DE102013201771A1 - Compressor of exhaust gas turbocharger mounted in internal combustion engine, forms with passage gap having passage gap inlet opening and passage gap outlet opening that are fluid connected with inlet and outlet channels of compressor - Google Patents

Abstract

The compressor (1) has a compressor housing (2) which is provided with compressor wheel (3) whose supporting end is mounted with blades (9). A passage gap (6) is formed between the compressor housing and compressor wheel and provided with passage gap inlet opening (7) and passage gap outlet opening(8) that are fluid-connected with the inlet channel (4) and outlet channel (5) of the compressor. The passage gap diameter of the passage gap in the region of passage gap inlet opening is set smaller or larger than passage gap diameter in the area of gap outlet opening. An independent claim is included for the exhaust gas turbocharger.

Description

The present invention relates to a compressor of an exhaust gas turbocharger and an exhaust gas turbocharger with such a compressor.

To increase the boost pressure in an internal combustion engine, an exhaust gas turbocharger is often used, by means of which more air and thus more oxygen per stroke can be introduced into a combustion chamber of the internal combustion engine. On account of the increased amount of introduced oxygen, more fuel can also be injected into the combustion chamber of the internal combustion engine and thus the power of the internal combustion engine can be increased. An essential component of such an exhaust gas turbocharger is a compressor which sucks fresh air from the environment of the internal combustion engine and compresses for introduction into the combustion chamber of the internal combustion engine.

Such a compressor usually comprises a compressor housing and a rotatably mounted therein and blades for conveying fresh air bearing compressor wheel. For the freewheel of the compressor in the compressor housing, a defined contour gap is usually provided between the compressor and the compressor housing, which fluidly connects an inlet channel with an outlet channel of the compressor. This contour gap is formed in the manner of a passage gap, which is bounded by the compressor housing and the compressor wheel and having a through-gap diameter, which can vary along the passage gap depending on manufacturing component tolerances. In order to minimize unwanted efficiency losses of the compressor and thus also of the exhaust gas turbocharger using the compressor due to leakage air flows, the passage gap in conventional compressors is often designed in the form of a so-called zero gap, i. the compressor wheel is brought into contact with this during installation in the compressor housing and the section of the compressor housing adjacent to the compressor wheel is "ground in" when the compressor wheel is first set in rotation, wherein material can be removed from the compressor housing.

The JP 2010-275950 A discloses a compressor of an exhaust gas turbocharger having a compressor housing and having a compressor wheel rotatably mounted on the compressor housing and rotor blades. Between the compressor housing and the compressor wheel a passage gap is provided with a passage gap inlet opening and a passage gap outlet opening.

The JP 2003-343486 discloses a compressor having a compressor housing and a compressor wheel rotatably mounted on the compressor housing and carrying rotor blades. Between the compressor housing and the compressor wheel a passage gap is provided with a passage gap inlet opening and a passage gap outlet opening. Along the passage gap a plurality of recesses are provided on the housing and / or on the compressor, in which the passage gap diameter of the passage gap is increased compared to the remaining passage gap.

The invention is concerned with the problem of providing an improved embodiment for a compressor of an exhaust gas turbocharger, which is characterized in particular by an improved efficiency with high reliability.

This problem is solved by the subject matter of the independent claims. Preferred embodiments are subject of the dependent claims.

The invention is based on the general idea of designing the passage gap between the compressor housing and the compressor wheel in such a way that a passage gap diameter in the region of the passage gap inlet opening is smaller or larger than in the region of the passage gap outlet opening. In this way, an aerodynamically particularly effective contour gap can be generated, which seals the inlet channel with respect to the outlet channel of the compressor against undesired leakage air flow in the region of the passage gap inlet opening, but at the same time in the region with a larger passage gap diameter in the region of the passage gap outlet opening optimum circulation of the blades of the compressor wheel with air allows.

