Patent Description:
Embodiments of the present disclosure generally relate to a wind turbine.

A wind turbine includes a rotor having a hub and multiple (typically three) blades connected to the hub. The rotor is connected to an input drive shaft of a gearbox. The blades transform wind energy into torque that drives a generator connected to an output shaft of the gearbox. The gearbox steps up the inherently low rotational speed of the rotor for the generator to efficiently convert the rotational mechanical energy to electricity, which is fed into a utility grid. Gearless direct drive wind turbines also exist. The drive shafts, generator, gearbox and other components are typically mounted within a nacelle that is positioned on top of a tower that may be a truss or tubular.

<FIG> illustrates a prior art lattice boom crawler crane having just assembled a wind turbine. To assemble the wind turbine, a high capacity lattice boom crane is required to hoist the nacelle on to the tower and then to hoist the rotor on to the nacelle. Since the wind turbines are usually located in remote locations, costs of deploying the crane to the wind turbine site can become substantial. Further, to increase capacity and efficiency, larger towers, longer blades, and heavier nacelles are currently in development, further exacerbating the installation cost (and maintenance cost if the nacelle must be removed) up to the point that it may be cost prohibitive to install the larger wind turbines, especially if the height capacity of the conventional lattice boom crane is exceeded.

<CIT> (hereinafter D1) discloses a method and device for the installation of a wind turbine. The assembly comprises a structural tower having an elongated tower frame with a longitudinally-extending rail member and a translatable crane assembly which is slidably engageable with the longitudinally-extending rail member. The structural tower consists of a plurality of tower sections. The tower sections are placed on top of each other by the crane assembly. In one embodiment of D1, shown in figures <NUM>- <NUM>, the nacelle is lifted by the crane assembly and installed on top of the upper tower section. Subsequently, as shown in figures <NUM> - <NUM>, the blades are lifted by the crane assembly and attached to the nacelle. <CIT> discloses a method of assembling a wind turbine comprising: placing a tower base in an upright position, the tower base comprising a tower base guide rail and a carriage, the carriage including an assembly rotatable around a horizontal axis between a loading position and an unloading position; connecting a tower body member to the assembly while the assembly is in the loading position; moving the carriage upwardly to a top of the tower base along the tower base guide rail while the assembly is in the loading position and rotating around a horizontal axis the assembly from the loading position to the unloading position such that the tower body member is positioned above the tower base.

Embodiments of the present disclosure generally relate to a wind turbine. In one embodiment, a method according to the independent method claim <NUM> is provided.

In another embodiment, a wind turbine according to the independent apparatus claim <NUM> is provided.

In yet another embodiment, a method according to the independent method claim <NUM> is also provided.

The present disclosure relates to a wind turbine <NUM> and methods of assembling the wind turbine. After assembly, the wind turbine <NUM> comprises a turbine tower <NUM>, a nacelle <NUM>, and a hub <NUM>. Blades <NUM> are attached to the hub <NUM>, thereby forming a rotor. The nacelle <NUM> and the hub <NUM> are operatively connected to the turbine tower <NUM> via a carriage <NUM>. The turbine tower <NUM> comprises a tower base <NUM> and tower body members <NUM>. Depending upon the shape of the tower base <NUM> and the tower body members <NUM>, the turbine tower may be semi-conical or semi-tubular and have a flat face. It is to be understood that the tower base <NUM> and the tower body members <NUM> are substantially identical to each other (e.g., having similar or identical material properties, shape, height, and/or weight). For example, the tower base <NUM> and each of the tower body members <NUM> can be constructed of steel and have a height of <NUM> feet. Alternatively, the tower base <NUM> and some (or all) of the tower body members <NUM> can differ from each other (e.g., having different material properties, shape, height, and/or weight). For example, the tower base <NUM> can be constructed of cement while some (or all) of the tower body members <NUM> are constructed of steel.

