Two-stage compressor with asymmetric second-stage inlet duct

Patent metadata

Field	Value
Publication number	US-10190596-B2
Application number	US-201615342131-A
Country	US
Kind code	B2
Filing date	Nov 3, 2016
Priority date	Nov 3, 2016
Publication date	Jan 29, 2019
Grant date	Jan 29, 2019

Abstract

A multi-stage compressor for a turbocharger includes a compressor housing that defines an aperture for receiving a compressor wheel for successively compressing air in first and second stages. First- and second-stage inlets are fluidly connected to the aperture in opposite axial directions, and first- and second-stage volutes extend at least partially annularly therearound so that each volute is configured to receive gas flowing generally radially outward from the compressor wheel. First and second passages fluidly connect the first-stage volute to the second-stage inlet. The passages approach the second-stage inlet from opposite radially inward directions, and are asymmetric with respect to any pair of orthogonal axes having an origin lying on the turbocharger rotary axis as viewed on a transverse cross-section that is normal to the turbocharger axis.

First claim

What is claimed is:

1. A turbocharger, comprising:
a center housing defining a bore extending therethrough in an axial direction, with bearings mounted in the bore and a rotatable shaft supported in the bearings so as to be rotatable about a turbocharger axis, the shaft having opposite ends, the center housing having axially opposite sides;
a compressor wheel mounted on one end of the shaft and a turbine wheel mounted on the other end of the shaft;
a compressor housing enclosing the compressor wheel and having opposite first and second sides, the second side mounted to one of the sides of the center housing;
a turbine housing mounted to the other side of the center housing enclosing the turbine wheel, the turbine housing defining an annular chamber surrounding the turbine wheel for receiving exhaust gas and directing the exhaust gas radially inwardly into the turbine wheel;
the compressor wheel having a first-stage impeller and a second-stage impeller arranged back-to-back, the compressor housing defining a first-stage inlet extending in the axial direction into the first side of the compressor housing for supplying air into the first-stage impeller, and defining a second-stage inlet extending opposite to the axial direction into the second side of the compressor housing for supplying air into the second-stage impeller, the compressor housing defining a generally annular first-stage volute surrounding the first-stage impeller for receiving air discharged therefrom, and a generally annular second-stage volute surrounding the second-stage impeller for receiving air discharged therefrom, the compressor housing further defining a second-stage outlet conduit through which air is discharged from the second-stage volute along a discharge direction;
wherein an XYZ coordinate system for the compressor is defined having a Y-axis that extends from the turbocharger axis through and along an imaginary radial line T-T that divides the second-stage volute from the second-stage outlet conduit, having an X-axis that is orthogonal to the Y-axis and is aligned along a direction opposite to the discharge direction along which air exits the second-stage volute, and having a Z-axis that is mutually orthogonal to the X- and Y-axes and follows a right-hand screw convention;
the compressor housing defining two separate first and second passages each extending from the first-stage volute and then proceeding generally radially inwardly into the second-stage inlet, wherein the first-stage volute comprises two generally semi-annular segments that collectively substantially encircle the first-stage impeller, the first passage being connected to one of the segments and the second passage being connected to the other of the segments, wherein the first and second passages in a cross-sectional plane that is normal to the Z-axis have a configuration as viewed along the Z-axis that is asymmetric with respect to the X-axis and is asymmetric with respect to the Y-axis; and
wherein the first and second passages leading into the second-stage inlet are defined respectively by first and second walls that form two diametrically opposite left-hand and right-hand tongues that act as a pinch point where the diameter D 1 ° is at a minimum, and wherein a radial line L 1 that lies in said cross-sectional plane and that extends between the tongues is angularly offset from the Y-axis.

2. The turbocharger of claim 1 , wherein each of the two segments of the first-stage volute has a cross-sectional size that increases in a direction toward a respective one of the passages extending generally tangentially therefrom.

3. The turbocharger of claim 1 , wherein a cross-sectional size of the second-stage volute increases in a direction toward the outlet conduit.

4. The turbocharger of claim 1 , wherein the diameter of the second-stage inlet is defined as D 1 , and wherein a diameter ratio D 1 /D 1 ° is in the range of 0.75 to 0.85.

5. The turbocharger of claim 4 , wherein the radial line L 1 that extends between the tongues is angularly offset from the Y-axis by an asymmetry angle Δ that is in the range of 15° to 30°.

6. The turbocharger of claim 1 , the first walls having left-hand and right-hand walls, the second walls having left-hand and right-hand walls, wherein the first and second left-hand walls form the left-hand tongue and the first and second right-hand walls form the right-hand tongue, wherein, at the tongues, a tangent to the right-hand wall of the first passage and a tangent to the left-hand wall of the second passage each forms an angle ALPHA with respect to the radial line L 1 , and a tangent to the left-hand wall of the first passage and a tangent to the right-hand wall of the second passage each forms an angle BETA with respect to the radial line L 1 , and the angle ALPHA exceeds the angle BETA by at least 15°.

Assignees

• Honeywell Int Inc
• Garrett Transportation I Inc

Inventors

• Kares Vaclav
• Houst Vit
• Lednicky Ondrej
• Nejedly Milan
• Mokos Michal
• Oslejsek Zbynek
• Turecek Daniel

Classifications

• F05D2220/40

  in turbochargers · CPC title

• F04D17/12 Primary

  Multi-stage pumps · CPC title

• F05D2240/20

  Rotors · CPC title

• F02C6/12

  Turbochargers, i.e. plants for augmenting mechanical power output of internal-combustion piston engines by increase of charge pressure · CPC title

• F04D29/285

  the compressor wheel comprising a pair of rotatable bladed hub portions axially aligned and clamped together · CPC title