Patent ID: 8926288
Filing Date: 2015-01-06
Classification: B64C

Abstract:
1. A rotor blade, in particular for a main rotor of a rotary-wing aircraft, made of fibre-reinforced plastic comprising a blade section, a connecting section for fastening the rotor blade to a drive device which comprises a sleeve-shaped connecting device with flat fibre layers running substantially in the plane of extension of the connection section and at least one bolt introduced substantially perpendicular to the plane of extension of the connecting section for fastening the connecting section to the drive device, characterised in that the connecting section comprises flat fibre layers extending in a transition from the blade section, in which at least one unidirectional fibre layer is inserted between reinforcing layers and does not fill the entire connecting section, the sleeve-shaped connecting device being formed by drilled holes through the connecting section providing a bearing-stress connection with the flat fibre layers of the connecting section being loaded by one bolt for each hole, wherein each of the holes has a first edge distance extending between a side edge of said connecting section and said hole, and a second edge distance extending between a front edge of said connecting section and said hole, the first edge distance being less than the second edge distance; wherein the front edge and the side edges of the connecting section are provided by an outer perimeter of the connecting section; and wherein a first fibre layer of the flat fibre layers has a concave edge along the outer perimeter of the layer to form a recess opposed to the front edge of the connecting section, the concave edge being generally symmetrical about a longitudinal axis of the rotor blade.