U.S. patent application number 16/779020 was filed with the patent office on 2021-08-05 for compressor 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 Jason P. LOCHNER, William E. MCKINNEY, James A. SCHAEFER.
Application Number | 20210239113 16/779020 |
Document ID | / |
Family ID | 1000004644804 |
Filed Date | 2021-08-05 |
United States Patent
Application |
20210239113 |
Kind Code |
A1 |
SCHAEFER; James A. ; et
al. |
August 5, 2021 |
Compressor Bearing
Abstract
A compressor may include a shell assembly, a first scroll, a
second scroll, a driveshaft, and a bearing. The first scroll
includes a first end plate and a first spiral wrap extending from
the first end plate. The second scroll includes a second end plate
and a second spiral wrap extending from the second end plate. The
spiral wraps engage each other to form fluid pockets. The
driveshaft may engage one of the scrolls. The bearing supports the
driveshaft for rotation relative to the shell assembly. The bearing
includes first and second axial ends and an aperture extending
through the first and second axial ends. The driveshaft extends
through the aperture. The aperture is defined by an inner
diametrical surface of the bearing. The inner diametrical surface
may include a tapered portion that extends radially outward as the
tapered portion extends axially toward the first axial end of the
bearing.
Inventors: |
SCHAEFER; James A.; (Troy,
OH) ; LOCHNER; Jason P.; (Union, OH) ;
MCKINNEY; William E.; (Sidney, OH) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Emerson Climate Technologies, Inc. |
Sidney |
OH |
US |
|
|
Assignee: |
Emerson Climate Technologies,
Inc.
Sidney
OH
|
Family ID: |
1000004644804 |
Appl. No.: |
16/779020 |
Filed: |
January 31, 2020 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F04C 2240/601 20130101;
F04C 18/0215 20130101; F04C 29/0057 20130101; F04C 2240/52
20130101; F04C 2/025 20130101; F04C 2240/50 20130101 |
International
Class: |
F04C 2/02 20060101
F04C002/02; F04C 18/02 20060101 F04C018/02; F04C 29/00 20060101
F04C029/00 |
Claims
1. A compressor comprising: a shell assembly; a first scroll
disposed within the shell assembly and including a first end plate
and a first spiral wrap extending from the first end plate; a
second scroll including a second end plate and a second spiral wrap
extending from the second end plate, wherein the first and second
spiral wraps meshing engage each other to form moving fluid pockets
therebetween; a driveshaft drivingly engaging one of the first and
second scrolls; and a bearing supporting the driveshaft for
rotation relative to the shell assembly, wherein: the bearing
includes a first axial end, a second axial end, and an aperture
extending through the first and second axial ends, the driveshaft
extends through the aperture, the aperture is defined by an inner
diametrical surface of the bearing, the inner diametrical surface
including a tapered portion that extends radially outward as the
tapered portion extends axially toward the first axial end of the
bearing, and the inner diametrical surface includes a straight
portion disposed axially between the tapered portion and the second
axial end of the bearing, wherein the tapered portion is angled
relative to the straight portion.
2. The compressor of claim 1, wherein the first axial end of the
bearing is disposed axially between the second scroll and the
second axial end of the bearing.
3. (canceled)
4. The compressor of claim 2, wherein the bearing is a bi-metal
bearing.
5. The compressor of claim 4, wherein the bearing includes an
aluminum cladding.
6. The compressor of claim 1, wherein the driveshaft includes a
concentric portion and an eccentric crank pin extending from an
axial end of the concentric portion.
7. The compressor of claim 6, wherein the bearing supports the
concentric portion, and wherein the eccentric crank pin is disposed
axially between the bearing and the second end plate.
8. The compressor of claim 7, further comprising another bearing
supporting the concentric portion of the driveshaft.
9. The compressor of claim 1, further comprising a motor assembly
disposed within the shell assembly and drivingly engaging the
driveshaft.
10. The compressor of claim 1, further comprising a bearing housing
fixed to the shell assembly, wherein the bearing is disposed within
the bearing housing.
