Variable pitch propeller rotor

Patent metadata

Field	Value
Publication number	US-9302765-B2
Application number	US-201213458386-A
Country	US
Kind code	B2
Filing date	Apr 27, 2012
Priority date	May 16, 2011
Publication date	Apr 5, 2016
Grant date	Apr 5, 2016

Abstract

A bladed rotor comprises a rotor body 2 carrying blades 6 , whose pitch can be varied by means of a pitch input shaft 10 . The pitch input shaft 10 drives the respective blade 6 about a spanwise axis X of the blade through a harmonic drive reduction gear 14 . The harmonic drive reduction gear 14 comprises a wave generator 16 which is fixed for rotation on the pitch input shaft 10 and a flex spline which meshes with a circular spline 20 and is secured to the blade 6.

First claim

The invention claimed is:

1. A variable pitch bladed rotor comprising a rotor body carrying a plurality of blades, each blade having a blade root supported by bearings in a blade hub of the rotor body so as to be pivotable relative to the rotor body about respective spanwise pitch axes, each blade being drivably coupled to a pitch control mechanism by a respective pitch input shaft which is aligned with the pitch axis and which is drivingly connected to the blade by a harmonic drive reduction gear, the harmonic drive reduction gear comprising a circular spline in toothed engagement with a flex spline and a wave generator arranged to generate a travelling wave in the flex spline, wherein the circular spline is fixedly mounted on the blade hub and the flex spline is secured to the blade root.

2. A variable pitch bladed rotor as claimed in claim 1 , in which each blade is pivotably mounted in a respective blade hub secured to the rotor body and the circular spline is provided on an inner surface of the blade hub.

3. A variable pitch bladed rotor as claimed in claim 1 , in which the wave generator is fixed for rotation with the pitch input shaft.

4. A gas turbine engine provided with a variable pitch bladed rotor in accordance with claim 1 .

5. A gas turbine engine as claimed in claim 4 , in which each pitch input shaft extends across an annular gas flow path of the gas turbine engine.

6. A gas turbine engine as claimed in claim 5 , in which each pitch input shaft is accommodated within a respective sleeve extending across the gas flow path.

7. A gas turbine engine as claimed in claim 6 , in which each sleeve has an aerodynamic profile.

8. A gas turbine engine as claimed in claim 4 , in which the gas turbine engine is an open rotor gas turbine engine.

9. A gas turbine engine as claimed in claim 4 , in which the gas turbine engine is a ducted fan engine or a turboprop engine.

Assignees

• Thornton Stewart T
• Simms Paul
• Mcfarlane Colin W R
• Rolls Royce Plc

Inventors

• Thornton Stewart T
• Simms Paul
• Mcfarlane Colin W R

Classifications

• B64D2027/005

  Aircraft with an unducted turbofan comprising contra-rotating rotors, e.g. contra-rotating open rotors [CROR] · CPC title

• B64C11/32

  mechanical · CPC title

• Y02T50/66

  Cross-Sectional Technologies · mapped topic

• B64C11/306 Primary

  specially adapted for contrarotating propellers · CPC title

• Y02T50/60

  Efficient propulsion technologies, e.g. for aircraft · CPC title