The present subject matter relates generally to wind turbines and, more particularly, to bearings for wind turbines having wire races.
Wind power is considered one of the cleanest, most environmentally friendly energy sources presently available, and wind turbines have gained increased attention in this regard. A modern wind turbine typically includes a tower, a generator, a gearbox, a nacelle, and one or more rotor blades. The rotor blades capture kinetic energy from wind using known airfoil principles and transmit the kinetic energy through rotational energy to turn a main shaft coupling the rotor blades to a gearbox, or if a gearbox is not used, directly to the generator. The generator then converts the mechanical energy to electrical energy that may be deployed to a utility grid.
Modern wind turbines include many bearings to provide rotational movement of its various components. For example, to properly orient the nacelle and the rotor blades relative to the direction of the wind, wind turbines typically include one or more yaw and/or pitch bearings. Such bearings are typically slewing bearings which are rotational ball bearings that support a heavy but slow-turning or slow-oscillating load. Typical yaw and/or pitch bearings include an outer and inner race with a plurality of ball or roller bearings configured between the inner and outer races. As such, yaw bearings permit rotation of the nacelle and are mounted between the tower and the nacelle, whereas pitch bearings permit rotation of the rotor blades and are mounted between the rotatable hub and one of the rotor blades. In addition, wind turbines typically include one or more roller bearings configured with the main shaft to permit rotation thereof. Alternatively, in wind turbines without a main shaft, such roller bearings may be used to permit rotation of the hub with respect to the nacelle.
As wind turbines continue to increase in size, such bearings must similarly increase in size due to increased loading from longer rotor blades. With longer rotor blades also comes increased loads acting on the wind turbine bearings, which are typically very expensive and can be difficult to access and replace. In addition, increasing the size of such bearings and current materials of construction can limit manufacturing capabilities thereof, e.g. in materials and/or providing heat treatment thereto.
Accordingly, an improved bearing that addresses the aforementioned issues would be welcomed in the technology.
Aspects and advantages of the invention will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the invention.
In one aspect, the present disclosure is directed to a bearing assembly for a wind turbine. The bearing assembly includes an outer race, an inner race, at least one row of a plurality of rolling elements positioned between the inner and outer races such that at least one of the inner race or the outer race rotates with respect to the other, and at least one wire race arranged with the plurality of rolling elements between the inner and outer races.
In one embodiment, the bearing assembly may include at least two wire races or at least four wire races arranged with the row of rolling elements, thereby forming a two-point or four-point contact bearing, respectively. In other embodiments, the plurality of rolling elements may include at least two rows of rolling elements. In such embodiments, the bearing assembly may include at least one wire race arranged with each of the at least two rows of rolling elements. More specifically, in certain embodiments, the bearing assembly may include at least four wire races arranged with each of the at least two rows of rolling elements, thereby forming an eight-point contact bearing.
In another embodiment, either or both of the inner or outer races may be radially split.
In further embodiments, the inner and outer races may be constructed of a first metal alloy, whereas the wire race(s) may be constructed of second metal alloy. More specifically, the second metal alloy may have at least one improved characteristic in comparison to the first metal alloy. For example, the second metal alloy may have a higher strength, an increased hardness, or improved contact fatigue capability than the first metal alloy. In further embodiments, the wire race(s) may optionally include a coating. In addition, it should be understood that the wire race(s) may have any suitable a cross-sectional shape, including but not limited to a circle, a square, an oval, a crescent shape, a hemispherical shape, a rectangle, or similar.
In several embodiments, the bearing assembly may further include a wire-retention feature configured to prevent the at least one wire race from rotating.
In additional embodiments, the bearing assembly may correspond to a pitch bearing or a yaw bearing of the wind turbine. In another embodiment, the plurality of rolling elements may include ball bearings or roller bearings.
In another aspect, the present disclosure is directed to a bearing assembly for a wind turbine. The bearing assembly includes a stationary component of the wind turbine, an annular race rotatable relative to the stationary component, a plurality of rolling elements positioned between the stationary component and the annular race, and at least one wire race arranged with the plurality of rolling elements between the stationary component and the annular race.
In one embodiment, the stationary component may be a hub or a tower of the wind turbine. It should be further understood that the bearing assembly may further include any one of or a combination of the features and/or embodiments as described herein.
In yet another aspect, the present disclosure is directed to a bearing assembly for a wind turbine. The bearing assembly includes a stationary component of the wind turbine, a rotatable component of the wind turbine rotatable relative to the stationary component, an annular race fixed relative to the rotatable component, a plurality of roller bearings positioned adjacent to the rotatable component, and at least one wire race arranged with the plurality of roller bearings.
