WO2017067635A1

WO2017067635A1 - Controller for an exhaust gas turbocharger

Info

Publication number: WO2017067635A1
Application number: PCT/EP2016/001651
Authority: WO
Inventors: Joachim Delitz
Original assignee: Ihi Charging Systems International Gmbh
Priority date: 2015-10-19
Filing date: 2016-10-05
Publication date: 2017-04-27
Also published as: DE102015117750A1

Abstract

The invention relates to a controller for an exhaust gas turbocharger comprising an exhaust gas pipe section (2) through which a flow can pass, a bearing section, and a flow-through air guiding section (13), wherein the exhaust gas pipe section (2) is connected by means of the bearing section to the air guiding section (13), and wherein a turbine wheel of the exhaust gas turbocharger (1) is received rotatably in the exhaust gas pipe section (2). The turbine wheel is connected non-rotatably to a compressor wheel, which is received rotatably in the air guiding section (13), by means of a rotor shaft which is received rotatably in the bearing section. In order to bypass the turbine wheel a bypass channel (8) is formed in the exhaust gas pipe section (2) and can be opened or closed by means of a cover element (11) of the controller (7), and the controller (7) has a shaft (16) rotatably mounted in the exhaust gas pipe section (2). The shaft (16) is connected to the cover element (11) and, at the end (19) of the shaft facing away from the cover element (11), is connected to a connecting element (15) in order to move the cover element (11). According to the invention, in order to reduce a flow through the controller (7) in the region of the shaft (16), the controller (7) is designed to reduce the pressure, starting from the bypass channel (8), in the direction of the connecting element (15).

Description

Regulating device for an exhaust gas turbocharger

The invention relates to a control device for an exhaust gas turbocharger in the

Preamble of claim 1 specified type.

Publication DE 11 2009 002 230 T5 discloses an exhaust-gas turbocharger with a control device in an exhaust-gas guide section. The regulating device is for opening and closing a bypass channel in the flow-through

Exhaust gas guide section provided for bypassing a turbine wheel of the exhaust gas guide section rotatably arranged in the exhaust gas guide section in a wheel chamber of the exhaust gas guide section. It comprises a movement device with a shaft having a rotation axis and a cover element, wherein the movement device is provided for moving the cover element. The cover serves to open or close a flow cross-section of the bypass channel by means of a rotary movement of the cover about an axis of rotation. With such a control device, it is possible in certain operating points of the exhaust gas turbocharger, in particular at operating points with large flow rates, to bypass the turbine wheel completely or partially, so that a more efficient operation of the exhaust gas turbocharger can be realized. In a simplest embodiment, the cover is formed, for example in the form of a plate. The problem is in principle that it can come to exhaust leaks from flowing out of the bypass duct exhaust into the environment.

It is therefore an object of the present invention to provide an improved control device for an exhaust gas turbocharger of the type specified in the preamble of patent claim 1. This object is achieved by a control device for an exhaust gas turbocharger having the features of patent claim 1.

A control device according to the invention for an exhaust gas turbocharger, which has a flow-through exhaust gas guide section, a bearing section and a

wherein the exhaust gas guide section is connected to the air guide section by means of the bearing section, and wherein a turbine wheel of the exhaust gas turbocharger is rotatably received in the exhaust gas guide section, and wherein the turbine wheel is provided with a compressor wheel, which in the

Air guide portion is rotatably received, by means of a Laufzeugwelle which is rotatably received in the bearing portion, rotatably connected, and wherein for bypassing the turbine wheel in the exhaust guide portion, a bypass channel is formed, has a cover for opening or closing the

Bypass channels on. The control device comprises a rotatably mounted in the exhaust guide portion shaft, wherein the shaft is connected to the cover. At its end facing away from the cover, the shaft is connected to a connecting element for movement of the cover. To reduce a flow of the rule device in the shaft is the

Regulating device, starting from the bypass channel in the direction of

Connecting element designed to reduce pressure. Basically, the leakage is dependent on a pressure gradient in the region of the control device. Due to the pressure gradient results in a flow starting from the bypass channel via the shaft into the environment, since a remote from the bypass channel formed end of the shaft, which is connected to the connecting element, opens into the environment. In order to avoid the flow from the bypass channel into the environment, and thus to reduce or avoid exhaust gas leakage, it is therefore intended to form the control device such that the pressure in the region of the control device is reduced.

In one embodiment, a first groove and / or a second groove are provided in the exhaust gas guide portion, wherein the first groove and / or the second groove of the shaft are open opposite. The advantage is that the groove becomes one

Cross-sectional enlargement of a flow cross section of the shaft along flowing exhaust gas leads. This cross-sectional enlargement causes a

Pressure reduction.

