U.S. patent application number 17/064725 was filed with the patent office on 2022-04-07 for heat dissipation assembly for a linear compressor.
The applicant listed for this patent is Haier US Appliance Solutions, Inc.. Invention is credited to Gregory William Hahn, Andrey P. Vinnik.
Application Number | 20220106953 17/064725 |
Document ID | / |
Family ID | |
Filed Date | 2022-04-07 |
United States Patent
Application |
20220106953 |
Kind Code |
A1 |
Hahn; Gregory William ; et
al. |
April 7, 2022 |
HEAT DISSIPATION ASSEMBLY FOR A LINEAR COMPRESSOR
Abstract
A linear compressor includes a housing defining a sump for
collecting a lubricant and a pump for circulating the lubricant
within the housing. A heat dissipation assembly includes a
distribution conduit that is fluidly coupled to a hot oil
collection point and defines a plurality of discharge ports for
distributing the lubricant along the housing and back into the
sump. A flow restricting member may be positioned under or wrapped
around the distribution conduit to restrict the flow of
lubricant.
Inventors: |
Hahn; Gregory William;
(Mt.Washington, KY) ; Vinnik; Andrey P.;
(Louisville, KY) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Haier US Appliance Solutions, Inc. |
Wilmington |
DE |
US |
|
|
Appl. No.: |
17/064725 |
Filed: |
October 7, 2020 |
International
Class: |
F04B 39/06 20060101
F04B039/06; F25D 23/00 20060101 F25D023/00; F04B 39/02 20060101
F04B039/02 |
Claims
1. A compressor defining an axial direction and a vertical
direction, the compressor comprising: a housing defining a sump for
collecting lubricant; a casing positioned within the housing for
slidably receiving a piston, the casing defining a hot oil
collection point; a pump for circulating the lubricant within the
housing, the pump comprising a pump inlet positioned within the
sump; and a heat dissipation assembly comprising: a distribution
conduit extending along an inner surface of the housing, the
distribution conduit defining a fluid inlet fluidly coupled to the
hot oil collection point for receiving the lubricant; and a
plurality of discharge ports defined within the distribution
conduit for dripping the lubricant along the housing and back into
the sump.
2. The compressor of claim 1, wherein the plurality of discharge
ports is spaced equidistantly along a length of the distribution
conduit.
3. The compressor of claim 1, wherein the plurality of discharge
ports comprises greater than 50 apertures.
4. The compressor of claim 1, wherein each of the plurality of
discharge ports are positioned and oriented for directing the
lubricant onto the inner surface of the housing.
5. The compressor of claim 1, wherein each of the plurality of
discharge ports are defined on a bottom of the distribution
conduit.
6. The compressor of claim 1, wherein each of the plurality of
discharge ports is an orifice or a discharge nozzle.
7. The compressor of claim 1, wherein the heat dissipation assembly
further comprises: a flow restricting member positioned over the
plurality of discharge ports for restricting the lubricant from
passing through the plurality of discharge ports.
8. The compressor of claim 7, wherein the flow restricting member
is a spring element extending around the distribution conduit.
9. The compressor of claim 7, wherein the flow restricting member
is a woven fabric or a screen mesh positioned over the plurality of
discharge ports.
10. The compressor of claim 1, wherein the distribution conduit
extends around an entire circumference of the housing.
11. The compressor of claim 1, wherein the compressor is a linear
compressor.
12. The compressor of claim 1, wherein the heat dissipation
assembly further comprises: a supply tube providing fluid
communication between the hot oil collection point and the fluid
inlet of the distribution conduit.
13. The compressor of claim 1, wherein the distribution conduit is
attached directly to the housing.
14. A heat dissipation assembly for a compressor, the compressor
comprising a housing defining a sump for collecting lubricant, a
casing positioned within the housing for slidably receiving a
piston, the casing defining a hot oil collection point, and a pump
for circulating the lubricant within the housing, the heat
dissipation assembly comprising: a distribution conduit extending
along an inner surface of the housing, the distribution conduit
defining a fluid inlet fluidly coupled to the hot oil collection
point for receiving the lubricant; and a plurality of discharge
ports defined within the distribution conduit for dripping the
lubricant along the housing and back into the sump.
15. The heat dissipation assembly of claim 14, wherein the
plurality of discharge ports comprises greater than 50 apertures
that are spaced equidistantly along a length of the distribution
conduit.
16. The heat dissipation assembly of claim 14, wherein each of the
plurality of discharge ports are defined on a bottom of the
distribution conduit.
17. The heat dissipation assembly of claim 14, further comprising:
a flow restricting member positioned over the plurality of
discharge ports for restricting the lubricant from passing through
the plurality of discharge ports.
18. The heat dissipation assembly of claim 17, wherein the flow
restricting member is a spring element extending around the
distribution conduit or a woven fabric or a screen mesh positioned
over the plurality of discharge ports.
19. The heat dissipation assembly of claim 14, wherein the
distribution conduit extends around an entire circumference of a
lower portion of the housing and a supply tube providing fluid
communication between the hot oil collection point and the fluid
inlet of the distribution conduit.
20. The heat dissipation assembly of claim 14, wherein the
compressor is a linear compressor.
Description
FIELD OF THE INVENTION
[0001] The present subject matter relates generally to linear
compressors, and more particularly, to heat dissipation systems for
linear compressors.
