Linear compressor

Abstract

A linear compressor according to one embodiment of the present invention includes a cylinder, a piston reciprocating in an axial direction inside the cylinder, a first muffler unit combined with the piston, a back cover including an opening part formed in a radial central region, disposed at a rear of the piston, and a second muffler unit combined with the opening part. The first muffler unit includes an inner guide disposed inside the piston, and a first suction muffler disposed at a rear of the inner guide. The second muffler unit includes a second suction muffler communicating with the first suction muffler, combined with the opening part, and a muffler body surrounding the second suction muffler. The second muffler unit includes a rib protruding from an outer side surface or an inner side surface.

Description

Technical Field

[0001] This invention relates to linear compressors, and more specifically, to a linear compressor that compresses refrigerant by means of the linear reciprocating motion of a piston. Background Technology

[0002] Generally, a compressor is a device that receives power from a power-generating device such as a motor or turbine and compresses working fluids such as air or refrigerant. Specifically, compressors are widely used in industrial and household products, especially in vapor compression refrigeration cycles (hereinafter referred to as "refrigeration cycles").

[0003] Such compressors can be classified into reciprocating compressors, rotary compressors, and scroll compressors based on the way they compress the refrigerant.

[0004] Reciprocating compressors compress fluids by creating a compression space between the piston and cylinder and by using the linear reciprocating motion of the piston. Rotary compressors compress fluids by using eccentrically rotating rollers inside the cylinder. Scroll compressors compress fluids by using a pair of spiral scrolls that mesh and rotate.

[0005] Recently, the use of linear compressors, which utilize linear reciprocating motion without a crankshaft, has been gradually increasing among reciprocating compressors. Linear compressors offer advantages such as improved efficiency and simpler structure due to the lower mechanical losses incurred when converting rotary motion into linear reciprocating motion.

[0006] In a linear compressor, the cylinder is located inside a housing forming a sealed space and constitutes a compression chamber, while the piston covering the compression chamber reciprocates inside the cylinder. The linear compressor repeats the following process: when the piston is at bottom dead center (BDC), fluid in the sealed space is drawn into the compression chamber; when the piston is at top dead center (TDC), the fluid in the compression chamber is compressed and expelled.

[0007] The linear compressor contains a compression unit and a drive unit. The compression unit resonates under the action of the resonant spring due to the movement generated by the drive unit, and performs the process of compressing and discharging the refrigerant.

[0008] The linear compressor repeatedly performs the following series of processes: under the action of the resonant spring, the piston reciprocates at high speed inside the cylinder while drawing refrigerant into the housing through the suction pipe. Then, with the help of the piston's forward movement, the refrigerant is discharged from the compression space and moves towards the condenser through the discharge pipe.

[0009] On the other hand, linear compressors can be classified into oil-lubricated linear compressors and gas-lubricated linear compressors according to their lubrication method.

[0010] An oil-lubricated linear compression mechanism is characterized by storing a predetermined amount of oil inside the housing, which is used to lubricate the cylinder and piston.

[0011] The gas-lubricated linear compressor mechanism does not store oil inside the housing. Instead, it guides a portion of the refrigerant discharged from the compression space to the space between the cylinder and the piston, using the gas pressure of the refrigerant to lubricate the space between the cylinder and the piston.

[0012] In oil-lubricated linear compressors, the supply of relatively cool-temperature oil between the cylinder and piston prevents overheating due to motor heat or compression heat. Therefore, oil-lubricated linear compressors suppress the increase in specific volume caused by the refrigerant being heated as it is drawn into the compression chamber of the cylinder, thus preventing suction losses in advance.

[0013] However, in oil-lubricated linear compressors, if the oil discharged into the refrigeration cycle along with the refrigerant is not smoothly recovered into the compressor, an oil shortage may occur inside the compressor housing. Such an oil shortage inside the housing can lead to a decrease in the reliability of the compressor.

[0014] On the other hand, compared with oil-lubricated linear compressors, gas-lubricated linear compressors can be miniaturized, and since they use refrigerant to lubricate the cylinder and piston, they have the advantage of not reducing the reliability of the compressor due to lack of oil.

[0015] Generally, muffler units used to reduce noise are combined with pistons. In this case, there is a problem that the noise reduction effect is reduced due to limited space.

[0016] Existing patent literature

[0017] (Patent Document 1) Korean Patent Publication No. 10-1484324B (Publication Date: 2015.01.20). Summary of the Invention

[0018] The purpose of this invention is to provide a linear compressor that can reduce noise by improving the performance of the muffler unit.

[0019] Another object of the present invention is to provide a linear compressor that can improve the rigidity of components by means of ribs formed in the second muffler unit.

[0020] Another objective of this invention is to provide a linear compressor that neither affects the flow of refrigerant inside the second intake muffler nor hinders the rigidity of the second intake muffler.

[0021] Another objective of this invention is to provide a linear compressor capable of improving the rigidity of a second intake muffler in multiple directions.

[0022] Another objective of this invention is to provide a linear compressor capable of guiding the engagement direction of a second intake muffler including a first flange unit.

[0023] Another objective of this invention is to provide a linear compressor capable of guiding the position of the muffler cover relative to the muffler body.

[0024] Another objective of this invention is to provide a linear compressor capable of guiding the position of the muffler body relative to the rear cover.

[0025] A linear compressor according to one aspect of the present invention for achieving the above-mentioned objectives includes: a cylinder; a piston that reciprocates axially within the cylinder; a first muffler unit coupled to the piston; a rear cover including an opening formed in a radially central region and disposed behind the piston; and a second muffler unit coupled to the opening. The first muffler unit includes: an internal guide disposed within the piston; and a first intake muffler disposed behind the internal guide. The second muffler unit includes: a second intake muffler communicating with the first intake muffler and coupled to the opening; and a muffler body surrounding the second intake muffler. The second muffler unit includes ribs protruding from an outer or inner side.

[0026] Therefore, the performance of the muffler unit can be improved by adding a second muffler unit, thereby reducing the noise of the linear compressor.

[0027] In addition, the rigidity of the muffler unit can be improved by forming ribs in the second muffler unit.

[0028] Additionally, the rib may include: a first rib that protrudes radially outward from the outer peripheral surface of the second intake muffler and extends in a circumferential direction.

[0029] In this case, the outer peripheral surface of the second intake muffler may include a first connecting hole, which connects the interior of the second intake muffler with the space between the second intake muffler and the muffler body, and the first rib may overlap with the first connecting hole in the circumferential direction.

[0030] Therefore, the flow of refrigerant inside the second intake muffler is not affected, and the rigidity of the second intake muffler is improved.

[0031] Additionally, the second intake muffler may include: a first cylindrical portion; a first flange unit extending radially outward from the front of the first cylindrical portion; and a second flange unit extending radially outward from the central region of the first cylindrical portion. The rib may include: a second rib extending axially between the first flange unit and the second flange unit.

[0032] In this case, the second rib may include: a first region extending axially on the outer peripheral surface of the first cylindrical portion; a second region connected to the first region, protruding rearward from the back side of the first flange unit and extending radially; and a third region connected to the first region, protruding forward from the front side of the second flange unit and extending radially.

[0033] Furthermore, the second rib may overlap with the first rib, and the radial protrusion length of the second rib may be greater than the radial protrusion length of the first rib.

[0034] Therefore, vibrations applied to the second intake muffler can be countered by increasing the rigidity of the second intake muffler in multiple directions.

[0035] Additionally, the second intake muffler may include: a first cylindrical portion; and a first flange unit extending radially outward from the front of the first cylindrical portion, the ribs including: a third rib protruding forward from the front of the first flange unit and extending radially.

[0036] Therefore, in addition to the first cylindrical part, the rigidity of the first flange unit can also be improved.

[0037] Additionally, the third rib may include a plurality of third ribs spaced apart from each other along the circumferential direction, and some of the plurality of third ribs may be formed in a shape different from that of the others.

[0038] This allows for guidance of the engagement direction of the second intake muffler, which includes the first flange unit.

[0039] In addition, the third rib may not overlap with the second rib in the axial direction.

[0040] This not only improves the rigidity of the second intake muffler, but also enhances space efficiency.

[0041] Additionally, the muffler body may include: a second cylindrical portion disposed radially outward of the second intake muffler, with openings at the front and rear of the central region, the space between the inner and outer sides being blocked at the front and open at the rear; the rib may include: a fourth rib protruding radially outward from the outer periphery of the second cylindrical portion and extending axially.

[0042] This improves the rigidity of the muffler body.

[0043] Additionally, the muffler body may include a third flange unit extending inward from the inner side of the second cylindrical portion, and the rib may include a fifth rib formed in the area between the inner side of the second cylindrical portion and the front side of the third flange unit.

[0044] This improves the rigidity of the area connecting the second cylindrical section and the third flange unit.

[0045] In addition, the fifth rib can move further away from the front of the third flange unit and closer to the inner side of the second cylindrical portion.

[0046] This allows the position of the second flange unit relative to the third flange unit to be guided.

[0047] Additionally, the muffler body may include: a plurality of first grooves, recessed from the outer side of the second cylindrical portion and spaced apart from each other in the circumferential direction; the first grooves may include: a bottom surface; a first step portion connecting the bottom surface and the outer side of the second cylindrical portion and extending in the circumferential direction; and a second step portion and a third step portion connecting the bottom surface and the outer side of the second cylindrical portion and extending in the axial direction; the back side of the first step portion may include a rearwardly extending sixth rib.

[0048] This allows for an increase in the rigidity of multiple first slots.

[0049] Additionally, the second muffler unit may include a muffler cover disposed between the muffler body and the rear cover, the muffler cover being mounted on the sixth rib.

[0050] In addition, the sixth rib may include: an inner rib formed on the inner side; and an outer rib formed on the radially outer side of the inner rib, wherein the axial length of the outer rib may be greater than the axial length of the inner rib.

[0051] This allows the position of the muffler cover relative to the muffler body to be guided.

[0052] Additionally, the muffler cover may include: a ring portion extending in a circumferential direction; and a first extension portion extending rearward from the outer side of the ring portion. The rib may include: a plurality of seventh ribs formed between the back side of the ring portion and the inner side of the first extension portion and spaced apart from each other in a circumferential direction.

[0053] This improves the rigidity of the muffler cover.

[0054] Additionally, the muffler cover may include a joint portion that protrudes radially outward from the first extension portion, and a straight line extending the joint portion may be disposed between a plurality of the seventh ribs. The inner side of the fourth rib may include a second groove that is recessed outward, and the joint portion is disposed in the second groove.

[0055] This not only improves the rigidity of the muffler cover and the muffler body, but also guides the position of the muffler cover relative to the muffler body.

