US20110243736A1

US20110243736A1 - Joint sleeve for a rotor blade assembly of a wind turbine

Info

Publication number: US20110243736A1
Application number: US12/963,159
Authority: US
Inventors: Eric Lee Bell
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 2010-12-08
Filing date: 2010-12-08
Publication date: 2011-10-06
Also published as: CN102536634A; DK201170668A; DE102011056176A1

Abstract

A joint sleeve for assembling together a first blade section and a second blade section of a rotor blade assembly is disclosed. The joint sleeve may include an outer surface and an inner surface defining a cavity. The cavity may be configured to receive a joint end of the first blade section and a joint end of the second blade section. The joint sleeve may also include a plurality of openings defined between the outer and inner surfaces. The openings may be configured to receive fasteners for securing the joint ends of the first and second blade sections within the cavity. Additionally, a profile of the outer surface may be configured to generally correspond to an aerodynamic profile of the first and second blade sections such that a substantially continuous aerodynamic profile is defined between the first and second blade sections when the joint ends are inserted within the cavity.

Description

FIELD OF THE INVENTION

The present subject matter relates generally to rotor blades of a wind turbine and, more particularly, to a joint sleeve for joining blade sections of a rotor blade assembly.

BACKGROUND OF THE INVENTION

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 modern wind turbine typically includes a tower, generator, gearbox, nacelle, and one or more rotor blades. The rotor blades capture kinetic energy from wind using known foil principles and transmit the kinetic energy through rotational energy 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.
To ensure that wind power remains a viable energy source, efforts have been made to improve the overall performance of wind turbines by modifying the size, shape and configuration of wind turbine rotor blades. One such modification has been to alter the configuration of the tip of the rotor blade. In particular, blade tips may be specifically designed to enhance or improve various aspects of a rotor blade's performance. For example, certain blade tips may be designed to operate efficiently in specific wind classes. Additionally, blade tips may be configured to enhance specific operating conditions of the wind turbine, such as by being configured to lower torque or reduce noise.
Thus, given that different operating advantages may be provided to a wind turbine depending on the configuration of the blade tip, it would be advantageous to have an attachment device that allowed for the quick and efficient assembly and disassembly of blade tips on and from a rotor blade. However, known attachment devices are typically complex and are manually intensive to install. Additionally, such attachment devices make it difficult to accurately align the blade tip with the remainder of the rotor blade.
Accordingly, there is a need for a simple and efficient attachment device for joining two blade sections of a rotor blade assembly.

BRIEF DESCRIPTION OF THE INVENTION

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.
In one aspect, the present subject matter discloses a rotor blade assembly for a wind turbine. The rotor blade assembly generally includes a first blade section having a joint end and defining an aerodynamic profile and a second blade section having a joint end and defining an aerodynamic profile. The rotor blade assembly also includes a joint sleeve having an inner surface and an outer surface. The inner surface may generally define a cavity configured to receive the joint ends of the first and second blade sections. Additionally, the rotor blade assembly may include a plurality of fasteners configured to secure the joint ends of the first and second blade sections within the cavity. Further, a profile of the outer surface of the joint sleeve may generally correspond to the aerodynamic profiles of the first and second blade sections such that a substantially continuous aerodynamic profile is defined between the first and second blade sections when the joint ends are inserted within the cavity.
In another aspect, the present subject matter discloses a joint sleeve for assembling together a first blade section and a second blade section of a rotor blade assembly. The joint sleeve may include an outer surface and an inner surface defining a cavity. The cavity may have a root end configured to receive a joint end of the first blade section and a tip end configured to receive a joint end of the second blade section. The joint sleeve may also include a plurality of openings defined between the outer and inner surfaces. The openings may be configured to receive a plurality of fasteners for securing the joint ends of the first and second blade sections within the cavity. Additionally, a profile of the outer surface may be configured to generally correspond to an aerodynamic profile of the first and second blade sections such that a substantially continuous aerodynamic profile is defined between the first and second blade sections when the joint ends are inserted within the cavity.
In a further aspect, the present subject matter discloses a tip assembly for a rotor blade of a wind turbine. The tip assembly may generally include a joint sleeve having an inner surface defining a cavity and an outer surface defining an aerodynamic profile. The joint sleeve may also include a tip end and a root end. The tip assembly may also include a tip section extending between a joint end disposed within the cavity and a blade tip. The tip section may define an aerodynamic profile generally corresponding to the aerodynamic profile of the joint sleeve at the tip end. Additionally, tip assembly may include a plurality of fasteners configured to secure the joint end of the tip section within the cavity. Further, a portion of the cavity disposed at the root end of the joint sleeve may be configured to receive an end of a separate section of the rotor blade.
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 invention and, together with the description, serve to explain the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures, in which:

