| 主权项 |
1. A rotor for a rotorcraft, the rotor having a hub carrying a plurality of lift assemblies, each lift assembly having a retention and mobility member connected to at least one plate of the hub, said rotor having a single abutment mechanism for each lift assembly to limit upward and downward flapping movement of the lift assembly under predetermined conditions, wherein each abutment mechanism for a lift assembly comprises:
an abutment track arranged on a rear face of the retention and mobility member facing an axis of rotation in elevation of the rotor; a single cylindrical abutment hinged to at least one plate of said hub by hinge means to be movable solely in pivoting about a movement axis between an engagement position in which the flapping movement is limited by the abutment, and a disengagement position in which the movement is not limited by the abutment, said abutment extending over a height in elevation along said movement axis and over a length along a longitudinal axis that is arranged substantially parallel to a span direction of the lift assembly when in the engagement position, and over a width along a transverse axis perpendicular to the movement axis and to the longitudinal axis, the length being greater than the width, the height being greater than the length; a fly-weight constrained to pivot with the cylindrical abutment and laterally offset relative to the longitudinal axis when in the engagement position; and a return spring exerting a force on the mechanism to tend to position the abutment in the engagement position. |
