Linear compressor

Abstract

The present invention relates to a linear compressor. The linear compressor according to an embodiment of the present invention comprises: a cylinder forming a compression space; a piston inserted into the cylinder and having suction ports for suctioning a refrigerant into the compression space; and a suction valve for opening or closing the suction ports to control the amount of the refrigerant suctioned into the compression space. The piston may comprise a valve wall facing the compression space and a stepped valve seating surface in the valve wall to seat the suction valve.

Description

Linear compressor

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

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

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

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

[0005] The above linear compressor includes a suction valve provided on a piston, and the refrigerant within the piston can be sucked into the compression space of the cylinder when the suction valve is opened (refrigerant suction action). The piston may include a plurality of ports for sending the refrigerant into the compression space.

[0006] According to conventional linear compressors, since the plurality of ports are formed eccentrically to one side from the center of the piston, there was a problem in that the opening amount of the intake valve was excessive and consequently, damage occurred due to bending of the intake valve.

[0007] In addition, there was a problem in that the number of ports was relatively small, which increased the amount of refrigerant that had to be sucked in per port, and consequently caused the size of the ports to become too large.

[0008] If the size of the above port becomes too large, the amount of deformation (bulging amount) caused by the suction valve being pressed during the compression of the compression space (compression action of the refrigerant) increases, and consequently, there was a problem in that the suction valve was damaged.

[0009] The linear compressor further includes a discharge valve provided on the discharge side of the compression space of the cylinder, and the high-temperature refrigerant compressed in the compression space can be discharged to the discharge cover side through the open discharge valve.

[0010] Meanwhile, during the process of compressing the refrigerant in the above compression space, a collision may occur between the suction valve and the discharge valve, and accordingly, there was a problem in that the suction valve was subjected to deformation by being pressed and plastic deformation was induced by the discharge valve.

[0011] In addition, there was a problem in that gouging or wear occurred on the valve seating surface of the piston during the process of the intake valve repeatedly opening and closing.

[0012] Information on prior art related to linear compressors is as follows.

[0013] Korean Published Patent Application 10-2006-0091645 (August 21, 2006), Title of Invention: Installation Structure of Suction Valve for Linear Compressor

[0014] The present invention aims to provide a linear compressor capable of increasing suction efficiency and preventing valve damage by improving the structure of the suction valve and piston.

[0015] The present invention aims to provide a linear compressor capable of increasing the intake volume of refrigerant while reducing deformation caused by bulging of the intake valve by appropriately proposing the size and number of intake ports formed on the piston.

[0016] The present invention aims to provide a linear compressor capable of improving the suction efficiency of a piston and appropriately adjusting the opening amount of a suction valve by proposing the positions of a plurality of suction ports formed on a piston.

[0017] The present invention aims to provide a linear compressor capable of reducing the opening amount of the intake valve by proposing a shape for the intake valve, thereby preventing the intake valve from bending or being damaged by impact to the piston.

[0018] The present invention aims to provide a linear compressor capable of preventing collision between the suction valve and the discharge valve when refrigerant is compressed in the compression space of the cylinder by forming the valve seating surface of the piston with a step.

[0019] The present invention aims to provide a linear compressor capable of improving suction efficiency by forming a recess between the suction valve and the suction port having a cross-sectional area larger than that of the suction port, thereby reducing the contact area between the suction valve and the piston and ensuring that the pressure of the suction refrigerant acts evenly on the suction valve.

[0020] The present invention aims to provide a linear compressor that can prevent the amount by which the suction valve is pressed into the recess by appropriately proposing the axial depth of the recess, that is, when the refrigerant is compressed in the time domain where high pressure acts, i.e., the compression space.

[0021] The present invention aims to provide a linear compressor capable of maintaining good rigidity of the intake valve by appropriately proposing the thickness of the intake valve, while simultaneously improving valve responsiveness and reducing the impact force on the piston by lowering the weight of the intake valve.

[0022] In particular, the purpose is to provide a linear compressor that can prevent the stress acting on the bridge from increasing beyond a set stress while controlling the opening amount of the intake valve to an appropriate level by appropriately proposing the width of a bridge connecting a shielding part that opens and closes the port of a piston among the intake valves and a fastening part to which a fastening member is coupled.

[0023] A linear compressor according to an embodiment of the present invention may include a cylinder forming a compression space, a piston inserted into the cylinder and having a suction port for sucking refrigerant into the compression space, and a suction valve for opening or closing the suction port to control the amount of refrigerant sucked into the compression space.

[0024] The above piston may include a valve wall facing the compression space and a valve seating surface formed at a step on the valve wall on which the suction valve is seated.

[0025] With this configuration, the height at which the suction valve protrudes from the valve wall can be reduced, thereby preventing the suction valve from being damaged by collision with surrounding structures during the refrigerant compression process.

[0026] The above piston further includes a recess connected to the suction port, which is formed with a greater step from the seating surface, and the recess may be formed between the suction port and the seating surface.

