Friction and wear failure mechanism analysis of QT600-3 ductile iron elevator traction sheave

Abstract

Elevators play a significant role in the daily lives. The traction sheave is the primary component responsible for bearing the force within an elevator system. The elevator car is propelled through the friction generated between the steel wire rope and the groove of the traction sheave. Over time, Prolonged operation results in significant wear between the traction sheave and the steel wire rope. This paper adopts a multi-methodological approach, utilizing macro and micro morphology analysis, equivalent friction coefficient analysis, and cloth hardness testing to elucidate the underlying causes of traction sheave failure. Groove C exhibits the most severe wear, with a maximum wear depth exceeding that of the other grooves by 2.4 mm. Measurements indicate that the $\beta$angle of groove C is 101°and the $\gamma$angle is 11°, which are significantly below the specified requirements. Additionally, measurements of grooves A, B, D, and E reveal that their$\gamma$angles are all less than 35°, thus failing to meet the specified standards. The average hardness of the material is 208.9 HBW. The friction coefficient of groove C under loading and braking conditions is 0.23, while the friction coefficient under holding conditions is 2.11. The findings reveal that wear is the predominant factor contributing to the deterioration of the traction wheel. The surface of the worn rope groove is characterized by numerous abrasive particles, pits, cracks, scratches, and other forms of surface damage. The deterioration of surface quality and the emergence of uneven surface roughness after wear further exacerbate the progression of uneven wear. The hardness of the base material does not meet established standards. Finally, to extend the service life of the traction sheaves and prevent accidents, we propose several improvement recommendations.