Jointed wind turbine rotor blade with chord-wise extended pin bushing designed to minimize chord-wise clearance

Abstract

A rotor blade includes a first blade segment and a second blade segment extending in opposite directions from a chord-wise joint. The first blade segment includes a beam structure connected to the second blade segment via a receiving section. A chord-wise gap exists between an edge of the beam structure and an edge of the receiving section. The beam structure defines a first pin joint slot, and the receiving section defines a second pin joint slot aligned with the first pin joint slot. A first bushing and a second bushing are arranged in the first ends of the first pin joint slot and the second pin joint slot, each having a flange extending within the chord-wise gap. As such, the flanges abut each other within the chord-wise gap so as to fill the chord-wise gap with a predetermined defined gap or interference. In addition, a chord-wise extending pin is positioned to pass through the bushing so as to secure the first blade segment and the second blade segment together.

Description

Technical Field

[0001] The present disclosure relates generally to wind turbines, and more particularly to a jointed wind rotor blade having chord-wise extending pin bushings designed to eliminate chord-wise gaps between joined blade segments. Background Art

[0002] Wind power is considered one of the cleanest and most environmentally friendly energy sources currently available, and wind turbines have gained increasing attention in this regard. A modern wind turbine typically includes a tower, a generator, a gearbox, a nacelle, and a rotor having a rotatable hub with one or more rotor blades. The rotor blades use the known airfoil principle to capture the kinetic energy of the wind. The rotor blades transmit kinetic energy in the form of rotational energy to rotate a shaft that couples the rotor blades to a gearbox (or, if a gearbox is not used, directly to a generator). The generator then converts the mechanical energy into electrical energy that can be distributed to a utility grid.

[0003] A rotor blade generally includes a suction side shell and a pressure side shell, which are typically formed using a molding process, with the shells joined together at a join line along the leading and trailing edges of the blade. Furthermore, the pressure and suction shells are relatively lightweight and have structural properties (e.g., stiffness, bending resistance, and strength) that are not configured to withstand bending moments and other loads imposed on the rotor blade during operation. Therefore, to increase the stiffness, bending resistance, and strength of the rotor blade, the main shell is typically reinforced using one or more structural members (e.g., opposing spar caps with a shear web configured therebetween) that join the internal pressure and suction side surfaces of the shell halves. The spar caps and / or shear webs may be constructed from a variety of materials, including, but not limited to, fiberglass laminate composites and / or carbon fiber laminate composites.

[0004] As wind turbines continue to increase in size, rotor blades also increase in size. Consequently, larger rotor blades may be constructed in segments that can be assembled on-site via one or more pin joints. Increasing blade length requires additional blade support because gravity stretches along the increased length, creating a greater bending moment than in shorter rotor blades. Pin joints are configured to allow the blade tip to flex to absorb some of this load.

[0005] Such pin joints typically include a beam structure of a first blade segment that is received within a receiving section of a second blade segment, with chord-wise extending pins extending through first and second pin joint slots in the beam structure and receiving section, respectively, thereby joining the first and second segments together. Often, because the beam structure is typically narrower than the receiving section, a chord-wise gap exists at the leading and trailing edges of such pin joints between the beam structure and the receiving section. Minimizing this gap benefits pin joint performance. For example, minimizing the gap provides a continuous load path, structural efficiency, and minimized translation in the chord-wise direction, which also minimizes wear.

[0006] Accordingly, the present disclosure is directed to jointed wind rotor blades having chord-wise extending pin bushings designed to eliminate chord-wise gaps between joined blade segments. Summary of the Invention

[0007] Aspects and advantages of the invention will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the invention.

