WO2015057126A1 - Wind turbine rotor bearing arrangement - Google Patents

Wind turbine rotor bearing arrangement Download PDF

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Publication number
WO2015057126A1
WO2015057126A1 PCT/SE2014/051026 SE2014051026W WO2015057126A1 WO 2015057126 A1 WO2015057126 A1 WO 2015057126A1 SE 2014051026 W SE2014051026 W SE 2014051026W WO 2015057126 A1 WO2015057126 A1 WO 2015057126A1
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WO
WIPO (PCT)
Prior art keywords
bearing
support structure
wind turbine
rolling
rolling bearing
Prior art date
Application number
PCT/SE2014/051026
Other languages
French (fr)
Inventor
Hans Wendeberg
Jonas Kullin
Original Assignee
Aktiebolaget Skf
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Aktiebolaget Skf filed Critical Aktiebolaget Skf
Publication of WO2015057126A1 publication Critical patent/WO2015057126A1/en

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F03—MACHINES OR ENGINES FOR LIQUIDS; WIND, SPRING, OR WEIGHT MOTORS; PRODUCING MECHANICAL POWER OR A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR
    • F03D—WIND MOTORS
    • F03D80/00—Details, components or accessories not provided for in groups F03D1/00 - F03D17/00
    • F03D80/70—Bearing or lubricating arrangements
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C19/00—Bearings with rolling contact, for exclusively rotary movement
    • F16C19/22—Bearings with rolling contact, for exclusively rotary movement with bearing rollers essentially of the same size in one or more circular rows, e.g. needle bearings
    • F16C19/34—Bearings with rolling contact, for exclusively rotary movement with bearing rollers essentially of the same size in one or more circular rows, e.g. needle bearings for both radial and axial load
    • F16C19/36—Bearings with rolling contact, for exclusively rotary movement with bearing rollers essentially of the same size in one or more circular rows, e.g. needle bearings for both radial and axial load with a single row of rollers
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C19/00—Bearings with rolling contact, for exclusively rotary movement
    • F16C19/54—Systems consisting of a plurality of bearings with rolling friction
    • F16C19/546—Systems with spaced apart rolling bearings including at least one angular contact bearing
    • F16C19/547—Systems with spaced apart rolling bearings including at least one angular contact bearing with two angular contact rolling bearings
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C19/00—Bearings with rolling contact, for exclusively rotary movement
    • F16C19/54—Systems consisting of a plurality of bearings with rolling friction
    • F16C19/56—Systems consisting of a plurality of bearings with rolling friction in which the rolling bodies of one bearing differ in diameter from those of another
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C23/00—Bearings for exclusively rotary movement adjustable for aligning or positioning
    • F16C23/06—Ball or roller bearings
    • F16C23/08—Ball or roller bearings self-adjusting
    • F16C23/082—Ball or roller bearings self-adjusting by means of at least one substantially spherical surface
    • F16C23/086—Ball or roller bearings self-adjusting by means of at least one substantially spherical surface forming a track for rolling elements
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C33/00—Parts of bearings; Special methods for making bearings or parts thereof
    • F16C33/30—Parts of ball or roller bearings
    • F16C33/34—Rollers; Needles
    • F16C33/36—Rollers; Needles with bearing-surfaces other than cylindrical, e.g. tapered; with grooves in the bearing surfaces
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
    • F05B—INDEXING SCHEME RELATING TO WIND, SPRING, WEIGHT, INERTIA OR LIKE MOTORS, TO MACHINES OR ENGINES FOR LIQUIDS COVERED BY SUBCLASSES F03B, F03D AND F03G
    • F05B2240/00—Components
    • F05B2240/50—Bearings
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C19/00—Bearings with rolling contact, for exclusively rotary movement
    • F16C19/54—Systems consisting of a plurality of bearings with rolling friction
    • F16C19/546—Systems with spaced apart rolling bearings including at least one angular contact bearing
    • F16C19/547—Systems with spaced apart rolling bearings including at least one angular contact bearing with two angular contact rolling bearings
    • F16C19/548—Systems with spaced apart rolling bearings including at least one angular contact bearing with two angular contact rolling bearings in O-arrangement
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C2360/00—Engines or pumps
    • F16C2360/31—Wind motors
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00—Energy generation through renewable energy sources
    • Y02E10/70—Wind energy
    • Y02E10/72—Wind turbines with rotation axis in wind direction
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

