# US 8,770,942 B2 · Blade and laminated protective sheet for the blade

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- Number: US 8,770,942 B2
- Document ID: US8770942B2
- Status: Granted
- Kind: B2
- Application number: 13/807,127
- Filed: 2012-01-25
- Published: 2013-04-25
- Granted: 2014-07-08
- Earliest claimed: 2011-01-26
- Assignees: Fujikura Rubber Ltd.
- Applicants: Hitoshi Saitou; Takato Nakamura; Nobuaki Suzuki
- Inventors: Hitoshi Saitou; Takato Nakamura; Nobuaki Suzuki
- Web page: https://patentgrep.com/patent/US8770942B2

## CPC

- F03D 1/0675: {of the blades}
- F05B 2230/90: Coating; Surface treatment
- F05B 2280/702: Reinforcements
- Y02E 10/72: Wind turbines with rotation axis in wind direction
- Y02P 70/50: Manufacturing or production processes characterised by the final manufactured product
- F03D: WIND MOTORS
- F05B: INDEXING SCHEME RELATING TO WIND, SPRING, WEIGHT, INERTIA OR LIKE MOTORS, TO MACHINES OR ENGINES FOR LIQUIDS COVERED BY SUBCLASSES F03B, F03D AND F03G
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS

## Abstract

A scratch-resistant blade such as an FRP wind turbine blade and a blade protective sheet which can be easily repaired when scratched. A blade is provided with a laminated protective sheet bonded to at least part of a leading edge of an FRP blade body of said blade, wherein the laminated protective sheet comprises an adhesive layer, a intermediate fabric layer and a durable surface layer, in that order from the blade body.

## Claims

### Claim 1

A blade comprising:
an FRP blade body with a leading edge that has a circular arc shape in a cross section orthogonal to a longitudinal direction of said blade body, wherein a distal end of said leading edge, which is farthest from a rotational center of said blade body, comprises a tapered distal end, having a narrowing thickness in cross section orthogonal to said longitudinal direction of said blade body and having a narrowing width in said cross section from said leading edge to a trailing edge of said blade body; and
a laminated protective sheet being bonded to at least said tapered distal end of said leading edge of said blade body, over two sides thereof that extend toward said trailing edge from a generating line of said arc-shaped cross section,
wherein said laminated protective sheet comprises an adhesive layer, a intermediate fabric layer and a durable surface layer, in that order from the blade body side, and
wherein a distal end of said laminated protective sheet that is farthest from said rotational center of said blade body is in the shape of a curved surface which is convex toward said distal end of said laminated protective sheet and which extends continuously over said two sides of said blade body, and a curved periphery of said convex curved surface is formed as an arc about a point on said generating line.

### Claim 2 (depends on 1)

The blade according to claim 1, wherein said laminated protective sheet comprises a slit for making said laminated protective sheet follow a shape of said tapered distal end with no gaps or wrinkles when bonded to said tapered distal end.

### Claim 3 (depends on 1)

The blade according to claim 1, wherein a laminated protective sheet holding recess, which corresponds in shape to said laminated protective sheet and has substantially the same depth as a thickness of said laminated protective sheet, is formed at said tapered distal end of said blade body, said laminated protective sheet being positioned in said laminated protective sheet holding recess and bonded therein.

### Claim 4 (depends on 1)

The blade according to claim 1, wherein said durable surface layer includes a rubber layer which includes hydrogenated acrylonitrile-butadiene rubber as a rubber component.

### Claim 5 (depends on 4)

The blade according to claim 4, wherein said durable surface layer is approximately 0.5.+−.0.2 mm in thickness.

### Claim 6 (depends on 1)

The blade according to claim 1, wherein said intermediate fabric layer includes a layer made of a fabric impregnated with nitrile rubber.

### Claim 7 (depends on 6)

The blade according to claim 6, wherein said intermediate fabric layer is approximately 0.3.+−.0.05 mm in thickness.

### Claim 8 (depends on 1)

The blade according to claim 1, wherein said adhesive layer includes a rubber layer which includes butyl rubber as a rubber component.

### Claim 9

A laminated protective sheet comprising:
an adhesive layer;
an intermediate fabric layer; and
a durable surface layer,
in that order from a blade body side of said laminated protective sheet, which is for a blade and is bonded at the blade body side to a surface of an FRP blade body,
wherein a leading edge of said blade body has a circular arc shape in a cross section orthogonal to a longitudinal direction of said blade body,
wherein a distal end of said leading edge, which is farthest from a rotational center of said blade body, includes a tapered distal end, having a narrowing thickness in cross section orthogonal to said longitudinal direction of said blade body and having a narrowing width in said cross section from said leading edge to a trailing edge of said blade body,
said laminated protective sheet being bonded to said tapered distal end of said leading edge of said blade body over two sides thereof that extend toward said trailing edge from a generating line of said arc-shaped cross section, and a distal end of said laminated protective sheet that is farthest from said rotational center of said blade body being in the shape of a curved surface which is convex toward said distal end of said laminated protective sheet and which extends continuously over said two sides of said blade body, a curved periphery of said convex curved surface being formed as an arc about a point on said generating line.

### Claim 10 (depends on 9)

The laminated protective sheet for a blade according to claim 9, comprising a slit for making said laminated protective sheet follow a shape of said tapered distal end with no gaps or wrinkles when said laminated protective sheet is bonded to said tapered distal end.

### Claim 11 (depends on 9)

The laminated protective sheet for a blade according to claim 9, wherein said durable surface layer includes a rubber layer which includes hydrogenated acrylonitrile-butadiene rubber as a rubber component.

### Claim 12 (depends on 11)

The laminated protective sheet for a blade according to claim 11, wherein said durable surface layer is approximately 0.5.+−0.0.2 mm in thickness.

### Claim 13 (depends on 9)

The laminated protective sheet for a blade according to claim 9, wherein said intermediate fabric layer includes a layer made of a fabric impregnated with nitrile rubber.

### Claim 14 (depends on 13)

The laminated protective sheet for a blade according to claim 13, wherein said intermediate fabric layer is approximately 0.3.+−.0.05 mm in thickness.

### Claim 15 (depends on 9)

The laminated protective sheet for a blade according to claim 9, wherein said adhesive layer includes a rubber layer which includes butyl rubber as a rubber component.