Note: Descriptions are shown in the official language in which they were submitted.
21 97361
IMPROVED SUCTION INLET CONNECTOR
FOR HERMETIC COMPRESSOR
The present invention relates generally to a
hermetic compressor assembly and, more
particularly, to a direct suction compressor
assembly having a crankcase mounted within a
hermetically sealed housing. Suction gas is
delivered directly to the crankcase, or a cylinder
head attached to the crankcase, from a refrige~ant
system suction line outside the housing by means
of a suction inlet connector or adaptor. In
general, prior art hermetic compressor assemblies
comprise a hermetically sealed housing having a
compressor mechanism mounted therein. The
compressor mechanism includes a crankcase or
cylinder block having a cylinder/compression
chamber formed therein for compressing and
discharging gaseous refrigerant.
In a high side reciprocating compressor,
which is characterized by a pressurized housing,
suction gas received from a refrigeration system
is introduced directly into the compression
chamber, or at least a suction cavity adjacent the
compression chamber. This is generally
accomplished by means of a conduit extending from
outside the housing to the compression chamber
within the crankcase. This configuration is
commonly referred to as a direct suction
compressor assembly. In direct suction compressor
assemblies, a suction inlet conduit is introduced
through the hermetically sealed housing, through a
discharge chamber formed in the housing, and into
a suction inlet bore formed in the
crankcase/cylinder block or cylinder head. The
suction inlet bore is directly or indirectly, such
as through a suction cavity formed in the cylinder
2 2197361
head, in communication with the compression
chamber. That portion of the tubing external to
the housing may comprise part of a suction
accumulator or may constitute a fitting to which a
suction line of a refrigeration system is
attached.
one problem associated with assembly of
direct suction type compressors concerns
misalignment of the suction inlet bore of the
crankcase with respect to the suction inlet
opening and inlet fitting in the housing sidewall
and the suction conduit therebetween.
Misalignment can lead to excessive stress and
material degradation with respect to the suction
conduit and related coupling devices.
Manufacturing tolerances for component parts of
the direct suction compressor assembly, i.e.,
parts having apertures and openings through which
the suction conduit extends, may complicate
compressor assembly and result in undesirable
stress on the suction conduit once the compressor
is assembled.
A second problem associated with the above-
characterized direct suction compressor assembly
occurs during compressor operation and relates to
the transmission of vibration and noise from the
compressor assembly to the housing by means of the
suction conduit and associated linkages
therebetween. Specifically, the compressor
mechanism may undergo slight excursions in
response to axial, radial, and torsional forces
acting thereupon during compressor operation.
Consequently, the nature of the linkage between
the compressor mechanism and the stationary
housing determines the extent to which vibration
and noise are imparted to the housing.
2 1 97361
The suction inlet connector must also
withstand such forces and maintain seal integrity
to prevent leakage from the interior of the
housing. One common prior art approach to
compensating for radial spacing and movement
between the housing and the crankcase suction
inlet opening is the provision of an O-ring seal
within the suction inlet bore and/or the suction
inlet fitting to allow the suction conduit to
variably penetrate into the bore. Typically, this
approach utilizes a fitting at the housing opening
which is welded to the housing and brazed to the
conduit. A primary problem of this arrangement is
that it provides for only one degree of freedom
for movement of the compressor during operation,
radial movement.
Another prior art approach to compensating
for misalignment involves a suction tube connector
directed to compensating for spacing variations
between the housing and the compressor crankcase.
A tube is disposed radially inwardly from the
housing sidewall and is provided with a slotted
conical flange at one end to abut against the
crankcase in the general area of the suction inlet
bore. The divergent end of the conical flange has
a diameter greater than the suction inlet bore,
thereby permitting alignment variations.
With respect to suction line connectors for
use in indirect suction hermetically sealed
compressor assemblies, i.e., low side compressors
where the suction gas enters into the interior
space of the housing, a suction line adapter
device is known which is attached to the housing
as by welding. This adapter comprises two pieces,
one of which is welded to the housing at the
location of the opening therethrough and the other
21 97361
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being a coupling member attachable to a
refrigeration system suction line as by brazing or
the like. The coupling member with suction line
attached thereto is then screwed onto the fitting
welded to the housing for sealing engagement
therewith. A nut threadably engages each of the
two components and brings them forcibly together
at a surface to surface juncture having an O-ring
seal seated there between.
