DESCRIPTION The invention relates to an axial air bearing arrangement as per the preamble of claim 1 and to a radial air bearing arrangement as per the preamble of claim 10.

Air bearing arrangements have a base support. This can be, for example, a component part of a housing of a turbocharger. A bearing plate and a spring plate are arranged in the base support. The bearing plate is shaped in accordance with the shaft to be mounted and rests against the shaft, if the shaft is not rotating. If the shaft begins to rotate, an air cushion begins to build up between the outer surface of the shaft and the inner surface of the bearing plate, so that the bearing plate lifts off from the shaft counter to the pressure of the spring plate and therefore the shaft is mounted in a virtually wear- free manner by way of an air cushion. For this purpose, the bearing plate and the spring plate are arranged in the base support. This base support can represent both a bearing sleeve and a housing component.

It is an object of the present invention to provide air bearing arrangements of the type indicated in the preamble of claims 1 and 9 which can have a simple construction and can be mounted easily.

This object is achieved by the features of the independent claims. The dependent claims relate to preferred refinements of the invention.

In the axial air bearing arrangement and in the radial air bearing arrangement, provision is made in each case according to the invention of a plurality of pairs of spring plate and bearing plate. The spring plates and bearing plates at least in groups have a multi-part design as separate plates, i.e. they are not connected to one another via a ring. "At least in groups" in this context means that two or more adjacent plates can by all means be connected to one another.

Within the context of the axial and radial air bearing arrangement, it is preferably provided that at least one fastening tab is formed on the spring plate and/or on the bearing plate. The fastening tab projects into a cutout in the base support. A spring element is preferably located in turn on the fastening tab. The fastening tab can be fixed to the base support by means of this spring element. Particularly when the plates have a multi-part design, the use of fastening tabs with spring elements simplifies the mounting of the plates, since said fastening tabs can independently hold firm in the cutouts during assembly of the air bearing arrangement.

In the preferred embodiment, the invention solves the problem relating to fastening in a simple manner by small fastening tabs, optionally with the spring elements. As a result, the bearing plates and/or spring plates can be held down on the base support and are securely fixed in the assembly process.

The at least one spring element both in the radial air bearing arrangement and in the axial air bearing arrangement can be used for connecting the fastening tab to the base support in a form-fitting and/or in a force-fitting manner. In the case of the form- fitting connection, the spring element engages behind the base support. In the case of the force-fitting connection, the spring element spreads apart into the base support.

In the axial air bearing arrangement, the spring plates and bearing plates are preferably arranged so as to overlap one another and are distributed along the circumference. A plurality of pairs each consisting of one spring plate and one bearing plate are located along the circumference. In this respect, in each case at least one fastening tab of a spring plate is inserted in a further cutout in an adjacent bearing plate. It is preferable that a holder is formed on at least one spring plate, and a holding region is located on at least one bearing plate. The holder of the spring plate of a first pair overlaps with the holding region of the bearing plate of an adjacent pair. The overlapping and stable arrangement is thus formed. In the process, the spring plate with the holder presses the holding region of the bearing plate down.

Instead of the designation "air bearing arrangement", it is also possible to refer to a "foil bearing arrangement".

Further details, features and advantages of the invention become apparent from the following description of exemplary embodiments with reference to the drawing, in which:

Figure 1 shows a radial air bearing arrangement according to the invention as per a first exemplary embodiment,

Figure 2 shows a base support of the illustration shown in Figure 1,

Figure 3 shows a spring plate of the illustration shown in Figure 1 ,

Figure 4 shows a bearing plate of the illustration shown in Figure

1, Figure 5 shows an axial air bearing arrangement according to the invention as per a second exemplary embodiment,

Figure 6 shows a spring plate of the illustration shown in Figure 5,

Figure 7 shows a bearing plate of the illustration shown in Figure 5,

Figure 8 shows the axial air bearing arrangement according to the invention as per the second exemplary embodiment during assembly, and

Figure 9 shows a possible use for the air bearing arrangements according to the invention of both exemplary embodiments.

Figure 1 shows an isometric view of a radial air bearing arrangement 1. The radial air bearing arrangement 1 comprises a cylindrical base support 2 with a central cylindrical recess 7. The base support 2 is, for example, a bearing shell or is an integral component part for example of a turbine housing of a turbocharger. The base support 2 is shown in detail in Figure 2. A shaft (not shown) is seated in the recess 7 and is mounted by the radial air bearing arrangement 1. As shown in Figure 2, the base support 2 comprises three cutouts 6 on each of its end faces.

Axial directions 9 pointing in opposite directions, radial directions 10 pointing in opposite directions and circumferential directions 11 pointing clockwise and counterclockwise are defined with respect to the radial air bearing arrangement 1 for the explanation of components which are arranged in relation to one another.

