Method for replacing a sliding pad of a rotational sliding bearing, sliding bearing and wind turbine

Abstract

A method for replacing a sliding pad of a rotational sliding bearing, wherein the bearing includes a plurality of sliding pads each supporting an annual rotatable part of the bearing on a stationary part of the bearing in an axial direction and/or a radial direction, including the steps: removing a load of the rotatable part from the sliding pad to be removed by releasing a force applied to the sliding pad and/or by applying a force to the rotatable part, removing the sliding pad in an axial and/or a radial direction, inserting a replacement sliding pad, supporting the rotatable part on the replacement sliding pad by applying a force to the replacement sliding pad and/or by removing the force applied to the rotatable part.

Claims

1. A method for replacing a sliding pad of a rotational sliding bearing, wherein the bearing comprises a plurality of sliding pads each supporting an annular rotatable part of the bearing on a stationary part of the bearing in an axial direction and/or a radial direction, the method comprising: removing a load of the annular rotatable part from the sliding pad to be removed by releasing a force applied to the sliding pad and/or by applying a force to the annular rotatable part; removing the sliding pad in the axial and/or the radial direction; inserting a replacement sliding pad, and supporting the annular rotatable part on the replacement sliding pad by applying a force to the replacement sliding pad and/or by removing the force applied to the angular rotatable part; wherein the stationary part comprises a plurality of axial and/or radial openings arranged circumferentially and/or axially displaced in the circumference of the stationary part, and the plurality of sliding pads are removable and/or insertable through the plurality of axial and/or radial openings; wherein the stationary part is annular, wherein the annular rotatable part is arranged on an outer circumference of the stationary part, wherein the annular rotatable part is supported on the stationary part by the plurality of sliding pads in the radial and/or the axial direction, wherein the sliding pad is replaced from an interior of the stationary part.

2. The method according to claim 1, wherein the sliding pad is fixed to the bearing by a bolted connection applying a force to the sliding pad, wherein the force is released by untightening of the bolted connection, and/or by a form-fit connection, wherein the sliding pad is arranged in a cavity or a recess of the stationary part.

3. The method according to claim 1, wherein the force is applied to the annular rotatable part using an actuator arrangement comprising at least one actuator.

4. The method according to claim 3, wherein an axial force on the annular rotatable part of the bearing for replacement of an axially supporting sliding pad and/or a radial force for replacement of a radially supporting sliding pad is applied by the actuator arrangement.

5. The method according to, claim 3, wherein at least one actuator of the actuator arrangement is detachably mounted to the bearing prior to a removal of a load from the sliding pad to be replaced and/or that at least one actuator of the actuator arrangement is permanently mounted to the bearing.

6. The method of claim 3, wherein the actuator arrangement comprises at least one mechanical actuator and/or at least one hydraulic actuator.

7. The method according to, claim 1, wherein prior to an insertion of the replacement sliding pad, a surface treatment of a surface of the stationary part and/or a surface of the rotatable part is conducted.

Description

BRIEF DESCRIPTION

(1) Some of the embodiments will be described in detail, with reference to the following figures, wherein like designations denote like members, wherein:

(2) FIG. 1 shows an embodiment of a wind turbine;

(3) FIG. 2 shows a detailed view on an embodiment of a sliding bearing;

(4) FIG. 3 shows a perspective view on the embodiment of the sliding bearing;

(5) FIG. 4 shows a second embodiment of a sliding bearing;

(6) FIG. 5 shows a third embodiment of a sliding bearing;

(7) FIG. 6 shows a fourth embodiment of a sliding bearing;

(8) FIG. 7 shows a fifth embodiment of a sliding bearing;

(9) FIG. 8 shows a sixth embodiment of a sliding bearing;

(10) FIG. 9 shows a seventh embodiment of a sliding bearing; and

(11) FIG. 10 shows an insertion of a milling device during a method for replacing a sliding pad according to embodiments of the invention.