Definitions

  • the present invention relates to rolling bearing arrangements for wind turbine rotors, and more specifically to a wind turbine rotor bearing
  • the present invention also relates to a wind turbine arrangement and to a method for manufacturing a wind turbine rotor bearing arrangement.
  • the bearing arrangement must support both axial and radial loads, wherein the axial loads commonly comprises axial loads transferred from the turbine blades during operation as well as axial loads arising from the weight of the rotor and turbine blade arrangement which is commonly mounted with a tilted angle in relation to the horizontal plane in order to reduce the risk of collision between the turbine blades and the wind turbine tower. Also, the bearing arrangement must support overturning moment of the wind turbine rotor hub.
  • a general object of the present invention is to provide an improved wind turbine rotor bearing arrangement, a wind turbine arrangement and a method for manufacturing a wind turbine rotor bearing arrangement.
  • the present invention relates to a wind turbine rotor bearing arrangement, comprising a first and a second support structure for supporting a rotor of a wind turbine, which rotor has a main axis of rotation R, wherein the first support structure is arranged to rotate with the rotor, and the second support structure is fixed and arranged to be non-rotatably mounted to a wind turbine nacelle frame.
  • first rolling bearing forms a radially outer bearing
  • second rolling bearing is arranged radially inside the first rolling bearing by a bearing radial distance A, and the first support location and second support location are axially aligned.
  • the invention is based on the realization by the inventors that an improved and more compact wind turbine rotor bearing arrangement is realized by providing a set of axialiy locating rolling bearings which are radially separated and axially align.
  • the solution advantageously allows for axial and radial load bearing capacity while the axial width of arrangement may be considerably decreased, thereby reducing the nacelle weight of the complete wind turbine.
  • size and cross- section can be smaller with increasing bearing radial dimension, which allows for more optimized design in terms of compactness and weight of the first rolling bearing. For example, increased bearing radial dimension of the first rolling bearing improves the moment load bearing capability of the turbine rotor arrangement.
  • the design according to the present invention allows for efficient mounting, dismounting and replacement of the components of the rotor arrangement.
  • wind turbine rotor arrangement according to the present invention is further advantageous in that the design allows for improved operation and performance of direct driven, or gear less, wind turbine generator
  • the reduced distance reduce the negative effect from material deflections of the support structures portions located between the first rolling bearing and the generator, thereby improving the alignment and relative orientation between the rotor and stator. For example, this allows for an improved and more accurate airgap between the rotor and stator.
  • the wind turbine rotor bearing arrangement may for example be arranged for a horizontal rotor axis, or near horizontal rotor axis, type wind turbine, or for a vertical rotor axis, or near vertical rotor axis, type wind turbine.
  • the contact angle of at least one of the first and second rolling bearings is angled in relation to the axis of rotation.
  • at least one of the first and second roiling bearings, or both is an angular contact rolling bearing, such as an angular contact roller bearing or an angular contact ball bearing, arranged to support axial loads.
  • the contact angles of the first and second rolling bearings are angled in relation to the axis of rotation, wherein the first rolling bearing is arrange to axially locate the first support structure in relation to the second support structure in a first axial direction D1 , and the second rolling bearing is arrange to axially locate the first support structure in relation to the second support structure in a second axial direction D2, the second axial direction being opposite the first axial direction.
  • the first and second rolling bearings are advantageously arranged to cooperate to axially locate and fixate the first support structure in relation to the second support structure.
  • the contact angle of at least one or both of the first and second rolling bearings is between 5 and 90 degrees, or between 5 and 60 degrees, or between 10 and 45 degrees, or between 15 and 25 degrees.
  • Suitable contact angle configuration of the first and second rolling bearing allows for suitable radial and axial load bearing capacity.
  • the first rolling bearing has a relatively large contact angle and is adjusted to bear axial loads
  • the second rolling bearing has a relatively small contact angle and is adjusted to bear radial loads, or vice versa.
  • the first rolling bearing has a larger axial load bearing capacity in relation to the second rolling bearing in order to bear the axial load from the weight of a tilted wind turbine rotor arrangement and from the force transferred to the rotor from the turbine blades during operation,
  • the contact angle may be defined as the angle between the line along which the resulting load is transmitted via a roller element from one raceway to another, typically along an axial center portion of the roller.
  • the contact angle of the first and second bearings may also be described as the angle between the rotational axis of the rolling elements, such as rollers, and the axial direction of the rotor shaft.
  • a first pressure center of the first rolling bearing and a second pressure center of the second rolling bearing are separated in the axial direction by a pressure center distance B.
  • the pressure center distance B equals or exceeds the axial width of the second rolling bearing, or 50 % of the outer radius of the second rolling bearing, or the outer radius of the second rolling bearing, or the outer diameter of the second rolling bearing, or 200 % of the outer diameter of the second rolling bearing, or 10 times the outer diameter of the second rolling bearing.
  • the first rolling bearing comprises a rotating ring with a raceway for a first set of rolling elements and a non-rotating ring with raceway for the first set of rolling elements
  • the second rolling bearing comprises a rotating ring with a raceway for second set of rolling elements and a non-rotating ring with raceway for the second set of rolling elements
  • the rotating ring of the first rolling bearing and the rotating ring of the second rolling bearing are mounted to the first support structure, and the non-rotating ring of the first rolling bearing and the non-rotating ring of the second rolling bearing are mounted to the second support structure.
  • Each one of the first and second rolling bearings comprises an inner and an outer ring, wherein one of the rings is a rotating ring and the other is a non-rotating ring.
  • the rotating ring of the first rolling bearing is formed by the inner ring
  • the rotating ring of the second rolling bearing is formed by the outer ring
  • the rotating ring of the first rolling bearing is formed by the outer ring
  • the rotating ring of the second rolling bearing is formed by the outer ring.
  • the rotating ring of the first rolling bearing is formed by the inner ring
  • the rotating ring of the second rolling bearing is formed by the inner ring.
  • the rotating ring of the first rolling bearing is formed by the outer ring
  • the rotating ring of the second rolling bearing is formed by the inner ring
  • the outer raceways of the first and second roller bearings are facing towards or away from each other in the axial direction.
  • the first and second rolling bearings may also be arranged such that the outer raceways are facing in the same axial direction.
  • the first and second bearings are axialiy displaced in relation to each other by an axial bearing distance C defined between axial centers of the first and second rolling bearings, wherein the axial bearing distance is within a distance
  • the bearing radial distance A equals or exceeds a distance corresponding to the axial extension of the second rolling bearing, or equals or exceeds a distance corresponding to 50 % of the outer radius of the second rolling bearing, or equals or exceeds a distance corresponding to the outer radius of the second rolling bearing, or equals or exceeds a distance corresponding to 150 % of the outer radius of the second rolling bearing, or equals or exceeds a distance corresponding to the outer diameter of the second rolling bearing, or equals or exceeds a distance corresponding to 200 % of the outer diameter of the second rolling bearing.
  • the bearing radial distance A is larger than, or at least two, or four, or ten times as large as, the axial bearing distance C.
  • the first support structure is disc-shaped and comprises a first bearing seat with a seating surface arranged in retaining abutment with rotating ring of the first rolling bearing, and a second bearing seat with a seating surface arranged in retaining abutment with rotating ring of the second rolling bearing, wherein the first and second bearing seats are axialiy aligned and radially separated in relation to each other.
  • the bearing seats advantageously ensure correct and secure attachment of the rotating rings of the first and second rolling bearings to the first support structure.
  • each bearing seat comprises a seat surface facing in a radially inward or radially outward direction.
  • the seat surface may be cylindrical or tapered.
  • the first and/or second rolling bearing is a tapered roller bearing, spherical roller thrust bearing, angular contact spherical roller bearing, toroidal roller bearing, angular contact toroidal roller bearing, a cylindrical roller bearing, or a combination of two of these rolling bearing types.
  • the first and/or second rolling bearing is a ball bearing, allowing for reduced friction.
  • the large contact zone provided by the large radial dimension of the first rolling bearing allows for suitable load bearing properties and durability of the ball bearing.
  • each raceway of each bearing has a curved cross-section when taken in a plane coinciding with the axial direction of the inner or outer rings.
  • each roller is provided with a raceway contacting surface having a curved cross-section when taken in a plane coinciding with the rotational axis of the roller.
  • the rollers are barrel-shaped having a convex raceway- contacting surface.
  • the curvature of the outer raceway has a radius of curvature corresponding to, or being equal to, the radius of the outer raceway and the rollers are arranged to move in relation to the outer raceway and travel with the inner raceway during self- aligning movement of the spherical bearing.
  • the curvature of the outer raceway has a radius of curvature exceeding the radius of the outer raceway, which allows for some axial displacement of the rollers in relation to the raceway, wherein the rollers are arranged to move in relation to both the outer raceway and the inner raceway during self-aligning movement of the toroidal bearing.
  • the ratio between the curvature radius and the raceway radius is more than 1.1 , or 1.2, or 1.5, 2, or 5.
  • the first roiling bearing and/or the second rolling bearing is a single row rolling bearing, i.e.
  • the rotor is only supported by the first rolling bearing at the first support location, wherein the first rolling bearing comprises only one row of rollers which axially locate the rotor in the first axial direction.
  • the normal direction of the contacting surface of the first and/or second bearing raceways along the complete, or full length of the, raceway along the axial direction is inclined in relation to the radial direction of the rotor.
  • the second support structure further comprises an axial center bore allowing for reduced weight and access-way to the hub unit for hub control equipment.
  • the outer non-rotating ring of the second rolling bearing may be mounted inside the axial center bore of the second support structure.
  • the first and/or second rolling bearings may be arranged with a positive internal operational clearance, negative internal operational clearance, or no internal operational clearance.
  • the bearings may be arranged to have substantially no axial play, or be arranged with a suitable axial play, depending on the preferred wind turbine rotor shaft design.
