Wind power turbine and method of removing a bearing from a wind power turbine

[0001] The present invention relates to a wind turbine.

[0002] In particular, the present invention relates to a wind turbine equipped with a tubular electric generator as described in US Patent No. 7385306B2 and patent application EP 2148090A1, to which the present description refers by way of example only.

[0003] A wind turbine of a different construction is shown in document WO 2006 / 000214A1.

[0004] Wind turbines usually comprise a nacelle, a rotary assembly attached to the nacelle that rotates about an axis of rotation, and at least one bearing or bearing assembly between the nacelle and the rotary assembly. The bearing and bearings in the bearing assembly are usually roller bearings that wear out and must eventually be replaced. Replacing a bearing or bearing assembly is a complex, labor-intensive task that requires dismantling a part of the wind turbine and invariably involves significant downtime. It is also a dangerous operation, due to the weight of the bearing and the components supported by it, which is directly proportional to the size of the gas turbine.

[0005] Document EP 1772624A2 describes a method of removing a bearing assembly from a wind turbine which, in addition to dismantling the bearing assembly from the rotating assembly and the nacelle, also includes manipulating the bearing assembly within the nacelle along and transversely to the axis of rotation, as shown in Fig.

7. As mentioned, this is a labor-intensive occupation, which is even more difficult due to exercising in a limited space inside the gondola.

[0006] The same also applies to the wind turbine described in patent application DE 10 2004 028 746 A1, which requires a similar procedure to change a single bearing.

[0007] The purpose of the present invention is a wind turbine designed to the known state of the art.

is to provide a limitation of the disadvantages [0008] Another object of the present invention is to provide a wind turbine adapted to allow easy removal of the bearing and installation, especially to reduce downtime.

[0009] According to the present invention, a wind turbine is provided for generating electricity, which wind turbine comprises a nacelle; electric generator having a stator and rotor; a rotary assembly connected to the nacelle to rotate about an axis of rotation; and a bearing positioned between the gondola and the rotary assembly, the gondola comprising a first sector which is located at the bearing, is removable from the gondola and is adapted to form, when removed, an opening in the gondola to allow passage of the bearing and a second complementary sector relative to first sector and connected to the first sector around the axis of rotation to form a ring to support the bearing.

[0010] The bearing can thus be removed from the nacelle by simply displacing the bearing radially with respect to the axis of rotation and can be changed faster and safer by reducing the movement of the rotating assembly.

[0011] The first sector is therefore a bearing support sector and, when removed, allows direct access to the bearing from outside the nacelle.

[0012] In another preferred embodiment of the invention, the ring is connected to the rest of the gondola by a sliding connection which slides in a direction parallel to the axis of rotation and allows adjustment by a few millimeters to the position of the ring relative to the rest of the gondola.

[0013] The nacelle design allows the bearing to move slightly relative to other parts of the rotating assembly.

[0014] In another preferred embodiment of the invention, the rotary assembly comprises a rotor; a hub; blades extending from the hub and a connecting element located between the hub and the rotor at the bearing and detachably connected to the rotor and the hub.

[0015] By releasing the connecting element from the rotor and hub, the rotor need not be removed from the rotary assembly, thereby greatly reducing the axial movement of the bearing and / or the rotary assembly within the nacelle.

[0016] Another object of the invention is to provide a simple, practical method for removing a bearing.

[0017]

According to the present invention, a method of removing a bearing from a wind turbine is provided, which wind turbine comprises a nacelle; electric generator having a stator and rotor; a rotary assembly that includes a rotor, hub and blades extending from the hub and connected to the nacelle to rotate about an axis of rotation; and a bearing positioned between the gondola and the rotary assembly and the gondola includes a first sector located at the bearing; wherein the method is characterized in that it comprises the steps of removing the first sector from the nacelle to form a hole near the bearing large enough to allow passage of the bearing; releasing the bearing at least partially from the rotary assembly; removing the bearing through a hole in the nacelle; and fixing the hub to the nacelle before removing the first sector.

