Fluid cooled marine turbine housing

Abstract

A method of reworking a corroded turbine housing for a turbocharger of a marine engine so that the corroded housing may be restored and reused. A turbine housing includes a central aperture for containing a turbine blade assembly and directing exhaust gases past the turbine blades in a turbocharger. The central aperture of a used turbine housing often is corroded such that the central aperture is enlarged and allows significant leakage. The corrosion may be removed and the aperture enlarged to receive an insert. The insert may have an insert aperture that is slightly larger than the diameter of a turbine blade assembly. The insert restores the sidewalls of the aperture through the turbine housing so that the amount of exhaust gases leaking past a turbine blade assembly is significantly reduced, thereby restoring the efficiency of the turbocharger and improving performance of the engine to which the turbocharger is attached.

Description

FIELD OF THE INVENTION

This invention is directed generally to turbochargers, and more particularly to turbine housings of turbochargers usable in fluid cooled marine engines.

BACKGROUND

A turbocharger is usable on engines to increase the power delivered by the engine. More specifically, turbochargers increase the power produced by an internal combustion engine by compressing intake air of a combustion engine using energy found in the exhaust gases produced by the engine. A turbocharger receives exhaust air from an engine and directs the exhaust air into a turbine assembly. The exhaust air rotates turbine blades of a turbine blade assembly about a shaft at a high speed. The turbine blade assembly is positioned within the turbine housing such that the turbine blades are in close proximity to a surface forming a central aperture extending through the turbine housing. Attached to the shaft in a separate compartment is a plurality of combustor blades forming a combustor blade assembly. As the exhaust gases rotate the turbine assembly, the shaft rotates and, in turn, rotates the combustor assembly. The rotating combustor blades compress intake air, thereby adding energy to the intake air that is passed into the combustion chambers during combustion. The release of the added energy in the combustion chamber increases the overall output of the engine.

In many conventional turbine housings, the walls forming the central aperture corrode over time due primarily to engine use. More specifically, the walls corrode due to the corrosive components in the exhaust gases that flow through the aperture. The walls may also corrode should a leak develop in the exhaust cooling system and seawater used in the exhaust cooling system contacts the aperture. Seawater, together with corrosive elements and heat found in the exhaust gases, corrode the side walls forming the aperture that extends through the turbine housing. The corrosion causes the size of the aperture extending through the turbine housing to increase, which also causes the gap between the turbine blades and the side wall to increase as well. Conventional turbine housings typically have a gap of about 0.020 inch between the tips of the turbine blades and the side wall. The exhaust gases and salt air can increase the size of the gap to 0.060 of an inch or more. The increased size of the gap enables more exhausts gases to pass through the aperture without passing through the turbine assembly and producing work on the turbine blades. Thus, the increase gap size reduces the efficiency of the turbocharger and the engine to which the turbocharger is mounted.

Diesel engines having corroded turbine housings produce heavy black smoke, burn more fuel, and are generally less efficient than engines that have turbine housings with apertures that fit closely with the turbine blades. In fact, corroded turbine housings can often greatly reduce the power output of an engine to such an extent that the performance of a boat in which the engine is mounted is greatly impacted. Thus, a need exists for a method of remanufacturing worn out turbine housings to restore efficiency to worn out turbine housings.

SUMMARY OF THE INVENTION

This invention relates to a turbine housing for a turbocharger for a marine engine and, more specifically, to a method of remanufacturing a turbine housing to repair corroded components. The turbine housing may be formed from an exhaust channel for receiving exhaust gases and may have a generally toroidal flow path surrounding a central aperture. The turbine housing may also include a cooling channel, which, in at least one embodiment, may have a generally toroidal shape and be positioned proximate to the exhaust channel for preventing premature fail of the housing and other related components. The central aperture of the turbine housing may be sized to accommodate a shaft that supports a turbine blade assembly and transmits rotational motion axially from the turbine blade assembly to a compressor blade assembly. The central aperture may also be sized to receive an insert. The aperture may be enlarged using a CNC machine or other appropriate device.

