Patent Description:
Wind power is considered one of the cleanest, most environmentally friendly energy sources presently available, and wind turbines have gained increased attention in this regard. A modem 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 capture kinetic energy of wind using known airfoil principles. The rotor blades transmit the kinetic energy in the form of rotational energy so as to turn a shaft coupling the rotor blades to a gearbox, or if a gearbox is not used, directly to the generator. The generator then converts the mechanical energy to electrical energy that may be deployed to a utility grid.

The rotor blades generally include a suction side shell and a pressure side shell typically formed using molding processes that are bonded together at bond lines along the leading and trailing edges of the blade. Further, the pressure and suction shells are relatively lightweight and have structural properties (e.g., stiffness, buckling resistance and strength) which are not configured to withstand the bending moments and other loads exerted on the rotor blade during operation. Thus, to increase the stiffness, buckling resistance and strength of the rotor blade, the body shell is typically reinforced using one or more structural components (e.g. opposing spar caps with a shear web configured therebetween) that engage the inner pressure and suction side surfaces of the shell halves. The spar caps and/or shear web may be constructed of various materials, including but not limited to glass fiber laminate composites and/or carbon fiber laminate composites.

As wind turbines continue to increase in size, the rotor blades also increase in size. Thus, larger rotor blades may be constructed in segments that can be assembled on site via one or more pin joints. Increasing the blade length requires additional blade support, because gravity pulls along the increased length to create a larger bending moment than in shorter rotor blades. As such, certain jointed rotor blades may include a first blade segment having a beam structure that is received within a receiving section of a second blade segment that is further secured together via one or more span-wise and/or chord-wise extending pins that transfer the blade bending moment from one segment to the other. Thus, the pin joints are configured to allow the blade tip to flex to withstand some of this load.

<CIT> describes a method of manufacturing a sectional blade and a sectional blade for a wind turbine blade comprising a leeward shell and a windward shell, and with the blade comprising at least a first blade section and a second blade section connected in a blade joint. In a portion of the blade the first and second blade sections overlap such that the leeward shell of the blade portion forms part of the first blade section and the windward shell of the blade portion forms part of the second blade section.

<CIT> describes a wind turbine blade including 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 extending lengthways that structurally connects with the second blade segment at a receiving section, wherein the beam structure forms a portion of an internal support structure and includes a shear web connected with a suction side spar cap and a pressure side spar cap.

Accordingly, the art is continually seeking improved jointed rotor blades for wind turbines that address the aforementioned issues. As such, the present disclosure is directed to an improved span-wise extending pin for joining rotor blade segments of a rotor blade of a wind turbine.

In one aspect, the present disclosure is directed 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. The first blade segment includes a beam structure having a receiving end. The second blade segment includes a receiving section that receives the beam structure of the first blade segment. Further, the receiving section includes a chord-wise member having a pin joint slot defined therethrough. The rotor blade also includes at least one span-wise extending pin extending from the receiving end of the beam structure and into the pin joint slot so as to secure the first and second blade segments together. The span-wise extending pin includes a distal portion having a length defined by a first end and an opposing, second end. The distal portion has a conical shape extending for at least a portion of the length thereof for providing ease of insertion of the span-wise extending pin into the pin joint slot. The pin also includes a pin portion adjacent to the distal portion. The pin portion has a first section and a second section. The second section is secured within the beam structure. The first section extends span-wise from the receiving end of the beam structure. Moreover, the pin includes a proximal portion having a rod member that extends span-wise through and secures together the pin portion and the distal portion.

In one embodiment, the distal portion may further include at least one through hole for providing improved torqueing capability. In addition, the conical shape may extend the length of the distal portion from the first end to the second end. Alternatively, the conical shape may extend from the first end to an intermediate location of the distal portion before the second end. In such embodiments, the distal portion may include an extended, uniform body section adjacent to the conical shape.

