BE1029770B1 - Rotor bearing unit for a wind turbine and method for adjusting the preload in a rotor bearing unit - Google Patents

Abstract

The invention relates to a rotor bearing unit (1) for a wind turbine comprising a sleeve-like inner connecting structure (2) which extends along a central axis (A), a sleeve-like outer connecting structure (3) arranged coaxially with the inner connecting structure (2) and two axial mutually spaced tapered roller bearings (4, 5) each having at least one inner bearing ring (6, 7') fastened to the inner connecting structure (2) and at least one outer bearing ring (8', 9') fastened to the outer connecting structure (3) , wherein at least one radially extending fastening flange (10, 11, 12, 13) with an axial fastening surface (14) is formed on the inner (2) and/or the outer connecting structure (3), and wherein the fastening flange (10, 11 , 12, 13) is assigned to one of the bearing rings (6, 7', 8', 9'), which has a first hole circle (16) through which the bearing ring (6 , 7′, 8′, 9′) is screwed to the axial fastening surface (14) of the fastening flange (10, 11, 12, 13) while introducing an axial prestress into the rotor bearing unit (1), and a method for adjusting the axial prestress in such a rotor bearing unit.

Description

Rotor bearing unit for a wind turbine and

Method of adjusting the preload in a rotor bearing unit

State of the art

The invention relates to a rotor bearing unit for a wind turbine according to the preamble of claim 1 and a method for setting an axial preload in a

Rotor bearing unit according to the preamble of claim 13.

Rotor bearings of wind turbines are used on the one hand to transmit the power torque from the rotating hub to a generator arranged in the nacelle.

The torque is transmitted either directly from the hub to the generator (in the so-called direct drive) or from the hub to an intermediate generator

Transmission as a torque-speed converter. On the other hand, the rotor bearings must be designed to be able to derive the reaction forces and torques that occur via the stationary components of the rotor bearing and the wind energy installation into the foundation of the wind energy installation.

Depending on the design of the wind turbine, the rotor bearing is designed with a rotating outer ring or with a rotating inner ring to which the hub is connected. The nacelle of the wind turbine is standing with the other

connected to the ring of the rotor bearing. Both grease and oil lubricated bearings with and without water cooling are known.

In order to meet the requirements of a rotor bearing, essentially two designs of rotor bearings are known. With the so-called torque bearing, as is known, for example, from WO 2012/136632 A1, the rotor is mounted via a single large roller bearing. In this design, the large roller bearing is usually designed either as a multi-row roller slewing ring or as a double tapered roller bearing, which due to their design are suitable for absorbing both the forces that occur and the moments. However, in order to ensure sufficient flexural rigidity for absorbing the moments that occur with a single bearing point, bearing rings with particularly large dimensions, in particular with high radial ring thicknesses, are required. Transport and assembly of the rotor bearings on site are correspondingly more difficult. The bearing rings are usually only surface-hardened in the area of the rolling element raceways. Which he-

The required high radial ring thickness can be used to introduce a bolt circle on which the bearing rings are each directly screwed to a connecting structure of the hub or the nacelle.

An alternative design for rotor bearings comprises at least two large roller bearings that are axially spaced apart from one another, the outer and inner bearing rings of which are each connected to one another via connecting structures. Adjusted tapered roller bearings or fixed-loose bearings can be used as roller bearings, for example. Bending moments introduced into the rotor bearing are transferred via the load-side roller bearing as the fulcrum and the connected connection structure to the load-remote roller bearing.

The connection structure acts like a lever to convert the acting moments into forces acting radially and/or axially on the bearing facing away from the load. This bearing concept, known as a so-called two-point or multi-point bearing, has the advantage of achieving sufficiently high flexural rigidity with comparatively small radial dimensions of the roller bearings used. With such a bearing, a case-hardened roller bearing steel is usually used for the bearing rings and for the connecting structures

Cast iron part used, on or in which the bearing rings are installed with the formation of an interference fit. The bearing rings are installed in a complex manner by thermal shrinking onto or into the associated connection structure. Removal of the bearing rings is only possible with considerable effort and requires the use of pressure oil, for example. Nevertheless, removing the bearing rings harbors the risk of damaging the bearing seats and thus destroying the entire rotor bearing unit. Overall the

Force transmission with shrunk-on roller bearing rings in the connection construction, which is usually designed as a cast component, is at risk of wear, setting and cracking.

In order to avoid complex assembly of the bearing rings by shrinking them on site, it is known from EP 2 710 271 B1, for example, to implement the two-point bearing concept in a ready-to-install rotor bearing unit, which is attached to the connecting constructions of the roller bearings, referred to there as the stator unit or rotor unit a flange to

Have connection to the machine frame or the hub of the wind turbine.

The disadvantage of this type of construction is that problems occur regularly, which result from what is known as ring creep and from a change in the axial prestressing of the rotor bearing unit.

