A system for driving a tilt rotor between vertical and horizontal using a variable displacement motor controlled in response to a swash angle of the motor measured in a feedback loop.

A system for driving a tilt rotor between vertical and horizontal using a variable displacement motor controlled in response to a swash angle of the motor measured in a feedback loop.

A rotary blade aircraft includes an airframe, a rotor shaft driven about a rotor axis, and a plurality of rotor blades driven by the rotor shaft about the rotor axis. The rotary blade aircraft includes a swashplate assembly coupled to the plurality of rotor blades. The swashplate assembly is operable to move the plurality of rotor blades about a respective longitudinal axis. The rotary blade aircraft includes a hydraulic control servo coupled between the airframe and the swashplate assembly. The hydraulic control servo is operable to move the swashplate assembly relative to the rotor axis. The rotary blade aircraft includes a harmonic control actuator coupled between the airframe and the swashplate assembly. The harmonic control actuator is operable independently relative to the hydraulic control servo to move the swashplate assembly relative to the rotor axis to reduce vibration at selected frequencies in the airframe.

A rotary blade aircraft includes an airframe, a rotor shaft driven about a rotor axis, and a plurality of rotor blades driven by the rotor shaft about the rotor axis. The rotary blade aircraft includes a swashplate assembly coupled to the plurality of rotor blades. The swashplate assembly is operable to move the plurality of rotor blades about a respective longitudinal axis. The rotary blade aircraft includes a hydraulic control servo coupled between the airframe and the swashplate assembly. The hydraulic control servo is operable to move the swashplate assembly relative to the rotor axis. The rotary blade aircraft includes a harmonic control actuator coupled between the airframe and the swashplate assembly. The harmonic control actuator is operable independently relative to the hydraulic control servo to move the swashplate assembly relative to the rotor axis to reduce vibration at selected frequencies in the airframe.

An autopilot system includes an actuator arrangement that receives control signals to influence the flight of the helicopter in a selected one of a plurality of different flight modes. A control stick input arrangement allows flight mode selection and control with no more than a particular one of the pilot's hands in the engaged position on the stick and without moving the hand away from the engaged position. A slaved gyro output signal is based on no more than the set of sensor outputs used by the autopilot such that an autopilot display presents autopilot flight mode information while displaying a slaved gyro output. The autopilot provides for pilot selection of one of a subset of the plurality of flight modes which is customized based on a current flight status of the helicopter. An automatic autorotation mode is provided.

A rotor actuation system includes a swashplate assembly comprised of a stationary swashplate and a rotating swashplate operatively connected together for relative rotation about a rotor axis. A cyclic actuator is operatively connected to the stationary swashplate to tilt the swashplate assembly off axis from the rotor axis for cyclic control. A collective actuator is operatively connected to the swashplate assembly to move the swashplate axially along the rotor axis for collective control. The cyclic actuator and the collective actuator are operatively connected to the swashplate assembly to respectively actuate cyclic and collective control independent of one another.

A rotor actuation system includes a swashplate assembly comprised of a stationary swashplate and a rotating swashplate operatively connected together for relative rotation about a rotor axis. A cyclic actuator is operatively connected to the stationary swashplate to tilt the swashplate assembly off axis from the rotor axis for cyclic control. A collective actuator is operatively connected to the swashplate assembly to move the swashplate axially along the rotor axis for collective control. The cyclic actuator and the collective actuator are operatively connected to the swashplate assembly to respectively actuate cyclic and collective control independent of one another.

A helicopter includes annular rotors surrounding a fuselage. Rotor blades extend radially outwardly from each annular rotor. One or more motors is provided. Each motor rotates a roller, which drives each annular rotor by traction. In an embodiment with two rotors, one rotor rotates in one direction and the other rotor rotates in the opposite direction. A swash device with a grooved outer cylindrical surface engages the free end of a crank arm of each rotor blade to provide collective and cyclic pitch control. Actuators, which may be electromechanical or hydraulic, control positioning and movement of the swash device. Batteries, an electric generator and/or a hydrogen fuel cell may supply electric power.

A propeller pitch control system for a turboprop engine of an aircraft includes a negative torque sensor, a full feather control valve assembly, and a feather valve assembly. The feather valve assembly is responsive to fluid pressures from the negative torque sensor and the control valve assembly to move between a plurality of positions. An engine control unit or a manual user interface can also be used to control the position of the feather.

A magnetorheological fluid clutch apparatus comprises an input rotor adapted to be coupled to a power input, the input rotor having a first set of at least one input shear surface, and a second set of at least one output shear surface. An output rotor is rotatably mounted about the input rotor for rotating about a common axis with the input rotor, the output rotor having a first set of at least one output shear surface, and a second set of at least one output shear surface, the first sets of the input rotor and the output rotor separated by at least a first annular space and forming a first transmission set, the second sets of the input rotor and the output rotor separated by at least a second annular space and forming a second transmission set. Magnetorheological fluid is in each of the annular spaces, the MR fluid configured to generate a variable amount of torque transmission between the sets of input rotor and output rotor when subjected to a magnetic field. A pair of electromagnets are configured to deliver a magnetic field through the MR fluid, the electromagnets configured to vary the strength of the magnetic field, whereby actuation of at least one of the pair of electromagnets results in torque transmission from the at least one input rotor to the output rotor.