Description:FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
AND
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(See section 10; rule 13)
1. TITLE OF THE INVENTION:

“FOUNDATION ARRANGEMENT FOR HYBRID TOWER”
2. APPLICANT:

(a) Name : Suzlon Energy Limited
(b) Nationality : Indian
(c) Address : Shrimali Society, Near Shri Krishna
Complex, Navrangpura, Ahmedabad 380 009, Gujarat, India

3. PREAMBLE TO THE DESCRIPTION:

The following specification particularly describes the invention and the manner in which it is to be performed.

TITLE OF INVENTION

FOUNDATION ARRANGEMENT FOR HYBRID TOWER

FIELD OF INVENTION

One aspect of the present invention is directed to foundation adapter for a foundation arrangement of a lattice section of a hybrid tower of a wind turbine; a further aspect of the present invention is directed to a foundation arrangement for a hybrid tower of a wind turbine having said foundation adapter and a further aspect is directed to a wind turbine having a hybrid tower with said foundation arrangement.

BACKGROUND

Different types of foundations for hybrid towers are known in prior art. Normally the foundation connection for distribution forces from the tower to the foundation comprises stubs and brackets which are connected with screws. Therefore a limited amount of brackets can be used. So the amount cannot increase unlimited with higher loads because of higher towers and/or heavier nacelles of wind tur-bine. Furthermore after embedding the stubs and brackets in assembled stated in foundation a retightening of nuts during maintenance of stubs and brackets is not possible. This results in a disadvantage that with increasing forces the loads acting on the brackets getting to high and the risk of damages increases.

OBJECT OF THE INVENTION

So it is one object of the present invention to provide a solution which limits the amount of brackets and to keep the loads in a manner that the risk of damage is reduced or avoided.

SUMMARY OF THE INVENTION

The above-mentioned object is solved with a foundation adapter according to a first aspect of the present invention.

According to this, the foundation adapter for anchoring in a concrete part of a lattice section comprising a joint connector for connecting a corner bar and cross braces of a lattice section and an anchor plate which receives a plurality of anchor bolts for fixing the joint connector.

Advantageously, in assembled state the anchor plate acts as an abutment for counteracting against tensile forces. More advantageously, a plurality of anchor bolts means four to eight anchor bolts, preferred eight anchor bolts, more preferred up to 16 anchor bolts.

With the present invention higher loads can be handled because of a better force distribution from the hybrid tower to the foundation. Furthermore, with this foundation adapter the end of bolts are above the foundation, which makes it possible to retighten the nuts for a better fixation.

In a preferred embodiment of said foundation adapter, the joint connector has two symmetrical parts, preferred four symmetrical parts. Advantageously, the symmetrical parts can be made as casted parts, welded parts or other machine manufactured parts.

In a preferred embodiment of said foundation adapter, each symmetrical part is a single casted component.

In a preferred embodiment of said foundation adapter, each symmetrical part of the joint connector comprises a ground plate, on one side of the ground plate is arranged an angle profile for connecting the corner bar and at opposite side of ground plate is arranged a distance element.

In a preferred embodiment of said foundation adapter, the symmetrical parts connected with angle bracket at angle profile.

A second aspect of the present invention is directed to a foundation arrangement, which solves the above-mentioned object.

According to the present invention, the foundation arrangement for connecting a lattice section comprises a concrete part and said foundation adapter for anchoring in a concrete part of a lattice section. The foundation adapter comprises a joint connector for connecting a corner bar and cross braces of a lattice section and an anchor plate which receives a plurality of anchor bolts for fixing the joint connector. So the benefits of the foundation adapter apply also for the foundation arrangement.

According to a preferred embodiment of said foundation arrangement, the foundation adapter is arranged at the concrete part in such a manner that the anchor plate is arranged at bottom of the concrete part, the anchor bolts running through the concrete part and ending in a grout arranged on top of concrete part, where the joint connector is connected to the anchor bolts.

According to a preferred embodiment of said foundation arrangement, the distance element of joint connector is arranged in grout of the concrete part.

According to a preferred embodiment of said foundation arrangement, the joint connector of the foundation adapter is screwed to the anchor bolts.

A third aspect of the present invention is directed to a wind turbine, which solves the above-mentioned object.

According to the present invention, the wind turbine comprises a hybrid tower, wherein the hybrid tower having said foundation arrangement for connecting a lattice section. The foundation arrangement comprises a concrete part and said foundation adapter for anchoring in a concrete part of a lattice section. The foundation adapter comprises a joint connector for connecting a corner bar and cross braces of a lattice section and an anchor plate which receives a plurality of anchor bolts for fixing the joint connector. So the benefits of the foundation adapter apply also for the foundation arrangement.