[0027] The cross-sectional area of ​​the recess can be formed to be larger than the cross-sectional area of ​​the suction port. With this configuration, the refrigerant inside the piston can act on the suction valve over a relatively large area through the recess, thereby facilitating the opening of the suction valve and increasing suction efficiency.

[0028] The axial depth of the above-mentioned depression may be formed to be equal to the thickness of the suction valve or slightly larger than the thickness of the suction valve.

[0029] The valve wall of the above piston includes a first wall part having a ring shape, and the seating surface may be formed with a step on the inner circumference side of the first wall part.

[0030] The above-mentioned seating surface has a ring shape, and the above-mentioned first wall part can surround the above-mentioned seating surface.

[0031] The above-mentioned recess is formed with a step on the inner circumference side of the above-mentioned seating surface, and the bottom surface of the above-mentioned recess can form a port surface where the suction port is formed.

[0032] The above piston includes a fastening hole into which a fastening member is inserted for coupling with the above intake valve, and the fastening hole may be formed in a second wall part provided on the inner side of the above recess.

[0033] The axial height of the second wall part may be the same as the axial height of the seating surface. That is, the seating surface and the second wall part may be located on the same plane.

[0034] The above suction port includes a plurality of suction ports, and the plurality of suction ports may include a first port group and a second port group separated from each other based on an extension line passing through the center of the fastening hole.

[0035] The first port group and the second port group may have shapes that are symmetrical to each other with respect to the extension line.

[0036] The first port group and the second port group may each include a plurality of ports.

[0037] The distance between the first port group and the second port group may be greater than the distance between multiple ports provided in the first port group and the second port group, respectively.

[0038] The number of ports and the positions of the ports provided in the first port group and the second port group can be determined to reduce the opening amount of the suction valve, thereby reducing the stress applied to the suction valve and securing a sufficient safety factor relative to the material fatigue limit of the suction valve.

[0039] The first port group and the second port group may each include five or more ports. For example, the first port group and the second port group may each include six ports.

[0040] The suction valve may include a shield having a size capable of covering the plurality of suction ports. The shield may have a ring shape.

[0041] The shielding member may include a first shielding member configured to shield a plurality of ports constituting the first port group and a second shielding member configured to shield a plurality of ports constituting the second port group.

[0042] The suction valve may include a fastening portion having a fastening hole into which the fastening member is coupled, provided in the inner space of the shielding portion.

[0043] The above-mentioned fastening portion may include a guide groove in which an assembly pin (a component of the manufacturing device) required for aligning the suction valve with the piston is located. The guide groove may have a shape that is recessed from the outer surface of the fastening portion. Multiple guide grooves may be provided on both sides of the fastening portion.

[0044] The suction valve further includes a bridge connecting the shielding part and the connecting part, and the shielding part may be supported by the connecting part by the bridge when performing an opening and closing operation.

[0045] The above bridge can connect the outer surface of the fastening part and the inner surface of the shielding part. The above bridge may be provided in multiple numbers on both sides of the fastening part.

[0046] The radial thickness of the above bridge can be determined to an appropriate value so that it allows for smooth opening of the shielding portion (allowing for an opening amount of a set size) while simultaneously ensuring that the stress caused by bending in the bridge acts at a level below the set stress.

[0047] In one aspect of the present invention, a linear compressor may include: a cylinder forming a compression space; a piston inserted into the cylinder and reciprocating axially to form a suction port for drawing refrigerant into the compression space; and a suction valve installed on the piston to open or close the suction port.

[0048] The above piston may include a recess connected to the suction port and having a radial width greater than the radial width of the suction port.

[0049] The above-mentioned depression may be formed at the end of the piston where the suction valve is seated.

[0050] The recess may be formed between the suction valve and the suction port so that the refrigerant passing through the suction port flows into the recess.

[0051] The axial depth of the above-mentioned depression can be formed to be greater than the axial thickness of the above-mentioned suction valve.

[0052] The above piston includes a valve wall in which the suction port is formed, and the valve wall may include a first stepped portion extending axially from the end of the valve wall and a valve seating surface connected to the first stepped portion and extending radially, on which the suction valve is seated.

[0053] The valve wall may include a second stepped portion extending further in the axial direction from the valve seating surface and a port surface connected to the second stepped portion and having the suction port formed therein.

[0054] The above-mentioned recess may be defined by the second step portion and the port surface so as to be recessed from the valve seating surface.

[0055] The above piston includes a second wall part that forms a fastening hole to which a valve fastening member is coupled, and the second wall part may provide an additional seating surface on which the suction valve is placed.

[0056] The above-mentioned second wall part further includes a second step portion extending further in the axial direction, and the second step portion may be connected to a port surface forming the suction port.

[0057] The suction port includes a first port group and a second port group, each having a plurality of ports, and the first port group and the second port group may be arranged to face each other based on a radial extension line passing through the center of the valve wall.

[0058] The first port group and the second port group may be arranged symmetrically with respect to the radial extension line.

[0059] The gap (S2) between the first port group and the second port group is characterized by being larger than the gap between multiple ports constituting the first port group or the gap between multiple ports constituting the second port group.

