Patent Description:
The present disclosure relates to a compressor. More specifically, the present disclosure relates to a linear compressor for compressing a refrigerant by a linear reciprocating motion of a piston.

In general, a compressor refers to a device that is configured to receive power from a power generator such as a motor or a turbine and compress a working fluid such as air or a refrigerant. More specifically, the compressors are widely used in the whole industry or home appliances, especially a steam compression refrigeration cycle (hereinafter, referred to as "refrigeration cycle").

The compressors may be classified into a reciprocating compressor, a rotary compressor, and a scroll compressor according to a method of compressing the refrigerant.

The reciprocating compressor uses a method in which a compression space is formed between a piston and a cylinder, and the piston linearly reciprocates to compress a fluid. The rotary compressor uses a method of compressing a fluid by a roller that eccentrically rotates inside a cylinder. The scroll compressor uses a method of compressing a fluid by engaging and rotating a pair of spiral scrolls.

Recently, among the reciprocating compressors, the use of linear compressors that uses a linear reciprocating motion without using a crank shaft is gradually increasing. The linear compressor has advantages in that it has less mechanical loss resulting from switching a rotary motion to the linear reciprocating motion and thus can improve the efficiency, and has a relatively simple structure.

The linear compressor is configured such that a cylinder is positioned in a casing forming a sealed space to form a compression chamber, and a piston covering the compression chamber reciprocates inside the cylinder. The linear compressor repeats a process in which a fluid in the sealed space is sucked into the compression chamber while the piston is positioned at a bottom dead center (BDC), and the fluid of the compression chamber is compressed and discharged while the piston is positioned at a top dead center (TDC).

A compression unit and a drive unit are installed inside the linear compressor. The compression unit performs a process of compressing and discharging a refrigerant while performing a resonant motion by a resonant spring through a movement generated in the drive unit.

The piston of the linear compressor repeatedly performs a series of processes of sucking the refrigerant into the casing through a suction pipe while reciprocating at high speed inside the cylinder by the resonant spring, and then discharging the refrigerant from a compression space through a forward movement of the piston to move it to a condenser through a discharge pipe.

The linear compressor may be classified into an oil lubricated linear compressor and a gas lubricated linear compressor according to a lubrication method.

The oil lubricated linear compressor is configured to store a predetermined amount of oil in the casing and lubricate between the cylinder and the piston using the oil.

On the other hand, the gas lubricated linear compressor is configured not to store an oil in the casing, induce a part of the refrigerant discharged from the compression space between the cylinder and the piston, and lubricate between the cylinder and the piston by a gas force of the refrigerant.

The oil lubricated linear compressor supplies the oil of a relatively low temperature between the cylinder and the piston and thus can suppress the cylinder and the piston from being overheated by motor heat or compression heat, etc. Hence, the oil lubricated linear compressor suppresses specific volume from increasing as the refrigerant passing through a suction flow path of the piston is sucked into the compression chamber of the cylinder and is heated, and thus can prevent in advance a suction loss from occurring.

However, when the refrigerant and an oil discharged to a refrigeration cycle device are not smoothly returned to the compressor, the oil lubricated linear compressor may experience an oil shortage inside the casing of the compressor. The oil shortage inside the casing may lead to a reduction in the reliability of the compressor.

On the other hand, because the gas lubricated linear compressor can be made smaller than the oil lubricated linear compressor and lubricate between the cylinder and the piston using the refrigerant, the gas lubricated linear compressor has an advantage in that there is no reduction in the reliability of the compressor due to the oil shortage.

<FIG> is a cross-sectional perspective view of a partial configuration of a linear compressor according to a related art.

Referring to <FIG>, a linear compressor according to a related art is configured such that a refrigerant introduced in an intake pipe <NUM> coupled to a shell cover <NUM> of a casing is introduced into an intake muffler <NUM> through a guide member <NUM> coupled to a back cover <NUM> via an intake guide 116a.

<FIG> is a cross-sectional view of a partial configuration of a linear compressor according to a related art.

In the linear compressor according to the related art, a high-temperature refrigerant f1 between an inner surface of a side surface <NUM> connected to a rear surface <NUM> of the shell cover <NUM> and the back cover <NUM> is introduced in a space between the intake guide 116a and the back cover <NUM> and increases a temperature of a low-temperature suction refrigerant. In this case, there was a problem in that compression efficiency of the linear compressor is reduced.

<FIG> illustrate a fluid flow during an operation of a linear compressor according to a related art.

When a piston <NUM> linearly reciprocates in an axial direction, a high-temperature refrigerant outside the intake muffler <NUM> coupled to the piston <NUM> is introduced in a space between the intake muffler <NUM> and the guide member <NUM> and increases a temperature of a suction refrigerant. In this case, there was a problem in that compression efficiency of the linear compressor is reduced.

When the intake muffler <NUM> coupled to the piston <NUM> linearly reciprocates in the axial direction, there was a problem in that a refrigerant f2 causing a backflow in an expansion space of the intake muffler <NUM> interferes with the suction refrigerant and blocks the flow of the suction refrigerant.

<CIT> discloses a linear compressor having a suction guide which guides refrigerant suctioned through a suction inlet into a suction muffler.

An object of the present disclosure is to provide a linear compressor capable of reducing a noise generated by a suction refrigerant.

Another object of the present disclosure is to provide a linear compressor capable of minimizing a pressure loss due to an expansion of a suction refrigerant while reducing a noise.

Another object of the present disclosure is to provide a linear compressor capable of reducing interference with a suction refrigerant by reducing an amount of a refrigerant flowing back from an intake muffler.

Another object of the present disclosure is to provide a linear compressor capable of preventing a refrigerant outside an intake muffler from flowing back through a space between an intake flow path member and the intake muffler.

Another object of the present disclosure is to provide a linear compressor capable of increasing an efficiency of preventing a refrigerant outside an intake muffler from flowing back through a space between an intake flow path member and the intake muffler.

Another object of the present disclosure is to provide a linear compressor capable of preventing a refrigerant of a space between a rear surface of a back cover and a casing from being introduced into a space between an intake flow path member and an intake guide communicating with an intake pipe.

Another object of the present disclosure is to provide a linear compressor capable of preventing a refrigerant in front of a back cover from being introduced through a space between a radially outer surface of the back cover and an inner surface of a casing.

Another object of the present disclosure is to provide a linear compressor capable of preventing a collision of components due to a vibration generated during an operation of the linear compressor while preventing a refrigerant in front of a back cover from being introduced through a space between a radially outer surface of the back cover and an inner surface of a casing.

Another object of the present disclosure is to provide a linear compressor capable of preventing a refrigerant of a space between a rear surface of a heat blocking member and a casing from being introduced into a space between an intake flow path member and an intake guide communicating with an intake pipe.

Another object of the present disclosure is to provide a linear compressor capable of preventing a suction refrigerant introduced through an intake guide from being dissipated to the outside of an intake flow path member.

Another object of the present disclosure is to provide a linear compressor capable of coupling a back cover, a support spring, and an intake flow path member even without a separate process such as adhesion.

Another object of the present disclosure is to provide a linear compressor capable of preventing a reduction in an amount of a suction refrigerant by guiding a suction refrigerant, that is dissipated to the outside of an intake flow path member among a suction refrigerant introduced through an intake guide, to the inside of the intake flow path member.

Another object of the present disclosure is to provide a linear compressor capable of coupling a back cover, a support spring, an intake flow path member, and a heat blocking member even without a separate process such as adhesion.

To achieve the above-described and other objects, in one aspect of the present disclosure, there is provided a linear compressor comprising a casing, a back cover supported in the casing, an intake flow path member coupled to the back cover, and an intake muffler of which at least a portion linearly reciprocates inside the intake flow path member.

In this case, the intake flow path member comprises a first hole that is formed in a front surface of the intake flow path member and is penetrated by the intake muffler, and a flow path guide that extends axially forward from a rear surface of the intake flow path member and has an opened front and an opened rear.

A noise of a refrigerant passing through the intake flow path member can be reduced through an expansion space between the flow path guide and an inner surface of the intake flow path member. In this case, the present disclosure can prevent a compression loss of the linear compressor by minimizing a pressure loss due to an expansion of a suction refrigerant through the flow path guide.

The flow path guide comprises a plurality of holes that is spaced apart from each other and communicates an inside of the flow path guide with a space between the flow path guide and an inner surface of the intake flow path member.

Hence, the present disclosure can reduce interference with a suction refrigerant by reducing an amount of a refrigerant flowing back from the intake muffler, thereby preventing a loss of the suction refrigerant.

The flow path guide may be disposed inside the intake flow path member, and a diameter of the flow path guide may be greater than a diameter of the first hole.

The intake flow path member may comprise a partition wall disposed at an axially rear of the front surface of the intake flow path member and having a second hole penetrated by the intake muffler.

Hence, the present disclosure can prevent a refrigerant outside the intake muffler from flowing back through a space between the intake flow path member and the intake muffler.

A diameter of the second hole may be less than a diameter of the first hole.

Hence, the present disclosure can increase an efficiency of preventing a refrigerant outside the intake muffler from flowing back through a space between the intake flow path member and the intake muffler.

An axially rear end of the flow path guide may extend axially rearward from the rear surface of the intake flow path member and may protrude by passing through a third hole formed in a central area of the back cover.

