Bearing arrangement for wind turbine spindle
By using sets of tapered roller bearings with a headwind in the wind turbine, and using the tapered roller bearings arranged in series to share the axial load, the problem of excessive size of the wind turbine spindle bearing is solved, and the reduction of the outer diameter and cost is achieved.
Patent Information
- Application Number
- CN202380024261.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-07-26
- Publication Date
- 2025-03-28
AI Technical Summary
The existing wind turbine spindle bearing arrangement after increasing the blade length leads to excessive bearing size, making it difficult to achieve cost-effectiveness in manufacturing and transportation.
Using a set of tapered roller bearings against the wind, the payload center is offset in the axial direction of the headwind, and the load line is not parallel to reduce the required outer diameter by the first tapered roller bearing and the first tapered roller bearing arranged in series.
It effectively reduces the outer diameter of the bearing required for the wind turbine spindle, solves the problem of excessive bearing size in large wind turbines, and reduces manufacturing and transportation costs.
Smart Images
Figure CN119731431A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a bearing arrangement for supporting a main shaft of a wind turbine. Summary of the invention
[0002] In one aspect, the present invention provides a wind turbine main shaft support structure that is operable to provide rolling element support to a wind turbine main shaft for rotation about a central rotation axis within a housing. The wind turbine main shaft support structure includes an upwind set of tapered roller bearings that rotatably support the main shaft about the central rotation axis and are positioned adjacent to the upwind end of the main shaft. The upwind set of tapered roller bearings includes a first tapered roller bearing and a second tapered roller bearing in a series arrangement, wherein respective effective load centers are offset in an upwind axial direction. Respective load lines from the first tapered roller bearing and the second tapered roller bearing to respective effective load centers are non-parallel.
[0003] In another aspect, the present invention provides a wind turbine main shaft support structure that is operable to provide rolling element support between a wind turbine main shaft and a housing about a central rotational axis. The wind turbine main shaft support structure includes a set of tapered roller bearings that support the main shaft or the housing for rotation relative to the other about the central rotational axis. The set of tapered roller bearings includes a first tapered roller bearing and a second tapered roller bearing arranged in series with the first tapered roller bearing, so that the effective load center of both the first tapered roller bearing and the second tapered roller bearing is offset toward a first axial direction. Respective load lines from the first tapered roller bearing and the second tapered roller bearing to the respective effective load centers are non-parallel.
[0004] In yet another aspect, the present invention provides a wind turbine drive train configuration. The blade hub includes a plurality of blade mounts, and the blade hub is rotatable about a central axis of rotation. The generator has an input configured to be driven by rotation of the blade hub and operable in response to generating electrical power. The bearing arrangement includes a set of tapered roller bearings positioned about the central axis of rotation. The set of tapered roller bearings includes a first tapered roller bearing and a second tapered roller bearing arranged in series with the first tapered roller bearing, such that the effective load centers of both the first tapered roller bearing and the second tapered roller bearing are offset toward a first axial direction. The respective load lines from the first tapered roller bearing and the second tapered roller bearing to the respective effective load centers are non-parallel. BRIEF DESCRIPTION OF THE DRAWINGS
[0005] FIG. 1 schematically illustrates a conventional wind turbine configuration comprising a main shaft supported by bearings at a nacelle on a tower.
[0006] Figure 21 is a cross section of a wind turbine main shaft supported by a first single row tapered roller bearing at the upwind side and a second single row tapered roller bearing at the downwind side consistent with the conventional configuration of FIG. 1 .
[0007] Figure 3 yes Figure 2 Detailed view of a portion of the bearing supporting the main shaft.
[0008] Figure 4 is a partial cross-sectional view of a set of tapered roller bearings used to support the upwind end of a main shaft in a wind turbine.
[0009] Figure 5 yes Figure 4 Schematic diagram of a set of tapered roller bearings positioned at the upwind end of the main shaft, with the corresponding lines pointing to the effective load center. An additional tapered roller bearing is illustrated at the downwind end of the main shaft.
[0010] Figure 6 Is Figure 4 and Figure 5 Tapered roller bearings and Figure 5 Detailed cross-sectional view of the main shaft supported by an attached downwind single row tapered roller bearing in the housing.
