Aircraft gas turbine engine blade pitch change mechanism

Patent metadata

Field	Value
Publication number	US-11118464-B2
Application number	US-201816157256-A
Country	US
Kind code	B2
Filing date	Oct 11, 2018
Priority date	Oct 11, 2018
Publication date	Sep 14, 2021
Grant date	Sep 14, 2021

Abstract

Hydraulic pitch actuation mechanism includes vaned rotor within timing chamber surrounded by annular timing chamber wall within fan hub and variable area and volume retarding and advancing chambers within timing chamber. Timing pocket walls extend inwardly from timing chamber wall and interdigitated with timing vanes extending outwardly from vane shaft of vaned rotor. Hydraulic retarding and advancing fluid passages extend through fan drive shaft and through the fan hub to the retarding and advancing chambers respectively. Fluid passages include annular axially spaced apart retarding and advancing passage discharge sections, annular and axially spaced apart retarding and advancing passage entry sections spaced apart from and aft of retarding and advancing passage discharge sections respectively. Retarding and advancing connecting passage sections extend through fan drive shaft and fluidly connect retarding and advancing passage entry sections to retarding and advancing passage discharge sections. Hub passages through fan hub connect passage discharge sections to chambers.

First claim

What is claimed:

1. A hydraulic pitch actuation mechanism comprising:
a rotatable vaned rotor within a timing chamber surrounded by an annular timing chamber wall and centered within a fan hub,
variable area and volume retarding and advancing chambers within the timing chamber,
timing pocket walls extending radially inwardly from the annular timing chamber wall and interdigitated with timing vanes extending radially outwardly from a vane shaft of the rotatable vaned rotor, and
hydraulic retarding and advancing fluid passages extending through a fan drive shaft and through the fan hub to the retarding and advancing chambers respectively,
wherein the hydraulic retarding and advancing fluid passages include:
annular and axially spaced apart retarding and advancing passage discharge sections respectively; and
annular and axially spaced apart retarding and advancing passage entry sections respectively, and

wherein the retarding and advancing passage entry sections are axially spaced apart from and aft of the retarding and advancing passage discharge sections respectively.

2. The hydraulic pitch actuation mechanism as claimed in claim 1 , further comprising retarding and advancing connecting passage sections extending through the fan drive shaft and fluidly connecting the retarding and advancing passage entry sections to the retarding and advancing passage discharge sections respectively.

3. The hydraulic pitch actuation mechanism as claimed in claim 2 , further comprising retarding and advancing hub passages extending through the fan hub and fluidly connecting the retarding and advancing passage discharge sections to the retarding and advancing chambers respectively.

4. The hydraulic pitch actuation mechanism as claimed in claim 3 , further comprising the retarding and advancing passage discharge sections including annular axially spaced apart retarding and advancing discharge grooves respectively extending into the fan drive shaft and covered by an aft end of the fan hub.

5. The hydraulic pitch actuation mechanism as claimed in claim 4 , further comprising the retarding and advancing passage entry sections including annular axially spaced apart retarding and advancing entry grooves respectively extending into the fan drive shaft and covered by a shaft bearing support rotatably supporting the fan drive shaft.

6. The hydraulic pitch actuation mechanism as claimed in claim 5 , further comprising:
retarding and advancing fluid feed passages extending radially through the shaft bearing support to the retarding and advancing passage entry sections,
one or more oil feed passages extending through the shaft bearing support to the fan drive shaft for lubricating the fan drive shaft, and
retarding and advancing oil lines fluidly connecting the retarding and advancing fluid feed passages to retarding and advancing valves for draining and filling retarding and advancing oil flow in the retarding and advancing chambers respectively.

7. The hydraulic pitch actuation mechanism as claimed in claim 3 , further comprising:
a shaft bearing support rotatably supporting the fan drive shaft,
retarding and advancing fluid feed passages extending radially through the shaft bearing support to the retarding and advancing passage entry sections,
one or more oil feed passages extending through the shaft bearing support to the fan drive shaft for lubricating the fan drive shaft, and
retarding and advancing oil lines fluidly connecting the retarding and advancing fluid feed passages to retarding and advancing valves for draining and filling retarding and advancing oil flow in the retarding and advancing chambers respectively.

