17
field repair
Figure 15
Model 34.4 Final Assembly
5. Apply a coat of Permatex® Form-a-Gasket No. 2 to surface
of Geareducer case which mates with case cover. Lower
case cover subassembly onto case, piloting both shaft
subassemblies into their respective bores.
6. Install taper pins (20) to align bearing bores. Fasten case
cover to case with cap screws tightening to 45 ft·lbƒ
(61 N·m) torque.
7. a–Position top interstage cap shims (500) and install inter-
stage bearing cap with place bolts.
b–Adjust shims to give proper backlash—.006–.012" normal
(.152–.305mm)—between spiral bevel gears. See Gear
Setting Procedure, page 18.
c–When proper backlash has been set, tighten place bolts
to 90 ft·lbƒ (122 N·m) torque.
8. Fan shaft bearing must be preloaded to .001–.003" (.025–
.076mm) in the following manner:
a–Initially install a quantity of shims between case and bot-
tom cap to insure that axial bearing end play exists.
b–Mount a dial indicator to measure axial movement of fan
shaft. Support indicator stand on the cover or interstage
cap adjacent to fan shaft and position indicator to read on
machined top surface of fan shaft.
c–Rotate the fan shaft slowly in one direction until all down-
ward movement stops. Rotation is necessary to align the
bearing rollers and seat roller ends on cone lip. Record the
dial indicator reading or zero the indicator.
d–Move shaft in the opposite axial direction by attaching to
the shaft with a swivel joint and hoist or by turning Geareducer
over allowing the weight of the shaft assembly to seat the
bearings. If a hoist is used, the lifting force should be 700 lb
(317 kg) to sufficiently overcome the weight of the fan shaft
assembly. Rotate the shaft slowly in one direction until all axial
movement stops. Record the dial indicator reading.
➠
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7
6
5
4
4
4
10
11
9
5
8
3
1
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