U.S. patent application number 15/063061 was filed with the patent office on 2016-06-30 for hermetic electrical feedthrough assembly for a 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 Doug BLANKENSHIP, David R. GILLIAM, Scott G. HIX, Joseph A. NEWLAND, John W. TOLBERT, JR..
Application Number | 20160186737 15/063061 |
Document ID | / |
Family ID | 50187871 |
Filed Date | 2016-06-30 |
United States Patent
Application |
20160186737 |
Kind Code |
A1 |
TOLBERT, JR.; John W. ; et
al. |
June 30, 2016 |
HERMETIC ELECTRICAL FEEDTHROUGH ASSEMBLY FOR A COMPRESSOR
Abstract
An electrical feedthrough assembly for providing connection to
components of a compressor includes a housing having an inner
surface defining a channel. A sealed wire assembly is provided in
the channel. The sealed wire assembly includes a body having an
outer surface and a plurality of wires sealingly passing through
the body.
Inventors: |
TOLBERT, JR.; John W.;
(Bristol, TN) ; HIX; Scott G.; (Bristol, VA)
; GILLIAM; David R.; (Bristol, VA) ; NEWLAND;
Joseph A.; (Limestone, TN) ; BLANKENSHIP; Doug;
(Bristol, TN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Bristol Compressors International, LLC |
Bristol |
VA |
US |
|
|
Assignee: |
Bristol Compressors International,
LLC
Bristol
VA
|
Family ID: |
50187871 |
Appl. No.: |
15/063061 |
Filed: |
March 7, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14048027 |
Oct 7, 2013 |
9279425 |
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15063061 |
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12843429 |
Jul 26, 2010 |
8552293 |
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14048027 |
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61726672 |
Nov 15, 2012 |
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61726676 |
Nov 15, 2012 |
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Current U.S.
Class: |
417/228 ;
417/437 |
Current CPC
Class: |
F04B 35/04 20130101;
H02G 3/22 20130101; F04B 39/0276 20130101; H02G 15/013 20130101;
F04B 39/121 20130101; F04B 53/14 20130101; F04C 18/0207 20130101;
F04B 39/06 20130101; F04B 39/023 20130101 |
International
Class: |
F04B 39/12 20060101
F04B039/12; F04B 53/14 20060101 F04B053/14; F04B 39/02 20060101
F04B039/02; F04B 35/04 20060101 F04B035/04; F04B 39/06 20060101
F04B039/06 |
Claims
1.-5. (canceled)
6. A compressor comprising: a fluid compressing device; a shell
containing the fluid compressing device; and a wire feedthrough
assembly located in an aperture in the shell, the wire feedthrough
assembly including: a housing; a body positioned in a passageway in
the shell and connected to the housing to form a hermetic seal
between the housing and the body; and a plurality of wires embedded
in the body, each wire of the plurality of wires being individually
hermetically sealed by the body, and at least one of the wires
being connected to the fluid compressing device and configured to
supply control signals to the fluid compressing device.
7. The compressor according to claim 6, wherein the fluid
compressing device includes a heater, and at least one of the wires
supplies the control signals to the heater.
8. The compressor according to claim 7, wherein the heater is
configured to heat oil sump fluid in an oil sump, and the at least
one of the wires supplies the control signals to the heater to
control the heater to heat up the oil sump fluid.
9. The compressor according to claim 6, wherein the fluid
compressing device includes a compressor motor, and at least one of
the wires supplies the control signals to the compressor motor.
10. The compressor according to claim 9, wherein the at least one
of the wires supplies the control signals to the compressor motor
to turn the compressor motor on when a preset temperature threshold
is reached.
11. A compressor comprising: a shell containing the compressor
motor; a wire feedthrough assembly located in an aperture in the
shell, the wire feedthrough assembly including: a housing; a body
positioned in a passageway in the housing and connected to the
housing to form a hermetic seal between the housing and the body;
and a plurality of wires embedded in the body, each wire of the
plurality of wires being individually hermetically sealed by the
body; and a shield located on an outer surface of the shell and
configured to protect the wire feedthrough from damage.
12. The compressor according to claim 11, wherein the shield has a
circular cross-sectional shape.
13. The compressor according to claim 11, wherein the shield does
not surround a full 360 degrees around the wire feedthrough
assembly.
14. The compressor according to claim 11, wherein the shield
includes a cover that k parallel to the shell.
15. The compressor according to claim 14, wherein the cover
includes at least one hole to allow passage of the wires of the
wire feedthrough assembly.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part of U.S.
application Ser. No. 12/843,429, filed Jul. 26, 2010, entitled
HERMETIC ELECTRICAL FEEDTHROUGH ASSEMBLY FOR A COMPRESSOR AND
METHOD FOR MAKING THE SAME and this application claims the benefit
of U.S. Provisional Application No. 61/726,672, filed Nov. 15,
2012, entitled HERMETIC ELECTRICAL FEEDTHROUGH ASSEMBLY FOR A
COMPRESSOR, and U.S. Provisional Application No. 61/726,676, filed
Nov. 15, 2012, entitled SYSTEMS AND COMPRESSORS USING FLAMMABLE
REFRIGERANT, all of which Applications are incorporated by
reference herein in their entirety.
