摘要 |
A variable pitch propeller has a centrifugal lock for blocking blade pitch changes from a normal range of forward pitch angles toward both feathered and reverse positions at rotational speeds greater than a predetermined threshold. The lock mechanism has a pair of stop members rigidly connected to a rack yoke member that has geared engagement with respective propeller blade pinions, and a pair of mass elements that move outwardly in response to centrifugal force to block movement of the lock members outside of the normal range. A pair of springs are connected between the mass elements for biasing them inwardly from paths of the lock members. The yoke is displaced axially by an actuator having an annular hydraulic cylinder. A hydraulic control unit having a motorized leadscrew coupled to another annular hydraulic cylinder is fluid coupled to the actuator, and a simple control circuit provides colored indications of pitch settings.
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