Linear compressor

Abstract

An embodiment of the present invention may comprise: a suction valve for suctioning a low-pressure refrigerant; a discharge valve for discharging a compressed high-pressure refrigerant; a discharge cover assembly for forming a discharge chamber for the refrigerant discharged through the discharge valve; a frame for supporting the discharge cover assembly; and a cylinder which is supported inside the frame and into which a piston reciprocating in the axial direction is inserted. An embodiment may comprise a noise reduction device which is closer to the discharge valve than the suction valve and is provided to the discharge cover assembly.

Description

Linear compressor

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

[0002] In a reciprocating compressor, a compression space for compressing the working gas is formed between the piston and the cylinder, and the piston compresses the refrigerant introduced into the compression space as it moves in a straight line back and forth inside the cylinder.

[0003] Recently, among the aforementioned reciprocating compressors, many linear compressors have been developed that are simple in structure and can improve compression efficiency without mechanical losses occurring when converting the motor's rotational motion into linear motion, by directly connecting the piston to a drive motor that performs reciprocating linear motion.

[0004] Generally, a linear compressor is configured such that a piston moves in a reciprocating linear motion inside a cylinder driven by a linear motor within a sealed shell, drawing in and compressing refrigerant, and then discharging it.

[0005] The high-temperature refrigerant compressed in the compression space of the cylinder can flow toward the discharge cover via the discharge valve. The discharge cover is coupled to a frame supporting the cylinder and can form a discharge chamber through which the high-temperature discharge gas flows.

[0006] The movement of the aforementioned discharge valve can generate noise. For example, the discharge valve may produce noise by coming into contact with the cylinder. In addition, the flow of high-pressure refrigerant on the discharge side of the linear compressor generates noise. This noise manifests as vibration and acts as a fatigue load on the linear compressor. This noise causes consumer dissatisfaction.

[0007] The present invention aims to reduce the noise of a linear compressor.

[0008] The present invention aims to reduce consumer complaints caused by high-frequency noise in linear compressors.

[0009] The present invention aims to reduce broadband noise generated in a linear compressor.

[0010] The present invention aims to reduce noise in the main frequency band of an oil-less linear compressor.

[0011] The present invention aims to directly reduce noise in a linear compressor adjacent to the discharge valve where noise primarily occurs.

[0012] The present invention aims to provide a vacuum reduction structure in a narrow space on the discharge side of a linear compressor.

[0013] The present invention aims to reduce noise in a desired frequency band even if there is a difference between the design dimensions and the manufacturing dimensions of a linear compressor component.

[0014] An embodiment of the present invention may include: a suction valve for sucking in low-pressure refrigerant; a discharge valve for discharging compressed high-pressure refrigerant; a discharge cover assembly forming a discharge chamber for the refrigerant discharged through the discharge valve; a frame supporting the discharge cover assembly; and a cylinder supported inside the frame and into which a piston that reciprocates in the axial direction is inserted. An embodiment may include a noise reduction device provided to the discharge cover assembly and located closer to the discharge valve than to the suction valve.

[0015] The discharge cover assembly may include a first discharge cover forming a first discharge chamber for the high-pressure refrigerant, and a second discharge cover coupled to the first discharge cover and forming a discharge chamber for the high-pressure refrigerant discharged from the first discharge chamber. The noise reduction device may be provided on the first discharge cover.

[0016] The first discharge cover may include an inner wall defining the first discharge chamber, an outer wall defining the discharge chamber of the second discharge cover, a reinforcing rib extending radially from the inner surface of the first discharge chamber, and a connecting rib connected to the reinforcing rib and connecting the inner wall and the inner surface of the outer wall in a radial direction.

[0017] It may include a resonator having a resonance space in which at least a portion of the space is defined by the connecting rib, the inner wall, the outer wall, or the discharge valve.

[0018] The above resonator may include at least two units spaced apart in the circumferential direction.

[0019] An embodiment may include an opening connecting the resonance space and the first discharge chamber. The opening may be provided in the inner wall.

[0020] The above resonator may include a first resonator having a first resonance space size and a first opening, and a second resonator having a first resonance space size and a second opening.

[0021] The above resonator may include a first resonator having a first resonant frequency higher than 2.5KHz, and a second resonator having a second resonant frequency lower than 2.5KHz.

[0022] An embodiment may include a noise reduction device provided in the discharge cover assembly to reduce noise transmitted along the high-pressure refrigerant. The noise reduction device may include at least two resonators spaced circumferentially apart with respect to the central axis. The at least two resonators may have different resonant frequencies. One of the resonant frequencies may be higher than 2.5 kHz. The other of the resonant frequencies may be lower than 2.5 kHz.

[0023] The above noise reduction device may include a resonator. The resonator may include a resonance space spaced apart in a radial direction from the discharge chamber, and an opening connecting the resonance space and the discharge chamber. The opening may be closed by the front surface of the discharge valve. The resonator may include at least two.

[0024] The above resonators may have different resonant frequencies if they are not facing each other with respect to the central axis. The two resonators not facing each other with respect to the central axis may have the same resonant space but different aperture areas. The two resonators facing each other with respect to the central axis may have the same resonant frequency. The two resonators facing each other with respect to the central axis may have the same resonant space.

[0025] The above at least two resonators can be connected to each other through the discharge chamber.

[0026] An example may be provided as part of the assembly of the discharge cover when molding the discharge cover assembly provided of plastic.

[0027] The above noise reduction device may include at least two resonators with different resonant frequencies.

[0028] The above at least two resonators may provide a resonance space spaced apart in a radial direction from the discharge chamber. The resonance space may be closed by the discharge valve.

[0029] According to an embodiment of the present invention, by introducing a resonator to enhance the noise reduction effect using the pulsation of the discharged refrigerant, the noise of the linear compressor can be further reduced.

[0030] According to an embodiment of the present invention, by setting the band of the resonator to a high-frequency band, which is the main operating frequency of the linear compressor, the noise of the linear compressor can be reduced, thereby reducing consumer complaints.

[0031] According to an embodiment of the present invention, at least two resonators are provided to reduce broadband noise generated in various operating modes and various noise frequencies of a linear compressor.

[0032] According to an embodiment of the present invention, by performing an optimal design of the resonator, noise in the 2.5KHz band, which is the main frequency band of the oil-less linear compressor, can be reduced.

[0033] According to an embodiment of the present invention, a noise reduction device is provided adjacent to a discharge valve where significant noise is generated in a linear compressor. Accordingly, the purpose is to reduce noise on the discharge side of the linear compressor. Here, the noise reduction device may be a resonant device.

[0034] According to an embodiment of the present invention, at least one resonator can be provided directly in the discharge cover. Accordingly, a resonator can be provided in a narrow space on the discharge side of a linear compressor.

[0035] According to an embodiment of the present invention, at least two resonators are provided with similar sizes and / or values. Accordingly, even if slight deformation occurs during actual manufacturing, a noise reduction effect can be provided for adjacent noise frequency bands.

[0036] FIG. 1 is a cross-sectional view of a linear compressor according to an embodiment of the present invention.

[0037] FIG. 2 is a cross-sectional view taken along 2-2 of FIG. 1.

[0038] FIG. 3 is a perspective view showing a damping member installed on a first discharge cover according to an embodiment of the present invention.

[0039] FIG. 4 is an upper perspective view of a first discharge cover according to an embodiment of the present invention.

[0040] FIG. 5 is a plan view of a first discharge cover according to an embodiment of the present invention.

[0041] FIG. 6 is a lower perspective view of a first discharge cover according to an embodiment of the present invention.

[0042] FIG. 7 is a bottom view of a first discharge cover according to an embodiment of the present invention.

[0043] FIG. 8 is an upper perspective view of a damping member according to an embodiment of the present invention.

[0044] FIG. 9 is a lower perspective view of a damping member according to an embodiment of the present invention.

[0045] FIG. 10 is an upper perspective view of a second discharge cover according to an embodiment of the present invention.

[0046] FIG. 11 is a lower perspective view of a second discharge cover according to an embodiment of the present invention.

[0047] FIG. 12 is a bottom view of a second discharge cover according to an embodiment of the present invention.

[0048] FIG. 13 is an upper perspective view of a third discharge cover according to an embodiment of the present invention.

[0049] FIG. 14 is a lower perspective view of a third discharge cover according to an embodiment of the present invention.

[0050] FIG. 15 is a bottom view showing the second discharge cover and the third discharge cover combined according to an embodiment of the present invention.

[0051] FIG. 16 is a cross-sectional view showing the configuration of a discharge cover assembly according to an embodiment of the present invention.

[0052] FIG. 17 is a cross-sectional view showing the appearance of a refrigerant flowing through the discharge chamber of a discharge cover assembly according to an embodiment of the present invention.

[0053] FIG. 18 is a cross-sectional view of the first discharge cover and discharge valve assembly.

[0054] FIGS. 19 and FIGS. 20 are bottom perspective views of a discharge cover assembly, where FIG. 19 shows the discharge valve assembly removed, and FIG. 20 shows the discharge valve assembly attached.

[0055] FIG. 21 is a bottom view of the first discharge cover.

[0056] FIG. 22 is a drawing illustrating the space provided by the first discharge cover.

[0057] FIG. 23 is a diagram illustrating the operation of a resonator.

[0058] FIG. 24 is a drawing explaining the results of analyzing the noise filtration characteristics of the discharge cover mounted on the noise reduction device.

[0059] Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. It should be noted that in assigning reference numerals to the components of each drawing, the same components are given the same reference numeral whenever possible, even if they are shown in different drawings. Furthermore, in describing the embodiments of the present invention, if it is determined that a detailed description of related known components or functions would hinder understanding of the embodiments of the present invention, such detailed description is omitted.

