Roller bearing arrangement for mounting parts of a wind power plant and a wind power plant having a blade bearing designed in such a manner

Abstract

The invention relates to a rolling bearing arrangement (5) for mounting parts of a wind power plant (1), comprising three relatively rotatable annular elements (6-8) arranged concentrically with one another and at least regionally inside one another for connection to relatively rotatable parts of the wind power plant, wherein two relatively rotatable connecting elements (6-9) are separated from each other by a gap (9, 10) and partially or wholly overlap each other in the radial direction, wherein, further, provided in the region of a gap in radially overlapping regions of the annular connecting elements are at least two rows of rolling elements (34, 35), each of which rolls along a respective two raceways (32, 33) that overlap each other at least regionally in the radial direction, as well as at least one additional row of rolling elements (42) whose raceways do not overlap in the radial direction, wherein the radially innermost connecting element and the radially outermost connecting element are connected to one machine part and the radially middle connecting element is connected to the respectively other machine part.

Claims

1. A rolling bearing assembly for a large rolling bearing, comprising at least three relatively rotatable connecting elements arranged concentrically with one another, and at least regionally inside one another, each having a flat connecting surface for connection to one of two different plant components rotatable to each other, wherein each two of the three relatively rotatable connecting elements are separated from each other by a gap and at least partially overlap each other in their radial extent, wherein provided in the region of each of the two gaps in radially overlapping regions of the annular connecting elements are at least two rows of spherical rolling elements, each of which rolls along two raceways that overlap each other at least regionally in the radial direction, wherein the center points of the spherical rolling elements of the four rows of balls move along four circular paths around the axis of rotation of the rolling bearing, and the points at which these paths are intersected by a cross sectional plane of the rolling bearing radially to its axis of rotation lie at the corners of a quadrangle, wherein the radially innermost connecting element and the radial outermost connecting element are connected to one plant component, and the radially middle connecting element is connected to the other plant component, a) comprising at least one additional row of rolling elements whose raceways do not overlap in the radial direction, b1) wherein the rolling elements whose raceways do not overlap in the radial direction roll along a free end side of a nose of the middle connecting element and are arranged between two rows of rolling elements whose raceways overlap each other in the radial direction and are point-symmetric to the raceway cross sections of a diagonally offset row of balls, or b2) wherein the connecting line between two diametrically opposite corners of the quadrangle formed by the circular paths of the center points of the rolling elements rolling along raceways overlapping each other in the radial direction intersects a connection line between the centers of the fitted regions of the two raceway cross sections associated with each two rows of balls approximately perpendicularly.

2. The rolling bearing arrangement as in claim 1, wherein the radial overlap of said two connecting elements is equal to, or greater than, the radius of a rolling element rolling in the radially overlapping region.

3. The rolling bearing arrangement as in claim 2, wherein the overlapping raceways overlap along a radial extent that is equal to, or greater than, the radius of the rolling element.

4. The rolling bearing arrangement as in claim 1, wherein the middle connecting element is divided in the axial direction into at least three sections comprising a first section, disposed adjacent its connecting surface; a second section, adjacent its opposite end side; and, therebetween, a third section that projects, or recedes, to an equal extent in a radial direction relative to the first two.

5. The rolling bearing arrangement as in claim 1, wherein the rolling elements of different rows at mutually corresponding radial positions are of equal size.

6. The rolling bearing arrangement as in claim 5, wherein the spherical rolling elements of the four rows are the same size.

7. The rolling bearing arrangement as in claim 6, wherein the four rows of rolling elements are the same distance from the center radius of a coronal arrangement of fastening elements of the middle connecting element.

8. The rolling bearing arrangement as in claim 6, wherein the raceway cross sections of a rolling-element row are mirror-symmetrical, with respect to a main plane of the rolling bearing, to the raceway cross sections of an axially offset row of rolling elements.

9. The rolling bearing arrangement as in claim 8, wherein the raceway cross sections of a rolling-element row are mirror-symmetrical, with respect to a center axis located in a cross-sectional plane and extending parallel to the axis of rotation of the bearing, to the raceway cross sections of a radially offset row of balls.

10. The rolling bearing arrangement as in claim 9, wherein the raceway cross sections of a rolling-element row of a point in the cross-sectional plane are point-symmetric to the raceway cross sections of a axially and radially offset row of balls, and are point-symmetric under point reflection at an intersection point of a main plane with the parallel center axis.

11. The rolling bearing arrangement as in claim 10, wherein a contact angle of the spherical rolling elements rolling between a respective two raceways that overlap each other, at least regionally in the radial direction is 45, or more.