8. The hydraulic pitch actuation mechanism as claimed in claim 7 , further comprising a single solenoid operably connected to the retarding and advancing valves.

9. An aircraft turbofan gas turbine engine comprising:
a variable pitch fan including a plurality of variable pitch fan blades rotatably mounted in and extending radially outwardly from a fan hub,
each of the variable pitch fan blades being pivotable or rotatable about a pitch axis perpendicular or normal to an engine centerline axis,
a hydraulic pitch actuation mechanism including a rotatable vaned rotor within a timing chamber surrounded by an annular timing chamber wall and centered within the fan hub,
variable area and volume retarding and advancing chambers within the timing chamber,
timing pocket walls extending radially inwardly from the annular timing chamber wall and interdigitated with timing vanes extending radially outwardly from a vane shaft of the rotatable vaned rotor,
the vane shaft operably connected to the variable pitch fan blades for varying pitch angle of the variable pitch fan blades, and
hydraulic retarding and advancing fluid passages extending through a fan drive shaft and through the fan hub to the retarding and advancing chambers respectively,
wherein the hydraulic retarding and advancing fluid passages include:
annular and axially spaced apart retarding and advancing passage discharge sections respectively; and
annular and axially spaced apart retarding and advancing passage entry sections respectively, and

wherein the retarding and advancing passage entry sections are axially spaced apart from and aft of the retarding and advancing passage discharge sections respectively and fluidly connected by retarding and advancing connecting passage sections, respectively, extending through the fan drive shaft.

10. The aircraft turbofan gas turbine engine as claimed in claim 9 , further comprising retarding and advancing hub passages extending through the fan hub and fluidly connecting the retarding and advancing passage discharge sections to the retarding and advancing chambers respectively.

11. The aircraft turbofan gas turbine engine as claimed in claim 10 , further comprising:
the retarding and advancing passage discharge sections including annular axially spaced apart retarding and advancing discharge grooves respectively extending into the fan drive shaft and covered by an aft end of the fan hub,
the retarding and advancing passage entry sections including annular axially spaced apart retarding and advancing entry grooves respectively extending into the fan drive shaft and covered by a shaft bearing support rotatably supporting the fan drive shaft,
retarding and advancing fluid feed passages extending radially through the shaft bearing support to the retarding and advancing passage entry sections,
one or more oil feed passages extending through the shaft bearing support to the fan drive shaft for lubricating the fan drive shaft, and
retarding and advancing oil lines fluidly connecting the retarding and advancing fluid feed passages to retarding and advancing valves for draining and filling retarding and advancing oil flow in the retarding and advancing chambers respectively.

12. The aircraft turbofan gas turbine engine as claimed in claim 10 , further comprising:
a shaft bearing support rotatably supporting the fan drive shaft,
retarding and advancing fluid feed passages extending radially through the shaft bearing support to the retarding and advancing passage entry sections,
one or more oil feed passages extending through the shaft bearing support to the fan drive shaft for lubricating the fan drive shaft, and
retarding and advancing oil lines fluidly connecting the retarding and advancing fluid feed passages to retarding and advancing valves for draining and filling retarding and advancing oil flow in the retarding and advancing chambers respectively.

13. The aircraft turbofan gas turbine engine as claimed in claim 12 , further compr

Assignees

• Gen Electric

Inventors

• Perez Luis Mario Chan

Classifications

• F02K3/04

  the plant including ducted fans, i.e. fans with high volume, low pressure outputs, for augmenting the jet thrust, e.g. of double-flow type · CPC title

• F04D29/36 Primary

  adjustable {(flexible blades F04D29/382)} · CPC title

• F05D2240/24

  for turbines · CPC title

• F05D2230/60

  Assembly methods · CPC title

• B64C11/38

  fluid, e.g. hydraulic · CPC title