Two-piece rotor blade for a bearingless rotor of a helicopter

摘要

A rotor blade for a bearingless rotor of a helicopter includes a lift- generating airfoil blade, a flexbeam connecting the airfoil blade to a rotor head, and a control sleeve enclosing the flexbeam. The junction between the flexbeam and the airfoil blade is a separable junction (J) to allow the airfoil blade to be folded in a simple manner while maintaining a high lead-lag stiffness and reduced structural height of the junction (J). The junction (J) is formed by two connection arms (5. 1, 5.2) arranged side-by-side in the lead-lag plane (E.sub.R) of the rotor blade (R). Preferably, the two connection arms extend from the inboard end of the airfoil blade (3) and receive the head (1.1) of the flexbeam (1) therebetween lying in the lead-lag plane (E.sub.R). A connecting fixture (6) connects the connection arms (5.1, 5.2) to the flexbeam head (1.1) using fasteners such as bolts (V.sub.1, V.sub.2) that are spaced laterally from each other at a spacing distance of at least 1. 3 times the maximum width of the torsionally flexible portion of the flexbeam.