  • the bearings may also be arranged with an operational clearance, or play, in the radial direction.
  • the bearings may alternatively be arranged with a negative operational clearance, i.e. a preload, in order to e.g. enhance the stiffness of the bearing arrangement or to increase running accuracy.
  • the application of a preload may be provided by springs in order to prevent bearing damage as a result of sliding movements of the rolling elements.
  • first and/or second rolling bearings may, according to various embodiments, be separable bearings, wherein the inner and outer rings and the set of rolling elements are separable from each other.
  • the rolling bearings may be self-retaining such that the set of rolling elements and the inner and outer ring form a self-retaining bearing unit.
  • self-retention may be provided by provision of e.g. retention rings, retention sleeves, or retaining cages.
  • the rolling bearings may also be semi-self-retaining such that only the set of rolling elements and one of the inner or outer rings form a self-retaining unit.
  • the first and/or second rolling bearings may be provided with a coating for improved performance and operational reliability.
  • a suitable durable coating may be applied the respective rolling elements, inner raceways, outer raceways, inner rings, and/or outer rings.
  • a complete rolling bearing may be coated.
  • problems such as micropitting, smearing and inclusion-generated brittle flaking, and similar wear generated by e.g. high shear forces may be alleviated with a coating.
  • a coating may also be employed to reduce or avoid asperity interaction between rolling elements and raceways and/or for dynamic polishing of the raceways during operation.
  • the coating may be based on or comprise carbon, oxide, chromium, zinc, manganese and/or phosphate compounds. According to a further embodiment, the coating may be arranged to reduce or avoid dielectric breakdown of the rolling bearing components, for example by using a ceramic based coating acting as insulation.
  • the wind turbine rotor bearing arrangement may be equipped with sensors and measuring device for controlling the operation of the arrangement and for collected operational data in order to analyze maintenance requirements and to plan servicing activities. Sensors and measuring devices may also be use for detecting non-regular operation of the arrangement. Sensors and measuring devices may arranged to measure temperature, rotational speed, forces, vibration, currents alignment, but are not limited to those parameters. Data may be collected and communicated via cable or wireless
  • a wind turbine arrangement comprising a wind turbine bearing arrangement according to any one of the aforementioned embodiments, which wind turbine arrangement further comprises a nacelle frame, wherein the second support structure is mounted to the nacelle frame, a hub unit provided with rotor blades, which hub unit is mounted to the first support structure.
  • the wind turbine According to an exemplifying embodiment, the wind turbine
  • the present invention relates to a method for manufacturing a wind turbine bearing arrangement having a main axis of rotation, which method comprises providing:
  • a second support structure for supporting the rotor of a wind turbine, and arranging the second support structure to be non-rotatably mounted to a wind turbine nacelle frame, - a first rolling bearing and arranging it to support the first support structure in relation to the second support structure at a first support location, and
  • the method further comprising arranging the first and second rolling bearings in a coaxial configuration in relation to each other,
  • first rolling bearing as a radially outer bearing, providing the second rolling bearing radially inside the first rolling bearing by a bearing radial distance A, and
  • the method provides an improved wind turbine arrangement which is advantageous in similar manners as described in relation to the first aspect of the present invention.
  • the second support structure is to be understood to be fixed in relation to the main rotating movement of the first support structure during operation.
  • the non-rotating support structure may undergo other rotational movements, such as rotational movement when a complete wind turbine nacelle unit is rotated by yawing movement to face the wind in order to achieve suitable operation and favorable conditions for electric power generation.
  • Fig. 1a is a schematic cross-sectional view of an embodiment of the wind turbine rotor bearing arrangement according to the present invention.
  • Fig. 1b is an enlarged partial schematic cross-sectional view of the embodiment of the wind turbine rotor bearing arrangement in Fig. 1a.
  • Fig. 2 is a schematic perspective view of an embodiment of the wind turbine rotor bearing arrangement according to the present invention.
  • Fig. 3 is an enlarged partial schematic cross-sectional view of an embodiment of the wind turbine rotor bearing arrangement according to the present invention.
  • Fig. 4 is an enlarged partial schematic cross-sectional view of an embodiment of the wind turbine rotor bearing arrangement according to the present invention.
  • Fig. 5 is an enlarged partial schematic cross-sectional view of an embodiment of the wind turbine rotor bearing arrangement according to the present invention.
  • Fig. 6 is an enlarged partial schematic cross-sectional view of an embodiment of the wind turbine rotor bearing arrangement according to the present invention.
  • Fig. 7 is a schematic cross-sectional view of an embodiment of a wind turbine arrangement comprising a wind turbine rotor bearing arrangement according to the present invention.
  • FIG. 1a a schematic cross-sectional view of an embodiment of the wind turbine rotor bearing arrangement 1 according to the present invention, is illustrated.
  • An enlarged partial schematic cross-sectional view of the embodiment is illustrated in Fig. 1b.
  • the arrangement 1 comprises a first support structure 30 and a second support structure 35 which are rotationally connected in relation to a main axis of rotation R of the rotor arrangement.
  • the first support structure 30 is arranged to rotate with the rotor, and the second support structure 35 is fixed and arranged to be non-rotatably mounted to e.g. a wind turbine nacelle frame connected to a wind turbine tower via a yaw rotation device.
  • the first and second rolling bearings 100 and 200 are arranged in a coaxial configuration in relation to each other along rotational axis R, and cooperate to axially locate the first support structure 30 to the second support structure 35 in a stiff configuration, i.e. with reduced self-aligning capability.
  • the second support structure 35 comprises a radially outer member 37 extending radially outward to the first support 101 , at which the first rolling bearing 100 is attached.
  • the second support structure 35 further comprises a radially inner member 38 extending axially to the second support 201 , at which the second rolling bearing 200 is attached.
  • the second support structure 35 comprises a center bore 39 extending axially through the second support structure 35.
  • a locking device 33 is arranged to secure the second rolling bearing 200 to the first support structure 30, and a locking device 34 is arranged to secure the second rolling bearing 200 to the second support structure 35.
  • the outer radius of the second rolling bearing is indicated by 200r.
  • the first rolling bearing 100 is arranged in an radially outer position
  • the second rolling bearing 200 is arranged radially inside the first rolling bearing by a bearing radial distance A, defined between the radial centers of the first and second rolling bearings 100 and 200, as indicated in Figs. 1a-b.
  • the first support location 101 and second support location 201 are axialiy aligned, such that axial position of the first and second rolling bearings 100 and 200 are essentially aligned.
  • This design advantageously supports large moments, as well as large radial and axial loads, while providing optimized weight and compactness of the wind turbine in the axial direction.
  • the contact angle of the first and second roiling bearings 100 and 200 is inclined in relation to the axis of rotation in order to provide for axial locking between the support structures 30 and 35.
  • the contact angle ca1 of the first rolling bearing 100 prevents to first support structure 30 from displacement in the first axial direction D1
  • the contact angle ca2 of the second rolling bearing prevents the first support structure 30 from displacement in the second axial direction D2.
  • a first pressure center 102 of the first rolling bearing 100 along the rotational axis R is determined by the contact angle ca1
  • a second pressure center 202 of the second rolling bearing 200 along the rotational axis R is determined by the contact angle ca2.
  • the first and second pressure centers 102 and 202 are axialiy separated from each other by a pressure center distance B.
  • a sufficient pressure center distance B advantageously enables the wind turbine rotor bearing arrangement 1 to support moments while having a compact and axialiy aligned geometry of the first and second rolling bearings, such as self-aligning bearings.
  • the pressure center distance B may be employed to off-set the spherical self-aligning geometries of the first and second rolling bearings 100 and 200, such that a stiff moment bearing design based on self-aligning bearings may be provided.
  • first and second rolling bearings are inclined in the same direction, i.e. their outer raceways are tilted and facing towards the same axial direction D2.
  • first and second bearings 100 and 200 are axialiy aligned such that an advantageous axialiy compact design is provided.
  • first and second bearings 100 and 200 are axialiy displaced in relation to each other only by a limited axial bearing distance C defined between axial centers of the first and second roiling bearings 100 and 200, as indicated, such that the wind turbine rotor bearing arrangement 1 has a pancake type architecture.
  • the radially separated first and second roiling bearings 100 and 200 may be arranged to have substantially no axiai play, or be arranged with a suitable axial play, depending on the preferred wind turbine rotor design.
  • the wind turbine rotor bearing arrangment 1 is provided with a first and second rolling bearings 100 and 200 of different size and load bearing capacity.
  • the arrangement is configured for different axial load bearings capacity in the first and second axiai directions, allowing for a manufacturing of compact wind turbines with reduced weight.
  • the first rolling bearing 00 it is a spherical type roller bearing comprising an inner ring which forms the rotating ring 110, an outer ring which forms the non-rotating ring 120, and a set of rolling elements 103 formed of rollers arranged in an intermediate configuration between the inner and outer rings.
  • the second rolling bearing 200 is a spherical type roller bearing comprising an outer ring which forms the rotating ring 210, an inner ring which forms the non-rotating ring 220, and a set of rolling elements 203 formed of rollers arranged in an intermediate configuration between the inner and outer rings.
  • the rotating inner ring 110 is attached to and fixated in relation the first support structure 30, at bearing seat 31a.
  • the outer non- rotating ring 120 is attached to and fixated in relation to the second support structure 35, at bearing seat 36a.
  • the rotating outer ring 210 is attached to and fixated in relation the first support structure 30, at bearing seat 31 b, and the inner non-rotating ring 220 is attached to and fixated in relation to the second support structure 35, at bearing seat 36b.
  • each rolling elements 103 is formed of a symmetrical bearing roller and has a curved raceway-contacting surface arranged in contact with a curved raceways of the inner and outer rings 110 and 120; and 210 and 220.
  • Each roller has a symmetrical convex, or barrel-shaped, profile, i.e. an axially center portion having an increase radial width in relation to the opposite axial end portions.
  • Fig. 2 is a schematic perspective view of an embodiment of the wind turbine rotor bearing arrangement according to the present invention is illustrated, which arrangement is arranged and configured in a similar manner as the wind turbine rotor bearing arrangement as described with reference to Fig. 1a-b, unless stated or illustrated differently.