Further, a suction line adaptor is known
which comprises a pair of L-fittings respectively
attached to the housing and the crankcase at
axially spaced locations thereon, and a connecting
pipe inside the housing between the pair of L-
15 fittings axially perpendicular to and disposed
between the housing and the crankcase. The
connecting pipe is capable of moving relative to
one or both of the L-fittings to compensate for
variations in radial and axial spacing between the
20 housing and the crankcase. A problem with such a
suction tube adapter is that space is required
between the crankcase and the housing sidewall
within the housing. Also, this type of adaptor
complicates assembly and is not suitable for high
25 side compressor applications.
Prior suction inlet adapters and couplings
for use in direct suction type hermetic
compressors are disclosed in U.S. Patent No,
4,844,705 (Ganaway) and U.S. Patent No. 4,969,804
30 (Ganaway), which are hereby incorporated into this
document by reference and which are assigned to
the assignee of the present invention. U.S.
Patent No. 4,844,705 discloses a suction line
adapter which includes a tubular insert disposed
35 between the suction inlet bore of the crankcase
and the suction inlet opening formed in the
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housing sidewall. The tubular insert is sealed
with respect to the suction inlet bore of the
crankcase by use of an O-ring. The tubular insert
is sealed with respect to the suction inlet
opening of the housing by use of an outwardly
extending flange disposed between three component
parts of a suction inlet adapter coupling. U.S.
Patent No. 4,969,804 discloses a tubular insert
which is sealed at one end to the suction inlet
bore of the crankcase by use of an O-ring. The
tubular insert is sealed at the opposite end with
respect to the suction inlet opening in the
housing by use of an O-ring and a three-piece
suction adapter coupling.
Typically during compressor operation,
discharge gas is discharged from the compression
chamber directly into the discharge chamber within
the housing and surrounding the motor and
compressor mechanism. Because the discharge gas
is at a higher temperature relative to the suction
gas temperature and because the motor operating
efficiency decreases as the motor temperature
increases due to heat absorbed from the
surrounding discharge gas, the overall compressor
efficiency is adversely affected.
The present invention overcomes the
disadvantages associated with prior art suction
line adapters and connectors by providing an
improved suction inlet connector assembly which
compensates for as much as eight degrees of
misalignment between the compressor mechanism and
the housing. The improved suction inlet connector
compensates for a higher degree of axial, radial,
and torsional alignment and movement of the
compressor mechanism relative to the housing. The
improved suction inlet connector accomplishes
21 9~1 3 6 1
misalignment compensation while maintaining the
integrity of its sealed relationship relative to
the crankcase and housing to prevent leakage from
the interior of the housing. The improved suction
inlet connector also minimizes the transmission of
vibration and noise to the housing to provide
quieter operation.
The improved suction line connector or
adapter of the present invention is generally for
use in a direct suction hermetic compressor
assembly. Typically, the compressor assembly
includes a housing, a motor, and a compressor
mechanism that undergoes limited axial, radial,
and torsional movement. The improved suction line
connector includes a suction conduit that extends
through a discharge pressure space within the
housing, intermediate a suction inlet bore in the
crankcase of the compressor mechanism and a
suction inlet fitting mounted on the sidewall of
the housing. The ends of the suction inlet
conduit are sealingly engaged with the suction
inlet bore of the crankcase and the suction inlet
fitting of the housing. The connector assembly
permits axial and angular movement of the suction
conduit relative to the suction inlet bore and
suction inlet fitting in response to movement of
the compressor mechanism relative to the housing.
In one embodiment, the improved suction
connector is sealingly connected at one end to a
suction inlet bore formed in a cylinder head
attached to a crankcase. The suction inlet
connector assembly is provided with an annular
sealing mechanism comprising a spring-energized
seal. Both ends of the tubular suction conduit
are provided with semi-spherical protuberances. A
recess is formed in either the semi-spherical
~ 97361
protuberances or in the suction inlet bore and in
the suction inlet fitting. In the context of the
present invention, it will be understood that the
term "spherical" is not narrowly defined to
include only those shapes having a constant
radius. Rather, the term "spherical" is intended
to apply to any surface that is wholly or
partially arcuate or convex.
Each groove or recess receives an annular
spring-energized seal. In this manner, the
spring-energized seals at either end of the
suction conduit are disposed intermediate the
suction conduit and the suction inlet fitting and
suction inlet bore, respectively. The spring-
energized seal preferably comprises a canted-coil,
deflection type spring disposed between facing u-
cup rings so as to provide a "double spring" which
provides fast response to rapid pressure changes
experienced on either side of the seal. The high
deflection, canted-coil type spring is adapted to
maintain sealing reliability at zero pressure
differential.
