Rolling Bearing Assembly And Wind Turbine Equipped Therewith

Abstract

A rolling bearing arrangement comprising two rings arranged concentrically and at least regionally one inside the other, and a gap between the rings, such that the rings are rotatable in opposite directions about an axis at the center of the rings and perpendicular to a ring plane, wherein at least one raceway is closed on itself in a circular shape in a plane and is provided with at least one row of symmetrical rolling bodies between the rings, wherein the rolling bodies of one row are guided at generally equidistant spacings by a cage having at least one disk-shaped region is placed in continuously circumferential, groove-shaped depression in the region of the raceway of one bearing ring, and wherein the cage is shaped like a comb, comprising a plurality of spacers that are joined together along a spine region, and, between every two neighboring spacers, a respective pocket for receiving a respective rolling body.

Description

[0001] The invention is directed to a rolling bearing arrangement, particularly in the context of a (drivable) rotary joint, preferably for a main, blade and/or nacelle bearing of a wind turbine, comprising two annular connecting elements arranged concentrically to each other and at least regionally one inside the other, and comprising a gap between said connecting elements, such that the latter are rotatable in opposite directions about an imaginary axis at the center of the connecting elements and approximately perpendicular to the ring plane, wherein at least one raceway that is closed on itself in a circular shape in a plane and is provided for at least one row of rotationally symmetrical rolling bodies rolling between the connecting elements is disposed between the connecting elements in the region of a gap portion surrounding the axis of rotation at an approximately constant radius, wherein the rolling bodies of one row are guided at approximately equal spacings by a cage having at least one approximately disk-shaped region that is placed in a continuously circumferential, groove-shaped depression in the region of the raceway of one connecting element, and wherein the cage is shaped like a comb, comprising a plurality of spacers that are joined together by simple connection along a spine region, and, between every two neighboring spacers, a respective pocket for receiving a respective, preferably spherical, rolling body, wherein the opening of a pocket extends continuously in the top face of the cage, over the opposite edge thereof from the spine region and on into the bottom face thereof; the invention is further directed to a wind turbine equipped with at least one such rolling bearing.

[0002] Rolling bearings, or rotary joints provided with rolling bearings--some of these being drivable joints--have applications in a great many areas. Large rolling bearings, for example with a raceway diameter of 1000 mm or more, are used, inter alia, in wind turbines, preferably in wind turbines having a wind wheel with one or more vanes and an axis of rotation that is pitched roughly parallel to the wind direction during operation. Such large rolling bearings are relied on in particular to support the blades and the nacelle as a whole, but also to serve as the main bearing or rotor bearing supporting the hub of a wind turbine; with suitable dimensioning, they can absorb all the axial and radial forces and tilting moments that occur. In many such applications, for example in the case of blade bearings, preloaded, i.e. play-free, raceways are used. One advantage of this is improved load distribution in the raceway system, and thus improved service life. A frequent choice here is a four-point type of bearing, i.e., a bearing with spherical rolling bodies and two raceways shaped so that each ball has two contact points with each raceway. Such bearings are easy to preload. However, particularly in the case of such four-point bearings, combined loads in the raceway system (axial and radial forces and tilting moments) can cause different contact angles to develop between a ball and a raceway; moreover, depending on the load combination and the position of a given individual rolling body, four-point contact may even give way to two-point contact. Such displacement of the contact points of individual rolling bodies can alter their positions relative to adjacent balls; consequently, to prevent the balls from becoming unevenly distributed, a cage is often inserted to maintain consistent ball spacing. A cage does call for a larger gap width than a cageless rolling bearing does, since the connection between the spacers of the cage must not be below a certain minimum thickness for reasons of stability. This reduces the achievable load-carrying capacity, since the contact area of a rolling body approaches the edge of a raceway more often and at greater speeds.

[0003] It has already been proposed, therefore--for example in DE 33 00 655 A1--to provide in the region of a raceway a dedicated groove in which are guided individual cage segments each of which has, for example, two pockets for receiving a respective a rolling body, such that, despite the use of a cage, the width of the gap between the two annular connecting elements need not be increased compared to an embodiment that has mutually separated intermediate pieces instead of a cage. A disadvantage, however, is that here, instead of a single cage, it is necessary to use a large number of small cage segments with only two receiving pockets apiece for rolling bodies, with the result that assembly becomes very onerous precisely in the case of large rolling bearings with diameters on the order of approximately 1000 mm or more. What is more, cage segments that are only loosely juxtaposed can create additional problems in preloaded bearings, since under the substantial forces acting on a large rolling bearing during operation, for example in a wind turbine, the individual cage segments can shift despite best efforts, as a result of which individual rolling bodies can jam and thus suffer increased wear.

