The unilateral walking deviation of the excavator will reduce the construction efficiency and other problems. There are many fault points causing walking deviation. Without professional maintenance experience, many operators can't solve it accurately. This article will share the solutions to the deviation of walking alone for reference only.
The excavator will deviate to the left when walking alone, but it is normal when doing compound action.
1. Fault analysis
Through the analysis of fault phenomenon, there are two reasons: 1) internal abnormality of main pump or failure of regulator. 2) This fault is caused by oil leakage inside the distributor.
2. Troubleshooting
1) First, we checked the pressure of the main pump and the traveling motor. When the front moves to overflow, the overflow pressure is normal. The pressure of the front pump of the two speed instrument is slightly lower than the normal pressure, and the working pressure of the rear pump is normal. Check that the traveling overflow pressure of the left and right traveling motors is normal, and judge that the traveling motor works normally.
2) Since the overflow pressure of the left and right traveling motors is normal, it is analyzed that the flow of one pump may be too small, resulting in traveling deviation. Exchange the front and rear main pump regulators, and there is no change in the traveling deviation direction, so the regulator fault is eliminated. The output high-pressure oil pipes of the front and rear pumps were interchanged, and it was found that the walking deviation direction had not changed, so the main pump fault was eliminated.
3) Next, the working oil pipes of the left and right traveling motors were interchanged, and it was found that the deviation direction changed, so the fault occurred on the distributor. After measuring the overflow pressure at the rear root, it is found that the pressure is abnormal, but because the compound action does not deviate, it has nothing to do with the travel valve core. If the overflow pressure at the rear root is abnormal, disassemble the check valve on the distributor. It is found that the check valve is stuck by foreign matters and is in the normally open position.
Since the one-way valve is in the normally open position, when walking alone, the pressure oil of the front pump controls the swashplate angle of the front pump through the one-way valve, so that the swashplate angle of the front pump becomes smaller, resulting in reduced flow and travel deviation.
3. Troubleshooting
After disassembling the check valve, remove foreign matters, and then carefully clean it. After installation, the commissioning fault disappears.
