Abstract: A kit of parts to provide a reconfigurable epicyclic gear system, The kit of parts includes at least one sun gear; a planet carrier; a plurality of sets of planet gears configured to be mounted on the planet carrier and to mesh with the at least one sun gear; and a plurality of ring gears configured to mesh with the plurality of sets of planet gears; wherein the at least one sun gear, the plurality of sets of planet gears and the plurality of ring gears all have the same modulus such that they can be arranged in different configurations that each produce a different output torque.

Abstract: An epicyclic gear assembly includes: a sun gear rotatable about an axis (A); a plurality of planetary gears arranged around and in meshing engagement with the sun gear such that rotation of the sun gear about its axis causes corresponding rotation of each of the planetary gears about their own axes; and an outer ring gear arranged around and in meshing engagement with the plurality of planetary gears such that rotation of the planetary gears causes rotation of the outer ring gear about the axis A and relative to the fixed outer rings. The assembly also includes a backlash reduction mechanism between the planetary gears and the outer ring gear. The backlash reduction mechanism includes a planetary gear carrier with a plurality of carrier segments each carrying a respective one of the planetary gears, the segments together defining an annular carrier having a bore therethrough.

Abstract: An axial flux electric motor for an aircraft includes a first motor section having a first stator and a first rotor, and a second motor section having a second stator and a second rotor. The first and second rotors are mounted on a common axle. The first rotor is secured to the common axle by a first set of connecting elements. The second rotor is secured to the common axle by a second set of connecting elements. The first set of connecting elements is arranged to break when the relative torque between the common axle and the first rotor is greater than a first particular threshold. The second set of connecting elements is arranged to break when the relative torque between the common axle and the second rotor is greater than a second particular threshold.

Abstract: An asymmetric torque limiter having an axis of rotation including a first annular friction disk, a second annular friction disk a skewed roller disk a first resilient member and a second resilient member. The second annular friction disk is concentrically arranged with the first annular friction disk. The skewed roller disk is in contact with the second annular friction disk. The skewed roller disk includes a plurality of skewed rollers mounted in an annular retainer. The plurality of skewed rollers are about a respective roller axis, each roller axis being skewed to a radial direction passing through the skewed roller from the axis of rotation. The first resilient member is attached to the first annular friction disk and is configured to bias the first annular friction disk toward an input shaft. The second resilient member is configured to bias the skewed roller disk toward the second annular friction disk.

Abstract: A gear device for a gear system for an aircraft includes: an input stage epicyclic gear comprising an input stage sun, an input stage carrier and an input stage ring; and an output stage epicyclic gear comprising an output stage sun, an output stage carrier and an output stage ring. A first input stage component of the input stage sun, the input stage carrier and the input stage ring is fixed to a corresponding first output stage component of the output stage sun, the output stage carrier and the output stage ring, wherein a second input stage component of the input stage sun, the input stage carrier and the input stage ring is fixed to a corresponding second output stage component of the output stage sun, the output stage carrier and the output stage ring. The second input stage component is different from the first input stage component.

Abstract: An epicyclic gear assembly includes: a sun gear rotatable about an axis (A); a plurality of planetary gears arranged around and in meshing engagement with the sun gear such that rotation of the sun gear about its axis causes corresponding rotation of each of the planetary gears about their own axes; and an outer ring gear arranged around and in meshing engagement with the plurality of planetary gears such that rotation of the planetary gears causes rotation of the outer ring gear about the axis A and relative to the fixed outer rings. The assembly also includes a backlash reduction mechanism between the planetary gears and the outer ring gear. The backlash reduction mechanism includes a planetary gear carrier with a plurality of carrier segments each carrying a respective one of the planetary gears, the segments together defining an annular carrier having a bore therethrough.

Abstract: An electromechanical actuator, EMA, having a plurality of modes. The EMA includes a housing, a motor fixed relative to the housing, the motor having an output shaft, the output shaft defining an axis (X) of the EMA and a first sun gear connected for rotation with the output shaft. The system includes an output arranged to be driven by rotation of the first sun gear, wherein the output is arranged to have a neutral position and to be movable away from the neutral position within a positive quadrant and away from the neutral position within a negative quadrant and a ratchet comprising a ratchet wheel and a pawl. The system also has a torque limiter having a predetermined torque limit and arranged to limit torque transfer between the first sun gear and the output.

