Reliable pitch tube for a blade pitch control system of a wind turbine

Abstract

A pitch tube for a blade pitch control system of a wind turbine includes a tube body extending from a first axial end to a second axial end, for passing supply lines through a transmission. The tube body is designed in multiple parts and made of a non-conductive material only in an axial partial region in order to electrically insulate the first axial end in relation to the second axial end and/or in order to electrically insulate the tube body in relation to the transmission.

Claims

1. A pitch tube for a blade pitch control system of a wind turbine, the pitch tube comprising a tube body extending from a first axial end to a second axial end, for passing supply lines through a transmission, said tube body designed of multiple parts and made of a non-conductive material only in an axial partial region in order to electrically insulate the first axial end in relation to the second axial end and/or in order to electrically insulate the tube body in relation to the transmission.

2. The pitch tube of claim 1, wherein the tube body comprises an insulating tube made of the non-conductive material, and a sleeve arranged radially outside the insulating tube and made of a material which is different than the non-conductive material, for providing a bearing surface and/or a contacting or non-contacting sealing surface in relation to the transmission.

3. The pitch tube of claim 2, wherein the material of the sleeve is steel.

4. The pitch tube of claim 1, wherein the tube body comprises an inner tube made of a material which is different than the non-conductive material, and an insulating sleeve arranged radially outside the inner tube and made of the non-conductive material, for providing a bearing surface and/or a contacting or non-contacting sealing surface in relation to the transmission.

5. The pitch tube of claim 4, wherein the inner tube made is made of steel.

6. The pitch tube of claim 1, wherein the tube body comprises an insulating tube made of the non-conductive material, and an inner tube made of a material which is different than the non-conductive material, wherein the insulating tube and the inner tube are connected to each other consecutively in an axial direction.

7. The pitch tube of claim 6, wherein the tube body comprises two of said inner tube, with the insulating tube arranged in the axial direction between the two inner tubes.

8. The pitch tube of claim 6, further comprising a flange connection designed to connect the insulating tube and the inner tube to each other so as to be fixed against movement.

9. The pitch tube of claim 6, wherein the insulating tube and the inner tube are connected to each other so as to be axially secured.

10. The pitch tube of claim 6, wherein the insulating tube is made of steel.

11. The pitch tube of claim 6, wherein the insulating tube and the inner tube are inserted into each other in an axial connection region.

12. The pitch tube of claim 11, further comprising an axial securing element designed to secure the insulating tube and the inner tube in the axial direction, said axial securing element being a radially extending connector and/or a securing ring and/or a groove nut outside the connection region.

13. The pitch tube of claim 12, wherein the radially extending connector is in the connection region.

14. The pitch tube of claim 11, further comprising a sleeve arranged in the connection region and made of a material which is different from the non-conductive material for providing a bearing surface and/or a contacting or non-contacting sealing surface in relation to the transmission, and/or the pitch tube further comprising an insulating sleeve arranged in the connection region and made of the non-conductive material for providing a bearing surface and/or a contacting or non-contacting sealing surface in relation to the transmission.

15. The pitch tube of claim 14, wherein the sleeve is made of steel.

16. The pitch tube of claim 11, further comprising a clamping ring arranged in the connection region and designed to press together the insulating tube with the inner tube so as to be fixed against movement.

17. The pitch tube of claim 1, wherein the axial partial region produced from the non-conductive material is designed as a load-dissipating tube piece for the multi-part tube body.

18. A transmission for a wind turbine, the transmission comprising a pitch tube which comprises a tube body extending from a first axial end to a second axial end, for passage of supply lines through the transmission, said tube body designed of multiple parts and made of a non-conductive material only in an axial partial region in order to electrically insulate the first axial end in relation to the second axial end and/or in order to electrically insulate the tube body, the transmission further comprising a transmission housing, wherein the first axial end of the tube body on a generator-side axial side of the transmission housing protrudes from the transmission housing and/or the second axial end of the tube body on a rotor-side axial side of the transmission housing facing away from the generator-side axial side protrudes from the transmission housing.

19. The transmission of claim 18, wherein the pitch tube is mounted and/or guided in the transmission so as to be relatively rotatable and relatively axially displaceable.

Description

BRIEF DESCRIPTION OF THE DRAWING

(1) The invention is explained below by way of example with reference to the accompanying drawings using preferred exemplary embodiments, wherein the features presented below can each represent an aspect of the invention both individually and in combination. In the drawings:

(2) FIG. 1: shows a schematic perspective view of a wind turbine,

(3) FIG. 2: shows a schematic sectional view of part of the wind turbine from FIG. 1,

(4) FIG. 3: shows a schematic sectional view of a first embodiment of a pitch tube for the wind turbine from FIG. 1,

(5) FIG. 4: shows a schematic sectional view of a second embodiment of a pitch tube for the wind turbine from FIG. 1,

(6) FIG. 6: shows a schematic sectional view of a third embodiment of a pitch tube for the wind turbine from FIG. 1, and

(7) FIG. 6: shows a schematic sectional view of a fourth embodiment of a pitch tube for the wind turbine from FIG. 1.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

(8) The wind turbine 10 shown in FIG. 1 can be used to generate electrical energy from wind power. For this purpose, the wind turbine 10 has a rotor 12, which, wind-powered by wind, can be rotated. The rotor 12 is coupled to a drive train 14. For this purpose, the rotor 12 is connected to a rotor shaft 16, which is coupled within the drive train 14 to a transmission 18 to convert the torque introduced via the rotor 12 and the rotor shaft 16. The torque converted in the transmission 18 is supplied via a motor shaft 19 to an electric machine which is operated in generator mode and can form a generator 20. The electrical energy generated by the electric machine can be supplied to a rechargeable battery and/or to a power grid. In the illustrated exemplary embodiment, the drive train 14 is completely accommodated in a nacelle 22, which is attached to an upper free end of a stationary tower 24. The rotor 12, the transmission 18 and the generator 20 can be arranged coaxially to one another and can preferably run at an angle to the horizontal.

