When the excavator is in the middle position after the rotary operation, the phenomenon that the excavator is inclined to turn at a large angle under the action of inertia force will often appear, which makes the machine unable to be in the position the operator wants to reach. According to experience, this kind of fault phenomenon is often related to the failure of rotary braking, insufficient braking force, release of brake oil pressure, swing lock solenoid valve, rotary brake pad, rotary brake seal, etc. In this case, the following steps can be followed to troubleshoot the diagnosis.
1. check the circuit part of swing lock valve, check whether the connection between the connecting terminals and terminals of the line is reliable with a multimeter. Confirm the short circuit and open circuit between the lines according to the electrical schematic diagram. At the same time, check whether the relevant solenoid valve measuring coil and valve core work normally.
2. measure the release brake oil pressure, and the normal range of brake oil pressure should be about 3Mpa. If normal, go to the next step.
3. check the swing motor, remove the swing motor, check whether the spring spring is normal and if it is broken, and check whether the sealing ring on the brake pressure plate is in good condition.
4. check the brake return circuit and check whether the throttle hole of the return circuit is smooth. If the return circuit is blocked, it will lead to too slow oil return and prolonged time, thus delaying the actual operation time of the brake part, thus causing the rotation to stop in time according to the requirements of the operator. In case of such failure, the relevant components can be removed for cleaning, especially for orifice and small oil passage.
