Multi-load path actuator with fault detection

Abstract

The present invention provides an actuator comprising: a first motor and a second motor; a first drive linkage and a second drive linkage; and a pivot support configured to pivot about a pivot axis, the pivot support being connected to the first drive linkage and the second drive linkage at a first support connector and a second support connector offset from the pivot axis by a first offset distance and a second offset distance, the motors and the first and second drive linkages being configured to provide a first load path and a second load path between a drive housing and the pivot support, such that in a first operating state the pivot support is in a force-balanced orientation about the pivot axis; and a proximity detector positioned to detect when the pivot support rotates away from the force-balanced orientation about the pivot axis beyond a threshold, wherein the proximity detector detects a force imbalance on the pivot support caused by a fault in one of the first or second drive linkages.

Description

Technical Field

[0001] This invention relates generally to the field of actuators, and more specifically to actuators having dual load paths and fault detection. Background Technology

[0002] Horizontal stabilizer trim actuators (HSTAs) are known in the art. U.S. Patent No. 4,637,272 relates to an actuation system using a common ball screw in a primary load path and a secondary load path. U.S. Patent No. 6,755,375 relates to an actuation system having two independent actuators acting between a common support and a common flight control surface. U.S. Patent No. 4,179,944 relates to an actuation system that provides for releasing the actuators after the ball screw assembly has jammed.

[0003] Screw-driven actuators are also known in the art and typically include a screw that is threaded into a nut and driven by a motor. The relative rotation between the screw and the nut produces axial displacement between them. Summary of the Invention

[0004] The bracket references to corresponding parts, portions, or surfaces in the disclosed embodiments are for illustrative purposes only and not for limiting purposes. This disclosure provides an actuator assembly (15) configured to impart a range of motion from an animal body (18) relative to a structure (16). The actuator assembly includes: a first sub-actuator (30) having a first motor (31) and a first drive linkage mechanism (35). 35) is configured to be linearly driven relative to the drive housing (80); a second sub-actuator (60) including a second motor (61) and a second drive linkage (65) configured to be linearly driven relative to the drive housing (80); a pivot support (81) connected to both the first drive linkage (35) and the second drive linkage (65) and configured about a pivot axis (8). 2) Pivoting; the pivot support (81) is connected to the first drive linkage (35) at a first support connector (38) offset from the pivot axis (82) by a first vertical offset distance (39); the pivot support (81) is connected to the second drive linkage (65) at a second support connector (68) offset from the pivot axis (82) by a second vertical offset distance (69); the first motor (31) and the first drive linkage (36) are configured to be in the drive housing (80) and the pivot support (81) provides a first load path; the second motor (61) and the second drive linkage (65) are configured to provide a second load path different from the first load path between the drive housing (80) and the pivot support (81); the first support connector (38) supports the first drive linkage (35) and the second support connector (68) supports the second drive linkage (65) such that, in the first operating state, the pivot support (81) is in a force-balanced orientation about the pivot axis (82). Figure 3 ); proximity detectors (40, 41, 70) are positioned to detect when the pivot support (81) rotates about the pivot axis (82) away from the force balance orientation beyond the rotation threshold. Figure 4 ); and wherein the proximity detector (40, 41, 70) detects that the force imbalance on the pivot support (81) caused by a fault in one of the first drive linkage or the second drive linkage exceeds the fault threshold.

[0005] The proximity detector may include a contact detector configured such that a force imbalance caused by a fault in one of the first or second drive linkage mechanisms exceeds a fault threshold, causing the pivot support (81) to rotate away from the force balance orientation beyond a rotation threshold and contact the contact detector, thereby detecting the fault. The actuator assembly may include a slave body (18) connected to the pivot support (81), and the proximity detector may include a proximity sensor (40, 70) disposed on either the pivot support or the slave body, and a sensor target (41) disposed on the other of the pivot support or the slave body.

