ADJUSTABLE BEARING ARRANGEMENT, ESPECIALLY FOR WIND TURBINES

Description

[0001] The invention relates to a bearing arrangement comprising a first rolling bearing with an inner ring and an outer ring, a second rolling bearing with an inner ring and an outer ring, a first spacer element seated between the inner rings of the rolling bearings, and a second spacer element seated between the outer rings of the rolling bearings for adjusting a bearing preload.

[0002] A bearing arrangement is shown in EP 3 650 689 A1. Bearing arrangements are used in gearbox construction and are subject to increasing demands, particularly in the drive trains of wind turbines. This applies to both the loads during operation and the requirement for quick and precise assembly and adjustment. Indirect adjustment methods for bearing arrangements exist, but these are associated with high uncertainties. Furthermore, axial preloads of bearing arrangements cannot be directly measured in terms of geometric dimensions. It is common practice to specify a desired preload and, based on this, to calculate the axial width of the spacers between the bearing rings, manufacture the spacers as calculated, and then assemble the bearings including the spacers. However, it cannot always be guaranteed that the specified preload will be achieved.EP 2 679 867 A1 and US 2020 / 362917 A1 also show bearing arrangements for wind turbines.

[0003] The bearing preload is adjusted by modifying the axial width of the inner spacer relative to the axial width of the outer spacer. Calculating the required axial width dimensions of the spacer rings necessitates a large number of measurements. Due to inherent manufacturing tolerances, a reliable assembly process for bearing arrangements in the described range cannot be guaranteed, as the required accuracy of the adjustment cannot be achieved.

[0004] There is therefore a constant need for a high-performance bearing arrangement that is precisely adjustable, quick to assemble, and cost-effective to manufacture. The invention aims to provide a technical solution that offers an improvement in at least one of these aspects.

[0005] The problem is solved by a bearing arrangement with the features of claim 1. Preferred embodiments are specified in the dependent claims and the following description, each of which, individually or in combination, can represent an aspect of the invention. When a feature is presented in combination with another feature, this serves only 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.

[0006] One embodiment relates to a bearing arrangement comprising a first rolling bearing with an inner ring and an outer ring, a second rolling bearing with an inner ring and an outer ring, a first spacer element seated between the inner rings of the rolling bearings, and a second spacer element seated between the outer rings of the rolling bearings for setting a bearing preload and consisting of at least two circumferentially opposed arc pieces, wherein the second spacer element extends in a radial direction to the first spacer element, forming a radial gap, and an oil supply channel extending in a radial direction is formed in the first and second spacer elements.

[0007] The spacer rings can be ring-shaped. In particular, the first or inner spacer ring can be designed as a sleeve, fitting snugly onto the shaft. The two inner bearing rings, in conjunction with the first spacer element, are axially clamped against the shaft by a locking element. The inner bearing rings preferably fit snugly onto the shaft. Both the fit and the axial clamping via the locking element are intended to prevent relative rotation of the bearing rings with respect to the shaft during normal operation.

[0008] The second spacer element is composed of multiple parts. The individual parts can be assembled to form the ready-to-use spacer element. The individual parts can be identical or different from one another. At a minimum, the multiple individual parts differ in their circumferential position within the bearing arrangement in its final assembled state. The individual parts are designed as arcs, where "arc" refers to the mathematical concept of a circular arc, such that each arc lies on one arc length of the circumference of the bearing arrangement. Preferably, the multiple individual parts of a second spacer element can be assembled to form a circumferentially closed ring. It is preferred if the second spacer element is composed of two arcs. Each of the arcs then expediently encloses 180° of the circumference. Alternatively, the spacer ring can also be composed of three or more arcs.Here too, a uniform distribution across the circumference is initially the most suitable option. However, it can also be advantageous, and in certain arrangements practical, to have a non-uniform distribution of the arc segments of a spacer element.