In a further embodiment, a movement gap exists between the connecting element and a wall arranged opposite the connecting element, which wall is formed adjacent to the first groove. The advantage is one

Reduction of friction losses, since the connecting element is movably arranged opposite the wall.

The movement gap preferably has a value of 0.2 to 0.3 mm in the axial direction.

To further prevent leakage in the region of the control device, the shaft has a shoulder, which is remote from the first end of the shaft. In other words, that is, facing the cover member

trained end of the shaft is designed the paragraph. The advantage of the paragraph is the achievement of an optimized surface-power ratio, so that an increased contact pressure of the shaft to the exhaust gas guide portion and thus an improved sealing effect can be formed. Another advantage of the paragraph is the fact that due to the paragraph positioned one of the shaft facing

Deflection edge is formed, which leads to a further pressure loss.

Preferably, the step is such that an outer diameter of the shoulder is greater than a second diameter of the shaft. Thus, there is no weakening of the shaft due to the necessary for the formation of the paragraph different diameters.

In a further embodiment, a further movement gap is formed between the shoulder and a wall opposite the shoulder, whereby a further friction-reduced movement of the shaft is realized.

In a further embodiment, the first groove and / or the second groove are formed as a half-groove. In a further embodiment, a sealing element is arranged in the first groove and / or in the second groove. The sealing element is for additional assurance of

Preventing the leakage in the control device arranged.

In a further embodiment, the sealing element has a V-shaped cross section. The advantage is that it realizes an additional seal, in particular in the case of grooves designed as half-grooves, since it can be installed prestressed.

Increases, for example, the groove due to thermal expansion, the

Relax sealing element, wherein it increases its axial extent and thus further formed at its opposite cross-sectional ends of the groove and against the wall. In addition, the V-shaped cross-section forms a kind of pocket, in which additionally leakage exhaust gas can accumulate.

In a further embodiment, at least one full groove is formed in a middle section of the shaft between the first end of the shaft and the second end of the shaft of the shaft. The advantage of this Vollnut is to see in the cause of a further pressure reduction. Another advantage is an additional reduction of friction losses.

In a further embodiment, the connecting element is integrally connected to the shaft at the first end of the shaft. The advantage is that due to the

cohesive connection formed over a circumference of the shaft between the shaft and the connecting element formed gap, which is due to the two separate from each other formed components, completely fluid-tight. Preferably, the cohesive connection is a

Welded joint.

In a further embodiment, the first groove and / or the second groove and / or the full grooves are formed in a bushing comprising the shaft, wherein the bushing is received in the exhaust gas guide section. The advantage of the bush is firstly to be seen in a reduction of a friction loss, since independent of the material of the exhaust gas guide section corresponding material can be used. Of Furthermore, the advantage of a bush is the possibility of easier machining of an inner surface of the bush, which is arranged opposite the shaft, and accordingly should have a very low roughness. An additional advantage is the simplified processing capability of the socket and thus a so-called handling of the bushing in comparison to the exhaust gas guide section. The socket

To provide pressure-reducing with, for example, grooves designed in the manufacturing process easier than the example. Grooves in a corresponding provided for the shaft

Insert receiving opening in the exhaust gas guide section.

Another advantage, especially in mass production, is the socket

symmetrical form. In other words, the bush is formed symmetrically relative to a center line formed transversely to its longitudinal axis. Thus, their installation in the exhaust gas guide section is independent of their shape along its longitudinal axis. The advantage is the avoidance of incorrect installation of the socket.

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

Feature combinations as well as the features and feature combinations 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. Identical or functionally identical elements are assigned identical reference numerals. Show it:

1 is a perspective view of an exhaust gas turbocharger with a

Adjustment element acc. the prior art, and

2 shows a longitudinal section of a control device according to the invention for an exhaust gas turbocharger.

A known from the prior art, as shown in FIG. 1 trained

Exhaust gas turbocharger 1 has a flow-through exhaust gas guide section 2. This comprises an inlet channel 4 for the entry of a fluid flow in the

Exhaust gas guide section 2, in general exhaust of an internal combustion engine, a spiral channel 5 downstream of the inlet channel 4 for conditioning the flow and an outlet channel 3 downstream of the spiral channel 5, via which the exhaust gas from the exhaust gas guide section 2 can escape targeted. Between the spiral channel 5 and the outlet channel 3, a wheel chamber 6 is formed, in which a not-shown turbine wheel is rotatably received.

