DE102013019020A1 - Turbomachine, especially for a motor vehicle - Google Patents

Abstract

The invention relates to a turbomachine (10), comprising a housing (12) with a rotatably mounted on this rotor (14) about a rotation axis (16) relative to the housing (12), which has a shaft (18) and at least one the shaft (18) rotatably connected impeller (20), and with at least one thrust bearing (22) by means of which the rotor (14) in the axial direction on the housing (12) is mounted, wherein the thrust bearing (22) at least one on Rotor (14) held first permanent magnet (24) and at least one housing-fixed second permanent magnet (26), wherein the first permanent magnet (24) in the radial outward direction at least partially covered by the second permanent magnet (26), wherein the permanent magnets (24 , 26) each generate a magnetic field with a magnetic flux extending in the axial direction.

Description

The invention relates to a turbomachine, in particular for a motor vehicle, according to the preamble of patent claim 1.

Such a turbomachine is the US 2007/0069597 A1 to be known as known. The turbomachine comprises a housing and a rotor. The rotor is rotatably mounted on the housing about an axis of rotation relative to the housing. In addition, the rotor comprises a shaft and at least one rotatably connected to the shaft impeller. This means that the shaft and the impeller can rotate together about the axis of rotation relative to the housing. The impeller is designed as a compressor and serves to compress air. The compressed air can be supplied to a fuel cell. By means of the fuel cell, for example, chemical reaction energies of a supplied fuel and an oxidizing agent are converted into electrical energy.

The turbomachine further comprises at least one thrust bearing, by means of which the rotor is mounted in the axial direction on the housing. The thrust bearing comprises at least one first permanent magnet held on the rotor and at least one second permanent magnet fixed to the housing. In other words, the second permanent magnet is arranged at least indirectly on the housing.

This thrust bearing is part of an auxiliary storage device, which is provided in addition to a main storage device. The main bearing device comprises hydrodynamic air bearings, by means of which the rotor in the axial direction and radial direction in its normal operating state, that is at high rotational speeds of the rotor, is stored. The auxiliary bearing device is used for axial and radial bearings of the rotor at a standstill and at very low speeds, for example, when the rotor is accelerated from standstill and thereby brought into its normal operating condition. Due to the use of both the main storage device and the auxiliary storage device, there is a high space requirement of the bearing of the rotor and a high complexity and a high number of parts of the turbomachine.

The DE 102 16 447 C1 discloses an exhaust gas turbocharger with a shaft on which a turbo wheel and a compressor wheel sit and which is guided in radial bearings and at least one thrust bearing. The thrust bearing is designed as an active magnetic bearing with an electromagnet, an axial sensor and a regulator for controlling the electromagnet acting on the electrical current. It is envisaged that the radial bearings are designed as passive magnetic bearing with axial magnetic flux generating permanent magnets.

Finally, the reveals WO 2009/115149 A1 a turbocharger having a shaft. On the shaft, a turbine wheel and a compressor wheel are arranged. The shaft is mounted via a magnetic bearing assembly in a housing of the turbocharger.

Object of the present invention is therefore to provide a turbomachine, especially for a motor vehicle of the type mentioned, in which a particularly simple, space-saving and cost-effective storage of the rotor can be realized.

This object is achieved by a turbomachine having the features of patent claim 1. Advantageous embodiments with expedient and non-trivial developments of the invention are specified in the remaining claims.

In order to further develop a turbomachine, in particular for a motor vehicle, the type specified in the preamble of claim 1 such that a particularly simple, space-saving and cost-effective mounting of the rotor can be realized, it is inventively provided that the first permanent magnet in the radial direction to the outside is at least partially covered by the second permanent magnet, wherein the permanent magnets each generate a magnetic field with a magnetic flux extending in the axial direction. Thus, by means of the permanent magnets, a particularly simple, but at the same time sufficiently stable mounting of the rotor in the axial direction, wherein this axial bearing not only for supporting the rotor at a standstill of the rotor and at very low speeds, but also for supporting the rotor in its normal operating state at very high speeds can be used. In other words, it is preferably provided that the permanent magnets are provided for axially supporting the rotor in all operating states of the rotor. In other words, the realizable by the permanent magnets, axial bearing of the rotor is sufficient to support the rotor in all operating conditions. Thus, the use of both a main storage device and an auxiliary storage device can be dispensed with. By means of the permanent magnets, it is namely possible to safely store the rotor in the axial direction at standstill, at low speeds and at the same time higher rotational speeds. Thus, an axial, passive magnetic bearing of the high-speed rotor is created, which can be displayed with a very small number of parts and thus particularly cost and space.