Ring creep is a phenomenon that occurs with rings mounted in interference fit at high operating forces and moments and is amplified with large bearing diameters. The operational forces cause a local weakening of the interference fit due to bulging of the bearing ring and local displacement of the bearing ring in relation to the associated connection structure. Ring creep causes abrasion and corrosion in the

Favors the fit joint, making the problem self-reinforcing over time. Eventually, this can lead to bearing damage or failure of the entire rotor bearing assembly. A known measure for reducing ring creep is to increase the cross-section of the bearing rings in order to be able to generate a greater contact pressure in the fitting joint.

Due to the maximum specified by the wind turbine manufacturer

Available, radial space, the radial ring cross-section can only

Costs of the diameter and/or the length of the rollers used as rolling bodies are increased, which leads to a shorter service life of the rotor bearing unit, among other things due to the increased number of rollovers.

In the case of the known rotor bearing unit, the axial preload is an important variable that must be set with sufficient accuracy. If the axial preload is too low or if there is axial play, the rotor bearing unit loses its flexural rigidity, which can lead to shocks, axial thrust and also tilting under different wind loads, which means that subsequent components, such as the gearbox or generator, are subjected to higher loads and their service life and efficiency be negatively affected. Excessive preload has a negative effect on the load on the bearing components and the connection structures and also leads to increased bearing friction.

In the solution known from EP 2 710 271 B1, the axial preload is applied by a bearing clamping ring screwed to the stator unit on the bearing clamping ring mounted on the stator unit

inserted bearing ring. This setting of the preload is on the one hand imprecise and error-prone, because the locally generated axial preload is different from the prevailing im

Press fit of the bearing ring with the stator unit depends on the radial contact forces present.

It is also susceptible to changes due to settling during operation Settling in the compression of the bearing clamping ring can lead to a reduction in the axial preload. A further disadvantage of the known method for introducing an axial prestress by means of a prestressing ring is that the prestress achieved can generally only be determined by calculation from the geometric dimensions of the individual components. Due to the summation of the component tolerances, the mathematical determination of the prestress achieved is only imprecisely possible. A sufficiently accurate control measurement in the assembled state is also not possible.

Disclosure of Invention

The object of the invention is therefore to specify a rotor bearing unit for a wind turbine and a method for adjusting the axial preload in such a rotor bearing unit, which improves the accuracy of the adjustment of the axial preload,

Settling and the need for maintenance is reduced and the service life of the rotor bearing unit is increased.

This object is achieved by a rotor bearing unit having the features of claim 1.

This creates a rotor bearing unit for a wind turbine that includes a sleeve-like internal connection structure that extends along a central axis. The rotor bearing unit also includes a sleeve-like outer connecting structure arranged coaxially with the inner connecting structure and two tapered roller bearings arranged axially spaced apart from one another, each with at least one inner bearing ring secured to the inner connecting structure and at least one outer bearing ring secured to the outer connecting structure. On the inner and/or outer connecting structure is at least one radially extending

Mounting flange formed with an axial mounting surface. According to the invention, one of the bearing rings, which has a first hole circle, is assigned to the fastening flange. The bearing ring associated with the mounting flange is screwed to the axial mounting surface of the mounting flange by the bolt circle, introducing an axial prestress into the rotor bearing unit.

In the rotor bearing unit according to the invention, the inner and outer connection construction with the two tapered roller bearings form a preload circuit which is formed by mounting the

Mounting flange associated bearing ring is closed. The axial screw connection of the bearing ring causes both the attachment of the bearing ring to the connecting structure and the introduction of an axial preload determined by an undersize between the inner and outer connecting structure. By the same, axial

Direction of action of the fastening and the prestressing forces of the bearing ring is an exact setting of a predetermined axial prestressing, unaffected by radially acting fastening forces, as they occur, for example, when using a press fit

Attachment of the bearing ring may occur. This creates a ready-to-install rotor bearing unit with preloaded tapered roller bearings that is designed for the highest cyclic loads.

The bolted installation of the bearing ring is also advantageous because the mechanical fixing of the bearing ring makes ring creep impossible, so that ring creep is reliably avoided even under the highest loads. Corrosion on the mounting surface of the

Bearing ring and a resulting adjustment of the axial preload are thus reduced by the assembly of the rotor bearing unit according to the invention, as a result of which the susceptibility to maintenance of the rotor bearing unit is reduced and the service life is extended.

The screw connection is preferably designed to completely transmit the forces and moments acting on the screwed bearing ring via the tapered roller bearing of the screwed bearing ring during operation of the wind energy installation. The screw connection is therefore part of the flow of forces of the rotor bearing unit for deriving the operational forces of the wind energy installation into the tower or the foundation of the wind energy installation. Preferably, the screw connection forms the sole attachment of the bearing ring to the associated connection structure, as a result of which particularly simple assembly and disassembly of the bearing ring is made possible.

