Ayaka FUJII’s research while affiliated with Mitsubishi Electric Corporation and other places

Elevators run vertically by suspension ropes, therefore each rope has to be adjusted correctly to fulfill each tension balance. That contributes to establish a long life against elevator ropes. If a groove wear of the traction sheave causes difference against other grooves, the difference induces rope tension fluctuation while changing the car position. Conventional elevator models to evaluate the rope tension have not considered the detailed winding behavior of the rope on the sheave. As the winding amount of the rope contains the rope deformation, the deformation should be considered to evaluate the rope length and the rope tension in an elevator tension model. This paper shows a simple elevator model with a single spring model against the rope. The derived model can not only calculate the appropriate winding amount against the rope spring model, but also get a faster solution even though the elevator system has a complicated roping configuration. The proposed simulation model is validated by experiments.

Elevators run vertically by suspension ropes, therefore each rope has to be adjusted correctly to fulfill each tension balance. That contributes to establish a long life against elevator ropes. If a groove wear of the traction sheave causes difference against other grooves, the difference induces rope tension fluctuation while changing the car position. Conventional elevator models to evaluate the rope tension have not considered the detailed winding behavior of the rope on the sheave. As the winding amount of the rope contains the rope deformation, the deformation should be considered to evaluate the rope length and the rope tension in an elevator tension model. This paper shows a simple elevator model with a single spring model against the rope. The derived model can not only calculate the appropriate winding amount against the rope spring model, but also get a faster solution even though the elevator system has a complicated roping configuration. The proposed simulation model is validated by experiments.

A 2:1 roping elevator system shows a complicated vibration behavior under a disturbance from the traction motor, because the disturbance does not only cause a vertical vibration to the elevator, but also induces a rotational vibration against a suspension sheave of the elevator. As the rotational vibration affects the vertical vibration of the elevator car, an analytical model of the elevator system is introduced to evaluate the relation between the vertical vibration and the rotational one. With the derived analytical model, an eigen mode analysis and a transient time analysis show the mechanism of the rotational vibration under several conditions, such as a car position and a building height.

Traction elevators are suspended by multiple ropes. Uneven sheave wears affect the rope tension during the elevator operation. If the tension condition reaches to the critical traction ratio, a rope slip occurs. As the rope slip also affects the rope tension, a tension calculation with rope slip is necessary to evaluate the relation between the groove wear and the rope tension. In this paper, a tension evaluation model is derived by including the rope slip behavior and then the influence of the rope tension due to the groove wear is evaluated.

The 2:1 roping elevator system shows complicated vibration behavior under a disturbance from the traction machine, because the disturbance does not only cause the vertical vibration to the car, but also induces the rotational vibration against the car's suspension sheave. To evaluate the relation between the sheave's rotational vibration and the car vertical vibration, an analytical model is introduced for the 2:1 roping elevator system. The eigen mode analysis indicates that the amplitude of rotational vibration mode against the car suspension sheave, which induces the car vertical vibration, increases more when the sheave is closer to the traction machine at the top floor. The model also reveals that the higher ordered mode of the sheave's rotational vibration in high-rise buildings interferes with the target rotational vibration mode, so that the mode coupling contributes to reducing the car vibration.