Engines- Hydraulics System

Hydraulics Main Purpose

multiply force

Force is a...

push or pull

Pascal's Law

P=F/A

Military hydraulic systems operate at _______.

3000 psi

Two Hydraulic Systems on Aircraft

Power and Utility

Power Hydraulics operate _____.

Flight Controls

Utility Hydraulics operate ______.

Utility systems and backup flight controls.

Reservoir

SHAFT: storage, heat dissipation, aeration, FOD, thermal expansion

Two types of Reservoir:

1. Pressurized

2. Non-Pressurized

Non-Pressurized Res (Function and Aircraft)

vented to the atmosphere, typically found in cargo and large aircraft that do not perform violent maneuvers.

Pressurized Res (Function and Aircraft)

used on high performance aircraft to maintain positive fluid flow at high altitudes and attitudes. pressurized by compressor bleed air.

Two types of hydraulic pumps:

Hand and Power

Two types of power hydraulic pumps:

Variable - metered flow (reads current pressure AKA system demands and changes output)

Constant - supplies steady flow, requires a pressure regulator or an unloader valve

Pressure Regulator/ Unloader Valve

only utilized with a constant displacement pump, if the system pressure is in excess the valve will redirect hyd fluid back to the res.

Check Valve

ensures one-way flow (prevents backflow)

Accumulator

SEAS: shock absorption, emergency use (1x), assist during peak operations, shutdown with assistance of check valve

Filter

filters FOD out, differential pressure indicator to monitor the condition of the filter

Relief Valve

"pressure limiting device", prevents pressure build up protecting seals from bursting or any damage to the system

Pressure Gauge

indicate amount of pressure in the system (PSI)

Pressure Switch

Low Pressure Switch, pictured in diagram. Indicates a pressure drop that falls below allowable limits. Will turn on a warning light in the cockpit.

Hydraulic Fuse

detect leaks and prevents excessive loss of fluid by isolating specific parts, allows remaining subsystem to operate

Selector Control Valve

direct flow of fluid to the actuator, can be reversed to return fluid to the res.

Actuator

convert fluid pressure to mechanical motion

How if force multiplication achieved in a hydraulic system?

reducing linear displacement movement