METHOD OF DIE CASTING COMPRESSOR HOUSINGS

METHODE DE COULEE SOUS PRESSION DE CARTERS DE COMPRESSEUR

English Abstract

A compressor housing is provided for a compressor impeller. The compressor housing comprises an outer shell including an outer section, a midsection, and a center section. The midsection of the outer shell forms an upper volute wall portion of the compressor housing, and the center section forms an inlet for the compressor housing. A diffuser is also provided that is comprised of a center section, a base section, and an outer section. The center section of the diffuser has a substantially cylindrical outer edge received within a complementary substantially cylindrical mating surface in the outer shell center section. The diffuser base section has a raised first mating projection for engagement with the first mating surface of the midsection of the outer shell. The diffuser outer section has a raised second mating projection for engagement with a second mating surface of the midsection of the outer shell. A back plate is also provided that is formed of a generally circular structure. The diffuser base section has a generally flat lower surface for engagement with a generally flat upper surface of the back plate. The outer shell midsection, the diffuser and the back plate form the volute wall portion of a compressor housing.

French Abstract

La présente description concerne un carter de compresseur destiné à une roue de compresseur. Le carter de compresseur comprend une coque externe comprenant une section externe, une section intermédiaire et une section centrale. La section intermédiaire de la coque externe constitue une partie de cloison de volute supérieure du carter du compresseur, et la section centrale constitue une entrée pour le carter du compresseur. Un diffuseur comportant une section centrale, une section de base et une section externe est également prévu. La section centrale du diffuseur est pourvue d'un bord externe quasiment cylindrique qui s'adapte à une surface de contact complémentaire quasiment cylindrique, dans la section centrale de la coque externe. La section de base du diffuseur comporte une première saillie de contact surélevée qui s'engage dans la première surface de contact de la section intermédiaire de la coque externe. La section externe du diffuseur comporte une seconde saillie de contact surélevée qui s'engage dans une seconde surface de contact de la section intermédiaire de la coque externe. Une plaque d'appui constituée d'une structure globalement circulaire est également prévue. La section de base du diffuseur comporte une surface inférieure globalement plate qui coïncide avec une surface supérieure globalement plate de la plaque d'appui. La section intermédiaire de la coque externe, le diffuseur et la plaque d'appui constituent la partie de cloison de volute d'un carter du compresseur.

Claims

CLAIMS
What is claimed is:
1. A compressor housing for a compressor impeller comprising:
an outer shell including an outer section, a midsection and a center section,
the
midsection forming an upper volute wall portion of the compressor housing, and
the center
section forming an inlet concentric with the compressor impeller,
a diffuser including a center section, a base section, and an outer section,
the center
section having a substantially cylindrical outer edge received in a
complementary substantially
cylindrical mating surface in the outer shell center section,
the diffuser base section having a raised first mating projection for
engagement with a
first mating surface of the midsection of the outer shell,
the diffuser outer section having a raised second mating projection for
engagement with a
second mating surface of the midsection of the outer shell,
the outer shell midsection and the diffuser forming a volute wall portion of
the
compressor housing.
2. The compressor housing of claim 1
wherein the diffuser center section and base section are formed of a first
single
continuous structure and the diffuser outer section is formed of a second
single continuous
structure.
3. The compressor housing of claim 1
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further comprising a back plate, the back plate formed of a generally circular
structure
having a generally flat upper surface,
the diffuser base section having a generally flat lower surface for engagement
with the
generally flat upper surface of the back plate,
the back plate forming a lower volute wall portion of the compressor housing.
4. The compressor housing of claim 1
wherein the complementary substantially cylindrical mating surface is the
outer shell
center section is located on an inner wall of the outer shell center section
and includes a ledge
against which an upper edge of the diffuser center section is engaged.
5. The compressor housing of claim 1
wherein the upper edge of the diffuser center section is a generally circular
structure.
6. The compressor housing of claim 1
wherein the first mating surface of the midsection of the outer shell
comprises a generally
flat surface.
7. The compressor housing of claim 1
wherein the second mating surface of the midsection of the outer shell
comprises a ledge
against which an upper edge of the diffuser outer section raised second mating
projection is
engaged.