[0008] In one aspect, the present disclosure relates to a rotor blade for a wind turbine. The rotor blade includes a first blade segment and a second blade segment extending in opposite directions from a chord-wise joint. Each of the first and second blade segments includes at least one shell member defining an airfoil surface and an internal support structure. The first blade segment includes a longitudinally extending beam structure that is structurally connected to the second blade segment via a receiving section. The rotor blade also includes at least one chord-wise gap between an edge of the beam structure and an edge of the receiving section. The beam structure defines a first pin joint slot, and the receiving section defines a second pin joint slot aligned with the first pin joint slot. The rotor blade also includes a first bushing disposed in a first end of the first pin joint slot. The first bushing includes a flange that extends within the chord-wise gap and surrounds the first end of the first pin joint slot. The rotor blade also includes a second bushing disposed in a first end of the second pin joint slot. The second bushing also includes a flange that extends within the chord-wise gap and surrounds the first end of the second pin joint slot. Furthermore, the flanges of the bushings abut each other with a chordwise gap so as to fill the chordwise gap with a predetermined defined gap or interference. As such, the flanges are configured to partially fill the chordwise gap to define a precisely defined gap or interference, or may be designed to completely fill the chordwise gap. Furthermore, the rotor blade includes at least one chordwise extending pin positioned through the first and second bushings of the first and second pin joint slots to secure the first and second blade segments together.

[0009] In one embodiment, the rotor blade may further include a pair of first bushings disposed in a first end of the first pin joint slot and an opposite second opening of the first pin joint slot, respectively, and a pair of second bushings disposed in a first end of the second pin joint slot and an opposite second opening of the second pin joint slot, respectively. In such an embodiment, a chord-wise extending pin is positioned through the pair of first and second bushings of the first and second pin joint slots to secure the first and second blade segments together.

[0010] In another embodiment, the chord-wise gap is positioned adjacent to the trailing edge and / or the leading edge of the rotor blade.

[0011] In other embodiments, the chord-wise width of the abutment flange is greater than the chord-wise width of the chord-wise gap to create an interference fit. For example, in such embodiments, the chord-wise width of the abutment flange is approximately 1.5 millimeters (mm) greater than the chord-wise width of the chord-wise gap. In several embodiments, the first and second bushings may further include a coating material, for example, having a coefficient of friction less than about 0.2.

[0012] In additional embodiments, the first bushing and the second bushing are constructed of a metal or metal alloy. Thus, in such embodiments, the metal or metal alloy may include a material tolerance of approximately + / - 0.025 millimeters (mm) over a span of 1000 mm.

[0013] In another aspect, the present disclosure relates to a method for assembling a rotor blade. The method includes forming a first blade segment and a second blade segment via a molding process. Each of the first and second blade segments has at least one shell component defining an airfoil surface and an internal support structure. The first blade segment has a longitudinally extending beam structure, while the second blade segment has a receiving section. The method also includes determining the size of at least one chord-wise gap between an edge of the beam structure and an edge of the receiving section when the beam structure is received within the receiving section. Furthermore, the method includes providing a first pair of metal bushings in opposite ends of a first pin joint slot in the beam structure. Each of the first pair of metal bushings has a flange. Furthermore, the method includes providing a second pair of metal bushings in opposite ends of a second pin joint slot in the receiving section, each of the second pair of metal bushings having a flange. Furthermore, the method includes positioning one of the flanges from the first pair of metal bushings and one of the flanges from the second pair of metal bushings such that the flanges abut each other within the chord-wise gap, thereby filling the chord-wise gap with a predetermined defined gap or interference fit. The method also includes positioning the first and second blade segments in opposite directions from the chord-wise joint. Additionally, the method includes inserting the beam structure into the receiving section such that the first pin joint slot of the beam structure is aligned with the second pin joint slot of the receiving section. Additionally, the method includes inserting at least one chord-wise extending pin through the first and second pairs of bushings within the first and second pin joint slots to secure the first and second blade segments together.

[0014] In one embodiment, the method further includes determining a size of a chordwise gap between an edge of the beam structure and an edge of the receiving section when the beam structure is received in the receiving section after the molding process is completed, and then machining the plurality of flanges of the plurality of metal bushings to remove an interference therewith that is greater than the chordwise gap.

[0015] In another embodiment, providing a first pair of metal bushings in opposite ends of the first pin joint slot and providing a second pair of metal bushings in opposite ends of the second pin joint slot of the receiving section may also include pouring the first pair of metal bushings and the second pair of metal bushings in the first pin joint slot and the second pin joint slot, respectively, so that when the beam structure is inserted into the receiving section, the flanges of the first pair of metal bushings and the second pair of metal bushings completely fill the chord-wise gap.

