EP2791476A1

EP2791476A1 - Turbine for an exhaust gas turbocharger

Info

Publication number: EP2791476A1
Application number: EP12805584.5A
Authority: EP
Inventors: Thomas Ihli
Original assignee: IHI Charging Systems International GmbH
Current assignee: IHI Charging Systems International GmbH
Priority date: 2011-12-16
Filing date: 2012-12-04
Publication date: 2014-10-22
Also published as: JP5951795B2; JP2015500436A; CN103998724A; WO2013087155A1; DE102011121330A1; CN103998724B; US20140286759A1; US9611750B2

Abstract

The invention relates to a turbine for an exhaust gas turbocharger, comprising a turbine housing (18) having a receiving chamber for a turbine wheel of the turbine, at least two guide blades (10) that are arranged upstream of the turbine wheel, succeed one another in the circumferential direction of the turbine wheel and are fixed relative to the turbine housing (18) in order to deflect exhaust gas to be delivered by the turbine wheel, and at least one actuating element (16) by means of which a flow cross-section of the turbine through which the waste gas can flow is variably adjustable and which is movable relative to the turbine housing (18) in the axial direction of the turbine between at least one closed position that narrows the flow cross-section and at least one open position that frees the flow cross-section, wherein the actuating element (16) is arranged in a space (14) between the guide elements (10) delimited in the circumferential direction by the guide elements (10) at least in the closed position.

Description

Turbine for an exhaust gas turbocharger

The invention relates to a turbine for an exhaust gas turbocharger according to the preamble of patent claim 1.

DE 10 2008 053 169 A1 discloses a turbine for an exhaust gas turbocharger with a variable turbine geometry, which has guide vanes. The vanes are rotatably supported between a vane carrier and a cover plate. The

Guide vanes serve to divert exhaust gas of an internal combustion engine so that the exhaust gas can flow to a turbine wheel of the turbine in a streamlined manner.

Since the exhaust gas flows around the guide vanes, the vanes are exposed to very high exhaust gas temperatures. In order to avoid jamming of the vanes, so-called function gaps between the vanes and the vane support and between the vanes and the cover plate are provided. Through this function column, the vanes due to the

Expose temperature, without causing jamming. These functional gaps are required for both diesel engines and gasoline engines. In gasoline engines there are particularly high exhaust gas temperatures, especially in comparison to diesel engines, so that in particular in gasoline engines, the function gaps are very large form.

Alternative to rotatable vanes is the use of relative to a

Turbine housing of the turbine immovable guide vanes known, which by means of a cover in a first position at least partially covered and in

In contrast, at least a second position of the cover are releasable. The cover is in the axial direction of the turbine relative to the

Sliding turbine housing. By means of such a sliding element, the functional gaps described at the beginning can lead to undesirable flow losses can be avoided. However, the sliding elements covering the guide vanes or overlapping in the radial direction have a relatively high complexity, which leads to high costs for the turbine.

It is therefore an object of the present invention to provide a turbine for an exhaust gas turbocharger, which is efficiently adaptable to different exhaust gas mass flows and has only low costs.

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

Such a turbine for an exhaust gas turbocharger comprises a turbine housing, which has a receiving space for a turbine wheel of the turbine. The turbine further comprises at least two vanes arranged upstream of the turbine wheel for diverting exhaust gas to be supplied to the turbine wheel. The vanes are immovable relative to the turbine housing, i. firmly and follow in the circumferential direction of

Turbine wheel on each other.

In addition, at least one adjusting element is provided, by means of which a flow cross section of the turbine through which the exhaust gas can flow is variably adjustable. The adjusting element is movable relative to the turbine housing between at least one closing position which narrows the flow cross-section and at least one open position which releases the flow cross-section in contrast.

According to the invention, it is provided that the adjusting element is arranged at least in the closed position in a space bounded in the circumferential direction by the guide elements between the guide elements. In other words, the flow cross section and thus the region of the guide elements, via which the exhaust gas is supplied to the receiving space or the turbine wheel, by moving the actuating element in the

Interspace between the guide elements variably adjustable. The actuating element does not cover the guide elements upstream or downstream of the guide elements but fluidly blocks the intermediate space between the guide elements at least partially in the closed position or releases the intermediate space at least partially in the open position. As a result, the turbine according to the invention can be adapted to different requirements

Adapted exhaust gas mass flows and also at different exhaust gas mass flows, i. at high exhaust gas mass flows and in contrast low

Exhaust gas mass flows are efficiently operated. This variable adjustability of the turbine according to the invention is relatively simple, inexpensive and

space-saving way created.

