DE202015007276U1 - Exhaust gas turbocharger with air-cooled housing - Google Patents

Abstract

Exhaust gas turbocharger (1), comprising • a housing (9) with a compressor section (10), a turbine section (11) and a bearing section (12), • a compressor (3) with a compressor wheel (13) arranged in the compressor section (10), A turbine (4) with a turbine wheel (14) arranged in the turbine section (11), a shaft (15) mounted in the bearing section (12), the shaft (15) connecting the turbine wheel (14) to the compressor wheel (13) , and • a cooling structure (8) with at least one cooling channel and / or a cooling chamber, which is formed at least in the turbine section (11) of the housing (9), • wherein compressed air from the compressor (3) can be branched off and into the cooling structure (8) can be introduced.

Description

The invention relates to an exhaust gas turbocharger which is used in conjunction with an internal combustion engine.

Exhaust gas turbochargers on internal combustion engines are used to drive a turbine with the exhaust gas of the internal combustion engine. The turbine in turn compresses the charge air of the internal combustion engine via a compressor. Contact with the exhaust gas exposes the turbocharger to very high temperatures. Accordingly, relatively high-quality materials must be used for the housing and the other components of the exhaust gas turbocharger. Depending on the design and application, cooling of certain components also makes sense.

It is an object of the invention to provide an exhaust gas turbocharger that can be used permanently with cost-effective production and low-maintenance operation. In particular, the exhaust gas turbocharger should have optimized cooling, so that, in particular for the housing, inexpensive and easy to use in the production materials can be used.

The solution of this object is achieved by the features of claim 1. The dependent claims have advantageous embodiments of the invention to the subject.

Thus, the object is achieved by an exhaust gas turbocharger according to the invention. The exhaust gas turbocharger is used on an internal combustion engine. In particular, the exhaust gas turbocharger is used in a motor vehicle. The exhaust gas turbocharger comprises a housing. The housing in turn can be subdivided into a compressor section, a turbine section and a bearing section. The individual sections of the housing can be made separately, for example by individual casts. Furthermore, it is also intended to manufacture two or all three sections in one piece. In the following, a very effective cooling of the housing, in particular of the turbine section will be described. Because of this cooling, a relatively inexpensive and easy to handle metal can be selected for the housing and other components of the exhaust gas turbocharger.

The exhaust gas turbocharger further includes a compressor. The compressor comprises the compressor section of the housing and a compressor wheel arranged in the compressor section. Furthermore, a turbine is provided. The turbine includes the turbine section of the housing and a turbine wheel disposed therein.

Between the compressor section and the turbine section is the bearing portion of the housing. In this bearing section, a shaft is rotatably mounted. The two ends of the shaft are rotatably connected to the turbine wheel and the compressor wheel. By impingement of the turbine wheel with the exhaust gas of the internal combustion engine, the turbine wheel, the shaft and the compressor wheel are set in rotation. As a result, air can be compressed in the compressor for the internal combustion engine.

In the housing, a cooling structure is formed. This cooling structure comprises at least one cooling channel and / or at least one cooling chamber. Furthermore, the cooling structure may comprise partitions or webs which separate a plurality of cooling channels or cooling chambers from each other or be used to guide the air in the cooling structure. In particular, the housing is formed at least in places double-walled to represent this cooling structure. At least part of the cooling structure is provided in the turbine section of the housing, since the greatest temperatures occur here.

According to the invention, it is provided that compressed air is branched off from the compressor and introduced into the cooling structure. There is thus an air cooling. In this case, no separate compressor is necessary, but it is used compressed air from the compressor.

Preferably, a supply air guide is formed. The supply air duct branches off downstream of the compressor wheel and guides the compressed air into the cooling structure. The supply air guide is integrated in the housing and / or arranged as a separate component outside of the housing. It is also possible to integrate a section of the supply air duct in the housing and to provide a further section of the supply air duct outside the housing as a separate component.

When integrating the supply air guide in the housing free spaces are formed in the housing, which are used to guide the supply air. These free spaces lead in particular through the compressor section and / or the storage section. It also comes at least partially to a cooling of the compressor section or bearing section.

There are different possibilities for the branching of the supply air duct: it is preferably provided that the branch is formed in the compressor section of the housing.

In this case, the supply air duct branches off, in particular, on a compressor flange or upstream of the compressor flange. This results in a very compact design and it requires no additional components.