In order to adapt an operating behavior of the turbine 2 to the fluid flow, a control device 7 for opening or closing a bypass channel 8 in the flow-through exhaust gas guide section 2 for bypassing the wheel chamber 6 in the exhaust gas guide section 2 is provided in the exhaust gas guide section 2. The bypass channel 8 has an inlet opening 9, wherein the inlet opening 9 with the aid of the control device 7 is completely or partially closed or can be opened completely or partially. According to a positioning of the control device 7, it is possible that the fluid flow flows completely or partially against the wheel chamber 6 and thus the turbine wheel rotatably received in the wheel chamber 6, or flows completely or only partially past the turbine wheel rotatably received in the wheel chamber 6.

A cover 11 of the control device 7 is movably received in the bypass channel 8, and thus in the exhaust guide section 2, wherein the cover 11 is mounted executable in the bypass channel 8 for opening or closing the inlet opening 9 a predominantly rotational movement. In other words, the cover member 11 is for setting an effective

Flow cross-section of the inlet opening 9 a rotatable movement in the bypass channel 8 positioned executable.

The regulating device 7 has a movement device 12 for the rotational movement of the cover element 11. The movement device 12 comprises, in addition to a pressure measuring device 10 for measuring a boost pressure of a

Air guide portion 13, a control rod 14, a connecting element 15, a shaft 16 with a rotation axis 17 and a lever arm 18, on which the cover 1 is fixed.

The required movement of the cover 11 is by means of the control rod 14, which is connected at one end to the pressure measuring device 10, on the

Connecting element 15, which is connected to the other end of the control rod 14, transferable. Due to a compound of the connecting element 5 with the

Control rod 14 and the shaft 16, the transmitted to the connecting element 15 movement is forwarded to the shaft 16, which is connected at its first end 19 to the connecting element 15. The shaft 16 is rotatable in

Exhaust gas guide section 2 mounted in a through hole 36 by means of a sleeve 20, so that the usually translational movement of the control rod 14 is converted by means of the shaft 16 in a rotational movement.

At a second end 21 of the shaft 16, the lever arm 18 is formed, which serves to receive the cover 11. About the lever arm 18 having a longitudinal axis 22 which is fixedly connected to the shaft 16, the rotational movement of the shaft 16 is transmitted to the cover 11, so that the lever arm 18 as

Connecting element between the cover 11 and the shaft 16 is formed.

A control device 7 according to the invention of the exhaust gas turbocharger 1 is formed as shown in FIG. To avoid leakage from the bypass channel 8 via the shaft 16 in the environment, thus reducing the flow of the control device

7 in the region of the shaft 16, the control device 7 is starting from the bypass channel

8 formed in the direction of the connecting element 15 pressure-reducing.

To reduce pressure, a first groove 24 is formed between the connecting element 15 and the sleeve 20, in which a first sealing element 23 in the form of a

Sealing ring is added. The sealing ring 23 has a V-shaped cross-section. The first groove 24 extends from an inner surface 25 of the bushing 20 radially over a groove depth NT. The first groove 24 is formed on a connecting element 15 facing the first female end 26 in the form of a half-groove. For limiting the first groove 24 in the axial direction, in other words in the direction of the connecting element 15, the connecting element 15, the first groove 24 is arranged covering. In this case, a movement gap 27 is provided between the connecting element 15 and the sleeve 20, which allows a freedom of movement of the shaft 16 in the sleeve 20, taking into account a thermally induced expansion of the sleeve 20 and the connecting element 15. Thus, the movement gap 27 between the connecting element 15 and the connecting element 15 opposite wall, in this embodiment, the wall of the sleeve 20 is formed.

The tightness against leakage is ensured due to the v-shaped cross section of the first sealing element 23, since it is designed to be adaptable to its axial extent along the longitudinal axis 22 due to its elastic property. The movement gap 27 preferably has an axial extent of 0.2-0.3 mm.

The shaft 16 is integrally connected to the connecting element 15 at its first end, preferably by means of a welded connection.

At a second socket end 28 opposite the first socket end 26 of the socket 20, a second groove 29 is formed. This second groove 29 is also configured in the form of a half-groove, wherein for limiting the second groove 29 in the axial direction, the shaft 16 extends radially beyond the second groove 29. In other words, the shaft 16 in the region of the second groove 29 has a first diameter D1, which is greater than a trained in the vast majority of the sleeve 20 second diameter D2.

In the second groove 29, a second sealing element 30 is arranged, which is formed in the form of a sealing ring and also having a V-shaped cross section.

