| 摘要 |
<p>A thrust ball bearing (276) comprises a plurality of balls (266) held in a holder portion (268), an upper race (264) and a lower race (270) respectively disposed above and below the balls (266), and a raceway groove (271) disposed at a position of the lower race (270) where the balls (266) roll. A lubricant is supplied sufficiently by the raceway groove (271) to the surface of the balls (266) to thereby maintain satisfactory sliding of the thrust ball bearing (276) and improve reliability.</p> |