Hence, the present disclosure can prevent a refrigerant of a space between a rear surface of the back cover and the casing from being introduced into a space between the intake flow path member and the intake guide communicating with the intake pipe.

The linear compressor may further comprise a heat blocking member coupled to a rear surface of the back cover and protruding radially outward further than the back cover.

Hence, the present disclosure can prevent a refrigerant in front of the back cover from being introduced through a space between a radially outer surface of the back cover and an inner surface of the casing.

An outer surface of the heat blocking member may be disposed adjacent to an inner surface of the casing.

Hence, the present disclosure can prevent a collision of components due to a vibration generated during an operation of the linear compressor while preventing a refrigerant in front of the back cover from being introduced through a space between a radially outer surface of the back cover and an inner surface of the casing.

An axially rear end of the flow path guide may extend axially rearward from the rear surface of the intake flow path member and may protrude by passing through a fourth hole formed in a central area of the heat blocking member.

Hence, the present disclosure can prevent a refrigerant of a space between the rear surface of the heat blocking member and the casing from being introduced into a space between the intake flow path member and the intake guide communicating with the intake pipe.

The linear compressor may further comprise an intake guide communicating with an intake pipe that is coupled to the casing and sucks a refrigerant from an outside. A diameter of the flow path guide may be greater than a diameter of the intake guide.

Hence, the present disclosure can prevent a suction refrigerant introduced through the intake guide from being dissipated to the outside of the intake flow path member.

The linear compressor may further comprise a support spring comprising an inner portion connected to the intake guide, an outer portion connected to the back cover, and a connection portion connecting the inner portion and the outer portion. The intake flow path member may comprise an extension extending radially outward from the rear surface of the intake flow path member, and the outer portion of the support spring, the extension, and the back cover may be coupled by a fastening member.

Hence, the present disclosure can couple the back cover, the support spring, and the intake flow path member even without a separate process such as adhesion.

The back cover may comprise a third hole that is formed in a central area and is penetrated by the flow path guide, and a plurality of fifth holes that is disposed radially outward further than the third hole and is spaced apart from each other in a circumferential direction. The plurality of fifth holes may communicate with a space between an inner surface of the intake flow path member and the flow path guide.

Hence, the present disclosure can prevent a reduction in an amount of a suction refrigerant by guiding a suction refrigerant, that is dissipated to the outside of the intake flow path member among a suction refrigerant introduced through the intake guide, to the inside of the intake flow path member.

To achieve the above-described and other objects, in another aspect of the present disclosure, there is provided a linear compressor comprising a casing, a back cover supported in the casing, an intake flow path member coupled to the back cover, an intake muffler of which at least a portion linearly reciprocates inside the intake flow path member, and a heat blocking member coupled to a rear surface of the back cover and protruding radially outward further than the back cover.

The linear compressor may further comprise an intake guide communicating with an intake pipe that is coupled to the casing and sucks a refrigerant from an outside. The heat blocking member may comprise a fourth hole formed in a central area of the heat blocking member, and a diameter of the fourth hole may be greater than a diameter of the intake guide.

The linear compressor may further comprise a support spring comprising an inner portion connected to the intake guide, an outer portion connected to the back cover, and a connection portion connecting the inner portion and the outer portion. The intake flow path member may comprise an extension extending radially outward from a rear surface of the intake flow path member. The outer portion of the support spring, the extension, the back cover, and the heat blocking member may be coupled by a fastening member.

Hence, the present disclosure can couple the back cover, the support spring, the intake flow path member, and the heat blocking member even without a separate process such as adhesion.

The intake flow path member may comprise a first hole that is formed in a front surface of the intake flow path member and is penetrated by the intake muffler, and a flow path guide that protrudes axially forward from a rear surface of the intake flow path member and has an opened front and an opened rear.

An outer diameter of the flow path guide may be less than a diameter of the first hole.

Based on the intake muffler moving rearward, a front area of the flow path guide may be disposed inside the intake muffler.

The intake flow path member may comprise a first hole that is formed in a front surface of the intake flow path member and is penetrated by the intake muffler, and a flow path guide that protrudes axially rearward from a central area of a rear surface of the intake flow path member and has an opened front and an opened rear.

According to an embodiment, the present disclosure can provide a linear compressor capable of reducing a noise generated by a suction refrigerant.

According to an embodiment, the present disclosure can provide a linear compressor capable of minimizing a pressure loss due to an expansion of a suction refrigerant while reducing a noise.

According to an embodiment, the present disclosure can provide a linear compressor capable of reducing interference with a suction refrigerant by reducing an amount of a refrigerant flowing back from an intake muffler.

According to an embodiment, the present disclosure can provide a linear compressor capable of preventing a refrigerant outside an intake muffler from flowing back through a space between an intake flow path member and the intake muffler.

According to an embodiment, the present disclosure can provide a linear compressor capable of increasing an efficiency of preventing a refrigerant outside an intake muffler from flowing back through a space between an intake flow path member and the intake muffler.

According to an embodiment, the present disclosure can provide a linear compressor capable of preventing a refrigerant of a space between a rear surface of a back cover and a casing from being introduced into a space between an intake flow path member and an intake guide communicating with an intake pipe.

According to an embodiment, the present disclosure can provide a linear compressor capable of preventing a refrigerant in front of a back cover from being introduced through a space between a radially outer surface of the back cover and an inner surface of a casing.

According to an embodiment, the present disclosure can provide a linear compressor capable of preventing a collision of components due to a vibration generated during the operation of the linear compressor while preventing a refrigerant in front of a back cover from being introduced through a space between a radially outer surface of the back cover and an inner surface of a casing.

According to an embodiment, the present disclosure can provide a linear compressor capable of preventing a refrigerant of a space between a rear surface of a heat blocking member and a casing from being introduced into a space between an intake flow path member and an intake guide communicating with an intake pipe.

According to an embodiment, the present disclosure can provide a linear compressor capable of preventing a suction refrigerant introduced through an intake guide from being dissipated to the outside of an intake flow path member.

According to an embodiment, the present disclosure can provide a linear compressor capable of coupling a back cover, a support spring, and an intake flow path member even without a separate process such as adhesion.

According to an embodiment, the present disclosure can provide a linear compressor capable of preventing a reduction in an amount of a suction refrigerant by guiding a suction refrigerant, that is dissipated to the outside of an intake flow path member among a suction refrigerant introduced through an intake guide, to the inside of the intake flow path member.

According to an embodiment, the present disclosure can provide a linear compressor capable of coupling a back cover, a support spring, an intake flow path member, and a heat blocking member even without a separate process such as adhesion.

The accompanying drawings, which are included to provide a further understanding of the present disclosure and constitute a part of the detailed description, illustrate embodiments of the present disclosure and serve to explain technical features of the present disclosure together with the description.

Reference will now be made in detail to embodiments of the disclosure, examples of which are illustrated in the accompanying drawings.

In embodiments of the disclosure, when an arbitrary component is described as "being connected to" or "being coupled to" other component, it should be understood that another component(s) may exist between them, although the arbitrary component may be directly connected or coupled to the other component.

It will be noted that a detailed description of known arts will be omitted if it is determined that the detailed description of the known arts can obscure embodiments of the disclosure. The accompanying drawings are used to help easily understand various technical features and it should be understood that embodiments presented herein are not limited by the accompanying drawings. As such, the present disclosure should be understand to extend to any alterations, equivalents and substitutes in addition to those which are particularly set out in the accompanying drawings.

In addition, a term of "disclosure" may be replaced by document, specification, description, etc..

<FIG> is a perspective view of a linear compressor according to an embodiment of the disclosure.

Referring to <FIG>, a linear compressor <NUM> according to an embodiment of the disclosure may include a shell <NUM> and shell covers <NUM> and <NUM> coupled to the shell <NUM>. In a broad sense, the shell covers <NUM> and <NUM> can be understood as one configuration of the shell <NUM>.

Legs <NUM> may be coupled to a lower side of the shell <NUM>. The legs <NUM> may be coupled to a base of a product on which the linear compressor <NUM> is mounted. For example, the product may include a refrigerator, and the base may include a machine room base of the refrigerator. As 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 shell <NUM> may have a substantially cylindrical shape and may be disposed to lie in a horizontal direction or an axial direction. <FIG> illustrates that the shell <NUM> is extended in the horizontal direction and has a slightly low height in a radial direction, by way of example. That is, since the linear compressor <NUM> can have a low height, there is an advantage in that a height of the machine room can decrease when the linear compressor <NUM> is installed in, for example, the machine room base of the refrigerator.

A longitudinal central axis of the shell <NUM> coincides with a central axis of a main body of the compressor <NUM> to be described later, and the central axis of the main body of the compressor <NUM> coincides with a central axis of a cylinder <NUM> and a piston <NUM> constituting the main body of the compressor <NUM>.

A terminal <NUM> may be installed on an external surface of the shell <NUM>. The terminal <NUM> may transmit external electric power to a drive unit <NUM> of the linear compressor <NUM>. More specifically, the terminal <NUM> may be connected to a lead line of a coil 132b.