[0009] The second spacer element has an axial width dimension, so that a bearing preload is established, at least indirectly, via this second spacer element. The axial width dimension of the second spacer element can be used to definitively set the desired bearing preload after the bearing assembly has been provisionally mounted at least once. As a result of the provisional mounting, the tolerance-based dimensions become final mounting dimensions, resulting in an easily measurable value. This value could, for example, be the axial play of the provisionally mounted bearing assembly, and this measured value can be used to determine or calculate the final axial width dimension of the second spacer element.

[0010] The two spacer elements can fill at least a large portion of the axial space between the two bearings in a radial direction. In a specific embodiment, the second spacer element may extend radially inwards from a circumferential region of the outer rings. While the inner, first spacer element extends only within the radial height of the inner bearing rings, the outer, second spacer element extends both inwards beyond the outer bearing rings and into the circumferential region of the rolling elements.

[0011] In a preferred embodiment of the bearing arrangement, the radially extending oil supply channel has at least one oil outlet bore. This makes it possible to selectively supply lubricating oil to the rolling elements in the areas where the greatest axial forces prevail. Preferably, the second spacer element can have several axially extending openings extending around its circumference.

[0012] The radial gap formed between the first and second spacer elements should be kept so narrow that the lubricating oil, which is guided through the oil passage from the second to the first spacer element, experiences only a minimal pressure loss at the gap. If it is necessary to minimize pressure loss as much as possible, a gap seal can be integrated into the gap.

[0013] In a preferred embodiment of the bearing arrangement, the second spacer element has a first groove around its outer circumference for receiving a locking element positively connected to a surrounding housing. This makes it possible to at least hinder rotation of the outer bearing rings with the shaft or relative rotation between the outer bearing rings and the surrounding housing. To prevent such relative rotation, it is particularly preferred that the second spacer element has a second keyway around its outer circumference for receiving a key positively connected to at least one of the outer rings.

[0014] In a preferred embodiment of the bearing arrangement, the at least two circumferential arc sections are screwed together and / or connected via dowel pins. Screwing or pinning the arc sections together increases dimensional accuracy.

[0015] Furthermore, the first and / or second rolling bearing can be designed as axial tapered roller bearings, tapered roller bearings, angular contact ball bearings, or axial spherical roller bearings. Such rolling bearings advantageously allow an axial load on the outer or inner ring to be introduced as a compressive load into the inclined rolling elements and transferred to the inner or outer ring. This ensures that the axial force exerted on the bearing arrangement can be transferred permanently and reliably from the inner ring to the outer ring or vice versa. In particular, the first and second rolling bearings are arranged in an O-arrangement relative to each other.

[0016] The problem is further solved by a method for mounting a bearing arrangement as described between a housing and a shaft, in which a preliminary mounting of the shaft equipped with the bearing arrangement takes place inside the housing, a measure of axial play between shaft and housing is determined, and after disassembly of the shaft from the housing, a final mounting of the shaft equipped with the bearing arrangement takes place inside the housing, wherein the second spacer element of the bearing arrangement has an axial width dimension increased by the determined measure of axial play compared to the preliminary mounting.

[0017] The assembly process is divided into a first step of preliminary assembly, including axial play measurement, and a second step of final assembly with adjustment of the desired preload. The underlying principle of the process is that the preliminary assembly of the bearing arrangement limits the tolerance ranges of certain component dimensions to their actual values. This means that these component dimensions no longer contribute their respective tolerance ranges to determining the final axial width of the second spacer element. Instead, these component dimensions, with their actual values, contribute to the axial play measurement, which then represents a measurable value. This measured axial play value has a single measurement tolerance range. The determined axial play measurement is then used to determine the final axial width of the second spacer element.In a preferred embodiment of the method, the axial clearance is corrected by at least one tolerance dimension of a housing inner diameter and / or one tolerance dimension of a bearing outer ring diameter. This means, in particular, that the final axial width dimension of the second spacer element results from only a few dimensions subject to tolerances, since, as previously described, the tolerance influence of various component dimensions has been eliminated.

[0018] The problem is further solved by a drive train for a wind turbine, comprising a shaft assembly for the torque-transmitting connection of a multi-blade rotor with a generator, wherein the hollow shaft assembly has a housing and a hollow shaft rotatably mounted in the housing and the hollow shaft is mounted in the housing via a bearing arrangement as described.

