Linear compressor having radial stoppers

A linear compressor is provided that may include a compressor casing including a cylindrical shell and a pair of shell that covers both ends of the shell; a frame fixed to an inside of the shell; a cylinder accommodated in the shell and defining a compression space for a refrigerant; a piston inserted into the cylinder to linearly reciprocate in an axial direction of the cylinder and compress the refrigerant provided to the compression space; a motor assembly including a motor that provides power for a linear reciprocating motion to the piston, and a motor support that supports the motor; a spring that allows a resonant motion of the piston; a back cover that supports the spring; and a stopper provided in one of the pair of shell covers and contacting the back cover when the motor assembly vibrates in a radial direction of the cylinder, thereby preventing the motor assembly from colliding with the shell.

CROSS-REFERENCE TO RELATED APPLICATION(S)

The present application claims the benefits of priority to Korean Patent Application No. 10-2016-0054910, filed in Korea on May 3, 2016, which is herein incorporated by reference in its entirety.

BACKGROUND

A linear compressor is disclosed herein.

Cooling systems are systems in which a refrigerant circulates to generate cool air. In such a cooling system, processes of compressing, condensing, expanding, and evaporating the refrigerant are repeatedly performed. The cooling system includes a compressor, a condenser, an expansion device, and an evaporator. Also, the cooling system may be installed or provided in a home appliance including a refrigerator or an air conditioner.

In general, compressors are machines that receive power from a power generation device, such as an electric motor or a turbine, to compress air, a refrigerant, or various gaseous working fluids, thereby increasing a pressure and a temperature. The compressors are being widely used in home appliances or industrial fields.

Such a compressor is largely classified into a reciprocating compressor, a scroll compressor, and a rotary compressor. In recent years, development of a linear compressor belonging to one kind of reciprocating compressor has been actively carried out. The linear compressor may be directly connected to a drive motor, in which a piston is linearly reciprocated, to improve compression efficiency without mechanical loss due to movement conversion and have a simple structure.

In general, the linear compressor suctions a gaseous refrigerant while a piston is moved to linearly reciprocate within a cylinder by a linear motor and then compresses the suctioned refrigerant at a high-temperature and a high-pressure to discharge the compressed refrigerant. A linear compressor and a refrigerator including the same are disclosed in Korean Patent Publication No. 10-2016-0009306, published on Jan. 26, 2016, which is hereby incorporated by reference.

The linear compressor includes a suction part, a discharge part, a compressor casing, a compressor body, and a body support. The body support is configured to support the compressor body within the compressor casing and disposed on each of both ends of the compressor body.

The body support includes a plate spring. The plate spring is mounted in a direction perpendicular to an axial direction of the compressor body. In this case, the plate spring may have high transverse rigidity (rigidity with respect to a direction that extends perpendicular to the axial direction of the compressor body) and low longitudinal rigidity (rigidity with respect to the axial direction of the compressor body).

However, according to the related art document, a lateral stiffness of the plate spring may prevent the motor assembly from colliding with the compressor casing during operation of the compressor, but there may occur a problem that the motor assembly collides with the compressor casing in the process of transferring the compressor or a product equipped with the compressor.

That is, vibration generated during transfer of the compressor is significantly greater than vibration generated during operation of the compressor. Thus, in the process of transferring the compressor, it is highly likely that at least a portion of the motor assembly, the frame contacting the motor assembly, and the stator cover will collide with the compressor casing. As such, when the motor assembly, the frame, or the stator cover collides with the compressor casing, an impact is transferred to the motor assembly, causing damage to the motor assembly.

Also, the compressor body may be spaced apart from each cover when the compressor is in a stopped state, but the compressor body may collide with a cover of any one side due to axial shaking of the compressor body in the process of transferring the compressor. When an impulse of the compressor body and the cover is great, the plate spring may be deformed.

The impulse of the compressor body and the cover increases as an axial movement amount (or a moving distance) of the compressor body increases. In the case of the related art document, as there is no structure for reducing an axial moving distance of the compressor body, it is highly likely that the plate spring will be deformed in the process of transferring the compressor.

DETAILED DESCRIPTION

Hereinafter, exemplary embodiments will be described in detail with reference to the accompanying drawings. Where possible, like reference numerals have been used to indicate like elements, and repetitive disclosure has been omitted.

FIG. 1is a perspective view illustrating an outer appearance of a linear compressor according to an embodiment.FIG. 2is an exploded perspective view illustrating a shell and a shell cover of the linear compressor according to an embodiment.

Referring toFIGS. 1 and 2, a linear compressor10according to an embodiment may include a shell101and shell covers102and103coupled to the shell101. In a broad sense, each of the shell covers102and103may be understood as one component of the shell101. Therefore, the shell101and the shell covers102and103may be collectively referred to as a compressor casing or a casing.

A leg50may be coupled to a lower portion of the shell101. The leg50may be coupled to a base of a product in which the linear compressor10is installed or provided. For example, the product may include a refrigerator, and the base may include a machine room base of the refrigerator. For another example, the product may include an outdoor unit of an air conditioner, and the base may include a base of the outdoor unit.

The shell101may have an approximately cylindrical shape and be disposed to lie in a horizontal direction or an axial direction. InFIG. 1, the shell101may extend in the horizontal direction and have a relatively low height in a radial direction. That is, as the linear compressor10has a low height, when the linear compressor10is installed or provided in the machine room base of the refrigerator, a machine room may be reduced in height.

A terminal108may be installed or provided on an outer surface of the shell101. The terminal108may transmit external power to a motor (see reference numeral140ofFIG. 3) of the linear compressor10. The terminal108may be connected to a lead line of a coil (see reference numeral141cofFIG. 3).

A bracket109may be installed or provided outside of the terminal108. The bracket109may include a plurality of brackets that surrounds the terminal108. The bracket109may protect the terminal108against an external impact.

Both sides of the shell101may be open. The shell covers102and103may be coupled to both open sides of the shell101. The shell covers102and103may include a first shell cover102coupled to one open side of the shell101and a second shell cover103coupled to the other open side of the shell101. An inner space of the shell101may be sealed by the shell covers102and103.

InFIG. 1, the first shell cover102may be disposed at a first or right portion of the linear compressor10, and the second shell cover103may be disposed at a second or left portion of the linear compressor10. That is, the first and second shell covers102and103may be disposed to face each other.