The insert may include an insert aperture extending through the insert. The insert aperture may be configured to fit closely with a turbine blade assembly. In at least one embodiment, the gap between the tips of the turbine blades in the turbine blade assembly and side walls forming the central aperture is between about 0.015 inch and 0.025 inch. The insert may also include an insert position fixator for positioning the insert in the central aperture of the turbine housing. In at least one embodiment, the insert position fixator may be formed from a collar on the insert and a ring on the wall forming the central aperture positioned to mate with the collar on the insert.

The insert may be sized to produce an interference fit when inserted into a central aperture of the turbine housing. The insert may be pressed into the central aperture using a press. Alternatively, insertion of the insert into the central aperture may be facilitated by first heating the turbine housing to increase the size of the central aperture or cooling the insert to reduce the outer diameter of the outer housing, or both. The insert may be inserted into the central aperture of the turbine housing until the insert has substantially passed through the central aperture and the collar on the insert contacts the ring on the surface forming the central aperture of the turbine housing. The temperature of the components may be returned to ambient temperature to create an interference fit between the insert and the turbine housing.

An advantage of this invention is that the reworked turbine housings have reduced sized central apertures that reduce the gaps between the side walls forming the central apertures and turbine blades of turbine blade assemblies, thereby increasing the efficiency of engines to which the turbine housings are attached. This results in a tremendous cost savings as new turbine housings having a cost greater than the reworked turbine housings need not be purchased. Thus, use of this invention results in a significant cost savings.

These and other embodiments are described in more detail below.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and form a part of the specification, illustrate embodiments of the presently disclosed invention and, together with the description, disclose the principles of the invention.

FIG. 1 is an exploded perspective view of a turbine for a turbocharger in a marine engine showing aspects of this invention.

FIG. 2 is an assembled perspective view of the turbine shown in FIG. 1.

FIG. 3 is a perspective view of a portion of a turbine housing shown in detail 3-3 in FIG. 1.

FIG. 4 is a cross-sectional view of a turbine housing of this invention taken at section line 4-4 shown in FIG. 3.

FIG. 5 is a perspective view of an insert configured to be inserted into a central aperture of a turbine housing.

DETAILED DESCRIPTION OF THE INVENTION

As shown in FIGS. 1-5, this invention is directed to a turbine housing 10 of a turbocharger 12 having an insert 14 that enables a turbine housing 10 to be repaired in a manner that is less costly than conventional remanufacturing processes and enables corroded turbine housings 10 to be repaired rather than having to be replaced. The insert 14 enables a worn out conventional turbine housing to be reworked to perform according to original specifications or even better. The method of remanufacturing a conventional turbine housing entails enlarging a corroded aperture in the conventional turbine housing to accept an insert having an insert aperture configured in accordance with tolerances equivalent to original specifications for the conventional turbine housing or even tighter tolerances. Thus, the insert 14 enables a central aperture of a turbine housing 10 to be restored to its original size so that the gap between tips of the turbine blades and the surface forming the central aperture is as small as possible, thereby increasing the efficiency of the system and reducing the loss due to exhaust gases passing through the gap.

As shown in FIG. 1, the turborcharger 12 may be formed from a turbine housing 10 and a combustor housing 16. The turbine housing 10 may be configured to receive exhaust gases from a marine engine and pass those gases through a turbine blade assembly 18 housed in the turbine housing 10. More specifically, as shown in FIG. 4, the turbine housing 10 includes an exhaust gas channel 20 for receiving exhaust gases from combustion chambers of a marine engine. In at least one embodiment, the exhaust gas channel 20 may have a generally toroidal shape with an opening 22 on an inside surface of the turbine housing 10 proximate a central axis 24 enabling exhaust gases to flow into contact with the turbine blades 26.

The turbine housing 10 may also include a cooling system 28 for removing heat from the housing 10 to prevent premature failure. In at least one embodiment, as shown in FIG. 4, the turbine housing 10 may have a cooling channel 30 adjacent to the exhaust gas channel 20. The cooling channel 30 may have one or more inlets 32 and one or more outlets 34. Use of the inlets 32 and outlets 34 may be based upon space available where the turbocharger 12 is mounted to an engine and based upon available space in an engine room. The cooling channel 30 may be sized based upon the flow rate of exhaust air through the exhaust gas channel 20, convection rates, materials, and other factors. Water from the engine may be passed through the cooling channel 30 as a cooling fluid to eliminate excess heat from the turbine housing 10.

