For Komatsu pc130-8m0 excavator unable to walk, we should know the cause of the failure. Of course, there are many kinds of failure to walk. This paper describes the causes and maintenance methods of the failure to walk on the left side of the excavator with examples. It is sorted out and shared that an excavator fails to walk on the left side during operation.
Specific details: according to the operator of the excavator, the oil pollution was caused by the broken oil seal of the stick cylinder Disassemble the oil pipe and each valve core of the main control valve, clean them and reassemble the test machine. The left side of the machine still cannot walk.
Maintenance analysis:
1. The left travel main valve of the excavator is stuck,
2. The left travel pilot valve of the excavator is faulty,
3. There is a problem with the walking balance valve on the left side of the excavator,
4. The excavator linear travel valve is faulty,
5. The excavator travel motor or reducer is faulty
6. The left traveling oil circuit at the rotary joint of the excavator center is in collusion.
Troubleshooting:
First, check the left pilot oil pressure. Use a pressure gauge on site to measure that the output oil pressure of the left travel pilot valve is 3.5Mpa, which is normal The left and right pilot pressure oil pipes were adjusted and tested, and the fault remained the same, thus eliminating the possibility of failure of the pilot valve.
Disassemble and inspect the left travel main valve Other functions of the machine work normally, indicating that the main pump controlling the left travel is normal Remove the left travel main valve, move the main valve core by hand, and feel that the valve core slides freely without jamming The left travel main valve was cleaned for many times, and the machine was tested after reassembly. The fault still exists.
Check the balance valve and safety valve, remove the left travel motor, remove the central transmission shaft of the reducer, remove the balance valve for cleaning, and then reinstall it for testing. The machine still cannot travel Remove the two safety valves on the left motor and exchange them with the safety valves of the right travel motor. The fault remains after commissioning.
The linear travel valve was disassembled and inspected. According to the analysis, if the left travel valve core is normal and the excavator is operated to travel left, the high-pressure oil pipe directly connected to the travel motor should have a large amount of pressure oil When removing one oil pipe on the left travel motor, almost no oil flows out of the oil pipe when the excavator is operated When operating in the opposite direction, the oil pipe flows out, but the pressure is very low (return pressure) Considering that each valve element has been removed, the installation direction of the valve element of the linear travel valve may be wrong After the valve core of the linear travel valve is installed in reverse, the fault of the machine disappears.
The fault of this example belongs to the fault caused by the wrong installation of the valve element. The reason is that the installation direction and position were not paid attention to when the valve element was disassembled for cleaning or inspection Therefore, during the disassembly of hydraulic components, it is necessary to remember the installation direction, sequence and position of each component, and do not lose, MIS install or omit parts, otherwise the old faults may not be eliminated, and new faults may be added.
