U.S. patent application number 13/711205 was filed with the patent office on 2013-07-11 for compressor with compliant thrust bearing.
This patent application is currently assigned to EMERSON CLIMATE TECHNOLOGIES, INC.. The applicant listed for this patent is EMERSON CLIMATE TECHNOLOGIES, INC.. Invention is credited to Nicholas J. Altstadt, Harry B. Clendenin, Wei H. Sun.
Application Number | 20130177465 13/711205 |
Document ID | / |
Family ID | 48744054 |
Filed Date | 2013-07-11 |
United States Patent
Application |
20130177465 |
Kind Code |
A1 |
Clendenin; Harry B. ; et
al. |
July 11, 2013 |
COMPRESSOR WITH COMPLIANT THRUST BEARING
Abstract
A bearing housing may include a body portion, a hub, and a
thrust bearing. The body portion may include a radially inwardly
facing first annular surface. A structure may extend radially
outward from the body portion. The hub may extend axially from the
body portion and may include a radially inwardly facing second
annular surface adapted to rotatably support a shaft. The thrust
bearing may extend axially from the body portion and may include an
outer surface, a thrust surface, an inner surface, and an undercut
feature formed in one of the inner and outer surfaces. The undercut
feature may define a cantilevered portion of the thrust
bearing.
Inventors: |
Clendenin; Harry B.;
(Sidney, OH) ; Sun; Wei H.; (West Chester, OH)
; Altstadt; Nicholas J.; (Sidney, OH) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
EMERSON CLIMATE TECHNOLOGIES, INC.; |
Sidney |
OH |
US |
|
|
Assignee: |
EMERSON CLIMATE TECHNOLOGIES,
INC.
Sidney
OH
|
Family ID: |
48744054 |
Appl. No.: |
13/711205 |
Filed: |
December 11, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61583916 |
Jan 6, 2012 |
|
|
|
Current U.S.
Class: |
418/55.1 ;
384/420 |
Current CPC
Class: |
F04C 2240/54 20130101;
F04C 29/00 20130101; F04C 2270/16 20130101; F04C 18/0215
20130101 |
Class at
Publication: |
418/55.1 ;
384/420 |
International
Class: |
F04C 29/00 20060101
F04C029/00 |
Claims
1. A thrust bearing for a compressor having first and second
working members, the thrust bearing comprising: an axially facing
thrust surface configured to support one of the first and second
working members; a first surface adjacent said thrust surface; a
second surface adjacent said thrust surface; an annular undercut
feature formed in only one of said first and second surfaces, said
one of said first and second surfaces including a first radially
facing portion disposed axially between said thrust surface and a
first axial end of said undercut feature and a second radially
facing portion disposed adjacent a second axial end of said
undercut feature, said second radially facing portion being spaced
apart from a drive shaft bearing.
2. The thrust bearing of claim 1, wherein said first and second
surfaces are annular surfaces.
3. The thrust bearing of claim 1, wherein said undercut feature is
formed in said first surface, and wherein said first surface is
disposed radially inward relative to said second surface.
4. The thrust bearing of claim 1, wherein said undercut feature
includes an axially extending surface that is substantially
parallel to and coaxial with said first and second surfaces.
5. The thrust bearing of claim 1, wherein said undercut feature
includes a V-shaped cross section.
6. The thrust bearing of claim 1, wherein said undercut feature
includes a U-shaped cross section.
7. The thrust bearing of claim 1, wherein a radial depth of said
undercut feature is less than or equal to approximately one-fifth
an axial distance between said thrust surface and said undercut
feature.
8. The thrust bearing of claim 1, wherein a radial depth of said
undercut feature is between approximately one-fifth and
approximately two times an axial distance between said thrust
surface and said undercut feature.
9. The thrust bearing of claim 1, wherein a radial depth of said
undercut feature is between approximately two times and
approximately eight times an axial distance between said thrust
surface and said undercut feature.
10. The thrust bearing of claim 1, wherein a radial depth of said
undercut feature is more than or equal to approximately eight times
an axial distance between said thrust surface and said undercut
feature.
11. The thrust bearing of claim 1, wherein said undercut feature
includes an axial dimension of at least approximately 2.5
millimeters.
12. A bearing housing comprising: a body portion including a
radially inwardly facing first annular surface; a hub extending
axially from said body portion and including a radially inwardly
facing second annular surface adapted to rotatably support a shaft;
a thrust bearing extending axially from said body portion and
including an outer surface, an inner surface, a thrust surface
between said outer and inner surfaces, and an undercut feature
formed in one of said outer and inner surfaces, said undercut
feature defining a cantilevered portion of said thrust bearing,
said undercut feature being directly adjacent said first annular
surface.
13. The bearing housing of claim 12, wherein said undercut feature
is formed in said outer surface.
14. The bearing housing of claim 12, wherein said undercut feature
is formed in said inner surface.