The suction inlet bore in the crankcase or
cylinder head and the suction inlet fitting of the
housing may be provided with concave surfaces to
effectively mate with the protuberances at the
ends of the suction inlet conduit. The spherical
shaped ends in conjunction with the spring-
energized seals effectively seal the suction inlet
conduit to the inlet bore and the suction fitting
over a wide range of misalignment between the
compressor mechanism and the housing.
Accordingly, the improved suction inlet connector
is subject to lessened stress associated with
axial and radial misalignment, without drastically
redistributing the main tensile preload.
2 1 9736 1
An alternative spring-energized seal
arrangement utilizes an annular C-shaped ring
which is loaded by a single canted-coil spring. A
recess in which an 0-ring is received may be
provided in the C-shaped ring to enhance sealing.
The spring-energized seals seal gaps between parts
having static and/or dynamic rotary and
reciprocating motion by providing a near constant
spring force which compensates for changes due to
initial deflection, wear, temperature changes, and
tolerance variations. The seals may be press-fit
into respective receiving grooves formed in one or
both ends of the suction inlet conduit or the
suction inlet fitting and the suction inlet bore.
As a further sealing means, an annular backup disc
spring may be disposed intermediate the suction
inlet conduit and the refrigerant system suction
line. The interface of the suction conduit, the
disc spring, and the refrigerant system suction
line occurs at the suction inlet fitting.
The spherical shaped protuberances of the
suction inlet conduit and the mating concave
surfaces of the suction inlet bore and the suction
inlet fitting permit the suction inlet conduit to
effectively pivot in multi-angle directions
relative to the crankcase and/or housing so as to
compensate for compressor component misalignment.
This compensation for misalignment lessens
material stress, noise, and vibrations, and
extends part life.
An advantage of the suction line connector of
the present invention is that an improved seal
connection between the housing sidewall fitting
and the suction inlet bore in the crankcase, or
cylinder head, is provided which tolerates a wide
range of axial, radial, and torsional misalignment
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and movement of the compressor mechanism relative
to the housing.
Another advantage of the improved suction
line connector is a compressor assembly
characterized by improved manufacturing tolerances
associated with the housing and crankcase
machining and improved assembly tolerances
associated with compressor component assembly.
Another advantage of the improved suction
line connector is the diminution in noise
transmission and vibrations from the crankcase to
the housing.
In one embodiment, the present invention
provides a reciprocating hermetic refrigerant
compressor having a hermetically sealed housing, a
compressor mechanism, a motor, and a suction inlet
connector. The hermetically sealed housing
includes a sidewall having a suction inlet
opening. The compressor mech~n;sm is disposed in
the housing and includes a crankcase and cylinder
head combination. The crankcase and cylinder head
combination includes a cylinder and a suction
cavity in communication with a suction inlet bore.
A suction inlet fitting is provided on the housing
sidewall and extends radially outwardly from the
housing sidewall.
The suction inlet connector comprises a
suction inlet conduit which is received in the
suction inlet fitting and first and second spring-
energized couplings. The suction inlet bore
provides communication between the suction cavity
and the suction inlet conduit. The first spring-
energized coupling is interposed between the
suction inlet conduit and the crankcase and
cylinder head combination and is adapted to seal a
first end of the suction inlet conduit with the
2 1 ~/36 1
suction inlet bore. The second spring-energized
coupling is interposed between the suction inlet
conduit and the suction inlet fitting and is
adapted to seal a second end of the suction inlet
conduit with the suction inlet fitting.
The first and second couplings are adapted to
maintain their respective seals in the event of
misalignment between the suction inlet conduit,
the suction inlet fitting, and the crankcase and
cylinder head combination. The first end of the
suction inlet conduit is at least partially semi-
spherical, whereby the compressor mechanism is
permitted to move in multi-angle directions and
the suction inlet connector maintains its seal
despite angular misalignments so as to reduce
torsional and inertial vibrations.
Another aspect of the present invention
involves establishing bi-directional flow paths of
discharge gas in a discharge plenum formed in the
crankcase for cooling the motor during compressor
operation. The present invention provides a
discharge gas passage formed in the crankcase
which communicates between the discharge cavity
formed in the cylinder head and a discharge plenum
formed in the crankcase and surrounding the lower
portions of the stator and rotor. During
compressor operation, discharge gas is forcibly
expelled from the compression chamber through a
discharge valve and into the discharge cavity
formed in the cylinder head. A valve plate
intermediate the cylinder head and the crankcase
is provided with a discharge aperture, whereby
discharge gas is communicated from the discharge
cavity, through the discharge passage, and into
the discharge plenum.