11. A compressor comprising: a first scroll including a first end
plate and a first spiral wrap extending from the first end plate; a
second scroll including a second end plate and a second spiral wrap
extending from the second end plate, wherein the first and second
spiral wraps meshing engage each other to form moving fluid pockets
therebetween; a driveshaft drivingly engaging the second scroll;
and a bearing housing assembly supporting the driveshaft for
rotation, the bearing housing assembly including a fixed bearing
housing and a bearing disposed within the bearing housing, wherein:
the bearing housing supports the second scroll, the bearing
includes a first axial end, a second axial end, and an aperture
extending through the first and second axial ends, the driveshaft
extends through the aperture, the aperture is defined by an inner
diametrical surface of the bearing, and the inner diametrical
surface including a tapered portion that extends radially outward
as the tapered portion extends axially toward the first axial end
of the bearing.
12. The compressor of claim 11, wherein the first axial end of the
bearing is disposed axially between the second scroll and the
second axial end of the bearing.
13. The compressor of claim 12, wherein the inner diametrical
surface includes a straight portion disposed axially between the
tapered portion and the second axial end of the bearing, wherein
the tapered portion is angled relative to the straight portion.
14. The compressor of claim 13, wherein the driveshaft includes a
concentric portion and an eccentric crank pin extending from an
axial end of the concentric portion.
15. The compressor of claim 14, wherein the bearing supports the
concentric portion, and wherein the eccentric crank pin is disposed
axially between the bearing and the second end plate.
16. The compressor of claim 15, further comprising another bearing
supporting the concentric portion of the driveshaft.
17. The compressor of claim 16, wherein the bearing is a bi-metal
bearing.
18. The compressor of claim 17, wherein the bearing includes an
aluminum cladding.
19. The compressor of claim 11, further comprising a motor assembly
drivingly engaging the driveshaft.
Description
FIELD
[0001] The present disclosure relates to a compressor, and more
particularly, to a compressor bearing.
BACKGROUND
[0002] This section provides background information related to the
present disclosure and is not necessarily prior art.
[0003] Heat-pump systems, air-conditioning systems, and other
working-fluid-circulation systems 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 heat-pump system in which the
compressor is installed is capable of effectively and efficiently
providing a cooling and/or heating effect on demand.
SUMMARY
[0004] This section provides a general summary of the disclosure,
and is not a comprehensive disclosure of its full scope or all of
its features.
[0005] The present disclosure provides a compressor that may
include a shell assembly, a first scroll, a second scroll, a
driveshaft, and a bearing. The first scroll may be disposed within
the shell assembly and may include a first end plate and a first
spiral wrap extending from the first end plate. The second scroll
may include a second end plate and a second spiral wrap extending
from the second end plate. The first and second spiral wraps
meshing engage each other to form moving fluid pockets
therebetween. The driveshaft may drivingly engage one of the first
and second scrolls. The bearing may support the driveshaft for
rotation relative to the shell assembly. The bearing includes a
first axial end, a second axial end, and an aperture extending
through the first and second axial ends. The driveshaft extends
through the aperture. The aperture is defined by an inner
diametrical surface of the bearing. The inner diametrical surface
may include a tapered portion that extends radially outward as the
tapered portion extends axially toward the first axial end of the
bearing.
[0006] In some configurations of the compressor of the above
paragraph, the first axial end of the bearing is disposed axially
between the second scroll and the second axial end of the
bearing.
[0007] In some configurations of the compressor of either of the
above paragraphs, the inner diametrical surface includes a straight
portion disposed axially between the tapered portion and the second
axial end of the bearing. The tapered portion is angled relative to
the straight portion.
[0008] In some configurations of the compressor of any one or more
of the above paragraphs, the bearing is a bi-metal bearing.
[0009] In some configurations of the compressor of any one or more
of the above paragraphs, the bearing includes an aluminum
cladding.
[0010] In some configurations of the compressor of any one or more
of the above paragraphs, the driveshaft includes a concentric
portion and an eccentric crank pin extending from an axial end of
the concentric portion.
[0011] In some configurations of the compressor of any one or more
of the above paragraphs, the bearing supports the concentric
portion, and wherein the eccentric crank pin is disposed axially
between the bearing and the second end plate.
[0012] In some configurations, the compressor of any one or more of
the above paragraphs includes another bearing supporting the
concentric portion of the driveshaft.
[0013] In some configurations, the compressor of any of the above
paragraphs includes a motor assembly disposed within the shell
assembly and drivingly engaging the driveshaft.