[0056] Additionally, the rib may include an eighth rib, formed in the region of the second cylindrical portion that opens rearward between the inner and outer sides, protruding radially inward from the outer side of the second cylindrical portion and extending axially.

[0057] This not only improves space efficiency but also enhances the rigidity of the resonator in the muffler body.

[0058] Additionally, the rear cover may include: a support member; and a plurality of legs extending forward from the radially outer side of the support member and spaced apart from each other in a circumferential direction, wherein the fourth rib may contact the plurality of legs.

[0059] This allows the position of the muffler body relative to the rear cover to be guided.

[0060] A linear compressor of one aspect of the present invention for achieving the above-mentioned objectives may include: a cylinder; a piston that reciprocates axially inside the cylinder; a rear cover including an opening formed in a radially central region and disposed behind the piston; and a muffler unit coupled to the opening, the muffler unit including ribs protruding from an outer or inner side.

[0061] Therefore, the noise of the linear compressor can be reduced by improving the performance of the muffler unit.

[0062] In addition, the rigidity of the muffler unit can be improved by forming ribs in the muffler unit.

[0063] The present invention provides a linear compressor capable of reducing noise by improving the performance of the muffler unit.

[0064] The present invention provides a linear compressor that can improve the rigidity of components by means of ribs formed in the second muffler unit.

[0065] The present invention provides a linear compressor that neither affects the flow of refrigerant inside the second intake muffler nor hinders the rigidity of the second intake muffler.

[0066] The present invention provides a linear compressor capable of improving the rigidity of a second intake muffler in multiple directions.

[0067] The present invention provides a linear compressor capable of guiding the engagement direction of a second intake muffler including a first flange unit.

[0068] The present invention provides a linear compressor capable of guiding the position of the muffler cover relative to the muffler body.

[0069] The present invention provides a linear compressor capable of guiding the position of the muffler body relative to the rear cover. Attached Figure Description

[0070] Figure 1 This is a perspective view of a linear compressor according to an embodiment of the present invention.

[0071] Figure 2 This is a cross-sectional view of a linear compressor according to an embodiment of the present invention.

[0072] Figure 3 and Figure 4 This is a perspective view of a muffler unit according to an embodiment of the present invention.

[0073] Figure 5 This is an exploded perspective view of a muffler unit according to an embodiment of the present invention.

[0074] Figure 6 This is a perspective view of a second intake muffler according to an embodiment of the present invention.

[0075] Figure 7 This is a side view of a second inhalation muffler according to an embodiment of the present invention.

[0076] Figure 8 This is a cross-sectional view of a second intake muffler according to an embodiment of the present invention.

[0077] Figure 9 This is a front view of a second inhalation muffler according to an embodiment of the present invention.

[0078] Figure 10 This is a rear view of a second intake muffler according to an embodiment of the present invention.

[0079] Figure 11 and Figure 12 This is a perspective view of the muffler body according to an embodiment of the present invention.

[0080] Figure 13 This is a front view of the muffler body according to an embodiment of the present invention.

[0081] Figure 14 This is a rear view of the muffler body according to an embodiment of the present invention.

[0082] Figure 15 and Figure 16 This is a perspective view of a muffler cover according to an embodiment of the present invention.

[0083] Figure 17 This is a cross-sectional view of a piston, a muffler unit, and a rear cover according to an embodiment of the present invention.

[0084] Figure 18 This is a perspective view of a muffler unit and a rear cover according to an embodiment of the present invention.

[0085] Figure 19 This is an exploded cross-sectional perspective view of a muffler unit and a rear cover according to an embodiment of the present invention.

[0086] Figure 20 This is a rear view of the back cover according to an embodiment of the present invention.

[0087] Figure 21 and Figure 22 This is a rear view of the rear cover and muffler unit according to an embodiment of the present invention.

[0088] Figure 23 This is a perspective view of a piston, spring support, first resonant spring, muffler unit, and rear cover according to an embodiment of the present invention.

[0089] Figure 24 This is a block diagram of a multiple resonator according to an embodiment of the present invention.

[0090] Figure 25 This is a graph showing the transmission loss (TL) at different frequencies of a multiple resonator according to an embodiment of the present invention.

[0091] Figure 26 This is a graph showing the insertion loss (IL) of a muffler unit corresponding to the frequency of a prior art and an embodiment of the present invention.

[0092] Explanation of reference numerals in the attached figures

[0093] 100: Compressor; 101: Receiving space; 102: Suction space; 103: Compression space; 104: Discharge space; 110: Housing; 111: Outer shell; 112: First outer shell cover; 113: Second outer shell cover; 114: Suction pipe; 115: Discharge pipe; 115a: Circulation pipe; 116: First support spring; 116a: Suction guide; 116b: Suction side support member; 116c: Vibration damping member; 117: Second support spring; 117a: Support 117b: First support guide; 117c: Support cover; 117d: Second support guide; 117e: Third support guide; 118: Resonant spring; 118a: First resonant spring; 118b: Second resonant spring; 119: Spring support; 119a: Main body; 119b: Second joint; 119c: Support; 120: Frame; 121: Main body; 122: First flange; 123: Rear cover; 123a: Support bracket; 13 0: Drive unit; 131: Outer stator; 132: Coil winding body; 132a: Bollard; 132b: Coil; 133: Stator core; 134: Inner stator; 135: Moving part; 136: Magnet frame; 136a: First joint; 137: Stator cover; 140: Cylinder; 141: Second flange; 142: Gas inlet; 150: Piston; 151: Head; 152: Guide; 153: Third flange; 154: Suction port; 155: Suction 160: Inlet valve; 161: First silencer unit; 161a: First intake silencer; 162: Fourth flange; 170: Internal guide; 171: Exhaust valve assembly; 172: Valve spring; 180: Exhaust cover assembly; 181: First exhaust cover; 182: Second exhaust cover; 183: Third exhaust cover; 200: Second silencer unit; 210: Second intake silencer; 220: Silencer body; 230: Silencer cover; 240: Elastic member Detailed Implementation

[0094] The embodiments disclosed in this specification will now be described in detail with reference to the accompanying drawings, and the same or similar structural elements will be given the same reference numerals regardless of the drawing numbers, and repeated descriptions thereof will be omitted.

[0095] In describing the embodiments disclosed in this specification, if a structural element is referred to as "connected" or "coupled" to another structural element, it should be understood that it may be directly connected to or coupled to that other structural element, but there may also be other structural elements in between.

[0096] Furthermore, in describing the embodiments disclosed in this specification, detailed descriptions of relevant well-known technologies are omitted when it is determined that such detailed descriptions would obscure the essence of the invention. Additionally, the accompanying drawings are provided to facilitate understanding of the embodiments disclosed in this specification. The technical concepts disclosed in this specification are not limited to the drawings; the invention includes all modifications, equivalents, and substitutions made within the scope and technical concept of the invention.

[0097] Figure 1 This is a perspective view of a linear compressor according to an embodiment of the present invention.

[0098] Reference Figure 1 A linear compressor 100 according to an embodiment of the present invention may include a housing 111 and housing covers 112 and 113 connected to the housing 111. In a broad sense, the housing covers 112 and 113 can be understood as a structural element of the housing 111.

[0099] A support leg 20 may be attached to the underside of the housing 111. The support leg 20 may be attached to a base of a product on which the linear compressor 100 is mounted. For example, the product may include a refrigerator, and the base may include the refrigerator's mechanical compartment base. As another example, the product may include the outdoor unit of an air conditioner, and the base may include the outdoor unit's base.

[0100] The outer casing 111 can be approximately cylindrical in shape, and can be arranged horizontally or vertically. Figure 1 Based on this, the outer casing 111 can extend long in the lateral direction while having a low height in the radial direction. That is, the linear compressor 100 can have a low height, thus having the advantage of reducing the height of the mechanical compartment, for example, when the linear compressor 100 is installed in the base of the refrigerator's mechanical compartment.

[0101] In addition, the longitudinal central axis of the outer casing 111 may be aligned with the central axis of the main body of the compressor 100, which will be described later, and the central axis of the main body of the compressor 100 may be aligned with the central axis of the cylinder 140 and piston 150 that constitute the main body of the compressor 100.

[0102] A terminal 30 may be provided on the outer surface of the housing 111. The terminal 30 can supply external power to the drive unit 130 of the linear compressor 100. Specifically, the terminal 30 can be connected to the lead wire of the coil 132b.

[0103] A bracket 31 may be provided on the outside of the terminal block 30. The bracket 31 may include a plurality of brackets surrounding the terminal block 30. The bracket 31 can function to protect the terminal block 30 from external impacts, etc.

[0104] The outer casing 111 has open sides. Outer casing covers 112 and 113 can be attached to the two sides of the openings in the outer casing 111. Specifically, the outer casing covers 112 and 113 can include: a first outer casing cover 112, attached to one side of the opening in the outer casing 111; and a second outer casing cover 113, attached to the other side of the opening in the outer casing 111. The internal space of the outer casing 111 can be sealed by the outer casing covers 112 and 113.

[0105] by Figure 1 Based on this, the first housing cover 112 can be located on the right side of the linear compressor 100, and the second housing cover 113 can be located on the left side of the linear compressor 100. In other words, the first housing cover 112 and the second housing cover 113 can be configured to face each other. Furthermore, it can be understood that the first housing cover 112 is located on the refrigerant suction side, and the second housing cover 113 is located on the refrigerant discharge side.

[0106] The linear compressor 100 may include a plurality of pipes 114, 115, 40, which are disposed in the housing 111 or housing cover 112, 113 and are capable of drawing in, discharging or injecting refrigerant.

[0107] The plurality of pipes 114, 115, 40 may include: a suction pipe 114 for drawing refrigerant into the interior of the linear compressor 100; a discharge pipe 115 for discharging compressed refrigerant from the linear compressor 100; and a replenishment pipe 40 for replenishing refrigerant to the linear compressor 100.

[0108] For example, the suction pipe 114 can be connected to the first housing cover 112. Refrigerant can be drawn into the interior of the linear compressor 100 axially through the suction pipe 114.

[0109] The discharge pipe 115 can be engaged with the outer peripheral surface of the housing 111. The refrigerant drawn in through the suction pipe 114 can be compressed as it flows axially. The compressed refrigerant can then be discharged through the discharge pipe 115. The discharge pipe 115 can be positioned closer to the second housing cover 113 than the first housing cover 112.

[0110] The replenishment pipe 40 can be connected to the outer peripheral surface of the housing 111. Operators can inject refrigerant into the interior of the linear compressor 100 through the replenishment pipe 40.

