GB2186328A

GB2186328A - Turbine housings for turbochargers

Info

Publication number: GB2186328A
Application number: GB08603288A
Authority: GB
Inventors: Masami Shimizu
Original assignee: IHI Corp
Current assignee: IHI Corp
Priority date: 1986-02-11
Filing date: 1986-02-11
Publication date: 1987-08-12
Also published as: GB8603288D0

Abstract

A turbine housing for a turbocharger comprises two housing sections 2a, 2b separated in the axial direction and a partition plate 7 clamped between these sections thereby dividing the interior of the housing into two pathways 4a, 4b. The coefficient of thermal expansion of the partition plate may be less than that of the housing sections. The housing sections preferably define a groove 6 which accommodates the outer edge of the partition plate and there may be a clearance 'C' between the bottom of the groove and the outer edge of the partition plate. The partition plate may have a corrugated section adjacent its outer edge. <IMAGE>

Description

SPECIFICATION Turbine housings for turbochargers The present invention relates to turbine housings forturbochargers and is concerned with that type of housing in which the passage through which the exhaust gases are supplied to the turbine is divided by one or more partition wall or walls into two or more pathways.

Figure lisa diagrammatic radial sectional view of a known turbocharger turbine housing and Figure 2 is a sectional view on the line Il-Il of Figure 1.A partition wail 3 is formed integral with the interior of the gas turbine housing 2 for supplying the exhaust gases to the outer periphery of the turbine 1 and defines two paths 4a and 4b separated from each other in the axial direction of the turbine 1 so that interference of the exhaust gases from an engine can be avoided and pulsations thereof can be effectively utilized.

Thus in conventional turbochargers the partition wall 3 is integral with the turbine housing 2 so that even though thermally caused deformation of the partition wall 3 in the radial direction is reiatively large, the deformation of the partition wall 3 is restrained. As a result, substantiai mechanical stresses are produced which result in cracks 5.

Furthermore there is the problem that satisfactory dimensional accuracy cannot be ensured when die casting the housing because of its complex construction.

According to the present invention a turbine housing for a turbocharger comprises two or more housing sections separated in the axial direction and at least one partition plate clamped between two adjacent sections thereby dividing the interior of the housing into two or more pathways. Thus in the construction of the present invention thermal expansion of the partition wall can occur without any substantial risk of cracking or other damage and thus the integrity of the turbine housing is improved.

In one embodiment of the invention the opposing surfaces of the adjacent housing sections define a groove in which the outer edge of the partition plate is accommodated. It is preferred that there is a gap between the base of the groove and the outer edge of the partition plate. The partition plate may be made of a material whose coefficient of thermal expansion is iess, preferably substantially less, than that of the housing sections.

The adjacent housing sections and the partition plate clamped therebetween are preferably securely held in position by a separate retaining member, e.g. a channel-shaped member of annular or partannular shape.

In a further embodiment the partition plate has a corrugated portion adjacent its outer edge which is clamped between the adjacent housing sections.

The invention also embraces a turbocharger including such a turbine housing.

Further features, details and advantages of the present invention will be apparent from the following description of certain preferred embodiments which is given with reference to Figures 3 to 6 of the accompanying drawings which are sectional views similar to Figure 2 of first to fourth embodiments of the invention, respectively.

Referring first to Figure 3, the turbine housing 2 which has a similar configuration to that of Figure 1, is divided into two separate sections 2a and 2b in the axial direction of the turbine by a partition wall 7.

The housing comprises two engaging housing sections 2a and 2b whose engaging surfaces each afford a recess. The two recesses together constitute a recess or groove 6 in the internal surface of the housing. The outer edge of the partition plate or wall 7 is accommodated in the groove 6 whereby there is a small gap or clearance of depth C between the outer edge of the partition wall 7 and the bottom of the groove 6. Outwardly extending portions of the housing sections adjacent the groove 6 are securely joined together at 8 by welding, brazing or with bolts and nuts.

By virtue of the presence of the gap between the bottom of the groove 6 and the outer edge of the partition wall 7, expansion or deformation of the partition plate 7 due to changes in temperature can occur in the radial direction. As a consequence the partition plate 7 is substantially immune to thermal cracking and thus the integrity of the turbine housing is ensured. Moreover, since the turbine housing is sectionalised, its casting and the maintenance of the desired dimensional accuracy are facilitated.

The embodiment of Figure 4 is generally similar to that of Figure 3 but the partition plate 7' whose outer periphery is fitted into the groove 6 defined by the housing sections 2a and 2b is made of a material such as a ceramic or ferrite metal whose coefficient of thermal expansion is less than that of the remainder of the housing, preferably substantially less. By virtue of the reduced coefficient of expansion of the partition wall or plate 7' the latter is substantially immune to thermal cracking so that substantially the same effects and advantages can be attained as the first embodiment. Since the thermal deformation of the partition plate 7' is less than that in the first embodiment, the size of the gap between the bottom of the groove 6 and the periphery of the partition plate 7' may be reduced or eliminated, as shown in Figure 4.

In the embodiment of Figure 5, the turbine housing sections 2a and 2b do not define a groove between them and the partition plate 7 is simply clamped between them. The outwardly extending portions of the housing sections 2a and 2b are covered by a channel-section retaining ring 8 which is welded to the housing sections.

In the embodiment of Figure 6 the partition plate 7 has a corrugated portion 10 adjacent its outer periphery contiguous with which is a flat outer peripheral edge 11. The edge 11 is clamped between the housing sections 2a and 2b and is securely held in position. The corrugated portion 10 can readily deform to accommodate thermal expansion of the partition plate 7 whereby thermal cracking of the latter is avoided.

Claims

1. Aturbine housing for a turbocharger comprising two or more housing sections separated in the axial direction and at least one partition plate clamped between two adjacent sections thereby dividing the interior of the housing into two or more pathways.

2. A housing as claimed in claim 1 in which the opposing surfaces of the adjacent housing sections define a groove in which the outer edge of the partition plate is accommodated.

3. A housing as claimed in claim 2 in which there is a gap between the base of the groove and the outer edge of the partition plate.

4. A housing as claimed in any one of the preceding claims in which the partition plate is made of a material whose coefficient of thermal expansion is less than that of the housing sections.

5. A housing as claimed in claim 1 in which the adjacent housing sections and the partition plates are held in position by a separate retaining member.

6. A housing as claimed in claim 1 in which the partition plate has a corrugated portion adjacent its outer edge which is clamped between the adjacent housing sections.

7. A turbine housing for a turbocharger substantially as specifically herein described with reference to any one of Figures 3 to 6 of the accompanying drawings.

8. A turbocharger including a turbine housing as claimed in any one of the preceding claims.