A bracket <NUM> may be installed on the outside of the terminal <NUM>. The bracket <NUM> may include a plurality of brackets surrounding the terminal <NUM>. The bracket <NUM> may perform a function of protecting the terminal <NUM> from an external impact, etc..

Both sides of the shell <NUM> may be opened. The shell covers <NUM> and <NUM> may be coupled to both sides of the opened shell <NUM>. More specifically, the shell covers <NUM> and <NUM> may include a first shell cover <NUM> coupled to one opened side of the shell <NUM> and a second shell cover <NUM> coupled to the other opened side of the shell <NUM>. An inner space of the shell <NUM> may be closed by the shell covers <NUM> and <NUM>.

<FIG> illustrates that the first shell cover <NUM> is positioned on the right side of the linear compressor <NUM>, and the second shell cover <NUM> is positioned on the left side of the linear compressor <NUM>, by way of example. In other words, the first and second shell covers <NUM> and <NUM> may be disposed to face each other. It can be understood that the first shell cover <NUM> is positioned on a suction side of a refrigerant, and the second shell cover <NUM> is positioned on a discharge side of the refrigerant.

The linear compressor <NUM> may include a plurality of pipes <NUM>, <NUM>, and <NUM> that is included in the shell <NUM> or the shell covers <NUM> and <NUM> and can suck, discharge, or inject the refrigerant.

The plurality of pipes <NUM>, <NUM>, and <NUM> may include a suction pipe <NUM> that allows the refrigerant to be sucked into the linear compressor <NUM>, a discharge pipe <NUM> that allows the compressed refrigerant to be discharged from the linear compressor <NUM>, and a supplementary pipe <NUM> for supplementing the refrigerant in the linear compressor <NUM>.

For example, the suction pipe <NUM> may be coupled to the first shell cover <NUM>. The refrigerant may be sucked into the linear compressor <NUM> along the axial direction through the suction pipe <NUM>.

The discharge pipe <NUM> may be coupled to an outer circumferential surface of the shell <NUM>. The refrigerant sucked through the suction pipe <NUM> may be compressed while flowing in the axial direction. The compressed refrigerant may be discharged through the discharge pipe <NUM>. The discharge pipe <NUM> may be disposed closer to the second shell cover <NUM> than to the first shell cover <NUM>.

The supplementary pipe <NUM> may be coupled to the outer circumferential surface of the shell <NUM>. A worker may inject the refrigerant into the linear compressor <NUM> through the supplementary pipe <NUM>.

The supplementary pipe <NUM> may be coupled to the shell <NUM> at a different height from the discharge pipe <NUM> in order to prevent interference with the discharge pipe <NUM>. Here, the height may be understood as a distance measured from the leg <NUM> in a vertical direction. Because the discharge pipe <NUM> and the supplementary pipe <NUM> are coupled to the outer circumferential surface of the shell <NUM> at different heights, the work convenience can be attained.

On an inner circumferential surface of the shell <NUM> corresponding to a location at which the supplementary pipe <NUM> is coupled, at least a portion of the second shell cover <NUM> may be positioned adjacently. In other words, at least a portion of the second shell cover <NUM> may act as a resistance of the refrigerant injected through the supplementary pipe <NUM>.

Thus, with respect to a flow path of the refrigerant, a size of the flow path of the refrigerant introduced through the supplementary pipe <NUM> is configured to decrease by the second shell cover <NUM> while the refrigerant enters into the inner space of the shell <NUM>, and again increase while the refrigerant passes through the second shell cover <NUM>. In this process, a pressure of the refrigerant may be reduced to vaporize the refrigerant, and an oil contained in the refrigerant may be separated. Thus, while the refrigerant, from which the oil is separated, is introduced into the piston <NUM>, a compression performance of the refrigerant can be improved. The oil may be understood as a working oil present in a cooling system.

<FIG> is a cross-sectional view of a linear compressor according to an embodiment of the disclosure.

Hereinafter, a linear compressor according to the present disclosure will be described taking, as an example, a linear compressor that sucks and compresses a fluid while a piston linearly reciprocates, and discharges the compressed fluid.

The linear compressor may be a component of a refrigeration cycle, and the fluid compressed in the linear compressor may be a refrigerant circulating the refrigeration cycle. The refrigeration cycle may include a condenser, an expander, an evaporator, etc., in addition to the compressor. The linear compressor may be used as a component of the cooling system of the refrigerator, but is not limited thereto. The linear compressor can be widely used in the whole industry.

Referring to <FIG>, the compressor <NUM> may include a casing <NUM> and a main body accommodated in the casing <NUM>. The main body of the compressor <NUM> may include a frame <NUM>, the cylinder <NUM> fixed to the frame <NUM>, the piston <NUM> that linearly reciprocates inside the cylinder <NUM>, the drive unit <NUM> that is fixed to the frame <NUM> and gives a driving force to the piston <NUM>, and the like. Here, the cylinder <NUM> and the piston <NUM> may be referred to as compression units <NUM> and <NUM>.

The compressor <NUM> may include a bearing means for reducing a friction between the cylinder <NUM> and the piston <NUM>. The bearing means may be an oil bearing or a gas bearing. Alternatively, a mechanical bearing may be used as the bearing means.

The main body of the compressor <NUM> may be elastically supported by support springs <NUM> and <NUM> installed at both ends inside the casing <NUM>. The support springs <NUM> and <NUM> may include a first support spring <NUM> for supporting the rear of the main body and a second support spring <NUM> for supporting the front of the main body. The support springs <NUM> and <NUM> may include a leaf spring. The support springs <NUM> and <NUM> can absorb vibrations and impacts generated by a reciprocating motion of the piston <NUM> while supporting the internal parts of the main body of the compressor <NUM>.

The casing <NUM> may form a sealed space. The sealed space may include an accommodation space <NUM> in which the sucked refrigerant is accommodated, a suction space <NUM> which is filled with the refrigerant before the compression, a compression space <NUM> in which the refrigerant is compressed, and a discharge space <NUM> which is filled with the compressed refrigerant.

The refrigerant sucked from the suction pipe <NUM> connected to the rear side of the casing <NUM> may be filled in the accommodation space <NUM>, and the refrigerant in the suction space <NUM> communicating with the accommodation space <NUM> may be compressed in the compression space <NUM>, discharged to the discharge space <NUM>, and discharged to the outside through the discharge pipe <NUM> connected to the front side of the casing <NUM>.

The casing <NUM> may include the shell <NUM> formed in a substantially cylindrical shape that is open at both ends and is long in a transverse direction, the first shell cover <NUM> coupled to the rear side of the shell <NUM>, and the second shell cover <NUM> coupled to the front side of the shell <NUM>. Here, it can be understood that the front side is the left side of the figure and is a direction in which the compressed refrigerant is discharged, and the rear side is the right side of the figure and is a direction in which the refrigerant is introduced. Further, the first shell cover <NUM> and the second shell cover <NUM> may be formed as one body with the shell <NUM>.

The casing <NUM> may be formed of a thermally conductive material. Hence, heat generated in the inner space of the casing <NUM> can be quickly dissipated to the outside.

The first shell cover <NUM> may be coupled to the shell <NUM> in order to seal the rear of the shell <NUM>, and the suction pipe <NUM> may be inserted and coupled to the center of the first shell cover <NUM>.

The rear of the main body of the compressor <NUM> may be elastically supported by the first support spring <NUM> in the radial direction of the first shell cover <NUM>.

The first support spring <NUM> may include a circular leaf spring. An edge of the first support spring <NUM> may be elastically supported by a support bracket 123a in a forward direction with respect to a back cover <NUM>. An opened center portion of the first support spring <NUM> may be supported by a suction guide 116a in a rearward direction with respect to the first shell cover <NUM>.

The suction guide 116a may have a through passage formed therein. The suction guide 116a may be formed in a cylindrical shape. A front outer circumferential surface of the suction guide 116a may be coupled to a central opening of the first support spring <NUM>, and a rear end of the suction guide 116a may be supported by the first shell cover <NUM>. In this instance, a separate suction side support member 116b may be interposed between the suction guide 116a and an inner surface of the first shell cover <NUM>.

A rear side of the suction guide 116a may communicate with the suction pipe <NUM>, and the refrigerant sucked through the suction pipe <NUM> may pass through the suction guide 116a and may be smoothly introduced into a muffler unit <NUM> to be described later.

A damping member 116c may be disposed between the suction guide 116a and the suction side support member 116b. The damping member 116c may be formed of a rubber material or the like. Hence, a vibration that may occur in the process of sucking the refrigerant through the suction pipe <NUM> can be prevented from being transmitted to the first shell cover <NUM>.

The second shell cover <NUM> may be coupled to the shell <NUM> to seal the front side of the shell <NUM>, and the discharge pipe <NUM> may be inserted and coupled through a loop pipe 115a. The refrigerant discharged from the compression space <NUM> may pass through a discharge cover assembly <NUM> and then may be discharged into the refrigeration cycle through the loop pipe 115a and the discharge pipe <NUM>.

A front side of the main body of the compressor <NUM> may be elastically supported by the second support spring <NUM> in the radial direction of the shell <NUM> or the second shell cover <NUM>.

