# US 12,000,372 B2 · Wind turbine blade

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- Number: US 12,000,372 B2
- Document ID: US12000372B2
- Status: Granted
- Kind: B2
- Application number: 18/013,030
- Filed: 2021-07-01
- Published: 2023-10-19
- Granted: 2024-06-04
- Earliest claimed: 2020-07-03
- Assignees: Vestas Wind Systems A/S
- Applicants: Vestas Wind Systems A/S
- Inventors: Preben Kjeldsen; Thomas Schmidt
- Web page: https://patentgrep.com/patent/US12000372B2

## CPC

- F03D 1/0675: {of the blades}
- B29D 99/0025: {Producing blades or the like, e.g. blades for turbines, propellers, or wings}
- B29D 99/0028: {hollow blades}
- F03D 1/0641: {of the section profile of the blades, i.e. aerofoil profile}
- F03D 1/0677: {Longitudinally segmented blades; Connectors therefor}
- F03D 1/0681: {Spar caps}
- F03D 1/0682: {incorporated into the shell structure}
- F03D 1/0684: {Shear webs}
- F03D 1/0685: {Actuation arrangements for elements attached to or incorporated with the blade (controlling flaps or slats F03D7/0232)}
- F05B 2220/705: the other apparatus being a wind turbine
- F05B 2230/60: Assembly methods
- F05B 2240/21: for wind turbines
- F05B 2240/30: Characteristics of rotor blades, i.e. of any element transforming dynamic fluid energy to or from rotational energy and being attached to a rotor
- F05B 2260/30: Retaining components in desired mutual position
- 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
- B29D: PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE (making granules B29B9/00; making preforms B29B11/00)
- 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

In a first aspect of the invention there is provided a wind turbine blade comprising a blade shell that extends in a spanwise direction from a root end to a tip end, and in a chordwise direction from a leading edge to a trailing edge. The blade shell comprises a spar cap formed from a plurality of substantially planar strips of reinforcing material, the strips being arranged in a plurality of stacks extending longitudinally in the spanwise direction and arranged side-by-side in the chordwise direction. In each stack an uppermost strip defines an upper surface of the stack, a lowermost strip defines a lower surface of the stack, and longitudinal edges of the stacked strips define side surfaces of the stack. The blade further comprises a retaining clip comprising a plurality of side-by-side substantially U-shaped sections. The U-shaped sections each comprise a pair of mutually-spaced side portions defining a stack-receiving region therebetween, and the side portions are joined by a bridging portion. At least some of the stacks are located in the stack-receiving regions of the retaining clip, such that the side portions of the U-shaped sections abut side surfaces of the stacks. Each U-shaped section of the retaining clip is inverted with respect to its neighbouring U-shaped section(s) such that the bridging portions of the respective U-shaped sections extend alternately across the upper and lower surfaces of the stacks in the chordwise direction.

## Claims

### Claim 1

A wind turbine blade comprising:
a blade shell that extends in a spanwise direction from a root end to a tip end, and in a chordwise direction from a leading edge to a trailing edge, the blade shell comprising:
a spar cap formed from a plurality of substantially planar strips of reinforcing material, the strips being arranged in a plurality of stacks extending longitudinally in the spanwise direction and arranged side-by-side in the chordwise direction, whereby in each stack an uppermost strip defines an upper surface of the stack, a lowermost strip defines a lower surface of the stack, and longitudinal edges of the stacked strips define side surfaces of the stack;
a retaining clip comprising a series of substantially U-shaped sections each having a pair of mutually-spaced side portions defining a stack-receiving region therebetween, wherein the side portions are joined by a bridging portion, and wherein each U-shaped section is inverted with respect to its neighbouring U-shaped section;
wherein at least some of the stacks are located in the stack-receiving regions of the retaining clip, such that the side portions of the U-shaped sections abut side surfaces of the stacks, and each U-shaped section of the retaining clip is inverted with respect to its neighbouring U-shaped section(s) such that the bridging portions of the respective U-shaped sections extend alternately across the upper and lower surfaces of the stacks in the chordwise direction.

### Claim 2 (depends on 1)

The wind turbine blade of claim 1, wherein at least one U-shaped section of the retaining clip, comprises a return flange extending from a side portion of the U-shaped section substantially parallel to and spaced apart from the bridging portion of that U-shaped section, wherein a stack is located between the bridging portion and the return flange such that the bridging portion extends across one of the upper or lower surfaces of a stack and the return flange extends at least partially across the other of the upper or lower surfaces of the stack.

