PLAIN BEARING FOR A WIND TURBINE BLADE AND METHOD OF OPERATING A WIND TURBINE HAVING SUCH A PLAIN BEARING

• US 20110188988A1
• Filed: 01/10/2011
• Published: 08/04/2011
• Est. Priority Date: 01/10/2011
• Status: Active Grant

• Current Assignee: Vestas Wind Systems A/S
• Original Assignee: Vestas Wind Systems A/S
• Inventors: Wadehn, Jõrg
• Granted Patent: US 8,172,531 B2
• Time in Patent Office: Days
• US Class Current: 415/1
• CPC Class Codes: F03D 1/0658 Arrangements for fixing wind-engaging parts to a hub
• CPC Class Codes: F03D 17/00 Monitoring or testing of wind motors, e.g. diagnostics testing during commissioning of wind motors F03D13/30
• CPC Class Codes: F03D 80/70 Bearing or lubricating arrangements
• CPC Class Codes: F05B 2260/79 Bearing, support or actuation arrangements therefor
• CPC Class Codes: F16C 2233/00 Monitoring condition, e.g. temperature, load, vibration
• CPC Class Codes: F16C 2300/14 Large applications, e.g. bearings having an inner diameter exceeding 500 mm
• CPC Class Codes: F16C 2360/31 Wind motors in general F03D
• CPC Class Codes: F16C 32/0644 Details of devices to control the supply of liquids to the bearings
• CPC Class Codes: F16C 32/0692 for axial load only
• CPC Class Codes: Y02E 10/72 Wind turbines with rotation axis in wind direction

Abstract

A plain bearing assembly for mounting a blade to a hub of a wind turbine includes an outer member mountable to one of the blade or hub, and an inner member mountable to the other of the blade or hub and movable relative to the outer member. The plain bearing further includes fluid cavities associated with one of the outer or inner member and arranged to confront the other of the outer or inner member. The fluid cavities are coupled to a pressure source for establishing a pressurized fluid film between the inner and outer members. A method includes monitoring at least one parameter of the fluid film, comparing the at least one parameter to a threshold criteria, and altering a dynamic state of the wind turbine and/or altering the state of the blade bearing assembly if the threshold criteria is exceeded.

Claims

1. A plain bearing assembly for mounting a rotor blade to a rotor hub of a wind turbine, comprising:

an outer member configured to be mounted to one of the blade or the hub of the wind turbine and including an annular cavity;

an inner member configured to be mounted to the other of the blade or the hub of the wind turbine and positioned in the annular cavity so that the inner and outer members are movable relative to each other;

a plurality of fluid cavities associated with one of the outer or inner member, the cavities confronting the other of the outer or inner member,

wherein the fluid cavities are configured to be operatively coupled to a fluid supply and a pressure source for establishing a pressurized fluid film between the inner and outer members, the fluid film configured to support the loading of the blades so as to maintain separation of the inner and outer members, but yet allow relative movement therebetween.

2. The plain bearing assembly according to claim 1, further comprising a plurality of pads coupled to one of the outer or inner member, the fluid cavities being defined in a surface of the pads that confronts the other of the outer or inner member.

3. The plain bearing assembly according to claim 2, wherein the pads are generally arcuate in shape.

4. The plain bearing assembly according to claim 2, wherein the pads are movably coupled to one of the outer or inner member.

5. The plain bearing assembly according to claim 4, wherein the pads are coupled to one of the outer or inner member by at least one spring, the spring biasing the pads toward the other of the outer or inner member.

6. The plain bearing assembly according to claim 1, further comprising a support shell disposed between the inner and outer member and configured to support at least partial loading of the blade bearing assembly.

7. The plain bearing assembly according to claim 1, wherein the inner member is formed as an annular ring having an inner surface, an outer surface, an upper surface and a lower surface, and the outer member is formed as an annular ring having an outer wall, an upper wall coupled to the outer wall, and a lower wall coupled to the outer wall, the outer, upper and lower walls forming boundaries of the annular cavity.

8. The plain bearing assembly according to claim 7, wherein the inner surface of the inner member includes a plurality of teeth configured to cooperate with a pitch mechanism for moving one of the outer or inner member relative to the other of the outer or inner member.

9. The plain bearing assembly according to claim 7, wherein at least one pad is coupled to a lower surface of the upper wall and at least one pad is coupled to an upper surface of the lower wall.

10. A wind turbine, comprising:

a tower;

a nacelle located adjacent a top of the tower;

a rotor having a hub and a plurality of blades extending therefrom and configured to interact with the wind to rotate the rotor;

a blade bearing assembly for rotatably mounting the blades to the hub, the blade bearing assembly comprising a plain bearing assembly, comprising;

an outer member configured to be mounted to one of the blade or the hub of the wind turbine and including an annular cavity;

an inner member configured to be mounted to the other of the blade or the hub of the wind turbine and positioned in the annular cavity so that the inner and outer members are movable relative to each other; and

a plurality of fluid cavities associated with one of the outer or inner member, the cavities confronting the other of the outer or inner member,

wherein the fluid cavities are configured to be operatively coupled to a fluid supply and a pressure source for establishing a pressurized fluid film between the inner and outer members, the fluid film configured to support the loading of the blades so as to maintain separation of the inner and outer members, but yet allow relative movement therebetween; and

a pitch system for rotating a blade relative to the hub.

11. The wind turbine according to claim 10, further comprising a pump for pressurizing the fluid film between the outer and inner members of the blade bearing assembly.

12. A method of operating a wind turbine having a blade bearing assembly including an outer member coupled to one of a rotor blade or hub, an inner member coupled to the other of the rotor blade or hub, and a fluid film separating the outer and inner members, the wind turbine also having at least one sub-system capable of altering a dynamic state of the wind turbine, comprising:

monitoring at least one parameter of the fluid film indicative of a load on the blade;

comparing the at least one parameter to a threshold criteria; and

performing at least one of the following steps when the at least one parameter meets the threshold criteria;

i) altering the dynamic state of the wind turbine to reduce the load on the blade; and

ii) altering the state of the blade bearing assembly so as to better accommodate the load on the blade.

13. The method according to claim 12, wherein monitoring at least one parameter of the fluid film further comprises at least one of monitoring a pressure of the fluid film, monitoring a temperature of the fluid film, and monitoring a thickness of the fluid film.

14. The method according to claim 12, wherein altering the dynamic state of the wind turbine to reduce the load on the blade further comprises at least one of:

i) yawing the nacelle relative to the tower;

ii) pitching the blades of the wind turbine; and

iii) applying a brake to slow the speed of the rotor.

15. The method according to claim 12, wherein altering the state of the bearing assembly so as to better accommodate the load on the blade further comprises increasing the pressure in the fluid film.

16-21. -21. (canceled)