Hydraulic and Pneumatic Power Systems Flashcards
(22 cards)
What are three types of hydraulic fluids?
Vegetable, mineral and phosphate esters
Which color do mineral base and phosphate ester hydraulic fluids have?
Mineral - Red
Phosphate ester - light purple
What happens to plastic resin‘s, vinyl, compositions, lacquers, and oil base paint if exposed to a phosphate ester base hydraulic fluid such a Skydrol?
It becomes damaged, softens or peels
What precaution should be taken to minimize contamination during replacement of a hydraulic unit?
All lines should be plugged or capped after disconnecting
What would cause a hydraulic filter to go into open bypass, allowing unfiltered fluid into the system?
A clogged filter
What are two types of engine driven hydraulic pumps?
Constant-delivery, and variable-delivery
How does a gear type power pump operate?
Two meshed gears are driven by a power unit rotating in the housing. Fluid is carried around the outside of the gears and delivered to the outlet side as the gears rotate.
What feature is built into a hydraulic pump-driven system to prevent engine damage in the event of pump seizure or overload?
A Shear action in the pump drive shaft occurs
What is the purpose of a pressure relief valve?
To limit the amount of pressure to prevent failure of system components
What is the purpose of a pressure regulator?
To manage the output of the pump to maintain system pressure, and to allow the pump to turn without resistance
What is used in some hydraulic systems to supplement the power pump on several units are operating at the same time?
An accumulator
What are the different types of accumulators?
Piston, diaphragm and bladder
What must be accomplished with any accumulator prior to disassembling?
Make sure that the air or preload has been discharged
For what purposes are pneumatic systems used in some aircraft?
To operate brakes, doors, drive pumps and engine starting
What’s are sources of pneumatic power?
Storage bottles, vane-type pumps, and turbine engine compressor
What is the purpose of restrictors that are used the most aircraft pneumatic systems?
To control the rate of flow
What happens to excessive pressure in a pneumatic system?
A relief valve will bleed it to the atmosphere
Why should a pneumatic system be purged periodically?
To remove contamination and moisture
What are the results of exposing lacquers, oil based paint, plastic resin’s in vinyl compounds to phosphate, ester-based hydraulic fluid?
Materials will be damaged, softened, or paint will peel
Name several sources used to develop hydraulic pressure?
Hand pumps, engine driven pumps and electrically driven pumps
What type of components or systems are pneumatically operated in some aircraft?
Landing gear, brakes, flaps, and other mechanic actuators
Name several sources of pneumatic power
Storage bottles, engine bleed air, engine driven compressor, or vane type pumps
