SB--7--627 Page 18
the headplates from the case. One piece shafts permit
normal working loads for V--belt drives without the
addition of outboard bearings.
In rare instances, shaft replacement might be
necessary. Although removal is somewhat involved, it
is fairly simple if the following procedure is adhered to.
1.
Remove any obstructing oil lines from both ends
of the unit.
2.
Remove the gear case (see “Gear Inspection,”
page 15.
3.
Check the fixed end impeller clearance. This
clearance should be duplicated when repairs are
completed.
4.
Remove timing gears and hubs per instructions on
page 19.
5.
The impellers will now rotate freely in the case.
Position both impellers so that one--half of the tip
of the impellers can be seen when looking inside
the unit from either the intake or discharge
openings. Wedge a shim between the tips and the
case on both the top and bottom of each impeller,
locking them both in this position.
6.
Unbolt and remove the cover on the drive end of
the unit.
7.
Unbolt and remove the bearing cartridges from
both ends of the shaft being replaced as described
in “Bearing and Seal Replacement,” page 20.
8.
Remove the socket head cap screws on the gear
end of the shaft.
9.
The shaft can now be removed by driving it from
the drive side of the unit with a lead hammer and
hydraulic press.
10. Before installing a new shaft, remove all burrs and
coat the new shaft with anti--seize compound.
Slide the shaft in from the gear or fixed end toward
the drive end.
11. Rebolt the shaft, using new cap screws, to the
impellers and tighten with a torque wrench. See
FIGURE 13, page 17, for torque values.
12. Replace bearing cartridge per instructions on
page in “Bearing and Seal Replacement,” page
20.
13. Remove the shims that are locking the impellers
inside the case.
14. Set the impellers in the central timing position,
making certain that the tip and throat match marks
correspond. See “Determining Impeller Clear-
ances,” page 16, and replace timing gears and
hubs as outlined on page 19.
15. Retime the blower according to instructions on
page 17.
16. Remove the seal from the seal retainer mounted
on the drive cover.
17. Replace the cover on the drive end.
18. Install a new oil seal in the retainer that mounts to
the drive cover. Carefully center the seal on the
shaft.
19. Replace the gear case and any oil lines.
20. Relubricate and follow “Blower Startup Checklist,”
page 12.
Follow Blower Startup Checklist on
page 12 after every shutdown.