The tower base <NUM> includes a tower base guide rail 18a and a tower base rack 19a. The tower base rack 19a extends along the tower base guide rail 18a. Each of the tower body members includes a tower body guide rail 18b and a tower body rack 19b, with the tower body rack 19b extending along the tower body guide rail 18b. After the turbine tower <NUM> is formed (i.e., after at least one tower body member <NUM> is connected to the tower base <NUM>), the tower base guide rail 18a and the tower body guide rails 18b collectively form a rail track <NUM>. It is to be understood that as a vertical height of the turbine tower <NUM> is increased by adding additional tower body members <NUM>, a length of the rail track <NUM> will also increase because of the additional tower body guide rails 18b. After the turbine tower <NUM> is formed (i.e., after at least one tower body member <NUM> is connected to the tower base <NUM>), the tower base rack 19a and the tower body racks 19b collectively form a rack <NUM>. It is to be understood that as a vertical height of the turbine tower <NUM> is increased by adding additional tower body members <NUM>, a length of the rack <NUM> will also increase because of the additional tower body racks 19b.

As illustrated in <FIG>, the carriage <NUM> may include a pinion <NUM>, a bearing <NUM>, and a body <NUM>. The pinion <NUM> may be engageable with the rack <NUM> in a manner that facilities movement of the carriage <NUM> up the turbine tower <NUM>. The bearing <NUM> may be attached to the body <NUM>. Trolley wheels <NUM> may be disposed in and connected to the carriage body <NUM>. The trolley wheels <NUM> may be part of a trolley that includes an actuator for selectively engaging the trolley wheels with the rail track <NUM>. The bearing <NUM> may be adapted to either operatively connect the nacelle <NUM> to the carriage <NUM> or to operatively connect a crane platform <NUM> to the carriage. The bearing <NUM> may allow for rotation of the nacelle <NUM> relative to the body <NUM> subject to a rotary drive (not shown). The rotary drive may operated by a programmable logic controller (PLC, not shown) in order to point the nacelle <NUM> into the wind during operation of the wind turbine <NUM>. The rotary drive may include an electric motor (not shown) connected to the carriage body <NUM> and rotationally connected to a pinion (not shown) which meshes with a gear (not shown) of the bearing <NUM>. Operation of the rotary drive motor may rotate the nacelle <NUM> relative to the carriage body <NUM>. The rotary drive may further include a lock (not shown) for selectively rotationally connecting the nacelle <NUM> relative to the carriage body <NUM>. The lock may include a gear tooth (not shown) selectively engageable with the bearing gear via operation of a linear actuator (e.g., a solenoid) and a proximity or limit sensor to verify engagement of the tooth with the gear. Engagement of the gear with the tooth may rotationally connect the nacelle <NUM> to the carriage body <NUM>. Verification of engagement by the proximity/limit sensor may also prevent operation of the rotary drive motor when the rotary drive is locked. Alternatively, the lock may include a disk (not shown) incorporated in the rotary drive motor and a retainer for retaining the disk.

Collectively, the rail track <NUM> and the trolley wheels <NUM> may constitute a guide system. The rail track <NUM>, which includes the tower base guide rail 18a and the tower body guide rails <NUM>b, may be connected to a flat face of the tower base <NUM> and the tower body members <NUM>, respectively, such as by fastening or welding. It is to be understood that additional known methods could be used to connect the tower base guide rail 18a and the tower body guide rails 18b to the tower base <NUM> and the tower body members <NUM>, respectively. When engaged with the rail track <NUM>, the trolley wheels <NUM> may operatively connect the carriage body <NUM> to the rail track <NUM> in a manner that enables longitudinal movement (e.g., upward and/or downward movement) of the carriage <NUM> relative to the turbine tower <NUM> subject to operation of a drive system.

Collectively, the pinion <NUM>, the rack <NUM>, and an electric drive motor (not shown) may constitute the drive system that, upon operation, facilitates movement of the carriage <NUM> up and down the turbine tower <NUM>. A rotor of the drive motor (not shown) may be rotationally connected to pinion <NUM> and a housing of the drive motor (not shown) may be connected to the carriage body <NUM>. The pinion <NUM> may be supported by the carriage body <NUM> so that the pinion may rotate relative thereto. Operation of the drive motor may lift the carriage <NUM> longitudinally upward along the turbine tower <NUM>. For lowering the carriage <NUM>, the drive motor may be speed controllable to manage descent. Additionally, the drive system may further include a lock to selectively longitudinally support the carriage <NUM> from the turbine tower <NUM>. Alternatively, the drive system may further include a brake (not shown) to control descent of the carriage <NUM>.

