摘要 |
A tool driving unit for moving a tool in axial direction thereof and for rotating the tool about its axis. The tool driving unit comprises a spindle supported in the housing frame, a tool chuck mounted on the one end portion of the spindle for holding the tool, a first motor including a first hollow rotor and for rotating the spindle, a second motor including a second hollow rotor and for moving the spindle in the axial direction, means for transmitting a rotation of the first hollow rotor to the spindle, and means for converting a rotation of the second hollow rotor into axial movement of the spindle. The first rotor is rotated to rotate the spindle which corotatably engages the first rotor through the transmitting means. The second rotor is rotated, and the spindle is smoothly moved axially forwardly or rearwardly by the converting means which converts rotary motion of the second rotor to axial motion of the spindle. |