Windmill Blades

Abstract

To hold a blade main body to a connector while withstanding a centrifugal force applied on the blade main body, in a split-type blade in which the connector and the blade main body are split from each other.SOLUTION: A windmill blade 10 comprises a blade main body 52 and a connector 60. The connector 60 is connected to a root portion of the blade main body 52 and a hub 100. The connector 60 comprises a support shaft part 64 extending in a radial direction of a rotor center axis C1 of a windmill, and coated with an adhesive layer 69 at an external peripheral face 66. The blade main body 52 comprises a support cylinder part 50 covering the support shaft part 64. Fastening holes 68, 46 which are axis-aligned with respect to each other are formed at the support shaft part 64 and the support cylinder part 50. Rivets 80 being fastening shaft members are inserted into the fastening holes 68, 46 of the support shaft part 64 and the support cylinder part 50.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] Disclosed herein is a wind turbine blade for use in wind power generation. [Background technology]

[0002] A wind turbine used for wind power generation comprises blades, a hub, a nacelle, and a tower. Each wind turbine is provided with multiple blades (e.g., three) to catch the wind. The hub supports the roots of the multiple blades and is connected to the rotor shaft. The nacelle houses the gearbox and generator that are connected to the rotor shaft. The tower supports the blades, hub, and nacelle.

[0003] The blade includes a blade body and a connector that is connected to a base portion of the blade body and a hub. The connector and the hub are fastened with bolts or the like. Various methods have been proposed for connecting the connector to the blade body. In particular, for the connection between the connector and the blade body, a connecting means has been proposed for preventing the blade body from breaking and coming off from the connector due to centrifugal force acting on the blade body.

[0004] For example, in Patent Document 1, the blade body is molded from FRP (fiber reinforced plastic). The connector is cylindrical with claws protruding from its outer circumferential surface. The blade body and the connector are molded as one unit. Specifically, the blade body is molded so that the portion including the claws of the connector is embedded. During this molding, the reinforcing fibers of the FRP are wound so that they are caught on the claws of the connector. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2001-99047 A Summary of the Invention [Problem to be solved by the invention]

[0006] Incidentally, because wind turbine blades are particularly long, the risk of damage to the blades during transportation is reduced by transporting them in multiple parts to the installation site (such as a mountain ridge) and assembling them there, rather than transporting a finished product molded as a single unit in a factory to the installation site (such as a mountain ridge).

[0007] Therefore, this specification discloses a wind turbine blade in which the connector and the blade body are separate, and the blade body can be held by the connector against the centrifugal force applied to the blade body. [Means for solving the problem]

[0008] This specification discloses a wind turbine blade. The wind turbine blade comprises a blade body and a connector. The connector is connected to a root portion of the blade body and a hub. The connector comprises a support shaft portion extending in a radial direction of a central axis of the wind turbine rotor and having an adhesive layer applied to an outer circumferential surface. The blade body comprises a support tube portion covering the support shaft portion. Fastening holes are drilled in the radial direction in the support shaft portion and the support tube portion, and are aligned with each other. Fastening shaft members are inserted into the fastening holes in the support shaft portion and the support tube portion.

[0009] According to the above-mentioned configuration, the connector is bonded to the blade body by chemical bonding through the adhesive layer and mechanical bonding through the fastening shaft member. In particular, by inserting the fastening shaft member radially into the support shaft portion and the support tube portion, even if centrifugal force is generated in the blade body, the shear stress of the fastening shaft member prevents the blade body from coming off the connector.

[0010] In the above-described configuration, a plurality of rings may be provided on the outer circumferential surface of the support shaft, the rings extending in a radial direction of the support shaft and spaced apart from one another along the axial direction. In this case, an adhesive layer is applied between the rings.

[0011] According to the above-mentioned configuration, the thickness of the adhesive layer can be set to the projection diameter of the ring, and the thickness of the adhesive layer can be controlled.

[0012] In the above configuration, the fastening holes of the support shaft portion and the support cylindrical portion may be provided on the positive pressure side, which is the front side in the rotor central axis direction.

