磁気ディスクスピンドルモータ用玉軸受の回転非同期振れの低減 : 第3報, 回転非同期振れに及ぼす潤滑の影響

抄録

In this paper, we experimentally analyzed the influence of lubrication for Non Repeatable Runout(NRRO)of a ball bearing, and proposed the best design for a ball bearing used in HDD spindle motors with regard to NRRO and acoustic endurance. The results are summarized as follows : (1)In grease lubrication, NRRO fluctuated in accordance with torque fluctuation caused by grease splush. On the other hand, NRRO fluctuation was not observed in oil lubrication. (2)When ceramic balls were used, the acoustic increase was very small even when bearing was lubricated with minute amount of oil. (3)It was thought that the best design for a ball bearing used in HDD spindle motors was that the number of balls was 12, the material of balls was ceramic and the lubrication was minute amount of oil.