UAE

1. Creative Design &
Innovation
Section 3:
Advance Hydraulic
System
Mrs. Shamsa Aziz
Alshehhi

2. Learning Outcomes
Understand a light aircraft hydraulic system.
Understand the function of
components of a light aircraft
Hydraulic system.
Describe a hydraulic system filter.

3. engine driven pump accumulator unloading valve
a pump is driven by the
engine gearbox to give
the hydraulic system a
certain amount of
pressure and flow.
a component which
stores energy in the
form of hydraulic
pressure.
a valve that relieves
the pressure off the
pump by diverting the
fluid back to reservoir.
Key Vocabulary

4. low-pressure
return filter
A filter located in the
return line, just before
the fluid enters the
reserviour
Key Vocabulary
flap actuator
used to move the flap
(aerofoil attached to
the back of the wing)
in the aircraft.

5. What is the components of basic hydraulic system?
reservoir pump Non-return
valves
Selector
valves
actuator Pressure
relieve valve
Fluid
to hold the
liquid
(usually
to force the
liquid
through the
to force the
liquid to flow
on one
to ensure the
movement
of the fluid
to convert
the energy of
the liquid
to protect a
pressurized
system
Hydraulic
fluid stored
in the
reservoir

6. Basic Hydraulic System

7. Advance Hydraulic
System
The basic hydraulic system can be used in a simple hydraulic
applications which do not require a high level of power and
Efficiency.
In this lesson, you will learn about more powerful hydraulic system. It
contains more components, and is used in a wide range of

8. What is the difference between basic
hydraulic system and simple aircraft
hydraulic system?

9. System
Components
Reservoir
Engine
driven pump
Unloading
valve
Selector valves
Pressure relief
valves
Accumulator
Filter

10. The purpose of a reservoir in a hydraulic system is to:
1.have a supply of
hydraulic fluid available. 3.let vapor bubbles
escape from the
return line
2.let the hydraulic fluid
cool off and settle
The hydraulic fluid in the reservoir is

11. Engine driven pump
The purpose of pump is to give the hydraulic system a certain
amount at pressure and flow .The pumps are located and driven
by the engine gearbox. They are referred to as engine riven
pumps(EDPS)
Two types of pumps that can be used to deliver hydraulic pressure to the hydraulic system :
constant displacement pumps variable displacement pumps
(each piston move in and out of the
whole length of the cylinder- and
hence displaces the amount of fluid
(it is possible to vary the stroke length
that each piston travels –hence, the
pumps has an overall variable

12. Unloading Valve
Issue:-
The use of EDP creates a problem as the pumps still maintains pressure in the system
when it is not needed during flight , thereby wasting valuable engine power.
Solution:-
This problem is solved by the installation of a pump unloading valve.( also called
automatic cut-out valve).the fluid circulates freely from the pump to the reservoir and

13. 3- to allow limited
operation of
systems when
the EDP is
not running
1- to absorb
functions in
pressure
2-to ensure
immediate
response and
delivery
of pressurized fluid
on demand.
Accumulator
It is a component which stores energy in the form of hydraulic pressure.
The function s of accumulator are to:

14. Pressure relief valves
prevent failure of
components or
rupture of hydraulic
lines under excessive
pressures.
.
Excessive pressure can
be caused by a defect
(failure)in the pump or
by an increase in
temperature of an
enclosed amount of
hydraulic fluid.
To open the
valve ,pressure is
necessary that is
10%-20% higher
than the maximum
system pressure.
Pressure relief valves

15. Selector Valve
Selector valves is the first valve in the services system and not part of
the power system. The purpose of the selector valve is to direct fluid
to the appropriate side of an actuator and to provide a return path
for the fluid displaced from the opposite side of the actuator, back to
the reservoir.
Different types of selector valves used in hydraulic systems. The
selector valve is controlled by a servo motor. Which is controlled
automatically by the microcontroller in flight. Also, some selector
valves can be controlled on the ground manually by hand.

16. Filter
The extremely small operating clearances in modern hydraulic
pumps, valves and components , require very effective filtration of
the fluid .therefore, filters are rated by the size of particles, which
they can arrest. The size of these particles is measured in microns.
One micron is equal to one-millionth of a meter .particles as small as
40 microns are just visible with the naked eye.

17. THANKS FOR
YOUR ATTENTION