[0060] The piston includes a piston body extending in the axial direction and three piston flanges extending radially from the piston body, and among the three extension lines connecting the three piston flanges at the center of the piston, one extension line can be projected to pass through the area (A1) of the first port group and the other two extension lines can be projected to pass through the area (A2) of the second port group.

[0061] The first port group and the second port group may each be configured to include six ports.

[0062] The suction valve may include a port shielding part movably provided to open and close the suction port, a fastening part connected to the piston, and two bridges connecting the shielding part and the fastening part.

[0063] In another aspect of the present invention, a linear compressor may include a cylinder forming a compression space; a piston inserted into the cylinder and reciprocating axially, forming a plurality of suction ports for drawing refrigerant into the compression space; and a suction valve installed on the piston and opening or closing the plurality of suction ports.

[0064] The suction valve may include a ring-shaped port shield provided to be movably provided to open and close the plurality of suction ports, a fastening part provided on the inner side of the port shield and to which a valve fastening member is coupled, and a bridge connecting the port shield and the fastening part.

[0065] The above plurality of suction ports each include a first port group and a second port group composed of a plurality of ports, and the port shielding part may include a first shielding part that opens and closes the first port group and a second shielding part that opens and closes the second port group.

[0066] The above port shielding part may include a connection part provided between the first shielding part and the second shielding part and to which the bridge is connected.

[0067] The above bridge extends from the outer surface of the above-mentioned fastening part toward the inner surface of the above-mentioned port shielding part, and the radial width of the above-mentioned bridge can be varied in the direction toward the inner surface of the above-mentioned port shielding part.

[0068] The radial first width (w1) of the first point of the bridge adjacent to the above-mentioned fastening part may be larger than the radial second width (w2) of the second point between the first point and the inner circumference of the port shielding part.

[0069] The radial third width (w3) of the third point between the second point and the inner surface of the port shielding part may be larger than the radial second width (w2).

[0070] The outer surface of the above-mentioned fastening part includes first to fourth surfaces, and the first and second surfaces have assembly guide grooves formed therein for preventing misassembly of the suction valve, and the bridge can be connected to the third and fourth surfaces, respectively.

[0071] The above piston may include a valve seating surface on which the suction valve is seated; and a recess formed with a step between the suction port and the valve seating surface and having a cross-sectional area larger than the cross-sectional area of ​​the suction port.

[0072] According to an embodiment of the present invention, the structure of the intake valve and piston is improved to increase intake efficiency and prevent damage to the valve.

[0073] According to an embodiment of the present invention, by appropriately proposing the size and number of suction ports formed in the piston, the amount of refrigerant sucked in can be increased while reducing deformation caused by bulging of the suction valve.

[0074] According to an embodiment of the present invention, by proposing the positions of a plurality of suction ports formed in the piston, the suction efficiency of the piston can be improved and the opening amount of the suction valve can be appropriately adjusted.

[0075] According to an embodiment of the present invention, by proposing a shape for the intake valve, the opening amount of the intake valve is reduced, and accordingly, the intake valve can be prevented from bending or being damaged by impact to the piston.

[0076] According to an embodiment of the present invention, the valve seating surface of the piston is formed with a step so that a collision between the intake valve and the discharge valve can be prevented when the refrigerant is compressed in the compression space of the cylinder.

[0077] According to an embodiment of the present invention, a recess having a cross-sectional area larger than the cross-sectional area of ​​the port is formed between the suction valve and the suction port, thereby reducing the contact area between the suction valve and the piston and ensuring that the pressure of the suction refrigerant acts evenly on the suction valve, so as to improve suction efficiency.

[0078] According to an embodiment of the present invention, by appropriately proposing the axial depth of the depression, it is possible to prevent the amount by which the suction valve is pressed into the depression when the refrigerant is compressed in the time domain where high pressure acts, that is, in the compression space.

[0079] According to an embodiment of the present invention, by appropriately proposing the thickness of the intake valve, the rigidity of the intake valve can be maintained well, and at the same time, the weight of the intake valve can be reduced to improve the responsiveness of the valve and reduce the impact on the piston.

[0080] In particular, by appropriately proposing the width of a bridge connecting a shielding part that opens and closes the intake port of a piston among intake valves and a fastening part to which a fastening member is coupled, it is possible to control the opening amount of the intake valve to an appropriate level while preventing the stress acting on the bridge from increasing beyond a set stress.

[0081] FIG. 1 is a cross-sectional view of a linear compressor according to an embodiment of the present invention.

[0082] FIG. 2 is an exploded perspective view showing the configuration of a discharge cover assembly and a discharge valve assembly according to an embodiment of the present invention.

[0083] FIG. 3 is an exploded perspective view showing the configuration of a cylinder, a frame, and a piston according to an embodiment of the present invention.

[0084] Figure 4 is a cross-sectional view taken along 4-4 ​​of Figure 1.

[0085] FIG. 5 is a perspective view showing a suction valve coupled to a piston according to an embodiment of the present invention.

[0086] FIG. 6 is an exploded perspective view of a piston and a suction valve according to an embodiment of the present invention.

[0087] Figure 7 is an enlarged view of section "A" of Figure 6.