The second support spring <NUM> may include a circular leaf spring. An opened center portion of the second support spring <NUM> may be supported by a first support guide 117b in a rearward direction with respect to the discharge cover assembly <NUM>. An edge of the second support spring <NUM> may be supported by a support bracket 117a in a forward direction with respect to the inner surface of the shell <NUM> or the inner circumferential surface of the shell <NUM> adjacent to the second shell cover <NUM>.

Unlike <FIG>, the edge of the second support spring <NUM> may be supported in the forward direction with respect to the inner surface of the shell <NUM> or the inner circumferential surface of the shell <NUM> adjacent to the second shell cover <NUM> through a separate bracket (not shown) coupled to the second shell cover <NUM>.

The first support guide 117b may be formed in a cylindrical shape. A cross section of the first support guide 117b may have a plurality of diameters. A front side of the first support guide 117b may be connected to the second support spring <NUM>, and a rear side of the first support guide <NUM> may be inserted into a central opening of the discharge cover assembly <NUM>. A support cover 117c may be coupled to the front side of the first support guide 117b with the second support spring <NUM> interposed therebetween. A cup-shaped second support guide 117d that is recessed forward may be coupled to the front side of the support cover 117c. A cup-shaped third support guide 117e that corresponds to the second support guide 117d and is recessed rearward may be coupled to the inside of the second shell cover <NUM>. The second support guide 117d may be inserted into the third support guide 117e and may be supported in the axial direction and/or the radial direction. In this instance, a gap may be formed between the second support guide 117d and the third support guide 117e.

The frame <NUM> may include a body portion <NUM> supporting the outer circumferential surface of the cylinder <NUM>, and a first flange portion <NUM> that is connected to one side of the body portion <NUM> and supports the drive unit <NUM>. The frame <NUM> may be elastically supported with respect to the casing <NUM> by the first and second support springs <NUM> and <NUM> together with the drive unit <NUM> and the cylinder <NUM>.

The body portion <NUM> may wrap the outer circumferential surface of the cylinder <NUM>. The body portion <NUM> may be formed in a cylindrical shape. The first flange portion <NUM> may extend from a front end of the body portion <NUM> in the radial direction.

The cylinder <NUM> may be coupled to an inner circumferential surface of the body portion <NUM>. An inner stator <NUM> may be coupled to an outer circumferential surface of the body portion <NUM>. For example, the cylinder <NUM> may be pressed and fitted to the inner circumferential surface of the body portion <NUM>, and the inner stator <NUM> may be fixed using a separate fixing ring (not shown).

An outer stator <NUM> may be coupled to a rear surface of the first flange portion <NUM>, and the discharge cover assembly <NUM> may be coupled to a front surface of the first flange portion <NUM>. For example, the outer stator <NUM> and the discharge cover assembly <NUM> may be fixed through a mechanical coupling means.

On one side of the front surface of the first flange portion <NUM>, a bearing inlet groove 125a forming a part of the gas bearing may be formed, a bearing communication hole 125b penetrating from the bearing inlet groove 125a to the inner circumferential surface of the body portion <NUM> may be formed, and a gas groove 125c communicating with the bearing communication hole 125b may be formed on the inner circumferential surface of the body portion <NUM>.

The bearing inlet groove 125a may be recessed to a predetermined depth in the axial direction. The bearing communication hole 125b is a hole having a smaller cross-sectional area than the bearing inlet groove 125a and may be inclined toward the inner circumferential surface or the inside surface of the body portion <NUM>. The gas groove 125c may be formed in an annular shape having a predetermined depth and an axial length on the inner circumferential surface of the body portion <NUM>. Alternatively, the gas groove 125c may be formed on the outer circumferential surface of the cylinder <NUM> in contact with the inner circumferential surface of the body portion <NUM>, or formed on both the inner circumferential surface of the body portion <NUM> and the outer circumferential surface of the cylinder <NUM>.

In addition, a gas inlet <NUM> corresponding to the gas groove 125c may be formed on the outer circumferential surface of the cylinder <NUM>. The gas inlet <NUM> forms a kind of nozzle in the gas bearing.

The frame <NUM> and the cylinder <NUM> may be formed of aluminum or an aluminum alloy material.

The cylinder <NUM> may be formed in a cylindrical shape that is open at both ends. The piston <NUM> may be inserted through a rear end of the cylinder <NUM>. A front end of the cylinder <NUM> may be closed via a discharge valve assembly <NUM>. The compression space <NUM> may be formed between the cylinder <NUM>, a front end of the piston <NUM>, and the discharge valve assembly <NUM>. Here, the front end of the piston <NUM> may be referred to as a head portion <NUM>. The compression space <NUM> increases in volume when the piston <NUM> moves backward, and decreases in volume as the piston <NUM> moves forward. That is, the refrigerant introduced into the compression space <NUM> may be compressed while the piston <NUM> moves forward, and may be discharged through the discharge valve assembly <NUM>.

The cylinder <NUM> may include a second flange portion <NUM> disposed at the front end. The second flange portion <NUM> may bend to the outside of the cylinder <NUM>. The second flange portion <NUM> may extend in an outer circumferential direction of the cylinder <NUM>. The second flange portion <NUM> of the cylinder <NUM> may be coupled to the frame <NUM>. For example, the front end of the frame <NUM> may include a flange groove corresponding to the second flange portion <NUM> of the cylinder <NUM>, and the second flange portion <NUM> of the cylinder <NUM> may be inserted into the flange groove and coupled through a coupling member.

A gas bearing means may be provided to supply a discharge gas to a gap between the outer circumferential surface of the piston <NUM> and the outer circumferential surface of the cylinder <NUM> and lubricate between the cylinder <NUM> and the piston <NUM> with gas. The discharge gas between the cylinder <NUM> and the piston <NUM> may provide a floating force to the piston <NUM> to reduce a friction generated between the piston <NUM> and the cylinder <NUM>.

For example, the cylinder <NUM> may include the gas inlet <NUM>. The gas inlet <NUM> may communicate with the gas groove 125c formed on the inner circumferential surface of the body portion <NUM>. The gas inlet <NUM> may pass through the cylinder <NUM> in the radial direction. The gas inlet <NUM> may guide the compressed refrigerant introduced in the gas groove 125c between the inner circumferential surface of the cylinder <NUM> and the outer circumferential surface of the piston <NUM>. Alternatively, the gas groove 125c may be formed on the outer circumferential surface of the cylinder <NUM> in consideration of the convenience of processing.

An entrance of the gas inlet <NUM> may be formed relatively widely, and an exit of the gas inlet <NUM> may be formed as a fine through hole to serve as a nozzle. The entrance of the gas inlet <NUM> may further include a filter (not shown) blocking the inflow of foreign matter. The filter may be a metal mesh filter, or may be formed by winding a member such as fine thread.

The plurality of gas inlets <NUM> may be independently formed. Alternatively, the entrance of the gas inlet <NUM> may be formed as an annular groove, and a plurality of exits may be formed along the annular groove at regular intervals. The gas inlet <NUM> may be formed only at the front side based on the axial middle of the cylinder <NUM>. On the contrary, the gas inlet <NUM> may be formed at the rear side based on the axial middle of the cylinder <NUM> in consideration of the sagging of the piston <NUM>.

The piston <NUM> is inserted into the opened rear end of the cylinder <NUM> and is provided to seal the rear of the compression space <NUM>.

The piston <NUM> may include a head <NUM> and a guide <NUM>. The head <NUM> may be formed in a disc shape. The head <NUM> may be partially open. The head <NUM> may partition the compression space <NUM>. The guide <NUM> may extend rearward from an outer circumferential surface of the head <NUM>. The guide <NUM> may be formed in a cylindrical shape. The inside of the guide <NUM> may be empty, and the front of the guide <NUM> may be partially sealed by the head <NUM>. The rear of the guide <NUM> may be opened and connected to the muffler unit <NUM>. The head <NUM> may be provided as a separate member coupled to the guide <NUM>. Alternatively, the head <NUM> and the guide <NUM> may be formed as one body.

The piston <NUM> may include a suction port <NUM>. The suction port <NUM> may pass through the head <NUM>. The suction port <NUM> may communicate with the suction space <NUM> and the compression space <NUM> inside the piston <NUM>. For example, the refrigerant flowing from the accommodation space <NUM> to the suction space <NUM> inside the piston <NUM> may pass through the suction port <NUM> and may be sucked into the compression space <NUM> between the piston <NUM> and the cylinder <NUM>.

The suction port <NUM> may extend in the axial direction of the piston <NUM>. The suction port <NUM> may be inclined in the axial direction of the piston <NUM>. For example, the suction port <NUM> may extend to be inclined in a direction away from the central axis as it goes to the rear of the piston <NUM>.

A cross section of the suction port <NUM> may be formed in a circular shape. The suction port <NUM> may have a constant inner diameter. In contrast, the suction port <NUM> may be formed as a long hole in which an opening extends in the radial direction of the head <NUM>, or may be formed such that the inner diameter becomes larger as it goes to the rear.

The plurality of suction ports <NUM> may be formed in one or more of the radial direction and the circumferential direction of the head <NUM>.

The head <NUM> of the piston <NUM> adjacent to the compression space <NUM> may be equipped with a suction valve <NUM> for selectively opening and closing the suction port <NUM>. The suction valve <NUM> may operate by elastic deformation to open or close the suction port <NUM>. That is, the suction valve <NUM> may be elastically deformed to open the suction port <NUM> by the pressure of the refrigerant flowing into the compression space <NUM> through the suction port <NUM>. The suction valve <NUM> may be a lead valve, but is not limited thereto and may be variously changed.

