Method for mounting a rolling bearing arrangement of a shaft in a housing comprising a bearing seat and a pump device comprising a rolling bearing arrangement mounted in this manner

Abstract

The invention relates to a method for mounting a rolling bearing arrangement (1) of a shaft (2) in a bearing seat (20) for the rolling bearing arrangement (1), e.g. of a housing (21) comprising at least the following steps: a) Arranging at least two rolling bearings (3A, 3B) on the shaft (2); b) Thermal expansion of the bearing seat (20) by heating at least the bearing seat (20), e.g. the housing (21), to a diameter (D LS ), which is larger than the outer diameter (D AR ) of the outer rings (6A, 6B) of the rolling bearings (3A, 3B); c) Inserting the outer rings (6A, 6B) into the thermally expanded bearing seat (20); d) Axial preloading of the outer rings (6A, 6B) of the rolling bearings (3A, 3B) relative to each other towards or away from each other at least during a period of time following step a), in which the outer diameter (D AR) of the outer rings (6A, 6B) of the rolling bearings (3A, 3B) is less than or equal to the diameter (D LS ) of the bearing seat (20); e) Cooling the bearing seat (20) to form a transverse press fit between the outer rings (6A, 6B) of the rolling bearings (3A, 3B) and the bearing seat (20), whereby the axially preloaded state of the rolling bearings (3A, 3B) relative to each other is fixed. In the second aspect, the invention relates to a pumping device which has a rolling bearing arrangement that was assembled according to the inventive method.

Description

[0001] The invention relates to a method for mounting a rolling bearing arrangement of a shaft in a housing having a bearing seat and, in a second aspect, a rolling bearing arrangement mounted in this way having a pump device.

[0002] Typically, rotor shafts of electric motors in pumping devices are supported by plain or rolling bearings. Compact bearings are a well-known type of rolling bearing, which integrates multiple rolling bearings into a single, structurally defined bearing unit, thus providing a mechanically defined support structure. While such compact bearings have proven effective, even minor changes to the bearing geometry necessitate relatively costly modifications to the compact bearing. This is particularly true when a large number of different pumping devices, such as a pumping platform with slightly varying bearing seat geometries, need to be specifically adapted to customer requirements. In such cases, adapting a compact bearing is often expensive and uneconomical.

[0003] Furthermore, the demands for the quietest possible operation are constantly increasing, particularly for fluid pumps, and these demands are difficult or impossible to achieve with conventional rolling bearing arrangements. Additionally, the pump efficiency is reduced if the pump shaft, which carries the impeller, has an undefined preload with slight play. Such play increases the required clearance of the pump rotor within the pump housing, which is undesirable. Fluid pumps are manufactured in large quantities, making simplified assembly, especially tolerance-independent assembly, desirable. Moreover, the need to further increase or optimize the use of common parts and the standardization of bearing systems is growing. This can also lead to desirable supplier independence by enabling the selection of standard components.

[0004] The object of the invention is therefore to provide a method for assembling a rolling bearing arrangement that can address and solve the aforementioned increasing requirements. Furthermore, it is an object of the invention to provide a method for assembling a rolling bearing arrangement that can overcome, or at least reduce, the disadvantages of the prior art. In particular, quiet operation of the bearing and a defined bearing condition, especially a defined bearing preload condition, should be achieved.

[0005] These problems are solved by a method for mounting a rolling bearing arrangement of a shaft in a housing comprising a bearing seat for the rolling bearing arrangement with the features of claim 1. Furthermore, the problem is solved by a pumping device with the features of claim 9.