[0014] In some configurations, the compressor of any one or more of
the above paragraphs includes a bearing housing fixed to the shell
assembly, wherein the bearing is disposed within the bearing
housing.
[0015] In another form, the present disclosure provides a
compressor that may include a first scroll, a second scroll, a
driveshaft, and a bearing housing assembly. The first scroll may
include a first end plate and a first spiral wrap extending from
the first end plate. The second scroll may include a second end
plate and a second spiral wrap extending from the second end plate.
The first and second spiral wraps may meshing engage each other to
form moving fluid pockets therebetween. The driveshaft may
drivingly engaging the second scroll. The bearing housing assembly
may support the driveshaft for rotation. The bearing housing
assembly may include a fixed bearing housing and a bearing disposed
within the bearing housing. The bearing housing may support the
second scroll. The bearing includes a first axial end, a second
axial end, and an aperture extending through the first and second
axial ends. The driveshaft extends through the aperture. The
aperture is defined by an inner diametrical surface of the bearing.
The inner diametrical surface may include a tapered portion that
extends radially outward as the tapered portion extends axially
toward the first axial end of the bearing.
[0016] In some configurations of the compressor of the above
paragraph, the first axial end of the bearing is disposed axially
between the second scroll and the second axial end of the
bearing.
[0017] In some configurations of the compressor of either of the
above paragraphs, the inner diametrical surface includes a straight
portion disposed axially between the tapered portion and the second
axial end of the bearing, wherein the tapered portion is angled
relative to the straight portion.
[0018] In some configurations of the compressor of any one or more
of the above paragraphs, the driveshaft includes a concentric
portion and an eccentric crank pin extending from an axial end of
the concentric portion.
[0019] In some configurations of the compressor of any one or more
of the above paragraphs, the bearing supports the concentric
portion. The eccentric crank pin may be disposed axially between
the bearing and the second end plate.
[0020] In some configurations, the compressor of any one or more of
the above paragraphs includes another bearing supporting the
concentric portion of the driveshaft.
[0021] In some configurations of the compressor of any one or more
of the above paragraphs, the bearing is a bi-metal bearing.
[0022] In some configurations of the compressor of any one or more
of the above paragraphs, the bearing includes an aluminum
cladding.
[0023] In some configurations, the compressor of any one or more of
the above paragraphs includes a motor assembly drivingly engaging
the driveshaft.
[0024] 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
[0025] 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.
[0026] FIG. 1 is a cross-sectional view of a compressor according
to the principles of the present disclosure;
[0027] FIG. 2 is a schematic cross-sectional view of a driveshaft
and first and second bearings of the compressor of FIG. 1; and
[0028] FIG. 3 is a schematic cross-sectional view of the first
bearing.
[0029] Corresponding reference numerals indicate corresponding
parts throughout the several views of the drawings.
DETAILED DESCRIPTION
[0030] Example embodiments will now be described more fully with
reference to the accompanying drawings.
[0031] 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.
[0032] 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.
[0033] 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.
[0034] 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.
[0035] 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 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.
[0036] With reference to FIG. 1, a compressor 26 is provided that
may include a hermetic shell assembly 36, a first bearing housing
assembly 38, a second bearing housing assembly 39, a motor assembly
40, a driveshaft 41, a compression mechanism 42, and a seal
assembly 44. The compressor 26 may compress a working fluid (e.g.,
a refrigerant) and circulate the working fluid throughout a
vapor-compression system, for example.
[0037] The shell assembly 36 may form a compressor housing and may
include a cylindrical shell 54, an end cap 56 at an upper end
thereof, a transversely extending partition 58, and a base 60 at a
lower end thereof. The end cap 56 and the partition 58 may define a
discharge chamber 62. The partition 58 may separate the discharge
chamber 62 from a suction chamber 63. The partition 58 may include
a wear ring 64 and a discharge passage 65 extending therethrough to
provide communication between the compression mechanism 42 and the
discharge chamber 62. A discharge fitting 46 may be attached to
shell assembly 36 at an opening 66 in the end cap 56. The discharge
valve assembly 48 can be disposed within the discharge fitting 46
and may generally prevent a reverse flow condition. A suction inlet
fitting 50 may be attached to shell assembly 36 at an opening
68.