BACKGROUND OF THE INVENTION
[0002] Certain refrigerator appliances include sealed systems for
cooling chilled chambers of the refrigerator appliance. The sealed
systems generally include a compressor that generates compressed
refrigerant during operation of the sealed system. The compressed
refrigerant flows to an evaporator where heat exchange between the
chilled chambers and the refrigerant cools the chilled chambers and
food items located therein. Recently, certain refrigerator
appliances have included linear compressors for compressing
refrigerant. Linear compressors generally include a piston and a
driving coil. The driving coil generates a force for sliding the
piston forward and backward within a chamber. During motion of the
piston within the chamber, the piston compresses refrigerant.
[0003] An oil or lubricant supply system is typically included
within the compressor housing for lubricating the piston to reduce
friction losses due to rubbing of the piston against the wall of
the chamber, which can negatively affect an efficiency of an
associated refrigerator appliance. However, such linear compressors
often suffer from performance issues when the oil temperature is
high. For example, as oil is heated during operation of the
compressor, oil may be atomized or may otherwise splash around
which can cause mechanical losses in the springs or reliability
issues related to oil droplet entrainment into the suction gas
inlet. Certain linear compressors include external heat exchangers
that pass hot oil outside of the housing, but these heat exchangers
are complex, costly, and are prone to leaks.
[0004] Accordingly, a linear compressor with features for improved
performance would be desirable. More particularly, a linear
compressor with an improved system for dissipating heat from oil
would be particularly beneficial.
BRIEF DESCRIPTION OF THE INVENTION
[0005] Aspects and advantages of the invention will be set forth in
part in the following description, or may be apparent from the
description, or may be learned through practice of the
invention.
[0006] In one exemplary embodiment, a compressor defining an axial
direction and a vertical direction is provided. The compressor
includes a housing defining a sump for collecting lubricant, a
casing positioned within the housing for slidably receiving a
piston, the casing defining a hot oil collection point, a pump for
circulating the lubricant within the housing, the pump including a
pump inlet positioned within the sump. A heat dissipation assembly
includes a distribution conduit extending along an inner surface of
the housing, the distribution conduit defining a fluid inlet
fluidly coupled to the hot oil collection point for receiving the
lubricant and a plurality of discharge ports defined within the
distribution conduit for dripping the lubricant along the housing
and back into the sump.
[0007] In another exemplary embodiment, a heat dissipation assembly
for a compressor is provided. The compressor includes a housing
defining a sump for collecting lubricant, a casing positioned
within the housing for slidably receiving a piston, the casing
defining a hot oil collection point, and a pump for circulating the
lubricant within the housing. The heat dissipation assembly
includes a distribution conduit extending along an inner surface of
the housing, the distribution conduit defining a fluid inlet
fluidly coupled to the hot oil collection point for receiving the
lubricant and a plurality of discharge ports defined within the
distribution conduit for dripping the lubricant along the housing
and back into the sump.
[0008] These and other features, aspects and advantages of the
present invention will become better understood with reference to
the following description and appended claims. The accompanying
drawings, which are incorporated in and constitute a part of this
specification, illustrate embodiments of the invention and,
together with the description, serve to explain the principles of
the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] A full and enabling disclosure of the present invention,
including the best mode thereof, directed to one of ordinary skill
in the art, is set forth in the specification, which makes
reference to the appended figures.
[0010] FIG. 1 is a front elevation view of a refrigerator appliance
according to an example embodiment of the present subject
matter.
[0011] FIG. 2 is schematic view of certain components of the
example refrigerator appliance of FIG. 1.
[0012] FIG. 3 is a perspective, section view of a linear compressor
according to an exemplary embodiment of the present subject
matter.
[0013] FIG. 4 is another perspective, section view of the exemplary
linear compressor of FIG. 3 according to an exemplary embodiment of
the present subject matter.
[0014] FIG. 5 is a perspective view of a linear compressor with a
compressor housing removed for clarity according to an example
embodiment of the present subject matter.
[0015] FIG. 6 is a section view of the exemplary linear compressor
of FIG. 3 with a piston in an extended position according to an
exemplary embodiment of the present subject matter.
[0016] FIG. 7 is a section view of the exemplary linear compressor
of FIG. 3 with the piston in a retracted position according to an
exemplary embodiment of the present subject matter.
[0017] FIG. 8 provides a schematic, cross sectional view of the
exemplary linear compressor of FIG. 3 including a heat dissipation
assembly according to an exemplary embodiment of the present
subject matter.
[0018] FIG. 9 provides a top view of the exemplary linear
compressor of FIG. 3 including the exemplary heat dissipation
assembly of FIG. 8 according to an exemplary embodiment of the
present subject matter.
[0019] FIG. 10 provides a schematic view of certain components of
the exemplary heat dissipation assembly of FIG. 8 according to an
exemplary embodiment of the present subject matter.
[0020] Repeat use of reference characters in the present
specification and drawings is intended to represent the same or
analogous features or elements of the present invention.
DETAILED DESCRIPTION
[0021] Reference now will be made in detail to embodiments of the
invention, one or more examples of which are illustrated in the
drawings. Each example is provided by way of explanation of the
invention, not limitation of the invention. In fact, it will be
apparent to those skilled in the art that various modifications and
variations can be made in the present invention without departing
from the scope or spirit of the invention. For instance, features
illustrated or described as part of one embodiment can be used with
another embodiment to yield a still further embodiment. Thus, it is
intended that the present invention covers such modifications and
variations as come within the scope of the appended claims and
their equivalents.
