Tension fluctuation analysis of main ropes for 2:1 roping elevator by variations in groove depth of traction machine

As buildings have become taller in recent years, elevators, which provide vertical transportation within buildings, are becoming larger in capacity and tend to have longer lifting strokes. Generally, the rope-type elevator has multiple main ropes. As the cage capacity also increases and the rope length increases, the number of ropes increases to obtain the necessary strength. If the groove depths of the traction machine are not uniform, the tension is different for each rope of the main ropes, and the rope with a high load will deteriorate faster. In this paper, a tension fluctuation model for the main rope for 2:1 roping elevator where the traction machine has various groove depths is proposed. It was difficult to create a dynamic model because elevator system has many components, the properties of rope depend on the car position, and it needs to consider the slip for each rope. So, the static model is adopted. The validity of the proposed model is confirmed by comparing the rope tensions at the hitch with experimental results. Using the constructed model, the tension changes of the main ropes on the car side and counterweight side can be calculated, and the dimensional accuracy of the groove depth is proposed to keep the tension variation on each rope within an acceptable range.