[0060] In addition, terms such as first, second, A, B, (a), (b), etc., may be used when describing the components of the embodiments of the present invention. These terms are intended only to distinguish the components from other components, and the essence, order, or sequence of the components is not limited by the terms. Where it is stated that a component is "connected," "combined," or "connected" to another component, it should be understood that the component may be directly connected or connected to the other component, but that another component may also be "connected," "combined," or "connected" between each component.

[0061] FIG. 1 is a cross-sectional view of a linear compressor according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along 2-2 of FIG. 1.

[0062] Referring to FIGS. 1 and 2, a linear compressor (10) according to an embodiment of the present invention may include a shell (11) and a first shell cover (12) and a second shell cover (13) coupled to both sides of the shell (11). In a broad sense, the first shell cover (12) and the second shell cover (13) may be understood as components of the shell (11).

[0063] The shell (11) has a roughly cylindrical shape and can be arranged in a horizontally lying position or in an axially lying position. Based on FIG. 1, the shell (11) is extended horizontally and may have a somewhat lower height in the radial direction.

[0064] Since the linear compressor (10) can have a low height, for example, when the linear compressor (10) is installed on the base of the machine room of a refrigerator, there is an advantage that the height of the machine room can be reduced.

[0065] The above linear compressor (10) may include a plurality of pipes that are provided in the shell (11) or shell cover (12, 13) and can suck in, discharge, or inject refrigerant.

[0066] The plurality of pipes may include a suction pipe (14) that allows the refrigerant to be sucked into the interior of the linear compressor (10). The suction pipe (14) may be connected to the first shell cover (12). The refrigerant may be sucked into the interior of the linear compressor (10) along the axial direction through the suction pipe (14).

[0067] The plurality of pipes may further include a discharge pipe (not shown) for allowing compressed refrigerant to be discharged from the linear compressor (10) and a process pipe (not shown) for replenishing refrigerant to the linear compressor (10). For example, the discharge pipe and the process pipe may be connected to the outer surface of the shell (11).

[0068] Support devices (20, 90) that support the main body of the linear compressor (10) may be included on both sides of the shell (11). The support devices (20, 90) may include a first support device (20) that is coupled to the first shell cover (12) and elastically supports the main body of the linear compressor (10).

[0069] Here, the main body of the compressor refers to a component provided inside the shell (11), and may include, for example, a drive unit that moves back and forth and a support unit that supports the drive unit. The drive unit may include a piston (70), a permanent magnet (45), a supporter (33), and an intake muffler (25), etc. And, the support unit may include a resonant spring (30), a rear cover (31), a stator cover (32), a first support device (20), and a second support device (90), etc.

[0070] The first support device (20) may include a support bracket (21a) communicating with the suction pipe (14) and a support spring (21b) coupled to the support bracket (21a) and supported by the rear cover (31).

[0071] The above support device may include a second support device (90) that is coupled to the second shell cover (13) and supports the discharge cover assembly.

[0072] The linear compressor (10) may include a frame (50) provided inside the compressor shell (11) and a cylinder (60) inserted inside the frame (50). The cylinder (60) and the frame (50) may be made of a metal material, for example, aluminum or an aluminum alloy.

[0073] The above linear compressor (10) includes a piston (70) that moves in a reciprocating linear motion inside the cylinder (60). The piston (70) can move in an axial direction.

[0074] The above linear compressor (10) may further include a suction muffler (25) coupled to the piston (70) to reduce noise generated from the refrigerant sucked through the suction pipe (14).

[0075] The refrigerant sucked in through the suction pipe (14) flows into the interior of the piston (70) via the suction muffler (25). For example, as the refrigerant passes through the suction muffler (25), the flow noise of the refrigerant can be reduced. The suction muffler (25) may be composed of a plurality of mufflers combined.

[0076] The above linear compressor (10) may include a motor assembly (41, 43, 45) as a linear motor that provides driving force to the piston (70).

[0077] The motor assembly may include an outer stator (41) fixed to the frame (50) and arranged to surround the cylinder (60), an inner stator (43) spaced apart from the outer stator (41), and a permanent magnet (45) located in the space between the outer stator (41) and the inner stator (43).

[0078] A stator cover (32) is provided on one side of the outer stator (41). That is, one side of the outer stator (41) is supported by the frame (50), and the other side can be supported by the stator cover (32).

[0079] The permanent magnet (45) can move in a linear reciprocating motion due to the mutual electromagnetic force between the outer stator (41) and the inner stator (43). The permanent magnet (45) may be composed of a single magnet having one pole or may be composed of a plurality of magnets having three poles combined.

[0080] The above permanent magnet (45) can be installed in a magnet frame (46). The magnet frame (46) has a roughly cylindrical shape and can be positioned to be inserted into the space between the outer stator (41) and the inner stator (43).

[0081] The magnet frame (46) is coupled to the piston (70), and when the permanent magnet (45) reciprocates, the piston (70) can reciprocate in the axial direction together with the permanent magnet (45).

[0082] The above linear compressor (10) may further include a supporter (33) that supports the piston (70). The supporter (33) is coupled to the rear side of the piston (730), and the muffler (25) may be positioned to pass through the inside thereof. The piston (70), the magnet frame (46), and the supporter (33) may be connected by a fastening member.

[0083] The linear compressor (10) may include a rear cover (31) that is coupled to the stator cover (32), extends rearward, and is supported by a first support device (20). The rear cover (31) may be spring-supported by the supporter (33).

[0084] The rear cover (31) may include a plurality of support legs that are coupled to the rear of the stator cover (32).

[0085] The linear compressor (10) may include an inlet guide (23) coupled to the rear cover (31) to guide the inflow of refrigerant into the intake muffler (25). At least a portion of the inlet guide (23) may be inserted into the inside of the intake muffler (25).

[0086] The above linear compressor (10) may further include a plurality of resonant springs (30) each having an adjusted natural frequency so that the piston (70) can resonate.

[0087] The plurality of resonant springs (30) may include a plurality of first resonant springs supported between the supporter (33) and the stator cover (32), and a plurality of second resonant springs supported between the supporter (33) and the rear cover (31). Through the action of the plurality of resonant springs (30), stable movement of the drive unit reciprocating inside the linear compressor (10) is performed, and vibration or noise generation due to the movement of the drive unit can be reduced.

[0088] The frame (50) is understood as a configuration for fixing the cylinder (60), and, for example, the cylinder (60) can be pressed into the inside of the frame (50). The frame (50) can be arranged to surround the cylinder (60).

[0089] The above frame (50) has a hollow cylindrical shape and includes a frame body (51) that forms a space into which the cylinder (60) is inserted, and a frame flange (52) that extends radially from the front part of the frame body (51).

[0090] A cylinder sealing member (82) may be provided between the frame (50) and the cylinder (60). By means of the cylinder sealing member (82), the adhesion force may be increased during the press-fitting process between the frame (50) and the cylinder (60).

[0091] The cylinder sealing member (82) has a ring shape and can be installed on the inner surface of the frame (50) on which the flange (62) of the cylinder (60) is seated.

[0092] The above frame (50) may have a bearing channel (58) formed therein that extends axially from the frame flange (52) toward the frame body. A refrigerant acting as a gas bearing among the compressed discharge gas may flow through the bearing channel (58).

[0093] The refrigerant acting as the gas bearing is supplied between the cylinder body (61) and the piston (70) of the cylinder (60) to cause the piston (70) to float inside the cylinder (60).

[0094] Defines the direction.

[0095] "Axial direction" can be understood as the direction in which the piston (70) reciprocates, i.e., the up-and-down direction in FIG. 2. Among the "axial directions," the direction from the piston (70) toward the compression space (P) of the cylinder (60), i.e., the direction in which the refrigerant flows, is defined as "forward," and the opposite direction is defined as "rear." When the piston (70) moves forward, the compression space (P) is reduced, and when it moves rearward, the compression space (P) can be expanded.

[0096] On the other hand, "radial direction" is a direction perpendicular to the direction in which the piston (70) reciprocates, and can be understood as the horizontal direction of FIG. 2.

[0097] A compression space (P) in which refrigerant is compressed by the piston (70) may be formed inside the cylinder (60). An intake port for introducing refrigerant into the compression space (P) is formed at the front of the piston (70), and an intake valve (75) for selectively opening the intake port may be provided in front of the intake port.

[0098] The above suction port may be provided in multiple numbers. The multiple suction ports are spaced apart in the circumferential direction of the piston (70), and refrigerant is introduced into the compression space (P) through the multiple suction ports. The suction valve (75) may be connected to the front of the piston (70) by a fastening member (78), such as a screw or a bolt.

[0099] In front of the compression space (P), a discharge cover assembly (100, 200, 300) forming a discharge space for the refrigerant discharged from the compression space (P) may be provided. The discharge cover assembly (100, 200, 300) may be positioned in front of the frame (50).

[0100] The above discharge cover assembly may include a first discharge cover (100) and a second discharge cover (200) supported on the front of the frame (50). The first discharge cover (100) may be positioned inside the second discharge cover (200).

[0101] For example, the first discharge cover (100) can be press-fitted and fixed to the second discharge cover (200). The cover flange (150, see FIG. 3) of the first discharge cover (100) can be press-fitted into the inner circumference of the cover flange (250, see FIG. 10) of the second discharge cover (200). By press-fitting the first discharge cover (100) into the second discharge cover (200), the first and second discharge covers (100, 200) can be firmly fixed.

[0102] The internal space of the first discharge cover (100) and the internal space of the second discharge cover (200) can form a discharge path (also referred to as a "discharge room") for the refrigerant discharged from the compression space (P). For example, the refrigerant discharged from the compression space (P) can flow through the internal space of the first discharge cover (100), be discharged from the first discharge cover (100), and flow into the internal space of the second discharge cover (200).

