TM 5-4310-385-13
SECTION III. TECHNICAL PRINCIPLES OF OPERATION
1-13. GENERAL. This section contains a description of how the air compressor works. The overall system was
described in paragraph 1-9. The operation of the compressor unit is described in further detail in paragraph 1 -14, and
operation of the electric motor is described in paragraph 1-15, and electric motor controls are described in
paragraph 1-16.
1-14. OPERATION OF THE AIR COMPRESSOR UNIT
a.
The air compressor is a two stage air cooled type compressor powered by the electric motor through pulley, belts
and flywheel.
b.
The cycle starts with the low pressure piston (1) at the top of its stroke. When the piston moves down, it draws air
through the air filter and silencer (2) and inlet valve blade (3) into the cylinder. The air filter keeps dirt out of the cylinder
head.
c.
On the upstroke, inlet valve blade (3) closes and the low pressure piston (1) pushes air out into the intercooler (4)
through the exhaust valve blade (5). Compressing the air heats it up. The finned intercooler tubing (4) gets rid of some of
that heat before passing the air on to the high pressure head. The intercooler is cooled by air drawn by the flywheel fan
blades.
d.
The high pressure stage works the same as the low pressure stage except that the high pressure piston (6) goes
up when the low pressure piston (1) goes down. The low pressure piston draws air in while the high pressure piston
pushes air out.
COMPRESSOR UNIT
1. LOW PRESSURE (LP) PISTON
6. HIGH PRESSURE (HP) PISTON
2. AIR FILTER
7. HP INTAKE VALVE ASSEMBLY
3. LP INTAKE VALE
8. HP EXHAUST VALE ASSEMBLY
4. INTERCOOLER
9. AFTERCOOLER
5. LP EXHAUST VALVE
Operation of Compressor Unit
1-7