[0022] FIG. 1 depicts a refrigerator appliance 10 that incorporates
a sealed refrigeration system 60 (FIG. 2). It should be appreciated
that the term "refrigerator appliance" is used in a generic sense
herein to encompass any manner of refrigeration appliance, such as
a freezer, refrigerator/freezer combination, and any style or model
of conventional refrigerator. In addition, it should be understood
that the present subject matter is not limited to use in
appliances. Thus, the present subject matter may be used for any
other suitable purpose, such as vapor compression within air
conditioning units or air compression within air compressors.
[0023] In the illustrated example embodiment shown in FIG. 1, the
refrigerator appliance 10 is depicted as an upright refrigerator
having a cabinet or casing 12 that defines a number of internal
chilled storage compartments. In particular, refrigerator appliance
10 includes upper fresh-food compartments 14 having doors 16 and
lower freezer compartment 18 having upper drawer 20 and lower
drawer 22. The drawers 20 and 22 are "pull-out" drawers in that
they can be manually moved into and out of the freezer compartment
18 on suitable slide mechanisms.
[0024] FIG. 2 is a schematic view of certain components of
refrigerator appliance 10, including a sealed refrigeration system
60 of refrigerator appliance 10. A machinery compartment 62
contains components for executing a known vapor compression cycle
for cooling air. The components include a compressor 64, a
condenser 66, an expansion device 68, and an evaporator 70
connected in series and charged with a refrigerant. As will be
understood by those skilled in the art, refrigeration system 60 may
include additional components, e.g., at least one additional
evaporator, compressor, expansion device, and/or condenser. As an
example, refrigeration system 60 may include two evaporators.
[0025] Within refrigeration system 60, refrigerant flows into
compressor 64, which operates to increase the pressure of the
refrigerant. This compression of the refrigerant raises its
temperature, which is lowered by passing the refrigerant through
condenser 66. Within condenser 66, heat exchange with ambient air
takes place so as to cool the refrigerant. A fan 72 is used to pull
air across condenser 66, as illustrated by arrows Ac, so as to
provide forced convection for a more rapid and efficient heat
exchange between the refrigerant within condenser 66 and the
ambient air. Thus, as will be understood by those skilled in the
art, increasing air flow across condenser 66 can, e.g., increase
the efficiency of condenser 66 by improving cooling of the
refrigerant contained therein.
[0026] An expansion device 68 (e.g., a valve, capillary tube, or
other restriction device) receives refrigerant from condenser 66.
From expansion device 68, the refrigerant enters evaporator 70.
Upon exiting expansion device 68 and entering evaporator 70, the
refrigerant drops in pressure. Due to the pressure drop and/or
phase change of the refrigerant, evaporator 70 is cool relative to
compartments 14 and 18 of refrigerator appliance 10. As such,
cooled air is produced and refrigerates compartments 14 and 18 of
refrigerator appliance 10. Thus, evaporator 70 is a type of heat
exchanger which transfers heat from air passing over evaporator 70
to refrigerant flowing through evaporator 70.
[0027] Collectively, the vapor compression cycle components in a
refrigeration circuit, associated fans, and associated compartments
are sometimes referred to as a sealed refrigeration system operable
to force cold air through compartments 14, 18 (FIG. 1). The
refrigeration system 60 depicted in FIG. 2 is provided by way of
example only. Thus, it is within the scope of the present subject
matter for other configurations of the refrigeration system to be
used as well.
[0028] Referring now generally to FIGS. 3 through 9, a linear
compressor 100 will be described according to exemplary embodiments
of the present subject matter. Specifically, FIGS. 3 and 4 provide
perspective, section views of linear compressor 100, FIG. 5
provides a perspective view of linear compressor 100 with a
compressor shell or housing 102 removed for clarity, and FIGS. 6
and 7 provide section views of linear compressor when a piston is
in an extended and retracted position, respectively. It should be
appreciated that linear compressor 100 is used herein only as an
exemplary embodiment to facilitate the description of aspects of
the present subject matter. Modifications and variations may be
made to linear compressor 100 while remaining within the scope of
the present subject matter.
[0029] As illustrated for example in FIGS. 3 and 4, housing 102 may
include a lower portion or lower housing 104 and an upper portion
or upper housing 106 which are joined together to form a
substantially enclosed cavity 108 for housing various components of
linear compressor 100. Specifically, for example, cavity 108 may be
a hermetic or air-tight shell that can house working components of
linear compressor 100 and may hinder or prevent refrigerant from
leaking or escaping from refrigeration system 60. In addition,
linear compressor 100 generally defines an axial direction A, a
radial direction R, and a circumferential direction C. It should be
appreciated that linear compressor 100 is described and illustrated
herein only to describe aspects of the present subject matter.
Variations and modifications to linear compressor 100 may be made
while remaining within the scope of the present subject matter.
[0030] Referring now generally to FIGS. 3 through 9, various parts
and working components of linear compressor 100 will be described
according to an exemplary embodiment. As shown, linear compressor
100 includes a casing 110 that extends between a first end portion
112 and a second end portion 114, e.g., along the axial direction
A. Casing 110 includes a cylinder 117 that defines a chamber 118.
Cylinder 117 is positioned at or adjacent first end portion 112 of
casing 110. Chamber 118 extends longitudinally along the axial
direction A. As discussed in greater detail below, linear
compressor 100 is operable to increase a pressure of fluid within
chamber 118 of linear compressor 100. Linear compressor 100 may be
used to compress any suitable fluid, such as refrigerant or air. In
particular, linear compressor 100 may be used in a refrigerator
appliance, such as refrigerator appliance 10 (FIG. 1) in which
linear compressor 100 may be used as compressor 64 (FIG. 2).