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8. A compressor housing for a compressor impeller comprising:
an outer shell including an outer section, a midsection and a center section,
with the
center section forming an inlet concentric with the compressor impeller,
a diffuser including a center section, a base section and an outer section,
the center
section having a substantially cylindrical outer edge received in a
complementary substantially
cylindrical mating surface within the outer shell center section,
the diffuser base section having a raised first mating projection for
engagement with a
first mating surface on the midsection of the outer shell,
the diffuser outer section having a raised second mating projection for
engagement with a
second mating projection for engagement with a second mating surface on the
midsection of the
outer shell,
wherein the diffuser center section and base section are formed of a first
continuous
structure and the diffuser outer section is formed of a second continuous
structure,
the outer shell midsection and the diffuser base section and outer section
form a volute
wall of the compressor housing.
9. The compressor housing of claim 8
further comprising a back plate, the back plate formed of a generally circular
structure
having a generally flat upper surface,
the diffuser base section having a generally flat lower surface for engagement
with the
generally flat upper surface of the back plate,
the back plate forming a lower volute wall portion of the compressor housing.
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10. The compressor housing of claim 8
wherein the complementary substantially cylindrical mating surface is the
outer shell
center section is located on an inner wall of the outer shell center section
and includes a ledge
against which an upper edge of the diffuser center section is engaged.
11. The compressor housing of claim 8
wherein the upper edge of the diffuser center section is a generally circular
structure.
12. The compressor housing of claim 8
wherein the first mating surface of the midsection of the outer shell
comprises a generally
flat surface.
13. The compressor housing of claim 8
wherein the second mating surface of the midsection of the outer shell
comprises a ledge
against which an upper edge of the diffuser outer section raised second mating
projection is
engaged.
14. A method of assembling a compressor housing for a compressor impeller
comprising the
steps of:
providing an outer shell including an outer section, a midsection and a center
section, the
center section forming an inlet concentric with the compressor impeller,
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attaching to the outer shell a diffuser including a center section, a base
section and an
outer section, with the center section having a generally cylindrical outer
edge received in a
complementary generally cylindrical mating surface within the outer shell
section,
the diffuser base section having a raised first mating projection engaging a
first mating
surface on the midsection of the outer shell,
the diffuser outer section having a raised second mating projection engaging a
second
mating surface on the midsection of the outer shell,
the diffuser center section and base section being formed of a first
continuous structure
and the diffuser outer section being formed of a second continuous structure,
wherein the outer shell mid section and the diffuser base section and outer
section form a
volute wall of the compressor housing.
15. The method of assembling a compressor housing of claim 14
further comprising providing a back plate, the back plate formed of a
generally circular
structure having a generally flat upper surface,
the diffuser base section having a generally flat lower surface for engagement
with the
generally flat upper surface of the back plate,
the back plate forming a lower volute wall portion of the compressor housing.
16. The method of assembling a compressor housing of claim 14
wherein the complementary substantially cylindrical mating surface in the
outer shell
center section is located on an inner wall of the outer shell center section
and includes a ledge
against which our upper edge of the diffuser center sections is engaged.
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17. The method of assembling a compressor housing of claim 14
wherein the upper edge of the diffuser center section is a generally circular
structure.
18. The method of compressor housing of claim 14
wherein the first mating surface of the mid section of the outer shell
comprised of a
generally flat surface.
19. The method of assembling a compressor housing of claim 14
wherein the second mating surface of the mid section of the outer shell
comprises a ledge
against which an upper edge of the diffuser outer section raised second mating
projection is
engaged.
20. A method of assembling a compressor housing for a compressor impeller
comprising the
steps of:
providing an outer shell including an outer section, a midsection and a center
section, the
center section forming an inlet concentric with the compressor impeller,
attaching to the outer shell a diffuser including a center section, a base
section and an
outer section, with the center section having a generally cylindrical outer
edge received in a
complementary generally cylindrical mating surface within the outer shell
center section,
the diffuser base section having a raised first mating projection engaging a
first mating
surface on the midsection of the outer shell,
the diffuser outer section having a raised second mating projection engaging a
second
mating surface on the midsection of the outer shell,
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the diffuser being formed of a unitary structure comprising the center
section, base
section and outer section,
machining the diffuser to remove material between the base section and the
outer section
to form a first continuous structure comprising the center section and the
base section and a
second continuous structure comprising the outer section,
volute wall of the compressor housing.