[0006] The first drive linkage mechanism may include a first screw driver (35), and the second drive linkage mechanism may include a second screw driver (65). A first motor (31) may be configured to selectively rotate the first screw driver (35), and a second motor (61) may be configured to selectively rotate the second screw driver (65). The first screw driver (35) may include a first output piston (36) connected to a pivot support (81) at a first support connector (38) and translated by a drive housing (80); the first screw driver (35) may include a first shaft (37) rotatably supported by the drive housing (80); the first output piston (36) may engage with the first shaft (37) such that the first output piston (36) translates axially within a linear range of motion relative to the first shaft (37) and the drive housing (80) on the first central axis (37A) in response to relative rotation between the first shaft (37) and the first output piston (36) about a first central axis (37A); and the first motor may be configured to drive the rotation of the first shaft (37) relative to the drive housing (80) about the first central axis (37A). The second screw actuator (65) may include a second output piston (66) connected to a pivot support (81) at a second support connector (68) and translatably supported by a drive housing (80); the second screw actuator may include a second shaft (67) rotatably supported by the drive housing (80); the second output piston (66) may engage with the second shaft (67) such that the second output piston (66) translates axially within a linear range of motion relative to the second shaft (67) and the drive housing (80) on the second central axis (67A) in response to relative rotation between the second shaft (67) and the second output piston (66) about a second central axis (67A); and a second motor (61) may be configured to drive the rotation of the second shaft (67) about the second central axis (67A) relative to the drive housing (80). The first central axis (37A) and the second central axis (67A) may be substantially parallel. The pivot axis (82) and the first central axis (37A) may be substantially perpendicular. The first offset distance (39) can be approximately the same as the second offset distance (69).

[0007] A first motor (31) may be connected to a first drive linkage (35) and a second drive linkage (65) such that, in a first operating state, the first motor (31) selectively drives the pivot support (81) relative to the drive housing (80) via a first load path and a second load path; and a second motor (61) may be connected to the first drive linkage (35) and the second drive linkage (65) such that, in a first operating state, the second motor (61) selectively drives the pivot support (81) relative to the drive housing (80) via a first load path and a second load path. A linear actuator assembly may include gears (33, 34, 84, 64) between the first motor (31) and the first screw driver (35) and the second screw driver (65) such that, in the first operating state, both the first screw driver (35) and the second screw driver (65) are driven by the first motor (31) and rotate synchronously with each other in the first operating state. The linear actuator assembly may include gears (63, 64, 84, 34) between the second motor (61) and the first screw driver (35) and the second screw driver (65) such that both the first screw driver (35) and the second screw driver (65) can be driven by the second motor (61) in a first operating state and such that the first screw driver (35) and the second screw driver (65) rotate synchronously with each other in the first operating state. The gear assembly may include: a first motor gear (33) connected to the drive shaft (32) of a first motor (31); a second motor gear (63) connected to the drive shaft (62) of a second motor (61); a first drive gear (34) connected to the first shaft (37) of a first screw driver (35) and rotatably engaged with the first motor gear (33); a second drive gear (64) connected to the second shaft (67) of a second screw driver (65) and rotatably engaged with the second motor gear (63); and a synchronizing gear (84) rotatably engaged with both the first drive gear (34) and the second drive gear (64).

[0008] The first support connector (38) may include a first pin connector, wherein the pivot support (81) includes a first U-shaped clamp (42) and a first U-shaped clamping pin (43), and the first drive linkage includes a first pin opening (44) configured to receive the first U-shaped clamping pin (43), such that the pivot support (81) is pivotally connected to the first drive linkage via the first pin connector. The second support connector (68) may include a second pin connector, wherein the pivot support (81) includes a second U-shaped clamp (72) and a second U-shaped clamping pin (73), and the second drive linkage includes a second pin opening (74) configured to receive the second U-shaped clamping pin (73), such that the pivot support (81) is pivotally connected to the second drive linkage via the second pin connector. The first support connector (38) may include a first spherical bearing (45) between the pivot support (81) and the first drive linkage (35), and the second support connector (68) may include a second spherical bearing (75) between the pivot support (81) and the second drive linkage (65).

[0009] The actuator assembly may include a slave body (18) connected to a pivot mount (81) and a structure (16) connected to a drive housing (80), and the actuator assembly may be configured to impart a limited range of rotational motion to the slave body (18) relative to the structure (16) about a rotational output driven axis (20). The drive housing (80) may be connected to the structure (16) via a housing pivot connection (22). A first motor (31) and a second motor (61) may be supported by the drive housing (80). The slave body (18) may include an aircraft flight control surface. The flight control surface may be selected from the group consisting of a horizontal stabilizer, elevator, rudder, aileron, flap, leading-edge slats, and spoilers. The flight control surface may be a horizontal stabilizer (18), and the structure may be a vertical stabilizer (16).

[0010] The actuator assembly may include a slave body connected to the drive housing (80) and a structure connected to the pivot support (81), and the actuator assembly may be configured to give the slave body a limited range of rotational motion about the rotation output slave axis relative to the structure.