[0006] An inventive method for mounting a rolling bearing arrangement of a shaft in a bearing seat for the rolling bearing arrangement, e.g. of a housing, comprises at least the following steps: a) Arranging at least two rolling bearings on the shaft; b) Thermal expansion of the bearing seat by heating at least the bearing seat, e.g. the housing, to a diameter (D LS ), which is larger than the outer diameter (D AR ) the outer rings of the rolling bearings; c) Inserting the outer rings into the thermally expanded bearing seat; d) Axial preloading of the outer rings of the rolling bearings relative to each other in a longitudinal direction of the shaft, viewed towards or away from each other, at least during a period of time following step a), in which the outer diameter (D AR ) the outer rings of the rolling bearings is less than or equal to the diameter (D LS ) of the warehouse location; e) Cooling the bearing seat to form a transverse press fit between the outer rings of the rolling bearings and the bearing seat, whereby the axially preloaded state of the rolling bearings relative to each other is fixed.

[0007] The method according to the invention makes it possible to create a preload state by means of simple assembly steps, in particular avoiding significant assembly forces and adjustment work, which remains defined after assembly and does not change during operation of the bearing or only to an acceptable extent, i.e. insignificantly.

[0008] The insertion of the bearing into a thermally expanded bearing seat, which has a larger bearing seat diameter than the diameter of the outer rings of the rolling bearings, allows for virtually effortless insertion of the bearing-carrying shaft into the bearing seat. The preloaded bearing condition is fixed by a transverse press fit, which forms when a thermally expanded bearing seat, through cooling, conforms to the outer rings of the rolling bearings and the clearance fit transitions into an interference fit (transverse press fit) during assembly. In this pressed-in state, the outer rings of the bearings can no longer move relative to each other, thus maintaining the preload achieved during assembly.While clamping devices, such as spring washers or the like, which may be used to create the clamping state before assembly, can remain in the bearing after the cross-fit connection has been formed, this is not strictly necessary. A further advantage of the methods according to the invention is that, when the outer rings of two rolling bearings mounted on the shaft are preloaded away from each other, within the limits of the small but existing axial play of one rolling bearing, for example, a deep groove ball bearing, the bearing is removed from the bearing, thus forming a bearing arrangement of the two rolling / ball bearings that tends to operate in an O-arrangement. Conversely, when the outer rings are preloaded towards each other, a bearing arrangement is created that tends to correspond to an X-arrangement of the rolling bearings relative to each other.

[0009] The assembly method according to the invention, which in particular compensates for axial play in rolling bearings, allows the use of cost-effective ball bearings / rolling bearings without compromising the accuracy of the bearing guidance, noise, or expected friction. In particular, this enables the creation of a high-quality shaft bearing at low cost.

[0010] In a particular embodiment, a temperature (T) mont ), to which the bearing seat is heated for thermal expansion, is greater than a maximum occurring operating temperature (T B ) the rolling bearing arrangement and the bearing seat.

[0011] This ensures, in particular, that the cross-press fit is not prevented by heating of the entire bearing assembly during operation, i.e., the rolling bearings and the bearing seat. Especially when there are different thermal expansion coefficients of the bearing seat material and the ball bearing / shaft material, the assembly temperature T is, of course, advisable. mont at least high enough that even if operational material expansion occurs, the transverse compression joint between the bearings and the bearing seat is not loosened.

[0012] Viewed in the longitudinal direction along the shaft, for example, an aluminum bearing seat, which has a higher coefficient of thermal expansion than a steel shaft, can, at increasing operating temperature and with a maintained transverse fit, further increase the axial preload of the outer rings of the rolling bearings relative to each other, provided they are oriented in such a way that they point away from each other, since the thermal expansion of the aluminum bearing seat is greater than that of the shaft. This effect is negligible when selecting a material with only very slightly different coefficients of thermal expansion for the bearing seat, the shaft, and the outer bearing rings.

[0013] In a further embodiment of the invention, it may be advantageous that the axial preloading of the outer rings relative to each other is effected by means of a compression spring element, e.g. a wave spring ring, a disc spring or an elastically deformable polymer element, between the outer rings.

[0014] This allows, for example, the formation of a pre-assembled assembly V consisting of the shaft and the rolling bearings, already equipped with pre-tensioned outer rings. After heating the bearing seat, this assembly simply needs to be inserted into the bearing seat without requiring significant assembly forces. This measure also provides a simple way to achieve the desired O-arrangement of the rolling bearings relative to each other.