[0011] Figure 7 is a schematic diagram of a main shaft supported at the upwind end by a set of tapered roller bearings according to another configuration of the present disclosure, with corresponding lines pointing to coincident effective load centers. Additional tapered roller bearings are illustrated at the downwind end of the main shaft.
[0012] Figure 8 is based on Figure 7 Detailed cross-sectional view of the construction of the main shaft supported in the housing, which includes an upwind grouped tapered roller bearing and an additional downwind single row tapered roller bearing. DETAILED DESCRIPTION
[0013] Before any embodiments of the invention are explained in detail, it should be understood that the invention is not limited in its application to the details of construction and arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and can be practiced or implemented in various ways.
[0014] FIG. 1 illustrates a conventional wind turbine 10. The wind turbine 10 includes a set of turbine blades 15, such as three equally spaced blades 15, all of which are coupled to a hub 18, which is provided with a plurality of blade mounts 18A (e.g., a radially outwardly facing surface including a bolt pattern). The front side or "upwind" side of the hub 18 may be covered by a nose cone 20. A main shaft 25 is coupled to the hub 18 so that the main shaft 25 and the hub 18 rotate with the blades 15 in response to wind incident from the upwind side. The main shaft 25 forms part of a drive train configuration, wherein the main shaft 25 drives a generator 50, which is operable to generate electrical power in response to a rotational work input from the main shaft 25. The main shaft 25 may drive the generator 50 directly or through an intermediate gearbox (not shown). Between the hub 18 and the generator 50, the turbine main shaft 25 is supported relative to a fixed base plate 35 by a plurality of rolling element bearings 30, 32 to provide a plurality of support points. The bearings 30 , 32 generally define an upwind bearing location and a downwind bearing location axially spaced therefrom. As schematically illustrated by dashed lines, components of the wind turbine drive train configuration rearward of the hub 18 are disposed in a nacelle 40 located at the top of a tower 42 .
[0015] Combination Figure 2 and Figure 3 , showing the main shaft 25 and the support structure in more detail. As shown here, the main shaft 25 may include an upwind end 25A, which is connected to the hub 18 (for example, using threaded fasteners) to rotate with the hub 18 around the central rotation axis A. The upwind end 25A may include a radially extending flange. In contrast to the upwind end 25A, the main shaft 25 includes a downwind end 25B, which is farthest from the blades 15 and the hub 18 and closest to the generator 50 (Figure 1). From the upwind end 25A to the downwind end 25B, the exterior of the main shaft 25 may be cylindrical, or may have different shapes, at least a portion of which is conical or otherwise provided with different radial dimensions. The bearings 30, 32 contact the outer side surface of the main shaft 25 and support its rotation relative to the bearing housing 55. The first or upwind bearing 30 is located adjacent to the upwind end 25A. The main shaft 25 and / or the bearing housing 55 may have a designated bearing seat for one or both of the bearings 30, 32. The bearing housing 55 is securely secured to the base plate 35 (e.g., using threaded fasteners). The bearing housing 55 may be secured to the base plate 35 by a base plate adapter or a connecting fixture 58. The downwind end 25B of the main shaft 25 is supported by the bearing 32, which is adjacent to the connection between the bearing housing 55 and the base plate adapter 58. The bearings 30, 32 are single-row tapered roller bearings configured to support radial and axial loads. In particular, the two bearings 30, 32 define load lines L in opposite directions. The load line L of the upwind bearing 30 is angled toward the upwind direction U, and the load line L of the downwind bearing 32 is angled toward the downwind direction D.
[0016] Large wind turbines may have blade lengths of 50 meters or more, in some cases exceeding 100 meters. In order to facilitate the generation of increased electrical power from the turbine's generator 50, the blade length may be increased by the turbine designer. However, the increased blade length results in higher loads at the main shaft 25 and the bearings 30, 32 with higher load ratings (particularly the (one or more) upwind bearings 30 closest to the hub 18). Conventional main shaft bearing support structures used in newer high-power (e.g., 18MW) wind turbines may specify bearing sizes that make cost-effective manufacturing and transportation increasingly difficult or impossible. For example, a bearing outer diameter greater than 3.5 meters (e.g., 3.7 to 4.3 meters for the main shaft of an 18MW wind turbine) may be incompatible with available manufacturing equipment and unsuitable for various transportation (e.g., rail transportation). In response, the present disclosure provides one or more unique bearing structures that effectively reduce the required outer diameter for a given application (e.g., so that it does not exceed 3.5 meters for an 18MW wind turbine).
