Patent ID: 7506725
Filing Date: 2009-03-24
Classification: B66B

Abstract:
1. A control structure of ball screw type elevator comprising: a ball screw connected to an elevator car; an electric motor for rotating the ball screw and driving the elevator car to move upward and downward; a motion control unit for providing electric energy for the electric motor and controlling motor parameter of the electric motor; a current detecting unit for detecting current value of the electric motor, and for transmitting detected current value to a logic control unit; and the logic control unit for analyzing the current value detected by the current detecting unit and comparing the detected current value with predetermined point's normal value, when the detected current value is out of normal range, it will be treated as abnormal condition; wherein the abnormal condition treatment includes slowing down the speed of the ball screw, so as to prevent abnormal temperature increase of the ball screw.