[0019] The drive train can be designed for a wind turbine configured as a so-called medium-speed turbine. The hollow shaft assembly structurally comprises a housing, an axially short hollow shaft, and the described bearing arrangement, which rotatably supports the hollow shaft within the housing. The hollow shaft assembly can connect a gearbox on the input side to a generator on the output side, transmitting torque. The gearbox can include at least one planetary gear stage, with an advantageously driven sun gear connected to the hollow shaft. The generator can be connected to the housing of the hollow shaft assembly. The generator rotor can be connected to the hollow shaft of the hollow shaft assembly. With such a configuration and the described bearing arrangement, it is advantageous to omit separate bearings for the generator rotor within the generator housing.The generator rotor can be supported by the hollow shaft assemblies, in particular by the described bearing arrangement between the shaft and the housing of the hollow shaft assembly. Especially in the design of the drive train for medium-speed generators, the hollow shaft assembly can serve as a replacement for a coupling, which is commonly located between the gearbox and the generator.

[0020] The problem is further solved by a wind turbine comprising a nacelle to which a multi-blade rotor and a generator are rotatably attached, wherein the multi-blade rotor is connected to the generator via a drive train for torque transmission, and the drive train is configured as previously described. The drive train is housed in the nacelle and is configured according to a previously described embodiment of the drive train or the bearing arrangement used therein.

[0021] Furthermore, a computer program product for simulating the operating behavior of a bearing arrangement used in a wind turbine is disclosed, wherein the bearing arrangement is configured according to a previously described embodiment. For this purpose, the computer program product can include data on the kinematics of the rolling bearings and / or the hollow shaft. The computer program product can also include simulation routines configured to simulate the behavior of the rolling bearings and the spacer element based on information about the current operating conditions, such as rotational speed, torque, lubricant temperature, ambient temperature, axial stress, radial stress, and dimensions. This can include bending behavior, fatigue behavior, changes in axial preload, thermal behavior, and / or vibration behavior.The computer program product can also have a data interface through which information about the current operating state can be specified. Likewise, the computer program product can also have a data interface for outputting simulation results. Furthermore, results from the computer program product can be output to other simulation-oriented computer programs. According to the invention, the bearing arrangement, whose operating behavior can be simulated using the computer program product, is designed according to at least one of the embodiments outlined above.

[0022] The invention is explained below by way of example with reference to the accompanying drawings and preferred embodiments, wherein the features shown below can represent an aspect of the invention, either individually or in combination. The drawings show: Fig. 1 : a longitudinal section through a bearing arrangement, Fig. 2 , 3: Details of a spacer element of a bearing arrangement according to Figure 1 in perspective view; Fig. 4 : a further longitudinal section through the bearing arrangement according to Figure 1 and Fig. 5 : a perspective view of a wind turbine.

[0023] In Figure 1 Figure 10 schematically depicts an embodiment of a claimed bearing arrangement 10 in an assembled state. The bearing arrangement 10 comprises a first rolling bearing 20 and a second rolling bearing 30. The bearing arrangement 10 is arranged in a housing 2. A shaft 4 is rotatably mounted in the housing 2 about an axis of rotation A d via the bearing arrangement 10. The shaft 4 is designed as a hollow shaft. The assembly consisting of the housing 2, shaft 4, bearing arrangement 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 gearbox to a generator.