[0111] To avoid interference with the discharge pipe 115, the supplementary pipe 40 can be connected to the outer casing 111 at a different height than the discharge pipe 115. Here, height can be understood as the vertical distance starting from the support leg 20. By connecting the discharge pipe 115 and the supplementary pipe 40 to the outer circumference of the outer casing 111 at different heights, operational convenience can be achieved.

[0112] At least a portion of the second housing cover 113 may be disposed adjacent to the location on the inner circumferential surface of the housing 111 where the replenishment pipe 40 is attached. In other words, at least a portion of the second housing cover 113 may act as a barrier to the refrigerant injected via the replenishment pipe 40.

[0113] Therefore, from the perspective of refrigerant flow path, the refrigerant flowing in through the replenishment pipe 40 can be configured such that the flow path size decreases due to the second outer casing cover 113 as it enters the internal space of the outer casing 111, and then increases again after passing through it. During this process, the refrigerant pressure decreases, resulting in refrigerant vaporization. In this process, oil contained in the refrigerant can be separated. Therefore, the refrigerant compression performance can be improved by allowing the refrigerant with separated oil to flow into the interior of the piston 150. It can be understood that the oil is the working oil present in the cooling system.

[0114] Figure 2 This is a cross-sectional view used to illustrate the structure of the linear compressor 100.

[0115] The linear compressor of the present invention will now be described using a linear compressor that performs the action of drawing in and compressing refrigerant through the linear reciprocating motion of a piston, and then discharging the compressed fluid as an example.

[0116] A linear compressor can be a structural element of a refrigeration cycle, and the fluid compressed in a linear compressor can be the refrigerant circulating in the refrigeration cycle. Besides the compressor, a refrigeration cycle can also include a condenser, an expander, and an evaporator. Furthermore, linear compressors can be used as a structural element in the cooling system of a refrigerator, but are not limited to this; they are widely used throughout industry.

[0117] Reference Figure 2 The compressor 100 may include a housing 110 and a main body housed inside the housing 110. The main body of the compressor 100 may include a frame 120, a cylinder 140 fixed to the frame 120, a piston 150 that reciprocates linearly inside the cylinder 140, and a drive unit 130 fixed to the frame 120 and providing driving force to the piston 150, etc. Here, the cylinder 140 and the piston 150 may also be referred to as compression units 140 and 150.

[0118] The compressor 100 may include a bearing unit for reducing friction between the cylinder 140 and the piston 150. The bearing unit may be an oil bearing or a gas bearing. Alternatively, a mechanical bearing may be used as the bearing unit.

[0119] The main body of the compressor 100 can be elastically supported by support springs 116 and 117 located at both ends inside the housing 110. The support springs 116 and 117 may include a first support spring 116 supporting the rear of the main body and a second support spring 117 supporting the front of the main body. The support springs 116 and 117 may include leaf springs. The support springs 116 and 117 not only support the internal components of the compressor 100 main body but also absorb vibrations and impacts generated by the reciprocating motion of the piston 150.

[0120] The housing 110 can form a sealed space. The sealed space may include: a receiving space 101 for receiving the drawn-in refrigerant; a suction space 102 for filling the refrigerant before compression; a compression space 103 for compressing the refrigerant; and a discharge space 104 filled with the compressed refrigerant.

[0121] The refrigerant drawn in from the suction pipe 114 connected to the rear side of the housing 110 fills the receiving space 101, and the refrigerant in the suction space 102 connected to the receiving space 101 is compressed in the compression space 103 and discharged into the discharge space 104, and then discharged to the outside through the discharge pipe 115 connected to the front side of the housing 110.

[0122] The housing 110 may include: an outer shell 111, open at both ends and formed into a generally transversely elongated cylindrical shape; a first outer shell cover 112, joined to the rear side of the outer shell 111; and a second outer shell cover 113, joined to the front side of the outer shell 111. Here, the front side may be the left side of the drawing, i.e., the direction in which compressed refrigerant is discharged, and the rear side may be the right side of the drawing, i.e., the direction in which refrigerant flows in. Furthermore, the first outer shell cover 112 or the second outer shell cover 113 may be integrally formed with the outer shell 111.

[0123] The housing 110 can be made of a thermally conductive material. This allows heat generated inside the housing 110 to be quickly dissipated to the outside.

[0124] The first outer cover 112 can be combined with the outer cover 111 to seal the rear side of the outer cover 111, and the suction tube 114 can be inserted into and combined with the center of the first outer cover 112.

[0125] The rear side of the compressor body 100 can be elastically supported in the radial direction of the first housing cover 112 by the first support spring 116.

[0126] The first support spring 116 may include a circular leaf spring. The edge of the first support spring 116 may be elastically supported in the forward direction relative to the rear cover 123 by a support bracket 123a. The central portion of the opening of the first support spring 116 may be supported in the rearward direction relative to the first housing cover 112 by a suction guide 116a.

[0127] A through flow path can be formed inside the suction guide 116a. The suction guide 116a can be formed in a cylindrical shape. The front outer peripheral surface of the suction guide 116a can be engaged with the central opening of the first support spring 116, and the rear end can be supported by the first outer casing 112. At this time, a suction-side support member 116b can be separately provided between the inner surfaces of the suction guide 116a and the first outer casing 112.

[0128] The rear side of the intake guide 116a can be connected to the intake pipe 114, and the refrigerant drawn in through the intake pipe 114 can flow smoothly into the first muffler unit 160 described later via the intake guide 116a.

[0129] A vibration damping member 116c may be disposed between the intake guide 116a and the intake-side support member 116b. The vibration damping member 116c may be formed of a rubber material or the like. This prevents the transmission of vibrations generated during the intake of refrigerant through the intake pipe 114 to the first outer casing 112.

[0130] The second outer cover 113 can be combined with the outer cover 111 to seal the front side of the outer cover 111, and the discharge pipe 115 can be inserted into and combined with the second outer cover 113 through the circulation pipe 115a. The refrigerant discharged from the compression space 103 can be discharged into the refrigeration cycle through the circulation pipe 115a and the discharge pipe 115 after passing through the discharge cover assembly 180.

[0131] The front side of the compressor body 100 can be elastically supported in the radial direction by a second support spring 117 on the outer casing 111 or the second outer casing cover 113.

[0132] The second support spring 117 may include a circular leaf spring. The central portion of the opening of the second support spring 117 may be supported in the rearward direction relative to the ejector cap assembly 180 by the first support guide 117b. The edge portion of the second support spring 117 may be supported in the forward direction by the support bracket 117a relative to the inner side of the housing 111 or the inner peripheral surface of the housing 111 adjacent to the second housing cover 113.

[0133] and Figure 2In contrast, the edge of the second support spring 117 can also be supported in the forward direction by an additional bracket (not shown) combined with the second housing cover 113 relative to the inner side of the housing 111 or the inner peripheral surface of the housing 111 adjacent to the second housing cover 113.

[0134] The first support guide 117b can be formed in a cylindrical shape. The cross-section of the first support guide 117b can have a plurality of diameters. The front side of the first support guide 117b can be inserted into the central opening of the second support spring 117, and the rear side can be connected to the ejector cap assembly 180. The support cap 117c can be engaged with the front side of the first support guide 117b through the second support spring 117. A cup-shaped second support guide 117d that is recessed rearward can be engaged with the front side of the support cap 117c. A cup-shaped third support guide 117e that corresponds to the second support guide 117d and is recessed forward can be engaged with the inner side of the second outer cover 113. The second support guide 117d can be inserted into the inner side of the third support guide 117e and is supported axially and / or radially. At this time, a gap can be formed between the second support guide 117d and the third support guide 117e.

[0135] The frame 120 may include: a main body 121 that supports the outer peripheral surface of the cylinder 140; and a first flange 122 that is connected to one side of the main body 121 and supports the drive unit 130. The frame 120, together with the drive unit 130 and the cylinder 140, may be elastically supported relative to the housing 110 by a first support spring 116 and a second support spring 117.

[0136] The main body 121 may surround the outer peripheral surface of the cylinder 140. The main body 121 may be cylindrical. The first flange 122 may be formed extending radially from the front end of the main body 121.

[0137] A cylinder 140 may be attached to the inner circumferential surface of the main body 121. An inner stator 134 may be attached to the outer circumferential surface of the main body 121. For example, the cylinder 140 may be press-fitted and fixed to the inner circumferential surface of the main body 121, and the inner stator 134 may be fixed using an additional retaining ring (not shown).

[0138] An outer stator 131 may be attached to the rear side of the first flange portion 122, and a discharge cap assembly 180 may be attached to the front side. For example, the outer stator 131 and the discharge cap assembly 180 may be fixed by a mechanical coupling unit.

[0139] A bearing inlet groove 125a, which forms part of the gas bearing, can be formed on one side of the front surface of the first flange portion 122, and a bearing communication hole 125b, which extends from the bearing inlet groove 125a to the inner peripheral surface of the main body portion 121, can be formed on the inner peripheral surface of the main body portion 121, and a gas groove 125c, which communicates with the bearing communication hole 125b, can be formed.

[0140] The bearing inlet groove 125a can be formed by an axial recess of a predetermined depth, and the bearing connecting hole 125b can be formed at an angle towards the inner circumferential surface or inner side surface of the main body 121 with a hole having a cross-sectional area smaller than that of the bearing inlet groove 125a. Furthermore, the gas groove 125c can be formed in an annular shape with a predetermined depth and axial length on the inner circumferential surface of the main body 121. In contrast, the gas groove 125c can be formed in the portion of the outer circumferential surface of the cylinder 140 that connects to the inner circumferential surface of the main body 121, or it can be formed on both the inner circumferential surface of the main body 121 and the outer circumferential surface of the cylinder 140.

[0141] Additionally, a gas inlet 142 corresponding to the gas groove 125c can be formed on the outer peripheral surface of the cylinder 140. The gas inlet 142 forms a nozzle portion in the gas bearing.

[0142] On the other hand, the frame 120 and the cylinder 140 can be made of aluminum or aluminum alloy.

[0143] The cylinder 140 can be formed into a cylindrical shape with open ends. The piston 150 can be inserted through the rear end of the cylinder 140. The front end of the cylinder 140 can be closed by the discharge valve assembly 170. A compression space 103 can be formed between the cylinder 140, the front end of the piston 150, and the discharge valve assembly 170. Here, the front end of the piston 150 can be referred to as the head 151. When the piston 150 retracts, the volume of the compression space 103 increases; when the piston 150 advances, the volume of the compression space 103 decreases. That is, the refrigerant flowing into the compression space 103 can be compressed when the piston 150 advances and discharged through the discharge valve assembly 170.