[0004] From the disadvantages of the described prior art comes the problem initiating the invention, i.e., so to refine a cage-equipped rolling bearing arrangement of the aforementioned species that the assembly of the cage is as simple as possible; a further aim is to ensure that all the rolling bodies are maintained at the applicable uniform spacing without becoming jammed.

[0005] This problem is solved by the fact that the cage is completely interrupted in at least one location and is formed from a spring-elastic material, such that it can be elastically bent open and/or closed in the area, particularly the plane, of the approximately disk-shaped region.

[0006] A cage is preferably interrupted only once, and therefore, as a whole, is of one piece or simply connected. It is also possible, however--as may be the case with particularly large rolling bearings--to divide the cage two or three times, but, insofar as possible, no more than for example five times, preferably no more than four times, particularly no more than three times. The spring-elastic material is capable of changing its bending radius so that it can be placed in a groove optimally and with minimal effort, for which purpose it first must be forcibly deformed in order to be slipped past the end face of an annular connecting element to the raceway of the latter; once in the groove provided for it, the cage relaxes again, rebounding toward its original shape.

[0007] It has proven advantageous for the cage to consist of a metal, for example steel, preferably spring steel or quenched and tempered steel. Such a material particularly has a high compressive strength, so that it can withstand the high forces inside a rolling bearing.

[0008] Preferably, four, more or all of the spacers of the cage are connected to one another, such that three, more or all of the pockets each provided to receive a respective rolling body are connected to one another. Since displacements in the bearing are most likely to be caused by abutment locations between unconnected cage segments, these should be avoided insofar as possible.

[0009] The cage should be fashioned in such a way that should the distance between the end faces of two neighboring spacers change, their end faces do not deform, in particular their top and bottom edges do not shift in relation to each other. This is the only way to ensure that the rolling bodies will not jam even if the ring deforms, for example as a result of thermal expansion.

[0010] A preferred measure for obtaining high shear strength inside the cage is to make it from only one layer of material. At worst, macroscopic deformation of the material itself could cause jamming, but this is highly unlikely, especially if the cage is made of metal.

[0011] It is within the scope of the invention that at least one spacer has a greater height than the spine region of the cage. This makes it possible to surround a ball over a large area; the ball can thus be constantly forced into the particular desired position with very low surface pressure, hence extremely gently and with the utmost freedom from wear.

[0012] All the pockets of the cage should be open on the opposite longitudinal side of the cage from the spine region. On the one hand, this gives the cage good flexibility, since the pockets can open or tighten, as required; on the other hand, in this way all the pockets can be filled with rolling bodies from the same side or raceway, i.e., through one and the same fill opening.

[0013] According to the invention, the cage has at least one designated bending area, preferably in its spine region. This can preferably be a narrowing of the cross section of the cage, where its resistance to bending is lower, due to the more or less homogeneous properties of the cage material.

[0014] At least one designated bending area preferably extends transversely to the circumferential direction of the rolling bearing, for instance following a line of smallest cross section through it.

[0015] At least one such designated bending area can be provided in the region of a (or each) spacer, since the spacers are located between two adjacent rolling bodies, and thus any deformation in this area, for example as a result of hyperextension during assembly, will not cause a rolling body to become jammed.

[0016] The invention recommends configuring at least one designated bending area as a notch in the cage, particularly in the end face of the spine region. The cage is thereby intentionally given lines of weakness where it can deform under excessive loading without any adverse effect on its ability to function.

[0017] The maximum depth of at least one notch should approximately correspond to the minimum width of the spine region at the base of a pocket. The spine region can be completely interrupted at the notch locations, such that the cage is held together only by the spacers at those locations. This gives the cage very high flexibility in the region of the spacers. It should be noted that the spacers are not very deformable at all in their central vertical plane or plane of symmetry, but rather, right next to it*, i.e., approximately in or at the foot region of the two flanks of a spacer.

[0018] In addition, a notch should pass all the way through the spine region of the cage from its top face to its bottom face, so that the cage is uniformly flexible over the entire cross section of the spine and local overstrains are prevented.

[0019] It is within the scope of the invention that at least one notch has rounded edges, preferably at the edges extending vertically relative to the base of the rolling bearing, particularly in the region of the transition between the flanks of the notch, i.e. at the base of the notch, and/or beyond its two flanks, i.e., at the transition into the adjacent spine region.

