WO2016102128A1

WO2016102128A1 - Radial compressor, turbocharger and corresponding method for operating a radial compressor

Info

Publication number: WO2016102128A1
Application number: PCT/EP2015/077119
Authority: WO
Inventors: Jochen Doehring
Original assignee: Robert Bosch Gmbh
Priority date: 2014-12-22
Filing date: 2015-11-19
Publication date: 2016-06-30
Also published as: DE102014226809A1

Abstract

The invention relates to a radial compressor for a turbocharger, in particular of an internal combustion engine, and to a turbocharger comprising such a radial compressor. The invention further relates to a method for operating such a radial compressor. The radial compressor for a turbocharger has: a housing comprising an axial inlet channel and a radial outlet channel, which housing at least partially surrounds a compressor chamber; a compressor wheel, arranged in the compressor chamber, for conveying and compressing a gas; and a compound structure which has a shroud plate, a rear plate and at least one guide vane, wherein: the shroud plate and the rear plate are connected by means of the guide vane; the compound structure surrounds the compressor wheel at least partially; and wherein there is a first gap between the shroud plate and the compressor wheel and a second gap between the rear plate and the compressor wheel. The radial compressor further has a displaceable housing insert which is arranged in the compressor chamber in a region between the housing and the shroud plate, wherein the housing insert is adapted to control the width of the first and the second gap.

Description

description

title

Radial compressor, exhaust gas turbocharger and corresponding method for operating a centrifugal compressor

The present invention relates to a radial compressor for a

Exhaust gas turbocharger, in particular an internal combustion engine, and a

Exhaust gas turbocharger with such a radial compressor. The invention further relates to a method for operating such a radial compressor.

Exhaust gas turbochargers are used, for example, in internal combustion engines

Application to increase the pressure level in the fresh gas during the charge exchange process. Such an exhaust gas turbocharger can be equipped with a radial compressor, which has a compressor wheel, by means of which the respective gas can be conveyed and compressed. For this purpose, the compressor can have an axial input side and a radial output side, and be arranged in a compressor chamber. An inlet channel leads to the input side of the compressor wheel and in the case of an internal combustion engine to a low-pressure region of a fresh gas system equipped with the exhaust-gas turbocharger. One

Outlet channel leads away from the output side of the compressor wheel to

High pressure side of the fresh gas system. The compressor wheel is surrounded by the compressor housing within the compressor chamber. The compressor housing has a cover disk on an inner surface which is radial to the compressor wheel and a rear disk on an inner surface which is axial to the compressor wheel.

In order to ensure an undisturbed and in particular frictionless rotational movement of the compressor wheel in the exhaust gas turbocharger, there must remain a gap in the manner of a gap between the compressor wheel and a compressor housing forming the compressor chamber, so that Compressor and compressor housing are spaced from each other and therefore no disturbing frictional forces between these components can occur. Thus, the gap between the compressor wheel and the compressor housing is measured with two gap widths, namely the gap width between the compressor wheel and the cover plate of the compressor housing and between the compressor wheel and the rear wheel of the

Compressor housing. Too much formed gap, that is too large a gap width of the column described, leads to an undesirable

Power attenuation of the compressor, since such a gap leads to a reduction of the capacity.

DE 10 2012 217 381 A1 shows a radial compressor in which the gap width of a gap between the compressor wheel and the cover disk is adjustable.

Disclosure of the invention

The invention provides a radial compressor for an exhaust gas turbocharger according to claim 1, an exhaust gas turbocharger with such a radial compressor according to claim 7 and a corresponding operating method for a radial compressor according to claim 8.

Preferred developments are the subject of the respective subclaims. Advantages of the invention

The idea underlying the present invention is to provide an adjustment for the clearance between the compressor wheel and the compressor housing. For this purpose, the radial compressor on an axially and / or radially displaceable housing insert, which in a

Compressor space is arranged in a region between the compressor housing and a cover plate. The inventive adjustment of the entire space between the compressor housing and the compressor both column, that is both the gap between the Cover disc and the compressor wheel and the gap between the

Rear disc and the compressor wheel adjustable.

The cover disk and the rear disk are part of a composite, which additionally has at least one guide vane. The cover disk and the rear disk are connected by the guide vane. By connecting the cover plate with the rear pane through the vane a dependent Spaltbreiteneinstellungsmöglichkeit is given. This means that not both columns must be set separately, but that from the first gap width between the cover plate and the compressor already directly the second

Gap between the rear disc and the compressor results.

As a result, only one adjustment mechanism for the first or the second gap is necessary because the gap width of the other gap directly and directly results from the gap width of the set gap.