[0015] Furthermore, it can be advantageous to effect the axial preloading of the outer rings relative to each other by means of a magnet, which acts on the outer rings at least until a sufficiently firm transverse press fit is formed between the outer rings and the bearing seat.

[0016] Preloading the outer rings against each other using a magnet has the particular advantage that the magnet can be designed as an assembly aid, which can be removed after assembly, i.e., after the cross-pressing has formed (after the bearing seat has cooled), and does not remain in the bearing assembly. This makes it possible to save weight in the bearing assembly compared to, for example, the previously mentioned alternative solution with a spring washer or similar device. Furthermore, significantly fewer individual parts need to be handled during the assembly of the bearing assembly.

[0017] It is advantageous that, for axial preload, the outer rings are spring-loaded or magnetically preloaded in the longitudinal direction L of the shaft, either towards or away from each other.

[0018] When the outer rings are preloaded towards each other, an X-arrangement of the rolling bearings is created relative to each other, which can be particularly advantageous in the case of rolling bearings that are relatively far apart in the longitudinal direction of the shaft in order to support forces that are introduced into the shaft between the rolling bearings.

[0019] On the other hand, if the outer rings of the two rolling bearings are preloaded away from each other in the longitudinal direction of the shaft, an O-arrangement of the rolling bearings relative to each other can be achieved in a simple manner.

[0020] For some applications where a particularly space-saving design of the shaft bearing is important, it is advantageous for the shaft itself to have raceways for rolling elements and thus form an inner ring of the rolling bearing.

[0021] This eliminates the need for separate inner rings in the rolling bearings.

[0022] Suitable types of rolling bearings for the method according to the invention are deep groove ball bearings, shoulder ball bearings, angular contact ball bearings or tapered roller bearings. These can be preloaded in at least one axial direction in addition to the radial forces and are therefore suitable for the method according to the invention.

[0023] A particularly cost-effective design for the rolling bearing arrangement involves using at least two bearings of the same type, which offers cost advantages. Alternatively, it can also be designed with at least two bearings of different types, which, for example, allows for the consideration of high axial forces occurring in only one direction through appropriate bearing selection.

[0024] Pump device which has at least one rotor shaft rotatably mounted with respect to a housing, wherein a rolling bearing arrangement of the rotor shaft manufactured according to a method according to one of claims 1 to 8 is mounted.

[0025] The invention will be explained in more detail below using the drawing as an example. Fig. 1A, Fig. 1B: schematically a pre-assembly assembly for carrying out the assembly method according to the invention, consisting of a shaft and 3 rolling bearings, the outer rings of which are spring-loaded away from each other in the longitudinal direction of the shaft; Fig. 2A, Fig. 2B, Fig. 2C, Fig. 2D: schematically depicts an assembly sequence of the assembly method according to the invention, using the example of assembling a bearing / shaft assembly in a housing of a pump device: Fig. 3: schematically an example of an assembly step of the assembly method according to the invention with a pre-assembly assembly with non-preloaded bearing outer rings, in which the preload of the bearing outer rings is only applied during or after the insertion of the pre-assembly assembly into the bearing seat by means of a mechanical spring element; Fig. 4: schematically an example of an assembly step of the assembly method according to the invention with non-preloaded outer rings, in which the preloading of the outer rings only takes place during or after the insertion of the pre-assembly assembly into the bearing seat by means of a magnet; Fig. 5: schematically a result of the assembly process according to the invention with outer rings pre-tensioned towards each other in the longitudinal direction L of the shaft; Fig. 6: schematically a result of the assembly process according to the invention with outer rings pre-tensioned away from each other in the longitudinal direction of the shaft; Fig. 7: schematically illustrates the process of the assembly method according to the invention using a block diagram.