In a preferred embodiment, the passage gap diameter may monotonically increase or decrease monotonically along the passage gap from the passageway inlet port to the passageway clearance port. In this way, the sealing of the inlet channel to the outlet channel in the region of the passage gap inlet opening can be improved, whereas the optimal flow around the blade of the compressor wheel is ensured due to the monotonous increase or decrease of the passage gap diameter to the passage gap outlet opening.

In a preferred embodiment, the compressor wheel surface contour and / or the compressor housing surface contour may have a continuous contour. By means of such a continuous design of the compressor housing surface contour or the compressor wheel surface contour, an improved flow around the Rotor blades are ensured with air and thus the risk of unwanted separation of flow can be reduced.

Particularly advantageously, the compressor wheel surface contour of the compressor wheel and / or the compressor housing between the passage gap inlet opening and the passage gap outlet opening have a kink-free course. By "kink-free" it is meant that the mathematical derivation of the graph defined by the surface contour has a continuous course, that is to say in particular without jump. By means of such a kink-free course, the aerodynamic behavior of the flowing through the passage gap air leakage flow can be improved.

In a likewise particularly preferred alternative embodiment, however, the compressor wheel surface contour and / or the compressor housing surface contour can also have at least one step or at least one bend.

In a particularly preferred embodiment, the passage gap may have at least one gap section extending from the passage gap inlet opening and extending in the direction of the passage gap outlet opening, along which the passage gap forms a zero gap. In this way, the sealing properties of the compressor can be improved, which in turn can lead to an improvement in the efficiency of the exhaust gas turbocharger using the compressor. The zero gap can be generated for example by grinding the compressor housing by means of the impeller, after the impeller has been introduced into the compressor housing for the assembly of the compressor and has been set in rotation for the first time. By the rotation of the impeller and the associated grinding, in which material of the compressor housing can be removed from the surface, an ideally minimal gap is ground into the surface of the housing component, so that blades and housing component just no longer abut each other.

In an alternative preferred embodiment, the nip gap forming gap portion may be provided in the region of the passage gap outlet opening or extending therefrom and extending in the direction of the passage gap inlet opening.

Preferably, the compressor wheel surface contour and / or the compressor housing surface contour may at least partially have an elliptical, in particular a spherical segment, course.

The invention further relates to an exhaust gas turbocharger having a compressor with one or more of the aforementioned features and with a turbine wheel rotatably connected to the compressor by means of a rotor shaft. In an alternative embodiment, the compressor wheel can also be connected to another suitable drive device by means of the rotor shaft.

Other important features and advantages of the invention will become apparent from the dependent claims, from the drawings and from the associated figure description with reference to the drawings.

It is understood that the features mentioned above and those yet to be explained below can be used not only in the particular combination given, but also in other combinations or in isolation, without departing from the scope of the present invention.

Preferred embodiments of the invention are illustrated in the drawings and will be described in more detail in the following description, wherein like reference numerals refer to the same or similar or functionally identical components.

Show, in each case schematically,

1a a first embodiment of a compressor according to the invention in a longitudinal section, wherein a diameter of the passage gap in the region of the passage gap inlet opening is smaller than in the region of the passage gap outlet opening,

1b a second embodiment of a compressor according to the invention in a longitudinal section, wherein a diameter of a passage gap in the region of the passage gap inlet opening is larger than in the region of the passage gap outlet opening,

2a -C rough schematic representations of graphene with a step or a kink.

3 a first variant of the embodiment of 1a / 1b .

4 a second variant of the embodiment of 1a / 1b .

