Reinforced blade and spar

Patent metadata

Field	Value
Publication number	US-10407159-B2
Application number	US-201715806502-A
Country	US
Kind code	B2
Filing date	Nov 8, 2017
Priority date	Nov 8, 2016
Publication date	Sep 10, 2019
Grant date	Sep 10, 2019

Abstract

A spar for a propeller blade comprises central structural member extending from a root to a tip of the spar. A first portion of the central structural member extends from the root of the spar and a second portion extends from the tip and adjoins the first portion. The central structural member includes a first plurality of plies of composite material on a pressure side thereof and a second plurality of plies of composite material on a suction side thereof wherein the first plurality of plies are in contact with the second plurality of plies in the second portion from a leading edge to a trailing edge thereof. A plurality of yarns extends through the central structural member in at least the second portion.

First claim

The invention claimed is:

1. A spar for a propeller blade comprising:
a central structural member extending from a root to a tip of the spar, a first portion of the central structural member extending from the root of the spar and a second portion extending from the tip and adjoining the first portion, the central structural member including a first plurality of plies of composite material on a pressure side thereof and a second plurality of plies of composite material on a suction side thereof wherein the first plurality of plies are in contact with the second plurality of plies in the second portion from a leading edge to a trailing edge thereof; and
a plurality of yarns extending through the central structural member in at least the second portion.

2. The spar of claim 1 , further comprising a core region between the first and second plurality of plies in the first region only.

3. The spar of claim 2 , wherein the core region comprises a lightweight core material such as foam, honeycomb or balsa.

4. The spar of claim 1 , wherein the second portion extends along less than 70% of the span (S) but greater than 20% of the span (S) adjacent the tip, for example wherein the second portion extends along about a third of the span (S) adjacent the tip.

5. The spar of claim 1 , further comprising an outer structural member surrounding the core region and central structural member along the entire span of the spar.

6. The spar of claim 5 , wherein the outer structural member comprises unidirectional plies and has a variable thickness around the circumference of the spar.

7. The spar of claim 5 , wherein the yarns extend through the outer structural member and the central structural member.

8. The spar of claim 1 , wherein the central structural member has a maximum thickness adjacent a leading edge of the spar and a minimum thickness adjacent a trailing edge of the spar.

9. The spar of claim 8 , wherein a greater number of plies of the central structural member are positioned adjacent a leading edge than adjacent the trailing edge of the spar.

10. The spar of claim 1 , wherein the yarns are positioned at a plurality of positions across a chord (C) of the spar.

11. The spar of claim 1 , wherein a single yarn extends through the thickness of the spar more than once at different positions across the chord (C) of the spar.

12. The spar of claim 1 , wherein the spacing between adjacent yarns or portions of yarn extending through the thickness of the spar is constant.

13. The spar of claim 1 , wherein the spacing between adjacent yarns or portions of yarn extending through the thickness of the spar is greater towards the trailing edge of the spar.

14. A propeller blade 10 comprising the spar as set forth in claim 1 .

15. The propeller blade of claim 14 , wherein the spar extends along substantially the entire span (S) of the propeller blade.

16. A method of manufacturing a spar for a propeller blade comprising:
forming a central structural member having a first portion extending from the root of the spar and a second portion extending from the tip and adjoining the first portion, the central structural member including a first plurality of plies of composite material on a pressure side thereof and a second plurality of plies of composite material on a suction side thereof wherein the first plurality of plies are in contact with the second plurality of plies in the second portion from a leading edge to a trailing edge thereof; and
threading a plurality of yarns through the central structural member at least in the second portion.

17. The method of claim 16 , further comprising forming a central region between the first plurality of plies and the second plurality of plies in the first portion only.

18. The method of claim 16 , wherein the threading is performed with a vibrating needle or by tufting.

19. The method of claim 16 , wherein the central structural member is a pre-preg laminate sheet and the central region comprises a lightweight core material such as foam, honeycomb or balsa, in a portion of the spar adjacent a root thereof.

20. The method of claim 16 , further comprising surrounding the central structural member with an outer structural member, wherein the plurality of yarns extend through both the outer structural member and the central structural member.

Assignees

• Ratier Figeac Sas

Inventors

• Amat Pascal

Classifications

• B64C11/205

  for protecting blades, e.g. coating · CPC title

• D05B69/32

  Vibration-minimising devices · CPC title

• B32B2603/00

  Vanes, blades, propellers, rotors with blades · CPC title

• B32B5/18

  characterised by features of a layer {of} foamed material · CPC title

• B32B27/40

  comprising polyurethanes · CPC title