Wind turbine and pitch bearing of the wind turbine

1. A pitch bearing comprising:

at least two rings, each of the at least two rings being attached to a first or second wind turbine component, the first wind turbine component being a blade and the second wind turbine component being hub; and

at least one bearing reinforcement attached to at least one of the two rings,

wherein the at least one bearing reinforcement comprises a bearing reinforcement thickness that is variable along a circumferential direction of the pitch bearing,

wherein the at least one bearing reinforcement comprises two ends and a central part disposed between the ends in a circumferential direction of the pitch bearing wherein the bearing reinforcement thickness of the at least one bearing reinforcement is variable along the circumferential direction of the pitch bearing from the ends towards the central part of the at least one bearing reinforcement, wherein a ratio between a maximum bearing reinforcement thickness and a bearing thickness is at least 15%, and

wherein the at least one bearing reinforcement is attached to at least one of the two rings such that, in use, the at least one of the two rings is disposed, along the axial direction of the pitch bearing, between the at least one bearing reinforcement and the wind turbine component to which the at least one of the two rings is attached.

2. The pitch bearing according to claim 1 , wherein the bearing reinforcement thickness of the at least one bearing reinforcement reaches a maximum reinforcement thickness in the central part of the at least one bearing reinforcement.

3. The pitch bearing according to claim 1 , wherein the bearing reinforcement thickness of the at least one bearing reinforcement is variable along the circumferential direction of the pitch bearing from the ends towards the central part of the at least one bearing reinforcement in a symmetrical manner.

4. The pitch bearing according to claim 1 , wherein the at least one bearing reinforcement is attached to at least one of the two rings such that a maximum reinforcement thickness is located coinciding with an area of the pitch bearing subjected to the highest stresses or deformations in the pitch bearing.

5. The pitch bearing according to claim 1 , wherein the bearing reinforcement thickness is variable in the circumferential direction of the pitch bearing in a continuous manner in at least a part of the at least one bearing reinforcement.

6. The pitch bearing according to claim 1 , wherein the at least one bearing reinforcement comprises recesses in correspondence with bolts to provide a flat surface to support bolt heads.

7. The pitch bearing according to claim 1 , wherein the at least one bearing reinforcement thickness is variable in the circumferential direction of the pitch bearing in a discontinuous manner.

8. The pitch bearing according to claim 7 , wherein the at least one bearing reinforcement comprises at least two stacked reinforcing plates.

9. The pitch bearing according to claim 8 , wherein each one of the at least two stacked reinforcing plates has a different longitudinal dimension and is stacked along a different angular sector over the at least one of the two rings to which the at least one bearing reinforcement is attached.

10. The pitch bearing according to claim 9 , wherein one of the stacked reinforcing plates is closer to the at least one of the two rings to which the at least one bearing reinforcement is attached than the at least one other reinforcement plate of the stacked reinforcing plates and wherein the longitudinal dimension of the stacked reinforcing plate closer to the at least one of the two rings to which the at least one bearing reinforcement is attached is greater than the longitudinal dimension of the at least one other stacked reinforcing plate such that it extends along a greater angular sector over the at least one of the two rings to which the at least one bearing reinforcement is attached.

11. The pitch bearing according to claim 8 , wherein one of the stacked reinforcing plates is closer to the at least one of the two rings to which the at least one bearing reinforcement is attached than the at least one other reinforcement plate of the stacked reinforcing plates and wherein a thickness of the stacked reinforcing plate closer to the at least one of the two rings to which the at least one bearing reinforcement is attached is greater than a thickness of the at least one other stacked reinforcing plate.

12. The pitch bearing according to claim 8 , wherein one of the stacked reinforcing plate is closer to the at least one of the two rings to which the at least one bearing reinforcement is attached than the at least one other reinforcement plate of the stacked reinforcing plates and wherein a thickness of the stacked reinforcing plate closer to the at least one of the two rings to which the at least one bearing reinforcement is attached is smaller than a thickness of the at least one other stacked reinforcing plate.

13. The pitch bearing according to claim 8 , wherein the stacked reinforcing plates have substantially the same thickness.

14. The pitch bearing according to claim 1 , wherein a width of the at least one bearing reinforcement is substantially equal to a width of the at least one of the two rings to which the at least one bearing reinforcement is attached.

15. The pitch bearing according to claim 1 , wherein the pitch bearing is a rolling element bearing and the at least one bearing reinforcement is located coinciding with an area of the pitch bearing near to the position of an orifice for the insertion of the rolling element.

16. The pitch bearing according to claim 1 , wherein the at least two rings comprise an outer ring and an inner ring, wherein the at least one bearing reinforcement is attached to the outer ring.

17. The pitch bearing according to claim 16 , wherein the outer ring is attached to the hub, wherein the at least one bearing reinforcement is attached to a planar surface of the outer ring opposite to a planar surface closer to the hub.

18. A wind turbine comprising the pitch bearing according to claim 1 .

19. The pitch bearing according to claim 1 , wherein the ratio between the maximum bearing reinforcement thickness and the bearing thickness is at least 25%.