is proportional to the return of normal SSPU speed.
Once the oil pressure is equalized, the buffer spring
force recenters the buffer piston.
Now, picture the operation of all the mechanical
section components in reverse. As the SSPU load
decreases, the flyweights begin to move outward,
causing the governor pilot valve to rise. The oil on the
left side of the buffer piston drains to the oil sump,
thereby causing both the loading piston and the
power piston to move down. Once the fuel
requirement is met, movement of both the loading
piston and the power piston will stop, and the
governor pilot valve will recenter.
Speed Droop Function. The speed droop
function divides and balances loads between the
SSPUs. The speed droop function is automatic when
both generators are operating in parallel and driving
a common load.
The governor power piston, through linkages,
creates the speed droop function. The linkage
mechanism varies the speeder spring loads. The
linkage assembly has an adjustable pin that is
integral with the speed droop bracket. (See fig. 7-12.)
Any movement of the power piston will cause a
change in the position of the adjustable pin. The
changed position of the adjustable pin, in turn, will
determine the change in speeder spring force. No
change occurs when the speed adjustment lever pivot
Figure 7-13.Oil cooler, duplex oil filter, and
pin and the adjustable pin are on the same center
thermostatic valve installation.
line. As the adjustable pin moves from the center line,
however, the speeder spring force will change
accordingly.
Cooling for the Garrett's lube oil is provided by a
During electric governor control, the power
seawater type of oil cooler, such as the one shown in
piston will be in the maximum fuel flow position. This
figure 7-13. The cooler is equipped with a
position will be maintained throughout all load
thermostatic bypass valve.
conditions. Therefore, the speed droop function will
be inoperative during electric governor control.
The Garrett's lubrication system is composed of
During governor actuator control, the speed droop
the following major units:
linkage will not alter the speeder spring force.
Oil pump
LUBRICATION SYSTEM
Oil filter assembly
Oil inlet (filter) screen
The lubrication system for the Garrett ME-
831-800A is a full pressure, wet sump type. This
Oil manifold assembly
system provides lubricating oil to the SSPU
bearings, gear meshes, and shafts. It also
Oil cooler
provides lubrication to the ac generator and the
Thermostatic valve
load compressor.
Gearbox vent valve
The capacity of this oil system is 7.8 gallons.
The lower part of the gearbox forms the oil
Duplex oil filter assembly
sump, which is equipped with a filler cap and
Oil sample valve
dipstick for servicing.