Further advantages, features and details of the invention will become apparent from the following description of preferred embodiments and from the drawing. The features and feature combinations mentioned above in the description as well as the features and feature combinations mentioned below in the description of the figures and / or in the figures alone can be used not only in the respectively specified combination but also in other combinations or in isolation, without the scope of To leave invention.

The drawing shows in:

1 a schematic longitudinal sectional view of a turbomachine according to a first embodiment, in which a rotor is mounted by means of at least one axial bearing in the axial direction of a corresponding housing of the turbomachine, the thrust bearing comprises at least a first permanent magnet and at least one second permanent magnet, wherein the first permanent magnet in radially outward direction is at least partially covered by the second permanent magnet and wherein the permanent magnets each generate a magnetic field with extending in the axial direction magnetic flux;

2 a diagram illustrating the principle of operation of the thrust bearing according to 1 ;

3 a schematic longitudinal sectional view of the turbomachine according to a second embodiment; and

4 a schematic longitudinal sectional view of the turbomachine according to a third embodiment.

In the figures, the same or functionally identical elements are provided with the same reference numerals.

1 shows in a schematic longitudinal sectional view of a detail with a whole 10 designated turbomachine, in particular for a motor vehicle and in particular for a passenger car. 1 shows the turbomachine 10 according to a first embodiment. The turbomachine 10 includes an in 1 partially recognizable housing 12 as well as a whole with 14 designated rotor. The rotor 14 is about a rotation axis 16 relative to the housing 12 rotatable on the housing 12 stored. To the rotor 14 in the radial direction on the housing 12 to store, at least one radial bearing is used. This radial bearing is designed, for example, as a hydrodynamic air bearing. Alternatively, however, a sliding bearing or a rolling bearing is conceivable.

The rotor 14 includes a wave 18 , Which in the present case and at least in a length range is designed as a hollow shaft. In addition, the rotor includes 14 an impeller 20 , which rotatably with the shaft 18 connected is. At the wheel 20 it is a compressor wheel for compressing air. The compressor wheel is thus part of a compressor, by means of which air can be compressed.

The compressed air is supplied to, for example, an internal combustion engine for driving the motor vehicle. Alternatively or additionally, the motor vehicle may comprise at least one fuel cell, which can be supplied with the compressed air. By supplying the internal combustion engine and / or the fuel cell with the compressed air, a particularly efficient operation of these can be realized.

The rotor 14 For example, at least one in 1 unrecognizable turbine wheel of a turbine of the turbomachine 10 include. The turbine wheel is also rotatable with the shaft 18 connected. The turbine wheel, for example, driven by a gas, so that thereby the impeller 20 (Compressor wheel) over the shaft 18 can be driven by the turbine wheel. As a result, energy contained in the gas can be used to compress the air. The gas, by means of which the turbine wheel is driven, is, for example, exhaust gas of the internal combustion engine and / or exhaust air of the fuel cell.

In addition, it is preferably provided that the turbomachine 10 is designed as an electrically driven turbocompressor. This means that the turbomachine 10 at least one in 1 unrecognizable electric motor comprises. The electric motor comprises a stator which is at least indirectly on the housing 12 is held. Furthermore, the electric motor comprises a rotor which rotatably with the rotor 14 is coupled. The rotor is drivable by the stator, so that the rotor 14 can be powered by the electric machine. This makes it possible for the impeller 20 regardless of the mass flow of the gas to drive the turbine wheel. If, for example, the mass flow of the gas is very low or if the turbine wheel is not driven or flowed around at all by the gas, then the rotor can 14 nevertheless be driven by means of the electric motor, so that the air can be compressed.