Alternatively, the supply air duct can branch off after the compressor section of the housing. For this purpose, a corresponding diversion is integrated into the air duct between the exhaust gas turbocharger and the internal combustion engine.

Furthermore, an exhaust air duct is preferably provided, which discharges the heated cooling air from the cooling structure. Particularly preferably, it is provided that the exhaust air duct opens into the exhaust system. This results in the particular advantage of an increased oxygen content in the exhaust gas. This in turn leads to advantages in diesel particulate filters and catalysts.

Particularly preferably, the exhaust air duct opens downstream of the turbine wheel in the exhaust system. It is provided in particular that the exhaust air duct opens into the turbine section of the housing. This in turn results in a very compact design, since the exhaust air duct can be formed within the exhaust gas turbocharger. Alternatively, it is also possible to let open the exhaust duct downstream of the exhaust gas turbocharger in the exhaust system.

The turbine section of the housing usually comprises a volute section. The volute section extends radially outside the turbine wheel. At least one tide is formed in the volute section. Due to this flood, the exhaust gas is directed radially onto the turbine wheel. In the context of the invention, it is preferably provided that the cooling structure is formed at least partially in this volute section. In particular, this volute section is burdened by the high temperature of the exhaust gases and is advantageously cooled.

To describe the configuration of the cooling structure in the volute section, a first plane is defined. This first plane is perpendicular to the flow direction of the exhaust gases in the flood. In the first plane, the volute section is usually circular or oval. For best possible cooling, the cooling structure when viewed in the first plane extends over up to 360 ° of the volute section. For manufacturing reasons, however, it is not possible in every construction to make the cooling structure so large. Tests and calculations have shown that the cooling structure in the first plane, at least at one point of the volute section, should preferably extend over at least 45 °. Particularly preferably, the angle is at least 90 °, in particular at least 180 °.

In particular at the beginning of the volute section, close to the turbine flange, the cooling structure can also be formed over 360 °, since in this area the flood does not yet open radially to the turbine wheel.

For a further description of the design of the cooling structure, a second level is defined. This is perpendicular to the shaft and passes through the Volutenabschnitt. Also in the second level, the cooling structure should extend as far as possible over the volute section in order to achieve an optimum cooling result. For technical reasons, however, a limitation of the cooling structure may be necessary here as well. Thus, it is preferably provided that extends in the second plane, the cooling structure over at least 20 °, preferably at least 40 °, more preferably at least 80 ° of the volute section.

Preferably, a passive or active actuator for adjusting the branched off from the compressor air quantity is provided. This actuator is located in particular in or on the supply air. As a passive actuator, in particular a nozzle or a valve are provided. As active control elements controllable valves, in particular with electrical, electromagnetic, hydraulic or pneumatic actuators can be used.

Radially within the volute section, the turbine section of the housing usually has a rear wall section. This rear wall section is directly opposite the turbine wheel. The cooling structure according to the invention can also be formed at least in places in this rear wall section.

Further details, advantages and features of the present invention will become apparent from the following description of exemplary embodiments with reference to the drawing. It shows:

1 a schematic view of the exhaust gas turbocharger according to the invention according to all embodiments in conjunction with an internal combustion engine,

2 a sectional view of the exhaust gas turbocharger according to the invention according to a first embodiment,

3 a sectional view of the exhaust gas turbocharger according to the invention according to a second embodiment, and

4 - 5 two further views of the exhaust gas turbocharger according to the invention according to all embodiments.

In the following, two embodiments of an exhaust gas turbocharger 1 based on 1 to 5 explained in more detail. The figures show the invention schematically simplified. 1 . 4 and 5 show the exhaust gas turbocharger 1 in each case for both embodiments. The differences between the two embodiments are based on the 2 and 3 explained.

According to 1 includes the exhaust gas turbocharger 1 a compressor 3 and one the compressor 3 driving turbine 4 , In the turbine 4 flows exhaust 6 from an internal combustion engine 2 , Downstream of the turbine 4 The exhaust line usually leads to the exhaust system, optionally with diesel particulate filter and / or catalyst.

The compressor 3 sucks air 5 and compacts them. The compressed air 5 becomes the internal combustion engine 2 fed.

In purely schematic representation shows 1 , the cooling air compressed according to the invention 7 is branched off. In the exhaust gas turbocharger 1 is a cooling structure 8th educated. This cooling structure 8th is located at least partially on the turbine 4 , The branched cooling air 7 gets into this cooling structure 8th led around there the housing 9 ( 2 . 3 ) of the exhaust gas turbocharger 1 to cool.

