TM 55-1520-240-23-5
6-1
DRIVE SYSTEM
(Continued)
6-1
AFT TRANSMISSION
The aft transmission receives input torque from the
combining transmission through the aft drive shafting. It
transmits torque to the aft rotor shaft through a splined
connection.
NO BREAK - WORK HARDER
Spur gears in the transmission provide power to drive
pumps for the flight control and utility hydraulic systems
and two ac generators.
NO BREAK - WORK HARDER
The transmission is mounted above the ramp area of
cabin at the base of the pylon. Access is through hinged
baffles and a removable drip tray at the bottom of the
transmission.
AFT ROTOR SHAFT
The aft rotor shaft is splined to the top of the aft
transmission. It transmits input torque from the
transmission to the aft rotary-wing head and rotor
blades. The shaft turns in a bearing that is part of a
support bolted to the pylon structure.
NO BREAK - WORK HARDER
A slider shaft is mounted on the rotor shaft and bolted
to the support. It provides the bearing surface for aft
swashplate motion.
Lubrication System
Hot oil from the aft transmission and rotor shaft passes
through a circular oil cooler mounted on the aft end of
the transmission. The oil is cooled by a fan that pulls air
through the cooler. The fan is driven by the transmission
through a splined shaft.
NO BREAK - WORK HARDER
Oil is circulated by main and auxiliary pumps. The main
pump is at the aft end of the transmission. The auxiliary
pump is at the bottom of the transmission, covered by
the sump.
NO BREAK - WORK HARDER
The lubrication system is monitored and protected by
the following:
A combined indicating screen and chip detector,
and a temperature sensor on the aft transmission
sump. With 37 , a chip burnoff system lets the
chip detector burn off light fuzz and similar normal
debris before it activates indicators on the master
caution and maintenance panels.
NO BREAK - WORK HARDER
An inlet screen inside the aft transmission sump.
NO BREAK - WORK HARDER
Main and auxiliary pressure switches, a main inlet
screen and an auxiliary filter on the left side of the
aft transmission.
NO BREAK - WORK HARDER
A main filter at the aft left of the aft transmission.
In addition, the condition of oil at the aft rotor shaft
bearing is monitored by a chip detector, a pressure
switch, and a filter in the shaft support.
6-9
