Aircraft and planetary gear systems

Patent metadata

Field	Value
Publication number	US-9709136-B2
Application number	US-201514721803-A
Country	US
Kind code	B2
Filing date	May 26, 2015
Priority date	Jun 10, 2014
Publication date	Jul 18, 2017
Grant date	Jul 18, 2017

Abstract

Planetary gear systems, transmissions, and apparatuses include a plurality of compound planet gears, each having three gear stages, a first non-fixed annular gear, a second non-fixed annular gear, a fixed annular gear, and a non-fixed sun gear. A rotational input to the non-fixed sun gear results in opposite rotational outputs of the first non-fixed annular gear and the second non-fixed annular gear. Compound planet gears and carriers for planetary gear systems are also disclosed.

First claim

The invention claimed is:

1. A planetary gear system, comprising:
a plurality of compound planet gears configured to orbit around a primary rotation axis and each including three gear stages;
a first non-fixed annular gear configured to rotate about the primary rotation axis and operatively meshed with one of the three gear stages;
a second non-fixed annular gear configured to rotate about the primary rotation axis and operatively meshed with one of the three gear stages;
a fixed annular gear with a central axis that is coaxial with the primary rotation axis and operatively meshed with one of the three gear stages; and
a non-fixed sun gear configured to rotate about the primary rotation axis and operatively meshed with one of the three gear stages.

2. The planetary gear system of claim 1 , wherein the three gear stages include a larger planet gear stage having a larger pitch diameter, a smaller planet gear stage having a smaller pitch diameter less than the larger pitch diameter, and a smallest planet gear stage having a smallest pitch diameter. less than the smaller pitch diameter.

3. The planetary gear system of claim 2 , wherein the larger planet gear stage of each compound planet gear is operatively meshed with the first non-fixed annular gear, wherein the smaller planet gear stage of each compound planet gear is operatively meshed with the fixed annular gear and the non-fixed sun gear, and wherein the smallest planet gear stage of each compound planet gear is operatively meshed with the second non-fixed annular gear.

4. The planetary gear system of claim 2 , wherein the larger planet gear stage of each compound planet gear is a middle gear stage, wherein the smaller planet gear stage of each compound planet gear is a lower gear stage positioned below the middle gear stage, and wherein the smallest planet gear stage of each compound planet gear is an upper gear stage positioned above the middle gear stage.

5. The planetary gear system of claim 2 , wherein one of:
the smallest planet gear stage of each compound planet gear and the second non-fixed annular gear define a double helical gear configuration; and
the larger planet gear stage of each compound planet gear and the first non-fixed annular gear define a double helical gear configuration.

6. The planetary gear system of claim 2 , wherein one of:
the smallest planet gear stage of each compound planet gear and the second non-fixed annular gear define a spur gear configuration or a single helical gear configuration; and
the larger planet gear stage of each compound planet gear and the first non-fixed annular gear define a spur gear configuration or a single helical gear configuration.

7. The planetary gear system of claim 2 , wherein:
a ratio of a tooth count of the fixed annular gear to a tooth count of the smaller planet gear stage to a tooth count of the non-fixed sun gear approximately is 156:24:108;
a ratio of a tooth count of the first non-fixed annular gear to a tooth count of the larger planet gear stage approximately is 182:34; and
a ratio of a tooth count of the second non-fixed annular gear to a tooth count of the smallest planet gear stage approximately is 182:22.

8. The planetary gear system of claim 2 , wherein:
a ratio of a tooth count of the fixed annular gear to a tooth count of the smaller planet gear stage to a tooth count of the non-fixed sun gear is in the range of (110-200):(18-30):(80-150);
a ratio of a tooth count of the first non-fixed annular gear to a tooth count of the larger planet gear stage is in the range of (110-200):(18-40); and
a ratio of a tooth count of the second non-fixed annular gear to a tooth count of the smallest planet gear stage is in the range of (110-200):(20-26).