1 also shows in schematic view that the cooling air 7 after cooling the exhaust gas 6 is supplied.

The turbocharger 1 further comprises, as in the 2 and 3 is shown on both embodiments, the housing 9 , The housing 9 is divided into a compressor section 10 , a turbine section 11 and a storage section 12 , The storage section 12 lies between the turbine section 11 and the compressor section 10 , It is intended to each section 10 . 11 . 12 to manufacture as a one-piece or multi-part component. Furthermore, at least two of the sections can also be used 10 . 11 . 12 be manufactured as a common one-piece component.

The compressor 3 includes the compressor section 10 of the housing 9 and a compressor wheel disposed therein 13 , The turbine 4 includes the turbine section 11 of the housing 9 and a turbine wheel disposed therein 14 , In the storage section 12 of the housing 9 is a wave 15 rotatably mounted. The wave 15 is non-rotatable with the turbine wheel 14 and the compressor wheel 13 connected.

Radially outside the turbine wheel 14 is as components of the turbine section 11 a volute section 18 educated. This volute section 18 extends, as in particular in the 4 and 5 can be seen along an arc shape around the turbine wheel 14 , In the volute section 18 of the housing 9 At least one flood is formed. About this flood is the exhaust 6 radially on the turbine wheel 14 directed.

Especially the volute section 18 is a major thermal load through the exhaust 6 exposed. Therefore, as far as design and manufacturing specifications allow, the cooling structure 8th at least in places in the volute section 18 educated.

The cooling structure 8th is in 2 and 3 as a double-walled design of the housing 9 shown. This double-walled configuration represents at least one cooling chamber into which the cooling air 7 can be initiated. The actual geometry of the cooling structure 8th can be configured more complex, for example, with a plurality of cooling chambers and / or a plurality of cooling channels and corresponding partitions or webs.

In the first embodiment according to 2 runs a supply air duct 16 from the compressor 3 outside the case 9 to cooling structure 8th , Alternatively to this shows 3 with the second embodiment, an integration of the supply air 16 in the case 9 , Here is the supply air 16 as free space in the housing 9 educated. The supply air duct 16 runs along the compressor section 10 and the storage section 12 to the turbine section 11 ,

In both embodiments is an actuator 20 in the supply air duct 16 intended. With this control element 20 can the amount of cooling air 7 be regulated.

Both embodiments show that the cooling structure 8th at least in places on a back wall section 19 of the turbine section 11 can be trained. An essential part of the cooling structure 8th However, in both embodiments, the volute section is located 18 ,

2 and 3 show the exhaust gas turbocharger 1 in a view defined here as "first level". This plane is perpendicular to a flow direction of the exhaust gases 6 in the volute section 18 , The cooling structure 8th extends over an angle α of the Volutenabschnitts 18 , 2 shows a relatively large configuration of the angle α. In 3 the angle α is smaller, so here is the cooling structure 8th about half of the volute section 18 extends.

Independent of the positioning of the supply air duct 16 In the two embodiments, the angle α can be selected according to the design and manufacturing specifications. It is preferably provided that the angle α is at least one point at least 45 ° to a sufficient cooling of the volute section 18 to enable.

2 and 3 furthermore show an exhaust air duct 17 for removing the heated cooling air 7 from the cooling structure 8th in the exhaust 6 , Like the two 2 and 3 show, the exhaust air duct 17 as an external component outside the housing 9 be guided or in the housing 9 to get integrated.

4 and 5 show the exhaust gas turbocharger 1 for both embodiments in different views. The turbine 4 has a turbine flange 21 on. About this turbine flange 21 becomes the exhaust 6 are the turbine 4 initiated.

The compressor 3 has a compressor flange 22 on. About this compressor flange 22 becomes the compressed air 5 to the internal combustion engine 2 guided.

Based on 4 a "second level" is defined. The second level passes through the volute section 18 and is perpendicular to the shaft 15 , In the second level, the cooling structure extends 8th over an angle β. It is preferably provided that the angle β is at least 20 °. Particularly preferably, the angle α is at least 45 ° over the entire length of the cooling structure 8th in the second plane according to angle β.

