quote:Originally posted by Sam Pickens:Blue for pattern; plasti-gage for clearance.
quote:I don't see where blue will give you clearance; only pattern - am I missing something?
quote: I cant convince our Maintenance Manager to perform the scraping (due the vendor telling him it wasn't "necessary because nobody scrapes bearings anymore") if for nothing at all but to rule it out as a possible source of the heating.
quote:IEEE 1068-1996:"Reassembly of bearings. Split sleeve bearings that are either new replacements or have been rebuilt should be fitted to journals by bluing and scraping as in the following:1) Using a bearing scraping tool (typically a triangular Ãžle with the teeth ground off), scrape any side reliefs and lands to the clearances and contours recommended by the motor manufacturer. Apply a small amount of nondrying bluing compound to the shaft journal, spreading it out to form a uniform coating 1 - 2 in wide over the full length of the bottom of the journal. Lift the shaft slightly, roll the lower bearing half into place, then lower the shaft onto it, ensuring that the normal rotor weight is applied to the bearing. Turn shaft 1/2 to 1 revolution. Lift the shaft again, and roll the lower bearing half out. A pattern of very light blue and dark blue areas will be seen on the bearing surface. These correspond to high and low portions of the bearing surface, respectively. Scrape the high spots to make the light/dark pattern uniform; the fitting process should be repeated with bluing as required until at least 80% contact has been achieved. When this is complete, leave the lower bearing half in place with the rotor weight resting on it."2) Lay two or three pieces of lead wire or other calibrated deformable gage material on the journal, perpendicular to the shaft centerline; their ends within 1/2 in of the horizontal split line. Make sure the upper and lower bearing halves are clean. If shims are used between the halves, make sure they are clean also. Place the upper bearing half over the journal on the wires or gage. Install the upper bearing cap or housing and tighten its bolts to speciÃžcation. Then unbolt and remove the upper bearing housing and upper bearing half carefully. Measure the thickness of the lead wire or the clearance of the deformed material as instructed on the package. If the clearance is within limits, remove the wires or gage and proceed with reassembly. If it is not within limits, both bearing halves must be rebabbitted if too loose, or top half of bearing must be scraped if too tight."