[0088] FIG. 8 is a rear view of a piston according to an embodiment of the present invention, viewed from the rear.

[0089] FIG. 9 is a front view showing the valve wall configuration of a piston according to an embodiment of the present invention.

[0090] Figure 10 is a cross-sectional view taken along 10-10 of Figure 6.

[0091] Figure 11 is an enlarged cross-sectional view of section "B" of Figure 10.

[0092] FIG. 12 is a perspective view of a suction valve according to an embodiment of the present invention.

[0093] FIG. 13 is a front view of an intake valve according to an embodiment of the present invention.

[0094] FIG. 14 is a front view showing a suction valve installed on a piston according to an embodiment of the present invention.

[0095] FIG. 15 is a schematic diagram showing the combined appearance of a piston and an intake valve according to an embodiment of the present invention.

[0096] FIG. 16 is a schematic diagram showing the suction valve in an open state according to an embodiment of the present invention.

[0097] FIG. 17 is a cross-sectional view showing the flow of compressed refrigerant from the compression space of a cylinder to the discharge cover according to an embodiment of the present invention.

[0098] Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. It should be noted that in assigning reference numerals to the components of each drawing, the same components are given the same reference numeral whenever possible, even if they are shown in different drawings. Furthermore, in describing the embodiments of the present invention, if it is determined that a detailed description of related known components or functions would hinder understanding of the embodiments of the present invention, such detailed description is omitted.

[0099] In addition, terms such as first, second, A, B, (a), (b), etc., may be used when describing the components of the embodiments of the present invention. These terms are intended only to distinguish the components from other components, and the essence, order, or sequence of the components is not limited by the terms. Where it is stated that a component is "connected," "combined," or "connected" to another component, it should be understood that the component may be directly connected or connected to the other component, but that another component may also be "connected," "combined," or "connected" between each component.

[0100] FIG. 1 is a cross-sectional view of a linear compressor according to an embodiment of the present invention, FIG. 2 is an exploded perspective view showing the configuration of a discharge cover assembly and a discharge valve assembly according to an embodiment of the present invention, FIG. 3 is an exploded perspective view showing the configuration of a cylinder, a frame, and a piston according to an embodiment of the present invention, and FIG. 4 is a cross-sectional view taken along 4-4 ​​of FIG. 1.

[0101] Referring to FIGS. 1 to 4, a linear compressor (10) according to an embodiment of the present invention may include a shell (11) and a first shell cover (12) and a second shell cover (13) coupled to both sides of the shell (11). In a broad sense, the first shell cover (12) and the second shell cover (13) may be understood as components of the shell (11).

[0102] The shell (11) has a roughly cylindrical shape and can be arranged in a horizontally lying position or in an axially lying position. Based on FIG. 1, the shell (11) is extended horizontally and may have a somewhat lower height in the radial direction.

[0103] Since the linear compressor (10) can have a low height, for example, when the linear compressor (10) is installed on the base of the machine room of a refrigerator, there is an advantage that the height of the machine room can be reduced.

[0104] The above linear compressor (10) may include a plurality of pipes that are provided in the shell (11) or shell cover (12, 13) and can suck in, discharge, or inject refrigerant.

[0105] The plurality of pipes may include a suction pipe (14) that allows the refrigerant to be sucked into the interior of the linear compressor (10). The suction pipe (14) may be connected to the first shell cover (12). The refrigerant may be sucked into the interior of the linear compressor (10) along the axial direction through the suction pipe (14).

[0106] The plurality of pipes may further include a discharge pipe (not shown) for allowing compressed refrigerant to be discharged from the linear compressor (10) and a process pipe (not shown) for replenishing refrigerant to the linear compressor (10). For example, the discharge pipe and the process pipe may be connected to the outer surface of the shell (11).

[0107] Support devices (20, 90) that support the main body of the linear compressor (10) may be included on both sides of the shell (11). The support devices (20, 90) may include a first support device (20) that is coupled to the first shell cover (12) and elastically supports the main body of the linear compressor (10).

[0108] Here, the main body of the compressor refers to a component provided inside the shell (11), and may include, for example, a drive unit that moves back and forth and a support unit that supports the drive unit. The drive unit may include a piston (500), a permanent magnet (45), a supporter (33), and an intake muffler (25), etc. And, the support unit may include a resonant spring (30), a rear cover (31), a stator cover (32), a first support device (20), and a second support device (90), etc.

[0109] The first support device (20) may include a support bracket (21a) communicating with the suction pipe (14) and a support spring (21b) coupled to the support bracket (21a) and supported by the rear cover (31).

[0110] The above support device (20, 90) may include a second support device (90) that is coupled to the shell (11) and supports the discharge cover assembly.

[0111] The above linear compressor (10) may include a frame (50) provided inside the compressor shell (11) and a cylinder (60) inserted inside the frame (50).

[0112] The frame (50) is understood as a configuration for fixing the cylinder (60). For example, the cylinder (60) may be pressed into the inside of the frame (50). The cylinder (60) and the frame (50) may be made of a metal material, for example, aluminum or an aluminum alloy.