12. The rolling bearing arrangement as in claim 11, wherein at least one additional bearing location, whose contact angle is less than 45, said additional bearing location comprising a rolling bearing.

13. The rolling bearing arrangement as in claim 12, wherein the spherical rolling elements comprise a contact angle of less than 45 roll between two raceways disposed radially adjacent the radially overlapping region of the connecting elements.

14. The rolling bearing arrangement as in claim 13, wherein the rolling elements with a contact angle of less than 45 are configured as roller, or cylinder-shaped, with a longitudinal axis extending parallel to the axis of rotation of the bearing.

15. The rolling bearing arrangement as in claim 1, wherein provided in the middle connecting element, and/or in one or both of the respectively other connecting elements, are coronally distributed fastening bores comprising through-bores whose longitudinal axes are parallel to the axis of rotation of the bearing, with no internal thread.

16. The rolling bearing arrangement as in claim 1, wherein the middle connecting element, or one or both of the other connecting elements, is/are divided along a main plane of the bearing.

17. The rolling bearing arrangement as in claim 16, wherein an end side of each of two outer connecting elements embraces the middle connecting element on an end side thereof, so as to create a form lock that includes the rolling elements.

18. The rolling bearing arrangement as in claim 17, wherein the two outer connecting elements are contiguous with each other.

19. A wind power plant having a wind wheel that rotates on an axis that is generally parallel to the direction of the wind, wherein one or a plurality of elongated rotor blades are arranged projecting generally radially from a hub of a rotor, and such that each rotor blade can be rotated about its longitudinal axis by means of a respective blade bearing, wherein at least one of the blade bearings comprises at least three relatively rotatable connecting elements arranged concentrically with one another, and at least regionally inside one another, each having a flat connecting surface for connection to relatively rotatable parts of the wind power plant, wherein each two of the three relatively rotatable connecting elements are separated from each other by a gap and wholly or partially overlap each other in the radial direction, and wherein, provided in the region of each of the two gaps in the radially overlapping regions of the annular connecting elements, are at least two rows of spherical rolling elements, each of which rolls along a respective two raceways that overlap each other at least regionally in the radial direction, wherein the center points of the spherical rolling elements of the four rows of balls move along four circular paths around the axis of rotation of the rolling bearing, and the points at which these paths are intersected by a cross sectional plane of the rolling bearing radially to its axis of rotation lie at the corners of a quadrangle, wherein the radially middle connecting element is connected to the hub or the rotor blade, and the radially innermost connecting element and the radially outermost connecting element are connected to the other of the hub or the rotor blade, a) wherein the at least one of the blade bearings comprises at least one additional row of rolling elements whose raceways do not overlap in the radial direction, b1) wherein the rolling elements whose raceways do not overlap in the radial direction roll along a free end side of a nose of the middle connecting element and are arranged between two rows of rolling elements whose raceways overlap each other in the radial direction and are point-symmetric to the raceway cross sections of a diagonally offset row of balls, or b2) wherein the connecting line between two diametrically opposite corners of the quadrangle formed by the circular paths of the center points of the rolling elements rolling along raceways overlapping each other in the radial direction intersects a connection line between the centers of the fitted regions of the two raceway cross sections associated with each two rows of balls approximately perpendicularly.

20. The wind power plant as in claim 19, wherein screws or bolts passing through the middle connecting element are screwed into a back end of the rotor blade, or into the hub, or are connected thereto by means of a respective anchoring body embedded in the rotor blade, the anchoring body having an internal thread.

21. The wind power plant as in claim 20, wherein screws or bolts pass through the radially innermost and the radially outermost connecting elements and are screwed into the hub, or into the back end of the rotor blade, or are connected thereto.

22. The wind power plant as in claim 21, wherein provided on the hub or on the rotor blade is a connection region comprising two aprons arranged concentrically one inside the other, for connection to the radially innermost and the radially outermost connecting element of the blade bearing.

23. The wind power plant as in claim 22, and further comprising inspection bores, at least in a fork-shaped connecting region, through which fastening means of the middle connecting element are accessible.