In another embodiment, the span-wise extending pin may include a radial flange positioned between the first and second sections of the pin portion so as to provide further radial retention of the span-wise extending pin within the beam structure. In such embodiments, the radial flange abuts against the receiving end of the beam structure.

In further embodiments, the first section of the pin portion may have a first diameter and the second section may have a larger, second diameter. According to the invention, the pin portion may include a protruding feature at a distal end thereof for receiving the distal portion thereon. Furthermore, according to the invention, the pin portion includes an internal tapered opening at a distal end or a proximal end thereof for receiving the rod member. In several embodiments, at least a portion of an internal wall of the first section and/or second section of the pin portion may be hollowed out.

In particular embodiments, the proximal portion may also include a flange member secured within the beam structure of the first blade segment adjacent to the second section of the pin portion via the rod member. In such embodiments, the rod member may be threaded and secured within the pin portion and the distal portion via one or more fasteners. In further embodiments, the flange member may be sized to fit through the pin joint slot. In addition, the flange member may include one or more cut-outs for providing improved torqueing capability of the rod member.

In certain embodiments, the rotor blade may further include a retention assembly for the span-wise extending pin within the pin joint slot. For example, the retention assembly may include a bearing assembly, a bushing assembly, a threaded connection, an adhesive, a press-fit, or any other suitable retention feature. In another example, for example, the bearing assembly may include a bearing and a bearing retention housing. In such embodiments, the span-wise extending pin may be received with the bearing assembly or the bushing.

In another aspect, the present disclosure is directed to a pin for joining first and second blade segments of a rotor blade of a wind turbine. The pin includes a distal portion having a length defined by a first end and an opposing, second end. The distal portion has a conical shape extending for at least a portion of the length thereof for providing ease of insertion of the pin into a pin joint slot of one of the first and second blade segments. The pin also includes a pin portion adjacent to the distal portion. The pin portion includes a first section and a second section. The second section is configured for securing within a beam structure of the first blade segment. The first section extends span-wise from a receiving end of the beam structure. The pin also includes a proximal portion having at least a rod member that extends span-wise through and secures together the pin portion and the distal portion. It should be understood that the pin may further include any of the additional features as described herein.

In yet another aspect, the present disclosure is directed to a method of joining first and second blade segments of a rotor blade of a wind turbine. The method includes providing the first blade segment having a beam structure that extends in a generally span-wise direction and includes a receiving end. The method also includes providing a first pin joint slot in the receiving end of the beam structure. Further, the method includes inserting a proximal portion of a pin through the first pin joint slot and into the beam structure. The proximal portion has a rod member secured to a flange member. Moreover, the method includes inserting a pin portion of the pin at least partially through the first pin joint slot until a first section of the pin portion extends from the receiving end and a second section of the pin portion is positioned in a wall of the beam structure. In addition, the method includes blindly feeding the rod member of the proximal portion through the pin portion from within the beam structure until the flange member abuts against the second section of the pin portion. Further, the method includes securing the rod member within the pin portion. The method also includes installing a distal portion to a distal surface of first section of the pin portion. The distal portion includes a length defined by a first end and an opposing, second end. The distal portion includes a conical shape for at least a portion of the length thereof. Moreover, the method includes providing the second blade segment having a receiving section that extends in the generally span-wise direction. The receiving section has a chord-wise member with a second pin joint slot defined therethrough. In addition, the method includes inserting the beam structure of the first blade segment into the receiving section of the second blade segment. As such, the second pin joint slot first receives the distal portion of the span-wise extending pin of the beam structure so as to allow blind assembly of the first and second blade segments together at a chord-wise joint. It should be understood that the method may further include any of the additional features and/or steps as described herein.

In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope of the invention as defined in the appended set of claims.

