Controllable motor drive for four-quadrant operation

摘要

The invention relates to a controllable electric-motor drive for a four-quadrant operation, especially with a three-phase asynchronous motor. In order, in the case of such a drive, to obtain a characteristic comparable to a hydrostatic drive, a combination of drive components 1-4 is arranged between the drive shaft 5 of the motor M and the drive shaft 6 of the load L, which components can be selected using a control device ST, depending on a control command W and additional variables such as the rotational speed X2 of the load L, the loading X3 of the drive motor M and the direction of rotation X1. The drive shaft 5 of the motor M and the drive shaft 6 of the load L are coupled via an eddy-current coupling 1 having adjustable excitation or via a hydrodynamic coupling having adjustable degree of filling. A clutch 2 is arranged in parallel to the eddy-current coupling 1. As brakes, an eddy-current brake 3 having adjustable excitation or a hydrodynamic brake having adjustable degree of filling and a mechanical brake 4 engage on the drive shaft of the load L. Such a drive allows control of the rotational speed of the load L in all four quadrants at constant motor rotational speed, both synchronous running between the drive shaft 5 of the motor M and the drive shaft 6 of the load L and braking of the load L down to a standstill being possible. <IMAGE>