Abstract: A brake actuator is configured to perform either a braking operation, or an auto-adjustment operation of an air gap between an actuator output shaft and a brake stack. The brake actuator includes a conjugate ramp track containing a bearing ball, the conjugate ramp track being formed by matching ball ramp tracks of an input ball ramp and an output ball ramp. The output ball ramp is connected to the output shaft by a threaded interface to move the output shaft by rotation of the input ball ramp. The conjugate ramp track is a multi-angle ball ramp track thereby including areas of different gain. The input ball ramp is rotated in a first direction to perform the braking operation, and the input ball ramp is rotated in a second, opposite direction to perform the auto-adjustment operation. During the auto-adjustment operation, a position of the output shaft is automatically adjusted when the air gap has a dimension that is larger than an operable dimension to adjust the air gap to be within the operable dimension.

Abstract: A load detent assembly for restricting creep of a rotating assembly of an actuator used to actuate an aircraft flight control surface. The load detent assembly includes an engagement member having circumferentially spaced engagement surfaces/protruding portions, and a load detent having a stoppage member radially biasable towards the engagement member for interengagement between the engagement surfaces to restrict creep of the rotating assembly. One of the engagement member or the load detent is configured for rotation radially inward of the other of the engagement member or the load detent through at least 360 degrees of rotation. The other of the engagement member or the load detent is configured for being fixed radially outward of the one of the engagement member or the load detent.

Abstract: A control system includes a plurality of subsystems each operative to perform a unique vehicle function, a plurality of electronic controllers each operative to individually control at least one of the plurality of subsystems, wherein a number of subsystems is greater than a number of controllers, and a plurality of switching devices each operative to selectively connect any one of the plurality of subsystems to any one of the plurality of electronic controllers.

Abstract: An actuator assembly includes a primary load path for tightly coupling an actuated surface to a reference structure, and a secondary load path having a backlash portion for coupling the actuated surface to the reference structure with backlash, wherein the secondary load path is unloaded during an operative state of the primary load path and loaded during a failure state of the primary load path. A first sensor is configured to sense relative displacement between a portion of the primary load path and a portion of the secondary load path. A controller is operatively coupled to the first sensor, the controller configured to determine a load on the primary load path based on relative displacement sensed by the first sensor.

Abstract: A mechanical synchronization device for a distributed system. A plurality of actuators actuate movement of control surface components of an aircraft. Each actuator has a first end coupled to a structure of the aircraft and a second end coupled to a control surface component, and a drive path from a motion provider to the control surface component, the control surface component being configured to move along the respective drive path. A power module controller is operable to simultaneously output motor drive power from a power module through an electrical bus to at least two of the motion providers in a synchronous or nearly synchronous manner to actuate movement of control surface components. The mechanical synchronization device is between at least two of the actuators and transfers torque between the actuators to maintain symmetry between the actuators. A load limiting device may limit the power transferred through the mechanical synchronization device.

Abstract: An actuation system includes a power drive unit that drives a plurality of drive shafts that each has a first end individually connected to the power drive unit. The power drive unit includes a geartrain including a plurality of individual gears that are offset relative to each other along the gearbox, and a motor-driven rotation of one of the plurality of individual gears drives rotation of the other individual gears, and each of the plurality of individual gears rotates to drive rotation of a respective one of the plurality of drive shafts. A plurality of torque brakes is mounted to the gearbox, the torque brakes being mechanically coupled to respective individual gears and drive shafts. When the torque being passed through is above a predetermined threshold value, a locking of one of the torque brakes stops rotation of all gears simultaneously to maintain positional symmetry in the actuation system.

Abstract: A control system includes a plurality of subsystems each operative to perform a unique vehicle function, a plurality of electronic controllers each operative to individually control at least one of the plurality of subsystems, wherein a number of subsystems is greater than a number of controllers, and a plurality of switching devices each operative to selectively connect any one of the plurality of subsystems to any one of the plurality of electronic controllers.