By adjusting the column, the present invention also allows compensation of manufacturing tolerances in the manufacture of centrifugal compressors, due to which the gap between the

Compressor housing and the compressor can vary. By the

subsequent adjustment of the two gaps between the compressor wheel and

Cover disc and between the compressor and the rear wheel, which is provided with the present invention, manufacturing tolerances can be corrected. Since the width of the two columns adversely affects the efficiency of the centrifugal compressor, with the present invention, the efficiency of a centrifugal compressor, with constant manufacturing costs, can be improved.

According to a preferred embodiment, an inventive

Radial compressor additionally a control device which is adapted to determine an axial displacement of the compressor wheel and the position of the

Housing insert to adapt to the determined displacement of the compressor wheel on. This makes it possible to subsequently adapt the width of the two gaps even during compressor operation. Thus, the width of the column can be optimally adapted to an operating condition of the centrifugal compressor, such as the speed of the compressor wheel. According to a further preferred embodiment, the cover disk and the rear disk are non-detachably connected by the guide vane. This is a particularly cost-effective production possibility of a composite, which has a cover plate, a rear plate and at least one vane given. Thus, the composite may be integrally formed or made of a cast.

According to a further preferred embodiment, the cover plate, the rear pane, the housing insert and / or the housing in

outlet channel side first and second areas rounded edges. In this way, in the case of a shift of the composite relative to the compressor wheel, flow losses can be minimized. Rounded contours reduce turbulence of a fluid passing along it, and thus resistance losses, as compared to angular contours.

According to a further preferred embodiment, the cover plate covers a sealing gap between the housing and the housing insert. This reduces flow losses and also prevents the escape of the fluid to be compressed in the sealing gap.

According to a further preferred embodiment, a spring and a piston are arranged to control the housing insert. This provides a particularly cost-effective way to control the housing use. In addition, such adjustment is also manually adjustable.

The invention also relates to an exhaust gas turbocharger with a centrifugal compressor having one or more of the aforementioned features. The invention further relates to an operating method for a previously described radial compressor. According to this method, in a first step, a centrifugal compressor having one or more of the aforementioned features is provided. In a further step, a width of a first gap between a compressor wheel and a cover disk is determined. In a further step, a width of a second gap determined between the compressor wheel and a rear disc. Due to the two measurements mentioned above, in a next step, a position of a housing insert and a composite is controlled. Thus, the control of the position of the housing insert and / or the

Compound dependent on the gap between the compressor wheel and the

Cover disc and the gap between the compressor wheel and the

Rear window. In a preferred embodiment of the method for operating a centrifugal compressor, an axial displacement of the

Compressor wheel determined and in a further step, the position of

Housing insert and / or the composite due to the determined

Controlled axial displacement. Due to the additional measurement of

Axial displacement of the compressor wheel can be any measurement errors of the

Gap widths of the first and second gap can be compensated and consequently the two gaps between the compressor wheel and the cover and rear disc can be controlled even more precisely.

According to a further advantageous embodiment of the operating method for a radial compressor, the steps of determining the width of the first and second gaps and controlling the position of the housing insert and the composite based on the determined width of the first and second gap before a start-up of a compressor are performed. Further, the steps of determining an axial displacement of the compressor wheel and controlling the position of the housing insert and / or the assembly due to the determined axial displacement are performed continuously during the compressor operation. Thus, the position of the housing insert is made once, as part of a coarse adjustment. This coarse adjustment already covers a large part of the setting requirement of the position of the housing insert. During compressor operation, the widths of the adjusted gaps may continue to vary slightly by axial displacement of the compressor wheel. For these smaller changes in the gap widths, however, it is sufficient to monitor only the axial displacement of the compressor wheel. The measurement of the axial displacement eliminates the need to determine the first and second gap widths during compressor operation. Consequently, the need for the evaluation of the measurements of the first and second gap widths. As a result, the volume of data to be processed can be reduced.

Brief description of the drawings

Further features and advantages of the present invention will be explained below with reference to embodiments with reference to the figures.

Show it:

Fig. 1 is a schematic cross-sectional view of a

Embodiment of a radial compressor according to the invention; and

Fig. 2 is another schematic cross-sectional view of

Embodiment of the radial compressor according to the invention.

Embodiments of the invention

In the figures, like reference numerals designate the same or functionally identical elements.

FIG. 1 shows a schematic cross-sectional view of an embodiment of a radial compressor according to the invention.

