U.S. patent application number 15/869151 was filed with the patent office on 2018-07-12 for fluid compressor.
This patent application is currently assigned to Bristol Compressors International, LLC. The applicant listed for this patent is Bristol Compressors International, LLC. Invention is credited to Kevin Mumpower, Nicholas Sweet.
Application Number | 20180195511 15/869151 |
Document ID | / |
Family ID | 62782275 |
Filed Date | 2018-07-12 |
United States Patent
Application |
20180195511 |
Kind Code |
A1 |
Mumpower; Kevin ; et
al. |
July 12, 2018 |
FLUID COMPRESSOR
Abstract
A fluid compressor includes a housing, a compression chamber,
and a shaft including two vanes that each extend from the shaft to
contact an inner surface of the compression chamber. The shaft,
vanes, and inner surface of the compression chamber define at least
two suction pockets and at least two discharge compression pockets
arranged around a perimeter of the shaft. Each suction pocket is
between two discharge pockets and each discharge pocket is between
two suction pockets.
Inventors: |
Mumpower; Kevin; (Bristol,
VA) ; Sweet; Nicholas; (Bristol, VA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Bristol Compressors International, LLC |
Bristol |
VA |
US |
|
|
Assignee: |
Bristol Compressors International,
LLC
Bristol
VA
|
Family ID: |
62782275 |
Appl. No.: |
15/869151 |
Filed: |
January 12, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62445297 |
Jan 12, 2017 |
|
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|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F04C 29/12 20130101;
F04C 2240/20 20130101; F04C 29/023 20130101; F04C 29/045 20130101;
F04C 29/128 20130101; F04C 18/3446 20130101; F04C 2240/603
20130101; F04C 2240/40 20130101; F04C 2210/26 20130101 |
International
Class: |
F04C 18/344 20060101
F04C018/344; F04C 29/12 20060101 F04C029/12; F04C 29/02 20060101
F04C029/02 |
Claims
1. A fluid compressor comprising: a housing; a compression chamber;
and a shaft including two vanes that each extend from the shaft to
contact an inner surface of the compression chamber, the shaft,
vanes, and as surface of the compression chamber defining at least
two suction pockets and at least two discharge compression pockets
arranged around a perimeter of the shaft, each suction pocket being
between two discharge pockets and each discharge pocket being
between two suction pockets.
2. The fluid compressor as set forth in claim 1, further
comprising: discharge valves on a compression chamber cover
plate.
3. The fluid compressor as set forth in claim 1, further
comprising: discharge valves on a bearing hub.
4. The fluid compressor as set forth in claim 1, wherein the shaft
rotates symmetrically around a shaft centerline.
5. The fluid compressor as set forth in claim 1, wherein the motor
is fixed directly to an inner surface of the housing.
6. The fluid compressor as set forth in claim 1, wherein the shaft
includes an off center oil passage that runs from a top to a bottom
of the shaft.
7. The fluid compressor as set forth in claim 6, wherein the bottom
of the shaft extends into an oil sump within a lower bearing.
8. The fluid compressor as set forth in claim 1, wherein the
compressor includes exactly two discharge pockets and exactly two
suction pockets.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority under 35 U.S.C. .sctn.
119(e) to U.S. application Ser. No. 62/445,297, filed Jan. 12,
2017. This application is incorporated by reference herein in its
entirety.
BACKGROUND OF THE INVENTION
[0002] This application relates to various improvements in
structures for fluid compressors.
[0003] Refrigerant compressors are utilized to compress a
refrigerant for use in a refrigerant cycle.
[0004] In conventional rotary refrigerant compressors, energy may
be wasted due to vibration and noise created by the compression
cycle. These vibrations and noise are generated by the imbalance in
the loads during the compression cycle, as the loading on the
discharge pocket is different than the loading on the compression
pocket, which are located on opposite sides of the rotating shaft
from one another. Thus, the present inventors looked to find a way
to eliminate this unbalanced loading in the compressor.
[0005] The present invention seeks to address these
deficiencies.
SUMMARY OF THE INVENTION
[0006] In one embodiment of the present invention, a fluid
compressor includes a housing, a compression chamber, and a shaft
including two vanes that each extend from the shaft to contact an
inner surface of the compression chamber. The shaft, vanes, and
inner surface of the compression chamber define at least two
suction pockets and at least two discharge compression pockets
arranged around a perimeter of the shaft. Each suction pocket is
between two discharge pockets and each discharge pocket is between
two suction pockets.