  • the wind turbine rotor bearing arrangement 1 in Fig. 2 differs in that the first and second rolling bearings are arranged in an alternative configuration.
  • the bearing seats are adjusted to support the first and second rolling bearings in alternative axial directions.
  • the first and second rolling bearings are inclined in the opposite axial direction in comparison with the embodiment described with reference to Figs. 1a-b.
  • the outer raceways of the first and second rolling bearings are tilted and facing towards the same axial direction D2, as indicated in Fig. 2.
  • Locking device 33 is arranged to secure the first roiling bearing 100 to the first support structure 30, and locking device 34 is arranged to secure the first roiling bearing 00 to the second support structure 35.
  • FIG. 3 an enlarged partial schematic cross-sectional view of an embodiment of the wind turbine rotor bearing arrangement according to the present invention is illustrated, which arrangement is arranged and configured in a similar manner as the wind turbine rotor bearing arrangement as described with reference to Fig. 1a-b, unless stated or illustrated differently.
  • the wind turbine rotor bearing arrangement 1 in Fig. 3 differs in that the first and second rolling bearings are arranged in an alternative
  • the first rolling bearing 100 is a roller bearing comprising an outer ring which forms the rotating ring 110, an inner ring which forms the non-rotating ring 120, and a set of rolling elements 103 formed of rollers arranged in an intermediate configuration between the inner and outer rings.
  • the second rolling bearing 200 is a roller bearing comprising an outer ring which forms the rotating ring 2 0, an inner ring which forms the non-rotating ring 220, and a set of rolling elements 203 formed of rollers arranged in an intermediate configuration between the inner and outer rings.
  • the rotating outer ring 110 is attached to and fixated in relation the first support structure 30, at bearing seat 31a.
  • the inner non- rotating ring 120 is attached to and fixated in relation to the second support structure 35, at bearing seat 36a.
  • the rotating outer ring 2 0 is attached to and fixated in relation the first support structure 30, at bearing seat 31b, and the inner non-rotating ring 220 is attached to and fixated in relation to the second support structure 35, at bearing seat 36b.
  • the set of rolling elements 103 are circumferentially arranged in a row around the non-rotating inner ring 120, and the set of rolling elements 203 are circumferentiaily arranged in a row around the non-rotating inner ring 220.
  • the bearing seats are adjusted to support the first and second rolling bearings in alternative axial directions.
  • the first and second rolling bearings are inclined in the opposite axial direction in relation to each other.
  • the outer raceway of the first rolling bearing 100 is tilted and faces towards the axial direction D1.
  • Locking device 33 is arranged to secure the second rolling bearing 200 to the first support structure 30, and locking device 34 is arranged to secure the second rolling bearing 200 to the second support structure 35.
  • FIG. 4 is an enlarged partial schematic cross-sectional view of an embodiment of the wind turbine rotor bearing arrangement 1 according to the present invention, which arrangement is arranged and configured in a similar manner as the wind turbine rotor bearing arrangement as described with reference to Fig. 1a-b, unless stated or illustrated differently.
  • the wind turbine rotor bearing arrangement 1 in Fig. 4 differs in that the first and second rolling bearings are arranged in an alternative configuration.
  • the first rolling bearing 100 is a roller bearing comprising an inner ring which forms the rotating ring 10, an outer ring which forms the non-rotating ring 20, and a set of rolling elements 103 formed of rollers arranged in an intermediate configuration between the inner and outer rings.
  • the second rolling bearing 200 is a roller bearing comprising an inner ring which forms the rotating ring 210, an outer ring which forms the non-rotating ring 220, and a set of rolling elements 203 formed of rollers arranged in an intermediate configuration between the inner and outer rings.
  • the rotating inner ring 1 0 is attached to and fixated in relation the first support structure 30, at bearing seat 31a.
  • the outer non- rotating ring 120 is attached to and fixated in relation to the second support structure 35, at bearing seat 36a.
  • the rotating inner ring 210 is attached to and fixated in relation the first support structure 30, at bearing seat 31 b, and the outer non-rotating ring 220 is attached to and fixated in relation to the second support structure 35, at bearing seat 36b.
  • the set of rolling elements 103 are circumferentialiy arranged in a row around the rotating inner ring 110, and the set of rolling elements 203 are circumferentialiy arranged in a row around the rotating inner ring 210.
  • the bearing seats are adjusted to support the first and second rolling bearings in alternative axial directions.
  • the first and second rolling bearings are inclined in the opposite axial direction in relation to each other.
  • the outer raceway of the first rolling bearing 100 is tilted and faces towards the axial direction D2, as indicated.
  • Fig. 5 is an enlarged partial schematic cross-sectional view of an embodiment of the wind turbine rotor bearing arrangement 1 according to the present invention, which arrangement is arranged and configured in a similar manner as the wind turbine rotor bearing arrangement as described with reference to Fig. 1a-b, unless stated or illustrated differently.
  • the wind turbine rotor bearing arrangement 1 in Fig. 5 differs in that the first and second rolling bearings are arranged in an alternative configuration.
  • the first rolling bearing 100 is a roller bearing comprising an inner ring which forms the rotating ring 110, an outer ring which forms the non-rotating ring 120, and a set of rolling elements 103 formed of rollers arranged in an intermediate configuration between the inner and outer rings.
  • the second rolling bearing 200 is a roller bearing comprising an inner ring which forms the rotating ring 210, an outer ring which forms the non-rotating ring 220, and a set of rolling elements 203 formed of rollers arranged in an intermediate configuration between the inner and outer rings.
  • the rotating inner ring 110 is attached to and fixated in relation the first support structure 30, at bearing seat 31a, which bearing seat 31a is facing in a radially outward direction.
  • the outer non-rotating ring 120 is attached to and fixated in relation to the second support structure 35, at bearing seat 36a facing in a radially inward direction.
  • the rotating inner ring 210 is attached to and fixated in relation the first support structure 30, at bearing seat 31b facing in the radially outward direction
  • the outer non- rotating ring 220 is attached to and fixated in relation to the second support structure 35, at bearing seat 36b facing in the radially inward direction.
  • the set of rolling elements 103 are circumferentially arranged in a row around the rotating inner ring 110, and the set of rolling elements 203 are circumferentially arranged in a row around the rotating inner ring 2 0.
  • the bearing seats are adjusted to support the first and second rolling bearings in alternative axial directions.
  • the first and second rolling bearings are inclined in the opposite axial direction in relation to each other.
  • Locking device 33 is arranged to secure the second rolling bearing 200 to the first support structure 30.
  • Fig. 6 is an enlarged partial schematic cross-sectional view of an embodiment of the wind turbine rotor bearing arrangement 1 according to the present invention, which arrangement is arranged and configured in a similar manner as the wind turbine rotor bearing arrangement as described with reference to Fig. 1a-b, unless stated or illustrated differently.
  • the wind turbine rotor bearing arrangement 1 in Fig. 6 differs in that the first and second rolling bearings are arranged in an alternative configuration.
  • the first rolling bearing 100 is a roller bearing comprising an outer ring which forms the rotating ring, an inner ring which forms the non- rotating ring, and a set of rolling elements formed of rollers arranged in an intermediate configuration between the inner and outer rings.
  • the second rolling bearing 200 is a roller bearing comprising an outer ring which forms the rotating ring, an inner ring which forms the non-rotating ring, and a set of rolling elements formed of rollers arranged in an intermediate configuration between the inner and outer rings.
  • the rotating outer ring of the first rolling bearing is attached to and fixated in relation the first support structure 30, at a bearing seat is facing in a radially inward direction.
  • the inner non-rotating ring is attached to and fixated in relation to the second support structure 35, at a bearing seat facing in a radially outward direction.
  • the rotating outer ring of the second rolling bearing is attached to and fixated in relation the first support structure 30 at bearing seat facing in the radially inward direction, and the inner non-rotating ring is attached to and fixated in relation to the second support structure 35 at a bearing seat facing in the radially outward direction.
  • the set of rolling elements of the first rolling bearing are
  • a schematic partial side view of a wind turbine arrangement is arranged to secure the first rolling bearing 100 to the first support structure 30, by securing the rotating outer ring of the first rolling bearing 100 to the bearing seat of the first support structure 30.
  • a hub unit 72 comprising fixed or pitchable blades 73 are attached to the first support structure 30 which is rotationally connected to the second support structure 35 via first and second rolling bearings 100 and 200.
  • the second support structure 35 is secured to a nacelle frame 71 anchored to a wind turbine tower-like structure 76 via a yaw rotation device 75 arranged to rotate the nacelle around yaw axis Y.
  • the wind turbine arrangement 70 comprises a direct drive electric generator 74 comprising rotor member 74a attached to the first support structure 30 radially outside and adjacent the first rolling bearing 100, and a stator member 74b attached to the second support structure 35 radially outside and adjacent the first rolling bearing 100.
  • the rotor 74a and stator 74b are separated by an airgap 74c extending the in an axial direction coinciding the main axis of rotation R of the wind turbine rotor.
  • the generator may also be connected to the rotating first support structure 30 and hub unit 72 which a shaft extending through a central bore in the second support structure.
  • the generator may be directly coupled to the first support structure, or via a gearbox shifting the rotational speed of the rotor.
  • wind turbine rotor bearing arrangement 1 may according to an embodiment form part of a hydraulic wind turbine
  • the rotor may be coupled to a hydraulic pump arranged in the nacelle and which is coupled to a ground-based hydraulic motor and generator arrangement, such as an in-line or bent-axis generator motor.
  • the wind turbine rotor bearing arrangement 1 may also, according to an embodiment, form part of a wind turbine arrangement comprising a gear transmission arranged for driving a generator.
  • the rotor may be coupled to an input side of a gearbox via a rotor shaft, wherein an output side of the gearbox is coupled to a generator operating at a different rotational speed in relation to the rotational speed of the wind turbine rotor during operation.
  • the rotor shaft may be arranged to extend through the center bore 39 extending axially through the second support structure 35, wherein the rotor shaft is connected to the first support structure 30.
  • the wind turbine rotor bearing arrangement 1 is not limited to a horizontal type orientation and may also be used in wind turbines appliations involving vertical type rotor shaft orientations.
  • the orientation of the rotor shaft is defined in relation to its intended mounted operational position in a nacelle framing of an operational wind turbine.
  • the rolling bearings 100 and 200 may for example be attached to the bearing seats of the support structures 30 and 35 by means of press-fitting techniques and/or by using a suitable locking device, such as locking device 33, shown in Fig. 1a.

