Reinforcement tool for rear frame structure of a wind turbine nacelle

Abstract

A detachable reinforcement tool (1) for providing temporary reinforcement of a rear frame structure (6) for a nacelle of a wind turbine is disclosed. The rear frame structure (6) comprises a plurality of truss members (4) and a plurality of joints (5), each joint (5) interconnecting ends of at least two truss members (4). The reinforcement tool (1) comprises a reinforcement part (2), and attaching means (3) for detachably attaching the reinforcement part (2) to two different parts (4, 5) of the rear frame structure (6). The reinforcement tool (1) is arranged to provide a load transferring connection between two parts (4, 5) of the rear frame structure (6) when the reinforcement part (2) is attached to the two parts (4, 5) of the rear frame structure (6) by means of the attaching means (3). The rear frame structure (6) is capable of handling extreme loads without being designed to handle such loads permanently. Manufacturing costs and weight of the rear frame structure (6) are reduced.

Claims

1. A nacelle for a wind turbine, the nacelle comprising: a rear frame structure comprising: a plurality of parts, including a plurality of truss members and a plurality of joints, each joint interconnecting ends of at least two truss members, wherein the rear frame structure has at least one detachable reinforcement tool, the at least one reinforcement tool comprising: a reinforcement part; and attaching means for detachably attaching the reinforcement part to at least first and second parts of the plurality of parts of the rear frame structure, wherein the reinforcement tool provides a load transferring connection between the at least first and second parts of the rear frame structure, at least partly bypassing a third part of the plurality of parts that interconnects the at least first and second parts, wherein the reinforcement part is attached to the at least first and second parts of the rear frame structure by means of the attaching means.

2. The nacelle according to claim 1, wherein the load transferring connection provided by the reinforcement tool further transfers torque between the at least first and second parts of the plurality of parts of the rear frame structure.

3. The nacelle according to claim 1, wherein the attaching means is or comprises one or more bolts.

4. The nacelle according to claim 1, wherein the reinforcement part is made from steel.

5. The nacelle according to claim 1, wherein the first part includes a first joint of the plurality of joints, the second part includes a second joint of the plurality of joints, and the third part includes a truss member of the plurality of truss members having a first end connected to the first joint and a second end connected to the second joint, such that the reinforcement part is parallel to the truss member of the plurality of truss members, the reinforcement tool thereby being a load transferring connection between the first joint and the second joint, at least partly bypassing the truss member.

6. The nacelle according to claim 5, wherein the reinforcement part has a load-carrying capability which is equal to or higher than a load-carrying capability of the truss member which the reinforcement part is arranged in parallel to.

7. The nacelle according to claim 5, wherein the reinforcement part has a material thickness which is equal to or higher than a material thickness of the truss member which the reinforcement part is arranged in parallel to.

8. The nacelle according to claim 1, wherein the first part includes a first truss member of the plurality of truss members, the second part includes a second truss member of the plurality of truss members, and the third part includes a joint of the plurality of joints which interconnects the first truss member and the second truss member, such that the reinforcement part bridges the joint of the plurality of joints, the reinforcement tool thereby being a load transferring connection between the first truss member and the second truss member, at least partly bypassing the joint.

9. The nacelle according to claim 8, wherein the reinforcement part is or comprises at least one plate element.

10. The nacelle according to claim 8, wherein the reinforcement part has a load-carrying capability which is equal to or higher than a load-carrying capability of the joint which the reinforcement part bridges.

11. A nacelle for a wind turbine, the nacelle comprising: a rear frame structure, comprising: a plurality of parts, including a plurality of truss members and a plurality of joints, each joint interconnecting ends of at least two truss members, wherein the rear frame structure has at least one detachable reinforcement tool, the at least one reinforcement tool comprising: a reinforcement part; and attaching means for detachably attaching the reinforcement part to at least first and second parts of the plurality of parts of the rear frame structure, wherein the reinforcement tool is arranged to provide a load transferring connection between the at least first and second parts of the rear frame structure when the reinforcement part is attached to the at least first and second parts of the rear frame structure by means of the attaching means, wherein the first part includes a first truss member of the plurality of truss members, and the second part includes a second truss member of the plurality of truss members, and the third part includes a joint of the plurality of joints which interconnects the first truss member and the second truss member, such that the reinforcement part bridges the joint of the plurality of joints, the reinforcement tool thereby being a load transferring connection between the first truss member and the second truss member, bypassing the joint, wherein the joint is a pivot joint, and wherein the reinforcement tool further fixates the pivot joint.

