WO2008087443A1 - Blades - Google Patents

Blades Download PDF

Info

Publication number
WO2008087443A1
WO2008087443A1 PCT/GB2008/000189 GB2008000189W WO2008087443A1 WO 2008087443 A1 WO2008087443 A1 WO 2008087443A1 GB 2008000189 W GB2008000189 W GB 2008000189W WO 2008087443 A1 WO2008087443 A1 WO 2008087443A1
Authority
WO
WIPO (PCT)
Prior art keywords
blade
root member
along
composite
root
Prior art date
Application number
PCT/GB2008/000189
Other languages
French (fr)
Inventor
Lee Bateup
Original Assignee
Ge Aviation Systems Group Limited
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Ge Aviation Systems Group Limited filed Critical Ge Aviation Systems Group Limited
Publication of WO2008087443A1 publication Critical patent/WO2008087443A1/en

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B64—AIRCRAFT; AVIATION; COSMONAUTICS
    • B64C—AEROPLANES; HELICOPTERS
    • B64C11/00—Propellers, e.g. of ducted type; Features common to propellers and rotors for rotorcraft
    • B64C11/16—Blades
    • B64C11/20—Constructional features
    • B64C11/26—Fabricated blades
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C70/00—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts
    • B29C70/04—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts comprising reinforcements only, e.g. self-reinforcing plastics
    • B29C70/06—Fibrous reinforcements only
    • B29C70/10—Fibrous reinforcements only characterised by the structure of fibrous reinforcements, e.g. hollow fibres
    • B29C70/16—Fibrous reinforcements only characterised by the structure of fibrous reinforcements, e.g. hollow fibres using fibres of substantial or continuous length
    • B29C70/22—Fibrous reinforcements only characterised by the structure of fibrous reinforcements, e.g. hollow fibres using fibres of substantial or continuous length oriented in at least two directions forming a two dimensional structure
    • B29C70/222—Fibrous reinforcements only characterised by the structure of fibrous reinforcements, e.g. hollow fibres using fibres of substantial or continuous length oriented in at least two directions forming a two dimensional structure the structure being shaped to form a three dimensional configuration
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
    • B29D99/00—Subject matter not provided for in other groups of this subclass
    • B29D99/0025—Producing blades or the like, e.g. blades for turbines, propellers, or wings
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
    • F01D5/00—Blades; Blade-carrying members; Heating, heat-insulating, cooling or antivibration means on the blades or the members
    • F01D5/12—Blades
    • F01D5/28—Selecting particular materials; Particular measures relating thereto; Measures against erosion or corrosion
    • F01D5/282—Selecting composite materials, e.g. blades with reinforcing filaments
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
    • B29K2105/00—Condition, form or state of moulded material or of the material to be shaped
    • B29K2105/06—Condition, form or state of moulded material or of the material to be shaped containing reinforcements, fillers or inserts
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29L—INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES
    • B29L2031/00—Other particular articles
    • B29L2031/08—Blades for rotors, stators, fans, turbines or the like, e.g. screw propellers
    • B29L2031/082—Blades, e.g. for helicopters