[0103] The refrigerant flowing through the discharge chamber of the first discharge cover (100) and the discharge chamber of the second discharge cover (200) can be in a high-temperature gaseous state. The high-temperature heat can be transferred to the frame (50) supporting the first and second discharge covers (100, 200).

[0104] If high-temperature heat is excessively transferred to the frame (50), that heat becomes a factor that raises the temperature (suction temperature) of the refrigerant sucked into the compression space (P) of the cylinder.

[0105] If the above suction temperature increases, the volume of refrigerant per unit mass, that is, the specific volume of the refrigerant, increases, causing a decrease in volumetric efficiency, and consequently, a problem may arise in which the compression efficiency of the compressor decreases.

[0106] To prevent such problems, the first discharge cover (100) and the second discharge cover (200) according to an embodiment of the present invention may be composed of a material having a low heat transfer coefficient. The material having a low heat transfer coefficient may be a non-metallic material.

[0107] The first discharge cover (100) and the second discharge cover (200) may include plastic.

[0108] The first discharge cover (100) and the second discharge cover (200) may be made of the same plastic material, for example, polyamide (PA66) as a type of heat-resistant engineering plastic.

[0109] By making the first discharge cover (100) of the above-mentioned first discharge cover (100) of a plastic material, the amount of high-temperature heat within the first discharge cover (100) that is directly transferred to the frame (50) supporting the first discharge cover (100) or transferred to the second discharge cover (200) that is press-fitted to the first discharge cover (100) can be reduced.

[0110] By making the second discharge cover (200) of the above-mentioned second discharge cover (200) of a plastic material, the amount of high-temperature heat within the second discharge cover (200) that is directly transferred to the frame (50) supporting the second discharge cover (200) or transferred to the first discharge cover (100) that is press-fitted to the second discharge cover (200) can be reduced.

[0111] Ultimately, it is possible to prevent excessive transfer of high-temperature heat from the refrigerant present in the discharge chamber within the first and second discharge covers (100, 200) to the frame (50). Accordingly, the suction temperature of the refrigerant can be reduced and the compression efficiency of the compressor can be improved.

[0112] Since the first and second discharge covers (100, 200) are made of a relatively lightweight plastic material, there is a possibility that vibration and noise may occur in the first and second discharge covers (100, 200) due to the high-pressure refrigerant discharged from the compression space (P).

[0113] To prevent such problems, the discharge cover assembly according to the present embodiment may include a damping member (180) for reducing vibration of the first and second covers (100, 200).

[0114] The damping member (180) is mounted in the recess (140, see FIG. 4) of the first discharge cover (100), and the inner wall (238, see FIG. 11) of the second discharge cover (200) may be configured to support or press the damping member (180).

[0115] The damping member (180) can offset the magnitude of vibration and noise transmitted from one of the first and second discharge covers (100, 200) to the other. In particular, when the discharge valve (191) is turned on and off, the effect of reducing the magnitude of the valve tapping sound that is frictionally applied to the cylinder (60) can be expected.

[0116] In a structure in which the damping member (180) is mounted on the recess (140) of the first discharge cover (100), the recess (140) and the damping member (180) form a flow path through which refrigerant flows, and the flow path can be understood as defining a pulsation path to reduce pulsation that occurs when high-pressure discharge gas flows.

[0117] The above discharge cover assembly may include a third discharge cover (300) that supports the second discharge cover (200).

[0118] The third discharge cover (300) may have a roughly ring shape and be positioned to surround the rear portion of the second discharge cover (200). The third discharge cover (300) may support the cover flange (250) of the second discharge cover (200).

[0119] The third discharge cover (300) can be supported on the front of the frame (50).

[0120] The third discharge cover (300) is fastened to the frame flange (52) by a fastening member (not shown), and the front surface of the frame flange (52) can come into surface contact with the rear surface of the third discharge cover (300).

[0121] A frame fastening hole (55) into which the fastening member is inserted may be formed in the frame flange (52). Multiple frame fastening holes (55) may be formed. A cover fastening hole (335) may be formed in the third discharge cover (300) at a position corresponding to the frame fastening hole (55).

[0122] The above fastening member can be fastened to the frame fastening hole (55) and the cover fastening hole (335) to fix the frame (50) and the third discharge cover (300).

[0123] The third discharge cover (300) may be made of a material different from the first discharge cover (100) and the second discharge cover (200). The third discharge cover (300) may be made of a material having greater strength than the first discharge cover (100) and the second discharge cover (200).

[0124] The third discharge cover (300) may be made of a metal material, for example, aluminum. Since the third discharge cover (300) is connected to the frame (50) by the fastening member, a failure in connection may occur if the amount of deformation increases due to high heat. Therefore, the third discharge cover (300) may be made of a metal material so that the amount of thermal deformation is not large.

[0125] A frame sealing member (81) capable of increasing bonding strength and preventing refrigerant leakage may be provided at the portion where the second discharge cover (200) and the frame (50) are in surface contact. The frame sealing member (81) has a ring shape and may be installed between the rear surface of the second discharge cover (200) and the front surface of the frame (50).

[0126] The discharge cover assembly may include a discharge valve assembly (190). The discharge valve assembly may include a discharge valve (191) and a spring assembly (193, 195) that provides elastic force to the discharge valve (191) in a direction that brings it into close contact with the front end of the cylinder (60).

[0127] The above spring assembly (193, 195) may include a valve spring (193) composed of a leaf spring and a spring bracket (195) that surrounds the edge of the valve spring (193) to support the valve spring (193).

[0128] The discharge valve (191) is coupled to the central part of the valve spring (193). When the discharge valve (191) is opened, the refrigerant compressed in the compression space (P) of the cylinder (60) is discharged and flows into the internal space of the first discharge cover (100). When the discharge of the refrigerant is completed, the discharge valve (191) can be closed by the restoring force of the valve spring (193).

[0129] The above spring bracket (195) can be seated on the inner surface of the first discharge cover (100).

[0130] A sealing bracket (197) may be installed around the front end of the cylinder (60). For example, the sealing bracket (197) may have a ring shape. The sealing bracket (197) may be seated on the front flange of the cylinder (60) and supported on the rear of the spring bracket (195).

[0131] A bracket sealing member (83) may be provided between the sealing bracket (197) and the flange of the cylinder (60). The bracket sealing member (83) is provided on the contact surface between the sealing bracket (197) and the flange of the cylinder (60), and can prevent refrigerant from leaking through the space between the cylinder (60) and the spring assembly (193, 195).

[0132] FIG. 3 is a perspective view showing a damping member installed on a first discharge cover according to an embodiment of the present invention, FIG. 4 is an upper perspective view of the first discharge cover according to an embodiment of the present invention, FIG. 5 is a plan view of the first discharge cover according to an embodiment of the present invention, FIG. 6 is a lower perspective view of the first discharge cover according to an embodiment of the present invention, and FIG. 7 is a bottom view of the first discharge cover according to an embodiment of the present invention.

[0133] Referring to FIGS. 3 to 7, a first discharge cover (100) according to an embodiment of the present invention may include a cover body (110) forming a discharge chamber and a cover flange (150) provided at the rear end of the cover body (110) and supported by the frame (50).

[0134] The above cover body (110) may be configured to have a cap shape to form a discharge chamber for the refrigerant discharged from the discharge valve (191).

[0135] The above cover body (110) may include cylindrical outer walls (111a, 111b, 111c). The outer walls may include a first part (111a) forming a front portion and a second part (111b) connected to the cover flange (150). The first and second parts (111a, 111b) may be arranged in an axial direction.

[0136] The first part (111a) and the second part (111b) may be extended in a rounded manner in the circumferential direction to have a cylindrical shape.

[0137] The outer wall of the cover body (110) may be formed with a step. Specifically, the outer wall of the cover body (110) may include a step portion (111c) connecting the first part (111a) and the second part (111b).

[0138] The stepped portion (111c) may be connected to the second part (111b) by extending radially outward from the end of the first part (111a). Due to the stepped portion (111c), the outer diameter of the second part (111b) may be formed to be larger than the outer diameter of the first part (111a).

[0139] The above step portion (111c) may be configured to correspond to the position where the rear end of the recess (140) of the first discharge cover (100) is formed. That is, the recess (140) is not formed in the second part (111b), and the second part (111b) may be formed thicker than the first part (111a) so as not to be deformed or damaged during the press-fitting process with the second discharge cover (200).

[0140] The first discharge cover (100) may include a front wall (120) forming the front end of the first discharge cover (100). The front wall (120) may be positioned radially inward of the outer wall.

[0141] The above front wall (120) can form a discharge hole (123) that transmits the discharge gas present in the internal space of the first discharge cover (100), i.e., the discharge chamber, to the outside of the first discharge cover (100).

[0142] The first discharge cover (100) may include a discharge guide (126) that protrudes from the front wall (120) in a direction toward the discharge valve (191). The discharge guide (126) may form the discharge hole (123). That is, the discharge hole (123) may be formed by penetrating from the discharge guide (126) to the front wall (120).

[0143] The first discharge cover (100) may include an inner wall (130) extending toward the rear from the edge of the front wall (120). The inner wall (130) may be extended in a rounded manner in the circumferential direction to have a cylindrical shape.

[0144] The front wall (120), the inner wall (130), and the discharge guide (126) can define a discharge chamber within the first discharge cover (100).

[0145] A recess (140) may be formed between the outer walls (111a, 111b, 111c) and the inner wall (130). The recess (140) is formed to have a ring shape along the perimeter of the inner wall (130) and may be configured to be recessed from the front end of the first discharge cover (100) toward the rear. The rear end of the recess (140) may be formed at a height corresponding to the stepped portion (111c) of the outer wall.

