*TM 1-1500-204-23-5
Change 3
3-4.13
i.
Oil Circulation. Oil is circulated in each trans-
mission lubrication system by two separate elements of
the six--element lubrication pump in the combining trans-
mission. Oil flows from the oil tank through the pressure
pump, through the filter and relief valve assembly,
through the oil cooler, and through the check valve. Then
the oil flows into the transmission where it is sprayed
on thegears and bearings by various jets. Oil is scav-
enged from the sump by the scavenge section of the oil
pump and returned to the oil tank.
j.
Engine--Combining Transmission. The combin-
ing transmission is a central collection and distribution
point for the drive system. The combining transmission
is mounted in the lower forward section of the pylon.
Torque from the engine transmission is transmitted by
the combi£ng transmission and the forward and aft syn-
chronizing drive shafts to the forward and aft rotary--wing
drive transmission. Speed reduction is also attained with-
in the combining transmission. The output shaft drives
the lubricated pump. The three--section oil tank (one sec-
tion each for the combining transmission and each en-
gine transmission) forms the uppermost portion of the
combining transmission.
(1)
Oil System Components. The combining
transmission oil system is a complete and separate oil
system. The system includes the oil sump, oil tempera-
ture transmitter (bulb), oil pump, oil pressure transmitter
(transducer), filter and relief valve, bypass valve, trans-
mission lubricating jets, check valve, magnetic chip de-
tector, oil tank, and oil coolers.
NOTE
The reservoir for the oil system is the center
section of the three--section oil tank on the
combining transmission. The three--section
oil cooler and fan assembly is mounted on the
top section of the transmission.
(2)
Oil Circulation. Oil is circulated by two sepa-
rate elements: one pressure element and one scavenge
element of the six--element oil pump in the combining
transmission (Figure 3-3.L and 3-3.M). Oil is routed from
the oil tank through the filter and bypass valve and
through an external line to the oil cooler. The oil is then
routed by an external line through a check valve to the
transmission. In the transmission oil is distributed
through internal passages and jets and is sprayed on
bearings and gears. Oil is scavenged from the sump
through internal passages by the scavenge element of
the oil pump. The pump then pumps the oil to the tank.
A sight level gage is installed on the forward end of the
oil tank.
k.
Forward
Rotary--Wing
Drive
Transmission.
Torque is delivered to the forward rotary--wing drive
transmission by the forward synchronizing drive shaft
from the combining transmission (Figure 3-3.N). The for-
ward rotary--wing transmission then changes the direc-
tion of torque from a horizontal plane to a vertical plane.
This reduces the input shaft speed. The forward rotary--
wing transmission transmits the torque through the
rotary--wing drive shaft (mast) to the rotor bead.
(1)
Oil System Component. The oil system
serving the forward rotary--wing drive transmission is a
complete, separate system. It is a wet--sump system,
which includes the oil temperature transmitter (bulb),
screens, oil pressure pump, oil pressure transmitter
(transducer), relief valve, pressure filter, magnetic chip
detector, oil cooler, and No.1 flight control pump.
(2)
Oil Circulation. Oil from the sump flows
through the screen to the inlet of the pressure pump. The
pump pressurizes the system and pumps oil through the
filter and cooler and then back to the transmission. Drilled
and cored passages in the transmission distribute the oil
to lubricators and oil jets The lubricators and jets spray
the oil into the transmission bearings and onto the rotat-
ing gears.