12. A nacelle for a wind turbine, the nacelle comprising: a rear frame structure, comprising: a plurality of parts, including a plurality of truss members and a plurality of joints, each joint interconnecting ends of at least two truss members, wherein the rear frame structure has at least one detachable reinforcement tool, the at least one reinforcement tool comprising: a reinforcement part; and attaching means for detachably attaching the reinforcement part to at least first and second parts of the plurality of parts of the rear frame structure, wherein the reinforcement tool is arranged to provide a load transferring connection between the at least first and second parts of the rear frame structure when the reinforcement part is attached to the at least first and second parts of the rear frame structure by means of the attaching means, wherein the first part includes a first joint of the plurality of joints, the second part includes a second joint of the plurality of joints, and the third part includes a truss member of the plurality of truss members having a first end connected to the first joint and a second end connected to the second joint, such that the reinforcement part is parallel to the truss member of the plurality of truss members, the reinforcement tool thereby being a load transferring connection between the first joint and the second joint, bypassing the truss member, wherein the reinforcement part is or comprises at least one beam element.

13. A wind turbine comprising the nacelle according to claim 1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention will now be described in further detail with reference to the accompanying drawings in which

(2) FIG. 1 illustrates a reinforcement tool according to a first embodiment of the invention,

(3) FIG. 2 illustrates a reinforcement tool according to a second embodiment of the invention,

(4) FIG. 3 is a perspective view of a rear frame structure for a wind turbine nacelle having the reinforcement tool of FIG. 1 mounted thereon, and

(5) FIG. 4 is a perspective view of a rear frame structure for a wind turbine nacelle having the reinforcement tool of FIG. 2 mounted thereon.

DETAILED DESCRIPTION OF THE DRAWINGS

(6) FIG. 1 illustrates a reinforcement tool 1 according to a first embodiment of the invention. The reinforcement tool comprises a reinforcement part 2 in the form of a plate like element, and attaching means 3 in the form of bolts or splits. The attaching means 3 attach the reinforcement part 2 to four different truss members 4 of a rear frame structure for a nacelle of a wind turbine. The reinforcement part 2 bridges a joint 5 which interconnects the four truss members 4.

(7) Since the reinforcement part 2 is in the form of a plate like element, it is relatively stiff. Thereby the reinforcement part 2 provides a load transferring connection between the truss members 4. The load transferring connection bypasses the joint 5, i.e. the joint 5 itself does not form a part of the load path from one truss member 4 to another. Thus, in the case that a load is applied to one of the truss members 4, this load can be distributed among all of the four truss members 4 having the reinforcement part 2 attached thereto, without loading the joint 5. Accordingly, mounting the reinforcement tool 1 on the rear frame structure as shown in FIG. 1 allows extreme loads to be temporarily applied to one of the truss members 4. Such extreme loads may, e.g., be in the form of a crane mounted on one of the truss members 4.

(8) In the case that the joint 5 is a pivot joint, the reinforcement tool 1 further fixates the joint 5 in the sense that the reinforcement tool 1 prevents the joint 5 from performing pivotal movements when it is mounted on the rear frame structure as illustrated in FIG. 1. In the case that the pivotal movements of the joint 5 result in an adjustment of the angles between the respective truss members 4 connected to the joint 5, such angle adjustments are prevented when the reinforcement tool 1 is mounted on the rear frame structure, i.e. the truss members 4 are then fixed relative to each other.

(9) Furthermore, since the attaching means 3 are in the form of bolts or splits, the reinforcement tool 1 can easily be mounted on and detached from the rear frame structure. Accordingly, the reinforcement tool 1 can be mounted on the rear frame structure when extreme loads are expected, and detached when extreme loads are no longer expected. Accordingly, the rear frame structure is capable of handling extreme loads without having to design the rear frame structure to handle such extreme loads permanently, and thereby the manufacturing costs and the weight of the rear frame structure are maintained at a low level.