[0011] The first and second motors may include brushless DC permanent magnet motors. Faults may include wear or backlash exceeding a fault threshold in either the first or second drive linkage mechanism. The rotation threshold may be proportional to the fault threshold. Attached Figure Description

[0012] Figure 1 This is a representative partial perspective view of an embodiment of an improved actuator assembly on the horizontal stabilizer trim at the tail of a winged aircraft.

[0013] Figure 2yes Figure 1 A representative side view of the actuator shown.

[0014] Figure 3 It is roughly in Figure 2 The line AA is intercepted. Figure 2 The figure shows a longitudinal vertical cross-sectional view of the actuator.

[0015] Figure 4 yes Figure 3 The view shown depicts the actuator in an unbalanced position during fault detection. Detailed Implementation

[0016] First, it should be clearly understood that the same reference numerals are intended to be used consistently across several appendices. Figure 1 The same structural elements, portions, or surfaces are identified accordingly because such elements, portions, or surfaces can be further described or explained by the entire written specification, which is an integral part of the entire written specification. Unless otherwise stated, the drawings are intended to be read in conjunction with the specification (e.g., crosshairs, arrangement of parts, scale, extent, etc.) and are considered part of the entire written description of the invention. As used in the following description, the terms “horizontal,” “vertical,” “left,” “right,” “up,” and “down,” and their adjective and adverbial derivatives (e.g., “horizontally,” “to the right,” “upward,” etc.), simply refer to the orientation of the structure illustrated when a particular drawing is facing the reader. Similarly, the terms “inward” and “outward” generally refer to the orientation of a surface relative to its axis of elongation or axis of rotation.

[0017] An improved redundant actuator assembly with fault detection is provided, a first embodiment of which is generally indicated by 15. As shown, assembly 15 generally includes: first and second independently driven screw drivers 35 and 65, which define two independent load paths between housing 80 and pivot support 81; a first motor 31 and a second motor 61, which are configured to drive the first drive screw 35 and the second drive screw 65, respectively; gear arrangements 33, 34, 63, 64 and 84 between motors 31 and 61 and screw drivers 35 and 65, which are configured such that screw drivers 35 and 65 can both be driven by a single motor and that screw drivers 35 and 65 are synchronized with each other; pivot support 81. The pivot 81 supports a screw driver 35 on a first side of the pivot 82 and a screw driver 65 on a second side of the pivot 82, and is configured such that the pivot 81 is in a force-balanced orientation during normal operation; and a first proximity sensor 40 and a second proximity sensor 70, which are respectively located on opposite sides of the pivot 82 of the pivot 81, and are configured such that a force imbalance caused by a fault in one of the first or second drive linkage mechanisms exceeds a threshold, causing the pivot 81 to rotate away from its force-balanced orientation, and triggering one of the proximity sensors 40 or 70 to detect the fault.

[0018] like Figure 1 and Figure 2 As shown, the top end of each of the screw drives 35 and 65 is connected via a pivot support 81 to a mounting block 34 of a flight control surface 18, which in this embodiment is a horizontal stabilizer at the tail of the aircraft. The screw drives 35 and 65, along with the pivot support 81, are configured to give the horizontal stabilizer 18 a limited range of rotational movement about a rotational hinge axis 20 relative to a vertical stabilizer 16 via a horizontal stab hinge 19. The bottom end of each of the screw drives 35 and 65 is connected via a housing 80 to a mounting bracket 21 of a reference structure 16, which in this embodiment is a vertical stabilizer at the tail of the aircraft. In this embodiment, the housing 80 is connected to the vertical stabilizer 16 via a housing pivot connector 22. As shown, each of the screw drives 35 and 65 forms an independent load path, such that a single failure does not result in the loss of both load paths.

[0019] The screw actuator 35 typically includes an output piston 36 and a shaft 37. The piston 36 is connected to a pivot support 81 at a support connector 38 and is translated by a drive housing 80, allowing the piston 36 to translate linearly relative to the housing tube 80A, but not to rotate relative to the housing tube 80A. The shaft 37 is rotatably supported by the drive housing 80, allowing the shaft 37 to rotate relative to the housing tube 80A, but not to translate linearly relative to the housing tube 80A. An inner cylindrical bore of the piston 36 is threaded into a top nut of the shaft 37, allowing the piston 36 to translate axially within a linear range of motion relative to the shaft 37 and the drive housing 80 along the central axis 37A in response to relative rotation between the shaft 37 and the piston 36 about the central axis 37A. A motor 31 is configured to drive the rotation of the shaft 37 relative to the drive housing 80 about the central axis 37A. Thus, the screw actuator 35 can operate as a mechanical linear actuator that converts rotary motion into linear motion.

