KR20160010999A - A linear compressor - Google Patents

Abstract

The present invention relates to a linear compressor. According to an embodiment of the present invention, the linear compressor comprises: a shell; a cylinder; a piston; a discharge valve; a discharge cover; a first spring; and a damping device. The shell provides a discharge part. The cylinder is included inside the shell and forms a compression space for a refrigerant. The frame fixates the cylinder to the shell. The piston is positioned on the interior of the cylinder to perform a reciprocal movement in an axial direction. The discharge valve is positioned on one side of the cylinder to selectively discharge the refrigerant compressed in the compression space for the refrigerant. The discharge cover is coupled to the frame and has a resonance chamber for reducing the pulsation of refrigerant discharged by the discharge valve. The first spring is coupled to the discharge valve and provides a restoring force for the discharge valve. The damping device is installed on one side of the first spring and disperses the force applied to the discharge valve when the piston is abnormally operated.

Description

[0001] The present invention relates to a linear compressor,

The present invention relates to a linear compressor.

The cooling system is a system that generates cool air by circulating a coolant, and repeats the process of compressing, condensing, expanding, and evaporating the coolant. To this end, the cooling system includes a compressor, a condenser, an expansion device and an evaporator. The cooling system may be installed in a refrigerator or an air conditioner as a household appliance.

Generally, a compressor is a mechanical device that receives power from a power generating device such as an electric motor or a turbine to increase pressure by compressing air, refrigerant or various other operating gases. .

Such a compressor is broadly classified into a reciprocating compressor that compresses the refrigerant while linearly reciprocating the piston inside the cylinder so as to form a compression space in which a working gas is sucked and discharged between the piston and the cylinder. A rotary compressor for compressing the refrigerant while the roller is eccentrically rotated along the inner wall of the cylinder and a compression space for sucking and discharging the working gas between the roller and the cylinder, a scroll compressor in which a compression space in which an operating gas is sucked and discharged is formed between a fixed scroll and a fixed scroll and the orbiting scroll rotates along the fixed scroll to compress the refrigerant.

In recent years, among the reciprocating compressors, there has been developed a linear compressor in which a piston is directly connected to a driving motor that reciprocates linearly, so that compression efficiency can be improved without mechanical loss due to motion switching and a simple structure is constructed.

Normally, the linear compressor is configured to suck and compress the refrigerant while discharging the refrigerant while moving the piston in the sealed shell by reciprocating linear motion within the cylinder by the linear motor.

The linear motor is configured such that a permanent magnet is positioned between an inner stator and an outer stator, and the permanent magnet is driven to linearly reciprocate by the mutual electromagnetic force between the permanent magnet and the inner (or outer) stator. As the permanent magnet is driven in the state of being connected to the piston, the piston linearly reciprocates in the cylinder, sucks the refrigerant, compresses the refrigerant, and discharges the refrigerant.

Regarding the conventional linear compressor, the present applicant has been registered by applying a patent application (hereinafter referred to as a prior art document).

[Prior Art]

1. Registration No. 10-1307688, Date of Registration: September 5, 2013 Title of invention: Linear compressor

The linear compressor according to the prior art document includes a shell 110 that accommodates a number of components. The height of the shell 110 in the up-and-down direction is somewhat higher, as shown in Fig. 2 of the prior art.

An oil supply assembly 900 capable of supplying oil to the space between the cylinder 200 and the piston 300 is provided in the shell 110.

On the other hand, when the linear compressor is provided in the refrigerator, the linear compressor may be installed in a machine room provided at the rear lower side of the refrigerator.

In recent years, increasing the internal storage space of refrigerators has become a major concern for consumers. In order to increase the internal storage space of the refrigerator, it is necessary to reduce the volume of the machine room, and reducing the size of the linear compressor to reduce the volume of the machine room becomes a major issue.

However, the linear compressor disclosed in the prior art has a relatively large volume, which is not suitable for a refrigerator for increasing internal storage space.

In order to reduce the size of the linear compressor, it is necessary to make the main parts of the compressor small, but in this case, the performance of the compressor may be degraded.

In order to compensate for the problem of the performance degradation of the compressor, it may be considered to increase the operating frequency of the compressor. However, as the operating frequency of the compressor increases, the frictional force due to the oil circulated in the compressor increases, thereby deteriorating the performance of the compressor.

On the other hand, in the above-mentioned prior art, a discharge valve spring for supporting a discharge valve is composed of a coil spring. When the coil spring is applied to the discharge valve spring, there is a problem that the discharge valve rotates with respect to the coil spring, thereby causing wear of the discharge valve.

SUMMARY OF THE INVENTION The present invention has been proposed in order to solve such problems, and it is an object of the present invention to provide a linear compressor capable of reducing wear of a discharge valve.

A linear compressor according to an embodiment of the present invention includes: a shell provided with a discharge portion; A cylinder disposed inside the shell and forming a compression space for the refrigerant; A frame securing the cylinder to the shell; A piston provided to be axially reciprocable within the cylinder; A discharge valve provided at one side of the cylinder for selectively discharging compressed refrigerant in a compression space of the refrigerant; A discharge cover coupled to the frame and having a resonance chamber for reducing pulsation of refrigerant discharged through the discharge valve; A first spring coupled to the discharge valve and providing a restoring force to the discharge valve; And a damping device installed at one side of the first spring and dispersing a force acting on the discharge valve in an abnormal operation of the piston.

Further, the damping device includes a second spring.

The stopper may further include a stopper coupled to the first spring and limiting the amount of opening of the discharge valve.

Further, the stopper is installed between the first spring and the second spring.

The first spring further includes a first spacer provided between the first spring and the stopper for separating the first spring from the stopper.

Further, a second spacer that is seated on the discharge cover and supports the damping device is further included, and the second spacer separates the damping device from the discharge cover.

The first spring or the second spring includes a leaf spring.

Also, the elastic modulus of the second spring is formed to be larger than the elastic modulus of the first spring, the deformation of the second spring is restricted during normal operation of the piston, and during the abnormal operation of the piston, And the spring is deformed.

The stopper may further include: a stopper body capable of supporting the first spring; And a guide protrusion protruding from the stopper main body and movably coupled along the guide groove of the discharge cover.

The damping device includes a plurality of springs.

A spacer provided between the plurality of springs and the first spring to separate the plurality of springs from the first spring; And a damping mounting portion which is seated on the discharge cover and on which the plurality of springs are installed.

Further, the first spring and the fastening member for coupling the plurality of springs and the spacer are further included.

A linear compressor according to another aspect includes: a shell provided with a discharge portion; A cylinder disposed inside the shell and forming a compression space for the refrigerant; A piston reciprocatably provided in the cylinder in the longitudinal direction; A discharge valve provided at one side of the cylinder for selectively discharging compressed refrigerant in a compression space of the refrigerant; A discharge cover having a resonance chamber for reducing pulsation of the refrigerant discharged through the discharge valve; A first spring coupled to the discharge valve to provide a restoring force to the discharge valve; A stopper coupled to the first spring to limit an amount of deformation of the first spring; And a second spring coupled to the stopper and guiding movement of the stopper.

The first spring is coupled to the rear of the stopper, and the second spring is coupled to the front of the stopper.

The stopper may further include: a stopper body capable of supporting the first spring; And a first protrusion protruding from one surface of the stopper body and supporting the second spring.

The stopper may further include a second protrusion protruded from the first protrusion and inserted into the insertion hole of the second spring.

Further, when the refrigerant is discharged from the compression space, the first spring is deformed forward so that the discharge valve can move forward, and when the stopper is in an abnormal state in which the piston collides with the discharge valve, And the second spring is deformed forward so as to be movable.

According to the present invention, it is possible to reduce the size of the machine room of the refrigerator by reducing the size of the compressor including the internal parts, thereby increasing the internal storage space of the refrigerator.