15. The bearing housing of claim 14, further comprising another
undercut feature formed in said outer surface and defining another
cantilevered portion of said thrust bearing.
16. The bearing housing of claim 12, wherein said outer and inner
surfaces are annular surfaces, and said thrust surface is an
axially facing surface.
17. The bearing housing of claim 12, wherein said inner surface of
said thrust bearing and said first annular surface of said body
portion are substantially radially aligned with each other.
18. The bearing housing of claim 12, wherein a radial depth of said
undercut feature is less than or equal to approximately one-fifth
an axial distance between said thrust surface and said undercut
feature.
19. The bearing housing of claim 12, wherein a radial depth of said
undercut feature is between approximately one-fifth and
approximately two times an axial distance between said thrust
surface and said undercut feature.
20. The bearing housing of claim 12, wherein a radial depth of said
undercut feature is between approximately two times and
approximately eight times an axial distance between said thrust
surface and said undercut feature.
21. The bearing housing of claim 12, wherein a radial depth of said
undercut feature is greater than or equal to approximately eight
times an axial distance between said thrust surface and said
undercut feature.
22. The bearing housing of claim 12, wherein said hub and said
thrust bearing are integrally formed with said body portion.
23. A scroll machine comprising: a non-orbiting scroll; an orbiting
scroll engaging said non-orbiting scroll and configured to orbit
relative to said non-orbiting scroll; a drive shaft drivingly
engaging said orbiting scroll; a bearing housing including a body
portion, a hub extending axially from said body portion, and a
thrust bearing extending axially from said body portion, said hub
and said thrust bearing being integrally formed with said body
portion, said hub including a first annular surface supporting said
drive shaft, said thrust bearing including a second annular
surface, a third annular surface, and a thrust surface, said thrust
surface axially supporting said orbiting scroll, said thrust
bearing including an annular undercut feature formed in one of said
second and third annular surfaces.
24. The scroll machine of claim 23, wherein said second annular
surface is disposed radially inward relative to said third annular
surface, and wherein said second annular surface includes said
undercut feature, but said third annular surface does not include
an annular undercut feature.
25. The scroll machine of claim 23, wherein said one of the second
and third annular surfaces is substantially radially aligned with
an inner annular surface of said body portion.
26. The scroll machine of claim 23, wherein said body portion
includes a radially inwardly facing annular surface that is
directly adjacent said undercut feature.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional
Application No. 61/583,916, filed on Jan. 6, 2012. The entire
disclosure of the above application is incorporated herein by
reference.
FIELD
[0002] The present disclosure relates to a compressor having a
compliant thrust bearing.
BACKGROUND
[0003] This section provides background information related to the
present disclosure and is not necessarily prior art.
[0004] A climate-control system such as a heat-pump system, a
refrigeration system, an air conditioning system, or any other
working-fluid-circulation system may include a fluid circuit having
an outdoor heat exchanger, an indoor heat exchanger, an expansion
device disposed between the indoor and outdoor heat exchangers, and
a compressor circulating a working fluid (e.g., refrigerant or
carbon dioxide) between the indoor and outdoor heat exchangers.
Efficient and reliable operation of the compressor is desirable to
ensure that the climate-control system in which the compressor is
installed is capable of effectively and efficiently providing a
cooling and/or heating effect on demand. Furthermore, reducing wear
on components of the compressor may increase the longevity of the
compressor and the climate-control system.
SUMMARY
[0005] This section provides a general summary of the disclosure,
and is not a comprehensive disclosure of its full scope or all of
its features.
[0006] In one form, the present disclosure provides a thrust
bearing for a compressor having first and second working members.
The thrust bearing may include an axially facing thrust surface,
first and second surfaces, and an annular undercut feature. The
thrust surface may be configured to support one of the first and
second working members. The first surface may be adjacent the
thrust surface. The second surface may be adjacent the thrust
surface. In some embodiments, the undercut feature may be formed in
only one of the first and second surfaces. The one of the first and
second surfaces may include a first radially facing portion
disposed axially between the thrust surface and a first axial end
of the undercut feature and a second radially facing portion
disposed adjacent a second axial end of the undercut feature. The
second radially facing portion may be spaced apart from a drive
shaft bearing.
[0007] In other embodiments, both of the first and second surfaces
could include an undercut feature formed therein.
[0008] In some embodiments, the first and second surfaces could be
substantially coaxial, annular surfaces.
[0009] In some embodiments, the undercut feature may be formed in
the first annular surface, and the first annular surface may be
disposed radially inward relative to the second annular
surface.
[0010] In some embodiments, the undercut feature may include an
axially extending surface that is substantially parallel to and
coaxial with the first and second annular surfaces.
[0011] In some embodiments, the undercut feature may include a
V-shaped cross section. In other embodiments, the undercut feature
may include a U-shaped cross section.