219736~
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The vortex tube effect, known also as the
Ranque Vortex Tube effect, the Hilsch Tube effect,
the Ranque-Hilsch Tube effect, the Coanda effect,
and Maxwell's Demon, was discovered in 1928 by
George Ranque, and involves providing a dual
output flow arrangement consisting of a warmer
fluid flow path and a cooler fluid flow path from
a single or combined fluid source. The vortex
tube effect is accomplished in one respect by
introducing a compressed fluid source into a
vortex tube which is adapted to impart a spinning
motion on the fluid flowing therethrough. The
vortex tube effects the formation of an outer flow
path, which flows in one direction, and an inner
flow path, which flows in an opposite direction.
This effect is characterized in that the inner
flow path gives off kinetic energy in the form of
heat to the outer flow path, whereby an output of
cooler fluid occurs at one end of the vortex tube
and an output of warmer fluid occurs at an
opposite end of the vortex tube.
According to the present invention, the
spinning motion of the rotor imparts a spinning
vortex effect on the discharge gas collected in
the discharge plenum. The vortex effect causes an
inner flow path and an outer flow path to form.
The inner flow path flows in a direction opposite
the outer flow path and gives off kinetic energy
in the form of heat to the outer flow path. A
first gap is provided between the rotor and the
stator and a second gap is provided between the
casing and the stator. The cooler or reduced
temperature fluid in the inner flow path flows
from the discharge plenum through the first gap
and is discharged into the discharge chamber
formed in the compressor housing. The warmer or
21~7361
-
elevated temperature discharge gas in the outer
flow path travels through the second gap and is
discharged into the discharge gas chamber. By
circulating cooler fluid between the rotor and the
stator, the motor is effectively cooled, resulting
in enhanced motor operating efficiency and
increased overall compressor operating efficiency.
This is in dramatic contrast to direct suction
hermetic compressors of the prior art in which
discharge gas is discharged generally directly
into the discharge chamber of the housing after
compression.
Yet another advantage of the present
invention is that discharge gas collected in the
lS discharge plenum is subjected to the vortex tube
effect during compressor operation, thereby
effecting a continuous flow of cooler fluid
through a gap formed between the rotor and the
stator. The flow of cooler fluid effectively
cools the motor during compressor operation and
increases motor operating efficiency and overall
compressor operating efficiency.
In another embodiment, the present invention
provides a reciprocating hermetic refrigerant
compressor having a hermetically sealed housing, a
compressor mechanism, and a motor. The housing
provides a sidewall having a suction inlet
opening. The compressor mechanism is disposed in
the housing and comprises a crankcase having a
cylinder, a discharge passage, and a discharge
plenum formed therein. A cylinder head is
attached to the crankcase and includes a suction
cavity, a discharge cavity, and a suction inlet
bore formed therein. A piston is driven by a
crankshaft and is reciprocatingly received in the
cylinder.
~1 9736i
'
13
The motor includes a stator attached to the
crankcase, and a rotor attached to the crankshaft
and surrounded by the stator. A first gap is
formed between the rotor and the stator and a
second gap is formed between the stator and the
crankcase. During compressor operation discharge
gas travels through the discharge cavity, through
the discharge passage, and through the first and
second gaps. The rotor spins during compressor
operation resulting in the Ranque vortex tube or
Coanda effect, which accomplishes enhanced cooling
of the motor.
In a further embodiment, the present
invention provides a method of cooling a motor in
a hermetic refrigerant compressor. The compressor
includes a crankcase with a cylinder and a motor
having a stator and rotor. The method comprises
the following steps. Gas is discharged from the
cylinder during compressor operation into a
discharge gas plenum provided in the crankcase. A
spinning vortex of discharge gas is generated
within the discharge plenum, whereby an inner flow
path of cooler gas and an outer flow path of
warmer gas are formed. A first gap between the
stator and rotor and a second gap between the
stator and crankcase are formed in the compressor.
The cooler gas in the inner flow path travels
through the first gap and the warmer gas in the
outer flow path travels through the second gap.
The above mentioned and other features and
objects of this invention, and the manner of
attaining them, will become more apparent and the
invention itself will be better understood by
reference to the following description of
embodiments of the invention taken in conjunction
with the accompanying drawings, wherein:
2l 9736l
; -
14
Fig. 1 is a side-sectional view of the direct
suction hermetic refrigerant compressor of the
present invention.