[0020] The screw actuator 65 typically includes an output piston 66 and a shaft 67. The piston 66 is connected to a pivot support 81 at a support connector 68 and is translated by a drive housing 80, allowing the piston 66 to translate linearly relative to the housing tube 80B, but not to rotate relative to the housing tube 80B. The shaft 67 is rotatably supported by the drive housing 80, allowing the shaft 67 to rotate relative to the housing tube 80B, but not to translate linearly relative to the housing tube 80B. An inner cylindrical bore of the piston 66 is threaded into a top nut on the shaft 67, allowing the piston 66 to translate axially within a linear range of motion relative to the shaft 67 and the drive housing 80 along the central axis 67A in response to relative rotation between the shaft 67 and the piston 66 about a central axis 67A. A motor 61 is configured to drive the rotation of the shaft 67 relative to the drive housing 80 about the central axis 67A. Thus, the screw actuator 65 can operate as a mechanical linear actuator that converts rotary motion into linear motion.

[0021] like Figure 3 and Figure 4As shown, the shaft 37 of the screw drive 35 includes a large gear 34 at its bottom end, which meshes with and is rotatably driven by a corresponding small gear 33 on the output shaft 32 of the motor 31. The large gear 34 also meshes with a central idler gear 84. Similarly, the shaft 67 of the screw drive 65 includes a large gear 64 at its bottom end, which meshes with and is rotatably driven by a corresponding small gear 63 on the output shaft 62 of the motor 61. The large gear 64 also meshes with a central idler gear 84. The idler gear 84 links two separate load paths, allowing the two drive screws 35 and 65 to be synchronized or timed together, and allowing either the left motor 31 or the right motor 61 to drive both screw drives 35 and 65 (through the direct gear mechanism of the motor itself and through the idler gear 84 for the opposite side screw drives). Thus, the shaft 32 extends from the motor 31 and terminates at a gear 33 with outwardly facing teeth. Gear 33 engages with the outward-facing teeth of reduction gear 34 fixed to shaft 37. Gear 33 also engages with the outward-facing teeth of idler gear 84. As motor shaft 32 rotates, shaft 37 rotates relative to housing 80 about central axis 37A. As idler gear 84 rotates, shaft 37 also rotates relative to housing 80 about central axis 37A. Shaft 37 rotates about axis 37A in the opposite direction to the rotation of motor shaft 32 about motor axis and also in the opposite direction to the rotation of idler gear 84. As motor output shaft 32 and screw drive shaft 37 rotate, idler gear 84 rotates relative to housing 80. Shaft 62 extends from motor 61 and terminates at gear 63 with outward-facing teeth. Gear 63 engages with the outward-facing teeth of reduction gear 64 fixed to shaft 67. Gear 63 also engages with the outward-facing teeth of idler gear 84. As motor shaft 62 rotates, shaft 67 rotates relative to housing 80 about central axis 67A. As the idler gear 84 rotates, the shaft 67 also rotates relative to the housing 80 about the central axis 67A. The rotation of the shaft 67 about axis 67A is opposite to the rotation of the motor shaft 62 about the motor axis, and also opposite to the rotation of the idler gear 84. As the motor output shaft 62 and the screw drive shaft 67 rotate, the idler gear 84 rotates relative to the housing 80.

[0022] Although in this embodiment, the rotary coupling between motors 31 and 61 and screw drives 35 and 65 comprises a meshing gear train, it is contemplated that other gear drive combinations and / or various alternative rotary couplings may be used. For example, but not limited to, the screw drives may be mechanically linked to the motors via one or more belts, gears, pulleys, chains, sprockets, and / or any other suitable coupling configured to physically or mechanically link the subject elements.