BACKGROUND
[0002] The application generally relates to electrical connections
for compressors. The application relates more specifically to
providing electrical connections through the shell or housing of a
hermetic compressor.
[0003] FIG. 1 shows a top, partial cross-sectional view of a prior
art compressor 100. The compressor 100 has a shell 110 that
provides a hermetically scaled environment for electrical and
mechanical components inside the shell 110. To maintain proper
operation of the compressor 100, the integrity of the hermetically
sealed environment cannot be breached by the electrical connections
through the shell 110. Further, when a flammable refrigerant is
used in the compressor 100 as the working fluid, any sparking or
arcing inside the compressor 100 should be avoided.
[0004] One type of electrical connection into the hermetically
sealed environment of the shell 110 can be provided by a power
terminal 112. The power terminal 112 has to maintain the
hermetically sealed environment while withstanding the harsh
operating conditions associated with the compressor 100. The power
terminal 112 can be located within an aperture in the shell 110.
The power terminal 112 can have a cup-shaped metal collar 126 with
a bottom wall. The bottom wall has holes that permit conductor pins
128 to pass through to provide the electrical connection through
the shell 110. The collar 126 is sealed in the shell aperture by
welding and the pins 128 are sealed within the collar 126 by fused
glass insulation. To further stabilize the terminal 112, the fused
glass insulation surrounding the pins 128 can be covered with epoxy
or shielded by ceramic collars.
[0005] A fence 130 can surround and protect the power terminal 112.
A molded plug (not shown) can be configured to couple with the
fence 130 and, thereby, make an electrical connection with the pins
128 outside the shell 110. To accomplish this connection on the
outside of the shell, the pins 128 can be provided with a tab (not
shown). For example, each pin 128 may include an attached, e.g.,
welded, 0.250 inch tab that can connect to a 0.250 inch spade
connector crimped onto the end of a voltage supply wire or
conductor. Any of the previously described connections, e.g.,
pin-tab, tab-connector, connector-wire, can become corroded or
loose and result in arcing or sparking that can ignite the
surrounding atmosphere if the compressor 100 is located in a
hazardous or explosive environment, such as grain silos with grain
dust, areas with gasoline vapors, mines, etc.
[0006] In addition, the power terminal 112 relies on through air
and/or over surface clearance to insulate the terminal pins both
line to line and each line to ground, where the shell 110 and/or
collar or terminal body 126 are at earth ground potential. Even if
the connections and insulation are sound, there can be multiple
ways for an arc or spark to occur at the terminal pins 128 when the
pins 128 are energized. For example, a conductive atmosphere (e.g.,
contaminants and/or moisture) could reduce the dielectric
(insulation properties) between pins 128 and bridge the voltage.
Another example is that an excessive grid voltage could produce
corona or other micro conductivity that could also reduce the
dielectric between pins 128. A further example is that insects or
small wildlife can bridge the voltage between pins 128. A service
person may also inadvertently bridge the voltage between pins 128
with tools or other items while performing maintenance with the
terminal cover removed.
[0007] Plugs, tabs, connectors or wires similar to those used on
the outer ends of the pins 128 can be used on the inside end of the
pins 128 to accomplish the electrical connection between the
electrical components inside the shell 110 and the power terminal
112. When using a flammable refrigerant, the connection(s) at the
inner end of the pins 128 should not generate a spark or are due to
the risk of fire or explosion inside the shell 110.
[0008] There can be problems associated with the use of sealed
glass pin power terminals 112. The terminals 112 require extensive
tooling that is costly and not easily modified to add or subtract
pins 128 if additional or fewer electrical connections are
required. The prefabrication process is costly, complex and time
consuming. Further, as the terminals 112 are being welded to the
shell 110, the glass seals can be damaged and, thus, the assembly
must be discarded and replaced. The replacement of the assembly can
be quite costly as significant time and expense has already been
invested in pre-assembling the power terminal 112. Even worse, the
damaged glass seals may go undetected, resulting in an eventual
compressor failure. Further, the plug and the corresponding
electrical connections may become loose resulting in a compressor
failure. The additional parts and complexity needed to connect to
the pins 128 can add cost and create additional junctions that may
fail.
[0009] Therefore, what is needed is an electrical connection
through the shell of a hermetic compressor that can be easily
assembled and installed and that reduces the possibility of
sparking or arcing inside or outside of the compressor shell.
SUMMARY
[0010] The present application is directed to an electrical
feedthrough assembly for providing a connection to the internal
components of a compressor. The electrical feedthrough assembly
includes a housing having an inner surface defining a channel. A
sealed wire assembly is provided in the channel. The sealed wire
assembly includes a body having an outer surface defining at least
one groove and as plurality of wires sealingly passing through the
body. An o-ring fits in the grove(s) to provide a hermetic seal
between the body and the inner surface of the housing.