[0144] The cylinder 140 may include a second flange 141 disposed at its front end. The second flange 141 may be bent outward of the cylinder 140. The second flange 141 may extend along the outer periphery of the cylinder 140. The second flange 141 of the cylinder 140 may be coupled to the frame 120. For example, the front end of the frame 120 may have a flange groove corresponding to the second flange 141 of the cylinder 140, into which the second flange 141 of the cylinder 140 may be inserted and coupled using a coupling member.

[0145] On the other hand, a gas bearing unit can be provided, which can provide gas lubrication between the cylinder 140 and the piston 150 by supplying exhaust gas to the gap between the outer peripheral surface of the piston 150 and the outer peripheral surface of the cylinder 140. The exhaust gas supplied between the cylinder 140 and the piston 150 can provide a levitation force to the piston 150, thereby reducing the friction generated between the piston 150 and the cylinder 140.

[0146] For example, the cylinder 140 may include a gas inlet 142. The gas inlet 142 may communicate with a gas groove 125c formed on the inner circumferential surface of the body portion 121. The gas inlet 142 may extend radially through the cylinder 140. The gas inlet 142 may direct the compressed refrigerant flowing into the gas groove 125c between the inner circumferential surface of the cylinder 140 and the outer circumferential surface of the piston 150. Alternatively, for ease of manufacturing, the gas groove 125c may also be formed on the outer circumferential surface of the cylinder 140.

[0147] The inlet of the gas inlet 142 can be relatively wide, and the outlet can be a small through-hole to function as a nozzle. A filter (not shown) can be additionally provided at the inlet of the gas inlet 142 to block the inflow of foreign substances. The filter can be a mesh filter made of metal, or it can be formed by winding a component such as fine wire.

[0148] The gas inlet 142 can be formed independently in multiple ways, or its inlet can be formed as an annular groove, and its outlet can be formed at predetermined intervals along the annular groove. The gas inlet 142 can be formed only on the front side with the axial center of the cylinder 140 as a reference. In contrast, considering the downward movement of the piston 150, the gas inlet 142 can also be formed on the rear side with the axial center of the cylinder 140 as a reference.

[0149] The piston 150 is configured to be inserted from the open end of the cylinder 140 and to seal the rear of the compression space 103.

[0150] The piston 150 may include a head 151 and a guide portion 152. The head 151 may be formed in a disc shape. The head 151 may be partially open. The head 151 may divide a compression space 103. The guide portion 152 may extend rearward from the outer periphery of the head 151. The guide portion 152 may be formed in a cylindrical shape. The guide portion 152 may be formed such that its interior is hollow while a portion at its front is sealed by the head 151. The rear of the guide portion 152 may be open and connected to the first muffler unit 160. The head 151 may be a separate component combined with the guide portion 152. Alternatively, the head 151 and the guide portion 152 may be formed as a single unit.

[0151] Piston 150 may include a suction port 154. Suction port 154 may extend through head 151. Suction port 154 may connect suction space 102 and compression space 103 inside piston 150. For example, refrigerant flowing from receiving space 101 into suction space 102 inside piston 150 may be drawn into compression space 103 between piston 150 and cylinder 140 through suction port 154.

[0152] The intake port 154 may extend along the axial direction of the piston 150. The intake port 154 may be formed inclined to the axial direction of the piston 150. For example, the intake port 154 may extend in an inclined manner in a direction that is further away from the central axis as it moves toward the rear of the piston 150.

[0153] The cross-section of the suction port 154 can be circular. The suction port 154 can be formed with a constant inner diameter. Alternatively, the suction port 154 can be formed as an elongated hole with its opening extending radially along the head 151, or it can be formed with its inner diameter increasing towards the rear.

[0154] A plurality of suction ports 154 may be formed in at least one of the radial and circumferential directions of the head 151.

[0155] A suction valve 155, which selectively opens and closes the suction port 154, can be installed at the head 151 of the piston 150 adjacent to the compression space 103. The suction valve 155 can be actuated by elastic deformation, thereby opening or closing the suction port 154. That is, the suction valve 155 can be elastically deformed to open the suction port 154 by the pressure of the refrigerant flowing to the compression space 103 via the suction port 154. The suction valve 155 can be a reed valve, but is not limited to this, and can be modified in various ways.

[0156] The piston 150 can be connected to the movable member 135. The movable member 135 can reciprocate in the back-and-forth direction as the piston 150 moves. An inner stator 134 and a cylinder 140 can be disposed between the movable member 135 and the piston 150. The movable member 135 and the piston 150 can be connected to each other by a magnet frame 136 formed from the rear, bypassing the cylinder 140 and the inner stator 134.

[0157] The first muffler unit 160 can be coupled to the rear of the piston 150 and attenuate the noise generated during the process of refrigerant being drawn into the piston 150. The refrigerant drawn in through the suction pipe 114 can flow through the first muffler unit 160 to the suction space 102 inside the piston 150.

[0158] The first muffler unit 160 may include: a first intake muffler 161, which communicates with the receiving space 101 of the housing 110; and an internal guide 162, which is connected to the front of the first intake muffler 161 and guides the refrigerant to the intake port 154.

[0159] The first intake muffler 161 can be located behind the piston 150. The rear opening of the first intake muffler 161 can be configured adjacent to the intake pipe 114, and the front end is connected to the rear of the piston 150. The first intake muffler 161 has a flow path formed in the axial direction, thereby guiding the refrigerant in the receiving space 101 to the intake space 102 inside the piston 150.

[0160] The interior of the first intake muffler 161 can form a plurality of noise spaces separated by baffles. The first intake muffler 161 can be formed by combining two or more components together, for example, by pressing a second intake muffler into the interior of the first intake muffler to form a plurality of noise spaces. Furthermore, considering weight and insulation, the first intake muffler 161 can be made of plastic.

[0161] One side of the internal guide 162 can communicate with the noise space of the first intake muffler 161, while the other side can be deeply inserted into the interior of the piston 150. The internal guide 162 can be formed in a tubular shape. Both ends of the internal guide 162 can have the same inner diameter. The internal guide 162 can also be formed in a cylindrical shape. In contrast, the inner diameter of the front end, which is the discharge side, can be larger than the inner diameter of the rear end, which is the opposite side.

[0162] The first intake muffler 161 and the internal guide 162 can be configured in various shapes, which can be used to regulate the pressure of the refrigerant flowing through the first muffler unit 160. The first intake muffler 161 and the internal guide 162 can also be formed as a single unit.

[0163] The discharge valve assembly 170 may include: a discharge valve 171; and a valve spring 172 disposed on the front side of the discharge valve 171, elastically supporting the discharge valve 171. The discharge valve assembly 170 can selectively discharge compressed refrigerant in the compression space 103. Here, the compression space 103 is the space formed between the suction valve 155 and the discharge valve 171.

[0164] Discharge valve 171 can be configured to be supported on the front of cylinder 140. Discharge valve 171 can selectively open and close the front opening of cylinder 140. Discharge valve 171 can actuate by elastic deformation, thereby opening or closing compression space 103. Under the pressure of refrigerant flowing through compression space 103 to discharge space 104, discharge valve 171 can elastically deform to open compression space 103. For example, when discharge valve 171 is supported on the front of cylinder 140, compression space 103 can remain closed; when discharge valve 171 is separated from the front of cylinder 140, compressed refrigerant in compression space 103 can be discharged into the open space. Discharge valve 171 can be a reed valve, but is not limited to this.

[0165] Valve spring 172 can be disposed between discharge valve 171 and discharge cover assembly 180, providing axial spring force. Valve spring 172 can be a compression coil spring, or a leaf spring can be used considering space or reliability.

[0166] If the pressure in the compression chamber 103 is above the discharge pressure, the valve spring 172 deforms forward and opens the discharge valve 171, allowing refrigerant to be discharged from the compression chamber 103 and into the first discharge chamber 104a of the discharge cover assembly 180. Once the refrigerant has been completely discharged, the valve spring 172 can provide a restoring force to the discharge valve 171 to close it.

[0167] The process of refrigerant flowing into compression space 103 through suction valve 155 and being discharged from compression space 103 into discharge space 104 through discharge valve 171 will be described below.

[0168] During the reciprocating linear motion of the piston 150 inside the cylinder 140, if the pressure in the compression space 103 falls below the preset suction pressure, the suction valve 155 opens, and refrigerant is drawn into the compression space 103. Conversely, if the pressure in the compression space 103 exceeds the preset suction pressure, the refrigerant in the compression space 103 is compressed while the suction valve 155 is closed.

[0169] On the other hand, if the pressure in the compression space 103 becomes higher than the preset discharge pressure, the valve spring 172 deforms forward, thereby opening the discharge valve 171 connected to it, and the refrigerant is discharged from the compression space 103 to the discharge space 104 of the discharge cover assembly 180. Once the refrigerant has been discharged completely, the valve spring 172 provides a restoring force to the discharge valve 171, and the discharge valve 171 is closed, thereby sealing the front of the compression space 103.

[0170] The discharge cap assembly 180 can be disposed in front of the compression space 103 and form a discharge space 104 for receiving refrigerant discharged from the compression space 103. The discharge cap assembly 180 can attenuate noise generated during the discharge of refrigerant from the compression space 103 by engaging with the front of the frame 120. The discharge cap assembly 180 can accommodate the discharge valve assembly 170 and engage with the front of the first flange 122 of the frame 120. For example, the discharge cap assembly 180 can be engaged with the first flange 122 using a mechanical coupling member.

[0171] In addition, a gasket 165 for heat insulation and an O-ring 166 for suppressing refrigerant leakage in the discharge space 104 can be provided between the discharge cap assembly 180 and the frame 120.

[0172] The discharge cap assembly 180 can be made of a thermally conductive material. Therefore, if hot refrigerant flows into the discharge cap assembly 180, the heat of the refrigerant can be transferred to the housing 110 through the discharge cap assembly 180 and dissipated to the outside of the compressor.

[0173] The dispensing cap assembly 180 may consist of a single dispensing cap or may be configured as a plurality of dispensing caps connected in sequence. When the dispensing cap assembly 180 has a plurality of dispensing caps, the dispensing space 104 may include a plurality of spatial portions divided by each dispensing cap. The plurality of spatial portions may be arranged in a front-back direction and connected to each other.

[0174] For example, when there are three dispensing caps, the dispensing space 104 may include: a first dispensing space 104a, formed between the first dispensing cap 181 and the frame 120, which are coupled to the front side of the frame 120; a second dispensing space 104b, communicating with the first dispensing space 104a, formed between the second dispensing cap 182 and the first dispensing cap 181, which are coupled to the front side of the first dispensing cap 181; and a third dispensing space 104c, communicating with the second dispensing space 104b, formed between the third dispensing cap 183 and the second dispensing cap 182, which are coupled to the front side of the second dispensing cap 182.