The turbine housing 10 may also include an aperture 36. Used turbine housings 10 have apertures 36 that are corroded due to corrosive elements in the exhaust air, heat, saltwater from leaks in the cooling system, and other contaminants. Corroded and otherwise damaged portions of a turbine housing 10 may be repaired by first removing the corroded portions using, for instance, a CNC machine. The aperture 36 of a corroded housing may be enlarged a sufficient amount to accept the insert 14 into the aperture 36. The insert 14 may include an insert aperture 44 configured to accept the shaft 38 and the turbine assembly 18 with a minimal gap 37 between the tips 39 of the turbine blades 41 and the surface 43 forming the insert aperture 44. The insert 14 may have a generally tubular shape. In fact, the insert aperture 44 may be sized such that the gap 37 between the tips 39 of the turbine blades 41 and the surface 43 forming the insert aperture 44 is between about 0.015 and inch and 0.025 inch. By forming the insert 14 such that the gap 37 is within this range, increased performance of an engine is realized as energy loss due to exhaust gases passing through the gap 37 is greatly reduced.

The diameter of the insert aperture 44 may be varied based upon each manufacturer's specifications. More specifically, the insert aperture 44 may be sized based upon the size of the turbine blade assembly to fit within the insert aperture 44. Thus, numerous inserts 14 may be produced having different inner diameters for the insert aperture 44 that correspond to different diameters of turbine blade assemblies found in turbochargers produced by different manufacturers. This allows a turbocharger to be reworked in a much more expedient manner. The housing 10 need only be removed from an engine, and the aperture 36 enlarged by removing corroded portions to receive an insert 14. In at least one embodiment, the aperture 36 is generally cylindrical, although it may have other appropriate shapes in other embodiments. The aperture 36 may be sized to produce an interference fit with the insert 14. The aperture 36 may have a diameter that is slightly smaller than an outside diameter of the insert 14.

An insert 14 corresponding to the turbine assembly 18 in the particular turbocharger may be inserted into the turbine housing 10 to repair a damaged turbine housing 10. When inserted into the aperture 36, the insert 14 may extend substantially through the entire aperture 36. The insert 14 may be installed by pressing the insert 14 into the central aperture 36 using a press. Alternatively, the insert 14 may be installed by first heating the turbine housing to increase the diameter of the aperture 36 in the turbine housing or by cooling the insert 14 to reduce the diameter or both. The insert 14 may be inserted and the turbine housing 10 allowed to cool, or the insert heat up, or both, to form an interference fit with the insert 14. The turbine housing 10 may then be reinstalled on a turbo charger on a marine engine. The insert 14 may be used with a turbine housing 10 manufactured for use with the insert 14 or may be used with conventional turbine housings with the central apertures 36 that have been enlarged to receive an insert 14.

The insert 14 may also include an insert position fixator 46 for preventing the insert 14 from moving axially within the aperture 36. In at least one embodiment, the insert position fixator 46 may be formed from a collar 48 positioned on an outer surface 50 of the insert 14 and a ring 52 formed on an inner surface 54 of the turbine housing 10 forming the aperture 36. The collar 48 may be formed from a portion 56 of the outer surface 50 of the insert 14 that has a larger diameter or size than another portion 58 of the insert 14. Similarly, the ring 52 may be formed from a portion 60 having a larger diameter than another portion 62. The ring 52 corresponds with the collar 48 such that the insert 14 may be inserted into the aperture 36 to the point at which the collar 48 and ring 52 contact. The collar 48 and ring 52 may be cut into the insert 14 and wall forming the aperture 36, respectively, using a CNC milling machine or other appropriate device.

Use of the insert 14 enables damaged turbine housings 10 to be repaired in much less time than conventional turbine housings. For instance, if a turbine housing 10 with an insert 14 becomes corroded, the insert 14 may be removed and replaced with an undamaged insert 14 with little or no machining involved.

The foregoing is provided for purposes of illustrating, explaining, and describing embodiments of this invention. Modifications and adaptations to these embodiments will be apparent to those skilled in the art and may be made without departing from the scope or spirit of this invention.