(9) As shown in FIG. 2, a pitch tube 26 can run through the generator 20 and the transmission 18 as far as the rotor 12 in order to be able to route electrical and/or hydraulic supply lines to a blade pitch control system of the rotor. The pitch tube 2 can be mounted and/or sealed here on the rotor shaft 16 and on the motor shaft 19 so as to be rotatable relative thereto. In one embodiment, an, in particular one-piece, tube body 28 can be completely made of a non-conductive material and can be supported and sealed via metallic sleeves 30 pressed on the tube body 28. In another embodiment, the, in particular one-piece, tube body 28 can be made of an electrically conductive material, for example steel, while, for the electrical insulation of the transmission 18 in relation to the tube body 28, insulating sleeves 32 made of a non-conductive material can be pressed on the tube body 28 and, in addition to the electrical insulation, can support a bearing and/or sealing of the pitch tube 26.

(10) The rotor shaft 16 can be connected to a rotor 34 for rotation therewith, the rotor interacting electromagnetically with a stator 36 to form an electric machine of the generator 20. The generator 20 can be directly adjoined by a transmission housing 38 of the transmission 18, such that the material of the transmission housing 38 can also close an axial side of the generator 20 facing the transmission 18. The rotor shaft 19, which is connectable to the rotor 12, is an input shaft of the transmission 18, wherein in the illustrated exemplary embodiment, the transmission has a first planetary stage 40 and a second planetary stage 42 following in the axial direction.

(11) As shown in FIG. 3, the tube body 28 of the pitch tube 26 can also be produced from multiple parts and as a composite of different materials. The tube body 28 can have a metallic inner tube 44 and an insulating tube 46 made of the non-conductive material, said tubes being arranged consecutively in the axial direction and being connected to each other. The insulating tube 46 provides an electrically insulating axial partial region of the tube body 28, which blocks the transmission of electrical voltages and currents induced in the generator 20. Here, for example, the inner tube 44 can be inserted into the insulating tube 46 or vice versa. In an axial connection region 48, in which, in the illustrated exemplary embodiment, part of the inner tube 44 and part of the insulating tube 46 are arranged consecutively in the radial direction, the metallic sleeve 30, which forms a bearing surface 60 and/or a sealing surface 52 on its radially outer casing surface, can be provided. The sleeve 30 can, for example, be axially secured by means of a securing ring 56 inserted in the insulating tube 46. Preferably, the inner tube 44 and the insulating tube 46 are captively connected to each other axially via a radially extending connecting means 54, in particular pin. In particular, the at least one connecting means 54 is covered radially on the outside by the sleeve 30. In the illustrated exemplary embodiment, the insulating tube 46 is provided on the axial side facing the generator 20, while the inner tube 44 is provided on the axial side facing the rotor 12, with the reverse arrangement also being possible. This even permits an electrically conductive path between the inner tube 44 and the sleeve 30 via the connecting means 54, since the axial extent of the insulating tube 46 is of a size sufficient to provide electrical insulation between the generator 20 and the sleeve 30. Direct contact of the sleeve 30 with the connecting means 54 contacting the inner tube 44 can therefore be permitted, as a result of which the production and installation are simplified. In particular, it is possible to replace the sleeve 30 by a clamping ring, so that, when the clamping ring is tightened, the clamping ring can drive the connecting means 54 inward in the radial direction into the inner tube 44 in order to pin the insulating tube 46 to the inner tube 44.

(12) In the embodiment of the pitch tube 26 shown in FIG. 4, in comparison to the embodiment of the pitch tube 26 shown in FIG. 3, only a plug-in connection between the inner tube 44 and the insulating tube 46 is provided in the connection region 48. The connection between the inner tube 44 and the insulating tube 46 can be made with a force fit, for example by means of a press fit between the inner tube 44 and the insulating tube 46 in the connection region, and/or a material bond, for example by means of an adhesive layer between the inner tube 44 and the insulating tube 46 in the connection region, and/or a form fit, for example as a latching connection.

(13) In the embodiment of the pitch tube 26 shown in FIG. 5, in comparison to the embodiment of the pitch tube 26 shown in FIG. 3, the insulating tube 46 is provided in the axial direction between two inner tubes 44 which are inserted mirror-inverted to each other. In this case, a common, in particular insulating, sleeve 30 can be provided for covering all the connecting means 54 or in each case a separate sleeve 30, which sleeves can be arranged directly consecutively in the axial direction. In the illustrated exemplary embodiment, the one sleeve 30 can form the bearing surface 50 and the other sleeve the sealing surface 52, such that, as a result, different surface qualities can be provided easily and cost-effectively, optimized for the respective purpose.

(14) In the embodiment of the pitch tube 26 shown in FIG. 6, in comparison to the embodiment of the pitch tube 26 illustrated in FIG. 5, the insulating tube 46 is connected to the inner tubes 44 via flange connections 58. In this case, the various flange connections 58 are provided on different radii so that the material of the insulating tube 46 can provide sufficient electrical insulation between the fastening means of the respective flange connection 58.