[0113] The frame (50) is positioned to surround the cylinder (60). That is, the cylinder (60) can be positioned to be received inside the frame (50).

[0114] The above frame (50) has a hollow cylindrical shape and includes a frame body (51) that extends axially to allow the cylinder (60) to be inserted, and a frame flange (52) that extends radially outward from the front portion of the frame body (51).

[0115] Defines the direction.

[0116] "Axial direction" can be understood as the direction in which the piston (500) reciprocates, i.e., the up-and-down direction in FIG. 4. Among the "axial directions," the direction from the piston (500) toward the compression space (P) of the cylinder (60), i.e., the direction in which the refrigerant flows, is defined as "forward," and the opposite direction is defined as "rear." When the piston (500) moves forward, the compression space (P) is reduced, and when it moves rearward, the compression space (P) can be expanded.

[0117] On the other hand, "radial direction" is a direction perpendicular to the direction in which the piston (500) reciprocates, and can be understood as the horizontal direction in FIG. 4.

[0118] The above frame (50) may include a frame ledge (53) formed in the boundary area between the frame body (51) and the frame flange (52). The frame ledge (53) may include a support surface facing forward so as to support the rear end of the cylinder flange (62). The frame ledge (53) may extend in a circumferential direction to have a ring shape.

[0119] A cylinder sealing member (82) may be provided between the frame (50) and the cylinder (60). By means of the cylinder sealing member (82), the adhesion force may be increased during the press-fitting process between the frame (50) and the cylinder (60).

[0120] The cylinder sealing member (82) has a ring shape and can be installed on the inner surface of the frame (50) where the cylinder flange (62) of the cylinder (60) is seated, that is, on the frame jaw (53).

[0121] The above frame (50) may have a bearing channel (58) formed therein that extends axially from the frame flange (52) toward the frame body (51). A refrigerant acting as a gas bearing among the compressed discharge gas may flow through the bearing channel (58).

[0122] The refrigerant acting as the gas bearing is supplied between the cylinder body (61) of the cylinder (60) and the piston (500) to cause the piston (500) to float inside the cylinder (60).

[0123] The above-mentioned frame flange (52) may include fastening holes (55, 56) into which a predetermined fastening member is coupled for fastening the frame (50) and surrounding parts. A plurality of the fastening holes (55, 56) may each be arranged in the outer circumference of the frame flange (52).

[0124] The above fastening holes (55, 56) may include a first fastening hole (55) to which a predetermined fastening member is coupled for fastening the third discharge cover (300) and the frame (50). A plurality of the first fastening holes (55) may be spaced apart in the circumferential direction. For example, three first fastening holes (55) may be formed.

[0125] The above fastening holes (55, 56) may include a second fastening hole (56) to which a fastening member for fastening the frame (50) and the stator cover (32) is coupled. A plurality of the second fastening holes (56) may be spaced apart in the circumferential direction. For example, three of the second fastening holes (56) may be formed.

[0126] Since the plurality of first and second fastening holes (55, 56) are evenly arranged in the circumferential direction of the frame flange (52), the frame (50) is supported at three points by surrounding parts, namely the stator cover (32) and the third discharge cover (300), and can be stably joined.

[0127] The above frame flange (52) may include a terminal insertion part (57) that provides an extraction path for the terminal portion of the motor assembly (41, 43, 45). The terminal insertion part (57) is formed such that at least a portion of the frame flange (52) is cut in the front-rear direction, and a plurality of them may be provided and arranged in the circumferential direction.

[0128] The above cylinder (60) may include a cylinder body (61) extending in the axial direction and a cylinder flange (62) provided on the outer front side of the cylinder body (61).

[0129] The above cylinder body (61) has a cylindrical shape defined with respect to an axial central axis so that a piston (500) can be inserted, and can be inserted into the interior of the above frame body (51).

[0130] The cylinder flange (62) may be configured to extend in a circumferential direction to have a ring shape. The cylinder flange (62) may include a stepped projection to support surrounding parts.

[0131] In detail, the cylinder flange (62) may include a first flange (63) that supports the discharge valve assembly (400). The first flange (63) may include a first support surface facing forward to support the rear end of the discharge valve assembly (400). For example, the first flange (63) may have a ring shape extending in the circumferential direction.

[0132] The cylinder flange (62) may include a second flange (64) that supports the sealing bracket (85). The second flange (64) may include a second support surface facing forward to support the rear end of the sealing bracket (85). For example, the second flange (64) may have a ring shape extending in the circumferential direction.

[0133] The second jaw (64) may be located behind the first jaw (63).

[0134] The outer diameter of the second jaw (64) can be formed to be larger than the outer diameter of the first jaw (63).

[0135] The above linear compressor (10) includes a piston (500) that moves in a reciprocating linear motion inside the cylinder (60). The piston (500) can move in an axial direction.

[0136] The above linear compressor (10) may further include a suction muffler (25) coupled to the piston (500) to reduce noise generated from the refrigerant sucked through the suction pipe (14).