Referring now to the drawings, <FIG> illustrates a perspective view of one embodiment of a wind turbine <NUM> according to the present invention. In the illustrated embodiment, the wind turbine <NUM> is a horizontal-axis wind turbine. In addition, as shown, the wind turbine <NUM> may include a tower <NUM> that extends from a support surface <NUM>, a nacelle <NUM> mounted on the tower <NUM>, a generator <NUM> positioned within the nacelle <NUM>, a gearbox <NUM> coupled to the generator <NUM>, and a rotor <NUM> that is rotationally coupled to the gearbox <NUM> with a rotor shaft <NUM>. Further, as shown, the rotor <NUM> includes a rotatable hub <NUM> and at least one rotor blade <NUM> coupled to and extending outward from the rotatable hub <NUM>. As shown, the rotor blade <NUM> includes a blade tip <NUM> and a blade root <NUM>.

Referring now to <FIG>, a plan view of one of the rotor blades <NUM> of <FIG> is illustrated. As shown, the rotor blade <NUM> may include a first blade segment <NUM> and a second blade segment <NUM>. Further, as shown, the first blade segment <NUM> and the second blade segment <NUM> may each extend in opposite directions from a chord-wise joint <NUM>. In addition, as shown, each of the blade segments <NUM>, <NUM> may include at least one shell member defining an airfoil surface, such as a pressure side shell member and a suction side shell member. The first blade segment <NUM> and the second blade segment <NUM> are connected by at least an internal support structure <NUM> extending into both blade segments <NUM>, <NUM> to facilitate joining of the blade segments <NUM>, <NUM>. The arrow <NUM> shows that the segmented rotor blade <NUM> in the illustrated example includes two blade segments <NUM>, <NUM> and that these blade segments <NUM>, <NUM> are joined by inserting the internal support structure <NUM> into the second blade segment <NUM>. In addition, as shown, the second blade segment includes multiple spar structures <NUM> (also referred to herein as spar caps) that extend lengthwise for connecting with the beam structure <NUM> of the first blade segment <NUM> (which is shown in more detail in <FIG> and <FIG>).

Referring now to <FIG>, a perspective view of a section of the first blade segment <NUM> according to the present disclosure is illustrated. As shown, the first blade segment <NUM> includes a beam structure <NUM> that forms a portion of the internal support structure <NUM> and extends lengthwise for structurally connecting with the second blade segment <NUM>. Further, as shown, the beam structure <NUM> forms at least a part of a shear web <NUM> connected with a suction side spar cap <NUM> and a pressure side spar cap <NUM>. Moreover, as shown, the first blade segment <NUM> may include one or more first pin joints at a receiving end <NUM> of the beam structure <NUM>. In one embodiment, the pin joint may include a pin that is in a tight interference fit with a bushing. More specifically, as shown, the pin joint(s) may include at least one pin tube <NUM> located on the receiving end <NUM> of the beam structure <NUM>. Thus, as shown, the pin tube <NUM> may be oriented in a span-wise direction. Further, the first blade segment <NUM> may also include a pin joint slot <NUM> located on the beam structure <NUM>. Moreover, as shown, the pin joint slot <NUM> may be oriented in a chord-wise direction.

Referring now to <FIG>, a perspective view of a section of the second blade segment <NUM> according to the present disclosure is illustrated. As shown, the second blade segment <NUM> includes a receiving section <NUM> extending lengthwise within the second blade segment <NUM> for receiving the beam structure <NUM> of the first blade segment <NUM>. Further, as shown, the receiving section <NUM> may include the spar structures <NUM> that extend lengthwise for connecting with the beam structure <NUM> of the first blade segment <NUM>. In addition, as shown, the receiving section <NUM> may include a chord-wise member <NUM> having a span-wise pin joint slot <NUM> defined therethrough. Moreover, as shown, the receiving section <NUM> may include a chord-wise pin joint slot <NUM> defined therethrough that aligns with the pin joint slot <NUM> of the beam structure <NUM>.