<FIG> illustrates a crane rope 3a of crawler crane <NUM> placing the tower base <NUM> in an upright position. As illustrated in <FIG>, the tower base <NUM> may be positioned on a pad <NUM>. The pad <NUM> may be formed for receiving the tower base <NUM>. It is to be understood that the crawler crane <NUM> may be a rough terrain or all terrain crane and/or include other boom types, such as lattice or A-frame. <FIG> illustrates the crawler crane <NUM> releasably connecting the crane platform <NUM> to the carriage <NUM>. The crane platform <NUM> is a platform of a sufficient size to enable a crane to be located thereon. The crane that is positioned onto the crane platform <NUM> may be the crawler crane <NUM>. Alternatively, a crane other than crawler crane <NUM> could be positioned onto the crane platform <NUM>. As illustrated in <FIG>, the crawler crane <NUM> may be positioned onto the crane platform <NUM> by attaching a ramp <NUM> to the crane platform. After attaching ramp <NUM> to the crane platform <NUM>, the crawler crane <NUM> can be positioned onto the crane platform by driving the crawler crane up the ramp and onto the crane platform.

As illustrated in <FIG>, the carriage <NUM> and the crane platform <NUM> may be raised by the drive system to a top of the tower base <NUM> along the tower base guide rail 18a. The crane rope 3a of crawler crane <NUM> is connected to a first tower body member 16a. The crawler crane <NUM> is counterbalanced in a manner that enables the crane to lift the first tower body member 16a without toppling over or otherwise falling from crane platform <NUM>. As illustrated in <FIG>, the first tower body member 16a is being connected to the tower base <NUM> by the crawler crane <NUM>, thereby forming turbine tower <NUM>. The first tower body member 16a is connected to the tower base <NUM> in a manner such that the tower base guide rail 18a and the tower body guide rail 18b are aligned and the tower base rail 19a and the tower body rack 19b are aligned, enabling the carriage <NUM> to move from the tower base <NUM> to the first tower body member 16a and vice versa. The first tower body member 16a may be connected to the tower base <NUM> using fasteners (not shown). Alternatively, the first tower body member 16a may be connected to the tower base <NUM> using any other attachment means known to a person of ordinary skill in the art. A similar process is then repeated to connect additional body members <NUM> to the turbine tower <NUM>, thereby increasing a vertical height of the turbine tower. Every time an additional body member <NUM> is being prepared to be connected to the existing turbine tower <NUM>, the crane platform <NUM> may be raised to a top of the existing turbine tower along the rail track <NUM> before attaching the additional body member. Alternatively, in some situations, the crane platform <NUM> may only be raised to a top of the existing turbine tower <NUM> along the rail track <NUM> after two or more additional body members <NUM> have been connected to the turbine tower. The additional tower body members <NUM> are connected to the first tower body member 16a and each other in a manner such that the tower base guide rail <NUM>b and the tower body guide rails <NUM>b are aligned and the tower base rack 19a and the tower body rack 19b are aligned, thereby enabling the carriage <NUM> to move between the tower base, the first tower member, and each of the additional tower body members. Each of the additional tower members <NUM> can be connected to each other or to the first tower body member <NUM>a using fasteners (not shown) or any other attachment means known to a person of ordinary skill in the art.

<FIG> illustrates the crane platform <NUM> may be raised to a top of the turbine tower <NUM> along the rail track <NUM> before the crane rope <NUM>a of crawler crane <NUM> is connected to a top tower body member <NUM>b. The top tower body member <NUM>b may include a pivot system <NUM>. <FIG> illustrates the top tower body member <NUM>b being connected to the existing turbine tower <NUM>. The top tower body member <NUM>b is connected to a top body member of the existing turbine tower <NUM> in a manner such that the tower body guide rail <NUM>b of the top tower body member <NUM>b aligns with the rail track <NUM> of the existing turbine tower and the tower body rack <NUM>b aligns with the rack <NUM> of the existing turbine tower, thereby enabling the carriage to move between the existing turbine tower and the top tower body member. The top tower body member <NUM>b may be connected to a top tower body member of the existing turbine tower <NUM> using fasteners (not shown) or any other attachment means known to a person of ordinary skill in the art.