[0012] In some embodiments, a radial depth of the undercut feature
may be less than or equal to approximately one-fifth of an axial
distance between said thrust surface and the undercut feature. In
other embodiments, a radial depth of the undercut feature may be
between approximately one-fifth and approximately two times an
axial distance between said thrust surface and the undercut
feature. In other embodiments, a radial depth of the undercut
feature may be between approximately two times and approximately
eight times an axial distance between said thrust surface and the
undercut feature. In other embodiments, a radial depth of the
undercut feature may be greater than or equal to approximately
eight times an axial distance between said thrust surface and the
undercut feature.
[0013] In some embodiments, the undercut feature may include an
axial dimension of at least about 7.62 millimeters. In some
embodiments, the undercut feature may include an axial dimension of
approximately 2.5 millimeters or more. The axial dimension could be
an axial distance between the thrust surface and an axially distal
edge of the undercut feature. Alternatively, the axial dimension
could be an axial distance between upper and lower edges of the
undercut feature.
[0014] In another form, the present disclosure provides a bearing
housing that may include a body portion, a hub, and a thrust
bearing. The body portion may include a radially inwardly facing
first annular surface. The hub may extend axially from the body
portion and may include a radially inwardly facing second annular
surface adapted to rotatably support a shaft. The thrust bearing
may extend axially from the body portion and may include an outer
annular surface, an axially facing thrust surface, an inner annular
surface, and an undercut feature formed in one of the inner and
outer annular surfaces. The undercut feature may define a
cantilevered portion of the thrust bearing. The undercut feature
may be directly adjacent the first annular surface.
[0015] In some embodiments, the undercut feature may be formed in
the outer annular surface. In other embodiments, the undercut
feature may be formed in the inner annular surface. In still other
embodiments, undercut features may be formed in both of the inner
and outer surfaces and may define a pair of cantilevered portions
of the thrust bearing.
[0016] In some embodiments, the undercut feature may include an
axially extending surface that is substantially parallel to and
coaxial with the inner and outer annular surfaces.
[0017] In some embodiments, the inner annular surface of the thrust
bearing and the first annular surface of the body portion may be
substantially radially aligned with each other.
[0018] In some embodiments, the hub and the thrust bearing may be
integrally formed with the body portion.
[0019] In yet another form, the present disclosure provides a
scroll machine (e.g., a scroll compressor or a scroll expander)
that may include a non-orbiting scroll, an orbiting scroll, a drive
shaft, and a bearing housing. The orbiting scroll may engage the
non-orbiting scroll and may be configured to orbit relative to the
non-orbiting scroll. The drive shaft may drivingly engage the
orbiting scroll. The bearing housing may include a body portion, a
hub extending axially from the body portion, and a thrust bearing
extending axially from the body portion. The hub and the thrust
bearing may be integrally formed with the body portion. The hub may
include a first annular surface supporting the drive shaft. The
thrust bearing may include a second annular surface, a third
annular surface, and a thrust surface. The thrust surface may
axially support the orbiting scroll. The thrust bearing may include
an annular undercut feature formed in one of the second and third
annular surfaces.
[0020] In some embodiments, the body portion may include a radially
inwardly facing annular surface that is directly adjacent the
undercut feature.
[0021] Further areas of applicability will become apparent from the
description provided herein. The description and specific examples
in this summary are intended for purposes of illustration only and
are not intended to limit the scope of the present disclosure.
DRAWINGS
[0022] The drawings described herein are for illustrative purposes
only of selected embodiments and not all possible implementations,
and are not intended to limit the scope of the present
disclosure.
[0023] FIG. 1 is a cross-sectional view of a compressor according
to the principles of the present disclosure;
[0024] FIG. 2 is a plan view of a main bearing housing of the
compressor of FIG. 1;
[0025] FIG. 3 is a cross-sectional view of the main bearing housing
of FIG. 1;
[0026] FIG. 4 is a detail view of a portion of the main bearing
housing identified as detail 4 in FIG. 3;
[0027] FIG. 5 is a cross-sectional view of the main bearing housing
and an orbiting scroll member while the orbiting scroll member is
stationary relative to the main bearing housing;
[0028] FIG. 6 is an exaggerated, schematic, partial cross-sectional
view of the main bearing housing and the orbiting scroll member of
FIG. 5 while the orbiting scroll member is orbiting relative to the
main bearing housing;
[0029] FIG. 7 is a cross-sectional view of another main bearing
housing according to the principles of the present disclosure;
[0030] FIG. 8 is a detail view of a portion of the main bearing
housing identified as detail 8 in FIG. 7;
[0031] FIG. 9 is a cross-sectional view of yet another main bearing
housing according to the principles of the present disclosure;
[0032] FIG. 10 is a detail view of a portion of the main bearing
housing identified as detail 10 in FIG. 9;
[0033] FIG. 11 is a partial cross-sectional view of yet another
main bearing housing having an undercut feature according to the
principles of the present disclosure;
[0034] FIG. 12 is a partial cross-sectional view of yet another
main bearing housing having another undercut feature according to
the principles of the present disclosure; and
[0035] FIG. 13 is a partial cross-sectional view of yet another
main bearing housing having an another undercut feature according
to the principles of the present disclosure.
