Technical Standard For Maintenance Of Bearings Of Centrifugal Pumps

Rolling Bearings

1. The matching of bearing and shaft adopts base hole system, and the matching of bearing and shell adopts base shaft system.

Bearing size tolerance and rotational accuracy values according to the provisions of GB307-84.

2. According to the provisions of GB1031-83, the roughness Ra value of the journal and the inner hole of the bearing box is less than 1.6μm, and the roughness Ra value of the inner hole of the bearing box is less than 2.5μm.

3, with GCr15 and ZGCr15 steel manufacturing bearing ring and roller, the hardness value of the ring and roller should be 61~65HRC; When manufactured with GCr15SiMn and ZGCr15SiMn steel, the hardness value should be 60~64HRC. The hardness inspection method and the uniformity of hardness of the same part shall be in accordance with the provisions of JB1255.

4. Check the radial clearance and axial clearance of the bearing in accordance with GB4604-84.

5. The inner and outer ring raceways of rolling bearings should be free from peeling and serious wear, and there should be no cracks in the inner and outer rings; The ball should be free of wear, no serious deformation of the cage, no abnormal noise and vibration when rotating, and should gradually stop when stopping.

6, for class C tolerance tapered roller bearing, the contact accuracy between the roller and the ring raceway, under the action of a certain load, color inspection, contact traces should be continuous, contact length should not be less than 80 of the roller bus.

Sliding Bearing

1. for radial thick wall tile

(1) Use lead pressure method, lifting shaft method or other methods to measure the bearing clearance and tile shell interference, the shaft clearance meets the requirements, tile shell interference should be 0 ~ 0.02mm.

② Check the parts, there should be no damage and cracks, bearing should be no peeling, pores, cracks, grooves and partial wear burns.

(3) The contact between the bearing bush and the journal is checked by the coloring method, and the inspection Angle should not be 60° ~ 90° (the lower limit of the speed is higher than 1000r/min, and the upper limit of the speed is lower than 1000r/min). In the contact range, uniform contact is required. There should be 2 ~ 4 contact points per square centimeter. If the contact is bad, it must be scratched.

(4) Clean the bearing box, the oil hole is smooth, there shall be no cracks, leakage phenomenon.

The tile back and bearing seat should be closely and evenly fitted, checked by coloring method, and the contact area is not less than 50.

2. For radial thin-walled tiles

(1) The alloy layer of the bearing bush and the shell should be firmly and closely combined, and there should be no delamination and shelling phenomenon. The surface of the alloy layer and the split surface of the two half tiles should be smooth and smooth, and it is not allowed to have defects such as cracks, pores, heavy skin, slag inclusions and bumps.

② Tile back and bearing seat inner hole surface should be closely and evenly fit, with the coloring method to check, the inner diameter is less than 180mm, the contact area is not less than 85, the inner diameter is greater than or equal to 180mm, the contact area is not less than 70.

(3) The coupling gap and contact condition of bearing bushing and journal are guaranteed by machining accuracy. The contact area is generally not allowed to be scratched. If the contact is not uniform along the axial direction, it can be slightly repaired.

(4) After assembly, check with a 0.02mm stopper at the middle part, which should not be stuffed into the qualified.

3. For thrust bearings

① Bearing bush should be free from wear, deformation, crack, scratch, delamination, rolling and burn defects; The contact with the thrust plate should be uniform, the contact area should not be less than 70 and the whole circumference of each tile evenly distributed; The thickness difference of the tiles in the same group should not be more than 0.01mm. The oil inlet wedge of the tiles should be rounded according to the rotation direction to facilitate the entry of lubricating oil. The bearing surface of the back is flat and smooth.

② The adjustment gasket should be smooth, smooth, not flexing, with a thickness difference of not more than 0.01mm of gasket.

③ After the bearing cover is assembled, the thrust bearing clearance is repeatedly measured by the push shaft method, and the value should be within the required range. The thrust bearing clearance measured by this method must be consistent with that obtained on the side of the shaft displacement probe, and the indicated zero position of the displacement probe must be adjusted according to the provisions.

(4) The horizontal joint surface of the bearing shell is tight and in good position. The oil hole for measuring oil temperature is aligned with the tile cover eye without deviation. The oil hole is clean and smooth.