The radial compressor 100 comprises a compressor housing 101, which has an axial inlet channel 103 and a radial outlet channel 105. The compressor housing 101 at least partially surrounds a compressor chamber 107. In the compressor chamber 107 is a compressor wheel 109 for conveying and

Compressing a gas arranged. From the inlet channel 103 to

Exhaust passage 105 extends a composite 110, which comprises a cover plate 111, a guide vane 115 and a rear disc 113. Between the compressor wheel 109 and the cover plate 111 exists a first gap Sl. Between the compressor wheel 109 and the rear disk 113 exists a second gap S2. The radial compressor 100 further comprises a housing insert 117, which is formed in the compressor chamber 107 on the compressor housing 101. The housing insert 117 can be moved in the compressor chamber 107 both in an axial direction A and in a radial direction B. By moving the housing insert 117 in the directions A and / or B, the composite 110 shifts with respect to the compressor wheel 109. As a result, the widths of the gaps Sl and S2 also change. Due to the stiff VerbundllO of the cover plate 111, the rear plate 113 and the

Guide vane 115 results in the width of the gap S2 directly from the width of the gap Sl. For example, the composite 110 moves in the radial direction

B, the width of the gap Sl decreases and the width of the gap S2 increases.

In addition, the compressor 109 can be moved in the directions A and / or B.

The cover plate 111 covers a sealing gap 121 between the

Housing insert 117 and the compressor housing 101. This prevents that a gas to be compressed in the sealing gap 121 can escape. Consequently, flow losses are kept low.

FIG. 1 shows a purely schematic representation of a radial compressor.

In particular, the contours of the compressor housing 101 in the

Areas AI and A2 are not angular, but rounded to better lead a flow through the centrifugal compressor 100 can.

FIG. 2 shows a further cross-sectional view of the radial compressor 100. In addition, an adjustment mechanism for the housing insert 117 is shown schematically in FIG. The adjustment mechanism includes a spring 123 and a piston 125 which control the position of the housing insert 117. Although the present invention has been described in terms of preferred embodiments, it is not limited thereto. In particular, the materials and topologies mentioned are only examples and not limited to the illustrated examples.

The centrifugal compressor may be part of an exhaust gas turbocharger. Such an exhaust-gas turbocharger can have a turbine wheel connected in a rotationally fixed manner to the compressor wheel of the radial compressor by means of a rotor shaft.

Claims

Claims Claims

1. Radial compressor (100) for an exhaust gas turbocharger, in particular an internal combustion engine, comprising:

a housing (101) having an axial inlet channel (103) and a radial outlet channel (105) which at least partially surrounds a compressor chamber (107),

a compressor wheel (109) arranged in the compressor chamber for conveying and compressing a gas,

a composite (110) which a

Cover plate (111),

a rear window (113) and

at least one vane (115), wherein the cover disc and the rear disc are connected by the vane (115) and wherein the composite at least partially surrounds the compressor wheel, with a first gap between the cover disc and the compressor wheel

(51) and between the rear disc and the compressor wheel, a second gap

(52) exists, and

an axially and / or radially displaceable housing insert (117), which in the compressor chamber in a region between the housing and the

Cover disc is arranged, wherein the housing insert is adapted to control the width of the first and second gap (Sl, S2).

2. Radial compressor according to claim 1, which additionally comprises:

- A control device which is adapted to determine an axial displacement of the compressor wheel and to adjust the position of the housing insert to the determined displacement of the compressor wheel.

3. Radial compressor according to one of the preceding claims, wherein the cover plate and the rear plate are not detachably connected by the guide vane.

4. Radial compressor according to one of the preceding claims, wherein the cover plate, the rear pane, the housing insert and / or the housing in an outlet channel side first and second region (AI, A2) have rounded contours (119).

5. Radial compressor according to one of the preceding claims, wherein the cover plate covers a sealing gap (121) between the housing and the housing insert.

A centrifugal compressor according to any one of the preceding claims, wherein a spring (123) and a piston (125) are arranged to control the housing insert.

7. Exhaust gas turbocharger with a centrifugal compressor (100) according to any one of the preceding claims.

8. A method of operating a centrifugal compressor (100) according to any one of claims 1-6, comprising the following steps:

- Providing a centrifugal compressor according to one of claims 1-6;

Determining a width of a first gap (S1) between a compressor wheel (109) and a cover disk (111)

Determining a width of a second gap (S2) between the compressor wheel and a rear disk (113) - Controlling a position of a housing insert (117) and / or a composite (110) due to the determined width of the first and second gap.

9. A method of operating a radial compressor according to claim 8, which additionally comprises the following steps:

- Determining an axial displacement of the compressor wheel;

- Controlling the position of the housing insert and / or the composite due to the determined axial displacement.

10. A method of operating a centrifugal compressor according to claim 9, wherein the steps of

- Determining the width of the first and second nip as well

- controlling the position of the housing insert (117) and the composite (110) due to the determined width of the first and second gap;

be carried out before commissioning a compressor, and the

Steps of the

Determining an axial displacement of the compressor wheel (109);

- Controlling the position of the housing insert (117) and / or the composite (110) due to the determined axial displacement.

be made during the compressor operation of a regulation.