摘要 |
This invention provides a hydraulic elevator installation in which a variable hydraulic pump supplies pressure fluid to a hydraulic actuator connected to an elevator cage. The hydraulic pump functions to operate as a hydraulic motor with the pressure fluid discharged from the hydraulic actuator when the elevator is descending. The hydraulic pump is driven by an induction motor. The induction motor begins to function as an induction generator, recovering potential energy on the high speed rotation of the hydraulic motor while it is generating electricity. When the hydraulic pump has started its function as the hydraulic motor.
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