[0018] A non-limiting embodiment of the present invention will be described by way of example with reference to the accompanying drawings, in which:

Figure 1 shows a side view, with parts removed for clarity, of a wind turbine in accordance with the present invention;

Figure 2 shows on a larger scale a side view of the wind turbine of Figure 1, in partial section, with parts removed for clarity;

Figures 3 to 10 show cross sections, with parts removed for clarity, of the detail of Figure 2 in subsequent stages of the bearing removal method in accordance with the present invention.

[0019] The number 1 in Figure 1 indicates as a whole a wind turbine for generating electricity. The wind turbine 1 comprises a vertical support 2, a nacelle 3, an electric generator 4 and a rotary assembly 5 attached to the nacelle 3, rotating about the axis of rotation A1. The nacelle 3 in turn is mounted to the vertical support 2 to rotate around the axis of rotation A2.

[0020] The nacelle 3 is essentially a tubular element for supporting the rotary assembly 5, which extends partly inside and partly outside the nacelle 3. In the example shown in the figure, the nacelle 3 comprises a curved tubular element 6, a part of an electric generator 4 and a ring 7 containing two supplementary sectors 8, 9 attached to each other around the axis of rotation A1.

[0021] With reference to Figure 2, the electric generator 4 is tubular and comprises a stator 10 and a rotor 11. The stator 10 comprises a cylindrical wall 12 and stator segments 13 arranged around the axis of rotation A1 and attached to the inner face of the cylindrical wall 12 and the rotor 11 comprises a cylindrical wall 14 and rotor segments 15 arranged around the axis of rotation A1 and attached to the outer face of the cylindrical wall 14.

[0022] More specifically, the nacelle 3 comprises a curved tubular element 6; stator 10 or rather cylindrical wall 12 of stator 10 and ring 7.

[0023] Thus, the cylindrical wall 12 has two opposite ends with a flange attached to the curved tubular element 6 and the ring 7 by respective screw joints 16 and 17. More specifically, the ring 7 is slidably connected to the cylindrical wall 12 and is locked in its position by a screw connection 17, which includes screws parallel to the axis of rotation A1 and connecting the respective end surfaces of the ring 7 and the cylindrical wall 12. The ring 7 comprises cylindrical wall shaped protrusions 71 around the cylindrical wall 12 and in contact with the cylindrical wall 12 to form a telescopic connection; and tabs 71 are formed with slots 72 arranged around the axis of rotation A1, near the point where the face of the ring 7 contacts the face of the cylindrical wall 12.

[0024] More specifically, sectors 8 and 9 are hemispherical and connected by two screw joints 18 (only one is shown in Figure 2) to form a ring 7. In the example shown in the drawing, sector 8 is located below sector 9.

[0025] The wind turbine 1 comprises a bearing 19 between the nacelle 3 and the rotary assembly 5. In the example shown in the drawing, the wind turbine 1 comprises a single bearing 19 capable of withstanding axial and radial stresses between the nacelle 3 and the rotating assembly 5; it being understood, however, that the particular configuration shown in the drawings and described herein in no way limits the scope of protection of the present invention. The bearing 19 is attached to the outside of the ring 7, in the example shown in the figure it is attached directly to sectors 8 and 9 and is attached to the inside of the rotating assembly 5.

[0026] The rotary assembly 5 comprises a rotor 11; hub 20 and blades 21 attached to hub 20. In the example shown, the rotary assembly 5 also includes a connecting member 22 located between the rotor 11 and hub 20, at bearing 19 and substantially inside bearing 19. More specifically, bearing 19 is attached directly to connecting element 22, which is connected directly to the rotor 11. In other words, wind turbine 1 is a direct drive wind turbine.

[0027] With reference to Figure 3, the bearing 19 is a rolling bearing - in the example shown in the drawing, with inclined conical rollers - and includes an outer race 23, an inner race 24 and two conical roller rings. The outer race 23 is attached to the nacelle 3 - in the example shown in the figure, to the ring 7. More specifically, the outer race 23 is attached to the ring 7 through the flange 25 and the screw connection 26 that connects the flange 25, the outer race 23 and the ring 7. The flange 25 and the ring protrusion 7 define two opposing beads, each for a respective tapered roller ring.

