DE102020005817A1 - Bearing arrangement of a running gear on a housing of an exhaust gas turbocharger, in particular for a motor vehicle - Google Patents

Abstract

The invention relates to a bearing arrangement (10) for a rotor (12) on a housing (14) of an exhaust gas turbocharger (16), in which a shaft (18) of the rotor (12) is positioned in the axial direction of the shaft ( 18) is rotatably mounted on the housing (14), the axial bearing (22) being displaceable relative to the shaft (18) and relative to the housing (14) during operation of the exhaust gas turbocharger (16) in the radial direction of the shaft (18). is.

Description

The invention relates to a bearing arrangement of a rotor on a housing of an exhaust gas turbocharger, in particular for a motor vehicle, according to the preamble of patent claim 1.

Such a mounting arrangement of a running gear on a housing of an exhaust gas turbocharger is, for example, already DE 37 12 444 A1 to be taken as known. In the bearing arrangement, a shaft of the running gear, also referred to as a rotor, is rotatably supported on the housing through the intermediary of an axial bearing, ie via the axial bearing, in the axial direction of the shaft and is thus mounted. Forces acting in the axial direction of the shaft and also referred to as axial forces can thus be transmitted from the shaft via the axial bearing to the housing and thus supported by the housing, so that in particular excessive movements of the shaft in the axial direction of the shaft relative to the housing are avoided be able.

Furthermore, the DE 10 2007 060 226 A1 an axial bearing for mounting a shaft in a housing part, which is acted upon by a lubricant via a connection.

The object of the present invention is to further develop a bearing arrangement of the type mentioned at the outset in such a way that particularly efficient operation of the exhaust gas turbocharger can be implemented.

This object is achieved by a bearing arrangement having the features of patent claim 1. Advantageous configurations with expedient developments of the invention are specified in the remaining claims. In order to further develop a bearing arrangement of the type specified in the preamble of patent claim 1 in such a way that particularly efficient operation of the exhaust gas turbocharger can be implemented, it is provided according to the invention that the axial bearing designed, for example, as an axial bearing disk, during operation of the exhaust gas turbocharger, during which operation the rotor and thus rotating the shaft about an axis of rotation relative to the housing and preferably also relative to the axial bearing, is displaceable in the radial direction of the shaft relative to the shaft and relative to the housing, in particular in a targeted manner. The invention is based in particular on the following findings: conventionally, an axial bearing in an exhaust gas turbocharger, in particular one with plain bearings, contributes to a considerable extent to the friction loss of a bearing by means of which the rotor is rotatably mounted on the housing. The full load capacity of the axial bearing is only used for a very small proportion of the total operating time of the exhaust gas turbocharger. In other proportions that differ from this, a load capacity of the axial bearing that is lower than the full load capacity of the axial bearing is sufficient to support the running gear in the axial direction. Against this background, the idea of the invention is to set the load capacity of the axial bearing during operation, i.e. during operation, by moving the axial bearing in the radial direction of the shaft relative to the housing and relative to the shaft, in particular in such a way that the load capacity always satisfies a current operating state of the exhaust gas turbocharger or is adapted to the operating state. This means in particular that, for example, in a first operating state in which the full load capacity of the axial bearing is desirable or necessary for the axial bearing of the running gear, the axial bearing is shifted into a first position in the radial direction of the shaft in which the full load capacity of the Axial bearing for the axial storage of the running gear is available. In a second operating state of the exhaust gas turbocharger, in which the full load capacity of the axial bearing is not required for the axial bearing of the rotor, the axial bearing is or is shifted or pushed into a second position in which the full load capacity of the axial bearing for the axial bearing of the rotor is not available Available. The friction loss in the second position is lower than in the first position. By shifting the axial bearing into the respective position as required, the load-bearing capacity of the axial bearing can be adjusted so that overall the friction loss of the exhaust gas turbocharger can be kept particularly low. By shifting the axial bearing as required, in particular between the positions, it is possible to limit the friction loss of the axial bearing to a technical minimum during operation. As a result, a particularly high degree of efficiency of the exhaust gas turbocharger can be achieved, particularly in the main operating ranges.

By shifting the axial bearing between the positions as required, it can be ensured that only one supporting surface of the axial bearing that is absolutely necessary for the operation or for a sufficient, axial bearing of the running gear is engaged. This can be understood in particular as meaning that in the first position at least one wall region of the shaft and/or a bearing element fixed to the shaft at least in the axial direction of the shaft and preferably also non-rotatably connected to the shaft in the axial direction towards an impeller of the running gear by a for example the wing forming bearing area of the axial bearing is overlapped, wherein in the second position at least the bearing area is offset in the radial direction of the shaft to the outside of the wall area, so that in the second position the wall area of the shaft or the bearing element is in the axial direction of the impeller of the running gear hin is not overlapped by the storage area. This means that in the first position the bearing area is used for the axial bearing of the shaft. In the second position, the bearing area or the supporting surface is also not used for the axial bearing of the shaft or the rotor, so that overall the friction loss of the axial bearing and thus of the exhaust gas turbocharger can be kept particularly low. As a result, particularly efficient operation of the exhaust gas turbocharger can be guaranteed.