[0020] The rolling bodies are preferably embraced by the cage where their peripheral speed is highest as they roll, i.e., preferably approximately in the region of their equator. Particularly in an embodiment of this kind, the groove that guidingly receives the spine of the cage is located approximately centrally in the raceway of the connecting ring concerned, i.e., approximately at half the height of the raceway. Such an arrangement has the advantage that the rolling bodies are embraced on their plane of symmetry and therefore do not exchange radial forces with the cage, which thus experiences no bending moment transversely to its longitudinal direction.

[0021] It is sufficient if the rolling bodies are embraced over no more than 270.degree. of their circumference, for example only over 230.degree. of their circumference or less, preferably only over 190.degree. or less, particularly only over approximately 180.degree. of their circumference. The spacing elements of the cage should not be too long, since their free ends move the most during bending, so the spacing between these ends can change considerably. In particular, inelastic deformation of individual portions of the cage--during assembly, for example--could therefore cause individual rolling bodies to jam. This can be prevented if the length of the spacers approximately perpendicular to the cage spine, i.e., in the radial direction relative to the axis of rotation of a radial bearing, is equal to approximately only the (maximum) radius of a rolling body, i.e., the rolling bodies are embraced only over two diametrically opposite surface regions.

[0022] If--as the invention further provides--the inner face of at least one pocket for receiving a respective rolling body is at least regionally given a concave curvature parallel to the plane of the rolling bearing, approximately at the level of the spine region of the cage, then such a hollow curvature can be optimally adapted to the convex surface curvature of a rolling body, so that in the embraced region only a very small gap remains between the rolling body and the cage pocket, and the rolling bodies can therefore be guided so at closely toleranced spacings.

[0023] Further advantages are gained by having the concavely curved region follow approximately a semicircle or a smaller segment of a circle. This makes it possible to introduce the balls into the pocket from its open side, particularly after the rolling bearing is assembled, for example through a filling channel.

[0024] The subsequent filling of the cage with rolling bodies is also facilitated particularly by the fact that after the cage is placed in the groove provided for it, the radius of the concavely curved region in the area, particularly the plane, of the spine region of the cage is equal to or greater than the equatorial radius of curvature of the rolling body received in the pocket concerned. The rolling bodies can thus be introduced without any risk of jamming.

[0025] The invention is suited in particular for rolling bearings whose rolling bodies have a doubly curved, particularly doubly convexly curved, jacket surface or outer surface, preferably for spherical rolling bodies, particularly in the context of a four-point bearing.

[0026] Within the scope of a preferred embodiment, it can further be provided that the inner face of at least one pocket for receiving a respective rolling body has at least regionally a double concave curvature, i.e., is concavely curved in two mutually perpendicular directions. Spherical rolling bodies, in particular, can thus be embraced over a substantial area, making it possible to align the rolling bodies at uniform spacing with the least possible surface pressure, thus eliminating local overloading of the cage.

[0027] This aspect of the invention can be further enhanced in that the doubly concavely curved region of a pocket approximately follows the surface of a hemisphere or two spaced-apart quarter spheres, or follows one or two smaller segment(s) of a hollow sphere. A compromise is thereby reached between maximum encapsulation of a spherical rolling body and a large enough opening so that the balls can be subsequently introduced.

[0028] It follows from this that one or preferably both, depending on the direction of rotation of the rolling bearing front or back sides*, of a spacer each follow a segment of the surface of a hollow sphere, preferably each approximately one fourth of the surface of a hollow sphere or a smaller portion thereof. Assuming that the pockets receiving the rolling bodies are symmetrical to a vertical plane extending centrally between two spacers, this results in an arrangement in which a spacer has two mutually symmetrical, doubly concavely curved flanks on its front side and back side, referred to the particular direction of rotation.

[0029] A rolling bearing arrangement according to the invention can, by all means, have two or more mutually offset rows of rolling bodies, the offset being in the axial direction of the bearing. Under these circumstances, cages according to the invention are preferably inserted in all the rows of rolling bodies.

[0030] One, more or all of the rows of rolling bodies can be fashioned in the manner of a four-point ball bearing, particularly in the manner of a preloaded four-point ball bearing. A cage according to the invention is capable of applying the forces needed to align such preloaded rolling bodies without deformation.

[0031] The invention further provides that the gap between the two rings is sealed at one or preferably both end faces of the rolling bearing to keep out foreign bodies that might damage the raceways, the balls and/or the cage.

[0032] Sealing at both ends also makes it possible for the gap between the two rings, particularly within the two end-face seals, to be filled with a lubricant, particularly with grease. Since the grease cannot leak out, the regreasing interval can be chosen to be very long, which is especially advantageous precisely in the case of wind turbines, including, under some circumstances, in the offshore environment.

