and back to return. The rotary mechanical force
provided by the motor can be used to drive a gearbox,
torque tube, or jackscrew.
Hydraulic motors are commonly used cooperate
the wing flaps and radar equipment. Hydraulic
motors may be operated in either direction of rotation,
with the rotation being controlled by the direction of
flow to the valve plate ports. The direction of rotation
may be instantly reversed without damaging the
motor.
The direction of flow is controlled by a
selector valve.
A typical hydraulic motor is shown in figure 8-6.
This is a nine-cylinder, fixed-stroke motor. It is
self-lubricating and requires no line maintenance
other than periodic visual inspection for leakage. The
motor is equipped with a stub tooth spline, suitable for
engagement into the mechanical linkage of the unit to
be actuated on the aircraft.
Any shop maintenance that must be performed on
a hydraulic motor should be done in accordance with
instructions contained in the applicable Overhaul
Instruction Manual (03 series).
VALVES
Learning Objective: Identify typical valves in
a basic actuating system.
A valve is defined as a device that provides
control of the flow or pressure in a hydraulic system.
8-8
Figure 8-6.—Typical hydraulic motor.