The low complexity of the turbine according to the invention comes her

Functional safety benefits because the risk of malfunction of the actuating element, for example as a result of jamming, is very low. This is particularly advantageous in a gasoline engine in which particularly high exhaust gas temperatures occur and in which the control element is subjected to particularly high temperatures. However, it goes without saying that the turbine according to the invention can also be used in a diesel engine, diesel engine or in other internal combustion engines, in particular reciprocating internal combustion engines.

Due to the simplicity of the control element and thus the turbine, the actuator can also be made particularly time and cost. A further advantage is that no function gaps are provided between the guide elements and at these subsequent wall regions of the turbine, which would lead to flow losses. The guide elements can at least substantially without the exhaust gas

Secondary flow losses and thus at least substantially completely dissipate and supply the turbine wheel aerodynamic. This is conducive to the efficient operation of the turbine according to the invention.

In an advantageous embodiment of the invention, at least in the closed position, a first distance between the actuating element and a first of the guide elements of a second distance between the actuating element and the second guide element

differently. Thus, particularly favorable flow conditions for the exhaust gas can be adjusted. This leads to a particularly efficient operation of the turbine.

The turbine is preferably a radial turbine, in which the turbine wheel is at least substantially flowed in the radial direction of the exhaust gas. Likewise, it may be a so-called mixed-flow turbine, in which the turbine wheel is flowed by the exhaust gas obliquely to the radial direction and obliquely to the axial direction. If the actuating element is located at least partially in the intermediate space, then this can impart an axial component to the at least essentially radial flow when the exhaust gas from the actuating element and the guide elements in the direction of the

Turbine wheel flows. This can result in advantageous flow conditions, in particular for the mixed-flow turbine.

In a further advantageous embodiment of the invention, the adjusting element is at least in a region of the adjusting element, in which the adjusting element is arranged between the guide elements, the outer peripheral side formed as a straight circular cylinder. Thereby, the actuator can be made time and cost. This leads to a particularly low cost of the entire turbine. Furthermore, particularly favorable flow conditions for the exhaust gas are realized.

Alternatively, at least in the region of the adjusting element in which the adjusting element is arranged between the guiding elements, the adjusting element may be designed differently on the outer peripheral side of a straight circular cylinder. The control element can thus be configured as required in terms of its outer contour to represent advantageous flow conditions.

In a particularly advantageous embodiment of the invention, the adjusting element, at least in the region of the adjusting element, in which the adjusting element is arranged between the guide elements, an actuating element outer contour, which is formed as at least substantially corresponding counter-contour with a respective Leitelementaußenkontur the guide elements. In other words, that is

Stellelementaußenkontur at least partially conformed shape corresponding to the respective Leitelementaußenkontur. As a result, the flow cross-section can be narrowed or blocked particularly efficiently, which is accompanied by efficient operation of the turbine.

Preferably, the flow cross-section is maximally narrowed in the closed position and maximally released in the open position. It is advantageously provided that the actuating element is adjustable in at least one intermediate position between the open position and the closed position, wherein the flow cross-section is released in the intermediate position relative to the closed position and narrowed relative to the open position. Preferably, the actuator is in a plurality of intermediate positions and at least substantially continuously between the closed position and the

Open position adjustable. So the turbine can be particularly demand-driven and variable a variety of different exhaust gas mass flows adapted and operated efficiently.

In a further advantageous embodiment, a cover member is arranged on the adjusting element, which is arranged at least in the closed position in the intermediate space and by means of which, at least in the closed position a flow-through by exhaust, first portion of the gap in the axial direction of a in the axial direction of the first Subarea subsequent, second subarea of the

Interspace is fluidly isolated. By means of the cover undesirable large expansion losses can be avoided, especially when the flow of the exhaust gas, a very strong axial component is impressed after the exhaust flows from the actuator and the guide elements.

If more than two guide elements and thus more than one intermediate space are provided between the guide elements, then preferably an adjusting element is assigned to each intermediate space, by means of which the associated intermediate space and thus the respectively associated flow cross-section can be narrowed in the closed position and released in the open position on the other hand.

