Practical knowledge: maintenance of centrifugal pump bearings technical standards
A rolling bearing
1, the bearing and shaft with the use of base hole system, bearing and shell with the use of the base axis system.
Bearing size tolerances and rotational accuracy of the value according to the provisions of GB307-84.
2, with the journal bearings and bearing housing bore hole according to the provisions of GB1031-83, journal roughness Ra value of less than 1.6μm, bearing housing hole roughness Ra value of less than 2.5μm.
3, with GCr15 and ZGCr15 steel bearing rings and rollers, the hardness value of the ferrule and roller should be 61 ~ 65HRC; with GCr15SiMn and ZGCr15SiMn steel, the hardness value should be 60 ~ 64HRC. The hardness of the inspection methods and the hardness of the same parts according to the provisions of JB1255.
4, check the bearing radial clearance and axial clearance should be consistent with the provisions of GB4604-84.
5, rolling bearing inner and outer raceway raceway should be free from flaking, serious wear and tear, the inner and outer rings are not allowed to crack; ball should be no wear, cage no serious deformation, rotation no abnormal noise and vibration, stop gradually stop.
6, for C-class tolerance tapered roller bearings, roller and raceway raceway contact accuracy, under the action of a certain load, the color check, contact traces should be continuous, contact length should not be less than 80 of the roller bus.
Second, sliding bearings
1, for radial thick-walled tiles
â‘ using pressure lead method, lift the shaft method or other methods to measure the bearing clearance and the amount of interference with the shingles, shaft clearance to meet the requirements, tile interference should be 0 ~ 0.02mm.
â‘¡ check the various components, there should be no damage and cracks, bushings should be no flaking, pores, cracks, grooves and partial wear burn situation.
③ bearing bush contact with the color inspection method, check the angle should be no 60 ° ~ 90 ° (speed above 1000r / min take-off limit, speed less than 1000r / min to take the upper limit). In the contact area requires uniform contact, each square centimeter should have 2 to 4 contact points, if the contact is poor, you must scratch research.
â‘£ clean bearing box, the hole smooth, no cracks, leakage phenomenon.
⑤ tile back and bearing housings should be closely fit, with coloring inspection, the contact area of ​​not less than 50.
2, for the radial thin-walled tiles
â‘ bearing alloy layer and shingles should be firmly and closely integrated, no delamination, shelling phenomenon. The surface of the alloy layer and the facets in the two half-shingles should be smooth and flat, and do not allow cracks, pores, heavy skins, slag inclusions and bumps.
② tile back and bearing seat hole surface should be close and uniform fit, check with the coloring method, the inner diameter of less than 180mm, the contact area of ​​not less than 85, the inner diameter greater than or equal to 180mm, the contact area of ​​not less than 70.
â‘¢ bearings and journal with the gap and contact conditions are guaranteed by the machining accuracy, the contact area generally does not allow scraping, uneven contact along the axial direction, can be slightly modified.
â‘£ After assembly, the surface of the divider with 0.02mm feeler inspection, should not be inserted as qualified.
3, for thrust bearings
â‘ bearing bush should be free of wear, deformation, cracks, scratches, delamination, rolling and burn defects; contact with the thrust plate should be printed at the same impression, the contact area should be not less than 70 and the entire circumference of the tile evenly; Pad thickness difference should not be greater than 0.01mm, tile Babbitt should be rounded into the direction of rotation into the wedge, in order to facilitate the entry of lubricating oil ; back bearing surface smooth.
â‘¡ adjust the gasket should be smooth, flat, not bending, with a thickness difference of not more than 0.01mm layer gasket.
â‘¢ After the assembly of the bearing cap repeatedly push the shaft method to measure thrust bearing clearance, the value should be within the required range. The thrust bearing clearance measured by this method and measured by the shaft displacement probe must be the same, and adjust the indicated zero of the displacement probe as required.
â‘£ bearing shell horizontal joint surface tight, good bit. Oil temperature measuring oil hole and tile cover eye alignment, not skewed. Oil hole clean and smooth.
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