It is to be understood that during assembly of the turbine tower <NUM>, the crane rope 3a of the crawler crane <NUM> may connect to the tower base <NUM> or to any of the individual tower body members <NUM> in any manner recognized by a person of ordinary skill in the art. By assembling the turbine tower <NUM> using the method described in the previous paragraphs, crawler crane <NUM> only has to have the capability to lift a single member of the turbine tower <NUM> at a time (e.g. tower base <NUM> or tower body member <NUM>). Moreover, crawler crane <NUM> does not need to lift nacelle <NUM> and hub <NUM> to a top of the turbine tower <NUM> after the turbine tower has been assembled. Consequently, the size and cost of the crane needed to assemble turbine tower <NUM> can be reduced.

After the top tower body member 16b is connected, the crane platform <NUM> and the crawler crane <NUM> located thereon may be lowered along the rail track <NUM> by the drive system of the carriage <NUM>. Upon reaching a bottom of the tower base <NUM>, the ramp <NUM> may be reattached to the crane platform <NUM>, thereby enabling the crawler crane <NUM> to be removed from the crane platform. The ramp <NUM> may then be detached from the crane platform <NUM> and the crane platform <NUM> subsequently removed from the carriage <NUM>. As illustrated in <FIG>, the nacelle <NUM> and hub <NUM> may then be connected to the carriage <NUM>, such as by a flanged connection on the bearing <NUM>. The nacelle <NUM> and hub <NUM> may be connected to the carriage <NUM> in the vertical position by crawler crane <NUM>. The hub <NUM> may point upward (shown) or downward (not shown) in the vertical position. The bearing <NUM> may connect the nacelle <NUM> to the carriage body <NUM> and allow for rotation of the nacelle <NUM> relative to the body subject to a rotary drive (not shown). The rotary drive may operated by a programmable logic controller PLC (not shown) in order to point the nacelle <NUM> into the wind during operation. The rotary drive may include an electric motor (not shown) connected to the carriage body and rotationally connected to a pinion (not shown) which meshes with a gear (not shown) of the bearing <NUM>. Operation of the rotary drive motor may rotate the nacelle <NUM> relative to the carriage body <NUM>. The rotary drive may further include a lock (not shown) for selectively rotationally connecting the nacelle relative to the carriage body. The lock may include a gear tooth (not shown) selectively engageable with the bearing gear via operation of a linear actuator (i.e., a solenoid) and a proximity or limit sensor to verify engagement of the tooth with the gear. Engagement of the gear with the tooth may rotationally connect the nacelle <NUM> to the carriage body <NUM>. Verification of engagement by the proximity/limit sensor may also prevent operation of the rotary drive motor when the rotary drive is locked. Alternatively, the lock may include a disk (not shown) incorporated in the rotary drive motor and a retainer for retaining the disk.

<FIG> illustrates blades <NUM> may be attached to hub <NUM> to thereby form the rotor <NUM>. After the nacelle <NUM> and the hub <NUM> are connected to the carriage <NUM> and the rotor <NUM> formed, the drive system in combination with the guide system of the carriage may be used to raise the nacelle and rotor upwardly along the rail track <NUM>. <FIG> illustrates the nacelle <NUM> and hub <NUM> being raised by the carriage <NUM> along the rail track <NUM> at a location approximately half of the vertical height of turbine tower <NUM>. <FIG> illustrates the nacelle <NUM> and hub <NUM> beginning to pivot from the vertical position to a horizontal position via pivot system <NUM> of the top tower body member 16b. The pivot system <NUM> may include a horizontal guide track <NUM>, a curved guide track <NUM>, a horizontal rack <NUM>, and a curved rack <NUM>. The horizontal guide track <NUM> may be connected to rail track <NUM> via the curved guide track <NUM>. The horizontal rack <NUM> may be connected to rack <NUM> via the curved rack <NUM>. Upon reaching the curved guide track <NUM> and the curved rack <NUM>, the electric drive motor (not shown) enables the carriage <NUM>, which is currently in a vertical position, to move seamlessly from rack <NUM> to curved rack <NUM> along rail track <NUM> and curved guide track <NUM>. The electric drive motor (not shown) may continue to propel the carriage <NUM> forward on the curved rack <NUM> along curved guide track <NUM> until carriage seamlessly moves to horizontal rack <NUM> along horizontal guide track <NUM>. In this manner, the pivot system <NUM> may collectively pivot the carriage <NUM>, the nacelle <NUM>, and the hub <NUM> from the vertical position to the horizontal position. <FIG> and <FIG> illustrate the nacelle <NUM> and rotor <NUM> in the horizontal position and the wind turbine <NUM> ready for operation.

