Mechanical virtual elliptical drive

Patent metadata

Field	Value
Publication number	US-10520063-B2
Application number	US-201715494396-A
Country	US
Kind code	B2
Filing date	Apr 21, 2017
Priority date	Apr 21, 2017
Publication date	Dec 31, 2019
Grant date	Dec 31, 2019

Abstract

A mechanical virtual elliptical drive, including an input motor, a wobble plate, a stator gear, and an output plate. The input motor may have a rotation axis, a substantially flat surface, and a rounded protrusion extending from the flat surface. The wobble plate may have a wobble axis disposed at a non-zero angle relative to the rotation axis. The rounded protrusion of the motor may engage a substantially flat face of the wobble plate, thereby causing the wobble plate to nutate around the stator gear.

First claim

We claim:

1. A wobble plate drive, comprising:
an input motor having a rotation axis, a substantially flat surface perpendicular to the rotation axis, and at least one rounded protrusion extending from the substantially flat surface;
a wobble plate having a wobble axis disposed at a non-zero angle relative to the rotation axis of the input motor, a first substantially flat face perpendicular to the wobble axis and facing generally toward the input motor, a second face defining a plane parallel to the first face and facing generally away from the input motor, a plurality of face teeth disposed on the second face, and a plurality of wobble teeth disposed around a perimeter of the wobble plate between the first and second faces in a plane perpendicular to the wobble axis;
a stator gear having a plurality of stator teeth configured to engage with the plurality of wobble teeth; and
an output plate having an output axis substantially aligned with the rotation axis and a plurality of output teeth;
wherein the at least one rounded protrusion is configured to engage with the first face of the wobble plate, and the plurality of face teeth are configured to engage with the plurality of output teeth as the wobble plate nutates around the stator gear.

2. The wobble plate drive of claim 1 , wherein the at least one rounded protrusion includes two rounded protrusions, spaced apart by an angle between 80 and 100 degrees measured around the rotation axis.

3. The wobble plate drive of claim 2 , wherein the angle is 89 degrees.

4. The wobble plate drive of claim 1 , wherein the at least one rounded protrusion is a cartridge bearing.

5. The wobble plate drive of claim 1 , wherein the plurality of wobble teeth, the plurality of stator teeth, or both are defined by a compound involute of a circle and an ellipse.

6. The wobble plate drive of claim 1 , 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 coincides with a vertex of the frustoconical surface.

7. A wobble plate drive, comprising:
an input motor including two rounded protrusions extending from a substantially flat surface;
a stator gear having a stator axis;
a wobble plate having a wobble axis disposed at a non-zero angle relative to the stator axis and a substantially flat face oriented generally toward the input motor and contacting only one of the protrusions at a time, at a contact point on the flat face of the wobble plate; and
an output plate having an output axis substantially aligned with the stator axis;
wherein the input motor is configured to rotate the protrusions around the stator axis, thereby causing the wobble plate to nutate around the stator gear with the wobble axis precessing around the stator axis, and also thereby causing the contact point to move ahead of a point of closest approach of the wobble plate to the stator gear, as the point of closest approach of the wobble plate to the stator gear moves around the stator axis.

8. The wobble plate drive of claim 7 , wherein the wobble plate has a second face oriented generally away from the input motor, a plurality of face teeth disposed on the second face and configured to engage the output plate, and a plurality of wobble teeth disposed in a plane perpendicular to the wobble axis and configured to engage the stator gear.

9. The wobble plate drive of claim 8 , wherein the stator gear has a plurality of stator teeth, the output plate has a plurality of output teeth, the plurality of wobble teeth are configured to engage with the plurality of stator teeth, and the plurality of face teeth are configured to engage with the plurality of output teeth as the wobble plate nutates around the stator gear.

10. The wobble plate drive of claim 9 , wherein the plurality of wobble teeth and the plurality of stator teeth are each at least partially defined by a compound involute of a circle and an ellipse.

11. The wobble plate drive of claim 9 , 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 coincides with a vertex of the frustoconical surface.

12. The wobble plate drive of claim 7 , wherein the two rounded protrusions extending from the substantially flat surface of the input motor are spaced apart by an angle of 89 degrees measured around a rotation axis of the input motor.

13. The wobble plate drive of claim 7 , wherein the rounded protrusions are cartridge bearings.

14. The wobble plate drive of claim 7 , wherein the wobble plate is configured such that contact forces exerted on the wobble plate by any one of the input motor, the stator gear, or the output plate point in directions that are tangent to circles which lie in planes perpendicular to a rotation axis of the input motor.

15. A method for operating a wobble plate drive, comprising:
energizing a motor to rotate about a rotation axis, wherein the motor has a substantially flat surface and one or more rounded protrusions extending from the substantially flat surface;
engaging only one of the one or more rounded protrusions at a time with a substantially flat surface of a wobble plate, thereby causing the wobble plate to nutate;
engaging a plurality of wobble teeth of the wobble plate with a plurality of stator teeth of a stator gear as the wobble plate nutates, thereby causing the wobble plate to rotate; and
engaging a plurality of face teeth of the wobble plate with a plurality of output teeth of an output plate as the wobble plate nutates and rotates, thereby causing the output plate to rotate.

16. The method of claim 15 , wherein the motor includes two rounded protrusions extending from the substantially flat surface of the motor, spaced apart by an angle of 89° measured around the rotation axis.

17. The method of claim 15 , wherein the one or more rounded protrusions are cartridge bearings.

18. The method of claim 15 , wherein the plurality of wobble teeth and the plurality of stator teeth are each at least partially defined by a compound involute of a circle and an ellipse.

19. The method of claim 15 , 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 coincides with a vertex of the frustoconical surface.

20. The method of claim 15 , wherein the wobble plate is configured such that contact forces exerted on the wobble plate by any one of the motor, the stator gear, or the output plate point in directions that are tangent to circles which lie in planes perpendicular to the rotation axis.

Assignees

• Boeing Co

Inventors

• Atmur Robert J
• Sargent William Patrick

Classifications

• F16H23/00

  Wobble-plate gearings; Oblique-crank gearings · CPC title

• F16H23/10

  with rotary wobble-plates with plane surfaces · CPC title

• H02K41/065

  Nutating motors · CPC title

• H02K7/116

  with gears · CPC title

• H02K2213/03

  Machines characterised by numerical values, ranges, mathematical expressions or similar information · CPC title