U.S. patent application number 11/356877 was filed with the patent office on 2007-08-23 for pressure load compressor diffuser.
This patent application is currently assigned to Honeywell International, Inc.. Invention is credited to Voytek Kanigowski, Steven P. Martin, Christopher O. Meade.
Application Number | 20070196206 11/356877 |
Document ID | / |
Family ID | 37963613 |
Filed Date | 2007-08-23 |
United States Patent
Application |
20070196206 |
Kind Code |
A1 |
Martin; Steven P. ; et
al. |
August 23, 2007 |
Pressure load compressor diffuser
Abstract
The present invention relates to a turbocharger compressor
diffuser loading plate that is in contact with a vaned diffuser and
that is in communication with the compressor volute. The diffuser
loading plate is pressure loaded so that it moves axially in
response to pressure thereby maintaining an effective seal of the
open side of the vaned diffuser. The present invention minimizes a
loss in compressor performance caused by movement of the compressor
housing.
Inventors: |
Martin; Steven P.; (Walnut,
CA) ; Meade; Christopher O.; (Redondo Beach, CA)
; Kanigowski; Voytek; (Fountain Valley, CA) |
Correspondence
Address: |
HONEYWELL TURBO TECHNOLOGIES
23326 HAWTHORNE BOULEVARD, SUITE #200
TORRANCE
CA
90505
US
|
Assignee: |
Honeywell International,
Inc.
|
Family ID: |
37963613 |
Appl. No.: |
11/356877 |
Filed: |
February 17, 2006 |
Current U.S.
Class: |
415/191 |
Current CPC
Class: |
F05D 2250/52 20130101;
F04D 29/444 20130101; F04D 29/083 20130101 |
Class at
Publication: |
415/191 |
International
Class: |
F01D 9/00 20060101
F01D009/00; F04D 29/54 20060101 F04D029/54 |
Claims
1. A turbocharger compressor comprising: a housing having a volute;
a backplate attached to an exterior surface of said housing; an
impeller rotatably mounted within said housing; an annular vaned
diffuser disposed in said housing between said volute and said
impeller, said vaned diffuser axially facing an axially facing
surface of said backplate; and a diffuser loading plate adjacent to
said vaned diffuser, said loading plate in communication with said
volute via a pressure port, and said diffuser loading plate
moveable in response to pressure from said volute so that said
diffuser loading plate imposes an axially directed pressure load to
provide a seal on an open end of said vaned diffuser.
2. The compressor of claim 1 further comprising a pressure loading
cavity adjacent to said diffuser loading plate and in fluid
communication with said pressure port.
3. The compressor of claim 1 wherein said vaned diffuser and said
diffuser loading plate are integral.
4. The compressor of claim 1 wherein said vaned diffuser is located
between said backplate and said diffuser loading plate.
5. The compressor of claim 1 wherein said diffuser loading plate is
located between said backplate and said vaned diffuser.
6. The compressor of claim 1 wherein said diffuser loading plate
comprises a disc.
7. A compressor diffuser assembly for placement in a fluid
passageway between a compressor impeller and a compressor volute,
said assembly comprising: an annular vaned diffuser adapted to be
placed between the volute and the impeller so that said vaned
diffuser axially faces an axially facing surface of a compressor
backplate; a diffuser loading plate adjacent to said vaned
diffuser; and a pressure port in communication with said volute and
said diffuser loading plate; said diffuser loading plate moveable
in response to pressure from said volute so that said diffuser
loading plate imposes an axially directed pressure load to provide
a seal on an open end of said vaned diffuser.
8. The assembly of claim 7 further comprising a pressure loading
cavity adjacent to said diffuser loading plate and in fluid
communication with said pressure port
9. The assembly of claim 7 wherein said vaned diffuser and said
diffuser loading plate are integral.
10. The assembly of claim 7 wherein said diffuser loading plate
comprises a disc.
11. A vaned diffuser assembly for use in a turbocharger compressor,
said assembly comprising a diffuser loading plate in contact with a
vaned diffuser, and said assembly positionable between a housing
and a backplate of the compressor.
12. The assembly of claim 11 wherein said diffuser loading plate
and said vaned diffuser are integral.
Description
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] Not Applicable.