[0031] Linear compressor 100 includes a stator 120 of a motor that
is mounted or secured to casing 110. For example, stator 120
generally includes an outer back iron 122 and a driving coil 124
that extend about the circumferential direction C within casing
110. Linear compressor 100 also includes one or more valves that
permit refrigerant to enter and exit chamber 118 during operation
of linear compressor 100. For example, a discharge muffler 126 is
positioned at an end of chamber 118 for regulating the flow of
refrigerant out of chamber 118, while a suction valve 128 (shown
only in FIGS. 6-7 for clarity) regulates flow of refrigerant into
chamber 118.
[0032] A piston 130 with a piston head 132 is slidably received
within chamber 118 of cylinder 117. In particular, piston 130 is
slidable along the axial direction A. During sliding of piston head
132 within chamber 118, piston head 132 compresses refrigerant
within chamber 118. As an example, from a top dead center position
(see, e.g., FIG. 6), piston head 132 can slide within chamber 118
towards a bottom dead center position (see, e.g., FIG. 7) along the
axial direction A, i.e., an expansion stroke of piston head 132.
When piston head 132 reaches the bottom dead center position,
piston head 132 changes directions and slides in chamber 118 back
towards the top dead center position, i.e., a compression stroke of
piston head 132. It should be understood that linear compressor 100
may include an additional piston head and/or additional chambers at
an opposite end of linear compressor 100. Thus, linear compressor
100 may have multiple piston heads in alternative exemplary
embodiments.
[0033] As illustrated, linear compressor 100 also includes a mover
140 which is generally driven by stator 120 for compressing
refrigerant. Specifically, for example, mover 140 may include an
inner back iron 142 positioned in stator 120 of the motor. In
particular, outer back iron 122 and/or driving coil 124 may extend
about inner back iron 142, e.g., along the circumferential
direction C. Inner back iron 142 also has an outer surface that
faces towards outer back iron 122 and/or driving coil 124. At least
one driving magnet 144 is mounted to inner back iron 142, e.g., at
the outer surface of inner back iron 142.
[0034] Driving magnet 144 may face and/or be exposed to driving
coil 124. In particular, driving magnet 144 may be spaced apart
from driving coil 124, e.g., along the radial direction R by an air
gap. Thus, the air gap may be defined between opposing surfaces of
driving magnet 144 and driving coil 124. Driving magnet 144 may
also be mounted or fixed to inner back iron 142 such that an outer
surface of driving magnet 144 is substantially flush with the outer
surface of inner back iron 142. Thus, driving magnet 144 may be
inset within inner back iron 142. In such a manner, the magnetic
field from driving coil 124 may have to pass through only a single
air gap between outer back iron 122 and inner back iron 142 during
operation of linear compressor 100, and linear compressor 100 may
be more efficient relative to linear compressors with air gaps on
both sides of a driving magnet.
[0035] As may be seen in FIG. 3, driving coil 124 extends about
inner back iron 142, e.g., along the circumferential direction C.
In alternative example embodiments, inner back iron 142 may extend
around driving coil 124 along the circumferential direction C.
Driving coil 124 is operable to move the inner back iron 142 along
the axial direction A during operation of driving coil 124. As an
example, a current may be induced within driving coil 124 by a
current source (not shown) to generate a magnetic field that
engages driving magnet 144 and urges piston 130 to move along the
axial direction A in order to compress refrigerant within chamber
118 as described above and will be understood by those skilled in
the art. In particular, the magnetic field of driving coil 124 may
engage driving magnet 144 in order to move inner back iron 142 and
piston head 132 along the axial direction A during operation of
driving coil 124. Thus, driving coil 124 may slide piston 130
between the top dead center position and the bottom dead center
position, e.g., by moving inner back iron 142 along the axial
direction A, during operation of driving coil 124.
[0036] Linear compressor 100 may include various components for
permitting and/or regulating operation of linear compressor 100. In
particular, linear compressor 100 includes a controller (not shown)
that is configured for regulating operation of linear compressor
100. The controller is in, e.g., operative, communication with the
motor, e.g., driving coil 124 of the motor. Thus, the controller
may selectively activate driving coil 124, e.g., by inducing
current in driving coil 124, in order to compress refrigerant with
piston 130 as described above.
[0037] The controller includes memory and one or more processing
devices such as microprocessors, CPUs or the like, such as general
or special purpose microprocessors operable to execute programming
instructions or micro-control code associated with operation of
linear compressor 100. The memory can represent random access
memory such as DRAM, or read only memory such as ROM or FLASH. The
processor executes programming instructions stored in the memory.
The memory can be a separate component from the processor or can be
included onboard within the processor. Alternatively, the
controller may be constructed without using a microprocessor, e.g.,
using a combination of discrete analog and/or digital logic
circuitry (such as switches, amplifiers, integrators, comparators,
flip-flops, AND gates, and the like) to perform control
functionality instead of relying upon software.
[0038] Inner back iron 142 further includes an outer cylinder 146
and an inner sleeve 148. Outer cylinder 146 defines the outer
surface of inner back iron 142 and also has an inner surface
positioned opposite the outer surface of outer cylinder 146. Inner
sleeve 148 is positioned on or at inner surface of outer cylinder
146. A first interference fit between outer cylinder 146 and inner
sleeve 148 may couple or secure outer cylinder 146 and inner sleeve
148 together. In alternative exemplary embodiments, inner sleeve
148 may be welded, glued, fastened, or connected via any other
suitable mechanism or method to outer cylinder 146.