[0137] The refrigerant sucked in through the suction pipe (14) flows into the interior of the piston (500) via the suction muffler (25). For example, as the refrigerant passes through the suction muffler (25), the flow noise of the refrigerant can be reduced. The suction muffler (25) may be composed of a plurality of mufflers combined.

[0138] The above linear compressor (10) may include a motor assembly (41, 43, 45) as a linear motor that provides driving force to the piston (500).

[0139] The motor assembly may include an outer stator (41) fixed to the frame (50) and arranged to surround the cylinder (60), an inner stator (43) spaced apart from the inner side of the outer stator (41), and a permanent magnet (45) located in the space between the outer stator (41) and the inner stator (43).

[0140] A stator cover (32) is provided on one side of the outer stator (41). That is, one side of the outer stator (41) is supported by the frame (50), and the other side can be supported by the stator cover (32).

[0141] The permanent magnet (45) can move in a linear reciprocating motion due to the mutual electromagnetic force with the outer stator (41) and the inner stator (43). The permanent magnet (45) may be composed of a single magnet having one pole or may be composed of a plurality of magnets having three poles combined.

[0142] The above permanent magnet (45) can be installed in a magnet frame (46). The magnet frame (46) has a roughly cylindrical shape and can be positioned to be inserted into the space between the outer stator (41) and the inner stator (43).

[0143] The magnet frame (46) is coupled to the piston (500), and when the permanent magnet (45) reciprocates, the piston (500) can reciprocate in the axial direction together with the permanent magnet (45).

[0144] The linear compressor (10) may further include a supporter (33) that supports the piston (500). The supporter (33) is coupled to the rear side of the piston (500) and may be positioned so that the intake muffler (25) passes through its inner side. The piston (500), the magnet frame (46), and the supporter (33) may be connected by a fastening member.

[0145] The linear compressor (10) may further include a rear cover (31) that is coupled to the stator cover (32), extends rearward, and is supported by a first support device (20). The rear cover (31) may be spring-supported by the supporter (33).

[0146] The rear cover (31) may include a plurality of support legs that are coupled to the rear of the stator cover (32).

[0147] The above linear compressor (10) further includes an inlet guide part (23) that is coupled to the rear cover (31) and guides the inflow of refrigerant into the intake muffler (25).

[0148] The above linear compressor (10) may further include a plurality of resonant springs (30) each having a natural frequency adjusted so that the piston (500) can resonate.

[0149] The plurality of resonant springs (30) may include a plurality of first resonant springs supported between the supporter (33) and the stator cover (32) and a plurality of second resonant springs supported between the supporter (33) and the rear cover (31). Through the action of the plurality of resonant springs (30), stable movement of the drive unit reciprocating inside the linear compressor (10) is performed, and vibration or noise generation due to the movement of the drive unit can be reduced.

[0150] Inside the cylinder (60), a compression space (P) in which the refrigerant is compressed by the piston (500) may be formed. On the valve wall (513, see FIG. 6) of the piston (500), a suction port (516, see FIG. 6) is formed as a suction opening for introducing the refrigerant into the compression space (P), and a suction valve (550) for selectively opening the suction port (516) may be provided in front of the suction port (516).

[0151] The suction ports (516) may be provided in multiple numbers. The multiple suction ports (516) are spaced apart in the circumferential direction of the piston (500), and the refrigerant flowing inside the piston (500) is introduced into the compression space (P) through the multiple suction ports (516).

[0152] The suction valve (550) may be coupled to the front of the piston (500) by a valve fastening member (590), such as a screw or a bolt. The piston (500) may include a fastening hole (517, see FIG. 6) into which the valve fastening member (590) is inserted. For example, the fastening hole (517) may be formed approximately in the center of the piston (500).

[0153] In front of the compression space (P), a discharge cover assembly (100, 200, 300) forming a discharge space for the refrigerant discharged from the compression space (P) may be provided. The discharge cover assembly (100, 200, 300) may be positioned in front of the frame (50).

[0154] The above discharge cover assembly may include a first discharge cover (100) and a second discharge cover (200) supported on the front of the frame (50). The first discharge cover (100) may be positioned inside the second discharge cover (200).

[0155] For example, the first discharge cover (100) can be press-fitted and fixed to the second discharge cover (200). The cover flange (150) of the first discharge cover (100) can be press-fitted into the inner surface of the cover flange (250) of the second discharge cover (200).

[0156] In detail, the cover flange (150) of the first discharge cover (100) can be pressed into the inner surface of the cover flange (250) of the second discharge cover (200).

[0157] The first discharge cover (100) is pressed into the second discharge cover (200), thereby enabling a secure fixation of the first and second discharge covers (100, 200).

[0158] The internal space of the first discharge cover (100) and the internal space of the second discharge cover (200) can form a discharge path (also referred to as a "discharge room") for the refrigerant discharged from the compression space (P). For example, the refrigerant discharged from the compression space (P) can flow through the internal space of the first discharge cover (100), be discharged from the first discharge cover (100), and flow into the internal space of the second discharge cover (200).

[0159] The above discharge cover assembly may include a damping member (180) for reducing vibration of the first and second covers (100, 200).

