I. Insufficient oil supply of gear pump or establishment of high working pressure

When the gear pump sucks oil normally, but the hydraulic system moves slowly, it can move faster without load, while it is slow or even unable to move under load, and the gear pump body and oil temperature rise quickly, it may be a gear pump Internal leakage increases, resulting in insufficient oil supply to the gear pump or the establishment of a high working pressure. The reasons for the insufficient oil supply of the gear pump or the establishment of a high working pressure are not as follows:

1.Abrasion and scratching of the end face of the side plate of the gear pump causes the axial clearance of the gear pump to increase, which destroys the seal between the end face of the side plate and the gear end face, increases the internal leakage of the gear pump, and causes insufficient oil supply or establishment High working pressure. Side plate wear and scratches are generally caused by the oil being unclean, failing to regularly change the oil as required, and failing to clean the filtering device in a timely manner. Therefore, once the side plate is worn and scratched, check the oil cleanliness. If necessary, replace the oil and clean the filtering device. Otherwise, the side plate will wear quickly after the repaired or newly replaced gear pump is installed. And scratches.

2. The damage of the seal ring of the gear pump and the wear of the end face of the side plate will damage the sealing performance, increase the internal leakage of the gear pump, cause insufficient oil supply or establish a high working pressure.

(1) The sealing ring is damaged, deteriorated, aging and deformed and loses the sealing effect. If the new sealing ring is replaced, the fault can be eliminated.

(2) The end face of the side plate is abraded, which increases the axial clearance of the gear pump. This reason is simply impossible to replace the damaged seal ring, because after the new seal ring is installed, it will still be damaged quickly. The oil seal can only be renewed after the pump casing is repaired or the side plate is replaced.