Abstract: An actuation system includes a power drive unit that drives a plurality of drive shafts that each has a first end individually connected to the power drive unit. The power drive unit includes a geartrain including a plurality of individual gears that are offset relative to each other along the gearbox, and a motor-driven rotation of one of the plurality of individual gears drives rotation of the other individual gears, and each of the plurality of individual gears rotates to drive rotation of a respective one of the plurality of drive shafts. A plurality of torque brakes is mounted to the gearbox, the torque brakes being mechanically coupled to respective individual gears and drive shafts. When the torque being passed through is above a predetermined threshold value, a locking of one of the torque brakes stops rotation of all gears simultaneously to maintain positional symmetry in the actuation system.

Abstract: A load detent assembly for restricting creep of a rotating assembly of an actuator used to actuate an aircraft flight control surface. The load detent assembly includes an engagement member having circumferentially spaced engagement surfaces/protruding portions, and a load detent having a stoppage member radially biasable towards the engagement member for interengagement between the engagement surfaces to restrict creep of the rotating assembly. One of the engagement member or the load detent is configured for rotation radially inward of the other of the engagement member or the load detent through at least 360 degrees of rotation. The other of the engagement member or the load detent is configured for being fixed radially outward of the one of the engagement member or the load detent.

Abstract: A load detent assembly for restricting creep of a rotating assembly of an actuator used to actuate an aircraft flight control surface. The load detent assembly includes an engagement member having circumferentially spaced engagement surfaces/protruding portions, and a load detent having a stoppage member radially biasable towards the engagement member for interengagement between the engagement surfaces to restrict creep of the rotating assembly. One of the engagement member or the load detent is configured for rotation radially inward of the other of the engagement member or the load detent through at least 360 degrees of rotation. The other of the engagement member or the load detent is configured for being fixed radially outward of the one of the engagement member or the load detent.

Abstract: A mechanical synchronization device for a distributed system. A plurality of actuators actuate movement of control surface components of an aircraft. Each actuator has a first end coupled to a structure of the aircraft and a second end coupled to a control surface component, and a drive path from a motion provider to the control surface component, the control surface component being configured to move along the respective drive path. A power module controller is operable to simultaneously output motor drive power from a power module through an electrical bus to at least two of the motion providers in a synchronous or nearly synchronous manner to actuate movement of control surface components. The mechanical synchronization device is between at least two of the actuators and transfers torque between the actuators to maintain symmetry between the actuators. A load limiting device may limit the power transferred through the mechanical synchronization device.

Abstract: An actuator assembly includes a primary load path for tightly coupling an actuated surface to a reference structure, and a secondary load path having a backlash portion for coupling the actuated surface to the reference structure with backlash, wherein the secondary load path is unloaded during an operative state of the primary load path and loaded during a failure state of the primary load path. A first sensor is configured to sense relative displacement between a portion of the primary load path and a portion of the secondary load path. A controller is operatively coupled to the first sensor, the controller configured to determine a load on the primary load path based on relative displacement sensed by the first sensor.

Abstract: A load detent assembly for restricting creep of a rotating assembly of an actuator used to actuate an aircraft flight control surface. The load detent assembly includes an engagement member having circumferentially spaced engagement surfaces/protruding portions, and a load detent having a stoppage member radially biasable towards the engagement member for interengagement between the engagement surfaces to restrict creep of the rotating assembly. One of the engagement member or the load detent is configured for rotation radially inward of the other of the engagement member or the load detent through at least 360 degrees of rotation. The other of the engagement member or the load detent is configured for being fixed radially outward of the one of the engagement member or the load detent.

Abstract: A distributed electromechanical actuation system including multiple electromechanical actuators intended to operate together in a synchronous (or near synchronous) manner. Each individual actuator is powered by one or more induction motors or other appropriate motor such as a stepper motor. The induction motors are designed to have a very high pullout torque with very low slippage to the pull out point. The group of actuators is controlled from a single controller (e.g., an induction motor controller) that utilizes a Volts per Hertz type of open loop control where the bus voltage and frequency are controlled to assure that the motors always operate on the low slip side of the pull out point performance curve.

