U.S. patent application number 16/406288 was filed with the patent office on 2020-11-12 for linear compressor with oil splash shield.
The applicant listed for this patent is Haier US Appliance Solutions, Inc.. Invention is credited to Gregory William Hahn, Dimitar Tcholakov.
Application Number | 20200355176 16/406288 |
Document ID | / |
Family ID | 1000004067723 |
Filed Date | 2020-11-12 |
United States Patent
Application |
20200355176 |
Kind Code |
A1 |
Hahn; Gregory William ; et
al. |
November 12, 2020 |
LINEAR COMPRESSOR WITH OIL SPLASH SHIELD
Abstract
A linear compressor includes a housing defining a sump for
collecting a lubricant and a suction inlet for receiving a flow of
refrigerant into the housing. A pump circulates the lubricant
within the housing, e.g., for lubricating a piston that is movable
along the axial direction to compress the flow of refrigerant. A
flex mount is coupled to the piston and defines a channel inlet for
receiving the flow of refrigerant. A splash shield is positioned
within the housing between the channel inlet and a pump inlet along
the vertical direction, e.g., to prevent oil entrainment into the
flow of refrigerant.
Inventors: |
Hahn; Gregory William;
(Louisville, KY) ; Tcholakov; Dimitar;
(Louisville, KY) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Haier US Appliance Solutions, Inc. |
Wilmington |
|
DE |
|
|
Family ID: |
1000004067723 |
Appl. No.: |
16/406288 |
Filed: |
May 8, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F04B 39/04 20130101;
F04B 35/045 20130101; F04B 39/0276 20130101 |
International
Class: |
F04B 39/02 20060101
F04B039/02 |
Claims
1. A linear compressor defining an axial direction and a vertical
direction, the linear compressor comprising: a housing defining a
sump for collecting a lubricant and a suction inlet for receiving a
flow of refrigerant into the housing; a pump for circulating the
lubricant within the housing, the pump comprising a pump inlet
positioned within the sump; a piston being movable along the axial
direction within a chamber to compress the flow of refrigerant; a
flex mount coupled to the piston and defining a channel in fluid
communication with the chamber and a channel inlet for receiving
the flow of refrigerant from the suction inlet and into the
channel; and a splash shield positioned within the housing between
the channel inlet and the pump inlet along the vertical
direction.
2. The linear compressor of claim 1, wherein the splash shield is
mounted on the housing below the suction inlet.
3. The linear compressor of claim 1, wherein the splash shield is
positioned above a maximum oil fill line of the housing.
4. The linear compressor of claim 1, wherein the piston
reciprocates between a top dead center position and a bottom dead
center position along the axial direction, and wherein the channel
inlet is positioned over the splash shield when the piston is in
the top dead center position.
5. The linear compressor of claim 1, wherein the splash shield
defines a depth measured along the axial direction, wherein the
depth is greater than a stroke length of the piston.
6. The linear compressor of claim 1, wherein the splash shield is
arcuate.
7. The linear compressor of claim 1, wherein the splash shield
extends around the entire channel inlet.
8. The linear compressor of claim 1, wherein the splash shield
defines a width measured perpendicular to the axial direction
within a horizontal plane, the width being greater than an inlet
diameter of the channel inlet.
9. The linear compressor of claim 1, wherein the splash shield is
formed from metal.
10. The linear compressor of claim 1, wherein the splash shield is
formed from a thermoplastic.
11. The linear compressor of claim 1, wherein the suction inlet and
the channel inlet are positioned substantially within a single
horizontal plane.
12. The linear compressor of claim 1, wherein the suction inlet and
the channel inlet are positioned approximately at a midpoint of the
housing along the vertical direction.
13. The linear compressor of claim 1, wherein the axial direction
and the vertical direction are perpendicular.
14. The linear compressor of claim 1, wherein the splash shield is
closer to the channel inlet than the pump inlet.
15. A linear compressor defining an axial direction and a vertical
direction, the linear compressor comprising: a casing comprising a
cylinder defining a chamber; a piston being movable along the axial
direction within the chamber to compress a flow of refrigerant; a
channel inlet for receiving the flow of refrigerant from a suction
inlet; a pump for circulating the lubricant within the housing, the
pump comprising a pump inlet; and a splash shield positioned within
the housing between the channel inlet and the pump inlet along the
vertical direction.