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Abstract

The present invention relates to a wind turbine rotor bearing arrangement, comprising a first and a second support structure for supporting a rotor of a wind turbine having a main axis of rotation, a first roiling bearing supporting the first support structure in relation to the second support structure at a first support location, a second rolling bearing supporting the first support structure in relation to the second support structure at a second support, which first and second rolling bearings are arranged in a coaxial configuration in relation to each other. Furthermore, the first rolling bearing forms a radially outer bearing, and the second rolling bearing is arranged radially inside the first roiling bearing by a bearing radial distance, and the first support location and second support location are axially aligned. The present invention also relates to a wind turbine arrangement and to a method for manufacturing a wind turbine rotor bearing arrangement.

Description

WIND TURBINE ROTOR BEARING ARRANGEMENT
Field of the Invention
The present invention relates to rolling bearing arrangements for wind turbine rotors, and more specifically to a wind turbine rotor bearing
arrangement comprising a first and a second support structure for supporting a rotor of a wind turbine having a main axis of rotation.
The present invention also relates to a wind turbine arrangement and to a method for manufacturing a wind turbine rotor bearing arrangement.
Background Art
The trend to increase size and power output of wind turbines, as well as the tendency to locate wind turbines in more harsh environmental and difficult to access surroundings, such as off-shore, leads to increased demand for more durable, yet light weight wind turbine arrangements. Also, the development of wind turbines imposes lower maintenance requirements and easy service designs.
Typically, for a wind turbine with horizontal, or near horizontal, rotor orientation, the bearing arrangement must support both axial and radial loads, wherein the axial loads commonly comprises axial loads transferred from the turbine blades during operation as well as axial loads arising from the weight of the rotor and turbine blade arrangement which is commonly mounted with a tilted angle in relation to the horizontal plane in order to reduce the risk of collision between the turbine blades and the wind turbine tower. Also, the bearing arrangement must support overturning moment of the wind turbine rotor hub.
In order to support the wind turbine rotor arrangement in a suitable manner, different bearing configurations are known which may be adjusted for a given radial and axial load characteristic of a wind turbine rotor. However, known bearing designs typically require high manufacturing precision of the bearings raceways and raceway-contacting surfaces of the rolling elements, as well as high precision of the alignment between the rotor shaft and bearing housings structures at different support points along the axis of the rotor shaft. Furthermore, complex roller raceway geometries increase the precision and alignment requirements of the bearings, as well as increasing the mass and cost of material of the wind turbine arrangement. Also, in order to provide suitable axial location function, the required axial extension of known rolling bearing solutions imposes high space requirements and the overall size and weight of the wind turbine nacelle framing. Furthermore, known designs give rise to minor material deflections leading to decrease accuracy between relative rotating elements in the wind turbine rotor arrangement, such as the electric generator gap between the generator rotor and stator.
Summary of the Invention
In view of the above-mentioned and other drawbacks of the prior art, a general object of the present invention is to provide an improved wind turbine rotor bearing arrangement, a wind turbine arrangement and a method for manufacturing a wind turbine rotor bearing arrangement.
These and other objects are met by the subject matters provided in the independent claims. Preferred embodiments of the invention are presented in the dependent claims.
According to a first aspect thereof, the present invention relates to a wind turbine rotor bearing arrangement, comprising a first and a second support structure for supporting a rotor of a wind turbine, which rotor has a main axis of rotation R, wherein the first support structure is arranged to rotate with the rotor, and the second support structure is fixed and arranged to be non-rotatably mounted to a wind turbine nacelle frame. The
arrangement further comprises a first rolling bearing supporting, or rotatably connecting, the first support structure in relation to the second support structure at a first support location, a second rolling bearing supporting, or rotatably connecting, the first support structure in relation to the second support structure at a second support location, which first and second rolling bearings are arranged in a coaxial configuration in relation to each other. Moreover, the first rolling bearing forms a radially outer bearing, and the second rolling bearing is arranged radially inside the first rolling bearing by a bearing radial distance A, and the first support location and second support location are axially aligned.
The invention is based on the realization by the inventors that an improved and more compact wind turbine rotor bearing arrangement is realized by providing a set of axialiy locating rolling bearings which are radially separated and axially align. By radially separating and axially aligning the first and second rolling bearing, the solution advantageously allows for axial and radial load bearing capacity while the axial width of arrangement may be considerably decreased, thereby reducing the nacelle weight of the complete wind turbine. Considering the first rolling bearing, size and cross- section can be smaller with increasing bearing radial dimension, which allows for more optimized design in terms of compactness and weight of the first rolling bearing. For example, increased bearing radial dimension of the first rolling bearing improves the moment load bearing capability of the turbine rotor arrangement. Also, the design according to the present invention allows for efficient mounting, dismounting and replacement of the components of the rotor arrangement.
The wind turbine rotor arrangement according to the present invention is further advantageous in that the design allows for improved operation and performance of direct driven, or gear less, wind turbine generator
configurations, i.e. without gearbox between rotor and generator. In more detail, the increased radial dimension of the first rolling bearing
advantageousiy allows for a reduced distance between the first rolling bearing and the rotor and stator members of the generator. The reduced distance reduce the negative effect from material deflections of the support structures portions located between the first rolling bearing and the generator, thereby improving the alignment and relative orientation between the rotor and stator. For example, this allows for an improved and more accurate airgap between the rotor and stator.
The wind turbine rotor bearing arrangement may for example be arranged for a horizontal rotor axis, or near horizontal rotor axis, type wind turbine, or for a vertical rotor axis, or near vertical rotor axis, type wind turbine. According to an exemplifying embodiment, the contact angle of at least one of the first and second rolling bearings is angled in relation to the axis of rotation. For example, at least one of the first and second roiling bearings, or both, is an angular contact rolling bearing, such as an angular contact roller bearing or an angular contact ball bearing, arranged to support axial loads.
According to an exemplifying embodiment, the contact angles of the first and second rolling bearings are angled in relation to the axis of rotation, wherein the first rolling bearing is arrange to axially locate the first support structure in relation to the second support structure in a first axial direction D1 , and the second rolling bearing is arrange to axially locate the first support structure in relation to the second support structure in a second axial direction D2, the second axial direction being opposite the first axial direction. In other words, the first and second rolling bearings are advantageously arranged to cooperate to axially locate and fixate the first support structure in relation to the second support structure.
According to an exemplifying embodiment, the contact angle of at least one or both of the first and second rolling bearings is between 5 and 90 degrees, or between 5 and 60 degrees, or between 10 and 45 degrees, or between 15 and 25 degrees. Suitable contact angle configuration of the first and second rolling bearing allows for suitable radial and axial load bearing capacity. For example, the first rolling bearing has a relatively large contact angle and is adjusted to bear axial loads, and the second rolling bearing has a relatively small contact angle and is adjusted to bear radial loads, or vice versa. For example, the first rolling bearing has a larger axial load bearing capacity in relation to the second rolling bearing in order to bear the axial load from the weight of a tilted wind turbine rotor arrangement and from the force transferred to the rotor from the turbine blades during operation,
The contact angle may be defined as the angle between the line along which the resulting load is transmitted via a roller element from one raceway to another, typically along an axial center portion of the roller. The contact angle of the first and second bearings may also be described as the angle between the rotational axis of the rolling elements, such as rollers, and the axial direction of the rotor shaft. According to an exemplifying embodiment, a first pressure center of the first rolling bearing and a second pressure center of the second rolling bearing are separated in the axial direction by a pressure center distance B. According to various exemplifying embodiment, the pressure center distance B equals or exceeds the axial width of the second rolling bearing, or 50 % of the outer radius of the second rolling bearing, or the outer radius of the second rolling bearing, or the outer diameter of the second rolling bearing, or 200 % of the outer diameter of the second rolling bearing, or 10 times the outer diameter of the second rolling bearing. When the contact angles of the first and second rolling bearings are tilted in the same axial direction, increased pressure center distance B facilitates reduction of angular displacement of the arrangement.
According to an exemplifying embodiment, the first rolling bearing comprises a rotating ring with a raceway for a first set of rolling elements and a non-rotating ring with raceway for the first set of rolling elements, and the second rolling bearing comprises a rotating ring with a raceway for second set of rolling elements and a non-rotating ring with raceway for the second set of rolling elements.
According to an exemplifying embodiment, the rotating ring of the first rolling bearing and the rotating ring of the second rolling bearing are mounted to the first support structure, and the non-rotating ring of the first rolling bearing and the non-rotating ring of the second rolling bearing are mounted to the second support structure.
Each one of the first and second rolling bearings comprises an inner and an outer ring, wherein one of the rings is a rotating ring and the other is a non-rotating ring.
According to an exemplifying embodiment, the rotating ring of the first rolling bearing is formed by the inner ring, and the rotating ring of the second rolling bearing is formed by the outer ring.
According to an alternative design forming an exemplifying
embodiment, the rotating ring of the first rolling bearing is formed by the outer ring, and the rotating ring of the second rolling bearing is formed by the outer ring. According to yet an alternative design forming an exemplifying embodiment, the rotating ring of the first rolling bearing is formed by the inner ring, and the rotating ring of the second rolling bearing is formed by the inner ring.
According to an additional alternative design forming an exemplifying embodiment, the rotating ring of the first rolling bearing is formed by the outer ring, and the rotating ring of the second rolling bearing is formed by the inner ring.
According to an exemplifying embodiment, the outer raceways of the first and second roller bearings are facing towards or away from each other in the axial direction. The first and second rolling bearings may also be arranged such that the outer raceways are facing in the same axial direction.
According to an exemplifying embodiment, the first and second bearings are axialiy displaced in relation to each other by an axial bearing distance C defined between axial centers of the first and second rolling bearings, wherein the axial bearing distance is within a distance
corresponding to the outer radius of the second rolling bearing, or within a distance corresponding to the axial extension of the second rolling bearing, or within a distance corresponding to 50 % of the axial extension of the second rolling bearing, or within a distance corresponding to 20 % of the axial extension of the second rolling bearing.
According to an exemplifying embodiment, the bearing radial distance A equals or exceeds a distance corresponding to the axial extension of the second rolling bearing, or equals or exceeds a distance corresponding to 50 % of the outer radius of the second rolling bearing, or equals or exceeds a distance corresponding to the outer radius of the second rolling bearing, or equals or exceeds a distance corresponding to 150 % of the outer radius of the second rolling bearing, or equals or exceeds a distance corresponding to the outer diameter of the second rolling bearing, or equals or exceeds a distance corresponding to 200 % of the outer diameter of the second rolling bearing.
According to various exemplifying embodiments, in order to form an radially separated and axialiy align configuration between the first and second rolling bearings, the bearing radial distance A is larger than, or at least two, or four, or ten times as large as, the axial bearing distance C.
According to an exemplifying embodiment, the first support structure is disc-shaped and comprises a first bearing seat with a seating surface arranged in retaining abutment with rotating ring of the first rolling bearing, and a second bearing seat with a seating surface arranged in retaining abutment with rotating ring of the second rolling bearing, wherein the first and second bearing seats are axialiy aligned and radially separated in relation to each other. The bearing seats advantageously ensure correct and secure attachment of the rotating rings of the first and second rolling bearings to the first support structure.
According to a further exemplifying embodiment of the present invention, each bearing seat comprises a seat surface facing in a radially inward or radially outward direction. The seat surface may be cylindrical or tapered.
According to an exemplifying embodiment, the first and/or second rolling bearing is a tapered roller bearing, spherical roller thrust bearing, angular contact spherical roller bearing, toroidal roller bearing, angular contact toroidal roller bearing, a cylindrical roller bearing, or a combination of two of these rolling bearing types. For example, according to an exemplifying embodiment, the first and/or second rolling bearing is a ball bearing, allowing for reduced friction. Also, the large contact zone provided by the large radial dimension of the first rolling bearing allows for suitable load bearing properties and durability of the ball bearing.