BACKGROUND OF THE INVENTION
[0002] 1 Field of the Invention (Technical Field)
[0003] The present invention relates to turbocharger compressor
vaned diffusers, specifically to a diffuser plate that is axially
movable in response to pressure from the compressor housing volute
so that, as the compressor housing moves, an effective seal is
maintained on the open side of the compressor's vaned diffuser.
[0004] 2. Description of Related Art
[0005] Note that where the following discussion refers to a number
of publications by author(s) and year of publication, because of
recent publication dates certain publications are not to be
considered as prior art vis-a-vis the present invention. Discussion
of such publications herein is given for more complete background
and is not to be construed as an admission that such publications
are prior art for patentability determination purposes.
[0006] Turbochargers for pressurizing or boosting the intake air
stream into an internal combustion engine include an exhaust gas
turbine through which the engine's exhaust gas is routed so that
the exhaust gas turbine spins within the turbocharger housing. The
exhaust gas turbine is connected via a shaft to a radial air
compressor impeller disposed within the compressor housing so that
as the exhaust gas turbine turns, the compressor impeller also
turns within the compressor housing and causes intake air to
axially enter the compressor housing, go past the impeller, then
change direction past a diffuser before entering a compressor
housing volute. After the intake air is pressurized or boosted, it
exits the turbocharger to be mixed with fuel then sent to the
engine combustion chamber.
[0007] The diffuser in the compressor housing can either be part of
the compressor housing or it can be a separate component attached
within the compressor housing. By slowing down the air that is
taken into the compressor housing, the diffuser converts the
velocity energy to pressure energy and produces air boost pressure
in the turbocharger. The diffuser can include one or more vanes
that project outwardly from the diffuser surface and that extend in
a generally radial direction in line with the direction of air flow
coming from the compressor impeller. The vanes force the air
leaving the compressor impeller to flow in a particular direction,
reducing air flow velocity in a way that favors a particular
application demand such as a particular engine speed or torque
requirement. Thus, turbocharger compressors use vaned diffusers to
increase compressor stage efficiency.
[0008] Vane diffusers include those constructed as a separate
component of the compressor housing and that are shaped in the form
of an annular ring designed to fit against a backplate axial wall
surface. Typically, at least one pin is placed axially between the
vane diffuser and the backplate to prevent the vane diffuser from
rotating within the compressor hosing.
[0009] Typically, vaned diffusers are open sided and take advantage
of either the backplate or compressor housing to form the sealing
side of the diffuser. However, as compressor outlet pressures are
increased, the compressor housing tends to move, and the clamp load
that clamps the diffuser against the back plate is decreased
thereby impacting the effectiveness of the diffuser seal and
resulting in leakage around the diffuser. The loss of sealing
effectiveness and the resulting leakage causes a significant loss
of compressor efficiency.
[0010] Also typical in the prior art is an elastomeric O-ring that
is interposed, for example, between the vane diffuser and the
backplate to both provide an air leakage seal and to pressure load
the vane diffuser away from the backplate. This pressure loading is
used to urge the vane diffuser away from the backplate as the
compressor housing moves axially away from the backplate during
operation. Therefore, pressure loading is intended to keep the vane
diffuser in contact with the housing during such axial movement to
prevent compressor performance losses caused by air flow
restrictions between the compressor housing and the vane diffuser.
However, the O-ring energizer cannot provide both the range and
consistent degree of pressure loading that is required because the
ring force provided by the O-ring energizer decreases rapidly as
the vane diffuser is moved away from the backplate (thus effective
for only a very limited range of motion), and the known elastomers
are known to degrade and creep at high compressor operating
temperatures so that the energizer spring rate decreases over
time.
[0011] Another approach to ensure that the vane diffuser remains in
contact with the compressor housing as the compressor housing moves
during compressor operation is provided by U.S. Pat. No. 6,168,375
wherein the vaned diffuser is spring-loaded.
[0012] Other approaches to ensure for an effective seal of the vane
diffuser are desirable, particularly those that involve simple
components having few or no moveable parts.
