| 摘要 |
<p>The mechanism converts a rotary movement into a sliding reciprocating one. An electric motor has a hollow shaft through which a screwed spindle passes to form a track for a set of balls. At one or both ends the hollow shaft rotates with a nut enclosing the screwed spindle, and which acts on the spindle via balls running in the track. There can be a nut at each shaft end, screwing into it by externally threaded end portions, the threads being of opposite pitch. Where there is only one nut, there can be a guide for the spindle at the opposite end to the nut.</p> |