5 a second variant of the embodiment of 1a / 1b ,

In the 1a is a first embodiment of a compressor shown in a sectional view and with 1 designated. The compressor 1 includes a compressor housing 2 which partly or completely made of plastic. In the compressor housing 2 is a compressor wheel 3 arranged, which may comprise a rotor shaft, wherein the compressor wheel 3 about an axis A relative to the compressor housing 2 is rotatable adjustable. The rotor shaft can do this on a bearing housing of the compressor 1 comprehensive exhaust gas turbocharger be rotatably mounted. The rotor shaft and the bearing housing are not shown in the figures for clarity. The compressor wheel 3 can blades 9 include. The compressor 1 has an inlet channel 4 on, which may be formed as an axial inlet channel. The compressor 1 also has an outlet channel 5 on, which may be formed as a radial outlet channel. Between the compressor housing 2 and the compressor wheel 3 is a passage gap 6 provided, which the inlet channel 4 with the outlet channel 5 fluidly connects. The passage gap 6 points to the inlet channel 4 towards a passage gap inlet opening 7 and to the outlet channel 5 towards a passage gap outlet opening 8th on. The passage gap 6 has a passage gap diameter D, which is in the region of the passage gap inlet opening 7 smaller than in the area of the passage gap outlet opening 8th , Under passage gap diameter is the distance between the compressor housing 2 and blades 9 ,

By means of the in the region of the passage gap inlet opening 7 opposite the passage gap outlet port 8th reduced passage gap 6 a high sealing effect due to the reduced passage gap diameter D can be achieved, but at the same time is in the region of the passage gap-outlet opening 8th an optimal flow around the blades 9 the compressor wheel 3 with leakage airflow possible.

The passage gap diameter D can as in the 1a shown along the passage gap 6 from the passage gap inlet opening 7 to the passage gap outlet opening 8th grow monotonously.

In the 1b is a second embodiment of the compressor 1 shown, which differs from the basis of 1a explained in the first embodiment alone differs in that the passage gap 6 a passage gap diameter D, which in the region of the passage gap inlet opening 7 larger than in the area of the passage gap outlet opening 8th , The passage gap diameter D can be as in the 1b shown along the passage gap 6 from the passage gap inlet opening 7 to the passage gap outlet opening 8th decrease monotonously.

Also by means of a in the region of the passage gap inlet opening 7 opposite the passage gap outlet port 8th enlarged passage gaps 6 a very high sealing effect due to the reduced passage gap diameter D can be achieved. At the same time, in the area of the passage gap outlet opening 8th an optimal flow around the blades 9 the compressor wheel 3 with leakage airflow possible.

The embodiment variants explained below, in particular according to FIGS 3 to 5 , apply to both the first embodiment of the 1a as well as for the second embodiment of the 1b :
The compressor wheel surface contour 10 and / or the compressor housing surface contour 11 can at least partially have an elliptical, in particular a spherical segment-like course. A compressor wheel surface contour 10 the compressor wheel 3 between the passage gap inlet opening 7 and the passage gap outlet port 8th can have a gradual and kink-free course. By "kink-free" it is meant that the mathematical derivation of the graph defined by the surface contour has a continuous course, that is to say in particular without jump. By means of such a kink-free course, the aerodynamic behavior of the flowing through the passage gap air leakage flow can be improved.

In a similar way - as in the 1a and 1b also shown is a compressor housing surface contour 11 of the compressor housing 2 between the passage gap inlet opening 7 and the passage gap outlet port 8th be formed step and kink-free.

Such a completely step and kink-free training of both the compressor wheel surface contour 10 as well as the compressor housing surface contour 11 So in the examples of the 1a / 1b shown. In variants of the embodiment of 1a / 1b can the compressor wheel surface contour 10 and / or the compressor housing surface contour 11 but also at least one level 14 or at least a kink 15 exhibit.

Such a course of the compressor wheel surface contour 10 or the compressor housing surface contour 11 with a step 14 is in the 2a roughly sketched. The 2 B shows a contrast, a profile of the compressor wheel surface contour 10 or the compressor housing surface contour 11 with a kink 15 , The 2c shows a combination 12 from a kink 15 and one step 14 ,

In the 3 is a variant of the compressor 1 of the 1a / 1b shown in which the compressor housing surface contour 11 has a kink and stepless course, the course Compressor-surface contour 10 however, a kink 15 having.