[0016] In another aspect, the present disclosure relates to a rotor blade for a wind turbine. The rotor blade includes a first blade segment and a second blade segment extending in opposite directions from a chord-wise joint. Each of the first and second blade segments includes at least one shell member defining an airfoil surface and an internal support structure. The first blade segment includes a longitudinally extending beam structure that is structurally connected to the second blade segment via a receiving section. The rotor blade also includes at least one chord-wise gap between an edge of the beam structure and an edge of the receiving section. The beam structure defines a first pin joint slot, and the receiving section defines a second pin joint slot aligned with the first pin joint slot. The rotor blade also includes a first bushing disposed in a first end of the first pin joint slot. The first bushing includes a flange that extends within the chord-wise gap and surrounds the first end of the first pin joint slot. The rotor blade also includes a second bushing disposed in a first end of the second pin joint slot. The second bushing also includes a flange that extends within the chord-wise gap and surrounds the first end of the second pin joint slot. The rotor blade also includes at least one spacer member adjacent to one or more of the flanges of the bushing within the chord-wise gap. Additionally, the rotor blade includes at least one chord-wise extending pin positioned through the first and second bushings of the first and second pin joint slots to secure the first and second blade segments together.

[0017] In one embodiment, the chord-wise width of the adjacent flanges is less than the width of the chord-wise gap. In another embodiment, the spacing member may include one or more shims. In such an embodiment, the shims are configured to fill the remainder of the gap not filled by the adjacent flanges. In this manner, the shims and flanges completely fill the chord-wise gap.

[0018] In other embodiments, the spacing member may include one or more spring-loaded devices. In such embodiments, the spring-loaded devices may include conical coil springs, multi-layered wave coil springs, or a rubber viscoelastic ring. In one embodiment in which the spring-loaded devices correspond to the rubber viscoelastic ring, at least a portion of the rubber viscoelastic ring is positioned within a recessed portion of at least one of the flanges of the first and second bushings. Additionally, the spring rate of the rubber viscoelastic ring becomes nonlinear within a predetermined period of time, such that the rubber viscoelastic ring becomes rigid after the predetermined period of time.

[0019] In additional embodiments, the spacing member may be constructed from a metal or metal alloy. As such, the metal or metal alloy generally has a tight material tolerance of approximately + / - 0.025 millimeters (mm) per 1000 mm.

[0020] In certain embodiments, the spacing member may be positioned between the flanges of the first bushing and the second bushing. Alternatively, the spacing member may be arranged around the axis of one of the first bushing or the second bushing.

[0021] These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims.The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the present invention and, together with the description, serve to explain the principles of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] A complete and enabling disclosure of the invention, including the best mode thereof, to one of ordinary skill in the art is set forth in the specification with reference to the accompanying drawings, in which:

[0023] Figure 1 A perspective view illustrating one embodiment of a wind turbine according to the present disclosure;

[0024] Figure 2 shows a plan view of one embodiment of a rotor blade having a first blade segment and a second blade segment according to the present disclosure;

[0025] Figure 3 showing a perspective view of a section of one embodiment of a first blade segment according to the present disclosure;

[0026] Figure 4 showing a perspective view of one embodiment of a section of a second blade segment at a chordwise joint according to the present disclosure;

[0027] Figure 5 A joint assembly is shown of one embodiment of a rotor blade for a wind turbine having a first blade segment joined to a second blade segment in accordance with the present disclosure;

[0028] Figure 6 An exploded perspective view illustrating one embodiment of a joint assembly for a rotor blade of a wind turbine according to the present disclosure;

[0029] Figure 7 Show Figure 5 A cross-sectional view of the chord-wise joint along section line 7-7;

[0030] Figure 8 A cross-sectional view illustrating one embodiment of a chord-wise extending pin of a chord-wise joint of a rotor blade of a wind turbine according to the present disclosure, particularly illustrating a plurality of flanged bushings arranged at the leading and trailing edges of the pin;

[0031] Figure 9A a cross-sectional view of abutting flanges of a chord-wise joint of a rotor blade showing a shim arranged about the axis of one of the flanges in accordance with the present disclosure;

[0032] Figure 9B showing a cross-sectional view of abutting flanges of a chord-wise joint of rotor blades with a shim disposed therebetween according to the present disclosure;

[0033] Figure 10 showing a cross-sectional view of abutting flanges of a chord-wise joint of rotor blades with a conical disc spring disposed therebetween in accordance with the present disclosure;

