Drive control unit for hydraulic elevator
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United States of America Patent
Stats
-
Jan 25, 1994
Grant Date -
N/A
app pub date -
Nov 20, 1991
filing date -
Nov 20, 1990
priority date (Note) -
Expired
status (Latency Note)
Importance
Abstract
A drive control unit for a hydraulic elevator comprises: an inverter for variably driving the motor; a speed detector for detecting a rotating speed of the motor; a current detector for detecting a primary current of the motor; a speed control, unit for calculating a torque command value to the motor according to a deviation between the rotating speed detected by the speed detector and a speed command value; a torque control unit for controlling the inverter according to the rotating speed detected by the speed detector, the primary current detected by the current detector and the torque command value calculated by the speed control unit; a pump pressure detector for detecting the pump pressure of the hydraulic pump; a limiting means for limiting the torque command value output from the speed control unit when the pump pressure, detected by the pump pressure detector, decreases below a set value.
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