WO2016089641A1

WO2016089641A1 - Minimal water-cooling technology in conjunction with fully insulated aluminum turbine housing technology

Info

Publication number: WO2016089641A1
Application number: PCT/US2015/062058
Authority: WO
Inventors: Timm Kiener; Thomas Kritzinger; Wolfgang Wenzel
Original assignee: Borgwarner Inc.
Priority date: 2014-12-02
Filing date: 2015-11-23
Publication date: 2016-06-09

Abstract

A product that may be exposed to high temperatures and a method of forming the product are disclosed. According to the product and method, a shell may be formed from a first metal. A material may be applied to the outside of the shell. Tubes may be applied over the shell and the material in a circuitous fashion. The turbine housing may be cast from a second metal over the shell, the material, and the tubes.

Description

MINIMAL WATER-COOLING TECHNOLOGY IN CONJUNCTION WITH FULLY INSULATED ALUMINUM TURBINE HOUSING TECHNOLOGY

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of United States Provisional Application No. 62/086,224 filed December 2, 2014.

TECHNICAL FIELD

The field to which the disclosure generally relates includes

turbochargers for internal combustion engines.

BACKGROUND

Engine intake systems may typically include a single or multiple stage charging system where exhaust gas generated by the combustion of fuel passes through a turbine which drives a compressor. Air may be mixed with recirculated exhaust gases and is directed through the compressor which charges the intake system of the engine. SUMMARY OF ILLUSTRATIVE VARIATIONS

A product for conveying a heated fluid according to a number of variations as illustrated herein may include a shell having first and second openings. Anchor rings may be formed around the first and second openings and may have perforations. At least one coolant tube may be disposed about the shell. A metal housing may be cast over and substantially cover the shell and the coolant tubes and may extend through the perforations to secure the shell.

Other variations detailed herein, describe a turbine housing that may include a shell having an inlet opening to a first section of the shell that is substantially straight, and an outlet opening to a second section of the shell that is volute in shape. At least one coolant tube may be disposed about the shell in a circuitous shape. A metal housing may be cast over and substantially cover the shell and the coolant tube. Other illustrative variations may include a method of forming a turbine housing. According to the method, a shell may be formed from a first metal. A material may be applied to the outside of the shell. Tubes may be applied over the shell and the material in a circuitous fashion. The turbine housing may be cast from a second metal over the shell, the material, and the tubes.

Other illustrative variations within the scope of the invention will become apparent from the detailed description provided herein. It should be understood that the detailed description and specific examples, while disclosing variations within the scope of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Select examples of variations within the scope of the invention will become more fully understood from the detailed description and the accompanying drawings, wherein:

Figure 1 is a schematic illustration of a turbocharged engine system according to a number of variations.

Figure 2 is a perspective illustration of a two-piece volute shell according to a number of variations.

Figure 3 is a perspective illustration of a volute shell according to a number of variations.

Figure 4 is a perspective illustration of a volute shell with applied material according to a number of variations.

Figure 5 is a perspective illustration of a volute shell with applied material and tubes according to a number of variations.

Figure 6 is a fragmentary perspective illustration of a tube bundle according to a number of variations.

Figure 7 is a perspective illustration of a turbine housing according to a number of variations. DETAILED DESCRIPTION OF ILLUSTRATIVE VARIATIONS

The following description of the variations is merely illustrative in nature and is in no way intended to limit the scope of the invention, its application, or uses.

In the illustrative variation shown as an engine breathing system 10 of Figure 1 , an internal combustion engine 12 may have a number of cylinders for the controlled combustion of fuel to produce power. Exhaust gas

generated during combustion exits the engine 12 at an exhaust manifold 14 and may take one of two paths. In the first path, a high pressure exhaust gas recirculation (HP-EGR), passage 16 may lead to a heat exchanger 18 and then to a valve 20 for regulating the flow of exhaust gas through the HP-EGR loop. The high pressure designation relates to the unreduced exhaust gas pressure leaving the engine 12 upstream of a turbine rotor or turbine 30. The flow of exhaust gas through the HP-EGR loop may continue through the valve 20, when open, into an intake passage 24, and through an intake manifold 26 to the engine 12.

In the second exhaust gas path, exhaust gas may flow through the passage 28 to a turbine 30 where it may then be channeled through a turbine housing 32 in a passage around the turbine 30 and then exhausted out past the turbine 30, which rotates as a result. Exhaust gases may then flow out of the turbine housing 32 through a passage 33. The turbine housing 32 may include an inner wall 34 and an outer wall 36, with an air gap 38 in between. The air gap 38 may provide insulation so that the transfer of heat from the hot exhaust gases around the turbine 30 to the outer wall 36 is reduced.