[0036] Corresponding reference numerals indicate corresponding
parts throughout the several views of the drawings.
DETAILED DESCRIPTION
[0037] Example embodiments will now be described more fully with
reference to the accompanying drawings.
[0038] Example embodiments are provided so that this disclosure
will be thorough, and will fully convey the scope to those who are
skilled in the art. Numerous specific details are set forth such as
examples of specific components, devices, and methods, to provide a
thorough understanding of embodiments of the present disclosure. It
will be apparent to those skilled in the art that specific details
need not be employed, that example embodiments may be embodied in
many different forms and that neither should be construed to limit
the scope of the disclosure. In some example embodiments,
well-known processes, well-known device structures, and well-known
technologies are not described in detail.
[0039] The terminology used herein is for the purpose of describing
particular example embodiments only and is not intended to be
limiting. As used herein, the singular forms "a," "an," and "the"
may be intended to include the plural forms as well, unless the
context clearly indicates otherwise. The terms "comprises,"
"comprising," "including," and "having," are inclusive and
therefore specify the presence of stated features, integers, steps,
operations, elements, and/or components, but do not preclude the
presence or addition of one or more other features, integers,
steps, operations, elements, components, and/or groups thereof. The
method steps, processes, and operations described herein are not to
be construed as necessarily requiring their performance in the
particular order discussed or illustrated, unless specifically
identified as an order of performance. It is also to be understood
that additional or alternative steps may be employed.
[0040] When an element or layer is referred to as being "on,"
"engaged to," "connected to," or "coupled to" another element or
layer, it may be directly on, engaged, connected or coupled to the
other element or layer, or intervening elements or layers may be
present. In contrast, when an element is referred to as being
"directly on," "directly engaged to," "directly connected to," or
"directly coupled to" another element or layer, there may be no
intervening elements or layers present. Other words used to
describe the relationship between elements should be interpreted in
a like fashion (e.g., "between" versus "directly between,"
"adjacent" versus "directly adjacent," etc.). As used herein, the
term "and/or" includes any and all combinations of one or more of
the associated listed items.
[0041] Although the terms first, second, third, etc. may be used
herein to describe various elements, components, regions, layers
and/or sections, these elements, components, regions, layers and/or
sections should not be limited by these terms. These terms may be
only used to distinguish one element, component, region, layer or
section from another region, layer or section. Terms such as
"first," "second," and other numerical terms when used herein do
not imply a sequence or order unless clearly indicated by the
context. Thus, a first element, component, region, layer or section
discussed below could be termed a second element, component,
region, layer or section without departing from the teachings of
the example embodiments.
[0042] Spatially relative terms, such as "inner," "outer,"
"beneath," "below," "lower," "above," "upper," and the like, may be
used herein for ease of description to describe one element's or
feature's relationship to another element(s) or feature(s) as
illustrated in the figures. Spatially relative terms may be
intended to encompass different orientations of the device in use
or operation in addition to the orientation depicted in the
figures. For example, if the device in the figures is turned over,
elements described as "below" or "beneath" other elements or
features would then be oriented "above" the other elements or
features. Thus, the example term "below" can encompass both an
orientation of above and below. The device may be otherwise
oriented (rotated 90 degrees or at other orientations) and the
spatially relative descriptors used herein interpreted
accordingly.
[0043] With reference to FIGS. 1-6, a compressor 10 is provided
that may include a hermetic shell assembly 12, a motor assembly 14,
a compression mechanism 16, a first bearing-housing assembly 18,
and a second bearing-housing assembly 19.
[0044] The shell assembly 12 may form a compressor housing and may
include a cylindrical shell 20, an end cap 22 at an upper end
thereof, a transversely extending partition 24, and a base 26 at a
lower end thereof. The end cap 22 and the partition 24 may define a
discharge chamber 28. The partition 24 may separate the discharge
chamber 28 from a suction chamber 30. The partition 24 may include
a wear ring 31 defining a discharge passage 32 extending
therethrough to provide communication between the compression
mechanism 16 and the discharge chamber 28. A discharge fitting 34
may be attached to shell assembly 12 at an opening 36 in the end
cap 22. A discharge valve assembly 38 may be disposed within the
discharge fitting 34 and may generally prevent a reverse flow
condition through the discharge fitting 34. A suction inlet fitting
40 may be attached to shell assembly 12 at an opening 42.