Also, by increasing the operating frequency of the compressor, it is possible to prevent performance deterioration due to the reduced internal parts, and by applying gas bearings between the cylinder and the piston, frictional force that can be generated by the oil can be reduced.

In addition, the operation of the discharge valve for selectively discharging the high-pressure gas compressed in the compression chamber can be stably performed, and the amount of the impact that may occur during operation of the discharge valve is reduced, thereby reducing the wear of the discharge valve. As a result, it is possible to prevent foreign matter, which may occur due to wear of the discharge valve, from acting on the gas bearing.

Further, since the opening amount of the discharge valve is limited by the stopper and the time for closing the discharge valve is shortened, the response for operation of the discharge valve can be improved.

In addition, when a discharge valve is stably supported by providing a first valve spring for supporting the discharge valve and a second valve spring coupled to the front of the stopper, and an emergency situation occurs due to a control error of the compressor, When the piston and the discharge valve collide with each other, the stopper moves by the second valve spring, thereby preventing the discharge valve from being abraded or damaged by the collision.

The first valve spring supports the discharge valve, and the second valve spring is spaced apart from the first valve spring. When the emergency situation occurs, It is possible to prevent the discharge valve from being abraded or damaged by the collision.

Further, by constituting the resonance chamber in the discharge cover, the pulsation of the discharge gas can be reduced and the occurrence of noise can be reduced.

Further, by providing a plurality of filter devices inside the compressor, foreign matter or oil can be prevented from being contained in the compressed gas (or discharge gas) flowing into the outside of the piston from the nozzle portion of the cylinder.

As a result, by preventing the clogging of the nozzle of the cylinder, the action of the gas bearing can be effectively performed between the cylinder and the piston, thereby preventing the wear of the cylinder and the piston.

1 is a sectional view showing a configuration of a linear compressor according to a first embodiment of the present invention.
2 is a cross-sectional view showing a configuration of a suction muffler according to a first embodiment of the present invention.
3 is a cross-sectional view showing a peripheral configuration of the discharge cover and the discharge valve according to the first embodiment of the present invention.
4 is an exploded perspective view showing a structure of a cylinder and a frame according to a first embodiment of the present invention.
FIG. 5 is a cross-sectional view showing a combined state of a cylinder and a piston according to a first embodiment of the present invention.
6 is an exploded perspective view showing a structure of a cylinder according to a first embodiment of the present invention.
7 is an enlarged cross-sectional view of "A"
8 is a perspective view showing a discharge valve assembly coupled to a discharge cover according to the first embodiment of the present invention.
9 is an exploded perspective view of the discharge cover and the discharge valve assembly according to the first embodiment of the present invention.
10 is a view showing a configuration of a stopper according to the first embodiment of the present invention.
11 is a view showing the operation of the discharge valve assembly according to the first embodiment of the present invention.
12 is a cross-sectional view illustrating a refrigerant flow of a linear compressor according to a first embodiment of the present invention.
13 is a cross-sectional view showing the operation of the discharge valve assembly when the linear compressor according to the first embodiment of the present invention is operated.
FIG. 14 is a cross-sectional view showing the configuration of a discharge valve assembly according to a second embodiment of the present invention.
15 is a view showing the operation of the discharge valve assembly according to the second embodiment of the present invention.

Hereinafter, specific embodiments of the present invention will be described with reference to the drawings. It is to be understood, however, that the spirit of the invention is not limited to the embodiments shown and that those skilled in the art, upon reading and understanding the spirit of the invention, may easily suggest other embodiments within the scope of the same concept.

1 is a sectional view showing a configuration of a linear compressor according to a first embodiment of the present invention.

1, a linear compressor 100 according to a first embodiment of the present invention includes a substantially cylindrical shell 101, a first cover 102 coupled to one side of the shell 101, And a second cover 103 coupled to the second cover 103. [ The first cover 102 is disposed on the right side of the shell 101 and the second cover 103 is disposed on the left side of the shell 101. [ Can be combined.

In a broad sense, the first cover 102 and the second cover 103 can be understood as a constitution of the shell 101. [

The linear compressor 100 is provided with a cylinder 120 provided inside the shell 101, a piston 130 linearly reciprocating in the cylinder 120, and a driving force applied to the piston 130 A motor assembly 140 is included as a linear motor.

When the motor assembly 140 is driven, the piston 130 can reciprocate at a high speed. The operating frequency of the linear compressor 100 according to the present embodiment is approximately 100 Hz.

In more detail, the linear compressor 100 includes a suction unit 104 through which refrigerant flows and a discharge unit 105 through which refrigerant compressed in the cylinder 120 is discharged. The suction unit 104 may be coupled to the first cover 102 and the discharge unit 105 may be coupled to the second cover 103.

The refrigerant sucked through the suction portion 104 flows into the piston 130 through the suction muffler 150. In the course of the refrigerant passing through the suction muffler 150, the noise can be reduced. The suction muffler 150 is constructed by combining a first muffler 151 and a second muffler 153. At least a portion of the suction muffler 150 is located within the piston 130.

The piston 130 includes a substantially cylindrical piston body 131 and a piston flange portion 132 extending radially from the piston body 131. The piston body 131 reciprocates within the cylinder 120 and the piston flange 132 can reciprocate outside the cylinder 120.

The piston 130 may be made of an aluminum material (aluminum or aluminum alloy) which is a non-magnetic material. The piston 130 is made of an aluminum material to prevent the magnetic flux generated in the motor assembly 140 from being transmitted to the piston 130 and leaking to the outside of the piston 130. The piston 130 may be formed by a forging method.

Meanwhile, the cylinder 120 may be made of an aluminum material (aluminum or aluminum alloy) which is a nonmagnetic material. The material composition ratio of the cylinder 120 and the piston 130, that is, kind and composition ratio, may be the same.

Since the cylinder 120 is made of an aluminum material, the magnetic flux generated in the motor assembly 140 can be prevented from being transmitted to the cylinder 120 and leaking to the outside of the cylinder 120. The cylinder 120 may be formed by an extrusion rod processing method.

The piston 130 and the cylinder 120 are made of the same material (aluminum), so that the coefficients of thermal expansion are equal to each other. Since the piston 130 and the cylinder 120 have the same thermal expansion coefficient during the operation of the linear compressor 100 and the inside of the shell 100 has a high temperature (about 100 ° C) And the cylinder 120 can be thermally deformed by the same amount.

As a result, since the piston 130 and the cylinder 120 are thermally deformed in different sizes or directions, interference between the piston 130 and the cylinder 120 during movement of the piston 130 can be prevented have.

The cylinder (120) is configured to receive at least a portion of the suction muffler (150) and at least a portion of the piston (130).

A compression space P in which the refrigerant is compressed by the piston 130 is formed in the cylinder 120. A suction hole 133 for introducing a refrigerant into the compression space P is formed in a front portion of the piston 130. The suction hole 133 is selectively provided in front of the suction hole 133, A suction valve 135 is provided. At a substantially central portion of the suction valve 135, a fastening hole to which a predetermined fastening member is coupled is formed.

A discharge cover 200 which forms a discharge space or a discharge passage of the refrigerant discharged from the compression space P and a discharge space 200 which is coupled to the discharge cover 200 and which is connected to the compression space P, There is provided a discharge valve assembly for selectively discharging compressed refrigerant.

The discharge valve assembly includes a discharge valve 220 opened when the pressure in the compression space P becomes equal to or higher than a discharge pressure and introducing the refrigerant into the discharge space of the discharge cover 200, A plurality of valve springs 230 and 270 provided between the discharge cover 200 and applying an elastic force in the axial direction and a stopper 240 for limiting the amount of opening or opening of the discharge valve 220.