Common for both spherical roller and toroidal roller bearing types is that each raceway of each bearing has a curved cross-section when taken in a plane coinciding with the axial direction of the inner or outer rings. Also, each roller is provided with a raceway contacting surface having a curved cross-section when taken in a plane coinciding with the rotational axis of the roller. In other words, the rollers are barrel-shaped having a convex raceway- contacting surface. Furthermore, for a spherical type bearing, the curvature of the outer raceway has a radius of curvature corresponding to, or being equal to, the radius of the outer raceway and the rollers are arranged to move in relation to the outer raceway and travel with the inner raceway during self- aligning movement of the spherical bearing. For the a toroidal type bearing, the curvature of the outer raceway has a radius of curvature exceeding the radius of the outer raceway, which allows for some axial displacement of the rollers in relation to the raceway, wherein the rollers are arranged to move in relation to both the outer raceway and the inner raceway during self-aligning movement of the toroidal bearing. For example, for the toroidal type bearing, the ratio between the curvature radius and the raceway radius is more than 1.1 , or 1.2, or 1.5, 2, or 5.
According to an exemplifying embodiment, the first roiling bearing and/or the second rolling bearing is a single row rolling bearing, i.e.
comprising only a single row of rolling elements, such as single row spherical roller bearing or a single row toroidal roller bearing. Hence, the rotor is only supported by the first rolling bearing at the first support location, wherein the first rolling bearing comprises only one row of rollers which axially locate the rotor in the first axial direction.
For example, the normal direction of the contacting surface of the first and/or second bearing raceways along the complete, or full length of the, raceway along the axial direction, is inclined in relation to the radial direction of the rotor.
According to an embodiment, the second support structure further comprises an axial center bore allowing for reduced weight and access-way to the hub unit for hub control equipment. Also, the outer non-rotating ring of the second rolling bearing may be mounted inside the axial center bore of the second support structure.
According to various embodiments of the wind turbine rotor bearing arrangement, the first and/or second rolling bearings may be arranged with a positive internal operational clearance, negative internal operational clearance, or no internal operational clearance. For example, the bearings may be arranged to have substantially no axial play, or be arranged with a suitable axial play, depending on the preferred wind turbine rotor shaft design. The bearings may also be arranged with an operational clearance, or play, in the radial direction. The bearings may alternatively be arranged with a negative operational clearance, i.e. a preload, in order to e.g. enhance the stiffness of the bearing arrangement or to increase running accuracy. For example, the application of a preload may be provided by springs in order to prevent bearing damage as a result of sliding movements of the rolling elements.
Furthermore, the first and/or second rolling bearings may, according to various embodiments, be separable bearings, wherein the inner and outer rings and the set of rolling elements are separable from each other.
Alternatively, the rolling bearings may be self-retaining such that the set of rolling elements and the inner and outer ring form a self-retaining bearing unit. For example, self-retention may be provided by provision of e.g. retention rings, retention sleeves, or retaining cages. The rolling bearings may also be semi-self-retaining such that only the set of rolling elements and one of the inner or outer rings form a self-retaining unit.
Moreover, according to alternative further embodiments of the wind turbine rotor bearing arrangement, the first and/or second rolling bearings may be provided with a coating for improved performance and operational reliability. In more detail, a suitable durable coating may be applied the respective rolling elements, inner raceways, outer raceways, inner rings, and/or outer rings. Also, a complete rolling bearing may be coated. For example, problems such as micropitting, smearing and inclusion-generated brittle flaking, and similar wear generated by e.g. high shear forces may be alleviated with a coating. A coating may also be employed to reduce or avoid asperity interaction between rolling elements and raceways and/or for dynamic polishing of the raceways during operation. According to various embodiments, the coating may be based on or comprise carbon, oxide, chromium, zinc, manganese and/or phosphate compounds. According to a further embodiment, the coating may be arranged to reduce or avoid dielectric breakdown of the rolling bearing components, for example by using a ceramic based coating acting as insulation.
In addition, according to further exemplifying embodiments, the wind turbine rotor bearing arrangement may be equipped with sensors and measuring device for controlling the operation of the arrangement and for collected operational data in order to analyze maintenance requirements and to plan servicing activities. Sensors and measuring devices may also be use for detecting non-regular operation of the arrangement. Sensors and measuring devices may arranged to measure temperature, rotational speed, forces, vibration, currents alignment, but are not limited to those parameters. Data may be collected and communicated via cable or wireless
communication network to a control unit or to a central analysis system.
According to an exemplifying embodiment of the present invention, it relates to a wind turbine arrangement comprising a wind turbine bearing arrangement according to any one of the aforementioned embodiments, which wind turbine arrangement further comprises a nacelle frame, wherein the second support structure is mounted to the nacelle frame, a hub unit provided with rotor blades, which hub unit is mounted to the first support structure.
According to an exemplifying embodiment, the wind turbine
arrangement further includes a generator device comprising a rotor member mounted to the first support structure and a stator member mounted to the second support structure. For example, according to an exemplifying embodiment, the generator device is arranged on a radially outer side of the first rolling bearing. The wind turbine arrangement may further include a yaw rotation device for turning the complete nacelle frame and housing around a yaw axis. According to a further aspect thereof, the present invention relates to a method for manufacturing a wind turbine bearing arrangement having a main axis of rotation, which method comprises providing:
- a first support structure for supporting a rotor of a wind turbine and arranging the first support structure to rotate with the rotor,
- a second support structure for supporting the rotor of a wind turbine, and arranging the second support structure to be non-rotatably mounted to a wind turbine nacelle frame, - a first rolling bearing and arranging it to support the first support structure in relation to the second support structure at a first support location, and
- a second rolling bearing and arranging it to support the first support structure in relation to the second support structure at a second support location,
the method further comprising arranging the first and second rolling bearings in a coaxial configuration in relation to each other,
arranging the first rolling bearing as a radially outer bearing, providing the second rolling bearing radially inside the first rolling bearing by a bearing radial distance A, and
axially aligning the first support location and second support location in relation to each other.
The method provides an improved wind turbine arrangement which is advantageous in similar manners as described in relation to the first aspect of the present invention.
By being non-rotating, the second support structure is to be understood to be fixed in relation to the main rotating movement of the first support structure during operation. However, the non-rotating support structure may undergo other rotational movements, such as rotational movement when a complete wind turbine nacelle unit is rotated by yawing movement to face the wind in order to achieve suitable operation and favorable conditions for electric power generation.
Generally, other objectives, features, and advantages of the present invention will appear from the following detailed disclosure, from the attached dependent claims as well as from the drawings are equally possible within the scope of the invention.
Brief Description of Drawings
Embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings, wherein: Fig. 1a is a schematic cross-sectional view of an embodiment of the wind turbine rotor bearing arrangement according to the present invention.
Fig. 1b is an enlarged partial schematic cross-sectional view of the embodiment of the wind turbine rotor bearing arrangement in Fig. 1a.
Fig. 2 is a schematic perspective view of an embodiment of the wind turbine rotor bearing arrangement according to the present invention.
Fig. 3 is an enlarged partial schematic cross-sectional view of an embodiment of the wind turbine rotor bearing arrangement according to the present invention.
Fig. 4 is an enlarged partial schematic cross-sectional view of an embodiment of the wind turbine rotor bearing arrangement according to the present invention.
Fig. 5 is an enlarged partial schematic cross-sectional view of an embodiment of the wind turbine rotor bearing arrangement according to the present invention.
Fig. 6 is an enlarged partial schematic cross-sectional view of an embodiment of the wind turbine rotor bearing arrangement according to the present invention.
Fig. 7 is a schematic cross-sectional view of an embodiment of a wind turbine arrangement comprising a wind turbine rotor bearing arrangement according to the present invention.
It should be understood that the drawings are not true to scale and, as is readily appreciated by a person skilled in the art, dimensions other than those illustrated in the drawings are equally possible within the scope of the invention.
Detailed Description of Embodiments of the Invention
In the drawings, similar, or equal elements are referred to by equal reference numerals.
in Fig. 1a, a schematic cross-sectional view of an embodiment of the wind turbine rotor bearing arrangement 1 according to the present invention, is illustrated. An enlarged partial schematic cross-sectional view of the embodiment is illustrated in Fig. 1b.
The arrangement 1 comprises a first support structure 30 and a second support structure 35 which are rotationally connected in relation to a main axis of rotation R of the rotor arrangement. The first support structure 30 is arranged to rotate with the rotor, and the second support structure 35 is fixed and arranged to be non-rotatably mounted to e.g. a wind turbine nacelle frame connected to a wind turbine tower via a yaw rotation device.
A first rolling bearing 100 of self-aligning type supports and rotatably connects the first support structure 30 to the second support structure 35 at a first support location 101. A second rolling bearing 200 of self-aligning type supports and rotatably connects the first support structure to the second support structure at a second support location 201. The first and second rolling bearings 100 and 200 are arranged in a coaxial configuration in relation to each other along rotational axis R, and cooperate to axially locate the first support structure 30 to the second support structure 35 in a stiff configuration, i.e. with reduced self-aligning capability.
The second support structure 35 comprises a radially outer member 37 extending radially outward to the first support 101 , at which the first rolling bearing 100 is attached. The second support structure 35 further comprises a radially inner member 38 extending axially to the second support 201 , at which the second rolling bearing 200 is attached. As illustrated, the second support structure 35 comprises a center bore 39 extending axially through the second support structure 35. A locking device 33 is arranged to secure the second rolling bearing 200 to the first support structure 30, and a locking device 34 is arranged to secure the second rolling bearing 200 to the second support structure 35. The outer radius of the second rolling bearing is indicated by 200r.
The first rolling bearing 100 is arranged in an radially outer position, and the second rolling bearing 200 is arranged radially inside the first rolling bearing by a bearing radial distance A, defined between the radial centers of the first and second rolling bearings 100 and 200, as indicated in Figs. 1a-b. As further shown, the first support location 101 and second support location 201 are axialiy aligned, such that axial position of the first and second rolling bearings 100 and 200 are essentially aligned. This design advantageously supports large moments, as well as large radial and axial loads, while providing optimized weight and compactness of the wind turbine in the axial direction.
The contact angle of the first and second roiling bearings 100 and 200 is inclined in relation to the axis of rotation in order to provide for axial locking between the support structures 30 and 35. The contact angle ca1 of the first rolling bearing 100 prevents to first support structure 30 from displacement in the first axial direction D1 , and the contact angle ca2 of the second rolling bearing prevents the first support structure 30 from displacement in the second axial direction D2. A first pressure center 102 of the first rolling bearing 100 along the rotational axis R is determined by the contact angle ca1 , and a second pressure center 202 of the second rolling bearing 200 along the rotational axis R is determined by the contact angle ca2. As illustrated by load lines, the first and second pressure centers 102 and 202 are axialiy separated from each other by a pressure center distance B. A sufficient pressure center distance B advantageously enables the wind turbine rotor bearing arrangement 1 to support moments while having a compact and axialiy aligned geometry of the first and second rolling bearings, such as self-aligning bearings. In other words, the pressure center distance B may be employed to off-set the spherical self-aligning geometries of the first and second rolling bearings 100 and 200, such that a stiff moment bearing design based on self-aligning bearings may be provided.
In Figs. 1a-b, the first and second rolling bearings are inclined in the same direction, i.e. their outer raceways are tilted and facing towards the same axial direction D2.
As further illustrated, the first and second bearings 100 and 200 are axialiy aligned such that an advantageous axialiy compact design is provided. In more detail, first and second bearings 100 and 200 are axialiy displaced in relation to each other only by a limited axial bearing distance C defined between axial centers of the first and second roiling bearings 100 and 200, as indicated, such that the wind turbine rotor bearing arrangement 1 has a pancake type architecture.
The radially separated first and second roiling bearings 100 and 200 may be arranged to have substantially no axiai play, or be arranged with a suitable axial play, depending on the preferred wind turbine rotor design.
As further shown in Figs. 1a-b, the wind turbine rotor bearing arrangment 1 is provided with a first and second rolling bearings 100 and 200 of different size and load bearing capacity. Thereby, the arrangement is configured for different axial load bearings capacity in the first and second axiai directions, allowing for a manufacturing of compact wind turbines with reduced weight.