[0024] The first rolling bearing 20 comprises an inner ring 22, an outer ring 24, and rolling elements 23 arranged between them. Correspondingly, the second rolling bearing 30 also comprises an inner ring 32, an outer ring 34, and rolling elements 33 arranged between them. The first and second rolling bearings 20, 30 are arranged in an O-arrangement relative to each other. In the first and second rolling bearings 20, 30, the respective outer ring 24, 34 serves as a stationary component, as it is held rotationally fixed in the housing 2 when assembled. Correspondingly, the inner rings 22, 32 of the first and second rolling bearings 20, 30 each represent rotating components. A first spacer element 40 is located between the inner rings 22, 32 of the two rolling bearings 20, 30, and a second spacer element 42 is located between the outer rings 24, 34 of the two rolling bearings 20, 30.The first spacer element 40 holds the two inner rings 22, 32 axially spaced apart, and the second spacer element 42 holds the two outer rings 24, 34 axially spaced apart. Both spacer elements 40, 42 are annular in design, with the inner and first spacer element 40 in particular surrounding the shaft 4 in a sleeve-like manner. The second spacer element 42 can, for example, be composed of two arc-shaped pieces 44, as shown in the figure. Figure 2 will be explained.

[0025] The two inner rings 22, 32 of the rolling bearings 20, 30 are seated on the shaft 4 with a transition fit. This initially prevents the inner rings 22, 32 from rotating relative to the shaft 4. To further prevent rotation between the inner rings 22, 32 and the shaft 4, a slotted nut 12 is screwed onto the end of the shaft 4, which exerts an axial force on both inner rings 22, 32 and the first spacer element 40 against a shaft shoulder 26. In the assembled state of the bearing arrangement on the shaft 4 and in the housing 2, the two outer rings 24, 34 of the rolling bearings 20, 30 also sit with an interference fit in a receiving bore 28 of the housing 2. An axial force is applied via an adjusting ring 14 and a housing cover 16, which acts on the two outer rings 24, 34 and the inserted second spacer element 42 against a housing shoulder 18.This initially provides protection against relative rotation between outer rings 24, 34 and the housing 2. A further method of protection against relative rotation is described later in connection with the second spacer element 42.

[0026] In the Figure 2 and 3 The second distance element 42 is shown in detail in various perspective representations, which are essentially referred to collectively in the following. The second distance element 42 is shown here in a two-part version. The distance element 42 then consists of two arc-shaped pieces 441, 442 positioned opposite each other. The two opposing arc-shaped pieces 441, 442 form a fully enclosed ring.

[0027] The two large arc pieces 44 1 , 44 2 are screwed together by screws 36 and additionally positioned against each other by dowel pins 38.

[0028] The second spacer element 42 can, viewed in a longitudinal section, essentially be T-shaped, as is particularly evident in the Figure 1 The T-shape is formed by a radially outer spacer 60 and a web 62 extending radially inward from it. The spacer 60 serves to sit axially between the outer rings 24, 34 of the bearings 20, 30 and to maintain the outer rings 24, 34 at a defined axial distance. The second spacer 42 extends radially inward through the web 62 between the rolling elements 23, 33 of the bearings 20, 30. Preferably, the second spacer 42 extends radially inward to the first spacer 40, so that both spacer elements 40, 42 form a narrow radial gap 64 between them. The radial dimension of the gap 64 can vary depending on the application.

[0029] The radial dimension of the gap 64 can, for example, be chosen to be larger if lubrication of the rolling elements 23, 33 of the bearings 20, 30 is to be provided starting from the radially inner area of ​​the spacer element 42. In such a design, at least one radially extending oil supply channel 54 with axially directed oil outlet bores 56 on both sides is arranged in the second spacer element 42. Figure 2 The figure shows that two oil supply channels 54 are arranged around the circumference. Lubricating oil can be supplied to the rolling elements 23, 33 via the axially oriented oil outlet bores 56. Alternatively, only one oil supply channel 54 may be provided.

[0030] The radial dimension of the gap 64 can, for example, be chosen to be smaller if it is additionally intended that the oil supply channel(s) 54 have an oil passage bore 58 extending radially inwards, which is further discussed in connection with the Figure 4 will be addressed.

[0031] The second spacer element 42 forms a first groove 46 around its outer circumference. A key (not shown) accommodated in this groove allows the second spacer element 42 to be positively locked against rotation relative to the housing 2. Furthermore, the second spacer element 42 forms a second keyway groove 50 around its outer circumference. A key (not shown) accommodated in this groove allows the second spacer element 42 to be positively locked against rotation relative to at least one of the outer rings 24, 34.