24. A wind power plant having a wind wheel that rotates on an axis that is generally parallel to the direction of the wind, wherein one or a plurality of elongated rotor blades are arranged projecting generally radially from a hub of a rotor, and such that each rotor blade can be rotated about its longitudinal axis by means of a respective blade bearing, wherein one or more of the blade bearings are configured as a rolling bearing with a diameter of 0.5 m or more, and comprise at least two relatively rotatable connecting elements arranged concentrically with one another, and at least regionally inside one another, for connection to relatively rotatable parts of the wind power plant, wherein the two relatively rotatable connecting elements are separated from each other by a gap and wholly or partially overlap each other in the radial direction, and wherein, provided in the region of a gap in the radially overlapping regions of the annular connecting elements, are at least two rows of rolling elements, each of which rolls along a respective two raceways that overlap each other at least regionally in the radial direction, wherein at least one blade bearing comprises at least three relatively rotatable annular connecting elements, each of which is provided with a flat connecting surface for connection to the hub or to the rotor blade, wherein the three annular connecting elements are disposed radially overlappingly inside one another and the radially middle connecting element is connected to the hub or the rotor blade, and the radially innermost connecting element and the radially outermost connecting element are connected to the other of the hub or the rotor blade, wherein screws or bolts passing through the middle connecting element and are screwed into a back end of the rotor blade, or into the hub, or are connected thereto by means of a respective anchoring body embedded in the rotor blade, the anchoring body having an internal thread; wherein screws or bolts pass through the radially innermost and the radially outermost connecting elements and are screwed into the hub, or into the back end of the rotor blade, or are connected thereto; wherein provided on the hub or on the rotor blade is a connection region comprising two aprons arranged concentrically one inside the other, for connection to the radially innermost and the radially outermost connecting element of the blade bearing; further comprising inspection bores, at least in a fork-shaped connecting region, through which fastening means of the middle connecting element are accessible.

Description

(1) Further features, details, advantages and effects based on the invention will emerge from the following description of some preferred embodiments of the invention and by reference to the drawing. Therein:

(2) FIG. 1 shows a wind power plant according to the invention in front elevation;

(3) FIG. 2 is a cross section through a first embodiment of a rolling bearing according to the invention, installed between the hub and a rotor blade of the wind power plant according to FIG. 1, partially broken away;

(4) FIG. 3 is a representation corresponding to FIG. 2 of a second embodiment of the invention;

(5) FIG. 4 is a representation corresponding to FIG. 2 of a third embodiment of the invention;

(6) FIG. 5 is a representation corresponding to FIG. 2 of another embodiment of the invention; and

(7) FIG. 6 is a representation corresponding to FIG. 2 of a further modified embodiment of the invention.

(8) FIG. 1 shows, in a somewhat schematic view, a wind power plant 1 with a tower, a nacelle and a wind wheel 2 having a hub 3 that rotates about the so-called rotor axis or main axis, together with a plurality of elongated rotor blades 4 projecting from the hub 3 approximately radially to the rotor axis or main axis.

(9) The rotor axis or main axis is preferably oriented approximately in the direction of the wind flow, this being done by readjusting the rotor axis or main axis by rotating the nacelle about the vertical axis of the tower of the wind power plant.

(10) To keep the rotation speed of the wind wheel as constant as possible despite different wind strengths, or at least to keep it within a defined speed range, the rotor blades 4 can be rotated about their respective longitudinal axes and thus be pitched more into the wind or taken out of the wind, as needed. This function is performed by so-called blade bearings 5, each of which connects a respective rotor blade 4 to the hub 3.

(11) For active control of the pitch of the rotor blades, a circumferential ring gear, for example with a motor-driven pinion meshing with it, can be provided in the vicinity of a blade bearing 5 of this kind.

(12) FIG. 2 shows a broken-away cross section through a blade bearing 5, including the regions of the hub 3 and the rotor blade 4 that are connected to the bearing. Whereas in this case the rotor axis or main axis extends approximately horizontally under the illustrated detail, the axis of rotation of the blade bearing 5and thus the roughly coaxial longitudinal axis of the rotor blade 4is located to the right, past the margin of the illustrated detail, and extends there from top to bottom, i.e., radially and perpendicularly to the rotor axis or main axis. Whereas the region of the blade bearing 5 that is excerpted in FIG. 2 has a width on the order of approximately between 10 cm and 30 cm, the diameter of the blade bearing 5 in a large wind power plant is typically approximately between 0.5 m and 10 m, preferably between 1 m and 8 m, particularly between 2 m and 5 m, and is therefore well outside the area that can be depicted on the drawing sheet. Because of its large size, a blade bearing 5 is also commonly referred to as a large rolling bearing.

(13) The blade bearing 5 has a total of three annular connecting elements whose ring axes all extend coaxially with the axis of the rotor blade: Between a radially inner connecting element 6 and a radially outer connecting element 7, there is a middle connecting element 8. Since the respectively adjacent connecting elementsi.e., the radially inner connecting element 6 and the middle connecting element 8, on the one side, and the middle connecting element 8 and the radially outer connecting element 7, on the other sideare separated from each other in each case by a respective gap 9, 10, in the uninstalled state all three connecting elements 6-8 can be rotated at will relative to one another.