[0023] A pivoting or seesaw-type support 81 is connected to a mounting block 24, allowing it to pivot about a pivot axis 82 relative to the mounting block 24 and to a sensor target 41 fixed above the mounting block 24. The top end of the piston 36 of the screw driver 35 is connected to the pivot support 81 at a support connector 38, which is offset vertically by a distance 39 from the pivot axis 82 on a first side of the pivot. In this embodiment, the connector 38 is a pin-joint connector. The pivot support 81 has a U-shaped clamp-type first side arm 42 and a U-shaped clamp-type pin 43 oriented about the pivot axis 46. The top end of the piston 36 includes a corresponding opening 44 oriented about the pivot axis 46, configured to receive the U-shaped clamp pin 43, such that the pivot support 81 is pivotally connected to the piston 36 via the pin-joint connector 38. In this embodiment, the connector 38 includes a spherical bearing 45 between an opening 44 in the end portion of the piston 36 and a pin 43 of the pivot support 81. The spherical bearing 45 is a rotatable connection between the U-shaped clamp 42 of the pivot support 81 and the piston 36 about a connection center. The opening 44 in the end portion of the piston 36 has a race having a spherical inner diameter surface oriented about the connection center. The U-shaped clamp pin 43 rotatably supports the spherical bearing 45, which has an outer spherical diameter surface oriented about the connection center. The spherical bearing 45 is held in the race of the end portion of the piston 36, wherein the outer surface of the spherical bearing 45 spherically slides into contact with the inner surface of the race of the piston 36. Therefore, the race of the piston 36 and the spherical bearing 45 of the pivot support 81 can rotate relative to each other about the connection center of the connector 38 by at least two degrees of motion. The connection center of the pivot connector 38 between the pivot support 81 and the screw driver 35 is offset by a vertical distance 39 from the pivot axis 82.

[0024] The top end of the piston 66 of the screw driver 65 is connected to a pivot support 81 at a support connector 38, which is offset vertically by a distance 69 from the pivot axis 82 on a first side of the pivot 82. In this embodiment, the connector 68 is a pin-joint connector. The pivot support 81 has a U-shaped clamp-type first side arm 72 and a U-shaped clamp-type pin 73 oriented about the pivot axis 76. The top end of the piston 66 includes a corresponding opening 74 oriented about the pivot axis 76, which is configured to receive the U-shaped clamp pin 73, such that the pivot support 81 is pivotally connected to the piston 66 via the pin-joint connector 68. In this embodiment, the connector 68 includes a spherical bearing 75 located between the opening 74 in the end of the piston 66 and the pin 73 of the pivot support 81. The spherical bearing 75 is a rotational connection between the U-shaped clamp 72 of the pivot support 81 and the piston 66 about a connection center. The opening 74 in the end portion of piston 66 has a race with a spherical inner diameter surface oriented about the coupling center. A U-shaped clamp 73 rotatably supports a spherical bearing 75, which has an outer spherical diameter surface oriented about the coupling center. The spherical bearing 75 is held in the race of the end portion of piston 66, wherein the outer surface of the spherical bearing 75 spherically slides into contact with the inner surface of the race of piston 66. Therefore, the race of piston 66 and the spherical bearing 75 of pivot support 81 can rotate relative to each other about the coupling center of connector 68 by at least two degrees of motion. The coupling center of pivot connector 68 between pivot support 81 and screw driver 65 is offset vertically by a distance 69 from pivot axis 82, opposite to offset distance 39 or connector 38. In this embodiment, axis 46 coincides with axis 76, and offset distance 39 is the same distance as offset distance 69. Although connectors 38 and 68 include pin-joint connectors in this embodiment, it is contemplated that various other alternative rotary or pivot connectors may also be used. For example, but not limited to, spherical, universal, or general-purpose connectors may be used as alternatives.

[0025] Motor 31 includes a stator fixed relative to housing 80 and a rotor connected to output shaft 32 and driven to rotate relative to the stator about a drive axis. In this embodiment, motor 31 is a rotary brushless permanent magnet electric motor, its rotor having permanent magnets spaced apart around its inward-facing annular stator surfaces, and its stator having coils energized to drive the rotor and output shaft 32 in any rotational direction about the motor axis. Similarly, motor 61 includes a stator fixed relative to housing 80 and a rotor connected to output shaft 62 and driven to rotate relative to the stator about a drive axis. In this embodiment, motor 61 is a rotary brushless permanent magnet electric motor, its rotor having permanent magnets spaced apart around its inward-facing annular stator surfaces, and its stator having coils energized to drive the rotor and output shaft 62 in any rotational direction about the motor axis.

