Guide vane for a diffuser of a radial compressor

Abstract

A guide vane for a diffuser of a radial compressor which is arranged downstream of a receiving area for a compressor wheel is disclosed. The guide vane has a skeleton line where the skeleton line is elliptical at least in a sub-region.

Claims

1. An air guide for a diffuser of a radial compressor, wherein the diffuser is disposed downstream of a receiving region for a compressor wheel, comprising: a guide vane, wherein the guide vane has a skeleton line and wherein an entirety of the skeleton line is configured elliptically, wherein a vane inlet and a vane outlet of the guide vane intersect a common straight line and define a chord of the guide vane, wherein the skeleton line is an ellipse and wherein angles of intersection of the ellipse with the chord of the guide vane are in each case less than 45 and in total less than 80, and wherein a distance of a center point of the ellipse from a center point of the chord of the guide vane with respect to a chord axis is at most half a length of the chord.

2. A radial compressor, comprising: a receiving region for a compressor wheel of the radial compressor; a diffuser disposed downstream of the receiving region; and an air guide according to claim 1 disposed in the diffuser.

3. The radial compressor according to claim 2, wherein the radial compressor is disposed in an exhaust gas turbocharger of an internal combustion engine.

4. An exhaust gas turbocharger of an internal combustion engine, comprising: a radial compressor, wherein the radial compressor includes: a receiving region for a compressor wheel of the radial compressor; a diffuser disposed downstream of the receiving region; and a guide vane, wherein the guide vane has a skeleton line, wherein an entirety of the skeleton line is configured elliptically, and wherein the guide vane is disposed in the diffuser, wherein a vane inlet and a vane outlet of the guide vane intersect a common straight line and define a chord of the guide vane, wherein the skeleton line is an ellipse and wherein angles of intersection of the ellipse with the chord of the guide vane are in each case less than 45 and in total less than 80, and wherein a distance of a center point of the ellipse from a center point of the chord of the guide vane with respect to a chord axis is at most half a length of the chord.

5. The exhaust gas turbocharger according to claim 4, wherein the exhaust gas turbocharger is disposed in a motor vehicle.

Description

BRIEF DESCRIPTION OF THE DRAWING

(1) The drawing shows, in the single FIGURE, a schematic sectional view of a guide vane for a diffuser of a radial compressor, which diffuser is arranged downstream of a receiving region for a compressor wheel, with a skeleton line which is constructed elliptically at least in a part-region.

DETAILED DESCRIPTION OF THE DRAWING

(2) The drawing shows, in a schematic sectional view, a guide vane designated overall by 10 for a diffuser of a radial compressor arranged downstream of a receiving region for a compressor wheel. The radial compressor is preferably a component of an exhaust gas turbocharger, with which an internal combustion engine, configured for example as a reciprocating internal combustion engine, of a motor vehicle is equipped. In this case the internal combustion engine is designed for driving the motor vehicle and comprises an exhaust gas system through which exhaust gas from the internal combustion engine can flow as well as an intake duct through which air can flow. The air flowing through the intake duct is guided by means of the intake duct into at least one combustion chamber, in particular a cylinder, of the internal combustion engine.

(3) The exhaust gas turbocharger has a turbine which is arranged in the exhaust gas system and can be driven by the exhaust gas. For this purpose, the turbine includes a turbine housing as well as a turbine wheel which is arranged in the turbine housing and can be driven by the exhaust gas. The turbine wheel is rotatable about an axis of rotation relative to the turbine housing and is a component part of a rotor of the exhaust gas turbocharger. The rotor also includes the aforementioned compressor wheel as well as a shaft by which the turbine wheel and the compressor wheel are connected for conjoint rotation. In this way, the compressor wheel can be driven via the shaft of the turbine wheel, so thatduring the operation of the radial compressorair is compressed by means of the compressor wheel. As a result, energy contained in the exhaust gas can be used for compressing the air.

(4) The radial compressor is arranged in the intake duct and comprises a compressor housing in which the compressor wheel is arranged. In this case, the compressor wheel or the rotor is rotatable about the axis of rotation relative to the compressor housing. The receiving region in which the compressor wheel is arranged is delimited by the compressor housing.

