| 摘要 |
<p>A ball screw (26) includes a screw shaft (29), a nut (25) surrounding the screw shaft (29), andaplurality of balls (30) engageable with the screw shaft (29) and the nut (25) . Theball screw (26) includes first and second raceways (S, K). The first raceway (S) is defined between the screw shaft (29) and the nut (25), and has first and second ends (S1, S2). The second raceway (K) has first and second ends (K1, K2) respectively connected to the first and second ends (S1, S2) of the first raceway (S) for circulating the balls (30) into the first raceway (S). The second raceway (K) accommodates an odd number of balls (30) at the maximum at a time.</p> |
