Rotary-wing aircraft rotor head having resilient-return interblade ties with built-in damping
First Claim
1. A rotary-wing aircraft rotor head, of the type comprising a hub to which each blade of the rotor is held by a connection member fixed to the blade and connected to the hub with the aid of articulation means permitting angular oscillations of the blade about a single point on which the flapping axis, the lag axis and the longitudinal pitch change axis of the blade are convergent, the rotor head also comprising an interblade connection device consisting of elongated resilient-return ties with built-in damping, the number of which ties is equal to that of the blades and which are mounted substantially in a ring around the hub, so that each of them connects together two neighboring blades of the rotor, each tie comprising at least two rigid elongated members, each of which is provided with means for the articulated connection of a respective end of the tie to a respective one of the two blades connected by said tie, and which are connected to one another by at least one resilient return member of the two rigid members, for return to a relative initial position, and by at least one member damping all relative movement of the two rigid members, at least in the longitudinal direction of the tie, wherein said means for the articulated connection of each tie to a blade comprise a main ball whose center is situated on or in immediate proximity to the longitudinal pitch axis of the blade and which is retained, on the means connecting the blade to the hub, radially on the outside, relative to the center of the hub, of the point of intersection of the lag, flapping and pitch change axes, which point constitutes the single center of articulation of the connection means on the hub.
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Accused Products
Abstract
The invention relates to a rotor head having interblade ties with resilient return in lag and with built-in damping, wherein each tie is connected, to each of the two rotor blades joined by it, by articulation means comprising a main ball retained on a member connecting a blade to the hub and centered on or in immediate proximity to the pitch change axis of the corresponding blade.
A single main ball may be connected to the adjacent ends of two neighboring ties by a connection member having the shape of a V open towards the hub, or else each tie is connected to a connection member by a respective one of two main balls offset transversely in relation to the pitch change axis of the blade and/or radially along said axis.
Application to the main and/or auxiliary rotors of helicopters.
71 Citations
26 Claims
- 1. A rotary-wing aircraft rotor head, of the type comprising a hub to which each blade of the rotor is held by a connection member fixed to the blade and connected to the hub with the aid of articulation means permitting angular oscillations of the blade about a single point on which the flapping axis, the lag axis and the longitudinal pitch change axis of the blade are convergent, the rotor head also comprising an interblade connection device consisting of elongated resilient-return ties with built-in damping, the number of which ties is equal to that of the blades and which are mounted substantially in a ring around the hub, so that each of them connects together two neighboring blades of the rotor, each tie comprising at least two rigid elongated members, each of which is provided with means for the articulated connection of a respective end of the tie to a respective one of the two blades connected by said tie, and which are connected to one another by at least one resilient return member of the two rigid members, for return to a relative initial position, and by at least one member damping all relative movement of the two rigid members, at least in the longitudinal direction of the tie, wherein said means for the articulated connection of each tie to a blade comprise a main ball whose center is situated on or in immediate proximity to the longitudinal pitch axis of the blade and which is retained, on the means connecting the blade to the hub, radially on the outside, relative to the center of the hub, of the point of intersection of the lag, flapping and pitch change axes, which point constitutes the single center of articulation of the connection means on the hub.
Specification