During the use of small crawler excavator, there is a fault that one side of the excavator does not move and the traveling motor makes abnormal noise. Some operators do not know the cause of the fault. This article will explain how to analyze and check the fault when the excavator has this fault, which is for reference only.
1. Fault analysis
According to the analysis of fault phenomenon, the reasons for no action of walking are as follows:
1) There is no pilot pressure for travel, which can be caused by the failure to open the main control valve of travel.
2) If the main control valve of traveling is stuck, it cannot be opened even if there is pilot pressure, resulting in no action of traveling.
3) The traveling overflow valve failed, resulting in direct leakage of pressure oil in the main oil circuit.
4) Internal faults of the central rotary joint, such as leakage, chaotic oil circuit, direct connection of high and low pressure oil circuit, resulting in no action of walking.
5) The balance valve or brake oil circuit and brake hardware are faulty, resulting in the travel motor is always stuck and the motor cannot rotate.
6) In case of component failure of traveling motor, if the plunger and oil distribution plate inside the motor have internal leakage caused by high wear, the motor will also fail to work.
7) Failure of traveling reducer, such as jamming caused by high-temperature wear of motor shaft, damage and jamming of reduction gear, will lead to high-pressure overflow and failure to rotate.
8) If there is a compound action of walking and other actions, there is no action on one side or the action is very slow, the reason for the linear walking valve is not ruled out.
2. Fault analysis, troubleshooting and handling
If the condition of abnormal noise during traveling is added, the above fault causes can be eliminated, such as no pilot pressure, stuck main control valve, internal fault of central swivel and fault of linear traveling valve. The fault point may be due to the fault of travel overflow valve, balance valve or brake oil circuit and brake hardware, travel motor parts and travel reducer. In short, the cause of the fault is inside the motor and reducer, including the traveling overflow valve and balance valve on the motor.
According to this analysis idea. First, check that the pilot pressure and overflow pressure of the motor are normal. Then, we can eliminate the fault of traveling overflow valve. Secondly, disassemble the traveling reducer, the internal gear oil is of normal color, and the reduction gear is free of wear, which eliminates the fault of the reducer.
Finally, only the reasons for the travel brake system and motor are left. Disassemble the traveling motor, and there are no signs of wear on the appearance of these parts. However, the spring inside the balance valve has a broken section. In this case, the walking brake cannot be opened, which leads to no action.
After replacing the internal spring of the balance valve, the fault is removed.