Optionally, the air gap 38 may be filled with a material having insulating properties to enhance the amount of heat transfer reduction. Also optionally, the air gap 38 may have an inlet 40 connected to a passage 28, with a valve 42 to regulate the flow of exhaust gas into the air gap 38. Any admitted exhaust gas my exit the air gap 38 through an outlet 44 and to the passage 33. Exhaust gas may be selectively admitted to the air gap 38 to warm the turbine housing 32 when needed, such as when the aftertreatment system 46 has not yet reached optimal operating temperatures.

Through the action of routing exhaust gases to the turbine 30, the compressor 48 may be rotated through the shaft 50. The rotating compressor 48 may draw air in through an intake passage 52, which it compresses. This charges the intake system of the engine 12 through the passage 53, charge air cooler 54, intake throttle valve 56, passage 24 and intake manifold 26. The intake throttle valve 56 may be selectively throttled to enhance the flow of exhaust gas through the HP-EGR loop when desired. The compressor 48 may also draw exhaust gas through the low pressure exhaust gas

recirculation (LP-EGR) loop. A LP-EGR passage 58 may lead to a heat exchanger and then to a valve 62 for regulating the flow of exhaust gas through the LP-EGR loop. The low pressure designation relates to the reduced exhaust gas pressure leaving the turbine 30. The flow of exhaust gas through the LP-EGR loop may continue through the valve 62 when open, and into the compressor 48 and on to the engine 12 with the intake air.

A waste gate line 31 with a valve may provide a bypass around the turbine 30. Exhaust gas leaving the system 10 may proceed through the aftertreatment system 46 and an exhaust throttle valve 64 and on through the passage 65. The exhaust throttle valve 64 may selectively throttle flow when needed such as to increase the flow of exhaust gas through the LP-EGR loop. As a result, a system may be provided wherein the turbine housing 32 is subjected to high temperature exhaust gases. In addition to the air gap (or insulation containing space) 38, cooling features of the turbine housing 32 may be provided according to a number of variations.

As a feature of a number of variations, an air gap may be created between the hot exhaust gases flowing through the turbine and the turbine housing which may include forming a shell 68 as shown in Figure 2. The shell 68 may be formed in a manner to facilitate manufacturing in one piece or a number of sections such as through a first section 70 and a second section 72 that may be stamped, forged, cast or otherwise formed to the desired shape suitable for a turbine housing. Each section 70, 72 may include a generally circular central opening 74, 76 for receiving a turbine rotor. One or both sections 70, 72 may include missing sections 78, 79 that may assist in processing as will be described below. The sections 70, 72 may be connected together such as by crimping, welding, soldering, fastening, or another connection method.

Shown in Figure 3 a shell 68 includes an inlet 80, opening to a passage that proceeds through a substantially straight section 82 with a collar 84 extending laterally outward and forming a waste gate opening 86. The waste gate opening 86 may be closed by a waste gate seat when the turbine is assembled. The straight section 86 leads to a volute section 88 which has a decreasing diameter and curls around the opening 76. The volute section 88 may include an outlet in the form of circular or a semi-circular slot 90 through which exhaust gas entering the inlet 80 may be channeled to the turbine rotor.

The inlet 80 may be surrounded by a flange or flanges 92, 94 which have a plurality of openings or perforations 96. The flanges 92, 94 may serve as an anchor ring when the material of the turbine housing is cast around the shell 68 filling the perforations 96. Similarly, the center of the volute section 88 includes flanges 98, 99, which have openings 100 and which may serve as anchor rings when the material of the turbine housing is cast around the shell 68 filling the openings 100. The anchor rings secure the shell 68 in the cast housing. The shell 68 also includes the missing sections which form the opening 102 through which a core that may be used in the turbine housing casting process may be extracted from inside the shell.

Referring to Figure 4, the shell 68 is shown inverted from the

orientation shown in Figure 3. Material 104, 106 and 108 has been applied to the shell 68 with the anchor rings 95 and 99 exposed to a later application of molten metal during a casting process. The material 104, 106 and 108 may be a core material made of sand with an appropriate binder or another coring material as dictated by the casting process employed. The material 106 may result in an insulating air gap between the shell 68 and the metal turbine housing when removed after casting, and may be an insulating material that remains in the casting to insulate the outside of the shell from the housing. Visible through the opening 102 is material 108 which may be position inside the shell 68 and may be a core material. The opening 102 may assist in the de-coring process for removal of the material 108 and may be closed with a metal shell section after de-coring. In applications where the air gap is not needed and insulation may be used, appropriate material such as fiber mat, ceramic or other material may be substituted for the material 106 to be cast into the turbine housing.

