What are the reasons for uneven groove depths in the friction lining of a hoist?
2 Answers
The uneven groove depths in the friction lining of a hoist may be caused by insufficient tension between the wire rope and the pulley groove leading to sliding friction (common phenomenon), inflexible or obstructed rotation of the pulley bearing causing the wire rope to move while the pulley moves intermittently, or loose pulley bearings. Technical requirements for friction lining in friction hoists: The allowable coefficient of friction should not be lower than the required value for the hoisting system using this friction lining, but it should not be less than 0.20 at minimum. The friction lining should have good thermal stability. Classification of friction lining: According to the wire rope groove, friction lining can be divided into single-groove and double-groove types. Based on the coefficient of friction, it can be classified into ordinary lining and high-friction lining.
As an experienced maintenance worker who deals with hoists every day, I've seen many cases of uneven groove depths in friction linings. The main reason is still uneven force distribution: the drum was installed at an angle during assembly, the rope groove angle of the drum was improperly designed, or the lining itself had deviations in its grooves. This causes the wire rope to bear uneven force on the drum, with some areas being particularly tight, resulting in deeper grooves compared to adjacent ones—similar to how car brake discs develop grooves. Additionally, the quality of the lining should be noted; if there are significant differences in hardness and wear resistance, the shallower areas will naturally wear more slowly. Such issues should be addressed promptly upon discovery; otherwise, the lifespan of the entire wire rope will be affected.