[0007] These and other features of the present invention can be
best understood from the following specification and drawings, the
following of which is a brief description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a side cutaway view of a compressor in accordance
with one embodiment of the present invention;
[0009] FIG. 2 is a top view of the shaft and vane assembly shown in
FIG. 1;
[0010] FIG. 3 is a perspective view of a lower bearing and oil sump
of one embodiment of the present invention;
[0011] FIG. 4 is a perspective view of the compression chamber
without the shaft and vane assembly; and
[0012] FIG. 5 is a perspective view of a discharge valve assembly
of one embodiment of the present invention;
[0013] FIG. 6 is a perspective view of the motor in the housing
without the compression chamber assembly;
[0014] FIG. 7 is a perspective view of the upper bearing plate of
one embodiment of the present invention;
[0015] FIG. 8 is a top view of the shaft 30 of one embodiment of
the present invention;
[0016] FIG. 9 is a close up cross-sectional view of the connection
between the stator laminates and the housing of one embodiment of
the present invention;
[0017] FIG. 10 is a perspective view of a second embodiment of the
upper bearing plate of one embodiment of the present invention;
and
[0018] FIG. 11 is a cross-sectional side view of the connection
between the intake port and the compression chamber in a "no"
pressure embodiment of the present invention;
[0019] FIG. 12 is a cross-sectional side view of the connection
between the discharge port and the compression chamber in a "no"
pressure embodiment of the present invention;
[0020] FIG. 13 is a perspective view of a shaft according to
alternative embodiment of the present invention;
[0021] FIG. 14 are views of a compression chamber according to
alternative embodiment of the present invention;
[0022] FIG. 15 is a perspective view of a shaft detachable from a
vane holding portion according to another alternative embodiment of
the present invention; and
[0023] FIG. 16 is a perspective view of a vane holding portion of
the shaft shown in FIG. 15.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0024] FIG. 1 shows a fluid compressor 10 including a housing 25, a
shaft 30, a motor 50, upper bearing 60, and lower bearing 70. Shaft
30 has apertures 32 (labeled in FIG. 8) into which vanes 35 can
reciprocate back and forth as the shaft 30 turns. Motor 50 is
mounted directly to housing 20, and drives shaft 30. Lower bearing
70 includes oil sump 72 which collects oil that lubricates the
compressor parts as discussed herein. Thus, motor shaft 30 is
supported symmetrically at both ends of shaft 30 for concentric
motor rotor rotation for maximum efficiency and equal nominal air
gap dimensional control.
[0025] FIG. 2 shows a top view of the compression chamber 20.
Compression chamber 20, shaft 30, and vanes 35 cooperate to form
two compression pockets 36 and two discharge pockets 37. The
compression pockets 36 and discharge pockets 37 are on opposite
sides of the shaft from one another, so that the loading on
compressor 10 is balanced. Thus, compressor 10 generates
dramatically less vibration and noise, and less bearing load,
bearing friction, and wear. All motor torque and power is delivered
to the circumferential compression movement. This directly leads to
significant energy efficiency gains, and mechanism reliability, as
the motor consumes more power if the compressor generates
vibrations or noise. Further, the rotation of shaft 30 and balanced
compression allows for rotation on the shaft centerline, as opposed
to eccentric rotation in conventional rotary-type compressors. This
"concentric compression" allows for balanced high speed rotation
which then creates a very small displacement needed for a large
output capacity. Accordingly, the present invention provides
substantial energy and cost savings over conventional compressors
and substantial capacity increases creating greater displacements
in smaller material content.
[0026] In the embodiment shown in the figures, there are two
compression pockets 36 and two discharge pockets 37. However, more
than two compression pockets 36 and two discharge pockets 37 are
possible in the present invention. For example, there could be four
compression pockets 36 and four discharge pockets 37 arranged
around a perimeter of the shaft, and this would also lead to
balanced compression performance. All of these modifications are
within the scope of the invention as claimed.
[0027] In this regard, FIG. 13 shows an exemplary shaft 30
including a vane holding portion 33 with eight vane holding slots
34. FIG. 14 shows a compression chamber 20 that is configured to be
used with the eight vaned shaft of FIG. 13. Thus, the embodiment of
FIGS. 13 and 14 would include 8 vanes separating the compression
and discharge pockets, with a corresponding number of additional
intake and exhaust valves being included in the design.
Accordingly, compressors with more than two vanes (such as the
illustrated eight vaned compressor of FIGS. 13 and 14) are within
the scope of the invention as claimed.
[0028] In forming the compression pockets 36 and discharge pockets
37, shaft 30 comes in close proximity with the inside of the
compression chamber 20. This is achieved by tight clearances on the
two sides between shaft 30 and compression chamber 20 to prevent
high pressure to low pressure leak paths. In other embodiments,
compressor 10 can also have spring/pressure loaded/compliant vanes
in the compression chamber 20 to press against shaft 30 for sealing
and/or a compliant spring or pressure mechanism to provide a load
for pressure sealing.
[0029] FIG. 3 shows another view of lower bearing 70. The slope of
the oil sump 72 allows the use of less oil, 50% less in some
configurations. This reduces both the initial and maintenance costs
of the compressor, and forces the oil to drain to the oil pickup
point in the shaft.
