The Basic Hydraulic System Flashcards
Alternate hydraulic power sources
Separate standby electric emergency pump
Hydraulic motor pump
Ram Air Turbine (RAT)
High pressure air bottles
Accumulators
Components in a hydraulic system
Reservoir
Pump
Actuator or hydraulic motor
Fluid Lines
Valves
Hydraulic fluid
What is a check valve?
To control hydraulic fluid. Fluid can go one way but not the other. Often located on pressure lines and around hydraulic pumps
What is an orifice valve?
Lets full flow go in one direction. Restricted flow in the opposite direction.
What is a thermal relief valve?
Used to relieve excess fluid pressure from the system. Dumps excess pressure caused from the expansion of hot fluid.
Single-acting actuator system
Most basic of systems. A PUMP EXTENDS THE ACTUATOR WHEN PRESSURIZED AND SELECTOR VALVE SET TO ON
A SPRING OR OTHER FORCE WILL RETURN ACTUATOR TO THE ORIGINAL OFF POSITION WHEN SELECTOR VALVE IS PLACED IN THE OFF POSITION
Light vs Heavy aircraft hydraulic systems
Light-typically a single system
may only me a hand or foot pump
Heavy-2 or more separate systems
each system backed up by an alternate source
What is a selector valve?
A valve that rotates to send fluid to a specific component
What is a constant displacement pump?
Moves a specific amount of fluid with each pump. Needs regulation or a relief valve to protect from over pressurization
Pump control valve
Allows the pilot to turn off the pump load in order to save energy when the pump is not needed
Closed center hydraulic valves
Are hooked up in parallel so more than one can function at a time
Accumulator
Will keep pressure on the hydraulic system without the pump running for a short period