[0045] The motor assembly 14 may include a motor stator 44, a rotor
46, and a drive shaft 48. The motor stator 44 may be press fit into
the shell 20. The rotor 46 may be press fit on the drive shaft 48
and may transmit rotational power to the drive shaft 48. The drive
shaft 48 may be rotatably supported by the first and second
bearing-housing assemblies 18, 19. The drive shaft 48 may include
an eccentric crank pin 50 having a flat 52 thereon.
[0046] The compression mechanism 16 may include an orbiting scroll
54 and a non-orbiting scroll 56. The orbiting scroll 54 may include
an end plate 58 having a spiral wrap 60 on an first side thereof
and an annular flat thrust surface 62 on a second side. The thrust
surface 62 may interface with the first bearing-housing assembly
18, as will be subsequently described. A cylindrical hub 64 may
project downwardly from the thrust surface 62. A drive bushing 66
may be received within the hub 64. The crank pin 50 of the drive
shaft 48 may drivingly engage the drive bushing 66. The crank pin
flat 52 may drivingly engage mating surface (not shown) of the
drive bushing 66 to provide a radially compliant driving
arrangement. An Oldham coupling 68 may be engaged with the orbiting
and non-orbiting scrolls 54, 56 to prevent relative rotation
therebetween.
[0047] The non-orbiting scroll 56 may include an end plate 70 and a
spiral wrap 72 projecting downwardly from the end plate 70. The
spiral wrap 72 may meshingly engage the spiral wrap 60 of the
orbiting scroll 54, thereby creating a series of moving fluid
pockets. The fluid pockets defined by the spiral wraps 60, 72 and
end plates 58, 70 may decrease in volume as they move from a
radially outer position (e.g., at a suction pressure) to a radially
intermediate position (e.g., at an intermediate pressure that may
be higher than the suction pressure) to a radially inner position
(e.g., at a discharge pressure that may be higher than the
intermediate pressure) throughout a compression cycle of the
compression mechanism 16.
[0048] The end plate 70 may include a discharge passage 74 and an
annular recess 76. The discharge passage 74 is in communication
with at least one of the fluid pockets at the radially inner
position and allows compressed working fluid (at or near the
discharge pressure) to flow therethrough and into the discharge
chamber 28. The annular recess 76 may at least partially receive a
floating seal assembly 78 and may cooperate with the seal assembly
78 to define an axial biasing chamber 80 therebetween. The biasing
chamber 80 may receive intermediate-pressure fluid from a fluid
pocket in the intermediate position. A pressure differential
between the intermediate-pressure fluid in the biasing chamber 80
and fluid in the suction chamber 30 exerts a net axial biasing
force on the non-orbiting scroll 56 urging the non-orbiting scroll
56 toward the orbiting scroll 54 to facilitate a sealed
relationship therebetween.
[0049] The first bearing-housing assembly 18 may include a bearing
housing 82, a bearing 84, sleeves guides or bushings 86, and
fasteners 88. The bearing housing 82 may house the bearing 84 and
support the drive shaft 48 for rotational motion relative thereto.
The bearing housing 82 may also support the orbiting scroll 54 for
orbital motion relative thereto.
[0050] As shown in FIGS. 1-3, the bearing housing 82 may include a
body 90, a plurality of legs 92, a hub 94 (FIG. 3), and a thrust
bearing 96. The body 90 may be a generally annular member having an
annular inner surface 98 (FIG. 3) defined by a longitudinal axis
A1. The inner surface 98 may define a recess 99 in which the hub 64
of the orbiting scroll 54 may extend, as shown in FIG. 5. The legs
92 may extend radially outward from the body 90 and may engage the
shell 20, as shown in FIG. 1. Each of the legs 92 may include a
corresponding foot 100 having an aperture 102 adapted to threadably
receive the fasteners 88 (FIG. 1). The non-orbiting scroll 56 may
be secured to the feet 100 by the bushings 86 and fasteners 88.
[0051] The hub 94 may be a generally annular member including an
inner surface 104 that may be coaxial with the inner surface 98 of
the body 90. The hub 94 may extend axially downward (relative to
the view shown in FIG. 3) from the body 90. The hub 94 may receive
the bearing 84 that rotatably supports the drive shaft 48.
[0052] The thrust bearing 96 may be a generally annular member
defined by the longitudinal axis A1 and extending axially upward
(relative to the view shown in FIG. 3) from the body 90. As shown
in FIGS. 2 and 3, the thrust bearing 96 may include a radially
outer surface 106, a radially inner surface 108, and a thrust
bearing surface 110. As shown in FIG. 5, the thrust bearing surface
110 may matingly engage the thrust surface 62 of the orbiting
scroll 54 and may axially support the orbiting scroll 54. A film of
lubricant may be present between the thrust bearing surface 110 and
the thrust surface 62.