[0011] The present application is directed to a compressor
including a shell defining an opening. A weld housing has an outer
surface hermetically welded in the opening. The weld housing forms
an elongated channel to hold a sealed wire assembly. The sealed
wire assembly includes a body having an outer surface defining a
groove and wires sealingly passing through the body. An o-ring is
disposed in the groove to provide a hermetic seal between the body
and the weld housing.
[0012] The present application also includes a compressor including
a shell defining an opening and a wire assembly hermetically sealed
in the opening. The wire assembly includes a body and wires passing
through the body, wherein the body is an epoxy material that
hermetically seals the wires directly therein without additional
components. The body can have an outer surface defining at least
one groove that receives an o-ring. Additionally, the compressor
may have a housing with an outer surface hermetically secured to
the opening and an inner surface defining an elongated channel for
receiving the wire assembly.
[0013] One advantage of the present application is that it can
effectively provide a connection to the compressor components yet
maintain the integrity of the compressor shell through harsh
conditions such as swings in vacuum and pressure.
[0014] Another advantage of the present application is that it
simplifies the assembly of compressors and the compressor
components by eliminating the glass sealed power terminals.
[0015] A further advantage of the present application is that it
provides an electrical connection that can accommodate
modifications such as additional wires.
[0016] Still another advantage of the present application is that
the electrical connection is more resistant to water and moisture
such as from precipitation and condensation.
[0017] Another advantage of the present application is that the
electrical connection can be flexibly fabricated with larger or
smaller sized wires, as needed, based on lower or higher amperage
needs.
[0018] Other features and advantages of the present invention will
be apparent from the following, more detailed description of the
embodiments, taken in conjunction with the accompanying drawings
which show, by way of example, the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 shows a top, partial cross-sectional view of a prior
art compressor,
[0020] FIG. 2 shows an embodiment of a compressor using an
embodiment of an electrical feedthrough assembly.
[0021] FIG. 3 shows an outer perspective view of an embodiment of
an electrical feedthrough assembly for a compressor.
[0022] FIG. 4 shows an inner perspective view of the electrical
feedthrough assembly of FIG. 3.
[0023] FIG. 5 shows a perspective view of an embodiment of a weld
housing for the electrical feedthrough assembly of FIG. 3.
[0024] FIG. 6 shows a side, cross-sectional view of the weld
housing of FIG. 5.
[0025] FIG. 7 shows an embodiment of a side, cross-sectional view
of a weld housing mounted in a compressor shell.
[0026] FIG. 8 shows a perspective view of an embodiment of a scaled
wire assembly for the electrical feedthrough assembly of FIG.
3.
[0027] FIG. 9 shows a side view of the sealed wire assembly of FIG.
8.
[0028] FIG. 10 shows a side view of the sealed wire assembly of
FIG. 8 with the o-rings and snap ring removed.
[0029] FIG. 11 shows an end view of the sealed wire assembly of
FIG.
[0030] FIG. 12 shows a plan view of a snap ring for use on the body
of the scaled wire assembly of FIG. 8.
[0031] FIG. 13 shows a plan view of an o-ring for use on the body
of the sealed wire assembly of FIG. 8.
[0032] FIG. 14 shows an embodiment of a side, cross-sectional view
of a weld housing mounted in a compressor shell with a protective
shield.
[0033] FIGS. 15-17 show partial cross-sectional views of
embodiments of the sealed wire assembly positioned in the
compressor shell.
[0034] FIGS. 18 and 19 show partial cross-sectional views of
embodiments of the feedthrough assembly using a compression
fitting.
[0035] FIG. 20 shows an enlarged view of section A from FIG.
19.
[0036] FIG. 21 shows a partial cross-sectional view of a threaded
connection between a weld housing and a body.
[0037] Wherever possible, the same reference numbers will be used
throughout the drawings to refer to the same or like parts.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0038] FIG. 2 shows an embodiment of a hermetic compressor.
Compressor 2 may be connected to a refrigeration or heating,
ventilation and air conditioning (HVAC) system (not shown) having,
among other components, a condenser, expansion device and
evaporator in fluid communication with the compressor 2. The
compressor 2 is shown as a reciprocating compressor, but compressor
2 can be any suitable type of hermetic or semi-hermetic compressor
including, but not limited to, a rotary compressor, scroll
compressor, spool compressor, screw compressor, or centrifugal
compressor. The compressor 2 can be connected to an evaporator (not
shown) by a suction line that enters the suction port 14 of
compressor 2. The suction port 14 can be in fluid communication
with a suction plenum 12. Refrigerant gas from the evaporator
enters the compressor 2 through the suction port 14 and then flows
to the suction plenum 12 before being compressed. In one
embodiment, the refrigerant gas from the suction port 14 can fill
the interior space of the compressor housing before flowing to the
suction plenum. Some examples of the refrigerant gas that may be
used in compressor 2 are hydrofluorocarbon (HFC) based
refrigerants, for example, R-410A, R-407C, R-404A, R-134a and R-32
(a component of R410A and R407C); hydrofluoro olefin (HFO)
refrigerants, also known as "unsaturated HFCs," such as R1234yf;
inorganic refrigerants like ammonia (NH3), R-717 and carbon dioxide
(CO2), R-744; hydrocarbon based refrigerants such as propane
(R-290), isobutane (R-600a) or propene (R1270), or any other
suitable type of refrigerant. The hydrocarbon based refrigerants
may be referred to as "flammable" refrigerants and can have an
ASHRAE flammability class of 3. Other types of "flammable"
refrigerants can include R-32, ammonia (R-717) and HFO
refrigerants, each of which can have an ASHRAE flammability class
of 2 L.