BRIEF SUMMARY OF THE INVENTION
[0013] The present invention provides a movable diffuser loading
plate to provide a sealing surface against the open side of a
compressor vaned diffuser. Thus, an embodiment of the present
invention provides a turbocharger compressor comprising a housing
having a volute, a backplate attached to an exterior surface of the
housing, an impeller rotatably mounted within the housing, an
annular vaned diffuser disposed in the housing between the volute
and the impeller, said vaned diffuser axially facing an axially
facing surface of said backplate, and a diffuser loading plate
adjacent to the vaned diffuser, said loading plate in communication
with the volute via a pressure port, and said diffuser loading
plate moveable in response to pressure from the volute so that the
diffuser loading plate imposes an axially directed pressure load to
provide a seal on an open end of the vaned diffuser.
[0014] The compressor further comprises a pressure loading cavity
adjacent to the diffuser loading plate and in fluid communication
with the pressure port.
[0015] In an embodiment, the vaned diffuser and the diffuser
loading plate are integral.
[0016] In an embodiment, the vaned diffuser is located between the
back plate and the diffuser loading plate. In an alternative
embodiment, the diffuser loading plate is located between the
backplate and the vaned diffuser.
[0017] The diffuser loading plate may comprise a disc.
[0018] Another embodiment provides a compressor diffuser assembly
for placement in a fluid passageway between a compressor impeller
and a compressor volute, said assembly comprising an annular vaned
diffuser adapted to be placed between the volute and the impeller
so that the vaned diffuser axially faces an axially facing surface
of a compressor backplate, a diffuser loading plate adjacent to the
vaned diffuser, and a pressure port in communication with the
volute and the diffuser loading plate, said diffuser loading plate
moveable in response to pressure from the volute so that the
diffuser loading plate imposes an axially directed pressure load to
provide a seal on an open end of the vaned diffuser. The assembly
preferably further comprises a pressure loading cavity adjacent the
diffuser loading plate and in communication with the pressure
port.
[0019] In an embodiment, the vaned diffuser and the diffuser
loading plate are integral.
[0020] The diffuser loading plate preferably comprises a disc.
[0021] Still another embodiment provides a vaned diffuser assembly
for use in a turbocharger compressor, said assembly comprising a
diffuser loading plate in contact with a vaned diffuser, and said
assembly positionable between a housing and a backplate of the
compressor. The diffuser loading plate and the vaned diffuser may
be integral.
[0022] Other objects, advantages and novel features, and further
scope of applicability of the present invention will be set forth
in part in the detailed description to follow, taken in conjunction
with the accompanying drawings, and in part will become apparent to
those skilled in the art upon examination of the following, or may
be learned by practice of the invention. The objects and advantages
of the invention may be realized and attained by means of the
instrumentalities and combinations particularly pointed out in the
appended claims.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0023] The accompanying drawings, which are incorporated into, and
form a part of, the specification, illustrate one or more
embodiments of the present invention and, together with the
description, serve to explain the principles of the invention. The
drawings are only for the purpose of illustrating one or more
preferred embodiments of the invention and are not to be construed
as limiting the invention. In the drawings:
[0024] FIG. 1 is a cross section view of a turbocharger of an
embodiment of the present invention;
[0025] FIG. 2 is a close-up cross section of the compressor of the
embodiment of FIG. 1 wherein the vaned diffuser is located at the
backplate; and
[0026] FIG. 3 is a close-up cross section view of the compressor
wherein the vaned diffuser is located at the housing.
DETAILED DESCRIPTION OF THE INVENTION
[0027] The present invention provides a movable compressor diffuser
loading plate. The diffuser loading plate may be integral with a
vaned compressor diffuser so that the diffuser loading plate loads
the diffuser against the backplate or against the compressor
housing. Alternatively, the diffuser loading plate and the diffuser
may be non-integral so that the diffuser loading plate provides a
sealing surface against the open side of a vaned diffuser. In any
of these embodiments, the diffuser loading plate communicates with
the compressor outlet pressure via a pressure port. The diffuser
loading plate is free to move within the compressor stage assembly.
As the compressor outlet pressure increases, the pressure exerted
against the diffuser loading plate increases thus providing the
necessary load to provide a seal at the open side of the diffuser.
Even if the compressor housing moves, the pressure loading
maintains the sealing of the diffuser.
[0028] As used in the specification and claims herein, the terms
"a", "an", and "the" mean one or more.
[0029] Turning now to the figures, which describe a non-limiting
embodiment of the present invention that is illustrative of the
various embodiments within the scope of the present invention, FIG.
1 shows a cross-section of turbocharger 200 with exhaust gas
turbine 210 linked to impeller 110 within compressor assembly 100.