[0033] Further advantages are afforded by providing, in one annular connecting element, a filling channel that extends from one end face or jacket side to the raceway and serves to introduce rolling bodies, particularly balls. It has proven particularly effective to dispose the filling channel in an annular connecting element that does not have a groove for receiving the cage spine, so that the rolling bodies can be introduced into a pocket of the cage from the open side. Such a filling channel can preferably open into a connecting-element jacket surface that faces the gap, so that it can extend in a straight line, i.e., parallel to the base plane of the bearing.

[0034] Furthermore, one or preferably both annular connecting elements comprise coronally distributed fastening means for connection to a frame, machine part or system part, preferably coronally distributed bores perpendicular to an end face. Such an arrangement is the only way to ensure that the often high forces that occur between the mounted-together system components will be safely absorbed by a bearing according to the invention.

[0035] The invention can be developed further by providing at least one of the annular connecting elements with a continuously circumferential row of teeth, particularly on a jacket surface disposed oppositely from the gap. At such a continuously circumferential row of teeth, torques can be introduced into or tapped from the rotary joint, for example to deliberately move to a given angle of rotation and/or to keep the angle stable, and/or to drive the rotary joint.

[0036] The invention further provides a rotary drive, particularly one or more electric or hydraulic motors, for rotationally adjusting the two annular connecting elements relative to each other.

[0037] Such a rotary drive can, in this application, be coupled to a connecting element via a (respective) pinion, toothed wheel, worm or the like meshing with a continuously circumferential row of teeth of that connecting element, and can be affixed to the other annular connecting element or to a housing part or frame part attached thereto.

[0038] A rolling bearing according to the invention preferably finds application as a rotor bearing or main bearing of a wind turbine, and/or--particularly in the form of a rotary drive with an inwardly or outwardly toothed connecting ring--as a blade bearing of a wind turbine, and/or as a nacelle bearing of a wind turbine.

[0039] A wind turbine according to the invention is distinguished by a rotor bearing or main bearing configured according to the criteria articulated above, and/or by at least one blade bearing so constructed, and/or by a like-constructed nacelle bearing.

[0040] Further features, details, advantages and effects based on the invention will become apparent from the following description of a preferred embodiment of the invention and by reference to the drawing. Therein:

[0041] FIG. 1 is a cross section through the rings of a rolling bearing according to the invention;

[0042] FIG. 2 is perspective partial cutaway view of the outer ring of the rolling bearing from FIG. 1, together with a cage guided therein, having a plurality of pockets each provided to receive a respective rolling body, a rolling body being placed in one pocket by way of example;

[0043] FIG. 3 shows the cage of the rolling bearing from FIGS. 1 and 2 in perspective view and largely straightened out;

[0044] FIG. 4 is an enlarged representation of a detail from FIG. 2; and

[0045] FIG. 5 is a perspective representation of a cage according to another embodiment of the invention.

[0046] The rolling bearing 1 depicted by way of example in the drawing serves to rotatably connect a first system part or machine part to a foundation or to a second system part or machine part. For this purpose, the rolling bearing 1 is provided with two annular connecting elements 2, 3.

[0047] The section through the rolling bearing 1 illustrated in FIG. 1 reveals its internal construction. The typical structure of a radial bearing is evident, in which a first connecting element 2 is configured as a flat outer ring, which can be seen on the left in FIG. 1, while the second connecting element 3 is configured as an inner ring 3, on the right in FIG. 1, that is disposed concentrically inside the outer ring 2. The two connecting elements 2, 3 each have an approximately rectangular cross section. Between the inner jacket surface 4 of the outer connecting element 2 and the outer jacket surface 5 of the inner connecting element 3 there is a narrow gap 6 that runs approximately vertically and has a constant, very small width, such that the two connecting elements 2, 3 are rotatable in opposite directions about an axis that is at the center of the rings 2, 3 and perpendicular to the base plane of the bearing.

[0048] During such relative rotation, the two connecting elements 2, 3 are kept oriented exactly concentrically with each other by a multiplicity of rolling bodies 7 disposed in the gap 6 between the two connecting elements. These rolling bodies 7 each have a spherical shape and roll between two raceways 8, 9, one 8 disposed in the inner jacket surface 4 of the outer connecting element 2, and the other 9 in the outer jacket surface 5 of the inner connecting element 3.

[0049] Each of the two raceways 8, 9 has a cross section that is approximately semicircular but nevertheless differs minimally from the ball cross section; for example, the radius of the raceway cross section can be minimally larger than the radius of the ball cross section.

[0050] In the manner of a single-row four-point bearing, each rolling body 7 thus always has two nearly punctiform areas of contact with each of the two raceways 8, 9; these contact areas are always at an angle of .+-.45.degree. to each other, viewed from the center of a spherical rolling body 7, but can shift in various directions when the rolling bearing 1 is under load.

