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BR-102022011362-B1 - Aircraft Gear Systems and Methods of Transmitting Rotational Motion

BR102022011362B1BR 102022011362 B1BR102022011362 B1BR 102022011362B1BR-102022011362-B1

Abstract

AIRCRAFT GEAR SYSTEMS AND METHOD OF TRANSMITTING ROTATIONAL MOTION. A gear system is disclosed, having: first and second ground gears; a drive pin disposed along an axis of rotation of the gear system and configured to rotate about the axis of rotation; and an output gear supported by the first and second ground gears and configured to rotate by engagement between a wave generator portion of a drive pin, a wave generator bearing, a flexible spline, the output gear and the first and second ground gears, wherein the output gear defines: an output gear body; and the first and second output arms, respectively, extending radially outward from opposite sides of the output gear body to define respectively the first and second radial inner ends and the radial outer ends of the first and second output arms, such that the first and second radial outer ends are arranged on a radial axis extending through a radial center of the gear system.

Inventors

  • DERICK S. BALSIGER
  • ANDRZEJ ERNEST KUCZEK

Assignees

  • HAMILTON SUNDSTRAND CORPORATION

Dates

Publication Date
20260317
Application Date
20220609
Priority Date
20210811

Claims (16)

  1. 1. Gear system (100), comprising: first and second ground gears (110A, 110B); a drive pin (120) disposed along a rotation axis (130) of the gear system and configured to rotate about the rotation axis; and an output gear (140) supported by the first and second ground gears and configured to rotate by engagement between a wave generator portion of the drive pin (280), a wave generator bearing (142), a flexible spline (144), the output gear and the first and second ground gears, characterized in that the output gear (140) defines: an output gear body (150); the first and second output arms (160A, 160B), respectively, extending radially outward from opposite sides of the output gear body to, respectively, define the first and second radial inner ends (180A, 180B) and radial outer ends (190A, 190B) of the first and second output arms, such that the first and second radial outer ends are arranged on a radial axis (200) extending through a radial center (210) of the gear system wherein, the first ground gear includes a first set of mounting segments, including first and second mounting segments, which extend along the axis of rotation of the first ground gear and are circumferentially spaced from each other around the first ground gear to define rotation limiters for the first and second output arms.
  2. 2. Gear system (100) according to claim 1, characterized in that: the first and second output arms (160A, 160B) are shaped to respectively narrow from the first and second radial inner ends (180A, 180B) to the first and second radial outer ends (190A, 190B); and the first and second inner ends alternately engage the first and second mounting segments (270A, 270B) during rotation of the output gear in order to thereby limit the movement of the output gear.
  3. 3. Gear system (100) according to claim 1 or 2, characterized in that: the first ground gear (110A) defines a first ground gear body (240) which is ring-shaped, which defines a first ground gear opening limit, which defines a first ground gear opening through which the wave generator portion of the drive pin, the wave generator bearing and the flexible spline extend, the first ground gear being arranged on a first side of the output gear along the axis of rotation; the second ground gear (110B) is arranged on a second side of the output gear along the axis of rotation, wherein the first and second ground gears are connected to each other with the output gear between them along the axis of rotation, and the second ground gear has the same shape as the first ground gear, so that the second ground gear defines: a second ground gear body with a second ground gear opening limit, which defines a second opening of ground gear; and the first and second ground gears (110A, 110B) include, respectively, mounting elements arranged on the radial axis and configured to: be mounted to a moving component, and be mounted to a stationary component.
  4. 4. Gear system (100) according to any one of claims 1 to 3, characterized in that: the output gear body (150) defines an output gear opening limit (220), which defines an output gear opening (230) through which the wave generator portion (280) of the drive pin (120), the wave generator bearing (142) and the flexible spline (144) extend.
  5. 5. Gear system (100) according to claim 4, characterized in that: the wave generator portion (280) of the drive pin (120), the wave generator bearing (142) and the flexible spline (144) extend through the first ground gear opening, the output gear opening and the second ground gear opening and have the same length along the axis of rotation.
  6. 6. Gear system (100) according to any one of claims 1 to 5, characterized in that: the wave generator portion (280) of the drive pin (120) is defined at a first axial end of the drive pin and aligned, along the axis of rotation, with the first and second ground gear openings; and an input pin portion of the drive shaft is defined at a second axial end of the drive pin, wherein the input pin portion is cylindrical and the first and second axial ends are adjacent along the axis of rotation.
  7. 7. Gear system (100) according to claim 6, characterized in that: the flexible spline is located between the wave generator bearing and the first and second ground gear opening limits, and aligned along the axis of rotation with the first and second ground gear openings; and wherein, during rotation of the input shaft portion of the drive shaft: the flexible spline is engaged by the wave generator portion of the drive shaft; and the output gear is driven to rotate from the engagement of the flexible spline with the output gear and with the first and second ground gears.
  8. 8. Gear system (100) according to any one of claims 1 to 7, characterized in that: the wave generator bearing (142) is radially arranged around the wave generator portion of the drive pin and aligned along the axis of rotation with the first and second ground gear openings.
  9. 9. Gear system (100) according to any one of claims 1 to 8, characterized in that: the first and second output arms (160A, 160B) are shaped to respectively narrow from the first and second radial inner ends (180A, 180B) to the first and second radial outer ends (190A, 190B); and the first and second inner ends alternately engage the first and second mounting segments (270A, 270B) during rotation of the output gear in order to thereby limit the movement of the output gear.
  10. 10. Gear system according to any one of claims 1 to 9, characterized in that: the second ground gear defines a second set of mounting segments, including third and fourth mounting segments (350A, 350B), which extend along the axis of rotation of the second ground gear body; and the first mounting segment is fixed to the third mounting segment and the second mounting segment is fixed to the fourth mounting segment, whereby the first and second ground gears are connected to each other.
  11. 11. Gear system according to any one of claims 1 to 10, characterized in that: the mounting segments define ground gear mounting features; and the output arms define output arm mounting features, wherein the gear system is configured to be mounted on a moving component in a stationary structure.
  12. 12. Aircraft system, characterized in that it comprises: a stationary structure (390); and a movable component (380) mounted on the stationary structure by means of the gear system (100) as defined in any one of claims 1 to 11.
  13. 13. Aircraft system according to claim 12, characterized in that: the movable component is a control surface.
  14. 14. Aircraft system according to claim 12, characterized in that it additionally includes: a motor (400) operationally connected to the drive pin.
  15. 15. Method (900) of transmitting rotational motion to a moving component by means of a gear system (100), characterized in that it comprises: connecting (910) a stationary structure to the first and second ground gears (110A, 110B) of the gear system, wherein the gear system includes: a drive pin (120) disposed along a rotation axis (130) of the gear system; and an output gear (140) supported by the first and second ground gears and configured to rotate by engagement between a wave generator portion of the drive pin, a wave generator bearing, a flexible spline (144), the first and second ground gears and the output gear, wherein the output gear (140) defines: an output gear body (150); the first and second output arms (160A, 160B), respectively, extending radially outward from circumferentially opposite portions of the output gear body to define respectively the first and second radial inner ends (180A, 180B), and the radial outer ends (190A, 190B) of the first and second output arms, such that the first and second radial outer ends are disposed on a radial axis (200) extending through a radial center (210) of the gear system; connect (920) the moving component to the first and second output arms of the output gear of the gear system; and rotate (930A) the drive pin disposed along the axis of rotation of the gear system and rotatably drive the output gear from the rotation of the drive pin.
  16. 16. Method according to claim 15, characterized in that it further comprises: connecting (930B) a motor (400) to an input pin portion (300) of the drive pin before rotating the drive pin and rotating the drive pin with the motor.