[0032] Based on the Figure 4The possible oil supply through the second spacer element 42 is shown by means of an assembly. The interaction of the first spacer element 40 with the second spacer element 42 is characterized by a gap 64 with a small radial dimension. Initially, axially directed oil outlet bores 56 branch off from both sides of the oil supply channel 54 to lubricate the rolling elements 23, 33. Additionally, the oil supply channel 54 is provided with an oil passage bore 58 that extends radially inwards and through the first spacer element 40. Corresponding to the oil passage bore 58, a radial oil channel 66 is formed in the shaft 4, through which lubricating oil can reach, for example, a longitudinal toothing 68 on an inner circumference of the shaft 4.

[0033] The present bearing arrangement 10 is mounted with an axial preload between the housing 2 and the shaft 4. The assembly method used here is divided into a first step of preliminary assembly, including axial play measurement, and a second step of final assembly with adjustment of the required preload. First, both rolling bearings 20, 30, together with the first and second axially inserted spacer elements 40, 42, are placed on the shaft 4. The inner rings 22, 32 of the rolling bearings 20, 30 preferably have a transition fit with respect to the diameter of the shaft 4. Subsequently, the shaft 4 with the mounted rolling bearings 20, 30 is inserted into the receiving bore 28 of the housing 2. This completes the preliminary assembly.For this preliminary assembly, a second spacer element is provided, the axial width of which is dimensioned such that the preliminary mounted bearing assembly 10 allows axial play of the shaft 4 relative to the housing 2. This axial play is determined or measured using appropriate measuring instruments. Subsequently, the shaft 4, together with the rolling bearings 20, 30 and spacer elements 40, 42 held on it, is pulled out of the receiving bore 28 of the housing 2, and the second spacer element 42, which consists of at least two parts, is removed from between the two rolling bearings 20, 30. Due to the multi-part nature of the second spacer element 42, both rolling bearings 20, 30 can remain unchanged in their position on the shaft 2, since the curved sections 44 of the spacer element 42 between the rolling bearings 20, 30 can be removed.Following this, the final assembly of the bearing arrangement 10 takes place, whereby a second spacer element 42 with an increased axial width compared to the preliminary assembly is used. This increased axial width is composed of the axial width of the spacer element 42 from the preliminary assembly and the determined axial clearance dimension.

[0034] In the Figure 5Figure 70 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 torque-transmittingly connected to a main shaft 74, the main shaft 74 belonging to a drive train 76. The drive train 76 further comprises a gearbox 78, which is torque-transmittingly connected to the main shaft 74. The gearbox 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 received in a tapered housing section 86 of the gearbox 78. The housing section 86 can be designed as a separate housing 2. A bearing arrangement 10 is provided in the hollow shaft assembly 82. The bearing arrangement 10 is designed according to one of the embodiments described above.The bearing arrangement 10 is depicted in a computer program product suitable for simulating its operating behavior during operation of the wind turbine 70. Reference symbol list

[0035] 2 Housing 4 Shaft 10 Bearing arrangement 12 Slotted nut 14 Adjusting ring 16 Housing cover 18 Housing shoulder 20 Rolling bearing 22 Inner ring 23 Rolling element 24 Outer ring 26 Shaft shoulder 28 Mounting bore 30 Rolling bearing 32 Inner ring 33 Rolling element 34 Outer ring 36 Screw 38 Dowel pin 40 Spacer 42 Spacer 44 Elbow pieces 46 Keyway 50 Keyway 54 Oil supply channel 56 Oil outlet bore 58 Oil through bore 60 Spacer 62 Web 64 Radial gap 66 Oil channel 68 Longitudinal gearing 70 Wind turbine 71 Nacelle 72 Multi-blade rotor 74 Main shaft 76 Drive train 78 Gearbox 80 Planetary stage 82 Hollow shaft assembly 84 Generator 86 Housing section