In Figure 5 the shell 68 with applied sand cores is shown inverted from the orientation illustrated in Figure 4. A tube bundle 1 10 designed to direct coolant to the desired areas of the turbine housing may be applied over the shell 68 and any cores and insulating material. The tubes may be formed by bending, hydroforming or other means and may have circular, oval, flattened, or otherwise shaped cross sections that may vary at locations as needed to fit the design. Individual tubes may result in circuitous routes for fluid flow. The tube bundle 1 10 may include one tube or a plurality of tubes which are concentrated at their ends 1 12, 1 14 to facilitate connection through a manifold or other device. As shown in Figure 6, a bundle plate 1 16 may be applied to the ends 1 12, 1 14 of the tube bundle 1 10 to hold the ends in position. The bundle plate 1 16 may be welded, braced, crimped, clamped or otherwise connected with the tube bundle 1 10. Features such as braces or spacers may be used throughout the tube bundle 1 10 to maintain the designed positioning and spacing of tubes where needed. During casting, the tubes may be filled with salt or another appropriate material for support against the heat and pressure of the casting process. The fill material may be later removed after casting. The tubes may be used to flow coolant or for directing lubricant or other fluids to points within the turbine housing.

In Figure 7 a turbine housing 32 is shown cast over the shell 68 and the tube bundle 1 10 of Figure 5 which are encased in metal and not visible. Shortly before and during the casting process a vacuum or fluid flow may be applied to the tubes to aid molten metal flow over the outside of the tubes. Once the housing 32 is cast, the cores may be removed, the tubes emptied and other machining needed to complete the housing may be employed. The turbine housing 32 may have cast in manifolds 122, 124 where the ends 1 12, 1 14 of the tube bundle 1 10 with any bundle plates are disposed for

connection to an exterior flow circuit. The material used in the casting may be aluminum or another metal or alloy. Any cast in air gap, insulation, and cooling tubes may advantageously allow the use of lower cost materials other than higher temperature materials and at lighter weight than heavier housing designs employing cast fluid channels requiring more material. The use of tubes for creating the coolant channels in the casting may assist in forming smaller diameter coolant passages and in optimal location of coolant flow. The use of materials able to withstand higher temperatures may be limited to the shell 68.

The following description of variants is only illustrative of components, elements, acts, products and methods considered to be within the scope of the invention and is not in any way intended to limit such scope by what is specifically disclosed or not expressly set forth. Components, elements, acts, products and methods may be combined and rearranged other than as expressly described herein and still are considered to be within the scope of the invention.

Variation 1 may include a product for conveying a heated fluid which may include a shell having first and second openings. Anchor rings may be formed around the first and second openings and may have perforations. At least one coolant tube may be disposed about the shell. A metal housing may be cast over and substantially cover the shell and the coolant tubes and may extend through the perforations to secure the shell.

Variation 2 may include a product according to variation 1 wherein the heated fluid is exhaust gas from an internal combustion engine.

Variation 3 may include a product according to variation 1 or 2 wherein the first opening is an inlet configured for receiving exhaust gas and the second opening is an outlet in the form of a circular slot directing the exhaust gas to a turbine rotor.

Variation 4 may include a product according to any of variations

1 through 3 wherein an air gap is formed between the shell and the metal housing.

Variation 5 may include a product according to variation 4 which may have an inlet to the air gap and an outlet from the air gap. A valve may be positioned in the inlet for admitting fluid flow through the air gap.

Variation 6 may include a product according to any of variations 1 through 5 and may have a plurality of coolant tubes having ends concentrated at a bundle tube that is cast into the metal housing Variation 7 may include a product according to any of variations 1 through 6 wherein the shell may have a substantially straight section and a volute section. The first opening may lead to the straight section and the second opening may lead to the volute section and may be semi-circular in shape.

Variation 8 may include a product according to any of variations 1 through 7 wherein the metal housing may house a turbine rotor.

Variation 9 may include a turbine housing with a shell having an inlet opening to a first section of the shell that is substantially straight and an outlet opening to a second section of the shell that is volute in shape. At least one coolant tube may be disposed about the shell in a circuitous shape. A metal housing may be cast over and substantially cover the shell and the coolant tube.

Variation 10 may include a turbine housing according to variation 9 wherein an air gap may be formed between the shell and the metal housing.

Variation 1 1 may include a turbine housing according to variation 9 wherein insulation is positioned between the shell and the metal housing.

