Composite blade and method of manufacture

• US 8,075,280 B2
• Filed: 09/08/2008
• Issued: 12/13/2011
• Est. Priority Date: 09/08/2008
• Status: Active Grant

• Current Assignee: Siemens Energy Incorporated (Siemens AG)
• Original Assignee: Siemens Energy Incorporated (Siemens AG)
• Inventors: Jones, William F.
• Primary Examiner(s): Geyer, Scott B
• Application Number:
  US12/205,966
• Publication Number:
  US 20100061858A1
• Time in Patent Office: 1,191 Days
• Field of Search: 416/248
• US Class Current: 416/248
• CPC Class Codes: B29C 43/3642 Bags, bleeder sheets or cauls for isostatic pressing
• CPC Class Codes: B29C 66/02245 Abrading, e.g. grinding, sanding, sandblasting or scraping
• CPC Class Codes: B29C 66/1222 comprising at least a lapped joint-segment
• CPC Class Codes: B29C 66/1226 comprising at least one bevelled joint-segment
• CPC Class Codes: B29C 66/12822 comprising at least three overlap joint-segments
• CPC Class Codes: B29C 66/12841 comprising at least two butt joint-segments
• CPC Class Codes: B29C 66/30322 in the form of rugosity
• CPC Class Codes: B29C 66/5324 said single elements being substantially annular, i.e. of finite length B29C66/5326 takes precedence
• CPC Class Codes: B29C 66/612 Making circumferential joints
• CPC Class Codes: B29C 66/634 using an inflatable core
• CPC Class Codes: B29C 66/71 characterised by the composition of the plastics material of the parts to be joined welding bar compositions B29C65/125
• CPC Class Codes: B29C 66/721 Fibre-reinforced materials B29C66/729 takes precedence
• CPC Class Codes: B29C 66/7212 characterised by the composition of the fibres
• CPC Class Codes: B29C 66/72141 Fibres of continuous length
• CPC Class Codes: B29C 66/73161 Roughness or rugosity
• CPC Class Codes: B29C 66/73753 the to-be-joined area of at least one of the parts to be joined being partially cured, i.e. partially cross-linked, partially vulcanized
• CPC Class Codes: B29C 66/7394 characterised by the material of at least one of the parts being a thermoset
• CPC Class Codes: B29C 66/742 to metals or their alloys
• CPC Class Codes: B29C 66/81455 being a fluid inflatable bag or bladder, a diaphragm or a vacuum bag for applying isostatic pressure inflatable element positioned between the joining tool and a backing-up part B29C66/82421
• CPC Class Codes: B29D 99/0025 Producing blades or the like, e.g. blades for turbines, propellers, or wings
• CPC Class Codes: B29K 2063/00 : Use of EP, i.e. epoxy resins or derivatives thereof, as moulding material
• CPC Class Codes: B29K 2309/08 : Glass
• CPC Class Codes: B29L 2031/08 : Blades for rotors, stators, fans, turbines or the like, e.g. screw propellers
• CPC Class Codes: F01D 5/147 : Construction, i.e. structural features, e.g. of weight-saving hollow blades F01D5/148, F01D5/16 and F01D5/20 take precedence; blade shape F01D5/141; blades with cooling or heating channels or cavities F01D5/18; heating, heat-insulating or cooling means on blades F01D5/18
• CPC Class Codes: F01D 5/282 : Selecting composite materials, e.g. blades with reinforcing filaments
• CPC Class Codes: F01D 5/284 : Selection of ceramic materials
• CPC Class Codes: F01D 5/30 : Fixing blades to rotors; Blade roots ; Blade spacers
• CPC Class Codes: F04D 29/023 : especially adapted for elastic fluid pumps
• CPC Class Codes: F04D 29/34 : Blade mountings for axial flow compressors F04D29/322
• CPC Class Codes: F04D 29/388 : characterised by construction
• CPC Class Codes: F05D 2230/23 : by permanently joining parts together
• CPC Class Codes: F05D 2300/6033 : Ceramic matrix composites [CMC]
• CPC Class Codes: Y10T 29/49316 : Impeller making
• CPC Class Codes: Y10T 29/49336 : Blade making
• CPC Class Codes: Y10T 29/49337 : Composite blade