[0160] The damping member (180) may be composed of a deformable material. For example, the damping member (180) may be composed of a rubber material. The damping member (180) may be composed of a rubber material having heat resistance capable of withstanding the high temperature of the discharged gas.

[0161] The damping member (180) is mounted on the first discharge cover (100), and the second discharge cover (200) may be configured to support or press the damping member (180).

[0162] The damping member (180) can offset the magnitude of vibration and noise transmitted from one of the first and second discharge covers (100, 200) to the other. In particular, when the discharge valve (410) is turned on and off, the effect of reducing the magnitude of the valve tapping sound that is frictionally applied to the cylinder (60) can be expected.

[0163] The above discharge cover assembly may include a third discharge cover (300) that supports the second discharge cover (200).

[0164] The third discharge cover (300) may have a roughly ring shape and be positioned to surround the rear portion of the second discharge cover (200). The third discharge cover (300) may support the cover flange (250) of the second discharge cover (200).

[0165] The third discharge cover (300) can be supported on the front of the frame (50).

[0166] The third discharge cover (300) is fastened to the frame flange (52) by a fastening member (not shown), and the front surface of the frame flange (52) can come into surface contact with the rear surface of the third discharge cover (300).

[0167] The third discharge cover (300) may include a cover body (310) having a ring shape and a cover flange (330) extending radially outward from the cover body (310). The cover flange (330) may include a support surface supported by the frame (50).

[0168] A cover fastening hole (335) may be formed in the above cover flange (330) at a position corresponding to the frame fastening hole (55). The fastening member may be fastened to the first fastening hole (55) of the frame (50) and the cover fastening hole (335) to fix the frame (50) and the third discharge cover (300).

[0169] A frame sealing member (81) capable of increasing bonding strength and preventing leakage of refrigerant may be provided at the portion where the second discharge cover (200) and the frame (50) are in surface contact.

[0170] The above-mentioned frame sealing member (81) has a ring shape and can be installed between the rear surface of the second discharge cover (200) and the front surface of the frame (50). For example, the above-mentioned frame sealing member (81) can be installed between the front surface of the frame flange (52) and the cover flange (250) of the second discharge cover (200).

[0171] The linear compressor (10) may include a discharge valve assembly (400). The discharge valve assembly (400) may include a discharge valve (410) and a spring assembly (420) that provides elastic force to the discharge valve (410) in a direction that brings it into close contact with the front end of the cylinder (60).

[0172] The discharge valve (410) may, for example, have the shape of a disc and may include an avoidance groove (413) that is recessed from the rear portion toward the front. The avoidance groove (413) is understood as an "interference prevention groove" that prevents at least a portion of the piston (500) from interfering with the discharge valve (410) during the process in which the piston (500) moves forward to compress the refrigerant. Here, at least a portion of the piston (500) may include a valve fastening member (590) for fastening the suction valve (550) to the piston (500).

[0173] The above spring assembly (420) may include a valve spring (430) composed of a leaf spring and a spring bracket (450) that surrounds the edge of the valve spring (430) to support the valve spring (430).

[0174] The discharge valve (410) is coupled to the central part of the valve spring (430).

[0175] The discharge valve (410) opens when the pressure in the compression space (P) exceeds the discharge pressure, and the refrigerant compressed in the compression space (P) of the cylinder (60) is discharged and flows into the internal space of the first discharge cover (100). At this time, the valve spring (430) can be deformed in a direction that opens the discharge valve (410).

[0176] When the discharge of the refrigerant is completed, the discharge valve (450) can be closed by the restoring force of the valve spring (430).

[0177] The rim portion of the spring bracket (450) can be seated on the inner surface of the first discharge cover (100). The rear end of the spring bracket (450) can be seated on the first flange (63) of the cylinder flange (62).

[0178] A sealing bracket (85) may be installed around the front end of the cylinder (60). For example, the sealing bracket (85) may have a ring shape or a hollow cylindrical shape and may be positioned to surround at least a portion of the cylinder flange (62).

[0179] The sealing bracket (85) is seated on the second flange (64) of the cylinder flange (62) and can be supported on the rear surface of the spring bracket (450).

[0180] A bracket sealing member (83) may be provided between the sealing bracket (85) and the second flange (64) of the cylinder flange (62). The bracket sealing member (83) is provided on the contact surface between the sealing bracket (85) and the cylinder flange (62) and can prevent refrigerant from leaking through the space between the cylinder (60) and the spring assembly (420). The bracket sealing member (83) may have a ring shape.

[0181] Below, the configuration of the piston (500) and suction valve (550) is described in more detail with reference to the drawings.

[0182] FIG. 5 is a perspective view showing an intake valve coupled to a piston according to an embodiment of the present invention, FIG. 6 is an exploded perspective view of a piston and an intake valve according to an embodiment of the present invention, FIG. 7 is an enlarged view of section "A" of FIG. 6, FIG. 8 is a rear view of a piston according to an embodiment of the present invention viewed from the rear, FIG. 9 is a front view showing the valve wall configuration of a piston according to an embodiment of the present invention, FIG. 10 is a cross-sectional view cut along 10-10 of FIG. 6, and FIG. 11 is an enlarged cross-sectional view of section "B" of FIG. 10.