The linear compressor10further includes a plurality of pipes104,105, and106provided in the shell101or the shell covers102and103to suction, discharge, or inject the refrigerant. The plurality of pipes104,105, and106may include a suction pipe104through which the refrigerant may be suctioned into the linear compressor10, a discharge pipe105through which the compressed refrigerant may be discharged from the linear compressor10, and a process pipe through which the refrigerant may be supplemented to the linear compressor10.

For example, the suction pipe104may be coupled to the first shell cover102. The refrigerant may be suctioned into the linear compressor10through the suction pipe104in the axial direction.

The discharge pipe105may be connected to the shell101. The refrigerant suctioned through the suction pipe104may flow in the axial direction and then be compressed in a compression space, which will be described hereinafter. Also, the compressed refrigerant may be discharged through the discharge pipe105to the outside of the compressor10. The discharge pipe105may be disposed at a position which is adjacent to the second shell cover103rather than the first shell cover102.

The process pipe106may be coupled to the outer circumferential surface of the shell101. A worker may inject the refrigerant into the linear compressor10through the process pipe106.

The process pipe106may be coupled to the shell101at a height different from a height of the discharge pipe105to avoid interference with the discharge pipe105. The height may be understood as a distance from the leg50in the vertical direction (or the radial direction). As the discharge pipe105and the process pipe106are coupled to the outer circumferential surface of the shell101at the heights different from each other, a worker's work convenience may be improved.

A first stopper500may be disposed or provided on the inner surface of the first shell cover102. The first stopper500may prevent the compressor body100, particularly, the motor140from being damaged by vibration or an impact, which occurs when the linear compressor10is carried.

The first stopper500may be disposed adjacent to a back cover170, which will be described hereinafter. When the linear compressor10is shaken, the back cover170may come into contact with the first stopper500to prevent the motor140from directly colliding with the shell101. A fixing bracket440will be described with reference to the accompanying drawings.

FIG. 3is an exploded perspective view illustrating internal parts or components of the linear compressor according to an embodiment.FIG. 4is a cross-sectional view, taken along line I-I′ ofFIG. 1.

Referring toFIGS. 3 and 4, the linear compressor10according to an embodiment may include the shell101, a compressor body100accommodated in the shell101, and a plurality of support devices or supports200and300that supports the compressor body100. One of the plurality of support devices200and300may be fixed to the shell101, and the other one may be fixed to a pair of covers102and103. As a result, the compressor body100may be supported to be spaced apart from the inner circumferential surface of the shell101.

The compressor body100may include a cylinder120provided in the shell101, a piston130that linearly reciprocates within the cylinder120, and a motor140that applies a drive force to the piston130. When the motor140is driven, the piston130may reciprocate in the axial direction.

The compressor body100may further include a suction muffler150coupled to the piston130to reduce noise generated from the refrigerant suctioned through the suction pipe104. The refrigerant suctioned through the suction pipe104may flow into the piston130via the suction muffler150. For example, while the refrigerant passes through the suction muffler150, a flow noise of the refrigerant may be reduced.

The suction muffler150may include a plurality of mufflers151,152, and153. The plurality of mufflers151,152, and153may include a first muffler151, a second muffler152, and a third muffler153, which may be coupled to each other.

The first muffler151may be disposed or provided within the piston130, and the second muffler152may be coupled to a rear portion of the first muffler151. Also, the third muffler153may accommodate the second muffler152therein and extend to a rear side of the first muffler151. In view of a flow direction of the refrigerant, the refrigerant suctioned through the suction pipe104may successively pass through the third muffler153, the second muffler152, and the first muffler151. In this process, a flow noise of the refrigerant may be reduced.

The suction muffler150may further include a muffler filter155. The muffler filter155may be disposed on or at an interface on or at which the first muffler151and the second muffler152are coupled to each other. For example, the muffler filter155may have a circular shape, and an outer circumferential portion of the muffler filter155may be supported between the first and second mufflers151and152.

The “axial direction” may be understood as a direction in which the piston130reciprocates, that is, a horizontal direction inFIG. 4. Also, “in the axial direction”, a direction from the suction pipe104toward a compression space P, that is, a direction in which the refrigerant flows may be defined as a “frontward direction”, and a direction opposite to the frontward direction may be defined as a “rearward direction”. On the other hand, the “radial direction” may be understood as a direction which is perpendicular to the direction in which the piston130reciprocates, that is, a vertical direction inFIG. 4. The “axis of the compressor body” may represent a central line or central longitude axis in the axial direction of the piston130.

The piston130may include a piston body131having an approximately cylindrical shape and a piston flange part or flange132that extends from the piston body131in the radial direction. The piston body131may reciprocate inside of the cylinder120, and the piston flange part132may reciprocate outside of the cylinder120.

The cylinder120may be configured to accommodate at least a portion of the first muffler151and at least a portion of the piston body131. The cylinder120may have the compression space P in which the refrigerant may be compressed by the piston130. Also, a suction hole133, through which the refrigerant may be introduced into the compression space P, may be defined in a front portion of the piston body131, and a suction valve135that selectively opens the suction hole133may be disposed or provided on a front side of the suction hole133. A coupling hole, to which a predetermined coupling member135amay be coupled, may be defined in an approximately central portion of the suction valve135.

A discharge cover160that defines a plurality of discharge spaces for the refrigerant discharged from the compression space P and a discharge valve assembly161and163coupled to the discharge cover assembly160to selectively discharge the refrigerant compressed in the compression space P may be provided at a front side of the compression space P. The discharge cover assembly160may include a discharge cover165coupled to a front surface of the cylinder120to accommodate the discharge valve assembly161and163therein and a plurality of discharge mufflers coupled to a front surface of the discharge cover165. The plurality of discharge mufflers may include a first discharge muffler168acoupled to the front surface of the discharge cover165and a second discharge muffler168bcoupled to a front surface of the first discharge muffler168a; however, the number of discharge mufflers are not limited thereto.

The plurality of discharge spaces may include a first discharge space160adefined inside of the discharge cover165, a second discharge space160bdefined between the discharge cover165and the first discharge muffler168a, and a third discharge space160cdefined between the first discharge muffler168aand the second discharge muffler168b. The discharge valve assembly161and163may be accommodated in the first discharge space160a.

One or a plurality of discharge holes165amay be defined in the discharge cover165, and the refrigerant discharged into the first discharge space160amay be discharged into the second discharge space160bthrough the discharge hole165aand thus is reduced in discharge noise.