The axial bearing can be displaced in a targeted manner between the positions, in particular it can be displaced back and forth. It is preferably provided that the axial bearing is held or held in the positions relative to the shaft and relative to the housing, in particular in a targeted manner, that is to say it is fixed or can be fixed. For example, the axial bearing can be moved back and forth between the positions pneumatically and/or hydraulically and/or electrically or electromechanically.

Further advantages, features and details of the invention result from the following description of a preferred exemplary embodiment and from the drawing. The features and combinations of features mentioned above in the description and the features and combinations of features mentioned below in the description of the figures and/or shown alone in the figures can be used not only in the combination specified in each case, but also in other combinations or on their own, without going beyond the scope of the leave invention.

• 1 ausschnittsweise eine schematische Längsschnittansicht einer erfindungsgemäßen Lagerungsanordnung eines Laufzeugs an einem Gehäuse eines Abgasturboladers, wobei sich ein Axiallager in einer ersten Stellung befindet;
• 2 ausschnittsweise eine schematische Schnittansicht der Lagerungsanordnung, wobei sich das Axiallager in einer zweiten Stellung befindet;
• 3 ausschnittsweise eine schematische Vorderansicht der Lagerungsanordnung, wobei sich das Axiallager in der ersten Stellung befindet; und
• 4 ausschnittsweise eine schematische Vorderansicht der Lagerungsanordnung, wobei sich das Axiallager in der zweiten Stellung befindet.

Thereby drawing shows in:

• 1 a detail of a schematic longitudinal sectional view of a bearing arrangement according to the invention of a rotor on a housing of an exhaust gas turbocharger, with an axial bearing being in a first position;
• 2 a fragmentary schematic sectional view of the bearing arrangement, the axial bearing being in a second position;
• 3 A fragmentary schematic front view of the bearing arrangement, the axial bearing being in the first position; and
• 4 a fragmentary schematic front view of the storage arrangement, the axial bearing being in the second position.

Elements that are identical or have the same function are provided with the same reference symbols in the figures.

1 shows a detail of a schematic longitudinal sectional view of a bearing arrangement 10 of a running gear 12, also referred to as a rotor, on a housing 14, embodied, for example, as a bearing housing, of an exhaust gas turbocharger 16. The exhaust gas turbocharger 16 is used, for example, to convey air from an internal combustion engine of a motor vehicle designed, for example, as a motor vehicle, in particular a passenger car is supplied to condense. For this purpose, the exhaust gas turbocharger 16 includes, for example, a compressor for compressing the air and a turbine, which can be driven by the exhaust gas of the internal combustion engine. The compressor can be driven by the turbine. The rotor 12 comprises a shaft 18 and two running wheels which are connected to the shaft 18 in a rotationally fixed manner. One of the running wheels, designated 20, can be seen. In the bearing arrangement 10 , the rotor 12 is rotatably mounted on the housing 14 via the shaft 18 both in the radial direction of the shaft 18 and in the axial direction of the shaft 18 . The shaft 18 is rotatably mounted on the housing 14 in the axial direction of the shaft 18 with the intermediary of an axial bearing 22 designed as a bearing disk. This means that the shaft 18 can be or is supported at least indirectly on the axial bearing 22 in the axial direction of the shaft 18 , the axial bearing 22 being supported at least indirectly on the housing 14 in the axial direction of the shaft 18 . At the in 1 The exemplary embodiment shown provides a bearing element 24 which is formed separately from the shaft 18 and separately from the axial bearing 22 and is fixed to the shaft 18 at least in the axial direction of the shaft 18 . For example, the bearing element 24 is also connected to the shaft 18 in a rotationally fixed manner. The shaft 18 is or can be supported via the bearing element 24 in the axial direction of the shaft 18 on the axial bearing 22 on which the bearing element 24 can be or is supported directly in the axial direction of the shaft 18 . In particular, the shaft 18 can be supported at least indirectly on the axial bearing 22 in the axial direction of the shaft 18, while the shaft 18 and thus the running gear 12 as a whole rotate about an axis of rotation relative to the housing 14 and relative to the axial bearing 22. For example, the rotor 12 and thus the shaft 18 rotate about the axis of rotation relative to the housing 14 and relative to the axial bearing 22 during operation of the exhaust gas turbocharger 16.