[0051] The bearing is also preferably preloaded, i.e., play-free. The spherical rolling bodies 7 and/or the raceways 8, 9 are each minimally elastically deformed by this process.

[0052] In addition, the gap 6 is closed by a respective seal 12, 13 in the region of its debouchment at each of the two end faces 10, 11 of the bearing. The gap 6 thus sealed to the outside is filled with a lubricant, particularly with grease.

[0053] As can further be appreciated from FIG. 1, each of the two annular connecting elements 2, 3 comprises a relatively large number of coronally distributed fastening means, particularly in the form of fastening bores 14, 15, which optionally can be implemented as blind bores sunk from one bearing end face 10, 11 and/or as through-bores passing all the way through the particular connecting element 2, 3 between its two bearing end faces 10, 11, as illustrated in FIG. 1. Such fastening bores 14, 15 are used to screw in or push through machine screws that are simultaneously anchored to a machine part or system part.

[0054] In addition, one of those two jacket surfaces 16, 17 of the two connecting elements 2, 3 which face away from the gap 6 can be provided with teeth, with which a, for example, driven pinion, toothed wheel, worm or the like can be brought into engagement, while the housing of such a drive would preferably be fixable to the respective other connecting element 2, 3.

[0055] Roughly equidistant positions of the rolling bodies 7 along the raceways 8, 9 are kept as constant as possible by a cage 18, which is illustrated in isolation in FIG. 3.

[0056] Such a cage 18 preferably consists of a spring-elastic material, for example of spring steel, and can thus be bent without damage and without residual deformation.

[0057] It is, moreover, interrupted in at least one location and therefore has the shape of a strip with two ends 19, 20, i.e., is not endless. Owing to these two measures, the cage 18 need not be pre-bent to the raceway diameter of the rolling bearing 1, but can, where appropriate, be fabricated as a straight-extending part, particularly stamped or laser-cut from a (metal) sheet or (metal) strip. The cage could also be pre-bent to a standardized curvature and would still be usable for a large number of rolling bearings 1 irrespective of their exact raceway diameters; for this purpose, it could also be shortened by a given amount as needed.

[0058] FIG. 3 is a schematic construction diagram of the cage 18: the latter has the shape of a flat strip in which regularly recurring recesses 23, 24 are cut into both narrow longitudinal sides 21, 22, which, for example, were originally straight or extended concentrically with a common center.

[0059] Cut into longitudinal side 21 are larger recesses 23 having an approximately semicircular base area, whose radius is approximately equal to or minimally greater than the radius of a ball 7; these recesses 23 serve as pockets, each receiving a respective spherical rolling body 7.

[0060] Smaller recesses 24 are cut into the opposite longitudinal side 22; these notches 24 serve to locally reduce the stiffness of the cage 18, and can serve as designated bending areas if necessary.

[0061] The notches 24 are preferably each located on the line of symmetry between a respective two adjacent pocket recesses 23. Since the center-to-center distance between pocket recesses 23 is (slightly) larger than the width of a pocket recess 23, a projection remains right on the line of symmetry between two adjacent pocket recesses 23 and serves as the spacer 25 between two adjacent rolling bodies 7, to keep them from coming into direct contact and to ensure instead that the spacing between them remains the same. The free end face of such a spacer 25 can be rounded and/or have rounded edges.

[0062] Since the cage strip 18 is wider than the depth of a pocket recess 23, and thus is preferably wider than the radius of a ball 7 received therein, and is also wider than the depth of a notch 24, the spacers 25 are simply connected on the longitudinal side 22 facing the pockets 23; the result is a comb-like structure, with the tines of the comb corresponding to the spacers 25 and the comb spine or cage spine 26 corresponding to the region of the cage near its longitudinal side 22, which is incised only slightly by the notches 24.

[0063] The cage 18 is not bent like a cylinder jacket, according to the usual practice, and inserted in the gap 6 of the rolling bearing 1; instead, the cage spine 26 is bent in a plane in the manner of an annular disk and is placed in a circumferential groove 27 machined into a raceway 8, 9--in the illustrated case, in raceway 8 of the radially outer connecting element 2. Since this groove 27 is located (approximately) at half the height of the raceway 8 and thus divides the latter into two (approximately) equal large halves of approximately quarter-circle-shaped cross section, the flat cage 18 placed therein extends to the height of the centers of the spherical rolling bodies 7. The free ends of the spacers 25 lie approximately on a circular line that passes simultaneously through the centers of all the spherical rolling bodies 7.