An alternative pivot system may include a stop (not shown) having a proximity or limit sensor (not shown) in communication with the PLC disposed in the turbine tower <NUM>. In response to detection of the carriage <NUM>, the nacelle <NUM>, and the rotor <NUM> at the top of the turbine tower <NUM>, the PLC may lock the drive motor of the carriage and engage pivot fasteners (not shown) with corresponding holes (not shown) formed in the carriage body <NUM> and the rail track <NUM>, respectively, thereby pivoting the carriage body <NUM> to the rail track <NUM>. The pivot fasteners may each be engaged and retracted by a fastener actuator (not shown), such as a solenoid and spring. Each pivot actuator may include a proximity or limit sensor in communication with the PLC to verify engagement of the pivot fasteners with the carriage body holes. Once the PLC has verified engagement, the PLC may deactivate the driver motor and disengage the trolley wheels <NUM> from the rail track <NUM>. The alternative pivot system may further include a linear actuator (not shown), such as an electric motor and lead screw, disposed in a top of the turbine tower <NUM>. An end of the lead screw distal from the motor may have a clamp and a clamp actuator in communication with the PLC via flexible leads. The PLC may then operate the clamp actuator to engage a pivot rod or pin (not shown) connected to the carriage body <NUM>, thereby also pivoting the linear actuator to the carriage body. Once connected, the linear actuator may be operated to contract the lead screw, thereby pivoting the carriage <NUM>, the nacelle <NUM>, and the rotor <NUM> from the vertical position to the horizontal position. As the carriage <NUM>, the nacelle <NUM>, and the rotor <NUM> is pivoted, a tipping point may be reached. The linear actuator may be speed controlled to manage pivoting of the head after the tipping point is reached. Alternatively, a damper (not shown) may also be employed to control pivoting after carriage <NUM>, the nacelle <NUM>, and the rotor <NUM> tip from the vertical position to the horizontal position. Once the carriage <NUM>, the nacelle <NUM>, and the rotor <NUM> has been pivoted to the horizontal position, the linear actuator may be locked. A power cable (not shown) may be connected from a power converter (not shown) located in the turbine tower <NUM> and connected to the utility grid and the generator (not shown) of the nacelle <NUM>. The PLC may also be connected to various sensors and actuators of the nacelle <NUM> and the rotary drive of the carriage via a third power and data cable. Alternatively, the nacelle may have its own programmable logic controller and the PLC may be connected to the nacelle's programmable logic controller. Alternatively, one or more of the pivot system actuators may be omitted and the functions performed manually.

Should the nacelle <NUM>, hub <NUM>, and/or rotor <NUM> need to be serviced, the drive system of the carriage <NUM> may be employed in a reverse operation. The reverse operation of the drive system would enable the carriage <NUM>, the nacelle <NUM>, and the rotor <NUM> to be pivoted from the horizontal position to the vertical position via the pivot system <NUM>. The drive system could then be used to lower the carriage <NUM>, the nacelle <NUM>, and the rotor <NUM> to a base of the turbine tower <NUM>. The nacelle <NUM> and/or hub/rotor <NUM>, <NUM> may then be serviced at the base of the turbine tower <NUM> or removed and delivered to a service facility. Additionally, if severe weather, such as a hurricane, is forecast, the nacelle <NUM>, the hub <NUM>, and/or rotor <NUM> could be lowered to the base of the turbine tower <NUM> using the carriage <NUM> to offer more protection to these components of the wind turbine <NUM>.

<FIG> illustrate a method of assembling tower turbine <NUM> according to another embodiment of the present disclosure. Many of the elements associated with the embodiment illustrated in <FIG> are the same as the embodiment depicted in <FIG> and will not be repeated here. As illustrated in <FIG>, the crawler crane <NUM> is used to position a telescoping stiff-leg crane <NUM> onto the crane platform <NUM>. The telescoping stiff-leg crane <NUM> may be operated by a user from a ground surface, eliminating the need for the user to be located on the crane platform <NUM> as it is raised along turbine tower <NUM>. As illustrated in <FIG>, the telescoping stiff-leg crane <NUM> may be used to assemble the turbine tower <NUM> in a manner similar to using the crawler crane <NUM> positioned on the crane platform <NUM>.

