Fashion Bag How to judge the cause of the failure of swing motor?

How to judge the cause of the failure of swing motor?

1.Failure phenomenon and cause analysis

When the excavator works at a relatively low temperature, the driving force and rotation speed do not decrease significantly. When the oil temperature rises above 60 degrees Celsius,the rotation is weak,the rotation speed is unstable,and the rotation speed fluctuates.

If we find out the above faults occur, in addition to the pumps,valves and other components in the swing system.It is mainly due to the wear and tear of the internal motion matching parts of swing motor.Like the gap increases,the leakage increases,the return oil cannot be discharged in time,and the high-pressure oil leaks in large quantities,the pressure in the casing increases,the temperature of the oil increases,and the viscosity decreases.

2.Detection

• Pressure test

Use a blind plate to isolate the swing motor oil circuit from the main oil circuit, and use an oil pressure gauge to test the oil pressure of the rotary motor forward and reverse inlet and outlet oil ports, then the pressure value of the rotary motor is obtained. Then connect the oil circuit to make it in normal working, drop the excavator bucket and insert it on the ground. When the load of the rotary platform increases, the pressure of the relief valve is tested when the motor is driven, and the fault status can be determined by comparing the two sets of test data.

• Flow test

Connect the PFM-6 flowmeter to the oil circuit in series,test the inlet and outlet flow and pressure of the swing motor, and determine whether the output torque and speed of the swing motor reach its technical performance indicators, and at the same time, it can determine the fault location of the swing motor.

3.Troubleshooting

• The wear of the gap between the pistons and the cylinder pistons hole increases,resulting in serious gap leakage.

Need to replace the piston.

• The return spring is fatigued and the elastic force drops, resulting in the collusion of the high and low pressure oil circuits of the cylinder.

Need to replace spring.

• The wear of the sliding shoe and the piston accelerates the sliding dry friction between the sliding shoe and the bearing plate, resulting in an increase in the rotation resistance.

Need to repair or replacement.

• The bearing of the swing motor is damaged, and the bearing positioning fails.

Need to replace the specified type of bearing.

• The sealing surface of the safety method is worn.

Need to repair or replacement.

• The aging,failure and oil leakage of the hydraulic cylinder seals of the parking brake will cause the brake to not be completely released and the turning resistance will increase.

Need to replace the sealing element.

• The oil distribution surface of the valve plate and the cylinder block is worn, resulting in internal leakage and weak rotation.

Need to repair or replacement.

To sum up,if we find out the above-mentioned faults are often encountered during the use of the excavator.

We can summarize, analyze, and find out the parts where the fault occurred for maintenance, the excavator’s swing motor can work normally and stably.