(14) This is no longer the case in the installed state, however. As can be seen from FIG. 2, the radially inner connecting element 6 and the radially outermost connecting element 7 are fastened to the same connected structure, specifically, in the illustrated example, to the hub 3 of the wind wheel 2. In the installed state, therefore, these two connecting elements 6, 7 are no longer able to rotate relative to each other, but can rotate only relative to the respective middle connecting element 8, which is connected to the rotor blade 4.

(15) The function of securing the individual connecting elements 6-8 is performed by bores 11-13 distributed coronally over the particular ring and extending parallel to the axis of rotation of the blade bearing 5. These each open at a connecting surface 14-16 of the particular connecting element 6-8, against which a flat surface region in the vicinity of the jacket of the hub 3 or at the back end of the rotor blade 4 rests flushly or areally.

(16) Since the illustrated example comprises through-bores 11-13, preferably with no internal thread, these also open at the respectively opposite end face 17-19 of the particular connecting element 6-8. There, the heads 20 of screws 21 inserted through these openings 11-13, or nuts 23 threaded onto bolts 22 inserted through them, or similar threaded elements, have sufficient space for abutment. If these screws 21 or (stud or threaded) bolts 22 are screwed into bores 24-26 of the hub 3 or of the rotor blade 4 that are aligned with the respective bores 11-13 and they or nuts 23 threaded onto them are tightened, the particular connecting surfaces 14-16 are pressed friction-lockingly against the adjacent surface of the hub 3 or of the rotor blade 4.

(17) The bore 13 in the middle connecting element 8 is located approximately midway between the two gaps 9, 10. As can further be appreciated from FIG. 1, the depicted cross section of the blade bearing 5 overall is substantially symmetrical to the longitudinal axis 27 of the bore 13, which consequently will also be referred to as the center axis CA. All the spherical rolling elements 34 for transmitting axial forces are the same radial distance from this center axis CA.

(18) The internal structure of the blade bearing 5 has still another symmetry, however, specifically with respect to a horizontal main plane MP, which is intersected perpendicularly by the longitudinal axis 27 of the bore 13 and by the center axis CA and is also indicated in FIG. 2. All spherical rolling elements 34 for transmitting axial forces are the same axial distance from this main plane MP.

(19) Because of the Dual Symmetry of the Rolling Elements 34, their Center Points, in the Cross-Sectional Representation of FIG. 2, Lie at the Corners of an Imaginary Rectangle or Even a Square.

(20) In the embodiment according to FIG. 2, the radially innermost ring 6 and the radially outermost ring 7 are each configured as nose rings, each having a flange, referred to in technical jargon as a nose 28, that projects toward the particular gap 9, 10 or toward the middle connecting element 8. In the illustrated example, the cross sections of these two noses 28 are symmetrical to each other with respect to the axis of symmetry 27.

(21) These two noses 28 are each embraced on three sides by the middle connecting element 8, which is provided for this purpose with a respective circumferentially extending groove 29 on each of its two curved lateral surfaces 30, 31 facing toward the gaps 9, 10. In the illustrated example, these two grooves 29 are symmetrical to each other with respect to the axis of symmetry 27.

(22) As can further be seen from FIG. 2, the flanks of a nose 28 and those of the groove 29 embracing it overlap one another in the radial direction. The respective overlapping regions serve as raceways 32, 33, each for a respective row of rolling elements 34, 35. So that rolling elements 34, 35 can roll along each of these raceways 32, 33 without play, the maximum axial distance between two raceways 32, 33 assigned to the same rolling elements 34, 35 is equal to the diameter of those same rolling elements 34, 35. This means, on the one hand, that the maximum axial distance a between the mutually facing flanks 32 of a groove 29 is equal to the sum of the minimum axial extent e of the nose 28 plus twice the diameter d of a rolling element 34, 35: a=e+2*d; where the rolling elements 34, 35 are of different sizes, with diameters d.sub.1, d.sub.2, this becomes: a=e+d.sub.1+d.sub.2.

(23) In the embodiment according to FIG. 2, the rolling elements 34, 35 each have a spherical shape. This means that the cross sections of the raceways 32, 33 are each concavely curved, particularly along a circular arc. These curved raceway regions should also be referred to as the fitted region, since they have nearly the same diameter as the spherical rolling elements 34, 35 and thus fit snugly against their surfaces. As can further be seen from FIG. 2, the cross section through these raceway or fitted regions 32, 33 extends in each case along a circular arc with a center angle .sub.1, .sub.2 of 90 or more, but less than 180: 90.sub.1<180, 90<.sub.2<180, preferably: .sub.1=.sub.2=.