The turbomachine 10 according to the first embodiment comprises a thrust bearing 22 , by means of which the rotor 14 in the axial direction on the housing 12 is stored. The thrust bearing 22 includes at least one on the rotor 14 held, first permanent magnet 24 and at least one housing-fixed second permanent magnet 26 , This means that the second permanent magnet 26 at least indirectly on the case 12 is held.

How out 1 is recognizable, is the first permanent magnet 24 in the radial outward direction at least partially from the second permanent magnet 26 covered. Both permanent magnets 24 . 26 generate in each case a magnetic field with a magnetic flux extending in the axial direction. The magnetic flux of the first permanent magnet 24 is by a directional arrow 28 illustrates, wherein the magnetic flux of the second permanent magnet 26 by directional arrows 30 is illustrated. Out 1 is recognizable that the magnetic flux of the first permanent magnet 24 opposite to the magnetic flux of the second permanent magnet 26 is. The permanent magnets 24 . 26 be used for axial bearing of the rotor 14 in all operating conditions of the rotor 14 used. This means that the rotor 14 both at standstill, at low speeds and in contrast higher speeds by means of the thrust bearing 22 that is, by means of the permanent magnets 24 . 26 is stored axially. In other words, the rotor becomes 14 in the axial direction both at a standstill and at all possible speeds occurring by means of the permanent magnets 24 . 26 is stored. The use of main storage facilities and additionally provided auxiliary storage can be dispensed with.

1 shows the rotor 14 for example, in a rest position. Now for example - based on the image levels of 1 - a shift of the rotor 14 in the axial direction relative to the housing 12 to the right, this shift is called "+ x". This shift "+ x" is also in an in 2 shown diagram, using the in 2 recognizable diagram the operating principle of the thrust bearing 22 is illustrated. In contrast, results in a shift of the rotor 14 relative to the housing 12 in the axial direction to the left (relative to the image plane of 1 ), this displacement is called "-x". Also this displacement "-x" is in the in 2 shown diagram entered. In other words, on the abscissa 32 of the diagram, the axial displacement of the rotor 14 relative to the housing 12 applied.

On the ordinate 34 is one through the permanent magnets 24 . 26 enforceable force F applied, resulting from the displacement of the rotor 14 relative to the housing 12 resulting in the axial direction. From the displacement of the rotor 14 relative to the housing 12 in fact, a displacement of the permanent magnet also results in the axial direction 24 relative to the permanent magnet 26 in the axial direction. From this relative displacement of the permanent magnets 24 . 26 results - as from the diagram in 2 recognizable - a restoring force acting on the rotor 14 acts. The one thrust bearing 22 is basically sufficient for the axial bearing of the rotor 14 , However, the force-displacement curve illustrating the relationship between the axial displacement and the restoring force is 36 in the region of the rest position, that is in the region of the intersection of the abscissa 32 with the ordinate 34 relatively flat. This means that low axial forces lead to large axial displacements of the rotor 14 relative to the housing 12 to lead.

3 shows the whole with 10 designated turbomachine according to a second embodiment, wherein a double, axial magnetic bearing of the rotor 14 is provided. This double magnetic thrust bearing includes the thrust bearing 22 as well as in the axial direction of the thrust bearing 22 spaced, arranged second thrust bearing 38 , The function of the second thrust bearing 38 corresponds essentially to the function of the first thrust bearing 22 , Also the second thrust bearing 38 comprises at least a first permanent magnet 40 , which at least indirectly on the rotor 14 is held. Furthermore, the second axial bearing comprises 38 at least one second housing-fixed permanent magnet 42 , Also with the second thrust bearing 38 is the first permanent magnet 40 in the radial outward direction at least partially from the second permanent magnet 42 covered.

