WO2014005678A1

WO2014005678A1 - Turbine and corresponding exhaust gas turbocharger

Info

Publication number: WO2014005678A1
Application number: PCT/EP2013/001862
Authority: WO
Inventors: Jaenike LORENZ
Original assignee: Ihi Charging Systems International Gmbh
Priority date: 2012-07-06
Filing date: 2013-06-25
Publication date: 2014-01-09
Also published as: DE102012106090A1

Abstract

The invention relates to a turbine, comprising an exhaust gas guide section (3) through which gas can flow, and a turbine rotor (5), rotatably mounted in the exhaust gas guide section (3), with an axis of rotation (6), wherein the exhaust gas guide section (3) has a duct for through flow that is designed differently from one section to the next, wherein the duct is formed in one section to accommodate the turbine rotor (5) in the form of a rotor chamber (4) comprising a rotor chamber wall (13), and wherein a gap (15) is formed at least partially between an enveloping surface (14) of the turbine rotor (5) and the rotor chamber wall (13). According to the invention, the rotor chamber wall (13) has a tooth-shaped contour (23) at least in the area of the gap (15), said contour being formed in one extension direction of the axis of rotation (6).

Description

TURBINE AND ASSOCIATED EXHAUST BOLDER

The invention relates to a turbine in the preamble of claim 1

specified type and a turbine for an exhaust gas turbocharger according to claim 6.

The publication DE 696 04 154 T2 discloses a turbine, with a flow-through exhaust gas guide section and a turbine wheel rotatably received in the exhaust gas guide section. The exhaust gas guide section has a sectionally differently shaped channel for the flow through. In a section of the duct, this section is for receiving the turbine wheel as a wheel chamber

educated. This wheel chamber has a Radkammerwandung. Between this Radkammerwandung and the turbine wheel radially enveloping envelope a gap is formed. This gap serves to avoid contact of the turbine wheel and the wall of the wheel chamber during operation of the turbine.

The problem, however, is that the size of this gap, an efficiency of the turbine and thus their effectiveness depends. That is, the larger this gap, the greater are the efficiency losses, whereas if the gap is too small, the risk of touching the turbine wheel with the Radkammerwandung is increased.

The solution in the present disclosure is the attachment of an abradable seal. This means that before the first operation of the turbine, the gap is almost absent. Already with the first commissioning, however, the seal is worn down so far that a more or less contact-free position between the

Turbine and the wheel chamber is formed. The problem here is, however, that although a very small gap can be formed, which can realize a high efficiency corresponding to the turbine, but this gap is not maintained over the life of the turbine.

This is partly due to the fact that the sealing material is subject to aging, which does not correspond to aging of the exhaust gas guide section and, secondly, that the sealing material is not specifically abradable. That is, it is too partial Breaking out of sealing material may occur, whereby a strong loss of efficiency in operation occurs.

The aging of the sealing material is also at a significant rate on large

Temperature fluctuations attributable to the exhaust gas flowing through the turbine during operation of the turbine. No less cause these temperature fluctuations distortion of the exhaust gas guide section, which depending on the choice of the sealing material, the gasket itself or in a different ratio, so that it can cause breaks in the range of material pairings of exhaust gas guide section and seal.

The object of the present invention is to provide a turbine which has a high efficiency over the entire life of the turbine.

This object is achieved by a turbine having the features of patent claim 1. Advantageous embodiments with appropriate and non-trivial

Further developments of the invention are specified in the remaining claims.

To realize a turbine with a high efficiency, which is not only temporary, but over almost the entire life of the turbine achievable, the invention proposes a Radkammerwandung a wheel chamber of an exhaust gas guide section of the turbine at least in the region of a gap, which is rotatable between one in the wheel chamber recorded turbine wheel and the Radkammerwandung exists to design with a tooth-like contour, wherein the contour of the Radkammerwandung is formed in an extension direction of a rotation axis of the turbine wheel.

With the help of this tooth-like contour, it is possible to substantially reduce the gap between the turbine and the Radkammerwandung compared to conventional, the prior art turbines. This reduced gap leads to an increase in the turbine efficiency, since higher pressures upstream of the turbine wheel can be achieved. Furthermore, this increased turbine efficiency over almost the entire life of the turbine can be achieved because the tooth-like contour is formed in the Radkammerwandung. In other words, this means that the contour is not, for example, in the form of a coating on the Radkammerwandung

was applied, thus possibly even a non-metallic

Material having formed, but formed integrally with the wheel chamber is. This one-piece design can by chipless or machined

Forming be brought about, for example, directly in the casting process using a corresponding mold or for example by means of a milling process. Thus, the Radkammerwandung subject with their tooth-like contour the same aging conditions, which the exhaust gas guide section and

Accordingly, subject to the turbine and premature aging or detachment of a layer, as in the prior art, is no longer available here.