[0064] To enable the cage 18 to be bent easily into a circle corresponding to the particular gap diameter or raceway diameter, a notch 24 is provided across from each spacer body 25, on the line of symmetry thereof. The depth of each notch 24 approximately corresponds to the minimum width of the cage spine 26 in the region of the base of a pocket 23, or can even be greater than said width. The notches 24 can have an approximately V-shaped base surface, preferably with rounded edges in the region of the notch base and at the two regions of transition to the approximately straight longitudinal side 22 of the cage 8.

[0065] A notch 24 can be shaped so that a section through the cage 18 taken from the base of a notch 24 and/or from the thereto-adjacent region of a flank of the notch 24 and extending approximately radially with respect to the center of the adjacent pocket 23 has a relatively small cross section or even the smallest cross section of the cage 18, so that the latter has a tendency to bend at those locations as needed, owing to the weakness of the material there.

[0066] Even if, after bending has taken place there, residual deformation still remains as a result of local overloading, this would still have little impact on the ability of the inventive cage 18 to function, since the respective base areas of the adjacent pockets 23 would be changed very little by this and a rolling body 7 received in them thus would not become jammed.

[0067] FIG. 5 illustrates another embodiment of a cage 28 according to the invention.

[0068] Cage 28 differs from the previously described cage 18 primarily in the shape of the spacers 29, whereas the cage spine 30 that is to be placed in the groove 27 is identical to the cage spine 26 of cage 18. A horizontal longitudinal section along the main central plane of the cage 28 is also identical to a corresponding longitudinal section through cage 18.

[0069] In contrast to cage 18, however, cage 28 does not have a flat shape with a constant thickness, but rather, the spacers 28 additionally extend in the third dimension, upward and downward out of the plane of the cage spine 30.

[0070] Each spacer 29 is essentially bounded by five surfaces and is formed together with the cage spine 30 on the remaining side.

[0071] Correspondingly to the transverse curvature of the raceway 8, the top face 31 and the bottom face 32 of a spacer 28 have a curvature that is complementary thereto, so that they are able to slide in the raceway 8 with as little friction as possible. To this end, the transverse curvature diameter of the spacers 28 can be slightly smaller than the transverse curvature radius of the raceway 8. Where applicable, the top face 31 and the bottom face 32 can also have a slight curvature in the longitudinal direction of the cage 18, approximately corresponding to the longitudinal curvature of the raceway 8.

[0072] From the cage spine 30 outward, the top face 31 and the bottom face 32 diverge from each other to an end face 33 that joins the free edges of the two surfaces 31, 32. This end face 33 follows approximately the course of the gap 6 above and below the raceway 8; it can be flat or slightly curved in the manner of a cylinder jacket surface, correspondingly to the cylindrically curved course of the gap 6.

[0073] The two surfaces 35, 36 adjacent the neighboring pockets 34 of a spacer 28 each follow a segment of the surface of a hollow sphere; they form the counterpart to the spherical rolling bodies 7 received in these pockets 34, and are curved with approximately the same radius as they are, but concavely rather than convexly. These surfaces 35, 36 taper in the direction of the pocket 34 down to the cross section of the cage spine 30. However, they preferably continue thereinto without a step or bend, i.e., continuously and differentiably, preferably in the form of a portion of the surface of a cylinder jacket or hollow sphere.

[0074] The two mutually facing pocket boundary surfaces 35, 36 of neighboring spacers 28 could also pass directly into each other, especially if the pockets 34 do not extend into the groove 27, i.e., if their depth is equal to the width of the cage 28 minus the depth of the groove 27. Nevertheless, a gap of approximately constant width and extending approximately to the plane of the cage spine 30 should still remain between the facing pocket boundary surfaces 35, 36, so that the rolling body 7 received in the pocket 34 concerned has enough free space to form areal regions of contact with the raceway 8. Consequently, the area of each pocket boundary surface 35, 36 is preferably slightly less than one fourth the area of a hollow sphere.

[0075] Although in the illustrated embodiment the groove 27 is provided in the radially outwardly disposed connecting element 2, it could just as well be located in the radially inwardly disposed connecting element 3. The longitudinal side 22 of the cage 18, 28 that runs along the cage spine 26, 30 would then be concavely rather than convexly curved.

[0076] To fill the pockets 23, 34 after the connecting elements 2, 3 have been assembled, there is provided at least one sealable filling channel whose cross section is at least equal to the cross section of a spherical rolling body 7. Such a filling channel is preferably provided in the particular connecting element 2, 3 that does not have a groove 27; it begins at the raceway 8, 9 there and debouches in a surface region of that connecting element 2, 3 outside the gap 6, particularly beyond the two seals 12, 13, preferably at a jacket surface 16, 17 facing away from the gap 6. Should one of these two jacket surfaces 16, 17 be provided with continuously circumferential teeth, for example for coupling a rotary drive, then it is advisable to place the groove 27 in this same toothed connecting element 2, 3, whereas the fill opening(s) should be provided in the respective other, untoothed connecting element 2, 3.