Based on directional arrows 44 . 46 It can be seen that also the magnetic fluxes of the permanent magnets 40 . 42 are aligned opposite to each other. The thrust bearings 22 . 38 as well as their permanent magnets 24 . 26 respectively 40 . 42 are thus shifted from one another and thereby biased against each other so that compared to the first embodiment, higher forces can be absorbed in the axial direction or at a same force, a lesser displacement of the rotor 14 results. The above and below to the thrust bearing 22 and the permanent magnets 24 . 26 Described can easily on the second thrust bearing 38 and its permanent magnets 40 . 42 be transferred and vice versa.

Out 3 is the turbine of the turbomachine 10 recognizable. The turbine includes the in 3 With 48 designated turbine wheel, with the shaft 18 rotatably connected. Furthermore, it is off 3 a turbine housing 50 the turbine recognizable in which the turbine wheel 48 is included.

The first permanent magnet 24 is in a corresponding recess 52 of the impeller 20 added. Here is the first permanent magnet 24 completely in the recess 52 added. This means that the first permanent magnet 24 in the radial outward direction completely through the impeller 20 is covered.

Furthermore, it is provided that the permanent magnet 24 in the wheel 20 shrunk. This shrinkage can cause the impeller 20 and the permanent magnet 24 be balanced together. The magnetization can thus take place after the balancing process, whereby this is particularly easy to carry out. The second permanent magnet 26 For example, it is annular, so that it is around the axis of rotation 16 in the circumferential direction about the first permanent magnet 24 extends around.

4 shows the turbomachine 10 according to a third embodiment. Using the directional arrows 28 and 30 it can be seen that the magnetic fluxes of the permanent magnets 24 . 26 now pointing in the same direction. The same is the thrust bearing 38 intended. Also in the third embodiment, as in the second embodiment, a preloaded axial bearing is provided, by means of which high forces can be absorbed in the axial direction.

LIST OF REFERENCE NUMBERS

10

flow machine

12

casing

14

rotor

16

axis of rotation

18

wave

20

Wheel

22

thrust

24

first permanent magnet

26

second permanent magnet

28

arrow

30

arrow

32

abscissa

34

ordinate

36

Force-displacement curve

38

second thrust bearing

40

first permanent magnet

42

second permanent magnet

44

arrow

46

arrow

48

turbine

50

turbine housing

52

recess

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 2007/0069597 A1 [0002]
• DE 10216447 C1 [0005]
• WO 2009/115149 A1 [0006]

Claims (6)

Turbomachine ( 10 ), with a housing ( 12 ), with one around a rotation axis ( 16 ) relative to the housing ( 12 ) rotatably mounted on this rotor ( 14 ), which is a wave ( 18 ) and at least one with the shaft ( 18 ) rotatably connected impeller ( 20 ), and with at least one thrust bearing ( 22 ), by means of which the rotor ( 14 ) in the axial direction on the housing ( 12 ), wherein the thrust bearing ( 22 ) at least one on the rotor ( 14 ), the first permanent magnet ( 24 ) and at least one housing-fixed second permanent magnet ( 26 ), characterized in that the first permanent magnet ( 24 ) in the radial outward direction at least partially from the second permanent magnet ( 26 ) is covered, wherein the permanent magnets ( 24 . 26 ) each generate a magnetic field with a magnetic flux extending in the axial direction. Turbomachine ( 10 ) according to claim 1, characterized in that the permanent magnets ( 24 . 26 ) for supporting the rotor ( 14 ) in all operating states of the rotor ( 14 ) are provided. Turbomachine ( 10 ) According to one of claims 1 or 2, characterized in that the magnetic flux of the first permanent magnet ( 24 ) opposite to the magnetic flux of the second permanent magnet ( 26 ). Turbomachine ( 10 ) according to one of the preceding claims, characterized in that the first permanent magnet ( 24 ) in a corresponding recess ( 52 ) of the impeller ( 20 ) is recorded. Turbomachine ( 10 ) according to claim 4, characterized in that the first permanent magnet ( 24 ) completely in the recess ( 52 ) is recorded. Turbomachine ( 10 ) according to one of claims 4 or 5, characterized in that the first permanent magnet ( 24 ) in the impeller ( 20 ) has shrunk.

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