The radial air bearing arrangement 1 furthermore comprises a plurality of bearing plates 3 and a plurality of spring plates 4. One of the spring plates 4 is shown in Figure 3. Figure 4 shows one of the bearing plates 3 in detail.

Each bearing plate 3 has two fastening tabs 5. The fastening tabs 5 extend in the radial direction 10. Spring elements 8 are formed at the ends of each of the fastening tabs 5. The bearing plate 3, the fastening tabs 5 and the spring elements 8 are produced together in one piece, for example as a stamped and bent part.

Each spring plate 4 has two additional tabs 12, which likewise extend in the radial direction 10. In the assembled state as shown in Figure 1 , both the fastening tabs 5 and the additional tabs 12 each project into the cutouts 6 on the base support 2.

The spring elements 8 are formed in such a way that they engage behind the base support 2 at a radial outer side. As a result, the spring elements 8 ensure that there is a form-fitting connection between the respective bearing plate 3 and the base support 2. As a consequence of this, the connection with the spring elements 8 can also be referred to as a latching connection. In this case, the spring element 8 accordingly represents the latching lug, which engages behind the base support 2.

Figure 5 shows an axial air bearing arrangement 13. Identical or functionally identical components are denoted by the same reference numerals in all of the exemplary embodiments.

A plurality of separate bearing plates 3 and spring plates 4 are likewise provided. In each case one bearing plate 3 and one spring plate 4 form a pair with one lying on the other. The individual pairs are arranged distributed over the base support 2 along the circumferential direction 11. The base support 2 with the bearing plates 3 and spring plates 4 arranged thereon is configured for rotatable assembly on a counter disk (not shown).

As is shown by the dashed illustration in Figure 5, each spring plate 4 has two fastening tabs 5. The fastening tabs 5 project in the axial direction 9 into cutouts 6 (shown purely schematically) in the base support 2. When the air bearing arrangement 13 rotates with respect to a counter disk (not shown), ventilation stages 21 which have been stamped in bring about a buildup of pressure between the bearing plates 4 and the counter disk.

Figure 6 shows the design of a spring plate 4 in detail. Here, spring elements 8 are provided in turn at the end of the fastening tabs 5. These spring elements 8 are bent ends of the fastening tabs 5. The spring elements 8 ensure that the spring plates 4 are fixed in the cutouts 6 in the base support 2. In this respect, there are two variants: On the one hand, the spring elements 8 can anchor in the cutouts 6 in a force-fitting manner. On the other hand, it is possible that the spring elements 8 engage behind the base support 2 on an axially opposite side and therefore provide for a form-fitting connection.

Figure 7 shows one of the bearing plates 3 of the second exemplary embodiment. Each bearing plate 3 has two further cutouts 14. In the second exemplary embodiment, the fastening tabs 5 are inserted not only into the cutouts 6 in the base support 2, but also into the further cutouts 14 in an adjacent bearing plate 3.

This assembly is shown in detail in Figure 8. Individual bearing plates 3 and individual spring plates 4 have been omitted in Figure 8. It can be seen that in each case the fastening tabs 5 of a spring plate 4 are inserted into the further cutouts 14 in an adjacent bearing plate 13. An overlapping and therefore stable arrangement is thus formed for the axial air bearing arrangement 13.

A spring plate holding region 18 is formed on each of the spring plates 4, and a bearing plate holding region 19 is located on each bearing plate 3. The spring plate holding regions 18 of the spring plates 4 overlap in each case with the bearing plate holding region 19 of the bearing plates 3 of the adjacent pair. The overlapping and stable arrangement is thus formed.

Figure 8 furthermore shows ventilation holes 17 in the bearing plates 3 and in the base support 2. The ventilation holes 17 in the bearing plates 3 are aligned in each case with a ventilation hole 17 in the base support 2. Supporting lugs 22 extending areally from the bearing plate holding regions 19 support the bearing plates 3 against twisting about the axial direction 9.

Figure 9 shows an exemplary use for the radial air bearing arrangement 1 and the axial air bearing arrangement 13. Figure 9 shows a turbocharger 15 with a flanged electric machine 16. The rotor shaft of the electric machine 16 or the turbine shaft of the turbocharger 15 is in this case mounted by way of the radial air bearing arrangement 1 and the axial air bearing arrangement 13 as per the exemplary embodiments.

In addition to the above written disclosure of the invention, reference is hereby explicitly made to the illustrative presentation thereof in Figures 1 to 9.

LIST OF REFERENCE SIGNS

1 Radial air bearing arrangement

2 Base support

3 Bearing plate

4 Spring plate

5 Fastening tab

6 Cutout

7 Recess

8 Spring element

9 Axial direction

10 Radial direction

1 1 Circumferential direction

12 Additional tabs

13 Axial air bearing arrangement

14 Further cutout

15 Turbocharger

16 Electric machine

17 Ventilation holes

18 Spring plate holding region

19 Bearing plate holding region

20 End face

21 Ventilation stage

22 Supporting lugs