DETAILED DESCRIPTION

(12) In FIG. 1, a detail of a wind turbine 1 according to embodiments of the invention is shown. The wind turbine 1 comprises a sliding bearing 2, which supports a hub 3 on a stationary shaft 4 of the wind turbine. The sliding bearing 2 comprises an annular rotatable part 5, which is connected to the hub 3 of the wind turbine 1. Furthermore, the sliding bearing 2 comprises an annular stationary part 6, which is connected to the stationary shaft 4 of the wind turbine 1. It is possible that the stationary part 6 of the bearing is attached to the shaft 4 or that it is fabricated one-piece with the shaft 4.

(13) The sliding bearing 2 further comprises a plurality of radially supporting sliding pads 7 and a plurality of axially supporting sliding pads 8. The radially supporting sliding pads 7 support the rotatable part 5 of the bearing 2 on the stationary part 6 in a radial direction. In an embodiment, the radially supporting sliding pads 8 support the rotatable part 5 of the sliding bearing in an axial direction on the stationary part 6. Between the rotatable part 5 and the sliding pads 7, 8, a fluid film may be arranged allowing a sliding of the rotatable part 5 on the sliding pads 7, 8 during operation of the wind turbine 1.

(14) The rotatable part 5 is arranged on an outer circumference of the stationary part 6. The stationary part 6 comprises a plurality of openings 9, 10, wherein a plurality of first openings 9 each correspond to one of the radially supporting sliding pad 7, and a plurality of second openings 10 each correspond to one of the axially supporting sliding pad 8.

(15) As indicated by the arrow 11, a radially supporting sliding pad 7 can be removed through the corresponding opening 9 in a radial direction towards the centre of the stationary part 6 of the bearing 2. As indicated by the arrow 12, an axially supporting sliding pad 8 can be removed through the corresponding opening 10 towards the centre of the stationary part 6. After removal, the sliding pads 7, 8 can then be transported out of the bearing 2, or the wind turbine 1, respectively, as indicated by the arrow 13. After removal of the sliding pad 7, 8, a replacement sliding pad can be inserted at a position of the removed sliding pad 7, 8 in a reverse movement. In particular, the replacement of the sliding pads 7, 8 may be performed manually and/or by usage of a lifting device manually installed prior to the replacement procedure in the vicinity of the bearing 2.

(16) Since the rotatable part 5 of the sliding bearing 2 is supported on the stationary part 6 via the sliding pads 7, 8, a sliding pad 7, 8 to be removed has to be unloaded from the weight of the rotatable part 5, or the components of the wind turbine 1 connected to the rotatable part 5, respectively.

(17) It is also possible that the opening 9 is an axial opening of a radially cavity or a radially recess, in particular a radially inward recess in the outer circumference, of the stationary part housing the radially supporting sliding pad, so that the unloaded sliding pad may be removed in an axial direction from the recess axially towards one side of the bearing, in particular towards a side connected to the hub 3 of the wind turbine 1, and/or in a radial direction towards the interior of the bearing 2. Also, a tilted orientation of the opening 9 to the outer circumference of the stationary part 6 is possible so that the sliding pad 7 may be removed and/or replaced in a combined axial and radial movement. In a loaded state, the sliding pad 7 is fixed in a form-fit connection in the recess, wherein after unloading the sliding pad 7, a replacement of the sliding pad 7 becomes possible.

(18) In an embodiment of a method for replacing a sliding pad 7, 8 of a rotational sliding bearing 2 first a load of the rotatable part 5 from the sliding pad 7, 8 is removed by releasing a force applied to the sliding pad 7, 8 and/or by applying a force to the rotatable part 5. Afterwards, the unloaded sliding pad 7, 8 is removed in an axial and/or a radial direction and a replacement sliding pad 7, 8 is inserted. Then, the rotatable part 5 is supported on the replacement sliding pad 7, 8 by applying a force to the replacement sliding pad 7, 8 and/or by removing the force applied to the rotatable part 5.

(19) Different ways of unloading at least one of the sliding pads 7, 8 are described in relation to the following figures.