The piston <NUM> may be connected to a mover <NUM>. The mover <NUM> may reciprocate forward and backward according to the movement of the piston <NUM>. The inner stator <NUM> and the cylinder <NUM> may be disposed between the mover <NUM> and the piston <NUM>. The mover <NUM> and the piston <NUM> may be connected to each other by a magnet frame <NUM> that is formed by detouring the cylinder <NUM> and the inner stator <NUM> to the rear.

The muffler unit <NUM> may be coupled to the rear of the piston <NUM> to reduce a noise generated in the process of sucking the refrigerant into the piston <NUM>. The refrigerant sucked through the suction pipe <NUM> may flow into the suction space <NUM> inside the piston <NUM> via the muffler unit <NUM>.

The muffler unit <NUM> may include a suction muffler <NUM> communicating with the accommodation space <NUM> of the casing <NUM>, and an inner guide <NUM> that is connected to the front of the suction muffler <NUM> and guides the refrigerant to the suction port <NUM>.

The suction muffler <NUM> may be positioned in the rear of the piston <NUM>. A rear opening of the suction muffler <NUM> may be disposed adjacent to the suction pipe <NUM>, and a front end of the suction muffler <NUM> may be coupled to the rear of the piston <NUM>. The suction muffler <NUM> may have a flow path formed in the axial direction to guide the refrigerant in the accommodation space <NUM> to the suction space <NUM> inside the piston <NUM>.

The inside of the suction muffler <NUM> may include a plurality of noise spaces partitioned by a baffle. The suction muffler <NUM> may be formed by combining two or more members. For example, a second suction muffler may be press-coupled to the inside of a first suction muffler to form a plurality of noise spaces. In addition, the suction muffler <NUM> may be formed of a plastic material in consideration of weight or insulation property.

One side of the inner guide <NUM> may communicate with the noise space of the suction muffler <NUM>, and other side may be deeply inserted into the piston <NUM>. The inner guide <NUM> may be formed in a pipe shape. Both ends of the inner guide <NUM> may have the same inner diameter. The inner guide <NUM> may be formed in a cylindrical shape. Alternatively, an inner diameter of a front end that is a discharge side of the inner guide <NUM> may be greater than an inner diameter of a rear end opposite the front end.

The suction muffler <NUM> and the inner guide <NUM> may be provided in various shapes and may adjust the pressure of the refrigerant passing through the muffler unit <NUM>. The suction muffler <NUM> and the inner guide <NUM> may be formed as one body.

The discharge valve assembly <NUM> may include a discharge valve <NUM> and a valve spring <NUM> that is provided on a front side of the discharge valve <NUM> to elastically support the discharge valve <NUM>. The discharge valve assembly <NUM> may selectively discharge the compressed refrigerant in the compression space <NUM>. Here, the compression space <NUM> means a space between the suction valve <NUM> and the discharge valve <NUM>.

The discharge valve <NUM> may be disposed to be supportable on the front surface of the cylinder <NUM>. The discharge valve <NUM> may selectively open and close the front opening of the cylinder <NUM>. The discharge valve <NUM> may operate by elastic deformation to open or close the compression space <NUM>. The discharge valve <NUM> may be elastically deformed to open the compression space <NUM> by the pressure of the refrigerant flowing into the discharge space <NUM> through the compression space <NUM>. For example, the compression space <NUM> may maintain a sealed state while the discharge valve <NUM> is supported on the front surface of the cylinder <NUM>, and the compressed refrigerant of the compression space <NUM> may be discharged to an opened space in a state where the discharge valve <NUM> is spaced apart from the front surface of the cylinder <NUM>. The discharge valve <NUM> may be a lead valve, but is not limited thereto and may be variously changed.

The valve spring <NUM> may be provided between the discharge valve <NUM> and the discharge cover assembly <NUM> to provide an elastic force in the axial direction. The valve spring <NUM> may be provided as a compression coil spring, or may be provided as a leaf spring in consideration of an occupied space or reliability.

When the pressure of the compression space <NUM> is equal to or greater than a discharge pressure, the valve spring <NUM> may open the discharge valve <NUM> while deforming forward, and the refrigerant may be discharged from the compression space <NUM> and discharged to a first discharge space 104a of the discharge cover assembly <NUM>. When the discharge of the refrigerant is completed, the valve spring <NUM> provides a restoring force to the discharge valve <NUM> and thus can allow the discharge valve <NUM> to be closed.

A process of introducing the refrigerant into the compression space <NUM> through the suction valve <NUM> and discharging the refrigerant of the compression space <NUM> to the discharge space <NUM> through the discharge valve <NUM> is described as follows.

In the process in which the piston <NUM> linearly reciprocates inside the cylinder <NUM>, if the pressure of the compression space <NUM> is equal to or less than a predetermined suction pressure, the suction valve <NUM> is opened and thus the refrigerant is sucked into a compression space <NUM>. On the other hand, if the pressure of the compression space <NUM> exceeds the predetermined suction pressure, the refrigerant of the compression space <NUM> is compressed in a state in which the suction valve <NUM> is closed.

If the pressure of the compression space <NUM> is equal to or greater than the predetermined suction pressure, the valve spring <NUM> deforms forward and opens the discharge valve <NUM> connected to the valve spring <NUM>, and the refrigerant is discharged from the compression space <NUM> to the discharge space <NUM> of the discharge cover assembly <NUM>. When the discharge of the refrigerant is completed, the valve spring <NUM> provides a restoring force to the discharge valve <NUM> and allows the discharge valve <NUM> to be closed, thereby sealing the front of the compression space <NUM>.

The discharge cover assembly <NUM> is installed in front of the compression space <NUM>, forms a discharge space <NUM> for accommodating the refrigerant discharged from the compression space <NUM>, and is coupled to the front of the frame <NUM> to thereby reduce a noise generated in the process of discharging the refrigerant from the compression space <NUM>. The discharge cover assembly <NUM> may be coupled to the front of the first flange portion <NUM> of the frame <NUM> while accommodating the discharge valve assembly <NUM>. For example, the discharge cover assembly <NUM> may be coupled to the first flange portion <NUM> through a mechanical coupling member.

An O-ring <NUM> may be provided between the discharge cover assembly <NUM> and the frame <NUM> to prevent the refrigerant in a gasket <NUM> for thermal insulation and the discharge space <NUM> from leaking.

The discharge cover assembly <NUM> may be formed of a thermally conductive material. Therefore, when a high temperature refrigerant is introduced into the discharge cover assembly <NUM>, heat of the refrigerant may be transferred to the casing <NUM> through the discharge cover assembly <NUM> and dissipated to the outside of the compressor.

The discharge cover assembly <NUM> may include one discharge cover, or may be arranged so that a plurality of discharge covers sequentially communicates with each other. When the discharge cover assembly <NUM> is provided with the plurality of discharge covers, the discharge space <NUM> may include a plurality of spaces partitioned by the respective discharge covers. The plurality of spaces may be disposed in a front-rear direction and may communicate with each other.

For example, when there are three discharge covers, the discharge space <NUM> may include a first discharge space 104a between the frame <NUM> and a first discharge cover <NUM> coupled to the front side of the frame <NUM>, a second discharge space 104b between the first discharge cover <NUM> and a second discharge cover <NUM> that communicates with the first discharge space 104a and is coupled to a front side of the first discharge cover <NUM>, and a third discharge space 104c between the second discharge cover <NUM> and a third discharge cover <NUM> that communicates with the second discharge space 104b and is coupled to a front side of the second discharge cover <NUM>.

The first discharge space 104a may selectively communicate with the compression space <NUM> by the discharge valve <NUM>, the second discharge space 104b may communicate with the first discharge space 104a, and the third discharge space 104c may communicate with the second discharge space 104b. Hence, as the refrigerant discharged from the compression space <NUM> sequentially passes through the first discharge space 104a, the second discharge space 104b, and the third discharge space 104c, a discharge noise can be reduced, and the refrigerant can be discharged to the outside of the casing <NUM> through the loop pipe 115a and the discharge pipe <NUM> communicating with the third discharge cover <NUM>.

The drive unit <NUM> may include the outer stator <NUM> that is disposed between the shell <NUM> and the frame <NUM> and surrounds the body portion <NUM> of the frame <NUM>, the inner stator <NUM> that is disposed between the outer stator <NUM> and the cylinder <NUM> and surrounds the cylinder <NUM>, and the mover <NUM> disposed between the outer stator <NUM> and the inner stator <NUM>.

The outer stator <NUM> may be coupled to the rear of the first flange portion <NUM> of the frame <NUM>, and the inner stator <NUM> may be coupled to the outer circumferential surface of the body portion <NUM> of the frame <NUM>. The inner stator <NUM> may be spaced apart from the inside of the outer stator <NUM>, and the mover <NUM> may be disposed in a space between the outer stator <NUM> and the inner stator <NUM>.

The outer stator <NUM> may be equipped with a winding coil, and the mover <NUM> may include a permanent magnet. The permanent magnet may consist of a single magnet with one pole or configured by combining a plurality of magnets with three poles.