[0053] As shown in FIGS. 3 and 4, an annular groove or undercut
feature 112 (FIGS. 3 and 4) may be cast, machined, and/or otherwise
formed in the inner surface 108 of the thrust bearing 96 and/or in
the inner surface 98 of the body 90. The undercut feature 112 may
include an axially extending surface 114, an upper surface 116, and
a lower surface 118. The axially extending surface 114, the upper
surface 116, and the inner surface 108 may cooperate to form an
annular cantilevered portion 120 of the thrust bearing 96. While
not shown in FIG. 3, in some embodiments, another undercut feature
could be formed in the outer surface 106 of the thrust bearing
96.
[0054] In the particular embodiment shown in FIGS. 3 and 4, the
axially extending surface 114 may be radially outwardly offset from
the inner surface 108 of the thrust bearing 96 by about two
millimeters, for example. The upper surface 116 may be axially
offset from the thrust bearing surface 110 by about four
millimeters (or about 4.08 millimeters, as shown in FIG. 4), and
the upper surface 116 may be axially offset from the lower surface
118 by about thirteen and one-quarter millimeters (or about 13.23
millimeters, as shown in FIG. 4). Radii between the upper surface
116 and the axially extending surface 114 and between the lower
surface 118 and the axially extending surface 114 may be about one
and one-half of a millimeter (1.5 millimeters), as shown in FIG. 4.
Additional dimensions (expressed in millimeters) of an exemplary
bearing housing 82 are shown in FIG. 3. The exemplary dimensions
described above and/or shown in FIGS. 3 and 4 are provided to
illustrate the scale and relative proportions of various features
of a particular embodiment of the bearing housing 82. It will be
appreciated that in other embodiments, one or more dimensions
and/or proportions could vary from the dimensions and proportions
shown in FIGS. 3 and 4.
[0055] In some embodiments, the undercut feature 112 may reduce
localized stiffness of the thrust bearing 96 at or near the inner
surface 108 and/or the thrust bearing surface 110, for example.
This may reduce contact stress in the thrust bearing 96 at or near
the inner surface 108 and/or the thrust bearing surface 110 due to
axial loading of the orbiting scroll 54 onto the thrust bearing 96
during operation of the compressor 10. In some embodiments, the
cantilevered portion 120 of the thrust bearing 96 may be compliant
and may resiliently deflect downward in response to the orbiting
scroll 54 applying a sufficiently large axial load thereon.
[0056] FIG. 6 is an exaggerated illustration of deflection of the
end plate 58 of the orbiting scroll 54 that may occur while the
orbiting scroll 54 orbits relative to the non-orbiting scroll 56
during operation of the compressor 10. As illustrated in FIG. 6,
the end plate 58 may bow or deflect to a configuration whereby the
thrust surface 62 is generally convex.
[0057] As the orbiting scroll 54 orbits about the longitudinal axis
Al, a first portion 130 of the end plate 58 may exert a larger
axial downward force on the thrust bearing 96 than a second portion
132 of the end plate that is angularly opposite (i.e.,
one-hundred-eighty degrees apart from) the first portion 130.
The-areas of the end plate 58 that are defined as the first and
second portions 130, 132 may change in an orbital pattern around
the longitudinal axis Al relative to the thrust bearing 96.
[0058] While the orbiting scroll 54 is orbiting relative to the
non-orbiting scroll 56, the end plate 58 may exert a relatively
large axial force on the thrust bearing 96 at or near the first
portion 130, and may exert a relatively small or no axial force at
all on the thrust bearing 96 at or near the second portion 132. The
reduced stiffness in the thrust bearing 96 at or near the inner
surface 108 and the thrust bearing surface 110 may allow a portion
of the cantilevered portion 120 corresponding to the first portion
130 to resiliently deflect downward under the relatively large
axial load applied at or near the first portion 130. This may at
least locally reduce stress in the thrust bearing 96 and reduce
wear on the thrust bearing surface 110 and/or on the thrust surface
62 of the orbiting scroll 54.
[0059] With reference to FIGS. 7 and 8, another bearing housing 182
will be described. The structure and function of the bearing
housing 182 may be generally similar to that of the bearing housing
82 described above apart from any exceptions noted below and/or
shown in the figures. Therefore, similar features may not be
described again in detail. The bearing housing 182 could be
incorporated into the compressor 10 in place of the bearing housing
82.
[0060] The bearing housing 182 may include a body 190, a plurality
of legs 192, a hub 194, and a thrust bearing 196. The body 190 may
be a generally annular member having an annular inner surface 198
defined by a longitudinal axis A2. The thrust bearing 196 may be a
generally annular member defined by the longitudinal axis A2 and
extending axially upward (relative to the view shown in FIG. 7)
from the body 190. The thrust bearing 196 may include a radially
outer surface 206, a radially inner surface 208, and a thrust
bearing surface 210.