[0146] The above-mentioned recess (140) may be formed along the circumference of the discharge hole (123) formed in the center of the first discharge cover (100). Specifically, the discharge hole (123) may be formed in the center of the front wall (120), and the recess (140) may be formed along the outer circumference of the front wall (120).

[0147] The radial width of the above-mentioned recess (140) forms a first width (W1, see FIG. 5) and can be understood as the distance between the inner wall (130) and the first part (111a). The first width (W1) may be formed to be smaller than the width of the discharge chamber (A1, see FIG. 17) of the first discharge cover (100) and / or the width of the discharge chambers (A2, A3) of the second discharge cover (200).

[0148] The above-mentioned depression (140) can form a flow path for the discharged gas. The discharged gas exhibits a pulsation phenomenon in which the pressure or flow rate changes periodically, and noise may be generated by the pulsation.

[0149] In this embodiment, the flow path of the discharged gas can be formed roundly through the ring-shaped recess (140) and the length of the flow path can be formed long to reduce pulsation.

[0150] Additionally, the recess (140) is formed between the first discharge chamber (A2, see FIG. 17) and the second discharge chamber (A3, see FIG. 17) of the second discharge cover (200), and the cross-sectional area of ​​the recess (140) may be formed to be smaller than the cross-sectional area of ​​the first discharge chamber (A2) and / or the cross-sectional area of ​​the second discharge chamber (A3).

[0151] Accordingly, as the discharge gas flows from the first discharge chamber (A2), which has a relatively large cross-sectional area, to the recess (140), which has a small cross-sectional area, and then to the second discharge chamber (A3), which has a large cross-sectional area, the pulsating noise can be reduced.

[0152] The linear compressor (10) may further include a loop pipe (290, see FIG. 10) as a configuration for reducing pulsation. The loop pipe (290) is a pulsation pipe extending from the discharge cover assembly to the discharge pipe of the shell (11) and may be made of a flexible material to reduce pulsation noise.

[0153] The recess (140) of the first discharge cover (100) can be understood to form an additional pulsating pipe in addition to the loop pipe (290), and to form a pulsating flow path inside the recess (140).

[0154] A damping member (180) may be installed in the first discharge cover (100). The damping member (180) is inserted into the recess (140) and can cover the open front portion of the recess (140).

[0155] In the above-mentioned recess (140), a support projection (139, 111d) for supporting the damping member (180) may be provided.

[0156] The above support ridge may include a first support ridge (139) formed in a stepped manner on the outer surface of the inner wall (130). The first support ridge (139) protrudes from the outer surface of the inner wall (130) and may have a ring shape corresponding to the shape of the damping member (180).

[0157] The above support ridge may include a second support ridge (111d) formed in a stepped manner on the inner circumference of the outer wall (111a, 111b, 111c). The second support ridge (111d) protrudes from the inner circumference of the outer wall (111a, 111b, 111c) and may have a ring shape corresponding to the shape of the damping member (180).

[0158] When the damping member (180) is inserted into the recess (140), the rear end of the damping member (180) may be spaced apart from the rear end of the recess (140). The space between the rear end of the recess (140) and the rear end of the damping member (180) may form a flow path through which discharge gas flows.

[0159] The refrigerant discharged to the outside of the first discharge cover (100) through the discharge hole (123) can flow into the flow path within the recess (140). The first discharge cover (100) may include a configuration for guiding the refrigerant to flow into the interior of the recess (140).

[0160] In detail, the first discharge cover (100) may include a recess (125) that is recessed radially inward from the inner wall (130), that is, in a direction approaching the discharge hole (123). The recess (125) may be formed from the front wall (120) to the rear end of the recess (140).

[0161] As the above recess (125) is formed radially inward, the radial second width (W2, see FIG. 5) of the area of ​​the recess (140) where the recess (125) is formed in the ring-shaped recess (140) may be larger than the first width (W1).

[0162] The discharge gas discharged from the discharge hole (123) flows into the recess (125) through the recess (125) and can flow circumferentially at the rear of the damping member (180). The recess (125) can be understood as the inlet of a pulsating flow path formed within the recess (140).

[0163] The first discharge cover (100) may include a configuration for guiding the discharge of refrigerant within the recess (140) to the outside. Specifically, the first discharge cover (100) may include a protrusion (113) that protrudes radially outward from the outer wall, that is, in a direction away from the discharge hole (123).

[0164] The back surface of the above protrusion (113) can be understood as forming a recess (113a) that is recessed from the inner circumference of the outer wall. The recess (113a) may be formed from the front end of the recess (140) to the rear end of the recess (140). The recess (125) may be named "first recess" and the recess (113a) may be named "second recess".

[0165] As the above protrusion (113) is formed radially outward, the radial third width (W3, see FIG. 5) of the area of ​​the recess (140) in which the recess (113a) is formed among the ring-shaped recess (140) may be larger than the first width (W1).

[0166] The discharge gas flowing through the pulsating flow path within the recess (140) can be discharged from the recess (140) through the recess (113a). The recess (113a) can be understood as an outlet of the pulsating flow path formed within the recess (140).

[0167] The above recess (113a) can be connected to the second discharge chamber (A3, see FIG. 17) of the second discharge cover (200).

[0168] The center of the first discharge cover (100) may be formed at the center (C1) of the discharge hole (123). The first recess (125a) and the second recess (113a) may be formed opposite each other with respect to the center (C1).

[0169] The extension line (ℓ1) connecting the first recess (125a) and the second recess (113a) can pass through the center (C1) of the first discharge cover (100) and the discharge hole (123).

[0170] The first distance (d1) from the center (C1) to the first recess (125) can be formed to be shorter than the second distance (d2) from the center (C1) to the second recess (113a).

[0171] The discharge gas discharged from the discharge hole (123) flows into the recess (140) through the first recess (125) and flows in a clockwise and counterclockwise direction and can be discharged from the recess (140) at the second recess (113a).

[0172] The first recess (125) may be named the "inlet" of the pulsating channel formed in the recess (140) of the first discharge cover (100), and the second recess (113a) may be named the "outlet" of the pulsating channel.

[0173] At least a portion of the second discharge cover (200), for example, an inner wall (238, see FIG. 11), may be coupled to the damping member (180). The inner wall (238) may have a ring shape corresponding to the damping member (180).

[0174] By combining the inner wall (238) and the damping member (180), the internal space of the second discharge cover (200) can be divided into a plurality of discharge chambers (A2, A3, see FIG. 17).

[0175] That is, the refrigerant in the second discharge chamber (A2) of the second discharge cover (200) flows into the recess (140) through the first recess (125), and is discharged from the recess (140) through the second recess (113a) and flows into the third discharge chamber (A3) of the second discharge cover (200).

[0176] The first discharge cover (100) may include ribs for reinforcing the strength of the discharge cover made of plastic material. Specifically, the first discharge cover (100) may include an inner surface where reinforcing ribs (135) are installed. The inner surface of the first discharge cover (100) may be understood as a wall surface defining the discharge room.

[0177] The reinforcing rib (135) can be configured to protrude from the inner surface of the first discharge cover (100).

[0178] The reinforcing rib (135) may include a first portion that is connected to the discharge guide (126) and extends along the rear surface of the front wall (120). The first portion may extend radially.

[0179] The reinforcing rib (135) may include a second portion extending along the inner wall (130) from the rear of the front wall (120). The second portion is connected to the first portion and may extend axially (rearward).

[0180] By the configuration of the first part and the second part, the reinforcing rib (135) can be configured to be bent or rounded.

[0181] The above reinforcing ribs (135) are provided in multiple numbers, and the multiple reinforcing ribs (135) may be spaced apart in the circumferential direction. The multiple reinforcing ribs (135) may act as flow resistance bodies for the discharge gas flowing in the internal space of the first discharge cover (100) to reduce the magnitude of the pulsation.

[0182] The first discharge cover (100) may include a connecting rib (136) connecting the outer wall (111a, 111b, 111c) and the inner wall (130). For example, the connecting rib (136) may connect the rear end of the inner wall (130) and the inner surface of the second part (111b).

[0183] The above connecting ribs (136) are provided in multiple numbers, and the multiple connecting ribs (136) may be spaced apart in the circumferential direction. The multiple connecting ribs (136) may be connected to the multiple reinforcing ribs (135). The connecting ribs (136) can be understood as forming at least a portion of the reinforcing ribs (135).

[0184] The above connecting rib (136) may be positioned further back than the bottom surface (140a, see FIG. 7) of the above recess (140).

[0185] The inner surface of the first discharge cover (100) may have a stepped configuration by means of the outer walls (111a, 111b, 111c), the inner wall (130), and the connecting rib (136).

[0186] In detail, the axial length of the outer wall (111a, 111b, 111c) may be formed to be longer than the axial length of the inner wall (130). Additionally, the connecting rib (136) may extend radially outward from the rear end of the inner wall (130) and be connected to the inner circumference of the outer wall.

[0187] With this configuration, the inner surface of the first discharge cover (100) is configured to be stepped, and the discharge valve assembly (190) can be supported on the stepped inner surface of the first discharge cover (100).

[0188] The front edge of the discharge valve assembly (190) is supported by the connecting rib (136), and the outer surface of the discharge valve assembly (190) can be supported on the inner surface of the outer wall (111a, 111b, 111c). Of course, the size of the discharge valve assembly (190) will be configured to be sized to fit the stepped inner surface of the first discharge cover (100).

[0189] In order to prevent circumferential slip of the discharge valve assembly (190), a projection groove (132) into which a projection (not shown) of the discharge valve assembly (190) is inserted may be formed at the rear end of the inner wall (130). Multiple projection grooves (132) are formed in the circumferential direction, and by inserting multiple projections into the multiple projection grooves (132), unwanted rotation of the discharge valve assembly (190) during the refrigerant discharge process can be prevented.