BRIEF DESCRIPTION OF DRAWINGS

The invention will now be explained in more detail with respect to exemplary embodiments with reference to the enclosed drawings, wherein:

Figure 1 shows a wind turbine;

Figure 2 shows a hybrid tower for a wind turbine according to Fig. 1;

Figure 3 shows a foundation adapter according to one aspect of the invention;

Figure 4 shows a foundation arrangement for hybrid tower according to Fig. 2;

Figure 5 shows a connection area of foundation arrangement according to Fig. 4;

Figure 6 shows a side-view of connection area according to Fig. 5;

Figure 7 shows a cut-view of connection area according Fig. 5 in assembled state;

Figure 8 shows a preferred embodiment of joint connector of foundation adapter according to Fig. 3 and

Figure 9 shows joint connector according to Fig. 8 in assembled state.

The foregoing and other aspects will become apparent from the following de-tailed description of the invention when considered in conjunction with the ac-companying drawing figures.

DETAILED DESCRIPTION OF THE INVENTION

Figure 1 depicts a schematic view of a wind turbine 1 with a tower 2 and a nacelle 3. The tower 2 will be explained in detail in Fig. 2. Depending on given requirements the wind turbine 1 can be used for offshore or onshore applications. The nacelle 3 is rotatable mounted on the tower 2 which is indicated by a double arrow at the tower 2. The nacelle 3 incorporates a number of components like a drive train chain 4 comprising a rotor shaft 5 (also known as slow-speed-shaft) connecting a rotor 6 with a gear box 7. A high-speed-shaft 8 connects the gear box 7 with a generator 9. The generator 9 is connected with a plurality of electrical components indicated by box 10. Further the nacelle 3 comprises a yaw system 11 for rotating the nacelle 3 indicated by double arrow at tower 2. The rotor 6 comprises three rotor blades 12 which are mounted to a hub body (not shown). Latter is connected to the rotor shaft 5 of the drive train chain 4. The rotor blades 12 are adjustably mounted on the hub body indicated by double arrows at the rotor blade 12. This is realized by means of pitch drives 13, said pitch drives (not shown) being part of a pitch system 13. The pitch system controls the rotor speed to given set points. By means of pitch-drives, the rotor blades 12 may be moved about a rotor blade axes into different pitch positions which is indicated by double arrows at the rotor blade 13. Said rotor blade 6 axis extends in an axial direction of the rotor blades 13. Each rotor blade 13 is connected to the hub body via its blade bearing (not shown). The nacelle 3 is covered by a nacelle cover 14. The hub body is covered by a spinner 15, wherein the hub body and spinner 11 forming a hub 16.

Figure 2 depicts a hybrid tower 2, wherein an upper section of the hybrid tower 2 is designed as a tubular section 17 and a lower section of the hybrid tower 2 is designed as a lattice section 18. The tubular section 17 and the lattice section 18 are connected with each other by means of a transition arrangement 19. The lattice section 18 comprises at least three, in this embodiment, four corner bars 20 which are connected to each other by a number of cross girders 21 and cross braces 22. The corner bars 20 are designed for dissipating the bending moments acting perpendicularly to a tower axis 23 as well as for dissipating loads acting in the tower axis 23. The cross braces 22 of the lattice section 18 are designed for dissipating torsional moments acting around the tower axis as well as for dissipating forces acting perpendicularly to the tower axis 23. The corner bars 20 are arranged with an inclination angle to the tower axis 23. The tubular section 17 is connected to the lattice section 18 via the transition arrangement 19. For the tubular section 17 already existing tubular segments 24 can be used; here, for in-stance, the two uppermost segments 24 of the tubular section 17 are used. The transition arrangement 19 can be arranged on the level of the tip of the one rotor blade 12 located in the lowermost position. Hence the hybrid tower 2 is designed very slimly in the section of the rotor 6 so that it is ensured that the rotor blades 12 can freely move in relation to the hybrid tower 2 even at high deflection of the rotor blades 12. Below the rotor 6 the width of the lattice section 18 can be freely increased so that a large platform and thus a stable standing of the hybrid tower 2 can be guaranteed. The hybrid tower 2 is fixed to the ground with a foundation arrangement 25, which will be explained in detail in Fig. 4.