Fig. 2A is a sectional cutaway view showing a
first embodiment of the spring-energized seal used
with the suction inlet connector of the present
invention.
Fig. 2B is a sectional cutaway view of a
second embodiment of the spring-energized seal
utilized in the suction inlet connector of the
present invention.
Fig. 2C is a sectional cutaway view of a
third embodiment of the spring-energized seal for
use with the suction inlet connector of the
present invention.
Fig. 3A is a sectional cutaway view of a
first embodiment of the suction inlet connector
assembly of the present invention.
Fig. 3B is a cross-sectional cutaway view of
a second embodiment of the suction inlet connector
assembly of the present invention.
Fig. 4A is a side view of a first embodiment
of the suction inlet conduit associated with the
suction inlet connector of the present invention.
Fig. 4B is a side view of a second embodiment
of the suction inlet conduit utilized in the
- suction inlet connector assembly of the present
invention.
Fig. 4C is a side view of a third embodiment
of the suction inlet conduit associated with the
suction inlet connector assembly of the present
invention.
Fig. 4D is a side view of a fourth embodiment
of the suction inlet conduit associated with the
suction inlet connector assembly of the present
invention.
~ . 2l9736i
Fig. 4E is a side view of a fifth embodiment
of the suction inlet conduit associated with the
suction inlet connector assembly of the present
invention.
Fig. 4F is a side view of a sixth embodiment
of the suction inlet conduit associated with the
suction inlet connector assembly of the present
invention.
Fig. 5 is a cutaway sectional view of the
motor and crankcase of the present invention
illustrating the discharge gas flow paths
invention illustrating the discharge gas flow
paths associated with the vortex tube effect.
Fig. 6 is a cutaway sectional view of the
interface between the stator and crankcase of the
present invention, illustrating the
stator/crankcase gap.
In an exemplary embodiment of the invention
as shown in the drawings, and in particular by
referring to Fig. 1, compressor assembly 10 is a
direct suction hermetically sealed reciprocating
refrigerant compressor having a housing generally
designated at 12. The housing has a top portion
14 and a bottom portion 16. The two housing
portions are hermetically secured together as by
welding or brazing shown generally at interface
joint 18. Located within hermetically sealed
housing 12 is electric motor 20, crankcase 22,
cylinder head 24, and suction inlet connector
assembly 26. Electric motor 20 includes stator 28
and rotor 30 which has central aperture 32
provided therein into which is secured crankshaft
34 by an interference fit. Motor 20 is connected
to a source of electric power through a terminal
cluster (not shown) and is a three phase motor,
whereby bi- directional operation of compressor
21 97361
16
assembly 10 is achieved by changing the connection
of power at the terminal cluster. Also in housing
12 is discharge chamber 36 and oil sump 38.
During compressor operation, oil is drawn into
axial lubricating oil passageway 40, provided as a
center bore in crankshaft 34, via oil intakes 42
from sump 38. Radial oil passages extending
radially from axial lubricating oil passageway 40
through crankshaft 34 delivers lubricating oil to
various moving parts of the compressor mechanism
designated generally as 44.
Compressor mechanism 44 comprises crankcase
22, pistons 46, valve plate 48, and cylinder head
24. Crankcase 22 includes a plurality of mounting
lugs 50 to which motor stator 28 is attached such
that there is an annular air gap or channel 52
between stator 28 and rotor 30. Annular space 54,
intermediate the peripheral edge of separating
plate 56 and housing top portion 14, provides
communication between the top and bottom ends of
housing 12 for equalization of discharge pressure
within the entire housing interior.
Compressor mechanism 44 takes the form of a
reciprocating piston type compressor, wherein
crankcase 22 is generally made of cast iron or
aluminum and includes two radially disposed
cylinders 58. Pistons 46, cylinders 58, and valve
plate 48 define compression chamber 60. During
compressor operation and specifically during the
compression stroke, refrigerant gases are
compressed in compression chamber 60 and
discharged via discharge valve 62 through valve
plate 48 and into discharge cavity 64 formed in
cylinder head 24. Cylinder head 24 is preferably
made of cast iron or aluminum.
2~ 9~361
''
17
During the suction stroke, suction gas is
drawn into suction cavity 66 formed in cylinder
head 24 from a refrigerant system suction line 124
via suction inlet connector assembly 26. Suction
gas enters compression chamber 60 from suction
cavity 66 via suction valve 68 provided on suction
valve plate 48. In the alternative, a suction
plenum may be formed in the crankcase surrounding
cylinders 46, whereby suction gas may be drawn
directly into crankcase 22 and into cylinders 46
via apertures formed in the cylinder walls.