[0026] In a method according to the invention for mounting a rolling bearing arrangement 1 on a shaft 2, in step a) it is first provided to arrange at least two rolling bearings 3A, 3B successively on a region of the shaft 2 provided for receiving the bearings in the longitudinal direction L of the shaft 2. Such an arrangement can be effected, for example, by means of a conventional clamping or press fit of inner rings 4A, 4B of the rolling bearings 3A, 3B on the shaft 2. In the example according to the Fig. 1A, Fig. 1B is the selected rolling bearing type for the rolling bearings 3A, 3B, a so-called single-row deep groove ball bearing with balls 5A, 5B as rolling elements, which run in a known manner in running grooves of the inner rings 4A, 4B and in outer rings 6A, 6B.

[0027] Viewed in the longitudinal direction L, the inner rings 4A, 4B of the two rolling bearings 3A, 3B are spaced apart from each other by means of a spacer ring 7. The thickness of the spacer ring 7 determines the distance of a gap 8 between the two rolling bearings 3A, 3B.

[0028] In the gap 8 between the outer rings 6A, 6B of the rolling bearings 3A, 3B, surrounding the spacer ring 7, sits a compression spring element 9, which is pre-tensioned against the outer rings 3A, 3B and pushes them apart in the longitudinal direction L (see opposite arrows 10). With inner rings 4A, 4B fixedly mounted on the shaft 2, the pre-tensioning of the outer rings 6A, 6B initially eliminates any axial play within the rolling bearings 3A, 3B, because each outer ring 6A, 6B is supported against the corresponding inner ring 4A, 4B by the rolling elements 5A, 5B (e.g., by balls of the rolling bearings 3A, 3B). This creates a rolling bearing arrangement 1 in a so-called O-arrangement 11 with respect to the shaft 2. A rolling bearing arrangement 1 formed in this way on the shaft 2 runs without backlash in the longitudinal direction L (axial direction) and is also particularly quiet.

[0029] The shaft 2 and at least the rolling bearings 3A, 3B, possibly including the spacer ring 7 and the compression spring element 9, form a pre-assembly assembly V.

[0030] The storage arrangements according to the Fig. 1A and Fig. 1B are basically of identical construction, with only the rolling bearings 3A, 3B differing in the embodiment according to Fig. 1A are designed as open, i.e., unsealed, rolling bearings 3A, 3B and are therefore suitable, for example, for fluid flow, as may be desirable in a pump application. In contrast, the rolling bearings 3A, 3B in the embodiment according to Fig. 1A are designed as sealed rolling bearings 3A, 3B, which have sealing discs 12 in the usual manner. Such rolling bearings 3A, 3B are known as sealed rolling bearings 3A, 3B, optionally permanently lubricated with a lubricant.

[0031] In a further step (see also Fig. In steps 2A to 2D of the assembly method according to the invention, a bearing seat 20, which is present, for example, in a pump housing 21, is thermally expanded. This is done by heating at least the bearing seat 20 of the housing 21 to an inner diameter D. LS , which is equal to or greater than an outer diameter D AR the outer rings 6A, 6B of the rolling bearings 3A, 3B. The rolling bearing arrangement 1 on the shaft 2, i.e. the pre-assembled assembly V, is preferably not heated or at least remains at a temperature lower than the assembly temperature T. mont , which is for a thermal expansion of the bearing seat 20 to a dimension D LS This is necessary at a significantly lower temperature. This ensures that the thermal expansion of the bearing seat 20 reliably achieves the required inner diameter D. LS is equal to or greater than the outer diameter D AR This is in the Fig. 2A, Fig. 2B is graphically represented by a small radial gap between the outer rings 6A, 6B of the rolling bearings 3A, 3B and an inner surface of the bearing seat 20. In the graphical representation according to Fig. 2C and Fig. In 2D, this is not the case. The outer contours of the outer rings 6A, 6B coincide graphically with the inner contour of the bearing seat 20. This graphical difference between the Fig. 2A, Fig. 2B and the Fig. 2C and Fig. 2D is intentional and is intended to illustrate graphically the presence of radial play in the rolling bearings 3A, 3B when the bearing seat 20 or the housing 21 is heated.