The discharge valve assembly161and163may include a discharge valve161, which may be opened when a pressure of the compression space P is above a discharge pressure to introduce the refrigerant into the discharge space of the discharge cover assembly160and a spring assembly163fixed to the inside of the discharge cover165to provide elastic force in the axial direction to the discharge valve161. The spring assembly163may include a valve spring163athat applies elastic force to the discharge valve161and a spring support part or support163bthat supports the valve spring163ato the discharge cover165.

For example, the valve spring163amay include a plate spring. Also, the spring support part163bmay be integrally injection-molded to the valve spring163athrough an insertion-molding process, for example.

The discharge valve161may be coupled to the valve spring163a, and a rear portion or a rear surface of the discharge valve161may be disposed to be supported on the front surface of the cylinder120. When the discharge valve161is closely attached to the front surface of the cylinder120, the compression space P may be maintained in a sealed state. When the discharge valve161is spaced apart from the front surface of the cylinder120, the compression space P may be opened to discharge the refrigerant compressed in the compression space P to the first discharge space160a.

The compression space P may be a space defined between the suction valve135and the discharge valve161. Also, the suction valve135may be disposed on or at one side of the compression space P, and the discharge valve161may be disposed on or at the other side of the compression space P, that is, an opposite side of the suction valve135.

While the piston130linearly reciprocates within the cylinder120, when a pressure of the compression space P is less than a pressure inside of the suction muffler150, the suction valve135may be opened, and the refrigerant introduced into the suction muffler150suctioned into the compression space P. Also, when the refrigerant increases in flow rate, and thus, the pressure of the compression space P is greater than the pressure inside of the suction muffler150, the suction valve135may be closed to become a state in which the refrigerant is compressible.

When the pressure of the compression space P is greater than the pressure of the first discharge space106a, the valve spring163amay be elastically deformed forward to allow the discharge valve161to be spaced apart from the front surface of the cylinder120. Also, when the discharge valve161is opened, the refrigerant may be discharged from the compression space P to the first discharge space160a. When the pressure of the compression space P is less than the pressure of the first discharge space160aby the discharge of the refrigerant, the valve spring163amay provide a restoring force to the discharge valve161to allow the discharge valve161to be closed.

The compressor body100may further include a connection pipe162cthat connects the second discharge space160bto the third discharge space160c, a cover pipe162aconnected to the second discharge muffler168b, and a loop pipe162bthat connects the cover pipe162ato the discharge pipe105. The connection pipe162cmay have one or a first end that passes through the first discharge muffler168aand inserted into the second discharge space160band the other or a second end connected to the second discharge muffler158bto communicate with the third discharge space160c. Thus, the refrigerant discharged to the second discharge space160bmay be further reduced in noise while moving to the third discharge space160calong the connection pipe162c. Each of the pipes162a,162b, and162cmay be made of a metal material, for example.

The loop pipe162bmay have one or a first side or end coupled to the cover pipe162aand the other or a second side or end coupled to the discharge pipe105. The loop pipe162bmay be made of a flexible material. Also, the loop pipe162bmay roundly extend from the cover pipe162aalong the inner circumferential surface of the shell101and be coupled to the discharge pipe105. For example, the loop pipe162bmay be provided in a wound shape. While the refrigerant flows along the loop pipe162b, noise may be further reduced.

The compressor body100may further include a frame110. The frame110may be a part that fixes the cylinder120. For example, the cylinder120may be press-fitted into the frame110.

The frame110may be disposed or provided to surround the cylinder120. That is, the cylinder120may be inserted into an accommodation groove defined in the frame110. Also, the discharge cover assembly160may be coupled to a front surface of the frame110by using a coupling member.

The compressor body100may further include the motor140. The motor140may include an outer stator141fixed to the frame110to surround the cylinder120, an inner stator148disposed or provided to be spaced Inward from the outer stator141, and a permanent magnet146disposed or provided in a space between the outer stator141and the inner stator148.

The permanent magnet146may be linearly reciprocated by mutual electromagnetic force between the outer stator141and the inner stator148. Also, the permanent magnet146may be provided as a single magnet having one polarity or by coupling a plurality of magnets having three polarities to each other.

The permanent magnet146may be disposed or provided on the magnet frame138. The magnet frame138may have an approximately cylindrical shape and be disposed or provided to be inserted into the space between the outer stator141and the inner stator148.

Referring to the cross-sectional view ofFIG. 4, the magnet frame138may be bent forward after extending from the outer circumferential surface of the piston flange part or flange132in the radial direction. The permanent magnet146may be fixed to a front end of the magnet frame138. Thus, when the permanent magnet146reciprocates, the piston130may reciprocate together with the permanent magnet146in the axial direction.

The outer stator141may include coil winding bodies141b,141c, and141d, and a stator core141a. The coil winding bodies141b,141c, and141dmay include a bobbin141band a coil141cwound in a circumferential direction of the bobbin141b. The coil winding bodies141b,141c, and141dmay further include a terminal part or portion141dthat guides a power line connected to the coil141cso that the power line is led out or exposed to the outside of the outer stator141.

The stator core141amay include a plurality of core blocks in which a plurality of laminations may be laminated in a circumferential direction. The plurality of core blocks may be disposed or provided to surround at least a portion of the coil winding bodies141band141c.

A stator cover149may be disposed on one or a first side of the outer stator141. That is, the outer stator141may have one or a first side supported by the frame110and the other or a second side supported by the stator cover149.

The linear compressor10may further include a cover coupling member149athat couples the stator cover149to the frame110. The cover coupling member149amay pass through the stator cover149to extend forward to the frame110and then be coupled to the frame110.

That is, the cover coupling member149amay be coupled to the stator cover149and the frame110in a state in which one or a first side of the motor is supported to or by the frame110and the other or a second side of the motor is supported to the stator cover149. Therefore, the motor140, and the frame110and the stator cover149supporting the motor140may be collectively referred to as a “motor assembly”.

Also, as the frame110and the stator cover149are components supporting the motor140, the frame110and the stator cover149may be referred to as a “motor support part” or “motor support”.

The inner stator148may be fixed to an outer circumference of the frame110. Also, in the inner stator148, the plurality of laminations may be laminated outside of the frame110in the circumferential direction.