In order to now be able to implement a particularly efficient operation of the exhaust gas turbocharger 16, the axial bearing 22 during the operation of the exhaust gas turbocharger 16, i.e. in particular while the rotor 12 rotates about the axis of rotation relative to the housing 14 and relative to the axial bearing 22, in the radial Direction of the shaft 18 relative to the shaft 18 and relative to the housing 14 displaceable. The axial bearing 22 is between at least one in 1 shown, first position S1 and at least one in 2 shown, second position S2 in the radial direction of the shaft 18 relative to the shaft 18, in particular relative to the rotor 12, and relative to the housing 14 during operation of the exhaust gas turbocharger 16 displaceable. In the first position, the axial bearing 22 provides a higher load-carrying capacity, in particular its maximum load-carrying capacity, for the axial mounting of the running gear 12 compared to the second position S2. In particular, the axial bearing 22 in the first position S1 provides its maximum load-bearing capacity for axially supporting the running gear 12 . In the second position S2, for example, the axial bearing 22 provides its minimum load capacity for the axial bearing of the running gear 12, so that in the second position S2 a frictional loss of the axial bearing 22 and thus a frictional loss of the exhaust gas turbocharger 16 is lower than in the first position S1. Since the axial bearing 22 does not always provide its full load capacity for the axial bearing of the running gear 12, the friction loss of the axial bearing 22 and thus of the exhaust gas turbocharger 16 can be kept particularly low overall.

The axial bearing 22 can, for example, be shifted in a targeted manner between the positions S1, S2 and fixed in the positions S1, S2 relative to the shaft 18 and relative to the housing 14. In the first position S1, at least one wall region W of the bearing element 24 is overlapped or covered in the axial direction of the shaft 18 towards the impeller 20 by a bearing region L of the axial bearing 22, which is also referred to as a bearing surface or forms a bearing surface, so that in the first position S1 the Bearing area L is arranged in the axial direction of the shaft 18 between the wall area W and the impeller 20, in particular a further wall area W2 of the impeller 20.

in the in 2 The second position S2 shown, however, is that the bearing area L is offset outwards in the radial direction of the shaft 18 to the wall area W1 and also offset to the wall area W2, so that in the second position the wall area W is in the axial direction of the shaft 18 to the impeller 20 out is not overlapped or covered by the storage area L. In other words, in the second position S2, the bearing area L is not arranged between the wall areas W and W2. In this way, for example in the second position S2, friction between the bearing element 24 and the axial bearing 22 can be kept particularly low or reduced compared to the first position S1, so that particularly efficient operation of the exhaust gas turbocharger 16 can be achieved.

3 shows a detail of the bearing arrangement 10 in a schematic front view, with the axial bearing 22 being in the first position S1. 4 shows the bearing arrangement 10 as a detail in a schematic front view, with the axial bearing 22 being in the second position S2. Compared to the first position S1, the second position S2 is a position for a reduced carrying capacity and a reduced friction loss. If, during an operating period, the axial bearing 22 is temporarily in the first position S1 and temporarily in the second position S2, with the exhaust gas turbocharger 16 being operated during the operating period, in particular without interruption, the friction loss of the axial bearing 22 can be reduced compared to such an operating mode , in which the axial bearing 22 would be continuously or without interruption in the first position S1 throughout the entire service life. The efficiency of the exhaust gas turbocharger 16, also referred to as a turbocharger, can thus be increased.

Reference List

10

storage arrangement

12

walking gear

14

housing

16

exhaust gas turbocharger

18

wave

20

Wheel

22

thrust bearing

24

bearing element

L

storage area

S1

First position

S2

second position

W

wall area

W2

wall area

QUOTES INCLUDED IN DESCRIPTION

This list of the documents cited by the applicant was 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.

Patent Literature Cited

• DE 3712444 A1 [0002]
• DE 102007060226 A1 [0003]

Claims (4)

Bearing arrangement (10) of a rotor (12) on a housing (14) of an exhaust gas turbocharger (16), in which a shaft (18) of the rotor (12) mediated by an axial bearing (22) in the axial direction of the shaft (18) on the housing (14) is rotatably mounted, characterized in that the axial bearing (22) can be displaced in the radial direction of the shaft (18) relative to the shaft (18) and relative to the housing (14) during operation of the exhaust gas turbocharger (16). . Storage arrangement (10) after claim 1 , characterized in that the thrust bearing (22) during operation in the radial direction of the shaft (18) relative to the shaft (18) and relative to the housing (14) between at least a first position (S1) and at least a second position ( S2) displaceable and holdable in the positions (S1, S2) relative to the shaft (18) and relative to the housing (14). Storage arrangement (10) after claim 2 , characterized in that in the first position (S1) at least one wall region (W) of the shaft (18) and/or a bearing element (24) fixed to the shaft (18) at least in the axial direction of the shaft (18) in the axial direction of the shaft (18) towards an impeller (20) of the running gear (12) is overlapped by a bearing area (L) of the axial bearing (22), wherein in the second position (S2) at least the bearing area (L) is in the radial direction of the shaft (18) is offset outwards to the wall area (W). Bearing arrangement (10) according to one of the preceding claims, characterized in that the axial bearing (22) is a bearing washer.

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