Common failures and maintenance of hydraulic vane pump for injection molding machine

Problem Cause Solution A. No oil discharge 1. Rotation direction error (positive, counterclockwise) Immediately stops and corrects the rotation direction of the motor. 2. Check if the pump has no power to the rotating motor and check if the coupling or key is damaged. 3. The pump shaft is broken and the rotor is not turning to repair the pump. Check if the motor rotation speed is too high and if the shaft center is aligned with the center 4. Suction pipe is blocked and check the suction line 5. Suction filter screen is blocked Clean the suction filter screen 6 The tank filter replaces the larger suction strainer through insufficient flow, at least 2.2 times the pump flow per minute 7. The oil viscosity is too high. Replace the specified oil viscosity (according to the sample) 8. The number of revolutions is not enough to the pump minimum Speed ​​selection Motor return speed (according to sample) 9. Insufficient air tightness of the suction pipe Check the suction line 10. Fill the fuel tank filter above the oil level to above the oil level gauge Reference point 11. The blade cannot slide out of the rotor pocket Repair Pump B. High noise 1. Suction tube too small Inhalation vacuum of at least 200 mmHg or less 2. Inhalation strainer plug obstructs suction suction strainer screen 3. Tank strainer replaces larger suction strainer mesh by insufficient flow, at least pump per minute More than 2.2 times of the flow rate 4. The oil viscosity is too high. Replace the specified oil viscosity (according to the sample). 5. Use a double pump to correct the suction tube. 6. The suction line suction air locks the pump inlet flange and Check if other suction lines are 7. 7. Intake air at the oil seal of the pump shaft. Check whether the shaft is concentric. 8. Check whether the tank oil has air bubble return line configuration and length. 9. The fuel tank filter refuels above the oil level to the oil level meter. Cannot slide out of the rotor bore Repair pump 11. Coupling rattle Replace coupling and check shaft for concentricity 12. Cartridge air filter plugged or size too small Clean air filter or replace filter of appropriate size 13. Back speed is too high. Select motor back speed according to the pump maximum speed (according to the sample). 14. Set the pressure too high and check if the pressure gauge is set properly. 15. Pump the bearing damage and check if the shaft is concentric. Abrasive oils with abnormal cam ring wear are dirty. 17. Pump cover is tight. Torque wrench is used to reassemble the pump. 18. Pump is heavily worn (cam ring, rotor, manifold, vane) Clean oil is too dirty. Replace pump and hydraulic fluid. C. Insufficient flow 1. No oil Discharge method according to reference A. 2. Inhalation vacuum is too high. Cavitation caused by air inhalation. Inspect the strainer screen. Use hoses or straight tubes as much as possible. 3. Wear the rotor and manifold to repair the pump. 4. Pump cover is tight. Torque wrench re-assembles the pump 5. Replace the oil with too little oil, install cooler D seal Oil seal at leak seal Replace seal