(24) As can be seen, the flanks of a nose 28 and thus the raceways 32, 33 located there diverge toward the free end of the nose 28, specifically preferably symmetrically to each other with respect to an approximately central main plane of the blade bearing 5.

(25) Furthermore, the flanks of a groove 29 and thus the raceways 32, 33 located there reconverge toward each other in the axial direction in the region of the edge-shaped transition from the groove 29 to the respectively adjacent curved sections 36, 37; 38, 39 of the middle connecting element 8, specifically preferably symmetrically with respect to an approximately central main plane of the blade bearing 5.

(26) Sections 36, 38 are preferably disposed above the groove 29 and are each aligned with the respective section 37, 39 below the groove 29; consequently, end face 19 is not only parallel to but also approximately coextensive with the connecting surface 16 of the middle connecting element 8.

(27) As can further be seen from FIG. 2, in at least one gap 9, 10preferably in the region of the free end side 40 at least of the nose 28 located therethere is another bearing 41, particularly a fifth row of rolling elements 42. These also roll along two raceways 43, 44, which, however, are not located in radially overlapping regions of the particular connecting elements 6-8, but instead bridge the particular gap 9, 10 in the radial direction. Consequently, the axes of rotation of these rolling elements 42 are approximately parallel to the axis of rotation of the blade bearing 5, whereas the contact angles are approximately 0, corresponding to predominantly or exclusively radial force transmission. In the embodiment shown, this bearing is a rolling bearing with cylindrical or roller-shaped rolling elements 42 that have a smaller diameter than the spherical rolling elements 34, 35. This is not mandatory, however. The diameter could instead be chosen as different, and/or instead of rollers 42, ball-, needle-, cone- or barrel-shaped rolling elements, or a sliding bearing or other type of bearing, could be used for the radial bearing 41. Moreover, at least one such radial bearing 41 can be disposed in the radially inner gap 9 or in the radially outer gap 10 or in both. For the axial guidance of roller-shaped rolling elements 42, at least one raceway 43, 44 can be configured as a groove-shaped depression in the particular connecting element 6-8.

(28) As can further be seen from FIG. 2, the rolling-element rows 34, 35 in a common plane each have the same radial center-to-center distances A, A, B, B from a cylinder jacket defined by the center axes 27 of the fastening bores 13: A=A; B=B. Particularly preferable is an arrangement in which the center points of the rolling elements 34, 35 in all four rows of rolling elements are the same radial distance from the aforesaid virtual cylinder jacket: A=A=B=B.

(29) The raceways 32, 33, 43, 44 of a connecting element 6-8 are preferably formed along with the particular bores 11-13 by processing or shaping the same common base body.

(30) Since the two noses 28 of the innermost and the outermost connecting element 6, 7 are respectively embraced on three sides by the grooves 29 of the middle connecting element 8, assembly of the blade bearing 5 is possible only if the middle connecting element 8 is divided in the region of the groove 29, along a horizontal surface 45, into an upper ring 46 and a lower ring 47, which are simultaneously slid from both axial directions over the noses 28 of the radially innermost and the radial innermost [sic] connecting element 6, 7 and only then are connected to each other, particularly screwed together.

(31) Due to the presence of the through-bores 11-13, the bores 24-26 aligned therewith can be configured as blind bores with an internal thread 48, 49, into which the screws 21 or bolts 22 can be screwed. Depending on the nature of the material used for the hub 3 and/or the rotor blades 4, such an internal thread 48, 49 can be cut either into the particular material, such as into the hub 3 depicted in FIG. 2, or into a bushing 50 or other body which in turn is sunk into the connected structure, for example cast, glued and/or otherwise fastened therein. The radial width of the middle connecting element 8 or the radial width of its connecting surface 16 is preferably approximately equal to the radial thickness of the back end 52 of the rotor blade jacket 51, so the latter can be butted against the connecting surface 16 and fastened there.

(32) A connected structurein the example illustrated, the hub 3has two concentric mounting surfaces 53, 54, each located on the free end side of a respective one of two mutually concentric aprons 55, 56. These two aprons 55, 56 are connected at their bases by a radial web 57 to form an arrangement that has, on the whole, an approximately U-shaped cross section. To gain access to the bolts 22 or the nuts 23 threaded onto them, or to screws that are used instead, the web 57 is provided with a number of access bores 58 that is equal to the number of bores 13 in the middle connecting element 8, which access bores are preferably slightly larger than the maximum diameter of the nuts 23, screw heads 20 or similar fastening means. The jacket 59 of the hub 3 sits approximately in alignment with the radially outer apron 56 against the bottom side of the web 57.

