Blade pitch change mechanism

摘要

A lightweight and compact apparatus is provided for altering and controlling the pitch of a plurality of rotating blades during rotation using a mechanical clutch and gear arrangement driven by a rotational speed differential between the blade drive shaft and the blades. A first set of clutches and gears controls the direction of rotational power to the pitch change mechanism and is disengaged from rotation when desired blade pitch is established. A second set of clutches and gears controls the speed of rotational power applied to the pitch change mechanism. This pitch change mechanism includes a failsafe capability against pitch change through disengagement of the directional clutches except when needed, and an inherent rotational lock resulting from the rate change clutches' bias to simultaneous engagement. Variation of that speed of rotational power permits coarse and fine pitch adjustments at variable rates.