In preferred embodiments, the fastening flange is arranged at an axial end of the associated connection structure and the connection structure terminates in the axial direction with the axial fastening surface. In this case, the connection structure assigned to the screwed bearing ring ends at the radial one

Flange, so that the connection construction in particular does not have a section that encompasses the bearing ring or that supports it in the radial direction. The connecting structure, which is usually designed as a cast component, has a particularly simple design

Geometry that only needs to be finished to size in the area of the flat mounting surface. Furthermore, the overall height of the rotor bearing unit in the area of the tapered roller bearing is reduced in the radial direction to the radial dimension of the bearing ring. A structural height disadvantage, which arises from the reinforcement of the ring for the arrangement of the first hole circle, can thus be compensated for by dispensing with a section of the connection construction that encompasses the screwed bearing ring. With the same overall height, larger rollers can also be used as rolling bodies to optimize the service life of the rotor bearing unit. The rotor bearing unit is characterized by a particularly high static and dynamic load capacity, which is particularly advantageous for large hubs.

The bearing rings of the tapered roller bearings preferably have an inner diameter of more than 3 meters and particularly preferably of more than 5 meters.

Furthermore, the fastening flange is preferably arranged on the connecting structure on the side facing away radially from the respective other connecting structure. This arrangement of the mounting flange facilitates the assembly of the screwed bearing ring. Furthermore, embodiments of the rotor bearing unit with particularly low radial overall heights are possible in which the sleeve-like inner or outer connection construction has a larger inner or smaller outer diameter than the inner or

Has outer rings of tapered roller bearings. The sleeve-like base body of the connection construction preferably extends as an axial support between the bearing rings within their radial overall height.

To set a predetermined axial preload, the mounting surface of the

be made to measure and the bearing ring screwed directly to it. Alternatively, it is possible that an adapter ring for adjusting the axial preload of the rotor bearing unit is inserted in the screw connection between the mounting flange and the bearing ring. This has the advantage that during assembly and/or in the event of settling during operation, the axial preload can be adjusted by replacing or reworking the adapter ring without the

Rotor bearing unit must be completely dismantled.

In some embodiments, the tapered roller bearings are arranged in an O arrangement, the inner connecting structure is formed with at least one mounting flange which is bolted to the inner bearing ring of one of the two tapered roller bearings, and the remaining bearing rings are fastened to the respective associated connecting structure by means of a press fit. In this bearing arrangement, the screwing of the bearing rings within the preload circuit formed by the bearings and the connecting structures is provided on an inner bearing ring, through which the preload circuit is closed after assembly of the other components. This design combines the advantages of radially small, shrunken bearing rings with the simple and precise adjustment of the axial preload by screwing on the bearing ring that was screwed on last.

Alternatively, an X-arrangement of the tapered roller bearings is also conceivable, in which case at least one of the outer rings with the outer connection construction on the inventive

way is screwed.

In other embodiments, the tapered roller bearings are arranged in an back-to-back arrangement, the inner connecting structure is formed with two mounting flanges that are bolted to the inner races of the two tapered roller bearings, and the outer bearing rings are press-fitted into the outer connecting structure.

Alternatively, an X-arrangement of the tapered roller bearings is conceivable, in which case the two outer rings are screwed to the outer connecting structure in a manner according to the invention.

In further embodiments, the inner and the outer connecting structure are each formed with two fastening flanges, on which the inner and the outer

Bearing rings of the two tapered roller bearings are screwed. As a result, both bearing rings of the two tapered roller bearings are screwed to the connecting constructions and the time-consuming, close-tolerance machining of mating surfaces for a press fit and the assembly of bearing rings by means of a press fit, for example by thermal shrinking, can be completely dispensed with. This enables easy installation and removal of the bearing rings, if necessary also in the field.

Another advantage of using at least one, preferably two, fully bolted tapered roller bearings is the modular design. The connecting constructions and the tapered roller bearings are connected to each other via bolt circles as standardized interfaces and can be selected separately from one another and adapted to the respective application. In the case of further developments of the rotor bearing unit, no new casting models need to be created for the connection constructions, even if there are changes to the bearing rings used, as long as the bolt circle remains unchanged. In this way, bearings with different support angles, longer ones can be used in a simple way

Rollers, larger diameters, etc. can be used without changing the connection construction. Conversely, the bearing spacing can be adjusted for the same tapered roller bearings by using longer or shorter connecting structures. The prerequisites for the simple construction of a modular system for different

Turbine types are thus given.

Preferably, the one bolted to the inner or outer connecting structure

Bearing ring on an additional bolt circle for attachment of the rotor bearing unit in a - wind turbine. For the introduction of the additional pitch circle, the bolted bearing ring has an increased radial overall height, which strengthens the bearing ring and the

Bending stiffness of the rotor bearing unit increased.

The object is also achieved by a wind turbine with a tower, one on which

Tower-mounted nacelle and a rotor attached to the nacelle, the rotor on the

Gondola is rotatably mounted on a rotor bearing unit according to the invention. The inventive

current rotor bearing unit can be delivered in particular as a ready-to-install unit and in the

Wind turbine be mounted by screwing with nacelle and rotor.