Preferably, a separate cover is provided on each actuator. The control elements can also be assigned to the control elements common, one-piece cover. This keeps the number of parts of the turbine low.

For simple and simultaneous movement of the adjusting elements, these are preferably arranged on a common actuating element, for example an adjusting ring. In this case, the adjusting elements can be formed separately from one another and separately from the actuating element and connected to the actuating element.

As a result, the separately formed adjusting elements on the

Actuator connected together.

Alternatively, it is possible that the actuators are integrally formed with the actuator, i. the adjusting elements are also integrally formed with each other.

Preferably, the cover at least partially a

Cover element outer contour, which is designed as at least substantially corresponding counter contour with a respective guide element outer contour of the guide elements. Thereby, the gap can be efficiently divided fluidically, which is associated with advantageous flow conditions. In a further advantageous embodiment of the invention, the adjusting element or the adjusting elements are also movable in the radial direction. Thereby, the movement of the adjusting element can be adapted to the at least substantially designed as a three-dimensional blading guide elements and / or to the flow of the exhaust gas, especially in a mixed-flow turbine. Thus, the turbine can be adapted very well to different exhaust gas mass flows and operated efficiently.

Further advantages, features and details of the invention will become apparent from the following description of preferred embodiments and from the drawing. The features mentioned above in the description and

Combinations of features as well as the features and combinations of features mentioned below in the description of the figures and / or shown alone in the figures are not only in the respectively indicated combination, but also in others

Combinations or alone, without departing from the scope of the invention.

The drawing shows in:

1 shows a detail of a schematic cross-sectional view of a turbine for an exhaust gas turbocharger, which comprises an adjusting element for variably setting an effective flow cross-section of the turbine, wherein the actuating element is arranged at least in its closed position in a gap between two vanes;

2 shows a detail of a schematic cross-sectional view of another

Embodiment of the turbine of FIG. 1;

3 shows a detail of a schematic cross-sectional view of another

Embodiment of the turbine according to Figures 1 and 2.

4 shows a detail of a schematic cross-sectional view of another

Embodiment of the turbine according to FIGS. 1 to 3;

Fig. 5 shows a detail of a schematic longitudinal sectional view of another

Embodiment of the turbine according to FIGS. 1 to 4; 6 shows a detail of a schematic and developed longitudinal sectional view of the turbine of FIG. 5;

7 shows a detail of a schematic and developed longitudinal sectional view of a further embodiment of the turbine according to FIG. 6;

8 shows a detail of a schematic longitudinal sectional view of another

Embodiment of the turbine of FIG. 5;

9 shows a detail of a schematic longitudinal sectional view of another

Embodiment of the turbine of FIG. 8;

10 shows a detail of a schematic cross-sectional view of another

Embodiment of the turbine of FIG. 2;

Fig. 11 in fragmentary form a schematic longitudinal sectional view of the turbine

as shown in FIG. 10; and

FIG. 12 shows a detail of a schematic cross-sectional view of another

Embodiment of the turbine according to FIGS. 10 and 11.

Fig. 1 shows a detail of a turbine for an exhaust gas turbocharger

Internal combustion engine, which serves for example for driving a motor vehicle, in particular a passenger car. The turbine comprises a turbine housing, not shown in FIG. 1, with a receiving space in which a

Turbine wheel is added. The turbine wheel is rotatable relative to the turbine housing about an axis of rotation. The exhaust gas turbocharger also includes a compressor with a compressor wheel, which is drivable by the turbine wheel. For this purpose, the turbine wheel and the compressor wheel are rotatably connected to a shaft.

The turbine housing has at least one feed channel, via which exhaust gas can be supplied to the receiving space and the turbine wheel. The feed channel is designed as an annular channel and extends in the circumferential direction of the turbine wheel over its circumference. In the feed duct guide vanes 10 of the turbine are arranged. The vanes 10 serve to divert the exhaust, so that the exhaust gas

streamlined impeller blades 12 (Fig. 5) of the turbine wheel can flow.

This efficiently drives the turbine wheel, resulting in efficient operation of the entire turbine.

The guide vanes 10 follow each other in the circumferential direction of the turbine wheel. In Fig. 1, only two vanes 10 are shown. It is understood that the turbine may include more than two vanes 10. The guide vanes 10 are preferably arranged distributed in the circumferential direction of the turbine wheel over its circumference at least substantially uniformly and each have an airfoil.