[0039] The compressor 2 can use an electrical motor 18. As shown in
FIG. 2, motor 18 is an induction motor having a stator 21 and a
rotor 23, however any other suitable type of electrical motor may
be used. A shaft assembly 25 extends through the rotor 23. The
bottom end 29 of the shaft assembly 25 extends into an oil sump 405
and includes a series of apertures 27. Connected to the shaft
assembly 25 below the motor is a compression device. As shown in
FIG. 2, the compression device can be a piston assembly 31 that has
two pistons. A connecting rod 33 is connected to a piston head 34,
which moves back and forth within a cylinder 36. The cylinder 36
includes a gas inlet port 38 and a gas discharge port 41.
Associated with these ports 38, 41 are associated suction valves
and discharge valves. The gas inlet port 38 is connected to an
intake tube 55, which is in fluid communication with the suction
plenum 12.
[0040] The motor 18 can be activated by a signal in response to the
satisfaction of a predetermined condition, for example, an
electrical signal from a thermostat when a preset temperature
threshold is reached. While a thermostat is used as an example, it
should be known that any type of device or signal may be used to
activate the compressor. When the compressor is activated,
electricity is supplied to the stator 21, and the windings in the
stator 21 cause the rotor 23 to rotate. Rotation of the rotor 23
causes the shaft assembly 25 to turn. When the shaft assembly 25 is
turning, oil sump fluid in the oil sump 405 enters the apertures 27
in the bottom end 29 of the shaft and then moves upward through and
along the shaft 25 to lubricate the moving parts of the compressor
2.
[0041] Rotation of the rotor 23 also causes reciprocating motion of
the piston assembly 31. As the assembly 31 moves to an intake
position, the piston head 34 moves away from gas inlet port 38, the
suction valve opens and refrigerant fluid is introduced into an
expanding cylinder 36 volume. The gas is pulled from the suction
plenum 12 through the intake tube 55 to the gas inlet port 38 where
the gas passes through the suction valve and is introduced into the
cylinder 36. When the piston assembly 31 reaches a first end (or
top) of its stroke, shown by movement of the piston head 34 to the
right side of the cylinder 36 of FIG. 2, the suction valve closes.
The piston head 34 then compresses the refrigerant gas by reducing
the cylinder 36 volume. When the piston assembly 31 moves to a
second end (or bottom) of its stroke, shown by movement of piston
head 34 to the left side of cylinder 36 of FIG. 2, a discharge
valve is opened and the compressed refrigerant gas is expelled
through the gas discharge port 41. The compressed refrigerant gas
flows from the gas discharge port 41 into a muffler 51 then through
an exhaust or discharge tube 53 to exit the compressor 2 into a
conduit connected to a condenser.
[0042] The motor 18 can be positioned within the top portion of the
compressor 2, and the piston assembly 31 can be positioned below
the motor 18. The oil sump 405 can be located at the bottom portion
of the compressor 2. In one embodiment, a portion of the piston
assembly 31 can be submerged below the oil level in the oil sump
405. When the compressor is not operating, sonic of the refrigerant
in compressor 2 may condense and fall by force of gravity into the
oil sump 405 and mix with the oil in the oil sump 405 or be
absorbed into the oil in the oil sump. The oil in the oil sump 405
is used to lubricate the mechanical portions of the compressor 2,
such as shaft assembly 25. When liquid refrigerant mixes with the
oil, the resulting liquid is a less effective lubricant. To avoid
this problem, the oil sump fluid is heated with a heater 131 and
the refrigerant is evaporated from the oil, leaving oil in the oil
sump 405 to lubricate the components. The heater 131 can be
positioned within the oil sump and mounted or secured to any
suitable structure inside the compressor such as the piston
assembly 31 or an interior surface of a compressor shell 39.
[0043] Power can be provided to the motor 18 and the heater 131, or
any other electrical component inside the compressor shell 39, by
use of an electrical feedthrough assembly 10. As shown in FIG. 2,
the electrical feedthrough assembly 10 can be positioned in the top
cylindrical portion of the compressor 2. However, in other
embodiments, the electrical feedthrough assembly 10 can be
positioned at any suitable location in the compressor shell 39.
