| 摘要 |
<p>The device for controlling the spindle drive, comprises only one three-phase motor (60) for driving a spindle (50) of a machine tool and an electromagnetic relay (70) for selecting the delta or star connection of the windings (U,V,W) of the motor. When a heavy machining operation is to be carried out by rotating the spindle (50) at high speeds, the windings are connected in a delta form. When a contouring operation is to be carried out by rotating the spindle at a very low speed, (e.g 0.5 rpm), the windings are connected in a start form to produce a large torque. Compared with the conventional machining operation in which two motors were used, it is now possible to use only one motor.</p> |
