Multi-rope mine hoist winder sheaves are critical components of the hoisting system, and their proper maintenance directly affects operational safety and efficiency. The sheave device bears significant loads, especially in large-scale installations like the JKMD-6.2×4 type, where individual movable or fixed wheels can experience forces up to 821 kN. Improper operation or structural issues may cause abnormal noises, bolt shear failures, or other malfunctions, posing safety risks that must be addressed promptly.
1. Sheave Device Structure
The sheave system in a multi-rope hoist winder is installed on the headframe and serves to guide the steel ropes and adjust the hoist drum center distance according to operational requirements. Each sheave assembly consists of four wheels: one fixed wheel keyed to the sheave shaft and three movable wheels. The movable wheels rotate freely on the shaft with a slight axial gap (0.2–0.5 mm) to accommodate minor differences in rope velocity. Proper assembly ensures smooth rotation and balanced load distribution across all wheels.
2. Causes of Sheave Noise
During operation, friction between the bearing pads and the sheave shaft is the main source of stress. Adequate lubrication minimizes the shear force on the connecting bolts, while poor lubrication increases stress, potentially leading to bolt failure. Abnormal movement of the hoist container or misalignment of the drum path can create axial forces on the movable wheels, generating additional friction between wheels, fixed sheaves, and collars.
3. Solutions
Machining keyways on the movable wheel hubs and bearing pads and installing positioning keys secured by bolts can absorb tangential forces between the wheel hub and bearing pad. This prevents shear failure of the bolts and ensures stable operation of the trolley wire hoist sheave assembly.
4. Additional Measures
During installation, ensure proper alignment of the sheave, drum, and hoist axes to prevent rope misalignment.
Regularly inspect rope tension and adjust for balanced loads to reduce stress on the sheave assembly.
Maintain proper lubrication by periodically checking oiling systems, cleaning oil passages, and topping up lubricants to keep the sheave system in optimal condition.
In conclusion, the maintenance and alignment of the multi-rope mine hoist winder sheave, combined with positioning key installation, proper lubrication, and regular inspections, are essential to prevent malfunctions and extend service life. Implementing these measures ensures the long-term reliability and safety of the multi-rope mine hoist winder in mining operations.