<FIG> illustrate yet another method of assembling tower turbine <NUM> according to another embodiment of the present disclosure. Many of the elements associated with the embodiment illustrated in <FIG> are the same as the embodiment depicted in <FIG> and will not be repeated here. The method illustrated in <FIG> eliminates the use of a crane attached to carriage <NUM>. Instead, a rotating pole assembly <NUM> attached to carriage <NUM> may be used to assemble the turbine tower <NUM>. The rotating pole assembly <NUM> may include a platform <NUM>, a drive motor <NUM>, a pole <NUM>, and a support beam <NUM>. The support beam <NUM> is attached to a top of the pole <NUM>. A bottom of pole <NUM> is connected to the drive motor <NUM> such that upon operation of the drive motor <NUM>, the pole <NUM> and the support beam <NUM> attached thereto rotate. In this manner, the rotating pole assembly <NUM> may be rotated from a loading position to an unloading position. Although <FIG> indicates the rotating pole assembly <NUM> is rotated from the loading position to the unloading position counter-clockwise, it is to be understood that the rotating pole assembly could be rotated clockwise The drive motor <NUM> may be attached to a platform <NUM>, the platform being adapted to be connected to bearing <NUM> of the carriage <NUM>.

A first tower body member 16a is stood upright on a ground surface and is attached to the support beam <NUM> using fasteners (not shown) while the rotating pole assembly <NUM> is in the loading position. It is to be understood that the first tower body member 16a may be connected to the support beam in other manners known to a person of ordinary skill in the art. The loading position is a position in which the support beam <NUM> is extending outwardly from the tower base <NUM> or the turbine tower <NUM>, depending on the location of the carriage <NUM>. When the rotating pole assembly <NUM> is in the loading position, a tower body member <NUM> can be connected to the support beam <NUM>. As illustrated in <FIG>, after the first tower body member 16a is attached to the support beam <NUM>, carriage <NUM> moves upwardly along the rail track <NUM> and the rack <NUM> while the rotating pole assembly <NUM> is in the loading position. After the carriage is located at a top of the tower base <NUM>, the rotating pole assembly <NUM> is rotated via the drive motor <NUM> from the loading position to the unloading position (as illustrated in <FIG>). This results in the first tower body member 16a being positioned above the tower base <NUM>. The first tower body member 16a may then be connected to the tower base <NUM> while the rotating pole assembly <NUM> is in the unloading position. The first tower body member 16a is connected to the tower base <NUM> in a manner such that the tower base guide rail 18a and the tower body guide rail <NUM>b are aligned and the tower base rail <NUM>a and the tower body rack <NUM>b are aligned, enabling the carriage <NUM> to freely move from the tower base <NUM> to the first tower body member <NUM>a and vice versa. The first tower body member <NUM>a may be connected to the tower base <NUM> using fasteners (not shown). Alternatively, the first tower body member <NUM>a may be connected to the tower base <NUM> using any other attachment means known to a person of ordinary skill in the art. After the first tower body member <NUM>a is connected to the tower base <NUM>, the first tower body is disconnected from the support beam <NUM> of the rotating pole assembly <NUM>. The rotating pole assembly <NUM> may then be rotated from the unloading position to the loading position before the carriage <NUM> is lowered along the rail track and rack of the turbine tower <NUM>. After the carriage <NUM> is lowered, an additional tower body member <NUM> stood upright on a ground surface can be attached to the support beam <NUM>. The foregoing method may then be repeated to increase a vertical height of the turbine tower <NUM>.

It is to be understood that the various components of the wind turbine <NUM> (e.g., the nacelle <NUM>, the tower base <NUM>, tower body members <NUM>) may be delivered from a factory (not shown) to a windfarm site using a truck or trucks (not shown). Once the pad <NUM> has been formed at the windfarm site, either crawler crane <NUM> or an alternative crane may unload the various components of the wind turbine <NUM> from the truck(s) to a location near the pad <NUM> for assembly in a manner in accordance with the present disclosure. After the wind turbine <NUM> has been assembled, the wind turbine may then be connected to a utility grid (not shown). Should the wind turbine <NUM> need to be removed from the windfarm site, the wind turbine can also be disassembled. To disassemble the wind turbine, the nacelle <NUM> and the rotor <NUM> will be lowered to the base of the turbine tower <NUM> in a manner similar to that described above for servicing the components. The nacelle <NUM> will then be disconnected from the bearing <NUM> of the carriage <NUM> and the crane platform <NUM> would subsequently be connected. Crawler crane <NUM>, telescoping stiff-leg crane <NUM>, or the rotating pole assembly <NUM> can then be used to disassemble the turbine tower <NUM> in a method reverse of that described above such that tower boy members <NUM> can individually be disconnected and removed from the turbine tower <NUM> one at a time. After the turbine tower <NUM> is disassembled, the tower base <NUM> can be removed from pad <NUM>.