16. The linear compressor of claim 15, further comprising: a
housing defining a sump for collecting a lubricant and a suction
inlet for receiving a flow of refrigerant into the housing, wherein
the splash shield is mounted on the housing below the suction
inlet.
17. The linear compressor of claim 16, wherein the suction inlet
and the channel inlet are positioned substantially within a single
horizontal plane.
18. The linear compressor of claim 15, wherein the splash shield
defines a depth measured along the axial direction, wherein the
depth is greater than a stroke length of the piston.
19. The linear compressor of claim 15, wherein the splash shield is
arcuate.
20. The linear compressor of claim 15, wherein the splash shield
defines a width measured perpendicular to the axial direction
within a horizontal plane, the width being greater than an inlet
diameter of the channel inlet.
Description
FIELD OF THE INVENTION
[0001] The present subject matter relates generally to linear
compressors and oil splash shields 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.
[0003] 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. An oil 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 oil droplet entrainment into
the suction gas inlet. Such oil entrainment may result in valve
damage due to stress from increased valve extension. This occurs
during the expansion stroke from oil droplets impacting the surface
of the valve.
[0004] Accordingly, a linear compressor with features for
preventing oil droplet entrainment into the suction gas inlet
during operation of the linear compressor would be useful.
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 a first example embodiment, a linear compressor defines
an axial direction and a vertical direction. The linear compressor
includes a housing defining a sump for collecting a lubricant and a
suction inlet for receiving a flow of refrigerant into the housing,
a pump for circulating the lubricant within the housing, the pump
including a pump inlet positioned within the sump, and a piston
being movable along the axial direction within a chamber to
compress the flow of refrigerant. A flex mount is coupled to the
piston and defines a channel in fluid communication with the
chamber and a channel inlet for receiving the flow of refrigerant
from the suction inlet and into the channel and a splash shield is
positioned within the housing between the channel inlet and the
pump inlet along the vertical direction.
[0007] In a second example embodiment, a linear compressor defining
an axial direction and a vertical direction is provided. The linear
compressor includes a casing including a cylinder defining a
chamber, a piston being movable along the axial direction within
the chamber to compress a flow of refrigerant, and a channel inlet
for receiving the flow of refrigerant from a suction inlet. A pump
for circulates the lubricant within the housing and includes a pump
inlet and a splash shield is positioned within the housing between
the channel inlet and the pump inlet along the vertical
direction.
[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 according to an exemplary
embodiment of the present subject matter.
[0018] 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
[0019] 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.
[0020] 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.
[0021] 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.
[0022] 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.
[0023] 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 A.sub.C, 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.
[0024] 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.
[0025] 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.
[0026] Referring now generally to FIGS. 3 through 7, 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.
[0027] 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.
[0028] Referring now generally to FIGS. 3 through 7, 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 includes a cylinder 116 that defines a
chamber 118. Cylinder 116 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).
[0029] 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 valve 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.
[0030] A piston 130 with a piston head 132 is slidably received
within chamber 118 of cylinder 116. 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.
[0031] 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.
[0032] 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.
[0033] 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.
[0034] 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.
[0035] 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.
[0036] 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.
[0037] 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.
[0038] 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 116 as a
friction loss.
[0039] 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.
[0040] 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 116 and friction between piston 130 and cylinder
116 may be reduced.
[0041] As may be seen in the figures, piston head 132 of piston 130
has a 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 116 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.
[0042] 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.
[0043] 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 116, 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 116 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 116 relative to a rigid connection
between inner back iron 142 and piston 130.
[0044] 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.
[0045] 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.
[0046] 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.
[0047] Referring still to FIGS. 3 through 7, and now also referring
to FIG. 8, 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.
[0048] 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. 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.
[0049] 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, after which the oil 204 will seep
or flow out of the working components and down into sump 202 where
it is collected for recirculation. 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.
[0050] As also illustrated in the figures, linear compressor 100
may include a suction inlet 220 for receiving a flow of refrigerant
(e.g. identified herein by reference numeral 222, see FIG. 8).
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 222, through flex mount 160 towards
piston head 132. In this manner, desirable flow path of refrigerant
gas 222 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 126
may permit the compressed gas to exit chamber 118 when the desired
pressure is reached.