Another advantage of this invention is in particular in a tooth-like contour having a plurality of teeth that a quasi labyrinth seal similar seal between the overflow and the outlet channel is caused by the successively arranged in the flow direction teeth, resulting in a further increase in efficiency the turbine contributes.

Should it still due to minimal movements of the turbine wheel or due to expansions of the exhaust gas passage section through the strong

Temperature changes during operation of the turbine or the exhaust gas turbocharger come to solid state contacts between the turbine wheel and the Radkammerwandung, are due to the tooth-like contour of the Radkammerwandung exclusively selective contact before. In contrast to a contact that is greater than the point contact, these punctual contacts or contacts do not lead to wear, since the contact can be released again immediately. This is not the case with a larger surface contact, because under some circumstances this can lead to a so-called seizure and thus failure of the turbine and thus of the exhaust gas turbocharger.

Thus, a turbine is formed, which has a high efficiency and high durability.

To further increase the turbine efficiency, a filler material is provided, which is arranged between juxtaposed teeth of the contour.

As a result, due to the further sealing with the help of this filler, the efficiency can be additionally increased, wherein the filler, in particular formed of calcium carbonate, in a possible solid state contact does not have the tendency of seizure, but at a friction of the turbine wheel on the Radkammerwandung should have a rising or falling tendency to prevent prolonged solid contact.

In a further embodiment of the turbine according to the invention this has an adjustable nozzle with a contour sleeve, wherein the Radkammerwandung corresponds to a contour sleeve wall of the contour sleeve. Here is a particularly easy to design production of the tooth-like contour of the Radkammerwandung or the Konturhülsenwandung before. The particular simplicity is due to the fact that the contour sleeve can be produced as an individual component, that is to say independently of the exhaust gas guide section, and thus has easier handling, since it is a much smaller component. In general, however, also non-cutting or machining methods can be used here.

It is irrelevant whether it is an adjustable nozzle, which has a so-called axial slide and the grating blades are arranged immovable generally in the overflow of Abgasführungsabschnitts or if it is a so-called "rotary shovel" whose grid blades with the aid of Shovel shafts are movably positioned in the overflow channel

Embodiment principles have a contour sleeve whose Konturhülsenwandung, or the contour of the sleeve wall corresponding Radkammerwandung, which may have tooth-like contour, to increase the efficiency of the turbine.

The invention also relates to an exhaust gas turbocharger with a compressor and such a turbine. With the help of the above-mentioned advantages having turbine, an exhaust gas turbocharger can be realized, which is due to the increased

Turbine efficiency characterized by an increased overall efficiency over almost the entire life of the exhaust gas turbocharger. With this

Exhaust gas turbocharger according to the invention is particularly effective and fuel-reducing an internal combustion engine operable.

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 and the below in the figure description mentioned and / or alone in the figures features and feature combinations are not only in the specified combination, but also in others

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

The drawing shows in:

1 shows a longitudinal section of an exhaust gas guide section of a turbine of a

Exhaust gas turbocharger acc. the prior art,

2 shows a detail of the exhaust gas guide section according to FIG. Fig. 1,

Fig. 3 shows a detail of an exhaust gas guide portion of an inventive

Turbine of an exhaust gas turbocharger according to the invention,

4 shows the detail gem. Fig. 3 with possible contact areas between a turbine wheel of the turbine according to the invention and a Radkammerwandung the turbine of the invention and

5 shows a detail of the exhaust gas guide section according to FIG. Fig. 3 with a

schematic representation of a production of a tooth-like contour.

A turbine 2 of an exhaust gas turbocharger 1 of the prior art is constructed as shown in FIG. The exhaust gas turbocharger 1 has a flow-through exhaust gas guide section 3 of the turbine 2, which flows through a fluid, usually of exhaust gas of an internal combustion engine, not shown, to which the exhaust gas turbocharger 1 is connected. The turbine wheel 5, comprising an axis of rotation 6 and on a hub 7 of the turbine wheel 5 immovably arranged paddles 8, by means of a shaft 9 rotatably with a compressor wheel, not shown connected, which is rotatably connected in a non-illustrated wheel chamber of a non-illustrated through-flow air guide portion.

The turbine wheel 5 is acted upon by exhaust gas, wherein the turbine wheel 5 a

Rotational movement exerts, 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 not shown, fresh air can suck in, which in the not shown air duct section is compressed.

The exhaust gas guide section 3 has a spiral channel 10 upstream of the wheel chamber 4. For flow through the exhaust gas guide section 3, this upstream of the spiral channel 10 an inlet channel, not shown, downstream of the spiral channel 10 an overflow channel 11 and a downstream of the wheel chamber 4 formed outlet channel 12. Overall, therefore, the exhaust gas guide section 3 for

Through a sectionally differently configured channel, which in a first section in the form of the inlet channel, in a second section in the form of the spiral channel 10, in a third section in the form of the overflow channel 11, in a fourth section in the form of the wheel chamber 4 and in a fifth section in the form of the outlet channel 12 is configured.

