Abnormal walking of excavator is a common fault, such as walking deviation, walking weakness, unilateral walking jam and so on. After experiencing many situations, you will also have certain maintenance knowledge and be able to make simple judgment and repair of fault problems. During the use of the excavator, it is found that the left travel valve is operated to walk forward unilaterally, and the right crawler also walks forward slowly, but it is normal when the left travel valve is operated to walk backward unilaterally, and it is normal when the right travel valve is operated to walk unilaterally. Taking the excavator as an example, this article describes how to deal with this situation for reference only.
1. Fault analysis
Because this fault condition is very special, it is impossible to simply judge the specific fault cause. Maintenance personnel analyze from the following points:
1) The return of the travel valve core in front of the right travel foot valve is abnormal, and the travel main valve can be slightly opened.
2) The right traveling main valve core cannot return to the middle position and can still be slightly opened.
3) The oil seal of the left and right traveling motor oil passage of the central swivel is damaged.
4) The return position of the balance valve of the right travel motor is abnormal.
2. Troubleshooting
1) First, use the pressure gauge to detect the pilot secondary pressure of the right front walking guide pipe. When the pedal is in the natural state, the measured secondary pressure is 0bar. Determine that the pedal valve core is in the middle position, and eliminate the abnormal return of the pedal valve core.
2) Exchange the working oil pipes of the left and right traveling motors at the main control valve, and operate the right traveling foot valve. It is found that under the same experimental conditions, the fault is still on the right walking side, which is not changed by changing the working oil pipe. Then it is ruled out that the main valve core of right walking does not return to the middle position, restore the pipeline and continue the experiment.
3) Adjust the oil pipes at ports a and B of the right travel motor, operate the left travel pilot handle to test the excavator, and the fault phenomenon has not changed. The oil leakage fault of the central swivel oil seal is eliminated.
4) After the above inspection and troubleshooting, it is determined that the fault occurs in the right travel motor. Disassemble the hydraulic cover of the traveling motor and find that the balance valve of the traveling motor is stuck.
3. Troubleshooting
Grind the balance valve seat hole, replace the balance valve core and spring, clean the travel motor cover and confirm it is clean. After the valve core is free of jamming, test that the excavator works normally.
