Internal gear pump common faults: pump suction oil, output flow is not enough, pressure can not go up. The following gear pump fault repair method:

One, check the outer gear
1. The tooth surface is badly worn due to the bad material of gear (such as powder metallurgy gear) or heat treatment. For powder metallurgy gear, it is recommended to change to steel gear, and heat treatment.

Involute internal gear pump structure and the main parts to be repaired: 1 -- mining shaft; 2. External gear; 3 -- pump core assembly; 4 - the key; 5 -- thin wall bearing; 6 - bearing; 7 - oil seal; 8 - screw; 9 - washer; 10 - front cover; L1 - back cover; 12, 13 -- o-rings.
2, gear end face wear and tear. Gear end face wear and tear is not serious, can be ground and polished for reuse; If wear and strain is serious, the gear end face can be ground to size h1, outer gear ring h2, stator inner hole depth h3 should also be ground to the same size.

3. Tooth tip circular wear. Brush-plated gear cylindrical to compensate for wear.

Two, check the inner gear ring

1. When the fit gap between the outer circle of the inner tooth ring and the inner hole of the shell is too large, the outer circle of the inner tooth ring can be brushed and plated.

2. If the tooth side gap between the inner gear ring tooth surface and the gear tooth surface is too large, in areas where conditions are favorable (such as the pearl river delta region and the Yangtze river delta region), the copper inner gear ring and the outer gear can be re-processed with wire by linear cutting machine and replaced after heat treatment.