Solutions to the inability of the PC-1 excavator to work

A PC-1 type excavator in the cooler when the work is basically normal, but not to the various parts of action after 30min machine on the slow; when the oil temperature rose to 80 degrees above, each action is crawling, the machine is not working properly. After adjusting the control valve and variable mechanism, the effect is still not satisfactory. Then, one by one to detect the pump working pressure, cooler when the maximum working pressure is less than 20MPa, when the engine is only 10~15MPa, so it can not guarantee the actuator can work normally (normal working pressure should be 31.4MPa).

In order to find out the cause of the hydraulic system failure, it is decided to check as follows:

1, first disintegration check the main pump, found plunger, plunger sleeve, port plate and slipper wear are too much, the axial clearance is too big, need to adjust the machine replacement.

2, check the executing agency, no leakage, leakage and impact.

3, check the disintegration, directional control valve spool and valve that gap is too large, when the test pressure is 10MPa, the oil leakage is 2L/min, far higher than the standard value; valve and valve clearance reached 0.2mm, and the pressure control has obvious scar valve spool and the valve seat, the leakage will exceed the standard (200L/min).

When the test pressure reaches 15MPa, the main overflow valve is opened ahead of schedule (according to the standard should be opened at 31.4MPa), a large number of oil spills.

4, check other parts, such as cooling fan, motor, fan blade, hydraulic oil radiator, etc., are good.

To solve the above problems, we do the following:

1, first of all, the replacement of grinding main hydraulic pump plunger, plunger sleeve, the valve plate and the slipper, adjust the axial clearance, then installed and tested, then the pressure has increased significantly, up to 25MPa, but the temperature is too high, when the machine work after 1h, the oil temperature more than 100 DEG C, the machine does not work.

2 、 grinding direction control valve sleeve, chrome plated, fine grinding slide valve, at the same time, with the study of the main overflow valve, unloading overflow valve, safety valve and relief valve. When the machine is debugged, the work of the machine has been restored to normal.