Suction inlet connector assembly 26, as shown
throughout the figures in various embodiments,
comprises suction inlet conduit 70 which is
preferably made of steel, but can be molded from
plastic such as Valox, Nylon, etc., and is
received by suction inlet fitting 72. Suction
inlet fitting 72 extends radially outwardly from
lower housing portion 16 at suction inlet opening
74. A first end 76 of suction inlet conduit 70 is
received by suction inlet bore 78 provided in
cylinder head 24 adjacent suction inlet opening
74. The space within housing 12 between suction
inlet fitting 72 and suction inlet bore 78 is at
discharge pressure, whereas suction cavity 66 of
cylinder head 24 is at suction pressure.
Suction inlet seal 80 is disposed
intermediate suction inlet conduit 70 and suction
inlet bore 78. Suction inlet seal 80 seals
suction conduit 70 relative to cylinder head 24 at
suction inlet bore 78 so as to prevent leakage of
discharge gas within housing 12 into suction
cavity 66. In the embodiment shown in Fig. 1,
suction inlet fitting 72 is preferably made of
steel, but can be molded from plastic such as
Valox, Nylon, etc., and is sealingly secured, such
2197361
18
as by welding or by brazing, to lower housing
portion 16 and suction inlet conduit 70 so as to
prevent the escape of discharge gas from within
housing 12 to the area surrounding compressor
assembly 10.
Manufacturing tolerances inherent in
compressor assembly 10 may result in misalignment
of suction inlet bore 78 relative to suction inlet
opening 74 of housing 12. Further, during
compressor operation, compressor mechanism 44
moves in response to radial, axial, and torsional
forces, resulting in greater misalignment. Prior
art suction inlet connectors are subject to
material stress which may become excessive
depending upon the degree of misalignment.
Moreover, such misalignment may cause prior art
suction inlet connectors to become unsealed
relative to the suction inlet bore, thereby
resulting in the leakage of discharge gas into the
suction cavity.
According to the improved suction connector
of the present invention as shown in Figs. 1, 2A-
2C, and 3A-3B, first end 76 is provided with
spherical-shaped protuberance 92. In the context
of the present invention, it will be understood
that the term "spherical" is not narrowly defined
to include only those shapes having a constant
radius. Rather, the term "spherical" is intended
to apply to any surface that is wholly or
partially arcuate or convex, including but not
limited to elliptic, parabolic, and hyperbolic
surfaces. Suction inlet seal 80 is disposed in
annular seal recess or gland 90 formed in cylinder
head 24 at suction inlet bore 78. In the
alternative suction inlet conduits shown in Figs.
4B, 4C, 4E, and 4F, seal receiving recesses 90 may
2~ ~136~
19
be provided at either or both ends of suction
inlet conduit 70.
The spherical protuberance 92 at first end 76
of suction inlet conduit 70, in conjunction with
mating spherical surface 94 of suction inlet bore
78, allows suction inlet conduit 70 to pivot
relative to cylinder head 24 and suction inlet
opening 74 so as to compensate for misalignment
resulting from manufacturing tolerances or from
compressor operation. Seal 80 provides a
positive, fluid-tight seal between cup seal rings
82 and first end 76 so as to maintain seal
integrity over a wide range of misalignment
conditions. Spherical-shaped first end 76 permits
compressor mechanism 44 to move in a virtually
infinite number of multi-angled directions and
compensates for angular misalignments up to four
degrees.
Suction inlet seal 80 is provided in the form
of a spring-energized seal assembly which provides
a near constant spring force allowing seal 80 to
compensate for changes due to initial deflection,
wear, temperature changes, and/or tolerance
variations. Figs. 2A through 2C illustrate three
alternative embodiments of the spring-energized
seal assembly 80 which may be used to seal suction
inlet conduit 70 with respect to suction inlet
bore 78.
The suction inlet seal 80 illustrated in Fig.
2A includes opposedly facing U-cup annular rings
82 which are preferably made of teflon and are
loaded by a single canted-coil spring 84. Canted-
coil-spring 84 is disposed intermediate opposing
seal rings 82 and is preferably made of spring
steel or stainless steel. This bi-directional,
cylinder head mounted seal functions as a double
2197361
seal, whereby quick response to rapid pressure
changes experienced in either discharge gas pocket
86 or suction gas pocket 88 is achieved. Spring
84 is a high deflection type spring which
maintains seal integrity even at zero pressure
differential.
