Bearing assembly, in particular for wind turbines

Abstract

The invention relates to a bearing assembly 10, comprising a shaft element 12, a housing element 14, a first rolling bearing 20 having an inner ring 22 and an outer ring 24, a second rolling bearing 30 having an inner ring 32 and an outer ring 34, wherein the two rolling bearings are arranged with respect to one another so as to form an O-arrangement and support the shaft element with respect to the housing element in a rotatable manner about a rotational axis Ao, a distance structure which sits between the outer rings of the rolling bearings, and a grooved nut 42 which can be screwed onto the shaft element and indirectly against the inner ring of one of the two rolling bearings to produce a bearing play and / or bearing preload. A distance element is provided between the grooved nut and the inner ring. The grooved nut sets the distance element in an axial position with respect to the shaft element.

Description

[0001] Bearing arrangement, especially for wind turbines

[0002] Description

[0003] The invention relates to a bearing arrangement comprising a shaft element, a housing element, a first rolling bearing with an inner ring and an outer ring, a second rolling bearing with an inner ring and an outer ring, wherein the two rolling bearings are arranged to form an adjusted bearing arrangement and support the shaft element relative to the housing element so as to be rotatable about a rotation axis AD, a spacer structure seated between the outer rings of the rolling bearings and a groove nut which can be screwed onto the shaft element and indirectly against the inner ring of one of the two rolling bearings in order to generate a bearing clearance and / or a bearing preload.

[0004] Bearing assemblies are shown in EP 3 650 689 A1, DE 10 2020 133 993 A1 and DE 10 2013 226 519 A1. Bearing assemblies are used in gearbox construction and are subject to increasing demands, particularly in the drive trains of wind turbines. This applies both to the loads during operation and the requirement for assembly and adjustment, namely to carry out these quickly and precisely. Indirect adjustment methods for bearing assemblies exist, but these are associated with high levels of uncertainty. Furthermore, axial preloads of bearing assemblies cannot be directly measured in the form of geometric dimensions. It is common practice to specify a desired preload and, based on this, calculate the axial width of the spacers between the bearing rings, manufacture the spacers as calculated, and then assemble the bearings including the spacers.It cannot always be guaranteed that the specified preload will be achieved.

[0005] The bearing preload is adjusted using a spacer between the inner rings and a split spacer between the outer rings of the bearings. The inner rings are secured against rotation by axial clamping using the spacer. The axial clamping force is applied via a locknut screwed onto the hollow shaft. The outer spacer is secured against the hollow shaft housing by a radially inserted anti-rotation device, and the bearing outer rings are secured against the outer spacer by a key.

[0006] The bearing clearance or bearing preload is adjusted by adjusting the outer spacer. The size of the inner spacer can be determined in advance by measuring the individual components. The bearing preload is adjusted by adjusting the axial width of the inner spacer in relation to the axial width of the outer spacer. First, the bearing arrangement is pre-assembled with a temporary outer spacer, which creates a measurable bearing clearance. After measuring the bearing clearance, the outer spacer must be mechanically adjusted. For this, the pre-assembled assembly must be disassembled again. Due to the heating required to join the bearings to the hollow shaft and the temperature dependence of the resulting clearance, a time-consuming cooling process is necessary between assembly and measurement to ensure that the components are at the same temperature.In addition, there is the problem that the bearing inner rings move on the shaft, which in particular involves a relative rotation between the bearing inner ring and the shaft, but can also result in axial movement with loss of bearing preload.

[0007] There is therefore a constant need for a high-performance bearing assembly that is precisely adjustable, quickly assembled, and cost-effective to manufacture. The invention is based on the object of providing a technical solution that offers an improvement in at least one of the aforementioned aspects.

[0008] The object is achieved by a bearing arrangement having the features of claim 1. Preferred embodiments are specified in the subclaims and the following description, each of which, individually or in combination, may represent an aspect of the invention. If a feature is presented in combination with another feature, this merely serves to simplify the presentation of the invention and is in no way intended to imply that this feature cannot also be a further development of the invention without the other feature.

[0009] One embodiment relates to a bearing arrangement comprising a shaft element, a housing element, a first rolling bearing with an inner ring and an outer ring, a second rolling bearing with an inner ring and an outer ring, wherein the two rolling bearings are arranged to form an adjusted bearing arrangement and support the shaft element relative to the housing element so as to be rotatable about a rotation axis AD, a spacer structure seated between the outer rings of the rolling bearings and a locknut which can be screwed onto the shaft element and indirectly against the inner ring of one of the two rolling bearings to generate bearing clearance and / or bearing preload, wherein at least one key is provided between the inner rings of the rolling bearings and the shaft element in order to secure the inner rings against rotation relative to the shaft element.