(33) Of course, the arrangement can also be chosen to be exactly the opposite, i.e., the rotor blade 4 is provided with two mutually concentric aprons, each with a connecting surface for the innermost and the outermost connecting element 6, 7, and the hub then has only one connecting surface, for the middle connecting element 8.

(34) FIG. 3 shows a deviating arrangement. Here, the blade bearing 5 is nevertheless identical in design to the previously described one, and the manner of connection to the rotor blade 4 is also identical to the previously described technique; only the connected structure for connecting to the hub 3 deviates in this case:

(35) As in the previously described embodiment, the hub 3 has in its connecting region two aprons 55, 56, which are a distance apart that is approximately equal to the maximum radial width of the middle connecting element 8. These aprons 55, 56 are also connected to each other by a web 57. Furthermore, the hub jacket 59 sits against the bottom side of the web 57, i.e., the side facing away from the aprons 55, 56, only not in alignment with either of the two aprons 55, 56, but instead approximately exactly midway between them radially. This is possible becauseamong other reasonsthere are no access bores 58 whatsoever in this embodiment.

(36) The absence of access bores 58 in this embodiment makes for a special assembly sequence: The middle connecting element 8 of the blade bearing 5 is first screwed tightly to the rotor blade 4, and only then can the other two connecting elements 6, 7 be fastened to the hub 3. Disassembly takes place in exactly the reverse order.

(37) In the embodiment according to FIG. 4, both the rotor blade 4 and the hub 3 are identical in design to the corresponding elements from FIG. 2. Here, however, the blade bearing 5 itself has a different structure:

(38) The principle of three relatively rotatable connecting elements 6-8, each having a crown of through-bores 11-13 separated from each other by gaps 9, 10, is preserved here.

(39) The most consequential difference from the previously described blade bearing 5 is that here the noses 28 are not disposed on the radially innermost and the radially outermost connecting elements 6, 7, but on the middle connecting element 8, whereas the connecting elements 6, 7 that embrace each of said noses 28 on three sides each have a circumferential groove 29 on their lateral surface facing the respective gap 9, 10.

(40) As can further be seen from FIG. 4, the flanks of a nose 28 and of the groove 29 embracing it overlap each other in the radial direction. The respective overlapping regions each serve as raceways 32, 33 for a respective row of rolling elements 34, 35. So that respective rolling elements 34, 35 can roll without play along each of these raceways 32, 33, the maximum axial distance between two raceways 32, 33 assigned to the same rolling elements 34, 35 is equal to the diameter of those same rolling elements 34, 35. This means, by the same token, that the maximum axial distance a between the mutually facing flanks 32 of a groove 29 is equal to the sum of the minimum axial extent e of the nose 28 plus twice the diameter d of a rolling element 34, 35: a=e+2*d; where the rolling elements 34, 35 are of different sizes, with diameters d.sub.1, d.sub.2, this becomes: a=e+d.sub.1+d.sub.2.

(41) In the embodiment according to FIG. 4, the rolling elements 34, 35 each have a spherical shape. This means that the cross sections of the raceways 32, 33 are each concavely curved, particularly along a circular arc. These curved raceway regions should also be referred to as the fitted region, since they have nearly the same diameter as the spherical rolling elements 34, 35 and thus fit snugly against their surfaces. As can further be seen from FIG. 4, the cross section through these raceway or fitted regions 32, 33 extends in each case along a circular arc with a center angle .sub.1, .sub.2 of 90 or more, but less than 180: 90.sub.1<180, 90.sub.2<180, preferably: .sub.1=.sub.2=.

(42) As can be seen, the flanks of a nose 28 and thus the raceways 32, 33 located there diverge toward the free end of the nose 28, specifically preferably symmetrically to each other with respect to an approximately central main plane of the blade bearing 5.

(43) Furthermore, the flanks of a groove 29 and thus the raceways 32, 33 there reconverge toward each other in the axial direction in the region of the edge-shaped transition from the groove 29 to the respectively adjacent curved sections 36, 37; 38, 39 of the radially innermost and the radially outermost connecting element 6, 7, specifically preferably symmetrically with respect to an approximately central main plane of the blade bearing 5.

(44) Sections 36, 38 are preferably above the groove 29 and are each aligned with the respective section 37, 39 below the particular groove 29; consequently, the end faces 17-19 of the connecting elements 6-8 are not only parallel to, but also approximately coextensive with the particular connecting surface 14-16 of the connecting element 6-8.

