CN108869016B

CN108869016B - Stator

Info

Publication number: CN108869016B
Application number: CN201810447752.0A
Authority: CN
Inventors: T.弗吕许茨; J.布格豪斯; M.博伊尔勒
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2017-05-12
Filing date: 2018-05-11
Publication date: 2022-03-25
Anticipated expiration: 2038-05-11
Also published as: DE102017208036A1; CN108869016A

Abstract

The invention relates to a stator (12) for a medium gap machine (10), in particular for a compressor (2) or a turbine (3), having an annular stator yoke (14) and having a plurality of stator teeth (15) extending radially inward from the stator yoke (14) in the direction of a longitudinal center axis of the medium gap machine (10). Provision is made for at least one of the stator teeth (15) to be made at least partially of a powder-metallurgical iron, cobalt and/or nickel-based material.

Description

Stator

Technical Field

The invention relates to a stator for a medium gap machine, in particular for a compressor or a turbine, having an annular stator yoke and having a plurality of stator teeth extending from the stator yoke radially inward along a longitudinal center axis of the medium gap machine.

The invention further relates to a medium gap machine, in particular for a compressor and/or a turbine, having a stator and a rotor supported on a shaft that can rotate about a longitudinal center axis.

The invention further relates to a compressor or a turbine having a housing in which an impeller is arranged on a rotatably mounted shaft and having a medium gap machine operatively connected to the shaft.

The invention further relates to an exhaust-gas turbocharger having a compressor and a turbine.

Finally, the invention relates to a method for producing a stator for a medium gap machine, which stator has an annular stator yoke and has a plurality of stator teeth extending from the stator yoke radially inward along a longitudinal center axis of the medium gap machine.

Background

Stators of the type mentioned at the outset are known from the prior art. Thus, for example, publication DE 102014210451 a1 discloses a stator having an annular stator yoke and having a plurality of stator teeth which project inwards in the direction of the rotor. Such stator teeth are used to optimize the magnetic flux and to cool the stator. However, it is known that such stator teeth increase the flow resistance and thus lead to power losses when the medium is guided through the stator. The efficiency of the medium gap machine, compressor, turbine or exhaust gas turbocharger is thereby also reduced with such a conventional stator.

Furthermore, a media gap machine of the type mentioned at the outset is known from the prior art. Patent application EP 1995426 a1 thus discloses a medium gap machine with a stator and a rotor and stator teeth extending from the stator yoke. For guiding the medium, it is furthermore provided that the rotor has a maximum outer diameter which is at most 2/3 of the inner diameter of the stator. The medium can thus be guided through the medium gap machine in a simple manner. However, such a conventional media gap machine has disadvantages in that: the magnetic field acting between the rotor and the stator is weakened due to the large air gap and therefore particularly strong magnets are required. Thus, the efficiency in such a conventional medium gap machine is low.

Disclosure of Invention

In contrast, the stator according to the invention has the advantage that the medium to be guided between the stator teeth and/or between the stator and the rotor which can be arranged therein can be guided substantially without efficiency losses. In addition, such a stator has the advantage that the magnetic field acting between the stator and the rotor is particularly strong due to the good magnetic, in particular ferromagnetic, properties of the stator teeth. Furthermore, such a stator has the advantage that the flow resistance of the medium to be guided in the stator is low, and at least the stator teeth are very hard, robust, corrosion-resistant and at the same time have good elasticity. In this respect, according to the invention, at least one of the stator teeth is at least partially made of a powder-metallurgical iron, cobalt and/or nickel-based material. In contrast to conventional stator teeth, which are usually produced from electrical sheet metal, any desired shape of the stator teeth can be achieved by means of the production of iron, cobalt and/or nickel-based materials, in particular granules, from powder metallurgy. The stator teeth are also produced in a powder metallurgy process, in particular a thermoplastic molding process, in particular an injection molding process, and preferably in one of these processes.

Furthermore, it is preferably provided that the powder-metallurgical iron, cobalt and/or nickel-based material of the stator is a metallic glass, in particular a solid metallic glass. Metallic glass is particularly stable and corrosion resistant, and is therefore particularly well suited for use in stators. Furthermore, metallic glasses have very good magnetic properties, in particular good saturation polarization and excellent magnetic permeability. At the same time, it has a high electrical resistance, so that the eddy current losses in the stator are low.

The metallic glass specified in this context is designed to be particularly thin, it preferably covering at least partially the individual stator teeth or at least one of said stator teeth. Alternatively, however, the larger section and/or at least one of the stator teeth is made entirely of solid metallic glass. In this context, solid metallic glasses are also metallic glasses which have, in particular, a particularly high thickness, at least in sections. Therefore, a coating with metallic glass alone cannot be understood as a solid metallic glass. The solid metallic glass has a thickness of more than > 1 mm. In particular, in the case of at least one of the stator teeth being made entirely of metallic glass, this is to be understood as solid metallic glass.