21. The method of assembling a compressor housing of claim 20
further comprising providing a back plate, the back plate formed of a
generally circular
structure having a generally flat upper surface,
the diffuser base section having a generally flat lower surface for engagement
with the
generally flat upper surface of the back plate,
the back plate forming a lower volute wall portion of the compressor housing.
22. The method of assembling a compressor housing of claim 20
wherein the complementary substantially cylindrical mating surface in the
outer shell
center section is located on an inner wall of the outer shell center section
and includes a ledge
against which an upper edge of the diffuser center section is engaged.
23. The method of assembling a compressor housing of claim 20
wherein the upper edge of the diffuser center section is a generally circular
structure.
24. The method of assembling a compressor housing of claim 20
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wherein the first mating surface of the midsection of the outer shell
comprises a generally
flat surface.
25. The method of assembling a compressor housing of claim 20
wherein the second mating surface of the mid section of the outer shell
comprises a ledge
against which an upper edge of the diffuser outer section raised second mating
projection is
engaged.
26. A method of assembling a compressor housing for a compressor impeller
coprising the
steps of:
providing an outer shell including an outer section, a mid section and a
center section,
attaching to the outer shell a diffuser including a center section, a base
section and an
outer section, with the center section received in a complementary mating
surface within the
outer shell center section,
the diffuser base section having a first mating surface engaging a first
mating surface on
the midsection of the outer shell,
the diffuser outer section having a second mating surface engaging a second
mating
surface on the midsection of the outer shell,
the diffuser being formed of a unitary structure comprising the center
section, base
section and outer section,
machining the diffuser to remove material from between the base section and
the outer
section to form a first continuous structure comprising the center section and
the base section and
a second continuous structure comprising the outer section,
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wherein the outer shell midsection and the diffuser base section and outer
section form a
volute wall of the compressor housing.
27. The method of assembling a compressor housing of claim 26
further comprising providing a back plate, the back plate formed of a
generally circular
structure having a generally flat upper surface,
the diffuser base section having a generally flat lower surface for engagement
with the
generally flat upper surface of the back plate,
the back plate forming a lower volute wall portion of the compressor housing.
28. The method of assembling a compressor housing of claim 26
wherein the complementary substantially cylindrical mating surface in the
outer shell
center section is located on an inner wall of the outer shell center section
is located on an inner
wall of the outer shell center section and includes a ledge against which an
upper edge of the
diffuser center section is engaged.
29. The method of assembling a compressor housing of claim 26
wherein the upper edge of the diffuser center section is a generally circular
structure.
30. The method of assembling compressor housing of claim 26
wherein the first mating surface of the mid section of the outer shell
comprises a
generally flat surface.
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31. The method of assembling a compressor housing of claim 26
wherein the second mating surface of the midsection of the outer shell
comprises a ledge
against which an upper edge of the diffuser outer section raised second mating
projection is
engaged.
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Description

CA 02578420 2007-02-08
METHOD OF DIE CASTING COMPRESSOR HOUSINGS
BACKGROUND OF THE INVENTION
The present invention relates generally to compressor housings for compressor
impellers,
and, more particularly, to a compressor housing comprised of an outer shell
and a diffuser that
together form a volute shape for the compressor housing.
Housings for compressors are typically made of cast aluminum due to the volute
shape
required in the compressor outlet duct for aerodynamic performance. Aluminum
die casting is a
very desirable process for production of such housings due to the inherent
dimensional stability
for such die cast parts. One die cast aluminum compressor housing is disclosed
in U.S. Patent
No. 6,193,463.
