AIRSYS MOD 2 Flashcards
(49 cards)
This is the science relating to the behavior of liquids under various conditions and in aircraft, these systems provides a
means of operating large and
remote components that it would
not be possible to operate
satisfactorily by other means.
Hydraulics
Aircraft systems provide a means of
power transmission through the
medium of hydraulics through an
incompressible fluid via ___________
Pipelines and Actuators
Who stated “If a force is applied to a liquid in
a confined space, then this force
will be felt equally in all
directions”.
Blaise Pascal
This principle where all hydraulic systems operate.
Pascal’s Law
The force employed when a hydraulic
system is operated is caused by
________.
Without some form of restriction there can be no _________.
Pressure
In hydraulic systems, this restriction
is provided by movable pistons
which travel backwards and
forwards in cylinders. These
assemblies being known as
_______________.
hydraulic jacks or actuators
Formula of Pressure
P=F/A
Who invented a hydraulic press and observed that:
a) The smaller the area under
load, the greater the pressure
generated.
b) The larger the area under
pressure, the greater will be
the load available.
Joseph Brahma
The ____________ is a Passive
Hydraulic System where a force is
applied to a piston (piston A) only
when it is desired to move the load
(piston B).
Brahma Press
Different Kinds of Hydraulic Fluid Properties
Incompressible
Good Lubricating Properties
Good Viscosity
High Boiling Point/Low Freezing Point
High Flash Point/Non-Flammable
Chemically Inert/Non-Corrosive
Resistant to Evaporation
Free from Sludging and Foaming
Reasonably Priced
Readily Available
Equivalent to H515 NATO,
OM15, and MIL-H-5606F
Clean mineral hydraulic fluid
Colored red
Used with synthetic neoprene
rubber seals
Recommended for all hydraulic
systems under high pressures
and low or very low
temperatures (-54 C° to 90 C°)
DEF STAN 91-48
Phosphate ester based
synthetic hydraulic fluid
Purple in color
Used with Synthetic Butyl
Rubber Seals
Prolonged exposure will
damage skin and eyes
Very high flashpoint (170 C°)
Less prone to cavitation
SKYDROL
It is of major importance that
only the specified hydraulic oil
or its approved alternative is
used in a hydraulic system If
the incorrect fluid is added to a
system breakdown of the seals
is likely causing fluid leakage,
both internally within
components and externally
from the actuators.
Hydraulic Fluids
The friction between the walls of the pipes and the fluid depends upon:
a) Velocity of the fluid in the pipes.
b) Length, bore, and the internal finish of the
pipes.
c) Number of bends.
d) Viscosity of the oil.
These perform a very important
function in a hydraulic system,
which is preventing leakage of
fluid.
Seals
__________ seals, fitted between
sliding surfaces, may be of
many different shapes,
depending on their use and on
the pressure involved.
Dynamic
___________ ring seals are
effective in one direction only,
but ___ rings and square
section seals are often used
where pressure is applied in
either direction.
“U“ and “V”
“O”
Where high pressures are used,
an O-ring is normally fitted
with ____________ which
retains the shape of the seal
and prevents it from being
squeezed between the two
moving surfaces.
stiff backing ring
Dynamic seals require
___________ to remain effective.
Wetting of the bearing surface
or a slight seepage from the
seals is normally acceptable.
lubrication
If a seal of an incorrect material is used in a
system, the sealing quality will
be seriously __________, and this
may lead to failure of the
component.
degraded
Seals are easily damaged by
grit, and a _________ is often
installed on actuators to
prevent any grit that may be
deposited on the piston rod
from contaminating the seals.
wiper ring
6 components of a hydraulic system
Reservoir of oil
pump
Selector or Control Valve
Actuators or Jack
Filter
Relief Valve
Two types of Hydraulic Systems
Passive and Active Hydraulic Systems
This type of System is where a pump supplies the pressure
Active Hydraulic System
