Rotor hub mounted actuator for controlling a blade on a rotorcraft

A hub mounted actuation system providing control of a rotor blade on a rotorcraft, the rotor blade being attached to a rotor shaft that rotates with respect to an airframe, the system comprising:

• a stationary member mounted to the airframe, the stationary member having at least one stator formed on at least a portion of it;
• a rotary member attached to the rotor shaft and located adjacent to the stationary member;
• an intermediate member rotatable with respect to the stationary member, the intermediate member being supported by the rotary member, the intermediate member having a plurality of magnets spaced around its circumference adjacent to the stator on the stationary member such that when current is supplied to the stator on the stationary member a magnetic field is created that causes the intermediate member to move with respect to the rotary member;
• at least one actuator with a piston and a housing, the piston being slidable within the housing, the piston and housing defining a pressure chamber within the at least one actuator which contains a fluid to be pressurized, one of either the piston or the housing being attached to the rotary member and the other being attached to the intermediate member such that movement of the intermediate member with respect to the rotary member causes the piston to slide within the housing;
• and
• a linkage attached to a portion of the blade and the at least one actuator, the linkage adapted to displace the blade portion as a function of the movement of the piston within the housing.

A hub mounted actuation system providing control of a rotor blade on a rotorcraft, the rotor blade being attached to a rotor shaft that rotates with respect to an airframe, the system comprising:

• a stationary support mounted to the airframe, the stationary support having a stator attached to it;
• a rotary support engaged with the rotor shaft adjacent to the stationary support;
• an intermediate disk rotatable with respect to the stationary support, the intermediate disk being slidingly mounted to the rotary support such that the intermediate disk can move in-plane relative to the rotary support, the intermediate disk having a plurality of magnets spaced around its circumference adjacent to the stator such that each adjacent magnet is oppositely poled, the intermediate disk adapted to move relative to the rotary support when current is supplied to the stator which creates a magnetic field adjacent to the magnets;
• at least one actuator with a piston and a housing, the piston being slidable within the housing, the piston and housing defining a pressure chamber within the at least one actuator which contains a fluid to be pressurized, one of either the piston or the housing being attached to the rotary support and the other being attached to the intermediate disk such that movement of the intermediate disk with respect to the rotary support causes the piston to slide within the housing;
• and
• a linkage attached to a portion of the blade and the at least one actuator, the linkage adapted to displace the blade portion as a function of the motion of the piston within the housing.