Compressor assembly 100 is shown with housing 102 connected to
backplate 106. Impeller 110 is located within compressor assembly
100 and sends intake air into housing volute 104. Intake air is
slowed down by diffuser 120 which is disposed between housing 102
and backplate 106, is shown as being annular, and axially faces an
axially facing surface of backplate 106. Diffuser 120 is a vaned
diffuser, and is shown having vanes 121. Diffuser loading plate 130
is shown disposed between housing 102 and diffuser 120.
[0030] FIG. 2 shows a close-up of the embodiment of FIG. 1. In this
embodiment, diffuser loading plate 130 is shown as being integral
with diffuser 120. Diffuser loading plate is disposed between vaned
diffuser 120 and pressure loading cavity 140 and in communication
with pressure port 142. Diffuser loading plate 130 preferably
comprises a disc that is free to axially move or "float" within
compressor assembly 100 (although other geometries or shapes are
applicable and available to the construction and design of loading
plate 130). Thus, movable diffuser loading plate 130 is loaded via
air pressure to load diffuser 120 against backplate 106.
[0031] In another embodiment, shown in FIG. 3, the orientation of
diffuser loading plate 130 and diffuser 120 is reversed so that
diffuser 120 is adjacent housing 102, and diffuser loading plate
130 is located between diffuser 120 and backplate 106. In that
embodiment, pressure loading cavity 140 and pressure port 142 are
located in backplate 106.
[0032] As noted above, utilizing the same principles wherein
diffuser loading plate 130 can move within compressor assembly 100,
and as easily visualized referring to FIG. 2, another embodiment
does not integrate diffuser loading plate 130 with diffuser 120.
Thus, diffuser 120 is located at backplate 106, and diffuser
loading plate 130 is loaded via air pressure toward diffuser 121 to
seal any gap that might otherwise exist between vanes 121 and
diffuser loading plate 130.
[0033] In yet another embodiment using the principles described
above and wherein diffuser loading plate 130 and diffuser 120 are
not integral, and as easily visualized referring to FIG. 3,
diffuser 120 is connected to housing 102. Diffuser loading plate is
located adjacent backplate 106 between diffuser 120 and backplate
106. Thus, pressure cavity 140 and pressure port 142 are disposed
at backplate 106. Again, pressure loaded diffuser loading plate
moves axially against diffuser 120 to provide effective
sealing.
[0034] In all embodiments, as compressor outlet pressure is
increased (and compressor housing 102 moves axially away from
backplate 106) pressure is increased on diffuser loading plate 130
to maintain contact/sealing of an open side of diffuser 120 thus
maintaining high compressor efficiency.
[0035] It is also understood that pressure cavity 140 may be
comprise a continuous, generally annular cavity, or may comprise
open sections arranged in an annular configuration. The geometry
and orientation of cavity 140 may vary as understood by those
skilled in the art. Pressure port 142 may likewise vary in
orientation, geometry, etc.
[0036] It is also understood that in other embodiments, loading
other than pneumatic loading, such as, but not limited to,
mechanical loading of diffuser loading plate 130, may be
utilized.
[0037] The compressor housing, vaned diffuser, and backplate, in
accordance with the present invention, are attached together
according to conventional practice and are combined with other
parts conventionally associated with turbochargers to provide a
turbocharger for internal combustion engines that incorporates the
pressure loaded compressor diffuser of the present invention. Thus,
the present invention provides for the axial movement of an
integrated diffuser loading plate/vaned diffuser combination and,
alternatively, for the axial movement of a diffuser loading plate
that is not integral to the diffuser. In all
embodiments/applications, an effective seal of the open side of a
diffuser is maintained to thereby maintain a smooth air flow
transition with the compressor housing such that improved
compressor performance is provided.
[0038] The preceding examples can be repeated with similar success
by substituting the generically or specifically described
components, mechanisms, materials, and/or operating conditions of
this invention for those used in the preceding examples.
[0039] Although the invention has been described in detail with
particular reference to these preferred embodiments, other
embodiments can achieve the same results. Variations and
modifications of the present invention will be obvious to those
skilled in the art and it is intended to cover in the appended
claims all such modifications and equivalents. The entire
disclosures of all references, applications, patents, and
publications cited above are hereby incorporated by reference.
* * * * *