Elliptically interfacing gearbox

Patent metadata

Field	Value
Publication number	US-2017191549-A1
Application number	US-201614989760-A
Country	US
Kind code	A1
Filing date	Jan 6, 2016
Priority date	Jan 6, 2016
Publication date	Jul 6, 2017
Grant date	—

Abstract

An elliptically interfacing gearbox system may include an input plate having a rotation axis and a plurality of input teeth. The gearbox system may include a wobble plate having a wobble axis disposed at a non-zero angle relative to the rotation axis, a rear face, and a plurality of face teeth disposed on the rear face. The wobble plate may further include a first plurality of wobble teeth disposed in a first plane perpendicular to the wobble axis and a second plurality of wobble teeth disposed in a second plane perpendicular to the wobble axis. The second plane may be spaced from the first plane along the wobble axis. The gearbox system may include a stator gear having a plurality of stator teeth and an output plate having an output axis substantially aligned with the rotation axis and a plurality of output teeth. The plurality of input teeth may be configured to engage with the plurality of face teeth, the first plurality of wobble teeth may be configured to engage with the plurality of stator teeth, and the second plurality of wobble teeth may be configured to engage with the plurality of output teeth as the wobble plate nutates around the stator gear.

First claim

We claim:

1 . An elliptically interfacing gearbox system, comprising:
an input plate having a rotation axis and a plurality of input teeth; a wobble plate having a wobble axis disposed at a non-zero angle relative to the rotation axis, a rear face, a plurality of face teeth disposed on the rear face, a first plurality of wobble teeth disposed in a first plane perpendicular to the wobble axis, and a second plurality of wobble teeth disposed in a second plane perpendicular to the wobble axis, the second plane spaced from the first plane along the wobble axis; a stator gear having a plurality of stator teeth; and an output plate having an output axis substantially aligned with the rotation axis and a plurality of output teeth; wherein the plurality of input teeth are configured to engage with the plurality of face teeth, the first plurality of wobble teeth are configured to engage with the plurality of stator teeth, and the second plurality of wobble teeth are configured to engage with the plurality of output teeth as the wobble plate nutates around the stator gear.

2 . The elliptically interfacing gearbox system of claim 1 , wherein each tooth of the first plurality of wobble teeth is configured to engage a tooth of the plurality of stator teeth via rolling contact and each tooth of the second plurality of wobble teeth is configured to engage a tooth of the plurality of output teeth via rolling contact as the wobble plate nutates around the stator gear.

3 . The elliptically interfacing gearbox system of claim 1 , wherein the first plurality of wobble teeth engage with the plurality of stator teeth along one-fourth of the stator gear and the second plurality of wobble teeth engage with the plurality of output teeth along one-fourth of the output plate at any moment as the wobble plate nutates around the stator gear.

4 . The elliptically interfacing gearbox system of claim 1 , wherein each tooth of the first plurality of wobble teeth and the second plurality of wobble teeth has a wobble-tooth cross-sectional shape, each tooth of the plurality of stator teeth has a stator tooth cross-sectional shape, each tooth of the plurality of output teeth has an output tooth cross-sectional shape, and each wobble tooth cross-sectional shape, each stator tooth cross-sectional shape, and each output tooth cross-sectional shape is at least partially defined by a compound involute of a circle and an ellipse.

5 . The elliptically interfacing gearbox system of claim 1 , wherein the wobble plate is configured such that contact forces exerted on the wobble plate by any one of the input plate, the stator, and the output plate will point in directions that are tangent to circles which lie in planes perpendicular to the rotation axis.

6 . The elliptically interfacing gearbox system of claim 1 , wherein each of the first plurality of wobble teeth has an angular width, as measured in an angular direction around the wobble axis, that is less than one half of an angular spacing between adjacent stator teeth of the plurality of stator teeth, as measured in an angular direction around the rotation axis.