Referring now to <FIG>, an assembly <NUM> of the rotor blade <NUM> having the first blade segment <NUM> joined with the second blade segment <NUM> according to the present disclosure is illustrated. As shown, the assembly <NUM> illustrates multiple supporting structures beneath outer shell members of the rotor blade <NUM> having the first blade segment <NUM> joined with the second blade segment <NUM>. More specifically, as shown, the span-wise extending pin <NUM> of the receiving end <NUM> of the beam structure <NUM> is received within the span-wise pin joint slot <NUM> of the receiving section <NUM> so as to secure the first and second blade segments <NUM>, <NUM> together.

Referring now to <FIG>, an exploded perspective view of the multiple supporting structures of the assembly <NUM> towards the receiving section <NUM> of the rotor blade <NUM> is illustrated. As shown, the spar structures <NUM> are configured to receive the beam structure <NUM> and may include the chord-wise pin joint slot <NUM> that align with the pin joint slot <NUM> of the beam structure <NUM> through which a chord-wise extending pin <NUM> may be inserted. Further, as shown, the chord-wise extending <NUM> may be configured to remain in a tight interference fit within the aligning pin joint slots <NUM>, <NUM> such that spar structures <NUM> and the beam structure <NUM> are joined together during assembly. Further, <FIG> also illustrates the chord-wise member <NUM> that includes the pin joint slot <NUM> configured for receiving the pin tube <NUM> (also referred to herein as the span-wise extending pin <NUM>) of the beam structure <NUM>. As such, the pin tube <NUM> is configured to form a tight interference fit pined joint.

Referring now to <FIG>, a detailed, cross-sectional view of the chord-wise joint <NUM> according to the present disclosure is illustrated. As shown, the span-wise extending pin <NUM> that extends from the beam structure <NUM> of the first blade segment is received within the receiving section <NUM> of the second blade segment <NUM> through the chord-wise member <NUM>. In addition, as shown in <FIG>, the chord-wise member <NUM> may include the span-wise pin joint slot <NUM>. More specifically, as shown, the chord-wise member <NUM> may include a bearing assembly <NUM> received within the pin joint slot <NUM>. It should be understood that the chord-wise member <NUM> may also include a bushing assembly and/or other compliant structure in addition to or in the alternative of the bearing assembly <NUM>. Further, as shown, the bearing assembly <NUM> may include a bearing <NUM> received within a bearing retention housing <NUM>. In embodiments with a bushing assembly, the bushing assembly may similarly include a bushing received within a bushing retention housing. As such, the span-wise extending pin <NUM> may be received within the bearing <NUM> of the bearing assembly <NUM>. In additional embodiments, the bearing <NUM> may include a spherical bearing. Alternatively, the span-wise extending pin <NUM> may be received within a bushing (not shown).

Referring to <FIG>, multiple views of various embodiments of the components of the span-wise extending pin <NUM> of the rotor blade <NUM> are illustrated. As shown generally, the span-wise extending pin <NUM> may include a distal portion <NUM>, a pin portion <NUM> adjacent to the distal portion <NUM>, and a proximal portion <NUM> adjacent to the pin portion <NUM>. Further as shown in <FIG> and <FIG>, the distal portion <NUM> has a length <NUM> defined by a first end <NUM> and an opposing, second end <NUM>. Moreover, as shown, the distal portion <NUM> has a conical shape extending for at least a portion of the length <NUM> thereof for providing ease of insertion of the span-wise extending pin <NUM> into the pin joint slot <NUM>. For example, the conical shape may provide a lead-in angle to assist with blind assembly misalignment of the pin into the slot <NUM>, which is described in more detail below. More specifically, as shown in <FIG>, the conical shape of the distal portion <NUM> may extend the entire length <NUM> thereof, i.e. from the first end <NUM> to the second end <NUM>. In alternative embodiments, the conical shape may extend from the first end <NUM> to an intermediate location <NUM> of the distal portion <NUM>, e.g. before the second end <NUM>. In such embodiments, the distal portion <NUM> may include an extended, uniform body section <NUM> adjacent to the conical shape. In such embodiments, the extended body <NUM> is configured to reduce the length of the tapered portion, while maintaining extension for staged assembly. In addition, as shown, the distal portion <NUM> may further include at least one through hole <NUM> for providing improved torqueing capability. Moreover, as shown, the distal portion <NUM> may also include a threaded bore <NUM> that can be used to secure the distal portion to the pin portion <NUM>, which is described in more detail below.