[0190] The cover flange (150) may extend radially outward from the rear end of the cover body (110) to have a radius larger than that of the cover body (110). The cover flange (150) may have a roughly ring shape.

[0191] The rear end of the cover flange (150) may form a support surface (151) that contacts the frame (50). A reduction portion (152) may be formed at the rear end of the cover flange (150). The reduction portion (152) may be formed by indenting at least a part of the cover flange (150).

[0192] The above-mentioned weight loss portions (152) are formed in multiple numbers, and the multiple weight loss portions (152) are formed spaced apart in the circumferential direction, and the supporting surface (151) may be formed between the multiple weight loss portions (152).

[0193] By forming the above-mentioned weight reduction portion (152), the contact area between the first discharge cover (100) and the frame (50) can be reduced, and accordingly, the amount of heat transferred from the first discharge cover (100) to the frame (50) can be reduced.

[0194] The above cover flange (150) may include a recessed bearing groove (155) to guide at least a portion of the discharge gas refrigerant into the bearing channel (58). The bearing groove (155) is recessed from the outer surface of the cover flange (150) so as to be refrigerant-fluidly connected to the bearing channel (58).

[0195] For example, at least some of the refrigerant among the discharge gas present in the internal space of the second discharge cover (200) can flow into the bearing channel (58) through the bearing groove (155).

[0196] FIG. 8 is an upper perspective view of a damping member according to an embodiment of the present invention, and FIG. 9 is a lower perspective view of a damping member according to an embodiment of the present invention.

[0197] Referring to FIGS. 8 and 9, a damping member (180) according to an embodiment of the present invention may be provided in one of the areas where the first discharge cover (100) and the second discharge cover (200) are combined. In particular, the damping member (180) may be provided in a partition wall that divides the internal space of the second discharge cover (200) into two or more discharge rooms.

[0198] For example, the above partition wall may include an inner wall (238, see FIG. 11) provided in the second discharge cover (200).

[0199] The damping member (180) may have a ring shape with an empty interior to form a hollow portion (186).

[0200] The damping member (180) may be configured to be inserted into a recess (140) formed in the first discharge cover (180). Specifically, the damping member (180) may include a first part (181) that forms a groove (184) into which the inner wall (238) is inserted.

[0201] The first part (181) may include a ring-shaped inner surface portion (182) and a ring-shaped outer surface portion (183) surrounding the inner surface portion (182).

[0202] The first part (181) may include a groove (184) formed between the inner surface portion (182) and the outer surface portion (183). The groove (184) has a width in the radial direction and may have an inner wall (238) of the second discharge cover (200) inserted into it. For example, the inner wall (238) may be pressed into the groove (184).

[0203] The bottom surface (184a, 184b) of the above-mentioned groove (184) can connect the rear end of the inner surface portion (182) and the outer surface portion (183).

[0204] The damping member (180) may include a second part (185) that is connected to the rear end of the first part (181) and extends rearward. For example, the second part (185) may extend rearward from the bottom surface (184a, 184b) of the groove (184).

[0205] The second part (185) extends rearward from approximately the center of the rear end of the first part (181) and may be formed with a step relative to the first part (181). The first part (181) and the second part (182) may have an approximately Y shape.

[0206] The rear end of the first part (181) can be supported by a support ledge (139, 111d) provided in the recess (140). The support ledge (139, 111d) can support the bottom surface (184a, 184b).

[0207] The above bottom surfaces (184a, 184b) may include a first bottom surface (184a) supported by the first support ledge (139). The first bottom surface (184a) may connect the inner circumferential portion (182) and the second part (185).

[0208] The above bottom surfaces (184a, 184b) may include a second bottom surface (184b) supported by the second support ledge (111d). The second bottom surface (184b) may connect the outer surface portion (183) and the second part (185).

[0209] The second part (185) can extend into the recess (140) of the first discharge cover (100). The rear end of the second part (185) can form the rear end of the damping member (180).

[0210] The damping member (180) can reduce vibrations occurring between the first discharge cover (100) and the second discharge cover (200).

[0211] In addition, as described above, the damping member (180) can reduce the pulsating noise of the discharged gas by being inserted into the recess (140) of the first discharge cover (100) and defining a part of the pulsating flow path formed in the recess (140).

[0212] FIG. 10 is an upper perspective view of a second discharge cover according to an embodiment of the present invention, FIG. 11 is a lower perspective view of a second discharge cover according to an embodiment of the present invention, and FIG. 12 is a bottom view of a second discharge cover according to an embodiment of the present invention.

[0213] Referring to FIGS. 10 to 12, the second discharge cover (200) according to the second embodiment of the present invention forms an internal space that accommodates the first discharge cover (100), and the internal space may include a flow path for the refrigerant discharged from the discharge valve (191).

[0214] The second discharge cover (200) may include a cover body (210) that forms a discharge chamber for the refrigerant and a cover flange (250) provided at the rear end of the cover body (210) and supported by the frame (50).

[0215] The above cover body (210) may be configured to have a cap shape to form a discharge chamber for the refrigerant discharged from the discharge valve (191).

[0216] The above cover body (210) may include an outer wall (220, 230). The outer wall may include a first part (220) connected to the cover flange (250). The first part (220) may have a cylindrical shape by extending in a rounded manner in the circumferential direction.

[0217] The above outer wall may include a second part (230) extending forward from the front portion of the first part (220). The second part (230) may extend axially from the first part (220).

[0218] The second part (230) can be formed stepwise from the first part (220).

[0219] The size of the second part (230) may be formed to be smaller than the size of the first part (220). For example, the outer diameter or inner diameter of the second part (230) may be formed to be smaller than the outer diameter or inner diameter of the first part (220).

[0220] The second discharge cover (200) may further include a protrusion (233) extending radially outward from the second part (230). The protrusion (233) is connected to the first part (220) and may extend axially to the cover flange (250).

[0221] The above protrusion (233) may include a discharge hole (280) for discharging refrigerant from the discharge chamber of the second discharge cover (200).

[0222] The discharge hole (233) is formed on the side of the protrusion (233) and may be in communication with the internal space (discharge room) of the second discharge cover (200). The discharge hole (233) may be formed by being recessed from the side of the protrusion (233) and penetrating to the front wall (228) of the first part (220) (see FIG. 12).

[0223] A loop pipe (290) connected to a discharge pipe provided in the shell (11) of the linear compressor (10) may be connected to the discharge port (233). The refrigerant discharged from the discharge port (233) may flow to the discharge pipe through the loop pipe (290).

[0224] The loop pipe (290) is made of a flexible material and can be formed to be relatively long. The loop pipe (290) is connected to the discharge hole (233) and can extend along the outer surface of the second discharge cover (200).

[0225] The second discharge cover (200) may include a recess (235) that guides the extended position of the loop pipe (290). The recess (235) may be configured, for example, to have a shape that is recessed into the outer surface of the second part (230).

[0226] The above-mentioned loop pipe (290) can perform the function of reducing the pulsation of the discharge gas. That is, the above-mentioned loop pipe (290) can function as a pulsation reduction channel that reduces the pulsation of the discharge gas together with the recessed portion (140) of the above-mentioned first discharge cover (100).

[0227] The above protrusion (233) may include a plurality of grooves (234a, 234b). The plurality of grooves (234a, 234b) may allow for a reduction in the contact area with the frame (50) in order to reduce the amount of heat transferred from the high-temperature discharge gas to the frame (50).

[0228] In addition, the plurality of grooves (234a, 234b) may allow for an increase in the heat dissipation area to increase the amount of heat dissipated from the second discharge cover (200).

[0229] The plurality of grooves (234a, 234b) may include a first groove (224a) that is recessed from the outermost radial surface of the protrusion (233). The first groove (234a) may include a plurality of grooves that are formed axially from the second part (230) to the rear end of the second discharge cover (200) and are aligned in the circumferential direction. By the first groove (234a), the heat dissipation surface area of ​​the protrusion (233) may be increased.

[0230] The plurality of grooves (234a, 234b) may include a second groove (234b) formed on a contact surface (234c) that contacts the frame (50). The contact surface (234c) forms the rear end of the protrusion (233) and can be supported by the frame (50).

[0231] The second groove portion (234b) may include a plurality of grooves that are recessed forward from the contact surface (234c). The plurality of grooves of the second groove portion (234b) may be aligned in a circumferential direction.

[0232] The second discharge cover (200) may include a third part (240) extending forward from the second part (230). The third part (240) may protrude in a direction extending from the second part (230) toward the second shell cover (13). The third part (240) may be located adjacent to the second shell cover (13).

[0233] The above linear compressor (10) may include a cap member (285, see FIG. 2) to prevent noise that occurs when the second discharge cover (200) and the second shell cover (13) come into contact. The cap member (285) may be made of, for example, rubber material to absorb shock that may occur between the second discharge cover (200) and the second shell cover (13).

[0234] The third part (240) may include a first coupling hole (241) into which the cap member (285) is coupled. A protrusion of the cap member (285) is inserted into the first coupling hole (241), thereby facilitating the coupling of the second discharge cover (200) and the cap member (285). The first coupling hole (241) may, for example, be formed at the front end of the third part (240).

[0235] The third part (240) may include a second coupling hole (242) that is coupled to the second support device (90). The second coupling hole (242) is formed on the outer surface of the third part (240), and at least a portion of the second support device (90) may be coupled to the second coupling hole (242) to support the discharge cover assembly.