(5) Furthermore, the radial compressor also includes the aforementioned diffuser, which is arranged in the flow direction of the air through the radial compressor downstream of the receiving region and thus of the turbine wheel. The diffuser is a channel through which the air compressed by the compressor wheel and flowing off from the compressor wheel can flow or through which the air flows during the operation of the radial compressor. The diffuser is preferably configured as a radial diffuser, wherein the diffuser extends at least substantially in the radial direction.

(6) The radial compressor further includes a guiding means, which is also designated as a discharge guide vane assembly. The guiding means includes a plurality of guide vanes arranged in the diffuser and thus downstream of the receiving region or of the compressor wheel, of which the guide vane designated by 10 is shown in the drawing. The guide vanes arranged in the diffuser serve for guiding the air flowing through the diffuser, so that advantageous flow conditions can be obtained in the diffuser. The preceding and following statements relating to guide vanes 10 can be readily transferred to the other guide vanes of the discharge guide vane assembly.

(7) It can be seen from the drawing that the guide vane 10 has a skeleton line X. In order now to be able to obtain particularly advantageous flow conditions in the diffuser, the skeleton line X is configured elliptically at least in a part-region. In the present case, it is provided that the entire skeleton line X is configured elliptically. This means that the skeleton line X along its entire extent is configured elliptically, that is to say it is configured as part of an ellipse.

(8) The drawing also shows a diagram 12, which is used as a helpful diagram for designing the skeleton line X. It can be seen particularly clearly from the drawing that the skeleton line X of the guide vane 10 is designed as an ellipse with an elliptical thickening over the length of the chord C of the guide vane 10. In this case the guide vane 10 has a vane inlet 14, over which the air flows onto the guide vane 10 during the operation of the radial compressor. Furthermore, the guide vane 10 has a vane outlet 16, over which the air flows off from the guide vane 10. The vane inlet 14 and the vane outlet 16 intersect a common straight line and so define the chord C.

(9) Since the skeleton line X is designed elliptically, the skeleton line X is also designated below as an ellipse. The ellipse has precisely two angles of intersection with the chord C, wherein the angles of intersection of the ellipse with the chord C of the guide vane 10 are in each case, that is to say when considered individually, less than 45 and jointly, that is to say in total, always less than 80.

(10) An inlet radius of the guide vane 10 is designated by f.sub.r,3, wherein f.sub.r,4 designates an outlet radius of the guide vane 10. The inlet radius is also illustrated in the drawing by r.sub.3, wherein the outlet radius f.sub.r,4 is also illustrated by r.sub.4. Furthermore, a radius r.sub.2, can be seen in the drawing. Furthermore, the guide vane 10 has an inlet angle .sub.b,3 and an outlet angle .sub.b,4, wherein the guide vane 10, in particular the inlet region thereof in which air flows onto the guide vane 10, encloses the inlet angle .sub.b,3 with the radial. Furthermore, the guide vane 10, in particular the outlet region thereof over which air flows off from the guide vane 10, encloses the outlet angle .sub.b,4 with the radial, wherein this radial is illustrated in the drawing in each case by {right arrow over (r)}.

(11) Furthermore, the guide vane 10 has a maximum thickness b.sub.b and a so-called maximum thickness position f.sub.b. Furthermore, the length of the chord C is designated by l.sub.b. It has also proved particularly advantageous if the center point M of the ellipse with respect to the chord axis of the guide vane 10 does not lie further away from the center point S of the chord C than half the length l.sub.b of the chord C.

(12) Due to the configuration of the guide vane 10 illustrated in the drawing, in a flow channel which is delimited at least partially by the guide vane 10 and through which air can flow, it is possible to obtain an at least substantially uniform deceleration without excessive constriction on the front edge of the vane, wherein simultaneously a particularly large number of free geometry parameters can be produced. In this way, a discharge guide vane assembly design with an elliptical characteristic can be created for the diffuser preferably configured as a radial diffuser, so that particularly advantageous flow conditions can be produced in the diffuser.

LIST OF REFERENCE CHARACTERS

(13) 10 guide vane 12 diagram 14 vane inlet 16 vane outlet C chord S center point M center point X skeleton line db maximum thickness fb maximum thickness position fr3 inlet radius fr4 outlet radius l length r2 radius r3 inlet radius r4 outlet radius {right arrow over (r)} Radial b,3 inlet angle b,4 outlet angle