[0017] Tapered roller bearings have tapered rolling elements ("rollers") located between an inner race ("cone") and an outer race ("cup"). The contact angles defined between the rollers and the cone raceway and the cup raceway define vertices along the central axis of rotation or "main" axis (axis A in the figures of the present disclosure). The load on the bearing is considered to be perpendicular to the supported shaft at the intersection between the load line and the main axis. The load line extends perpendicular to the cup raceway from the midpoint of the roller contact. Tapered roller bearings can be provided in a variety of configurations, including face-to-face (or "X" - the load lines extend toward each other and an integral double cone can be provided) and back-to-back (or "O" - the load lines extend away from each other and an integral double cup can be provided). In both configurations, axial loads in two different directions can be supported. Furthermore, the tapered roller bearings may be provided in a tandem configuration in which two adjacent tapered roller bearings have load lines extending toward the same axial side so that the two tapered roller bearings distribute or share therebetween an axial load applied from one direction.
[0018] Figure 4 The diagram is used in Figures 1 to Figure 3 1 to 3. The tandem tapered roller bearing group 300 used in the wind turbine drive train configuration shown in FIG. For example, the tandem tapered roller bearing group 300 can be positioned at the upwind side of the wind turbine main shaft 25. In particular, the tandem tapered roller bearing group 300 can replace the tandem tapered roller bearing group 300 of FIG. 1 to 3. Figure 3 Single row tapered roller bearing 30. This is attached Figure 5 and Figure 6Due to the configuration of the first tapered roller bearing 30A and the second tapered roller bearing 30B of the tandem tapered roller bearing set 300, the first tapered roller bearing and the second tapered roller bearing share or distribute the axial load applied to the main shaft 25 in the downwind direction D (from the wind on the blades 15) between them. Figure 4 , but it will be appreciated that the load line extending perpendicular to the cup raceway from the respective midpoints of the roller contact points of both the first tapered roller bearing 30A and the second tapered roller bearing 30B extends downward and leftward. Axial loads in the opposite direction are supported by the tapered roller bearing 32 downwind.
[0019] Special reference Figure 4, the first tapered roller bearing 30A includes a cone 62 that provides an inner raceway for the tapered rolling element 64 and a cup 66 that provides an outer raceway for the tapered rolling element 64. The cone 62 has an inner surface configured to cooperate with the outer surface of the main shaft 25. The cup 66 has an outer surface configured to cooperate with the inner surface of the bearing housing 55. The second tapered roller bearing 30B includes a cone 72 that provides an inner raceway for the tapered rolling element 74 and a cup 76 that provides an outer raceway for the tapered rolling element 74. The cone 72 has an inner surface configured to cooperate with the outer surface of the main shaft 25. The cup 76 has an outer surface configured to cooperate with the inner surface of the bearing housing 55. Although not required in all embodiments, the outer side surfaces of the cups 66, 76 of the two bearings 30A, 30B may define a single shared outer diameter. As such, the bearing housing 55 may have a single pocket configured to receive the two bearings 30A, 30B. In some configurations, the outer diameter of each bearing 30A, 30B may be 3.5 meters or less. In other configurations, the outer diameter of one or both bearings 30A, 30B exceeds 3.5 meters. The cup 66 of the first bearing 30A and the cone 72 of the second bearing 30B may have a shared axial span, thereby defining an overlap in which the cup 66 is directly located radially outside the cone 72. The small inner diameter of the cup 66 of the bearing 30A is larger than the working point diameter of the roller 74 of the bearing 30B. In other words, the radially outermost point P1 (farthest from the center axis) occupied by the roller 74 of the assembled bearing 30B is closer to the center axis than the radially innermost point P2 on the cup 66, and this makes the installation of the series easier. The contact angle α1 defined by the raceway of the first cup 66 may be larger than the contact angle α2 defined by the raceway of the second cup 76. In some constructions, the contact angle α1 is 14 degrees to 30 degrees, or more particularly, the contact angle α1 may be 23 degrees to 29 degrees. In some constructions, the contact angle α2 is 10 degrees to 26 degrees, or more particularly, the contact angle α2 may be 14 degrees to 20 degrees. The roller 64 of the first upwind bearing 30A has a shorter length than the roller 74 of the second upwind bearing 30B. In other constructions, roller 64 is longer than roller 74, or rollers 64 and 74 have the same length. The cross-sectional area of rollers 64 and 74 taken at the midpoint of the roller length may be the same or different. The larger the roller pitch diameter of the roller 64 of the first bearing 30A, the greater number of rollers 64 can be allowed than the number of rollers 74 of the second bearing 30B in order to provide a higher rated load.