[0026] Proximity sensors 40 and 70 are positioned on either side of the pivot point 82 of the pivot support 81. Sensor 40 is offset vertically from the pivot axis 82 by a distance 49 on the first side of the pivot 82. Sensor 70 is offset vertically from the pivot axis 82 by a distance 79 on the second side of the pivot 82, where distances 49 and 79 are the same. Figures 1 to 3 As shown, during normal operation, the pivot support 81 is in a force-balanced orientation when the two load paths provide equal forces. When the pivot support 81 is in... Figure 3 In the force-balanced orientation shown, sensors 40 and 70 are each spaced a selected distance from target 41 on pivot support 81. When both screw actuators 35 and 65 are operating normally, pivot support 81 is generally balanced and remains within a central threshold, preventing sensor 40 or sensor 70 from moving within the fault range of sensor target 41 on mounting block 24. Screw actuators 35 and 65 both provide substantially the same force to pivot support 81 on each side of pivot axis 82, where the clockwise torque is equal to the counterclockwise torque on pivot support 81 about pivot axis 82. In this balanced orientation, sensors 40 and 70 will not sense that support 81 pivots too close to sensor target 41 in any way that would indicate an imbalance fault condition.

[0027] If, for example, when motor 31 or 61 drives pistons 36 and 66 upward, the screw driver 65 begins to exhibit wear or clearance exceeding a threshold, the torque from the screw driver 65 about the pivot axis 82 on the pivot support 81 will no longer counteract the torque from the screw driver 35 about the pivot axis 82 on the pivot support 81, and the pivot support 81 will therefore rotate clockwise about the pivot point 82, causing the proximity sensor 40 to move outside the threshold center position relative to the target 41 and within the fault range, or even potentially into contact with the sensor target 41, as... Figure 4As shown in the figure, in this unbalanced orientation, pin axis 46 is not perpendicular to axis 37A of the shaft, and pin axis 76 is not perpendicular to axis 67A of the shaft. When sensor 40 detects this unbalanced orientation, actuator 15 is commanded to stop and safely holds its position for the remainder of flight. If, for example, when motor 31 or 61 drives pistons 36 and 66 upward, screw driver 35 begins to exhibit wear or clearance exceeding a threshold, pivot support 81 will rotate counterclockwise about pivot point 82, causing proximity sensor 70 to move relative to target 41 beyond the threshold center position and into the fault range, or even potentially into contact with sensor target 41. When sensor 70 detects this unbalanced orientation, actuator 15 is commanded to stop and safely holds its position for the remainder of flight. If, for example, when motor 31 or 61 pulls down pistons 36 and 66, the screw driver 65 begins to exhibit wear or clearance exceeding a threshold, then the torque from the screw driver 65 about the pivot axis 82 on the pivot support 81 will no longer counteract the torque from the screw driver 35 about the pivot axis 82 on the pivot support 81, and the pivot support 81 will therefore rotate counterclockwise about the pivot point 82, causing the proximity sensor 70 to move relative to the target 41 beyond the threshold center position and within the fault range, or even potentially into contact with the sensor target 41. When the sensor 70 detects this unbalanced orientation, the actuator 15 is commanded to stop and safely maintain its position for the remainder of flight. If, for example, when motor 31 or 61 pulls down pistons 36 and 66, screw driver 35 begins to exhibit wear or clearance exceeding a threshold, then pivot support 81 will rotate clockwise about pivot point 82, causing proximity sensor 40 to move relative to target 41 beyond the threshold center position and within the fault range, or even potentially into contact with sensor target 41. When sensor 40 detects this unbalanced orientation, actuator 15 is commanded to stop and safely hold its position for the remainder of flight. Thus, a force imbalance exceeding a threshold caused by a fault in one of the first or second drive linkage mechanisms causes pivot support 81 to rotate away from its force-balanced orientation and triggers proximity sensors 40 and / or 70, thereby detecting the fault and triggering safe holding.

[0028] Proximity sensors 40 and 70 can be contact or non-contact sensors, contact stop switches, or other detectors. The proximity sensors can be positioned on a pivot support, or alternatively on an opposing structure. The proximity sensors can be positioned on either side of pivot 82, and so close to pivot support 81 that a force imbalance caused by a fault in one of the first or second load paths exceeds a threshold, causing pivot support 81 to rotate away from its force balance orientation and be detected by the sensor, thus detecting the fault.

