In response to the problem of emulsion lifting cranes (such as emulsion chain cranes) not working properly, a systematic investigation should be conducted based on their working principles (using emulsion as a power source, driving the chain up and down through motors, reduction mechanisms, braking systems, etc.). The specific solution is as follows:

1、 Troubleshooting of Power System Malfunctions

Abnormal supply of emulsion

Phenomenon: The crane has no movement or insufficient power.

Reason: Insufficient emulsion pressure, pipeline blockage or leakage.

Solution:

Check the pressure gauge of the emulsion pump station to ensure that the pressure is within the rated range (such as 0.6-3MPa for emulsion cranes used in coal mines).

Check whether the high-pressure rubber hose is damaged or blocked, clean or replace the pipeline.

Check the liquid level of the emulsion tank and promptly replenish the emulsion that meets the standards (such as an aqueous solution containing 3% -5% emulsion oil).

Motor failure

Phenomenon: Abnormal motor operation (such as overheating, abnormal noise) or complete failure to start.

Reason: Overload, bearing wear, insufficient brake clearance, or power supply issue.

Solution:

Check if the load exceeds the rated capacity (such as the rated load of emulsion chain hoist is usually 1-10 tons), and reduce the load.

Measure the temperature of the motor. If it overheats, stop the machine for cooling and check the lubrication of the bearings. If necessary, replace the bearings.

Adjust the brake clearance to the manufacturer's recommended value (such as 0.5-1mm) to avoid frictional heat generation.

Check if the power supply voltage is stable (such as three-phase voltage deviation not exceeding ± 10% of the rated value), repair the wiring or replace the fuse.

2、 Troubleshooting of the braking system

Brake failure

Phenomenon: The load drops or the position cannot be maintained.

Reason: Brake wear, hydraulic system leakage, or control valve malfunction.

Solution:

Check the thickness of the brake pads, and replace them if the wear exceeds 50%.

Check whether the brake hydraulic pipeline leaks, repair or replace the seals.

Test whether the control valve operates flexibly, clean the valve core or replace the faulty valve.

Braking delay

Phenomenon: Slow braking response, resulting in load shaking.

Reason: The viscosity of the brake hydraulic oil is too high or the oil return is not smooth.

Solution:

Replace the hydraulic oil that meets the standard (such as 46 # anti-wear hydraulic oil).

Clean the return oil filter element to ensure smooth oil flow.

3、 Troubleshooting of Chain and Transmission Mechanism

Chain stuck or broken

Phenomenon: The crane is not running smoothly or suddenly stops.

Reason: Chain wear, deformation, or insufficient lubrication.

Solution:

Check the elongation of the chain, and replace it if it exceeds 3%.

Clean the dirt on the surface of the chain and apply special lubricating grease (such as lithium based grease).

Check if the sprocket teeth are worn and replace the sprocket if necessary.

Abnormal noise from deceleration mechanism

Phenomenon: Metal friction sound is emitted during operation.

Reason: Gear wear, bearing damage, or poor lubrication.

Solution:

Disassemble the gearbox, check the gear meshing, and replace worn gears.

Replace the bearings and replenish lubricating oil (such as GL-5 heavy-duty gear oil).

4、 Troubleshooting of Control System Malfunctions

Operating valve malfunction

Phenomenon: Unable to control the lifting of the crane or incorrect direction.

Reason: Internal leakage of the operating valve, spring failure, or stuck valve core.

Solution:

Disassemble the operating valve, clean the valve core, and replace the seals.

Adjust the spring preload to the standard value.

Check if the handle travel is in place, repair or replace the operating mechanism.

Limit switch malfunction

Phenomenon: The crane overtravels or cannot be stopped.

Reason: Oxidation of limit switch contacts, position deviation, or circuit breakage.

Solution:

Clean the limit switch contacts and apply conductive paste.

Adjust the position of the limit switch to the end point of the rated travel.

Check if the connecting circuit is broken, repair or replace the wires.

5、 Environmental and maintenance factors

Poor working environment

Phenomenon: Frequent malfunctions or shortened lifespan of cranes.

Reason: High temperature, humidity, or corrosive gases.

Solution:

Install cooling fans or water jackets in high-temperature environments.

Apply anti rust paint (such as epoxy zinc rich primer) in humid environments.

Regularly clean the surface dirt of the equipment to avoid the adhesion of corrosive substances.

Insufficient maintenance

Phenomenon: The failure rate is gradually increasing.

Reason: Failure to maintain according to the prescribed cycle.

Solution:

Develop a maintenance plan (such as replacing emulsion every 500 hours and checking the brake system every 1000 hours).

Record fault history, analyze high-frequency issues, and optimize design.

6、 Safety precautions

Power off operation: Cut off the power supply and hang a warning sign before troubleshooting.

Personal protection: Wear a safety helmet and gloves to avoid direct contact with high temperatures or rotating parts.

Professional maintenance: Complex faults (such as motor overhaul, hydraulic system modification) need to be handled by certified personnel.

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