accuracy.
Insufficient preload: unable to effectively eliminate the gap between the ball and the raceway, prone to ball movement and impact during transmission, resulting in local wear and fatigue damage. In addition, the presence of gaps may also reduce the transmission accuracy of ball splines, affecting the normal operation of the equipment and indirectly affecting its service life. For example, in semiconductor manufacturing equipment that requires high-precision positioning, insufficient preloading can result in insufficient positioning accuracy of ball splines, and frequent small impacts can accelerate component damage.