(20) In FIG. 2, a first embodiment of a sliding bearing 2 is shown. Due to the section view, a sliding pad 7 is discernible supporting the rotatable part 5 on the stationary part 6. The radially supporting sliding pad 7 is engaged in an opening 10 of the stationary part 6 of the bearing 2. The radially supporting sliding pad 7 is in contact with the rotatable part 5 of the bearing 2 inside a bearing case, wherein the bearing case is formed by the rotatable part 5, the stationary part 6 and a bearing cover 14. The bearing case covers in particular the contact area between the sliding pad 7 and the rotatable part 5 as well as a fluid film in between the sliding pads 7, 8 and the rotatable part 5 of the bearing 2.

(21) The radially supporting sliding pad 7 is fixed to the bearing 2 by a bolted connection 24 comprising a plurality of bolts 15 fixating a cover plate 16 to the stationary part 6. By tightening the bolted connection 24, hence by bolting the plate 16 to the stationary part 6 using the bolts 15, the radially supporting sliding pad 7 is pressed against the rotatable part 5 of the bearing 2. In a mounted state of the radially supporting sliding pad 7, a force is acting on the sliding pad due to the weight of the rotatable part 5 of the bearing 2 and/or due to the bolted connection 24, respectively.

(22) For removing the load of the rotatable part 5 from the radially supporting sliding pad 7, the bolted connection 24 can be released and the plate 16 can be removed. Afterwards, the sliding pad 7 can be removed from the bearing 2 in a radial direction towards the centre of the stationary part 6. After insertion of a replacement sliding pad 7 into the opening 10, the plate 16 can be fixed again to the stationary part 6 by tightening the bolted connection 24. By tightening the bolted connection 24, the rotatable part 5 of the bearing 2 is supported again on the replaced sliding pad 7. When one of the radially supporting sliding pads 7 is unloaded, the rotatable part 5 on the bearing is supported on the remainder of the radially supporting sliding pad 7 of the bearing and/or the axially supporting sliding pads 9 of the bearing 2, respectively.

(23) In FIG. 3, a perspective view on the first embodiment of the sliding bearing 2 is shown. Besides a plurality of radially supporting sliding pads 7, the bearing 2 comprises a plurality of axially supporting sliding pads 8, which are fixed on the stationary part of the bearing each by a bolted connection 17 comprising a plurality of bolts (not shown) and a fixation member 18. Note that the bearing cover 14 is not shown, so that the axially supporting sliding pads 8 can be seen. Also, the radially supporting sliding pads 7 and their respective fixatures are not shown.

(24) The axially supporting sliding pads 8 support the rotatable part 5 of the bearing 2 to the stationary part 6 in the axial direction of the bearing 2. Also, one of the axially supporting sliding pads 8 may be unloaded by untightening the bolted connection 17 and by removing the fixation member 18. The axially supporting sliding pad 8 then may be removed in a radial direction, either in a radially outward direction from the bearing 2 or in a radially inward direction to the centre of the stationary part 6 through an opening 10 of the stationary part 6 of the bearing 2. A replacement sliding pad 8 may then be inserted through the opening 10 in a reverse movement and the rotatable part 5 may be supported on the replacement sliding pad 8 by tightening of the bolted connection 17 fixating the sliding pad 8 using the fixation member 18.

(25) In FIG. 4, a second embodiment of a sliding bearing 2 is shown. The bearing 2 comprises an actuator arrangement comprising a plurality of actuators 19. The actuators 19 are installed permanently inside the bearing case formed at least partly by the bearing cover 14, the rotatable part 5 and the stationary part 6 housing the sliding pads 7, 8 and a fluid film of the bearing 2. As actuator 19, a hydraulic jack is used. By the actuator 19, a displacement between the stationary part 6 and the rotatable part 5 can be created. The actuator 19 can therefore be connected for instance to a pump of the bearing 2 or of a wind turbine 1, which comprises the bearing 2, respectively. Also, a connection of the actuator 19 to an external pump is possible.