Between the guide vanes 10, a gap 14 is bounded in the circumferential direction of the guide vanes 10, through which the exhaust gas can flow on its way to the turbine wheel. In other words, the exhaust gas flows through one

Flow cross section of the gap 14 and thus the turbine. In Fig. 1, a gap 14 is shown. If more than two guide vanes 10 are provided, a plurality of intermediate spaces 14 and thus several are correspondingly also

Provided flow cross sections, which are to be flowed through by the exhaust gas. The multiple flow cross sections form a so-called effective

Flow cross-section of the turbine, which can be traversed by exhaust gas.

By adjusting the effective flow area, i. by narrowing and in contrast widening the effective flow cross section, the

Aufstauverhalten the turbine can be variably adjusted. As a result, the turbine can be adapted to different exhaust gas mass flows and thus to different operating points of the internal combustion engine.

For variable adjustment of the effective flow cross section is now a the

Intermediate space 14 associated bolt 16 is provided. If a plurality of intermediate spaces 14 are provided, then it is understood that each of the intermediate spaces 14 is assigned a respective pin 16. It is understood that what has been described above and below about the bolt 16 can also be applied to the plurality of bolts 16.

The bolt 16 is between a maximum effective flow cross-section releasing open position and the effective flow cross-section maximum narrowing closed position in the axial direction of the turbine displaced. Further, the bolt 16 can be adjusted at least substantially continuously between the closed position and the open position and adjusted accordingly in several intermediate positions between the open position and the closed position.

At least in the closed position and in the intermediate positions in which the effective flow cross-section is narrowed relative to the open position, the bolt 16 is arranged in the intermediate space 14 between the guide vanes 10. As a result, a particularly simple and robust variable turbine geometry of the turbine is shown. The guide vanes 10 are fixed relative to the turbine housing and, for example, integrally formed with the turbine housing or by means of a guide grid, which is inserted into the turbine housing and formed separately from the turbine housing.

As can be seen from FIG. 1, the bolt 16 is at least substantially in the form of a straight circular cylinder, at least in the region in which it is arranged or can be arranged in the intermediate space 14.

In FIG. 2, a first distance s1 between the pin 16 and one of

Guide vanes 10 and a second distance s2 between the bolt 16 and the other vane 10 is shown. As can be seen from FIG. 2, the distances s1, s2 can be different from one another. In the present case, the second distance s2 is greater than the first distance s1. In conjunction with FIG. 1, it can be seen that the distances s1, s2 can also be at least substantially equal. It is also possible that the first distance s1 is greater than the second distance s2. According to FIG. 3, the bolt 16 is arranged particularly close to the guide vanes 10.

As can be seen from FIG. 4, the bolt 16 can be formed differently on the outer peripheral side of a straight circular cylinder at least in the region in which it is arranged or can be arranged in the intermediate space 14. The bolt 16 may also be formed on the outer peripheral side at least substantially elliptical or at least substantially adapted in terms of its outer contour to outer contours of the guide vanes 10. In other words, the outer contour of the bolt 16 may be formed as a counter contour (negative contour) corresponding at least substantially to the outer contours of the guide vanes 10. In FIG. 5, the turbine housing is designated by 18. As can be seen from FIG. 5, the pin 16 can be movably supported relative to the turbine housing 18 on the turbine housing 18.

6 shows a plurality of bolts 16, which are displaceable relative to the turbine housing 18 in the axial direction by means of a sliding ring 20 common to the bolt 16. The bolts 16 are formed separately from the sliding ring 20 and secured to the sliding ring 20. For this purpose, the bolts 16 receptacles 22,

in particular grooves, in which the sliding ring 20 engages. Thus, the plurality of bolts 16 can be adjusted by means of only a single actuator via the sliding ring 20 in the axial direction.

Alternatively to the separate embodiment of the bolt 16 from the sliding ring 20, it is possible, according to FIG. 7, to form the sliding ring 20 integrally with the bolts 16. The bolts 16 are also integrally formed with each other.

As can be seen from FIGS. 6 and 7, the bolts 16 are respective ones

Assigned through holes of the turbine housing 18 through which the bolts 16 can protrude into the respective spaces.