[0175] Furthermore, the first discharge space 104a can be selectively connected to the compression space 103 via the discharge valve 171, the second discharge space 104b can be connected to the first discharge space 104a, and the third discharge space 104c can be connected to the second discharge space 104b. Thus, the discharge noise of the refrigerant discharged from the compression space 103 can be attenuated as it passes sequentially through the first discharge space 104a, the second discharge space 104b, and the third discharge space 104c. The refrigerant can then be discharged to the outside of the housing 110 via the circulation pipe 115a and the discharge pipe 115, which are connected to the third discharge cap 183.

[0176] The drive unit 130 may include: an outer stator 131 configured to surround the main body 121 of the frame 120 between the housing 111 and the frame 120; an inner stator 134 configured to surround the cylinder 140 between the outer stator 131 and the cylinder 140; and a moving member 135 configured between the outer stator 131 and the inner stator 134.

[0177] The outer stator 131 can be coupled to the rear of the first flange portion 122 of the frame 120, and the inner stator 134 can be coupled to the outer peripheral surface of the main body portion 121 of the frame 120. Furthermore, the inner stator 134 is disposed inside the outer stator 131 and spaced apart from the outer stator 131, and the moving member 135 can be disposed in the space between the outer stator 131 and the inner stator 134.

[0178] The outer stator 131 may be fitted with coil windings, and the moving part 135 may include a permanent magnet. The permanent magnet may consist of a single magnet having one pole, or it may consist of a combination of a plurality of magnets having three poles.

[0179] The outer stator 131 may include: a coil winding body 132, formed to surround the axial direction in a circumferential direction; and a stator core 133, which surrounds and is stacked around the coil winding body 132. The coil winding body 132 may include a hollow cylindrical spool 132a and a coil 132b wound along the circumferential direction of the spool 132a. The cross-section of the coil 132b may be circular or polygonal, for example, hexagonal. The stator core 133 may be composed of a plurality of lamination sheets stacked radially or a plurality of lamination blocks stacked circumferentially.

[0180] The front side of the outer stator 131 can be supported on the first flange 122 of the frame 120, and its rear side can be supported by the stator cover 137. For example, the stator cover 137 can be a hollow disk shape, with its front side supporting the outer stator 131 and its rear side supporting the resonant spring 118.

[0181] The inner stator 134 can be constructed by stacking a plurality of laminations along the circumferential direction on the outer peripheral surface of the main body 121 of the frame 120.

[0182] One side of the movable member 135 can be coupled to and supported by the magnet frame 136. The magnet frame 136 can be generally cylindrical in shape and configured to be inserted into the space between the outer stator 131 and the inner stator 134. Furthermore, the magnet frame 136 can be configured to engage with the rear side of the piston 150 and move together with the piston 150.

[0183] As an example, the rear end of the magnet frame 136 bends radially inward to form a first connecting portion 136a, which can engage with a third flange portion 153 formed behind the piston 150. The first connecting portion 136a of the magnet frame 136 and the third flange portion 153 of the piston 150 can be engaged by a mechanical connecting member.

[0184] Furthermore, a fourth flange 161a formed in front of the first intake muffler 161 and a fifth flange 162a formed behind the internal guide 162 can be provided between the third flange 153 of the piston 150 and the first joint 136a of the magnet frame 136. Therefore, the piston 150, the first muffler unit 160, and the moving member 135 can reciprocate together in a state where they are integrated as a single unit.

[0185] When current is applied to the drive unit 130, a magnetic flux is formed in the coil winding. Electromagnetic force is generated through the interaction between the magnetic flux formed in the coil winding of the outer stator 131 and the magnetic flux formed by the permanent magnet of the moving member 135, thereby allowing the moving member 135 to move. Furthermore, while the moving member 135 reciprocates axially, the piston 150, connected to the magnet frame 136, also reciprocates axially along with the moving member 135.

[0186] On the other hand, the drive unit 130 and the compression units 140 and 150 can be axially supported by the support springs 116 and 117 and the resonant spring 118.

[0187] The resonant spring 118 can effectively compress the refrigerant by increasing the vibration generated by the reciprocating motion of the moving part 135 and the piston 150. Specifically, the piston 150 can be made to resonate by adjusting the vibration frequency of the resonant spring 118 to correspond to the natural vibration frequency of the piston 150. In addition, the resonant spring 118 can guide the piston 150 to move stably, thereby reducing vibration and noise.

[0188] The resonant spring 118 can be a helical spring extending axially. Both ends of the resonant spring 118 can be connected to a vibrating body and a fixed body, respectively. For example, one end of the resonant spring 118 can be connected to the magnet frame 136, and the other end can be connected to the rear cover 123. Therefore, the resonant spring 118 can elastically deform between the vibrating body and the fixed body, with the vibrating body vibrating at one end of the resonant spring 118 and the fixed body fixed to the other end of the resonant spring 118.

[0189] The natural vibration frequency of the resonant spring 118 can be designed to match the resonant frequency of the moving part 135 and the piston 150 when the compressor 100 is running, thereby increasing the reciprocating motion of the piston 150. However, the rear cover 123, which is a fixed body, is elastically supported on the housing 110 by means of the first support spring 116, so it cannot be strictly considered fixed.

[0190] The resonant spring 118 may include a first resonant spring 118a and a second resonant spring 118b. With the spring support member 119 as a reference, the first resonant spring 118a is supported on the rear side, and the second resonant spring 118b is supported on the front side.

[0191] The spring support 119 may include: a main body 119a surrounding the first intake muffler 161; a second connecting part 119b bent radially inward from the front of the main body 119a; and a support part 119c bent radially outward from the rear of the main body 119a.

[0192] The front surface of the second connecting portion 119b of the spring support 119 can be supported by the first connecting portion 136a of the magnet frame 136. The second connecting portion 119b of the spring support 119 can be engaged with the piston 150. The inner diameter of the second connecting portion 119b of the spring support 119 can surround the outer diameter of the first intake muffler 161. For example, the second connecting portion 119b of the spring support 119, the first connecting portion 136a of the magnet frame 136, and the third flange portion 153 of the piston 150 can be sequentially arranged and then joined together by means of a mechanical component. At this time, as described above, the fourth flange portion 161a and the fifth flange portion 162a of the first intake muffler 161 can be disposed between the third flange portion 153 of the piston 150 and the first connecting portion 136a of the magnet frame 136 and fixed together.

[0193] The first resonant spring 118a can be disposed between the front of the rear cover 123 and the rear of the spring support 119. The second resonant spring 118b can be disposed between the rear of the stator cover 137 and the front of the spring support 119.

[0194] A plurality of first resonant springs 118a and second resonant springs 118b can be arranged circumferentially along the central axis. The first resonant springs 118a and second resonant springs 118b can be arranged side-by-side axially or staggered from each other. The first resonant springs 118a and second resonant springs 118b can also be arranged radially along the central axis at predetermined intervals. For example, three first resonant springs 118a and three second resonant springs 118b can be provided, and they can be arranged at 120-degree intervals from each other in the radial direction along the central axis.

[0195] The compressor 100 may include a plurality of sealing members capable of increasing the bonding force between the frame 120 and its surrounding components.

[0196] For example, the plurality of sealing members may include: a first sealing member, clamped at the portion where the frame 120 and the discharge cap assembly 180 meet, inserted into a mounting groove located at the front end of the frame 120; and a second sealing member, located at the portion where the frame 120 and the cylinder 140 meet, inserted into a mounting groove located on the outer surface of the cylinder 140. The second sealing member prevents refrigerant in the gas groove 125c formed between the inner circumferential surface of the frame 120 and the outer circumferential surface of the cylinder 140 from leaking to the outside, and can increase the bonding force between the frame 120 and the cylinder 140. Furthermore, the plurality of sealing members may also include a third sealing member, which is located at the portion where the frame 120 meets the inner stator 134 and inserted into a mounting groove located on the outer surface of the frame 120. Here, the first to third sealing members may be annular in shape.

[0197] The operation of the linear compressor 100 described above is as follows.

[0198] First, when current is supplied to the drive unit 130, the current flowing in the coil 132b creates a magnetic flux in the outer stator 131. This magnetic flux in the outer stator 131 generates an electromagnetic force, causing the moving member 135, which is equipped with a permanent magnet, to reciprocate linearly. This electromagnetic force is generated alternately in two directions: during the compression stroke, it is generated in the direction that pushes the piston 150 towards its top dead center (TDC) (forward direction); during the intake stroke, it is generated in the direction that pushes the piston 150 towards its bottom dead center (BDC) (rear direction). In other words, the drive unit 130 can generate a force, or thrust, that pushes the moving member 135 and the piston 150 in the direction of movement.

[0199] The piston 150, which performs linear reciprocating motion inside the cylinder 140, can repeatedly increase or decrease the volume of the compression space 103.

[0200] If piston 150 moves in the direction that increases the volume of compression space 103 (rearward direction), the pressure in compression space 103 decreases. At this time, the suction valve 155 installed in front of piston 150 opens, and the refrigerant remaining in suction space 102 is drawn into compression space 103 along suction port 154. This suction stroke can continue until the volume of compression space 103 is maximized and piston 150 is at bottom dead center.

[0201] When piston 150 reaches bottom dead center, it changes direction of motion and moves in the direction that reduces the volume of compression space 103 (forward direction), i.e., it performs the compression stroke. During the compression stroke, the pressure in compression space 103 increases, and the drawn-in refrigerant is compressed. If the pressure in compression space 103 reaches a set pressure, discharge valve 171 is pushed open by the pressure in compression space 103, causing cylinder 140 to open, and refrigerant can be discharged through the separated space into discharge space 104. This compression stroke can continue while piston 150 moves to top dead center, where the volume of compression space 103 is minimized.

[0202] During the repeated intake and compression strokes of piston 150, refrigerant flowing into the receiving space 101 inside compressor 100 through intake pipe 114 flows sequentially through intake guide 116a, first intake muffler 161, and internal guide 162 into intake space 102 inside piston 150. Refrigerant in intake space 102 can flow into compression space 103 inside cylinder 140 during piston 150's intake stroke. During piston 150's compression stroke, refrigerant in compression space 103 is compressed and discharged into discharge space 104, then discharged to the outside of compressor 100 via circulation pipe 115a and discharge pipe 115.