In preferred embodiments, the nacelle and the rotor each have a connection structure for mounting the rotor bearing unit and the rotor bearing unit is attached to the nacelle and/or the rotor by screwing the attachment flange to the associated bearing ring. The screws of the screw connection extend through the mounting flange, the bearing ring and the mounting holes in the respective adjacent construction. In this case, the screw connection of the bearing ring to the connection structure is used to fasten the rotor bearing unit to the associated connection structure. The screw connection thus not only transmits the operational forces within the rotor bearing unit, but at the same time provides the transmission of the forces to the adjacent components of the wind energy installation.

In some embodiments, the nacelle and the rotor have a connection structure for mounting the rotor bearing unit and the rotor bearing unit is attached to the nacelle and/or the rotor by means of a second screw connection of the respective connection structure to a second bolt circle of the bearing screwed to the connection structure - fixed around.

In terms of the method, the object is achieved by a method for setting an axial preload in a rotor bearing unit according to the invention, in which the axial preload of the rotor bearing unit is determined and, if there is a deviation from a target range, by installing at least one adapter ring in the screw connection between the mounting flange and the bearing ring or adjusted to the target range by reworking the mounting surface. Since the axial fastening surface of the fastening flange not only forms an anchoring point for the bearing ring, but also through its axial positioning

influences the axial preload of the rotor bearing unit, the axial preload can be adjusted by simply reworking the fastening surface and/or inserting a suitable adapter ring

Preload of the bearing unit can be adjusted. The matching adapter ring can, for example, be selected from a set of prefabricated adapter rings with different thicknesses or put together as a ring package from the set of prefabricated adapter rings. This saves reworking and saves time during assembly.

Provision is preferably made for the prestressing to be carried out in a partially assembled state of the rotor bearing unit before assembly of the screwed bearing ring to be assembled last

Measuring an axial distance between two reference surfaces is determined. The reference surfaces are on the mounting flange and the other bearing

ring of the tapered roller bearing, which is formed by mounting the bolted bearing ring. By measuring the partially assembled rotor bearing unit, the

Determination of the axial preload is particularly accurate, since no mathematical

Tolerances must be taken into account, but the actual values of the partially assembled

Rotor bearing unit can be used. In particular, taking into account the fact that the connection constructions, which are usually made as cast parts, are manufactured with significantly larger tolerances compared to the bearing ring to be screwed last, by far the largest part of the influencing factors on the axial preload are taken into account when measuring in the partially assembled state .

Alternatively or additionally, the axial preload in the assembled state

Rotor bearing unit introduced as a rolling element in one of the tapered roller bearings

Measuring roller are recorded depending on the circumferential angle of the tapered roller bearing.

Measuring rollers used as rolling elements are designed to detect the load on the measuring roller in the bearing depending on the position. When measuring the rotor bearing unit when there is no load, the variance of the measured values over one revolution can be used to infer an uneven axial preload. While deployed in a

In particular, time-dependent changes in the measured values at the same position can indicate a change in the axial prestress that has occurred during operation, which can necessitate a renewed adjustment of the axial prestress.

Alternatively or additionally, the axial preload in the assembled state

Rotor bearing unit using strain gauges and / or measuring washers on the

Screw connection can be determined by a differential measurement over time.

Further advantageous embodiments can be found in the following description and the dependent claims.

The invention is illustrated below with reference to the attached figures

Examples explained in more detail.

Brief description of the drawings

1 schematically shows a wind energy plant according to the invention, the rotor of which is rotatably mounted on the nacelle via a rotor bearing unit according to the invention,

Fig. 2 shows schematically a first embodiment of the invention

Rotor bearing unit with two tapered roller bearings, one of the inner bearing rings with the inner connection construction with the insertion of a

adapter ring is screwed,

Fig. 3 shows schematically a second embodiment of the invention

Rotor bearing unit, with the inner and outer bearing rings of the tapered roller bearings being bolted to the associated inner or outer connecting structure,

Fig. 4 shows schematically a third embodiment of the invention

Rotor bearing unit, where the inner bearing rings of both tapered roller bearings are bolted to the inner connecting structure,

5 schematically shows a variant of the exemplary embodiment according to FIG. 3, in which the bearing ring screwed to the outer connecting structure has an additional hole circle for attachment to a connecting structure of a wind energy plant.

Embodiments of the invention

In the various figures, the same parts are always provided with the same reference symbols and are therefore usually named or mentioned only once.

1 shows a wind energy installation 100 with a tower 110, a nacelle 120 fastened to the tower 110 and a rotor 130 fastened to the nacelle 120. FIG. The rotor 130 is rotatably mounted on the nacelle 120 via a rotor bearing unit 1 according to the invention, as is described in more detail below with regard to the exemplary embodiments shown in FIGS.

