Hydraulic excavator failure analysis of final drives
Updated: Dec 28, 2018
The hydraulic excavator's walking device is a hydraulic component that converts hydraulic energy into mechanical energy, and plays a forward and backward movement that carries the excavator displacement during the excavator working process. Its common faults are similar to those of the slewing motor, even simpler than the slewing, because its unidirectional force has little to do with the check valve. The check valve only acts to hold the working chamber and prevent system air pockets and assist the balancing valve. Anti-slope function.
1. The walking device is fast and slow. In the multi-pump and multi-circuit excavator, if this symptom occurs, first understand whether the multi-way valve has a confluence valve or a linear travel motor valve. If the multi-way valve with the valve is installed, it can be separately operated when other actions are performed and when other actions are not operated. When the other actions are operated one by one, the flow is faulty. When walking alone, it may be one of the pumps. There is a fault (measured pump pressure), the linear travel valve is generally a pilot oil circuit fault, can not open the linear travel valve in time;
2. The walking device has no action. When the oil circuit is working normally, it is also difficult to judge the cause of the fault. First, open the end cover to see that the gear transmission part is faulty, and then judge the cause of the final drive motor, such as the brake spool. Damping blockage or brake ring O-ring cut, causing no action;
3, walking can not enter, when a single direction is weak, first check the oil drain of the drain, if the drain is normal, it is the cause of the overflow valve stuck, such as the drain in the single direction of the drain The clearance with the cylinder is too large;
4, powerless. Under normal conditions, the oil path is weak, and the oil drain should be inspected. At this time, the final drives oil drain is large. The reason is that the oil pan and the oil cylinder, the oil cylinder and the plunger, the sliding shoe and the swash plate, the sang friction and wear are serious, or the main shaft and If the gap between the cylinders is too large and there is no large oil return to the drain port, there is a possibility that the brake ring O-ring is too drained and the brakes cannot be fully opened;
5, unilateral walking is weak and accompanied by separate operations when the other side rotates. If a single traveling device is operated, the other side will also rotate, which is generally caused by a leak in the rotating oil passage. At this time, the rotating oil passage should be repaired.
The crawler excavator travel device is roughly the above several faults, and hopes to learn more knowledge and technology in the future work, and can provide more help for after-sales service. https://www.spfinaldrives.com/