[0032] Once this state is reached, the pre-assembled unit V, consisting of the shaft 2 and the rolling bearings 3A, 3B, including any spacer rings 7 and compression spring elements 9, can be inserted into the bearing seat 20 in the longitudinal direction L of the shaft, i.e., in the axial direction, without force and preferably without contact between the outer surfaces of the outer rings 6A, 6B and an inner surface of the bearing seat 20. In this state, the outer rings 6A, 6B of the rolling bearings 3A, 3B are pre-tensioned away from each other in the axial direction (longitudinal direction L) of the shaft 2 by means of the compression spring element 9, as specified. Since the inner diameter D LS Since the outer diameter D AR is greater than or at least equal to the outer diameter D AR, no force is exerted on the outer rings 6A, 6B by contact with the bearing seat 20 when the pre-assembly assembly V is inserted in the axial direction. The pre-assembly assembly V is inserted, for example, up to a bottom-side stop 22 of the bearing seat 20.

[0033] In the exemplary embodiment according to the Fig. In sections 2A to 2D, the bearing seat 20 is – as specified – part of a pump housing 21, wherein the pump housing 21 is preferably heated as a whole to the assembly temperature Tmont, which also widens a seating surface 23 for a stator 24 of an electric motor. Before, after, or simultaneously with the insertion of the pre-assembly assembly V, the stator 24 can also be positioned axially with respect to its seating surface 23 in the housing 21. This procedure is particularly advantageous for the assembly of a pump unit.

[0034] Following the step described above, at least the bearing seat 20, preferably the entire housing 21, is cooled, thereby reducing the inner diameter DLS of the bearing seat 20, which had been enlarged by thermal expansion, to form a transverse press fit between the outer rings 6A, 6B of the rolling bearings 3A, 3B and the bearing seat 20. The dimensioning of the corresponding geometries of the bearing seat 20 in relation to the outer diameter D AR The ability to fit the outer rings 6A, 6B of the rolling bearings 3A, 3B in the cold state in such a way that a transverse press fit with sufficient overlap is formed is within the scope of expert skill and is essentially, of course, dependent on the size of the outer diameter D. AR The outer rings 6A, 6B of the rolling bearings 3A, 3B are dependent. Cooling of the bearing seat 20 results in a condition according to Fig. 2C, wherein the outer rings 6A, 6B of the rolling bearings 3A, 3B are fixed in their axially preloaded state relative to each other by the transverse press fit, and this axially preloaded state is thus maintained even after the bearing seat 20 has cooled down due to friction between the outer rings 6A, 6B and the bearing seat 20. In the example according to Fig. Furthermore, after the entire housing 21 has cooled down, the stator 24 is now also fixed in place by means of a transverse press fit with respect to its seating surface 23 using a pump device.

[0035] In the prescribed cooled state, where the axial preload of the rolling bearings 3A, 3B relative to each other is fixed as prescribed by the formation of the transverse press fit within the bearing seat 20, the function of the compression spring element 9, which is still present from the pre-assembly phase, is actually superfluous. However, it can no longer be sensibly removed and can therefore remain in the gap 8 between the rolling bearings 3A, 3B. As a result, the outer rings 6A, 6B are now axially preloaded relative to each other, which also applies during operation, for example, of the pump device 21 at an elevated operating temperature T. B which is preserved and thus ensures a reliable, backlash-free and quiet running bearing, which according to the invention can be produced in particular by standard components such as simple deep groove ball bearings.

[0036] Fig. 2D shows the state according to Fig. 2C, but without a representation of the stator 24.

