Many friends mentioned that they had encountered the situation of the excavator running off in the course of operation. What is the reason? And how to solve it?

1. The movement of the main valve spool of the walking excavator deflection is out of order

When the spring in the main valve becomes soft, broken or the valve core is stuck, the oil pressure may be reduced and the running deviation may be caused.

Solution: Measure whether the pressure of the main valve oil circuit is normal. If the main valve is damaged, it needs to be replaced or repaired immediately.

2. Balancing Valve for Dirt Entering the Parking Brake Oil Circuit on the Excavator Side

When the excavator is walking, if impurities and dirt block the orifice of the balance valve, the pressure oil can not enter the spring chamber of the balance valve through the orifice of the balance valve to push the balance valve core to move. Pressure oil can not enter the hydraulic system through the slot on the balance valve, the parking braking force can not be relieved, the walking motor can not rotate, so there will be running deviation.

Solution: Remove the balance valve for cleaning, we should pay attention to the disassembly and assembly can not have dirt, impurities into, in addition to remember to regularly replace the hydraulic oil and filter.

3. Oil Leakage of Safety Valve of Walking Motor

Leakage of oil in safety valve of walking motor will lead to low pressure in the system, which will lead to insufficient rotation of the walking motor and the phenomenon of running deviation.

Solution: Replace the safety valve of walking motor.

4. The degree of track tightening varies from side to side.

The tension of the left and right track is different, which will directly affect walking and lead to running deviation.

Solution: Butter the loose side to make it as tight as the other side.

5. Decreased performance of oil pumps

When the plunger of the pump flow regulator of a excavator is stuck in a certain position, or because of serious wear, internal leakage and insufficient system pressure, the speed of the walking motor will slow down and the running deviation will be caused.

Solution: Remove the hydraulic pump assembly from the excavator, replace the worn parts, repair the regulator, and replace the hydraulic oil and filter element.

6. The output pressure of the walking proportional valve on the deflection side of excavator is too low

The proportional valve can output the corresponding control oil pressure according to the length of the control stroke of the operating handle, so that the main control valve has the corresponding amount of movement, thus controlling the speed of the working device. If the filter core is blocked, the filter bypass valve opens, and the dirty hydraulic oil goes directly into the loop of the proportional valve without filtering, resulting in the block of the slide valve in the valve, and the control oil can not flow to the rotary main control valve through the rotary proportional valve on the deflection side of the excavator, resulting in running deviation.

Removal method: Clean valve body and oil circuit before phase, replace hydraulic oil and filter element.

7. Damage of walking suction valve on the deflection side of excavator

If the running suction valve is damaged, the spring inside the valve is soft or broken, the oil pressure in the main valve will be reduced, which will lead to the running deviation caused by the insufficient driving force of the walking motor.

Solution: Repair or replace oil suction valve.

8. Damage to Seal Ring of Central Rotary Joint

If the hydraulic oil filter element is replaced regularly, it may cause the bypass valve on the filter element to open and the unfiltered hydraulic oil directly enters the sliding surface of the central rotary joint. The impurities in the filter may damage the sealing ring and cause the leakage of pressure oil on one side, resulting in the different speed of the walking motors on both sides and the running deviation of the excavator. 。

Solution: Replace the oil on the rotary joint of the center; Replace the hydraulic oil and filter element.

At ordinary times, excavators should be regularly maintained and replaced with hydraulic oil and filter element in time; qualified hydraulic oil should be selected in use to keep the cleanliness of hydraulic oil and prevent pollution when changing oil; at the same time, hydraulic oil and filter element should be replaced in time according to regulations. Only by paying more attention to these details in peacetime, can we avoid bigger failures or even accidents.

1. 16