WO2013156121A1

WO2013156121A1 - Turbine for turbocharger

Info

Publication number: WO2013156121A1
Application number: PCT/EP2013/001052
Authority: WO
Inventors: Thomas Ihli; Manfred GUTHÖRLE; Klaus Sperling
Original assignee: Ihi Charging Systems International Gmbh
Priority date: 2012-04-19
Filing date: 2013-04-10
Publication date: 2013-10-24
Also published as: WO2013156047A2; DE102012103411A1; WO2013156047A3; WO2013156048A1; DE112012006245A5

Abstract

The invention relates to a turbine for a turbocharger, comprising an exhaust gas conduit section (5) through which a fluid can flow, and a turbine wheel (3) that can rotate about an axis of rotation (4) and is rotatably disposed in a turbine wheel chamber (6) of the exhaust gas conduit section (5). The exhaust gas conduit section (5) includes a helical duct (8) upstream of the turbine wheel chamber (6). A sleeve-shaped axial slide (9) is arranged in an axially movable manner in an overflow duct (10) of the exhaust gas conduit section (5) located between the helical duct (8) and the turbine wheel chamber (6), said axial slide being used to condition a fluid current flowing through the exhaust gas conduit section (5). The disclosed turbine further comprises an adjustment chamber (11) that includes a sliding device for axially moving the axial slide (9). According to the invention, a partition (13) is provided between the helical duct (8) and the adjustment chamber (11), said partition (13) radially at least partially surrounds the axial slide (9), and the partition (13) can be produced as a turbine (2) component that is separate from the exhaust gas conduit section (5).

Description

Turbine for an exhaust gas turbocharger

The invention relates to a turbine for an exhaust gas turbocharger specified in the preamble of claim 1. Art.

The published patent application DE 10 2009 050 951 A1 discloses a turbine for a

Exhaust gas turbocharger, with a flow-through exhaust gas guide section. in the

Exhaust guide section is a turbine wheel rotatable in a wheel chamber of the

Exhaust gas guide section positioned. Upstream of the wheel chamber, a spiral channel is provided in the exhaust gas guide portion, wherein between the spiral channel and the

Radkammer a transfer port of the exhaust gas guide section is arranged. In this overflow channel, a sleeve-shaped axial slide for conditioning of the exhaust gas flow passage portion flowing fluid flow is arranged axially displaceable. In a Verstellraum is a sliding device for the axial displacement of the

Axial slide provided. The axial slide is formed like a die and is axially slidable via a guide grid, which is immovably positioned in the overflow.

During operation of the turbine, for example with an internal combustion engine, changes in operating temperatures occur. Already at a start of an example

Passenger car with an internal combustion engine, the turbine is flowed through by hot exhaust gas, whereas the exhaust gas passage section itself still one of

Ambient temperature corresponding temperature. Components of the turbine, in particular those in a flow path of the exhaust gas through a

Depending on the operating point of the internal combustion engine are repeatedly exposed to different temperatures of the exhaust gas exhaust gas guide section of the turbine are positioned. The components of the turbine, in particular the exhaust gas guide section and the axial slide are made of metallic materials, which

Thermal expansion coefficients and even, if they are made of different materials, have different thermal expansion coefficients. This means that these components expand according to the temperature or

contract thus have a contour change. If different metallic materials are used for different components, they have Components to different contour changes, which in particular precludes a criterion of the gap freedom with simultaneous contactless compelling components with fixed components over a nearly complete operating range. This means that jamming is possible due to different expansion or distortion of the components guide grille and axial slide between the guide rail and the axial slide.

It is an object of the present invention to develop a turbine of the type mentioned in such a way that the turbine is operationally safe to operate.

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.