According to a further development of the invention, at least one of the stator teeth is made of a powder-metallurgical iron, cobalt and/or nickel-based material. The advantage of such a stator is that the at least one stator tooth is particularly stable and the efficiency of the dielectric gap machine with such a stator tooth is improved.

Furthermore, it is preferably provided that a plurality of stator teeth, in particular all stator teeth, are made of a powder-metallurgical iron, cobalt and/or nickel-based material. The stability of such a stator is advantageously further improved. Corrosion resistance and wear properties are also improved.

According to a preferred further development of the invention, the stator yoke is made of a powder-metallurgical iron, cobalt and/or nickel-based material. As a result, particularly good magnetic properties, particularly a high magnetic permeability, are advantageously obtained.

According to a further development of the invention, it is provided that the stator teeth are formed integrally with the stator yoke. This further improves the stability of the stator.

In addition or alternatively, it is preferably provided that the respective stator tooth is designed in a flow-optimized manner as a guide for the medium gap machine. Such stator teeth have the advantage that the flow resistance is low and thus the efficiency of the medium gap machine with such stator teeth is particularly high. The stator teeth are designed in a flow-optimized manner, in particular in the axial direction, along the longitudinal center axis of the medium gap machine. Alternatively or additionally, however, it is also provided that the stator teeth have a flow-optimized shape in the radial direction.

According to a preferred refinement of the invention, it is provided that the respective stator tooth has an oval, in particular elliptical, shape. Particularly advantageous flow characteristics are thereby obtained and the efficiency of the medium gap machine with such stator teeth is further improved.

The oval, in particular elliptical, shape of the respective stator tooth is preferably configured in the radial direction toward the longitudinal center axis of the medium gap machine and/or in the axial direction along the longitudinal center axis.

A medium gap machine according to the invention, in particular for a compressor and/or a turbine, with a stator and a rotor supported on a shaft rotatable about a longitudinal center axis, is characterized by the inventive design of the stator. The advantages already mentioned above are correspondingly achieved.

The compressor or turbine according to the invention is characterized by the inventive design of the medium gap machine. The advantages already mentioned are also obtained in this context.

The exhaust-gas turbocharger according to the invention is characterized by the inventive design of the compressor and/or the turbine. The advantages already mentioned are thereby obtained.

The method according to the invention for producing a stator is characterized in that at least one of the stator teeth is at least partially made of a powder-metallurgical iron, cobalt and/or nickel-based material.

Drawings

The invention is explained in more detail below with the aid of the figures.

To this end:

figure 1 shows an embodiment of an exhaust-gas turbocharger with a compressor, a turbine and a medium gap machine with a stator and a rotor in a simplified longitudinal section,

fig. 2 shows an embodiment of a medium gap machine according to the invention with a stator and a rotor in a cross-sectional view.

Detailed Description

Fig. 1 shows an exhaust-gas turbocharger 1 with a compressor 2 and a turbine 3 in a simplified longitudinal section. The compressor 2 has in particular a first impeller, in particular a compressor impeller 4 arranged on a shaft 5 in a rotationally fixed manner. The shaft 5 is itself rotatably mounted in a housing 6 of the exhaust-gas turbocharger 1. Furthermore, a second impeller, in this case a turbine wheel 7 of the turbine 3, is connected in a rotationally fixed manner to the shaft 5 at the end of the shaft 5 facing away from the compressor wheel 4. When the exhaust gas of the internal combustion engine flows to the turbine wheel 7 and thus drives it, the compressor wheel 4 is likewise brought into rotational motion, so that the fresh air supplied to the compressor wheel 4 is compressed and supplied to the internal combustion engine.

The rotatable mounting of the shaft 5 in the housing 6 can be realized in different ways. According to a first exemplary embodiment, the shaft 5 is rotatably mounted in the housing 6 by means of at least two bearings 8 and 9. Preferably, two roller bearings are present as bearings 8, 9. For axial support of the shaft 5, it can also be provided that one of the roller bearings is designed as an axial roller bearing.

Alternatively and according to the exemplary embodiment shown in fig. 1, it is provided that the bearing 8 is designed as a magnetic bearing and the bearing 9 serving as an axial bearing is designed as a roller bearing.

In order to be able to drive the compressor 2 in particular independently of the exhaust gas flow of the internal combustion engine, so that a high cylinder air charge can be achieved at any time in the cylinders of the internal combustion engine, it is also provided in this context that the exhaust gas turbocharger 1 has an electric gap machine 10. In this context, the medium gap machine is integrated into the compressor 2, wherein the rotor 11 of the medium gap machine 10 is arranged in a rotationally fixed manner on the end of the shaft 5 facing away from the turbine wheel 7. The stator 12, which interacts with the rotor 11, in particular with the energizable drive winding 17, is arranged coaxially to the rotor 11 in a housing-fixed manner in a flow channel 13 of the exhaust-gas turbocharger 1, which flow channel leads to the compressor wheel 4.