[0077] Thanks to the cage 18, 28, the rolling bodies 7 of the rolling bearing 1 are always guided at approximately equidistant relative positions, even under heavy loads. Rolling bearings 1 equipped with such cages 18, 28 can therefore also be operated in the preloaded state, the spherical rolling bodies 7 always being loaded in compression. Such high-load-capacity rolling bearings 1 are especially suitable for wind turbines, where they can be used as blade bearings, main rotor bearings and nacelle bearings.

TABLE-US-00001 List of Reference Numerals 1 Rolling bearing 2 Outer ring 3 Inner ring 4 Inner jacket surface 5 Outer jacket surface 6 Gap 7 Rolling body 8 Raceway 9 Raceway 10 Bearing end face 11 Bearing end face 12 Seal 13 Seal 14 Fastening bore 15 Fastening bore 16 Jacket surface 17 Jacket surface 18 Cage 19 End 20 End 21 Longitudinal side 22 Longitudinal side 23 Pocket recess 24 Notch 25 Spacer 26 Cage spine 27 Groove 28 Cage 29 Spacer 30 Cage spine 31 Top face 32 Bottom face 33 End face 34 Pocket 35 Pocket boundary surface 36 Pocket boundary surface

Claims

1. A rolling bearing assembly for a main blade or nacelle bearing of a wind turbine, the assembly comprising two annular connecting elements (2, 3) arranged concentrically to each other and at least regionally one inside the other, and forming a gap (6) between said connecting elements (2, 3), the connecting elements being rotatable in opposite directions about an axis at the center of said connecting elements (2, 3) and generally perpendicular to a ring plane, wherein at least one raceway (8, 9) is provided for at least one row of rotationally symmetrical rolling bodies (7) rolling between said connecting elements (2, 3) in the region of the gap surrounding the axis of rotation at a generally constant radius, wherein the said rolling bodies (7) of one row are guided at approximately equal spacings by a cage (18, 28) having at least one disk-shaped region that is placed in a continuously circumferential, groove-shaped depression (27) in the region of said raceway (8, 9) of one said connecting element (2, 3), and wherein said cage (18, 28) comprises a plurality of spacers (25, 29) that are connected to a spine (26, 30), and disposed between every two neighboring spacers (25, 29) is a recess (23, 34) for receiving the spherical rolling bodies (7), wherein the opening of a recess (23, 34) extends continuously in a top face of said cage (18, 28), over the opposite edge (21) thereof from said spine (26, 30) and into the bottom face thereof, wherein said cage (18, 28) is interrupted in at least one location and is formed from a spring-elastic material, such that it can be elastically bent open and closed in the plane of the disk-shaped region.

2. The rolling bearing assembly as in claim 1, wherein said cage (18, 28) is of steel.

3. The rolling bearing assembly as in claim 1, wherein said spacers (25, 29) of said cage (18, 28) are connected to one another, such that said recesses (23, 34) are connected to one another.

4. The rolling bearing assembly as in claim 3, wherein when a distance between end faces (33) of the two neighboring spacers (25, 29) changes, the end faces (33) top and bottom edges do not shift in relation to each other.

5. The rolling bearing assembly as in claim 1, wherein said cage (18, 28) consists of only one layer.

6. The rolling bearing assembly as in claim 1, wherein at least one of said spacers (25, 29) has a greater height than said spine (26, 30) of said cage (18, 28).

7. The rolling bearing assembly as in claim 1, wherein all of said recesses (23, 34) of said cage (18, 28) are open on the opposite longitudinal edge (21) of said cage (18, 28) from said spine (26, 30).

8. The rolling bearing assembly as in claim 1, wherein said cage (18, 28) has at least one designated bending area in the spine region thereof.

9. The rolling bearing assembly as in claim 1, wherein at least one bending area extends transversely to the circumferential depression of said rolling bearing (1).

10. The rolling bearing assembly as in claim 9, wherein at least one bending area is located in a region of a spacer (25, 29).

11. The rolling bearing assembly as in claim 9, wherein at least one bending area is configured as a recess (24) in said cage (18, 28), in an end face (22) of said spine (26, 30).

12. The rolling bearing assembly as in claim 11, wherein the maximum depth of said recess (24) approximately corresponds to a minimum width of said spine (26, 30) at a base of said recess (23, 34).