The plurality of valve springs 230 and 270 are provided with a first spring 230 disposed between the discharge valve 220 and the stopper 240 and a second spring 230 disposed between the discharge valve 220 and the stopper 240, Spring 270 is included. The first spring 230 may be installed on one side of the stopper 240 and the second spring 270 may be spaced from the first spring 230 and installed on the other side of the stopper 240. In other words, the stopper 240 may be installed between the first spring 230 and the second spring 270.

The valve springs 230 and 270 may include a plate spring, for example.

Here, the compression space P is understood as a space formed between the suction valve 135 and the discharge valve 220. The suction valve 135 is formed at one side of the compression space P and the discharge valve 220 can be provided at the other side of the compression space P, have.

The "axial direction" can be understood as a direction in which the piston 130 reciprocates, that is, a lateral direction in FIG. In the "axial direction", the direction from the suction portion 104 toward the discharge portion 105, that is, the direction in which the refrigerant flows is referred to as "forward" and the opposite direction is defined as "rearward".

On the other hand, "radial direction" can be understood as a direction perpendicular to the direction in which the piston 130 reciprocates, and in the longitudinal direction of Fig.

When the pressure in the compression space P is lower than the discharge pressure and the suction pressure is lower than the suction pressure in the reciprocating linear motion of the piston 130 in the cylinder 120, the suction valve 135 is opened, Is sucked into the compression space (P). On the other hand, when the pressure in the compression space P becomes equal to or higher than the suction pressure, the refrigerant in the compression space P is compressed while the suction valve 135 is closed.

Meanwhile, when the pressure in the compression space P becomes equal to or higher than the discharge pressure, the first spring 230 is deformed to open the discharge valve 220. The refrigerant is discharged from the compression space P, And is discharged to the discharge space of the discharge cover 200. When the discharge of the refrigerant is completed, the first spring 230 provides a restoring force to the discharge valve 220 so that the discharge valve 220 is closed.

The refrigerant flowing in the discharge space of the discharge cover 200 flows into the loop pipe 165. The loop pipe 165 is coupled to the discharge cover 200 and extends to the discharge part 105 to guide the compressed refrigerant in the discharge space to the discharge part 105. For example, the loop pipe 165 is rounded to have a shape wound in a predetermined direction, and is coupled to the discharge unit 105.

The linear compressor (100) further includes a frame (110). The frame 110 is configured to fix the cylinder 120 and can be fastened to the cylinder 120 by a separate fastening member. The frame 110 is disposed to surround the cylinder 120. That is, the cylinder 120 may be positioned to be received inside the frame 110. The discharge cover 200 may be coupled to the front surface of the frame 110.

On the other hand, at least a portion of the gas refrigerant discharged from the high-pressure gas refrigerant discharged through the opened discharge valve 220 flows to the outer peripheral surface side of the cylinder 120 through the space of the portion where the cylinder 120 and the frame 110 are coupled Can flow.

The refrigerant flows into the cylinder 120 through the gas inlet 122 (see FIG. 7) formed in the cylinder 120 and the nozzle 123 (see FIG. 7). The introduced refrigerant may flow into the space between the piston 130 and the cylinder 120 so that the outer circumferential surface of the piston 130 is spaced from the inner circumferential surface of the cylinder 120. Accordingly, the introduced refrigerant can function as a "gas bearing " which reduces friction with the cylinder 120 during reciprocation of the piston 130. [ That is, this embodiment does not adopt a bearing by oil.

The motor assembly 140 includes outer stator 141, 143 or 145 fixed to the frame 110 and arranged to surround the cylinder 120, an inner stator 148 (not shown) And permanent magnets 146 positioned in the space between the outer stator 141, 143, 145 and the inner stator 148.

The permanent magnets 146 can reciprocate linearly by mutual electromagnetic forces between the outer stator 141, 143, 145 and the inner stator 148. The permanent magnets 146 may be formed of a single magnet having one pole or a plurality of magnets having three poles.

The permanent magnet 146 may be coupled to the piston 130 by a connecting member 138. In detail, the connecting member 138 may be coupled to the piston flange portion 132 and may be bent and extended toward the permanent magnet 146. As the permanent magnet 146 reciprocates, the piston 130 can reciprocate axially together with the permanent magnet 146.

The motor assembly 140 further includes a fixing member 147 for fixing the permanent magnet 146 to the connecting member 138. The fixing member 147 may be formed by mixing glass fiber or carbon fiber with resin. The fixing member 147 is provided so as to surround the inside and the outside of the permanent magnet 146 to firmly maintain the state of engagement between the permanent magnet 146 and the connecting member 138.

The outer stator 141, 143, 145 includes the coil winding bodies 143, 145 and the stator core 141.

The coil winding bodies 143 and 145 include a bobbin 143 and a coil 145 wound around the bobbin 143 in the circumferential direction. The end face of the coil 145 may have a polygonal shape, and may have a hexagonal shape, for example.

The stator core 141 is formed by stacking a plurality of laminations in a circumferential direction, and may be arranged to surround the coil winding bodies 143 and 145.

A stator cover 149 is provided at one side of the outer stator 141, 143, 145. One side of the outer stator 141, 143, 145 may be supported by the frame 110 and the other side may be supported by the stator cover 149.

The inner stator 148 is fixed to the outer periphery of the frame 110. The inner stator 148 is formed by laminating a plurality of laminations in the circumferential direction from the outside of the frame 110.

The linear compressor 100 further includes a supporter 137 for supporting the piston 130 and a back cover 170 spring-coupled to the supporter 137.

The supporter 137 is coupled to the piston flange portion 132 and the connecting member 138 by a predetermined fastening member.

A suction guide portion 155 is coupled to the front of the back cover 170. The suction guide part 155 guides the refrigerant sucked through the suction part 104 into the suction muffler 150.

The linear compressor 100 includes a plurality of springs 176 whose natural frequencies are adjusted so that the piston 130 can resonate.

The plurality of springs 176 include a first spring supported between the supporter 137 and the stator cover 149 and a second spring supported between the supporter 137 and the back cover 170 do.

The linear compressor 100 further includes leaf springs 172 and 174 which are provided on both sides of the shell 101 to allow the internal parts of the compressor 100 to be supported by the shell 101.

The leaf springs 172 and 174 include a first leaf spring 172 coupled to the first cover 102 and a second leaf spring 174 coupled to the second cover 103. For example, the first leaf spring 172 can be fitted to a portion where the shell 101 and the first cover 102 are coupled, and the second leaf spring 174 can be engaged with the shell 101, 2 cover 103 is engaged.

2 is a cross-sectional view showing a configuration of a suction muffler according to a first embodiment of the present invention.

Referring to FIG. 2, a suction muffler 150 according to an embodiment of the present invention includes a first muffler 151, a second muffler 153 coupled to the first muffler 151, 151 and a first filter 310 supported by a second muffler 153. [

The first muffler 151 and the second muffler 153 are formed with a flow space portion in which the refrigerant flows. The first muffler 151 extends from the inside of the suction portion 104 toward the discharge portion 105 and at least a part of the first muffler 151 is connected to the inside of the suction guide portion 155 . The second muffler 153 extends from the first muffler 151 to the interior of the piston body 131.

The first filter 310 is installed in the flow space portion and is understood as a configuration for filtering foreign matters. The first filter 310 is made of a material having magnetism, so that foreign matters, particularly metal dirt, contained in the refrigerant can be easily filtered. For example, the first filter 310 may be made of a stainless steel material, and may have a predetermined magnetic property and may be prevented from rusting.

As another example, the first filter 310 may be coated with a magnetic material or may be configured to have a magnet attached to the surface of the first filter 310.