FIG. 2 shows a first exemplary embodiment of the rotor bearing unit 1 according to the invention for a wind turbine 100 (cf. FIG. 1). The rotor bearing unit 1 comprises a sleeve-like inner connection structure 2 extending along a central axis A, a sleeve-like outer connection structure 3 arranged coaxially with the inner connection structure 2 and two tapered roller bearings 4, 5 arranged axially spaced apart from one another in each case at least one inner bearing ring 6, 7' fastened to the inner connecting structure 2 and in each case at least one outer bearing ring 8', 9' fastened to the outer connecting structure 3. A radially extending attachment flange 10 with an axial attachment surface 14 is formed on the inner connecting structure 2 . The mounting flange 10 is a bearing ring 6 of the bearing rings 6, 7 ', 8',

9', which has a first pitch circle 16. The bearing ring 6 assigned to the fastening flange 10 is screwed through the hole circle 16 to the axial fastening surface 14 of the fastening flange 10 with the introduction of an axial prestress in the rotor bearing unit 1 .

The tapered roller bearings 4, 5 are arranged in FIG. 2 in an O arrangement. The inner connecting structure 2 is designed with a fastening flange 10, which is screwed to the inner bearing ring 6 of one of the two tapered roller bearings 4, and the remaining bearing rings 7', 8', 9' are press-fitted to the associated connecting structure 2 , 3 attached. If only one bearing ring is screwed to the assigned connection structure in the rotor bearing unit 1, the upwind-side bearing ring on the stationary connection structure is preferably selected for the screw connection because experience has shown that it is particularly at risk of being subject to ring migration. In the preferred O

Arrangement of the tapered roller bearings, this is the upwind inner ring 6.

The bearing ring 6 is screwed like all described within the scope of this disclosure

Bearing rings 6, 7, 8, 9 are preferably made of an inductively hardenable rolling bearing steel, for example 42CrMo4, and have an inductively hardened bearing raceway for the rolling elements 22. On the shrunken bearing rings 7', 8', 9', the bearing raceways are usually case-hardened together with the entire surface. In this case, inductive hardening of the raceways would lead to hardening distortion that is no longer tolerable due to the small ring cross-section. The use of inductively hardenable roller bearing steels for the bolted bearing rings 6, 7, 8, 9 has the advantage of better machinability, which means that the bolt circle 16, for example, can be introduced more easily. Inductively hardenable roller bearing steels, in particular 42CrMo4, have both high static and dynamic strengths and high notched impact strengths, so that high cyclic strengths can be achieved in the bearing areas of the rotor bearing unit 1.

The screw connection of the bearing ring 6 is designed to completely transmit the forces and moments acting on the screwed bearing ring 6 via the tapered roller bearing 4 of the screwed bearing ring 6 during operation of the wind energy installation 100 (cf. FIG. 1).

As shown in FIG. 2, the fastening flange 10 is preferably arranged at an axial end of the associated connection structure 2 and the connection structure 2 terminates with the axial fastening surface 14 in the axial direction.

The fastening flange 10 is preferably arranged on the connecting structure 2 on the side radially facing away from the respective other connecting structure 3 . A

Accordingly, the fastening flange on the inner connecting structure 2 preferably extends radially inwards and a fastening flange on the outer connecting structure 3 preferably extends radially outwards.

As also shown in FIG. 2, an adapter ring 15 for adjusting the axial prestressing of the rotor bearing unit 1 can be inserted in the screw connection between the fastening flange 10 and the bearing ring 6 .

The inner and/or the outer connecting structure 2, 3 can also have functional attachments 27. This can, for example, be a flange for connection to the rotor of a generator or to a gearbox input on the rotating

Act connection construction of the rotor bearing unit. Another functional add-on can be, for example, a locking device, by means of which a relative movement of the outer and inner connecting structure to one another can be blocked mechanically.

3 shows a second exemplary embodiment of the rotor bearing unit 1 according to the invention. In this embodiment, the inner connecting structure 2 and the outer connecting structure 3 are each provided with two mounting flanges 10, 11; 12, 13 trained. At the mounting flanges 10, 11; 12, 13, the inner bearing rings 6, 7 and the outer bearing rings 8, 9 of the two tapered roller bearings 4, 5 are screwed.

In a wind turbine 100 (cf. FIG. 1), its nacelle 120 and rotor 130 each have one

Having connection construction 160, 170 for the assembly of the rotor bearing unit 1, the rotor bearing unit 1 can be attached to the nacelle 120 and/or the rotor 130 by screwing the attachment flange 11, 12 to the associated bearing ring 7, 8, with screws 18 of the screw through the mounting flange 11, 12, the

Bearing ring 7, 8 and mounting holes 19 in the respective attachment structure 160, 170 extend. By using the same screw 21 to attach the

Bearing rings on the connection construction and the adjacent construction become more radial

Space and production costs saved.