Description

DECLARATION OF FEDERAL SUPPORT [001] This invention was made with the support of the Government under Government Contract No. W911W6-19-C-0029 granted by the Department of the Army. The Government has certain rights in the invention. FUNDAMENTALS [002] Exemplary embodiments refer to the technique of gear systems and, more specifically, to a compound harmonic gear system with double output arms. [003] Compound harmonic gear systems are configured to provide hinge line compound harmonics and can achieve higher power density compared to other gear systems. However, compound harmonic gear systems designed with a single output arm can lead to unbalanced load and large reactive forces on the arm. BRIEF SUMMARY [004] A gear system is disclosed, including: first and second ground gears; a drive pin disposed along an axis of rotation of the gear system and configured to rotate about the axis of rotation; and an output gear supported by the first and second ground gears and configured to rotate by engagement between a wave generator portion of a drive pin, a wave generator bearing, a flexible spline, the output gear and the first and second ground gears, wherein the output gear defines: an output gear body; and the first and second output arms, respectively, extending radially outward from opposite sides of the output gear body to define respectively the first and second radial inner ends and the radial outer ends of the first and second output arms, such that the first and second radial outer ends are disposed on a radial axis extending through a radial center of the gear system. [005] In addition to one or more aspects of the system, or as an alternative, the output gear body defines an output gear opening limit, which defines an output gear opening through which the wave generator portion of the drive pin, the wave generator bearing and the flexible spline extend. [006] In addition to one or more aspects of the system, or as an alternative, the first ground gear defines a first ground gear body that is ring-shaped; the first ground gear body defines a first ground gear opening limit, which defines a first ground gear opening through which the wave generator portion of the drive pin, the wave generator bearing and the flexible spline extend. [007] In addition to one or more aspects of the system, or as an alternative, the first ground gear is arranged on a first side of the output gear along the axis of rotation; the second ground gear on a second side of the output gear along the axis of rotation, wherein the first and second ground gears are connected to each other with the output gear between them along the axis of rotation; and the second ground gear has the same shape as the first ground gear, so that the second ground gear defines: a second ground gear body with a second ground gear opening limit that defines a second ground gear opening. [008] In addition to one or more aspects of the system, or as an alternative, the wave generator portion of the drive pin is defined at a first axial end of the drive pin and aligned along the axis of rotation with the first and second ground gear openings; and an input pin portion of the drive shaft is defined at a second axial end of the drive pin, wherein the input pin portion is cylindrical and the first and second axial ends are adjacent along the axis of rotation. [009] In addition to one or more aspects of the system, or as an alternative, the wave generator bearing arranged radially around the wave generator portion of the drive pin and aligned along the axis of rotation with the first and second ground gear openings. [0010] In addition to one or more aspects of the system, or as an alternative, the flexible spline is located between the wave generator bearing and the first and second ground gear opening limits and aligned along the axis of rotation with the first and second ground gear openings and in which, during rotation of the input pin portion of the drive pin: the flexible spline is engaged by the wave generator portion of the drive pin; and the output gear is driven to rotate from the engagement of the flexible spline with the output gear and the first and second ground gears. [0011] In addition to one or more aspects of the system, or as an alternative, the first ground gear includes a first set of mounting segments, including first and second mounting segments, which extend along the axis of rotation from the first ground gear body and are spaced circumferentially from each other, around the first ground gear body to set rotation limiters for the first and second output arms. [0012] In addition to one or more aspects of the system, or as an alternative, the first and second output arms are shaped to respectively narrow from the first and second radial inner ends to the first and second radial outer ends; and the first and second inner ends alternately engage the first and second mounting segments during output gear rotation to thereby limit output gear move