The wheel chamber 4 has a Radkammerwandung 13, which is formed opposite the turbine wheel 5. Between the wheel chamber wall 13 and an enveloping surface 4 of the turbine wheel 5, a gap 15 is formed in the area of the vanes 8 encompassed by the enveloping surface 14. This gap 15 serves to avoid a solid friction between the turbine wheel 5 and the Radkammerwandung 13. To avoid the solid friction of the gap 15 is to be formed as large as possible, whereas it should be designed to achieve a high efficiency of the turbine 2 as small as possible.

In the exhaust gas guide section 3, an adjustable nozzle 16 is arranged for conditioning the exhaust gas. The adjustable nozzle 16 is formed on a Leitgitterring 18 mounted grid blades 17 having formed, wherein the grid blades 17 are arranged rotatably in the overflow 11. Each of them is twistable

Grid blade 17 on a blade shaft 19 with a blade shaft axis 20.

Furthermore, the adjustable guide apparatus 16 has a contoured sleeve 21, which is arranged opposite the guide-grid ring 18 and in this embodiment serves to mount the blade shaft 19.

The Radkammerwandung 13 is formed by means of the contour sleeve 21, so that a turbine wheel 5 facing positioned Konturhülsenwandung 22 of

Radkammerwandung 13 corresponds. Likewise, however, the turbine could also be designed as a turbine without an adjustable nozzle. Then it would be common the Radkammerwandung 13 a wall which is formed with the exhaust gas guide portion 3 itself.

In Fig. 2, for clarity, a section of the exhaust gas guide section 3 gem. Fig. 1 shown. 3 shows a section of the exhaust gas guide section 3 of a turbine 2 according to the invention. The wheel chamber wall 13, here in the form of the

Contour sleeve wall 22 is formed, has in a longitudinal section along the

Rotary axis 6 a tooth-like contour 23 with teeth 24. The tooth-like contour 23 is predominantly formed in a region of the contour sleeve wall 22, which are opposite the wheel vanes 8 of the turbine wheel 5. In other words, the tooth-like contour 23 is formed predominantly in the region of the gap 15. With the aid of this tooth-like contour 23, an expansion of the gap 15 in the radial direction is reducible, because as shown in Fig. 4, resulting in a possible contact between the turbine wheel 5 and the Konturhülsenwandung 22 due to the tooth-like contour 23 much smaller contact areas 25, the in a special embodiment are formed point-like.

In this embodiment, a filling material 26 is provided between adjacent teeth 24 of the contour 23, which advantageously from

Calcium carbonate is formed.

5 shows a schematic representation of a production method for producing the tooth-like contour 23 of the wheel chamber wall 13 with the aid of a tool 27, for example in the form of a turning tool. The tooth-like contour 23 is introduced into the Radkammerwandung 13, for example by means of a process, the so-called sizing. A profile of the generated

Radkammerwandung 13 is then dependent on a cutting geometry, a delivery and a feed rate. It should be noted that the tooth-like contour 23 may also be formed in the form of a so-called "honeycomb" structure, wherein this "honeycomb" structure is preferably introduced by means of an erosion process.

Claims

claims

1. Turbine, with a flow-through exhaust gas guide section (3), and a in the exhaust guide section (3) rotatably received turbine wheel (5) having an axis of rotation (6), wherein the exhaust gas guide section (3) for flow through a sectionally differently shaped channel, wherein the channel in a section for receiving the turbine wheel (5) in the form of a wheel chamber (4) with a Radkammerwandung (13) is formed, and wherein at least partially between an envelope surface (14) of the turbine wheel (5) and the Radkammerwandung (13) has a gap ( 15) is formed,

characterized in that

the Radkammerwandung (13) at least in the region of the gap (15) has a tooth-like contour (23) which is formed in an extension direction of the rotation axis (6).

2. Turbine according to claim 1,

characterized in that

the tooth-like contour (23) has a plurality of teeth (24).

3. Turbine according to claim 1,

characterized in that

between adjacent teeth (24) of the plurality of teeth (24) of the contour (23) a filling material (26) is provided.

4. Turbine according to claim 2,

characterized in that

the filler material (26) is formed predominantly of calcium carbonate.

5. Turbine according to one of the preceding claims,

characterized in that

an adjustable guide device (16) is provided, with a contour sleeve (21), wherein the Radkammerwandung (13) corresponds to a contour sleeve wall (22) of the contour sleeve (21).

6. Exhaust gas turbocharger with a turbine according to one of claims 1 to 4.