KCB marine gear pump wear diagnosis and repair parts replacement
(1) gear wear repair
The wear parts of the gear are mainly the meshing of the teeth, the involute face and the two ends of the gear. 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, Park Taibang if only two ends of 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.
Diameter circle: d = mz = 3x12 = 36 (mm)
Tip height: ha = m (f0 + x) = 3x (l + 0.5) = 4.5 (mm)
Dedendum height: hf [= m (f0 + cx) = 3x (l + 0.25-0.5) = 2.25 (mm)
Tooth full height: h = ha + hf = 4.5 + 2.25 = 6.75 (mm)
Tip diameter: da = d + 2ha = 36 + 2x4.5 = 45 (mm)
Fixed chord thickness: sxn = m (Ï€ / 2 * cos2a + xsin2a) = 3x (1.387 + 0.6428x0.5) = 5.125 (mm)
Fixed tooth thickness measurement tooth height: hxn = m (Ï€ / 8 * sin2a + xsin2a) = 3x (0.7476x0.117x0.5) = 2.42 (mm)
Modulus m3 displacement coefficient x0.5
Tooth angle o20 fixed chord thickness sxn5.12
Addendum coefficient f1 fixed tooth thickness measured the highest tooth height hxn2.42
Number of teeth z12
(2) shaft wear repair
Gear pump shaft wear is mainly due to friction between the ends of the shaft 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, the rough rough shaft, fine car, the bearing parts to be heat treated, hardness hrc60-65, and then grinding, so that the bearing surface roughness ra parts Greater than 0.32μm; shaft circularity and cylindrical tolerance of 0.005mm; with the gear with h7 / h6, the surface roughness ra should not be greater than 0.63μm.
(3) pump body wear and tear after repair
Pump body surface wear is mainly arc-shaped section of the suction section.If there is a slight wear, use whetstone grinding to deburring 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 body should also be changed to the same size as that removed by grinding at both ends of the gear. Both ends of the pump body after reworking should meet the technical requirements.
(4) After the two end cover wear and tear repair
Gear pump end cover made of cast iron, there wear phenomenon, the slight grinding flat on the flat grinding, wear more serious grind on a flat grinder. 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 The parallelism tolerance of the line is o.olmm. After grinding the surface roughness ra should not be greater than 1.25μm.
(5) pump needle roller bearings repair and replacement
After the pump parts repair, the needle roller bearings should be replaced. The needle requirements are: the size of the needle roller diameter error should not exceed 0.003mm, the length tolerance of 0.1mm, with the shaft clearance should be around o.olmm; needle assembly according to the number of requirements filled bearing shell, Needle roller to be arranged parallel to each other.Industries Enclosures
Customized Equipment Enclosures,Waterproof Enclosures,Powder Coated Enclosures,Non-Standard Enclosures
FCX Metal Structure Co., Ltd. , https://www.fcxmetal.com