What are the common faults of electric bridge cranes

As an important lifting equipment, electric bridge cranes may encounter various malfunctions during use. Here are some common faults and their possible causes compiled by Shandong bridge crane manufacturers:

1、 Electrical malfunction

Electric motor overheating

Reason: The motor power does not match the actual working type of the mechanism, resulting in overload use; Low power supply voltage; There is a blockage in the mechanical transmission system that leads to increased resistance.

Solution: Adjust the motor power to adapt to the actual working type; Check and adjust the power supply voltage; Check the mechanical transmission system and clear any blockages.

Motor vibration

Reason: The motor shaft and the reducer shaft are not concentric; Motor bearings are damaged; The rotor of the electric motor is deformed.

Solution: Adjust the concentricity between the motor and the reducer; Replace damaged bearings; Repair or replace the deformed rotor.

Controller malfunction

Poor contact of contacts and welding by ignition; The positioning mechanism has malfunctioned; Severe contact erosion (poor contact between moving and stationary contacts, insufficient controller capacity, and short circuits between phases).

Solution: Check and clean the contacts, replace damaged contacts; Repair the positioning mechanism; Check and replace controllers with insufficient capacity, eliminate short circuit points.

Contactor malfunction

The coil generates high heat, excessive noise, and slow closing action.

Solution: Check if the coil is overloaded, eliminate the gap and dirt on the surface; Check and replace the overloaded coil; Adjust the spacing between the dynamic and static iron cores.

Electrical circuit malfunction

The fuse is blown; The main contactor is not engaged; The main contactor is released (tripped) during the operation of the crane.

Solution: Check and replace the blown fuse; Check the circuit voltage, fuse, controller handle position, emergency switch, and safety interlock switch to ensure that the circuit is functioning properly; Adjust the setting value of the overcurrent relay, check the sliding contact wire, track installation, and collector bracket to ensure normal power supply.

2、 Mechanical malfunction

brake failure

Brake failure and low braking torque; Cannot open the gate.

Reason: Oil stains on the surface of the brake wheel, severe wear of the brake pad lining, improper adjustment or fatigue of the main spring, improper adjustment of the electromagnetic stroke, etc.

Solution: Clean the oil stains on the surface of the brake wheel; Replace worn brake pad liners; Adjust the tension of the main spring; Adjust the stroke of the electromagnet again.

Vibration of reducer

Reason: Loose foundation screws of the reducer base; The input shaft is not concentric with the motor shaft; The output shaft is not concentric with the driven workpiece shaft; The stiffness of the supporting steel structure is poor.

Solution: Tighten the foot screws; Adjust the reducer to meet the concentricity requirement; Strengthen the support frame to increase its rigidity.

Car operation malfunction

Three legged running state (one wheel suspended); Slippery phenomenon.

Reason: Unqualified wheel manufacturing and poor installation accuracy; Oil stains or sand particles on the top surface of the track; The installation quality of the wheels is poor.

Solution: Replace or adjust the wheels; Clean up oil stains or sand particles on the top surface of the track; Adjust the installation position of the wheels.

Large vehicle operation malfunction

Wheel rim gnawing on track; Cheating and falling off track.

Reasons: Poor manufacturing of wheels, significant differences in clearance between transmission systems, poor installation accuracy of wheels, deformation of bridge structures, poor quality of track installation, etc.

Solution: Remake the wheels, eliminate excessive clearance in the transmission system, adjust the accuracy of wheel installation, repair the bridge, adjust the track, etc.