According to the invention, a dividing wall is provided between the spiral channel and the adjusting chamber, wherein the dividing wall is formed radially at least partially encompassing the axial slide, and wherein the dividing wall can be produced as a component of the turbine which is formed independently of the exhaust-gas guide section. The fact that the partition is independent of the exhaust gas guide section produced, the

Partition with a significantly improved accuracy, in other words be made with a significantly reduced tolerance limit and thus a much improved runnability of the axial slide can be achieved. The friction between the partition and the axial slide is significantly reduced and jamming of the

Axial slide in the operation of the turbine is improved by a much

Surface quality of both the partition and the axial slide largely excluded.

Furthermore, the dividing wall, as it is not integral with the

Exhaust guiding portion is formed to adjust the temperatures in their extent and thus forms together with the axial slide one of the due to temperature changes and consequently contour changes of

Exhaust pipe section independent system. Since the axial slide and the partition are functionally independent of each other formed components, there is a minimal gap between their opposing sections, which a contour change and yet secured mobility of the

Axial slider takes account. Thus, jamming of the axial slide during operation of the turbine is also avoidable for this reason. Another noteworthy, not negligible advantage of this turbine according to the invention is a significant reduction of a tendency to crack of the exhaust gas guide section. An integrally formed with the exhaust gas guide section partition may due to jamming of the axial slide and the stresses caused thereby in the exhaust gas guide section to cracks in

Lead exhaust section. Again, this is avoided with the turbine according to the invention, which thus has an outstanding reliability.

In one embodiment of the turbine according to the invention, the partition is at least partially formed as a wall of the spiral channel. Usually, the

Exhaust gas guide section produced by means of a casting process. It is known that each intermediate wall, each undercut, in a casting model, on the one hand, entails a considerably more expensive and therefore expensive casting process and an equally expensive and therefore expensive casting model. Thus, the turbine according to the invention, the partition between the spiral channel and the adjustment is made at least partially independent of the exhaust gas guide section, and which is at least partially formed as a wall of the spiral channel leads to a significant cost savings in the production of the exhaust gas guide section.

In a particularly simple and thus cost-effective design of the turbine, the partition is designed annular.

Advantageously, the partition by means of a hollow cylindrical sleeve in

Exhaust gas guide section fixed. The sleeve has the advantage that it realizes a simple, flexible and at the same time sealing fixation of the partition. The sleeve has the partition at one of its axial ends. At the other end she is on

Exhaust gas guide section fixable.

Alternatively, the partition is at a between the adjustment and the

Spiral channel formed intermediate wall formed supporting. This has the advantage that a simple holding device, which exclusively generates a contact force of the partition wall on the intermediate wall, is to be realized. Another advantage is that the intermediate wall is at least partially formed at the same time as a wall of the spiral channel. Since the partition wall is also at least partially formed as a wall of the spiral channel, it can be structurally made smaller to the extent in which the intermediate wall is already formed as a wall of the spiral channel. Indeed should have a minimum size of the partition to maintain the flexibility of the system

Axial slider dividing wall are respected.

If a second paragraph is provided on the partition, a particularly effective sealing while maintaining a flexible connection between the partition and the partition can be achieved.

A substantially improved sealing of the spiral channel with respect to the adjustment space can be achieved with a partition, whose axial surface facing the axial slide formed, curved relative to a lateral surface of the axial slide. In this embodiment of the turbine according to the invention, in addition to the improved sealing, due to the axial slide facing curved inner surface jamming the axial slide almost impossible.

In a further advantageous embodiment of the turbine according to the invention, a non-movable short grid is arranged in the overflow channel. During operation of the turbine, the axial slide is adapted to a section passing through the exhaust gas guide section

Fluid amount more or less pushed into the overflow. In other words, the axial slide serves to reduce or increase a cross-sectional area of the overflow channel. Preferably, the free cross-sectional area of the overflow is also low for small amounts of fluid, whereas at large amounts of fluid, for example at full load of an internal combustion engine, with which the exhaust gas turbocharger is thermodynamically connected, the cross-sectional area and thus the overflow is completely open. On the other hand at low loads the

Internal combustion engine is preferably to release only a small cross-sectional area, that is, the axial slide is to push so far into the overflow until this corresponding cross-sectional area is formed. Or the axial slide is to push completely into the overflow, so that it comes into contact with a wall of the exhaust gas guide section opposite it, and then, so that a minimal amount of fluid can act on the turbine wheel, formed through-flow, whereby an increased cost factor is brought about.