The compressor body100may further include a support137that supports the piston130. The support137may be coupled to a rear portion of the piston130, and the muffler150may be disposed or provided to pass through the inside of the support137. The piston flange part132, the magnet frame138, and the support137may be coupled to each other using a coupling member.

A balance weight179may be coupled to the support137. A weight of the balance weight179may be determined based on a drive frequency range of the compressor body100.

The compressor body100may further include a back cover170coupled to the stator cover149to extend backward. The back cover170may include three support legs, however, embodiments are not limited thereto, and the three support legs may be coupled to a rear surface of the stator cover149. A spacer181may be disposed or provided between the three support legs and the rear surface of the stator cover149. A distance from the stator cover149to a rear end of the back cover170may be determined by adjusting a thickness of the spacer181. The back cover170may be spring-supported by the support137.

The compressor body100may further include an inflow guide part or guide156coupled to the back cover170to guide an inflow of the refrigerant into the muffler150. At least a portion of the inflow guide part156may be inserted into the suction muffler150.

The compressor body100may further include a plurality of resonant springs176aand176bwhich may be adjusted in natural frequency to allow the piston130to perform a resonant motion. The plurality of resonant springs176aand176bmay include a first resonant spring176asupported between the support137and the stator cover149and a second resonant spring176bsupported between the support137and the back cover170. The piston130that reciprocates within the linear compressor10may be stably moved by the action of the plurality of resonant springs176aand176bto reduce vibration or noise due to the movement of the piston130.

The compressor body100may further include a plurality of sealing members or seals127and128that increases a coupling force between the frame110and the peripheral parts or portions around the frame110. The plurality of sealing members127and128may include a first sealing member or seal127disposed or provided at a portion at which the frame110and the discharge cover165are coupled to each other. The plurality of sealing members127and128may further include a second sealing member or seal128disposed or provided at a portion at which the frame110and the cylinder120are coupled to each other. Each of the first and second sealing members127and128may have a ring shape.

The plurality of support devices200and300may include a first support device or support200coupled to one or a first side of the compressor body100and a second support device or support300coupled to the other or a second side of the compressor body100. The first support device200may be fixed to the first shell cover102, and the second support device300may be fixed to the shell101. As axial vibration and radial vibration of the compressor body100may be absorbed by the plurality of support devices200and300, it is possible to prevent the compressor body100from directly colliding with the shell101or the shell covers102and103.

FIG. 5is a perspective view illustrating a state in which a back cover is fixed to a first shell cover by a first support device or support.FIGS. 6 and 7are perspective views illustrating the first support device and the first shell cover according to an embodiment.FIG. 8is a cross-sectional view showing a state in which the first support device is coupled to the first shell cover.FIG. 9is a plan view of the first plate spring.

Referring toFIGS. 5 to 9, the first support device200may be coupled to one of the first shell cover102or the second shell cover103in a state of being coupled to one side of the compressor body100. The first support device200may be coupled to one of the first shell cover102or the second shell cover103in a state of being spaced apart from an inner circumferential surface of the shell101. For example,FIG. 7illustrates a state in which the first support device200is coupled to the first shell cover102.

Although not limited thereto, the first support device200may be disposed or provided at a central portion of the first shell cover102. In this case, an axis or central longitudinal axis of the compressor body100may pass through the central portion of the first shell cover102, and thus, vibration of the compressor body100in the radial direction may be minimized while the compressor body100operates.

The first support device200may include a first plate spring210. When the first support device200is coupled to the first shell cover102, the first plate spring210may be fixed to the back cover170.

The first plate spring210may be disposed or provided to stand up within the shell101so that the axis of the compressor body100passes through a center of the first plate spring210.

When the first support device200includes the first plate spring210, the first support device200may be reduced in size. In addition, vibration of the compressor body100may be effectively absorbed, and also, collision between the compressor body100and the shell101may be prevented by a large transverse stiffness (stiffness in a direction perpendicular to an axial direction of the compressor body) and a small longitudinal stiffness (stiffness in the axial direction of the compressor body), which correspond to characteristics of the first plate spring210.

The first support device200may further include a first spring connection part or portion220connected to the first plate spring210. The first spring connection part220may allow the first support device200to be easily coupled to the first shell cover102.

A cover support part or portion102athat couples the first support device200may be provided on the first shell cover102. The cover support part102amay be integrated with the first shell cover102or coupled to the first shell cover102.

The first spring connection part220may be inserted into an accommodation part or portion102cof the cover support part102a. A buffer part or buffer230may be disposed or provided between the first spring connection part220and the cover support part102a. Thus, vibration transmitted from the first spring connection part220may not be transmitted to the cover support part102a, but be absorbed by the buffer part230. The buffer part230may be made of a rubber material or a material which is capable of absorbing an impact while being deformed by an external force.

Although is not limited thereto, the buffer part230may be fitted into the cover support part102a, and the first spring connection part220may be fitted into the buffer part230. Each of the accommodation part102cof the cover support part102aand the buffer part230may have a non-circular cross-section so that the buffer part230does not relatively rotate with respect to the cover support part102a. Also, a portion of the first spring connection part220, which is inserted into the buffer part230, may have a non-circular cross-section so that the first spring connection part220does not relatively rotate with respect to the buffer part230.

The buffer part230may include a first contact surface231that comes into contact with or contacts the first spring connection part220in the axial direction to absorb the vibration transmitted from the first support device200in the axial direction and a second contact surface232that comes into contact with or contacts the first spring connection part220in the radial direction to absorb vibration transmitted from the first support device200in the radial direction. The second contact surface232may have a shape which surrounds at least a portion of the first spring connection part220. An opening234through which the refrigerant may pass may be defined in the first contact surface231.

According to this embodiment, the first support device200may be coupled to the first shell cover102. As the buffer part230may be disposed or provided between the first support device200and the first shell cover102, transmission of vibration, which is generated while the compressor body100operates, into the shell101through the first shell cover102may be minimized.

In a case of this embodiment, vibration of the compressor body100in the axial direction may be absorbed by the first plate spring210, and vibration of the compressor body100in the radial direction may be absorbed by the buffer part230. Thus, transmission of vibration of the compressor body100into the shell101through the first shell cover102may be effectively reduced.

A refrigerant passage224through which the refrigerant suctioned through the suction pipe104may pass may be defined in the central portion of the first spring connection part220. For example, in a state in which the first spring connection part220is fitted into the buffer part230, the refrigerant passage224may be aligned with the opening234of the buffer part230.