[0203] Figure 3 and Figure 4 This is a perspective view of a muffler unit according to an embodiment of the present invention. Figure 5 This is an exploded perspective view of a muffler unit according to an embodiment of the present invention. Figure 6 This is a perspective view of a second intake muffler according to an embodiment of the present invention. Figure 7 This is a side view of a second inhalation muffler according to an embodiment of the present invention. Figure 8 This is a cross-sectional view of a second intake muffler according to an embodiment of the present invention. Figure 9 This is a front view of a second inhalation muffler according to an embodiment of the present invention. Figure 10 This is a rear view of a second intake muffler according to an embodiment of the present invention. Figure 11 and Figure 12 This is a perspective view of the muffler body according to an embodiment of the present invention. Figure 13 This is a front view of the muffler body according to an embodiment of the present invention. Figure 14 This is a rear view of the muffler body according to an embodiment of the present invention. Figure 15 and Figure 16 This is a perspective view of a muffler cover according to an embodiment of the present invention. Figure 17 This is a cross-sectional view of a piston, a muffler unit, and a rear cover according to an embodiment of the present invention. Figure 18 This is a perspective view of a muffler unit and a rear cover according to an embodiment of the present invention. Figure 19 This is an exploded cross-sectional perspective view of a muffler unit and a rear cover according to an embodiment of the present invention. Figure 20This is a rear view of the back cover according to an embodiment of the present invention. Figure 21 and Figure 22 This is a rear view of the rear cover and muffler unit according to an embodiment of the present invention. Figure 23 This is a perspective view of a piston, spring support, first resonant spring, muffler unit, and rear cover according to an embodiment of the present invention. Figure 24 This is a block diagram of a multiple resonator according to an embodiment of the present invention. Figure 25 This is a graph showing the transmission loss (TL) at different frequencies of a multiple resonator according to an embodiment of the present invention. Figure 26 This is a graph showing the insertion loss (IL) of a muffler unit corresponding to the frequency of a prior art and an embodiment of the present invention.

[0204] Reference Figures 3 to 23 The muffler units 160 and 200 of the linear compressor 100 in one embodiment of the present invention may include a first muffler unit 160 and a second muffler unit 200, but may also omit a part of the configuration, and may also include other additional configurations.

[0205] This can be understood as meaning that in this specification, "front" refers to the axial front and "rear" refers to the axial rear. Specifically, in Figure 2 In the middle, "front" can refer to the bottom, while "back" can refer to the top. Additionally, in... Figure 17 In the middle, "front" can refer to the left direction, while "back" can refer to the right direction.

[0206] As previously mentioned, the first muffler unit 160 may include a first intake muffler 161 and an internal guide 162.

[0207] The second muffler unit 200 can be combined with an opening 1230 formed in the radial central region of the rear cover 123. The second muffler unit 200 can provide an expansion space for noise attenuation between the piston 150 and the rear cover 123. Thus, the noise of the linear compressor 100 can be reduced by improving the performance of the muffler units 160 and 200.

[0208] The second muffler unit 200 may include ribs 2126, 2130, 2128, 2144, 2148, 2224, 2248, 2236, 2238, and 2235 protruding from its outer or inner side. Here, the outer side can be understood to include a radially outer peripheral surface, a front surface, and a back surface. This improves the rigidity of the second muffler unit 200.

[0209] The second muffler unit 200 may include a second intake muffler 210, a muffler body 220, and a muffler cover 230, but some of these components may be omitted, and additional components may be added.

[0210] The second intake muffler 210 can communicate with the first intake muffler 161. The diameter of the front end of the second intake muffler 210 can be larger than the diameter of the rear end of the first intake muffler 161. As the piston 150 reciprocates axially, the rear region of the first intake muffler 161, which is engaged with the piston 150, can move axially inside the second intake muffler 210.

[0211] The second intake muffler 210 can be combined with the rear cover 123. Specifically, the second intake muffler 210 can be combined with the opening 1230.

[0212] The second intake muffler 210 may include a first cylindrical portion 212. The first cylindrical portion 212 may be formed as a cylinder with openings at the front and rear. A first connecting hole 2122 may be formed on the outer peripheral surface of the first cylindrical portion 212. The front of the first cylindrical portion 212 may communicate with the first intake muffler 161. The diameter of the front end of the first cylindrical portion 212 may be larger than the diameter of the rear end of the first intake muffler 161. The first intake muffler 161 may be located inside the front end of the first cylindrical portion 212. The first cylindrical portion 212 may be combined with the rear cover 123.

[0213] The first cylindrical portion 212 may be formed with a first flange unit 214, a second flange unit 216, a third joint portion 218, a first rib 2126, 2130, a first connecting hole 2122, a second rib 2128, a second connecting hole 2124, a partition wall 2184, a protrusion 2142, and third ribs 2144, 2148.

[0214] The second intake muffler 210 may include a first flange unit 214. The first flange unit 214 extends radially outward from the front of the first cylindrical portion 212. The first flange unit 214 may overlap radially with the front end of the muffler body 220. A protrusion 2142 may be formed on the front side of the first flange unit 214, the protrusion 2142 being configured to be adjacent to the internal flow path and protruding forward. The radial protrusion length of the first flange unit 214 may be greater than the radial protrusion length of the second flange unit 216.

[0215] The second intake muffler 210 may include a second flange unit 216. The second flange unit 216 extends radially outward from the central region of the first cylindrical portion 212. The second flange unit 216 may be disposed between the first flange unit 214 and the third joint portion 218. The second flange unit 216 may contact the third flange unit 224 of the muffler body 220. Specifically, the back surface of the second flange unit 216 may contact the front surface of the third flange unit 224 of the muffler body 220. An elastic member 240 may be disposed between the second flange unit 216 and the third flange unit 224. In the figures, an example is shown where only the third groove 2244 is formed in the third flange unit 224; however, unlike this, the second flange unit 216 may also have a groove for disposing of the elastic member 240.

[0216] The second intake muffler 210 may include a third coupling portion 218. The third coupling portion 218 may be formed at the rear of the second intake muffler 210. The third coupling portion 218 may protrude radially outward from the rear end of the first cylindrical portion 212. The third coupling portion 218 may be formed in a shape corresponding to the opening 1230 of the rear cover 123. The third coupling portion 218 may pass through the opening 1230 of the rear cover 123 and be rotatably mounted on the back side of the rear cover 123. In this case, the third coupling portion 218 and the opening of the rear cover 123 may be elliptical or polygonal in shape.

[0217] This allows for a secure connection between the metal rear cover 123 and the non-metallic second muffler unit 200. Furthermore, the second intake muffler 210 can be attached to the opening 1230 of the rear cover 123 without the need for additional welding or other processes.

[0218] The second intake muffler 210 may include a first connecting hole 2122 formed on its outer peripheral surface. The first connecting hole 2122 may be formed in the first cylindrical portion 210. The first connecting hole 2122 may be formed between the first flange unit 214 and the second flange unit 216. The first connecting hole 2122 allows communication between the interior of the second intake muffler 210 and the space between the second intake muffler 210 and the muffler body 220. Here, the space between the second intake muffler 210 with the first connecting hole 2122 and the muffler body 220 may be referred to as the "first expansion space". The first connecting hole 2122 may include a plurality of first connecting holes 2122 spaced apart from each other in the circumferential direction. Thus, the noise filtering characteristics can be improved by adding an expansion chamber to the second muffler unit 200.

[0219] In one embodiment of the present invention, an example is described in which the first connecting hole 2122 is rectangular, but the shape of the first connecting hole 2122 can be varied.

[0220] The space between the second intake muffler 210 and the muffler body 220 may not overlap with the first intake muffler 161 in the axial direction. Only a portion of the space between the second intake muffler 210 and the muffler body 220 may overlap with the piston 150 in the axial direction. This not only improves the noise filtering characteristics of the muffler units 160 and 200, but also increases space efficiency.

[0221] The second intake muffler 210 may include a second connecting hole 2124 formed on its outer peripheral surface. The second connecting hole 2124 may be formed in the first cylindrical portion 210. The second connecting hole 2124 may be formed between the second flange unit 216 and the third joint portion 218. The second connecting hole 2124 allows communication between the interior of the second intake muffler 210 and the space between the second intake muffler 210, the muffler body 220, the muffler cover 230, and the rear cover 123. Here, the space between the second intake muffler 210, the muffler body 220, the muffler cover 230, and the rear cover 123 can be referred to as the "second expansion space". The second connecting hole 2124 may include a plurality of second connecting holes 2124 spaced apart from each other in the circumferential direction. Thus, noise filtering characteristics can be improved by adding an expansion chamber to the second muffler unit 200.

[0222] This specification describes an example where the second connecting hole 2124 is rectangular, but the shape of the second connecting hole 2124 can be varied.

[0223] The diameter of the space between the second intake muffler 210, the muffler body 220, the muffler cover 230, and the rear cover 123 can be larger than the diameter of the space between the second intake muffler 210 and the muffler body 220. This can improve the noise reduction efficiency of the second muffler unit.

[0224] The second intake muffler 210 may include a partition wall 2184. The partition wall 2184 may divide the internal space 2182 of the first cylindrical portion 212. The partition wall 2184 may be formed only in the rear region of the first cylindrical portion 212. The partition wall 2184 may overlap radially with the second connecting hole 2124. The partition wall 2184 may overlap radially with the space between the second intake muffler 210, the muffler body 220, the muffler cover 230, and the rear cover 123. This not only improves the refrigerant intake efficiency but also improves space efficiency.

[0225] The second intake muffler 210 may include first ribs 2126 and 2130. The first ribs 2126 and 2130 may protrude radially outward from the outer peripheral surface of the second intake muffler 210. The first ribs 2126 and 2130 may also protrude radially outward from the outer peripheral surface of the first cylindrical portion 212. The first ribs 2126 and 2130 may extend circumferentially. A portion of the first ribs 2126 and 2130 may be disposed between the first flange unit 214 and the second flange unit 216, and another portion may be disposed between the second flange unit 216 and the third connecting portion 218.

[0226] A portion of the first ribs 2126 and 2130 can overlap with the first connecting hole 2122 in the circumferential direction. This does not affect the flow of refrigerant inside the second intake muffler 210 and can improve the rigidity of the second intake muffler 210.

[0227] The first ribs 2126 and 2130 may include a plurality of first ribs 2126 and 2130 spaced apart from each other along the axial direction. In one embodiment of the present invention, an example is shown in which three of the plurality of first ribs 2126 and 2130 are arranged between the first flange unit 214 and the second flange unit 216, and two of the plurality of first ribs 2126 and 2130 are arranged between the second flange unit 216 and the third joint 218. However, the present invention is not limited thereto, and the number of the plurality of first ribs 2126 and 2130 can be varied.

