starboard sides of the craft. The BITE box is an indicator
Gas Turbine Generator Set
unit that receives gas turbine status signals from the
The basic internal components of the Sunstrand's
ESU. The BITE display identifies probable causes of
GTGS are shown in figure 7-23. There are two GTGSs
GTE shutdown.
on the LCAC; one mounted port, the other mounted
starboard. These sets are mounted in modules within
Gas Turbine Engine
plenum compartments.
The Sunstrand T-62T-40-7 engine is a radial-flow,
COMPONENTS AND DESIGN. Each GTGS
150-horsepower, single-stage compressor, single-stage
consists of an ac generator, air inlet housing, combustor
turbine, coupled gas turbine unit. Figure 7-24 provides
assembly, turbine assembly, and reduction gear drive
several views of this unit. The top and one side are shown
assembly. Filtered air within the plenum compartments
in view A. The front and rear are shown in view B.
is used for turbine inlet combustion air and generator
cooling.
The Sunstrand T-62T-40-T consists of the following
major units:
Enclosure Assembly. An enclosure assembly
houses each GTE and provides mounting for the turbine,
Compressor
exhaust connections, ship's pipes and drain connections,
and electrical connections. Access doors on the
Combustor
enclosure provide for access to the gas turbine
Turbine
components and enable inspection and maintenance.
Gear reduction drive
Generator. The generator is a 120/208-volt,
400-Hz, 60-kW ac generator. The GTE is a radial-flow,
In the following paragraphs, we will briefly discuss
150-horsepower, single-stage turbine, coupled gas
the Sunstrand and its associated equipment, including
turbine.
the electrical control devices, accessories, and piping.
Let's first start with the air inlet housing.
Control Components. The control components
for each GTGS are mounted in a controls enclosure
AIR INLET ASSEMBLY. The air inlet housing is
located in a compartment below the GTGS. (This
a contoured, cylindrical casting with forward and aft
location is on both port and starboard sides.)
flanges. The forward flange is bolted to an adapter,
which is bolted to the aft end of the reduction drive
The control components consist of a GCU, an ESU,
housing. The aft end of the air inlet housing is externally
and a K1 relay. The gas turbine is controlled and
flanged to permit attachment of the combustor
monitored by the ESU. The ESU contains all the logic
assembly. The air inlet housing thus serves as a rigid
circuitry to start, control, monitor, and shutdown the gas
member between the reduction drive assembly and the
turbine. The APU speed is monitored at the craft's alarm
combustor assembly. An air inlet screen assembly
and monitoring system. The ESU provides the signals
covers the intake portion of the housing.
to this system.
ROTOR ASSEMBLY. The rotor assembly
The GCU controls the operation of the generator. It
consists of a rotor shaft, single-stage centrifugal
provides voltage regulation, controls output voltage, and
compressor wheel, radial-inflow turbine wheel,
protects the generator from overvoltage, undervoltage,
bearing retainer and oil slinger nut, spacer, forward
underfrequency, overfrequency, and fault current. Relay
ball bearing, and aft roller bearing. The rotor shaft is
K1 (port and starboard sides) is a generator protective
mounted on bearings within a sleeve in the bore of the
device that opens and disconnects the generator when a
air inlet housing. The single forward ball bearing
fault is sensed by the ESU.
resists thrust and radial loads, while the aft roller
Current Transformer. A current transformer,
bearing resists radial loads only. The forward ball
located on both port and starboard sides, provides feeder
bearing is held in position by a retainer plate and an
fault protection for the generator. It will sense a short
oil slinger nut.
between the generator and any of its line contacts. If a
COMPRESSOR WHEEL ASSEMBLY. The
short exists, the current transformer will disconnect the
compressor wheel shoulders against a flange on the aft
generator.
end of the rotor shaft. Three threaded compressor bolts
BITE Annunciator Box Assemblies.- The BITE
are inserted through the flange into the compressor
annunciator box assemblies are located in the port and
wheel. These bolts maintain the alignment of the
7-27