Figure 3 depicts a foundation adapter 26 according to one aspect of the present invention. This foundation adapter 26 comprises a joint connector 27 for connecting a corner bar (not shown) and cross braces 22 of a lattice section 18. The joint connector 27 can be designed as single part or as two symmetrically parts. Latter embodiment is described in detail with Fig. 8. In both embodiments the joint connector 27 can be manufactured via casting or any other suitable method like welding. Furthermore the foundation adapter 26 comprises an anchor plate 28 on which a plurality of anchor bolts 29 for fixing the joint connector 27 are arranged. In described embodiment the foundation adapter 26 has in sum eight anchor bolts 29. The anchor plate 28 can be made of steel or any other suitable material. The anchor plate 28 can have any suitable shape. In shown embodiment the anchor plate 28 has a circular shape with a maximal diameter of 800 mm and a maximal thickness of 150 mm. However the dimensions can vary and depends on acting loads from hybrid tower 2. Same applies for the anchor bolts 29. In shown embodiment the anchor bolts are from type M39 and can be up to M64 and are 3900 mm long. The length of the anchor bolts 29 depends on the thick-ness of concrete part of foundation which will be explained in detail later. The anchor bolts 29 are attached to a ground plate 30 of the joint connector 27 with nuts (not shown). In particular the ground plate 30 has a circular shape, but other shapes are possible. In shown embodiment the ground plate 30 has a diameter of 625 mm and thickness of 70 mm. However the dimensions of the ground plate 30 can vary and depends on acting loads from hybrid tower 2. The joint connector 27 further having two angle profiles 31 for connecting corner bars (not shown) and can be up to four angle profiles 31, wherein the angle profiles 31 are attached on one side of the ground plate 30. These angle profiles 31 extending in a predetermined angle from the ground plate 30. This angle is determined by the inclination angle of the hybrid tower 2 to be connected. Especially the angle profile 31 has an L-shape. On opposite site of the ground plate 30 is arranged a distance element 32. This distance element 32 extends vertically from the ground plate 30. The shape of the distance element 32 can vary from embodiment to embodiment. For single part joint connector 27 the preferred shape of the distance element 32 is two crossed plates. For another embodiment, according to a symmetrically, two parts joint connector 27, the preferred shaped of the distance element 32 is an angle profile (see Fig. 8). In any case the distance element 32 has a length which depends on the high of grout of concrete part, which will be ex-plained in detail later. In shown embodiment the maximal length of the distance element 32 is 400 mm.

Figure 4 depicts a foundation arrangement 25 for the hybrid tower 2 according to a second aspect of present invention. The foundation arrangement 25 comprises said foundation adapter 26 and a concrete part 33. Latter extends from the anchor plate 28 to the ground plate 30 and envelops the anchor bolts 29. The anchor plate 28 is arranged at bottom of the concrete part 33, the anchor bolts 29 running through the concrete part 33 and ending in a grout 34 arranged on top of concrete part 33, where the joint connector 27 is connected to the anchor bolts 29. In particular, the concrete part 33 has a high of 3900 mm. In this arrangement the joint connector 27 functioned as corner leg for connecting the corner bar (not shown) and cross braces 22. The construction of the corner leg is equal to the joint connector and comprises the angle profiles 31 for connecting corner bars (not shown), wherein the angle profiles 31 are attached on one side of the ground plate 30. On opposite site of the ground plate 30 is arranged the distance element 32.

Figures 5 to 7 depict detailed view of the grout 34 on top of the concrete part 33. In shown embodiment the grout 34 has a circular shape, however other forms are possible. Important is that the diameter of grout 34 is greater than the diameter of the ground plate 30. In shown embodiment the grout 34 has a maximal diameter of 1000 mm. The deep of the grout 34 depends on size of the joint connector 27, which can vary with size of the hybrid tower 2. In shown embodiment the maxi-mal depth is 600 mm. In any case the anchor bolts 29 extending though the grout 34 so that the joint connector 27 can be fixed to them with nuts. In preferred embodiment shown in Fig. 6 the anchor bolts 29 extends over the grout 34 and concrete part 33. This improves the accessibility and mounting of the nuts. In Fig. 7 can be seen that the distance element 32 of joint connector 27 is arranged in the grout 34 of concrete part 33. The space between the distance element 32 and bot-tom of grout 34 is filled with another concrete (not shown). The joint connector 27 is screwed to the anchor bolts 29 above the ground plate 30 via nuts (not shown).

Figure 8 depicts a preferred embodiment of the joint connector 27. According to this the joint connector 27 has two symmetrically formed parts. In preferred embodiment these parts are made of steel manufactured by casting. However, other manufacturing types like welding are possible. Fig. 8a) depicts a first part of the joint connector 27. This first part comprises a ground plate 30a, on one side of the ground plate 30a is arranged one angle profile 31a for connecting the corner bar (not shown) and at opposite side of ground plate 30a is arranged a distance element 32a. In shown embodiment the distance element 32a is an angle plate. Fig. 8b) depicts a second part of the joint connector 27. This second part comprises a ground plate 30b, on one side of the ground plate 30b is arranged one angle profile 31b for connecting the corner bar (not shown) and at opposite side of ground plate 30b is arranged a distance element 32b. In shown embodiment the distance element 32b is an angle plate. For both parts applies that the angle profile 31a, 31b extending from the ground plate 30a, 30b with a pre-determined inclination angle. In particular this angle is of essential 8°. However this angle depends on the construction of the hybrid tower 2 which determines the inclination angle of attack of the corner bars (not sown). Especially the angle profiles 31a, 31b have an L-shape. The distance plate 32a, 32b extends in vertical direction from the ground plate 30a, 30b. In shown embodiment each ground plate 30a, 30b has four bores four receiving respective anchor bolts (not shown). In particular, the ground plate 30a, 30b has a radius of 312.5 mm. In preferred embodiment each part of the joint connector 27 has a high of 1550 mm. However this can vary with acting loads and design of corner bars.