[0013] When the blade body is exposed to wind, it is biased rearward in the direction of the rotor central axis. At this time, the positive pressure side of the support tube, which is the base of the blade body, receives a force that causes it to separate (peel off) from the support shaft of the connector. Fastening holes for the support shaft and the support tube are provided on the positive pressure side, and a fastening shaft member is inserted into the fastening hole, so that the axial force of the fastening shaft member can be used to prevent the support tube from peeling off from the support shaft.

[0014] In the above configuration, the blade body may include a front plate portion disposed on the positive pressure side and a rear plate portion disposed on the negative pressure side opposite to the positive pressure side. In this case, the front plate portion includes, as a part of the support tube portion, a front plate C-shaped tubular portion having a C-shaped cross section that partially covers the support shaft portion in the circumferential direction. The rear plate portion includes, as a part of the support tube portion, a rear plate C-shaped tubular portion that covers the entire circumference of the support shaft portion together with the front plate C-shaped tubular portion. The front plate C-shaped tubular portion and the rear plate C-shaped tubular portion include an overlapping portion where the two are overlapped. Furthermore, a fastening hole is drilled in the overlapping portion of the rear plate C-shaped tubular portion, and the overlapping portion of the front plate C-shaped tubular portion covers the overlapping portion of the rear plate C-shaped tubular portion including the fastening hole.

[0015] According to the above-mentioned configuration, the fastening hole and the fastening shaft member can be covered by the overlapping portion of the front plate C-shaped tubular portion, which prevents the fastening shaft member from being exposed and prevents a deterioration in aerodynamic characteristics due to the exposure. Effect of the Invention

[0016] According to the wind turbine blade disclosed in this specification, in a split-type blade in which the connector and the blade body are separated, it becomes possible to hold the blade body to the connector against the centrifugal force acting on the blade body. [Brief description of the drawings]

[0017] [Figure 1] FIG. 1 is a perspective view illustrating an example of an overall view of a wind turbine blade according to an embodiment of the present invention. [Diagram 2]FIG. 2 is a perspective view illustrating a connector. [Diagram 3] FIG. 4 is a perspective view illustrating a rear plate portion of a blade body. [Figure 4] FIG. 2 is a perspective view illustrating a front plate portion of a blade main body. [Diagram 5] FIG. 1 is a perspective view illustrating an assembly process (1 / 5) of the wind turbine blade according to the present embodiment. [Figure 6] FIG. 11 is a perspective view illustrating an assembly process (2 / 5) of the wind turbine blade according to the embodiment. [Figure 7] FIG. 11 is a perspective view illustrating an assembly process (3 / 5) of the wind turbine blade according to the embodiment. [Figure 8] FIG. 11 is a perspective view illustrating an assembly process (4 / 5) of the wind turbine blade according to the embodiment. [Figure 9] FIG. 11 is a perspective view illustrating an assembly process (5 / 5) of the wind turbine blade according to the embodiment. [Figure 10] 10 is a diagram illustrating a cross section taken along line AA in FIG. 9. [Figure 11] FIG. 2 is a diagram illustrating a cross section taken along line AA of a wind turbine blade according to another example of the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] A wind turbine blade 10 according to this embodiment will be described with reference to Figures 1 to 11. In Figures 1 to 11, an orthogonal coordinate system with axes C1, C2, and C3 is shown. Axis C1 indicates the rotor central axis of the wind turbine. Axis C2 is a radial axis relative to the rotor central axis and indicates the support central axis of the connector 60 (see Figure 2). Axis C3 is an axis perpendicular to the rotor central axis C1 and the support central axis C2.

[0019] 1 to 11, each component of the wind turbine blade 10 according to this embodiment will be described based on its orientation and position when attached to the hub 100.

[0020] 1 illustrates a wind turbine blade 10 according to this embodiment and a hub 100 to which the wind turbine blade 10 is attached. The hub 100 is capable of attaching a plurality of wind turbine blades 10, and bases 102 for attaching the wind turbine blades 10 are provided at equal intervals around the rotor central axis C1.

[0021] The wind turbine blade 10 comprises a blade body 52 and a connector 60. Fig. 2 shows an example of a perspective view of the connector 60 alone. The connector 60 is a connecting member that is connected to the root portion of the blade body 52 (i.e., the portion on the rotor central axis C1 side) and the hub 100. The connector 60 is made of a metal material, such as iron with an anti-rust coating.