[0020] like Figure 5 and Figure 6As illustrated in , a load line L is defined for each of the bearings 30A, 30B, 32. Due to the difference in contact angles α1, α2, the load lines of the first bearing 30A and the second bearing 30B of the group 300 are not parallel. The rolling elements are not interchangeable between the first bearing 30A and the second bearing 30B. The effective load center C1 of the first upwind bearing 30A of the group 300 is farther in the upwind direction U than the effective load center C2 of the second upwind bearing 30B of the group 300, and the axial distance between the effective load centers C1, C2 increases in the direction toward the center rotation axis A. Therefore, without changing the positions of the load centers C1, C2, the first bearing 30A and the second bearing 30B are not interchangeable. The downwind bearing 32 defines an additional effective load center C3. The effective load centers C1, C2, C3 are all located outside the axial span or range defined by the components of the group of bearings 30A, 30B, 32.
[0021] Figure 7 and Figure 8 The diagram is used as shown in Figure 1 to Figure 3 Another embodiment of a tandem tapered roller bearing set 400 for use in a wind turbine drive train configuration is shown in FIG. For example, the tandem tapered roller bearing set 400 may be positioned at the upwind side of the wind turbine main shaft 25. In particular, the tandem tapered roller bearing set 400 may replace the tandem tapered roller bearing set 400 of FIGS. 1 to 2 Figure 3 Single row tapered roller bearing 30, thus producing Figure 7 and Figure 8 Due to the configuration of the first tapered roller bearing 30C and the second tapered roller bearing 30D of the tandem tapered roller bearing set 400, the first tapered roller bearing and the second tapered roller bearing share or distribute the axial load applied to the main shaft 25 in the downwind direction D (from the wind on the blades 15). The axial load in the opposite direction U is supported by the downwind tapered roller bearing 32. Features not explicitly described herein will be described in the accompanying drawings and / or FIGS. 1 to 3. Figure 3 and Figures 4 to 6 understood from the above description.
[0022] The contact angle α1 of the first bearing 30C of the set 400 may be smaller than the contact angle α2 of the second bearing 30D. The larger roller pitch diameter of the first bearing 30C may allow for a greater number of rollers than the number of rollers of the second bearing 30D to provide a higher load rating. Figure 7 and Figure 8As illustrated in , a load line L is defined for each of the bearings 30C, 30D, 32. Due to the difference in contact angles α1, α2, the load lines L of the first bearing 30C and the second bearing 30D of the upwind bearing group 400 are not parallel. The rolling elements are not interchangeable between the first bearing 30C and the second bearing 30D. In particular, the effective load center C1 of the first bearing 30C of the group 400 coincides with the effective load center C2 of the second bearing 30D of the group 400. In other words, the effective load centers C1, C2 are represented by a single point along the central rotation axis A. Figures 4 to 6 This further improves the load sharing between the first bearing 30C and the second bearing 30D in the upwind bearing group 400 compared to the bearing group 300. The first bearing 30A and the second bearing 30B are not interchangeable without changing the positions of the load centers C1, C2. In some configurations, a method of manufacturing the bearing group 400 or the wind turbine drive train may include selecting one bearing (e.g., the first bearing 30C or the second bearing 30D) having a contact angle (e.g., α1 or α2), and then selecting the contact angle (e.g., α1 or α2) of another bearing (e.g., the other of the first bearing 30C and the second bearing 30D) to result in coinciding effective load centers C1, C2. The downwind bearing 32 defines an additional effective load center C3.