[0034] Figure 11 showing a cross-sectional view of abutting flanges of a chord-wise joint of a rotor blade with multiple layers of wave coil springs disposed therebetween in accordance with the present disclosure;

[0035] Figure 12 a cross-sectional view showing abutting flanges of a chord-wise joint of rotor blades with a rubber viscoelastic ring disposed therebetween according to the present disclosure; and

[0036] Figure 13 A flow chart illustrating one embodiment of a method for assembling a rotor blade according to the present disclosure is shown. DETAILED DESCRIPTION

[0037] Reference will now be made in detail to embodiments of the present invention, one or more examples of which are illustrated in the drawings. Each example is provided as an explanation of the present invention and is not a limitation of the present invention. In fact, it will be apparent to those skilled in the art that various modifications and variations may be made in the present invention without departing from the scope or spirit of the present invention. For example, a feature shown or described as part of an embodiment may be used with another embodiment to produce yet further embodiments. Therefore, it is intended that the present invention encompass such modifications and variations as fall within the scope of the appended claims and their equivalents.

[0038] Now refer to the figure, Figure 1 A perspective view of one embodiment of a wind turbine 10 according to the present invention is shown. In the illustrated embodiment, wind turbine 10 is a wind turbine with a horizontal axis. Alternatively, wind turbine 10 may be a wind turbine with a vertical axis. Furthermore, as shown, wind turbine 10 may include a tower 12 extending from a support surface 14, a nacelle 16 mounted on tower 12, a generator 18 positioned within nacelle 16, a gearbox 20 coupled to generator 18, and a rotor 22 rotationally coupled to gearbox 20 by a rotor shaft 24. Furthermore, as shown, rotor 22 includes a rotatable hub 26 and at least one rotor blade 28 coupled to and extending outwardly from rotatable hub 26. As shown, rotor blade 28 includes a blade tip 17 and a blade root 19.

[0039] Now refer to Figure 2 , showing Figure 1FIG2 is a plan view of one of the rotor blades 28 of FIG2. As shown, the rotor blade 28 may include a first blade segment 30 and a second blade segment 32. Furthermore, as shown, the first blade segment 30 and the second blade segment 32 may each extend in opposite directions from a chord-wise joint 34. Additionally, as shown, each of the blade segments 30, 32 may include at least one shell member, such as a pressure side shell member, a suction side shell member, a leading edge shell member, a trailing edge shell member, etc. Furthermore, as shown, the first blade segment 30 and the second blade segment 32 are connected by at least one internal support structure 36 that extends into the two blade segments 30, 32 to facilitate joining the blade segments 30, 32. Arrow 38 indicates that, in the example shown, the segmented rotor blade 28 includes two blade segments 30, 32, and the blade segments 30, 32 are joined by inserting the internal support structure 36 into the second blade segment 32.

[0040] Now refer to Figure 3 , shows a perspective view of a section of a first blade segment 30 according to the present disclosure. As shown, the first blade segment 30 includes a beam structure 40 that forms part of the internal support structure 36 and extends longitudinally for structural connection with the second blade segment 32. Furthermore, as shown, the beam structure 40 forms at least a portion of a shear web 42 that is connected to a suction side spar cap 44 and a pressure side spar cap 46.

[0041] Furthermore, as shown, the first blade segment 30 can include one or more pin joints 52 at a receiving end 54 of the beam structure 40. In one embodiment, for example, the pin joints 52 can include pins that form a tight interference fit with bushings. More specifically, as shown, the pins 52 can be oriented in a spanwise direction, i.e., along the span or length of the rotor blade 28, which is defined along an axis extending from the blade root 19 to the blade tip 17 of the rotor blade 28. Furthermore, the first blade segment 30 can also include at least one first pin joint slot 50 positioned on the beam structure 40. Furthermore, as shown, the first pin joint slot 50 can be oriented in a chordwise direction, i.e., along the chord of the rotor blade 28, which is defined along an axis extending from the leading edge to the trailing edge of the rotor blade 28.

