Patent ID: 6695254
Filing Date: 2004-02-24
Classification: B64C

Abstract:
A rotary-wing aircraft rotor with constant velocity drive in particular for a convertible aircraft with at least one tilting rotor, comprising:a rotor mast, capable of being driven in rotation about its longitudinal axis, a hub connected to said mast by a constant velocity drive mechanism and pivoting arrangement, allowing pivoting of the hub as a whole about any flapping axis converging with the axis of the mast and perpendicular to said axis of the mast, in such a way that said hub is capable of being driven in constant velocity rotation by said mast, about a geometrical axis of rotation of the hub which may be inclined in any direction about the axis of the mast, and at least two blades, each linked to said hub by a coupling retaining and hingeing its blade in pitch, wherein said constant velocity drive mechanism and pivoting arrangement comprises: a first gimbal driven in rotation by said mast about said axis of the mast and mounted so as to pivot about a first diametral axis of the mast, which is substantially perpendicular to said axis of the mast, by two first bearings diametrically opposite relative to said axis of the mast, a second gimbal also driven in rotation by said mast about said axis of the mast, and mounted so as to pivot about a second diametral axis of said mast, which is substantially perpendicular to said axis of the mast and to said first diametral axis and converging therewith substantially on said axis of the mast, by two second bearings diametrically opposite relative to said axis of the mast, said first gimbal being in addition hinged to said hub by two first ball joint connections, diametrically opposite relative to said axis of the mast and each centred substantially in a plane defined by said axis of the mast and said second diametral axis, said second gimbal being in addition hinged to said hub by two second ball joint connections, diametrically opposite relative to said axis of the mast and each centred substantially in a plane defined by said axis of the mast and said first diametral axis in such a way that the blades are driven in rotation by two torque transmission trains each comprising said mast, one respectively of the gimbals, the corresponding two ball joint connections and two bearings, and said hub said torque transmission trains having substantially the same torsional rigidity, and at least one of the components of each torque transmission train having a flexibility in deformation about the axis of rotation of the hub.