[0236] The cap member (285) includes an insertion projection (286, see FIG. 16) that is inserted into the second coupling hole (242), and the insertion projection (286) can form the coupling hole (285a, see FIG. 16). At least a portion of the second support device (90) can be coupled to the second coupling hole (242) of the third part (240) through the coupling hole (285a).

[0237] The cover flange (250) forms the rear end of the second discharge cover (200) and may have an outer diameter and an inner diameter larger than that of the discharge body (210). For example, the cover flange (250) may have a ring shape.

[0238] The above cover flange (250) may include a contact surface (251) that contacts the frame (50). The contact surface (251) may form a rear end of the cover flange (250) and extend along the outer circumference of the cover flange (250) to have a ring shape.

[0239] The above cover flange (250) may include an outer surface portion (252) that forms the exterior of the cover flange (250) and defines the outer diameter of the cover flange (250), and an inner surface portion (253) that supports the first discharge cover (100) and defines the inner diameter of the cover flange (250).

[0240] The above cover flange (250) may include a projection (255) extending radially inward from the inner circumferential portion (253). The projection (255) may define a step difference between the cover body (210) and the cover flange (250).

[0241] The inner surface portion (253) and the jaw (255) can support the cover flange (150) of the first discharge cover (100). For example, the first discharge cover (100) is pressed into the inner side of the second discharge cover (200), and the inner surface portion (253) and the jaw (255) can provide a press-fit surface of the first discharge cover (100).

[0242] The second discharge cover (200) may include an inner wall (238) protruding from the inner surface of the outer wall (220, 230). The inner wall (238) may be configured to extend rearward from the rear end of the second part (230).

[0243] The inner wall (238) can extend from the second part (230) toward the recess (140) of the first discharge cover (100).

[0244] The inner wall (238) has a ring shape and may have a size corresponding to the recess (140) so that it can be inserted into the recess (140) of the first discharge cover (100).

[0245] The inner wall (238) can be inserted into the groove (184) of the damping member (180).

[0246] By connecting the inner wall (238) to the first discharge cover (100) through the damping member (180), vibration and noise generated from the second discharge cover (200) and the first discharge cover (100) can be reduced.

[0247] The inner wall (238) can divide the internal discharge space (discharge room) of the second discharge cover (200) into a first discharge room (A2, see FIG. 17) and a second discharge room (A3, see FIG. 17). The first discharge room (A2) forms an inner discharge room of the inner wall (238), and the second discharge room (A3) forms an outer discharge room of the inner wall (238).

[0248] The second discharge chamber (A3) is arranged to surround the first discharge chamber (A2), and the refrigerant of the first discharge chamber (A2) can flow into the recess (140) of the first discharge cover (100) and be discharged into the second discharge chamber (A3). That is, the second discharge chamber (A3) can form a downstream flow path of the first discharge chamber (A2).

[0249] The second discharge cover (200) may include reinforcing ribs (227, 237) to reinforce the strength of the cover made of a non-metallic material. The reinforcing ribs (227, 237) are provided in the discharge chamber of the second discharge cover (200) and act as a flow resistance for the refrigerant, thereby reducing the discharge pulsation of the refrigerant.

[0250] The above reinforcing ribs (227, 237) may include a first reinforcing rib (227) provided on the inner surface of the first part (220). The first reinforcing rib (227) may include a first portion (227a) protruding from the inner circumference of the first part (220). The first portion (227a) may extend in the axial direction.

[0251] The first reinforcing rib (227) may include a second part (227b) that is bent from the first part (227a) and extends radially. The second part (227b) may be placed in an area connecting the first part (220) and the second part (230).

[0252] For example, the first part (220) includes a shear wall (228) that defines a step with respect to the second part (230), and the second part (227b) may be provided on the inner surface of the shear wall (228) of the first part (220).

[0253] The first reinforcing ribs (227) are provided in multiple numbers, and the multiple first reinforcing ribs (227) may be spaced apart from each other in the circumferential direction of the first part (220). By arranging the multiple first reinforcing ribs (227), strength reinforcement in the axial and radial directions of the first part (220) can be achieved.

[0254] In addition, the plurality of first reinforcing ribs (227) can act as flow resistance for the refrigerant flowing through the second discharge chamber (A3, see FIG. 17) to reduce the pulsating noise of the refrigerant.

[0255] The above reinforcing ribs (227, 237) may include a second reinforcing rib (237) provided on the inner surface of the second part (230). The second reinforcing rib (237) may include a first portion (237a) protruding from the inner circumference of the second part (230). The first portion (237a) may extend in the axial direction.

[0256] The second reinforcing rib (237) may include a second part (237b) that is bent from the first part (237a) and extends radially. The second part (237b) may be placed in an area connecting the second part (230) and the third part (240).

[0257] For example, the second part (230) includes a shear wall (236) that defines a step with respect to the third part (240), and the second part (237b) may be provided on the inner surface of the shear wall (236) of the second part (230).

[0258] The above second reinforcing ribs (237) are provided in multiple numbers, and the multiple second reinforcing ribs (237) may be spaced apart from each other in the circumferential direction of the second part (230). By arranging the multiple second reinforcing ribs (237), strength reinforcement in the axial and radial directions of the second part (230) can be achieved.

[0259] In addition, the plurality of second reinforcing ribs (237) can act as flow resistance for the refrigerant flowing through the first discharge chamber (A2, see FIG. 17) to reduce the pulsating noise of the refrigerant.

[0260] The third part (240) may include a weight reduction section (245). The weight reduction section (245) may include a recessed portion that is recessed forward from the rear end of the third part (240). By the weight reduction section (245), the weight of the third part (240) is reduced, and the amount of vibration of the second discharge cover (200) can be reduced.

[0261] FIG. 13 is an upper perspective view of a third discharge cover according to an embodiment of the present invention, FIG. 14 is a lower perspective view of a third discharge cover according to an embodiment of the present invention, and FIG. 15 is a bottom view showing the second discharge cover and the third discharge cover combined according to an embodiment of the present invention.

[0262] Referring to FIGS. 13 to 15, a discharge cover assembly according to an embodiment of the present invention may include a third discharge cover (300) supported on a frame (50). The third discharge cover (300) may support the second discharge cover (200) on the frame (50).

[0263] The third discharge cover (300) may have a ring shape to include a portion that surrounds the outer circumference of the second discharge cover (200).

[0264] The third discharge cover (300) may include a cover body (310) that defines an insertion space (312) into which at least a portion of the second discharge cover (200) is inserted. The cover body (310) may have a roughly ring shape.

[0265] The above cover body (310) may be configured to contact or support the outer surface of the second discharge cover (200). The above cover body (310) may include an inner surface portion (311) that surrounds the cover flange (250) of the second discharge cover (200).

[0266] The inner surface portion (311) extends in the axial direction, and the axial length of the inner surface portion (311) may correspond, for example, to the axial length of the cover flange (250) of the second discharge cover (200).

[0267] The above cover body (310) may include a projection (313) that extends radially inward from the inner circumferential portion (311) to support the front portion of the cover flange (250). The projection (313) may form a supporting surface of the second discharge cover (200) together with the inner circumferential portion (311).

[0268] The above third discharge cover (300) can be fastened to the frame (50) by means of a fastening member, for example, a screw.

[0269] The third discharge cover (300) may include a cover flange (330) extending radially outward from the cover body (310). The cover flange (330) may include a support surface (331) supported by the frame (50). The support surface (331) may form the rear end of the third discharge cover (330).

[0270] The above cover flange (330) may include a fastening hole (335) for fastening with the frame (50). The fastening hole (335) is formed by penetrating the cover flange (330), and the fastening member may be fastened to the frame (50) by penetrating the fastening hole (335).

[0271] The above cover flanges (330) are provided in multiple numbers, and the third discharge cover (300) can be firmly fixed to the frame (50) through the multiple cover flanges (330). For example, the multiple cover flanges (330) may include three cover flanges, but the number of cover flanges (330) is not limited thereto.

[0272] The third discharge cover (300) may include a protrusion support member (340) that supports a protrusion (233) of the second discharge cover (200). The protrusion support member (340) may be configured to protrude radially outward from the cover body (310) to accommodate at least a portion of the protrusion (233).

[0273] The above third discharge cover (300) may include a terminal cover portion (351) that covers a terminal portion (not shown). The terminal portion is provided on the outer stator (41) and can be understood as a configuration that guides a power line to be drawn out to the outside of the outer stator (41).

[0274] The terminal cover portion (351) may be configured to extend radially outward from the cover body (310) and cover the front end of the terminal portion.

[0275] The third discharge cover (300) may include a terminal leg (352) connected to the terminal cover portion (351). The terminal leg (352) may extend rearward from the terminal cover portion (351) to support the side of the terminal portion.

[0276] The third discharge cover (300) may include a cover bracket (353) that protrudes radially outward from the cover body (310) and is located opposite the terminal cover portion (351) with respect to the center of the third discharge cover (300).

[0277] By means of the cover bracket (353), the center of gravity of the third discharge cover (300) can be prevented from shifting toward the terminal cover part (351).

[0278] The third discharge cover (300) may be made of a material different from that of the first and second discharge covers (100, 200).

[0279] The third discharge cover (300) may be made of a material that is heavier and has higher strength than the first and second discharge covers (100, 200).

[0280] The third discharge cover (300) may be made of a metal material. For example, the third discharge cover (300) may be made of aluminum.

[0281] In order to reduce the amount of heat transferred from the third discharge cover (300) to the frame (50), if the third discharge cover (300) is made of a non-metallic material like the first and second discharge covers (100, 200), thermal shrinkage may occur due to the high-temperature discharge gas, and a problem arises in that a failure in fastening between the third discharge cover (300) and the frame (50) occurs due to the thermal shrinkage.

[0282] Accordingly, in this embodiment, the third discharge cover (300) connected to the frame (50) is made of a metal material with a low thermal deformation rate, thereby reducing the failure rate of connection to the frame (50).

