Platform mounted components

• US 7,198,472 B2
• Filed: 11/21/2005
• Issued: 04/03/2007
• Est. Priority Date: 12/10/2004
• Status: Active Grant

• Current Assignee: Rolls-Royce PLC (Rolls-Royce Holdings Plc)
• Original Assignee: Rolls-Royce PLC (Rolls-Royce Holdings Plc)
• Inventors: McMillan, Alison J, Booth, Stephen J
• Primary Examiner(s): Look; Edward K.
• Assistant Examiner(s): White; Dwayne J
• Application Number:
  US11/282,602
• Publication Number:
  US 20060127217A1
• Time in Patent Office: 498 Days
• Field of Search: 415/200, 416/234, 416/241.R, 416/DIG.5, 298/892.2, 298/892.1, 298/892.3, 298/897.1
• US Class Current: 416/234
• CPC Class Codes: B29C 66/43441 with two right angles, e.g. for making T-shaped pieces, H-shaped pieces
• CPC Class Codes: B29C 66/721 Fibre-reinforced materials B29C66/729 takes precedence
• CPC Class Codes: B29K 2105/06 containing reinforcements, fillers or inserts
• CPC Class Codes: B29L 2031/08 Blades for rotors, stators, fans, turbines or the like, e.g. screw propellers
• CPC Class Codes: B29L 2031/082 Blades, e.g. for helicopters
• 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: F04D 29/023 especially adapted for elastic fluid pumps
• CPC Class Codes: F04D 29/324 Blades
• CPC Class Codes: F05D 2240/80 Platforms for stationary or moving blades
• CPC Class Codes: F05D 2300/518 Ductility
• CPC Class Codes: F05D 2300/6034 Orientation of fibres, weaving, ply angle
• CPC Class Codes: Y02T 50/60 Efficient propulsion technologies, e.g. for aircraft
• CPC Class Codes: Y10T 29/49325 Shaping integrally bladed rotor
• CPC Class Codes: Y10T 29/49337 Composite blade

Abstract

A platform arrangement for components such as aerofoil vanes 1, 21 is provided whereby the necessary rigidity provided by the platform does not create excess problems with respect to stress and strain fatigue failure at thinner sections of the component. The leading edge 6, 26 and trailing edge 7, 27 of a vane generally have a thinner section and so when subject to greater flex deformation such flex deformation may lead to premature failure through stress and strain. Structural configurations are now provided which comprise cut out windows 24 in the platform 22 beneath the edges 26, 27 or alternatively differential material types at these locations with a less stiff nature. Generally, a backing member 25 is provided below an integral platform layer 22 to create generally greater stiffness in the platform unit formed by the combination but in accordance with the present invention this backing member 25 may include the cut out windows 24 or have the necessary differential material types for variable flexibility compliance at portions of reduced component cross-section.

Claims

1. A platform arrangement for supporting a component having variable cross-section thickness in a first direction, the component formed at least in part from a composite material of variable cross-section thickness, characterized in that at least a portion of the composite material extends into the platform to form therein a layer of composite material of variable cross-section thickness in a second direction, the variation of cross-section thickness in the second direction of the layer corresponding to the variation of cross-section thickness in the first direction of the component, so as to provide more compliance in those regions of the platform adjacent to the regions of the component having a relatively thin cross-section in the first direction compared with the rest of the component.

2. A platform arrangement as claimed in claim 1, in which the second direction is substantially perpendicular to the first direction.

3. A platform as claimed in claim 2, in which the component is part of an annular array of components able to rotate about an axis, and the first direction is a circumferential direction and the second direction is a radial direction.

4. A platform arrangement as claimed in claim 1, in which the fibers in the portion of the composite material in the platform are substantially unidirectional.

5. A platform arrangement as claimed in claim 4, in which the fibers in the portion of the composite material in the component are not substantially unidirectional.

6. A platform arrangement as claimed in claim 1, in which the component is integral with the platform.

7. A platform arrangement as claimed in claim 1, in which the platform comprises a backing member.

8. A platform arrangement as claimed in claim 7, in which part of the backing member is formed of material of relatively low stiffness compared with the material of the rest of the backing member, so as to provide more compliance in those regions of the platform adjacent to the regions of the component having a relatively thin cross-section compared with the rest of the component.

9. A platform arrangement as claimed in claim 1, in which the component is an aerofoil vane with a leading edge and a trailing edge.

10. A platform as claimed in claim 9, in which the platform has more compliance adjacent to the leading and trailing edges of the aerofoil vane.

12. A gas turbine engine incorporating a platform arrangement as claimed in claim 1.

13. A vane assembly for a gas turbine engine comprising a platform arrangement as claimed in claim 1.

11. A platform arrangement for a component substantially as described in this specification, with reference to and as shown in the accompanying drawings.