[0044] The feedthrough assembly 10 can be used to provide power,
control and/or communication signals to the compressor motor 18 and
the heater 131. The feedthrough assembly 10 can eliminate all
inside and outside terminal connections at the compressor shell 39
for the motor 18 and heater 131 by permitting the corresponding
power and control conductors or wires to pass through the
compressor shell 39 without interruption, i.e., a continuous
conductor or wire is used. In addition to the elimination of the
terminal connections, the power terminal fences, fence covers, and
cover gaskets can also be eliminated with the use of the
feedthrough assembly 10. A weld housing 20 (sec FIG. 3) of the
feedthrough assembly 10 is welded or brazed or otherwise suitably
secured into the compressor shell 39 (see FIG. 7) during
fabrication and is then later used to house a sealed wire assembly
40. The sealed wire assembly 40, with its embedded wires or
conductors, can be connected into the motor stator 21 and the
heater 131 during fabrication. Upon placement of the stator 21 and
heater 131 in the compressor 2, the sealed wire assembly 40 can be
pulled through the weld housing 20 to a stop position incorporated
into the weld housing 20. A snap ring device or other suitable
mechanism or technique can then be used to secure the sealed wire
assembly 40 in the weld housing 20.
[0045] FIGS. 3 and 4 show outer and inner perspective views,
respectively, of an embodiment of an electrical feedthrough
assembly 10 for a compressor. The feedthrough assembly 10 includes
a weld housing 20 and a sealed wire assembly 40 hermetically sealed
and retained within the weld housing 20. The outer surface of the
weld housing 20 can be hermetically welded within an opening of a
compressor shell (see FIG. 7). One or more wires 42 (3 wires are
shown in FIGS. 3 and 4) can extend through the wire assembly 40 to
interconnect electrical components within the compressor shell with
electrical components outside the compressor shell. The wires 42
can be used to send high voltage and/or low voltage signals, i.e.,
power and/or control signals, through the compressor shell. In
another embodiment, one of the wires 42 can be ribbon cable.
[0046] FIGS. 5 and 6 show perspective and side cross-sectional
views, respectively, of the weld housing 20. The weld housing 20
has a substantially cylindrical central portion 22 that defines an
inner channel 24. The length 28 of the inner channel 24 is
relatively longer than the thickness of a compressor shell and/or
the bottom wall of a traditional metal collar. Thus, the inner
channel 24 provides significantly more surface area 26 for the wire
assembly 40 to seal against. The outer neck 30 of the weld housing
20 narrows in diameter by way of a shoulder portion from the
diameter of central portion 22 to permit the wire assembly 40 to be
retained against the shoulder portion of the outer neck 30 by the
internal pressure of the compressor. The inner end 32 of the weld
housing 20 has a conical shape that expands in diameter from the
diameter of central portion 22. As a result, if the weld housing 20
were to become dislodged, the internal compressor pressure would
hold the inner end 32 of the weld housing 20 against the compressor
shell 39. As shown in FIG. 7, the weld housing 20 is welded into
the opening is the compressor shell 39 by the central portion 22
adjacent inner end 32.
[0047] In one embodiment, the weld housing 20 can have a generally
circular configuration for the inner channel 24. However, in other
embodiments, the inner channel 24 of the weld housing 20 may be
configured to have a shape such as a square, triangle, rectangle,
or oval. The weld housing 20 can be formed from various materials
such as plastic, polymer, glass, ceramic and/or metals, e.g.,
brass, aluminum, copper, stainless steel and steel. Similarly, the
compressor shell could be formed from various materials such as
plastic, ceramic and/or metals. If the compressor shell and/or weld
housing are formed from a non-metallic material, different
attachment techniques, e.g., adhesive, may need to be used to
attach the weld housing to the compressor shell.
[0048] FIGS. 8 and 9 show perspective and side views, respectively,
of the sealed wire assembly 40, wherein the wire assembly 40 is
ready to be inserted into the weld housing 20. As best seen in
FIGS. 3 and 4, a body 44 of the wire assembly 40 is relatively
longer than the weld housing 20 so that, when assembled, an inner
portion 50 and an outer portion 52 of the body 44 extend from the
weld housing 20. In one embodiment, the body 44 can have a length
of 1.3 inches, but can be longer or shorter depending on the size
of the weld housing 20 and other design factors. The outer portion
52 of the body 44 is shaped complimentarily to engage with the
shoulder portion of the outer neck 30 of the weld housing 20.
[0049] FIG. 10 shows a side view of the sealed wire assembly of
FIG. 8 with the snap ring or fastener 56 and o-rings 58 removed.
The outer portion 52 includes a slot 54 for receiving the snap ring
56 as shown in FIG. 12. When disposed or positioned in the slot 54,
the snap ring 56 prevents the body 44 from moving inward in the
weld housing 20. The snap ring 56 can be carbon steel with an oil
dip coating or stainless steel. However, in other embodiments, the
snap ring 56 can be replaced with other suitable fastening devices
such as tabs or nubs connected to the compressor shell 39 or weld
housing 20 that can be bent against the body 44 to prevent axial
movement of the body 44 or the addition of latches to the body 44
that can snap into the weld housing 20 to retain the body 44. In
still further embodiments, the snap ring 56 and corresponding slot
54 may not be used to hold the body in the weld housing and
alternative retention techniques and devices can be used. For
example, the body 44 may have a threaded outer surface that can
mate or engage with either a nut or similar fastener external to
the weld housing 20 or that can mate or engage with a threaded
inner surface of the weld housing 20 to form a threaded connection
200 (see FIG. 21). The threaded inner surface can extend over the
entire inner surface of the weld housing 20 or can extend over a
portion of the inner surface of the weld housing 20, e.g., the
inner surface of the outer neck 30. Similarly, the threaded outer
surface can extend over the entire outer surface of the body 44 or
can extend over a portion of the outer surface of the body 44. To
hermetically seal the threaded connection, an adhesive or epoxy can
be used or placed between the threaded outer surface and the
threaded inner surface, nut or fastener portion. In another
example, the body 44 may incorporate a protrusion or groove that
can mate or engage with a corresponding groove or protrusion in the
central portion 22 of the weld housing 20 to prevent the body 44
from moving in the weld housing 20. In a further example, the body
44 can include a protrusion or lip that can compress against the
weld housing 20 to hold the body 44 in position.
