Sealing assembly

Abstract

It comprises a first member with a plate attached and substantially covering at least one portion of a second member (20), both members being rotatable relative to each other and defining a tortuous way, and it further comprises a brush sealing attached to the first member and resting on a siding plate in the second member such that an inner gap formed between said first and second members is sealed. A flexible member may be provided between the brush sealing and the first member for joining them in a flexible way.

Claims

1. A sealing assembly comprising: a first member that is part of or is attached to a wind turbine nacelle and extends in a longitudinal direction towards a wind turbine rotor hub, and a second member that is part of or is attached to the wind turbine rotor hub and extends in a longitudinal direction towards the wind turbine nacelle; the second member rotatable relative to the first member, the first member and the second member spaced apart and defining an inner gap therebetween, the inner gap defining a first portion of a tortuous gap, a plate attached to the first member and extending in a longitudinal direction towards the wind turbine rotor hub, the plate spaced from the second member, wherein the plate and the second member define a second portion of the tortuous gap, the sealing assembly further comprises a brush type sealing, the brush type sealing comprising: a first set of bristles extending from an end of the first member at a first direction; a second set of bristles extending from an opposite side of the end of the first member at a second direction that is opposite to the first direction; and wherein the first and second sets of bristles create a seal between the end of the first member and the second member to seal the inner gap.

2. The scaling assembly as claimed in claim 1, further comprising a first sliding plate spaced from and parallel to a first side of the first member, and a second sliding plate spaced from and parallel to an opposite second side of the first member, the fast set of bristles extending transversely from the first side of the first member to the first sliding plate, and the second set of bristles extending transversely from the second side of the first member to the second sliding plate.

3. The sealing assembly as claimed in claim 2, wherein the brush type sealing is further provided with a band running at least along some of the bristles.

4. The sealing assembly as claimed in claim 2, further comprising a third set of bristles adjacent the first set of bristles and extending transversely to the first sliding plate, and a fourth set of bristles adjacent the second set of bristles and extending transversely to the second sliding plate.

5. The sealing assembly as claimed in claim 2, wherein the assembly further comprises a flexible member fitted to the end of the first member, the first and second sets of bristles extending transversely from opposite sides of the flexible member.

6. The sealing assembly as claimed in claim 5, wherein the flexible member comprises a rubber strip.

7. The sealing assembly as claimed in claim 5, wherein the flexible member is corrugated in shape.

8. The sealing assembly as claimed in claim 1, wherein the brush type sealing comprises a holding mechanism carrying the bristles.

9. The sealing assembly as claimed in claim 1, wherein the first portion of the tortuous gap comprises at least two changes of direction.

10. The sealing assembly as claimed in claim 1, wherein at least part of the brush type sealing is made of polyamide.

11. A wind turbine comprising a nacelle and a rotor hub, the hub having a portion that is rotatably mounted on a corresponding portion of the nacelle, wherein it is further provided with a sealing assembly suitable for sealing a gap formed between the portion of the nacelle and the portion of the hub, the sealing assembly comprising the sealing assembly of claim 1.

12. The sealing assembly as claimed in claim 1, wherein the first and second directions are oppositely inclined relative to the first member.

13. The sealing assembly as claimed in claim 1, wherein the first and second directions are perpendicular and opposite relative to the first member.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Particular examples of the present sealing assembly will be described in the following. This description is provided by way of non-limiting examples with reference to the appended drawings.

(2) In the drawings:

(3) FIG. 1 is a half-seen half-section of a first example of the present sealing assembly;

(4) FIGS. 1a-1d are corresponding half-seen half-sections of the first examples of the sealing assembly in FIG. 1 showing the radial and axial relative movements of the first and second members of the sealing assembly;

(5) FIG. 2 is a half-seen half-section of a second example of the sealing assembly;

(6) FIGS. 2a-2d are corresponding half-seen half-sections of the second example of the sealing assembly in FIG. 2 showing the radial and axial relative movements of the first and second members of the sealing assembly;

(7) FIG. 3 is a half-seen half-section of a variant of the flexible member in the second example of the sealing assembly; and

(8) FIG. 4 is a sectional part view of a further variant of the second example of the sealing assembly, particularly relating to the way the brush sealing is attached to the flexible member.

DETAILED DESCRIPTION OF EXAMPLES

(9) Referring now to the drawings, like reference numerals generally represent identical or corresponding parts throughout the figures. A sealing assembly indicated at 100 comprises a first member 10 and a second member 20. At least one of the first member 10 and the second member 20 can be made of glass reinforced plastics or similar materials suitable for wind turbine applications or the like.