[0042] Now refer to Figure 4 , shows a perspective view of a section of a second blade segment 32 according to the present disclosure. As shown, the second blade segment 32 includes a receiving section 60 that extends longitudinally within the second blade segment 32 for receiving the beam structure 40 of the first blade segment 30. Furthermore, as shown, the receiving section 60 may include one or more spar structures 66 (similar to the spar caps 44, 46) that extend longitudinally for connection to the beam structure 40 of the first blade segment 30. Additionally, as shown Figure 5, the receiving section 60 may include a chord-wise member 48 having a span-wise pin joint slot 56 defined therethrough for receiving the pin joint 52. Also, as shown, the receiving section 60 may include a chord-wise second pin joint slot 58 defined therethrough that aligns with the first pin joint slot 50 of the beam structure 40.

[0043] Now refer to Figure 5 , an assembly 70 of a rotor blade 28 having a first blade segment 30 coupled to a second blade segment 32 according to the present disclosure is shown. As shown, the assembly 70 illustrates a plurality of support structures beneath the outer shell component of the rotor blade 28. More particularly, as shown, the span-wise extending pins 52 of the receiving end 54 of the beam structure 40 are received within the span-wise pin joint slots 56 of the receiving section 60 to secure the first and second blade segments 30, 32 together. Additionally, as shown, the first and second pin joint slots 50, 58 are aligned, and the chord-wise extending pins 62 are secured therethrough to secure the first and second blade segments 30, 32 together.

[0044] Now refer to Figure 6 , shows an exploded perspective view of the multiple support structures of the assembly 70 toward the blade tip of the rotor blade 28. As shown, the receiving section 60 is configured to receive the beam structure 40 and may include a chord-wise second pin joint slot 58 that aligns with the first pin joint slot 50 of the beam structure 40 through which the chord-wise extending pin 62 may be inserted. Furthermore, as shown, the chord-wise extending pin 62 may be configured to be retained in a tight interference fit within the aligned pin joint slots 50, 58 such that the receiving section 60 and the beam structure 40 are joined together during assembly. Furthermore, Figure 6 Also shown is the chord-wise member 48 , which includes a radial pin joint slot 56 configured to receive the pin 52 of the beam structure 40 .

[0045] Now refer to Figure 7 , showing Figure 5FIG2 is a cross-sectional view of a rotor blade assembly 70 taken along line 7-7. More particularly, as shown, the beam structure 40 is received within the receiving section 60. Furthermore, as shown, a leading edge chord-wise gap 51 and a trailing edge chord-wise gap 53 exist between the edges of the beam structure 40 and the receiving section 60. Additionally, as shown, a chord-wise extending pin 62 is positioned through the chord-wise joint 34 to secure the internal support structures 40, 60 of the first and second blade segments 30, 32 together. Furthermore, as shown, the first and second pin joint slots 50, 58 of the beam structure 40 and the receiving section 60, respectively, may include a plurality of pairs of bushings 55, 56, 57, 58 for receiving the chord-wise extending pins 62 therethrough. For example, as shown, the beam structure 40 and the receiving section 60 may each include a leading edge bushing 56, 55 and a trailing edge bushing 57, 58, respectively, disposed within opposite ends of the first and second pin joint slots 50, 58. In certain embodiments, the various bushings 55 , 56 , 57 , 58 described herein may also include a coating material having, for example, a coefficient of friction of less than about 0.2.

[0046] Still refer to Figure 7 The chord-extending pin 62 may optionally include one or more structural inserts 88, 90 disposed therein. For example, as shown, the chord-extending pin 62 may include a first structural insert 88 disposed at its trailing end and a second structural insert 90 disposed at its leading end. Furthermore, as shown, the structural inserts 88, 90 may be aligned with the bushings 55, 56, 57, 58. In certain embodiments, the structural inserts 88, 90 may be steel inserts pressed into the pin 62 to provide additional reinforcement in high-load areas.

[0047] In addition, if Figure 7 and Figure 8, each of the bushings 55, 56, 57, 58 may include flanges 61, 63, 65, 67, respectively, two of which are on the leading edge side of the rotor blade 28 and two of which are on the trailing edge side of the rotor blade 28. More specifically, as shown, the first bushing 55 may include a flange 61 that extends within the chord-wise gap 51 and surrounds the first end of the first pin joint slot 50. Similarly, the second bushing 56 may include a flange 65 that extends within the chord-wise gap 51 and surrounds the first end of the second pin joint slot 58. Furthermore, as shown, the flanges 61, 65 of the first and second bushings 55, 56 abut each other within the chord-wise gap 51 so as to fill the chord-wise gap 51 with a predetermined defined gap or interference. Similarly, on opposite sides of the first and second pin joint slots 50, 58, the rotor blade 28 may include opposing bushings 57, 58 with flanges 63, 67 within another chord-wise gap 63 between the beam structure 40 and the receiving section 60. Thus, as shown, a chord-wise extending pin 62 is positioned through the bushings 55, 56, 57, 58 of the first and second pin joint slots 50, 58 to secure the first and second blade segments 30, 32 together.

