# US 9,434,467 B2 · Catcher ring arrangement

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- Number: US 9,434,467 B2
- Document ID: US9434467B2
- Status: Granted
- Kind: B2
- Application number: 13/914,961
- Filed: 2013-06-11
- Published: 2013-12-26
- Granted: 2016-09-06
- Earliest claimed: 2012-06-22
- Assignees: ROLLS-ROYCE plc
- Applicants: Rolls-Royce PLC
- Inventors: Kenneth John Mackie; Kenneth Franklin Udall
- Web page: https://patentgrep.com/patent/US9434467B2

## CPC

- B64C 11/08: for non-adjustable blades
- B64C 11/06: for variable-pitch blades
- B64D 2027/005: {Aircraft with an unducted turbofan comprising contra-rotating rotors, e.g. contra-rotating open rotors [CROR]}
- F01D 5/3023: {of radial insertion type, e.g. in individual recesses}
- Y02T 50/60: Efficient propulsion technologies, e.g. for aircraft
- B64C: AEROPLANES; HELICOPTERS
- B64D: EQUIPMENT FOR FITTING IN OR TO AIRCRAFT; FLIGHT SUITS; PARACHUTES; ARRANGEMENT OR MOUNTING OF POWER PLANTS OR PROPULSION TRANSMISSIONS IN AIRCRAFT
- F01D: NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES (machines or engines for liquids F03; non-positive displacement pumps F04D)
- Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION

## Abstract

This invention relates to a blade assembly comprising: a hub which is rotatable about an axis; at least one blade having an aerofoil portion and a root, wherein the root is coupled to the hub using a primary retention device which prevents radial separation of the root and hub in normal use; and, a secondary retention device which comprises an annular catcher having a restriction through which the root portion cannot radially pass, the restriction being located radially outwardly and radially spaced from the root part during use.

## Claims

### Claim 1

A blade assembly comprising:
a hub which is rotatable about an axis;
at least one blade having an aerofoil portion and a root, wherein the root is coupled to the hub using a primary retention device which prevents radial separation of the root and the hub in normal use; and
a secondary retention device which comprises an annular catcher having a restriction aperture through which the root cannot radially pass, the restriction aperture being located radially outwardly and radially spaced from the root during use, wherein
the annular catcher comprises at least two sections that abut one another along a parting line, the parting line passing through the restriction aperture,
the at least two sections are annular rings defining the restriction aperture and at least one additional restriction aperture, and
the parting line passes through each of the at least one additional restriction aperture.

### Claim 2 (depends on 1)

The blade assembly as claimed in claim 1, wherein a portion of the blade passes through the restriction aperture, in use.

### Claim 3 (depends on 2)

The blade assembly as claimed in claim 2, wherein the restriction aperture is axi-symmetric.

### Claim 4 (depends on 1)

The blade assembly as claimed in claim 1, wherein the parting line lies on a circumferential midline of the annular catcher.

### Claim 5 (depends on 1)

The blade assembly as claimed in claim 1, wherein the at least two sections of the annular catcher are attached to one another via a plurality of fasteners.

### Claim 6 (depends on 1)

The blade assembly as claimed in claim 1, wherein the annular catcher is radially located around the hub by three or more locating assemblies.

### Claim 7 (depends on 6)

The blade assembly as claimed in claim 6, wherein the locating assemblies include at least one two part connector having male and female portions.

### Claim 8 (depends on 7)

The blade assembly as claimed in claim 7, wherein at least one part of the locator assemblies is local to the restriction aperture.

### Claim 9 (depends on 1)

The blade assembly as claimed in claim 1, wherein the hub is nested within at least a portion of the annular catcher.

### Claim 10 (depends on 1)

The blade assembly as claimed in claim 1, wherein the annular catcher is fixedly attached to the hub via a flanged portion.

### Claim 11 (depends on 1)

The blade assembly as claimed in claim 1, wherein the annular catcher is generally polygonal.

### Claim 12 (depends on 1)

The blade assembly as claimed in claim 1, wherein the annular catcher includes two side rails which are axially spaced relative the axis.

### Claim 13 (depends on 12)

The blade assembly as claimed in claim 12, further comprising a web portion which extends between side rails.