摘要 |
A speed control system for a hydraulic elevator, in which, actuating a hydraulic pump by driving an induction motor in forward direction, oil is supplied to a hydraulic cylinder for upward travel of an elevator cage, while the hydraulic pump is driven to discharge the oil from the hydraulic cylinder by driving the induction in reverse direction for downward travel of the cage. The induction motor is a single two-speed motor, which is switched to drive the hydraulic pump in one of the two speeds as desired, thus subjecting the elevator cage to two-speed control.
|