[0010] In this case, the axis of rotation AD defines the axial direction, so that the respective radial directions arise from this axial direction. The shaft element can be designed as a hollow shaft, depending on the underlying configuration. In this configuration, the shaft element can be positively connected via a spline to a sun shaft of a planetary stage, which is arranged upstream in the torque flow. The hollow shaft element can centrally accommodate a pitch tube through which electrical and / or hydraulic lines are routed. The housing element can be a flange section of the entire gearbox housing, whereby this flange section is set against the main gearbox housing part and is closed on the other side with a cover element. The cover element can provide passages for one or more gearbox shafts.

[0011] The two rolling bearings, arranged in an O-arrangement, can be designed as spherical roller bearings, tapered roller bearings, angular contact ball bearings, or spherical roller thrust bearings. Such rolling bearings advantageously allow axial loads on the outer ring or inner ring to be transmitted as compressive loads to the inclined rolling elements and then transferred to the inner ring or outer ring, respectively. This allows the axial force exerted on the bearing arrangement to be permanently and reliably transmitted from the inner ring to the outer ring, or vice versa.

[0012] In a preferred embodiment of the bearing assembly, a spacer element is provided between the grooved nut and the inner ring, wherein the shaft element and the spacer element each form opposing contact shoulders, and the grooved nut fixes the spacer element in an axial position relative to the shaft element. By using a key for circumferentially securing the inner rings, an inner spacer element located between the inner rings can be omitted. This eliminates the need for a component that, in the conventional bearing assembly, had to be manufactured with high-precision manufacturing quality and a high degree of fit.

[0013] In a further preferred embodiment, the outer spacer structure is designed as an integral radial collar of the housing element. This also eliminates the need for a separate component in this area, reducing the number of parts and simplifying assembly. In a further advantageous embodiment, the spacer structure extends in the radial direction to the shaft element, forming a radial gap, and an oil supply channel running in the radial direction is formed in the spacer structure and the shaft element. Furthermore, in an advantageous development, at least one feather key can be provided between the outer rings of the rolling bearings and the housing element, to secure the outer rings relative to the housing element against relative rotation of the two components.

[0014] In a further preferred embodiment, the contact shoulder of the spacer element is arranged radially within an outer diameter of the hollow shaft element. This means that the hollow shaft element supports the inner rings of the rolling bearings on the outer diameter and forms a complementary contact shoulder to the contact shoulder of the spacer element, at which the hollow shaft element reduces to a second, smaller outer diameter.

[0015] The object is also achieved by a method for assembling a bearing arrangement according to one of the preceding claims between a housing element and a shaft element, in which a preliminary assembly of the shaft equipped with the bearing arrangement takes place within the housing, a dimension of an axial play between the inner ring and the spacer element is determined, after disassembly of the grooved nut and the spacer element a final assembly with the bearing arrangement takes place, wherein the spacer element has an axial width dimension adapted by the determined dimension of the axial play compared to the preliminary assembly.

[0016] In a preferred embodiment of the method, before final assembly, a shoulder of the spacer element to be positioned between the grooved nut and the hollow shaft element is adjusted in its axial width dimension by the specific amount of axial play.

[0017] The object is further achieved by a drive train for a wind turbine, comprising a hollow shaft assembly for the torque-transmitting connection of a multi-blade rotor to a generator, wherein the hollow shaft assembly comprises a bearing arrangement according to one of the preceding claims. A particularly preferred embodiment includes a gearbox housing comprising the hollow shaft assembly, which comprises a flange on the generator side for connecting the generator, wherein the housing element of the bearing arrangement is connected to the gearbox housing via a screw connection.

[0018] The object is also achieved by a wind turbine comprising a nacelle to which a multi-blade rotor and a generator are rotatably mounted, wherein the multi-blade rotor is connected to the generator via a drive train in a torque-transmitting manner and the drive train is designed as previously described.