Claims

1. Bearing arrangement (10), comprising a first anti-friction bearing (20) with an inner ring (22) and an outer ring (24), a second anti-friction bearing (30) with an inner ring (32) and an outer ring (34), a first spacer element (40) which is seated between the inner rings (22, 32) of the anti-friction bearings (20, 30), and a second spacer element (42) which, in order to adjust a bearing prestress, is seated between the outer rings (24, 34) of the anti-friction bearings (20, 30) and consists of at least two curved pieces (441, 442) which are adjusted circumferentially against one another, characterized in that the second spacer element (42) extends in the radial direction with the formation of a radial gap (64) to the first spacer element (40), and an oil supply channel (54, 58) which runs in the radial direction is formed in the first and second spacer element (40, 42).

2. Bearing arrangement (10) according to Claim 1, characterized in that the second spacer element (42) configures a first groove (46) on the outer circumference, for receiving a securing element which is connected to a surrounding housing.

3. Bearing arrangement (10) according to Claim 1 or 2, characterized in that the second spacer element (42) configures a second keyway (50) on the outer circumference, for receiving a key which is connected in a positively locking manner to at least one of the outer rings (24, 34).

4. Bearing arrangement (10) according to one of Claims 1 to 3, characterized in that the oil supply channel (54) which runs in the radial direction has at least one oil outlet bore (56).

5. Bearing arrangement (10) according to Claim 4, characterized in that the oil supply channel (54) of the second spacer element (42) has two oil outlet bores (56) which are directed axially on both sides.

6. Bearing arrangement (10) according to one of Claims 1 to 5, characterized in that the radial gap (64) has a small radial dimension such that, in operation of the bearing arrangement (10), the radial gap (64) has a substantially sealing effect between the two spacer elements (40, 42).

7. Bearing arrangement (10) according to Claim 6, characterized in that the radial dimension of the radial gap (64) is between 0.1 mm and 1 mm, preferably between 0.1 mm and 0.3 mm.

8. Bearing arrangement (10) according to one of Claims 1 to 7, characterized in that the at least two circumferential curved pieces (441, 442) are screwed against one another and / or are connected via locating pins (38).

9. Bearing arrangement (10) according to one of Claims 1 to 8, characterized in that the first and / or second anti-friction bearing (20, 30) are / is configured as an axial tapered roller bearing, as a tapered roller bearing, as an angular contact ball bearing, or as an axial self-aligning roller bearing.

10. Bearing arrangement (10) according to one of Claims 1 to 9, characterized in that the first and the second anti-friction bearings (20, 30) are arranged in an O-arrangement with respect to one another.

11. Method for mounting a bearing arrangement (10) according to one of the preceding claims between a housing (2) and a shaft (4), comprising the steps of provisional mounting of the shaft (4) which is fitted with the bearing arrangement (10) takes place within the housing (2) or an apparatus which represents the housing (2), a dimension of an axial play between the housing (2) or the apparatus which represents the housing (2) and the shaft (4) is determined, and, after dismantling of the shaft (4) from the housing (2), final mounting of the shaft (4) which is fitted with the bearing arrangement (10) takes place within the housing (2), wherein the second spacer element (42) of the bearing arrangement (10) comprises, with respect to the provisional mounting, an axial width dimension which is increased at least by the defined dimension of the axial play.

12. Method according to the preceding claim, wherein the dimension of the axial play is corrected in a manner which is dependent on at least one tolerance dimension of a housing internal diameter and / or on a tolerance dimension of a bearing outer ring diameter.

13. Drive train (76) for a wind power plant, comprising a shaft assembly (82) for the torque-transmitting connection of a multiple blade rotor (72) to a generator (84), the shaft assembly (82) having a housing (2) and a shaft (4) which is mounted rotatably in the housing (2), and the shaft (4) being mounted in the housing (2) via a bearing arrangement (10) according to one of Claims 1 to 10.

14. Wind power plant (70), comprising a nacelle (71), to which a multiple blade rotor (72) and a generator (84) are attached rotatably, the multiple blade rotor (72) being connected in a torque-transmitting manner via a drive train (76) to the generator (84), and the drive train (76) being configured according to Claim 13.