FIG. 1 illustrates a perspective view of a wind turbine of conventional construction;

FIG. 2 illustrates a perspective view of one embodiment of a rotor blade assembly in accordance with aspects of the present subject matter;

FIG. 3 illustrates a partial, perspective view of the rotor blade assembly shown in FIG. 2;

FIG. 4 illustrates a perspective view of one embodiment of a joint sleeve suitable for use with the disclosed rotor blade assembly in accordance with aspects of the present subject matter;

FIG. 5 illustrates a partial, cross-sectional view of one embodiment of the attachment of several components of the disclosed rotor blade assembly in accordance with aspects of the present subject matter;

FIG. 6 illustrates a partial, cross-sectional view of another embodiment of the attachment of several components of the disclosed rotor blade assembly in accordance with aspects of the present subject matter; and,

FIG. 7 illustrates a perspective view of an embodiment of a tip assembly in accordance with aspects of the present subject matter.

DETAILED DESCRIPTION OF THE INVENTION

Reference now will be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. 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 or spirit of the invention. For instance, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents.
In general, the present subject matter is directed to a joint sleeve for joining together blades sections of a rotor blade assembly. In particular, the joint sleeve may define a cavity configured to receive an end of each blade section. For example, the cavity may generally have a shape corresponding to the shape of the ends of the blade sections, such as by having a tapered, aerodynamic profile corresponding to the tapered, aerodynamic profiles of the blade section ends. Suitable fasteners may then be inserted around the periphery of the joint sleeve to secure the ends of the blade sections within the cavity.
The disclosed joint sleeve may generally provide for the quick and efficient assembly and disassembly of a rotor blade. As such, a blade section may be easily removed from and re-assembled onto the rotor blade for purposes of maintenance, repairs and/or for upgrading the performance of the rotor blade. For example, it may be preferable to vary the tip section of the rotor blade depending on the wind turbine operating conditions and/or the desired performance of the rotor blade assembly. Thus, by using the disclosed joint sleeve, tip sections having differing dimensions, configurations and/or aerodynamic features may be efficiently assembled onto the rotor blade and/or replaced as desired. For example, a straight tip section (e.g., a tip section extending in a substantially spanwise direction) may be replaced with a winglet-type tip section or vice versa. Similarly, a winglet having a particular configuration may be replaced with a winglet having a different configuration.
Referring now to the drawings, FIG. 1 illustrates perspective view of a wind turbine 10 of conventional construction. The wind turbine 10 includes a tower 12 with a nacelle 14 mounted thereon. A plurality of rotor blades 16 are mounted to a rotor hub 18, which is, in turn, connected to a main flange that turns a main rotor shaft. The wind turbine power generation and control components are housed within the nacelle 14. It should be appreciated that the wind turbine 10 of FIG. 1 is provided for illustrative purposes only to place the present subject matter in an exemplary field of use. Thus, one of ordinary skill in the art should readily appreciate that the scope of the present subject matter is not limited to any particular type of wind turbine configuration.
Referring now to FIGS. 2-4, embodiments of a rotor blade assembly 100 and a joint sleeve 102 for joining together first and second blade sections 104, 106 of the rotor blade assembly 100 are illustrated in accordance with aspects of the present subject matter. In particular, FIG. 2 illustrates a perspective view of one embodiment of the rotor blade assembly 100. FIG. 3 illustrates a partial, perspective view of the rotor blade assembly 100 illustrated in FIG. 2, particularly illustrating the joint sleeve 102 disposed between the blade sections 104, 106 of the rotor blade assembly 100. Additionally, FIG. 4 illustrates a perspective view of one embodiment of the joint sleeve 102.
As shown, the rotor blade assembly 100 includes a first blade section 104, a second blade section 106 and a joint sleeve 102 configured to join the blade sections 104, 106 together. In general, the rotor blade assembly 100 may be configured such that, when the first and second blade sections 104, 106 are attached within the joint sleeve 102, a complete rotor blade, defining a substantially aerodynamic profile, is formed. Thus, the complete rotor blade assembly 100 may generally include a blade root 108 (defined by the first blade section 104) configured to be mounted to the hub 18 (FIG. 1) of a wind turbine 10 and blade tip 110 (defined by the second blade section 106) disposed opposite the blade root 108. The rotor blade assembly 100 may also include a span 112 defining the total length between the blade root 108 and the blade tip 110 and a chord 114 defining the total length between the leading edge 116 and the trailing edge 118. As is generally understood, the chord 114 may vary in length with respect to the span 112 as the rotor blade extends from the blade root 108 to the blade tip 110.