Referring to <FIG>, <FIG>, and <FIG>, various embodiments of the pin portion <NUM> are illustrated according to the present disclosure. As shown, the pin portion <NUM> has a first section <NUM> and a second section <NUM>. As shown particularly in <FIG>, the second section <NUM> of the pin portion <NUM> is secured within a wall of the beam structure <NUM>. Further, as shown, the first section <NUM> extends span-wise from the receiving end <NUM> of the beam structure <NUM>. In addition, as shown in <FIG>, the first section <NUM> of the pin portion <NUM> may have a first diameter D<NUM>, whereas the second section <NUM> may have a larger, second diameter D<NUM>.

In further embodiments, as shown particularly in <FIG>, the pin portion <NUM> may also include a radial flange <NUM> positioned between the first and second sections <NUM>, <NUM> so as to provide further radial retention of the span-wise extending pin <NUM> within the beam structure <NUM>. In such embodiments, as shown, the radial flange <NUM> is configured to abut against the receiving end <NUM> of the beam structure <NUM>. In certain embodiments, the radial flange <NUM> may be welded between the first and second sections <NUM>, <NUM> of the pin portion <NUM>, formed integrally with the first and second sections <NUM>, <NUM> of the pin portion <NUM>, or separately attached the radial flange between the first and second sections <NUM>, <NUM> of the pin portion <NUM>, e.g. as a c-clip or in sections.

In another embodiment, as shown in <FIG>, the pin portion <NUM> may include a protruding feature <NUM> or boss at a distal end thereof for receiving the distal portion <NUM> thereon. In additional embodiments, as shown in <FIG>, the pin portion <NUM> may include an internal tapered opening <NUM> at a distal end <NUM> or a proximal end <NUM> thereof, e.g. for receiving the rod member <NUM> described herein. More specifically, as shown in <FIG> and <FIG>, the internal tapered opening <NUM> is located at proximal end <NUM> of the pin portion <NUM>. Alternatively, as shown in <FIG>, the internal tapered opening <NUM> is located at the distal end <NUM> of the pin portion <NUM>. In addition, as shown in <FIG>, at least a portion of an internal wall <NUM> of the first section <NUM> and/or second section <NUM> of the pin portion <NUM> may be hollowed out.

In addition, as shown in <FIG>, the pin portion <NUM> may also include a transitional region <NUM> between the first and second sections <NUM>, <NUM>. More specifically, as shown the transitional region <NUM> may be tapered or filleted. In such embodiments, the bending moment is generally at a maximum at the interface of the flange <NUM> and the second section <NUM> and a minimum at the interface of the transitional region <NUM> and the first section <NUM>. Therefore, a smaller diameter spherical bearing may be used with the first section <NUM> than would otherwise be allowed with a two-section pin portion.

Referring to <FIG>, <FIG>, and <FIG>, various embodiments of the proximal portion <NUM> are illustrated according to the present disclosure. As shown particularly in <FIG>, the proximal portion <NUM> has a rod member <NUM> that extends span-wise through and secures together the pin portion <NUM> and the distal portion <NUM>. In such embodiments, as shown in <FIG> and <FIG>, the rod member <NUM> may be threaded and secured within the pin portion <NUM> and the distal portion <NUM> via one or more fasteners <NUM> (e.g. nuts). In addition, as shown in <FIG>, the threaded rod member <NUM> may include an anti-rotation tab <NUM> to allow tightening of the nuts <NUM> onto the pin <NUM>. In addition, as shown in <FIG>, <FIG>, and <FIG>, the proximal portion <NUM> may also include a flange member <NUM> secured to the rod member <NUM>, e.g. through a threaded bore <NUM>. As such, the rod member <NUM> may extending through the flange member <NUM>, which in turn, may be secured within the beam structure <NUM> of the first blade segment <NUM> adjacent to the second section <NUM> of the pin portion <NUM>.