[0050] The outer surface 46 of the body 44 also defines two grooves
48 that are within the central portion 22 of the weld housing 20,
when assembled. Each groove 48 receives an o-ring or other similar
gasket 58 (as shown in FIG. 13) to create a hermetic seal between
the body 44 and the central portion 22 of the weld housing. The
o-rings 58 may be a resiliently flexible material such as parker
compound C8873-70 available from Parker-Hannifin Corp. of
Cleveland, Ohio. In other embodiments, the outer surface 46 of the
body 44 may have only one groove 48 to receive an o-ring or 3 or
more grooves to receive o-rings. In still further embodiments, the
threaded connection embodiment and/or the protrusion embodiment
and/or the protrusion and-groove embodiment may also be used to
form the hermetic seal between the body 44 and the weld housing 20.
In additional embodiments, the body 44 does not include grooves 48
and can be compressively or interference fit within the weld
housing 20 to form the hermetic seal. In still further embodiments,
an adhesive, glue, putty, cyanoacrylate or epoxy may be used to
connect the body 44 and the weld housing 20 and/or form the
hermetic seal between the body 44 and the weld housing 20. In yet
another embodiment, depending on the material used for the body 44,
e.g., glass, epoxy or high temperature plastic, the body 44 can be
resistance welded into the weld housing 20.
[0051] Referring now to FIGS. 8-10, the body 44 may be fabricated
from a material such as an epoxy material, a polymer material, a
glass material, a ceramic material or any other suitable material
and can include passages 60, each of which carries a wire or
conductor 42. The wires or conductors 42 do not have any insulation
or other protections within the body 44, i.e., the "bare" metal is
exposed, except that at each end of the body 44, each of the wires
or conductors 42 can have an interface or transition portion with
insulation embedded within the body 44 to provide the appropriate
protection to the wires or conductors 42 once they extend outside
of the body 44. The wires 42 are buried, encased or embedded and
fixed in the passages 60 such that the seal around the wires 42 is
hermetic. The hermetic seal is formed from the material of the body
44 adhering and/or bonding with the bare metal of the wire or
conductor 42. The wires 42 can use insulation and/or protective
coatings on both the internal and external sides of the body 44 to
provide protection to the metal conductors. For example, the wires
42 can use a polytetrafluoroethylene (PTFE), machine tool wire
(MTW), a thermoplastic, high heat-resistant, nylon (THHN), air
thermoplastic, heat-resistant wet (THW) insulation or coating. In
another embodiment, the wires 42 can have a PTFE inner coating and
a machine tool wire (MTW), a thermoplastic, high heat-resistant,
nylon (THHN), or thermoplastic, heat-resistant wet (THW) outer
coating.
[0052] To assemble an embodiment of the feedthrough assembly 10 in
the shell of a compressor, an empty weld housing 20 is welded into
an opening in the shell 39. The desired number of wires 42 are
hermetically embedded in the body 44. The o-rings 58 are placed in
the respective grooves 48, and then the inner ends 64 of the wires
42 are connected to the compressor components. The outer ends 66 of
the wires 42 are routed or directed through the weld housing 20.
The body 44 is disposed or positioned within the weld housing 20
such that the o-rings 58 contact the weld housing 20 to form a
hermetic seal with the weld housing 20. To further secure the body
44 in the weld housing 20, the snap ring 56 clips into the slot
54.
[0053] It is envisioned that many techniques, now known and later
developed, can successfully accomplish the hermetic seals required
to practice the present application. For example, the weld housing
20 does not have to be welded to the shell, rather the weld housing
20 could be epoxied, glued, press-fit, form a groove that retains
an o-ring or otherwise hermetically affixed within the opening.
Similarly, the body 44 could be hermetically sealed within the weld
housing 20 simply by being oversized and formed from a material
that has scaling properties such that no o-rings are needed, i.e.,
a compression fit. The compression fit of the body 44 within the
weld housing 20 could also provide additional sealing pressure on
the wire(s) 42 as well. Epoxy, interference fits, glue and the like
could also sealingly hold the body 44 in place.
[0054] In one embodiment, the body 44 could also be shaped to be
held in place by outward pressure such that the snap ring is
unnecessary. In another embodiment, the body 44 can be easily
replaced with a new body 44 that includes additional wires in the
event that additional electrical power or control connections are
desired (see e.g., FIG. 2). In the case where the compressor shell
is thick enough, such as to accommodate a flammable refrigerant,
the body 44 may be sized and configured to directly seal to the
shell without a weld housing 20.
