MARINE CORPS TM 6115-34/8
MAINTENANCE OF ENGINE
The gas turbine engine
the starter spur gear. The starter spur
consists of the combustion chamber case
gear transmits the power to a quill
assembly, turbine assembly, and the
shaft that drives the oil pump gear.
gearbox. The engine is a single-shaft
design with the compressor and turbine
The overhaul proce-
wheels mounted on a common shaft. Power
dures follow the methods and use the
produced by the turbine wheel is specifications recommended by the
manufacturer for the successful overhaul
generator and oil pump drive assemblies
of the major
components of the gas
in the gearbox.
Due to the precision
specifications and torque values should
Assembly. During engine operation, air
be strictly followed. Long engine life
is drawn in through the compressor air
and efficient operation depend on the
inlet, compressed by the vanes of the
compressor impeller, and distributed to
inspections, repairs, and adjustments
the outer chamber of the combustion
Terminology used in relation
chamber case. The compressed air then
to general defects is defined in table
passes through holes in the combustion
chamber and through three fuel injection
chamber. Fuel is atomized in the fuel
(1) Note the following:
compressed air, and injected into the
(a) The inspection area must be
combustion chamber where it is ignited
thoroughly clean and the air should be
by the spark igniter. Once combustion
has started, the igniter is deenergized
and combustion is self-sustaining.
(b) The area must be well
fuel in the combustion chamber expands
(c) Cover inspection tables with
rapidly and is forced through the vanes
clean, dry paper.
Keep special gages
of the turbine nozzle and against the
and indicators in cabinet lockers when
vanes of the turbine wheel.
not in use.
the turbine wheel to rotate.
is transmitted to the
(d) Openings uncovered during
shaft which then transmits it to the
inspection and repair shall be closed
accessory drives located in the gearbox.
with appropriate covers, plugs, or caps.
DO NOT USE TAPE.
(e) Inspection limits set forth
shouldered shaft imparts rotary power to
in this manual are manufacturing and
oil pump drive
normal wear limits.
Before condemning a
assemblies in the gearbox.
the specifications for
power is picked up by a pinion spur gear
operating limits with the mating part.
that turns the output spur gear. The
In many instances, mating or seating
output spur gear transmits the power to
surfaces for ball or roller bearings,
the generator shouldered shaft and to
and friction bearings on