Gear pump maintenance are as follows: First, the demolition Before disassembly should be fully prepared, familiar with the equipment structure, process, running state; Disassembly should be careful to avoid damage to equipment parts. Second, review the data Gear pump parts with the gap, should do a comprehensive inspection, the standard part of the gap in Table 1--1. Third, check the parts removed for a detailed examination of the gear for color inspection, does not allow the existence of cracks; shaft conical qualified, the surface shall not be scratched, the maximum allowable roughness Ra of 1.6μm; Bracket, pump body shall not have obvious defects. Fourth, the repair or replacement of excessive parts should be replaced, repair of parts, repair should meet the standards. 5. Assemble and adjust the axial clearance between gear end face and end cap and bracket by adjusting the thickness of the seal between the end cap, bracket and pump body; when the end cap bolt is fastened, the force is symmetrical and even, When the rotor is tightly pressed, the bolts should be loosened when it encounters the rotor. When the packing or oil seal is added, the rotor still needs to be tightly pressed while tightly pressing the cover, so it can not be too dead. Sixth, the test hydraulic pressure test for 1.5 times the working pressure, keep 5min does not leak, run the test, no leakage, the normal operation of the sound, no abnormal vibration, the outlet pressure to meet the requirements of qualified. Table 1--1 Gap of each part of gear pump Item Parameter Range Meshing top clearance of gear / mm Total axial clearance of gear end face and end cap / mm Radial clearance of tooth top and housing / mm Shaft diameter and radial direction of sliding bearing Clearance / mm Gear and shaft with the bearing Cylindrical and end cap bore with Needle bearing Inner sleeve with Needle roller bearings Outer ring and bore with Needle roller bearings Without inner ring and needle matching Packing Gland Radial clearance of shaft / mm Coupling with shaft Shaft clearance at both ends / mm 0.2 ~ 0.3 0.15 ~ 0.10 0.10 ~ 0.15 (1 ~ 2) d / 1000 H7 / m6 R7 / h6 Js6 K7 H7 / h6 0.4 ~ 0.5 H7 / k6 2 ~ 4