[0029] Actuator assembly 15 is a dual-load-path linear actuator with fault detection, which can be used as an HSTA. It must be fail-safe, meaning it will retain its position after failure in one of the dual load paths. The HSTA described herein is a simple solution to this problem with far fewer components, lower cost, and less complexity. However, actuator assembly 15 can be arranged, for example, but not limited to, to act between other airfoil elements or aircraft flight control surfaces and the aircraft fuselage or other reference structures to adjust the orientation of that surface relative to the fuselage or other reference surface. For example, flight control surfaces can be stabilizers, elevators, rudders, ailerons, flaps, leading-edge slats, and spoilers.

[0030] Several modifications may be made to the disclosed embodiments. For example, but not limited to, housing 80 may be attached to horizontal stabilizer 18, and pivot support 81 may be attached to vertical stabilizer 16, wherein sensor target 41 is correspondingly positioned on vertical stabilizer 16 relative to sensors 40 and 70 on pivot support 81. Therefore, although one form of redundant actuator assembly with fault detection has been shown and described, and several modifications have been discussed, those skilled in the art will readily appreciate that various additional changes may be made without departing from the scope of the invention as defined and distinguished by the following claims.

Claims

1. An actuator assembly configured to impart a range of motion to an animal body relative to a structure, the actuator assembly comprising: A first sub-actuator, comprising a first motor and a first drive linkage mechanism configured to be linearly driven relative to a drive housing; The second sub-actuator includes a second motor and a second drive linkage mechanism, the second drive linkage mechanism being configured to be linearly driven relative to the drive housing; A pivot support, which is connected to both the first drive linkage and the second drive linkage and is configured to pivot about a pivot axis; The pivot support is connected to the first drive linkage mechanism at a first support connector that is offset from the pivot axis by a first offset distance perpendicular to the pivot axis. The pivot support is connected to the second drive linkage mechanism at a second support connector that is offset from the pivot axis by a second vertical offset distance. The first motor and the first drive linkage are configured to provide a first load path between the drive housing and the pivot support; The second motor and the second drive linkage are configured to provide a second load path, different from the first load path, between the drive housing and the pivot support; The first support connector supports the first drive linkage mechanism and the second support connector supports the second drive linkage mechanism, such that in the first operating state, the pivot support is in a force balance orientation about the pivot axis; A synchronous coupling, which is mechanically engaged independently of the pivot support with both the first drive linkage mechanism and the second drive linkage mechanism, thereby connecting the first load path with the second load path, such that in the first operating state, the first drive linkage mechanism and the second drive linkage mechanism are driven by the first motor and / or the second motor, respectively achieving rotatable synchronization between the first motor and the first support connector and between the second motor and the second support connector, and being driven linearly together; A proximity detector is positioned to detect when the pivot support rotates away from the force balance orientation about the pivot axis beyond a rotation threshold. as well as Wherein, the proximity detector detects that the force imbalance on the pivot support caused by a fault in one of the first drive linkage mechanism or the second drive linkage mechanism exceeds a fault threshold.

2. The actuator assembly according to claim 1, wherein, The proximity detector includes a contact detector configured such that a force imbalance caused by a fault in one of the first or second drive linkage mechanisms, exceeding the fault threshold, causes the pivot support to rotate away from the force balance orientation beyond the rotation threshold and contact the contact detector, thereby detecting the fault.

3. The actuator assembly of claim 2, comprising a slave body connected to the pivot support, wherein the proximity detector comprises a proximity sensor disposed on either the pivot support or the slave body and a sensor target disposed on the other of the pivot support or the slave body.

4. The actuator assembly according to claim 1, wherein, The first drive linkage mechanism includes a first screw driver, and the second drive linkage mechanism includes a second screw driver.

5. The actuator assembly according to claim 4, wherein, The first motor is configured to selectively rotate the first screw driver, and the second motor is configured to selectively rotate the second screw driver.

6. The actuator assembly of claim 5, wherein: The first screw driver includes a first output piston, which is connected to the pivot support at the first support connector and is translatably supported by the drive housing; The first screw driver includes a first shaft that is rotatably supported by the drive housing; The first output piston engages with the first shaft such that, in response to relative rotation between the first shaft and the first output piston about a first central axis, the first output piston translates axially within a linear range of motion relative to the first shaft and the drive housing along the first central axis; and The first motor is configured to drive the first shaft to rotate about the first central axis relative to the drive housing.

7. The actuator assembly of claim 6, wherein: The second screw driver includes a second output piston, which is connected to the pivot support at the second support connector and is translatably supported by the drive housing; The second screw driver includes a second shaft that is rotatably supported by the drive housing; The second output piston engages with the second shaft, such that the second output piston, in response to the relative rotation between the second shaft and the second output piston about the second central axis, translates axially within a linear range of motion relative to the second shaft and the drive housing on the second central axis. as well as The second motor is configured to drive the second shaft to rotate relative to the drive housing about the second central axis.

