TM 5-4310-451-14
1-14. AIR COMPRESSOR ASSEMBLY (Con’t).
b.
Cooling and Lubricating System.
(1)
The air compressor cooling and lubrication system is designed to provide adequate lubrication as
will as maintain the proper operating temperature of the unit.
(2)
The cooling and lubrication system consists of a main oil filter (6), a thermal valve (3), bearing oil filter (8), and oil
stop valve (7), in addition to an oil cooler (4) and fan (5).
(3)
Oil is used in the system as a coolant and lubricant. Oil is housed in the oil separator (1). Upon startup of
the air compressor assembly, the temperature of the oil is cool and routing to the oil cooler (4) is not necessary. The oil,
taking the path of least resistance, flows to the thermal valve (3).
(4)
The thermal valve (3) has two entrance ports, A and B, and one exit port. Port A accepts oil from the oil
separator (1) and Port B accepts oil from the oil cooler (4).
(5)
The oil first enters the thermal valve (3) and then flows on to the air compressor (2), bypassing the oil
cooler (4) As the air compressor assembly continues to operate, the temperature of the oil rises and Port A of the thermal
valve begins to close. The closing of Port A forces a portion of the oil through the oil cooler. The oil cooler is a radiator-
type cooler that works In conjunction with fan (5). The fan forces air through the radiator-tube oil cooler reducing the
temperature of the oil. From the oil cooler, the oil is routed back to the thermal valve, entering at Port B.
Before the temperature of the oil becomes high enough to completely close Port A, cooled oil entering at Port B is missed
with warmer oil entering at Port A. When the temperature of the oil reaches 1400F (60 C), Port A is completely closed,
causing all oil to flow to the oil cooler.
1-14
