| 摘要 |
<p>A drive and feed unit for a transfer machine comprises a spindle which may be rotated by an electric motor and advanced by a cam mechanism. The cam mechanism is fed transverse to the axis of rotation of the spindle by a hydraulic motor which is controlled to feed at a constant rate. A follower attached to the spindle transmits translation from the cam mechanism to the spindle. The cam mechanism includes a pair of cams that straddle the spindle and are of identical shape. The spindle is supported in the housing by a bearing assembly which includes a sleeve rotatable relative to the housing but held against relative axial movement. The spindle is slidably supported by the sleeve. A tapping unit may be incorporated on the spindle and includes a sleeve attached to the spindle. The sleeve has an external thread of the same pitch as the thread to be tapped which engages with a nut mounted on the sleeve. The nut moves with the cam follower and is prevented from rotating so that rotation of the spindle causes axial displacement of the spindle relative to the housing.</p> |