[0037] In Fig. Figure 3 shows assembly step c) of inserting the outer rings 6A, 6B into the bearing seat 20 with its axial stop 21. This is a simplified representation without the previously described pump housing 21, but it also applies to an assembly situation according to the prescribed [document / guideline]. Fig. 2A to 2D transferable. For clarification, although no radial gaps are drawn, it should be noted that the bearing seat 20 is shown according to Fig. 3 at the assembly temperature T montThe assembly tool is located. By means of an assembly tool punch 30, which carries the compression spring element 9 on its end face 31, a compressive force is exerted on the outer ring 6B in the direction of the outer ring 6A when the pre-assembly assembly V is inserted. This force is supported on the end face 31 of the assembly punch 30 on one side and on the outer ring 6B on the other. The outer ring 6A is axially supported against the stop 21, resulting in a preload of the outer rings 6A and 6B towards each other. This preload via the assembly punch 30 and the compression spring element 9 is maintained until the bearing seat 20 has cooled sufficiently and the transverse press fit between the bearing outer rings 6A and 6B and the inside of the bearing seat 20 has been formed.

[0038] In this embodiment, it is advantageous that the compression spring element 9 is not trapped between the outer rings 6A, 6B and can be removed after assembly together with the mounting die 30. Thus, no compression spring element 9 remains in the finished rolling bearing assembly 1, which leads to an additional weight reduction and, particularly in mass production, to a saving in components. Furthermore, the illustrated assembly situation differs according to Fig. 3 of the above-described features are achieved by the fact that the shaft 2 itself provides the raceways for the balls 5, so that the illustrated rolling bearings 3A, 3B do not have inner rings 4A, 4B. This also contributes in particular to a space-saving design in the radial direction R and also saves material and weight. In the Fig. The procedure described in Figure 3 involves a method in which the preload of the outer rings 6A, 6B of the rolling bearings 3A, 3B is only applied at the moment the outer rings 6A, 6B are inserted into the thermally expanded bearing seat 20, because only in this state does the mounting plunger 30 exert an axial force on the outer ring 6B of the rolling bearing 3B via the compression spring element 9. This is intended to illustrate that it is not absolutely necessary to provide axial preload between the outer rings 6A, 6B during the pre-assembly assembly V. This can also be done during step c) of the assembly method according to the invention.

[0039] In the embodiment according to Fig. Figure 4 describes a modified method for applying the axial preload to the outer rings 6A, 6B relative to each other. The pre-assembled assembly V is not actively preloaded in the axial direction or in the longitudinal direction L of the shaft 2 during insertion, particularly shortly before the outer rings 6A, 6B are inserted into the thermally expanded bearing seat 20 (step c) of the inventive method). This preloading only occurs after the outer rings 6A, 6B have been inserted into the thermally expanded bearing seat 20 by means of a ring magnet 40, which is arranged externally over the bearing seat 20, specifically encompassing it. The ring magnet 40 is, for example, a permanent magnet or an electromagnet, which, through the orientation of its magnetic field lines, provides an axial preload to the outer rings 6A, 6B, which are still freely movable in the axial direction within the bearing clearances in this state. In the illustrated example according to Fig. 4. The magnetic field lines 100 ensure that the outer rings 6A, 6B are magnetically biased towards each other. A dashed line 100, shown in Fig. Figure 4 is intended to schematically and in a highly simplified manner show the course of a magnetic field line of the ring magnet 40. Of course, other designs besides the ring magnet 40 are also suitable. The essential point is that a magnetic field, whether permanently present or switchable, is applied in such a way that an axial preload of the outer rings 6A, 6B relative to each other occurs before a transverse press fit is formed by cooling the bearing seat 20 according to step e) of the method according to the invention, at least to the extent that the loss of the axial preload of the outer rings 6A, 6B is eliminated or reduced.