Claims

1. A turbine housing for a turbocharger of a marine engine, comprising:

a turbine housing body configured to contain a turbine blade assembly and including a generally toroidal shaped exhaust channel and an aperture extending through the housing body at a center of the body; and

at least one insert having an outer surface configured to fit into the aperture and an insert aperture extending through the at least one insert and sized to receive a bearing assembly.

2. The turbine housing of claim 1, further comprising at least one cooling channel proximate to the exhaust channel for removing heat from the turbine housing.

3. The turbine housing of claim 1, further comprising at least one insert position fixator on the aperture in the turbine housing body for positioning the at least one insert in the turbine housing.

4. The turbine housing of claim 3, wherein the at least one insert position fixator comprises a ring protruding from a surface of the aperture in the turbine housing body and a collar extending from an outer surface of the at least one insert configured to mate with the ring protruding from the aperture.

5. The turbine housing of claim 1, wherein the at least one insert extends substantially through aperture in the turbine housing body.

6. The turbine housing of claim 1, wherein the at least one insert forms an interference fit with a surface forming the aperture extending through the turbine housing body.

7. The turbine housing of claim 6, wherein the at least one insert has an outer diameter that is larger than a diameter of the aperture in the turbine housing body.

8. The turbine housing of claim 1, wherein the at least one insert is tubular.

9. A turbine housing for a turbocharger of a marine engine, comprising:

a turbine housing body configured to contain a turbine blade assembly and including a generally toroidal shaped exhaust channel and an aperture extending through the housing body at a center of the body;

at least one insert having an outer surface configured to fit into the aperture and an insert aperture extending through the at least one insert and sized to receive a bearing assembly;

at least one cooling channel proximate to the exhaust channel for removing heat from the turbine housing; and

at least one insert position fixator on the aperture in the turbine housing body for positioning the at least one insert in the turbine housing.

10. The turbine housing of claim 9, wherein the at least one insert position fixator comprises a ring protruding from a surface of the aperture in the turbine housing body and a collar extending from an outer surface of the at least one insert configured to mate with the ring protruding from the aperture.

11. The turbine housing of claim 9, wherein the at least one insert forms an interference fit with a surface forming the aperture extending through the turbine housing body.

12. The turbine housing of claim 9, wherein the at least one insert has an outer diameter that is larger than a diameter of the aperture in the turbine housing body.

13. A method of remanufacturing a turbine housing of a turbocharger for a water cooled marine engine, comprising:

enlarging an aperture extending through a turbine housing body of a turbocharger, wherein the turbine housing body is configured to contain a turbine blade assembly and includes an exhaust channel, a cooling channel proximate the exhaust channel, and the aperture in the body;

forming an insert having an exterior configuration adapted to fit inside the aperture and an insert aperture extending through the insert and sized to form a minimal gap between a turbine blade assembly and the insert; and

inserting the insert into the aperture.

14. The method of remanufacturing a turbine housing of claim 13, further comprising forming at least one insert position fixator on the aperture in the turbine housing body and on an outer surface of the insert.

15. The method of remanufacturing a turbine housing of claim 14, wherein forming at least one insert position fixator on the aperture in turbine housing body comprises forming a first section of a surface forming the aperture from a first diameter and a second section of a surface forming the aperture from a second diameter, whereby the second diameter is smaller than the first diameter.

16. The method of remanufacturing a turbine housing of claim 14, wherein forming the at least one insert position fixator on an outer surface of the insert comprises forming a collar having an outer diameter that is larger than a diameter of another portion of the outer surface of the insert.

17. The method of remanufacturing a turbine housing of claim 13, further comprising heating the turbine housing sufficiently to increase a size of the aperture to enable the insert to be inserted.

18. The method of remanufacturing a turbine housing of claim 13, further comprising cooling the insert sufficiently to reduce a size of the insert to enable the insert to be inserted.

19. The method of remanufacturing a turbine housing of claim 13, wherein inserting the insert into the aperture comprises pressing the insert into the aperture.

20. The method of remanufacturing a turbine housing of claim 13, wherein forming an insert having a minimal gap between a turbine blade assembly and the insert comprises forming an insert capable of establishing a minimal gap between a turbine blade assembly and the insert between about 0.015 inch and 0.025 inch.