The outer stator <NUM> may include a coil winding <NUM> surrounding the axial direction in the circumferential direction and a stator core <NUM> stacked while surrounding the coil winding <NUM>. The coil winding <NUM> may include a hollow cylindrical bobbin 132a and a coil 132b wound in a circumferential direction of the bobbin 132a. A cross section of the coil 132b may be formed in a circular or polygonal shape, for example, may have a hexagonal shape. In the stator core <NUM>, a plurality of lamination sheets may be laminated radially, or a plurality of lamination blocks may be laminated along the circumferential direction.

The front side of the outer stator <NUM> may be supported by the first flange portion <NUM> of the frame <NUM>, and the rear side thereof may be supported by a stator cover <NUM>. For example, the stator cover <NUM> may be provided in a hollow disc shape, a front surface of the stator cover <NUM> may be supported by the outer stator <NUM>, and a rear surface thereof may be supported by a resonant spring <NUM>.

The inner stator <NUM> may be configured by stacking a plurality of laminations on the outer circumferential surface of the body portion <NUM> of the frame <NUM> in the circumferential direction.

One side of the mover <NUM> may be coupled to and supported by the magnet frame <NUM>. The magnet frame <NUM> has a substantially cylindrical shape and may be disposed to be inserted into a space between the outer stator <NUM> and the inner stator <NUM>. The magnet frame <NUM> may be coupled to the rear side of the piston <NUM> to move together with the piston <NUM>.

As an example, a rear end of the magnet frame <NUM> is bent and extended inward in the radial direction to form a first coupling portion 136a, and the first coupling portion 136a may be coupled to a third flange portion <NUM> formed in the rear of the piston <NUM>. The first coupling portion 136a of the magnet frame <NUM> and the third flange portion <NUM> of the piston <NUM> may be coupled through a mechanical coupling member.

A fourth flange portion 161a in front of the suction muffler <NUM> may be interposed between the third flange portion <NUM> of the piston <NUM> and the first coupling portion 136a of the magnet frame <NUM>. Thus, the piston <NUM>, the muffler unit <NUM>, and the mover <NUM> can linearly reciprocate together in a combined state.

When a current is applied to the drive unit <NUM>, a magnetic flux may be formed in the winding coil, and an electromagnetic force may occur by an interaction between the magnetic flux formed in the winding coil of the outer stator <NUM> and a magnetic flux formed by the permanent magnet of the mover <NUM> to move the mover <NUM>. At the same time as the axial reciprocating movement of the mover <NUM>, the piston <NUM> connected to the magnet frame <NUM> may also reciprocate integrally with the mover <NUM> in the axial direction.

The drive unit <NUM> and the compression units <NUM> and <NUM> may be supported by the support springs <NUM> and <NUM> and the resonant spring <NUM> in the axial direction.

The resonant spring <NUM> amplifies the vibration implemented by the reciprocating motion of the mover <NUM> and the piston <NUM> and thus can achieve an effective compression of the refrigerant. More specifically, the resonant spring <NUM> may be adjusted to a frequency corresponding to a natural frequency of the piston <NUM> to allow the piston <NUM> to perform a resonant motion. Further, the resonant spring <NUM> generates a stable movement of the piston <NUM> and thus can reduce the generation of vibration and noise.

The resonant spring <NUM> may be a coil spring extending in the axial direction. Both ends of the resonant spring <NUM> may be connected to a vibrating body and a fixed body, respectively. For example, one end of the resonant spring <NUM> may be connected to the magnet frame <NUM>, and the other end may be connected to the back cover <NUM>. Therefore, the resonant spring <NUM> may be elastically deformed between the vibrating body vibrating at one end and the fixed body fixed to the other end.

A natural frequency of the resonant spring <NUM> may be designed to match a resonant frequency of the mover <NUM> and the piston <NUM> during the operation of the compressor <NUM>, thereby amplifying the reciprocating motion of the piston <NUM>. However, because the back cover <NUM> provided as the fixing body is elastically supported by the first support spring <NUM> in the casing <NUM>, the back cover <NUM> may not be strictly fixed.

The resonant spring <NUM> may include a first resonant spring 118a supported on the rear side and a second resonant spring 118b supported on the front side based on a spring supporter <NUM>.

The spring supporter <NUM> may include a body portion 119a surrounding the suction muffler <NUM>, a second coupling portion 119b that is bent from the front of the body portion 119a in the inward radial direction, and a support portion 119c that is bent from the rear of the body portion 119a in the outward radial direction.

A front surface of the second coupling portion 119b of the spring supporter <NUM> may be supported by the first coupling portion 136a of the magnet frame <NUM>. An inner diameter of the second coupling portion 119b of the spring supporter <NUM> may cover an outer diameter of the suction muffler <NUM>. For example, the second coupling portion 119b of the spring supporter <NUM>, the first coupling portion 136a of the magnet frame <NUM>, and the third flange portion <NUM> of the piston <NUM> may be sequentially disposed and then integrally coupled via a mechanical member. In this instance, the description that the fourth flange portion 161a of the suction muffler <NUM> can be interposed between the third flange portion <NUM> of the piston <NUM> and the first coupling portion 136a of the magnet frame <NUM>, and they can be fixed together is the same as that described above.

The first resonant spring 118a may be disposed between a front surface of the back cover <NUM> and a rear surface of the spring supporter <NUM>. The second resonant spring 118b may be disposed between a rear surface of the stator cover <NUM> and a front surface of the spring supporter <NUM>.

A plurality of first and second resonant springs 118a and 118b may be disposed in the circumferential direction of the central axis. The first resonant springs 118a and the second resonant springs 118b may be disposed parallel to each other in the axial direction, or may be alternately disposed. The first and second resonant springs 118a and 118b may be disposed at regular intervals in the radial direction of the central axis. For example, three first resonant springs 118a and three second resonant springs 118b may be provided and may be disposed at intervals of <NUM> degrees in the radial direction of the central axis.

The compressor <NUM> may include a plurality of sealing members that can increase a coupling force between the frame <NUM> and the components around the frame <NUM>.

For example, the plurality of sealing members may include a first sealing member that is interposed at a portion where the frame <NUM> and the discharge cover assembly <NUM> are coupled and is inserted into an installation groove provided at the front end of the frame <NUM>, and a second sealing member that is provided at a portion at which the frame <NUM> and the cylinder <NUM> are coupled and is inserted into an installation groove provided at an outer surface of the cylinder <NUM>. The second sealing member can prevent the refrigerant of the gas groove 125c between the inner circumferential surface of the frame <NUM> and the outer circumferential surface of the cylinder <NUM> from leaking to the outside, and can increase a coupling force between the frame <NUM> and the cylinder <NUM>. The plurality of sealing members may further include a third sealing member that is provided at a portion at which the frame <NUM> and the inner stator <NUM> are coupled and is inserted into an installation groove provided at the outer surface of the frame <NUM>. Here, the first to third sealing members may have a ring shape.

An operation of the linear compressor <NUM> described above is as follows.

First, when a current is applied to the drive unit <NUM>, a magnetic flux may be formed in the outer stator <NUM> by the current flowing in the coil 132b. The magnetic flux formed in the outer stator <NUM> may generate an electromagnetic force, and the mover <NUM> including the permanent magnet may linearly reciprocate by the generated electromagnetic force. The electromagnetic force is generated in a direction (forward direction) in which the piston <NUM> is directed toward a top dead center (TDC) during a compression stroke, and is alternately generated in a direction (rearward direction) in which the piston <NUM> is directed toward a bottom dead center (BDC) during a suction stroke. That is, the drive unit <NUM> may generate a thrust which is a force for pushing the mover <NUM> and the piston <NUM> in a moving direction.

The piston <NUM> linearly reciprocating inside the cylinder <NUM> may repeatedly increase or reduce volume of the compression space <NUM>.

When the piston <NUM> moves in a direction (rearward direction) of increasing the volume of the compression space <NUM>, a pressure of the compression space <NUM> may decrease. Hence, the suction valve <NUM> mounted in front of the piston <NUM> is opened, and the refrigerant remaining in the suction space <NUM> may be sucked into the compression space <NUM> along the suction port <NUM>. The suction stroke may be performed until the piston <NUM> is positioned in the bottom dead center by maximally increasing the volume of the compression space <NUM>.

The piston <NUM> reaching the bottom dead center may perform the compression stroke which switching its motion direction and moving in a direction (forward direction) of reducing the volume of the compression space <NUM>. As the pressure of the compression space <NUM> increases during the compression stroke, the sucked refrigerant may be compressed. When the pressure of the compression space <NUM> reaches a setting pressure, the discharge valve <NUM> is pushed out by the pressure of the compression space <NUM> and is opened from the cylinder <NUM>, and the refrigerant can be discharged to the discharge space <NUM> through a separation space. The compression stroke can continue while the piston <NUM> moves to the top dead center at which the volume of the compression space <NUM> is minimized.

