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What should I do if the hydraulic motor of excavator fails

When the excavator platform rotates, it stops and moves suddenly, that is, the rotation is discontinuous. Slow speed and insufficient strength. First, judge that the hydraulic motor may have failed. Hydraulic motor is an energy conversion device, that is, the input liquid pressure energy is converted into mechanical energy output. If the efficiency of hydraulic motor itself is not considered, the input of energy should be equal to the output. Therefore, the weak rotation of the hydraulic motor must be the reduction of the energy input to the hydraulic motor. When the energy is difficult to overcome the rotation resistance of the platform, the rotation stops. According to the principle of hydraulic transmission, the hydraulic motor rotates by liquid pressure. When the hydraulic motor is stopped when the control valve is connected to the pressure oil circuit, it must be stopped because the working pressure of the oil input into the plunger cylinder of the hydraulic motor is not enough to overcome the running resistance of the platform. When the accumulated energy is enough to overcome the resistance, the hydraulic motor makes the hydraulic motor jump and rotate to overcome the resistance, the oil pressure in the system drops sharply, and the motor stops again. In this way, the platform rotation is discontinuous, or the rotation is discontinuous due to the excessive resistance to prevent the hydraulic motor from rotating.

The reason for the excessive rotation resistance of the hydraulic motor leads to the low mechanical efficiency of the motor itself. For example, the friction resistance between the plunger and the mating friction pair is too large, the friction resistance between the swashplate and the plunger is too large, the friction resistance caused by poor bearings is too large, or the mechanical transmission efficiency of the transmission box is low. Or it is caused by excessive mechanical friction resistance of the turntable of the platform.

If the boom hydraulic cylinder of the working device works normally, the fault of discontinuous rotation of the hydraulic motor should be at the end of the hydraulic motor and transmission, that is, the mechanical transmission box and platform turntable.

(1) Check the hydraulic motor safety valve. Try to adjust the safety valve at the lower part of the hydraulic motor control valve. Unscrew the nut of the safety valve, rotate the adjusting screw plug with an internal hexagonal wrench, and change the pressure by 2.345mpa every turn. Therefore, the pressure gauge test should be 9.8MPa. If it is lower than 9.8MPa, it indicates that the fault of discontinuous rotation is mostly caused by the low set pressure of the hydraulic motor.

(2) Check the hydraulic motor and mechanical transmission part. If the hydraulic motor does not rotate to the constant pressure of 8 s, it indicates that the hydraulic motor does not rotate to the constant pressure of 8 s.

Touch the shell of the hydraulic motor by hand. If it feels hot, it indicates that the friction force of the hydraulic motor is too large, which proves that it is the fault cause of discontinuous rotation and should be eliminated. If the temperature of the hydraulic motor is normal, you can use the hand mold to observe the temperature of the transmission box and rotary table, or observe the lubrication. If there are parts with high temperature and poor lubrication, it indicates that most of the faults are caused by discontinuous rotation, that is, excessive friction resistance, which should be eliminated.

What should I do if the hydraulic motor of excavator fails

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