Common faults, causes, and troubleshooting methods of gear pumps
Stainless steel gear pumps are prone to the following faults during their use:
1. Wear of internal parts of oil pump
Wear of internal parts of the oil pump can cause internal leakage. The large leakage area between the floating shaft sleeve and the gear end face is the main part causing internal leakage. This part of the leakage accounts for about 50% to 70% of the total internal leakage. The volumetric efficiency of gear pumps with wear and internal leakage decreases, and the output power of the oil pump is significantly lower than the input power. All of its losses are converted into thermal energy, which can cause the oil pump to overheat. If the joint plane is pressed tightly, the floating shaft sleeve will have a small amount of movement during operation, causing wear and tear, resulting in slow or impossible lifting of agricultural tools. Such floating shaft sleeves must be replaced or repaired.
2. Wear of oil pump housing
Mainly due to the wear of the floating shaft sleeve hole (the normal clearance between the gear shaft and the shaft sleeve is 0.09~0.175mm, and the maximum should not exceed 0.20mm). The gear works under the pressure of oil, and the tip of the gear is close to the oil pump housing, causing wear on the low-pressure chamber of the pump body. Another type of wear is the circumferential wear of the working surface inside the casing, which is mainly caused by impure added oil, so it is necessary to add oil without impurities.
3. Oil seal wear, rubber seal aging
The rubber oil seal of the unloading plate has aged and deteriorated, losing its elasticity, and losing its sealing and isolation effect on the high-pressure and low-pressure oil chambers. This will generate oil pressure from the high-pressure oil chamber to the low-pressure oil chamber, known as "internal leakage", which reduces the working pressure and flow rate of the oil pump. The normal working pressure of CB46 gear pump is 100-110kg/square centimeter, the normal oil delivery capacity is 46L/min, and the standard unloading plate rubber oil seal is 57 × 43. The self tightening oil seal is PG25 × forty-two × The 10 type skeleton oil seal is damaged or fails for a long time, and air is sucked into the oil pump from the gap between the oil seal and the main shaft journal or from the joint between the oil inlet adapter and the oil pump housing. It enters the oil tank through the return oil pipe, generating a large number of bubbles in the oil tank. This can cause a decrease in oil in the fuel tank and an increase in oil in the engine oil sump, causing the lifting of agricultural tools to be slow or impossible. The oil seal must be replaced to troubleshoot this problem.
4. Insufficient or no oil pressure in the oil pump: the working device lifts slowly, shaking or unable to lift during lifting; There are bubbles in the fuel tank or oil pipe; When lifting, the hydraulic system emits a "chirp" sound; When the tractor is first started, the working device can be lifted. After working for a period of time, the oil temperature rises, but the lifting is slow or cannot be lifted; It can be lifted under light loads, but cannot be lifted under heavy loads. Inlet pump valve
Fault cause:
(1) The oil level of the hydraulic oil tank is too low;
(2) Not using hydraulic oil according to the season;
(3) The oil inlet pipe is severely blocked by dirt;
(4) The oil seal of the driving gear of the oil pump is damaged, and air enters the hydraulic system;
(5) The "O" shaped sealing ring of the oil pump inlet and outlet joints or bent joints is damaged, the fastening bolts or inlet and outlet pipe nuts of the bent joints are not tightened, and air enters the hydraulic system;
(6) Internal leakage of the oil pump and aging of the sealing ring;
(7) The end face of the oil pump or the end face of the main and driven gear shaft sleeves is worn or scratched, and the unevenness of the two shaft sleeve end faces exceeds the tolerance;
(8) Internal leakage caused by incorrect assembly of internal parts of the oil pump;
(9) Installing a "left handed" and "right handed" oil pump caused damage to the skeleton oil seal
1. Wear of internal parts of oil pump
Wear of internal parts of the oil pump can cause internal leakage. The large leakage area between the floating shaft sleeve and the gear end face is the main part causing internal leakage. This part of the leakage accounts for about 50% to 70% of the total internal leakage. The volumetric efficiency of gear pumps with wear and internal leakage decreases, and the output power of the oil pump is significantly lower than the input power. All of its losses are converted into thermal energy, which can cause the oil pump to overheat. If the joint plane is pressed tightly, the floating shaft sleeve will have a small amount of movement during operation, causing wear and tear, resulting in slow or impossible lifting of agricultural tools. Such floating shaft sleeves must be replaced or repaired.
2. Wear of oil pump housing
Mainly due to the wear of the floating shaft sleeve hole (the normal clearance between the gear shaft and the shaft sleeve is 0.09~0.175mm, and the maximum should not exceed 0.20mm). The gear works under the pressure of oil, and the tip of the gear is close to the oil pump housing, causing wear on the low-pressure chamber of the pump body. Another type of wear is the circumferential wear of the working surface inside the casing, which is mainly caused by impure added oil, so it is necessary to add oil without impurities.
3. Oil seal wear, rubber seal aging
The rubber oil seal of the unloading plate has aged and deteriorated, losing its elasticity, and losing its sealing and isolation effect on the high-pressure and low-pressure oil chambers. This will generate oil pressure from the high-pressure oil chamber to the low-pressure oil chamber, known as "internal leakage", which reduces the working pressure and flow rate of the oil pump. The normal working pressure of CB46 gear pump is 100-110kg/square centimeter, the normal oil delivery capacity is 46L/min, and the standard unloading plate rubber oil seal is 57 × 43. The self tightening oil seal is PG25 × forty-two × The 10 type skeleton oil seal is damaged or fails for a long time, and air is sucked into the oil pump from the gap between the oil seal and the main shaft journal or from the joint between the oil inlet adapter and the oil pump housing. It enters the oil tank through the return oil pipe, generating a large number of bubbles in the oil tank. This can cause a decrease in oil in the fuel tank and an increase in oil in the engine oil sump, causing the lifting of agricultural tools to be slow or impossible. The oil seal must be replaced to troubleshoot this problem.
4. Insufficient or no oil pressure in the oil pump: the working device lifts slowly, shaking or unable to lift during lifting; There are bubbles in the fuel tank or oil pipe; When lifting, the hydraulic system emits a "chirp" sound; When the tractor is first started, the working device can be lifted. After working for a period of time, the oil temperature rises, but the lifting is slow or cannot be lifted; It can be lifted under light loads, but cannot be lifted under heavy loads. Inlet pump valve
Fault cause:
(1) The oil level of the hydraulic oil tank is too low;
(2) Not using hydraulic oil according to the season;
(3) The oil inlet pipe is severely blocked by dirt;
(4) The oil seal of the driving gear of the oil pump is damaged, and air enters the hydraulic system;
(5) The "O" shaped sealing ring of the oil pump inlet and outlet joints or bent joints is damaged, the fastening bolts or inlet and outlet pipe nuts of the bent joints are not tightened, and air enters the hydraulic system;
(6) Internal leakage of the oil pump and aging of the sealing ring;
(7) The end face of the oil pump or the end face of the main and driven gear shaft sleeves is worn or scratched, and the unevenness of the two shaft sleeve end faces exceeds the tolerance;
(8) Internal leakage caused by incorrect assembly of internal parts of the oil pump;
(9) Installing a "left handed" and "right handed" oil pump caused damage to the skeleton oil seal