[0039] Outer cylinder 146 may be constructed of or with any
suitable material. For example, outer cylinder 146 may be
constructed of or with a plurality of (e.g., ferromagnetic)
laminations. The laminations are distributed along the
circumferential direction C in order to form outer cylinder 146 and
are mounted to one another or secured together, e.g., with rings
pressed onto ends of the laminations. Outer cylinder 146 may define
a recess that extends inwardly from the outer surface of outer
cylinder 146, e.g., along the radial direction R. Driving magnet
144 is positioned in the recess on outer cylinder 146, e.g., such
that driving magnet 144 is inset within outer cylinder 146.
[0040] Linear compressor 100 also includes a pair of planar springs
150. Each planar spring 150 may be coupled to a respective end of
inner back iron 142, e.g., along the axial direction A. During
operation of driving coil 124, planar springs 150 support inner
back iron 142. In particular, inner back iron 142 is suspended by
planar springs 150 within the stator or the motor of linear
compressor 100 such that motion of inner back iron 142 along the
radial direction R is hindered or limited while motion along the
axial direction A is relatively unimpeded. Thus, planar springs 150
may be substantially stiffer along the radial direction R than
along the axial direction A. In such a manner, planar springs 150
can assist with maintaining a uniformity of the air gap between
driving magnet 144 and driving coil 124, e.g., along the radial
direction R, during operation of the motor and movement of inner
back iron 142 on the axial direction A. Planar springs 150 can also
assist with hindering side pull forces of the motor from
transmitting to piston 130 and being reacted in cylinder 117 as a
friction loss.
[0041] A flex mount 160 is mounted to and extends through inner
back iron 142. In particular, flex mount 160 is mounted to inner
back iron 142 via inner sleeve 148. Thus, flex mount 160 may be
coupled (e.g., threaded) to inner sleeve 148 at the middle portion
of inner sleeve 148 and/or flex mount 160 in order to mount or fix
flex mount 160 to inner sleeve 148. Flex mount 160 may assist with
forming a coupling 162. Coupling 162 connects inner back iron 142
and piston 130 such that motion of inner back iron 142, e.g., along
the axial direction A, is transferred to piston 130.
[0042] Coupling 162 may be a compliant coupling that is compliant
or flexible along the radial direction R. In particular, coupling
162 may be sufficiently compliant along the radial direction R such
that little or no motion of inner back iron 142 along the radial
direction R is transferred to piston 130 by coupling 162. In such a
manner, side pull forces of the motor are decoupled from piston 130
and/or cylinder 117 and friction between piston 130 and cylinder
117 may be reduced.
[0043] As may be seen in the figures, piston head 132 of piston 130
has a piston cylindrical side wall 170. Cylindrical side wall 170
may extend along the axial direction A from piston head 132 towards
inner back iron 142. An outer surface of cylindrical side wall 170
may slide on cylinder 117 at chamber 118 and an inner surface of
cylindrical side wall 170 may be positioned opposite the outer
surface of cylindrical side wall 170. Thus, the outer surface of
cylindrical side wall 170 may face away from a center of
cylindrical side wall 170 along the radial direction R, and the
inner surface of cylindrical side wall 170 may face towards the
center of cylindrical side wall 170 along the radial direction
R.
[0044] Flex mount 160 extends between a first end portion 172 and a
second end portion 174, e.g., along the axial direction A.
According to an exemplary embodiment, the inner surface of
cylindrical side wall 170 defines a ball seat 176 proximate first
end portion. In addition, coupling 162 also includes a ball nose
178. Specifically, for example, ball nose 178 is positioned at
first end portion 172 of flex mount 160, and ball nose 178 may
contact flex mount 160 at first end portion 172 of flex mount 160.
In addition, ball nose 178 may contact piston 130 at ball seat 176
of piston 130. In particular, ball nose 178 may rest on ball seat
176 of piston 130 such that ball nose 178 is slidable and/or
rotatable on ball seat 176 of piston 130. For example, ball nose
178 may have a frusto-spherical surface positioned against ball
seat 176 of piston 130, and ball seat 176 may be shaped
complementary to the frusto-spherical surface of ball nose 178. The
frusto-spherical surface of ball nose 178 may slide and/or rotate
on ball seat 176 of piston 130.
[0045] Relative motion between flex mount 160 and piston 130 at the
interface between ball nose 178 and ball seat 176 of piston 130 may
provide reduced friction between piston 130 and cylinder 117, e.g.,
compared to a fixed connection between flex mount 160 and piston
130. For example, when an axis on which piston 130 slides within
cylinder 117 is angled relative to the axis on which inner back
iron 142 reciprocates, the frusto-spherical surface of ball nose
178 may slide on ball seat 176 of piston 130 to reduce friction
between piston 130 and cylinder 117 relative to a rigid connection
between inner back iron 142 and piston 130.
[0046] Flex mount 160 is connected to inner back iron 142 away from
first end portion 172 of flex mount 160. For example, flex mount
160 may be connected to inner back iron 142 at second end portion
174 of flex mount 160 or between first and second end portions 172,
174 of flex mount 160. Conversely, flex mount 160 is positioned at
or within piston 130 at first end portion 172 of flex mount 160, as
discussed in greater detail below.