In general, the first and second blade sections 104, 106 of the rotor blade assembly 100 may be configured similarly to any suitable blade section and/or blade segment known in the art. For example, each blade section 104, 106 may include a body shell 120 serving as the outer casing/covering of the blade section 104, 106 and one or more structural components (not shown) for providing stiffness and/or strength to the blade section 104, 106 (e.g., a shear web/spar cap assembly). Additionally, each blade section 104, 106 may generally define an aerodynamic profile. For instance, the body shells 120 of each blade section 104, 106 may be configured to define an airfoil shaped cross-section, such as a symmetrical or cambered airfoil shaped cross-section. Thus, as shown in FIG. 3, each body shell 120 may generally define a pressure side 122, and a suction side 124 extending between a leading edge 126 and trailing edge 128.
It should be appreciated that the body shells 120 may generally be formed from any suitable material. For instance, in one embodiment, each body shell 120 may be formed entirely from a laminate composite material, such as a carbon fiber-reinforced composite or a glass fiber-reinforced composite. Alternatively, one or more portions of each body shell 120 may be configured as a layered construction and may include a core material, formed from a lightweight material such as wood (e.g., balsa), foam (extruded polystyrene foam) or a combination of such materials, disposed between layers of laminate composite material.
Additionally, the first and second blade sections 104, 106 may each include a joint end 130, 131 terminating within the joint sleeve 102. Thus, in the illustrated embodiment, the first blade section 104 may generally extend from the blade root 108 of the rotor blade assembly 100 to its joint end 130 within the joint sleeve 102. Similarly, the second blade section 102 may generally extend from its joint end 131 within joint sleeve 102 to the blade tip 110 of the rotor blade assembly 100. Further, as will be described in greater detail below with reference to FIGS. 5 and 6, the joint ends 130, 131 of the blade sections 104, 106 may define a particular profile in order to facilitate insertion of the joint ends 130, 131 within the joint sleeve 102. For instance, in several embodiments, the joint ends 130, 131 of each blade section 104, 106 may define a tapered or stepped profile corresponding to a tapered or stepped profile defined in the joint sleeve 102.
Moreover, as shown in FIGS. 2 and 3, the first blade section 104 may generally extend lengthwise along a substantial portion of the span 112 of the rotor blade assembly 100 such that the joint sleeve 102 is disposed at an outboard position on the rotor blade generally proximate to the blade tip 110. As such, the second blade section 106 may generally be configured as an outboard or tip section of the rotor blade assembly 100. Thus, in the illustrated embodiment, the second blade section 106 may be configured similarly to the outboard portion of a conventional rotor blade 16 (FIG. 1), such as by extending in a substantially spanwise direction between the joint end 131 of the blade section 106 and the blade tip 110. Alternatively, as will described below with reference to FIG. 7, the second blade section 106 may be configured as a winglet-type tip section or may otherwise have any other suitable tip configuration know in the art.
It should be appreciated that, in embodiments in which the second blade section 106 is configured as an outboard or tip section of the rotor blade assembly 100, the second blade section 106 may generally define a relatively short length 132. For example, in several embodiments, the second blade section 106 may define a length 132 which is less than 10 meters (m) long, such as less than 5 m long or less than 3 m long and all other subranges therebetween. However, in alternative embodiments, the second blade section 106 need not be configured as a tip section of the rotor blade assembly 100 and, thus, may generally define any suitable length 132, such as a length greater than or equal to 10 m. In such embodiments, it should be appreciated that the joint sleeve 102 may generally be disposed at any suitable location along the span 112 of the rotor blade assembly 100, such as by being located at a more inboard position closer to the blade root 108.
