Effect of Surface Periodic Structures on Coefficient of Rolling Friction of Thrust Ball Bearing

In order to investigate effects of texture on coefficient of rolling friction, grating-like periodic structures of submicron size were formed on raceway grooves of thrust ball bearing. The periodic structures were self-organizingly produced by using linearly polarized femtosecond laser pulses with low fluence. The effects of the periodic structures on coefficient of rolling friction were investigated by torque test equipment. It was shown that radial periodic structures reduce coefficient of rolling friction. In the case of full width pattern, average decreasing rate of friction was about 10 percent. The decreasing rate was boosted by remaining unprocessed area on the centerline of the raceway groove. The most effective unprocessed width was about the same as Hertzian contact width between the raceway groove and rolling elements. The effective pattern achieved 36 percent decrease in the rolling friction at the rotational speed of 3.9m/s.