### Claim 3 (depends on 1)

The wind turbine blade of claim 1, wherein an end of the retaining clip comprises a locating flange, and the locating flange extends in the chordwise direction beneath a blade shell component located adjacent the spar cap.

### Claim 4 (depends on 3)

The wind turbine blade of claim 3, wherein the locating flange extends from a side portion of an endmost U-shaped section.

### Claim 5 (depends on 4)

The wind turbine blade of claim 4, wherein at least one U-shaped section of the retaining clip comprises a return flange extending from a side portion of the U-shaped section substantially parallel to and spaced apart from the bridging portion of that U-shaped section, wherein a stack is located between the bridging portion and the return flange such that the bridging portion extends across one of the upper or lower surfaces of a stack and the return flange extends at least partially across the other of the upper or lower surfaces of the stack, and wherein the locating flange is substantially co-planar with the return flange and the two flanges extend chordwise in opposite directions from the side portion of an endmost U-shaped section.

### Claim 6 (depends on 1)

The wind turbine blade of claim 1, wherein the side-by-side stacks are spaced apart in the chordwise direction by the side portions of the U-shaped sections of the retaining clip.

### Claim 7 (depends on 1)

The wind turbine blade of claim 1, comprising one or more pairs of retaining clips arranged side-by-side in the spanwise direction, wherein the U-shaped sections of one of the retaining clips in each pair are inverted relative to the U-shaped sections of the other retaining clip in the pair.

### Claim 8 (depends on 1)

The wind turbine blade of claim 1, comprising a plurality of retaining clips, or a plurality of pairs of retaining clips, mutually spaced in the spanwise direction.

### Claim 9 (depends on 1)

The wind turbine blade of claim 1, wherein one or more of the stacks comprises a tapered end region and the or each retaining clip is positioned outside of the tapered end region.

### Claim 10 (depends on 1)

The wind turbine blade of claim 1, wherein a chordwise cross-sectional profile of the stack-receiving regions of the retaining clip substantially corresponds in shape to a chordwise cross-sectional profile of the stacks.

### Claim 11 (depends on 1)

The wind turbine blade of claim 1, wherein side portions of the U-shaped sections have a height that substantially corresponds to a height of the stacks and the bridging portions of the U-shaped sections have a length that substantially corresponds to a chordwise width of the stacks.

### Claim 12 (depends on 1)

The wind turbine blade of claim 1, wherein the or each retaining clip is formed of a fibre-reinforced polymer material.

### Claim 13 (depends on 1)

The wind turbine blade of claim 1, wherein the retaining clip is a pre-cured component.

### Claim 14

A retaining clip for a wind turbine blade spar cap configured to retain strips of reinforcing material in a stacked formation and restrict movement of a plurality of stacks of strips relative to one another, the clip comprising:
a series of substantially U-shaped sections each having a pair of mutually-spaced side portions defining a stack-receiving region therebetween, wherein the side portions are joined by a bridging portion, wherein each U-shaped section is inverted with respect to its neighbouring U-shaped section; wherein at least some of the stacks are configured to be located in the stack-receiving regions of the retaining clip such that the side portions of the U-shaped sections abut side surfaces of the stacks, and the bridging portions of the respective U-shaped sections are configured to extend alternately across the upper and lower surfaces of the stacks in a chordwise direction.

### Claim 15 (depends on 14)

A method of manufacturing a wind turbine blade, the method comprising:
providing a blade shell mould that extends in a spanwise direction from a root end to a tip end, and in a chordwise direction from a leading edge to a trailing edge;
providing a plurality of substantially planar strips of reinforcing material;
arranging the strips in the mould in a plurality of stacks to form at least part of a spar cap, the stacks extending in the spanwise direction and being arranged side-by-side in the chordwise direction, whereby in each stack an uppermost strip defines an upper surface of the stack, a lowermost strip defines a lower surface of the stack, and longitudinal edges of the stacked strips define side surfaces of the stack;
providing the retaining clip of claim 14; and
arranging at least some of the stacks in the stack-receiving regions of the retaining clip, such that the side portions of the U-shaped sections abut the side surfaces of the stacks, and the bridging portions of the respective U-shaped sections extend alternately across the upper and lower surfaces of the stacks in the chordwise direction.