Still referring to FIGS. 2-4, the joint sleeve 102 of the disclosed rotor blade assembly 100 may generally be configured as an attachment device for joining the first and second blade sections 104, 106. Thus, it should be appreciated that the joint sleeve 102 may generally have any suitable configuration that permits the joint ends 130, 131 of the blade sections 104, 106 to be received within the joint sleeve 102. For example, in several embodiment, the joint sleeve 102 may have a hollow or a substantially hollow configuration for receiving the joint ends 130, 131 of the blade sections 104, 106. In particular, as shown in FIG. 4, the joint sleeve 102 may generally include an inner perimeter or inner surface 134 defining a cavity 136 extending between a root end 138 and a tip end 140 of the joint sleeve 102. As such, the joint end 130 of the first blade section 104 may be configured to be received within the portion of the cavity 136 defined at the root end 138 of the joint sleeve 102 and the joint end 131 of the second blade section 106 may be configured to be received within the portion of the cavity 136 defined at the tip end 140 of the joint sleeve 102.
It should be appreciated that the joint ends 130, 131 of the blade sections 104, 106 may generally be attached within the cavity 136 of the joint sleeve 102 using any suitable means. For example, in one embodiment, the joint ends 130, 131 may be bonded within the joint sleeve 102 using any suitable adhesive. In another embodiment, a plurality of fasteners 142 may be utilized to secure the joint ends 130, 131 within the joint sleeve 102. For example, as shown in FIGS. 3 and 4, the joint sleeve 102 may define a plurality of openings 144 extending between its inner and outer surfaces 134, 146, with each opening 144 being configured to receive a fastener 142. Specifically, a plurality of openings 144 may be defined proximate to the root end 138 of the joint sleeve 102 to permit a like number of fasteners 142 to be inserted through the openings 144 and attached to the joint end 130 of the first blade section 104. Similarly, a plurality of openings 144 may be defined proximate the tip end 140 of the joint sleeve 102 to permit a like number of fasteners 142 to be inserted through the openings 144 and attached to the joint end 131 of the second blade section 106. It should be readily appreciated that the openings 144 may be defined in the joint sleeve 102 so as to form any suitable bolt hole pattern. For example, in one embodiment, the openings 144 may form a single row along the root and tips ends 138, 140 of the joint sleeve 102. In another embodiments, multiple rows (e.g., two or more rows) of openings 144, being aligned or offset from one another, may be defined in the root and tip ends 138, 140 of the joint sleeve 102.
It should also be appreciated that the fasteners 142 described herein may generally comprise any suitable fasteners known in the art. For example, in several embodiments, the fasteners 142 may be configured as threaded fasteners, such as threaded bolts, screws and other suitable threaded fastening devices. In other embodiments, the fasteners may comprise other suitable fastening and/or attachment devices, such as pins, clips, brackets, rods, rivets, bonded fasteners and the like.
The disclosed joint sleeve 102 may also define a substantially aerodynamic profile. For example, as shown in FIG. 4, the joint sleeve 102 may define an airfoil-shaped cross-section. Thus, similar to the first and second blade sections 104, 106, the outer surface 146 of the joint sleeve 102 may generally define a pressure side 148 and a suction side 150 extending between a leading edge 152 and a trailing edge 152. Additionally, in several embodiments of the present subject matter, the aerodynamic profile defined by the joint sleeve 102 may generally correspond to or otherwise match the aerodynamic profiles of the first and second blade sections 104, 106. In particular, the aerodynamic profile of the joint sleeve 102 at the root end 138 may generally correspond to the aerodynamic profile of the first blade section 102 in an area adjacent to its joint end 130. Similarly, the aerodynamic profile of the joint sleeve 102 at the tip end 140 may generally correspond to the aerodynamic profile of the second blade section 106 in an area adjacent to its joint end 131. As such, when the blade sections 104, 106 are assembled together within joint sleeve 102, the rotor blade assembly 100 may generally define a substantially continuous aerodynamic profile along its entire span 112. For instance, as shown in FIG. 3, the joint sleeve 102 may be configured such that a substantially flush, aerodynamic surface is defined at the interface of the first blade section 104 and the root end 138 of the joint sleeve 102 and at the interface of the second blade section 106 and the tip end 140 of the joint sleeve 102. Thus, the rotor blade assembly 100 may generally define a continuous aerodynamic surface between the first and second blade sections 104, 106.
