| 摘要 |
In a vertical machining center, a spindle-drive sleeve (41) is axially immovable in the machine frame, but rotates about its longitudinal axis to rotate a spindle (19) mounted in the sleeve for rotation by the sleeve while axially slidable independent of the sleeve. A linear drive, non-rotating ball screw (61) connected to the upper end of the spindle is driven axially by a rotationally powered, axially anchored ball nut (82) to advance and retract the spindle in the sleeve. A drawbar coupling system (121, 123, 136) extends inside the spindle from the top to the bottom to connect any one of various toolholders in an index disk (21) which is rotatable for positioning toolholders sequentially in line with the spindle axis. A pneumatically actuated drawbar operatior shaft extends inside and coaxially with the ball screw from the top to the bottom. |