[0047] In addition, flex mount 160 includes a tubular wall 190
between inner back iron 142 and piston 130. A channel 192 within
tubular wall 190 is configured for directing compressible fluid,
such as refrigerant or air, though flex mount 160 towards piston
head 132 and/or into piston 130. Inner back iron 142 may be mounted
to flex mount 160 such that inner back iron 142 extends around
tubular wall 190, e.g., at the middle portion of flex mount 160
between first and second end portions 172, 174 of flex mount 160.
Channel 192 may extend between first and second end portions 172,
174 of flex mount 160 within tubular wall 190 such that the
compressible fluid is flowable from first end portion 172 of flex
mount 160 to second end portion 174 of flex mount 160 through
channel 192. In such a manner, compressible fluid may flow through
inner back iron 142 within flex mount 160 during operation of
linear compressor 100. A muffler 194 may be positioned within
channel 192 within tubular wall 190, e.g., to reduce the noise of
compressible fluid flowing through channel 192.
[0048] Piston head 132 also defines at least one opening 196.
Opening 196 of piston head 132 extends, e.g., along the axial
direction A, through piston head 132. Thus, the flow of fluid may
pass through piston head 132 via opening 196 of piston head 132
into chamber 118 during operation of linear compressor 100. In such
a manner, the flow of fluid (that is compressed by piston head 132
within chamber 118) may flow within channel 192 through flex mount
160 and inner back iron 142 to piston 130 during operation of
linear compressor 100. As explained above, suction valve 128 (FIGS.
6-7) may be positioned on piston head 132 to regulate the flow of
compressible fluid through opening 196 into chamber 118.
[0049] Referring still to FIGS. 3 through 9, a lubrication system
200 will be described which may be used with linear compressor 100.
Specifically, lubrication system 200 is configured for circulating
a lubricant, e.g., such as oil, through the working or moving
components of linear compressor 100 to reduce friction, improve
efficiency, etc. Although lubrication system 200 is described
herein with respect to linear compressor 100, it should be
appreciated that aspects of lubrication system 200 may apply to any
other suitable compressor or machine that requires continuous
lubrication.
[0050] As shown, housing 102 generally defines a sump 202 which is
configured for collecting oil (e.g., as identified herein by
reference numeral 204, see FIG. 8). Specifically, sump 202 is
defined in the bottom portion of lower housing 104. Lubrication
system 200 further includes a pump 206 for continuously circulating
oil 204 through components of linear compressor 100 which need
lubrication. In this regard, for example, pump 206 may include a
pump inlet 208 positioned proximate bottom of housing 102 within
sump 202. Pump 206 may draw in oil 204 from sump 202 through pump
inlet 208 before circulating it throughout linear compressor 100,
e.g., via a supply conduit 210 (FIG. 7). Although only one supply
conduit 210 is shown in the figures for clarity, it should be
appreciated that lubrication system 200 may include any suitable
number of supply conduits, nozzles, and other distribution features
in order to provide oil 204 to various components throughout linear
compressor 100.
[0051] Notably, according to the illustrated embodiment, pump inlet
208 is positioned very near and faces the bottom of lower housing
104. In this manner, pump 206 may readily draw in oil 204 even when
oil levels are low. Specifically, linear compressor 100 may be
configured for receiving oil 204 not to exceed a max oil fill line
212. For example, the max oil fill line 212 is identified in FIG.
8, and may for example extend less than half the way up lower
housing 104, less than a quarter of the way up lower housing 104,
or lower. During operation, pump 206 may circulate oil 204
throughout linear compressor 100 before being recirculated, as will
be described in further detail below. Although not illustrated
here, it should be appreciated that lubrication system 200 may
include various features for treating, filtering, or conditioning
oil 204 during recirculation, such as various filters, screens,
etc. In addition, it should be appreciated that although pump 206
is illustrated as being positioned within sump 202, it could be
positioned at any other location and may include a fluid passage
that draws oil 204 from sump 202.
[0052] As also illustrated in the figures, linear compressor 100
may include a suction inlet 220 for receiving a flow of
refrigerant. Specifically, suction inlet 220 may be defined on
housing 102 (e.g., such as on lower housing 104), and may be
configured for receiving a refrigerant supply conduit to provide
refrigerant to cavity 108. As explained above, flex mount 160
includes tubular wall 190, which defines channel 192 for directing
compressible fluid, such as refrigerant gas, through flex mount 160
towards piston head 132. In this manner, desirable flow path of
refrigerant gas is through suction inlet 220, through channel 192,
through opening 196, and into chamber 118. Suction valve 128 may
block opening 196 during a compression stroke and a discharge valve
116 may permit the compressed gas to exit chamber 118 when the
desired pressure is reached.
[0053] Flex mount 160 may further define a channel inlet 222 which
is positioned proximate a second end portion 174 of flex mount 160
for drawing gas and from suction inlet 220 or cavity 108 into
channel 192. Specifically, channel inlet 222 may be an opening on
flex mount 160 which extends substantially within a horizontal
plane (same vertical position) and opens toward suction inlet 220.
Specifically, according to the illustrated embodiment, channel
inlet 222 and suction inlet 220 may be positioned substantially
within the same horizontal plane. According to the illustrated
embodiment, suction inlet 220 and channel inlet 222 are also
positioned proximate a midpoint of housing 102 along a vertical
direction V. However, it should be appreciated that according to
alternative embodiments, suction inlet 220 and channel inlet 222
may be positioned at any other suitable locations within housing
102.