[0048] In such embodiments, the chord-wise width of the abutting flanges (i.e., flanges 61 and 63 or flanges 63 and 67) is greater than the chord-wise width of the chord-wise gaps 51 and 53 to create an interference fit. For example, in certain embodiments, the chord-wise width of the abutting flanges may be approximately 1.5 millimeters (mm) greater than the chord-wise width of the chord-wise gaps 51 and 53. For example, in certain embodiments, the bushings 55, 56, 57, and 58 may be constructed of a metal or metal alloy. In such embodiments, the metal or metal alloy may include a material tolerance of approximately + / - 0.025 millimeters (mm) over a span of 1000 mm. Therefore, as will be discussed herein, the flanges 61, 63, 65, and 67 may be machined to eliminate some of the interference to ensure a precise fit within the chord-wise gaps 51 and 53.

[0049] Now refer to Figure 9A and Figure 9B , the chord-wise joint 34 of the rotor blade 28 may include at least one spacing member 72 adjacent to one or more of the flanges 61, 63, 65, 67 of the bushings 55, 56, 57, 58 within the chord-wise gaps 51, 53, rather than two of the flanges completely filling the chord-wise gaps 51, 53. In such embodiments, the chord-wise width of the adjacent flanges (e.g., flanges 61 and 65) is less than the width of the chord-wise gap 51. Thus, the spacing member 72 is configured to fill the remaining space within the gap 51. For example, as Figure 9A and Figure 9BAs shown in FIG, the spacing member 72 may include one or more spacers 74. In such embodiments, the spacing member 72 may be constructed of a metal or metal alloy. As such, the metal or metal alloy generally has a tight material tolerance of approximately + / - 0.025 millimeters (mm) per 1000 mm. Additionally, as shown in FIG. Figure 9A As particularly shown in FIG, the spacing member 72 may be arranged about the axis of one or more of the bushings (e.g., axis 78 of bushing 55). Figure 9B As shown in FIG, a spacing member 72 can be disposed between the flanges 61, 65 of the adjacent bushings 55, 56. In such an embodiment, the shim 74 is configured to fill the remainder of the gap not filled by the adjacent flanges. As such, the shim 74 and the flanges 61, 63 completely fill the chord-wise gap 51 (or gap 53).

[0050] Now refer to Figure 10-12 , the spacing member 72 may alternatively be one or more spring loaded devices 76. More particularly, as Figure 10 As shown in FIG, the spring loading device 76 may include a conical coil spring 80. Alternatively, as shown in FIG. Figure 11 As shown in FIG, the spring loading device 76 may include a multi-layer wave coil spring 82. In yet another embodiment, as shown in FIG. Figure 12 As shown in FIG, the spring-loading device 76 may include a rubber viscoelastic ring 84. In such an embodiment, as shown, at least a portion of the rubber viscoelastic ring 84 may be located within a recess 86 of at least one of the flanges 61, 65 of the first and second bushings 55, 56. As such, a portion of the rubber is not enclosed, thereby interacting with the opposing bushing surface. The rubber viscoelastic ring 84 may be particularly well-suited for short compression cycles because its spring constant will eventually become nonlinear and the captured portion of the rubber will become exponentially stiffer.

[0051] Now refer to Figure 13 , a flow chart 100 is shown for a method of assembling a rotor blade according to the present disclosure. In general, reference will be made herein to Figure 1-12 The method 100 is described with reference to the wind turbine 10 and rotor blade 28 shown in FIG. However, it should be understood that the disclosed method 100 may be implemented with rotor blades having any other suitable configuration. Figure 13 While steps are depicted as being performed in a particular order for purposes of illustration and discussion, the methods discussed herein are not limited to any particular order or arrangement. Using the disclosure provided herein, one skilled in the art will appreciate that the various steps of the methods disclosed herein may be omitted, rearranged, combined, and / or adjusted in various ways without departing from the scope of the present disclosure.