[0038] The first bearing housing assembly 38 may be fixed relative
to the shell 54 and may include a main bearing housing 70, a first
bearing 72, sleeves guides or bushings 74, and fasteners 76. The
main bearing housing 70 may house the first bearing 72 therein and
may define an annular flat thrust bearing surface 78 on an axial
end surface thereof. The main bearing housing 70 may include
apertures 80 extending therethrough and receiving the fastener
assemblies 76. The second bearing housing assembly 39 may be fixed
relative to the shell 54 and may include a lower bearing housing
71, a second bearing 73.
[0039] The motor assembly 40 may include a motor stator 82 and a
rotor 84. The motor stator 82 may be press fit into the shell 54.
The rotor 84 may be press fit on the driveshaft 41 and may transmit
rotational power to the driveshaft 41. The driveshaft 41 may be
rotatably supported within the first and second bearing housing
assemblies 38, 39. The driveshaft 41 may include a concentric
portion 87 and an eccentric crank pin 88 having a flat 90 thereon.
The first and second bearings 72, 73 may support (i.e., contact)
the concentric portion 87 of the driveshaft 41 for rotation
relative to the shell assembly 36. In the configuration shown in
FIG. 1, the rotor 84 is disposed between the first and second
bearings 72, 73 in an axial direction (i.e., a direction along a
rotational axis of the driveshaft 41).
[0040] The compression mechanism 42 may include an orbiting scroll
92 and a non-orbiting scroll 94. The orbiting scroll 92 may include
an end plate 96 having a spiral wrap 98 on an upper surface thereof
and an annular flat thrust surface 100 on a lower surface. The
thrust surface 100 may interface with the annular flat thrust
bearing surface 78 on the main bearing housing 70. A cylindrical
hub 102 may project downwardly from thrust surface 100 and may
include a drive bushing 104 disposed therein. The drive bushing 104
may include an inner bore 105 in which the crank pin 88 is
drivingly disposed. The crank pin flat 90 may drivingly engage a
flat surface in a portion of the inner bore 105 to provide a
radially compliant driving arrangement. An Oldham coupling 106 may
be engaged with the orbiting and non-orbiting scrolls 92, 94 to
prevent relative rotation therebetween.
[0041] The non-orbiting scroll 94 may include an end plate 108 and
a spiral wrap 110 projecting downwardly from the end plate 108. The
spiral wrap 110 may meshingly engage the spiral wrap 98 of the
orbiting scroll 92, thereby creating a series of moving fluid
pockets. The fluid pockets defined by the spiral wraps 98, 110 may
decrease in volume as they move from a radially outer position (at
a suction pressure) to a radially intermediate position (at an
intermediate pressure) to a radially inner position (at a discharge
pressure) throughout a compression cycle of the compression
mechanism 42.
[0042] The end plate 108 may include a discharge passage 112, a
discharge recess 114, an intermediate passage 116, and an annular
recess 118. The discharge passage 112 is in communication with one
of the fluid pockets at the radially inner position and allows
compressed working fluid (at the discharge pressure) to flow
through the discharge recess 114 and into the discharge chamber 62.
The intermediate passage 116 may provide communication between one
of the fluid pockets at the radially intermediate position and the
annular recess 118. The annular recess 118 may encircle the
discharge recess 114 and may be substantially concentric therewith.
The annular recess 118 may include an inner surface 119 and an
outer surface 121.
[0043] The annular recess 118 may at least partially receive the
seal assembly 44 and may cooperate with the seal assembly 44 to
define an axial biasing chamber 120 therebetween. The biasing
chamber 120 receives fluid from the fluid pocket in the
intermediate position through the intermediate passage 116. A
pressure differential between the intermediate-pressure fluid in
the biasing chamber 120 and fluid in the suction chamber 63 exerts
a net axial biasing force on the non-orbiting scroll 94 urging the
non-orbiting scroll 94 toward the orbiting scroll 92. In this
manner, the tips of the spiral wrap 110 of the non-orbiting scroll
94 are urged into sealing engagement with the end plate 96 of the
orbiting scroll 92 and the end plate 108 of the non-orbiting scroll
94 is urged into sealing engagement with the tips of the spiral
wrap 98 of the orbiting scroll 92.