Definitions

  • This invention relates to blades and to methods of forming blades.
  • the invention is more particularly concerned with blades of composite construction, such as used in propellers, turbomachines or helicopters.
  • Propeller and other blades are increasingly being made of composite fibre materials because of the considerable weight reduction compared with metal blades.
  • One end of the composite blades is fixed securely with a metal blade root member, by which the blade is secured with a rotating hub.
  • the fixing arrangement relies on producing a thickened region in the shape of a wedge at the in-board end of the blade.
  • the thickened region is produced by separating layers of the fibre and inserting additional composite layers of different thicknesses to form the desired wedge shape. The wedge region is trapped between an inner metal component of the root and an outer metal sleeve having a machined wedge profile.
  • Centrifugal force applied to the blade as it rotates causes a force to be applied to move the wedge end of the blade into a narrower part of the wedge profile formed by the mounting structures of the root.
  • a filament or tape of composite material can be wrapped around the blade where it embraces the metal root.
  • a composite blade assembly including a composite blade and a root member, one end of the blade extending along the root member and being secured therewith, the blade including a plurality of layers of braided material, the thickness of the blade material in the region of the root member being thickened by altering the braid angle of the braided material.
  • the root member and the thickened region of the blade are preferably formed with cooperating profiles to resist separation of the blade from the root member.
  • the root member preferably has an increased lateral dimension towards its outer end.
  • the blade assembly may include an outer sleeve extending around the root member and the thickened region of the blade.
  • a method of forming a blade for attachment to a root member including braiding multiple fibre layers along an outer part of the blade with a first braid angle and altering the braid angle along an inner part of the blade to produce a thickened region for attachment to the root member.
  • the braid angle may be changed from approximately 45° along the outer part to approximately 70° along the inner part.
  • a blade made by a method according to the above other aspect of the present invention.
  • Figure 1 is a partly cross-sectional side elevation view of the inner end of the blade assembly.
  • Figure 2 is a partly cross-sectional side elevation view of an alternative blade assembly.
  • FIG. 1 With reference first to Figure 1 there is shown the inboard end of a propeller blade assembly comprising a root member 1 and a blade 2.
  • the assembly with one or more other blade assemblies, would be fixed to a rotatable hub structure (not shown) by inserting the root members into respective mounting recesses in the hub.
  • the root member 1 is machined from a metal and is solid with a circular section.
  • the root member 1 is divided into two portions.
  • the inboard, left-hand portion 10 has a cylindrical shape and a constant diameter along its length except for a shallow circular flange 11 about halfway along the portion.
  • the outboard, right-hand portion 12 flares laterally outwardly to an increased diameter at its right-hand end, with a generally parabolic external profile.
  • the blade 2 has a circular section at its left-hand, inboard end 22 and this extends along and around the outside surface of the right-hand end of the root member 1, with its left-hand end locating against the right-hand side of the flange 11 on the root member.
  • the blade or aerofoil 2 is of a composite fibre and resin material, typically carbon-fibre and glass-fibre reinforced epoxy resin with a central polyurethane foam core at its outboard end (not shown).
  • the invention is not confined to carbon and glass fibre construction, but can be used with other fibre types, nor does it depend on the inclusion of a separate core either of foam or any other material.
  • the fibres are braided and arranged in multiple layers 20, one on top of the other. Figure 1 shows seven layers 20 but there could be any number of two or more layers.
  • the layers 20 are braided by a triaxial braiding process where the fibres are woven in three axes simultaneously. This is used to produce both the outer aerofoil sections of the blade and the main load-carrying spar structure that interfaces with the metal root member 1.
  • the blade 2 has a radially-thickened region 21 at its inboard end. This thickened region 21 is produced by changing the braid angle gradually from approximately 45° to approximately 70° in the region so that it is gradually thickened along its length, being thicker towards its left-hand, inboard end.
  • the change in braiding angle is arranged so that the inner surface of the braided layers 20 thickens with a profile corresponding to that of the external surface of the root member 1; the external diameter of the blade 2 remains substantially constant along its rear end.
  • the change in braiding angle also results in an increase in hoop strength of the root wedge region 21, that is, an increase in the strength resisting radial expansion of the layers of the blade 2.
  • This increase in strength can be sufficient to remove the need for any outer sleeve or other external structure to retain the blade on the root member. This can enable the weight of the blade assembly to be reduced.
  • an outer sleeve 3 can be added in the manner shown in Figure 2.
  • Components in Figure 2 that are the same as those in Figure 1 have been given the same reference number with the addition of 100.
  • the sleeve 3 is of cylindrical shape and is made of a rigid metal.
  • the sleeve 3 is closed at its inboard end 31 by an inwardly projecting flange 32 secured with the root member 101 just on the inboard side of the flange 111.
  • the outboard end 33 of the sleeve 3 just on the inboard side of the outboard end of the root member 101.
  • the sleeve 3, therefore, traps the thickened region 121 of the blade 102 in a wedge-shape recess between the surface of the root member 101.

Abstract

A composite blade assembly is disclosed including a composite blade or aerofoil (2) and a root member (1). One end of the blade (2) extends along the root member (1) and is secured therewith. The blade (2) includes a plurality of layers of braided material (20). The thickness of the blade material in the region of the root member (1) is thickened by altering the braid angle of the braided material.