[0061] A first annular groove or undercut feature 212 may be cast,
machined, and/or otherwise formed in the inner surface 208 of the
thrust bearing 196 and/or in the inner surface 198 of the body 190.
The first undercut feature 212 may include an axially extending
surface 214, an upper surface 216, and a lower surface 218. The
axially extending surface 214, the upper surface 216, and the inner
surface 208 may cooperate to form a first annular cantilevered
portion 220 of the thrust bearing 196.
[0062] A second annular groove or undercut feature 222 may be cast,
machined, or otherwise formed in the outer surface 206 of the
thrust bearing 196. The second undercut feature 222 may include an
axially extending surface 224, an upper surface 226, and a lower
surface 228. The axially extending surface 224, the upper surface
226, and the outer surface 206 may cooperate to form a second
annular cantilevered portion 230 of the thrust bearing 196.
[0063] The first and second undercut features 212, 222 may reduce
localized stiffness of the thrust bearing 196 at or near the outer
surface 206, the inner surface 208, and/or the thrust bearing
surface 210, for example. This may reduce at least local contact
stress in the thrust bearing 196 at or near the outer surface 206,
the inner surface 208, and/or the thrust bearing surface 210 due to
axial loading of the orbiting scroll 54 onto the thrust bearing 196
during operation of the compressor 10. In some embodiments, one or
both of the first and second cantilevered portions 220, 230 of the
thrust bearing 196 may be compliant and resiliently deflect
downward in response to the orbiting scroll 54 applying a
sufficiently large axial load thereon.
[0064] FIGS. 7 and 8 illustrate dimensions (in millimeters) of an
exemplary embodiment of the bearing housing 182. The exemplary
dimensions are provided to illustrate the scale and relative
proportions of various features of a particular embodiment of the
bearing housing 182. It will be appreciated that in other
embodiments, one or more dimensions and/or proportions could vary
from the dimensions and proportions shown in FIGS. 7 and 8. For
example, in some embodiments, an axial dimension of either or both
of the first and second undercut features 212, 222 may include an
axial dimension of at least about 7.62 millimeters. Although, in
other embodiments, either or both of the first and second undercut
features 212, 222 may include an axial dimension of less than 7.62
millimeters.
[0065] With reference to FIGS. 9 and 10, another bearing housing
282 will be described. The structure and function of the bearing
housing 282 may be substantially identical to that of the bearing
housing 182 described above apart from any exceptions noted below
and/or shown in the figures. Therefore, similar features may not be
described again in detail. The bearing housing 282 could be
incorporated into the compressor 10 in place of the bearing housing
82, 182.
[0066] Like the bearing housing 182, the bearing housing 282 may
include a thrust bearing 296 that extends axially upward (relative
to the view shown in FIG. 9) from a body 290. The thrust bearing
296 may include a radially outer surface 306, a radially inner
surface 308, and a thrust bearing surface 310. A first annular
groove or undercut feature 312 may be formed in the inner surface
308 of the thrust bearing 296 and/or in an inner surface 298 of the
body 290. A second annular groove or undercut feature 322 may be
formed in the outer surface 306 of the thrust bearing 296.
[0067] FIGS. 9 and 10 illustrate dimensions (in millimeters) of an
exemplary embodiment of the bearing housing 282. The exemplary
dimensions are provided to illustrate the scale and relative
proportions of various features of a particular embodiment of the
bearing housing 282. It will be appreciated that in other
embodiments, one or more dimensions and/or proportions could vary
from the dimensions and proportions shown in FIGS. 9 and 10.
[0068] With reference to FIG. 11, another thrust bearing 496 will
be described. The structure and function of the thrust bearing 496
may be substantially similar to that of any of the thrust bearings
96, 196, 296 described above apart from any exceptions noted below
and/or shown in the figures. Therefore, similar features may not be
described again in detail. The thrust bearing 496 could be
incorporated into any of the bearing housings 82, 182, 282
described above, for example.
[0069] The thrust bearing 496 may include an annular surface 507
and a thrust bearing surface 510. The annular surface 507 shown in
FIG. 11 could be either a radially inner surface (e.g., similar to
the inner surfaces 108, 208, 308) or a radially outer surface
(e.g., similar to the outer surfaces 106, 206, 306). An undercut
feature 512 may be formed in the annular surface 507. The undercut
feature 512 may be generally V-shaped and may include an upper
surface 516, a lower surface 518, and an apex 520. An angle between
the upper and lower surfaces 516, 518 may be less than or equal to
ninety degrees. The undercut feature 512 may form a cantilevered
portion 530 of the thrust bearing 496. In some embodiments, a
radial depth of the apex 520 relative to the annular surface 507
may be substantially greater than an axial distance between an
upper end 517 of the upper surface 516 and the thrust bearing
surface 510. This may further reduce at least local stiffness in
the thrust bearing 496 and may facilitate additional compliance or
resilient deflection of the cantilevered portion 530.