7 . The elliptically interfacing gearbox system of claim 1 , wherein the wobble plate is configured to:
a) rotate, according to a first gear ratio between the input plate and the wobble plate, in response to a rotation of the input plate, b) nutate, according to a second gear ratio between the wobble plate and the stator gear, in response to the rotation of the wobble plate, and c) drive a rotation of the output plate, according to a third gear ratio between the wobble plate and the output plate, in response to the nutation of the wobble plate.

8 . The elliptically interfacing gearbox system of claim 7 , wherein a total gear ratio of the elliptically interfacing gearbox system, which depends upon the first gear ratio, the second gear ratio, and the third gear ratio, is at least 1000:1.

9 . The elliptically interfacing gearbox system of claim 1 , wherein the input plate is a first input plate, the wobble plate is a first wobble plate, the stator gear is a first stator gear, and the output plate is a first output plate, further comprising:
a second wobble plate having a second wobble axis; a second stator gear; and a second output plate; wherein the second wobble plate is configured to engage with the first output plate and rotate in response to a rotation of the first output plate, engage with the second stator gear and nutate in response to the rotation of the second wobble plate, and engage with the second output plate and drive a rotation of the second output plate in response to the nutation of the second wobble plate.

10 . A wobble plate for use in an elliptically interfacing gearbox system, the wobble plate comprising:
a wobble axis; a first plurality of wobble teeth disposed in a first plane perpendicular to the wobble axis; a second plurality of wobble teeth disposed in a second plane perpendicular to the wobble axis, the second plane spaced along the wobble axis from the first plane; and a plurality of face teeth disposed in a third plane perpendicular to the wobble axis, the third plane spaced along the wobble axis from the first plane and the second plane; wherein at least one of the first plurality of wobble teeth and the second plurality of wobble teeth has a cross-sectional shape at least partially defined by a compound involute of a circle and an ellipse.

11 . The wobble plate of claim 10 , wherein the wobble plate is configured such that contact forces exerted on the wobble plate by another gear or plate in the elliptically interfacing gearbox system will point in directions that are substantially perpendicular to a line parallel to the wobble axis and radial lines extending from points of contact to the wobble axis.

12 . The wobble plate of claim 10 , wherein each tooth of the second plurality of wobble teeth has an angular width that is less than one half of an angular spacing between adjacent teeth of the second plurality of wobble teeth, as measured in an angular direction around the wobble axis.

13 . The wobble plate of claim 10 , wherein each tooth of the first plurality of wobble teeth and the second plurality of wobble teeth has two engaging surfaces with each of the two engaging surfaces defined by a compound involute of a circle and an ellipse, the two engaging surfaces defining opposite sides of the tooth.

14 . The wobble plate of claim 10 , wherein the plurality of face teeth are disposed on a frustoconical surface of the wobble plate, the frustoconical surface configured such that a center of mass of the wobble plate is a vertex of the frustoconical surface.

15 . A method for operating an elliptically interfacing gearbox mechanism, comprising:
rotating an input plate including a plurality of input teeth; engaging the plurality of input teeth with a plurality of face teeth of a wobble plate, thereby causing the wobble plate to nutate about a fulcrum; engaging a first plurality of wobble teeth of the wobble plate with a plurality of stator teeth of a stator gear as the wobble plate nutates; and engaging a second plurality of wobble teeth of the wobble plate with a plurality of output teeth of an output plate as the wobble plate nutates.

16 . The method of claim 15 , wherein each tooth of the first plurality of wobble teeth, the second plurality of wobble teeth, the plurality of stator teeth, and the plurality of output teeth has a face defined by a compound involute of a circle and an ellipse.

17 . The method of claim 15 , wherein the s

Assignees

• Boeing Co

Inventors

• Atmur Robert J
• Sargent William Patrick

Classifications

• F16H1/32

  in which the central axis of the gearing lies inside the periphery of an orbital gear · CPC title

• F16H55/08

  Profiling · CPC title

• F16H1/321 Primary

  the orbital gear being nutating · CPC title

• F16H57/023 Primary

  Mounting or installation of gears or shafts in the gearboxes, e.g. methods or means for assembly · CPC title