Figure 9 depicts a symmetrically, two part joint connector 27 in assembled state. The symmetrical parts are connected with at least one angle bracket (not shown) at angle profiles 31a, 31b. In preferred embodiment, the angle profiles 31a, 31b are connected with one angle bracket. The angle bracket can be mounted with screws, rivets or any other suitable method for connecting. In preferred embodiment, each flange of the angle profile 31a, 31b has a maximal length of 315 mm and maximal thickness of 35 mm. In shown embodiment the maximal thickness of the ground plate 30a, 30b is 150 mm. Furthermore the cross braces 22 are L- or C-shaped profiles. The angle bracket is dimensioned with a maximal length of 250 mm and a maximal thickness of 35 mm. As mentioned above the distance element 32a, 32b is shaped as angle plate. This angle plate has a maximal flange length of 315 mm and a maximal thickness of 35 mm. The angle plate is maxi-mal 295 mm heigh.

The previous disclosed dimensions are only examples for a specific embodiment and don’t restrict the scope of present invention and only serves as demonstration for described embodiment. All dimension depending on the acting loads of the hybrid tower 2, which increases with high of the hybrid tower 2 and weight of nacelle 3 and rotor 6.

LIST OF REFERENCE SIGNS

1 wind turbine
2 tower
3 nacelle
4 drive train chain
5 rotor shaft
6 rotor
7 gear box
8 high-speed-shaft
9 generator
10 electrical components
11 yaw system
12 rotor blades
13 pitch system
14 nacelle cover
15 spinner
16 hub
17 tubular section
18 lattice section
19 adapter arrangement
20 corner bars
21 cross girders
22 cross braces
23 tower axis
24 tubular segments
25 foundation arrangement
26 foundation adapter
27 joint connector
28 anchor plate
29 anchor bolts
30 ground plate
30a ground plate of first part
30b ground plate of second part
31 angle profile
31a angle profile of first part
31b angle profile of second part
32 distance element
32a distance element of first part
32b distance element of second part
33 concrete part
34 grout


, Claims:We Claim:

1. A foundation adapter (26) for anchoring in a concrete part of a lattice section, comprising a joint connector (27) for connecting a corner bar and cross braces of a lattice section and an anchor plate (28) which receives a plurality of anchor bolts (29) for fixing the joint connector (27).

2. The foundation adapter (26) according to claim 1, wherein the joint connector (27) has two symmetrical parts.

3. The foundation adapter (26) according to claim 2, wherein each symmetrical part of the joint connector (27) is a single casted component.

4. The foundation adapter (26) according to claim 2 or 3, wherein each symmetrical part of the joint connector (27) comprises a ground plate (30a, 30b), on one side of the ground plate (30a, 30b) is arranged an angle profile (31a, 31b) for connecting the corner bar and at opposite side of ground plate (30a, 30b) is arranged a distance element (32a, 32b).

5. The foundation adapter (26) according to one of the claims 2 to 4, wherein the symmetrical parts of joint connector (27) connected with angle bracket (35) at angle profiles (31a, 31b)

6. A foundation arrangement (25) for connecting a lattice section having a concrete part (33), characterized by a foundation adapter (26) according to one of the claims 1 to 5.

7. The foundation arrangement (25) according to claim 6, wherein the anchor plate (28) is arranged at bottom of the concrete part (33), the anchor bolts running through the concrete part (33) and ending in a grout (34) arranged on top of concrete part (33), where the joint connector (27) is connected to the anchor bolts (29).

8. The foundation arrangement (25) according to claim 7 or 8, wherein distance element (32) of joint connector (27) is arranged in grout (34) of concrete part (33).

9. The foundation arrangement (25) according to one of the claims 7 to 9, wherein the joint connector (27) is screwed to the anchor bolts (29).

10. A hybrid tower (2) for a wind turbine characterized by a foundation arrangement (25) according to one of the claims 6 to 9.

11. A wind turbine (1) having a hybrid tower (2) according to claim 10, characterized by a foundation arrangement (25) according to one of the claims 6 to 9.

Dated this 21st day of March, 2024

Nandan Pendsey
(IN/PA – 726)
Authorized Agent of the Applicant
To
The Controller of Patents
The Patents Office
Mumbai