The first filter 310 may be a mesh type having a plurality of filter holes, and may have a substantially disc shape. The filter hole may have a diameter or a width of a predetermined size or less. For example, the predetermined size may be about 25 [mu] m.

The first muffler 151 and the second muffler 153 can be assembled by press-fitting. The first filter 310 may be fitted to the first muffler 151 and the second muffler 153 by press-fitting.

For example, one of the first muffler 151 and the second muffler 153 may have a groove portion and the other may include a protrusion portion into which the groove portion is inserted. The first filter 310 may be supported by the first and second mufflers 151 and 153 while both side portions of the first filter 310 are interposed between the groove and the protrusion.

More specifically, the first muffler 151 and the second muffler 153 move in a direction in which the first filter 310 is positioned between the first and second mufflers 151 and 153, The both sides of the first filter 310 can be fitted and fixed between the groove and the protrusion.

As described above, the first filter 310 is provided in the suction muffler 150, so that the foreign matter having a predetermined size or more of the refrigerant sucked through the suction unit 104 can be filtered by the first filter 310 . Accordingly, the foreign matter is contained in the refrigerant acting as the gas bearing between the piston 130 and the cylinder 120, and can be prevented from flowing into the cylinder 120.

Further, since the first filter 310 is firmly fixed to the press-fitted portion of the first and second mufflers 151 and 153, the suction muffler 150 can be prevented from being separated from the first filter 310.

FIG. 3 is a cross-sectional view showing a peripheral structure of a discharge cover and a discharge valve according to a first embodiment of the present invention, and FIG. 4 is an exploded perspective view showing a structure of a cylinder and a frame according to the first embodiment of the present invention.

3 and 4, the linear compressor 100 according to the first embodiment of the present invention further includes a discharge valve 220 selectively opened to discharge the refrigerant compressed in the compression space P .

The rear surface of the discharge valve 220 may be installed to be in contact with the front portion of the cylinder 120. The refrigerant in the compression space P is compressed while the rear surface of the discharge valve 220 is in contact with the front portion of the cylinder 120. [ When the pressure in the compression space P becomes equal to or higher than the discharge pressure, the rear surface of the discharge valve 220 is separated from the front portion of the cylinder 120 to open the discharge valve 220, The compressed refrigerant is discharged through the spaced spaces.

The linear compressor 100 is provided with a first spring 230 coupled to a front of the discharge valve 220 to elastically support the discharge valve 220, And a second spring 270 coupled to the stopper 240 for guiding movement of the stopper 240 during an abnormal operation of the compressor 100.

The discharge valve 220 is provided with an insertion protrusion 222 coupled to the first spring 230. The stopper 240 includes protrusions 246 and 247 coupled to the second spring 270.

The elastic modulus K2 of the second spring 270 may be greater than the elastic modulus K1 of the first spring 230. The first spring 230 is deformed and the second spring 270 is not deformed when the compressor 100 is operated normally, that is, when the discharge valve 220 is normally opened or closed. have.

Specifically, the pressure of the compression space P is formed to be equal to or higher than the discharge pressure, and when the discharge valve 220 is opened, the first spring 230 has a forwardly deforming movement, (240) interferes with the first spring (230) in front of the first spring (230) to prevent excessive deformation of the first spring (230).

On the other hand, when a control error of the compressor 100 occurs, an abnormal operation can be performed. In the abnormal operation, an abnormal operation of the piston 130 is included. For example, when the piston 130 moves forward excessively and collides with the discharge valve 220 with a force exceeding a predetermined force, the piston 130 deforms to the second spring 270 as well as the first spring 230, 240 can be moved forward. Therefore, the impact applied to the discharge valve 220 can be mitigated.

The linear compressor (100) includes a plurality of spacers (250, 260) for providing a deformation space of the valve springs (230, 270). The plurality of spacers 250 and 260 may include a first spacer 250 disposed between the first spring 230 and the stopper 240 and a second spacer 250 disposed in front of the second spring 270 260).

The first spacer 250 may be separated from the first spring 230 and the stopper 240 by a predetermined distance to secure a space in which the first spring 230 can be deformed. The set distance may be determined by the adjustable thickness of the first spacer 250.

The second spacer 260 is positioned between the second spring 270 and the discharge cover 200 so that the second spring 270 can be separated from the discharge cover 200 and stably supported do. The second spacer 260 secures a space in which the second spring 270 can be deformed.

The linear compressor 100 includes a second filter 320 disposed between the frame 110 and the cylinder 120 for filtering the high-pressure gas refrigerant discharged through the discharge valve 220. The second filter 320 may be positioned at a portion where the frame 110 and the cylinder 120 are coupled to each other or at a coupling surface.

Specifically, the cylinder 120 includes a substantially cylindrical cylinder body 121 and a cylinder flange portion 125 extending radially from the cylinder body 121.

The cylinder body 121 includes a gas inflow portion 122 into which the discharged gas refrigerant flows. The gas inlet 122 may be recessed in a substantially circular shape along the outer circumferential surface of the cylinder body 121.

A plurality of gas inflow portions 122 may be provided. The plurality of gas inlet portions 122 are provided with gas inlet portions 122a and 122b (see FIG. 6) located at one side from the axial center portion of the cylinder body 121 and gas inlet portions (See Fig. 6).

The cylinder flange portion 125 is provided with a coupling portion 126 to be engaged with the frame 110. The coupling portion 126 may be configured to protrude outward from the outer circumferential surface of the cylinder flange portion 125. The fastening portion 126 may be coupled to the cylinder fastening hole 118 of the frame 110 by a predetermined fastening member.

The cylinder flange portion 125 includes a seating surface 127 that is seated on the frame 110. The seating surface 127 may be a rear portion of the cylinder flange 125 extending radially from the cylinder body 121.

The frame 110 includes a frame body 111 surrounding the cylinder body 121 and a cover coupling part 115 extending in the radial direction of the frame body 111 and coupled to the discharge cover 200, .

The cover engaging portion 115 is provided with a plurality of cover fastening holes 116 into which the fastening members coupled to the discharge cover 200 are inserted and a plurality of cylinder fastening holes 116 into which the fastening members coupled to the cylinder flange portions 125 are inserted. And a fastening hole 118 is formed. The cylinder fastening hole 118 is formed at a position slightly recessed from the cover engaging portion 115.

The frame 110 is provided with a depressed portion 117 which is recessed rearward from the cover engaging portion 115 and into which the cylinder flange portion 125 is inserted. That is, the depressed portion 117 may be disposed so as to surround the outer circumferential surface of the cylinder flange portion 125. The depressed depth of the depressed portion 117 may correspond to the front and rear width of the cylinder flange portion 125.

A predetermined refrigerant flow space may be formed between the inner circumferential surface of the depression 117 and the outer circumferential surface of the cylinder flange portion 125. [ The high-pressure gas refrigerant discharged from the discharge valve 220 can flow toward the outer circumferential surface of the cylinder body 121 via the refrigerant flow space. The second filter 320 may be installed in the refrigerant flow space to filter the refrigerant.

In detail, a seating part provided stepwise is formed at the rear end of the depression 117, and a ring-shaped second filter 320 can be seated in the seating part.

When the cylinder 120 is coupled to the frame 110 in a state where the second filter 320 is seated in the seating part, the cylinder flange 125 is positioned in front of the second filter 320, The second filter 320 is pressed. That is, the second filter 320 may be interposed between the seating portion of the frame 110 and the seating surface 127 of the cylinder flange portion 125.

The second filter 320 blocks the foreign matter from the high-pressure gas refrigerant discharged through the opened discharge valve 220 from flowing into the gas inlet 122 of the cylinder 120, As shown in FIG.

For example, the second filter 320 may include a nonwoven fabric made of PET (Polyethylene Terephthalate) fiber or an absorbent. The PET has an advantage of excellent heat resistance and mechanical strength. It is also possible to block foreign matter of 2 mu m or more in the refrigerant.