8. The actuator assembly of claim 7, wherein, The first central axis and the second central axis are substantially parallel.

9. The actuator assembly of claim 8, wherein, The pivot axis is substantially perpendicular to the first central axis.

10. The actuator assembly of claim 9, wherein, The first offset distance is substantially the same as the second offset distance.

11. The actuator assembly of claim 5, wherein: The first motor is connected to both the first drive linkage mechanism and the second drive linkage mechanism, such that in the first operating state, the first motor selectively drives the pivot support relative to the drive housing via the first load path and the second load path; as well as The second motor is connected to both the first drive linkage mechanism and the second drive linkage mechanism, such that in the first operating state, the second motor selectively drives the pivot support relative to the drive housing via the first load path and the second load path.

12. The actuator assembly of claim 11, comprising a gear arrangement between the first motor and the first screw driver and the second screw driver, such that both the first screw driver and the second screw driver are driveable by the first motor in the first operating state, and such that the first screw driver and the second screw driver rotate synchronously with each other in the first operating state.

13. The actuator assembly of claim 12, comprising a gear arrangement between the second motor and the first screw driver and the second screw driver, such that both the first screw driver and the second screw driver are driveable by the second motor in the first operating state, and such that the first screw driver and the second screw driver rotate synchronously with each other in the first operating state.

14. The actuator assembly of claim 13, wherein, The gear mechanism includes: A first motor gear, the first motor gear being connected to the drive shaft of the first motor; The second motor gear is connected to the drive shaft of the second motor; A first drive gear is connected to the first shaft of the first screw driver and rotatably engages with the first motor gear. A second drive gear, the second drive gear being connected to the second shaft of the second screw driver and rotatably engaged with the second motor gear; and The synchronizing coupling includes a synchronizing gear, which rotatably engages with both the first driving gear and the second driving gear.

15. The actuator assembly of claim 1, wherein, The first support connector includes a first pin connector, wherein the pivot support includes a first U-shaped clamp and a first U-shaped clamp pin, and the first drive linkage includes a first pin opening configured to receive the first U-shaped clamp pin, such that the pivot support is pivotally connected to the first drive linkage via the first pin connector.

16. The actuator assembly of claim 15, wherein, The second support connector includes a second pin connector, wherein the pivot support includes a second U-shaped clamp and a second U-shaped clamp pin, and the second drive linkage includes a second pin opening configured to receive the second U-shaped clamp pin, such that the pivot support is pivotally connected to the second drive linkage via the second pin connector.

17. The actuator assembly of claim 16, wherein, The first support connector includes a first spherical bearing located between the pivot support and the first drive linkage mechanism, and the second support connector includes a second spherical bearing located between the pivot support and the second drive linkage mechanism.

18. The actuator assembly of claim 1, comprising a slave body connected to the pivot support and a structure connected to the drive housing, wherein, The actuator assembly is configured to impart a limited range of rotational motion to the slave body relative to the structure about a rotational output slave axis.

19. The actuator assembly of claim 18, wherein, The drive housing is connected to the structure via a housing pivot connector.

20. The actuator assembly of claim 19, wherein, The first motor and the second motor are supported by the drive housing.

21. The actuator assembly of claim 18, wherein, The animal body includes the flight control surface of the aircraft.

22. The actuator assembly of claim 21, wherein, The flight control surfaces are selected from a group consisting of a horizontal stabilizer, elevator, rudder, aileron, flaps, leading-edge slats, and spoilers.

23. The actuator assembly of claim 21, wherein, The flight control surface is a horizontal stabilizer, and the structure is a vertical stabilizer.

24. The actuator assembly of claim 1, comprising a slave body connected to the drive housing and a structure connected to the pivot support, wherein, The actuator assembly is configured to impart a limited range of rotational motion to the slave body relative to the structure about a rotational output slave axis.

25. The actuator assembly of claim 1, wherein, Each of the first motor and the second motor comprises a brushless DC permanent magnet motor.

26. The actuator assembly of claim 1, wherein, The fault includes wear or clearance in the first or second drive linkage mechanism exceeding the fault threshold.

27. The actuator assembly of claim 1, wherein, The rotation threshold is proportional to the fault threshold.

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