Abstract: An electromechanical actuator (EMA) includes: a stationary body portion; a movable body portion configured to move relative to the stationary body portion; an actuation element connecting the stationary body portion and the movable body portion and configured to actuate the movable body portion relative to the stationary body portion; a surface acoustic wave (SAW) sensor disposed on the actuation element; a first interface component disposed on the stationary body portion at an interface between the stationary body portion and the movable body portion; and a second interface component disposed on the movable body portion at the interface between the stationary body portion and the movable body portion. The second interface component is configured to transmit signals between the SAW sensor and the first interface component. The first interface component and the second interface component define an inductive position sensor to determine the position of the second interface component.

Abstract: An electromechanical actuator (EMA) includes a plurality of modes and includes an electrical motor having a motor shaft extending along an axis (A) and that drives the shaft to rotate about the axis and a gear assembly mounted around, and in geared connection with the shaft, to rotate with the shaft. The EMA output is connected to the gear assembly such that rotation of the motor shaft causes rotation of the output via the gear assembly, the output rotating at a speed which is a predetermined fraction of the speed of rotation of the motor shaft based on the gear ratio of the gear assembly. The EMA also includes a synchroniser comprising a first conical portion connected to an end of the motor shaft, and a second conical portion connected to a ratchet. The synchroniser has an engaged position and a disengaged position.

Abstract: A method of manufacturing a gear includes: providing a shaft; forming a groove into the shaft; and inserting a tooth into the groove such that the tooth is retained in the groove by an interference fit. A retainer can also be fixed to the shaft such that the tooth is retained in the groove by the retainer in addition to the interference fit.

Abstract: A kit of parts to provide a reconfigurable epicyclic gear system, The kit of parts includes at least one sun gear; a planet carrier; a plurality of sets of planet gears configured to be mounted on the planet carrier and to mesh with the at least one sun gear; and a plurality of ring gears configured to mesh with the plurality of sets of planet gears; wherein the at least one sun gear, the plurality of sets of planet gears and the plurality of ring gears all have the same modulus such that they can be arranged in different configurations that each produce a different output torque.

Abstract: A gear device for a gear system for an aircraft includes: an input stage epicyclic gear comprising an input stage sun, an input stage carrier and an input stage ring; and an output stage epicyclic gear comprising an output stage sun, an output stage carrier and an output stage ring. A first input stage component of the input stage sun, the input stage carrier and the input stage ring is fixed to a corresponding first output stage component of the output stage sun, the output stage carrier and the output stage ring, wherein a second input stage component of the input stage sun, the input stage carrier and the input stage ring is fixed to a corresponding second output stage component of the output stage sun, the output stage carrier and the output stage ring. The second input stage component is different from the first input stage component.

Abstract: An asymmetric torque limiter having an axis of rotation including a first annular friction disk, a second annular friction disk a skewed roller disk a first resilient member and a second resilient member. The second annular friction disk is concentrically arranged with the first annular friction disk. The skewed roller disk is in contact with the second annular friction disk. The skewed roller disk includes a plurality of skewed rollers mounted in an annular retainer. The plurality of skewed rollers are about a respective roller axis, each roller axis being skewed to a radial direction passing through the skewed roller from the axis of rotation. The first resilient member is attached to the first annular friction disk and is configured to bias the first annular friction disk toward an input shaft. The second resilient member is configured to bias the skewed roller disk toward the second annular friction disk.

Abstract: An electromechanical actuator, EMA, having a plurality of modes. The EMA includes a housing, a motor fixed relative to the housing, the motor having an output shaft, the output shaft defining an axis (X) of the EMA and a first sun gear connected for rotation with the output shaft. The system includes an output arranged to be driven by rotation of the first sun gear, wherein the output is arranged to have a neutral position and to be movable away from the neutral position within a positive quadrant and away from the neutral position within a negative quadrant and a ratchet comprising a ratchet wheel and a pawl. The system also has a torque limiter having a predetermined torque limit and arranged to limit torque transfer between the first sun gear and the output.

Abstract: An electromechanical actuator (EMA) includes a plurality of modes and includes an electrical motor having a motor shaft extending along an axis (A) and that drives the shaft to rotate about the axis and a gear assembly mounted around, and in geared connection with the shaft, to rotate with the shaft. The EMA output is connected to the gear assembly such that rotation of the motor shaft causes rotation of the output via the gear assembly, the output rotating at a speed which is a predetermined fraction of the speed of rotation of the motor shaft based on the gear ratio of the gear assembly. The EMA also includes a synchroniser comprising a first conical portion connected to an end of the motor shaft, and a second conical portion connected to a ratchet. The synchroniser has an engaged position and a disengaged position.