(45) As can further be seen from FIG. 4, in at least one gap 9, 10preferably in the region of the free end side 40 of the nose 28 therethere is another bearing 41, particularly a fifth row of rolling elements 42. These also roll along two raceways 43, 44, which, however, are not located in radially overlapping regions of the particular connecting elements 6-8, but instead bridge the particular gap 9, 10 in the radial direction. Consequently, the axes of rotation of these rolling elements 42 are approximately parallel to the axis of rotation of the blade bearing 5, whereas the contact angles are approximately 0, corresponding to predominantly or exclusively radial force transmission. In the embodiment shown, this bearing is a rolling bearing with cylindrical or roller-shaped rolling elements 42 that have a smaller diameter than the spherical rolling elements 34, 35. This is not mandatory, however. The diameter could instead be chosen as different, and/or instead of rollers 42, ball-, needle-, cone- or barrel-shaped rolling elements, or a sliding bearing or other type of bearing, could be used for the radial bearing 41. Moreover, at least one such radial bearing 41 can be disposed in the radially inner gap 9 or in the radially outer gap 10 or in both. For the axial guidance of roller-shaped rolling elements 42, at least one raceway 43, 44 can be configured as a groove-shaped depression in the particular connecting element 6-8.

(46) The raceways 32, 33, 43, 44 of a connecting element 6-8 are preferably formed along with the particular bores 11-13 by processing or shaping the same common base body.

(47) Since the two noses 28 of the middle connecting element 8 are respectively embraced on three sides by the grooves 29 of the other two connecting elements 6-8, assembly of the blade bearing 5 is possible only if the radially innermost and the radial outermost connecting elements 6, 7 are each divided in the region of the respective groove 29, along a horizontal surface 45, respectively into an upper ring 46 and a lower ring 47, which are simultaneously slid from both axial directions over the noses 28 of the middle connecting element 8 and only then are connected to each other, particularly screwed together.

(48) In the wind power plant 1.sup.(3) according to FIG. 5, the wind wheel 2.sup.(3) differs from the previously described embodiment 1, 2 in only a few details; the basic structure is nearly identical.

(49) A first difference lies in the fact that in embodiment 1.sup.(3), 2.sup.(3), instead of a single radial bearing 41, 42; 42, two radial bearings 42a.sup.(3), 42b.sup.(3) are provided, specifically one in the gap 9.sup.(3) between the radially innermost connecting element 6.sup.(3) and the middle connecting element 8.sup.(3) and one in the gap 10.sup.(3) between the middle connecting element 8.sup.(3) and the radially outermost connecting element 7.sup.(3). In this arrangement, the rolling elements of the radial bearings 42a.sup.(3), 42b.sup.(3) can each be received in a trough-shaped depression in a connecting element 6.sup.(3), 7.sup.(3), 8.sup.(3), preferably in the middle connecting element 8.sup.(3). The rolling elements of the radial bearings 42a.sup.(3), 42b.sup.(3) are preferably disposed at the same height.

(50) Whereas the radially middle connecting element 8.sup.(3) differs little from the previously described middle connecting element 8, there are several deviations with regard to the other two connecting elements 6.sup.(3) 7.sup.(3)

(51) In contrast to connecting elements 6, 7, connecting elements 6.sup.(3), 7.sup.(3) are in direct contact. This contact region is located on an end side of the middle connecting element 8.sup.(3), preferably in axial prolongation of a gap 9.sup.(3), 10.sup.(3), particularly the radially inner gap 9.sup.(3). Here, a cylinder-segment-shaped outer surface of the radially innermost connecting element 6.sup.(3) rests against a hollow-cylindrical surface inside the radially outermost connecting element 7.sup.(3). This areal contact causes a centering of the two connecting elements 6.sup.(3), 7.sup.(3).

(52) To form a direct contact, in contrast to the embodiment according to FIG. 3, here the two outer connecting elements 6.sup.(3), 7.sup.(3) are configured as much taller in the axial direction than the middle connecting element 8.sup.(3). In the region of the protrusion in the axial direction, at least one of the two connecting elements 6.sup.(3), 7.sup.(3) has a circumferential flange 60. This flange 60 extends all the way to the respectively other connecting element 6.sup.(3), 7.sup.(3) and there forms a contact along a contact surface 61.

(53) The flange 60 is provided with through-holes 62 whose diameter is larger than the maximum diameter of the nut 23 or of the head 63 of a screw 64 that is screwed through the middle connecting element 8.sup.(3) and on into a rotor blade 4. The number of through-holes 62 is the same as the number of screw bushings 50 in the rotor blade 4, and their distribution over the circumference is identical to the distribution of the screw bushings 50 over the circumference of the end side of the rotor blade. Due to the larger diameter of the through-holes compared to the nuts 23 or screw heads 63, it is possible to fit a socket wrench through the openings or through-holes 62 and onto a screw element, i.e. a nut 23 or a screw head 63, and tighten it in this way.

