Rotors Flashcards
Rotor system
rotor system consists of a four bladed, fully articulated main rotor and a four bladed tail rotor assembly with two teetering rotor hubs.
Swept tip
Reduces effects of compressibility
Blades
Fully composite with mesh honey comb
Main Rotor Head
The main rotor head allows the blades to flap, feather, lead, and lag independently. The head consists of a hub assembly, pitch housings, rotor dampers, and lead-lag links, controlled by the cyclic and collective controls through a swashplate mounted about the static mast.
Pitch Housing
The pitch housing permits blade pitch changes in response to flight control movements transmitted through the swashplate
Feather bearings
are installed inboard on the pitch housing to allow vertical and horizontal loads to be transferred from pitch housing to the hub.
Strap Pack
Centrifugal loads are transmitted by each strap assembly to the hub.
Lead Lag Links
Lead-lag links are connected to the outboard end of each pitch housing and are secured in place by a pin and two bearings allowing the links to move horizontally. The pin goes through the “V” portion of each strap within the pitch housing.
Lead Lag Damper Assembly
Two damper as-semblies control lead-lag movement of each main rotor blade. Each damper attaches outboard to a link lug and inboard to a trunnion at the pitch housing. The dampers contain elastomeric elements that distort to allow the blade to lead or lag.
Blade attachment (main)
Each blade is secured to its lead lag link by two blade attachment pins. These pins can be removed without the use of tools for replacement or pivot stowing.
TAIL ROTOR ASSEMBLY
The tail rotor is a semi-rigid, teetering system.
Tail Rotor Blades
Two pairs of blades, each pair fastened to its own delta hinged hub, provide anti-torque action and directional control. Each blade has one stainless steel spar and two aluminum spars. Doublers, adhesive, and rivets attach the blade to the blade root. Brackets on the root fitting hold chord-wise bal-ance weights. Span-wise balance weights are installed in blade tip caps.
Tail Rotor Fork
A titanium fork houses four elastomeric teetering bearings and drives the rotating swashplate through an attached scissors assembly.
Blade Pitch Changes (TR)
The tail rotor assembly is splined to, and driven by, the tail rotor gearbox drive shaft which passes through a static mast. One pitch link for each blade, attached to the rotating swashplate and pitch horn, causes blade movement about two pitch change bearings in the blade root. Centrifugal forces are carried by strap assemblies attached outboard to the blade root and inboard at the hub center. An elastomeric bearing assembly positions the hub and strap pack in the tail rotor fork.
Tail rotor spins how much faster
4 times faster than main rotor