[0283] FIG. 16 is a cross-sectional view showing the configuration of a discharge cover assembly according to an embodiment of the present invention, and FIG. 17 is a cross-sectional view showing the appearance of a refrigerant flowing through the discharge chamber of a discharge cover assembly according to an embodiment of the present invention.

[0284] Referring to FIGS. 16 and 17, a discharge cover assembly according to an embodiment of the present invention may be supported on a frame (50). The discharge cover assembly may include a first discharge cover (100) and a second discharge cover (200) that are stacked in the axial direction.

[0285] The first and second discharge covers (100, 200) are installed to contact the frame (50), and in order to reduce the amount of heat transfer from the first and second discharge covers (100, 200) to the frame (50), the first and second discharge covers (100, 200) may be made of a non-metallic material, for example, a plastic material.

[0286] The discharge cover assembly may include a third discharge cover (300) that is fastened to the frame (50). The third discharge cover (300) may be configured to surround at least a portion of the second discharge cover (200) so as to press the second discharge cover (200) toward the frame (50).

[0287] The third discharge cover (300) can be connected to the frame (50). To prevent failure in connection between the third discharge cover (300) and the frame (50), the third discharge cover (300) may be made of a metal material with low thermal deformation, for example, aluminum.

[0288] The above discharge cover assembly may include a discharge chamber through which high-pressure discharge gas discharged from the discharge valve (191) flows.

[0289] The above discharge chamber may include a first discharge chamber (A1) formed in the internal space of the first discharge cover (100). The first discharge chamber (A1) may be formed to face the discharge valve (191) as an internal space defined by the inner wall (130) of the first discharge cover (100).

[0290] When the discharge valve (191) is opened, the first discharge chamber (A1) is connected to the compression space (P), and the refrigerant compressed in the compression space (P) can flow into the first discharge chamber (A1).

[0291] The refrigerant in the first discharge chamber (A1) is discharged from the first discharge cover (100) through the discharge hole (123) of the first discharge cover (100), and the discharged refrigerant can flow to the first discharge chamber (A2) of the second discharge cover (200).

[0292] The first discharge chamber (A2) above can be understood as one area among the discharge chambers formed in the internal space of the second discharge cover (200), and as the inner space of the inner wall (238) of the second discharge cover (200).

[0293] The inner wall (238) is inserted into the recess (140) of the first discharge cover (100), and a damping member (180) is interposed in the area where the inner wall (238) and the recess (140) are joined, thereby reducing vibration and noise generated in the first and second discharge covers (100, 200).

[0294] The inner wall (238) can be understood as a partition wall that divides the discharge chamber of the second discharge cover (200) into a first discharge chamber (A2) and a second discharge chamber (A3). The second discharge chamber (A3) can be understood as an outer space of the inner wall (238).

[0295] For convenience of explanation, the first discharge chamber (A1) of the first discharge cover (100) and the first and second discharge chambers (A2, A3) of the second discharge cover (200) may be named, in order, the first discharge chamber (A1), the second discharge chamber (A2), and the third discharge chamber (A3).

[0296] The refrigerant of the second discharge chamber (A2) can flow into the recess (140) of the first discharge cover (100) through the inlet of the pulsating passage formed in the recess (140), that is, the first recess (125). Since the second discharge chamber (A2) and the third discharge chamber (A3) are separated from each other by the inner wall (238) being coupled to the recess (140), the refrigerant of the second discharge chamber (A2) may be restricted from flowing directly into the third discharge chamber (A3).

[0297] The refrigerant introduced into the recess (140) can flow along the ring shape of the recess (140) and be discharged from the recess (140) through the second recess (113a) formed on the opposite side of the first recess (125). The second recess (113a) can function as an outlet for the pulsating flow path.

[0298] The pulsating noise generated from the discharged refrigerant can be reduced by the refrigerant flowing through a pulsating path formed along the shape of the recess (140).

[0299] The second recess (113a) can be connected to the outer space of the inner wall (238), that is, the third discharge chamber (A3). Accordingly, the refrigerant discharged from the second recess (113a) can flow into the third discharge chamber (A3).

[0300] The third discharge chamber (A3) can be connected to the discharge hole (280) of the second discharge cover (200). Accordingly, the refrigerant of the third discharge chamber (A3) can be discharged to the outside of the second discharge cover (200) through the discharge hole (280) and discharged to the discharge pipe of the shell (11) through the loop pipe (290).

[0301] Meanwhile, in order to reinforce the strength of the first and second discharge covers (100, 200) composed of a relatively light and weak material, the discharge cover assembly may include a plurality of reinforcing ribs (135, 227, 237).

[0302] The plurality of reinforcing ribs (135, 227, 237) may include reinforcing ribs (135) provided on the first discharge cover (100). The reinforcing ribs (135) are provided on the inner surface of the first discharge cover (100) and act as a flow resistance for the refrigerant flowing through the first discharge chamber (A1) to reduce pulsating noise.

[0303] The above plurality of reinforcing ribs (135, 227, 237) may include a first reinforcing rib (227) provided on the second discharge cover (200). The first reinforcing rib (227) is provided on the inner surface of the first part (220) of the second discharge cover (100) and acts as a flow resistance for the refrigerant flowing through the third discharge chamber (A3) to reduce pulsating noise.

[0304] Noise reduction using pulsation as in the above-described embodiment may be insufficient. An embodiment for reducing noise will be described.

[0305] FIG. 18 is a cross-sectional view of the first discharge cover and discharge valve assembly. FIG. 19 and FIG. 20 are bottom perspective views of the discharge cover assembly, where FIG. 19 shows the discharge valve assembly removed and FIG. 20 shows the discharge valve assembly fastened.

[0306] Refer to FIGS. 18 to 20.

[0307] A portion of the protrusion may be inserted into the protrusion groove (132). The protrusion groove may be larger than the protrusion. In this case, only a portion of the protrusion groove may be occupied. The protrusion groove may not be blocked. An embodiment may include the case where the protrusion is not provided. In the description of the resonator, the protrusion groove may be referred to as a groove.

[0308] The groove (132) may provide a space that passes radially through the inner wall (130). The opening of the groove may be closed by the discharge valve assembly (190). The opening may be positioned at the rear of the groove. The opening of the groove may be closed by the front of the spring bracket (195).

[0309] A resonance space (133) may be provided outside the radial direction of the above-mentioned groove (132). The resonance space (133) may be provided together with the first discharge cover when it is provided. The resonance space (133) may be molded together with the first discharge cover when it is molded. No separate work may be required to provide the resonance space. Accordingly, there is an advantage that no separate work or separate parts are required to provide the resonator.

[0310] The opening of the resonance space can be closed by the discharge valve assembly (190). The opening can be positioned at the rear of the resonance space. The opening of the resonance space can be closed by the front of the spring bracket (195).

[0311] The resonance space (133) may provide a space closed by the first discharge cover and the discharge valve assembly. The resonance space may be opened only by the groove (132).

[0312] The resonator can reduce noise generated in the discharge valve assembly. The resonator can be part of a noise reduction device. The noise reduction device may be located closer to the discharge side than to the suction side of the linear compressor. The noise reduction device can effectively reduce noise in a specific band generated on the discharge side of the linear compressor. Here, the specific band may include 2.5KHz.

[0313] The above resonance space and the above groove can provide a resonator.

[0314] The above resonator may utilize a Helmholtz resonator. A Helmholtz resonator (or Helmholtz resonator) is a resonator that has the characteristic of absorbing sound waves at a specific frequency, namely the resonance frequency. A Helmholtz resonator can exhibit a high sound absorption effect in the region centered on the resonance frequency. The resonance frequency of the resonator may vary depending on the inlet cross-sectional area (A), the inlet length (l), and the internal volume (V) of the resonator. The larger the inlet cross-sectional area (A), the higher the resonance frequency may be. The larger the inlet length (l) and the internal volume (V) of the resonator, the lower the resonance frequency becomes.

[0315] In the embodiment, the inlet cross-sectional area (A) may be different from each other. Accordingly, the resonant frequencies of at least two resonators may be different from each other. The length (l) of the inlet of at least two resonators and / or the internal volume (V) of the resonators may be different from each other. In this case, the overall shape of the first discharge cover (100) may be deformed, which may not be desirable. For example, the thickness of the inner wall (130) and the outer wall (111) providing at least two resonators may be different, or the position of the rib (136) may be different. In this case, the different shapes and forms may affect the performance of the first discharge cover and the performance of the linear compressor.

[0316] At least two of the above resonators may be provided. The at least two resonators may have different resonant frequencies. The at least two different resonant frequencies may be adjacent to each other. The at least two different resonant frequencies may be adjacent to 2.5KHz. Among the at least two different resonant frequencies, there may be at least one resonant frequency above and below 2.5KHz. The at least two different resonant frequencies may differ by 0.1KHz. The at least two different resonant frequencies may differ by 0.05 to 0.5KHz.

[0317] By having at least two of the above resonant frequencies adjacent, noise in a predetermined band generated in an oil-less linear compressor can be reduced. The predetermined band may be a high-frequency band. Here, the center frequency of the high-frequency band may be 2.5KHz.

[0318] When molding a discharge cover made of plastic, tolerances may occur in the resonator. For example, the protrusion may become slightly larger or smaller during molding. In this case, even if the first resonant frequency of one of the first resonators changes, the second resonant frequency of the other second resonator may be adjacent. The second resonant frequency can compensate for the inaccuracy of the first resonant frequency. Accordingly, when at least two of the resonant frequencies are adjacent, the effect of noise reduction in the high-frequency band can be achieved even if dispersion occurs due to the tolerance of the resonant frequencies.

