I. What is Rope Adjustment?
Rope adjustment refers to the operation of adjusting the effective length of the hoist wire rope to ensure that the conveyances (cage or skip) can accurately stop at the shaft collar and each level. Its essence is to change the relative position between the drum and the main shaft (for drum winders) or to balance the tension of each wire rope (for friction hoists), thereby restoring the positioning accuracy of the hoisting system.
II. Why is regular rope adjustment necessary?
During long-term operation, the wire rope is subjected to continuous tension and undergoes elastic elongation, causing the conveyance stopping position to gradually shift. If rope adjustment is not carried out in time, the following problems may occur: the conveyance cannot accurately align for loading or unloading, hoisting efficiency decreases, uneven wire rope tension accelerates wear, and in severe cases, may even cause overwind or cage fall accidents. Regular rope adjustment is a necessary measure to ensure the safe and precise operation of the hoisting system.
III. Which equipment requires rope adjustment?
Almost all drum winders require rope adjustment:
l Double-drum single-rope winder: Adjusts the movable drum through the clutch to correct the stopping positions of the two conveyances.
l Single-drum winder: Adjusts single-side rope length through the rope adjustment mechanism.
l Multi-rope friction hoist:Balances the tension of each wire rope.
IV. Conditions that trigger rope adjustment
Rope adjustment is primarily used to correct the length difference between the two drum wire ropes, ensuring that both conveyances (such as cages) can accurately stop at the designated positions. The following situations typically trigger rope adjustment:
1. Changing hoisting level:When the mine needs to switch from the current level to another level for hoisting, the stopping positions of both conveyances change, and the rope length must be readjusted.
2. Natural elongation of wire rope: Under long-term heavy loads, the wire rope undergoes elastic elongation, causing the conveyance stopping position to gradually shift, requiring periodic correction.
3. Replacing wire rope: The length and elasticity of a new rope differ from the old one, so rope adjustment must be performed after replacement, and adjustments may be frequent during this period.
4. Handling accidents or emergencies: For example, if a conveyance is in an abnormal position in the shaft, rope adjustment may be needed to restore normal operation.
5. Regular maintenance: To ensure long-term stable operation of the equipment, rope adjustment is also part of periodic maintenance.
V. Rope adjustment procedures
Double-drum single-rope winder (2JK series):
(1) Rope adjustment must be led by maintenance personnel, assisted by the operator, with a safety supervisor present.
(2) Lock the other drum before adjustment. The conveyances must be positioned at the shaft collar or shaft bottom stopping points and must be empty.
(3) Place the clutch handle in the "disengaged" position and operate the rope adjustment switch.
(4) After rope adjustment is completed, re-engage the clutch and confirm that the locking device is properly in place. Conduct test runs (one empty load and one full load) to confirm tension balance before resuming normal operation.
Single-drum winder:
l Adjust single-side rope length through the rope adjustment mechanism.
l The operation is relatively simple, but the conveyance must still be empty.
Multi-rope friction hoist:
l Achieve tension balance by adjusting the hydraulic locking devices or changing the diameter of the deflection sheave.
l The tension difference between each wire rope must be kept within the specified range.
VI. Key safety precautions for rope adjustment
1. Conveyances must be empty: During rope adjustment, the braking torque changes. Both conveyances must be completely unloaded. Carrying personnel or materials is strictly prohibited.
2. Secure first, then disengage: Before opening the clutch, the movable drum must be securely locked using mechanical means (such as a braking device or chain block). The clutch can only be opened after the drum is completely secured.
3. Designated personnel for command and coordination: Rope adjustment must be led by maintenance personnel, assisted by the operator, with a designated safety supervisor.
4. Strictly prohibit improper operations: Hoisting operations are strictly prohibited during rope adjustment. Emergency braking must not be used as a substitute for normal stopping except in emergencies. The clutch must not be operated outside of rope adjustment procedures.
5. Test run after rope adjustment: After rope adjustment is completed, one empty load test run and one full load test run must be conducted to confirm tension balance before resuming normal operation.
Hebi Wanfeng Mining Machinery Manufacturing Co., Ltd. produces the 2JK series double-drum single-rope winders, featuring a high-strength modular design with reliable movable drum clutch and locking devices to ensure safe and efficient rope adjustment. For more product information or technical support, please contact us.
Wynne Wang
Hebi Wanfeng Mining Machinery Manufacturing Co., Ltd.
Tel:13839216889
Email:wynne@wf-cn.com
Website:www.mininghoist.com