[0019] The invention will be explained below by way of example with reference to the accompanying drawings using preferred embodiments, wherein the features presented below can represent an aspect of the invention both individually and in combination. They show:

[0020] Fig. 1 : a longitudinal section through a conventional bearing arrangement,

[0021] Fig. 2: a longitudinal section through an embodiment of a claimed bearing arrangement, Fig. 3: a detail of the bearing arrangement according to Fig. 2 and Fig. 4: a perspective view of a wind turbine.

[0022] Figure 1 schematically shows an embodiment of a conventional bearing assembly 10 in an assembled state. The bearing assembly 10 has a first rolling bearing 20 and a second rolling bearing 30. The bearing assembly 10 is arranged in a housing element 12. A shaft element 14 is held in the housing element 12 via the bearing assembly 10 so as to be rotatable about a rotation axis Ad. The shaft element 14 is designed as a hollow shaft in the present case. The assembly comprising the housing element 12, the shaft element 14, the bearing assembly 10, and other components can be referred to as a hollow shaft assembly. As will be described later, the hollow shaft assembly can drive a transmission to a generator. The first rolling bearing 20 comprises an inner ring 22, an outer ring 24, and rolling elements 23 arranged therebetween. Correspondingly, the second rolling bearing 30 also comprises an inner ring 32, an outer ring 34, and rolling elements 33 arranged therebetween.The first and second rolling bearings 20, 30 are arranged in an O-arrangement to one another. In the first and second rolling bearings 20, 30, the respective outer ring 24, 34 serves as a stationary component, since they are held in the housing element 12 in a rotationally fixed manner when assembled. Correspondingly, the inner rings 22, 32 of the first and second rolling bearings 20, 30 each represent rotating components. A first spacer sleeve 56 is seated between the inner rings 22, 32 of the two rolling bearings 20, 30, and a second spacer sleeve 58 is seated between the outer rings 24, 34 of the two rolling bearings 20, 30. The two inner rings 22, 32 are held axially spaced apart by the first spacer sleeve 56, and the two outer rings 24, 34 are held axially spaced apart by the second spacer sleeve 58.

[0023] The two inner rings 22, 32 of the rolling bearings 20, 30 sit with a fit on the shaft element 14. To secure against relative rotation between the inner rings 22, 32 and the shaft element 14, a grooved nut 42 is screwed onto the end of the shaft element 14, which nut applies an axial force to both inner rings 22, 32 and the seated first spacer sleeve 56 against a shaft shoulder 26. When the bearing arrangement is mounted on the shaft element 14 and in the housing element 12, the two outer rings 24, 34 of the rolling bearings 20, 30 also sit with a fit in a receiving bore 28 of the housing element 12. An axial force is applied via a housing cover 16, which applies the two outer rings 24, 34 and the seated second spacer sleeve 58 against a housing shoulder 18. This initially provides protection against relative rotation between outer rings 24, 34 and the housing element 12.

[0024] Figure 2 schematically shows an embodiment of a claimed bearing assembly 10 in an assembled state. The bearing assembly 10 of Figure 2 corresponds in its basic structure to the bearing assembly described for Figure 1 and is described below essentially with regard to its differences. A spacer structure 40 is provided, which is seated between the outer rings 24, 34 of the two rolling bearings 20, 30. The spacer structure 40 can be designed as an integral radial collar of the housing element 14. Alternatively, the spacer structure 40 can also be designed as a separate spacer sleeve. In the present case, a screwable grooved nut 42 is also seated on the shaft element 12. However, a spacer element 44 is also seated between the grooved nut 42 and the inner ring 22 of the rotor-side rolling bearing 20.The grooved nut 42 thus indirectly generates a bearing clearance or a bearing preload in the bearing arrangement 10 via the spacer element 44, depending on the axial position of the grooved nut 42 on the shaft element 12. The grooved nut 42 can be secured against rotation relative to the shaft element 12 in a suitable manner or by suitable means. The spacer element 44 and the shaft element 12 each form contact shoulders 46, 48 that are opposite to one another (see Figure 3). The opposing contact shoulders 46, 48 secure the shaft element 12 and the spacer element 44 in a form-fitting manner in an axial position relative to one another.

[0025] A key 36, 38 is provided between each of the inner rings 22, 32 of the rolling bearings 20, 30 and the shaft element 12 to secure the inner rings 22, 32 against rotation relative to the shaft element 12. Receptacle grooves 62, 64 are provided in the shaft element 12 to accommodate the respective key 36, 38. Additionally, the key 36, 38 can be secured from the radial direction relative to the shaft element 12 by a screw connection 66, 68.