It should be appreciated that, in several embodiments, an additional surface feature may be applied to or positioned over the seams formed at the interfaces of the blade sections 104, 106 and the ends 138, 140 of the joint sleeve 102 to ensure that a substantially smooth aerodynamic surface is achieved. For example, in a particular embodiment, several plies of a laminate composite material may be applied around the outer perimeter of the rotor blade assembly 100 at the joint seams, such as by using a wet lay-up process, to provide a substantially flush aerodynamic surface between the blade sections 104, 106 and the joint sleeve 102.
It should also be appreciated that the joint sleeve 102 may generally be formed from any suitable material. For example, in one embodiment, the joint sleeve 102 may be formed from a metal, such as aluminum, steel and the like. In other embodiments, the joint sleeve 102 may be formed from a laminate composite material, such as various fiber-reinforced composites, or any other suitable non-metallic material.
Referring now to FIGS. 5 and 6, there is illustrated partial, cross-sectional views of two embodiments of the disclosed rotor blade assembly 100, particularly illustrating the attachment of the first and second blade sections 104, 106 within the joint sleeve 102. As indicated above, the joint ends 130, 131 of the blade sections 104, 106 may generally be configured to be attached within the cavity 136 defined by the joint sleeve 102 such that a substantially continuous aerodynamic profile is defined along the span 112 (FIG. 2) of the rotor blade assembly 100 and, particularly, at the interfaces between the root and tip ends 138, 140 of the joint sleeve 102 and the blade shells 120 of the blade sections 104, 106. Thus, in several embodiments, a cross-sectional height 156 of each blade section 104, 106 may generally be reduced at the joint ends 130, 131 to permit the joint ends 130, 131 to be inserted within the joint sleeve 102 and to ensure that a substantially continuous or flush surface is defined between the blade sections 104, 106 and the joint sleeve 102.
For example, as shown in FIG. 5, in one embodiment, at least a portion of the joint ends 130, 131 of the blade sections 104, 106 may define a tapered profile, such as by configuring the blade shells 120 to have a tapered thickness 158, in order to permit the joint ends 130, 131 to be positioned with the joint sleeve 102. Additionally, the joint sleeve 102 may define a corresponding tapered profile so that the outer surface 146 of the joint sleeve 102 is positioned substantially flush with the outer surfaces 160 of the blade shells 120. Thus, as shown, the joint sleeve 102 may generally define tapered widths 162 at its root and tip ends 138, 140 corresponding to the tapered thicknesses 158 of the blade shells 120. It should be appreciated that, although the tapered widths 162 of the joint sleeve 102 are shown as defining a substantially sharp or knife edge at the root and tip ends 138, 140, the tapered widths 162 need not define such sharp or knife edges. For example, in one embodiment, the tapered profile of the joint sleeve 102 may be configured to extend only partially along the tapered profiles of the blade sections 104, 106 such that relatively thin, blunt edges may be defined at the root and tip ends 138, 140 of the joint sleeve 102. In such an embodiment, an additional surface feature, such as the laminate plies described above, may be applied at the root and tip ends 138, 140 to ensure that a substantially continuous aerodynamic surface is defined between the blade sections 104, 106 and the joint sleeve 102.
Alternatively, as shown in FIG. 6, the joint ends 130, 131 of the blade sections 104, 106 may define a stepped profile, such as by configuring the blade shells 120 to have a stepped reduction in thickness 164 at the root and tip ends 138, 140 of the joint sleeve 102. In such an embodiment, the joint sleeve 102 may generally define a width 166 substantially equal to the reduction in thickness defined in the blade shells 120 so that the outer surface 146 of the joint sleeve 102 is positioned substantially flush with the outer surfaces 160 of the blade shells 120. In further embodiments, it should be appreciated that the joint sleeve 102 and/or the joint ends 130, 131 of the blade sections 104, 106 may generally have any other suitable configuration that permits the joint ends 130, 131 to be inserted within the joint sleeve 102.
In general, the tapered or stepped profiles defined at the joint ends 130, 131 of the blade sections 104, 106 may be formed using any suitable means. For example, in one embodiment, the tapered or stepped profiles may be a molded feature of the blade shells 120, such as by creating a mold having a tapered/stepped profile defined therein or by placing a mold insert defining the tapered/stepped profile within the mold as the blade shells 120 are being formed. In another embodiment, the tapered or stepped profile may be machined into the blade shells 120 after the shells 120 have been formed, such as by using any suitable machining process and/or any suitable machining equipment. Additionally, it should be appreciated that the corresponding profile of the joint sleeve 102 may generally be formed using any suitable means. For example, in one embodiment, the joint sleeve 102 may be molded or otherwise formed to include the corresponding profile. In another embodiment, the corresponding profile may be machined into the joint sleeve 102 using any suitable machining process and/or any suitable machining equipment.
