Fan drive gear system mechanical controller

Patent metadata

Field	Value
Publication number	US-2016369702-A1
Application number	US-201414902034-A
Country	US
Kind code	A1
Filing date	Jul 3, 2014
Priority date	Jul 7, 2013
Publication date	Dec 22, 2016
Grant date	—

Abstract

A fan drive gear system for a turbofan engine includes a geared architecture and a gear controller supporting the geared architecture and controlling rotation of the geared architecture relative a static structure.

First claim

What is claimed is:

1 . A fan drive gear system for a turbofan engine comprising:
a geared architecture; and a gear controller supporting the gear assembly and controlling rotation of the geared architecture relative to a static structure, the gear controller varies an effective speed reduction ratio of the geared architecture by controlling rotation of the geared architecture relative to the static structure.

2 . The fan drive gear system as recited in claim 1 , wherein the geared architecture defines a fixed speed reduction ratio in a static condition in which the geared architecture does not rotate relative to the static structure.

3 . The fan drive gear system as recited in claim 1 , wherein the gear controller varies rotation of the geared architecture between the static condition and a free condition where the geared architecture rotates at a speed substantially equal to a speed of an input shaft.

4 . The fan drive gear system as recited in claim 3 , wherein the geared architecture defines a fixed speed reduction ratio in the static condition and the controller defines an effective speed reduction ratio by controlling rotation relative to the input shaft.

5 . The fan drive gear system as recited in claim 3 , wherein the effective speed reduction ratio is equal to or less than the fixed speed reduction ratio.

6 . The fan drive gear system as recited in claim 1 , wherein the geared architecture includes a controlled portion coupled to the gear controller.

7 . The fan drive gear system as recited in claim 6 , wherein the geared architecture includes a sun gear driven by an input shaft, a plurality of planet gears driven by the sun gear and a ring gear circumscribing the planet gears.

8 . The fan drive gear system as recited in claim 7 , wherein the controlled portion comprises the ring gear.

9 . The fan drive gear system as recited in claim 7 , wherein the controlled portion comprises the plurality of planet gears.

10 . The fan drive gear system as recited in claim 1 , wherein the gear controller includes impellers extending into a flow path for generating a resistance force for controlling rotation of the geared architecture.

11 . The fan drive gear system as recited in claim 1 , wherein the gear controller comprises an electric device generating a resistance force for controlling rotation of the geared architecture.

12 . The fan drive gear system as recited in claim 1 , wherein the gear controller comprises a hydraulic device for generating a resistance force for controlling rotation of the geared architecture.

13 . The fan drive gear system as recited in claim 1 , wherein the gear controller comprises a support housing coupled to the gear assembly and rotatable with the geared architecture and a resistance coupling disposed between the support housing and a static structure for generating a resistance force for controlling rotation of the geared architecture.

14 . The fan drive gear system as recited in claim 13 , wherein the support housing includes an outer diameter with a plurality of gear teeth coupled to a pinion gear, a speed of the pinion gear controlled by the resistance coupling to control rotation of the geared architecture.

15 . A method of assembling a fan drive gear system for turbofan engine comprising:
coupling a fan to a geared architecture gear assembly; and supporting the geared architecture with a gear controller configured to control rotation of the gear assembly relative to an input structure.

16 . The method as recited in claim 15 , including configuring the gear controller for controlling rotation of the geared architecture between a static condition and a free condition where the geared architecture rotates at a speed substantially equal to a speed of the input structure.

17 . The method as recited in claim 16 , wherein the gear assembly is configured to define a fixed gear reduction ratio in the static condition and the gear controller defines an effective speed reduction ratio by controlling rotation of the geared architecture relative to the input structure.

18 . The method as recited in claim 15 , wherein the gear controller comprises a support housing and a resistance coupling and assembly includes attaching the geared architecture to the support housing and engaging the resistance coupling between the support housing and a fixed structure of the turbofan engine.

Assignees

• United Technologies Corp

Inventors

• Otto John R
• Coffin James B

Classifications

• F02C3/113

  with variable power transmission between rotors · CPC title

• F16H3/724

  using externally powered electric machines · CPC title

• F04D25/028

  the driving means being a planetary gear · CPC title

• F04D29/053

  Shafts · CPC title

• F16H3/72

  with a secondary drive, e.g. regulating motor, in order to vary speed continuously · CPC title