In further embodiments, the flange member <NUM> may be sized to fit through the pin joint slot <NUM>. For example, as shown in <FIG>, the flange member <NUM> may have a cap shape with trimmed corners <NUM> to assist in assembling the flange member <NUM> through pin joint slot <NUM>. In addition, as shown, the flange member <NUM> may include one or more cut-outs <NUM> for providing improved torqueing capability of the rod member <NUM> during assembly. <FIG> illustrates a perspective view of yet another embodiment of the flange member <NUM> having trimmed corners <NUM> and a threaded bore <NUM> for receiving the rod member <NUM>. Still any other suitable shapes may be utilized for the flange member <NUM>.

Referring now to <FIG>, a process flow diagram of one embodiment of assembling the span-wise extending pin <NUM> into the receiving end <NUM> of the beam structure <NUM> of the first blade segment <NUM> is illustrated. As shown in <FIG>, the pin joint slot <NUM> is drilled into the receiving end <NUM> of the beam structure <NUM>. After drilling the pin joint slot, the proximal portion <NUM> of the span-wise extending pin <NUM> can be inserted into the pin joint slot <NUM>. As shown in <FIG>, the pin portion <NUM> of the span-wise extending pin <NUM> is inserted into the pin joint slot <NUM> such that the first section <NUM> of the pin portion <NUM> extends from the receiving end <NUM> of the beam structure <NUM> and the second section <NUM> of the pin portion <NUM> fits within the pin joint slot <NUM>, e.g. either through a press-fit, shrink fit, adhesion, or threaded connection. As shown in <FIG>, the rod member <NUM> of the proximal portion <NUM> is maneuvered towards the pin portion <NUM>. As shown in <FIG>, the rod member <NUM> of the proximal portion <NUM> is inserted through the pin portion <NUM> until the flange member <NUM> abuts against the second section <NUM> of the pin portion <NUM>. As shown in <FIG>, one or more fasteners <NUM> are secured around the rod member <NUM> of the proximal portion <NUM> so as to secure the rod member <NUM> through the pin portion <NUM>. As shown in <FIG>, the distal portion <NUM> is aligned with the first section <NUM> of the pin portion <NUM>. As shown in <FIG>, the distal portion <NUM> is secured to the first section <NUM> of the pin portion <NUM>.

Referring now to <FIG>, a flow chart <NUM> of a method of joining first and second blade segments of a rotor blade of a wind turbine according to the present disclosure is illustrated. In general, the method <NUM> will be described herein with reference to the wind turbine <NUM> and the rotor blade <NUM> shown in <FIG>. However, it should be appreciated that the disclosed method <NUM> may be implemented with rotor blades having any other suitable configurations. In addition, although <FIG> depicts steps performed in a particular order for purposes of illustration and discussion, the methods discussed herein are not limited to any particular order or arrangement. One skilled in the art, using the disclosures provided herein, will appreciate that various steps of the methods disclosed herein can be omitted, rearranged, combined, and/or adapted in various ways without deviating from the scope of the present disclosure.