Considering the first rolling bearing 00, it is a spherical type roller bearing comprising an inner ring which forms the rotating ring 110, an outer ring which forms the non-rotating ring 120, and a set of rolling elements 103 formed of rollers arranged in an intermediate configuration between the inner and outer rings. The second rolling bearing 200 is a spherical type roller bearing comprising an outer ring which forms the rotating ring 210, an inner ring which forms the non-rotating ring 220, and a set of rolling elements 203 formed of rollers arranged in an intermediate configuration between the inner and outer rings.
In more detail, the rotating inner ring 110 is attached to and fixated in relation the first support structure 30, at bearing seat 31a. The outer non- rotating ring 120 is attached to and fixated in relation to the second support structure 35, at bearing seat 36a. The rotating outer ring 210 is attached to and fixated in relation the first support structure 30, at bearing seat 31 b, and the inner non-rotating ring 220 is attached to and fixated in relation to the second support structure 35, at bearing seat 36b.
The set of roiling elements 103 are circumferentially arranged in a row around the rotating inner ring 110, and the set of rolling elements 203 are circumferentially arranged in a row around the non-rotating inner ring 210. As shown, each rolling elements is formed of a symmetrical bearing roller and has a curved raceway-contacting surface arranged in contact with a curved raceways of the inner and outer rings 110 and 120; and 210 and 220. Each roller has a symmetrical convex, or barrel-shaped, profile, i.e. an axially center portion having an increase radial width in relation to the opposite axial end portions.
Fig. 2 is a schematic perspective view of an embodiment of the wind turbine rotor bearing arrangement according to the present invention is illustrated, which arrangement is arranged and configured in a similar manner as the wind turbine rotor bearing arrangement as described with reference to Fig. 1a-b, unless stated or illustrated differently. In particular, the wind turbine rotor bearing arrangement 1 in Fig. 2 differs in that the first and second rolling bearings are arranged in an alternative configuration.
As shown the bearing seats are adjusted to support the first and second rolling bearings in alternative axial directions. In more detail the first and second rolling bearings are inclined in the opposite axial direction in comparison with the embodiment described with reference to Figs. 1a-b. The outer raceways of the first and second rolling bearings are tilted and facing towards the same axial direction D2, as indicated in Fig. 2.
Locking device 33 is arranged to secure the first roiling bearing 100 to the first support structure 30, and locking device 34 is arranged to secure the first roiling bearing 00 to the second support structure 35.
In Fig. 3, an enlarged partial schematic cross-sectional view of an embodiment of the wind turbine rotor bearing arrangement according to the present invention is illustrated, which arrangement is arranged and configured in a similar manner as the wind turbine rotor bearing arrangement as described with reference to Fig. 1a-b, unless stated or illustrated differently. In particular, the wind turbine rotor bearing arrangement 1 in Fig. 3 differs in that the first and second rolling bearings are arranged in an alternative
configuration.
In more detail, the first rolling bearing 100 is a roller bearing comprising an outer ring which forms the rotating ring 110, an inner ring which forms the non-rotating ring 120, and a set of rolling elements 103 formed of rollers arranged in an intermediate configuration between the inner and outer rings. The second rolling bearing 200 is a roller bearing comprising an outer ring which forms the rotating ring 2 0, an inner ring which forms the non-rotating ring 220, and a set of rolling elements 203 formed of rollers arranged in an intermediate configuration between the inner and outer rings.
Furthermore, the rotating outer ring 110 is attached to and fixated in relation the first support structure 30, at bearing seat 31a. The inner non- rotating ring 120 is attached to and fixated in relation to the second support structure 35, at bearing seat 36a. The rotating outer ring 2 0 is attached to and fixated in relation the first support structure 30, at bearing seat 31b, and the inner non-rotating ring 220 is attached to and fixated in relation to the second support structure 35, at bearing seat 36b.
The set of rolling elements 103 are circumferentially arranged in a row around the non-rotating inner ring 120, and the set of rolling elements 203 are circumferentiaily arranged in a row around the non-rotating inner ring 220. The bearing seats are adjusted to support the first and second rolling bearings in alternative axial directions. In more detail the first and second rolling bearings are inclined in the opposite axial direction in relation to each other. The outer raceway of the first rolling bearing 100 is tilted and faces towards the axial direction D1. Locking device 33 is arranged to secure the second rolling bearing 200 to the first support structure 30, and locking device 34 is arranged to secure the second rolling bearing 200 to the second support structure 35. Fig. 4 is an enlarged partial schematic cross-sectional view of an embodiment of the wind turbine rotor bearing arrangement 1 according to the present invention, which arrangement is arranged and configured in a similar manner as the wind turbine rotor bearing arrangement as described with reference to Fig. 1a-b, unless stated or illustrated differently. In particular, the wind turbine rotor bearing arrangement 1 in Fig. 4 differs in that the first and second rolling bearings are arranged in an alternative configuration.
In more detail, the first rolling bearing 100 is a roller bearing comprising an inner ring which forms the rotating ring 10, an outer ring which forms the non-rotating ring 20, and a set of rolling elements 103 formed of rollers arranged in an intermediate configuration between the inner and outer rings. The second rolling bearing 200 is a roller bearing comprising an inner ring which forms the rotating ring 210, an outer ring which forms the non-rotating ring 220, and a set of rolling elements 203 formed of rollers arranged in an intermediate configuration between the inner and outer rings.
Furthermore, the rotating inner ring 1 0 is attached to and fixated in relation the first support structure 30, at bearing seat 31a. The outer non- rotating ring 120 is attached to and fixated in relation to the second support structure 35, at bearing seat 36a. The rotating inner ring 210 is attached to and fixated in relation the first support structure 30, at bearing seat 31 b, and the outer non-rotating ring 220 is attached to and fixated in relation to the second support structure 35, at bearing seat 36b.
The set of rolling elements 103 are circumferentialiy arranged in a row around the rotating inner ring 110, and the set of rolling elements 203 are circumferentialiy arranged in a row around the rotating inner ring 210. The bearing seats are adjusted to support the first and second rolling bearings in alternative axial directions. In more detail the first and second rolling bearings are inclined in the opposite axial direction in relation to each other. The outer raceway of the first rolling bearing 100 is tilted and faces towards the axial direction D2, as indicated.
Fig. 5 is an enlarged partial schematic cross-sectional view of an embodiment of the wind turbine rotor bearing arrangement 1 according to the present invention, which arrangement is arranged and configured in a similar manner as the wind turbine rotor bearing arrangement as described with reference to Fig. 1a-b, unless stated or illustrated differently. In particular, the wind turbine rotor bearing arrangement 1 in Fig. 5 differs in that the first and second rolling bearings are arranged in an alternative configuration.
In more detail, the first rolling bearing 100 is a roller bearing comprising an inner ring which forms the rotating ring 110, an outer ring which forms the non-rotating ring 120, and a set of rolling elements 103 formed of rollers arranged in an intermediate configuration between the inner and outer rings. The second rolling bearing 200 is a roller bearing comprising an inner ring which forms the rotating ring 210, an outer ring which forms the non-rotating ring 220, and a set of rolling elements 203 formed of rollers arranged in an intermediate configuration between the inner and outer rings.
Furthermore, the rotating inner ring 110 is attached to and fixated in relation the first support structure 30, at bearing seat 31a, which bearing seat 31a is facing in a radially outward direction. The outer non-rotating ring 120 is attached to and fixated in relation to the second support structure 35, at bearing seat 36a facing in a radially inward direction. The rotating inner ring 210 is attached to and fixated in relation the first support structure 30, at bearing seat 31b facing in the radially outward direction, and the outer non- rotating ring 220 is attached to and fixated in relation to the second support structure 35, at bearing seat 36b facing in the radially inward direction.
The set of rolling elements 103 are circumferentially arranged in a row around the rotating inner ring 110, and the set of rolling elements 203 are circumferentially arranged in a row around the rotating inner ring 2 0. The bearing seats are adjusted to support the first and second rolling bearings in alternative axial directions. In more detail the first and second rolling bearings are inclined in the opposite axial direction in relation to each other. Locking device 33 is arranged to secure the second rolling bearing 200 to the first support structure 30.
Fig. 6 is an enlarged partial schematic cross-sectional view of an embodiment of the wind turbine rotor bearing arrangement 1 according to the present invention, which arrangement is arranged and configured in a similar manner as the wind turbine rotor bearing arrangement as described with reference to Fig. 1a-b, unless stated or illustrated differently. In particular, the wind turbine rotor bearing arrangement 1 in Fig. 6 differs in that the first and second rolling bearings are arranged in an alternative configuration.
In more detail, the first rolling bearing 100 is a roller bearing comprising an outer ring which forms the rotating ring, an inner ring which forms the non- rotating ring, and a set of rolling elements formed of rollers arranged in an intermediate configuration between the inner and outer rings. The second rolling bearing 200 is a roller bearing comprising an outer ring which forms the rotating ring, an inner ring which forms the non-rotating ring, and a set of rolling elements formed of rollers arranged in an intermediate configuration between the inner and outer rings.
Furthermore, the rotating outer ring of the first rolling bearing is attached to and fixated in relation the first support structure 30, at a bearing seat is facing in a radially inward direction. The inner non-rotating ring is attached to and fixated in relation to the second support structure 35, at a bearing seat facing in a radially outward direction. The rotating outer ring of the second rolling bearing is attached to and fixated in relation the first support structure 30 at bearing seat facing in the radially inward direction, and the inner non-rotating ring is attached to and fixated in relation to the second support structure 35 at a bearing seat facing in the radially outward direction.
The set of rolling elements of the first rolling bearing are
circumferentially arranged in a row around the non-rotating inner ring, and the set of rolling elements of the second rolling bearing are circumferentially arranged in a row around the non-rotating inner ring. The bearing seats are adjusted to support the first and second rolling bearings in alternative axial directions. In more detail the first and second rolling bearings are inclined in the opposite axia! direction in relation to each other. Locking device 33 is arranged to secure the first rolling bearing 100 to the first support structure 30, by securing the rotating outer ring of the first rolling bearing 100 to the bearing seat of the first support structure 30. In Fig. 7, a schematic partial side view of a wind turbine arrangement
70 comprising an embodiment of the wind turbine rotor bearing arrangement 1 according to the present invention is shown. As illustrated, a hub unit 72 comprising fixed or pitchable blades 73 are attached to the first support structure 30 which is rotationally connected to the second support structure 35 via first and second rolling bearings 100 and 200. The second support structure 35 is secured to a nacelle frame 71 anchored to a wind turbine tower-like structure 76 via a yaw rotation device 75 arranged to rotate the nacelle around yaw axis Y. As further shown, the wind turbine arrangement 70 comprises a direct drive electric generator 74 comprising rotor member 74a attached to the first support structure 30 radially outside and adjacent the first rolling bearing 100, and a stator member 74b attached to the second support structure 35 radially outside and adjacent the first rolling bearing 100. The rotor 74a and stator 74b are separated by an airgap 74c extending the in an axial direction coinciding the main axis of rotation R of the wind turbine rotor.
The generator may also be connected to the rotating first support structure 30 and hub unit 72 which a shaft extending through a central bore in the second support structure. The generator may be directly coupled to the first support structure, or via a gearbox shifting the rotational speed of the rotor.
Furthermore, the wind turbine rotor bearing arrangement 1 may according to an embodiment form part of a hydraulic wind turbine
arrangement comprising a hydraulic drive-train for driving a generator. For example, the rotor may be coupled to a hydraulic pump arranged in the nacelle and which is coupled to a ground-based hydraulic motor and generator arrangement, such as an in-line or bent-axis generator motor.
The wind turbine rotor bearing arrangement 1 may also, according to an embodiment, form part of a wind turbine arrangement comprising a gear transmission arranged for driving a generator. For example, the rotor may be coupled to an input side of a gearbox via a rotor shaft, wherein an output side of the gearbox is coupled to a generator operating at a different rotational speed in relation to the rotational speed of the wind turbine rotor during operation. With reference to Fig. 1a, the rotor shaft may be arranged to extend through the center bore 39 extending axially through the second support structure 35, wherein the rotor shaft is connected to the first support structure 30.
The wind turbine rotor bearing arrangement 1 is not limited to a horizontal type orientation and may also be used in wind turbines appliations involving vertical type rotor shaft orientations. The orientation of the rotor shaft is defined in relation to its intended mounted operational position in a nacelle framing of an operational wind turbine. The rolling bearings 100 and 200 may for example be attached to the bearing seats of the support structures 30 and 35 by means of press-fitting techniques and/or by using a suitable locking device, such as locking device 33, shown in Fig. 1a.
It should be noted that the invention has mainly been described above with reference to a few embodiments. However, as is readily appreciated by a person skilled in the art, other embodiments than the ones disclosed above are equally possible within the scope of the invention, as defined by the appended patent claims.
In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. A single apparatus or other unit may fulfill the functions of several items recited in the claims. The mere fact that certain features or method steps are recited in mutually different dependent claims does not indicate that a combination of these features or steps cannot be used to advantage.

