| 摘要 |
A helicopter rotor (10, 29) includes a rotor hub (11, 30) supporting a plurality of rotor blades, and a pitch control means comprising a universal joint (21, 45) adapted to permit both tilting and axial vertical movements of the control means to change the pitch of the rotor blades both cyclically and collectively. The universal joint has three radially extending pins (22) each supporting a radially slidable and rotatable bearing (23) having a spherical external surface (25), the bearings being located in generally axially extending tracks (26) having a circular cross-sectional shape for rolling engagement by the bearings. Axial movements are permitted by rolling of the bearings along the tracks and tilting movements by a combination of rolling and a sliding movement of the bearings along the pins. Several embodiments are described and illustrated. |
