Type B pump body and the end cover on both sides of the gear pump for direct contact with the hard seal, if the flatness of contact surface can not meet the specified requirements, the pump at work to inhale air;
Also, the end cover of the pump and also for direct contact between gland, air also easy invasion;
If the gland for plastic products, because of its damage or deformation due to temperature change, also can make the untight seal and into the air.
Rule out the failure of the method is: when the pump body and pump cover the requirements of the flatness of less than, can on the tablet press with carborundum grinding back and forth '8' glyph route, can also be on the surface grinding machine grinding, make its flatness is not more than 5 microns, and need to make sure that the plane and hole of the vertical degree requirements;
For the leakage of pump cover and gland, coating epoxy resin adhesives can be used to seal.
Commonly used on the pump shaft seal skeleton oil seal type.
If card tight lips spring fall off, or oil seal is installed inside, or the labial ministry is strain, aging, will make the oil seal the back-end often is in a state of negative pressure and suction air, can replace the new oil seal commonly.
Inside the fuel tank of oil is not enough, or suction tubing not advanced to the oil under the surface, the pump will be sucked in air, this time should be added to the tank oil to oil lines;
If return pipe mouth above oil level, sometimes because of instantaneous negative pressure in the system and make the air to fill into the system, so the return pipe mouth in general should be inserted below the oil level.
From the installation position of the pump oil level is too high, especially in the pump speed to reduce, because cannot guarantee oil pump suction cavity necessary cause lack of oil absorption and inhalation of air vacuum.
At this time should be adjusted with the relative height of oil pump, make it meet the requirements of regulations.