[0040] Fig. Figure 5 shows another possibility for the axial preloading of outer rings 6A, 6B of the rolling bearings 3A, 3B, wherein the compression spring element 9 is not arranged in the gap 8 between the rolling bearings 3A, 3B, but is arranged axially opposite the stop 22 of the bearing seat 20, pressing against the outer ring of the rolling bearing 3B. To maintain the axial force exerted by the compression spring element 9 on the outer ring 6B towards the outer ring 6A, which in turn is axially supported by the stop 22, a retaining ring 50 can be provided, which is recessed in a retaining ring groove 51 in the bearing seat 20. With the arrangement according to Fig. 5. Thus, an axial preload of the outer rings 6A, 6B towards each other is achieved, which is then fixed after cooling according to step e) of the inventive method when a transverse press fit is formed. The illustration according to Fig. Figure 5 also shows an arrangement of the rolling bearings 3A, 3B without inner rings 4A, 4B. The raceways for the rolling elements 5 are as described in connection with Fig. 3 previously described, incorporated into the shaft surface. This also determines the axial distance between the rolling bearings 3A and 3B, so that, as in the embodiment according to Fig. 3. For the formation of the gap 8, no spacer ring 7, as it is in the Fig. 1A, Fig. As shown in 1B, it is necessary.

[0041] Unlike the Fig. 5 shows Fig. 6 a rolling bearing arrangement 1 assembled according to the invention, in which the compression spring element 9 is arranged to exert a spring-like pressure on the outer rings 6A, 6B in the gap 8 between the rolling bearings 3A, 3B without the provision of a spacer ring 7. The outer rings 6A, 6B are thus preloaded away from each other. The embodiment according to Fig. Figure 6 also shows that when the bearing seat 20 has cooled down, i.e., when the outer rings 6A, 6B have formed a transverse press fit in the bearing seat 20, a retaining ring 50, as used in connection with Fig. Figure 5 shows that this may also be unnecessary. In the cooled state of the bearing seat 20 after step e) of the method according to the invention, the outer rings 6A, 6B of the rolling bearings 3A, 3B are fixed in the longitudinal direction L of the shaft 2, i.e., in the axial direction, with respect to the bearing seat 20, so that, comparable to the situations according to the Fig. 1A and Fig. 1B the compression spring element 9 is no longer necessary to maintain the axial preload. However, it can easily remain in the gap 8.

[0042] Fig.Figure 7 schematically illustrates the assembly process according to the invention using a block diagram. First, according to step a) of the method according to the invention, at least two rolling bearings 3A, 3B are arranged on the shaft 2. In a further step b), the bearing seat 20 is thermally expanded by heating at least the bearing seat 20 of the housing 21. The heating is carried out such that the bearing seat has an inner diameter D LS at the assembly temperature Tmont, where the inner diameter D LS is larger than an outer diameter D AR the outer rings 6A, 6B of the rolling bearings 3A, 3B, so that they can be inserted into the thermally expanded bearing seat 20 with clearance or exactly without clearance, in any case avoiding significant axial forces (step c)).

[0043] In a further step d), the outer rings 6A, 6B of the rolling bearings 3A, 3B are axially preloaded relative to each other in a longitudinal direction L of the shaft 2. The axial preloading of the outer rings 6A, 6B is carried out either towards each other or away from each other. Step d) is always performed after step a) and can occur before or during step b), before or during step c), but in any case before the formation of the transverse press fit between the outer rings 6A, 6B of the rolling bearings 3A, 3B and the bearing seat 20.The preload applied to the outer rings 6A, 6B in step d), either towards or away from each other, is maintained for at least as long as necessary until the bearing seat 20 cools and a transverse press fit between the outer rings 6A, 6B of the rolling bearings 3A, 3B and the bearing seat 20 is sufficiently tight to fix the outer rings 6A, 6B of the rolling bearings 3A, 3B in their axial position relative to each other. Afterwards, if necessary, the axial preload, which was applied to prepare for assembly before the formation of the transverse press fit, can be released. The desired permanent axial preload is maintained by the transverse press fit once it has formed.