As the suction stroke and the compression stroke of the piston <NUM> are repeated, the refrigerant introduced into the accommodation space <NUM> inside the compressor <NUM> through the suction pipe <NUM> may be introduced into the suction space <NUM> inside the piston <NUM> by sequentially passing the suction guide 116a, the suction muffler <NUM>, and the inner guide <NUM>, and the refrigerant of the suction space <NUM> may be introduced into the compression space <NUM> inside the cylinder <NUM> during the suction stroke of the piston <NUM>. After the refrigerant of the compression space <NUM> is compressed and discharged to the discharge space <NUM> during the compression stroke of the piston <NUM>, the refrigerant may be discharged to the outside of the compressor <NUM> via the loop pipe 115a and the discharge pipe <NUM>.

<FIG> is a perspective view of a partial configuration of a linear compressor according to an embodiment of the present disclosure. <FIG> is an exploded perspective view of a partial configuration of a linear compressor according to an embodiment of the present disclosure. <FIG> is a cross-sectional perspective view of a partial configuration of a linear compressor according to an embodiment of the present disclosure. <FIG> is a perspective view of a back cover and an intake flow path member of a linear compressor according to an embodiment of the present disclosure. <FIG> is a cross-sectional view of a partial configuration of a linear compressor according to an embodiment of the present disclosure. <FIG> is a cross-sectional view of an intake flow path member of a linear compressor according to an embodiment of the present disclosure.

Referring to <FIG>, a linear compressor <NUM> according to an embodiment of the present disclosure may include a casing <NUM>, an intake pipe <NUM>, an intake guide 116a, a back cover <NUM>, an intake flow path member <NUM>, an intake muffler <NUM>, a heat blocking member <NUM>, a fastening member 123a, and a first support spring <NUM>. However, the linear compressor <NUM> may be implemented including more or less components according to an embodiment.

In an embodiment of the present disclosure, it can be understood that an axial direction means a vertical direction in <FIG> and a horizontal direction in <FIG>, an axially front means a downward direction in <FIG> and a left direction in <FIG>, and an axially rear means an upward direction in <FIG> and a right direction in <FIG>.

The casing <NUM> may include a shell <NUM> formed in a cylindrical shape that is open at both ends and is extended in the axial direction, a first shell cover <NUM> coupled to an axially rear side of the shell <NUM>, and a second shell cover <NUM> coupled to an axially front side of the shell <NUM>.

The intake pipe <NUM> may be coupled to the casing <NUM>. The intake pipe <NUM> may pass through the second shell cover <NUM>. The intake pipe <NUM> may communicate with the intake guide 116a. The intake pipe <NUM> may guide a suction refrigerant introduced from the outside to the intake guide 116a.

The intake guide 116a may have a through passage formed therein. The through passage of the intake guide 116a may communicate with the intake pipe <NUM> and the intake flow path member <NUM>. The through passage of the intake guide 116a may communicate with a flow path guide <NUM> of the intake flow path member <NUM>. The intake guide 116a may be entirely formed in a cylindrical shape. An axially rear end of the intake guide 116a may be supported by the casing <NUM>. The axially rear end of the intake guide 116a may be supported by a front surface of the first shell cover <NUM>. A front area of the intake guide 116a may be coupled to an inside portion of the first support spring <NUM>.

The back cover <NUM> may be disposed in the casing <NUM>. The back cover <NUM> may be supported in the casing <NUM>. The intake flow path member <NUM> may be coupled to the back cover <NUM>. The back cover <NUM> may be coupled to the first support spring <NUM>. The back cover <NUM> may support a rear end of a first resonance spring 118a. The back cover <NUM> may be coupled to a stator cover <NUM>.

The back cover <NUM> may include a rear surface <NUM>, at least one first area <NUM> extending axially forward from a radially outer area of the rear surface <NUM>, and a second area <NUM> bending radially outward from each of the at least one first area <NUM>.

The heat blocking member <NUM> may be coupled to the rear surface <NUM> of the back cover <NUM>. The intake flow path member <NUM> may be disposed on a front surface positioned opposite the rear surface <NUM> of the back cover <NUM>. The rear surface of the back cover <NUM> may include a third hole <NUM> formed in the central area. The third hole <NUM> may be penetrated by the flow path guide <NUM>.

The intake flow path member <NUM> may be disposed at a radially inside of at least one first area <NUM> of the back cover <NUM>. A radially inner surface of at least one first area <NUM> of the back cover <NUM> may be radially spaced apart from an outer surface of the intake flow path member <NUM>.

The second area <NUM> of the back cover <NUM> may be coupled to the stator cover <NUM>. In an embodiment of the present disclosure, the second area <NUM> of the back cover <NUM> and the stator cover <NUM> are bolted to each other as an example, but the present disclosure is not limited thereto and may be variously changed.

The intake flow path member <NUM> may be coupled to the back cover <NUM>. At least a portion of the intake muffler <NUM> may linearly reciprocate inside the intake flow path member <NUM>. Specifically, a rear area <NUM> of the intake muffler <NUM> may linearly reciprocate axially inside the intake flow path member <NUM>. The intake flow path member <NUM> may be formed in a cylindrical shape in which a central portion of a front surface <NUM> and a center portion of a rear surface <NUM> are opened.

The intake flow path member <NUM> may include a first hole <NUM> formed in the front surface <NUM>. The first hole <NUM> may be penetrated by a rear area <NUM> of the intake muffler <NUM>. A diameter of the first hole <NUM> may be greater than an outer diameter of the rear area <NUM> of the intake muffler <NUM>.

The intake flow path member <NUM> may include the flow path guide <NUM> extending axially forward from the central portion of the rear surface <NUM>. The flow path guide <NUM> may be formed in a cylindrical shape in which a front and a rear are opened. A suction refrigerant passing through the intake guide 116a may be introduced into the flow path guide <NUM>. A noise of the refrigerant passing through the intake flow path member <NUM> can be reduced through an expansion space formed between the flow path guide <NUM> and the inner surface of the intake flow path member <NUM>. In this case, the flow path guide <NUM> can minimize a pressure loss due to the expansion of the suction refrigerant to prevent a compression loss of the linear compressor <NUM>.

The flow path guide <NUM> includes a plurality of holes <NUM> that is spaced apart from each other and communicates the inside of the flow path guide <NUM> with a space between the flow path guide <NUM> and the inner surface of the intake flow path member <NUM>. A cross-section of the plurality of holes <NUM> is described to be formed in a circular shape as an example, but the present disclosure is not limited thereto and may be formed in an oval shape. Hence, the present disclosure can reduce an amount of refrigerant flowing back from the rear area <NUM> of the intake muffler <NUM> and reduce interference with the suction refrigerant to prevent a loss of the suction refrigerant.

The flow path guide <NUM> may be disposed in the intake flow path member <NUM>. A diameter of the flow path guide <NUM> may be greater than a diameter of the first hole <NUM>. The diameter of the flow path guide <NUM> may be greater than a diameter of the intake guide 116a. Hence, the present disclosure can prevent the suction refrigerant introduced through the intake guide 116a from being dissipated to the outside of the intake flow path member <NUM>.

The intake flow path member <NUM> may include a partition wall <NUM> disposed at the axially rear of the front surface <NUM>. The partition wall <NUM> may include a second hole <NUM> penetrated by the rear area <NUM> of the intake muffler <NUM>. A diameter of the second hole <NUM> may be greater than a diameter of the rear area <NUM> of the intake muffler <NUM>.

A rear end of the flow path guide <NUM> may extend rearward from the rear surface <NUM> of the intake flow path member <NUM>. An axially rear end <NUM> of the flow path guide <NUM> may pass through the third hole <NUM> formed in the central area of the back cover <NUM> and protrude rearward. Hence, the present disclosure can prevent the refrigerant between the rear surface <NUM> of the back cover <NUM> and the casing <NUM> from being introduced into a space between the intake flow path member <NUM> and the intake guide 116a. Specifically, the present disclosure can prevent the refrigerant between the rear surface <NUM> of the back cover <NUM> and an inner surface of the first shell cover <NUM> from being introduced into the space between the intake flow path member <NUM> and the intake guide 116a and from causing interference with the suction refrigerant, and can prevent the suction refrigerant introduced into the flow path guide <NUM> via the intake guide 116a from being dissipated.

The intake flow path member <NUM> may include an extension <NUM> extending radially outward from the rear surface <NUM>. A fastening hole formed in the extension <NUM> may be penetrated by the fastening member 123a. <FIG> describes and illustrates that the extension <NUM> extends radially outward from the rear surface <NUM> of the intake flow path member <NUM> by way of example, but the present disclosure is not limited thereto. For example, the extension <NUM> may extend radially outward and axially rearward from the rear surface <NUM> of the intake flow path member <NUM>, thereby improving space efficiency.

The intake muffler <NUM> may be coupled to a piston <NUM>. The intake muffler <NUM> may axially reciprocate together with the piston <NUM>. At least a portion of the intake muffler <NUM> may linearly reciprocate inside the intake flow path member <NUM>. Specifically, the rear area <NUM> of the intake muffler <NUM> may linearly reciprocate inside the intake flow path member <NUM>.