Claims

1. A wind turbine rotor bearing arrangement (1), comprising
- a first and a second support structure (30, 35) for supporting a rotor of a wind turbine, which rotor has a main axis of rotation (R), wherein the first support structure is arranged to rotate with the rotor, and the second support structure is fixed and arranged to be non-rotatably mounted to a wind turbine nacelle frame,
- a first rolling bearing (100) supporting (rotatably connecting) the first support structure in relation to the second support structure at a first support location (101),
- a second rolling bearing (200) supporting (rotatably connecting) the first support structure in relation to the second support structure at a second support location (201), which first and second rolling bearings are arranged in a coaxial configuration in relation to each other,
characterized in that the first rolling bearing (100) forms a radially outer bearing, and the second rolling bearing (200) is arranged radially inside the first rolling bearing by a bearing radial distance (A),
and that the first support location (101) and the second support location (201) are axially aligned.
2. The wind turbine rotor bearing arrangement (1) according to any one of the preceding claims, wherein the contact angle of at least one of the first and second rolling bearings (100, 200) is angled in relation to the axis of rotation.
3. The wind turbine rotor bearing arrangement (1) according to any one of the preceding claims, wherein the contact angles of the first and second rolling bearings (100, 200) are angled in relation to the axis of rotation, wherein the first rolling bearing is arrange to axially locate the first support structure in relation to the second support structure in a first axial direction (D1), and the second rolling bearing is arrange to axially locate the first support structure in relation to the second support structure in a second axial direction (D2), the second axial direction being opposite the first axial direction.
4. The wind turbine rotor bearing arrangement (1) according to any one of claims 2-3, wherein the contact angle (ca1 , ca2) of at least one or both of the first and second rolling bearings {100, 200) is between 5 and 90 degrees, or between 5 and 60 degrees, or between 0 and 45 degrees, or between 15 and 25 degrees. 5. The wind turbine rotor bearing arrangement (1 ) according to any one of the preceding claims, wherein a first pressure center (102) of the first rolling bearing (100) and a second pressure center (202) of the second rolling bearing are separated in the axial direction by a pressure center distance (B). 6. The wind turbine rotor bearing arrangement (1) according to any one of the preceding claims, wherein the first rolling bearing (100) comprises a rotating ring (110) with a raceway (111) for a first set of rolling elements (103) and a non-rotating ring (120) with raceway (121) for the first set of rolling elements (103), and the second rolling bearing (200) comprises a rotating ring (210) with a raceway (211) for second set of rolling elements (203) and a non- rotating ring (220) with raceway (22 ) for the second set of rolling elements (203).
7. The wind turbine rotor bearing arrangement (1) according to claim 6, wherein the rotating ring (110) of the first rolling bearing (100) and the rotating ring (210) of the second roiling bearing (200) are mounted to the first support structure, and the non-rotating ring (120) of the first rolling bearing (100) and the non-rotating ring (220) of the second rolling bearing (200) are mounted to the second support structure.
8. The wind turbine rotor bearing arrangement (1) according to any one of the preceding claims, wherein the first and second bearings (100, 200) are axially displaced in relation to each other by an axial bearing distance (C) defined between axial centers of the first and second rolling bearings (100, 200), wherein the axial bearing distance (C) is
within a distance corresponding to the outer radius of the second rolling bearing (200),
or within a distance corresponding to the axial extension of the second rolling bearing (200),
or within a distance corresponding to 50 % of the axial extension of the second rolling bearing (200),
or within a distance corresponding to 20 % of the axial extension of the second rolling bearing (200).
9. The wind turbine rotor bearing arrangement (1) according to any one of the preceding claims, wherein the bearing radial distance (A) equals or exceeds a distance corresponding to the axial extension of the second rolling bearing (200),
or equals or exceeds a distance corresponding to 50 % of the outer radius of the second rolling bearing (200),
or equals or exceeds a distance corresponding to the outer radius of the second rolling bearing (200),
or equals or exceeds a distance corresponding to 150 % of the outer radius of the second rolling bearing (200),
or equals or exceeds a distance corresponding to the outer diameter of the second rolling bearing (200),
or equals or exceeds a distance corresponding to 200 % of the outer diameter of the second rolling bearing (200).
10. The wind turbine rotor bearing arrangement (1) according to any one of the preceding claims, wherein the first support structure is disc-shaped and comprises
a first bearing seat (31a) with a seating surface arranged in retaining abutment with rotating ring (1 0) of the first rolling bearing (100), and
a second bearing seat (31b) with a seating surface arranged in retaining abutment with rotating ring (210) of the second rolling bearing (200), wherein the first and second bearing seats (31a, 3 b) are axially aligned and radially separated in relation to each other.
11. The wind turbine rotor bearing arrangement (1) according to any one of the preceding claims, wherein the first and/or second rolling bearing is a tapered roller bearing, spherical roller thrust bearing, angular contact spherical roller bearing, toroidal roller bearing, angular contact toroidal roller bearing, a cylindrical roller bearing, or a combination of these. 2. The wind turbine rotor bearing arrangement (1) according to any one of the preceding claims, wherein the first and/or second rolling bearing (100, 200) is a ball bearing.
13. A wind turbine arrangement (70) comprising a wind turbine bearing arrangement (1) according to any one of the preceding claims, further comprising
a nacelle frame (71), where in the second support structure is mounted to the nacelle frame,
a hub unit (72) provided with rotor blades (73), which hub unit is mounted to the first support structure (30).
14. A wind turbine arrangement (70) according to claim 13, further including a generator device (74) comprising a rotor member (74a) mounted to the first support structure (30) and a stator member (74b) mounted to the second support structure (35).
15. Method for manufacturing a wind turbine bearing arrangement having a main axis of rotation, which method comprises providing:
- a first support structure (30) for supporting a rotor of a wind turbine and arranging the first support structure to rotate with the rotor,
- a second support structure (35) for supporting the rotor of a wind turbine, and arranging the second support structure to be non-rotatably mounted to a wind turbine nacelle frame,
- a first rolling bearing (100) and arranging it to support the first support structure in relation to the second support structure at a first support location (101), and
- a second rolling bearing (200) and arranging it to support the first support structure in relation to the second support structure at a second support location (201),
the method further comprising arranging the first and second rolling bearings in a coaxial configuration in relation to each other,
arranging the first rolling bearing (100) as a radially outer bearing, providing the second rolling bearing (200) radially inside the first rolling bearing by a bearing radial distance (A), and
axially aligning the first support location (101) and second support location (201) in relation to each other.
PCT/SE2014/051026 2013-10-17 2014-09-08 Wind turbine rotor bearing arrangement WO2015057126A1 (en)

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Application Number Priority Date Filing Date Title
SE1300659 2013-10-17
SE1300659-8 2013-10-17

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2021047728A1 (en) * 2019-09-10 2021-03-18 Schaeffler Technologies AG & Co. KG Torque transmitting system with concentrically arranged rolling bearings, drive unit, and drive assembly
WO2023094168A1 (en) * 2021-11-24 2023-06-01 Aktiebolaget Skf An angular contact self-aligning toroidal rolling element bearing

Citations (6)

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Publication number Priority date Publication date Assignee Title
US2488929A (en) * 1945-10-22 1949-11-22 Palumbo Vincent Antifriction bearing of the angle type
US5820272A (en) * 1996-02-26 1998-10-13 Okuma Corporation Bearing structure for a rotating shaft
US20040081379A1 (en) * 2001-12-11 2004-04-29 Naomi Shirasawa Multi-stage cross roller bearing
DE102004035587A1 (en) * 2004-07-22 2006-02-09 Ina-Schaeffler Kg Bearing has three rings, between which ball bearings or rollers are mounted, rings having bevel gear toothing on their faces
US20060201076A1 (en) * 2005-03-11 2006-09-14 The Will-Burt Company Support bearing assembly
DE102008049813A1 (en) * 2008-09-30 2010-04-01 Schaeffler Kg Rotary connection, for example for a wind turbine and wind turbine with the rotary joint

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2488929A (en) * 1945-10-22 1949-11-22 Palumbo Vincent Antifriction bearing of the angle type
US5820272A (en) * 1996-02-26 1998-10-13 Okuma Corporation Bearing structure for a rotating shaft
US20040081379A1 (en) * 2001-12-11 2004-04-29 Naomi Shirasawa Multi-stage cross roller bearing
DE102004035587A1 (en) * 2004-07-22 2006-02-09 Ina-Schaeffler Kg Bearing has three rings, between which ball bearings or rollers are mounted, rings having bevel gear toothing on their faces
US20060201076A1 (en) * 2005-03-11 2006-09-14 The Will-Burt Company Support bearing assembly
DE102008049813A1 (en) * 2008-09-30 2010-04-01 Schaeffler Kg Rotary connection, for example for a wind turbine and wind turbine with the rotary joint

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2021047728A1 (en) * 2019-09-10 2021-03-18 Schaeffler Technologies AG & Co. KG Torque transmitting system with concentrically arranged rolling bearings, drive unit, and drive assembly
CN114341512A (en) * 2019-09-10 2022-04-12 舍弗勒技术股份两合公司 Torque transmission system, drive unit and drive assembly with concentrically arranged rolling bearings
WO2023094168A1 (en) * 2021-11-24 2023-06-01 Aktiebolaget Skf An angular contact self-aligning toroidal rolling element bearing

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