[0044] Referring now to FIGS. 2 and 3, the first and second
bearings 72, 73 are annular members that support the driveshaft 41
for rotation during operation of the compressor 26. Either or both
of the first and second bearings 72, 73 could be bi-metal aluminum
bearings (e.g., the first bearing 72 is shown in FIG. 3 with a
steel substrate 140 with an aluminum cladding 142 or plating). In
some embodiments, either or both of the first and second bearings
72, 73 could be formed from any other metal(s), polymer(s), or any
combination of metal(s) and polymer(s), etc. The first bearing 72
includes an aperture 130 defining an inner diametrical surface 131
of the first bearing 72. The aperture 130 defines a rotational axis
R of the driveshaft 41 and extends through a first axial end 132
and a second axial end 134 of the first bearing 72. The driveshaft
41 extends through the aperture 130.
[0045] The inner diametrical surface 131 of the first bearing 72
may include a generally straight portion 136 and a tapered portion
138. The tapered portion 138 extends radially outward from the
straight portion 136 as the tapered portion 138 extends axially
toward the first axial end 132 of the first bearing 72. The tapered
portion 138 may be oriented at an angle A relative to the straight
portion 136. The tapered portion 138 may have a length L (extending
in an axial direction) from the first axial end 132 to an axial end
of the straight portion 136. The tapered portion 138 can be
machined, coined, or otherwise formed into the inner diametrical
surface 131. While the tapered portion 138 is shown in FIGS. 2 and
3 as having a constant slope over the length L, in some
embodiments, the tapered portion 138 could have a non-constant
slope over the length L (e.g., the tapered portion 138 could have a
curved cross section and/or a cross section with multiple segments
with differing slopes).
[0046] During operation of the compressor 26, the driveshaft 41 may
deflect or bend (an exaggerated shaft deflection is shown in FIG.
2). Such deflection causes increased edge-loading on prior-art
bearings, which can lead to undesirable wear on such bearings
(particularly on bearings with an aluminum substrate or cladding).
The tapered portion 138 of the first bearing 72 of the present
application reduces edge-loading and associated wear, and can
prolong the usable life of the bearing 72 (especially in
embodiments where the bearing 72 is a bi-metal aluminum bearing).
In addition to reducing wear, the tapered portion 138 may reduce
friction between the bearing 72 and the driveshaft 41 by
distributing the load more favorably, which may result in an
improved oil film layer on the bearing 72. This reduction in
friction and improved oil film layer can improve the efficiency of
the compressor 26.
[0047] The angle A and length L of the tapered portion 138 may be
selected to substantially match an angle at which the driveshaft 41
deflects during operation of the motor assembly 40 at a selected
rotational speed (or range of speeds) and/or under selected load
conditions. In addition to motor speed and load, the amount of
deflection may depend on the stiffness of the driveshaft 41.
Testing and/or finite-element-analysis can be conducted to
determine the amount of driveshaft deflection and the dimensions of
the angle A and length L. It should be understood that the angle A
shown in FIGS. 2 and 3 is exaggerated for illustration purposes and
is not necessarily drawn to-scale. That is, the angle A may be
quite small. In one example, the angle A may be selected such that
the tapered portion 138 extends radially outward by about 0.25
millimeters (250 microns) or less over the length L.
[0048] In some configurations, the entire inner diametrical surface
131 could be tapered--i.e., the tapered portion 138 could extend
from the first axial end 132 to the second axial end 134 of the
first bearing 72. In some configurations, the first bearing 72
could include a second tapered portion (similar to the tapered
portion 138) formed adjacent to the second axial end 134 such that
the straight portion 136 could be disposed between the tapered
portion 138 at the first axial end 132 and the second tapered
portion at the second axial end 134. In some configurations, the
first bearing 72 could include a tapered portion only at the second
axial end 134. In some configurations, the second bearing 73 could
include one or more tapered portions (like the tapered portion 138)
at either or both axial ends of the second bearing 73. In other
configurations, the inner diametrical surface of the second bearing
73 may be entirely straight (like the straight portion 136).
[0049] 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. 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 variations are not to be regarded as a departure
from the disclosure, and all such modifications are intended to be
included within the scope of the disclosure.
* * * * *