The first plate spring210may include an outer rim211, an inner rim215, and a plurality of connection parts or portions219having a spirally rounded shape and connecting the outer rim211to the inner rim215. More particularly, the plurality of connection parts219may be formed by a plurality of spiral holes defined inside of the metal plate having an approximately circular shape.

A plurality of rounded extension parts or extensions216may be spaced apart from the inner rim215in the circumferential direction on an outer edge of the inner rim215. The plurality of connection parts219may be connected to the plurality of rounded extension parts216, respectively.

A through-hole through which the first spring connection part220may pass may be defined in a center of the metal plate having the approximately circular shape. A hole or slit extending in a spiral shape from an outer edge to an inner edge of the metal plate may be defined. A plurality of the hole or slit may be provided to form the first plate spring210having a predetermined elasticity.

That is, an outermost edge of the plurality of holes or slits extending in the spiral shape may be located at a point which is spaced a predetermined distance from an outer edge of the metal plate in the circumferential direction. An innermost edge of the plurality of holes or slits may be located at a point which is spaced a predetermined distance from an inner edge of the metal plate in the circumferential direction. A boundary between the plurality of holes or slits may be defined as the connection part219.

The first spring connection part220may be integrally formed with the inner rim215by insert injection molding, for example. The first spring connection part220may include a first portion that comes into contact with or contacts a first surface of the inner rim215, a second portion222that comes into contact with or contacts a second surface which is opposite to the first surface, and a third portion223that passes through the through-hole218defined inside of the inner rim215to connect the first portion221to the second portion222to prevent the first spring connection part220from being separated in the axial direction of the compressor body100in a state in which the first spring connection part220is insert-injection-molded to the inner rim215. The third portion223may pass through the through-hole218, and the first and second portions221and222may extend from an outer circumferential surface of the first portion223in the radial direction. Also, the first portion221and the second portion222may be spaced a distance corresponding to a thickness of the first plate spring210from each other.

Thus, each of the first and second portions221and222may have a diameter greater than a diameter of the through-hole218of the inner rim215. That is, each of the first and second portions221and222may have a diameter greater than a diameter of the third portion223. When the first spring connection part220is completely inserted into the buffer part230, a rear end of the third portion223may come into contact with or contact the first contact surface231of the buffer part230.

At least one hole217may be defined in the extension part216so that the first spring connection part220does not relatively rotate with respect to the first plate spring210in a state in which the first spring connection part220is inset injection-molded to the first plate spring210. A plurality of the hole217may be provided spaced apart from each other in the circumferential direction of the inner rim215. The plurality of holes217may be defined in positions which are spaced apart from the through-hole218of the inner rim215in the radial direction.

While the first spring connection part220is insert-injection-molded to the first plate spring210, a resin solution for forming the first spring connection part220may be filled into the plurality of holes217. Thus, after the first spring connection part220is insert-injection-molded to the first plate spring210, the resin solution filled into the plurality of holes217may be cured to act as rotation resistance, thereby preventing the first spring connection part220from relatively rotating with respect to the first plate spring210.

If the first plate spring210and the first spring connection part220relatively rotate with respect to each other in a state in which the first plate spring210is fixed to the compressor body100, and the first spring connection part220is fixed to the first shell cover102, the compressor body100may rotate around the axis while the compressor body100operates to increase vibration of the compressor body100in the radial direction and/or the circumferential direction. However, according to this embodiment, as the relative rotation between the plate spring210and the spring connection part220is prevented, vibration of the compressor body100in the radial direction and/or the circumferential direction while the compressor body100operates may be reduced.

The first spring connection part220may further include a rounded extension part or extension226having a same shape as each of the rounded extension parts216of the inner rim215. The extension part226may be disposed or provided in a same shape on front and rear surfaces of the first plate spring210, and then, the front extension part and the rear extension part may be connected by the resin solution filled into the plurality of holes217.

A plurality of internal extension parts or extensions213may be disposed or provided on an inner circumferential surface212of the outer rim211. The plurality of internal extension parts213may be disposed or provided to be spaced apart from each other in the circumferential direction of the outer rim211, and the plurality of connection parts219may be respectively connected to the plurality of internal extension parts213.

In this embodiment, each of the internal extension parts213is connected to each of the connection parts219, a possibility of damage of a connection point between the outer rim211and the connection part219due to vibration in the axial direction may be reduced. Also, a coupling hole214may be defined in each of the plurality of internal extension parts213, and a back cover coupling member240that couples the first plate spring210to the back cover170may pass through the coupling hole214.

The back cover coupling member240may include a cover insertion part or portion241that passes through the coupling hole172of the back cover170, a contact part or contact242that comes into contact with or contacts the back cover170, and a spring insertion part or portion243that passes through the coupling hole214of the first plate spring210.

The contact part242may have a diameter greater than a diameter of each of the cover insertion part241and the spring insertion part243. Thus, when the cover insertion part241is inserted into the coupling hole172of the back cover170to allow the contact part242to be closely attached to the back cover170, the first plate spring210and the back cover170may be spaced a length of the contact part242from each other. A washer250may be coupled to the spring insertion part243to prevent the first plate spring210from being separated from the back cover coupling member240in a state in which the spring insertion part233passes through the coupling hole214of the first plate spring210.

The back cover170may include a cover body171that defines the coupling hole172, and a plurality of coupling legs174that extends from the cover body171toward the motor140. Each of the plurality of coupling legs174may be coupled to a rear surface of the stator cover149. A number of the plurality of first stoppers500may be equal to a number of coupling legs174.

The plurality of first stoppers500may extend from the inner circumferential surface of the first shell cover102toward the axis of the compressor body100. The plurality of first stoppers500may be spaced apart from the inner circumferential surface of the first shell cover102in the circumferential direction. Also, the plurality of coupling legs174may be spaced apart in the circumferential direction of the cover body171.

The plurality of first stoppers500may include a fixing part or portion502fixed to the inner circumferential surface of the first shell cover102, an extension part or extension504bent at the fixing part502in the radial direction of the compressor body100, and a contact part or contact506bent at an end of the extension part504and extending in parallel to the axis of the compressor body100. The fixing part502may be fixed to the inner circumferential surface of the first shell cover102by welding, for example; however, embodiments are not limited to a method of fixing the fixing part502.

