10
Installation of Fan Shaft
1. Press ring gear hub (
5
) and the upper and lower bearing
cones (
411
and
412
) on the fan shaft (
201
). Install ring gear
(
101
) on ring gear hub and tighten cap screws to 55 ft·lbƒ
(75 N·m) .
2 Install the bottom cap using old shim pack or make up
equivalent thickness shim pack (
420
).
3. Press bottom fan shaft bearing cup (
411
) in bore.
4. Install fan shaft assembly in case.
5. Press upper fan shaft bearing cup (
412
) in cover. Apply a
bead of sealant to the cover flange inboard of the bolt holes.
Install cover on case. Install dowel pins in cover and drive flush
with top of cover.
6. Install cap screws and tighten to 20 ft·lbƒ (27 N·m).
7.
Install bearing retainer using old shim pack (
420
) or equivalent
and tighten cap screws to 20 ft·lbƒ (27 N·m).
5. Rotate the fan shaft several turns in each direction to seat the
bearing rollers. With a dial indicator and using the Geareducer
case as a reference, measure and adjust the fan shaft bearings
to .001-.003" (.025-.076mm) endplay. The endplay is adjusted
by adding shims (
420
) under the bearing retainer.
Installation of Pinion Cage
1. Find the difference between the pinion setting distance of
the old gear and the new pinion gear and adjust the old shim
pack (
320
) or make a new shim pack to compensate for the
different setting distances.
Example:
Pinion setting distance of old gear
4.883
Pinion setting distance of new gear
4.878
Difference
.005
Remove .005 from shim pack.
2. Install pinion cage subassembly into case.
Note
—Engage pinion gear tooth with "X" marked on end between
ring gear teeth marked with "X’s". Care must be taken not to damage
the pinion gear teeth by forcing them into the ring gear teeth.
Gear Setting Procedure
The proper mounting of the gear set is essential to obtain long
life and smooth operation of the gears. The pinion and ring gears
were positioned approximately in the preceding steps. The correct
gear position is determined by the gear backlash.
With the "X" marked tooth on the pinion gear engaged between
the two "X" marked teeth on the ring gear, check the backlash with
a dial indicator as shown in Figure 5. Lock the pinion shaft against
rotation. The amount of movement of the fan shaft, measured
at a distance equal to the outside radius of the ring gear is the
backlash. The backlash on all ratios should be between .007 and
.014" (.18 and .36mm). With the "X" teeth engaged, the backlash
should be approximately in the middle of the allowable range.
Check the backlash at three other points around the ring gear to
be sure the backlash is within the specified limits. Adjust ring gear
axially by removing or adding shims (
420
) at bottom bearing cap.
Note
—To maintain bearing adjustment corresponding shim (
420
)
adjustment must be made at the bearing retainer.
Example:
Removing .003" shims at the bottom bearing retainer
requires the addition of .003" shims at the top bearing retainer
to maintain correct bearing adjustment.
Recheck the backlash to make sure it is within the proper limits.
COLLAR
SET SCREW
TOP VIEW
OF INDICATOR
POINT OF MEASUREMENT
OUTSIDE RADIUS OF GEAR
DIAL INDICATOR
Figure 5
Gear Backlash Measurement
field repair
Summary of Contents for MARLEY Geareducer 1800
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