Abstract

A method of making a composite blade that is attachable to a rotating shaft using a conventional metal blade attachment. A blade is formed from a composite material with a blade root at one end thereof. A metallic member having an external shape conforming to a conventional metal blade root is shaped with an interior cavity having an opening for receipt of the blade root. Before the composite material is fully cured, a bladder is formed into or is inserted into an end of the blade root and inflated, thereby forcing the composite material into intimate contact with the interior cavity of the metallic member, thereby ensuring a fret-free interface upon final curing of the composite material. The interior cavity of the metallic member may be shaped or surfaced to improve the load carrying capability there between.

Claims

1. A blade comprising:

a composite material defining an airfoil and an extending blade root;

a metallic connecting element surrounding the blade root;

the metallic connecting element comprising an inner portion in intimate non-fretting attachment with the composite material and an outer portion defining a metal blade attachment geometry for allowing the blade to be removeably attached to a metal disk;

wherein the metallic connecting element comprises a metallic fiber layer formed in an outer region of the blade root.

2. A blade comprising:

a composite material defining an airfoil and an extending blade root;

a metallic connecting element surrounding the blade root;

the metallic connecting element comprising an inner portion in intimate non-fretting attachment with the composite material and an outer portion defining a metal blade attachment geometry for allowing the blade to be removeably attached to a metal disk;

wherein the metallic connecting element comprises an interior cavity with an opening at a proximate end for receipt of the blade root and an opening at a distal end larger than the opening at the proximate end.

3. The blade of claim 2, wherein the interior cavity comprises a stepped geometry between the proximate end opening and the distal end opening.

4. The blade of claim 2, wherein the interior cavity comprises a tapered geometry between the proximate end opening and the distal end opening.

5. A blade comprising:

a composite material defining an airfoil and an extending blade root;

a metallic connecting element surrounding the blade root;

the metallic connecting element comprising an inner portion in intimate non-fretting attachment with the composite material and an outer portion defining a metal blade attachment geometry for allowing the blade to be removeably attached to a metal disk;

wherein the metallic connecting element comprises an interior cavity comprising a roughened surface.

6. A method of making a blade comprising the steps of:

shaping from composite material a blade including a blade root;

shaping a metallic member for receipt of said blade root, said metallic member comprising an exterior geometry adapted for attachment to a metal disc and comprising an Interior cavity formed therein with an opening in a proximate end for receipt of said blade root and an opening at the distal end thereof larger than said opening in said proximate end;

when said composite material of said turbine blade is still pliable and not yet fully cured, inserting said blade root into said interior cavity;

positioning a bladder in the distal end of said blade root within said interior cavity and attaching said bladder to a source of compressed fluid;

inflating said bladder in order to expand said composite material into intimate contact with said interior cavity of said metallic member; and

,

continue curing said turbine blade with said metallic member attached until fully cured, whereby said composite blade is firmly secured to said metallic member.

7. The method as in claim 6 wherein said metallic member is shaped into a metallic sleeve adapted for attachment to said metal disc and having a stepped interior cavity between said proximate end and said distal end.

8. The method as in claim 7 further including the step of roughening interior surfaces of said interior cavity prior to insertion of said blade root.

9. The method as in claim 7, further comprising removing the bladder after the step of inflating and backfilling the space previously filled by the bladder with a filler material.

10. The method as in claim 6, further comprising positioning the bladder in the distal end of the blade root during the step of shaping the blade root from composite material.

11. A method of making a blade comprising the steps of:

shaping of composite material a blade including a blade root;

surrounding the composite material blade root with a metallic layer, an outer surface of the composite material blade root in conformal contact with an inner surface of the metallic layer, and an outer surface of the metallic layer comprising an attachment shape corresponding to a shape of a disk to which the blade will be attached during use; and

curing the composite material;

forming the metallic layer with metallic fiber on the composite material blade root to a suitable thickness; and

,

when said composite material is cured, forming the attachment shape in the metallic layer.