[0052] As shown at (102), method 100 may include forming a first blade segment 30 and a second blade segment 32 via a molding process. As mentioned, the first blade segment includes a longitudinally extending beam structure 40, and the second blade segment 32 includes a receiving section 60 that receives the beam structure 40. As shown at (104), method 100 may include determining the size of at least one chord-wise gap between an edge of the beam structure 40 and an edge of the receiving section 60 when the beam structure 40 is received within the receiving section 60. As shown at (106), method 100 may include providing a first pair of metal bushings 55, 57 in opposite ends of a first pin joint slot 50 of the beam structure 40. As mentioned, each of the first pair of metal bushings 55, 57 has a flange 61, 63. As shown at (108), method 100 may include providing a second pair of metal bushings 56, 59 in opposite ends of a second pin joint slot 58 of the receiving section 60. As mentioned, each of the second pair of metal bushings 56, 59 also includes a flange 65, 67. Thus, as shown at (110), method 100 includes positioning one of the flanges 61, 63 from the first pair of metal bushings 55, 57 with one of the flanges 65, 67 from the second pair of metal bushings 56, 59 so that the flanges abut one another within the chord-wise gap (i.e., gaps 51, 53) so as to fill the chord-wise gap with a predetermined defined gap or interference. As shown at (112), method 100 may include placing the first and second blade segments 30, 32 in opposite directions from the chord-wise joint 34. As shown at (114), method 100 may include inserting the beam structure 40 into the receiving section 60 such that the first pin joint slot 50 of the beam structure 40 is aligned with the second pin joint slot 58 of the receiving section 60. As shown at (116), the method 100 may include inserting at least one chord-wise extending pin 62 through the first and second pairs of bushings 55, 56, 57, 59 within the first and second pin joint slots 50, 58 to secure the first and second blade segments 30, 32 together.

[0053] In one embodiment, the size of the chord-wise gaps 61, 63 may be determined after the molding process is complete. In such an embodiment, the method 100 may include machining the plurality of flanges 61, 63, 65, 67 of the plurality of metal bushings 55, 56, 57, 59 to remove the interference thereof that is greater than the chord-wise gaps 51, 53.

[0054] In another embodiment, providing the first and second pairs of metal bushings 55, 57, 56, 58 in opposite ends of the first and second pin joint slots 50, respectively, may further include potting the first and second pairs of metal bushings 55, 57, 56, 58 in the first and second pin joint slots 50, 58, respectively, such that the flanges 61, 63, 65, 67 of the first and second pairs of metal bushings 55, 57, 56, 58 completely fill the chord-wise gap when the beam structure 40 is inserted into the receiving section 60. In such an embodiment, the gaps 51, 53 may be completely avoided by including the bushings in their seats during the potting process. More particularly, higher precision features in the composite mold are configured to register seats for the bushings by any combination of: features in the continuous mold itself, features created by mold inserts (e.g., foam mandrels in a closed mold or block, and / or chord pin inserts), features established by co-infused components, bushings infused with composite, tooling to precisely place the bushings, and / or tooling to establish critical dimensions (e.g., with respect to between bushing flange interface planes).

[0055] The skilled person will recognize the interchangeability of various features from different embodiments. Similarly, the various method steps and features described and other known equivalents for each such method and feature can be mixed and matched by those of ordinary skill in the art to form additional systems and techniques according to the principles of this disclosure. Of course, it will be understood that not all of these goals or advantages described above can be achieved according to any particular embodiment. Therefore, for example, it will be appreciated by those skilled in the art that the systems and techniques described herein can be embodied or performed in a manner that realizes or optimizes an advantage or group of advantages as taught herein, without necessarily realizing other goals or advantages as taught or suggested herein.

[0056] While only certain features of the invention have been illustrated and described herein, many modifications and changes will occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention.

[0057] This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.