Due to the exclusive use of screwed bearing rings 6, 7, 8, 9, the geometry of the connection structures 2, 3 is simplified in this exemplary embodiment.

An inner and an outer ring stack is formed from two bearing rings and the inner or outer connecting structure 2, 3 arranged between them by axial screwing. It can thus simple cast models for the connection structures 2, 3 with

Standard bearings or ready-to-install sealed bearings can be combined, which means that developments for new turbine generations can be implemented more quickly. Furthermore, the axial dimensions of the connecting structures 2, 3 on the area between the

Tapered roller bearings 4, 5 reduced, which brings advantages in manufacturing, logistics, assembly and the quality of the cast components. All of the bearing rings 6 , 7 , 8 , 9 can be easily assembled and disassembled without endangering the rotor bearing unit 1 . On both sides of the bearing rings, rings or adjoining constructions can be made of any

material are used. In order to prevent radial displacement of the bearing rings in the screw connection, the axial ring contact surfaces can be blasted and/or coated to increase the coefficient of friction.

Otherwise, the explanations for the first exemplary embodiment apply accordingly.

Fig. 4 shows a third exemplary embodiment of the rotor bearing unit according to the invention, in which the tapered roller bearings 4, 5 are arranged in an O arrangement, the inner connecting construction 2 is designed with two fastening flanges 10, 11, which are connected to the inner bearing rings 6, 7 of the two tapered roller bearings 4, 5 are screwed, and the outer bearing rings 8', 9' are fastened in the outer connecting structure 3 by means of a press fit.

For the rest, the comments on the first and second exemplary embodiment apply accordingly.

Fig. 5 shows a variant of the second embodiment, in which the outer

Connection structure 3 bolted bearing ring 8 a second pitch circle 17 for a

Fastening the rotor bearing unit 1 in a wind turbine 100 (see FIG. Fig. 1). In the case shown, the second bolt circle 17 is used to fasten the rotor bearing unit 1 to the connecting structure 160 of the hub 150. Depending on the position of the bolted

Bearing ring 6, 7, 8, 9 in the rotor bearing unit and of the wind turbine type, the second pitch circle 17 can also be provided on a bolted inner bearing ring 6, 7 and/or can be used for attachment to the other connecting structure 170.

With the variant shown in FIG. 5, a wind energy plant 100 is created with a rotor bearing unit 1, in which the nacelle 120 and the rotor 130 each have a connecting structure 160, 170 for mounting the rotor bearing unit 1 and the rotor bearing unit 1 on the nacelle 120 and/or the rotor 130 by means of a second screw

Exercise 20 of the respective connecting structure 160, 170 is attached to the second bolt circle 17 of the bearing ring 8 screwed to the connecting structure 3.

A separate second bolt circle 17 for connection to the connecting structure 160, 170 offers particular advantages in terms of flexibility when designing the connecting structure 160, 170, since the rotor bearing unit 1 can be more easily adapted to a given bolt circle of the connecting structure 160, 170. Furthermore, the assembly of the rotor bearing unit 1 can be simplified by a separate circle of holes 17 and the guidance of the power flow under operational loads can be optimized.

The assembly of the rotor bearing unit takes place in the O shown in Figures 2 to 5

Arrangement of the tapered roller bearings 4, 5 in the following steps:

First, the bearing rings 7 or 7', 8 or 8' and 9 or 9' are fastened to the associated connection structures 2, 3. For this purpose, if present, the bearing rings 7', 8', 9' to be fastened with a press fit are first mounted on the associated connection structure 2, 3 by thermal shrinking. For the correct axial positioning of the bearing rings, shaft shoulders are provided on the connecting structures 2, 3, which form mechanical stops for the bearing rings 7', 8', 9'. The mechanical stops are each positioned on the side of the bearing ring 7', 8', 9' so that they can absorb the forces acting on the bearing ring 7', 8', 9' under the effect of the axial preload.

If necessary, the bearing rings 7', 8', 9' that are shrunk on or shrunk can each be additionally secured by retaining rings 26.

The remaining bearing rings 7, 8, 9 are screwed to the associated flange 11, 12, 13 of the associated connecting structure 2, 3. For this purpose, screws are passed through the bolt circle 16 of the bearing ring 7, 8, 9 and holes in the mounting flange 11, 12, 13. Insofar as the screw connection is also intended to serve to fasten the rotor bearing unit 1 to the connecting structure 160, 170 of the hub 150 or nacelle 120,

Factory initially used a smaller number of mounting screws, which are then at

Mounting the rotor bearing unit 1 in the wind turbine on site can be replaced by the screws 18. Separate bores (not shown) can also be provided in the bearing ring and connection construction for the assembly screws.

The connection structures 2, 3 with the mounted bearing rings 7, 8, 9 are then guided into one another and the rolling elements 22 of the rolling bearing 5 are inserted.