(26) To unload one or more radially supporting sliding pads 7, especially one or more radially supporting sliding pads 7 that are arranged circumferentially next to the depicted actuator 19, a small displacement of approximately 1 mm of the rotatable part 5 is sufficient to unload the sliding pad 7. The displacement is created by applying a force to the rotatable part 5 using the actuator 19. After applying a force to the rotatable part 5, hence after pushing the rotatable part 5 slightly away from the stationary part 6, or the radially supporting sliding pad 7, respectively, the radially supporting sliding pad 7 is unloaded from the rotatable part 5 and can be removed. Therefore, for instance a cover plate 16 like previously described may be unattached to remove the radially sliding pad 7 through a corresponding opening 9.

(27) In FIG. 5, a third embodiment of a sliding bearing 2 is shown. In this embodiment, the hydraulic jack used as actuator 19 is attached to an inner wall of the stationary part 6 and therefore outside of the bearing case of the sliding bearing 2. The actuator 19 is fixed to the stationary part 6 and connected to the rotatable part 5 by a piston 20 of the actuator 19. The piston 20 is arranged in an orifice 23 of the stationary part 6. Therefore, a displacement between the rotatable part 5 and the stationary part 6 of the bearing 2 can be created by pushing away slightly the rotatable part 5 from the stationary part 6 to unload at least one radially supporting sliding pad 7 in the vicinity of the actuator 19. The actuator 19 is a radial actuator applying a force in the radial direction to the rotatable part 5.

(28) In FIG. 6, a fourth embodiment of a sliding bearing 2 is shown. The sliding bearing 2 comprises a plurality of actuators 19 arranged between a protrusion 21 of the stationary part 6 and a rotatable part 5 of the bearing 2. The protrusion protrudes from the outer circumference of the stationary part 6 adjacent to the rotatable part 5. By the actuators 19, which may be each a hydraulic jack, an axial displacement between the rotatable part 5 and the stationary part 6 of the bearing 2 can be created to unload at least one of the axial sliding pads 8 located next to the actuator 19.

(29) The axially supporting sliding pads 8 are arranged circumferentially displaced to the actuators 19. In an alternative position 22, the actuators 19 may be arranged between the rotatable part 5 of the bearing 2 and a protrusion of the stationary part 6, which is created by the bearing cover 14 attached to the stationary part 6. In particular, a plurality of actuators 19 and a plurality of axially supporting sliding pads 8, especially a plurality of pairs of adjacently arranged sliding pads 8, are arranged alternatingly in circumferential direction. The actuators 19 may be arranged in both positions, for instance alternatingly. In both positions, the actuators 19 are axial actuators applying an axial force to the rotatable part 5.

(30) After unloading one or more of the axial sliding pads 8 using one or more of the actuators 19, the axial sliding pad 8 can be removed through the opening 10 in a radially inward direction of the stationary part 6. Afterwards, in a method for replacing the sliding pad, a replacement sliding pad 8 can be inserted through the opening 10 and the rotatable part 5 can be supported again on the replacement sliding pad 8 by removing the force applied to the rotatable part 5 by the actuator 19.

(31) Besides the positioning of the actuator 19 inside the bearing case of the bearing 2, also positioning of at least one actuator 19 to the outside of the bearing case is possible as described in the following embodiments.

(32) In FIG. 7, a fifth embodiment of a sliding bearing 2 is shown. In this embodiment, the actuator 19 is arranged outside of the bearing case of the bearing 2. The actuator 19 is fixed to a bearing cover 14 of the bearing 2 and is therefore fixed to the stationary part 6 of the bearing 2. The actuator 19 is connected to the rotatable part 5 of the bearing by a piston 20 of the actuator 19 that is arranged in an orifice of the bearing cover 14, so that a displacement between the rotatable part 5 and the stationary part 6 can be created using the actuator 19. By pushing the rotatable part 5 away from the bearing cover 14, the one or more axially supporting sliding pads 8 circumferentially adjacent to the actuator 19 are unloaded and may be removed as previously described through the opening 10 of the stationary part 6 of the bearing 2.