The high-pressure gas refrigerant that has passed through the space between the inner circumferential surface of the depression 117 and the outer circumferential surface of the cylinder flange portion 125 passes through the second filter 320 and the refrigerant is filtered .

FIG. 5 is a cross-sectional view showing a combined state of the cylinder and the piston according to the first embodiment of the present invention, FIG. 6 is an exploded perspective view showing the construction of the cylinder according to the first embodiment of the present invention, "A ".

5 to 7, the cylinder 120 according to the first embodiment of the present invention includes a cylinder body having a substantially cylindrical shape and forming a first body end 121a and a second body end 121b 121 and a cylinder flange portion 125 extending radially outward from the second body end portion 121b of the cylinder body 121. [

The first body end 121a and the second body end 121b form both ends of the cylinder body 121 with respect to the axial center 121c of the cylinder body 121. [

The cylinder body 121 is formed with a plurality of gas inlet portions 122 through which at least a portion of the high-pressure gas refrigerant discharged through the discharge valve 220 flows. A third filter 330 as a "filter member " may be disposed in the plurality of gas inflow portions 122.

The plurality of gas inlet portions 122 are configured to be recessed from the outer peripheral surface of the cylinder body 121 by a predetermined depth and width. The refrigerant may be introduced into the cylinder body 121 through the plurality of gas inlet portions 122 and the nozzle portion 123.

The introduced refrigerant is positioned between the outer circumferential surface of the piston 130 and the inner circumferential surface of the cylinder 120 and functions as a gas bearing for the movement of the piston 130. That is, the outer circumferential surface of the piston 130 is kept spaced from the inner circumferential surface of the cylinder 120 by the pressure of the introduced refrigerant.

The plurality of gas inlet portions 122 are provided with a first gas inlet portion 122a and a second gas inlet portion 122b located at one side from the axial center portion 121c of the cylinder body 121, And a third gas inflow portion 122c located on the other side from the direction center portion 121c.

The first and second gas inflow portions 122a and 122b are located closer to the second body end portion 121b with respect to the axial center portion 121c of the cylinder body 121, The first body portion 122c may be located closer to the first body end 121a with respect to the axial center portion 121c of the cylinder body 121. [

That is, the plurality of gas inlet portions 122 are arranged in an asymmetric number with reference to the axial center portion 121c of the cylinder body 121.

Referring to FIG. 1, the internal pressure of the cylinder 120 is higher at the side of the second body end 121b closer to the discharge side of the compressed refrigerant, as compared with the side of the first body end 121a close to the suction side of the refrigerant. A larger number of gas inlet portions 122 are formed on the second body end portion 121b side to enhance the function of the gas bearing and a relatively small gas inlet portion 122 on the first body end portion 121a side ) Can be formed.

The cylinder body 121 further includes a nozzle part 123 extending from the plurality of gas inflow parts 122 toward the inner circumferential surface of the cylinder body 121. The nozzle unit 123 is formed to have a width or a size smaller than the gas inlet 122.

A plurality of nozzle portions 123 may be formed along the gas inlet portion 122 extending in a circular shape. The plurality of nozzle units 123 are disposed apart from each other.

The nozzle unit 123 includes an inlet 123a connected to the gas inlet 122 and an outlet 123b connected to the inner circumferential surface of the cylinder body 121. The nozzle unit 123 is formed to have a predetermined length from the inlet 123a toward the outlet 123b.

The refrigerant flowing into the gas inlet 122 is filtered by the third filter 330 and then flows to the inlet 123a of the nozzle 123. The refrigerant flows into the cylinder 123 along the nozzle 123, (120). The refrigerant flows into the inner space of the cylinder 120 through the outlet portion 123b.

The piston 130 is moved away from the inner circumferential surface of the cylinder 120 by the pressure of the refrigerant discharged from the outlet portion 123b, that is, from the inner circumferential surface of the cylinder 120. That is, the pressure of the refrigerant supplied to the inside of the cylinder 120 provides the lifting force or floating pressure to the piston 130.

The recessed depth and width of the plurality of gas inflow portions 122 and the length L of the nozzle portion 123 are determined by the rigidity of the cylinder 120, the amount of the third filter 330, The size of the pressure drop of the refrigerant passing through the portion 123, and the like.

For example, if the recessed depth and width of the plurality of gas inflow portions 122 are too large or the length of the nozzle portion 123 is too small, the rigidity of the cylinder 120 may be weakened. On the other hand, if the recessed depth and width of the plurality of gas inlet portions 122 are too small, the amount of the third filter 330 that can be installed in the gas inlet portion 122 may be too small.

If the length of the nozzle part 123 is too large, the pressure drop of the refrigerant passing through the nozzle part 123 becomes too large, so that a sufficient function as a gas bearing can not be achieved.

The diameter of the inlet portion 123a of the nozzle portion 123 is larger than the diameter of the outlet portion 123b. The flow cross sectional area of the nozzle portion 123 is gradually decreased from the inlet portion 123a toward the outlet portion 123b with respect to the flow direction of the refrigerant.

In detail, when the diameter of the nozzle part 123 is too large, the amount of the refrigerant flowing into the nozzle part 123 of the high-pressure gas refrigerant discharged through the discharge valve 220 becomes excessively large, Is increased. On the other hand, if the diameter of the nozzle part 123 is too small, the pressure drop in the nozzle part 123 becomes large, and the performance as a gas bearing is reduced.

Therefore, in this embodiment, the diameter of the inlet 123a of the nozzle 123 is relatively increased to reduce the pressure drop of the refrigerant flowing into the nozzle 123, and the diameter of the outlet 123b So that the inflow amount of the gas bearing through the nozzle unit 123 can be adjusted to a predetermined value or less.

The third filter 330 functions to block foreign substances from entering into the cylinder 120 and adsorb the oil contained in the refrigerant. Here, the predetermined size may be 1 [mu] m.

The third filter 330 includes a thread wound around the gas inlet 122. In detail, the thread may be made of PET (Polyethylene Terephthalate) material and have a predetermined thickness or diameter.

The thickness or diameter of the thread may be determined to an appropriate value in consideration of the strength of the thread. If the thickness or diameter of the thread is too small, the strength of the thread becomes too weak to be easily broken, and when the thickness or diameter of the thread becomes too large, The gap in the gas inlet 122 becomes too large and the filtering effect of the foreign matter becomes low.

For example, the thickness or diameter of the thread is formed in units of several hundreds of micrometers, and the thread may be composed of a plurality of strands of a spun thread of several tens of μm.

The thread is wound several times and its end is fixed with a knot. The number of times the thread is wound can be appropriately selected in consideration of the degree of pressure drop of the gas refrigerant and the filtering effect of foreign matter. If the number of windings is too large, the pressure drop of the gas refrigerant becomes too large, and if the number of windings is too small, filtering of the foreign matter may not be performed well.

The tension force of the thread is formed in an appropriate size in consideration of the deformation of the cylinder 120 and the fixing force of the thread. If the tension is too large, the cylinder 120 may be deformed. If the tension is too small, the thread may not be fixed to the gas inlet 122.

FIG. 8 is a perspective view showing a discharge valve assembly coupled to the discharge cover according to the first embodiment of the present invention, FIG. 9 is an exploded perspective view of the discharge cover and the discharge valve assembly according to the first embodiment of the present invention, FIG. 11 is a view showing the operation of the discharge valve assembly according to the first embodiment of the present invention. FIG. 11 is a view showing the structure of a stopper according to the first embodiment of the present invention.

8-11, a linear compressor 100 according to the first embodiment of the present invention is provided with a discharge passage connected to a front of the frame 110 to discharge refrigerant discharged from the compression space P The discharge cover 200 is provided.