The axial preload in the rotor bearing unit 1 is now set by determining the axial preload of the rotor bearing unit 1 and, if there is a deviation from a target range, by installing an adapter ring 15 in the last screw connection 21 between the mounting flange 10 and the bearing ring 6 or by reworking the mounting surface 14 is set within the target range.

In the described partially assembled state of the rotor bearing unit 1, the axial prestressing is carried out before assembly of the bearing ring 6 which is screwed on last and is to be assembled

Measurement of an axial distance D from two reference surfaces F1, F2, which are arranged on the mounting flange 10 and the already installed, other bearing ring 8 of the tapered roller bearing 4, which is formed by installing the screwed bearing ring 6. The preload results from the O-arrangement of the tapered roller bearings, taking into account the geometric dimensions of the last to be mounted

Bearing ring 6 remaining axial undersize of the inner components 2, 6, 7 of the rotor bearing unit 1 compared to the outer components 3, 8, 9.

The reference surface F1 is preferably formed by the fastening surface 14 on the fastening flange 10 assigned to the bearing ring 6 to be fitted last, and the reference surface F2 is one of the end faces of the other bearing ring 8. The distance D between the reference surfaces F1, F2 is also preferably measured several points distributed over the circumference of the rotor bearing unit 1 or continuously over the circumference. Depending on the position, the fastening surface 14 can be reworked or the adapter ring 15 can be manufactured.

After the fastening surface 14 has been reworked and/or the adapter ring 15 has been inserted, the rotor bearing unit 1 can be finally assembled by assembling the last bearing ring 6 .

The axial preload in the rotor bearing unit 1 can also be monitored after final assembly and/or during operation and readjusted if necessary. For this purpose, the axial preload in the assembled state of the rotor bearing unit 1 can preferably be as a

Rolling elements 22 in one of the tapered roller bearings 4, 5 introduced measuring roller 23 depending on the circumferential angle of the tapered roller bearing 4, 5 are included.

Alternatively or additionally, the axial preload in the assembled state

Rotor bearing unit 1 are determined by means of strain gauges 24 and / or measuring washers 25 on the screw by a differential measurement over time. For this purpose, after the rotor bearing unit has been installed in the wind energy installation 100, at least one reference measurement is taken under load. The results of later measurements with a comparable load situation can then be compared with the reference measurement. If the deviations exceed a permissible maximum, the axial preload is reset/readjusted.

All of the embodiments shown in the figures can be within the scope of

Also carry out the knowledge of a specialist with an X-arrangement of the tapered roller bearings.

In the case of an X arrangement, the bearing ring that is screwed on last is to be fastened to the outer connecting structure.

Furthermore, the person skilled in the art is aware that the solutions presented in the figures for both internally rotating and externally rotating rotor bearing units with a fat or a

Oil lubrication can be used. For this purpose, suitable sealing systems on the

provide tapered roller bearings of the rotor bearing unit.

LIST OF REFERENCE NUMERALS 1 rotor bearing unit 2 inner connecting structure 3 outer connecting structure 4,5 tapered roller bearing 6,7,7' inner bearing ring 8,8,9,9' outer bearing ring 10,11,12,13 fastening flange 14 fastening surface

Adapter ring 16 first circle of holes 17 second circle of holes 18 screws 15 19 fastening bores 20, 21 screw connection 22 rolling element 23 measuring roller 24 strain gauges

Measuring washer 26 Circlip 27 Functional attachment 100 Wind turbine 25 110 Tower 120 Nacelle 130 Rotor 140 Rotor blade 150 Hub 160 Connection structure of the hub 170 Connection structure of the nacelle

A Axis of the rotor bearing unit

D distance

F1, F2 reference surface

Claims (16)

