| 摘要 |
A spindle unit comprises a rotatable shaft (1) in which annular grooves (1a) of semicircular cross section are formed to receive balls (2) of upper and lower ball bearings. The outer races (3) of the ball bearings are defined by cylindrical sleeves with tapered surfaces which engage against the balls. The balls are spaced by annular retainers (2A) of metal or synthetic resin. Each retainer may have an axial split to facilitate assembly. <IMAGE> |