The discharge cover 200 is provided with a cover body 200a for forming a discharge passage for the refrigerant discharged through the discharge valve 220 and a cover body 200b extending outwardly from the cover body 200a in the radial direction, And a pipe connecting portion 202 for discharging the refrigerant passed through the discharge passage of the discharge main body 200a to the outside of the discharge cover 200. [ The frame coupling part 201 forms the rear surface of the discharge cover 200 and the pipe connection part 202 can be connected to the loop pipe 165.

The discharge cover 200 may be provided with a discharge valve assembly. The discharge valve assembly includes a discharge valve 220, first and second springs 230 and 270, a stopper 240, and first and second spacers 250 and 260.

In detail, the cover body 200a of the discharge cover 200 includes a plurality of stepped portions 203 and 205 which are stepped forward from the frame engaging portion 201. As shown in FIG. The plurality of stepped portions 203 and 205 include a first stepped portion 203 formed to be recessed rearward from the frame engaging portion 201 and a second stepped portion 203 formed rearward from the first stepped portion 203 toward the resonance chamber 212 And a second stepped portion 205 formed to be further recessed.

The cover body 200a further includes a step connecting portion 203a extending radially inward from the first step portion 203 and connected to the second step portion 205. [ That is, the cover body 200a is configured so as to extend radially inwardly from the first stepped portion 203 and then further depressed rearward to form the second stepped portion 205. [

The first stepped portion 203 includes a discharge hole 204 for guiding the refrigerant passed through the discharge passage of the cover body 200a to the pipe connecting portion 202 and discharging the refrigerant from the discharge cover 200 do. The discharge hole 204 is formed through at least a part of the first step 203. The refrigerant discharged through the discharge valve 220 may flow to the pipe connection portion 202 via the discharge hole 204.

The cover body 200a further includes a resonance chamber 212 which is recessed further from the second stepped portion 205 and forms a space for reducing pulsation of the refrigerant. A plurality of resonance chambers 212 may be formed. At least a portion of the refrigerant discharged through the discharge valve 220 may flow into the space of the resonance chamber 212.

The cover body 200a further includes a seating part 210 dividing the plurality of resonance chambers 212 and capable of supporting the second spacers 260. The plurality of resonance chambers 212 are further recessed forward from the seating portion 210 and may be formed at positions spaced apart from each other by the seating portion 210.

The cover body 200a is formed with a first guide groove 206 as a "guide channel" for guiding at least a part of the refrigerant discharged through the discharge valve 220 to the plurality of resonance chambers 212. [ The first guide groove 206 extends forward from the step connecting portion 203a toward the second stepped portion 205. The first guide groove 206 may be formed by cutting at least a part of the step connecting portion 203a and the second stepped portion 205. [

A plurality of the first guide grooves 206 may be formed corresponding to the number of the resonance chambers 212. The plurality of first guide grooves 206 may be spaced apart from each other.

At least a part of the refrigerant discharged through the open discharge valve 220 flows into the plurality of resonance chambers 212 along the first guide groove 206 to thereby occur during the operation of the compressor Can be reduced.

The cover body 200a is formed with a second guide groove 207 for guiding the engagement of the stopper 240. The second guide groove 207 guides the engagement of the guide protrusion 243 of the stopper 240. The second guide groove 207 may be formed by cutting at least a part of the step connection portion 203a and the second step portion 205. [

A plurality of the second guide grooves 207 may be formed corresponding to the number of the guide protrusions 243 of the stopper 240. The plurality of second guide grooves 207 may be spaced apart from each other.

The discharge valve 220 is provided with a valve body 221 which is selectively in contact with the front surface of the cylinder flange 125 of the cylinder 120 and a valve depression 223 which is recessed forward from the valve body 221, . At least a part of the piston 130 is prevented from interfering with the discharge valve 220 when the piston 130 is moved forward to compress the refrigerant, Home ". At least a part of the piston 130 includes a fastening member for fastening the suction valve 135 to the piston 130.

The discharge valve 220 further includes an insertion protrusion 222 protruding forward from the valve body 221 and coupled to the first spring 230. The insertion protrusion 222 may be coupled to the first insertion hole 232 formed in the first spring 230.

Sectional shape of the insertion protrusion 222 and the first insertion hole 232 may have a non-circular shape. In one example, the cross-sectional shape may be polygonal. Therefore, when the discharge valve 220 is opened and closed while the insertion protrusion 222 is inserted into the first insertion hole 232, the discharging valve 220 can be prevented from rotating . As a result, it is possible to prevent the unstable behavior of the discharge valve 220. In particular, in the case of a linear compressor using a gas bearing rather than an oil bearing as in the present embodiment, The wear of the discharge valve due to the unstable behavior can be reduced.

The first spring 230 includes a plate spring, and may have a substantially disc shape.

In detail, the first spring 230 is coupled to the front of the discharge valve 220 so that the discharge valve 220 can be elastically moved. The first spring 230 has a first spring body 231 having a plurality of cutouts and an insertion protrusion 222 formed at an approximate center of the first spring body 231, A first insertion hole 232 to be inserted is included.

The plurality of cutouts are configured to have a spiral shape, and the first springs 230 may be elastically deformed by the plurality of cutouts.

The first spring 230 includes a spring depression 233 which is recessed from the outer circumferential surface of the first spring body 231. The spring depression (233) guides the position of the guide protrusion (243) of the stopper (240).

On the front side of the first spring 230, the stopper 240 is provided.

In detail, the stopper 240 includes a stopper body 241 that restricts the amount of deformation of the first spring 230 during the deformation of the first spring 230. The stopper body 241 has a substantially disc shape and may be installed at a position where the first spring 230 may interfere with the first spring 230 when the first spring 230 is deformed by more than a predetermined amount.

The stopper 240 further includes a valve avoiding hole 242 penetrating from the stopper body 241. The valve evacuation hole 242 penetrates from the substantially central portion of the stopper body 241 to prevent the stopper body 241 from interfering with the insertion protrusion 222 of the discharge valve 220. That is, in order to prevent the stopper body 241 from interfering with the insertion protrusion 222 when the insertion protrusion 222 is moved forward in the process of opening the discharge valve 220, Provides an interference avoiding space.

The stopper 240 further includes a guide protrusion 243 protruding rearward from the rear surface of the stopper body 241 and guiding the engagement with the discharge cover 200. The guide protrusion 243 moves into the cover body 200a along the second guide groove 207 when the stopper 240 is coupled to the discharge cover 200. [

The guide protrusion 243 may be coupled to the spring depression 233 of the first spring 230 and the spacer groove 252 of the first spacer 250. Accordingly, the first spring 230, the stopper 240, and the first spacer 250 can be stably coupled.

For example, the stopper 240 may be press-fitted into the second guide groove 207 in a state where the guide protrusion 243 is coupled to the spring depression 233 and the spacer groove 252 have. Therefore, the stopper 240 can be stably coupled to the discharge cover 200 without a separate fastening member.

The first spacer 250 may be interposed between the first spring 230 and the stopper 240 so that the first spring 230 may be spaced apart from the stopper 240.

More specifically, the first spacer 250 includes a first spacer body 251 having a substantially ring shape and a second spacer body 251 which is recessed from the outer circumferential surface of the first spacer body 251 and is positioned at the position of the guide protrusion 243 of the stopper 240 And a spacer groove 252 for guiding the spacer.

A second spring 270 for guiding the movement of the stopper 240 during an emergency operation of the compressor 100 is included in the front of the stopper 240. The second spring 270 is configured to elastically support the stopper 240.

