Page 178 - Practical Machinery Management for Process Plants Major Process Equipment Maintenance and Repair

160 Major Process Equipment Maintenance and Repair

fore the shaft is placed in the wheel. Place the shaft into the bore of the
hub. After the shaft is partially into the wheel, set both ends of the shaft
on supports, and turn the wheel to align the keyway. Alignment is simpli-
fied if the shaft keyway is on top during alignment. When aligned, push
wheel to correct position. Select the key marked “1” or “2” in double
wheel and, after coating the key with white lead and oil, tap into keyway
as marked. Tighten the wheel set screws only after wheel and shaft are in
place on the bearing and the inlet bell adjustment has been made.

Install Inlet Bells or VlVb

Place the inlet bells of fixed or variable vanes over the shaft, making
sure that the rotation arrow mark on the inlet part corresponds to the
housing and wheel marking. Take care not to damage the journal section
of the shaft.

Prepare and install Bearlngs
Remove the caps from the bearings and carefully clean the bearing sur-
faces with solvent. Apply a coating of clean oil with a clean applicator.
Some installers pour oil over the surface so that contamination cannot
occur. Cover immediately with a clean cloth to keep out contaminants.
Inspect and clean the oil rings, then put the shaft seals and oil rings in a
safe location so they will not be damaged before they are installed.

Bearing lnstallatlon
Depending upon the application, a variety of ball, roller, and sleeve
bearings are used. Generalized information for each type follows:
1. If a bearing is disassembled, mark its position in relation to each
part to avoid reassembly errors. Do not mix parts of one bearing
with another.
2. Determine the type of pillow block and location of fixed bearing.
3. Check all nameplates on fan for any special instructions.
4. Mount bearings in position on the shaft per specific directions that
apply to your type of bearing.
5. Clean the shaft and remove burrs or other irregularities. Be sure the
bearing is not to be seated on worn flat sections.
6. After final alignment, tighten and dowel whenever possible.