(10) FIG. 2 illustrates a reinforcement tool 1 according to a second embodiment of the invention. The reinforcement tool 1 comprises a reinforcement part 2 in the form of a beam and attaching means 3 in the form of bolts or splits. The attaching means 3 attach the reinforcement part 2 to two different joints 5 of a rear frame structure for a nacelle of a wind turbine. The reinforcement part 2 is arranged in parallel to a truss member 4 of the rear frame structure having its ends connected to the two joints 5 having the reinforcement part 2 attached thereto. Thereby the reinforcement part 2 provides a load transferring connection between the joints 5, and the load transferring connection bypasses the truss member 4, i.e. the truss member 4 does not form part of the load path between the joints 5.

(11) The reinforcement tool 1 allows extreme loads to be applied to the rear frame structure at a position corresponding to the position of the truss member 4 being connected to the joints 5 having the reinforcement part 2 attached thereto, without excessively loading the truss member 4. In order to obtain this, the extreme loads are instead applied to the reinforcement part 2, and the load is then transferred, by means of the reinforcement tool 1, to the joints 5, without applying loads to the truss member 4. The extreme loads could, e.g., be in the form of a crane mounted on the reinforcement part 2.

(12) Similarly to the embodiment described above with reference to FIG. 1, the reinforcement tool 1 of FIG. 2 can easily be mounted on and detached from the rear frame structure, according to whether or not extreme loads are expected. Accordingly, the rear frame structure is capable of handling extreme loads without having to design the rear frame structure to handle such extreme loads permanently, and thereby the manufacturing costs and the weight of the rear frame structure are maintained at a low level.

(13) FIG. 3 is a perspective view of a rear frame structure 6 for a wind turbine nacelle having the reinforcement tool 1 of FIG. 1 mounted thereon. The rear frame structure 6 comprises a plurality of truss members 4 and a plurality of joints 5 interconnected to form a truss structure with the joints 5 arranged in the node points of the truss structure. The rear frame structure 6 is attached to a main frame 7 of the nacelle, the main frame 7 carrying a main bearing 8. The reinforcement tool 1 is mounted across one of the joints 5 in such a manner that it provides a load transferring connection between the truss members 4 attached to the joint 5, in the manner described above with reference to FIG. 1.

(14) FIG. 4 is a perspective view of a rear frame structure 6 for a wind turbine nacelle having the reinforcement tool 1 of FIG. 2 mounted thereon. The rear frame structure 6 comprises a plurality of truss members 4 and a plurality of joints 5 interconnected to form a truss structure with the joints 5 arranged in the node points of the truss structure. The rear frame structure 6 is attached to a main frame 7 of the nacelle, the main frame 7 carrying a main bearing 8. The reinforcement tool 1 is mounted in parallel to one of the truss members 4 in such a manner that it provides a load transferring connection between the two joints 5 having the truss member 4 attached thereto, in the manner described above with reference to FIG. 2.

(15) In further embodiments, the invention relates to a nacelle of a wind turbine, the nacelle comprising a rear frame structure (6), the rear frame structure (6) comprising a plurality of truss members (4), and a plurality of pivot joints (5), wherein each pivot joint (5) interconnects ends of at least two truss members (4), thereby forming a truss structure with the pivot joints (5) arranged in node points of the truss structure, and wherein at least some of the pivot joints (5) are adjustable in such a manner that an angle between two truss members (4) being interconnected via a pivot joint (5) is adjustable by means of the pivot joint (5), wherein the rear frame structure (6) has at least one detachable reinforcement tool (1) mounted thereon for providing temporary reinforcement of said rear frame structure (6).

(16) In an embodiment, the rear frame structure (6) defines at least a bottom part and two side parts.

(17) In an embodiment, the rear frame structure (6) further defines a top part.

(18) In an embodiment, all of the truss members (4) are of substantially identical length.

(19) In an embodiment, at least one of the pivot joints (5) comprises a base part and at least two connecting parts, each connecting part being attached to the base part via a hinge structure, and each connecting part being arranged to be connected to or form part of a truss member (4).

(20) In an embodiment, at least one of the pivot joints (5) is/are provided with a locking mechanism allowing substantially free pivotal movements of the pivot joints (5) when the locking mechanism is in an unlocked position, and wherein such free pivotal movement is prevented or restricted when the locking mechanism is in a locked position.

(21) In an embodiment, the truss structure defines one or more triangles, the sides of the triangle(s) being formed by truss members (4), and the vertices of the triangle(s) being formed by pivot joints (5).