Created on:2021-10-21 14:02

Troubleshooting of internal gear pump

Troubleshooting of internal gear pump

(1) The pressure fluctuates greatly.

1) Air is mixed in the system. Remove air.

2) Insufficient suction, air entrained. Increase the oil suction pipe diameter.

3) The pressure valve itself in the hydraulic system cannot work normally. Replace the pressure valve.

4) Two parts of the pump are damaged. Replace or repair parts.

5) The tooth profile accuracy of inner and outer rotors () is poor. Most of the internal and external cycloidal gears are pressed by powder metallurgy molds. Molds and other reasons will affect the tooth profile accuracy of cycloidal gears. The user can revise it. Those seriously damaged must be replaced.

6) The pump body and front and rear covers have large eccentricity error due to poor processing, or the matching clearance between the outer rotor and the pump body is too large. At this time, check the eccentricity and ensure that the eccentricity error is within ± 0.02mm. The fit clearance between the outer rotor and the pump body shall be 0.04 ~ 0.06mm

7) The matching relationship between inner and outer rotors does not meet the requirements. When the radial and end face runout of the inner and outer rotors is large, the inner and outer rotors shall be corrected in time to make each accuracy meet the technical requirements; When the backlash of the inner and outer rotors is too large, the inner and outer rotors shall be replaced to ensure that the backlash is within 0.07mm.

(2) Unable to absorb oil or insufficient oil absorption.

1) The inner rotor does not rotate. Check whether the worm, worm gear or gear of the oil pump drive system, the fastening screw or locating pin of the inner rotor are loose, and whether the worm gear and the main shaft worm mesh normally.

2) The rotation direction of the inner rotor is inconsistent with that of the prime mover, resulting in the exchange of oil inlet and outlet. Confirm whether the machine rotates in the working direction.

3) The oil outlet pipeline is blocked. Check whether the oil outlet pipe is bent or damaged.

4) The oil inlet screen is blocked. Clean the filter screen and remove the blockage.

5) The inner and outer rotors are seriously worn, resulting in the failure to form a closed cavity. Replace the inner and outer rotors.

6) The end face of the oil inlet pipe is in contact with the bottom surface of the oil groove, resulting in poor oil inlet. Ensure that there is a certain distance between the end face of the oil inlet pipe and the bottom surface of the oil groove to make the oil inlet smooth.

7) Draw air from the suction port of the pump. Ensure that the connections of the pump suction channel are closely connected without air leakage, and the suction inlet is immersed in oil at a certain depth.

8) The oil level in the tank is too low. Ensure that the oil level in the oil tank reaches a certain height.

(3) The pressure rise is not high.

1) Draw air from the suction port of the pump. Ensure that the connections of the pump suction channel are closely connected without air leakage, and the suction inlet is immersed in oil at a certain depth.

2) Inner rotor speed is too low. Check whether the power transmission connection from the main shaft to the inner rotor is loose or slipping.

3) The oil suction port is partially blocked. Check whether the area of oil suction port is sufficient and effective.

4) The meshing state of worm gear, worm or gear is not good, and the time difference is good, resulting in high and low internal rotor speed. Check whether the worm, worm gear or gear of the oil pump drive system, the fastening screw or locating pin of the inner rotor are loose, and whether the worm gear and the main shaft worm mesh normally.

(4) The noise of cycloidal rotor oil pump is too loud.

1) The oil level is too low to absorb air, or the filter screen is partially blocked, resulting in insufficient oil absorption. Add oil or clean the filter screen to make the oil absorption smooth.

2) Parts are severely worn. Replace the pump with a new one or severely worn parts.

3) The position of the meshing point of pump power transmission has changed. During adjustment, pay attention to keep the original meshing point of the machine transmission gear.

(5) The cycloidal rotor oil pump leaks oil.

1) The fastening screw or connector of the pump body is loose. Tighten the screw or connector.

2) The seal is damaged. Replace the seal.

3) Poor sealing of oil outlet flange. Remove dirt and burrs and reinstall.

4) The pump body and cover are deformed or damaged. Repair or replace the cycloid rotor oil pump.

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