Patent ID: 8011478
Filing Date: 2011-09-06
Classification: B66B

Abstract:
1. A vibration damping system for an elevator, comprising: a damping device that is provided between a cab and a car frame for supporting the cab and whose damping coefficient can be changed; a vibration sensor provided on the car frame; an actuator mounted on the car frame for controlling force that presses against a guide rail; a guide roller that rotatably moves along the guide rail provided in a hoistway; a speed detection means for detecting the traveling speed of a reference elevator car; and a calculation unit for receiving the traveling speed detected by the speed detection means and a vibration detected by the vibration sensor, calculating control signals for the damping device and the actuator, and outputting the control signals to the damping device and the actuator, the calculation unit controlling the actuator so as to suppress a vibration detected by the vibration sensor, the calculation unit controlling the damping device in such a way that, in the case where the traveling speed exceeds a predetermined value, the damping coefficient of the damping device is rendered larger than that in the case where the traveling speed is the same as or smaller than the predetermined value, the predetermined value being larger than the traveling speed corresponding to the frequency of a first-mode inherent vibration in which an antinode of the vibration falls within the space between the car frame and the guide rail, and the predetermined value being smaller than the traveling speed corresponding to the frequency of a second-mode inherent vibration in which an antinode of the vibration falls within the space between the car frame and the cab.