As shown at (<NUM>), the method <NUM> may include providing the first blade segment <NUM> having the beam structure <NUM> that extends in a generally span-wise direction and includes a receiving end <NUM>. As shown at (<NUM>), the method <NUM> may include providing a first pin joint slot <NUM> in the receiving end <NUM> of the beam structure <NUM>. As shown at (<NUM>), the method <NUM> may include inserting the proximal portion <NUM> of the span-wise extending pin <NUM> through the first pin joint slot <NUM> and into the beam structure <NUM>. As shown at (<NUM>), the method <NUM> may include inserting the pin portion <NUM> of the pin <NUM> at least partially through the first pin joint slot <NUM> until the first section <NUM> of the pin portion <NUM> extends from the receiving end <NUM> of the beam structure <NUM> and the second section <NUM> of the pin portion <NUM> is positioned in a wall of the beam structure <NUM>. As shown at (<NUM>), the method <NUM> may include blindly feeding the rod member <NUM> of the proximal portion <NUM> through the pin portion <NUM> from within the beam structure <NUM> (i.e. without a visual) until the flange member <NUM> abuts against the second section <NUM> of the pin portion <NUM>. As shown at (<NUM>), the method <NUM> may include securing the rod member <NUM> within the pin portion <NUM>. As shown at (<NUM>), the method <NUM> may include installing the distal portion <NUM> to a distal surface of first section <NUM> of the pin portion <NUM>. As shown at (<NUM>), the method <NUM> may include providing the second blade segment <NUM> having the receiving section <NUM> that extends in the generally span-wise direction. As shown at (<NUM>), the method <NUM> may include inserting the beam structure <NUM> of the first blade segment <NUM> into the receiving section <NUM> of the second blade segment <NUM>. As such, the second pin joint slot <NUM> first receives the distal portion <NUM> of the span-wise extending pin <NUM> of the beam structure <NUM> so as to allow blind assembly of the first and second blade segments <NUM>, <NUM> together at the chord-wise joint <NUM>.

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.

Claim 1:
A rotor blade (<NUM>) for a wind turbine (<NUM>), comprising:
a first blade segment (<NUM>) and a second blade segment (<NUM>) extending in opposite directions from a chord-wise joint (<NUM>), each of the first and second blade segments (<NUM>, <NUM>) comprising at least one shell member defining an airfoil surface, the first blade segment (<NUM>) comprising a beam structure (<NUM>) having a receiving end (<NUM>), the second blade (<NUM>) segment comprising a receiving section (<NUM>) that receives the beam structure (<NUM>) of the first blade segment (<NUM>), the receiving section (<NUM>) comprising a chord-wise member (<NUM>) having a pin joint slot (<NUM>) defined therethrough; and,
at least one span-wise extending pin (<NUM>) extending from the receiving end (<NUM>) of the beam structure (<NUM>) and into the pin joint slot (<NUM>) so as to secure the first and second blade segments (<NUM>, <NUM>) together, the span-wise extending pin (<NUM>) comprising:
a distal portion (<NUM>) comprising a length (<NUM>) defined by a first end (<NUM>) and an opposing, second end (<NUM>), the distal portion (<NUM>) comprising a conical shape extending for at least a portion of the length (<NUM>) thereof for providing ease of insertion of the span-wise extending pin (<NUM>) into the pin joint slot (<NUM>);
a pin portion (<NUM>) adjacent to the distal portion (<NUM>), the pin portion (<NUM>) having a first section (<NUM>) and a second section (<NUM>), the second section (<NUM>) secured within the beam structure (<NUM>), the first section (<NUM>) extending span-wise from the receiving end (<NUM>) of the beam structure (<NUM>); and,
a proximal portion (<NUM>) comprising at least a rod member (<NUM>) that extends span-wise through and secures together the pin portion (<NUM>) and the distal portion (<NUM>),
characterized in that
the pin portion (<NUM>) further comprises a protruding feature (<NUM>) at a distal end (<NUM>) thereof for receiving the distal portion (<NUM>) thereon, and
wherein the pin portion (<NUM>) further comprises an internal tapered opening (<NUM>) at a distal end (<NUM>) or a proximal end (<NUM>) thereof for receiving the rod member (<NUM>).