[0026] The spacer structure 40 extends radially to the shaft element 12, forming a radial gap 50 (see Figure 3). In addition, an oil supply channel 52 extending radially can be formed in the spacer structure 40 and the shaft element 12, for example, to ensure lubrication of components located radially within the shaft element 12. The oil supply channel 52 can also have a plurality of oil bores 53, for example one on each side, exiting in the axial direction for lubrication of the first and second rolling bearings 20, 30. A key 54 is provided between the outer rings 22, 32 of the rolling bearings 20, 30 and the housing element to secure the outer rings 22, 32 relative to the housing element. In this case, the housing element 14 is separated from a flange 53 via a parting line 51.

[0027] The adjustment of the bearing clearance of the bearing assembly 10 is explained with additional reference to Figure 3, which shows a section of the bearing assembly 10 shown in Figure 2. Figure 3 shows the situation after the shaft element 12 and the housing element 14 have been provisionally mounted over the bearing assembly 10. It can be seen that in this provisional assembly situation, an axial gap 69 is located between the spacer element 44 and the inner ring 22 of the rolling bearing 20. The axial gap 69 can be understood as an axial play that would theoretically exist during operation of the bearing assembly 10. This axial gap 69 or axial play can be measured using suitable measuring devices, which are not shown here. The axial gap 69 or axial play is, with the otherwise fixed axial position of the inner ring 22 relative to the shaft element 12, dependent on the value denoted by B a designated width dimension of the contact shoulder 46 of the spacer element 44.

[0028] Following this, the grooved nut 42 and the spacer element 44 are dismantled. The spacer element 44 is then either in its width dimension B a processed or another spacer element 44 with a changed width dimension B is used a This modified width dimension B a is compared to the original width dimension B athe preliminary assembly has been adjusted by a setting value determined from the axial gap 69, plus or minus the desired preload or the desired play. Finally, a final assembly takes place with the bearing clearance of the bearing arrangement 10 adjusted accordingly. In the method described, the bearing arrangement 10 remains assembled in the housing element 14, so that on the one hand the assembly effort can be reduced and on the other hand the risk of pre-damage to the components is reduced. In addition, the additional cooling process after the final assembly is eliminated. Figure 4 shows an embodiment of a wind turbine 70. The wind turbine 70 comprises a nacelle 71 to which a multi-blade rotor 72 is rotatably attached. The multi-blade rotor 72 is connected to a main shaft 74 in a torque-transmitting manner, wherein the main shaft 74 belongs to a drive train 76.The drive train 76 further comprises a transmission 78, which is connected to the main shaft 74 in a torque-transmitting manner. The transmission 78 has at least one planetary stage 80 and is in turn coupled to a generator 84 via a hollow shaft assembly 82. The hollow shaft assembly 82 is accommodated in a tapered housing section 86 of the transmission 78. The housing section 86 can be designed as a separate housing 2. A bearing assembly 10 is provided in the hollow shaft assembly 82. The bearing assembly 10 is designed according to one of the embodiments described above.

