Analysis of lock nut loosening in a forklift drive axle

摘要

The present study investigates the cause of the loosening of the lock nut in a forklift drive axle. Structural analysis of the wheel shaft assembly revealed that the slippage on the contact surface of the lock nut was considerable, especially when the preloads on the bearing set were lacking. Macroscopic observation of the worn out contact surface revealed that circular scratches were formed whose radii were nearly the same as the slippage distance in the structural analysis results. Experimental simulation of the loosening of the lock nut was successfully carried out.