[0319] At least two of the above resonators according to an embodiment will be described.

[0320] The above resonator may have a resonance space (133) that can be defined by the inner wall, the outer wall, the inner surface of the connecting rib (136), and the front surface of the spring bracket. The opening of the resonance space may be defined by the inner surface of the projection (132) and the front surface of the spring bracket. The connecting rib may provide a boundary for adjacent resonance spaces.

[0321] At least two of the above resonance spaces may be provided. The resonance spaces may be arranged circumferentially with respect to the central axis of the piston. The resonance spaces may be arranged at equal intervals. Eight (133a to 133d) of the above resonance spaces may be provided. Two of the above resonance spaces may be positioned symmetrically with respect to the central axis. Accordingly, the noise cancellation effect by resonators of the same resonance frequency can be greatly increased. For example, two resonance spaces facing each other at the center of the first discharge cover may both have a resonance frequency of 2.7KHz. For the same resonance space, the above opening of the same specification may be provided. The above opening may be defined by its length (l) and area (A).

[0322] Refrigerant may not flow into the resonance space. Vibrational energy may flow into the resonance space. Vibrational energy flowing in through the opening may be canceled out or damped inside the resonance space.

[0323] At least one of the above-mentioned openings may be provided for each resonance space. The above-mentioned opening may be provided in the centrifugal direction of each resonance space. Each opening may face the central axis of the first discharge cover. Accordingly, the noise cancellation effect of the resonance frequency can be greatly enhanced. The specifications of the above-mentioned opening may be provided differently depending on the type of resonator. The above-mentioned opening may have the same length (l) but different area (A). By varying the area (A), the resonance frequency can be adjusted.

[0324] FIG. 21 is a bottom view of the first discharge cover. FIG. 22 illustrates the space provided by the first discharge cover, and the space includes a resonance space.

[0325] Refer to Figs. 21 and 22.

[0326] A virtual line connecting a pair of projection grooves (132) of the same specification may pass through the central axis of the first discharge cover. For example, a virtual line connecting two first projection grooves (132a) may pass through the central axis of the first discharge cover. Here, the virtual line may be orthogonal to the axial direction of the piston. A virtual line connecting any pair of projection grooves (132a to 132d) may pass through the central axis of the first discharge cover. Accordingly, the noise cancellation effect can be greatly increased. Accordingly, the destructive interference of vibration energy can be greatly increased.

[0327] Due to the arrangement (132a to 132d) of the above-mentioned protrusions, the resonant frequency of each resonator may be the same for a pair of opposing resonators. Here, the resonant frequency may include an engineering error.

[0328] At least two resonance spaces (133) may be provided. The size, shape, and / or form of at least two of the resonance spaces may be the same. The size, shape, and / or form of all of the resonance spaces may be the same. The size, shape, and / or form of two adjacent resonance spaces may be symmetrical to each other. Two resonance spaces facing each other may be mirrored. The first resonance space (133a) and the fourth resonance space (133d) may be provided larger than other resonance spaces. An inner wall (130) and a rib (136) may be provided to provide a flow path along the recess (125). In this case as well, a noise reduction effect in the high-frequency band may be achieved by the dispersion of multiple resonance frequencies.

[0329] The above opening may be provided by a projection groove (132). The above opening may be provided in the center of the inner surface of the resonance space (133). The above opening may connect the resonance space (133) and the first discharge chamber (A1) of the first discharge cover. The resonance space may be arranged radially with respect to the first discharge chamber.

[0330] The first discharge chamber may further include reinforcing ribs (135) extending in a radial direction. Eight reinforcing ribs (135) may be provided. The reinforcing ribs (135) may be connected to the connecting ribs (136) of the resonance space. The height and width of the reinforcing ribs and the connecting ribs may differ. The reinforcing ribs and the connecting ribs may protrude from corresponding surfaces and extend in a radial direction. The operation of the resonator can be enhanced by the reinforcing ribs and the connecting ribs.

[0331] The size and number of the above-mentioned resonance spaces can be adjusted. By using this, the resonance frequency of the resonator can be adjusted. By using this, the magnitude of the attenuated noise can be adjusted. The size and length of the above-mentioned aperture can be adjusted. By using this, the resonance frequency of the resonator can be adjusted.

[0332] Figure 23 is a diagram explaining the operation of a resonator.

[0333] Refer to FIG. 23. The resonator may include at least two resonant spaces (133) connected to the first discharge chamber (A1). The resonator may include a set of at least two small resonators. The resonator may include eight small resonators distinguished by resonant frequencies. The eight small resonators may be connected to each other by the same space.

[0334] Each small resonator (NC 1 to NC 8) can have its resonant frequency changed by the opening (132).

[0335] Figure 24 is the result of analyzing the noise filtration characteristics of the discharge cover mounted on the noise reduction device.

[0336] Refer to Fig. 24. Each resonator had a different aperture area. For example, experiments were conducted with aperture diameters of 2.7, 2.8, 2.9, and 3.0 (in millimeters). As a result, it can be seen that transmission loss performance can be secured with a center frequency of 2.5KHz.

[0337] Accordingly, noise in a specific frequency band on the discharge side of the oil-less linear compressor can be reduced. Consequently, the fatigue load of the linear compressor can be reduced. Consequently, user complaints regarding noise can be reduced.

[0338] A linear compressor according to an embodiment of the present invention comprises a noise reduction device in the discharge cover of the linear compressor. Here, the noise reduction device may be provided all at once during the molding of the discharge cover. As a result, the noise of the linear compressor can be reduced without providing a noise reduction device as a separate component. Consequently, industrial applicability is significant.

Claims

suction valve that sucks in low-pressure refrigerant A discharge valve for discharging compressed high-pressure refrigerant; A discharge cover assembly forming a discharge chamber for the refrigerant discharged through the above discharge valve; A frame supporting the above discharge cover assembly; A cylinder into which a piston that reciprocates axially is inserted, supported inside the above frame; and A linear compressor comprising a noise reduction device provided in the discharge cover assembly, which is adjacent to the discharge valve than the suction valve. In Article 1, The above discharge cover assembly is, A first discharge cover forming a first discharge chamber of the above-mentioned high-pressure refrigerant, and It includes a second discharge cover coupled to the first discharge cover and forming a discharge chamber for high-pressure refrigerant discharged from the first discharge chamber, and The above noise reduction device is a linear compressor provided on the first discharge cover. In Article 2, The above-mentioned first discharge cover is, The inner wall defining the first discharge chamber above, The outer wall defining the discharge chamber of the second discharge cover above, A reinforcing rib extending radially from the inner surface of the first discharge chamber, and A linear compressor comprising a connecting rib connected to the reinforcing rib and radially connecting the inner wall and the inner surface of the outer wall. In Paragraph 3, A linear compressor comprising a resonator having a resonance space in which at least a portion of the space is defined by the connecting rib, the inner wall, the outer wall, or the discharge valve. In Article 4, The above resonator is a linear compressor comprising at least two resonators spaced apart in the circumferential direction. In Article 4, A linear compressor including an opening connecting the resonance space and the first discharge chamber. In Article 6, The above opening is a linear compressor provided in the inner wall. In Article 4, The above resonator is, A first resonator having the size of a first resonance space and a first opening, and A linear compressor comprising a second resonator having a first resonance space size and a second opening. In Article 4, The above resonator is, A first resonator having a first resonant frequency higher than 2.5KHz, and A linear compressor comprising a second resonator having a second resonant frequency lower than 2.5KHz. suction valve that sucks in low-pressure refrigerant A discharge valve for discharging compressed high-pressure refrigerant; A discharge cover assembly forming a discharge chamber for the refrigerant discharged through the above discharge valve; A frame supporting the above discharge cover assembly; A cylinder into which a piston is inserted that is supported inside the above frame and reciprocates axially having a central axis; and A linear compressor comprising a noise reduction device provided in the discharge cover assembly to reduce noise transmitted along the high-pressure refrigerant. In Article 10, The above noise reduction device is a linear compressor comprising at least two resonators spaced circumferentially apart with respect to the central axis. In Article 11, The above at least two resonators are linear compressors with different resonant frequencies. In Article 12, Any one of the above resonant frequencies is higher than 2.5KHz, and Another of the above resonant frequencies is a linear compressor lower than 2.5KHz. In Article 10, The above noise reduction device includes a resonator, and the resonator is, A resonance space spaced radially apart from the above discharge chamber, and A linear compressor including an opening that connects the resonance space and the discharge chamber. In Article 14, The above resonator includes at least two, Two resonators that do not face each other with respect to the above central axis have different resonant frequencies. Two resonators that do not face each other with respect to the above central axis have the same resonance space but different opening areas. Two resonators facing each other with respect to the central axis have the same resonant frequency, and A linear compressor satisfying at least one of the conditions that two resonators facing each other around the central axis have the same resonance space. In Article 14, The above opening is a linear compressor that can be closed by the front surface of the discharge valve. In Article 14, A linear compressor in which at least two resonators are connected to each other through the discharge chamber. suction valve that sucks in low-pressure refrigerant A discharge valve for discharging compressed high-pressure refrigerant; A discharge cover assembly forming a discharge chamber for the refrigerant discharged through the above discharge valve; A frame supporting the above discharge cover assembly; A cylinder into which a piston that reciprocates axially is inserted, supported inside the above frame; and A linear compressor comprising a noise reduction device provided as part of the discharge cover assembly during the molding of the discharge cover assembly provided in plastic. In Article 18, The above noise reduction device is a linear compressor comprising at least two resonators having different resonant frequencies. In Article 19, The above at least two resonators provide a resonance space spaced apart in the radial direction from the discharge chamber, and The above resonance space is a linear compressor closed by the above discharge valve. .

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