1, the gap between the tooth tip of the wheel and the pump shell is generally not more than 25 mm, such as increased can be replaced gear;

2. The gap between the end of the wheel and the shell cover should generally be within the range of 0.08-1OMM. If the clearance size must be changed, the gasket thickness on the end cover can be adjusted;

3, the clearance between the axle and the bushing, generally should be within 0.03 a 0.05mm, such as excessive wear of the bushing, it will increase the center distance of the two gears, but also inevitably lead to the increase of m and radial clearance between the meshing tooth tendency. Therefore, the wear of the shaft sleeve must be replaced beyond the range;

4. Inclination clearance of gear meshing teeth is generally not allowed to exceed 0.20mm. If the meshing tooth wear has exceeded the range, the gear should be replaced. Secondly, it should be checked whether the increase of the lateral clearance caused by the wear of the sleeve teeth.