[0044] The method according to the invention makes it possible to provide a low-noise and at least axially backlash-free rolling bearing for a shaft in a particularly simple manner using standard components, and the assembly method of the rolling bearing is particularly suitable for mass production. According to the invention, a rolling bearing achieved in this way is characterized in particular by a particularly low weight, durability, and a low requirement for individual parts. 1 Rolling bearing arrangement 2nd wave 3A, 3B rolling bearings 4A, 4B inner rings 5A, 5B Rolling element, ball 6A, 6B outer rings 7 Spacer ring 8 gaps 9 Compression spring element 10 opposing arrows 11 O-arrangement 12 sealing washers 20 bearing seat 21 cases 22 attacks 23 Seating area 30 mounting stamps 31 Front 40 Magnet 50 retaining rings 51 Retaining ring groove 100 magnetic field line V Pre-assembly unit L Longitudinal direction R Radial direction D LS Inner diameter D AR Outer diameter of the outer ring T mont temperature T B maximum operating temperature

Claims

[1] Method for mounting a rolling bearing arrangement (1) of a shaft (2) in a bearing seat (20) for the rolling bearing arrangement (1), for example a housing (21) comprising at least the following steps: a) Arranging at least two rolling bearings (3A, 3B) on the shaft (2); b) Thermal expansion of the bearing seat (20) by heating at least the bearing seat (20) of the housing (21) to an inner diameter (D LS ), which is larger than the outer diameter (D AR ) of the outer rings (6A, 6B) of the rolling bearings (3A, 3B); c) Inserting the outer rings (6A, 6B) into the thermally expanded bearing seat (20); d) Axial preloading of the outer rings (6A, 6B) of the rolling bearings (3A, 3B) relative to each other in a longitudinal direction (L) of the shaft (2) viewed towards or away from each other at least during a period of time following step a), in which the outer diameter (D AR) of the outer rings (6A, 6B) of the rolling bearings (3A, 3B) is less than or equal to the inner diameter (D LS ) of the bearing seat (20); e) Cooling at least of the bearing seat (20) to form a transverse press fit between the outer rings (6A, 6B) of the rolling bearings (3A, 3B) and the bearing seat (20), whereby the axially preloaded state of the rolling bearings (3A, 3B) relative to each other is fixed. [2] Method according to claim 1, characterized by , that a temperature (T mont ), to which the bearing seat (20) is heated for thermal expansion, is greater than a maximum occurring operating temperature (T B ) the rolling bearing arrangement (1) and the bearing seat (20). [3] Method according to claim 1 or 2, characterized by , that the axial preloading of the outer rings (6A, 6B) relative to each other is effected by means of a compression spring element (9), e.g. a wave spring ring, a disc spring or an elastically deformable polymer element, between the outer rings (6A, 6B). [4] Method according to any of the preceding claims, characterized by , that the axial preloading of the outer rings (6A, 6B) towards each other is effected by means of a magnet (40) which acts on the outer rings (6A, 6B) at least until a sufficiently firm transverse press fit is formed between the outer rings (6A, 6B) and the bearing seat (20). [5] Method according to any of the preceding claims, characterized by , that for axial preload the outer rings (6A, 6B) are spring-loaded or magnetically preloaded towards or away from each other. [6] Method according to any of the preceding claims, characterized by , that the shaft (2) itself has raceways for rolling elements (5) and thus forms an inner ring (4A, 4B) of the rolling bearings (3A, 3B). [7] Method according to any of the preceding claims, characterized by, that deep groove ball bearings, shoulder ball bearings, angular contact ball bearings or tapered roller bearings are used as rolling bearings (3A, 3B). [8] Method according to any of the preceding claims, characterized by , that the rolling bearing arrangement (1) is formed from at least two rolling bearings (3A, 3B) of the same design or from at least two rolling bearings (3A, 3B) of different designs. [9] Pump device which has at least one shaft (2) rotatably mounted with respect to a housing (21), wherein a rolling bearing arrangement (1) of the shaft (2) is mounted according to a method according to one of claims 1 to 8.

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