In a further embodiment of the present subject matter, one of the tapered or stepped profiles of the blade shells 120 or the corresponding profile of the joint sleeve 102 may be initially formed and/or machined and then scanned to permit the exact geometry of such profile(s) to be known. For example, in one embodiment, a metrology or other 3-D scan may be performed on the tapered profiles of the joint ends 130, 131 of each blade section 104, 106. In such an embodiment, the tapered width 162 of the joint sleeve 102 may then be formed and/or machined based on the scan to ensure that the tapered width 162 corresponds the tapered profiles of the blade sections 104, 106.
Referring still to FIGS. 5 and 6, in several embodiments, the openings 144 defined in the joint sleeve 102 may include recessed features 170 for recessing the fasteners 142 between the inner and outer surfaces 134, 146 of the joint sleeve 102. In particular, the openings 144 may be configured such that the fasteners 142 are recessed partially or fully within the joint sleeve 102. For example, as shown in FIGS. 5 and 6, the recessed openings 144 may be configured such that the top surface 168 of each fastener 142 is positioned substantially flush with the outer surface 146 of the joint sleeve 102. As such, the joint sleeve 102 may generally define a substantially continuous aerodynamic profile between its root and tip ends 138, 140.
It should be appreciated that the size, shape and/or configuration of the recessed features 170 of the openings 144 may generally vary depending on the size, shape and/or configuration of the fasteners 142 being used to attach the joint ends 130, 131 of the blade sections 104, 106 within the joint sleeve 102. For example, as shown in FIG. 5, the fasteners 142 may generally comprise threaded fasteners having a fastener head 172 defining a tapered diameter. In such an embodiment, the openings 144 formed in the joint sleeve 102 may generally define a corresponding tapered diameter such that the fastener head 172 may be fully recessed within the joint sleeve 102. In another embodiment, shown in FIG. 6, the openings 144 may be configured as counterbored holes having a shape and/or configuration corresponding to the shape and/or configuration of the fastener head 172.
Referring still to FIGS. 5 and 6, to ensure proper attachment of the blade sections 104, 106 within the joint sleeve 102, the disclosed rotor blade assembly 100 may also include features for retaining the disclosed fasteners 142 within the joint ends 130, 131 of the blade sections 104, 106. For example, in embodiments in which the fasteners 142 are configured as a threaded fasteners (e.g., threaded bolts), the rotor blade assembly 100 may include a plurality of female threaded members 174 configured to receive the threaded fasteners 142 such that a clamped interface is provided between the inner surface 134 of the joint sleeve 102 and the joint ends 130, 131 of the blade sections 104, 106. Thus, as shown in FIGS. 5 and 6, a plurality of female threaded members 174 may be configured to be aligned with the openings 144 defined in the joint sleeve 102 such that the fasteners 142 may be inserted through the openings 144 and screwed into the threaded members 174. For instance, in the embodiment shown in FIG. 5, the threaded members 174 may comprise a plurality threaded channels or plugs 176 configured to be mounted or otherwise disposed within the joint ends 130, 131 of the blade sections 104, 106. In another embodiment, the threaded members 174 may comprise a plurality of nuts 178 mounted directly or indirectly to an inner surface 182 of the blade shells 120. For example, as shown in FIG. 6, the nuts 178 may be mounted onto a ganged channel or nut plate 180 extending around the inner perimeter of each blade shell 120. It should be appreciated that the nuts 178 may generally comprise any suitable nut known in the art, including conventional, threaded nuts and floating nuts. Additionally, in alternative embodiments, it should be appreciated that the threaded members 174 may have any other suitable configuration that permits the fasteners 142 to be securely attached to the joint ends 130, 131 of the first and second blade sections 104, 106.
