INTRODUCTION
Hydraulics is based on a very simple fact of nature - you cannot compress a liquid. You can compress a gas (think about putting more and more air into a tire, the more you put in, the higher the pressure). If you're really strong you can compress a solid mass as well. But no matter how much pressure you apply onto a liquid, it isn't possible to compress it. Now if you put that liquid into a sealed system and push on it at one end, that pressure is transmitted through the liquid to the other end of the system. The pressure is not diminished.
Aircraft Hydraulics Definition
It is a system where liquid under pressure is used to transmit this energy. Hydraulic systems take engine power and convert it to hydraulic power by means of a hydraulic pump. This power can be distributed throughout the airplane by means of tubing that runs through the aircraft. Hydraulic power may be reconverted to mechanical power by means of an actuating cylinder, or turbine.
(1) - A hydraulic pump converts mechanical power to hydraulic power
(2) - An actuating cylinder converts hydraulic power to mechanical power
(3) - Landing Gear
(4) - Engine power (mechanical HP) If an electrical system were used instead of a hydraulic system, a generator would take the place of the pump and a motor would take the place of the actuating cylinder
Some Hydraulic Systems in Aircrafts
1. Primary control boosters 2. Retraction and extension of landing gear 3. Sweep back and forth of wings 4. Opening and closing doors and hatchways 5. Automatic pilot and gun turrets 6. Shock absorption systems and valve lifter systems 7. Dive, landing, speed and flap brakes 8. Pitch changing mechanism, spoilers on flaps 9. Bomb bay doors and bomb displacement gears
2.Principles of Operation
Part of the hydraulic system is the actuating cylinder whose main function is to change hydraulic (fluid) power to