In one embodiment, the annular race may be integrated with the rotatable component. In another embodiment, the rotatable component may include a hub of the wind turbine, whereas the stationary component may include a housing of the wind turbine. It should be further understood that the bearing assembly may further include any one of or a combination of the features and/or embodiments as described herein.
These and other features, aspects and advantages of the present invention will be further supported and described with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.
A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures, in which:
Reference now will be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents.
In general, the present disclosure is directed to a bearing assembly for a wind turbine having at least one wire race. As such, the bearing assembly of the present disclosure provides numerous advantages not present in the cited art. For example, the wire races of the present disclosure provide raceway surfaces that can be made from a high-strength bearing steel or other specialized material, such that improved reliability of the bearing can be achieved with minimum high-cost material, i.e. the inner and/or outer races can be made from lower cost material and can be sized for maximum stiffness. The resultant bearing assembly is more economical than conventional bearings. Further, the wire races provide stiffer bearing raceways that better distribute rotor loads across the ball or roller bearings and help reduce contact stress, thereby improving bearing reliability. Moreover, the bearing assembly of the present disclosure can handle increased loads due to larger rotor blades without requiring larger ball bearings or more expensive roller bearings.
The present invention is described herein as it may relate to wind turbine bearings, including, at least, yaw bearings, pitch bearings, main bearings, and/or similar. It should be appreciated, however, that the unique bearings in accordance with principles of the present invention is not limited to use with a wind turbine, but is applicable to any suitable bearing application.
Referring now to the drawings,
Referring now to
Additionally, the wind turbine 10 may include one or more yaw drive mechanisms 56 mounted to and/or through a bedplate 58 positioned atop the wind turbine tower 12. Specifically, each yaw drive mechanism 56 may be mounted to and/or through the bedplate 58 so as to engage a yaw bearing 60 coupled between the bedplate 58 and the tower 12 of the wind turbine 10. The yaw bearing 60 may be mounted to the bed plate 58 such that, as the yaw bearing 60 rotates about a yaw axis 62 of the wind turbine 10, the bedplate 58 and, thus, the nacelle 14 are similarly rotated about the yaw axis.
In general, it should be appreciated that the yaw drive mechanisms 56 may have any suitable configuration and may include any suitable components known in the art that allow such mechanisms 56 to function as described herein. For example, as shown in
Referring still to
Referring now to
Moreover, as shown, the rotor blade 20 may also include a plurality of T-bolts or root attachment assemblies 40 for coupling the blade root 20 to the hub 18 of the wind turbine 10. In general, each root attachment assembly 40 may include a barrel nut 42 mounted within a portion of the blade root 22 and a root bolt 44 coupled to and extending from the barrel nut 42 so as to project outwardly from a root end 46 of the blade root 22. By projecting outwardly from the root end 46, the root bolts 44 may generally be used to couple the blade root 22 to the hub 18 (e.g., via one of the pitch bearings 68), as will be described in greater detail below.
Referring now to
Referring particularly to
Further, as shown in the embodiment of
Such relative rotation of the outer and inner races 74, 76 may be achieved using a pitch adjustment mechanism 72 (
As shown in
Thus, as shown in
Referring now to
Referring now to
Further, in such embodiments, as shown, the bearing assembly 70 includes a stationary component of the wind turbine 10, a rotatable component of the wind turbine 10, i.e. rotatable relative to the stationary component, an annular race 75 fixed relative to the rotatable component, a plurality of rolling elements 78 positioned adjacent to the rotatable component, and at least one wire race 80 arranged with the plurality of rolling elements 78. More specifically, as shown, the rolling elements 78 may correspond to roller bearings 88. In addition, the stationary component may correspond to a housing 90 of the wind turbine 10. For example, in certain embodiments, the housing 90 may correspond to the bedplate 58 or a pillow block 95 on the wind turbine 10. Further, as shown, the rotatable component may include the hub 18 of the wind turbine 10. In one embodiment, as shown, the annular race 75 may be secured to the hub 18 via any suitable mechanical fasteners (not shown). Alternatively, the annular race 75 may be integrated with the rotatable component, i.e. the hub 18.
In further embodiments, the race(s) 74, 75, 76 may be constructed of a first metal alloy, whereas the wire race(s) 78 may be constructed of second metal alloy. More specifically, the second metal alloy may have at least one improved characteristic in comparison to the first metal alloy. For example, the second metal alloy may have a higher strength, an increased hardness, or improved contact fatigue capability than the first metal alloy. More specifically, in one embodiment, the second metal alloy material may include 52100 alloy steel, whereas the first metal alloy may include a less expensive 42Cr alloy steel. As such, the bearing of the present disclosure provides improved reliability and cost benefits over bearings made of single materials.