[0023] In some constructions, the downwind bearing 30B of the upwind bearing group 300 (or the downwind bearing 30D of the upwind bearing group 400) may be constructed as a double row double outer race ("TDO") having a downwind bearing 32. The TDO bearing uses a shared double cup outer ring and two single cones as inner rings, with or without spacers. The TDO design is similar to the design shown in the aforementioned embodiments, but has a greatly reduced axial spacing between the upwind bearing support position and the downwind bearing support position, instead of being separated by a distance of 1 meter or more (e.g., 1m-4m or more). In some constructions, the axial spacing between relatively angled bearings (e.g., between bearing 30B and bearing 32, or between bearing 30D and bearing 32) may be less than 1m, such as no axial spacing.
[0024] Although the bearing arrangements of the foregoing embodiments are generally described for a rotating inner ring design in which the housing is stationary and the shaft is rotating, the features presented herein may also be applied to rotating housing applications in which the inner ring and shaft are stationary. In such embodiments, the downwind bearing support location may be provided with a tandem bearing set according to the general description of the bearing sets 300, 400 disclosed above (e.g., rather than an upwind bearing support location as shown in those embodiments). As such, the bearing set 300 or 400 may be constructed as a mirror image of the bearing set in the included figures and moved to the location of the bearing 32 (the bearing 32 itself may be mirrored and positioned adjacent the upwind end).
[0025] Various changes can be envisaged from the embodiments shown without departing from the invention. Various features of the invention are set out in the appended claims.
Claims
1. A wind turbine main shaft support configuration operable to provide rolling element support to a wind turbine main shaft for rotation about a central rotation axis within a housing, the wind turbine main shaft support configuration comprising: an upwind set of tapered roller bearings rotatably supporting the main shaft about the central axis of rotation and located adjacent an upwind end of the main shaft, wherein the upwind set of tapered roller bearings comprises a first tapered roller bearing and a second tapered roller bearing in a tandem arrangement, wherein respective effective load centres are offset in an upwind axial direction, and Wherein respective load lines from the first tapered roller bearing and the second tapered roller bearing to the respective effective load centers are non-parallel.
2. The wind turbine main shaft support structure according to claim 1, wherein: The respective payload centers are located at two separate points along the central rotational axis.
3. The wind turbine main shaft support structure according to claim 1, wherein: The first tapered roller bearing of the upwind group of tapered roller bearings is positioned in the upwind axial direction of the second tapered roller bearing of the upwind group of tapered roller bearings, and wherein a first contact angle defined by a raceway of the cup portion of the first tapered roller bearing is smaller than a second contact angle defined by a raceway of the cup portion of the second tapered roller bearing.
4. The wind turbine main shaft support structure according to claim 3, wherein: The respective payload centers are located at a common point along the central rotational axis.
5. The wind turbine main shaft support structure according to claim 3, wherein: The radially outermost point occupied by the set of rollers of the second tapered roller bearing is closer to the central axis of rotation than the radially innermost point on the cup of the first tapered roller bearing.
6. The wind turbine main shaft support structure according to claim 3, wherein: The first contact angle is 14 degrees to 30 degrees, and the second contact angle is 10 degrees to 26 degrees.
7. The wind turbine main shaft support structure according to claim 3, wherein: The first contact angle is 23 degrees to 29 degrees, and the second contact angle is 14 degrees to 20 degrees.
8. The wind turbine main shaft support structure according to claim 1, further comprising a downwind tapered roller bearing, the downwind tapered roller bearing rotatably supporting the main shaft about the central rotation axis and positioned at a position spaced apart from the upwind end in the downwind axial direction, wherein: A load line from the downwind tapered roller bearing extends to an effective load center spaced from the downwind tapered roller bearing in the downwind axial direction.
9. A wind turbine main shaft support configuration operable to provide rolling element support between a wind turbine main shaft and a housing about a central rotational axis, the wind turbine main shaft support configuration comprising: a set of tapered roller bearings supporting the spindle or the housing for rotation relative to the other about the central axis of rotation, wherein the set of tapered roller bearings comprises a first tapered roller bearing and a second tapered roller bearing arranged in series with the first tapered roller bearing, such that effective load centers of both the first tapered roller bearing and the second tapered roller bearing are offset toward a first axial direction, and Wherein respective load lines from the first tapered roller bearing and the second tapered roller bearing to respective effective load centers are non-parallel.