9. The planetary gear system of claim 2 , wherein:
a ratio of a pitch diameter of the fixed annular gear to a pitch diameter of the smaller planet gear stage to a pitch diameter of the non-fixed sun gear approximately is 156:24:108;
a ratio of a pitch diameter of the first non-fixed annular gear to a pitch diameter of the larger planet gear stage approximately is 182:34; and
a ratio of a pitch diameter of the second non-fixed annular gear to a pitch diameter of the smallest planet gear stage approximately is 182:22.

10. The planetary gear system of claim 2 , wherein:
a ratio of a pitch diameter of the fixed annular gear to a pitch diameter of the smaller planet gear stage to a pitch diameter of the non-fixed sun gear is in the range of (110-200):(18-30):(80-150);
a ratio of a pitch diameter of the first non-fixed annular gear to a pitch diameter of the larger planet gear stage is in the range of (110-200):(18-40); and
a ratio of a pitch diameter of the second non-fixed annular gear to a pitch diameter of the smallest planet gear stage is in the range of (110-200):(20-26).

11. The planetary gear system of claim 2 , wherein a diametral pitch of the smaller planet gear stage approximately is 6, a diametral pitch of the larger planet gear stage approximately is 6, and a diametral pitch of the smallest planet gear stage approximately is 6.

12. The planetary gear system of claim 1 , wherein a rotational input to the non-fixed sun gear results in opposite rotational outputs of the first non-fixed annular gear and the second non-fixed annular gear at substantially the same frequency of rotation.

13. The planetary gear system of claim 1 , further comprising:
a carrier that interconnects the plurality of compound planet gears.

14. The planetary gear system of claim 13 , wherein the carrier does not define an input or an output of the planetary gear system.

15. The planetary gear system of claim 13 , wherein the carrier includes an inner wall positioned radially inward from the plurality of compound planet gears, and at least one radial flange extending radially outward from the inner wall, wherein the at least one radial flange defines a plurality of bores corresponding to the plurality of compound planet gears, and wherein each of the plurality of compound planet gears is positioned within a respective one of the plurality of bores.

16. The planetary gear system of paragraph 15 , further comprising:
a plurality of bearing elements supported within the plurality of bores between the carrier and the plurality of compound planet gears.

17. The planetary gear system of claim 15 , wherein the at least one radial flange includes an upper radial flange and a lower radial flange, and wherein the plurality of bores includes a plurality of upper bores defined by the upper radial flange and a plurality of lower bores defined by the lower radial flange.

18. The planetary gear system of 17 , wherein each compound planet gear includes an upward facing shoulder and a downward facing shoulder positioned below the upward facing shoulder, wherein the upward facing shoulder is engaged with a respective one of the plurality of bearing elements and the downward facing shoulder is engaged with a respective one of the plurality of bearing elements to restrict vertical movement of the plurality of compound planet gears relative to the carrier.

19. A transmission, comprising:
the planetary gear system of claim 1 ;
an input shaft operatively coupled to the non-fixed sun gear;
a first output shaft operatively coupled to the first non-fixed annular gear;
a second output shaft operatively coupled to the second non-fixed annular gear; and
a housing operatively coupled to the fixed annular gear;
wherein rotation of the input shaft in a first rotational direction results in rota

Assignees

• Boeing Co

Inventors

• Bouwer Scott Hendrik
• Pierce Christopher C
• Robuck Mark Joseph

Classifications

• F16H2200/2028

  using a Ravigneaux set with 6 connections · CPC title

• F16H3/663 Primary

  with conveying rotary motion between axially spaced orbital gears, e.g. a stepped orbital gear or Ravigneaux · CPC title

• F16H37/0813

  with only one input shaft · CPC title

• F16H37/0806

  with a plurality of driving or driven shafts · CPC title

• F16H1/46

  Systems consisting of a plurality of gear trains each with orbital gears, {i.e. systems having three or more central gears} · CPC title