A Komatsu 250 hydraulic excavator has no brake on the left and right sides during operation, and the hydraulic motor rotates slowly after the excavator
The reason why the motor of the hydraulic excavator does not rotate and the action is slow, and the reason why the excavator does not brake:
The joint screwed into the oil drain hole of the hydraulic motor housing is too long, causing friction with the rotor
Heavy load, insufficient pump oil supply pressure The coaxiality of the output shaft of the hydraulic motor is seriously out of tolerance or the output shaft is too long, which rubs against the hydraulic motor, the rotor and the rear cover
The reason why the hydraulic excavator motor does not rotate and operates slowly is that the excavator is not braked for repair:
During the on-site test run, it was found that there was rotation, but there was no brake, and there was a sound during the rotation. Since the rotary motor of the excavator was disassembled and the pump liner plane and the cylinder plug were replaced, it was suspected that the assembly was wrong. After the motor was opened, no abnormality was found. The meshing trace of the gear was found on the end cover of the motor spline, and the connecting teeth were turned to check. It was found that the gasket under the central sun gear was worn out at the place in the last drawing, which did not play a limiting role. When the motor was rotated, The four-star gear moves upward. When it reaches the top position, the central sun gear is empty, resulting in no brake. After the forced stop, the four-star gear returns downward. The rotation is normal. The noise is caused by the central sun gear grinding under the four-star gear
Increase the oil supply pressure of the pump or increase the overflow pressure of the overflow valve. Check the length of the oil drain joint. Remove the hydraulic motor and check the output shaft of the hydraulic motor Komatsu pc220-7 excavator fault inspection conclusion: the coaxiality of the output shaft of the hydraulic motor is seriously out of tolerance. The fault disappears after replacing the new limit washer