Description

BLADES
This invention relates to blades and to methods of forming blades.
The invention is more particularly concerned with blades of composite construction, such as used in propellers, turbomachines or helicopters.
Propeller and other blades are increasingly being made of composite fibre materials because of the considerable weight reduction compared with metal blades. One end of the composite blades is fixed securely with a metal blade root member, by which the blade is secured with a rotating hub. There are many different arrangements for securing composite blades with the metal root. Often, the fixing arrangement relies on producing a thickened region in the shape of a wedge at the in-board end of the blade. Typically, the thickened region is produced by separating layers of the fibre and inserting additional composite layers of different thicknesses to form the desired wedge shape. The wedge region is trapped between an inner metal component of the root and an outer metal sleeve having a machined wedge profile. Centrifugal force applied to the blade as it rotates causes a force to be applied to move the wedge end of the blade into a narrower part of the wedge profile formed by the mounting structures of the root. Alternatively, instead of the outer metal sleeve, a filament or tape of composite material can be wrapped around the blade where it embraces the metal root.
Examples of composite blades are described in, EP0735161, GB646636 and It is important that the retention of the blade with its root is secure enough to resist the high forces met during use but it is also important to minimize the overall weight of the blade arrangement.
It is an object of the present invention to provide an alternative blade assembly and method.
According to one aspect of the present invention there is provided a composite blade assembly including a composite blade and a root member, one end of the blade extending along the root member and being secured therewith, the blade including a plurality of layers of braided material, the thickness of the blade material in the region of the root member being thickened by altering the braid angle of the braided material.
The root member and the thickened region of the blade are preferably formed with cooperating profiles to resist separation of the blade from the root member. The root member preferably has an increased lateral dimension towards its outer end. The blade assembly may include an outer sleeve extending around the root member and the thickened region of the blade.
According to another aspect of the present invention there is provided a method of forming a blade for attachment to a root member including braiding multiple fibre layers along an outer part of the blade with a first braid angle and altering the braid angle along an inner part of the blade to produce a thickened region for attachment to the root member. The braid angle may be changed from approximately 45° along the outer part to approximately 70° along the inner part.
According to a further aspect of the present invention there is provided a blade made by a method according to the above other aspect of the present invention.
An aircraft propeller blade assembly according to the present invention, will now be described, by way of example, with reference to the accompanying drawing, in which:
Figure 1 is a partly cross-sectional side elevation view of the inner end of the blade assembly; and
Figure 2 is a partly cross-sectional side elevation view of an alternative blade assembly.
With reference first to Figure 1 there is shown the inboard end of a propeller blade assembly comprising a root member 1 and a blade 2. The assembly, with one or more other blade assemblies, would be fixed to a rotatable hub structure (not shown) by inserting the root members into respective mounting recesses in the hub.
The root member 1 is machined from a metal and is solid with a circular section. The root member 1 is divided into two portions. The inboard, left-hand portion 10 has a cylindrical shape and a constant diameter along its length except for a shallow circular flange 11 about halfway along the portion. The outboard, right-hand portion 12 flares laterally outwardly to an increased diameter at its right-hand end, with a generally parabolic external profile.
The blade 2 has a circular section at its left-hand, inboard end 22 and this extends along and around the outside surface of the right-hand end of the root member 1, with its left-hand end locating against the right-hand side of the flange 11 on the root member. The blade or aerofoil 2 is of a composite fibre and resin material, typically carbon-fibre and glass-fibre reinforced epoxy resin with a central polyurethane foam core at its outboard end (not shown). The invention is not confined to carbon and glass fibre construction, but can be used with other fibre types, nor does it depend on the inclusion of a separate core either of foam or any other material. The fibres are braided and arranged in multiple layers 20, one on top of the other. Figure 1 shows seven layers 20 but there could be any number of two or more layers.
In particular, the layers 20 are braided by a triaxial braiding process where the fibres are woven in three axes simultaneously. This is used to produce both the outer aerofoil sections of the blade and the main load-carrying spar structure that interfaces with the metal root member 1. The blade 2 has a radially-thickened region 21 at its inboard end. This thickened region 21 is produced by changing the braid angle gradually from approximately 45° to approximately 70° in the region so that it is gradually thickened along its length, being thicker towards its left-hand, inboard end. The change in braiding angle is arranged so that the inner surface of the braided layers 20 thickens with a profile corresponding to that of the external surface of the root member 1; the external diameter of the blade 2 remains substantially constant along its rear end. By changing the braiding angle in this way, the thickened region 21 is provided without the need to separate layers and insert additional material.
The change in braiding angle also results in an increase in hoop strength of the root wedge region 21, that is, an increase in the strength resisting radial expansion of the layers of the blade 2. This increase in strength can be sufficient to remove the need for any outer sleeve or other external structure to retain the blade on the root member. This can enable the weight of the blade assembly to be reduced.
Where additional strength is necessary, an outer sleeve 3 can be added in the manner shown in Figure 2. Components in Figure 2 that are the same as those in Figure 1 have been given the same reference number with the addition of 100. The sleeve 3 is of cylindrical shape and is made of a rigid metal. The sleeve 3 is closed at its inboard end 31 by an inwardly projecting flange 32 secured with the root member 101 just on the inboard side of the flange 111. The outboard end 33 of the sleeve 3 just on the inboard side of the outboard end of the root member 101. The sleeve 3, therefore, traps the thickened region 121 of the blade 102 in a wedge-shape recess between the surface of the root member 101.
It will be appreciated that this invention is not restricted to aircraft propeller blades but could be used for other blades.