[0228] The second intake muffler 210 may include a second rib 2128. The second rib 2128 may extend axially between the first flange unit 214 and the second flange unit 216. The second rib 2128 may include: a first region 2128b extending axially on the outer peripheral surface of the first cylindrical portion 212; a second region 2128a connected to the first region 2128b, protruding rearward from the back side of the first flange unit 214 and extending radially; and a third region 2128c connected to the first region 2128b, protruding forward from the front side of the second flange unit 216 and extending radially.

[0229] The second rib 2128 may overlap with a portion of the first ribs 2126 and 2130. The radial protrusion length of the second rib 2128 may be greater than the radial protrusion length of the first ribs 2126 and 2130.

[0230] Therefore, vibrations applied to the second intake muffler 210 can be countered by increasing the rigidity of the second intake muffler 210 in multiple directions.

[0231] The second intake muffler 210 may include third ribs 2144 and 2148. The third ribs 2144 and 2148 may be formed on the first flange unit 214. The third ribs 2144 and 2148 may protrude forward from the front of the first flange unit 214. The third ribs 2144 and 2148 may protrude radially. This improves the rigidity of the first flange unit 214.

[0232] The third ribs 2144 and 2148 may include a plurality of third ribs 2144 and 2148 spaced apart from each other in a circumferential direction. The plurality of third ribs 2144 and 2148 may be configured radially with respect to the central region of the first flange unit 214. A portion 2144 of the plurality of third ribs 2144 and 2148 may be formed with a different shape than another portion 2148. This can guide the engagement direction of the second intake muffler 210, which includes the first flange unit 214.

[0233] The third ribs 2144 and 2148 can be non-overlapping with the second rib 2128 in the axial direction. This not only improves the rigidity of the second intake muffler 210, but also improves space efficiency.

[0234] The area where the third ribs 2144 and 2148 connect with the protrusion 2142 can be formed as a curved surface 2146.

[0235] The muffler body 220 may surround the second intake muffler 210. With the second intake muffler 210 engaged with the opening 2130, the muffler body 220 may be press-fitted into the rear cover 123. The muffler body 220 may include a second cylindrical portion 222 and a third flange unit 224.

[0236] The second cylindrical portion 222 can be disposed radially outside the second intake muffler 210. The second cylindrical portion 222 can be formed into a cylindrical shape with a rear opening. Specifically, the second cylindrical portion 222 can be a shape with a front and rear opening in the central region, and the front of the space between the inner side 222b and the outer side 222c is blocked and the rear is open.

[0237] The third flange unit 224 can extend inward from the inner side 222b of the second cylindrical portion 222. The inner region of the third flange unit 224 can overlap axially with the outer region of the second flange unit 216. The third flange unit 224 can contact the second flange unit 216. Specifically, the front side of the third flange unit 224 can contact the back side of the second flange unit 216. Thus, when the third joint portion 218 of the second intake muffler 210 is engaged with the opening 1230 of the rear cover 123, the muffler body 220 can be pressed together between the second intake muffler 210 and the rear cover 123.

[0238] An elastic member 240 may be disposed between the third flange unit 224 and the second flange unit 216. The third flange unit 224 may include a third groove 2244 for accommodating the elastic member 240. This specification describes an example where only the third flange unit 224 has the third groove 2244 formed, but the third groove 2244 may be formed on at least one side of the front of the third flange unit 224 and the back of the second flange unit 216. The third groove 2244 may extend circumferentially. This allows for guiding the position of the elastic member 240 disposed between the second intake muffler 210 and the muffler body 220, and not only eliminates the gap between the second intake muffler 210 and the muffler body 220, but also enables the second muffler unit 200 to be press-fitted into the rear cover 123, thereby improving the stability of the fit.

[0239] A hole 2242 may be formed in the central region of the third flange unit 224. The first cylindrical portion 212 of the second intake muffler 210 may be disposed inside the hole 2242.

[0240] The muffler body 220 may include a resonant communication hole 2228. The resonant communication hole 2228 may be formed on the inner surface 222b of the second cylindrical portion 222. The resonant communication hole 2228 allows communication between the space between the second intake muffler 210 and the second cylindrical portion 222, and between the muffler body 220 and the muffler cover 230. The resonant communication hole 2228 also allows communication between the space between the second intake muffler 210 and the second cylindrical portion 222, and between the second cylindrical portion 222 and the ring portion 234.

[0241] The resonant connection hole 2228 can be configured adjacent to the third flange unit 224. Thus, noise generated in the piston 150 can easily flow into the resonator through the resonant connection hole 2228.

[0242] The space between the second cylindrical portion 222 and the ring portion 234 can be understood as the space between the inner side surface 222b, the outer side surface 222c, the front surface 222a of the second cylindrical portion 222, and the ring portion 234. The space between the second cylindrical portion 222 and the ring portion 234 can be called a "resonator".

[0243] The resonator, which serves as the space between the inner side 222b, outer side 222c, front side 222a, and ring 234 of the second cylindrical portion 222, can form a space sealed by the second cylindrical portion 222 and the ring 234, except for the resonant connecting hole 2228.

[0244] The axial length of the space between the muffler body 220 and the muffler cover 230 can be greater than the radial length. The space between the muffler body 220 and the muffler cover 230 can be axially non-overlapping with the piston 150.

[0245] By adding a resonator, noise in the low or mid frequencies of the 1.25kHz band can be reduced.

[0246] The muffler body 220 may include a fourth rib 2224. The fourth rib 2224 may protrude radially outward from the outer side 222c or outer peripheral surface of the second cylindrical portion 222. The fourth rib 2224 may extend axially. This can improve the rigidity of the muffler body 220.

[0247] The fourth rib 2224 can contact the leg 1234 of the rear cover 123. The rear cover 123 may include: a support member 1232 having an opening 1230; a plurality of legs 1234 extending forward from the radially outer side of the support member 1232 and spaced apart from each other in the circumferential direction; and a plurality of extension members 1236 extending radially from the support member 1232 and spaced apart from each other in the circumferential direction. The fourth rib 2224 may include a plurality of fourth ribs 2224 spaced apart from each other in the circumferential direction. The plurality of fourth ribs 2224 can contact the plurality of legs 1234 respectively. Thus, the position of the muffler body 220 relative to the rear cover 123 can be guided, and the muffler body 220 can be press-fitted into the rear cover 123.

[0248] The muffler body 220 may include a fifth rib 2248. The fifth rib 2248 may be formed in the region between the inner side surface 222b of the second cylindrical portion 222 and the front surface of the third flange unit 224. Specifically, the fifth rib 2248 may extend from the inner side surface 222b of the second cylindrical portion 222 to the front surface of the third flange unit 224. This improves the rigidity of the region connecting the second cylindrical portion 222 and the third flange unit 224.

[0249] The fifth rib 2248 can move further away from the front of the third flange unit 224 and closer to the inner surface 222b of the second cylindrical portion 222. Specifically, the length of the fifth rib 2248 from the inner surface 222b of the second cylindrical portion 222 can become shorter as it moves further away from the front of the third flange unit 224. This allows the position of the second flange unit 216 relative to the third flange unit 224 to be guided.

[0250] The muffler body 220 may include a plurality of first grooves 2222. The plurality of first grooves 2222 may be formed recessed inward from the outer side 222c of the second cylindrical portion 222. The plurality of first grooves 2222 may also be formed recessed rearward from the front side 222a of the second cylindrical portion 222. The plurality of first grooves 2222 may be spaced apart from each other in the circumferential direction. In one embodiment of the invention, a case of three first grooves 2222 is described, but the invention is not limited to this, and the number of first grooves 2222 can be varied.

[0251] The first groove 2222 may include: a bottom surface 2222a; a first step portion 2222b, which connects the bottom surface 2222a with the outer surface 222c of the second cylindrical portion 222 and extends in the circumferential direction; and a second step portion and a third step portion 2222c, which connect the bottom surface 2222a and the outer surface 222c of the second cylindrical portion 222 and extend in the axial direction.

[0252] A plurality of first grooves 2222 can overlap axially with the support portion 119c of the spring support 119. This prevents interference between the muffler body 220 and the spring support 119 and improves space efficiency.

[0253] In the circumferential direction, resonators can be formed between a plurality of first slots 2222. Specifically, in the circumferential direction, spaces between the muffler body 220 and the muffler cover 230 can be formed between the plurality of first slots 2222. More specifically, in the circumferential direction, spaces between the inner side 222b, outer side 222c, front side 222a, and ring portion 234 of the second cylindrical portion 222 can be formed between the plurality of first slots 2222. In the circumferential direction, a plurality of resonant connecting holes 2228 can be arranged between the plurality of first slots 2222. This not only prevents interference with other structures but also improves space efficiency.

[0254] The muffler body 220 may include sixth ribs 2236 and 2238. The sixth ribs 2236 and 2238 may extend rearward from the back side of the first step portion 2222b of the first groove 2222. This can improve the rigidity of the plurality of first grooves 2222.

[0255] The sixth ribs 2236 and 2238 may include: an inner rib 2236 formed on the inner side; and an outer rib 2238 disposed radially outward of the inner rib 2236. The axial length of the outer rib 2238 may be greater than the axial length of the inner rib 2236. Specifically, the protrusion length of the outer rib 2238 from the first step portion 2222b may be greater than the protrusion length of the inner rib 2236 from the first step portion 2222b. This allows for guidance of the position of the muffler cover 230 relative to the muffler body 220.

[0256] The muffler cover 230 can be mounted on the sixth ribs 2236 and 2238. A ring portion 234 can be mounted on the outer rib 2238, and a second extension portion 232 can be mounted on the inner rib 2236.

[0257] The muffler body 220 may include guide grooves 2226. Guide grooves 2226 may be formed on the front surface 222a of the second cylindrical portion 222. Guide grooves 2226 may include a plurality of guide grooves 2226 spaced apart from each other in the circumferential direction. Guide grooves 2226 may overlap with the fourth rib 2224 in the radial direction. Therefore, when the second muffler unit 200 is attached to the rear cover 123, the correct attachment direction can be guided to the user.

[0258] The region 2234 in the muffler body 220 that opens rearward between the inner side 222b and the outer side 222c can be referred to as a "resonator". This region 2234 can be sealed by the muffler cover 230. That is, this can be understood as having the same meaning as the space between the muffler body 220 and the muffler cover 230.

[0259] The muffler body 220 may include an eighth rib 2235. The eighth rib 2235 may be formed in a region 2234 of the muffler body 220 that opens rearward between the inner side surface 222b and the outer side surface 222c. The eighth rib 2235 may be formed in the space between a plurality of first grooves 2222. Specifically, the eighth rib 2235 may be formed in the space between the second step portion and the third step portion 2222c. The eighth rib 2235 may protrude inward from the outer side surface 222c of the muffler body 220. This not only improves space efficiency but also increases the rigidity of the resonator of the muffler body 220.