[0029] List of reference symbols

[0030] 10 Bearing arrangement

[0031] 12 Shaft element

[0032] 14 Housing element

[0033] 16 Housing cover

[0034] 18 Case shoulder

[0035] 20 rolling bearings

[0036] 22 inner ring

[0037] 23 rolling elements

[0038] 24 Outer ring

[0039] 26 wave shoulder

[0040] 28 mounting hole

[0041] 30 rolling bearings

[0042] 32 inner ring

[0043] 33 rolling elements

[0044] 34 Outer ring

[0045] 36 key

[0046] 38 key

[0047] 40 Distance structure

[0048] 42 Locknut

[0049] 44 Spacer element

[0050] 46 Investment shoulder

[0051] 48 Investment shoulder

[0052] 50 radial gap

[0053] 51 Separation joint

[0054] 52 Oil supply channel

[0055] 53 oil drilling

[0056] 53 Flange 54 Key

[0057] 56 spacer sleeve

[0058] 58 spacer sleeve

[0059] 62 mounting groove 64 mounting groove

[0060] 66 screw connection

[0061] 68 screw connection

[0062] 69 axial gap

[0063] 70 Wind turbine 71 Nacelle

[0064] 72 multi-blade rotor

[0065] 74 Main shaft

[0066] 76 Drivetrain

[0067] 78 Gearbox 80 Planetary stage

[0068] 82 Hohl well enb augrupp e

[0069] 84 Generator

[0070] 86 Housing section

Claims

P a t e n t a n s p r ü c h e 1. Bearing arrangement (10) comprising a shaft element (12), a housing element (14), a first rolling bearing (20) with an inner ring (22) and an outer ring (24), a second rolling bearing (30) with an inner ring (32) and an outer ring (34), wherein the two rolling bearings (20, 30) are arranged to form an adjusted bearing arrangement and support the shaft element (12) relative to the housing element (14) so ​​as to be rotatable about a rotation axis AD, a spacer structure (40) seated between the outer rings (24, 34) of the rolling bearings (20, 30), and a grooved nut (42) which can be screwed onto the shaft element (12) and indirectly against the inner ring (22, 32) of one of the two rolling bearings (20, 30) to generate a bearing clearance and / or a bearing preload, characterized in that between the inner rings (22, 32) the rolling bearings (20, 30) and the shaft element (12) are provided with at least one feather key (36, 38) in each case to secure the inner rings (22, 32) against rotation relative to the shaft element (12).

2. Bearing arrangement (10) according to claim 1, characterized in that the keys (36, 38) are secured, preferably from the radial direction, relative to the shaft element (12).

3. Bearing arrangement (10) according to claim 1 or 2, characterized in that the keys (36, 38) are each secured by a screw connection (66, 68).

4. Bearing arrangement (10) according to one of claims 1 to 3, characterized in that a spacer element (44) is provided between the grooved nut (42) and the inner ring (22, 32), wherein the shaft element (12) and the spacer element (44) each form abutment shoulder (46, 48) which is opposite to one another, and the grooved nut (42) fixes the spacer element (44) in an axial position relative to the shaft element (12).

5. Bearing arrangement (10) according to one of claims 1 to 4, characterized in that the spacer structure (40) is designed as an integral radial collar of the housing element (14).

6. Bearing arrangement (10) according to one of claims 1 to 5, characterized in that the spacer structure (40) extends in the radial direction to form a radial gap (50) to the shaft element (12) and an oil supply channel (52) extending in the radial direction is formed in the spacer structure (40) and the shaft element (12).

7. Bearing arrangement (10) according to claim 6, characterized in that the oil supply channel (52) has a plurality of oil bores (53) emerging in the axial direction for oiling the first and second rolling bearings (20, 30).

8. Bearing arrangement (10) according to one of claims 1 to 7, characterized in that at least one feather key (54) is provided between the outer rings (22, 32) of the rolling bearings (20, 30) and the spacer structure (40) for securing the outer rings (22, 32) relative to the spacer structure (40).

9. Bearing arrangement (10) according to one of claims 1 to 8, characterized in that the contact shoulder (46) of the spacer element (44) is arranged radially inside an outer diameter of the shaft element (12).

10. A method for assembling a bearing arrangement (10) according to one of the preceding claims between a housing element (14) and a shaft element (12), in which a preliminary assembly of the shaft element (12) equipped with the bearing arrangement (10) takes place within the housing element (14), a dimension of an axial play between the inner ring (22, 32) and the spacer element (44) is determined, after disassembly of the grooved nut (42) and the spacer element (44) a final assembly with the bearing arrangement (10) takes place, wherein the spacer element (44) is adapted in its axial width dimension compared to the preliminary assembly.

11. Method according to claim 10, wherein, before final assembly, a shoulder of the spacer element (44) to be positioned between the grooved nut (42) and the shaft element (12) is adjusted in its axial width dimension by the determined amount of axial play.

12. Drive train (76) for a wind turbine, with a hollow shaft assembly (82) for the torque-transmitting connection of a multi-blade rotor (72) to a generator (84), wherein the hollow shaft assembly (82) comprises a bearing arrangement (10) according to one of claims 1 to 9.

13. Drive train according to claim 12, characterized in that a gearbox housing comprising the hollow shaft assembly is provided, which comprises a flange on the generator side for connecting the generator, wherein the housing element of the bearing arrangement is connected to the gearbox housing via a screw connection.

14. Wind turbine (70) comprising a nacelle (71) to which a multi-blade rotor (72) and a generator (84) are rotatably mounted, wherein the multi-blade rotor (72) is connected to the generator (84) via a drive train (76) in a torque-transmitting manner and the drive train (76) is designed according to claim 12 or 13.

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