[0028] The inner race 24 is attached to the connecting member 22, which includes a ring 27 and a flange 28 connected to the ring 27 and hub 20 via a screw connection 29. In other words, the inner race 24 is axially gripped - with respect to the axis of rotation A1 - between the bead 28 and a bead formed on the ring

27.

[0029] The rotor 11 is also attached to the connecting element 22 by means of a screw connection 30.

[0030] Hub 20 comprises a flange 31 partially facing connecting element 22 and ring 7 and connecting hub 20 with connecting element 22 and ring 7.

[0031] The flange 31 is connected to the connecting element 22 by means of a screw connection 29 and is connected to the ring 7 by means of a screw connection 32 and washers 33 inserted inside the gap between the facing parts of the ring 7 and the flange 31 as shown in Figure 4.

[0032] Removing bearing 19 generally includes: dismantling sector 8 from the nacelle 3 to form an opening 34 at bearing 19, large enough to allow passage of bearing 19, as shown in Figure 10; at least partially detaching the bearing 19 from the rotary assembly 5, as shown in Figures 5, 6 and 7; and removing sector 8, bearing 19 and connecting member 22 through the opening 34 in the nacelle 3.

[0033] The method of removing bearing 19 includes fastening the hub 20 to the nacelle 3, as shown in Figure 4, before disconnecting the bearing 19 from the rotary assembly 5 and removing sector 8.

[0034]

In other words, the connecting element 22 is detached from the rotor 11 (Figure 5) and hub 20 (Figure 7). In fact, sector 8, bearing 19 and connecting element 22 are removed simultaneously from the nacelle 3 and connected together, as shown in Figure 10.

[0035] More specifically, the method of removing bearing 19 dies down the first step (Figure 4) of fastening the hub flange 31 to both sectors 8 and 9 by means of a screw connection 32 and washers 33 to lock the rotary assembly 5 in a given position relative to the nacelle 3. Then the rotor 11 is locked in a given position relative to the stator 10 by inserting seals between the rotor 11 and the stator 10, in a known manner, not shown in the drawings. In other words, the rotor is attached to the nacelle 3 independently of the hub 20.

[0036] Next, the rotor 11 is detached from the rotary assembly 5 by removing the screws of the screw joint 30 as shown in Figure 5.

[0037] With reference to Figure 6, the screws of the screw joint 17 are loosened and the ring 7, bearing 19, hub 20, connecting element 22 and blades 21 are separated by a few millimeters from the rest of the gondola - in the example shown in the drawing from the wall 12 - in direction parallel to the axis of rotation A1 to create a gap between the rotor and the connecting element 22.

[0038] The washers, not shown in the drawings, are inserted through the slots 72 and the bolts of the screw joint 17 are re-tensioned so as to move the rotor 11 a few millimeters away from the connecting element 22.

[0039] With reference to Figure 7, the screws of the screw joint 29 are removed to detach the connecting element 22 from the hub 20.

[0040] With reference to Figure 8, some of the bolt connector bolts 26 are removed to release the outer race 23 of the bearing 19 from sector 9.

[0041] Referring to Figure 9, some of the bolt connector 17 bolts are removed to free sector 8 from the nacelle 3 and bolt connectors 18 (Figure 2) are also removed to release sector 8 from the nacelle 3 and pull out sector 8, bearing 19, connecting element 22 and collar 55 of the nacelle

3.

[0042] The removal operation may be carried out using a crane or jack not shown in the drawings.

[0043] As will be clear, the movement of the bearing 19 is the rotation of A1.

from the above description, the only one radial to the axis [0044] The movements of the other components are limited to only a few millimeters.

[0045] The new bearing is installed by performing the bearing removal sequence in reverse order.

[0046] As will be clear from the above description, the present invention has many advantages.

[0047] Of course, changes may be made to the wind turbine and the method described herein, without however departing from the scope of the appended claims. In particular, the present invention also applies to wind turbines equipped with more than one bearing and other than tubular electric generators.

[0048] In the above description, specific reference is repeatedly made, for simplicity, to screw joints, which was to mean joints made using bolts and nuts or bolts screwed directly on one of the parts to be joined, but they can be replaced by any another type of releasable connector.

WILIC S.AR.L

Proxy:

77P32365PL00

EP 2 372 145 B1