Gear pump parts wear repair skills: 1, the gear wear and tear repair: gear wear parts mainly tooth meshing, involute face and gear at both ends of the plane. Slight wear, the tooth surface can be whetstone grinding, both ends of the flat grinding on the flat light. Serious wear gear teeth should be replaced with new gear, if only the ends of the gear wear, grinding grinding in the surface grinder. After changing the gear mapping, the modulus m = 3, the number of teeth z = 12, the tooth angle α = 20 °, the tooth top height coefficient f0 = 1, the tooth positive displacement coefficient x1 = x2 = 0.5, The dimensions are calculated as follows. Index circle diameter: d = mz = 3X12 = 36 (mm) Height of tooth tip: ha = m f0 + x = 3X l + 0.5 = 4.5 mm Root height: hf = m f0 + Total tooth height: h = ha + hf = 4.5 + 2.25 = 6.75 (mm) Tip diameter: Da = d + 2ha = 36 + 2X4.5 = (Mm) Fixed chord thickness: Sxn = m (π / 2 * cos2a + xsin2a) = 3X (1.387 + 0.6428X0.5) = 5.125 (mm) Tooth height for fixed chord thickness measurement: hxn = m /8*sin2a+xsin2a)=3X(0.7476X0.117X0.5)=2.42(mm) Modulus m3 Displacement Coefficient x0.5 Profile Angle o20 ° Fixed String Thickness Sxn5.12 Tip Height Coefficient f1 Fixed Chord Tooth thickness measurement of the highest tooth height hxn2.42 Number of teeth z12 2, the shaft wear and tear repair: gear pump shaft wear mainly due to friction between the shaft ends and the support needle roller wear, so that smaller shaft diameter. If it is slightly worn, the shaft can be enlarged by plating a hard chrome to make the shaft repaired. If the shaft wear serious, 45 steel or 40Cr steel should be re-manufactured, shaft rough rough, fine car, the bearing parts to be heat treated, the hardness of HRC60-65, and then grinding, the bearing surface roughness Ra with parts Greater than 0.32μm; shaft roundness and cylindrical tolerance of 0.005mm; with the gear with the H7 / h6, the surface roughness Ra should not exceed 0.63μm. 3, the pump body wear and tear repair: pump body surface wear is mainly oil-absorbing section arc-shaped face .If there is a slight wear, can be used whetstone after grinding grinding to use. The pump body is made of cast iron casting blank, severe wear and tear should be replaced when the new pieces. If both ends of the gear in the pump are repaired by grinding, the width of the pump should be changed to the same size as that of the two ends of the gear. The two ends of the pump after reworking should meet the technical requirements as shown in Fig.3. 4, both ends of the cover wear repair: Gear pump cover made of cast iron, there wear phenomenon, the slight flat grinding grinding, wear more serious grind surface grinding machine. After grinding the end cap and the pump body with the connection plane contact should not be less than 85% flatness tolerance, the end of the hole centerline vertical tolerance, the tolerance of the parallelism of both ends and the center of the two axis hole Line parallel tolerance are O.Olmm. After grinding the surface roughness Ra should not exceed 1.25μm. 5, pump needle roller bearings repair and replacement: pump parts repair, needle roller bearings should be replaced. Needle on the needle is: the size of the needle roller diameter error should not exceed 0.003mm, the length tolerance of 0.1mm, and the shaft with the gap should be around O.Olmm; needle roller assembly according to the number of requirements filled bearing shell, Needle roller to be arranged parallel to each other.