Page 267 - Practical Machinery Management for Process Plants Major Process Equipment Maintenance and Repair

Power Transmission Gears 249

Figure 6-24. Coupling alignment.

4. Hand rotate shaft “B” around shaft “A.” Always rotate the gear
shafts in the direction they will turn under load. Do not reverse ro-
tation during alignment check.
5. Record the outside diameter and face indicator readings at 12
o’clock, three o’clock, six o’clock, and nine o’clock positions.
Shift shaft “B” into the same relative axial position prior to each
face reading; that is, with prize bar, move shaft axially in one direc-
tion until all axial clearance is removed.
6. Correct alignment as needed. Consider the anticipated thermal and
mechanical movements as discussed on page 257.

Shaft Operating Positions

At operating load and temperature, the final positions of the shafts of a
gear unit will differ from their positions under no load and ambient tem-