[0030] An additional feature of the present invention is that it
can be configured as a high pressure machine (motor/oil area is
exposed to high pressure fluid), a low pressure machine (motor/oil
area is exposed to low pressure), or a "no" pressure machine
(motor/oil area not exposed to fluid). In this regard, FIGS. 2, 4,
and 5 show a low pressure machine configuration in which low
pressure fluid enters the lower part of the compressor and high
pressure fluid exits a top of the compressor. FIG. 4 shows intake
aperture 22 in the floor of the compression chamber, through which
low pressure gas enters the compression pockets 36. (A second
intake aperture 22 is on an opposite side of the compression
chamber and is not visible in FIG. 4.)
[0031] FIG. 5 shows high pressure exit valves 40 on a top of the
compressor, as well as low pressure intake passage 42 and
electrical feedthrough 48. Electrical feedthrough 48 is similar to
that disclosed in U.S. Pat. No. 9,279,435, which is incorporated
herein by reference in its entirety.
[0032] Further, "no" pressure machines may have two configurations.
FIG. 11 shows a side cutaway view of a first embodiment of a "no"
pressure machine in which the fluid comes in the bottom of
compression chamber 20 and is discharged through the top of
compression chamber 20. In this embodiment, fluid to be compressed
enters the housing through low pressure intake passage 42. The
fluid passes through passage 122 in flange 120 so that it does not
enter the volume surrounding the motor/oil area, but travels
directly to holes 62 in lower bearing flange 65 and passes through
intake aperture 22. Thus, the fluid enters compression chamber 20
without ever being exposed to the motor/oil area. After
compression, the fluid passes through discharge valves 40, as also
shown in FIG. 5.
[0033] FIG. 12 shows a side cutaway view of a first embodiment of a
"no" pressure machine in which the fluid comes in the top of
compression chamber 20 and is discharged through the bottom of
compression chamber 20. In this embodiment, fluid to be compressed
enters the housing through intake aperture 22. After compression,
the fluid passes through discharge valves 64 in lower bearing
flange 65, and then through passage 122 in flange 120 so that it
does not enter the volume surrounding the motor/oil area. The fluid
then leaves the housing through discharge port 49.
[0034] In the "no" pressure configuration, the volume around the
motor contains ambient air and, in contrast to the high and low
pressure embodiments, does not contain oil. Thus, both "no"
pressure configurations must have sufficient lubrication for the
compressor parts without the oil used in the high and low pressure
embodiments.
[0035] FIG. 6 shows the motor 50 within the housing 25. As noted
above, motor 50 is directly mounted to and in contact with the
inner surface of housing 25. Further, the outer surface of housing
25 may have heat dissipation fins and micro surface textures to
enhance heat dissipation. For example, FIG. 9 shows a close up of
the contact between the motor laminate layers 52 and the housing
25. (Although the housing has a circular cross-section, the housing
is shown in this view as having straight sides due to the small
scale.) Each stator laminate layer 52 has a thickness of
approximately 0.020 inches. Each stator laminate layer 52 may then
line up with a corresponding heat dissipation fin 26 on an outer
surface of housing 25 to promote heat transfer from the laminate
layer 52, through housing 25, and out corresponding fin 26. Fin 26
is shown with a triangular cross-section, but any shape or
configuration suitable for heat dissipation is possible. These
modifications are within the scope of the invention as claimed.
[0036] FIG. 7 shows the upper bearing flange 65 which includes
upper bearing 60 and holes 62. In the low pressure machine shown in
FIGS. 2, 4, and 5, holes 62 are in fluid communication with intake
aperture 22 in the floor of the compression chamber. In contrast,
in the high pressure machine configuration, holes 62 would be
discharge holes with discharge valves 64 (shown in FIG. 10) mounted
over the holes 62.
[0037] FIG. 8 shows a top view of shaft 30. Shaft 30 includes
apertures 32 in which the vanes 35 reciprocate. Further, shaft 30
includes off center oil delivery passage 34. Oil delivery passage
34 uses centrifugal force to send oil out for increasing pressure
and sending oil up to bearing 60. Vent holes in passage 34 supply
lubrication to all moving surfaces.
[0038] FIGS. 15 and 16 show another alternative embodiment of the
shaft 30. In this embodiment, the shaft 30 and the vane holding
portion 33 are constructed as separate pieces that are then fit
together during assembly, instead of the unitary machined shaft
shown in FIG. 13 (for example). This allows for axial compliance
and leeway during assembly and use. This allows for tight seals
within the compression chamber while reducing wear due to
manufacturing tolerances. Two piece shafts such as that shown in
FIGS. 15 and 16 are also within the scope of the invention as
claimed.
[0039] A worker of ordinary skill in this art would recognize that
certain modifications would come within the scope of this
invention. For that reason, the following claims should be studied
to determine the true scope and content of this invention.
* * * * *