Abstract: An air driven turbine having variable pitched blades is provided that includes a pitch change mechanism and associated control circuits for automatically adjusting the pitch of the blades during either rotating or non-rotating operational modes of the air driven turbine. The pitch control mechanism includes a resettable overspeed protection device which is directly actuated by an overspeed condition of the turbine and operates independently from the pitch change mechanism to move the blades to a failsafe, feathered, or coarse pitch, low speed position. The pitch control mechanism utilizes a linear actuator in the form of an acme screw drive. The air driven turbine includes a ball ramp thrust bearing for attaching the blades to a hub of the turbine in such a manner that during rotation of the turbine actuation loads on the pitch change mechanism are reduced.

Abstract: An air driven turbine having variable pitched blades is provided that includes a pitch change mechanism for adjusting the pitch of the blades during either rotating or non-rotating operational modes of the air driven turbine. The pitch control mechanism includes a resettable overspeed protection device which is directly actuated by an overspeed condition of the turbine and operates independently from the pitch change mechanism to move the blades to a failsafe, feathered, or coarse pitch, low speed position. The pitch control mechanism utilizes a linear actuator in the form of an acme screw drive. The air driven turbine includes a ball ramp thrust bearing for attaching the blades to a hub of the turbine in such a manner that during rotation of the turbine actuation loads on the pitch change mechanism are reduced.

Abstract: An actuator suitable for use as an ejection jack for deploying an aircraft mounted ram air turbine is provided. The actuator utilizes a spring powered ballscrew operatively coupled to a centrifugally actuated brake in such a manner that the brake limits the speed of reciprocating movement of the ballscrew. The problems of fluid leakage and slow deployment at cold temperatures, often encountered in prior ejection jacks utilizing hydraulic dashpots for speed control, are thus eliminated. The actuator also includes a locking device for locking the actuator in either an extended or a retracted position. Features are also provided for attaching an external drive mechanism in a manner allowing the ballscrew to be utilized for resetting the actuator to an initial non-extended position.