An elevator rope for high-rise building is forcibly excited by the displacement of the building caused by earthquakes and wind forces. In high-rise building, the elevator rope may resonate with the natural frequency of the building; hence, effective solution to reduce the rope displacement is demanded. In this paper, a method to suppress the transverse vibration of elevator rope using vertical vibration of counterweight is proposed. Rope lateral vibration is controlled by fluctuating rope tension using up-and-down motion of this counterweight. Finite difference analyses of rope vibration with counterweight are performed to verify the validity of this method. Experiments involving forced vibration of a rope whose length is constant are performed. In the experiments, guide bar is used to suppress the rotation motion of the rope. As a result, rope sway is reduced to about 1/2, when the cage is stopped. The optimal natural frequency of vertical vibration of counterweight is about 2 times of the natural frequency of the rope lateral vibration.

No abstract