Claims

1. A rotor blade for a wind turbine, comprising: a first blade segment and a second blade segment, the first blade segment and the second blade segment extending in opposite directions from a chord-wise joint, each of the first blade segment and the second blade segment comprising at least one shell member defining an airfoil surface and an internal support structure, the first blade segment comprising a longitudinally extending beam structure, the beam structure being structurally connected to the second blade segment via a receiving section, wherein at least one chord-wise gap exists between an edge of the beam structure and an edge of the receiving section, the beam structure defining a first pin joint slot, the receiving section defining a second pin joint slot aligned with the first pin joint slot; a first bushing disposed in a first end of the first pin joint slot, the first bushing including a flange extending within the chordwise gap and surrounding the first end of the first pin joint slot; a second bushing disposed in the first end of the second pin joint slot, the second bushing including a flange extending within the chordwise gap and surrounding the first end of the second pin joint slot; as well as at least one chord-wise extending pin positioned through the first and second bushings of the first and second pin joint slots to secure the first and second blade segments together, wherein the rotor blade includes at least one spacing member adjacent one or more of the flanges of the first and second bushings within the chord-wise gap, the at least one spacing member comprising one or more shims or one or more spring loaded devices.

2. The rotor blade according to claim 1, wherein: The rotor blade also includes a pair of first bushings disposed in a first end of the first pin joint slot and an opposite second opening of the first pin joint slot, respectively, and a pair of second bushings disposed in a first end of the second pin joint slot and an opposite second opening of the second pin joint slot, respectively.

3. The rotor blade according to claim 2, characterized in that The chord-wise extending pin is positioned through the pair of first and second bushings of the first and second pin joint slots to secure the first and second blade segments together.

4. The rotor blade according to claim 1, wherein: The chord-wise gap is positioned adjacent to a trailing edge and / or a leading edge of the rotor blade.

5. The rotor blade according to claim 1, wherein: At least one of the first bushing and the second bushing includes a coating material comprising a coefficient of friction less than 0.

2.

6. The rotor blade according to claim 1, wherein: The first bushing and the second bushing are made of metal or a metal alloy.

7. The rotor blade according to claim 6, characterized in that The metal or metal alloy includes a material tolerance of + / - 0.025 millimeters (mm) over a span of 1000 mm.

8. The rotor blade according to claim 1, wherein: The chordwise width of the abutting flange is less than the width of the chordwise gap such that the one or more shims and the flange completely fill the chordwise gap.

9. The rotor blade according to claim 8, characterized in that The one or more spring loading devices include conical coil springs, multi-layer wave coil springs or rubber viscoelastic rings.

10. The rotor blade according to claim 9, characterized in that When the one or more spring loaded devices correspond to the rubber viscoelastic ring, at least a portion of the rubber viscoelastic ring is located within a recess of at least one of the flanges of the first bushing and the second bushing.

11. The rotor blade according to claim 1, wherein: The at least one spacing member is constructed from a metal or metal alloy including a material tolerance of + / - 0.025 millimeters (mm).

12. The rotor blade according to claim 1, wherein: The at least one spacing member is positioned between flanges of the first bushing and the second bushing, or is disposed about an axis of one of the first bushing or the second bushing.

13. A method for assembling a rotor blade, the method comprising: forming a first blade segment and a second blade segment via a molding process, each of the first blade segment and the second blade segment having at least one shell member defining an airfoil surface and an internal support structure, the first blade segment having a longitudinally extending beam structure, the second blade segment having a receiving section; determining a size of at least one chord-wise gap between an edge of the beam structure and an edge of the receiving section when the beam structure is received within the receiving section; providing a first pair of metal bushings in opposite ends of a first pin joint slot of the beam structure, each of the first pair of metal bushings including a flange; providing a second pair of metal bushings in opposite ends of the second pin joint slot of the receiving section, each of the second pair of metal bushings including a flange; disposing at least one spacing member adjacent one or more of the flanges of the first and second pairs of metallic bushings within the chordwise gap, the at least one spacing member comprising one or more shims or one or more spring-loaded devices; placing the first blade segment and the second blade segment in opposite directions from the chordwise joint; inserting the beam structure into the receiving section such that the first pin joint slot of the beam structure is aligned with the second pin joint slot of the receiving section; as well as At least one chordally extending pin is inserted through the first and second pairs of bushings within the first and second pin joint slots to secure the first and second blade segments together.

14. The method according to claim 13, characterized in that The method further comprises: determining a size of at least one chord-wise gap between an edge of the beam structure and an edge of the receiving section when the beam structure is received within the receiving section after the molding process is completed; and The flanges of the metal bushings are machined to remove an interference greater than the chordwise clearance.

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