Variation 12 may include a turbine housing according to any of variations 9 through 1 1 wherein the shell may be configured to flow exhaust gas from the inlet to the outlet and wherein a waste gate opening may be formed in the first section to divert exhaust gas from reaching the outlet.

Variation 13 may include a turbine housing according to any of variations 9 through 12 wherein the shell may include an anchor ring around each of the inlet and the outlet. The anchor rings may have perforations and the metal housing may be cast to extend through the perforations to anchor the shell in the metal housing.

Variation 14 may include a method of forming a turbine housing. According to the method, a shell may be formed from a first metal. A material may be applied to the outside of the shell. Tubes may be applied over the material in a circuitous fashion. The turbine housing may be cast from a second metal over the shell, the material, and the tubes. Variation 15 may include a method as set forth in variation 14 and may further include the step of filling the shell with a core material before casting the housing.

Variation 16 may include a method as set forth in variations 14 wherein the material is a core material and may include the step of removing the core material after casting the housing.

Variation 17 may include a method as set forth in any of variations 14 through 16 and may further include the step of filling the tubes for support before casting the housing.

Variation 18 may include a method as set forth in any of variations 14 through 17 and may further include the step of connecting a bundle plate to the tubes.

Variation 19 may include a method as set forth in any of variations 14 through 18 and may further include the step of forming an anchor ring with perforations in the shell wherein the perforations are configured to receive the second metal when the housing is cast.

Variation 20 may include a method as set forth in variation 14 wherein the material is an insulating material.

The above description of select variations within the scope of the invention is merely illustrative in nature and, thus, variations or variants thereof are not to be regarded as a departure from the spirit and scope of the invention.

Claims

CLAIMS What is claimed is:

1 . A product for conveying a heated fluid comprising a shell having first and second openings with anchor rings around the first and second openings, the anchor rings having perforations; at least one coolant tube disposed about the shell; and a metal housing cast over and substantially covering the shell and the at least one coolant tube, and the metal housing extending through the perforations.

2. The product according to claim 1 wherein the heated fluid is exhaust gas from an internal combustion engine.

3. The product according to claim 1 wherein the first opening is an inlet configured for receiving an exhaust gas and the second opening is an outlet in the form of a circular slot directing the exhaust gas to a turbine rotor.

4. The product according to claim 1 wherein an air gap is formed between the shell and the metal housing.

5. The product according to claim 4 further comprising an inlet to the air gap and an outlet from the air gap with a valve in the inlet for admitting fluid flow through the air gap.

6. The product according to claim 1 further comprising a plurality of coolant tubes having ends concentrated at a bundle tube, the plurality of coolant tubes cast into the metal housing.

7. The product according to claim 1 wherein the shell has a substantially straight section and a volute section and wherein the first opening leads to the straight section and the second opening leads to the volute section and is circular in shape.

8. The product according to claim 1 wherein the metal housing houses a turbine rotor.

9. A turbine housing comprising a shell having an inlet opening to a first section of the shell that is substantially straight and an outlet opening to a second section of the shell that is volute in shape; at least one coolant tube disposed about the shell in a circuitous shape; and a metal housing cast over and substantially covering the shell and the at least one coolant tube.

10. The turbine housing according to claim 9 wherein an air gap is formed between the shell and the metal housing.

1 1 . The turbine housing according to claim 9 wherein insulation is positioned between the shell and the metal housing.

12. The turbine housing according to claim 9 wherein the shell is configured to flow exhaust gas from the inlet to the outlet and wherein a waste gate opening is formed in the first section to divert exhaust gas from reaching the outlet.

13. The turbine housing according to claim 9 wherein the shell includes an anchor ring around each of the inlet and the outlet, the anchor rings having perforations, wherein the metal housing is cast to extend through the perforations to anchor the shell in the metal housing.

14. A method of forming a turbine housing comprising the steps of : a. forming a shell from a first metal;

b. applying a material to an outside of the shell;

c. applying tubes over the material in a circuitous fashion; and

d. casting a housing from a second metal over the shell, the material, and the tubes.

15. The method as set forth in claim 14 including the step of filling the shell with a core material before casting the housing.

16. The method as set forth in claim 14 wherein the material is a core material and including the step of removing the core material after casting the housing.

17. The method as set forth in claim 14 including the step of filling the tubes for support before casting the housing.

18. The method as set forth in claim 14 including the step of connecting a bundle plate to the tubes.

19. The method as set forth in claim 14 including the step of forming an anchor ring with perforations in the shell wherein the perforations are configured to receive the second metal when the housing is cast.

20. The method as set forth in claim 14 wherein the material is an insulating material.