The heat blocking member <NUM> may be coupled to the rear surface <NUM> of the back cover <NUM>. The heat blocking member <NUM> may protrude radially outward further than the back cover <NUM>. The heat blocking member <NUM> may be disposed closer to a side surface <NUM> of the first shell cover <NUM> than the back cover <NUM>. Hence, a refrigerant in the front of the back cover <NUM> can be prevented from moving to the rear area of the back cover <NUM> through the space between the radially outer surface of the back cover <NUM> and the inner surface of the casing <NUM>. Specifically, a refrigerant that is positioned in front of the back cover <NUM> and has a higher temperature than a temperature of the suction refrigerant can be prevented from being introduced into the rear area of the back cover <NUM> through a space between the radially outer surface of the back cover <NUM> and the side surface <NUM> of the first shell cover <NUM>, thereby preventing an increase in the temperature of the suction refrigerant.

The heat blocking member <NUM> may be spaced apart from the inner surface of the casing <NUM>. The heat blocking member <NUM> may be spaced apart from the inside of the side surface <NUM> of the first shell cover <NUM>. Hence, the present disclosure can prevent a collision of the components due to vibration generated during the operation of the linear compressor <NUM>.

The heat blocking member <NUM> may include a fourth hole <NUM> formed in the central area. The fourth hole <NUM> may be penetrated by the axially rear end <NUM> of the flow path guide <NUM>. Specifically, the axially rear end <NUM> of the flow path guide <NUM> may pass through the fourth hole <NUM> and protrude rearward further than the heat blocking member <NUM>. Hence, the present disclosure can prevent the refrigerant between the heat blocking member <NUM> and the casing <NUM> from being introduced into the space between the intake flow path member <NUM> and the intake guide 116a. Specifically, the present disclosure can prevent the refrigerant positioned between the heat blocking member <NUM> and the inner surface of the first shell cover <NUM> from being introduced into the space between the intake flow path member <NUM> and the intake guide 116a and from causing interference with the suction refrigerant, and can prevent the suction refrigerant introduced into the flow path guide <NUM> via the intake guide 116a from being dissipated.

An area adjacent to the fourth hole <NUM> of the heat blocking member <NUM> may protrude axially forward. At the same time, an area adjacent to the third hole <NUM> in the rear surface <NUM> of the back cover <NUM> may protrude axially forward. Hence, space efficiency can be improved.

The first support spring <NUM> may be a 'plate spring'. The first support spring <NUM> may be coupled to the intake guide 116a, the back cover <NUM>, the heat blocking member <NUM>, and the intake flow path member <NUM>.

The first support spring <NUM> may include an inner portion <NUM> connected to the intake guide 116a, an outer portion <NUM> connected to the back cover <NUM>, and a connection portion <NUM> connecting the inner portion <NUM> and the outer portion <NUM>. The outer portion <NUM> may be coupled to the back cover <NUM>, the intake flow path member <NUM>, and the heat blocking member <NUM>.

The fastening member 123a may couple the back cover <NUM>, the first support spring <NUM>, the intake flow path member <NUM>, and the heat blocking member <NUM>. Specifically, the fastening member 123a may sequentially pass through a fastening hole formed in the outer portion <NUM> of the first support spring <NUM>, a fastening hole formed in the heat blocking member <NUM>, a fastening hole formed in the rear surface <NUM> of the back cover <NUM>, and a fastening hole formed in the extension <NUM> extending radially outward from the rear surface <NUM> of the intake flow path member <NUM> to simultaneously couple the back cover <NUM>, the first support spring <NUM>, the intake flow path member <NUM>, and the heat blocking member <NUM>. Hence, the present disclosure can improve the space efficiency and can couple the back cover <NUM>, the first support spring <NUM>, the intake flow path member <NUM>, and the heat blocking member <NUM> without a separate process such as adhesion.

<FIG> illustrate modified examples of an intake flow path member of a linear compressor according to an embodiment of the present disclosure.

Referring to <FIG>, a diameter of the second hole <NUM> may be less than a diameter of the first hole <NUM>. The second hole <NUM> may be disposed radially closer to the outer surface of the rear area <NUM> of the intake muffler <NUM> than the first hole <NUM>. Specifically, a distance d1 between the second hole <NUM> and the rear area <NUM> of the intake muffler <NUM> may be less than a distance d2 between the first hole <NUM> and the rear area <NUM> of the intake muffler <NUM>. Hence, the present disclosure can prevent the refrigerant outside the intake muffler <NUM> from flowing back through the space between the rear area <NUM> of the intake muffler <NUM> and the intake flow path member <NUM>.

Referring to <FIG>, the flow path guide <NUM> may protrude only rearward from the rear surface <NUM> of the intake flow path member <NUM>. The flow path guide <NUM> may be formed in a cylindrical shape in which a front and a rear are opened.

Referring to <FIG>, the flow path guide <NUM> may protrude axially forward and rearward from the rear surface <NUM> of the intake flow path member <NUM>. The flow path guide <NUM> may be formed in a cylindrical shape in which a front and a rear are opened. In this case, the plurality of holes <NUM> may not be formed in the flow guide <NUM>.

<FIG> is a perspective view illustrating a modified example of a back cover and an intake flow path member of a linear compressor according to an embodiment of the present disclosure. <FIG> is a cross-sectional perspective view illustrating a modified example of a partial configuration of a linear compressor according to an embodiment of the present disclosure.

Referring to <FIG> and <FIG>, the flow path guide <NUM> may protrude axially forward. The flow path guide <NUM> may be formed in a cylindrical shape in which a front and a rear are opened. An outer diameter of the flow path guide <NUM> may be less than a diameter of the first hole <NUM> formed in the front surface <NUM> of the intake flow path member <NUM> and a diameter of the second hole <NUM> formed in the partition wall <NUM>. In this case, when the rear area <NUM> of the intake muffler <NUM> moves rearward, the front area of the flow path guide <NUM> may be disposed in the rear area <NUM> of the intake muffler <NUM>. Hence, the present disclosure can prevent the refrigerant outside the intake muffler <NUM> from flowing backward through the space between the intake flow path member <NUM> and the rear area <NUM> of the intake muffler <NUM>.

The back cover <NUM> may include a plurality of fifth holes <NUM> disposed radially outward further than the third hole <NUM>. The plurality of fifth holes <NUM> may be spaced apart from each other in a circumferential direction. The plurality of fifth holes <NUM> may communicate with a space between the inner surface of the intake flow path member <NUM> and the flow path guide <NUM>. Hence, the present disclosure can prevent a reduction in an amount of suction refrigerant by guiding the suction refrigerant, that is dissipated to the outside of the intake flow path member <NUM> among the suction refrigerant introduced through the intake guide 116a, to the inside of the intake flow path member <NUM>.

<FIG> and <FIG> describe and illustrate that the flow path guide <NUM> protrudes axially forward, by way of example. However, it is obvious that the flow path guide <NUM> can protrude rearward from the rear surface <NUM>. <FIG> and <FIG> illustrate that the heat blocking member <NUM> is omitted, but the heat blocking member <NUM> can be disposed. In this case, the heat blocking member <NUM> may include a plurality of sixth holes (not shown) formed at a position opposite the fifth holes <NUM>.

<FIG> illustrate a fluid flow in an intake flow path member and an intake muffler during an operation of a linear compressor according to an embodiment of the present disclosure.

Referring to <FIG>, when the piston <NUM> moves axially forward, the rear area <NUM> of the intake muffler <NUM> coupled to the piston <NUM> moves forward. In this case, the refrigerant in the space between the flow path guide <NUM> and the inner surface of the intake flow path member <NUM> through the plurality of holes <NUM> can be prevented from flowing back into the flow path guide <NUM>. Hence, the present disclosure enables a smooth flow of the suction refrigerant passing through the intake flow path member <NUM> and thus can improve the compression efficiency of the linear compressor <NUM>.

Some embodiments or other embodiments of the present disclosure described above are not exclusive or distinct from each other. Some embodiments or other embodiments of the present disclosure described above can be used together or combined in configuration or function.

For example, configuration "A" described in an embodiment and/or the drawings and configuration "B" described in another embodiment and/or the drawings can be combined with each other. That is, even if the combination between the configurations is not directly described, the combination is possible except in cases where it is described that it is impossible to combine.

Claim 1:
A linear compressor comprising:
a casing (<NUM>);
a main body accommodated and elastically supported in the casing (<NUM>), wherein the main body comprises a frame (<NUM>), a cylinder (<NUM>) fixed to the frame (<NUM>), a piston (<NUM>) configured to linearly reciprocate inside the cylinder (<NUM>), and a drive unit (<NUM>) coupled to the frame (<NUM>) and configured to give a driving force to the piston (<NUM>);
a back cover (<NUM>) coupled to the main body and supported in the casing (<NUM>);
an intake flow path member (<NUM>) coupled to the back cover (<NUM>); and
an intake muffler (<NUM>) coupled to the piston (<NUM>), of which at least a portion linearly reciprocates inside the intake flow path member (<NUM>),
wherein the intake flow path member (<NUM>) comprises a first hole (<NUM>) that is formed in a front surface (<NUM>) of the intake flow path member (<NUM>) and through which the intake muffler (<NUM>) is movable, and a flow path guide (<NUM>) that extends axially forward from a rear surface (<NUM>) of the intake flow path member (<NUM>) and has an opened front and an opened rear,
characterized in that the flow path guide (<NUM>) comprises a plurality of holes (<NUM>) that are spaced apart from each other and allow an inside of the flow path guide (<NUM>) to communicate with a space located between the flow path guide (<NUM>) and an inner surface of the intake flow path member (<NUM>).