[0022] The connector 60 includes a flange 62 and a support shaft portion 64. With reference to Figures 1 and 2, the flange 62 serves as a fastening portion for the hub 100, and is seated on a seat 102 of the hub 100. The flange 62 is, for example, disk-shaped, and the dimensions are determined so that the diameter of the flange 62 fits into the seat 102 of the hub 100.

[0023] A plurality of fastening holes 63 are drilled through the flange 62 in the thickness direction. For example, a plurality of fastening holes 63 are provided at equal intervals in the circumferential direction on the disk surface of the flange 62. These fastening holes 63 are aligned with fastening holes (not shown) provided in the base 102 of the hub 100, and a fastening shaft member such as a bolt is screwed in, thereby fastening the connector 60 to the hub 100.

[0024] The support shaft portion 64 extends from the center of the flange 62 in the radial direction of the rotor central axis C1 (the direction of the support central axis C2). The support shaft portion 64 may be, for example, cylindrical or columnar. Fig. 2 illustrates the support shaft portion 64 having a cylindrical shape, which is lighter than the two shapes.

[0025] The support shaft portion 64 has a plurality of rings 67 on its outer circumferential surface 66. The rings 67 protrude from the outer circumferential surface 66 in the radial direction of the support shaft portion 64. The rings 67 are provided at intervals (e.g., at equal intervals) along the central axis C2 direction of the support shaft portion 64.

[0026] The ring 67 functions as a shim or spacer for controlling the amount of adhesive layer 69 (see FIG. 5) to be described later. As shown in FIG. 5 to be described later, an adhesive layer 69 is formed between the rings 67, 67. Furthermore, the support shaft portion 64 (see FIG. 2) of the connector 60 is surrounded by the support tube portion 50 of the blade body 52 (see FIG. 1). At this time, the ring 67 abuts against the inner surface of the support tube portion 50. This abutment prevents the adhesive from being pushed out, making it possible to hold an appropriate amount of adhesive between the support shaft portion 64 and the support tube portion 50.

[0027] Fastening holes 68 are drilled in the outer peripheral surface 66 of the support shaft portion 64. The fastening holes 68 are provided between the multiple rings 67. The fastening holes 68 are drilled in the radial direction of the support shaft portion 64. The diameter of the fastening holes 68 is determined so as to be, for example, equal to or greater than the diameter of a shaft portion 82 and less than the diameter of a head portion 84 of a rivet 80 (fastening shaft member) in Fig. 6 which will be described later.

[0028] When the wind turbine blade 10 is attached to the hub 100, the fastening hole 68 is provided on the pressure side, which is the front side along the rotor central axis C1. The pressure side refers to the side where the blade body 52 mainly receives wind. For example, the connector 60 is fastened to the hub 100 so that the hole axis of the fastening hole 68 is parallel to the rotor central axis C1.

[0029] As described later, a rivet 80, which is a fastening shaft member, is inserted into the fastening hole 68 and the fastening hole 46 (see FIG. 6) of the blade body 52. ​​As illustrated in FIG. 10 described later, when the positive pressure side of the blade body 52 is subjected to wind, the blade body 52 is urged rearward along the rotor central axis C1, as illustrated by urging force F1. At this time, a urging force F2 is applied to the root portion of the blade body 52 such that the support cylinder portion 50 is separated from the support shaft portion 64.

[0030] Here, since the fastening holes 46, 68 are drilled on the positive pressure side and the rivet 80 is inserted so as to intersect with the positive pressure surface, an axial force that resists the biasing force F2 is obtained from the rivet 80. This axial force prevents the support tube portion 50 from peeling off from the support shaft portion 64.

[0031] 2, a plurality of fastening holes 68 (and the fastening holes 46 of the blade body 52) are provided along the support central axis C2. For example, two fastening holes 68 (and the fastening holes 46) are provided.