Also, in order to prevent the fixing part502from being separated from the first shell cover102while the back cover170collides with the first stopper500, in a state in which the fixing part502is fixed to the inner circumferential surface of the first shell cover102, a length of the fixing part502extending in parallel to the axis of the compressor body100may be about ½ or more of a length of the first shell cover102extending in parallel to the axis of the compressor body100. The fixing part502and the contact part506may extend in opposite directions with respect to the extension part504.

In a state in which the compressor body100is coupled to the first shell cover102by the first support device200, the plurality of coupling legs174may be respectively disposed to face the plurality of first stoppers500. The plurality of coupling legs174may be respectively spaced apart from the plurality of first stoppers500.

When the compressor body100is not operated, an interval between the shell101and the motor140is greater than an interval between the frame110and the shell101and an interval between the stator cover149and the shell101. Therefore, according to embodiments, the motor140does not directly collide with the shell101even when the compressor body100vibrates in the radial direction.

However, the frame110and the stator cover149directly contact and support the motor140. Therefore, if one or more of the frame110and the stator cover149collides with the shell101, an impact is transferred to the motor140, and thus, it is highly likely that the motor140will be damaged. According to embodiments, in order to prevent the frame110and the stator cover149from colliding with the shell101when the compressor body100vibrates in the radial direction, an interval between each of the plurality of coupling legs174and each of the plurality of first stoppers500may be less than an interval between the frame110and the shell101and an interval between the stator cover149and the shell101, in a state in which the compressor body100is not operated. In other words, the interval between each of the plurality of coupling legs174and the contact part506of each of the plurality of first stoppers500may be less than a minimum interval between the motor assembly and the shell101.

Therefore, even when the compressor body100vibrates in the radial direction in a process of transferring the linear compressor10, one or more of the plurality of coupling legs174may contact one or more of the plurality of first stoppers500, thereby limiting a vibration width (or vibration displacement). Consequently, it is possible to prevent the frame110and the stator cover149from colliding with the shell101, thereby preventing damage to the motor140.

The back cover170and the plurality of first stoppers500may be made of a metal material so as to prevent the back cover170and the plurality of stoppers500from being deformed by collision of the plurality of coupling legs174and the plurality of first stoppers500. Also, the back cover170may be coupled to the stator cover149, and the contact part506of each of the plurality of first stoppers500may contact a region adjacent to the cover body171at each of the plurality of coupling legs174, so as to minimize transfer of an impact to the stator cover149due to an impact caused by collision of one or more of the plurality of coupling legs174and one or more of the plurality of first stoppers500.

For example, due to vibration, the contact part506of each of the plurality of first stoppers500may contact a region between a line bisecting the plurality of coupling legs174in the axial direction and the cover body171. According to embodiments, as the plurality of first stoppers500are spaced apart in the circumferential direction of the first shell cover102, it is possible to effectively prevent the frame110and the stator cover149from colliding with the shell101, regardless of a vibrating direction of the compressor body100.

Also, as the plurality of first stoppers500are disposed in the first shell cover102, it is possible to prevent the plurality of coupling legs174from colliding with the shell101, and thus, it is possible to prevent noise from being generated by the collision. The plurality of first stoppers500may be formed in the shell101.

Also, according to embodiments, as the contact part506extends from the extension part504in a direction parallel to the axis of the compressor body100, one or more of the plurality of coupling legs174come into surface contact with or contacts one or more of the plurality of first stoppers500due to the radial vibration of the compressor body100. As a result, the plurality of coupling legs174may be rapidly aligned in the horizontal shape.

On the other hand, a recess part or recess171amay be formed in the cover body171. The recess part171amay be recessed from the cover body171toward the motor140. Therefore, as illustrated inFIG. 8, the spring coupling part220may maintain a state of being spaced apart from the recess part171awhen the compressor body100is not operated.

When the compressor body100moves toward the first spring coupling part220(a rightward direction inFIG. 8) due to axial vibration of the compressor body100, if the recess part171acontacts the first spring coupling part220, the compressor body100does not move in the rightward direction any more. Therefore, a moving distance in the axial direction of the compressor body100is reduced, thereby preventing the first plate spring210from being excessively deformed. That is, in this embodiment, the first spring coupling part220acts as a “third stopper” limiting a movement in one direction during axial vibration of the compressor body100.

In this embodiment, the recess part171ais formed in the cover body171so as to limit the axial movement of the compressor body100while preventing an increase in length in the axial direction of the linear compressor10. On the other hand, the recess part171amay define a refrigerant opening173through which the refrigerant flowing along the refrigerant passage224of the first spring coupling part220may pass.

FIGS. 10 and 11are exploded perspective views of a second support device or support according to an embodiment.FIG. 12is a cross-sectional view illustrating a state in which the second support device is coupled to the discharge cover according to an embodiment.

Referring toFIGS. 10 to 12, the second support device300may be coupled to the shell101in a state of being connected to the compressor body100. The second support device300may include a second plate spring310.

In this embodiment, as the second support device300is coupled to the shell101, a phenomenon in which the compressor body100droops down may be reduced. When the drooping of the compressor body100is reduced, collision between the compressor body100and the shell101while the compressor body100operates may be prevented.

The second support device300may further include a second spring connection part or portion320connected to a center of the second plate spring310. The second spring connection part320may be coupled to the discharge cover assembly160.

The discharge cover assembly160may include a cover protrusion166to which the second spring connection part320may be coupled. The cover protrusion166may be integrated with the discharge cover assembly160or coupled to the discharge cover assembly160. As illustrated inFIG. 4, the cover protrusion166may be mounted on a central portion of a frontmost (or outermost) discharge muffler168b.

An insertion part or portion167inserted into the second spring connection part320may protrude from a front surface of the cover protrusion166. The insertion part167may have an outer diameter less than an outer diameter of the cover protrusion166.

In a state in which the insertion part167is inserted into the second spring connection part320, a projection322may be disposed or provided on one of the insertion part167or an inner circumferential surface321of the second spring connection part320to prevent the cover protrusion166and the second spring connection part320from relatively rotating with respect to each other, and a projection accommodation groove169into which the projection322may be accommodated may be defined in the other one. For example,FIGS. 10 and 11illustrate a state in which the projection322is disposed or provided on the inner circumferential surface321of the second spring connection part320, and the projection accommodation groove169is defined in the insertion part167.

The second support device300may further include a coupling member330that couples the second spring connection part320to the cover protrusion166. The coupling member330may pass through the second spring connection part320and then be coupled to the insertion part167.