Abstract: An actuator for actuating movement of a control surface relative to a structure can include a high-efficiency assembly and a low-efficiency assembly. The high-efficiency assembly can be connectable between a control surface and a structure for providing a first load transfer assembly and the assembly can have minimum backlash. The low-efficiency assembly is connectable between the control surface and the structure for providing a second load transfer assembly. The low-efficiency or irreversible assembly can be disposed in parallel relationship to the high-efficiency assembly and can have a higher backlash than the low-efficiency assembly. The low-efficiency assembly can be unloaded in normal operation.

Abstract: A distributed electromechanical actuation system including multiple electromechanical actuators intended to operate together in a synchronous (or near synchronous) manner. Each individual actuator is powered by one or more induction motors or other appropriate motor such as a stepper motor. The induction motors are designed to have a very high pullout torque with very low slippage to the pull out point. The group of actuators is controlled from a single controller (e.g., an induction motor controller) that utilizes a Volts per Hertz type of open loop control where the bus voltage and frequency are controlled to assure that the motors always operate on the low slip side of the pull out point performance curve.

Abstract: An actuator for actuating movement of a control surface relative to a structure can include a high-efficiency assembly and a low-efficiency assembly. The high-efficiency assembly can be connectable between a control surface and a structure for providing a first load transfer assembly and the assembly can have minimum backlash. The low-efficiency assembly is connectable between the control surface and the structure for providing a second load transfer assembly. The low-efficiency or irreversible assembly can be disposed in parallel relationship to the high-efficiency assembly and can have a higher backlash than the low-efficiency assembly. The low-efficiency assembly can be unloaded in normal operation.

Abstract: An actuator (30) for actuating translation movement of a component (32) (e.g., a horizontal stabilizer) relative to a structure (34) (e.g., an aircraft's rear fuselage). The actuator (30) comprises a control-motion-providing assembly (40) having a drive path from a motion provider (52) to the component (32), a motion-permit-prevent assembly (42), and a sensing system (94) which senses a failure in the drive path. The motion-permit-prevent assembly (42) comprises a screw member (74), which is not part of the drive path, and a nut member (76). Upon detection drive-path failure by the sensing system (94), the motion-permit-prevent assembly (42) converts from a motion-permitting mode (whereat relative rotation between the screw-nut members (74/76) is permitted) to a motion-preventing mode (whereat relative rotation of the screw-nut members (74/76) is prevented). In the motion-preventing mode, the component (32) is locked or immobilized.

Abstract: The invention provides a method for controlling an electromechanical servomechanism (20) for moving an output member relative to a variable load (38). The servomechanism includes: a motor (37) having at least one coil (32A, 32B or 32C) adapted to be supplied with current and having a rotor (33) with an output shaft (35); a mechanical transmission (36) arranged between the output shaft and the load, the transmission having a mechanical friction related to the load; a servoamplifier (30) arranged to supply current to the motor coil in response to an input signal (in line 29); a command signal (in line 21) for commanding the position of the load; a load position feedback signal (in line 23) compared (in summing point 22) to the command signal and arranged to produce an error signal (in line 24); and means (28) for generating an offset signal (in line 26) that is summed (in summing point 25) with the error signal to modify the servoamplifier input signal (in line 29).

Abstract: A pressure-control device (20) includes a controllable variable-displacement reversible hydraulic motor (21) having a pressure port (22) and a return port (23); a source of pressurized fluid (Ps); a fluid return (R); and a pressure regulating valve (24) operatively interposed between the source, return and pressure port. The pressure regulating valve is operatively arranged to maintain a predetermined pressure at the pressure port regardless of the direction of flow through the pressure port.