(33) To remove an axially supporting sliding pad 8 arranged on the opposing side of the rotatable part 5, an actuator 19 may be attached in an alternative position 32 to the protrusion 21 of the stationary part 6 to allow for a displacement between the rotatable part 5 and a stationary part 6 of the bearing 2 in an opposing direction, so that the axially supporting sliding pad 8 between the protrusion 21 and the rotatable part 5 of the bearing 2 may be removed.

(34) In FIG. 8, a sixth embodiment of a sliding bearing 2 is shown. In this embodiment, the actuator 19 is fixed to the rotating part 5 of the bearing 2. Therefore, the actuator 19 may be fixed for instance to a hub 3 connected to the rotating part 5 of the bearing using a fixture 25. A displacement between the rotatable part 5 and the stationary part 6 of the bearing 2 can be created using the piston 20 of the actuator 19 so that at least one axially sliding pads 8 arranged between the bearing cover 14 and the rotatable part 5 can be unloaded and removed as previously described.

(35) Also, an attachment of the actuator 19 on an opposing side is possible as depicted by the alternative position 26, in which the actuator 19 is fixed to the rotatable part 5 using a fixture 27 to unload the axially supporting sliding pad 8 between the rotatable part 5 and the protrusion 21 of the stationary part 6.

(36) In FIG. 9, a seventh embodiment of a sliding bearing 2 is shown. In this embodiment, a mechanical actuator comprising a base section 28 and a threaded bolt 29 is used as an actuator 19. The displacement between the rotatable part 5 and a stationary part 6 of the bearing 2 can be created by actuation of the bolt 29. The bolt 29 of the actuator 19 can be actuated for instance manually or using an electric motor connector to the bolt 29. By moving the bolt 29 through a threaded portion of the base section 28, a displacement between the rotatable part 5 and the stationary part 6 of the bearing 2 can be created to unload one or more axially supporting sliding pads 8. During replacement of the sliding pad 8, the rotatable part 5 is supported by the mechanical actuator.

(37) In an embodiment, such a mechanical actuator can be also used as an alternative to a hydraulic actuator in the respective positionings. It is also possible to use a mechanical actuator in addition to a hydraulic actuator, wherein the mechanical actuator is used to secure the rotatable part 5 in its displaced position.

(38) In FIG. 10, a milling tool 30 inserted in an opening 10 corresponding to an axially supporting sliding pad 8 is shown schematically. The milling tool 30 comprises a cover 31 corresponding to the shape of the opening 10 covering a surface trimming portion of the milling tool 30 from the interior of the bearing 2, so that for instance a surface treatment of a portion of the stationary part 6 and/or the rotatable part 5 can be conducted without the risk of dirt entering the interior of the bearing 2, or the interior of the bearing case of the bearing 2, respectively. In an embodiment, a milling tool 30 with a cover 31 corresponding to the shape of an opening 9 for replacement of a radially supporting sliding pad 7 may be used.

(39) The step of surface treatment can be conducted in a method for replacing a sliding pad 7, 8 after removing the sliding pad 7, 8 and prior to the insertion of a replacement sliding pad. The surface treatment may be conducted to account for damage and/or wear of the rotatable part 5 and/or the stationary part 6.

(40) In all embodiments, the actuator arrangement and/or the bearing 2 may comprise a mechanical fixture device which fixes the rotatable part 5 in its displaced position for securing it for instance in the event of a power loss of a hydraulic actuator or a mechanical actuator, respectively. It is in particular possible that a bearing 2 comprises a plurality of actuators 19 arranged in different positions combining two or more of the aforementioned embodiments.

(41) Although the present invention has been disclosed in the form of embodiments and variations thereon, it will be understood that numerous additional modifications and variations could be made thereto without departing from the scope of the invention.

(42) For the sake of clarity, it is to be understood that the use of a or an throughout this application does not exclude a plurality, and comprising does not exclude other steps or elements.