_ BE2021/5740 PATENT CLAIMS 1. Rotor bearing unit for a wind turbine (100) comprising a sleeve-like inner connection structure (2) which extends along a central axis (A), a sleeve-like outer connection structure (3) arranged coaxially with the inner connection structure (2) and two tapered roller bearings (4, 5) arranged axially spaced apart, each with at least one inner bearing ring (6, 7, 7°) fastened to the inner connecting structure (2) and at least one outer bearing ring fastened to the outer connecting structure (3). Bearing ring (8, 8', 9, 9°), on the inner (2) and/or the outer connecting structure (3) at least one radially extending fastening flange (10, 11, 12, 13) with a axial fastening surface (14), characterized in that the fastening flange (10, 11, 12, 13) is assigned one of the bearing rings (6, 7, 8, 9) which has a first hole circle (16) through which the the bearing ring (6, 7, 8, 9) assigned to the mounting flange (10, 11, 12, 13) while introducing an axial preload into the rotor bearing unit (1) on the axial mounting surface (14) of the mounting flange (10, 11 , 12, 13) is screwed. 2. Rotor bearing unit according to claim 1, characterized in that the screwing is designed to the operation of the wind turbine (100) on the tapered roller bearings (4, 5) of the screwed bearing ring (6, 7, 8, 9). to fully transmit the forces and moments acting on the screwed bearing ring (6, 7, 8, 9). 3. Rotor bearing unit according to claim 1 or 2, characterized in that the fastening flange (10, 11; 12, 13) is arranged at an axial end of the associated connection structure (2; 3) and the connection structure (2; 3) ends with the axial fastening surface (14) in the axial direction. 4. Rotor bearing unit according to one of claims 1 to 3, characterized in that the fastening flange (10, 11, 12, 13) on the connecting structure (2; 3) on the side facing away radially from the other connecting structure (3; 2). - is ordered. 5. Rotor bearing unit according to one of claims 1 to 4, characterized in that in the screw connection between the mounting flange (10, 11, 12, 13) and the bearing ring (6; 7; 8; 9) an adapter ring (15) for Setting the axial preload of the rotor bearing unit (1) is inserted. 6. Rotor bearing unit according to one of claims 1 to 5, characterized in that the tapered roller bearings (4, 5) are arranged in an O arrangement, the inner connection construction (2) with at least one mounting flange (10, 11) is formed, the one of the two tapered roller bearings (4; 5) is screwed to the inner bearing ring (6; 7), and the other bearing rings (7; 6, 8, 9) are fastened to the assigned connection structure (2, 3) by means of a press fit . 7. Rotor bearing unit according to one of claims 1 to 6, characterized in that the tapered roller bearings (4, 5) are arranged in an O arrangement, the inner connection construction (2) with two mounting flanges (10, 11) is formed with the inner bearing rings (6, 7) of the two tapered roller bearings (4, 5) are screwed, and the outer bearing rings (8, 9) are fastened in the outer connecting structure (3) by means of a press fit. 8. Rotor bearing unit according to one of claims 1 to 6, characterized in that the inner (2) and the outer connecting structure (3) are each formed with two fastening flanges (10, 11; 12, 13) on which the inner ( 6, 7) and the outer bearing rings (8, 9) of the two tapered roller bearings (4, 5) are screwed together. 9. Rotor bearing unit according to one of claims 1 to 8, characterized in that the bearing ring (6, 7; 8, 9) screwed to the inner (2) or outer connecting structure (3) has a second bolt circle (17) for attachment the rotor bearing unit (1) in a wind turbine (100). 10. Wind energy installation with a tower (110), a nacelle (120) attached to the tower and a rotor (130) attached to the nacelle (120), characterized in that the rotor (130) is attached to the nacelle (120) is rotatably mounted via a rotor bearing unit (1) according to one of claims 1 to 9. 11. Wind power plant according to claim 10, characterized in that the nacelle (120) and the rotor (130) have a connecting structure (160, 170) for the assembly of the rotor bearing unit (1) and the rotor bearing unit (1) on the nacelle (120) and/or the rotor (130) is attached to the associated bearing ring (6, 7, 8, 9) by means of the screw connection of the attachment flange (10, 11, 12, 13), with screws (18) of the screw connection passing through the attachment flange ( 10, 11, 12, 13), the bearing ring (6, 7, 8, 9) and fastening bores (19) in the respective adjacent construction (160, 170). 12. Wind power plant according to claim 10 with a rotor bearing unit (1) according to claim 9, characterized in that the nacelle (120) and the rotor (130) have a connection construction (150, 160) for the assembly of the rotor bearing unit (1) and the rotor bearing unit (1) on the nacelle (120) and/or the rotor (130) by means of a second screw connection (20) of the respective connection structure (160, 170) on the second hole circle (17) of the connection structure (2, 3) bolted bearing ring (6, 7, 8, 9). 13. A method for setting an axial preload in a rotor bearing unit (1) according to one of claims 1 to 9, characterized in that the axial preload of the rotor bearing unit (1) is determined and, if it deviates from a target range, by installing at least one adapter ring (15) in the screw connection (21) between the mounting flange (10, 11, 12, 13) and the bearing ring (6, 7, 8, 9) or by reworking the mounting surface (14) within the specified range. 14. The method according to claim 13, characterized in that the prestressing in a partially assembled state of the rotor bearing unit (1) before assembly of the last bolted bearing ring (6, 7, 8, 9) to be assembled by measuring an axial distance (D) of two Reference surfaces (F1, F2) is determined on the fastening flange (10, 11, 12, 13) and the already mounted, other bearing ring (7, 6, 9, 8) of the tapered roller bearing (4, 5), which by the assembly of the screwed bearing ring (6, 7, 8, 9) is formed, are arranged. 15. The method according to claim 13 or 14, characterized in that the axial bias in the assembled state of the rotor bearing unit (1) by a rolling element (22) in one of the tapered roller bearings (4, 5) introduced measuring roller (23) depending on Circumferential angle of the tapered roller bearing (4, 5) is added. 16. The method according to any one of claims 13 to 15, characterized in that the axial bias in the assembled state of the rotor bearing unit (1) by means Strain gauges (24) and/or measuring washers (25) on the screw connection is determined by a differential measurement over time.