[0055] In one embodiment, the wires or conductors 42 can have a
non-linear path or passage through the body 44. The use of the
non-linear path can enable a wire 42 to exit the body 44 at a
location other than the end of the body, e.g., the side of the
body, to simplify wiring connections on either or both or the
inside and outside of the compressor shell.
[0056] In one embodiment, the distance the components of the
feedthrough assembly 10, e.g., the outer neck 30 and/or the body
44, project from the compressor shell 39 can be minimized to reduce
the possibility of damage to the components from contact during
handling or other operations. In another embodiment as shown in
FIG. 14, a protective shield 70 can be connected to the compressor
shell 39 and surround the outer portions of the feedthrough
assembly 10 to protect the feedthrough assembly components from
contact and damage. The protective shield 70 can have any suitable
cross-sectional shape, e.g., circle, oval, square, rectangle, etc.
In another embodiment, the protective shield 70 may not surround a
full 360 degrees around the components of the feedthrough assembly
10 to permit better access to the feedthrough assembly 10. In still
another embodiment, the shield 70 may have a cover that is parallel
to the compressor shell 39 to provide additional protection to the
feedthrough assembly 10. The cover can include an opening or other
features to permit the passage of the wires from the feedthrough
assembly 10.
[0057] In another embodiment, the wire assembly 40 can be mounted
and hermetically sealed in the compressor shell 39 without the use
of the weld housing 20. As shown in FIGS. 15-17, the wire assembly
40 passes through an opening in the compressor shell 39 and can be
mounted and hermetically sealed using any suitable technique. The
wire assembly 40 of FIGS. 15-17 can have a body 44 with a first
portion 202 having a first dimension corresponding to the opening
in the compressor shell and a second portion 204 having a second
dimension greater than the opening in the compressor shell 39. The
first portion 202 is sized to permit the first portion 202 to pass
through the opening in the compressor shell 39 and the second
portion 204 is sized to stop axial movement of the body 44 from the
compressor shell 39. As shown in FIGS. 15-17, to form the hermetic
seal between the body 44 and the inner surface of the compressor
shell 39, an o-ring, gasket, polymer material or other sealing
device 206 can be placed between the second portion 204 and the
compressor shell and compressed to form the hermetic seal. As shown
in FIG. 15, a plate 208 can be connected to the compressor shell 39
and used to compress the body 44 and o-ring 206 to form the
hermetic seal and retain the body 44 in position. The plate 208 can
have a center opening to permit the passage of the wires 42 to the
internal components of the compressor. The plate 208 can be made
from a single, integral piece or can be formed from a plurality of
separate pieces.
[0058] As shown in FIG. 16, one or more tabs 210 can be connected
to the compressor shell 39 near the opening for the body 44. A
cover 212 can connect to the tab(s) 210 to compress the body 44 and
o-ring 206 to form the hermetic seal and retain the body 44 in
position. The cover 212 can connect to the tabs 210 using a
fastening device such a bolt, screw or rivet 214. The cover 212 can
have a center opening to permit the passage of the wires 42 to the
internal components of the compressor. The cover 212 can be made
from a single, integral piece or can be formed from a plurality of
separate pieces.
[0059] As shown in FIG. 17, a threaded connection 216 between the
body 44 and a fastener 218, e.g., a nut, can be used to compress
the o-ring 206 to form the hermetic seal between the o-ring 206 and
the compressor shell 39 and retain the body 44 in the opening. The
outer surface of the first portion 202 of the body 44 can be
threaded to mate with a threaded inner surface of the fastener 218.
The fastener 218 can be held in position by an optional set screw
220 or other similar fastening device that engages the body 44. In
the embodiments of FIGS. 15-17, the second portion 204 of the body
44 is located inside the compressor shell 39, however, in other
embodiments, the configurations of FIGS. 15-17 can be reversed and
the second portion 204 of the body 44 can be located outside of the
compressor shell 39.
[0060] FIGS. 18-20 show embodiments of the feedthrough assembly 10
using compression fittings. A fitting 220 can be welded or attached
to the inner surface of the compressor shell 39. The body 44 can be
positioned in the fitting 220 and can be compressed by a fastener
or nut 222 to hold the body 44 in position. The fastener 222
compresses the body 44 through a threaded connection 224 with the
fitting 220. The fastener 222 can have a center opening to permit
the passage of the wires 42 to the internal components of the
compressor. In FIG. 18, the body 44 can be hermetically sealed
within the compressor shell 39 by the compression of a ferrule 226
into the fitting 220 when the fastener 222 is connected. The
ferrule 226 can be positioned on the outer surface of the body 44
and can be compressed by the body 44 as the fastener 222 is
connected to the fitting 220. In FIGS. 19 and 20, the body 44 can
be hermetically sealed in the compressor shell 39 by the
compression of ribs 230 when the fastener 222 is connected. The
ribs 230 can be positioned on the inner surface of the fitting 220
and can be compressed by the body 44 as the fastener 222 is
connected to the fitting 220.
