WO2013156120A1

WO2013156120A1 - Turbocharger

Info

Publication number: WO2013156120A1
Application number: PCT/EP2013/001051
Authority: WO
Inventors: Thomas Ihli
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: DE102012103416A1

Abstract

The invention relates to a turbocharger comprising an exhaust gas conduit section (2) through which a fluid can flow, and a turbine wheel (4) that is rotatably accommodated in a turbine wheel chamber (9) of the exhaust gas conduit section (2) by means of a shaft (5) having an axis of rotation (6). The exhaust gas conduit section (2) includes an intake duct to admit a fluid current into the exhaust gas conduit section (2), a helical duct (7) downstream of the intake duct to condition the fluid current, an inflow duct (8) between the helical duct (7) and the turbine wheel chamber (9), and a discharge duct (10) downstream of the turbine wheel chamber (9) to discharge the fluid current from the exhaust gas conduit section (2). The turbine wheel chamber (9) has a chamber contour (11) which surrounds the turbine wheel (4) and the longitudinal axis (12) of which is coaxial with the axis of rotation (6). According to the invention, the chamber contour (11) includes an approximately concave contour in a first contour region (14) of the turbine wheel chamber (9), concave being in relation to the longitudinal axis (12), and an approximately convex contour, which axially adjoins the approximately concave contour, in a second contour region (15) axially adjoining the first contour region (14).

Description

turbocharger

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

An exhaust gas turbocharger is known from patent EP 1 334 262 B1, with a flow-through exhaust gas guide section and a turbine wheel which is rotatably received by means of a shaft with a rotation axis in a wheel chamber of the exhaust gas guide section. The exhaust guide section has an inflow passage for entering a fluid flow into the exhaust guide section, a spiral passage positioned downstream of the inflow passage for conditioning the fluid flow, and an inflow passage positioned downstream of the scroll passage and upstream of the wheel chamber and an exit passage formed downstream of the wheel chamber for exiting the fluid flow from the exhaust passage section. The wheel chamber has a turbine wheel

enveloping chamber contour with a coaxial to the axis of rotation of the turbine wheel

Longitudinal axis. A subdivision of the chamber contour into regions having different geometric shapes results in cylindrically pronounced contour regions and an approximately concave contour region which extends between the regions of the contour

cylindrical contour regions is arranged.

With the help of this typical chamber contour, a usually unique change of a flow direction of the fluid flow from the inflow channel via the wheel chamber into the outlet channel can be achieved. It results with the help of this wheel chamber, starting from the radial flow direction, an axial flow direction. If, as is also apparent from the patent, an inflow of the turbine wheel takes place from the Radrücken ago, is usually also only a single change in the flow direction, starting from a so-called semi-axial flow direction in an axial

Flow direction realized.

The object of the invention is to provide an exhaust-gas turbocharger which has an improved turbine efficiency and consequently an increased turbine efficiency Has exhaust gas turbocharger performance with only minor design changes.

This object is achieved by an exhaust gas turbocharger with the characteristics of

Patent claim 1 solved. Advantageous embodiments with expedient and non-trivial developments of the invention are specified in the remaining claims.

The invention is based on an exhaust gas turbocharger, whose chamber contour in a first contour region of the wheel chamber with respect to a longitudinal axis an approximately concave contour and in a second contour region, which axially to the first

Contour area is then formed, an axially adjacent to the approximately concave contour has approximately convex contour. The advantage of this

Chamber contour is that the fluid flow in the flow direction, regardless of a flow direction in the region of a Radeintritts, that is, regardless of a positioning of the inflow, at least a first change of

Flow direction and a second change in the flow direction in the wheel chamber can be impressed. In principle, on the one hand, as the flow path in the area of the wheel chamber, i. in the turbine wheel, and on the other hand to form a swirl a larger exhaust gas turbocharger performance can be achieved. Due to the at least two changes in the flow direction of the fluid flow in the wheel chamber and, accordingly, in the turbine wheel, a swirl which is stronger than a one-time change in the flow direction is longer and a longer one

Flow path obtained.