Claims

CLAIMS:
1. A composite blade assembly including a composite blade and a root member, one end of the blade extending along the root member and being secured therewith, the blade including a plurality of layers of braided material, the thickness of the blade material in the region of the root member being thickened by altering the braid angle of the braided material.
2. A composite blade assembly according to claim 1, wherein the root member and the thickened region of the blade are formed with cooperating profiles to resist separation of the blade from the root member.
3. A composite blade assembly according to claim 1 or claim 2, wherein the root member has an increased lateral dimension towards its outer end.
4. A composite blade assembly according to any one of the preceding claims, wherein the braid angle is altered from approximately 45° along the outer part to approximately 70° along the inner part.
5. A composite blade assembly according to any one of the preceding claims, wherein the blade assembly includes an outer sleeve extending around the root member and the thickened region of the blade.
6. A method of forming a blade for attachment to a root member including braiding multiple fibre layers along an outer part of the blade with a first braid angle and altering the braid angle along an inner part of the blade to produce a thickened region for attachment to the root member.
7. A method according to claim 6, wherein the braid angle is changed from approximately 45° along the outer part to approximately 70° along the inner part.
8. A method according to claim 6 or claim 7, wherein an outer sleeve is provided extending around the root member and the thickened region of the blade.
9. A blade made by a method according to any one of claims 6 to 8.
PCT/GB2008/000189 2007-01-20 2008-01-18 Blades WO2008087443A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB0701099.4 2007-01-20
GB0701099A GB2449058B (en) 2007-01-20 2007-01-20 Blades

Publications (1)

Publication Number Publication Date
WO2008087443A1 true WO2008087443A1 (en) 2008-07-24

Family

ID=37846682

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/GB2008/000189 WO2008087443A1 (en) 2007-01-20 2008-01-18 Blades

Country Status (2)

Country Link
GB (1) GB2449058B (en)
WO (1) WO2008087443A1 (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2206597A2 (en) 2009-01-07 2010-07-14 GE Aviation Systems Limited Method and apparatus for manufacturing composite spars
US8500407B1 (en) 2010-03-28 2013-08-06 The Boeing Company Composite blade root-end drill-through lug and attachment method
WO2014209456A1 (en) * 2013-06-25 2014-12-31 The Boeing Company Systems and methods for blade attachment
WO2021157675A1 (en) * 2020-02-04 2021-08-12 Hapsmobile Inc. Propeller blade-to-hub coupler for an unmanned aerial vehicle

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2970943B1 (en) 2011-01-31 2014-02-28 Eurocopter France BLADE AND METHOD FOR MANUFACTURING THE SAME

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB646636A (en) 1942-03-06 1950-11-29 Lockheed Aircraft Corp Improvements in or relating to a gas-turbine blade and method of making same
US3713753A (en) * 1968-08-10 1973-01-30 Messerschmitt Boelkow Blohm Fiber reinforced plastic laminate construction of an airfoil wing type member
US5222297A (en) * 1991-10-18 1993-06-29 United Technologies Corporation Composite blade manufacture
EP0735161A1 (en) 1995-03-31 1996-10-02 Optical Radiation Corp. Electroformed shield for a jet engine fan blade and a method of forming such a shield
US5881972A (en) 1997-03-05 1999-03-16 United Technologies Corporation Electroformed sheath and airfoiled component construction
US20020008177A1 (en) * 2000-07-19 2002-01-24 Aero Composites, Inc. Composite airfoil assembly
US20050042109A1 (en) * 2003-08-22 2005-02-24 Kovalsky David A. Braided spar for a rotor blade and method of manufacture thereof