[0054] Referring now specifically to FIGS. 6 through 10, linear
compressor 100 may further include features for expelling or
dissipating heat that has built up in the oil or lubricant or
elsewhere within linear compressor 100. Specifically, according to
exemplary embodiments, linear compressor 100 includes a heat
dissipation assembly 230 that is positioned within cavity 108 and
helps facilitate the discharge of thermal energy from within cavity
108 to outside of housing 102. Although an exemplary heat
dissipation assembly 230 is described herein, it should be
appreciated that variations and modifications to heat dissipation
assembly 230 may be used while remaining within the scope of the
present subject matter. For purposes of explaining aspects of the
present subject matter, heat dissipation assembly 230 will be
described below as being used with lubrication system 200 of linear
compressor 100. However, it should be appreciated that aspects of
heat dissipation assembly 230 may be used in other compressors and
in other lubrication systems while remaining within the scope of
the present subject matter.
[0055] In general, heat dissipation assembly 230 discharges or
expels heat from lubricant 204 that is absorbed during operation of
linear compressor 100. In this regard, for example, hot lubricant
204 may be transferred directly from the moving components of
linear compressor 100 to a hot oil collection point 232. In this
regard, heat dissipation assembly 230 may have any suitable
mechanism, tubing, or other features for collecting lubricant 204
and discharging it through hot oil collection point 232 so that it
may be cooled by heat dissipation assembly 230, returned to sump
202, and recirculated. For example, according to one exemplary
embodiment, hot oil collection point 232 may be defined on casing
110 for passing heated lubricant 204 from casing 110.
[0056] As best shown in FIGS. 6 through 10, heat dissipation
assembly 230 includes a distribution conduit 240 that extends along
an inner surface 242 of housing 102. Distribution conduit 240
defines a fluid inlet 244 that is fluidly coupled to hot oil
collection point 232 on casing 110. Distribution conduit may
further define a plurality of discharge ports 246 that are
configured for spraying, dripping, or otherwise depositing the flow
of lubricant 204 along the housing 102 so that it may re-collect in
sump 202 before being recirculated by pump 206. In this manner, oil
204 is urged through the working components of linear compressor
100 to minimize friction and improve operating efficiency,
absorbing heat during the process. The heated oil 204 and then
exits casing 110 through hot oil collection point 232 where it is
distributed around housing 102 within distribution conduit 240. The
heated oil 204 is then sprayed onto housing 102 which has a lower
temperature than the heated oil 204. As the heated oil 204 flows
down housing 102 and re-collects in sump 202, thermal energy may be
transferred from the oil 204 to housing 102 where it may be
expelled into the ambient environment. In this manner, oil 204 may
be recirculated at a cooler temperature, thereby improving
performance and lifetime of linear compressor 100.
[0057] In general, distribution conduit 240 may be fluidly coupled
in any manner or by any mechanism to any point or points on casing
110 for receiving heated oil 204. For example, according to the
illustrated embodiment, heat dissipation assembly 230 includes a
supply tube 250 that extends between and provides fluid
communication between hot oil collection point 232 and fluid inlet
244 of distribution conduit 240. In this regard, for example,
supply tube 250 may be a flexible conduit that is routed from hot
oil collection point 232 to distribution conduit 240. According to
alternative embodiments, distribution conduit 240 may be directly
coupled to casing, e.g., via hot oil collection point 232 or
through any other outlet of casing 110.
[0058] Distribution conduit 240 may generally have any suitable
size, position, and configuration for distributing oil 204 as
needed to facilitate operation of heat dissipation assembly 230 and
cooling of linear compressor 100. For example, according to the
illustrated embodiment, distribution conduit 240 extends around the
entire circumference of housing 102 within a single horizontal
plane. More specifically, according to the illustrated embodiment,
distribution conduit 240 is a circular conduit that is mounted
directly to lower housing 104 via mounting brackets 252. In
general, mounting brackets 252 are configured for reducing the
transfer of vibrations from distribution conduit 240 onto housing
102.
[0059] Although distribution conduit 240 is illustrated as being
mounted directly to lower housing 104, it should be appreciated
that according to alternative embodiments any other suitable
mounting location and mechanism may be used. For example, according
to alternative embodiments, distribution conduit 240 may be mounted
directly to casing 110, such that distribution conduit 240 simply
suspended near housing 102. Alternatively, distribution conduit 240
may mounted within upper housing 106 such that heated oil 204 is
discharged along a larger surface area of housing 102 before it is
collected within sump 202. In addition, although distribution
conduit 240 is illustrated as a circular conduit extending in a
single horizontal plane, it should be appreciated that distribution
conduit may have any other suitable cross sectional shape and may
be routed through housing in any other suitable pattern or
position, e.g., in a serpentine manner, zig-zagged, etc. Other
configurations are possible and within the scope of the present
subject matter
[0060] According to exemplary embodiments, distribution conduit 240
may be formed from any material which is sufficiently rigid to
maintain a fluid passageway and contain a flow of lubricant 204
therein. For example, according to the illustrated embodiment,
distribution conduit 240 is a small conduit formed from metal.
According to alternative embodiments, distribution conduit 240 may
be formed by injection molding, e.g., using a suitable plastic
material, such as injection molding grade Polybutylene
Terephthalate (PBT), Nylon 6, high impact polystyrene (HIPS),
Perfluoroalkoxy (PFA), Flourinated ethylene propylene (FEP), or
acrylonitrile butadiene styrene (ABS). Alternatively, according to
the exemplary embodiment, these components may be extruded
(tubing), compression molded, e.g., using sheet molding compound
(SMC) thermoset plastic or other thermoplastics. According still
other embodiments, distribution conduit 240 may be formed from any
other suitable rigid material.
