rotor system-razon, manugas

8/18/2019 Rotor System-razon, Manugas

1/14

CEBU AERONAUTICAL TECHNICALSCHOOL

HELICOPTER ROTORSYSTEM


2/14

ROTOR SYSTEM

A helicopter main rotor or rotorsystem is a type of fan that is used togenerate both the aerodynamic lift forcethat supports the weight of the helicopter ,and thrust which counteractsaerodynamic drag in forward ight. Eachmain rotor is mounted on a vertical mastover the top of the helicopter, as opposedto a helicopter tail rotor , which isconnected through a combination ofdrive shaft (s) and gearboxes along the tailboom. A helicopter s rotor is generallymade up of two or more rotor blades. !he

blade pitch is typically controlled by aswashplate connected to the

http://en.wikipedia.org/wiki/Fan_(mechanical)http://en.wikipedia.org/wiki/Lift_(force)http://en.wikipedia.org/wiki/Helicopterhttp://en.wikipedia.org/wiki/Thrusthttp://en.wikipedia.org/wiki/Drag_(force)http://en.wikipedia.org/wiki/Tail_rotorhttp://en.wikipedia.org/wiki/Drive_shafthttp://en.wikipedia.org/wiki/Blade_pitchhttp://en.wikipedia.org/wiki/Swashplate_(helicopter)http://en.wikipedia.org/wiki/Helicopter_flight_controlshttp://en.wikipedia.org/wiki/Swashplate_(helicopter)http://en.wikipedia.org/wiki/Blade_pitchhttp://en.wikipedia.org/wiki/Drive_shafthttp://en.wikipedia.org/wiki/Tail_rotorhttp://en.wikipedia.org/wiki/Drag_(force)http://en.wikipedia.org/wiki/Thrusthttp://en.wikipedia.org/wiki/Helicopterhttp://en.wikipedia.org/wiki/Lift_(force)http://en.wikipedia.org/wiki/Fan_(mechanical)


3/14

DESIGN A helicopter rotor is powered by the engine, through thetransmission, to the rotating mast. !he mast is acylindrical metal shaft which extends upward from"and isdriven by"the transmission. At the top of the mast is theattachment point for the rotor blades called the hub. !herotor blades are then attached to the hub. #ain rotorsystems are classi$ed according to how the main rotorblades are attached and move relative to the main rotorhub. !here are three basic primary types% hingless or rigid ,semi&rigid , or fully articulated.

'nli e the small diameter fans used in turbofan etengines, the main rotor on a helicopter has a *uite largediameter, permitting a large volume of air to beaccelerated. !his permits a lower downwash velocity for agiven amount of thrust. As it is more e+icient at lowspeeds to accelerate a large amount of air by a small

degree than a small amount of air by a large degree itgreatly increases the aircraft s energy e+iciency and this

http://en.wikipedia.org/wiki/Turbofanhttp://en.wikipedia.org/wiki/Turbofan


4/14

THREE PRIMARY TYPES

OF ROTOR SYSTEM


5/14

HINGLESS RIGIDROTOR The term "rigid rotor" usually refersto a hingeless rotor system with

blades flexibly attached to the hub.Irven Culver of Lockheed developedone of the first rigid rotors, whichwas tested and developed on aseries of helicopters in the ! #sand !$#s. In a rigid rotor system,each blade flaps and drags aboutflexible sections of the root. % rigidrotor system is mechanically simplerthan a fully&articulated rotor system.Loads from flapping and lead'lagforces are accommodated throughrotor blades flexing, rather thanthrough hinges. (y flexing, theblades themselves compensate forthe forces which previously re)uiredrugged hinges. The result is a rotorsystem that has less lag in thecontrol response, because the rotorhas much less oscillation. The rigidrotor system also negates thedanger of mast bumping inherent insemi&rigid rotors

http://en.wikipedia.org/w/index.php?title=Irven_Culver&action=edit&redlink=1http://en.wikipedia.org/w/index.php?title=Irven_Culver&action=edit&redlink=1


6/14

SEMI! RIGID ROTOR The *emirigid rotor can also bereferred to as a teetering orseesaw rotor. This system isnormally composed of two bladeswhich meet +ust under a commonflapping, or teetering hinge at the

rotor shaft. This allows the bladesto flap together in oppositemotions like a seesaw . This underslinging of the blades below theteetering hinge, combined with anade)uate dihedral or coning angleon the blades, minimi es

variations in the radius of eachblade-s center of mass from theaxis of rotation as the rotor turns,which in turn reduces the stresson the blades from lead and lagforces caused by coriolis effect .*econdary flapping hinges mayalso be provided to providesufficient flexibility to minimi ebouncing. eathering isaccomplished by the featheringhinge at the blade root, whichallows changes to the pitch angleof the blade.

http://en.wikipedia.org/wiki/Seesawhttp://en.wikipedia.org/wiki/Coriolis_effecthttp://en.wikipedia.org/wiki/Coriolis_effecthttp://en.wikipedia.org/wiki/Seesaw


7/14


8/14


9/14


10/14


11/14

$la%e Mo&ements

4eathering2ollective

2yclic2oning4lapping

3ead53ag (6unting 7r 1ragging)


12/14


13/14


14/14

GRO"P '(ROTORSYSTEMS

89% A:;E3

rotor system-razon, manugas

Documents