P-9-TM-457-35
T.O. 35C2-3-442-2
TM-07464A-35
TM 5-6115-457-34
Legend to figure 8-24:
13.
Bolt (3)
Lock washer (3)
1.
14.
2.
Adapter
Nut (3)
15.
3.
Lock washer (3)
Gasket
Bolt
4.
16.
Seal
Nut
5.
17.
Nut
Lock washer
18.
6.
Locknut
7.
Gasket
19.
Ring
8.
20.
Bolt (4)
Bearing
9.
21.
Lock washer (4)
Gear
10.
22.
Cover
Bearing
11.
Gasket
23.
Shaft
12.
Bolt (2)
24.
Adapter
Section XV. GOVERNOR ACTUATOR UNIT (PRECISE SET ONLY)
1. Check for 4 to 6 VDC at test
8-108. GENERAL.
points AB and CD of electric governor con-
The governor actuator unit is located
trol unit (A and D are positive), with engine
on the right side of engine, mounted on top
operating. If voltage at either point is
of the utility governor. The actuating unit
approximately 15 volts, the malfunction is
is an electro-hydraulic servo motor that
a result of an open in an actuator valve
receives intelligence from the electric con-
coil, or connecting circuit.
trol unit and converts this low level elec-
trical information to proportional high level
2. Check that the throttle linkage is
hydraulic pressures that position the engine
not badly worn or disconnected. A worn
throttle by the action of a piston and a float-
linkage can cause sluggish response or
ing lever pivot linkage system. The gover-
drifting frequency. A disconnected or
nor actuator unit is composed of control
broken linkage can cause overspeed, shut-
valves, a piston, a linkage assembly and
down, or no response. Also check linkage
core and armature assembly,
for binding due to dirt or distortion.
3. Check condition of hydraulic
8-109. TEST AND REMOVAL.
filter and the level of hydraulic oil. Either
a. Symptom and Isolation of malfunction.
a clogged or dirty filter or low oil level
A malfunction of the hydraulic throttle actu-
can reduce the hydraulic pressure required
ator is usually indicated by engine shutdown
to operate the actuator.
or overspeed when the Start-Run-Stop
switch is transferred from the START to
4. Check pressure output of hydrau-
the RUN position, frequency drift observed
lic actuator by removing plugs in ports Al
on the frequency meters, sluggish response
and A2 (figure 8-25) and inserting 0 to 400
to load changes, or no response in load
PSI range gauges. The pressure at each
changes. To isolate the malfunction, pro-
port should be 160 25 PSI and equal, with
ceed as follows:
engine operating under governor control.
8-53