This leads to an increase in the turbine efficiency and an increase in the exhaust gas turbocharger performance. An advantage underlying this advantage in a

Combination of the exhaust gas turbocharger with an internal combustion engine is a reduction of fuel emission due to lower fuel quantity at the same torque and / or the same power of an internal combustion engine.

Another advantage is a reduction of the wheel chamber in its radial extent and thus a reduction of a turbine housing, since at the same

Exhaust gas turbocharger performance due to the increase in exhaust gas turbocharger performance of the exhaust gas turbocharger invention, a diameter of the turbine wheel can be reduced. This leads to a reduction of the weight of the exhaust gas turbocharger, whereby in combination with an internal combustion engine, a further reduction of the fuel emission can be achieved. In one embodiment of the exhaust gas turbocharger according to the invention, an inflow channel upstream of the wheel chamber has a first arranged parallel to the axis of rotation

Flow axis for axial alignment of the fluid flow. Due to the fact that the inflow channel has a first flow axis arranged parallel to the axis of rotation, the turbine wheel, starting from the inflow channel, is not only flowed through in a semi-axial manner, as in a semi-axial inflow, but the fluid flow has a pronounced axial inflow of the turbine wheel. This is another

Increasing the swirl of the fluid flow achievable, so that an increase in

Exhaust gas turbocharger performance is feasible.

An additional increase in the turbine efficiency can be achieved in that the outlet channel downstream of the wheel chamber has a coaxial with the axis of rotation second flow axis for axial alignment of the fluid flow. Thus, a combination of an axial turbine and a radial turbine can be achieved, wherein the

Fluid flow in the axial direction can occur in the correspondingly formed turbine wheel at a large circumferential radius and the turbine wheel, due to the radial deflection in the turbine wheel, can leave the turbine wheel at a smaller radius than the circumferential radius.

Characterized in that the fluid flow can undergo a double deflection in the exhaust gas turbocharger according to the invention, it is possible to combine a large swirl in the circumferential direction with a small peripheral speed on a ride out of the turbine wheel.

In a further embodiment of the exhaust gas turbocharger according to the invention, the turbine wheel advantageously has a wheel contour corresponding to the chamber contour in the form of an envelope, a minimum gap being formed between the chamber contour and the envelope for the friction-free rotation of the turbine wheel. The smaller this minimum gap, the higher efficiency of the exhaust gas turbocharger can be achieved.

In a further embodiment, a flow direction-changing guide device with a first plurality of guide vanes is arranged in the inflow channel. With the help of this guide is a further change in direction of the exhaust gas flow and thus a swirl of the exhaust gas flow aufprägbar, whereby a further increase in efficiency of the exhaust gas turbocharger can be achieved. In a further embodiment, the guide device has a guide vane ring rotatable about the rotation axis and having a second plurality of guide vanes. The rotatable vane ring is provided to change an effective flow area of the fluid flow onto the turbine wheel. Thus, the effective

Flow cross section are adapted to an operating range of the exhaust gas turbocharger, such that in the respective operating ranges of the exhaust gas turbocharger

highest possible efficiency of the exhaust gas turbocharger can be achieved. This means that a large pressure upstream of the turbine wheel can be achieved with simultaneously small masses of fluid, whereby an increase in output of the exhaust gas turbocharger can be realized. In an advantageous embodiment, the first plurality of guide vanes is arranged immovably.

The first plurality of the guide vanes may be arranged adapted to an installation situation of the exhaust gas turbocharger upstream of the guide vane ring or downstream of the vane ring, so that a suitable positioning of an adjusting mechanism of the

Guide vane ring is to be considered.

Advantageously, to reduce flow losses and thus to further increase the efficiency of the exhaust gas turbocharger, the first plurality of

Vanes and the second plurality of vanes at their in a first

Stellposition formed opposite end surfaces congruent.