[0032] Returning to FIG. 1, the blade body 52 comprises the wing portion 11, which is the main portion, and the support cylinder portion 50, which is the base portion on the rotor central axis C1 side. The shape of the wing portion 11 is determined based on the desired aerodynamic characteristics, etc. Details of this shape are known and therefore will be omitted. Furthermore, both end portions in the width direction (C3 axis direction) and the outer end portion in the radial direction (C2 axis direction) of the wing portion 11 are, for example, flat plate-shaped. The support cylinder portion 50 covers the support shaft portion 64 of the connector 60.

[0033] The blade body 52 includes a front plate portion 20 on the front side (in other words, the positive pressure side) along the rotor central axis C1 direction, and a rear plate portion 40 on the rear side (negative pressure side). The front plate portion 20 and the rear plate portion 40 are both made of, for example, FRP (fiber reinforced plastic).

[0034] 3 illustrates a perspective view of the rear plate portion 40 alone. In addition to the wing piece 41, which is the main part, the rear plate portion 40 includes a rear plate C-shaped tubular portion 42 and a rear plate flange 48. The rear plate C-shaped tubular portion 42 is a part of the support tubular portion 50, and partially covers the support shaft portion 64 of the connector 60 in the circumferential direction as shown in FIG. 6, which will be described later.

[0035] For example, the central angle (α1+α2) of the arc of the rear plate C-shaped tubular portion 42 is determined to exceed 270°. When the rear plate C-shaped tubular portion 42 is deployed in a clockwise direction taking the axis C3 in FIG. 3 as the reference (0°), an overlapping portion 44 is formed in the terminal angle range α2 of the rear plate C-shaped tubular portion 42. For example, the overlapping portion 44 is formed to be thinner than other portions of the rear plate C-shaped tubular portion 42. This reduced thickness L1 is configured to be equal to the plate thickness L2 of the front plate portion 20 (see FIG. 4), for example.

[0036] The overlapping portion 44 is overlapped with the overlapping portion 24 of the front plate portion 20. The overlapping portions 24, 44 are provided, for example, over the entire radial length of the blade body 52. ​​A fastening hole 46 is drilled in the overlapping portion 44 in the thickness direction thereof.

[0037] The fastening holes 46 are provided in the same number and at the same pitch as the fastening holes 68 of the connector 60. As described later, in the assembly process of the wind turbine blade 10, the fastening holes 68 of the connector 60 and the fastening holes 46 of the rear plate portion 40 are aligned with each other. As described above, the connector 60 is disposed on the hub 100 so that the fastening holes 68 face the pressure side, and therefore the fastening holes 46 of the rear plate portion 40, which are aligned with the fastening holes 68, also face the pressure side.

[0038] Fig. 3 illustrates an enlarged view of the fastening hole 46. The fastening hole 46 includes a large diameter portion 46A and a small diameter portion 46B which are coaxial with each other, in that order from the exposed surface side in Fig. 3. A seat portion 46C is provided at the transition portion between the large diameter portion 46A and the small diameter portion 46B.

[0039] The diameter of small diameter portion 46B is determined so as to be equal to or greater than the diameter of shaft portion 82 of rivet 80 (see FIG. 6), which is the fastening shaft member, and less than the diameter of head 84. On the other hand, the diameter of large diameter portion 46A is determined so as to exceed the diameter of head 84 of rivet 80. Also, the depth of large diameter portion 46A is determined so as to exceed the thickness (axial dimension) of head 84. In other words, when rivet 80 is inserted into fastening hole 46, head 84 of rivet 80 is received in large diameter portion 46A.

[0040] A rear plate flange 48 is provided on the end of the rear plate C-shaped cylindrical portion 42 opposite to the overlapping portion 44. The rear plate flange 48 extends, for example, parallel to the axis C3, in other words, perpendicular to the rotor central axis C1. For example, the rear plate flange 48 extends over the entire radial length of the rear plate portion 40.

[0041] 4 illustrates the front plate portion 20. The front plate portion 20 includes a front plate C-shaped tube portion 22 and a front plate flange 28 in addition to a wing piece 21 which is a main portion.

[0042] The front plate C-shaped cylinder portion 22 is a part of the support cylinder portion 50, and partially covers in the circumferential direction the support shaft portion 64 of the connector 60. The front plate C-shaped cylinder portion 22, together with the rear plate C-shaped cylinder portion 42, covers the entire circumference of the support shaft portion 64 of the connector 60.