Furthermore, it is preferably provided that the cooling structure 8th at the turbine flange 21 starts. At the beginning of the volute section 18 , ie near the turbine flange 21 , the tide does not yet open to the turbine wheel 14 , In this area, the cooling structure can be fully formed, ie with an angle α of 360 °. Especially in this area is the cooling structure 8th an annular cavity in the double-walled housing 9 ,

The branch of the supply air duct 16 takes place advantageously in the compressor section 10 of the housing 9 , ie before (with respect to the flow direction of the air 5 ) or on the compressor flange 22 , Furthermore, it is preferably provided that the exhaust air duct 17 at the turbine section 11 of the housing 9 , ie before (with respect to the flow direction of the exhaust gas 6 ) or on the turbine flange 21 empties.

In addition to the above written description of the invention is to the additional disclosure hereby explicitly to the drawings of the invention in the 1 to 5 Referenced.

LIST OF REFERENCE NUMBERS

1

turbocharger

2

internal combustion engine

3

compressor

4

turbine

5

air

6

exhaust

7

cooling air

8th

cooling structure

9

casing

10

compressor section

11

turbine section

12

bearing section

13

compressor

14

turbine

15

wave

16

supply air

17

exhaust air

18

scroll portion

19

Rear wall portion

20

actuator

21

turbine flange

22

Verdichterflansch

Claims (10)

Exhaust gas turbocharger ( 1 ), comprising • a housing ( 9 ) with a compressor section ( 10 ), a turbine section ( 11 ) and a storage section ( 12 ), • a compressor ( 3 ) with a in the compressor section ( 10 ) arranged compressor wheel ( 13 ), • a turbine ( 4 ) with one in the turbine section ( 11 ) arranged turbine wheel ( 14 ), • one in the storage section ( 12 ) mounted shaft ( 15 ), where the wave ( 15 ) the turbine wheel ( 14 ) with the compressor wheel ( 13 ), and • a cooling structure ( 8th ) with at least one cooling channel and / or a cooling chamber, which at least in the turbine section ( 11 ) of the housing ( 9 ), where from the compressor ( 3 ) compressed air branchable and into the cooling structure ( 8th ) can be introduced. Exhaust gas turbocharger according to claim 1, characterized by a supply air duct ( 16 ) downstream of the compressor wheel ( 13 ) branches off and to the cooling structure ( 8th ), whereby the supply air duct ( 16 ) in the housing ( 9 ) is integrated and / or as a separate component outside the housing ( 9 ) runs. Exhaust gas turbocharger according to claim 2, characterized in that the supply air duct ( 16 ) at the compressor section ( 10 ) of the housing ( 9 ) branches off. Exhaust gas turbocharger according to one of the preceding claims, characterized by an exhaust air duct ( 17 ) from the cooling structure ( 8th ) the exhaust gas ( 6 ), preferably downstream of the turbine wheel ( 14 ), opens. Exhaust gas turbocharger according to claim 4, characterized in that the exhaust air duct ( 17 ) in the turbine section ( 11 ) of the housing ( 9 ) opens. Exhaust gas turbocharger according to one of the preceding claims, characterized in that • in the turbine section ( 11 ) of the housing ( 9 ) a volute section ( 18 ), wherein the volute section ( 18 ) the turbine wheel ( 14 ) radially surrounds and at least one flood forms by the exhaust gas ( 6 ) radially on the turbine wheel ( 14 ) is conductive, and • wherein the cooling structure ( 8th ) at least partially in the volute section ( 18 ) is trained. Exhaust gas turbocharger according to claim 6, wherein a first plane is defined, which is perpendicular to the flow direction of the exhaust gas ( 6 ) is in the flood, whereby the cooling structure ( 8th ) in the first plane at an angle α over at least 45 °, preferably at least 90 °, particularly preferably at least 180 °, of the volute section (FIG. 18 ). Exhaust gas turbocharger according to claim 6 or 7, wherein a second plane is defined perpendicular to the shaft ( 19 ), wherein the cooling structure ( 8th ) in the second plane at an angle β over at least 20 °, preferably at least 40 °, particularly preferably at least 80 °, of the volute section (FIG. 18 ). Exhaust gas turbocharger according to one of the preceding claims, characterized by a passive or active control element ( 20 ) for adjusting the compressor ( 3 ) branched off air quantity. Exhaust gas turbocharger according to one of the preceding claims, characterized in that the housing ( 9 ), in particular in the turbine section ( 11 ), to form the cooling structure ( 8th ) is formed at least in places double-walled.

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