10. The wind turbine main shaft support structure according to claim 9, wherein: The respective payload centers are located at two separate points along the central rotational axis.
11. The wind turbine main shaft support structure according to claim 9, wherein: The first axial direction is an upwind direction, and the first tapered roller bearing is located further in the upwind direction than the second tapered roller bearing.
12. The wind turbine main shaft support structure according to claim 11, wherein: A first contact angle defined by a raceway of the cup of the first tapered roller bearing is smaller than a second contact angle defined by a raceway of the cup of the second tapered roller bearing.
13. The wind turbine main shaft support structure according to claim 12, wherein: The first contact angle is 14 degrees to 30 degrees, and the second contact angle is 10 degrees to 26 degrees.
14. The wind turbine main shaft support structure according to claim 12, wherein: The first contact angle is 23 degrees to 29 degrees, and the second contact angle is 14 degrees to 20 degrees.
15. The wind turbine main shaft support structure according to claim 11, wherein: The radially outermost point occupied by the set of rollers of the second tapered roller bearing is closer to the central axis of rotation than the radially innermost point on the cup of the first tapered roller bearing.
16. The wind turbine main shaft support structure according to claim 11, wherein: The set of tapered roller bearings includes an additional tapered roller bearing positioned closer to the downwind end of the main shaft than the first tapered roller bearing and the second tapered roller bearing, wherein a load line from the additional tapered roller bearing extends in a second axial direction opposite the upwind direction to an effective load center spaced apart from the additional tapered roller bearing.
17. The wind turbine main shaft support structure according to claim 9, wherein: The respective payload centers are located at a common point along the central rotational axis.
18. A wind turbine drive train configuration, comprising: a blade hub including a plurality of blade mounts, the blade hub being rotatable about a central rotational axis; a generator having an input configured to be driven by rotation of the blade hub and operable in response to generating electrical power; and a bearing arrangement comprising a set of tapered roller bearings positioned about the central axis of rotation, wherein the set of tapered roller bearings comprises a first tapered roller bearing and a second tapered roller bearing arranged in series with the first tapered roller bearing, such that effective load centers of both the first tapered roller bearing and the second tapered roller bearing are offset toward a first axial direction, and Wherein respective load lines from the first tapered roller bearing and the second tapered roller bearing to respective effective load centers are non-parallel.
19. The wind turbine drive train configuration of claim 18, wherein: The generator is an 18 MW generator and both the first tapered roller bearing and the second tapered roller bearing have an outer diameter of no more than 3.5 metres.
20. The wind turbine drive train configuration of claim 18, wherein: The respective payload centers are located at a common point along the central rotational axis.
21. The wind turbine drive train configuration of claim 18, wherein: The respective payload centers are located at two separate points along the central rotational axis.
22. The wind turbine drive train configuration of claim 18, wherein: The first axial direction is an upwind direction, and the first tapered roller bearing is located further in the upwind direction than the second tapered roller bearing.
23. The wind turbine drive train configuration of claim 22, wherein: A first contact angle defined by a raceway of the cup of the first tapered roller bearing is smaller than a second contact angle defined by a raceway of the cup of the second tapered roller bearing.
24. The wind turbine main shaft support structure according to claim 23, wherein: The first contact angle is 14 degrees to 30 degrees, and the second contact angle is 10 degrees to 26 degrees.
25. The wind turbine main shaft support structure according to claim 23, wherein: The first contact angle is 23 degrees to 29 degrees, and the second contact angle is 14 degrees to 20 degrees.
26. The wind turbine drive train configuration of claim 22, wherein: The radially outermost point occupied by the set of rollers of the second tapered roller bearing is closer to the central axis of rotation than the radially innermost point on the cup of the first tapered roller bearing.
27. The wind turbine drive train configuration of claim 22, wherein: The set of tapered roller bearings includes an additional tapered roller bearing positioned closer to the downwind end of the main shaft than the first tapered roller bearing and the second tapered roller bearing, wherein a load line from the additional tapered roller bearing extends in a second axial direction opposite to the upwind direction to an effective load center spaced apart from the additional tapered roller bearing.