The second spring connection part320may be integrally molded to the second plate spring310through the injection-molding process, for example. The second spring connection part320may be made of a rubber material to absorb vibration, for example.

Thus, the second spring connection part320may include first to third portions to prevent the second spring connection part320from being separated from the second plate spring310in the axial direction of the compressor body100in a state in which the second spring connection part320is insert-injection-molded to the second plate spring310. The second spring connection part320may include the first portion323which extends from an outer circumferential surface of the third portion325passing through a hole defined in a center of the second plate spring310in the radial direction to come into contact with or contact a first surface of the second plate spring310and the second portion324which extends from the outer circumferential surface of the third portion325in the radial direction to come into contact with or contact a second surface of the second plate spring310. The second surface may be defined as a surface opposite to the first surface. A diameter of the first portion323and the second portion324may be greater than a diameter of the inner circumferential surface316of the second plate spring310.

The second plate spring310may include an outer rim311, an inner rim315, and a plurality of connection parts319having a spirally rounded shape and connecting the outer rim311to the inner rim315. More particularly, the plurality of connection parts319may be formed by a plurality of spiral holes defined inside of the metal plate having an approximately circular shape.

A hole through which the third portion325may pass may be defined in a center of the metal plate having the approximately circular shape. A hole or slit extending in a spiral shape from an outer edge to an inner edge of the metal plate may be defined. A plurality of the hole or slit may be provided to complete the second plate spring310having a predetermined elasticity.

That is, an outermost edge of the plurality of holes or slits extending in the spiral shape may be located at a point which is spaced a predetermined distance from an outer edge of the metal plate in a circumferential direction. An innermost edge of the plurality of holes or slits may be located at a point which is spaced a predetermined distance from an inner edge of the metal plate in the circumferential direction. A boundary between the plurality of holes or slits may be defined as the connection part319. In order to prevent the second spring coupling part320from rotating with respect to the second plate spring310in a state in which the second spring coupling part320is insert-injection-molded to the second plate spring310, the inner rim315may define holes that perform a same function as the plurality of holes217defined in the first plate spring210.

The second plate spring310may further include a plurality of fixed parts or portions that extends from an outer circumferential surface of the outer rim311in the radial direction.

The second support device300may further include a washer340fixed to a front surface of the second spring connection part320by the coupling member330. The washer340may include a coupling part or portion342closely attached to the front surface of the second spring connection part320and a bent part or portion344bent from an edge of the coupling part342to extend toward the second shell cover103. The bent part344may have a cylindrical shape.

A second stopper400may be disposed or provided at a center of a rear surface (or an inner surface) of the second shell cover103. The second stopper400(or an additional stopper) may suppress vibration of the compressor body100in the axial direction to minimize deformation of the second plate spring310and prevent the shell101from colliding due to vibration of the compressor body100in the radial direction.

The second stopper400may include a fixed part or portion402fixed to the second shell cover103and a restriction part or restrictor404bent from the fixed part402to extend toward the second plate spring310. For example, the restriction part404may have a cylindrical shape. The restriction part404may have an inner diameter greater than an outer diameter of the bent part344of the washer340.

Thus, the bent part344of the washer340may be accommodated in a region defined by the restriction part404, and an outer circumferential surface of the bent part344of the washer340may be spaced apart from an inner circumferential surface of the restriction part404of the second stopper400.

In a state in which the compressor body100is not operated, an interval between the outer circumferential surface of the bent part344of the washer340and the inner circumferential surface of the limiting part404of the second stopper400may be less than the interval between the stator cover149and the shell101. Therefore, when the compressor body100vibrates in the radial direction during the process of operating the linear compressor10or the process of transferring the linear compressor10, the outer circumferential surface of the bent part344of the washer340contacts the inner circumferential surface of the limiting part404of the second stopper400. Thus, radial movement of the compressor body100is limited, thereby preventing the compressor body100from colliding with the shell101.

Also, in a state in which operation of the linear compressor10is stopped, the bent part344may be spaced apart from the fixed part402. Thus, while the linear compressor10operates, when the compressor body100vibrates in the axial direction, the bent part344of the washer340may come into contact with or contact the fixed part402of the second stopper400to restrict movement of the compressor body100in the axial direction.

For another example, the second stopper400may include only the limiting part404, and the limiting part404may be fixed to the second shell cover103.

The support device300may include a buffer part or buffer380fitted into the fixed part312of the second plate spring310, a washer370disposed or provided on or at a front surface of the buffer part380, and a coupling bolt360(or a coupling member) that passes through the washer370and is inserted into the buffer part380.

FIG. 13is a cross-sectional view illustrating a state in which the second support device is fixed to the shell. Referring toFIG. 13, the shell101may be provided with a fixing bracket440that fixes the second support device300.

The fixing bracket440may include a fixed surface441fixed to the shell101, and a coupling surface bent from the fixed surface441to extend in the radial direction of the compressor body100. A coupling hole444to which the coupling bolt360may be coupled may be defined in the coupling surface442.

The buffer part380may be coupled to the second plate spring310to prevent the vibration of the compressor body100in the radial direction from being transmitted to the coupling bolt360. The buffer part380may be integrated with the second plate spring310through the insert injection molding, for example. That is, the buffer part380may be insert-injection-molded to the second plate spring310to form one body in such a manner in which the buffer part380is fitted into a hole defined in the fixed part312. A through-hole382through which the coupling bolt360may pass may be defined in a center of the buffer part380.

The coupling bolt360may include a body361having a cylindrical shape, a coupling part or portion363that extends from an end of the body361and is coupled to the coupling surface442, and a head365that protrudes from an outer circumferential surface of the body361. The coupling part363may have a diameter less than a diameter of the body361. Thus, the body361may include a stepped surface362.

The coupling part363of the coupling bolt360may be coupled to the coupling surface442in a state of passing through the buffer part380. Also, the stepped surface362of the body361may press the coupling surface442. Thus, the coupling part363may not be coupled to the buffer part380, and the body may be maintained in a contact state with the buffer part380.

According to this embodiment, when vibration of the compressor body in the radial direction is transmitted to the buffer part380, the vibration may be sufficiently absorbed by the buffer part380to prevent the vibration from being transmitted to the coupling bolt360.