In several embodiments of the present subject matter, the disclosed rotor blade assembly 100 may also include a divider 184 configured to separate the joint end 130 of the first blade section 104 from the joint end 131 of the second blade section 106 within the joint sleeve 102. The divider 131 may also serve as a stop for locating or positioning the joint ends 130, 131 of the blade sections 104, 106 within the joint sleeve 102. For example, in one embodiment, the divider 184 may be positioned within the joint sleeve 102 such that, when the joint ends 130, 131 of the blade sections 104, 106 are inserted fully within the joint sleeve 102 and contact the divider 184, the threaded members 174 disposed within or mounted to the blade shells 120 may generally be aligned with the openings 144 defined in the joint sleeve 102.
It should be appreciated that the divider 184 may generally have any suitable configuration that permits the divider 184 to function as described herein. For instance, as shown in FIGS. 5 and 6, the divider 184 may be configured as a relatively thin member extending around the inner perimeter of the joint sleeve 102 substantially perpendicularly to the inner surface 134. Additionally, as shown in FIG. 5, in one embodiment, the divider 184 may extend inwardly from the inner surface 134 only partially into the cavity 136 defined by the joint sleeve 102. Alternatively, as shown in FIG. 6, the divider 184 may be configured to extend from the inner surface 134 throughout the entire cavity 136 so as to divide the cavity 136 into two separate cavities.
Referring now to FIG. 7, there is illustrated a perspective view of a tip assembly 200 in accordance with aspects of the present subject matter. In general, the tip assembly 200 may include a joint sleeve 202 and a tip section 206. The joint sleeve 202 may generally be configured similarly to the joint sleeve 102 described above with reference to FIGS. 2-6. Thus, the joint sleeve 202 may define a cavity 136 (FIG. 4) extending between a tip end 240 and a root end 238 of the joint sleeve 202. The portion of the cavity 136 defined at the tip end 240 may generally be configured to receive a joint end 231 of the tip section 206. For example, the joint sleeve 202 and the joint end 231 of the tip section 206 may define corresponding tapered profiles such that the joint end 231 may be inserted into the joint sleeve 202 and attached therein using a plurality of fasteners 242. Additionally, the joint sleeve 202 may define an aerodynamic profile generally corresponding to the aerodynamic profile of the tip section 206. As such, when the tip section 206 is inserted within the joint sleeve 202, the tip assembly 200 may generally define a substantially continuous aerodynamic profile between the joint sleeve 202 and the tip section 206.
In general, the tip section 206 may extend from the joint end 231 to a blade tip 210 and may have any suitable tip configuration known in the art. For example, in one embodiment, the tip section 206 may be configured as a straight tip section, such as by being configured similar to the second blade section 106 described above with reference to FIGS. 2 and 3 and extending in a substantially spanwise direction between the joint end 231 and the blade tip 210. In another embodiment, shown in FIG. 7, the tip section 206 may be configured as a winglet-type tip section. As such, a winglet 290 may generally be defined between the joint end 231 and the blade tip 210. It should be appreciated that the winglet 290 may have any suitable configuration known in the art. For example, the winglet 290 may be configured as a suction side winglet or as a pressure side winglet. Additionally, the winglet 290 may define any suitable sweep angle, cant angle, toe angle and/or twist angle, all of which are commonly known terms in the aerodynamic art. Further, the winglet 290 may define any suitable radius of curvature and may have any suitable aspect ratio (i.e., ratio of the span of the winglet 290 to the planform area of the winglet 290).
It should be appreciated that the disclosed tip assembly 200 may generally be configured as a replaceable tip for a rotor blade. Thus, the tip assembly 200 may be configured to be attached to any suitable inboard blade segment or section of a rotor blade. For example, the portion of the cavity 136 (FIG. 4) defined at the root end 238 of the joint sleeve 202 may be configured to receive an end (not shown) of an inboard blade section (not shown), such as by being configured to receive the joint end 130 of the first blade section 104 described above with references to FIGS. 2-6. Thus, in one embodiment, the end of the inboard blade section may be formed, machined or otherwise shaped so as to define a tapered profile corresponding to a tapered profile defined in the cavity 136 at the root end 238 such that the blade section may be inserted into the joint sleeve 202. Similar to the embodiments described above, the blade section may then be attached within the joint sleeve 202 using a plurality of fasteners 242 inserted through the openings 244 defined along the root end 238.
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 languages of the claims.