As the turbine tower <NUM> is being assembled, an additional support system <NUM> may be utilized for enhanced safety. The additional support system <NUM> is illustrated in <FIG>. The additional support system <NUM> is shown in <FIG> and includes angles <NUM>, steel cables <NUM>, and an anchor system <NUM>. Each angle <NUM> has a first end with a through-hole <NUM> and a second end with a through-hole <NUM>. Each angle <NUM> is adapted to have the first end attached to a single member of the turbine tower <NUM> (e.g., tower base <NUM> or tower body member <NUM>) using a fastener, and the second end attached to the anchor system <NUM> via steel cable <NUM>. The fastener passes through the through-hole <NUM> in the first end of the angle <NUM> to attach the angle to the member of the turbine tower <NUM>. The steel cable passes through the through-hole <NUM> in the second end of the angle <NUM> to attach the steel cable <NUM> to the angle. The steel cable <NUM> is then run from the angle <NUM> to the anchor system <NUM> located on a ground surface. The anchor system <NUM> may comprise a winch <NUM> and a deadman <NUM>. The second end of the angle <NUM> is adapted to protrude outwardly from the member of the turbine tower <NUM> to which the angle is attached.

As the turbine tower <NUM> is being assembled, the additional support system <NUM> may be installed by placing one or more angles <NUM> between each of the tower body members <NUM> as they are connected to the existing turbine tower <NUM>. For example, before an additional tower body member <NUM> is connected to the existing turbine tower <NUM>, the first end of the angle <NUM> can be fastened to the top tower body member of the existing turbine tower <NUM>. A steel cable <NUM> may subsequently be attached to the second end of the angle <NUM> and run to the anchor support system <NUM>. The additional tower body member <NUM>, which may contain a grooved region to accommodate angle <NUM>, is then connected to the top tower body member of the existing turbine tower <NUM> in any manner set forth in the present disclosure. This same method of attaching an angle <NUM> to the top tower body member <NUM> of the existing turbine tower <NUM> may be used as each additional tower body member <NUM> is attached to the turbine tower. The angles <NUM> may be arranged to protrude outwardly from the turbine tower <NUM> on a side generally opposite the carriage <NUM>. Because each of the cables attached to the second end of the angles are generally attached to the same deadman, the cables form a waterfall pattern. In this manner, the additional support system serves as a counterbalance to the weight placed upon the turbine tower <NUM> as a result of the carriage <NUM> and anything attached thereto (e.g., crane <NUM>, crane platform <NUM>, nacelle <NUM> and hub <NUM>) moving upwardly or downwardly along the rail track <NUM> and rack <NUM>. In other words, the cables of the additional support system will be in tension while the side of the turbine tower <NUM> to which the carriage <NUM> is attached will be in compression, with the tension forces and compression forces balancing each other to provide additional support to the turbine tower. It is also to be understood that the additional support system may also be used between the first tower body member and the tower base.

Claim 1:
A method of assembling a wind turbine (<NUM>), comprising:
placing a tower base (<NUM>) having a round cross section in an upright position, the tower base including a tower base guide rail (18a) attached to an outer side wall of the tower base and a carriage (<NUM>), the carriage being movable along the tower base guide rail and including a crane (<NUM>) attached thereto; and
connecting a first tower body member (16a) having a similar or identical shape as the tower base to the tower base to form a turbine tower (<NUM>), the first tower body member including a first tower body guide rail (18b) attached to an outer side wall of the tower member and being connected to the tower base in a manner such that the tower base guide rail axially aligns with the first tower body guide rail to collectively form a rail track (<NUM>), the carriage being movable up and down the turbine tower along the rail track,
wherein the carriage is connected to the tower base in a vertical position and a top tower body member of the turbine tower comprises a pivot system (<NUM>) for pivoting the carriage from the vertical position to a horizontal position when the carriage arrives at the top of the turbine tower.