[0260] The muffler cover 230 can be disposed between the muffler body 220 and the rear cover 123. The muffler cover 230 can be mounted on the sixth ribs 2236 and 2238. When the second intake muffler 210 is engaged with the opening 1230, the muffler cover 230 can be pressed into and engaged with the rear cover 123. The muffler cover 230 can be formed in an overall ring shape or a circular band shape.

[0261] The muffler cover 230 may include a ring portion 234, a first extension portion 236, and a second extension portion 232. The central region of the ring portion 234 may be open. The ring portion 234 may extend circumferentially. The ring portion 234 may be formed in a ring shape or a circular band shape. The first extension portion 236 may extend rearward from the outer side or outer end of the ring portion 234. The second extension portion 232 may extend forward from the inner side or inner end of the ring portion 234.

[0262] The ring portion 234 and the second extension portion 232 can contact the muffler body 220. The second extension portion 232 can be placed on the inner rib 2236. The ring portion 234 can be placed on the outer rib 2238. The first extension portion 236 can contact the rear cover 123. The outer surface of the first extension portion 236 and the inner surface of the second extension portion 232 can contact the second cylindrical portion 222. Thus, when the third connecting portion 218 of the second intake muffler 210 is connected to the opening 1230 of the rear cover 123, the muffler cover 230 can be pressed together between the muffler body 220 and the rear cover 123.

[0263] The ring portion 234 can seal the rear of the opening between the inner side surface 222b and the outer side surface 222c of the second cylindrical portion 222. The outer side surface of the first extension portion 236 can contact the second cylindrical portion 222.

[0264] The muffler cover 230 may include a seventh rib 238. The seventh rib 238 may be formed between the back surface of the annular portion 234 and the inner surface of the first extension 236. The seventh rib 238 may include a plurality of seventh rib members 2382, 2384 spaced apart from each other in the circumferential direction. The plurality of seventh rib members 2382, 2384 may face each other. A support bracket 123a may be disposed between the plurality of seventh rib members 2382, 2384. This allows for guiding the position of the muffler cover 230 and improves the rigidity of the muffler cover 230.

[0265] The muffler cover 230 may include a fourth joint 2364. The fourth joint 2364 may protrude radially outward from the first extension 236. A straight line extending the fourth joint 2364 may be arranged between a plurality of seventh rib members 2382, 2384. The fourth joint 2364 may be positioned within a second groove 2230 formed by recessing from the inside to the outside of the fourth rib 2224. The fourth joint 2364 may include a plurality of fourth joints 2364 spaced apart from each other in a circumferential direction. This not only improves the rigidity of the muffler cover 230 and the muffler body 220 but also guides the position of the muffler cover 230 relative to the muffler body 220.

[0266] Figure 24 This is a block diagram of a multiple resonator according to an embodiment of the present invention. The space between the internal guide 162 and the piston 150 is described as the first resonator HR1, and the additional resonator, which serves as the space between the second cylindrical portion 222 and the ring portion 234, is described as the second resonator HR2.

[0267] Reference Figure 25It can be confirmed that, compared with the case where only the transmission loss in the 100Hz band is improved when only the first resonator HR1 is present, and the case where only the transmission loss in the 250Hz band is improved when only the second resonator HR2 is present, the transmission loss in both the 100Hz and 250Hz bands is improved when the first resonator HR1 and the second resonator HR2 are linearly configured, and the transmission loss in the frequency band (e.g., 200Hz) between each resonator HR1 and HR2 is also improved.

[0268] It can be confirmed that, when applying the linear compressor 100 of an embodiment of the present invention, the first resonator HR1 can improve the transmission loss in the 800Hz band, the second resonator HR2 can improve the transmission loss in the 1.25kHz band, and the transmission losses in the 800Hz and 1.25kHz bands can also be improved.

[0269] Reference Figure 26 It can be confirmed that, compared with the prior art, the noise reduction characteristics of the muffler units 160 and 200 of the linear compressor 100 of an embodiment of the present invention are improved. Specifically, noise in the low-frequency or mid-frequency band between 800Hz and 1.2kHz is reduced, as is noise in the high-frequency band between 2kHz and 2.5kHz. Here, the insertion loss IL can be understood as the difference in sound level before and after the installation of the muffler units 160 and 200, expressed in dB.

[0270] The embodiments or other embodiments described above are not exclusive or distinct from each other. The structural elements or functions of any of the embodiments or other embodiments of the present invention described above can be used together or combined.

[0271] For example, this means that structure A, as illustrated in a particular embodiment and / or figure, can be combined with structure B, as illustrated in other embodiments and / or figures. That is, even if the combination between structures is not directly described, it is implied that they can be combined unless explicitly stated that they cannot be combined.

[0272] Therefore, the detailed description above should not be construed as limiting in all respects, but rather as exemplary. The scope of protection of this invention should be determined by a reasonable interpretation of the appended claims, and all modifications within the equivalent scope of this invention fall within its scope.

Claims

1. A linear compressor, wherein, include: Cylinder; The piston reciprocates axially inside the cylinder. The first muffler unit is coupled to the piston; The rear cover includes an opening formed in the radial central region and is disposed behind the piston; as well as The second muffler unit is integrated with the opening. The first muffler unit includes: Internal guides, disposed inside the piston; and The first intake muffler is located behind the internal guide. The second muffler unit includes: A second intake muffler, connected to the first intake muffler, and coupled to the opening; and The muffler body surrounds the second intake muffler. The second intake muffler includes: First cylindrical section; The first flange unit extends radially outward from the front of the first cylindrical portion; and The second flange unit extends radially outward from the central region of the first cylindrical portion; The second muffler unit includes a rib protruding from the outer or inner side; The ribs include: The first rib protrudes radially outward from the outer peripheral surface of the second intake muffler and extends circumferentially; and The second rib extends axially between the first flange unit and the second flange unit.

2. The linear compressor according to claim 1, wherein, The outer peripheral surface of the second intake muffler includes a first communicating hole, which connects the interior of the second intake muffler with the space between the second intake muffler and the muffler body. The first rib overlaps with the first connecting hole in the circumferential direction.

3. The linear compressor according to claim 1, wherein, The second rib includes: The first region extends axially on the outer peripheral surface of the first cylindrical portion; The second region, connected to the first region, protrudes rearward from the back of the first flange unit and extends radially; and The third region, connected to the first region, protrudes forward from the front of the second flange unit and extends radially.

4. The linear compressor according to claim 1, wherein, The second rib overlaps with the first rib, and the radial protrusion length of the second rib is greater than that of the first rib.

5. The linear compressor according to claim 1, wherein, The second intake muffler includes: First cylindrical section; and The first flange unit extends radially outward from the front of the first cylindrical portion. The ribs include: The third rib protrudes forward from the front of the first flange unit and extends radially.

6. The linear compressor according to claim 5, wherein, The third rib comprises a plurality of third ribs spaced apart from each other along the circumferential direction. One of the plurality of the third ribs is formed in a shape different from that of the other.

7. The linear compressor according to claim 5, wherein, The third rib does not overlap with the second rib in the axial direction.

8. The linear compressor according to claim 1, wherein, The muffler body includes: The second cylindrical portion is located radially outside the second intake muffler, with openings at the front and rear of the central region. The space between the inner and outer sides is blocked at the front and open at the rear. The ribs include: The fourth rib protrudes radially outward from the outer circumference of the second cylindrical portion and extends axially.

9. The linear compressor according to claim 8, wherein, The muffler body includes: The third flange unit extends inward from the inner side of the second cylindrical portion. The ribs include: The fifth rib is formed in the area between the inner side of the second cylindrical portion and the front side of the third flange unit.

10. The linear compressor according to claim 9, wherein, The fifth rib moves further away from the front of the third flange unit and closer to the inner side of the second cylindrical portion.

11. The linear compressor according to claim 9, wherein, The muffler body includes: A plurality of first grooves are formed by recesses from the outer side of the second cylindrical portion into the inner side and are spaced apart from each other along the circumferential direction. The first slot includes: Bottom surface; A first stepped portion connects the bottom surface and the outer surface of the second cylindrical portion, extending in a circumferential direction; and The second and third stepped portions connect the bottom surface and the outer surface of the second cylindrical portion, extending axially. The back side of the first stepped portion includes a sixth rib extending rearward.

12. The linear compressor according to claim 11, wherein, The second muffler unit includes: A muffler cover is disposed between the muffler body and the rear cover. The muffler cover is mounted on the sixth rib.

13. The linear compressor according to claim 12, wherein, The sixth rib includes: Medial ribs, formed on the medial side; and The outer rib is formed radially outward of the inner rib. The axial length of the outer side reinforcement is greater than the axial length of the inner side reinforcement.

14. The linear compressor according to claim 12, wherein, The muffler cover includes: The ring extends along the circumference; and The first extension extends rearward from the outer side of the ring portion. The ribs include: A plurality of seventh ribs are formed between the back side of the ring portion and the inner side surface of the first extension portion and are spaced apart from each other in the circumferential direction.

15. The linear compressor according to claim 14, wherein, The muffler cover includes: The joint protrudes radially outward from the first extension. The straight lines extending from the joint are arranged between the plurality of the seventh ribs. The inner side of the fourth rib includes a second groove, which is recessed outward, and the joint is disposed in the second groove.

16. The linear compressor according to claim 14, wherein, The ribs include: The eighth rib is formed in the region of the second cylindrical portion that opens rearward between the inner and outer sides, protruding radially inward from the outer side of the second cylindrical portion and extending axially.

17. The linear compressor according to claim 8, wherein, The rear cover includes: Supporting components; and A plurality of legs extend forward from the radially outer side of the supporting member and are spaced apart from each other in a circumferential direction. The fourth rib contacts the plurality of the legs.

18. A linear compressor, wherein, include: Cylinder; The piston reciprocates axially inside the cylinder. The rear cover includes an opening formed in the radial central region and is disposed behind the piston; as well as The muffler unit is combined with the opening. The silencer unit includes: A suction muffler is attached to the opening. The muffler body surrounds the intake muffler; The inhalation silencer includes: First cylindrical section; The first flange unit extends radially outward from the front of the first cylindrical portion; and The second flange unit extends radially outward from the central region of the first cylindrical portion; The muffler unit includes ribs protruding from the outer or inner side; The ribs include: The first rib protrudes radially outward from the outer peripheral surface of the intake muffler and extends in a circumferential direction; and The second rib extends axially between the first flange unit and the second flange unit.

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