The exhaust gas turbocharger according to the invention is predestined for especially small

Turbinenraddurchmesser, so that a weight of the running gear, which corresponds to the composite of the compressor wheel, the turbine wheel and the shaft, compared to

Exhaust gas turbochargers according to the prior art can be reduced with the same performance, so that at the same end performance a much improved

Response as a result of a reduction of a moment of inertia of the running tool is achievable. This leads to a reduction of the so-called and known "turbo lag", so not only an improved acceleration of the with the

inventive exhaust gas turbocharger equipped motor vehicle can be achieved, but also a reduction in fuel consumption can be achieved.

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

Feature combinations as well as those mentioned below in the figure description and / or features and feature combinations shown alone in the figures are not only in the combination given, but also in others

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

The drawing shows in

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

Exhaust gas turbocharger according to the prior art in a first variant,

2 shows a section through an exhaust gas guide section of a turbine of a

Exhaust gas turbocharger according to the prior art in a second

Variant,

3 shows a section through an exhaust gas guide section of a turbine of an exhaust gas turbocharger according to the invention,

4 shows a detail of a section through an exhaust gas guide section of FIG

Turbine of the exhaust gas turbocharger according to the invention with a guide,

Fig. 5 in a development a section of a plan view of the

Guide device acc. 4,

Fig. 6a is a detail of a development of a plan view of the

Guide device acc. 5 in a first position,

Fig. 6b a detail of a development of a plan view of the guide gem. Fig. 5 in a second position and

Fig. 6c a detail of a development of a plan view of the guide gem. Fig. 5 in a third position.

A flow-through exhaust-gas guide section 2, shown in FIG. 1, of a turbine of an exhaust-gas turbocharger 1 according to the prior art in a first variant is in an exhaust-gas tract of an internal combustion engine, not shown in more detail Gasoline engine or a diesel engine is provided. The exhaust gas turbocharger 1 further includes a non-illustrated throughflow fresh air guide portion and a bearing portion, not shown, which is arranged in a non-illustrated intake tract of the internal combustion engine.

The exhaust gas turbocharger 1 has a running gear 3, which comprises a not-shown compressor wheel for sucking and compressing combustion air, a turbine wheel 4 for expansion of exhaust gas and a compressor wheel with the turbine wheel 4 rotatably connecting shaft 5 with a rotation axis 6. The shaft 5 is rotatably mounted in the bearing portion of the exhaust gas turbocharger 1, which is positioned between the air guide portion and the exhaust gas guide portion 2.

For the inflow of the exhaust gas into the exhaust gas guide section 2, a non-illustrated inlet channel in the exhaust gas guide section 2 is formed for the entry of a fluid flow. In general, it can be assumed that it is in a combination of the exhaust gas turbocharger with an internal combustion engine, in particular a

Reciprocating piston engine in which fluid is exhaust gas, that is a combusted air-fuel mixture of the internal combustion engine.

The inlet channel is used to condition the exhaust gas, which in the operation of the

Internal combustion engine, the turbine wheel 4 is set in a rotating motion. With the help of the shaft 5, the compressor wheel is also rotated, so that it

Suction and compressed combustion air.

Downstream of the inlet channel is in the exhaust gas guide section 2, a spiral channel. 7

arranged, which serves to provide a rotationally symmetrical flow. Furthermore, the spiral channel 7 is formed as a connecting channel between the inlet channel, not shown, and an inflow channel 8, which is positioned downstream of the spiral channel 7.

Downstream of the inflow channel 8, a wheel chamber 9 is arranged in the exhaust gas guide section 2, in which the turbine wheel 4 is rotatably received. Downstream of the wheel chamber 9, the exhaust gas guide section 2 has an outlet channel 10 for

Escape of the exhaust gas from the exhaust gas guide section 2. The wheel chamber 9 has a turbine wheel 4 enveloping chamber contour 1 1. A longitudinal axis 12 of the chamber contour 11 is formed coaxially with the axis of rotation 6. The chamber contour 11 is cylindrical in a first contour region 14, wherein in the flow direction according to the flow arrow 13 a to the first

Contour region 14 adjacent second contour region 15 with respect to

Longitudinal axis 12 is approximately concave. In a further contour region, which is adjacent to the second contour region 15 in the direction of the flow arrow 13

is formed adjacent, the chamber contour 11 is repeatedly cylindrical

educated. According to this chamber contour 11, the flow fluid is imparted a unique change in the flow direction.