The short lattice is now dimensioned so that it releases a low-efficiency for the turbine low-efficiency cross-sectional area at low fluid quantities. This means that a minimum amount of fluid can flow through the exhaust gas guide section and one for this

Fluid amount optimal turbine efficiency can be achieved. With the help of the im

Overflow channel arranged short grid can now the axial slide cost shovel-free, for example, hollow cylindrical, are designed because due to the short grid for a small amount of fluid optimal minimum cross-sectional area of the overflow even when the axial slide with the short grid to

Blocking of the remaining cross-sectional area of the overflow, is released.

In an advantageous embodiment, the short grid has a guide ring on its surface facing the axial slide. In an operating point of the turbine for small amounts of fluid in which the axial slide is positioned touching the short grid, in other words, in which the axial slide blocks the cross-sectional area of the overflow channel which is not influenced by the short grid, the fluid quantity is fed exclusively to the turbine wheel via the short grid. An axial displacement of the axial slide to release a larger cross-sectional area, such that a contact between the short grid and the axial slide is canceled, leads briefly to a reduction in the efficiency of the turbine due to a low pressure loss. This pressure loss is eliminated by means of the guide ring and a break in efficiency due to a displacement of the axial slide towards a complete release of the cross-sectional area is avoided.

Advantageously, the axial slide to increase the turbine efficiency, especially in the case of a contact between the axial slide and the short grid having positioning of the axial slide at its the short grid facing annular surface on an annular ridge. The increase of

Efficiency is due to an improved seal between the axial slide and the short grid by means of the annular ridge. This annular web can be attached to an arbitrary position on the surface facing the short lattice, a so-called front side.

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.

The drawing shows in: 1 shows a detail of a longitudinal section through an exhaust gas guide section of a turbine according to the invention of an exhaust gas turbocharger,

2 shows a detail of a longitudinal section through an exhaust gas guide section of a turbine according to the invention of an exhaust gas turbocharger in a variant,

3 shows a detail of a longitudinal section through an exhaust gas guide section of a turbine according to the invention of an exhaust gas turbocharger in a further variant,

4a is a detail view of a partition in a first variant,

4b is a detail view of the partition in a second variant,

Fig. 4c is a detail view of the partition in a third variant and

Fig. 4d is a detail view of the partition in a fourth variant.

A turbine 2 according to the invention of an exhaust-gas turbocharger 1 is constructed along a rotation axis 4 of a turbine wheel 3 of the turbine 2 in accordance with a longitudinal section shown in FIG. 1. A flow-through exhaust gas guide section 5 of the turbine 2, which of a fluid, usually of exhaust gas of a not shown

Internal combustion engine, with which the exhaust gas turbocharger 1 is thermodynamically connected, is flowed through, has a wheel chamber 6 for receiving the

Turbine wheel 3 on. The turbine wheel 3 is rotatably connected by means of a shaft 7 with a compressor wheel, not shown, which rotatably in a non-illustrated wheel chamber of a flow-through, not shown

Air guide section is connected. The turbine wheel 3 is acted upon by exhaust gas, wherein the turbine wheel 3 exerts a rotational movement and this rotational movement is transmitted by means of the rotationally fixed connection with the compressor wheel not shown on this, so that the compressor wheel, not shown, can suck in fresh air, which is not shown in detail Air guide section is compressed. The exhaust gas guide section 5 has a spiral channel 8 upstream of the wheel chamber 6. In the exhaust gas guide section 5 is an axially displaceable, sleeve-shaped

Axial slide 9 is arranged, which is hineinschiebbar in a positioned between the wheel chamber 6 and the spiral channel 8 overflow channel 10 of the exhaust gas guide section 5 for conditioning the fluid flow to the turbine wheel. 3

The axial slide 9 is axially displaceable by means of a sliding device, not shown in detail, which is at least partially accommodated in a displacement chamber 11 of the exhaust gas guide section 5. The adjusting chamber 11 is formed axially adjacent to the spiral channel 8 on the one hand and has, for the limitation of the adjusting chamber 11, axially on the other hand a disc-shaped cover 12, which on

Exhaust gas guide section 5 by means of fastening means, such as

Screws or pins, is fixed.