Fig. 2B illustrates suction inlet seal 80
comprising C-shaped annular seal ring 96 in
combination with canted-coil spring 98. As
described above, a near constant spring force is
exerted at upper surface 100, which maintains
constant contact with semi-spherical protuberance
92 of suction inlet conduit first end 76
throughout a wide range of misalignment
conditions.
Fig. 2C illustrates a third embodiment of
suction inlet seal 80, wherein generally C-shaped
seal ring 102 is acted upon by canted-coil spring
104 so as to maintain contact with protuberance 92
of first end 76. In this manner, seal 80
maintains seal integrity and prevents leakage of
discharge gas from discharge pocket 86 into
suction gas pocket 88. In addition, 0-ring seal
106 is disposed in recess 108 of seal ring 102
enhance seal integrity.
According to the present invention as
illustrated in Figs. 3A and 3B, a second spring-
energized seal 110 may be provided intermediate
suction inlet conduit 71 and suction inlet fitting
72. Second seal 110 affords greater compensation
for misalignment and enables suction inlet
connector assembly 26 to maintain seal integrity
over an even wider range of misalignment.
Protuberance 92 at first end 76 operates in
conjunction with suction inlet seal 80 at suction
inlet bore 78 as described above. Second end 112
21 2/ 97361
of suction inlet conduit 71 is surrounded by and
engages with annular seal 110 so as to prevent
leakage of discharge gas from discharge gas pocket
114 into suction inlet conduit 71 or to the area
surrounding compressor assembly 10. Spring-
energized seal 110 comprises C-shaped seal ring
116 and canted-coil spring 118 and is received in
recess or gland 120 formed in suction inlet
fitting 72. Disc spring 122 is disposed
intermediate suction inlet conduit 71 and
refrigerant system suction line 124, which is
typically secured to suction inlet fitting 72 by
brazing or welding.
Fig. 3B illustrates alternative suction inlet
conduit 126 having spherical protuberances 92 at
both first end 76 and second end 112. First
suction inlet seal 80 is disposed in recess 90
formed in suction inlet bore 78. Second seal 110,
comprising C-shaped seal ring 116 and canted-coil
type spring 118, is disposed in annular recess 128
formed in protuberance 92 at second end 112. Seal
110 via seal ring 116 maintains contact with inner
surface 130 of suction inlet fitting 72 and inner
recess surface 132 to maintain a sealed
relationship between suction inlet conduit 126 and
suction inlet fitting 72 throughout a wide range
of misalignment conditions.
Spherical surface 134 of protuberance 92 at
second end 112 allows suction inlet conduit 126 to
pivot with respect to suction inlet fitting 72.
This pivoting motion compensates for misalignment
conditions between compressor mechanism 44 and
housi-ng 12, particularly between suction inlet
bore 78 and suction inlet opening 74,
respectively. Disc spring 122 is disposed
intermediate suction inlet conduit 126 and
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refrigerant system suction line 124 to maintain a
sealed relationship therebetween. Protuberance
136 extends from the outer surface of refrigerant
system suction line 124 and abuts surface 138 of
suction inlet fitting 72 so as to limit the
introduction of suction line 124 into suction
inlet fitting 72. A screen-filter (not shown) may
be provided between end 112 and incoming suction
inlet line 124.
Figs. 4A through 4F illustrate six
alternative embodiments of the suction inlet
conduit utilized in the improved suction inlet
connector assembly in accordance with the present
invention. These alternative conduits utilize
protuberances 92 and seal ring recesses 90 in
various combinations and arrangements. These
arrangements are not exhaustive and are merely
provided as examples of the types of conduits
which may be used to effect the enhanced
misalignment compensation function of the present
invention.
Another aspect of the present invention
involves establishing bi-directional flow paths of
discharge gas in discharge plenum 140 formed in
crankcase 22. During compressor operation,
discharge gas is expelled from compression chamber
60 via discharge valve 62 and is received in
discharge cavity 64 formed in cylinder head 24.
From cavity 64, discharge gas passes through
discharge aperture 142 formed in valve plate 48,
through discharge gas passage 144 formed in
crankcase 22, and into discharge plenum 140.