In a second variant of the prior art acc. 2, the chamber contour 11 has a predominantly, with reference to the longitudinal axis 12, concave first contour region 14. The adjacent to the first contour region 14

formed second contour region 15 has a cylindrically shaped contour.

An exhaust gas turbocharger 1 according to the invention is designed according to FIG. 3. The wheel chamber 9 has a chamber contour 11 with a first contour region 14 and a second contour region 15. Relative to the longitudinal axis 12, the chamber contour 11 in the first contour region 14 has an approximately concave contour and in the second contour region 15, which is formed axially adjacent to the first contour region 14, formed an approximately convex contour axially adjacent to the approximately concave contour. Due to this chamber contour 11 a double change of the flow direction 13 of the exhaust gas is forced, whereby an increase in efficiency of the exhaust gas turbocharger 1 can be achieved.

The inflow channel 8 upstream of the wheel chamber 9 has a first flow axis 16 arranged parallel to the axis of rotation 6 or to the longitudinal axis 12, so that upstream of the wheel chamber 9 the exhaust gas is aligned with the turbine wheel 4 upstream

Wheel chamber 9 is impressed, whereby the turbine 4 is axially, ie in the direction of its axis of rotation 6 is flowed through by the exhaust gas. In other words, due to the parallel flow axis 16, one corresponding to an axial turbine

Flow of the turbine wheel 4 allows.

The outlet channel 10, which is arranged downstream of the wheel chamber 9 in the exhaust gas guide section 2, has a coaxially formed with the axis of rotation 6 second

Flow axis 17 for the axial alignment of the exhaust gas. This is the the

Exhaust gas guide section 2 of the exhaust gas turbocharger 1 according to the invention flowing fluid from the inflow channel 8 a two-time change of the fluid in Area of the wheel chamber 9 imprinted.

A wheel contour 18 of the turbine wheel 4 is in the form of an envelope of the

Turbine wheel 4 formed corresponding to the chamber contour 11. In other words, an outer contour 19 of the turbine wheel 4 is formed so that a plurality of vanes 20 of the turbine wheel at its the chamber contour 11th

opposite outer edges 21, the chamber contour 1 is formed accordingly, wherein between the chamber contour 11 and the outer edges 21, a movement gap for free rotation movement of the turbine wheel 4 is formed.

A further embodiment of the exhaust gas turbocharger according to the invention is gem. Fig. 4 is formed. So that at low loads and low speeds of the

Internal combustion engine as well as at high loads and high speeds of

Internal combustion engine the greatest possible exhaust gas turbocharger efficiency can be achieved, the exhaust gas is additionally conditioned by means of a guide 22, which in

Exhaust passage section 2 in the inflow passage 8, comprising a first plurality of vanes 23, is arranged. The guide 22 is annular, extending over a full largest circumference of the turbine wheel 4 extending. The first plurality of guide vanes 23 is arranged immovably in the inflow channel 8. With the aid of the first plurality of guide vanes 23, a change in direction can be imparted to the fluid.

The guide 22 further comprises a rotatable about the rotation axis 6

Leitschaufelring 24 with a second plurality of vanes 25. The Leitschaufelring 24 is positioned downstream of the first plurality of vanes 23 in the inflow channel 8 movable. With the help of the vane ring 24, the fluid is another

Change of direction imprintable.

In an alternative embodiment not shown, the first plurality of vanes 23 are disposed downstream of the vane ring 24. That is, the first plurality of vanes 23 are positioned between the wheel chamber 9 and the rotatable vane ring 24.

5 shows in a detail of a development of a top view of the guide 22, the guide 22 with the first plurality of vanes 23 and the rotatable vane ring 24 with the second plurality of vanes 25, wherein the rotatable vane ring 24 has a first setting position. In this position is It can be seen that in this embodiment, the first plurality of vanes 23 and the second plurality of the vanes 25 at their, in this first setting position of the rotatable vane ring 24, opposite end surfaces, a first end face 26 of the first plurality of vanes 23 and a second end face 27th the second plurality of vanes 25, are formed congruent. The vane ring 24 is rotatable in the direction of the rotary arrow 28.