[0070] It will be appreciated that in some embodiments, the
specific shape and proportions of the undercut feature 512 may
differ from that described above. For example, in some embodiments,
the undercut feature 512 could be asymmetrical. That is, one of the
upper and lower surfaces 516, 518 may be angled more or less than
the other of the upper and lower surfaces 516, 518 relative to the
longitudinal axis A1, A2, A3 of the bearing housing 82, 182, 282.
In some embodiments, the lower surface 518 could be substantially
parallel to the longitudinal axis A1, A2, A3. Additionally or
alternatively, one of the upper and lower surfaces 516, 518 may be
longer or shorter than the other of the upper and lower surfaces
516, 518.
[0071] With reference to FIG. 12, another thrust bearing 596 will
be described. The structure and function of the thrust bearing 596
may be substantially similar to that of any of the thrust bearings
96, 196, 296, 496 described above apart from any exceptions noted
below and/or shown in the figures. Therefore, similar features may
not be described again in detail. The thrust bearing 596 could be
incorporated into any of the bearing housings 82, 182, 282
described above, for example.
[0072] The thrust bearing 596 may include an annular surface 607
and a thrust bearing surface 610. The annular surface 607 shown in
FIG. 12 could be either a radially inner surface (e.g., similar to
the inner surfaces 108, 208, 308) or a radially outer surface
(e.g., similar to the outer surfaces 106, 206, 306). An undercut
feature 612 may be formed in the annular surface 607. The undercut
feature 612 may be generally V-shaped and may include an upper
surface 616, a lower surface 618, and an apex 620. An angle between
the upper and lower surfaces 616, 618 may be greater than or equal
to ninety degrees. The undercut feature 612 may form a cantilevered
portion 630 of the thrust bearing 596. A radial depth of the
undercut feature 612 may be substantially more shallow than the
radial depth of the undercut feature 512 shown in FIG. 11.
[0073] With reference to FIG. 13, another thrust bearing 696 will
be described. The structure and function of the thrust bearing 696
may be substantially similar to that of any of the thrust bearings
96, 196, 296, 496, 596 described above apart from any exceptions
noted below and/or shown in the figures. Therefore, similar
features may not be described again in detail. The thrust bearing
696 could be incorporated into any of the bearing housings 82, 182,
282 described above, for example.
[0074] The thrust bearing 696 may include an annular surface 707
and a thrust bearing surface 710. The annular surface 707 shown in
FIG. 13 could be either a radially inner surface (e.g., similar to
the inner surfaces 108, 208, 308) or a radially outer surface
(e.g., similar to the outer surfaces 106, 206, 306). An undercut
feature 712 may be formed in the annular surface 707. The undercut
feature 712 may include an upper surface 716, a lower surface 718,
and an axially extending surface 720. The undercut feature 712 can
be generally U-shaped. The upper and lower surfaces 716, 718 may be
substantially parallel to each other and the thrust bearing surface
710 and may be substantially perpendicular to the axially extending
surface 720. The undercut feature 712 may form a cantilevered
portion 730 of the thrust bearing 696. In some embodiments, a
radial depth of the axially extending surface 720 relative to the
annular surface 707 may be approximately equal to an axial distance
between the upper surface 716 and the thrust bearing surface 710.
In other embodiments, the radial depth of the axially extending
surface 720 relative to the annular surface 707 may be less than or
greater than the axial distance between the upper surface 716 and
the thrust bearing surface 710.
[0075] It will be appreciated that in some embodiments, the
specific shape and proportions of the undercut feature 712 may
differ from that described above. For example, in some embodiments,
the undercut feature 712 could be formed such that the surface 720
has a curved or semicircular cross-sectional profile. In some
embodiments, an entire cross-sectional profile of the undercut
feature 712 could be curved or semicircular. In some embodiments,
the upper and/or lower surfaces 716, 718 could be angled relative
to the longitudinal axis A1, A2, A3.
[0076] The foregoing description of the embodiments has been
provided for purposes of illustration and description. It is not
intended to be exhaustive or to limit the disclosure. For example,
the sizes, proportions, shapes, and/or configurations of the thrust
bearings 96, 196, 296, 496, 596, 696 and/or the undercut features
112, 212, 222, 312, 322, 520, 620, 720 described above could be
modified or varied from the sizes, proportions, shapes, and/or
configurations described above and/or shown in the figures to suit
a given application. Furthermore, individual elements or features
of a particular embodiment are generally not limited to that
particular embodiment, but, where applicable, are interchangeable
and can be used in a selected embodiment, even if not specifically
shown or described. The same may also be varied in many ways. Such
modifications and variations are not to be regarded as a departure
from the disclosure, and all such modifications and variations are
intended to be included within the scope of the disclosure.
* * * * *