[0061] In another embodiment, additional items or components can be
embedded in the body 44 to provide additional strength and/or
functionality to the body 44. For example, a sleeve can be embedded
in the body to improve the rigidity of the body 44 and depending on
the configuration of the sleeve to possibly be used to form an
interference or compression fit with the weld housing 20.
[0062] In one embodiment, terminals or pins can be embedded or
encased in the body 44 instead of wires. The connecting wires can
then be connected to the terminals using conventional techniques
such as plugs or connectors. For example, slide-on T-blocks could
be used to connect the motor on the inside with standard
wire/insulation connections on the outside. However, in another
embodiment, the motor wire(s) could be connected to the pins or
terminals on the inside and a slide-on wiring harnesses, with or
without 0.250 inch tabs, could be used for connections on the
outside.
[0063] In another embodiment, multiple bodies 44 can be used for
electrical connections inside the shell, with each body 44 having
one or more embedded wires 42. The multiple bodies 44 can be
positioned in corresponding weld housings 20 and/or in
corresponding openings in the compressor shell 39. In another
embodiment, the multiple bodies 44 can be positioned, sealed and
retained within a single weld housing 20. In still another
embodiment, the feedthrough assembly 10 can use a split, i.e., 2
piece, assembly that is pressed together to form the hermetic seal
of the body 44 with respect to the compressor shell 39. The pieces
can be pressed together, e.g., inside to outside, to secure the
feedthrough assembly 10 in the compressor shell 39 and prevent
axial movement of the body 44 in both directions, i.e., inside and
outside. The hermetic seal can be formed by the compression of
o-rings or other sealing devices against both the internal and
external surfaces of the compressor shell 39 as the pieces are
pressed together. In one embodiment, an adhesive or sealant can be
used when pressing the pieces together to further provide a
hermetic seal.
[0064] In a further embodiment, the centerline of the feedthrough
assembly 10 can be positioned at an angle of less than 90 degrees
or greater than 90 degrees with respect to the compressor shell to
permit the wires 42 to be more easily routed and connected.
[0065] As would be appreciated by those of ordinary skill in the
pertinent art, the functions of several elements of the present
application may, in alternative embodiments, be carried out by
fewer elements, or a single element. Similarly, in some
embodiments, any functional element may perform fewer, or
different, operations than those described with respect to the
shown embodiment. Also, functional elements shown as distinct in
the drawings may be incorporated within other functional elements,
separated in different hardware or distributed in various ways in a
particular implementation. Further, relative size and location are
merely somewhat schematic and it is understood that not only the
same but many other embodiments could have varying depictions.
[0066] All relative descriptions herein such as above, below, left,
right, up, and down are with reference to the Figures, and not
meant in a limiting sense. Relative descriptions such as inner and
inward are with reference to being a direction toward the interior
of a compressor shell whereas outer and outward are a direction
away from the compressor. The shown feedthrough assemblies can be
understood as providing exemplary features of varying detail of
certain embodiments, and therefore, components, modules, elements,
and/or aspects of the illustrations can be otherwise added to,
combined, interconnected, sequenced, separated, interchanged,
positioned, and/or rearranged without materially departing from the
disclosed systems or methods. Additionally, the shapes and sizes of
components are also exemplary and unless otherwise specified, can
be altered without materially affecting or limiting the disclosed
technology.
[0067] It is important to note that the construction and
arrangement of the present application as shown in the various
exemplary embodiments is illustrative only. Although only a few
embodiments have been described in detail in this application,
those who review this application can readily appreciate that many
modifications are possible (e.g., variations in sizes, dimensions,
structures, shapes and proportions of the various elements, values
of parameters (e.g., temperatures, pressures, etc.), mounting
arrangements, use of materials, colors, orientations, etc.) without
materially departing from the novel teachings and advantages of the
subject matter described in the application. For example, elements
shown as integrally formed may be constructed of multiple parts or
elements, the position of elements may be reversed or otherwise
varied, and the nature or number of discrete elements or positions
may be altered or varied. Accordingly, all such modifications are
intended to be included within the scope of the present
application. The order or sequence of any process or method steps
may be varied or re-sequenced according to alternative embodiments.
In the claims, any means-plus-function clause is intended to cover
the structures described herein as performing the recited function
and not only structural equivalents but also equivalent structures.
Other substitutions, modifications, changes and omissions may be
made in the design, operating conditions and arrangement of the
exemplary embodiments without departing from the scope of the
present application. Accordingly, the present application is not
limited to a particular embodiment, but extends to various
modifications that nevertheless fall within the scope of the
appended claims.
[0068] Furthermore, in an effort to provide a concise description
of the exemplary embodiments, all features of an actual
implementation may not have been described (i.e., those unrelated
to the presently contemplated best mode of carrying out the
invention, or those unrelated to enabling the invention). It should
be appreciated that in the development of any such actual
implementation, as in any engineering or design project, numerous
implementation specific decisions may be made. Such a development
effort might be complex and time consuming, but would nevertheless
be a routine undertaking of design, fabrication, and manufacture
for those of ordinary skill having the benefit of this disclosure,
without undue experimentation.
* * * * *