Pitch bearing for wind turbine rotor blades

1. A pitch bearing for a wind turbine rotor having a rotor hub and at least one rotor blade, comprising:

a cylindrical inner bearing ring connectable to a rotor blade of the wind turbine rotor;

a cylindrical outer bearing ring connectable to the rotor hub of the wind turbine rotor; and

an annular reinforcement section that adjoins to the cylindrical outer bearing ring at its radial outer surface such that at least a portion of the wall thickness of the outer bearing ring is increased,

wherein the wall thickness of the outer bearing ring decreases continually from the axial outer end, or from a portion of constant wall thickness that is located at the axial outer end, towards the axial inner end of the outer bearing ring, the decrease of the wall thickness relative to the decrease of the radial forces from the axial outer end towards the axial inner end.

2. The pitch bearing as claimed in claim 1 , wherein the reinforcement section is formed by an increased wall thickness of the outer bearing ring in a ring portion adjoining the outer bearing's axial outer end towards the outer bearing's axial inner end.

3. The pitch bearing as claimed in claim 1 , wherein the wall thickness of the outer bearing ring decreases continuously from the portion of constant wall thickness that is located at the axial outer end to the axial middle of the outer bearing ring.

4. A wind turbine comprising a rotor comprising:

a rotor arranged along a rotational axis of the turbine;

a plurality of blades arranged circumferentially around the rotor; and

at least one pitch bearing according to claim 1 .

5. The wind turbine as claimed in claim 4 , wherein the reinforcement section is formed by an increased wall thickness of the outer bearing ring in a ring portion adjoining the outer bearing's axial outer end towards the outer bearing's axial inner end.

6. The wind turbine as claimed in claim 4 , wherein the wall thickness of the outer bearing ring decreases continuously from the axial outer end towards the axial inner end of the outer bearing ring.

7. The wind turbine as claimed in claim 6 , wherein a wall thickness of the outer bearing ring is constant in a ring portion extending from the outer bearing ring's axial inner end to an axial middle of the outer bearing ring.

8. A pitch bearing for a wind turbine rotor with a rotor hub and at least one rotor blade, comprising:

a cylindrical inner bearing ring connectable to a rotor blade of the wind turbine rotor;

a cylindrical outer bearing ring connectable to the rotor hub of the wind turbine rotor; and

an annular reinforcement section that adjoins to the cylindrical outer bearing ring at its radial outer surface such that at least a portion of the wall thickness of the outer bearing ring is increased in the radial direction, the annular reinforcement section comprising at least two separate ring segments joined together via a connector inside the adjoining ring segments, the connector arranged tangentially in relation to the adjoining ring segments, and the annular reinforcement section joined to the outer bearing ring via a radial connection.

9. The pitch bearing as claimed in claim 8 , wherein the at least two separate ring segments are releasably joined together.

10. The pitch bearing as claimed in claim 9 , wherein the at least two separate ring segments are releasably joined together by bolting.

11. The pitch bearing as claimed in claim 10 , wherein the at least two separate ring segments adjoin the radial outer surface of the cylindrical outer bearing ring.

12. The pitch bearing as claimed in claim 8 , wherein the at least two separate ring segments are releasably joined to the outer bearing ring.

13. The pitch bearing as claimed in claim 8 , wherein the annular reinforcement section does not extend below a top most rolling element relative to an axial outer end of the outer bearing ring.