The sudden interruption of the pneumatic hoist during operation may be caused by issues with the air source, brake system failure, abnormal control components, load or operation problems, mechanical blockage, and insufficient lubrication. The following is a specific analysis:

1、 Gas source issue

Compressed air is unstable

Reason: Fluctuations in gas supply pressure (such as below 6 bar or above 8 bar), leaks or blockages in gas supply pipelines.

Impact: The speed of the pneumatic motor decreases or stops, causing the hoist to stall.

Case: A factory experienced a sudden drop in air pressure due to a malfunction of the air compressor, causing the hook of the pneumatic hoist to suddenly fall, almost resulting in an accident.

Solution: Install a pressure gauge to monitor air pressure in real time, regularly check the sealing of the gas supply pipeline, and use a stabilizing valve to stabilize the gas source.

Compressed gas not air

Reason: Misuse of flammable gases such as oxygen, nitrogen, and liquefied petroleum gas.

Impact: May cause explosion or mechanical fatal damage.

Standard requirement: Dry and clean compressed air (ISO 8573-1 standard) must be used.

2、 Brake system malfunction

Brake failure

Reason: Brake spring aging, brake disc wear, or hydraulic system leakage.

Impact: Unable to lock the brake disc when out of breath, resulting in objects falling from a high altitude.

Case: A construction site experienced a brake spring fracture, causing the suspension hook to rapidly fall and smash ground equipment.

Solution: Check the brake clearance every month, replace aging springs, and regularly test the gas cut-off protection function.

Brake wheel rusted and died

Reason: Long term idle or humid environment leads to rusting of brake wheels and end caps.

Impact: When starting, the brake wheel cannot be disengaged, and the motor only makes a "hum" sound without rotating.

Solution: Apply anti rust oil before idle, and remove the brake wheel to clean the corroded surface when reusing.

3、 Abnormal control components

Start switch malfunction

Reason:

The power supply system is not delivering power;

Main/control circuit electrical damage, circuit disconnection or poor contact;

The motor terminal voltage is more than 10% lower than the rated value.

Impact: The hoist does not respond after pressing the start switch.

Case: A certain enterprise experienced poor contact due to aging wiring, resulting in frequent shutdowns of the pneumatic hoist. After maintenance, it was discovered that the control circuit was disconnected.

Solution:

Test the power supply with a test pen;

Repair the main/control circuit and replace damaged electrical appliances;

Measure the input voltage of the motor with a multimeter to ensure it meets the rated value.

Control handle malfunction

Reason: The valve body inside the handle is stuck, the speed control valve is not calibrated, or foreign objects have entered.

Impact: The up/down operation is not flexible or the speed is not adjustable.

Solution: Clean the handle weekly and use compressed air to blow away dust from the valve body; Calibrate the speed control valve quarterly.

4、 Load or operational issues

Overloaded operation

Reason: The load exceeds the rated value, resulting in insufficient starting torque of the motor.

Impact: The motor only makes a "humming" sound without rotating, and in severe cases, it may burn out the motor.

Case: A logistics warehouse was overloaded by 20%, and the pneumatic hoist motor overheated and caught fire, burning the control cabinet.

Solution: Install a torque limiter, monitor the load value in real-time, and prohibit exceeding 90% of the rated load.

Slant pulling and hanging

Reason: The hook was offset during operation, resulting in poor contact between the current collector and the sliding contact wire.

Impact: Electric hoist (similar to pneumatic hoist) suddenly stops, motor phase loss burns out.

Solution: Standardize operation, ensure that the hook is lifted vertically, and avoid lateral tension.

5、 Mechanical blockage and insufficient lubrication

Pneumatic motor blockage

Reason: Dust and impurities enter the interior of the motor.

Impact: The motor is stuck due to dry grinding, and the hoist cannot operate.

Solution: Regularly replace or clean the air filter to keep the air source clean.

Insufficient lubrication

Reason: The sprocket, bearings, and other parts were not lubricated in a timely manner.

Impact: Increased friction leads to inflexibility or jamming of movement.

Case: A steel plant experienced pitting corrosion on the tooth surface due to the lack of lubrication of the sprocket, resulting in an increase of 20000 yuan in maintenance costs.

Solution: Add lubricating grease to the sprocket and drum every week, and choose wear-resistant and high-temperature resistant models.

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