| 摘要 |
A milling machine includes a C-shaped frame, tool support member movable in a vertical direction, a saddle member movable in a transverse direction, a work table movable in a longitudinal direction, a tool drive unit and two oppositely positioned and removable bearing ways associated with each direction of travel. For the vertical axis the bearing ways are between the C-shaped frame and the tool support member. The tool drive unit includes a hollow tool spindle and a drive motor with a vertically extending hollow output shaft which is rigidly and coaxially connected to the hollow tool spindle. Each vertical axis bearing way longitudinally extends in a vertical direction and includes an outer race portion attached to the C-shaped frame and a ball circulating track portion attached to the tool support member. Reciprocating relative motion between the tool support member and the C-shaped frame occurs at the two bearing way locations and the drive motor for the tool moves with the hollow tool spindle in a vertical direction. |