(10) In the example shown in the figures, the first member of the sealing assembly 100 corresponds to a part of a wind turbine nacelle 10 (of a wind turbine 200) and specifically to the connecting part that receives the rotor hub of the wind turbine 200. The second member 20 of the sealing assembly 100 corresponds to a part of a wind turbine rotor hub 20 and specifically to a part of the rotor hub 20 to be rotatably mounted to the wind turbine nacelle.

(11) The first member 10 and the second member 20 of the sealing assembly 100 are mutually rotatable. In the examples shown in the examples of the drawings, the second member 20 of the sealing assembly 100 can be rotated relative to the first member 10 around an axis of rotation x. As shown in the figures, the axis of rotation x is the axis of revolution of both the first and the second members 10, 20 of the sealing assembly 100.

(12) A gap or tolerance 50 is defined between the first member 10 and the second member 20 of the sealing assembly 100. Due to the particular large dimensions of the first and the second members 10, 20, the gap 50 is relatively large in size. The sealing assembly 100 is highly effective for a tight closure of gap 50 even during operation of the wind turbine in which the first and the second members 10, 20 axially and/or radially move to each other and therefore gap 50 is variable over time when in use.

(13) As shown in the figures of the drawings, the first member 10 of the sealing assembly 100 includes a plate 10a attached thereto. The plate 10a is arranged such that it substantially covers at least one upper portion or segment of the second member 20. In other words, the plate 10a can extend over the entire angular length of the second member or only over a segment thereof, for example over a segment of 120° of the second member 20 in the uppermost portion of the nacelle. This avoids water direct ingress into the nacelle of the wind turbine.

(14) The first member 10 and the second member 20 of the sealing assembly 100 are shaped in a way that a tortuous way is defined inside the sealing assembly 100. The tortuous way is depicted in the figures and indicated by dashed line 30. This tortuous way 30 defines a labyrinth exhibiting at least three main changes of direction inside the sealing assembly 100. The main changes of direction have been indicated at A, B, C in the figures. This labyrinth is particularly suitable for preventing external water from entering the first member 10 or at least for reducing the passage of water into the first member 10, i.e. inside the wind turbine. Further examples are possible in which the number of changes of direction inside the sealing assembly 100 are more than three, or even less.

(15) The examples of the sealing assembly 100 further comprise a brush type sealing 40. The brush sealing 40 shown in the first example in FIGS. 1-1d comprises one pair of sets of bristles 70a, 70b. The bristles 70a, 70b in each pair extend such that they substantially close the inner gap 50 between the first member 10 and the second member 20. The bristles 70a, 70b are mounted in a pre-biased condition against an inner wall of the second member 20 of the sealing assembly 100.

(16) The bristles 70a, 70b are preferably made of polyamide. Other suitable materials having a certain degree of flexibility could be alternatively used for the bristles 70a, 70b. The bristles 70a, 70b are carried by a suitable holding mechanism 60.

(17) In the example shown in FIGS. 1-1d, the sets of bristles 70a, 70b are arranged inclined relative to each other. Both sets of bristles 70a, 70b are in turn inclined relative to the inner wall of the second member 20 as shown in FIG. 1.

(18) The sets of bristles 70a, 70b comprise a first end. This first end is attached to one end portion 80 of the first member 10 by means of a holding mechanism 60. The holding mechanism 60 comprises a plate 86 and a screw-nut assembly 85. Other suitable holding mechanisms can be alternatively or additionally used. The sets of bristles 70a, 70b further comprise a second end that rests and presses on a sliding plate 90. The sliding plate 90 may be attached to or be part of the second member 20. The sliding plate 90 is made of stainless steel or any other material suitable so that the free ends of the bristles 70a, 70b rest and slide thereon, especially when the second member 20 is rotated relative to the first member 10, that is, when the wind turbine is in operation.

(19) In this particular example, radial misalignments between the first member and the second member 10, 20 as shown in FIGS. 1a and 1b are efficiently compensated. Compensation for axial and radial misalignments is due to the flexibility of the bristles 70a, 7b themselves and to the width of the sliding plate 90. Axial and radial misalignments between the first member and the second member 10, 20 are also efficiently compensated as shown in FIGS. 1c and 1d.

(20) Reference is now made to an alternative example of the sealing assembly 100 shown in FIGS. 2-2d of the drawings. In this alternative example of the sealing assembly 100, the brush sealing 40 comprises two pairs of sets of bristles 70c, 70d, 70e, 70f made of polyamide. Other suitable materials having a certain degree of flexibility could be alternatively used for the bristles 70c, 70d, 70e, 70f.