Fig. 2 shows a simplified illustration of the media gap machine 10 in cross-section. Here, in particular, the stator 12 and the rotor 11 of the medium gap machine 10 are shown. The stator 12 has a circular-ring-shaped stator yoke 14 from which a plurality of stator teeth 15, of which only one is provided with a reference numeral in this context, which are arranged uniformly distributed over the circumference of the stator yoke 14, project radially inward and point in the direction of the rotor 11 or the axis of rotation of the shaft 5. The stator teeth 15 end radially spaced apart from the rotor 11, so that an air gap is present between the stator teeth 15 and the rotor 11.

The stator teeth 15 have an oval shape at least in their respective end regions projecting from the drive winding in the direction of the rotor 11. The stator teeth 15 are shaped in particular in the mentioned end region as an oval cross section. However, in an axial longitudinal section, along the longitudinal center axis of the medium gap machine 10, the stator teeth 15, particularly preferably also only in the mentioned end regions, are shaped oval or oval and are thus flow-optimized. This results in particularly favorable flow properties for the medium flowing through the medium gap machine 10 and a higher efficiency of the medium gap machine 10.

Furthermore, the stator teeth 15, in this case the stator yoke 14, and optionally also the stator yoke 14, are made in particular in one piece with the stator yoke 14 from a powder-metallurgical iron, cobalt and/or nickel-based material. This improves the magnetic permeability of the stator 12, the corrosion resistance of the stator 12, and the efficiency of the dielectric gap machine 10.

Claims

1. A stator (12) for a medium gap machine (10), which stator has an annular stator yoke (14) and has a plurality of stator teeth (15) extending radially inwards from the stator yoke (14) in the direction of a longitudinal centre axis of the medium gap machine, characterized in that at least one of the stator teeth (15) is at least partly made of a powder-metallurgical iron, cobalt and/or nickel-based material, the stator tooth (15) having an oval shape at least in its respective end region protruding from the drive winding in the direction of the rotor.

2. The stator (12) of claim 1 wherein the powder metallurgical iron, cobalt and/or nickel based material is a metallic glass (16).

3. A stator (12) according to claim 1 or 2, characterized in that at least one of the stator teeth (15) consists of a powder metallurgical iron, cobalt and/or nickel based material.

4. A stator (12) according to claim 1 or 2, characterized in that the plurality of stator teeth (15) are made of powder metallurgical iron, cobalt and/or nickel based material.

5. A stator (12) according to claim 1 or 2, characterized in that the stator yoke (14) is made of a powder metallurgical iron, cobalt and/or nickel based material.

6. A stator (12) according to claim 1 or 2, characterized in that the stator teeth (15) are constructed integrally with the stator yoke (14).

7. Stator (12) according to claim 1 or 2, characterized in that the respective stator tooth (15) is configured in a flow-optimized manner as a guide for a medium gap machine.

8. A stator (12) according to claim 1 or 2, wherein the respective stator teeth (15) have an oval shape.

9. Stator (12) according to claim 1, characterized in that the medium gap machine is used for a compressor (2) or a turbine (3).

10. The stator (12) of claim 2 wherein the metallic glass is solid metallic glass.

11. A stator (12) according to claim 4, characterized in that all stator teeth (15) are made of powder metallurgical iron, cobalt and/or nickel based material.

12. The stator (12) according to claim 8, wherein the respective stator teeth (15) have an elliptical shape.

13. A medium gap machine (10) having a stator (12) and a rotor (11) supported on a shaft rotatable about a longitudinal centre axis, characterized in that the stator (12) according to any one of claims 1 to 12 is constructed.

14. A medium gap machine (10) according to claim 13, characterized in that it is used for a compressor (2) or a turbine (3).

15. A compressor (2) or a turbine (3) having a housing in which impellers (4, 7) are arranged on a rotatably mounted shaft (5) and which has a medium gap machine (10) in operative connection with the shaft (5), characterized in that the medium gap machine (10) according to claim 13 is constructed.

16. An exhaust-gas turbocharger (1) having a compressor (2) and a turbine (3), characterized in that the compressor (2) and/or the turbine (3) according to claim 15 are constructed.

17. A method for manufacturing a stator (12) according to any one of claims 1-12 for a medium gap machine (10), the stator having an annular stator yoke (14) and a plurality of stator teeth (15) extending radially inwards from the stator yoke (14) along a longitudinal centre axis of the medium gap machine (10), characterized in that at least one of the stator teeth (15) is at least partly made of a powder metallurgical iron, cobalt and/or nickel based material.