Walking weakness fault is a common fault of excavator. Because of the construction environment and high load working intensity of the excavator, the common actions of the excavator are prone to failure. When a fault occurs, the fault can be solved by accurately finding the fault point for maintenance or replacing the damaged parts. This article will share the troubleshooting process of a brand of crawler excavator with weak right walking, hoping to be used as a reference.
1. Fault phenomenon
When one side of the right travel is found to be weak during construction, in serious cases, the right travel motor does not respond when pushing the right travel operating rod. The walking speed and strength on the left side are normal.
2. Troubleshooting
The maintenance personnel make analysis before maintenance according to the working principle of the traveling motor. The following reasons may lead to this fault phenomenon.
① The traveling motor itself is faulty. ② The travel pilot valve is faulty. ③ Oil seal tightness of central swivel. ④ Excessive wear clearance between the right travel valve core and the valve body and failure of the main valve and unloading valve. ⑤ Main pump failure. ⑥ The split and merge solenoid valve is faulty.
1) First, change the positions of the two oil outlets of the main pump. After exchanging the positions, the fault phenomenon appears that the right motor is normal and the left motor is unable to travel. This eliminates the problems of travel motor, central swivel, travel pilot valve and right travel valve core.
2) Next, eliminate the remaining fault points. A brand of excavator has two working modes. The hydraulic system in working mode a is in confluence state, and the hydraulic system in working mode l is in shunting state. When the operating handle is neutral, the hydraulic oil is directly connected with the oil tank through the unloading valve to maintain the system pressure at 40kg / cm2.
3) The data is obtained by measuring the front and rear pumps with a wall meter. When in working mode a, the pressure of the front pump is 394kg / cm2 for the front pump and 40kg / cm2 for the rear pump. The pump pressure before and after normal state is 394kg / cm2. Judge that the machine is in the shunting state, measure that the merging and shunting solenoid valves work normally, and eliminate the merging and shunting solenoid valve.
4) Next, change the positions of the two relief valves. The measured data is the same as above, so the fault of overflow valve is eliminated.
5) Finally, check the unloading valve. Remove the unloading valve from the main valve and disassemble the unloading valve. After opening, it was found that the valve core was stuck by foreign matters, resulting in the valve core being normally open. The output hydraulic oil of the front pump is connected with the oil tank through the unloading valve, resulting in low working pressure of the front pump.
There are many reasons for a fault performance. By understanding its working principle and troubleshooting in sequence, we can find the fault point of the problem. In addition, it should be noted that due to the complex working conditions and heavy load of the excavator, it still needs to be maintained and tested on time. In this way, it can not only find the fault phenomenon in time, but also repair it quickly, so as to save time, maintenance cost and other cost investment.