To delimit the spiral channel 8 with respect to the adjustment chamber 11, an annular partition wall 13 is formed, which is arranged by means of a hohizylinderförmigen sleeve 14 with an annular disc 15 in the exhaust gas guide section 5 almost immovable.

The partition wall 13 is the axial slide 9 radially formed completely comprehensive, wherein the partition wall 13 is made as a independently of the exhaust gas guide section 5 formed component of the turbine 2.

The annular partition wall 13 is arranged on a spiral channel 8 facing the end of the sleeve 14 and is formed as a partial wall 18 of the spiral channel, wherein a first inner diameter DU of the partition wall 13 is smaller than a second inner diameter DI2 of the sleeve 14. A first outer diameter DA1 the partition wall 13 corresponds to a second outer diameter DA2 of the sleeve 14. At its end remote from the spiral channel 8 end of the sleeve 14 annular disc 15 is arranged. The annular disc 15 has a third inner diameter DI3, which corresponds to the second inner diameter DI2 of the sleeve 14, and a third

Outer diameter DA3, which is greater than the second outer diameter DA2 of the sleeve 14. The annular disc 15 is formed as a holder of the sleeve 14 in the exhaust gas guide portion 5 and facing the lid 12 in a lid 12

positioned flange 16 of the exhaust gas guide section 5 by means of others

Fixing means clamped fixed.

Ideally, the partition wall 13 on its inner surface 31, which the

Inner diameter DU has curved, s. Fig. 4a, 4b, 4c and 4d. In other words, the outer surface 31 of the partition wall 13 facing a lateral surface 32 of the axial slide 9 is arched relative to the lateral surface 32. Due to the domed formed inner surface 31, or in other words due to the crowned design, the partition 13 at her

Inner surface 31, a possible friction surface between the axial slide 9 and the partition 13 is so greatly reduced that jamming is no longer possible. Even if the axial slide 9 assumes a position in which with a straight

formed canting would occur alone, due to a radius R, which has the curved inner surface 31 due to its curvature, tilting due to slippage of the axial slide 9 at the radius R is not possible.

The annular disc 15 is thus on the one hand as a holder of the sleeve 14 in

Exhaust gas guide section 5 is formed and consequently, since the partition wall 13 is formed integrally with the sleeve 14, formed as a support of the partition wall 13, and on the other hand, it has a sealing function for gas-tightness of the exhaust gas guide section 5 from the environment. Due to the clamping fixation of the annular disc 15 is achieved on the one hand a seal of the adjustment chamber 11 relative to the environment and on the other hand, a seal of a minimum gap 17 between the sleeve 14 and the exhaust gas guide section 5, which is formed in the region of the sleeve 14, this bordering.

In a variant of the turbine according to the invention shown in FIG. 2, the partition 13 is annular, with a fixation of the partition wall in the exhaust guide section 5 by means of a support of the partition 13 on an intermediate wall 9, which between the adjustment 11 and the spiral channel 8 partially projecting, annular is formed, and a pin-shaped holding means is provided.

For support, the intermediate wall 19 has a first annular shoulder 20 and the partition wall 13 a second annular shoulder 21, wherein the first annular shoulder 20 and the second annular shoulder 21 are complementary to each other, so that the first annular shoulder 20 and the second annular Paragraph 21 can be arranged opposite each other. The first annular shoulder 20 and the second annular shoulder 21 could also be formed like a toothed ring, wherein the teeth of the first annular shoulder 20 and the second annular shoulder 21 would be at least partially overlapping. In an embodiment not shown, only the partition wall 13, the second annular shoulder 21, wherein the shoulder 21 is arranged to produce a contact surface of the intermediate wall 19 opposite one another.

