The main function of the rotary device of hydraulic excavator is to connect the rotary table of the excavator with the vehicle of the excavator, so as to ensure that the excavator can not tip over and that the rotary action of the excavator is light and flexible. There are several common faults of excavator slewing device.
There are many parts related to the upper body rotation fault of excavator, such as main pump, self pressure reducing valve, rotary operating handle, rotary locking switch, rotary locking solenoid valve, rotary motor, rotary reducer and rotary bearing, which bring great difficulties to the diagnosis of upper body rotation fault of excavator. But in general, fault detection should follow the principle from simple to complex, one by one analysis, elimination, should not be in the case of no detailed analysis of the problem blindly disassembly parts. For the upper body rotation fault of excavator, it is generally checked one by one according to the following steps.
1. Check whether the main pump and the self pressure reducing valve have faults. If the excavator only has the upper body and can't rotate, and other working devices operate normally, since the main pump and the self pressure reducing valve are the common components of the hydraulic part of the excavator, the faults of the main pump and the self pressure reducing valve can be easily eliminated.
2. Check the rotary reducer and rotary support for failure. The judgment of this kind of fault can be confirmed by whether the excavator has abnormal noise or vibration before the fault. In general, if the rotary reducer or rotary support fails, there will be abnormal noise or vibration. If there is abnormal noise or vibration, it may be the problem of rotary reducer or rotary support.
3. If the above fault is eliminated, measure the slewing control pressure to determine whether the slewing control pressure is in the normal range. At the same time, check the rotary main valve core to see whether it moves flexibly in the valve body and whether it is stuck. If the valve core is normal, it means that the main oil circuit can reach the rotary motor smoothly.
4. Check whether the rotary locking switch is in the "off" position, and measure the voltage at both ends of the switch and the resistance of the rotary locking solenoid valve coil with a multimeter to see whether they are normal. If it is normal, use a pressure gauge with appropriate range to measure the pressure at the outlet of the control oil circuit of the rotary solenoid valve, and operate the excavator to rotate. If the measured pressure is too low, it means that the oil pressure to release the brake is too low, so that the upper body of the excavator can not rotate.
