If the running pneumatic hoist fails to work, it needs to be checked one by one from the four core modules of the air source system, power components, control components, and transmission structure. Combined with the fault symptoms and professional tools, the problem can be quickly located. The following are specific solutions:

1、 Troubleshooting of gas source system

Insufficient gas source pressure

Phenomenon: The gourd starts weakly or does not move at all, accompanied by a buzzing sound from the motor.

Reason: The output pressure of the air compressor is lower than 0.4MPa (standard working pressure 0.4-0.6MPa), or there is an air circuit leak.

Solution:

Use a pressure gauge to check the outlet pressure of the air compressor. If it is lower than 0.4MPa, adjust the pressure valve of the air compressor or repair the air compressor.

Check if there is any air leakage at the connections of the air circuit (such as the trachea and joints), and replace the aging trachea or sealing ring.

Case: A pneumatic hoist in a chemical plant experienced insufficient pressure due to a ruptured air pipe. After replacing the air pipe, it resumed operation.

Gas impurity pollution

Phenomenon: Motor operation is stuck, the sound is muffled, and even completely stopped.

Reason: Compressed air contains oil, moisture, or dust, which can clog the muffler or enter the interior of the motor.

Solution:

Remove the muffler and blow it clean with compressed air. If the blockage is severe, it needs to be replaced.

Check the air filter. If the filter element turns black or accumulates water, replace the filter element and drain the condensate.

Preventive measures: Install a three-stage filtration device (oil-water separator+precision filter+activated carbon filter) at the inlet of the gas source.

2、 Troubleshooting of power components

Motor blade stuck

Phenomenon: The motor does not respond after manipulating the joystick, or the sound is abnormal when rotating.

Reason: Dry grinding caused by blade wear, deformation, or dry lubricating oil.

Solution:

Disassemble the motor and check if the blades are cracked or worn. If damaged, replace the blades (single acting blade motors need to be replaced as a set).

Clean the inside of the motor, apply specialized pneumatic lubricating oil (such as ISO VG32 pneumatic oil), reassemble and manually test run.

Case: A pneumatic hoist in a certain automobile factory cannot start due to blade jamming. After replacing the blades and adding lubricating oil, it was restored.

Brake system malfunction

Phenomenon: The gourd stalls (heavy objects suddenly fall) or the brake wheel cannot be released when starting.

Reason: Brake pad wear, spring failure, or rust on brake wheel and end cap.

Solution:

Remove the brake wheel and check the thickness of the brake pads. If it is less than 2mm, it needs to be replaced.

Clean the corroded parts of the brake wheel and end cover, apply anti rust grease, and readjust the brake clearance (0.5-1mm).

Attention: The brake system needs regular maintenance and inspection every 3 months.

3、 Control component fault repair

Start switch malfunction

Phenomenon: The motor does not respond after pressing the switch, or poor contact causes intermittent operation.

Reason: The trigger, pin, or steel ball (air valve) inside the switch is worn, or the circuit contact is poor.

Solution:

Disassemble the switch, check if the trigger is deformed, if the steel ball is detached, and replace damaged parts.

Use a multimeter to check if the switch circuit is open, repair or replace the wiring terminals.

Case: The pneumatic hoist in a logistics center cannot be started due to the detachment of the switch steel ball. After replacing the steel ball, it was restored.

Speed control valve malfunction

Phenomenon: The speed of the gourd cannot be adjusted, or the directional valve controls the series movement.

Reason: The positioning steel ball of the speed control valve is worn, the ventilation valve is broken, or the gear switch is damaged.

Solution:

Disassemble the speed control valve, replace the worn steel ball or ventilation valve, and adjust the position of the gear switch.

Use a pneumatic tester to test the output pressure of the speed control valve to ensure compliance with the standard (0.2-0.5MPa).

4、 Solution to transmission structure faults

Gear/bearing wear

Phenomenon: The gourd makes abnormal noises during operation, or the transmission is weak.

Reason: Parts such as planetary gears and bearings wear out after long-term use.

Solution:

Disassemble the reducer, check whether the gear teeth are corroded, whether the bearings are stuck in rolling, and replace damaged parts.

Apply high-temperature grease (such as NLGI No.2), reassemble and test the transmission efficiency.

Case: A pneumatic hoist in a steel plant made abnormal noise due to gear wear. After replacing the gear, it resumed smooth operation.

Chain/hook stuck

Phenomenon: The chain gets stuck when lifting or lowering heavy objects, or the hook cannot rotate.

Reason: Chain entanglement, rust on the hook bearing, or wear on the sprocket.

Solution:

Organize the chain to ensure orderly winding and avoid crossing.

Disassemble the hook, clean the bearing and add lubricating oil. If the bearing is damaged, it needs to be replaced.

Check if the sprocket teeth are intact, and replace the sprocket if it is severely worn.

5、 Systematic maintenance suggestions

Daily checklist

Gas source pressure (0.4-0.6MPa), gas cleanliness (no oil/moisture), and gas pipe connection (no leakage).

Motor sound (no abnormal friction sound), brake system (reliable braking), chain/hook (no jamming).

Switch/speed control valve (flexible operation), instrument display (normal pressure/speed).

Regular maintenance cycle

Daily: Clean the surface dust and check the tracheal connection.

Weekly: Drain condensate and clean air filters.

Monthly: Check the thickness of brake pads and lubricate the chains/hooks.

Quarterly: Disassemble the motor for cleaning, replace lubricating oil, and inspect gear/bearing wear.

Emergency response process

Step 1: Immediately stop the machine, cut off the gas source, and prevent secondary faults.

Step 2: Based on the fault symptoms (such as no movement, abnormal noise, stall), preliminarily determine the cause.

Step 3: Use professional tools (pressure gauge, multimeter, endoscope) to locate the fault point.

Step 4: Replace damaged parts or clean blocked areas, and resume operation after testing.

Step 5: Record the fault symptoms, handling measures, and replacement parts, and improve the maintenance file.

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