[0061] Discharge ports 246 that are defined distribution conduit
240 may have any suitable number, shape, size, and configuration
for suitably directing the flow of heated oil 204 on the desired
portions of housing 102. For example, according to the illustrated
embodiment, the plurality of discharge ports 246 include greater
than 10, greater than 25, greater than 50, greater than 75, or
greater than 100 discharge ports 246 that are spaced equidistantly
along a length of distribution conduit 240. According to still
other embodiments, distribution conduit 240 may define regions that
do not include discharge ports 246, e.g., at certain locations
where the distribution of oil 204 may be undesirable, e.g., such as
proximate suction inlet 220.
[0062] According to an exemplary embodiment, discharge ports 246
are simple apertures 260 that are drilled, machined, punched, or
otherwise formed within distribution conduit 240. According to
still other embodiments, each discharge port 246 may include a
discharge nozzle mounted over the aperture 260 for selectively
controlling the flow rate and direction of the flow of oil 204.
According to the illustrated embodiment, discharge ports 246 (e.g.,
apertures 260) are defined on a bottom side 262 of distribution
conduit 240. However, according to alternative embodiments,
discharge ports 246 may be defined on the sides, the top, or any
other suitable location along distribution conduit 240. For
example, discharge port 246 may be angled downward along the
vertical direction and away from a vertical centerline of linear
compressor 100. In this manner, the flow of oil 204 is urged
directly toward and down lower housing 104 into sump 202. According
still other embodiments, discharge ports 246 may be positioned and
oriented in any other suitable manner for directing oil 204 onto
inner surface 242 of housing 102.
[0063] Notably, due to the pressure and flow of oil 204 within
distribution conduit 240 it may be desirable to restrict the flow,
e.g., to prevent splashing and/or atomization of oil 204. Thus, as
best shown in FIG. 10, heat dissipation assembly 230 further
includes one or more flow restricting members 270 that are
positioned over discharge ports 246 for restricting oil 204 from
passing through discharge port 246. For example, two different flow
restricting members 270 are illustrated in FIG. 10. It should be
appreciated that these flow restricting members 270 may be used
alone or in conjunction with one another. Specifically, flow
restricting members 270 may include a coiled spring element 272
that extends around the outer diameter of distribution conduit 240
and acts to restrict flow out of discharge ports 246. According to
alternative embodiments, flow restricting member 270 may be a woven
fabric or screen mesh 274 that is positioned over the plurality of
discharge ports 246 for restricting flow therethrough. It should be
appreciated that any suitable flow restricting member 270 may be
used according to alternative embodiments. For example, cross
members or mesh screens may be formed within apertures 260 during
the manufacturing process or may be overmolded onto distribution
conduit 240 conduit after it is constructed.
[0064] The heat dissipation assembly 230 described above may be
used to cool the operation of a linear compressor, such as linear
compressor 100, or any other compressor. Specifically, heat
dissipation assembly 230 may use a mechanism for spraying oil onto
the walls of the compressor housing for achieving improved thermal
discharge and compressor efficiency. In specific, according to an
exemplary embodiment, the heat dissipation assembly 230 uses the
spray mechanism (e.g., distribution conduit 240) to spray oil onto
an inside surface of the shell evenly and in a controlled manner,
such that the shell then conducts the heat to the outer skin wall.
The slow flow of oil inside the wall allows the oil to cool.
[0065] Distribution conduit 240 operates by receiving hot oil that
leaves the cylinder under force of pump 206. The distribution
conduit 240 is provided with multiple holes (e.g., discharge ports
246), and oil is forced out through multiple holes along the
bottom-outer periphery. The oil runs down the wall around the
entire lower shell inner wall section (losing heat to the wall).
The slow flowing oil dribbles down the wall allow cooling of the
oil before it reaches the sump. The oil is maintained in liquid
form and gives up minimal heat to the suction gas inside the shell.
The flow of the oil may be slowed by using a porous or flow
restrictive surface (e.g., flow restricting member 270) as the oil
comes out of holes in the tubing. For example, a close-fitting
spring may be used to cover the outer diameter of the distribution
conduit 240 and provide further flow resistance without atomizing
the oil. By contrast, similar materials can be used like a screen
or woven nylon or other polymer material to induce oil flow
resistance. The flow resistance material allows the oil to evenly
flow down the inner wall (also provides a built-in filter for
debris as the oil flows through the sock or spring structure which
is placed over the distribution conduit 240). By starting with the
hottest oil at the top of the structure, the oil flows down to the
bottom cooled in the sump before it recirculated into the oil pump
and the compression cylinder and piston where it picks up the heat
again in a continuous cycle. The enhanced invention provides low
cost method to achieve better efficiency and avoids extra braze
joints outside the shell.
[0066] The written description uses examples to disclose the
invention, including the best mode, and also to enable any person
skilled in the art to practice the invention, including making and
using any devices or systems and performing any incorporated
methods. The patentable scope of the invention is defined by the
claims, and may include other examples that occur to those skilled
in the art. Such other examples are intended to be within the scope
of the claims if they include structural elements that do not
differ from the literal language of the claims, or if they include
equivalent structural elements with insubstantial differences from
the literal languages of the claims.
* * * * *