The second spring 270 has a substantially disk-shaped second spring body 271 and a second insertion hole 272 penetrating the substantially central portion of the second spring body 271 and coupled to the stopper 240. [ . The second insertion hole 272 may have a non-circular shape, for example, a polygonal shape, similar to the shape of the first insertion hole 232 of the first spring 230.

The stopper 240 includes protrusions 246 and 247 protruding forward from the front surface of the stopper body 241. The protrusions 246 and 247 include a first protrusion 246 protruding forward from the stopper body 241 and a second protrusion 247 protruding further forward from the first protrusion 246.

The first protrusion 246 functions as a supporting device for the second spring 270 and the second protrusion 247 is inserted into the second insertion hole 272 of the second spring 270, And can function as a device.

The second protrusion 247 is formed to have a diameter enough to be inserted into the second insertion hole 272 of the second spring 270. The diameter of the first protrusion 246 is larger than that of the second insertion hole 272 of the second spring 270. The first protrusion 246 protrudes from the rear of the second spring 270, So that the second spring 270 can be supported.

FIG. 11 shows a state in which the second spring 270 is deformed to guide the movement of the stopper 240 during an emergency operation of the compressor 100. FIG.

More specifically, the emergency operation of the compressor 100 includes an operation in which the piston 130 and the discharge valve 220 collide with each other due to a control error of the compressor. In this case, the force or the load F acting on the discharge valve 220 is a force or a load acting on the discharge valve 220 during the normal operation of the compressor 100, that is, a force acting on the discharge refrigerant Or greater than the load.

Accordingly, when the compressor 100 is operated in an emergency, the second spring 270 is deformed so that the stopper 240 is moved forward, so that a force or a load applied to the discharge valve 220 is transmitted to the stopper 240 and the second spring 270. [0053] As a result, wear of the discharge valve 220 can be reduced.

The elastic modulus of the second spring 270 is greater than the elastic modulus of the first spring 230. Therefore, in the process of opening / closing the discharge valve 220 during normal operation of the compressor 100, the second spring 270 may not be deformed. On the other hand, when an excessive force or a load acts on the discharge valve 220 during abnormal operation of the compressor 100, the second spring 270 may be deformed to guide the movement of the stopper 240 .

The second spacer 260 is seated on the seating portion 210 of the cover body 200a to support the second spring 270. That is, the second spacer 260 is positioned between the seating part 210 and the second spring 270 so that the second spring 270 can be separated from the seating part 210 . When the second spring 270 is deformed, a space between the second spring 270 and the seating part 210 may provide a space in which the second spring 270 can be deformed.

The second spacer 260 is provided with a second spacer body 261 having a hollow disc shape that supports the front surface of the second spring 270 and a second spacer body 261 having a hollow shape extending rearward along the periphery of the spacer body 261, Section 262 is included. The rim portion 262 is configured to surround the outer circumferential surface of the second spring 270 to support the second spring 270.

The second spring 270 and the second spacer 260 are positioned between the seating part 210 of the discharge cover 200 and the stopper 240 of the discharge cover 200 when the stopper 240 is press- (240).

FIG. 12 is a cross-sectional view showing a refrigerant flow in a linear compressor according to a first embodiment of the present invention, and FIG. 13 is a sectional view showing an operation of a discharge valve assembly in operation of a linear compressor according to a first embodiment of the present invention .

12 and 13, the refrigerant flows into the interior of the shell 101 through the suction portion 104, and flows into the suction muffler 150 through the suction guide portion 155.

The refrigerant flows into the second muffler 153 via the first muffler 151 of the suction muffler 150 and flows into the interior of the piston 130. [ In this process, the suction noise of the refrigerant can be reduced.

On the other hand, the refrigerant can be filtered through the first filter 310 provided in the suction muffler 150, and the foreign matter having a predetermined size (25 mu m) or more can be filtered.

The refrigerant passing through the suction muffler 150 and existing in the piston 130 is sucked into the compression space P through the suction hole 133 when the suction valve 135 is opened.

When the refrigerant pressure in the compression space P becomes equal to or higher than the discharge pressure, the discharge valve 220 is opened, the refrigerant is discharged to the discharge space of the discharge cover 200 through the opened discharge valve 220, Flows to the discharge portion 105 through the loop pipe 165 coupled to the compressor 200, and is discharged to the outside of the compressor 100.

When the discharge valve 220 is opened, the first spring 230 may be elastically deformed forward, and the stopper 240 may prevent the first spring 230 from being deformed by more than a predetermined amount have.

In particular, as in the present embodiment, when the linear compressor 100 is operated at a high frequency, the opening degree of the discharge valve 220, that is, the movement distance of the discharge valve 220, becomes large. Accordingly, when the discharge valve 220 is closed, the amount of impact applied to the discharge valve 220 increases, thereby increasing the amount of wear of the discharge valve 220. In particular, such wear can be increased when oil is not used and gas bearings are applied.

Accordingly, in this embodiment, the discharge valve 220 is resiliently supported by the first spring 230, and the stopper 240 is installed on one side of the valve spring 230 to open the discharge valve 220 The amount or opening degree may be limited.

At least a part of the refrigerant in the discharge space of the discharge cover 200 is separated from the space existing between the cylinder 120 and the frame 110, that is, the inner peripheral surface of the depression 117 of the frame 110, And can flow toward the outer circumferential surface of the cylinder body 121 via a flow space formed between the outer circumferential surfaces of the cylinder flange portions 125 of the cylinder 120.

At this time, the refrigerant can pass through the second filter 320 interposed between the seating surface 127 of the cylinder flange portion 125 and the seating portion 113 of the frame 110, (2 탆) or more can be filtered. The oil in the refrigerant can be adsorbed to the second filter 320.

The refrigerant having passed through the second filter 320 flows into a plurality of gas inflow portions 122 formed on the outer circumferential surface of the cylinder body 121. As the refrigerant passes through the third filter 330 provided in the gas inlet 122, the foreign matter having a predetermined size (1 μm or more) contained in the refrigerant can be filtered, and the oil contained in the refrigerant can be adsorbed have.

The refrigerant that has passed through the third filter 330 flows into the cylinder 120 through the nozzle unit 123 and is positioned between the inner circumferential surface of the cylinder 120 and the outer circumferential surface of the piston 130, 130) from the inner circumferential surface of the cylinder 120 (gas bearing).

The diameter of the inlet portion 123a of the nozzle portion 123 is larger than the diameter of the outlet portion 123b so that the sectional area of the refrigerant flowing in the nozzle portion 123, . For example, the diameter of the inlet portion 123a may be at least two times the diameter of the outlet portion 123b.

As such, the high-pressure gas refrigerant acts as a bearing for the reciprocating piston 130 bypassed into the cylinder 120, thereby reducing wear between the piston 130 and the cylinder 120 . By not using the oil for the bearing, even if the compressor 100 is operated at a high speed, friction loss due to oil can be prevented.

Further, by providing a plurality of filters on the path of the refrigerant flowing in the compressor 100, the foreign matter contained in the refrigerant can be removed, thereby improving the reliability of the refrigerant serving as the gas bearing. Accordingly, it is possible to prevent a phenomenon that the piston 130 or the cylinder 120 is abraded by foreign matter contained in the refrigerant.

Further, by removing the oil contained in the refrigerant by the plurality of filters, frictional loss due to oil can be prevented from occurring. The first filter 310, the second filter 320, and the third filter 330 may be collectively referred to as a "refrigerant filter device" in that they filter the refrigerant to serve as a gas bearing.

13, when the compressor 100 performs an abnormal operation due to a control error of the compressor 100 during the normal operation of the compressor 100, the second spring 270 is deformed The stopper 240 can be moved forward (see FIG. 11).

In detail, due to a control error of the compressor 100, a phenomenon that the reciprocating piston 130 collides with the discharge valve 220 may occur. At this time, the force applied to the discharge valve 220 may be greater than the force applied to the discharge valve 220 when the discharge valve 220 is normally opened, as described with reference to FIG.