For fixing the partition wall 13 to the intermediate wall 19 is gem. Fig. 2, a pin-shaped holding device 22 is provided. The holding device 22 is connected at one end to the dividing wall 13 and at the other end it is supported on an inner wall of the lid 12 positioned facing the adjusting space 11, so that the dividing wall 13 has a contact pressure on the intermediate wall 19.

In a further embodiment according to. Fig. 3, the partition 13 is fixed by means of an arc-shaped holding device 22 on the intermediate wall 19. This arc-shaped holding device 22 is supported to generate the contact pressure on a wall 11 23 delimiting the adjustment chamber 11 exhaust guide section. This arc-shaped holding device 22 may be formed in the form of a ring or in the form of ring sections.

In a particular variant of the turbine 2 according to the invention, a short grille 24, which is arranged in the overflow channel 10 opposite the axial slide 9, is arranged

Exhaust gas guide section 5 is formed immovable. The short grid 24 has an axial first length LK which is smaller than an axial second length LÜ of the

Overflow 10, and is thus formed only partially covering the overflow channel 10. The short grid 24 has guide vanes 25, which are arranged to flow around a grid ring 26. On a side facing the axial slide 9 formed surface 27 of the short grid 24, a guide ring 28 is formed. For improved conditioning, an annular web 30 is arranged on an annular surface 29 of the axial slide 9 facing the short grille 24.

Claims

claims

1. Turbine for an exhaust gas turbocharger, with a flow-through

Exhaust gas guide section (5) and with a about an axis of rotation (4) rotatable turbine wheel (3) which rotatably in a wheel chamber (6) of the

Exhaust gas guide section (5) is positioned, wherein the exhaust gas guide section (5) upstream of the wheel chamber (6) has a spiral channel (8), wherein in a between the spiral channel (8) and the wheel chamber (6) positioned

Overflow (10) of the exhaust gas guide portion (5) a sleeve-shaped

Axial slide (9) for conditioning a the exhaust gas guide section (5) flowing fluid flow is arranged axially displaceable, and with a displacement chamber (11) with a sliding device for the axial displacement of the axial slide (9),

characterized in that

a partition wall (13) is provided between the spiral channel (8) and the adjustment space (11), the partition wall (13) forming the axial slide (9) radially at least partially encompassing, and wherein the partition wall (13) is independent of the one Exhaust gas guide section (5) formed component of the turbine (2) can be produced.

2. Turbine according to claim 1,

characterized in that

the partition (13) is at least partially formed as a wall (18) of the spiral channel (8).

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

characterized in that the partition (13) is designed annular.

4. Turbine according to claim 3,

characterized in that

the partition (13) by means of a hollow cylindrical sleeve (14) in the exhaust gas guide section (5) is fixed.

5. Turbine according to claim 3,

characterized in that

the partition wall (13) is designed to be supported on an intermediate wall (19) formed between the adjusting space (11) and the spiral channel (8).

6. Turbine according to claim 5,

characterized in that

the partition wall (13) is formed supportingly with the aid of a second shoulder (21) on the intermediate wall (19).

7. Turbine according to one of the preceding claims,

characterized in that

the partition wall (13) has an inner surface (31) formed facing the axial slide (9), wherein the inner surface (31) is arched relative to a lateral surface (32) of the axial slide (9).

8. Turbine according to one of the preceding claims,

characterized in that

an immovable short grid (24) in the overflow channel (10) is arranged.

9. Turbine according to claim 6,

characterized in that

the short grid (24) has a guide ring (28) on its surface (27), which faces the axial slide (9).

10. Turbine according to claim 6 or 7,

characterized in that

the axial slide (9) formed on its the short grid (24) facing Ring surface (29) has an annular ridge (30).