The washer370may be interposed between the head365of the coupling bolt360and the buffer part380. When the coupling part363is coupled to the coupling surface442, the head365may press the washer370. The washer370may press the buffer part380to the coupling surface442. Thus, a pressed degree of the buffer part380may be secured by a pressing force applied from the head365. When the pressed degree of the buffer part380is secured, vibration of the buffer part380itself may be prevented.

Also, in a state in which the buffer part380comes into contact with the coupling surface442, the fixed part312of the second plate spring310may be spaced apart from the coupling surface in the axial direction. Thus, it may prevent vibration from the fixed part312of the second plate spring310from being directly transmitted to the coupling surface442.

According to embodiments disclosed herein, even when the compressor body vibrates in the radial direction in the process of transferring the linear compressor, the first stopper may limit the radial movement of the compressor body. Thus, it is possible to prevent the motor assembly from colliding with the shell, and thus, it is possible to prevent the motor from being damaged.

Further, even when the compressor body vibrates in the radial direction in the process of transferring the linear compressor, the second stopper may limit radial movement of the compressor body. Thus, it is possible to prevent the motor assembly from colliding with the shell, and thus, it is possible to prevent the motor from being damaged.

Furthermore, the back cover supporting the spring unit may include the cover body and the coupling leg, and the first stopper may contact the coupling leg at a position adjacent to the cover body. Thus, it is possible to minimize transfer of an impact between the coupling leg and the first stopper toward the motor.

Also, as the plurality of first stoppers are spaced apart in the circumferential direction of the first shell cover, it is possible to prevent the motor assembly from colliding with the shell, regardless of a vibrating direction of the compressor body. Additionally, as the linear compressor includes the second stopper limiting the axial movement of the compressor body, it is possible to prevent damage caused by excessive deformation of the second plate spring supporting the compressor body.

In a state in which the compressor body and the first support device are coupled to each other, movement of the compressor body may be limited by the first support device when the compressor body moves in the axial direction. Thus, it is possible to prevent damage caused by excessive deformation of the first plate spring constituting or forming the first support device.

Embodiments disclosed herein provide a linear compressor capable of preventing a motor assembly from colliding with a shell in a transfer process or an operation process of a compressor body. Embodiments disclosed herein also provide a linear compressor capable of preventing deformation of a plate spring for supporting a compressor body by limiting an axial movement of a compressor body to a certain range during a transfer process or an operation process of the compressor body.

Embodiments disclosed herein provide a linear compressor that may include a compressor casing including a cylindrical shell and a pair of shell covers that covers both ends of the shell; a frame fixed to an inside of the shell; a cylinder accommodated in the shell and defining a compression space for a refrigerant; a piston inserted into the cylinder to linearly reciprocate in an axial direction of the cylinder and compress the refrigerant provided to the compression space; a motor assembly including a motor that provides power for a linear reciprocating motion to the piston, and a motor support part or support that supports the motor; a spring unit or spring that allows a resonant motion of the piston; a back cover that supports the spring unit; and a stopper provided in one of the pair of shell covers and contacting the back cover when the motor assembly vibrates in a radial direction of the cylinder, thereby preventing the motor assembly from colliding with the shell.

An interval between the stopper and the back cover in the radial direction of the cylinder may be less than a minimum interval between the motor assembly and the shell. The plurality of stoppers may be spaced apart from each other in a circumferential direction of one of the shell covers.

The back cover may include a cover body; and a plurality of coupling legs bent at an edge of the cover body, extending in the axial direction of the cylinder, and spaced apart from each other in a circumferential direction of the cover body. When the motor assembly vibrates in the radial direction of the cylinder, one or more of the plurality of coupling legs may contact one or more of the plurality of stoppers. The one or more of the plurality of coupling legs may contact the one or more of the plurality of stoppers in a region between a line bisecting the coupling legs in the axial direction and the cover body.

The stopper may include a fixing part or portion fixed to one of the shell covers; an extension part or extension bent at an end of the fixing part and extending in a central direction of the shell; and a contact part or contact that extends from an end of the extension part in an extending direction of the coupling leg. The coupling leg may contact the contact part.

The linear compressor may further include a support device or support that couples the back cover to one of the shell covers. The support device may include a plate spring that supports the back cover, and when the back cover moves in the axial direction, the support device may contact the back cover to limit a movement of the back cover.

The plate spring may include an inner rim; an outer rim defined on or at an outer side of the inner rim; and a plurality of coupling parts or portions rounded in a spiral shape to couple the inner rim to the outer rim and spaced apart from each other in a circumferential direction of the plate spring.

The support device may include a spring coupling part or portion that passes through the inner rim, fixed to the inner rim, and coupled to one of the shell covers; and a back cover coupling member that couples the back cover to the outer rim and maintaining a state in which the plate spring is spaced apart from the back cover. When the back cover moves in the axial direction, the back cover may be contactable with the spring coupling part.

A recess part or recess may be recessed in a direction far away from one of the shell covers in an inside of the cover body. When the back cover moves in the axial direction, the spring coupling part may contact the recess part.

The linear compressor may further include a discharge cover assembly which may be coupled to the motor support part and from which the compressed refrigerant may be discharged; a support device or support that couples the discharge cover assembly to the shell and supports the compressor body; and an additional stopper provided in the other of the pair of shell covers and preventing the motor assembly from colliding with the shell. When the motor assembly vibrates in the radial direction, the additional stopper may be contactable with a portion of the support device. The additional stopper may include a cylindrical limiting part or portion, and the support device may include a washer that contacts the limiting part when the motor assembly vibrates in the radial direction.

The discharge cover assembly may include a discharge cover that accommodates the refrigerant discharged from the compression space; a discharge muffler disposed or provided on or at a front side of the discharge cover; and a cover protrusion that protrudes from a front surface of the discharge muffler. The support device may include a plate spring that supports the discharge cover assembly, and a spring coupling part or portion fixed to a center of the plate spring and supporting the cover protrusion.

The washer may include a fixing portion fixed to a front surface of the spring coupling part, and a cylindrical bent part or portion which may be bent and extend from an edge of the fixing part. An external diameter of the bent part may be less than an internal diameter of the limiting part. The additional stopper may include a fixing part or portion fixed to the other of the shell covers. The limiting part may extend from the edge of the fixing part. The bent part and the fixing part may be spaced apart in the axial direction of the cylinder. When the compressor body vibrates in the axial direction, the bent part may be contactable with the fixing part.

The details of one or more embodiments are set forth in the accompanying drawings and the description. Other features will be apparent from the description and drawings, and from the claims.