(21) The two pairs of sets of bristles 70c, 70d and 70e, 70f are arranged substantially vertical and parallel to each other, respectively. A flexible member 45 is provided between the brush sealing 40 and the first member 10 as shown in FIG. 2 of the drawings. The flexible member 45 joins the two pairs of sets of bristles 70c, 70d, 70e, 70f to the end portion 80 of the first member 10 in a flexible way. For this purpose, a screw-nut assembly 85 or any suitable fastening mechanism are provided at the end portion 80 of the first member 10.

(22) The flexible member 45 carries the two pairs of sets of bristles 70c, 70d and 70e, 70f through a holding mechanism 60. A first example of such holding mechanism 60 for the example of the sealing assembly 100 of FIG. 2 is shown in said FIG. 2. The holding mechanism 60 in this first example comprises a plate 86 that is attached to the end portion 80 of first member 10. The plate 86 of the holding mechanism 60 carries the two pairs of sets of bristles 70c, 70d, 70e, 70f. The plate 86 of the holding mechanism 60 extends between the ends of sets of bristles 70c, 70d, 70e, 70f. The holding mechanism 60 further comprises at least two sets of screws 87, 88 provided in the plate between the sets of bristles 70c, 70d, 70e, 70f as shown in FIG. 2 of the drawings.

(23) A second example of the holding mechanism 60 is shown in FIG. 4. The holding mechanism 60 comprises, as in the first example of the holding mechanism 86, a plate that is attached to the end portion 80 of the first member 10. The plate carries the sets of bristles 70c, 70d, 70e, 70f and extends from the ends of one pair of sets of bristles 70c, 70e further towards the end portion 80 of the first member 10. In this example, a first set of screws 87 is provided in the plate between the sets of bristles 70c, 70e and 70d, 70f and a second set of screws 88 is provided in a portion of the plate extending beyond the sets of bristles 70d, 70f towards the end portion 80 of the first member 10 such as shown in FIG. 4 of the drawings.

(24) In both example of the holding mechanism 60, corresponding nuts are provided for threadingly receiving the above mentioned screws 87, 88 for fastening the sets of bristles 70c, 70e and 70d, 70f to the flexible member 45.

(25) The flexible member 45 may be for example a rubber strip suitable for allowing radial misalignment between the first and second members 10, 20 to be compensated.

(26) In the example of the seal arrangement 100 shown in FIGS. 2-2d, two opposite parallel sliding plates 90a, 90b are provided. The sliding plates 90a, 90b extend substantially perpendicular to an inner wall of the second member 20. The sliding plates 90a, 90b are spaced apart and substantially parallel to each other. A clearance is defined between the sliding plates 90a, 90b. The two pairs of sets of bristles 70c, 70d, 70e, 70f each extend in said clearance, between both sliding plates 90a, 90b such that they substantially close the inner gap 50.

(27) In this example, axial misalignments are compensated by the bristles 70c, 70d, 70e, 70f moving forward and away from the second member as shown in FIGS. 2c and 2d. Radial misalignments are compensated due to the flexibility of member 45 as shown in FIGS. 2a and 2b.

(28) Although only a number of particular examples and examples of the sealing assembly have been disclosed herein, it will be understood by those skilled in the art that other alternative examples and/or uses and obvious modifications and equivalents thereof are possible. The present disclosure thus covers all possible combinations of the particular examples described.

(29) For example, the brush sealing 40 may comprise any suitable number of sets of bristles 70a-7d other than those disclosed above. In addition, the constructive characteristics of bristles 70a-7d such as their length, their relative inclination, etc. can be whatever according to the particular requirements. Such requirements are particularly in dependence upon the size of the parts involved and therefore the gap or tolerance to be sealed. On the other hand, the holding mechanism 86 used for attaching the bristles 70a, 70b to the first member 10 (in one example) or to the flexible member 45 (in an alternative example), could be replaced for any conventional mechanism suitable for fastening two elements to each other. In addition, the shape of the flexible member 45 for a proper accommodation of radial misalignments between the first and the second members 10, 20 may be straight in shape as shown in FIGS. 2-2d, or corrugated, as shown in FIG. 3. Other examples of the flexible member 45 than the rubber strip shown in the FIGS. 2-2d are also possible as long as they are suitable for allowing radial misalignment between the first and second members 10, 20 to be compensated.

(30) On the other hand, the present sealing assembly could be also used in applications other than the nacelle-rotor hub connection where a sealing assembly is needed for sealing two rotary parts in the wind turbine both in onshore and offshore applications. The present sealing assembly is also suitable for an efficient sealing of the pitch blade and/or the yaw drive mechanisms in a wind turbine, for example. In these applications, and possibly many others, the present sealing assembly is suitable for efficiently reducing air, water or dust particles from entering the wind turbine.

(31) The present disclosure should not be limited by particular examples, but should be determined only by a fair reading of the claims that follow.