(54) The ends of the two outer connecting elements 6.sup.(3), 7.sup.(3) that serve as respective connecting surfaces 65, 66, these being the ends facing toward the hub 3.sup.(3), preferably lie in a common plane that is intersected perpendicularly by the axis of rotation of the bearing. In this case, therefore, the region 67 of the hub 3.sup.(3) that is to be screwed together with them can also be configured as flat and continuous, i.e. as one piece, and can be screwed to the two connecting surfaces 65, 66. To accomplish this, the screws 21.sup.(3) engage through coronally distributed bores 68, 69 in the region 67 of the hub 3.sup.(3). Thus, they are not screwed in from the bearing end side that faces the rotor blade 4, and the bottom sides of the screw heads 70 therefore rest against the inner side of the hub region 67. The screw connections 21.sup.(3), 70 are optimized in that the bores 11.sup.(3), 12.sup.(3) do not pass all the way through the two outer connecting elements 6.sup.(3), 7.sup.(3), but instead are configured as blind bores. Under these circumstances, only the region of the bores 11.sup.(3), 12.sup.(3) where the bottom 71 of a blind hole 11.sup.(3), 12.sup.(3) is located is provided with an internal thread, so the screws 21.sup.(3), 70 anchor there only. The screw-attached hub region 67 has bores 72 that are aligned with the through-holes 62 of the flange 60 and through which the nuts 23 or screw heads 63 can be accessed.

(55) One advantage of this arrangement is that all the screw connections 20, 23 are accessible from the inside, by way of the hub 3.sup.(3).

(56) The case is similar for the embodiment of a wind power plant 1.sup.(4) according to FIG. 6, where the blade bearing 5.sup.(4) does not differ from the previously described embodiment 5.sup.(3); only the manner of installation in a wind power plant 1.sup.(4) is slightly different.

(57) Specifically, here the hub 3.sup.(4) and the rotor blade 4.sup.(4) are switched in terms of how they are connected. That is, the hub 3.sup.(4) is connected to the middle connecting element 8.sup.(4), whereas the rotor blade 4.sup.(4) is connected to the two outer connecting elements 6.sup.(4), 7.sup.(4). This is made possible by the fact that the rotor blade 4.sup.(4) is split, in the region of its back end, into two mutually concentric aprons 73, 74 that are spaced apart from each other in the radial direction, each of which has a flat connecting surface 75, 76 provided with respective coronally distributed blind bores 77, 78, each with at least one inserted threaded bushing 79. In this case, the therewith-aligned bores 11.sup.(4), 12.sup.(4) in the two outer connecting elements 6.sup.(4), 7.sup.(4) are configured as threadless through-bores, through each of which a respective screw can be inserted to fasten the rotor blade 4.sup.(4).

(58) The invention allows of various modifications. For example, the flange 60 could be or become connected along the contact surface 61 to the respectively other connecting element 6.sup.(3), 7.sup.(3) or 6.sup.(4), 7.sup.(4) in a punctiform or areal manner to further increase stability. In general, however, screwing both connecting elements 6, 7 jointly to a common machine partthe hub 3 or the rotor blade 4should render such a measure superfluous.

(59) TABLE-US-00001 List of Reference Numerals 1 Wind power plant 2 Wind wheel 3 Hub 4 Rotor blade 5 Blade bearing 6 Connecting element 7 Connecting element 8 Connecting element 9 Gap 10 Gap 11 Bore 12 Bore 13 Bore 14 Connecting surface 15 Connecting surface 16 Connecting surface 17 End face 18 End face 19 End face 20 Head 21 Screw 22 Bolt 23 Nut 24 Bore 25 Bore 26 Bore 27 Longitudinal axis 28 Nose 29 Groove 30 Lateral surface 31 Lateral surface 32 Raceway 33 Raceway 34 Rolling element 35 Rolling element 36 Section 37 Section 38 Section 39 Section 40 End side 41 Bearing 42 Rolling element 43 Raceway 44 Raceway 45 Surface 46 Upper ring 47 Lower ring 48 Internal thread 49 Internal thread 50 Bushing 51 Rotor blade jacket 52 End 53 Mounting surface 54 Mounting surface 55 Apron 56 Apron 57 Web 58 Access bore 59 Jacket 60 Flange 61 Contact surface 62 Through-hole 63 Screw head 64 Screw 65 Connecting surface 66 Connecting surface 67 Region 68 Bore 69 Bore 70 Screw head 71 Bottom 72 Bore 73 Apron 74 Apron 75 Connecting surface 76 Connecting surface 77 Blind bore 78 Blind bore 79 Threaded bushing