The spinning rotation of rotor 30 causes a
vortex tube or Coanda effect to occur in discharge
plenum 140. The vortex tube effect, also known as
the Ranque Vortex Tube effect, the Hilsch Tube
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23
effect, the Ranque-Hilsch Tube effect, and
Maxwell's Demon, transforms a single or combined
fluid flow into two fluid flows, consisting of a
warmer fluid flow path and a cooler fluid flow
path. The vortex tube effect is accomplished by
imparting a spinning motion on a fluid flow
source, whereby an outer flow path is formed which
flows in one direction and an inner flow path is
formed which flows in an opposite direction. This
effect is characterized in that the inner flow
path gives off kinetic energy in the form of heat
to the outer flow path, whereby an output of
cooler fluid flow occurs at one end of the vortex
tube and warmer fluid is output at an opposite end
of the vortex tube.
The compressor of the present invention, as
illustrated in Fig. 5, utilizes the vortex tube
effect as follows. Discharge gas at approximately
250-300 psi pressure enters discharge plenum 140
via discharge gas passage 144 and passes around
the inner surfaces of discharge plenum 140 and
external surface of the motor stator 28. The
spinning action of rotor 30 accelerates the
movement of the discharge gas in discharge gas
plenum 140 and imparts a spinning vortex flow
pattern 158 on such discharge gas flow. First
circumferential gap 52 is provided between rotor
30 and stator 28 and is preferably approximately
0.030" wide. Second gap 148 is circumferentially
located between stator 28 and separating plate 56
and is preferably approximately 0.050" wide. The
spinning discharge gas vortex moves in a direction
away-from crankshaft 34 and toward housing 12. A
definable portion of discharge gas is propelled
through path 154 and exits through second gap 148
into discharge chamber 36.
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The remaining discharge gas is forced back
through a central part 152 of spinning vortex 158,
so as to flow in a direction opposite outer flow
path 150 of spinning vortex 158. Inner flow path
152 moves in a direction away from housing 12 and
toward crankshaft 34. Spinning vortex 158
effectively cools the discharge gas flowing
through inner flow path 152. This cooler fluid
flows through cooler fluid flow path 156, between
stator 28 and rotor 30, through gap 52, and into
discharge chamber 36. Warmer discharge gas from
outer flow stream 150 travels through hot gas flow
path 154, formed between crankcase 22 and stator
28, through gap 148, and into discharge chamber
36. In this manner, motor 20 is effectively
cooled by the cooler discharge gas flow, thereby
enhancing motor operating efficiency and overall
compressor operating efficiency.
Stator 28 is affixed to crankcase 22 by a
plurality of bolts 160, as shown in Fig. 6. The
laminations which make up stator 28 are provided
with bolt apertures which, with the laminations
stacked and aligned one on top of the other, form
a bolt receiving bore through stator 28.
Separating plate 56 is disposed intermediate
stator 28 and crankcase 22 and is provided with a
bolt receiving hole. Crankcase 22 is provided
with a threaded receiving bore 162. In accordance
with the present invention, at least one spacer or
washer 164 per bolt is disposed intermediate
stator 28 and separating plate 56, or crankcase 22
in the absence of separating plate 56. Spacing
washer 164 spacially separates stator 28 from
separating plate 56, thereby establishing
intermediate space 166 and gap 148.
2 1 9 7361
The dimensions of gap 148 may be altered by
placing multiple or various width washers 164
intermediate stator 28 and separating plate 56.
The width of circumferential gap 148 determines
the temperature and flow rate of the discharge gas
flowing through cooler gas flow path 156 and
through rotor/stator gap 52. Enlarging gap 148
reduces the temperature and flow rate associated
with the discharge gas flowing through cooler gas
flow path 156 and gap 52. Reducing gap 148
increases the temperature and flow rate of the
discharge gas flowing through cooler gas flow path
156 and gap 52. In the preferred embodiment, gap
148 is sized to obtain maximum cooling efficiency,
which is reached when approximately 80% of the
discharge gas is directed toward and passes
through rotor/stator gap 52.
In this manner, the compressor of the present
invention utilizes the vortex tube effect to
effectively cool the motor windings and accelerate
the evacuation of discharge gas from discharge
plenum 140 of crankcase 22, resulting in enhanced
operating efficiency. Further, due to the high
velocity and increased volume of discharge gas
flowing through rotor/stator annular gap 52, rotor
30 is effectively lifted so as to reduced the load
on the lower part of the main bearing.
While this invention has been described as
having a preferred design, the present invention
can be further modified within the spirit and
scope of this disclosure. This application is
therefore intended to cover any variations, uses,
or adaptations of the invention using its general
principles. Further, this application is intended
to cover such departures from the present
disclosure as come within known or customary
2 1 97 36 1
practice in the art to which this invention
pertains and which fall within the limits of the
appended claims.