[0043] For example, the central angle (α3+α4) of the arc of the front C-shaped tubular plate portion 22 is determined to exceed 90°. When the front C-shaped tubular plate portion 22 is deployed in a counterclockwise direction with the axis C3 in Fig. 4 taken as the reference (0°), an overlapping portion 24 is formed in the terminal angle range α4 of the front C-shaped tubular plate portion 22. The overlapping portion 24 covers the overlapping portion 44 of the rear C-shaped tubular plate portion 42, including the fastening hole 46.

[0044] A front plate flange 28 is provided on the end of the front plate C-shaped cylindrical portion 22 opposite to the overlapping portion 24. The front plate flange 28 extends, for example, parallel to the axis C3, in other words, perpendicular to the rotor central axis C1. For example, the front plate flange 28 extends over the entire radial length of the front plate portion 20.

[0045] <Wind turbine blade assembly process> 5 to 10 illustrate an assembly process for the wind turbine blade 10 according to this embodiment. Note that the following illustrates an assembly process in a state in which the axis of the fastening hole 68 of the connector 60 is positioned parallel to the rotor central axis C1.

[0046] 5, an adhesive layer 69 is applied to the outer circumferential surface 66 of the connector 60 in the region between the rings 67. For example, the thickness of the adhesive layer 69 is determined to be equal to the thickness of the rings 67.

[0047] 6, the support shaft portion 64 of the connector 60 is partially covered (held in) by the rear plate C-shaped tubular portion 42 of the rear plate portion 40. At this time, the fastening hole 46 of the rear plate C-shaped tubular portion 42 and the fastening hole 68 of the connector 60 are aligned with each other.

[0048] Further, a rivet 80, which is a fastening shaft member, is inserted into the fastening holes 46, 68. As illustrated in Fig. 7, a head 84 of the rivet 80 is received within the large diameter portion 46A of the fastening hole 46 of the rear plate portion 40 (see Fig. 3).

[0049] By crushing the tip of the shaft 82 of the rivet 80, the rear plate 40 and the support shaft 64 are mechanically bonded together as shown in Fig. 10. In addition, the adhesive layer 69 chemically bonds the rear plate 40 and the support shaft 64 together.

[0050] Here, even if the crimping force (fastening force) of the rivet 80 is strong, the ring 67 provided on the outer circumferential surface 66 of the support shaft portion 64 abuts against the inner circumferential surface of the rear plate portion 40, restricting further intrusion (inward in the radial direction) of the rear plate portion 40. As a result, the adhesive layer 69 is prevented from being pushed outward.

[0051] 8, an adhesive layer 49 is applied to the rear plate flange 48 and the overlapping portion 44. As described above, the rear plate flange 48 and the overlapping portion 44 extend over the entire radial length (longitudinal direction, C2 axis direction) of the rear plate portion 40, and therefore the adhesive layer 49 is applied over the entire radial length of the rear plate portion 40.

[0052] 8 and 9, the overlapping portion 44 of the rear plate portion 40 and the overlapping portion 24 of the front plate portion 20 are overlapped, and the rear plate flange 48 and the front plate flange 28 are overlapped.

[0053] 10 illustrates an AA cross-sectional view (C1-C2 cross-sectional view) of the completed blade body 52 illustrated in FIG. 9. As described above, the rear plate 40 and the support shaft 64 are mechanically bonded to each other by the rivet 80, which is a fastening shaft member. The rear plate 40 and the support shaft 64 are chemically bonded to each other by the adhesive layer 69. As the blade body 52 rotates, centrifugal force is applied to the blade body 52. ​​At this time, shear stress acts on the rivet 80, which is a fastening shaft member, and breakage and separation of the rear plate 40 from the connector 60 are suppressed.

[0054] Furthermore, since the front plate portion 20 is chemically bonded to the rear plate portion 40 over the entire radial length by the adhesive layer 49, peeling of the front plate portion 20 from the rear plate portion 40 is suppressed.