Claims

1. A rotor blade assembly for a wind turbine, the rotor blade assembly comprising:

a first blade section including a joint end and defining an aerodynamic profile;

a second blade section including a joint end and defining an aerodynamic profile;

a joint sleeve having an inner surface and an outer surface, the inner surface defining a cavity configured to receive the joint ends of the first and second blade sections; and,

a plurality of fasteners configured to secure the joint ends of the first and second blade sections within the cavity,

wherein a profile of the outer surface of the joint sleeve generally corresponds to the aerodynamic profiles of the first and second blade sections such that a substantially continuous aerodynamic profile is defined between the first and second blade sections when the joint ends are inserted within the cavity.

2. The rotor blade assembly of claim 1, wherein the second blade section is configured as a tip section of the rotor blade assembly.

3. The rotor blade assembly of claim 2, wherein the tip section defines a winglet.

4. The rotor blade assembly of claim 1, wherein a tapered profile is defined at the joint ends of the first and second blade sections, the joint sleeve defining a tapered width generally corresponding to the tapered profile.

5. The rotor blade assembly of claim 1, wherein a stepped profile is defined at the joint ends of the first and second blade sections.

6. The rotor blade assembly of claim 1, wherein the plurality of fasteners comprises a plurality of threaded fasteners.

7. The rotor blade assembly of claim 6, further comprising a plurality of threaded members disposed at the joint ends of the first and second blade sections, the plurality of threaded members being configured to receive the plurality of threaded fasteners.

8. The rotor blade assembly of claim 1, further comprising a plurality of openings defined between the inner and outer surfaces of the joint sleeve, each of the plurality of openings defining a recessed feature configured to recess the plurality of fasteners within the joint sleeve.

9. The rotor blade assembly of claim 1, further comprising a divider configured to separate the joint ends of the first and second blade sections within the cavity.

10. A joint sleeve for assembling together a first blade section and a second blade section of a rotor blade assembly, the sleeve comprising:

an outer surface;

an inner surface defining a cavity, the cavity having a root end configured to receive a joint end of the first blade section and a tip end configured to receive a joint end of the second blade section; and,

a plurality of openings defined between the outer and inner surfaces, the plurality of openings being configured to receive a plurality of fasteners for securing the joint ends of the first and second blade sections within the cavity,

wherein a profile of the outer surface is configured to generally correspond to an aerodynamic profile of the first and second blade sections such that a substantially continuous aerodynamic profile is defined between the first and second blade sections when the joint ends are inserted within the cavity.

11. The joint sleeve of claim 10, wherein a tapered width is defined between the outer and inner surfaces.

12. The joint sleeve of claim 10, wherein each of the plurality of openings defines a recessed feature between the outer and inner surfaces.

13. The joint sleeve of claim 10, further comprising a divider configured to separate the joint ends of the first and second blade sections within the cavity.

14. The joint sleeve of claim 10, wherein the divider extends substantially perpendicularly from the inner surface.

15. The joint sleeve of claim 10, wherein an aerodynamic profile of the root end generally corresponds to the aerodynamic profile of the first blade section and an aerodynamic profile of the tip end generally corresponds to the aerodynamic profile of the second blade section.

16. A tip assembly for a rotor blade of a wind turbine, the tip assembly comprising:

a joint sleeve including an inner surface defining a cavity and an outer surface defining an aerodynamic profile, the joint sleeve further including a tip end and a root end,

a tip section extending between a joint end and a blade tip and defining an aerodynamic profile generally corresponding to the aerodynamic profile of the joint sleeve at the tip end, the joint end of the tip section being disposed within the cavity; and,

a plurality of fasteners configured to secure the joint end of the tip section within the cavity,

wherein a portion of the cavity disposed at the root end of the joint sleeve is configured to receive an end of a separate section of the rotor blade.

17. The tip assembly of claim 16, wherein the tip section defines a winglet.

18. The tip assembly of claim 16, wherein a tapered profile is defined at the joint end of the tip section, the joint sleeve defining a tapered width generally corresponding to the tapered profile.

19. The tip assembly of claim 16, further comprising a plurality of openings defined along the tip end of the joint sleeve and configured to receive the plurality of fasteners, each of the plurality of openings defining a recessed feature configured to recess the plurality of fasteners within the joint sleeve.

20. The tip assembly of claim 16, further comprising a plurality of openings defined along the root end of the joint sleeve, the plurality of openings being configured to receive a plurality of fasteners for securing the end of the separate section of the rotor blade within the cavity.