13. The rolling bearing assembly as in claim 11, wherein said recess (24) passes through said spine region of said cage (18, 28) from the top face thereof to the bottom face thereof.

14. The rolling bearing assembly as in claim 11, wherein at least one said recess (24) has rounded edges extending vertically in relation to the base of said rolling bearing (1), in the region of the transition between flanks of said recess (24) and/or beyond the two flanks of said recess.

15. The rolling bearing assembly as in claim 1, wherein said rolling bodies (7) are embraced by said cage (18, 28) where the peripheral speed of said rolling bodies is highest, hence generally in the regions of their equators.

16. The rolling bearing assembly as in claims 1, wherein said rolling bodies (7) are embraced over no more than about 180.degree. of their circumferences.

17. The rolling bearing assembly as in claims 1, wherein an inner face of at least one of said recesses for receiving a respective rolling body (7) is at least regionally provided, generally at the level of said spine (26, 30) of said cage (18, 28), with a concave curvature.

18. The rolling bearing assembly as in claim 17, wherein said concavely curved region follows generally a semicircle or a smaller segment of a circle.

19. The rolling bearing assembly as in claims 17, wherein after said cage (18, 28) is placed in the depression (27) provided therefor, the radius of the concavely curved region in the area of said spine (26, 30) of said cage (18, 28) is equal to, or greater than, the equatorial radius of curvature of the said rolling body (7) received in the respective recess.

20. The rolling bearing assembly as in claim 1, wherein said rolling bodies (7) have a doubly convexly curved outer surface.

21. The rolling bearing assembly as in claim 20, wherein said rolling bodies (7) comprise balls.

22. The rolling bearing assembly as in claim 1, wherein an inner face of at least one said recess for receiving a respective rolling body (7) has at least regionally a double concave curvature, i.e., is concavely curved in two mutually perpendicular directions.

23. The rolling bearing assembly as in claim 22, wherein the doubly concavely curved region of a said recess follows approximately a selected one of the surface of a hemisphere, or two spaced-apart quarter-spheres, or one or two smaller surface segment(s) of a hollow sphere.

24. The rolling bearing assembly as in claim 23, wherein depending on the direction of rotation of said rolling bearing (1), front or back sides (35, 36) of a spacer (25, 29) each follow a segment of a surface of a hollow sphere, each generally one fourth or less of the surface of a hollow sphere.

25. The rolling bearing assembly as in accordance with claim 1, wherein the rolling bodies comprise two or more mutually offset rows of rolling bodies (7), the offset being in the axial direction of said rolling bearing assembly (1).

26. The rolling bearing assembly as in claim 1, wherein one, more or all of the rows of said rolling bodies (7) and their raceways (8, 9) are fashioned in the manner of a preloaded four-point ball bearing.

27. The rolling bearing assembly as in claim 1, wherein said gap (6) between said connecting elements (2, 3) is sealed at both end faces (10, 11) of said rolling bearing (1).

28. The rolling bearing assembly as in one claim 27, wherein said gap (6) between said connecting elements (2, 3), within two end-face seals (12, 13), is filled with grease.

29. The rolling bearing assembly as in claim 27, wherein a filling channel extending from one end face or jacket surface (10, 11, 16, 17) to said raceway (8, 9) and serving to introduce the rolling bodies (7), is provided in one of said annular connecting elements (2, 3), that does not have a groove depression (27) for receiving said cage spine (26, 30).

30. The rolling bearing assembly as in claim 29, wherein both of said annular connecting elements (2, 3) comprise coronally distributed fastening means for connection to a frame, machine part or system part, the fastening means comprising coronally distributed bores (14, 15) perpendicular to an end face (10, 11).

31. The rolling bearing assembly as in claim 1, wherein at least one of said annular connecting elements (2, 3) has a continuously circumferential row of teeth on a jacket surface (16, 17) disposed oppositely from the gap (6).

32. The rolling bearing assembly as in claim 31, wherein said continuously circumferential row of teeth is provided on the annular connecting elements that has a depression (27) in which said cage spine is to be placed.

33. The rolling bearing assembly as in claim 1, and further comprising an electric motor for rotationally adjusting said two annular connecting elements (2, 3) relative to each other.

34. The rolling bearing assembly as in claim 32, wherein a rotary drive is coupled to one of said annular connecting elements (2, 3) via a pinion or toothed wheel or worm, or the like meshing with a continuously circumferential row of teeth, and is affixed to the other of said annular connecting elements (2, 3).

35. A wind turbine in combination with a rotor bearing or main bearing (1) configured according to claim 1.

36. A wind turbine, in combination with a blade bearing (1) configured according to claim 1.

37. A wind turbine, in combination with a nacelle bearing (1) configured according to claim 1.