[0051] Flex mount 160 may further define a channel inlet 230 which
is positioned proximate a second end portion 174 of flex mount 160
for drawing gas 222 and from suction inlet 220 or cavity 108 into
channel 192. Specifically, channel inlet 230 may be an opening on
flex mount 60 which extends substantially within a vertical plane
and opens toward suction inlet 220. Specifically, according to the
illustrated embodiment, channel inlet 230 and suction inlet 220 may
be positioned substantially within the same horizontal plane (e.g.
as indicated by reference numeral 232 in FIG. 8). According to the
illustrated embodiment, suction inlet 220 and channel inlet 230 are
also positioned proximate a midpoint of housing 102 along a
vertical direction V (see FIG. 8, e.g., perpendicular to the axial
direction A). However, it should be appreciated that according to
alternative embodiments, suction inlet 220 and channel inlet 230
may be positioned at any other suitable locations within housing
102.
[0052] Notably, during certain operating conditions, oil 204 from
sump 202 may have a tendency to splash, slosh, or otherwise entrain
itself with suction gas 222. However, it is desirable to prevent
the entrainment of oil within suction gas 222, as this may cause a
malfunction of valves, may cause piston overextension, or may cause
other operating issues for linear compressor 100. Therefore,
aspects of the present subject matter are directed to features for
reducing the likelihood of oil entrainment within gas 222.
[0053] Specifically, as illustrated in the figures, linear
compressor 100 further includes a splash shield 240 that is
positioned within housing 102 between channel inlet 230 and pump
inlet 208 along the vertical direction V. Splash shield 240 is
generally configured for preventing oil droplets from splashing
upward from sump 202 into a region near suction inlet 220 or
channel inlet 230. Specifically, according to the illustrated
embodiment, splash shield 240 is mounted on or is formed as a part
of lower housing 104, and is positioned just below suction inlet
220. In addition, in order to prevent oil 204 from being filled up
above splash shield 240, splash shield 240 is typically positioned
above a max oil fill line 212 defined by housing 102. According to
an exemplary embodiment, splash shield 240 is positioned closer to
channel inlet 230 than to pump inlet 208. According still other
embodiments, splash shield 240 is positioned within a top half of
lower housing 104 along the vertical direction V, or within a top
quarter or a top eighth of lower housing 104 along the vertical
direction V. Thus, during normal operation, splash shield 240
provides a physical barrier between oil 204 in sump 202 and channel
inlet 230.
[0054] In general, splash shield 240 may have any suitable
dimensions for blocking oil droplets from reaching channel inlet
230. For example, as best shown in FIG. 8, channel inlet 230 may
remain positioned directly over splash shield 240 while piston 130
is in a top dead center position (e.g. as shown by solid lines in
FIG. 8). In addition, splash shield 240 may be in direct contact
with lower housing 104 such that channel inlet 230 is "blocked"
throughout the full stroke of piston 130. In this regard, splash
shield may define a depth 242 measured along the axial direction A.
According to an exemplary embodiment, depth 242 is greater than a
stroke length 244 of piston 130, such that even at top dead center,
channel inlet 230 defines an overlap 246 with splash shield 240
along the axial direction A.
[0055] In addition, splash shield 240 may have any suitable size
and geometry for most effectively blocking oil droplets from being
entrained within gas 222. For example, as best illustrated in FIG.
5, splash shield 240 may be arcuate or curved around a lower end of
channel inlet 230. According still other embodiments, splash shield
240 may extend in a full circle all the way around channel inlet
230. Furthermore, splash shield 240 may define a width 250 that is
measured perpendicular to the axial direction A within a horizontal
plane. According to an exemplary embodiment, width 250 is greater
than an inlet diameter 252 of channel inlet 230. For example, width
250 may be greater than 1.5 times inlet diameter 252, greater than
two times inlet diameter 252, greater than four times inlet
diameter 252, or greater.
[0056] According to exemplary embodiments, splash shield 240 may be
formed from any material which is sufficiently rigid to prevent oil
entrainment into the flow of refrigerant gas 222. For example,
splash shield 240 may be formed by injection molding, e.g., using a
suitable plastic material, such as injection molding grade
Polybutylene Terephthalate (PBT) or Nylon 6. Alternatively,
according to the exemplary embodiment, these components may be
compression molded, e.g., using sheet molding compound (SMC)
thermoset plastic or other thermoplastics. According still other
embodiments, splash shield 240 may be formed from metal or any
other suitable rigid material, such as sheet metal.
[0057] 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.
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