In further variants are with respect to the course of compressor wheel surface contour 10 or compressor housing surface contour 11 various combinations conceivable; is exemplary in the 4 a variant with kink 15 and steps 14 in the course of the compressor wheel surface contour 10 or the compressor housing surface contour 11 shown. The passage gap diameter D varies along the passage gap 6 , wherein the passage gap diameter D as in the embodiment of 1a in the area of the passage gap inlet opening 7 smaller than in the area of the passage gap outlet opening 8th , It is clear that in the 4 shown variant on the second embodiment of the 1b is applicable, according to which the passage gap diameter D in the region of the passage gap inlet opening 7 larger than in the area of the passage gap outlet opening 8th ,

In the presentation of the 5 Finally, a variant is shown, according to which the passage gap 6 one from the passageway inlet port 7 outgoing and towards the passage gap outlet opening 8th extending gap section 13 along which the passage gap 6 forms a zero gap. In this way, the sealing properties of the passage gap 6 be significantly improved. In a variant of 5 can the gap section 13 in the manner of a zero gap also in the area of the passage gap outlet opening 8th be provided or emanate from this.

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

• JP 2010-275950A [0004]
• JP 2003-343486 [0005]

Claims (8)

Compressor ( 1 ) of an exhaust gas turbocharger, - with a compressor housing ( 2 ) and a rotatably mounted therein and blades ( 9 ) carrying compressor wheel ( 3 ), - between between compressor housing ( 2 ) and compressor wheel ( 3 ) a passage gap ( 6 ) with a passage gap inlet opening ( 7 ) and a passage gap outlet opening ( 8th ) is provided, which an inlet channel ( 4 ) of the compressor ( 1 ) with an outlet channel ( 5 ) fluidically connecting, - wherein a passage gap diameter (D) of the passage gap ( 6 ) in the region of the passage gap inlet opening ( 7 ) is smaller or larger than in the area of the passage gap outlet opening ( 8th ). Compressor ( 1 ) according to claim 1, characterized in that the passage gap diameter (D) along the passage gap ( 6 ) from the passageway inlet port (FIG. 7 ) to the passage gap outlet opening ( 8th ) increases monotonically or decreases monotonically. Compressor ( 1 ) according to claim 1 or 2, characterized in that - a compressor wheel surface contour ( 10 ) of the compressor wheel ( 3 ) between the passage gap inlet opening ( 7 ) and the passage gap outlet opening (FIG. 8th ) has a stepless course, and / or - a compressor housing surface contour ( 11 ) of the compressor housing ( 2 ) between the passage gap inlet opening ( 7 ) and the passage gap outlet opening (FIG. 8th ) has a stepless course. Compressor ( 1 ) according to one of claims 1 to 3, characterized in that - a compressor wheel surface contour ( 10 ) of the compressor wheel ( 3 ) between the passage gap inlet opening ( 7 ) and the passage gap outlet opening (FIG. 8th ) has a kink-free course, and / or - a compressor housing surface contour ( 11 ) of the compressor housing ( 2 ) between the passage gap inlet opening ( 7 ) and the passage gap outlet opening (FIG. 8th ) has a kink-free course. Compressor according to one of claims 1 to 3, characterized in that - the compressor wheel surface contour ( 10 ) of the compressor wheel ( 3 ) between the passage gap inlet opening ( 7 ) and the passage gap outlet opening (FIG. 8th ) has at least one step and / or at least one kink, and / or - the compressor housing surface contour ( 11 ) of the compressor housing ( 2 ) between the passage gap inlet opening ( 7 ) and the passage gap outlet opening (FIG. 8th ) has at least one step and / or at least one kink. Compressor according to one of the preceding claims, characterized in that the passage gap ( 6 ) at least one of the passage gap inlet opening ( 7 ) and in the direction of the passage gap outlet opening ( 8th ) extending gap portion ( 13 ), along which the passage gap ( 6 ) forms a zero gap. Compressor according to one of the preceding claims, characterized in that the compressor wheel surface contour ( 10 ) and / or the compressor housing surface contour ( 11 ) At least in sections, an elliptical, in particular a spherical segment-like course has. Exhaust gas turbocharger with a compressor ( 1 ) according to one of the preceding claims and one with the compressor wheel ( 3 ) By means of a rotor shaft rotatably connected turbine wheel.

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