In this case, the second spring 270 may be deformed together with the first spring 230. The stopper 240 can be moved forward by the deformation of the second spring 270.

Accordingly, the force applied to the discharge valve 220 can be absorbed by the second spring 270 and the stopper 240. As a result, wear of the discharge valve 220 can be prevented.

Hereinafter, a second embodiment of the present invention will be described. Since the present embodiment differs from the first embodiment in the structure of the discharge valve assembly, the differences will be mainly described, and the remaining portions will be described with reference to the first embodiment and the reference numerals.

FIG. 14 is a cross-sectional view illustrating a configuration of a discharge valve assembly according to a second embodiment of the present invention, and FIG. 15 is a view illustrating an operation of a discharge valve assembly according to a second embodiment of the present invention.

Referring to FIG. 14, the discharge valve assembly according to the second embodiment of the present invention includes a discharge valve 220 having an insertion protrusion 222, and an insertion portion 222 inserted into the insertion protrusion 222 of the discharge valve 220, A first spring 430 having a hole and providing a restoring force to the discharge valve 220 and damping devices 432, 434 and 436 spaced from the first spring 430.

The discharge valve assembly further includes a spacer 450 for separating the first spring 430 and the damping devices 432, 434, 436 from each other.

The damping devices 432, 434, 436 include a plurality of springs. The plurality of springs includes a second spring 432, and a third spring 434 and a fourth spring 436. [ The second, third, and fourth springs 432, 434, 436 may be coupled to each other and arranged in a front-to-rear direction.

The first spring 430 guides the opening of the discharge valve 220 while being deformed forward when the compressor 100 is operated normally, that is, when the compressed refrigerant is discharged from the compression space P. When the discharge of the compressed refrigerant is completed, the discharge valve 220 is provided with a restoring force to guide the discharge valve 220 to close.

The damping devices 432, 434 and 436 may be configured such that when a phenomenon occurs in which the piston 130 reciprocating due to a control error of the compressor 100 collides with the discharge valve 220 during an abnormal operation of the compressor 100, , And is configured to absorb an impact force acting on the discharge valve (220).

The elastic modulus of the second to fourth springs 432, 434, 436 constituting the damping devices 432, 434, 436 is larger than that of the first spring 430. During the normal operation of the compressor 100, the first spring 430 is deformed, but the second to fourth springs 432, 434 and 436 may not be deformed. The first to fourth springs 430, 432, 434, 436 may include leaf springs.

The linear compressor 100 further includes a damping mounting portion 460 on which the damping devices 432, 434, 436 are mounted. The damping mounting portion 460 is seated on the mounting portion 210 of the discharging cover 200 described in the first embodiment to support the damping devices 432, 434, 436.

The linear compressor 100 further includes a fastening member 480 that fixes the first spring 430 and the damping devices 432, 434, 436 to the damping mount 460. The fastening member 480 may be coupled to the damping mount 460 through the first spring 430, the spacer 450 and the damping devices 432, 434, 436.

Referring to FIG. 15, when a force F greater than a predetermined force acts on the discharge valve 220 during an abnormal operation of the compressor 100, the first spring 430 may be excessively deformed forward have.

The first spring 430 may press the damping devices 432, 434, 436, and the second to fourth springs 432, 434, 436 may be deformed forward.

As a result, the force acting on the discharge valve 220 can be transmitted to the damping devices 432, 434, and 436 by the deformation of the second to fourth springs 432, 434, and 436.

That is, the force acting on the discharge valve 220 can be absorbed by the damping devices 432, 434, and 436, thereby preventing the discharge valve 220 from being worn. As a result, foreign matter due to the abrasion of the discharge valve 220 acts on the nozzle portion 123 of the cylinder 120 to prevent the gas bearing from adversely affecting the gas bearing.

100: Linear compressor 101: Shell
110: frame 111: frame body
115: cover coupling portion 117: depression
120: cylinder 121: cylinder body
122: gas inlet part 123: nozzle part
123a: inlet portion 123b: outlet portion
125: cylinder flange part 127: seat face
130: Piston 140: Motor assembly
150: Suction muffler 165: Loop pipe
171,172: Plate spring 200: Discharge cover
204: Discharge hole 210:
212: resonance chamber 220: discharge valve
230: first spring 240: stopper
250: first spacer 260: second spacer
270: second spring 310: first filter
320: second filter 330: third filter

Claims (17)

A shell provided with a discharge portion;
A cylinder disposed inside the shell and forming a compression space for the refrigerant;
A frame securing the cylinder to the shell;
A piston provided to be axially reciprocable within the cylinder;
A discharge valve provided at one side of the cylinder for selectively discharging compressed refrigerant in a compression space of the refrigerant;
A discharge cover coupled to the frame and having a resonance chamber for reducing pulsation of refrigerant discharged through the discharge valve;
A first spring coupled to the discharge valve and providing a restoring force to the discharge valve; And
And a damping device installed at one side of the first spring for dispersing a force acting on the discharge valve during an abnormal operation of the piston. The method according to claim 1,
Wherein the damping device includes a second spring. 3. The method of claim 2,
And a stopper coupled to the first spring, the stopper limiting the amount of opening of the discharge valve. The method of claim 3,
And the stopper is installed between the first spring and the second spring. The method of claim 3,
And a first spacer provided between the first spring and the stopper for separating the first spring from the stopper. The method according to claim 1,
And a second spacer which is seated on the discharge cover and supports the damping device,
And the second spacer separates the damping device from the discharge cover. 3. The method of claim 2,
Wherein the first spring or the second spring includes a leaf spring. 3. The method of claim 2,
The elastic modulus of the second spring is formed to be larger than the elastic modulus of the first spring,
A deformation of the second spring is restricted during normal operation of the piston, and a deformation of the second spring occurs during an abnormal operation of the piston. The method of claim 3,
In the stopper,
A stopper body capable of supporting the first spring; And
And a guide protrusion protruding from the stopper main body and movably coupled along the guide groove of the discharge cover. 10. The method of claim 9,
Wherein the damping device includes a plurality of springs. 11. The method of claim 10,
A spacer provided between the plurality of springs and the first spring to separate the plurality of springs from the first spring; And
And a damping mounting portion that is seated on the discharge cover and on which the plurality of springs are installed. The method according to claim 1,
And a fastening member for coupling the first spring and the plurality of springs and the spacer. A shell provided with a discharge portion;
A cylinder disposed inside the shell and forming a compression space for the refrigerant;
A piston reciprocatably provided in the cylinder in the longitudinal direction;
A discharge valve provided at one side of the cylinder for selectively discharging compressed refrigerant in a compression space of the refrigerant;
A discharge cover having a resonance chamber for reducing pulsation of the refrigerant discharged through the discharge valve;
A first spring coupled to the discharge valve to provide a restoring force to the discharge valve;
A stopper coupled to the first spring to limit an amount of deformation of the first spring; And
And a second spring coupled to the stopper and guiding movement of the stopper. 14. The method of claim 13,
Wherein the first spring is coupled to the rear of the stopper, and the second spring is coupled to the front of the stopper. 14. The method of claim 13,
In the stopper,
A stopper body capable of supporting the first spring;
And a first protrusion protruding from one surface of the stopper main body and supporting the second spring. 16. The method of claim 15,
In the stopper,
And a second protrusion protruding from the first protrusion and inserted into the insertion hole of the second spring. 14. The method of claim 13,
Wherein when the refrigerant is discharged from the compression space, the first spring is deformed forward so that the discharge valve is movable forward,
And the second spring is deformed forward so that the stopper is movable forward when the piston is in an abnormal operation in which it collides with the discharge valve.

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