The protection and inspection methods for hydraulic winches cover five core areas: mechanical structure, hydraulic system, electrical system, safety devices, and operating standards. The specific methods are as follows:

1、 Mechanical structure protection and inspection

Brakes and clutches

Flexibility of action: Regularly check whether the brake can respond quickly, and replace the brake band immediately if the wear exceeds 8mm.

Gap adjustment: When the gap between the disc brake exceeds 2mm or the tension of the brake shoe is insufficient, it needs to be adjusted to the standard range to ensure that the braking force meets the standard (50.5MPa) during emergency braking.

Clutch free travel: The pedal free travel should be controlled between 12-14mm to avoid clutch failure due to excessive travel.

Wire rope and pulley

Wire breakage and deformation: Check the steel wire rope every shift. If the wire breakage within one twist is ≥ 10% or there is severe corrosion or distortion, it needs to be replaced immediately.

Flexibility of pulley rotation: Verify the bearing capacity of the pulley system through load testing to ensure no jamming or abnormal noise.

Transmission components

Gear meshing: Regularly inspect the gearbox gears, and repair or replace them if there is uneven tooth clearance, tooth cracking or peeling.

Bearing vibration: Monitor the vibration value of the main transmission device bearings. If it exceeds the standard, replace the bearings or adjust the assembly.

2、 Hydraulic system protection and inspection

Oil management

Regular replacement: Replace the hydraulic oil every 500 hours of operation or once a year to prevent system failure caused by oil quality deterioration.

Oil temperature control: Ensure that the oil temperature is within the range of 20-50 ℃. If the oil temperature is too high, it will accelerate the aging of the seals, while if it is too low, it will affect the lubrication effect.

Oil level check: Check the oil level in the fuel tank daily. If the oil level is below the red line, it should be refilled in a timely manner to avoid cavitation caused by suction.

Pipeline and sealing

Leakage inspection: Check hydraulic pipelines and joints weekly, and tighten or replace seals if leaks are found.

Filter cleaning: Clean the oil tank and filter monthly to prevent solid particles from entering the system, causing valve group jamming or motor wear.

Pressure and Flow

Pressure gauge calibration: Regularly calibrate the pressure gauge to ensure accurate readings, and check the overflow valve or pump station when the pressure is abnormal.

Flow testing: The flow rate of the system is detected by a flow meter. If the flow rate is insufficient, the pump station or pipeline should be checked for blockage.

3、 Electrical system protection and inspection

Motor and controller

Insulation resistance: Measure the insulation resistance of the motor every month, and if the value is lower than the standard, dry it or replace the motor.

Grounding inspection: Ensure that the motor is well grounded with a grounding resistance of ≤ 4 Ω to prevent safety accidents caused by leakage.

Controller contacts: Check the burn damage of the main controller and electromagnetic contactor contacts. If the burn damage exceeds the limit, it needs to be repaired or replaced.

protective device

Overload and undervoltage: Verify the action values of overload protection devices (such as thermal relays) and undervoltage protection devices (such as voltage relays) to ensure automatic shutdown in case of current overload or low voltage.

Speed limit and deceleration: Test speed limit protection devices (such as centrifugal speed limiters) and deceleration function protection devices (such as frequency converter deceleration curves) to ensure accurate speed control.

Console inspection

Instrument accuracy: Check the readings of pressure gauges, ammeters, and other instruments on the control panel, and calibrate or replace them if the error exceeds the limit.

Button sensitivity: Test the switch of each operation button to ensure flexible action and no jamming. The emergency stop button should respond within 0.5 seconds.

4、 Protection and Inspection of Safety Devices

Eight major protective devices

Anti roll protection: detected by the depth indicator screw nut transmission, adjustment or replacement is required when the action is not sensitive.

Overspeed protection: Test centrifugal or magneto electric overspeed protection devices, and trigger emergency braking when the speed exceeds 10%.

Loose rope protection: Check the reliability of the loose rope switch action, and stop the machine within 2 seconds when the steel wire rope is loose.

Brake gap protection: Monitor the gap between the brake shoe and the brake wheel, and adjust the brake when the gap exceeds the standard.

interlocking system 

Door lock interlock: Verify the interlocking function between the machine room door lock and the main power supply. The winch cannot be started when the door is not closed.

Foot brake interlock: Test the foot emergency brake switch. When pressed, immediately cut off the main power and issue an alarm signal.

5、 Operating standards and inspection

No load trial operation

Start sequence: Start the auxiliary pump first, observe the oil replenishment pressure (0.8-1MPa), servo pressure (2.5MPa), and operating pressure (3MPa), confirm that there are no abnormalities, and then start the main pump.

Braking test: Test the braking pressure during no-load operation, and accelerate at a constant speed after reaching 5 ± 0.5MPa, avoiding sudden pulling and pushing.

Load operation monitoring

Parameter recording: Record current, voltage, oil pressure and other data for each shift. The reading on the ammeter should not exceed 68A when unloaded, and should not exceed the rated current during normal operation.

Exception handling: In case of abnormal situations such as rolling or overspeed, immediately use the foot switch or the main power stop button and investigate the cause.

Shutdown and maintenance

Normal shutdown: Hold the operating lever and slowly pull it to the middle position. After the braking system is activated, stop the main and auxiliary oil pumps.

Long term parking: When not in use for a long time, store the machine in a dry and ventilated place, apply rust proof oil to metal parts to prevent corrosion.

The main equipment produced by Hebei Makita: stage electric hoist, electric chian hoist, wire rope electric hoist，Hand chain hoist, lever hoist, pneumatic hoist and other lifting equipment