SUMMARY OF THE INVENTION
A compressor housing is provided for a compressor impeller. The compressor
housing
comprises an outer shell including an outer section, a midsection, and a
center section. The
midsection of the outer shell forms an upper volute wall portion of the
compressor housing, and
the center section forms an inlet for the compressor housing. A diffuser is
also provided that is
comprised of a center section, a base section, and an outer section. The
center section of the
diffuser has a substantially cylindrical outer edge received within a
complementary substantially
cylindrical mating surface in the outer shell center section. The diffuser
base section has a raised
first mating projection for engagement with the first mating surface of the
midsection of the
outer shell. The diffuser outer section has a raised second mating projection
for engagement
with a second mating surface of the midsection of the outer shell. A back
plate is also provided
that is formed of a generally circular structure. The diffuser base section
has a generally flat
lower surface for engagement with a generally flat upper surface of the back
plate. The outer
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CA 02578420 2007-02-08
shell midsection, the diffuser and the back plate form the volute wall portion
of a compressor
25 housing.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings,
Fig. 1 is a perspective view in cross section of a compressor housing assembly
in
accordance with one embodiment of the present invention;
30 Fig. 2 is a perspective view in cross section of the outer shell of the
compressor housing
in accordance with one embodiment of the present invention;
Fig. 3 is a perspective view in cross section of a diffuser as cast prior to
machining in
accordance with one embodiment of the present invention;
Fig. 4 is a perspective view in cross section of an assembled outer shell and
diffuser prior
35 to machining in accordance with one embodiment of the present invention,
and
Fig. 5 is a perspective view in cross section of an assembled outer shell and
diffuser after
machining in accordance with one embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring to Fig. 1, a compressor housing in accordance with one embodiment of
the
40 present invention is shown generally at 15. Outer shell 10 is shown as
unitary structure, usually
comprised of a die cast aluminum piece. Although traditional foundry casting
could also be
utilized, outer shell 10 includes an outer section 11, a midsection 13, and a
center section 12.
Center section 12 is seen to be generally cylindrical in form, to provide air
inlet 18. Air outlet 16
is seen to comprise the end section of a volute formed by the compressor
housing assembly 15.
45 Outer section 11 is seen to be generally circular in structure with a
peripheral surface 44
facing downwardly therefrom. The inner surface 32 of outer shell midsection 13
is seen to
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CA 02578420 2007-02-08
provide an outer wall of the volute formed by compressor housing assembly 15.
Outer shell
housing midsection 13 is also seen to include the generally flat mating
surface 34 located
adjacent outer wall 32. Outer shell housing midsection 13 also includes shelf-
like mating surface
50 40 adjacent outer wall 32. Outer shell center section 12 is further seen to
comprise an inner shell
mating surface 31 that is generally circular in nature and is formed as an
indent or shelf on the
inner surface of outer shell center section 12.
Diffuser 20 is also usually formed of an aluminum die cast structure, but
could be formed
of aluminum cast in other manners such as traditional foundry casting.
However, die casting is
55 the preferred method of forming diffuser 20. Diffuser 20 is seen to
comprise a center section 22,
which is generally cylindrical in structure, a midsection 24 extending from
center section 22.
Diffuser 20 also is comprised of outer section 25 which in Figure 1 is seen to
be spaced from
diffuser midsection 24. Diffuser outer section 25 is seen to provide a volute
inner wa1133 that
forms a portion of the volute structure provided by compressor housing
assembly 15. Diffuser
60 outer section 25 also comprises a mating projection 38 extending from
volute inner wall 33 to
engage mating surface 40 of outer shell midsection 13. Further, diffuser outer
section 25 is seen
to have a generally flat and circular upper peripheral surface 42 which is
also to seen to engage
downwardly facing peripheral surface 44 of outer section 11.
Diffuser midsection 24 includes first mating projection 28 extending upwardly
from a
65 position adjacent volute inner wall portion 26 formed by an inner surface
of diffuser base
section 24. Fist mating projection 28 of diffuser 20 is seen to engage a
generally flat
downwardly facing mating surface 34 of outer shell midsection 13.
