Hydraulic Pumps
Name 3 types of constant delivery hydraulic pumps
Gear, Vane, Piston
What type of pump is a gerotor pump?
a combination internal-external gear pump
What is meant by the term pump depressurisation
stopping the output of the engine-driven hydraulic pump without mechanically disconnecting it from the engine
What is the filter element can be made of?
porous paper or wire gauze
What component, in a closed-circuit system, is used to direct fluid from the pump when it is not being used
Unloading Valve
What affects the output of a constant displacement hydraulic pump
RPM
What type of pump is used to move a relatively large volume of fluid but do not need to produce a very high pressure
vane pump
What are 4 power sources that power a pump
Engine, Pneumatic, Electric, RAT, Hydraulic
What are Filter modules equipped with to allow fluid to pass in the event of a filter blockage?
Bypass relief valve
What would be the pressure in an open circuit system with the selector valves in neutral?
minimal
Why do pumps have a case drain
to return oil used for lubrication and cooling from the pump case
What type of pump is used in a high pressure hydraulic system
Piston Pump
What controls the RMP in an air driven pump
Governor and speed control valve
What is the filter equipped with to indicate a filter bypass?
Bypass indicator (Pop out indicator) or Bypass transmitter
how is pressure controlled in a closed-circuit system to maintain 3000PSI
with a pressure regulator.
Describe an external gear pump
the teeth of bothgears project outwards from their centres.
The amount of hydraulic fluid that the pump can supply per unit of time depends on the:
Number of pistons
Rotation frequency (rpm)
Diameter of the pistons
Stroke length.
What is a power transfer unit
Transfers hydraulic power from one hydraulic system to another
What is a two stage filter?
A special two-stage filter is used in the return line of some large aircraft hydraulic systems in place ofthe standard single-element unit. This type of filter allows the use of an extremely fine element at lowflow rates without causing an excessive pressure drop.
What component controls the system pressure in case or a pressure regulation valve failure
Relief valve
What is incorporated in the drive shaft to protect the powersource or reduction gears if the pump fails because of excessive load or jammed parts.
A shear pin or shear section (quill shaft)
What component in the variable displacement pump changes the output of the pump
variable angle cam plate.
What is a RAT?
The RAT is an air turbine-driven hydraulic pump that provides emergency electric power or hydraulicpower if power is lost on both engines
What is the purpose of a shut off valve in the filter module head?
This prevents the system from emptying when changing the filter
how is pressure regulated in a hydraulic system with a variable displacement pump
By the pump