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5118257A (en) * 1990-05-25 1992-06-02 Sundstrand Corporation Boot attachment for composite turbine blade, turbine blade and method of making turbine blade
US7222387B2 (en) * 2002-10-28 2007-05-29 Valeo Electrical Systems, Inc. Windshield wiper system having tubular member
FR2861143B1 (en) * 2003-10-20 2006-01-20 Snecma Moteurs TURBOMACHINE BLADE, IN PARTICULAR BLADE OF BLOWER AND METHOD OF MANUFACTURING THE SAME

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB646636A (en) 1942-03-06 1950-11-29 Lockheed Aircraft Corp Improvements in or relating to a gas-turbine blade and method of making same
US3713753A (en) * 1968-08-10 1973-01-30 Messerschmitt Boelkow Blohm Fiber reinforced plastic laminate construction of an airfoil wing type member
US5222297A (en) * 1991-10-18 1993-06-29 United Technologies Corporation Composite blade manufacture
EP0735161A1 (en) 1995-03-31 1996-10-02 Optical Radiation Corp. Electroformed shield for a jet engine fan blade and a method of forming such a shield
US5881972A (en) 1997-03-05 1999-03-16 United Technologies Corporation Electroformed sheath and airfoiled component construction
US20020008177A1 (en) * 2000-07-19 2002-01-24 Aero Composites, Inc. Composite airfoil assembly
US20050042109A1 (en) * 2003-08-22 2005-02-24 Kovalsky David A. Braided spar for a rotor blade and method of manufacture thereof

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2206597A2 (en) 2009-01-07 2010-07-14 GE Aviation Systems Limited Method and apparatus for manufacturing composite spars
US8061253B2 (en) 2009-01-07 2011-11-22 Ge Aviation Systems Limited Composite spars
US8500407B1 (en) 2010-03-28 2013-08-06 The Boeing Company Composite blade root-end drill-through lug and attachment method
WO2014209456A1 (en) * 2013-06-25 2014-12-31 The Boeing Company Systems and methods for blade attachment
JP2016527128A (en) * 2013-06-25 2016-09-08 ザ・ボーイング・カンパニーＴｈｅ Ｂｏｅｉｎｇ Ｃｏｍｐａｎｙ System and method for blade mounting
US9682773B2 (en) 2013-06-25 2017-06-20 The Boeing Company Systems and methods for blade attachment
WO2021157675A1 (en) * 2020-02-04 2021-08-12 Hapsmobile Inc. Propeller blade-to-hub coupler for an unmanned aerial vehicle

Also Published As

Publication number Publication date
GB2449058A (en) 2008-11-12
GB2449058B (en) 2011-08-10
GB0701099D0 (en) 2007-02-28

Similar Documents

Publication Publication Date Title
US8043457B2 (en) Fibre placement tool
US8272841B2 (en) Propeller blade retention
US10683087B2 (en) Shrouded rotary assembly from segmented composite for aircraft
EP3069989B1 (en) Lightweight propeller blade with improved retention capacity
WO2008087443A1 (en) Blades
CA1311459C (en) Composite helicopter rotor hub
US5074753A (en) Rotor blade
US7972114B2 (en) Composite blade root structure
EP2660146B1 (en) Propeller blade with modified spar layup
US9505486B2 (en) Propeller blade having compliant adhesive at spar interface
EP3246250B1 (en) A monolithic blade, a rotorcraft rotor fitted with such a monolithic blade, and an associated rotorcraft
EP3095960B1 (en) Vane connection part structure and jet engine utilizing same
US20140133995A1 (en) Propeller blade with modified spar stiffness
US20130136616A1 (en) Propeller blade having a honeycomb spar core
EP3608090A1 (en) Composite connector and method of manufacturing the same
US4818179A (en) Composite helicopter rotor hub
US20160208616A1 (en) High modulus hybrid material rotor blade spar
EP3437991B1 (en) Rotor span-balance pocket
EP4001677B1 (en) A drive shaft with an integrated flange
US20130287585A1 (en) Propeller blade with lightweight insert
EP2910465A1 (en) Propeller blade and method
CN117222517A (en) Blade comprising a structure made of composite material and associated manufacturing method
EP3034783B1 (en) A blade arrangement of a jet engine or an aircraft propeller and corresponding engine
CN117940339A (en) Propeller for an aircraft turbomachine

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 08701867

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 08701867

Country of ref document: EP

Kind code of ref document: A1