To further secure the leakage reduction, the shaft 16 in the region of the second bushing end 28 has a shoulder 31 with an outer diameter DA, the taking into account a further movement gap 33 a groove depth NT of the second groove 29 corresponds. The groove depth NT of the first groove 24 does not correspond

The groove depth NT is dependent on a power of the exhaust gas turbocharger 1, or a maximum exhaust gas flow rate through the exhaust gas guide section 2.

The first groove 24 and the second groove 29 are thus formed opposite the shaft 16 open, wherein the grooves 24, 29 results in a cross-sectional enlargement of a flow cross-section of a along the shaft 16, flowing out of the bypass channel 8 Abgasleckagestromes. This cross-sectional enlargement leads to a pressure reduction.

The sleeve 20 has in this embodiment between the first groove 24 and the second groove 29, thus in a central portion 34, three further annular full grooves 32 which are formed as pressure-reducing chambers.

Transverse to the longitudinal axis 22, the bushing 20 has a center line 35, relative to which the bushing 20 is formed symmetrically. This means that the first groove 24 corresponds in size and orientation to its orientation in the bushing 20 of the second groove 29, wherein they are formed in mirror image to the center line 35 in the sleeve 20. Likewise, the full grooves 32 are arranged symmetrically relative to the center line 35.

In a further embodiment, not shown, the first groove 24, the second groove 29 and the full grooves 32 are formed directly in the exhaust gas guide section 2, since the control device 7 is made without a socket.

Claims

claims

1. A control device for an exhaust gas turbocharger, which comprises a flow-through exhaust guide portion (2), a bearing portion and a flow-through air guide portion (13), wherein the exhaust gas guide portion (2) by means of the bearing portion with the air guide portion (13) is connected, and wherein in the exhaust gas guide portion (2 ) a turbine wheel of the exhaust gas turbocharger (1) is rotatably received, and wherein the turbine wheel with a

Compressor, which is rotatably received in the air guide section (13), rotatably connected by means of a Laufzeugwelle which is rotatably received in the bearing section, and wherein for bypassing the turbine wheel in the exhaust guide section (2) a bypass channel (8) is formed, which by means of a cover (11) the control device (7) is to open or close, and wherein the control device (7) has a in the

Exhaust gas guide portion (2) rotatably mounted shaft (16), and wherein the shaft (16) is connected to the cover (11), and which at its from the cover (11) facing away from the first end (19) with a connecting element (15) connected to the movement of the cover (11),

characterized in that

for reducing a flow through the control device (7) in the region of the shaft (16), the control device (7), starting from the bypass channel (8) in the direction of the connecting element (15) is pressure-reducing, and wherein the shaft (16) has a shoulder (31 ), which is formed facing away from the first end (19) of the shaft (16), and wherein an outer diameter (DA) of the shoulder (31) is greater than a second diameter (D2) of the shaft (16).

2. Control device according to claim 1,

characterized in that

a first groove (24) and / or a second groove (29) is provided in the exhaust gas guide section (2), the first groove (24) and / or the second groove (29) being open towards the shaft (16).

3. Control device according to one of claims 1 or 2,

characterized in that

between the connecting element (15) and a wall (20; 2) arranged opposite the connecting element (15), which wall is formed adjacent to the first groove (24), there is a movement gap (27).

4. Control device according to claim 3,

characterized in that

the movement gap (27) in the axial direction has a value of 0.2 to 0.3 mm.

5. Control device according to one of the preceding claims,

characterized in that

a further movement gap (33) is formed between the shoulder (31) and a wall (20; 2) opposite the shoulder (31).

6. Control device according to one of the preceding claims,

characterized in that

the first groove (24) and / or the second groove (29) are formed as a half-groove.

7. Control device according to one of the preceding claims,

characterized in that

a sealing element (23; 30) is arranged in the first groove (24) and / or in the second groove (29).

8. Control device according to claim 7,

characterized in that the sealing element (23; 30) has a V-shaped cross-section.

9. Control device according to one of the preceding claims,

characterized in that

in a central portion of the shaft (16) between the first end (19) of the shaft (16) and the second end (21) of the shaft (16) of the shaft (16) opposite at least one full groove (32) is formed

10. Control device according to one of the preceding claims,

characterized in that

the connecting element (15) is materially connected to the shaft (16) at the first end (19) of the shaft (16).

11. Control device according to claim 10,

characterized in that

the cohesive connection is a welded connection.

12. Control device according to one of the preceding claims,

characterized in that

the first groove (24) and / or the second groove (29) and / or the full grooves (32) are formed in a socket (20) comprising the shaft (16), the socket (20) being received in the exhaust guide section (2) is.

13. Control device according to claim 12,

characterized in that

the bush (20) is symmetrical.