In further embodiments, the wire race(s) may optionally include a coating. For example, the coating may include any suitable coating material, including but not limited to black oxide, diamond-like carbon (DLC) and equivalents thereof, and/or a phosphate based coating. In addition, it should be understood that the wire race(s) may have any suitable a cross-sectional shape, including but not limited to a circle, a square, an oval, a crescent shape, a hemispherical shape, a rectangle, or similar.
In another embodiment, the race(s) 74, 75, 76 described herein may have a split configuration, e.g. to help with assembly of the bearing 68. More specifically, as shown in
Additionally, in several embodiments, a plurality of lubrication ports 92 may be defined through the race(s) 74, 75, 76. In general, each lubrication port 92 may be configured to supply a suitable lubricant (e.g., grease, etc.) from a location outside the bearing assembly 70 to a location between the race(s) 74, 75, 76. In addition, to maintain the lubricant within the bearing assembly 70, any gaps defined between the race(s) 74, 75, 76 may be sealed using suitable sealing mechanisms. For instance, as shown in
Referring now to
Further, as shown in
This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.
Number | Name | Date | Kind |
---|---|---|---|
2917351 | Franke et al. | Dec 1959 | A |
3002429 | Franke et al. | Oct 1961 | A |
3030158 | Pohler | Apr 1962 | A |
3141230 | Pohler et al. | Jul 1964 | A |
3144278 | Pohler | Aug 1964 | A |
3208804 | Stenert et al. | Sep 1965 | A |
3332728 | Gibson | Jul 1967 | A |
3370333 | Gibson | Feb 1968 | A |
3370337 | Gibson | Feb 1968 | A |
3453673 | Arnot | Jul 1969 | A |
3478402 | Schmude et al. | Nov 1969 | A |
3482892 | Pohler | Dec 1969 | A |
3543367 | Arnot | Dec 1970 | A |
3608661 | Arnot | Sep 1971 | A |
3700845 | Jonsson | Oct 1972 | A |
3709573 | Orkin | Jan 1973 | A |
3897843 | Hapeman et al. | Aug 1975 | A |
4003121 | Hagen et al. | Jan 1977 | A |
4007560 | Janssen | Feb 1977 | A |
4074394 | Kunig et al. | Feb 1978 | A |
4109361 | Hagen et al. | Aug 1978 | A |
4262991 | Wagener et al. | Apr 1981 | A |
4505525 | Wolzenburg | Mar 1985 | A |
4509871 | Herzog et al. | Apr 1985 | A |
4557532 | Teramachi | Dec 1985 | A |
4568205 | Basener | Feb 1986 | A |
4648728 | Erdelitsch et al. | Mar 1987 | A |
4778287 | Jacob et al. | Oct 1988 | A |
4906113 | Sague | Mar 1990 | A |
4989999 | Siemensmeyer | Feb 1991 | A |
5134863 | Hanna | Aug 1992 | A |
5275020 | Scherzinger | Jan 1994 | A |
5372485 | Sumser | Dec 1994 | A |
5428864 | Pemberton | Jul 1995 | A |
5454225 | Sumser | Oct 1995 | A |
5581969 | Kelleher | Dec 1996 | A |
5599110 | MacKendrick | Feb 1997 | A |
8196900 | Kempf | Jun 2012 | B2 |
8197145 | Neubert et al. | Jun 2012 | B2 |
8794847 | Dondaine et al. | Aug 2014 | B2 |
9017198 | Hoebel et al. | Apr 2015 | B2 |
9072486 | Limmer et al. | Jul 2015 | B2 |
9140342 | Hoebel et al. | Sep 2015 | B2 |
9590468 | Ritchey et al. | Mar 2017 | B2 |
20060120649 | Risberg | Jun 2006 | A1 |
20100284640 | Bergling | Nov 2010 | A1 |
20140252922 | Ritchey et al. | Sep 2014 | A1 |
20150276036 | Hoebel et al. | Oct 2015 | A1 |
20150306717 | Ehrhardt et al. | Oct 2015 | A1 |
20160025068 | Frank | Jan 2016 | A1 |
Number | Date | Country |
---|---|---|
301186 | Feb 1989 | EP |
2414704 | Sep 2013 | EP |
2414704 | Oct 2013 | EP |
2672147 | Dec 2013 | EP |
WO 0078057 | Dec 2000 | WO |
WO 2006122642 | Nov 2006 | WO |
WO 2009048402 | Apr 2009 | WO |
WO 2009048403 | Apr 2009 | WO |
WO 2010113115 | Oct 2010 | WO |
WO 2012046216 | Apr 2012 | WO |
WO 2013108072 | Jul 2013 | WO |
Number | Date | Country | |
---|---|---|---|
20180313337 A1 | Nov 2018 | US |