[0055] Furthermore, when the positive pressure side (right side of the drawing) of the blade body 52 receives wind, the wing portion 11 (see FIG. 1) of the blade body 52 is urged rearward in the direction of the rotor central axis C1, as indicated by urging force F1. At this time, a urging force F2 acts on the positive pressure side of the support cylinder portion 50, which is the base portion of the blade body 52, such that the support shaft portion 64 is peeled off. The axial force of the rivet 80, which is the fastening shaft member, acts against this urging force F2, suppressing the above-mentioned peeling.

[0056] In addition, because the heads 84 of the rivets 80 are covered by the front plate portion 20, the rivets 80 are prevented from being exposed to the pressure side. As a result, a decrease in the aerodynamic characteristics of the blade body 52 due to the rivets 80 is avoided.

[0057] <Another example of this embodiment> In the above-described embodiment, the rivet 80 is used as the fastening shaft member, but the wind turbine blade 10 according to this embodiment is not limited to this form. In short, the fastening shaft member may be any member that can prevent the rear plate portion 40 from moving (coming out) by shear stress when centrifugal force is applied to the rear plate portion 40 and can prevent the rear plate portion 40 from peeling off from the support shaft portion 64 by axial force.

[0058] 11, for example, a bolt 180 may be used as the fastening shaft member instead of the rivet 80. A nut 186 may be used together with the bolt 180. In this case, for example, the nut 186 may be a weld nut welded to the inner surface of the support shaft portion 64. The diameter of the large diameter portion 46A of the fastening hole 46 in the rear plate portion 40 exceeds the diameter of the head 184 of the bolt 180 and is set to a dimension that allows the insertion of a fastening tool. [Explanation of symbols]

[0059] 10 Wind turbine blade, 11 Wing portion, 20 Front plate portion, 22 Front plate C-shaped tube portion, 24 Overlapping portion of front plate portion, 28 Front plate flange, 40 Rear plate portion, 42 Rear plate C-shaped tube portion, 44 Overlapping portion of rear plate portion, 46 Fastening hole of rear plate portion, 46A Large diameter portion, 46B Small diameter portion, 46C Seat portion, 48 Rear plate flange, 49, 69 Adhesive layer, 50 Support tube portion, 52 Blade body, 60 Connector, 62 Flange, 64 Support shaft portion, 66 Outer circumferential surface of support shaft portion, 67 Ring, 68 Fastening hole of support shaft portion, 80 Rivet (fastening shaft member), 100 Hub.

Claims

1. A blade body; a connector connected to the root portion of the blade body and to a hub; A wind turbine blade comprising: the connector includes a support shaft portion extending in a radial direction of a central axis of the wind turbine rotor and having an adhesive layer applied to an outer peripheral surface thereof; The blade body includes a support cylinder portion that covers the support shaft portion, The support shaft portion and the support cylinder portion are provided with fastening holes drilled in the radial direction so as to be aligned with each other, A fastening shaft member is inserted into the fastening hole of the support shaft portion and the support cylinder portion, the fastening holes of the support shaft portion and the support cylinder portion are provided on a positive pressure side, which is a front side in the rotor central axis direction, The blade body includes a front plate portion disposed on the pressure side and a rear plate portion disposed on a negative pressure side opposite to the pressure side, The front plate portion includes, as a part of the support cylinder portion, a front plate C-shaped cylinder portion having a C-shaped cross section that partially covers the support shaft portion in a circumferential direction, the rear plate portion includes, as a part of the support cylinder portion, a rear plate C-shaped cylinder portion which covers an entire circumference of the support shaft portion together with the front plate C-shaped cylinder portion, The front plate C-shaped tubular portion and the rear plate C-shaped tubular portion have an overlapping portion where the two portions overlap with each other, The fastening hole is drilled in the overlapping portion of the rear plate C-shaped cylindrical portion, and the overlapping portion of the front plate C-shaped cylindrical portion covers the overlapping portion of the rear plate C-shaped cylindrical portion including the fastening hole. Windmill blades.

2. A wind turbine blade according to claim 1, A plurality of rings are provided on the outer circumferential surface of the support shaft portion at intervals along the axial direction, the rings protruding in a radial direction of the support shaft portion, The adhesive layer is applied between the rings. Windmill blades.

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