37- 1- 613 Page 48
FIGURE 7- 21
FIGURE 7- 22
22. Turn the unit end for end, gear end up. With a
depth micrometer on a perfectly flat parallel bar
across the bearing bore, measure the distance to
the shoulder in the bearing bore, FIGURE 7-22.
23. Remove tape from the shaft holding the bearing
spacers in place. Tap the spacer to be sure it is
solidly against the end of the rotor. This is impor-
tant for the next measurement. With a depth
micrometer on the same parallel bar used in Step
21, measure the distance to the end of the bearing
spacer, FIGURE 7-23. Measurement to the
spacer should be .020
” to .050” less than the
measurement to the shoulder. This clearance
insures free bearing float without the use of
shims.
24. Install both seals using the installation tools.
Expulsion port must be positioned down towards
bottom of the unit. Press the seals down and
verify seal face is below the bearing spacer face.
25. Coat the shaft extension and bore with oil. Slide
the bearing (25) over the shaft. Assemble the
press plate as shown in FIGURE 7-46, page 36
and press bearings in place, solidly against the
bear- ing spacer. Tighten nuts on the jackscrews
evenly to prevent cocking of the bearing. Use the
same procedure for both bearings. Bearing
retainer plates are not used at this end of the
blower.
26. Check the fit of the key (32) in the gear hub (9) and
pinion (7). Check the pinion, hub and shaft
extensions for burrs. Install the keys in the shafts,
making sure of a snug fit. Heat the pinion and hub
in oil or dry heat, such as an oven (NEVER USE
TORCH) to 350° F for thirty minutes minimum to
allow for complete heat penetration. If heating
with oil in a confined area, use of cooking oils will
prevent undesirable odors.
Lock the rotors from turning with a piece of hard
wood or belting. Install the hub and pinion and pull
tight with a locking device, FIGURE 7-27, page
46. Use the hub retainer (11) and screws (41) to
pull the hub up tight against the bearing.
As the hub and pinion cool, check for tightness.
The bearing and bearing spacer must be clamped
FIGURE 7- 23