Diffuser center section 22 is seen to be generally cylindrical in shape having
an outer
wall 30 that engages a complementary cylindrical cut portion 37 of outer shell
housing center
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CA 02578420 2007-02-08
70 section 12. Further, diffuser 20 includes an inlet mating projection 29
that engages a shelf-like
mating surface 31 of outer shell housing center section 12.
Back plate 14 is shown to be a generally flat, plate like structure having a
generally
circular outer circumference. Back plate 14 includes a generally flat upper
surface 52 adjacent
edge 54. Upper surface 52 of back plate 14 is seen to engage the lower surface
55 of diffuser
75 base section 24. Back plate 14 itself is generally comprised of a die cast
aluminum unitary piece,
but could be formed of aluminum cast in a traditional foundry manner.
Referring now to Figure 2 of the drawings, outer shell 10 is shown as an
aluminum die
cast unitary structure before finish machining. Outer shell 16 is seen to
comprise outer section
11, midsection 13, and generally cylindrical center section 12. Center section
12 is seen to form
80 air inlet 18, extending from volute section formed by outer shell 10 is
outlet 16. Midsection 13 is
seen to form on its inner surface an outer wall 32 of the volute. Outer
section 11 is seen to
include peripheral downwardly surface 44. Midsection 13 is seen to include
shelf-like mating
surface 40 as well as generally flat mating surface 34 on either side of outer
wall 32. Center
section 12 is seen to include a shelf-like mating surface 31 as well as an
inwardly formed
85 receiving surface 37 that is generally cylindrical in nature.
Referring now to Figure 3, diffuser 20 is shown as a unitary die cast
structure. Although
die casting from aluminum is the preferred manufacturing method for diffuser
20, traditional
foundry casting could also be utilized to produce the unitary aluminum
structure. Diffuser 20 is
seen to comprise outer section 25 of a generally circular configuration, base
section 24, and
90 center section 22. Center section 22 is seen to be generally cylindrical in
structure, having an
outer wa1130 and inlet mating projection 29 extending from the end of outer
wall 30. Transition
section 27 is seen to extend from diffuser base section to diffuser outer
section 25, and thereby
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CA 02578420 2009-06-02
forming the unitary diffuser 20 in an as cast addition. It is understood that
diffuser transition
section 27 is removed in a finishing operation by means such as a lathe
thereby forming diffuser
95 20 into two separate structures. One structure is comprised of center
section 22 and base section
24, and the other structure is comprised of diffiiser outer section 25.
Diffuser outer section 25 is seen to include peripheral surface 42 that is
generally flat.
Adjacent peripheral surface 42 is mating projection 38 extending upwardly and
terminating in
projection 38. Volute inner wa1133 is seen to be formed by the inner surface
of diffuser outer
100 section 25. Volute inner wa1126 is seen to be formed by a facing surface
of diffuser base section
24. Finally, diffuser center section 22 is seen to terminate at an inlet
mating projection 29 that
forms the top edge of diffuser center section 22. Outer wa1130 diffuser center
section 22 is seen
to be cylindrical in structure.
Referring now to Figure 4, diffuser 20 is seen to be fit into outer shell 10.
Such fitting
105 includes the engagement of inlet mating projection 29 against mating
surface 31 of housing
center section 12. Further, first mating projection 28 is seen to engage
generally flat mating
surface 34 of outer shell midsection 13. Mating projection 38 is seen to
engage shelf-like mating
surface 40 of housing midsection 13. Finally, peripheral surface 42 of
diffuser outer section 25
is seen to engage peripheral surface 44 of housing outer section 11. These
peripheral surfaces 42
110 and 44 are seen to be generally flat in their complementary engaging
surfaces.
Diffuser transition section 27 is seen to be present when diffuser 20 is fit
into outer shell
10. Referring to the embodiment shown Figure 5, finished machining has been
performed using
a means such as a lathe. Accordingly, in the view of Figure 5, transition
section 27 has been
removed. Accordingly, diffuser 20 is seen to comprise a unitary section of
center section 22 and
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CA 02578420 2007-02-08
115 base section 24, and a unitary outer section 25. Other components of
diffuser 20 and outer shell
are as described above for Figure 1.
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Representative Drawing