According to FIG. 8, the guide vanes 10 are formed by means of a guide grid, which is used as an insert element in the turbine housing 18. In the present case, the guide grid is integrally formed. However, it may also be formed in two or more pieces. The bolt 16 can be passed through a passage opening of the guide grid, in order to project into the intermediate space 14 via the passage opening.

FIG. 9 shows a possibility of sealing the guide grid or, in the present case, the turbine housing 18 against the bolt 16 passing through the guide grid or the turbine housing 18. For sealing, a sealing element 24 is provided, which is accommodated on the one hand in receiving grooves of the turbine housing 18 (or the guide grid) and on the other hand bears against the bolt 16. The sealing element 24 may be a piston ring. By means of this sealing, it is avoided that exhaust gas flows from the intermediate space 14 via the passage opening of the turbine housing 18 or the guide grid corresponding to the bolt 16 and thus flows past the turbine wheel or undirected onto the turbine wheel. According to FIGS. 10 and 11, a respective cover element 26 is arranged on each bolt 16, by means of which the intermediate space 14 is fluidic in a first partial region 28 through which exhaust gas can flow and in a second partial region 30 adjoining the first partial region 28 in the axial direction is divisible. Depending on the distance of the bolt 16 from the guide vanes 10 and the second portion 30 can be flowed through by the exhaust gas or at least substantially not. By means of the

Covering 26 can be avoided undesirably large expansion losses when the exhaust flows from the guide vanes 10 and of the guide vanes 10 in the axial direction subsequent walls of the turbine.

Instead of the respective, individual cover elements 26, the cover elements 26 may also be integrally formed with each other, whereby a one-piece

Gesamtabdeckelement is formed. This is shown in FIG. 12.

As indicated by areas B in FIG. 12, it is advantageous to arrange the cover elements 26, which are integral with one another, on the bolts 16 in such a way that relative movements are possible, for example due to thermal expansions and / or deformations during operation of the turbine.

Claims

claims

1. Turbine for an exhaust gas turbocharger, with a receiving space for a

Turbine wheel of the turbine having turbine housing (18) arranged with at least two upstream of the turbine wheel, in the circumferential direction of the turbine wheel successive and immovable relative to the turbine housing (18)

Guide vanes (10) for discharging exhaust gas to be supplied to the turbine wheel and having at least one adjusting element (16) by means of which one of the exhaust gas

flow-through flow cross-section of the turbine is variably adjustable and which is movable relative to the turbine housing (18) in the axial direction of the turbine between at least one closing the flow cross-section closed position and at least one flow cross section on the other hand releasing open position

characterized in that

the adjusting element (16) at least in the closed position in an intermediate space (14) bounded in the circumferential direction by the guide elements (10) between the

Guiding elements (10) is arranged. ,

2. Turbine according to claim 1,

characterized in that

at least in the closed position, a first distance (s1) between the adjusting element (16) and a first of the guiding elements (10) is different from a second distance (s2) between the adjusting element (16) and the second guiding element (10).

3. Turbine according to one of claims 1 or 2,

characterized in that

the adjusting element (16) is arranged at least in a region of the adjusting element (16) in which the adjusting element (16) is arranged between the guiding elements (10),

Outside circumference is formed as a straight circular cylinder.

4. Turbine according to one of claims 1 or 2,

characterized in that

Outside circumference of a straight circular cylinder is designed differently.

5. Turbine according to one of the preceding claims,

characterized in that

the adjusting element (16) at least in a region of the adjusting element (16), in which the adjusting element (16) between the guide elements (10) is arranged, a

Stellelementaußenkontur which, as with a respective

Leitelementaußenkontur the guide elements (10) is formed at least substantially corresponding mating contour.

6. Turbine according to one of the preceding claims,

characterized in that

a cover element (26) is arranged on the adjusting element (16) which is arranged in the intermediate space (14) at least in the closed position and by means of which at least in the closed position a first partial region (28) of the intermediate space (14) can be flowed through by exhaust gas axial direction of a in the axial direction of the first portion (28) adjoining the second portion (30) of the

Interspace (14) is fluidically isolated.

7. Turbine according to claim 6,

characterized in that

the cover element (26) at least in some areas has a covering element outer contour which is designed as a counter contour that is at least substantially corresponding with a respective guide element outer contour of the guide elements (10).

8. Turbine according to one of the preceding claims,

characterized in that

the adjusting element (16) is also movable in the radial direction.