FIGS. 6a to 6c show different setting positions of the guide vane ring 24. FIG. 6 a shows the first setting position according to FIG. Fig. 5. This first control position is set in an operation of the exhaust gas turbocharger 1 in conjunction with an internal combustion engine, in particular in the full load range of the internal combustion engine, as in

Full load range exhaust gas mass flow reaches its maximum value for the internal combustion engine. The second setting position shown in FIG. 6b is preferably to be set in the middle load range of the internal combustion engine, whereas in the lower one in particular

Load range of the internal combustion engine preferably according to a third adjustment position. Fig. 6c of the vane ring 24 is set. It should be noted that the guide vane ring 24 can not occupy exclusively the three mentioned setting positions, but that the guide vane ring 24 is rotatable about the rotation axis 6 over a rotation range of 360 °. This means that the guide blade ring 24 is adjustable according to the load range of the internal combustion engine and thus an operating range of the exhaust gas turbocharger 1, so that in each operating range an optimized efficiency of the exhaust gas turbocharger 1 can be achieved.

Claims

claims

1. Exhaust gas turbocharger with a flow-through exhaust gas guide section (2) and with the aid of a shaft (5) with a rotation axis (6) in a wheel chamber (9) of the exhaust gas guide section (2) rotatably received turbine wheel (4), wherein the exhaust gas guide section (2) a Inflow channel for entry of a

Fluid flow in the exhaust gas guide section (2), one downstream of the

Inlet channel positioned spiral channel (7) for conditioning the

Fluid flow and a downstream of the spiral channel (7) and upstream of the

Wheel chamber (9) positioned inflow channel (8) and a downstream of the

Radkammer (9) formed outlet channel (10) for the outlet of the fluid flow from the exhaust gas guide section (2), wherein the wheel chamber (9) enclosing the turbine wheel (4) chamber contour (11) with a rotation axis (6) coaxial longitudinal axis (12) having,

characterized in that

the chamber contour (11) in a first contour region (14) of the wheel chamber (9) has an approximately concave contour relative to the longitudinal axis (12) and subsequently in a second contour region (15) which is formed axially adjacent to the first contour region (14), has an approximately concave contour to the approximately concave contour, approximately convex contour.

2. Exhaust gas turbocharger according to claim 1,

characterized in that

the inflow channel (8) upstream of the wheel chamber (9) has a first flow axis (16) arranged in parallel to the axis of rotation (6) for the axial alignment of the

Having fluid flow.

3. Exhaust gas turbocharger according to claim 1 or 2,

characterized in that the outlet channel (10) has, downstream of the wheel chamber (9), a second flow axis (17) coaxial with the axis of rotation (6) for axial alignment of the fluid flow.

4. Exhaust gas turbocharger according to one of the preceding claims,

characterized in that

the turbine wheel (4) has a wheel contour (18) corresponding to the chamber contour (11) in the form of an envelope.

5. Exhaust gas turbocharger according to one of the preceding claims,

characterized in that

a flow direction-changing guide device (22) with a first plurality of guide vanes (23) is arranged in the inflow channel (8).

6. Exhaust gas turbocharger according to claim 5,

characterized in that

the guide device (22) has a guide blade ring (24) which is rotatable about the rotation axis (6) and has a second plurality of guide vanes (25).

7. Exhaust gas turbocharger according to claim 5 or 6,

characterized in that

the first plurality of vanes (23) are arranged immovably.

8. Exhaust gas turbocharger according to one of claims 5 to 7,

characterized in that

the first plurality of vanes (23) are located upstream of the vane ring (24).

9. Exhaust gas turbocharger according to one of claims 5 to 7,

characterized in that

the first plurality of vanes (23) are disposed downstream of the vane ring (24).

10. Exhaust gas turbocharger according to one of claims 6 to 9,

characterized in that

the first plurality of vanes (23) and the second plurality of

Guide vanes (25) at their in a first position of the guide vane ring (24) opposite end surfaces (26, 27) are formed congruent.