[0183] Referring to FIGS. 5 to 11, a linear compressor (10) according to an embodiment of the present invention may include a piston assembly (500, 550, 590) provided to be reciprocally movable in the axial direction, i.e., in the forward and backward direction, inside a cylinder (60).

[0184] The above piston assembly may include a piston (500), an intake valve (550) coupled to the front of the piston (500), and a valve fastening member (590) for coupling the intake valve (550) to a fastening hole (517) of the piston (500).

[0185] The above fastening hole (517) may be formed approximately in the center of the valve wall (513) of the piston (500). The valve fastening member (590) may pass through the through hole (573) of the suction valve (550) and be coupled to the fastening hole (517).

[0186] The valve wall (513) can form the front portion of the piston (500).

[0187] The above piston (130) may include a piston body (510) having a length extending in the axial direction and a piston flange (520) extending radially outward from the piston body (510).

[0188] The piston body (510) has the shape of a cylinder with a hollow interior, and a refrigerant passage (511) through which the refrigerant sucked into the linear compressor (10) flows can be formed inside the piston body (510).

[0189] The rear end of the piston body (510) is open so that the refrigerant can be sucked in. At least a portion of the suction muffler (25) can be inserted into the interior of the piston body (510) through the opened rear end of the piston body (510).

[0190] For example, at least a portion of the suction muffler (25) may be located in the refrigerant passage (511). The refrigerant passing through the suction muffler (25) may flow into the suction port (516) of the piston (500).

[0191] The above piston body (510) is inserted into the interior of the cylinder (60) and can reciprocate in the forward and backward directions.

[0192] The piston flange (520) may include a flange body (521) extending radially outward from the rear end of the piston body (510) and a flange fastening part (523) extending further radially outward from the flange body (521).

[0193] The above flange fastening portion (523) may include a fastening hole (524) into which a predetermined fastening member is coupled. The fastening member may pass through the fastening hole (524) and be coupled to the magnet frame (46) and the supporter (33).

[0194] The above flange fastening portions (523) are provided in multiple numbers, and the multiple flange fastening portions (523) may be spaced apart from each other and arranged on the outer surface of the flange body (132a). For example, the multiple flange fastening portions (523) may be provided in three numbers, and the piston (500) may be supported at three points on a surrounding structure.

[0195] The above fastening hole (524) is formed in each flange fastening part (523) and may include first to third fastening holes (524a, 524b, 524c).

[0196] The piston (500) may include a valve wall (513) that forms the front portion of the piston body (510) and has a seating surface on which the suction valve (550) is placed. The valve wall (513) may have a set thickness in the axial direction.

[0197] The valve wall (513) may include a suction port (516) that is selectively opened or closed by the suction valve (550). When the suction port (516) is opened, the refrigerant in the refrigerant path (511) can be sucked into the compression space (P) of the cylinder (60) through the suction port (516).

[0198] A plurality of suction ports (516) are formed, and the plurality of suction ports (516) are formed on the outer side of the fastening hole (517). The plurality of suction ports (516) may be arranged to surround the fastening hole (517).

[0199] The above multiple suction ports (516) may have the same size (diameter) as each other.

[0200] When defining a radial extension line (ℓ1) that bisects the valve wall (513), the plurality of suction ports (516) can be evenly distributed on both sides of the valve wall (513) based on the extension line (ℓ1).

[0201] In detail, the plurality of suction ports (516) may include a first port group (516a) and a second port group (516b) separated from each other based on an extension line (ℓ1) passing through the center (C) of the valve wall (513), that is, the center of the fastening hole (517).

[0202] The first port group (516a) is formed in a first area (A1) defined on one side of the extension line (ℓ1) within the area of ​​the valve wall (513), and the second port group (516b) may be formed in a second area (A2) defined on the other side of the extension line (ℓ1) within the area of ​​the valve wall (513).

[0203] The first port group (516a) and the second port group (516b) may have shapes that are symmetrical to each other with respect to the extension line (ℓ1).

[0204] When defining three extension lines (ℓ2~ℓ4) that extend from the center (C) of the valve wall (513) to the center of the first to third fastening holes (524a, 524b, 524cd) of the piston flange (520), one of the three extension lines (ℓ2~ℓ4) may be projected to pass through the first area (A1) of the first port group (516a), and the remaining two extension lines (ℓ3,ℓ4) may be projected to pass through the second area (A2) of the first port group (516b).

[0205] The first port group (516a) and the second port group (516b) may each include a plurality of ports.

[0206] The distance (S2) between the first port group (516a) and the second port group (516b) may be greater than the distance (S1) between multiple ports provided in the first port group (516a) and the second port group (516b).

[0207] The first extension line (ℓ1) can be extended into the space between the first area (A1) of the first port group (516a) and the second area (A2) of the second port group (516b).

[0208] The first port group (516a) and the second port group (516b) may each include five or more ports. For example, the plurality of suction ports (516) may include 12 suction ports, and the first port group (516a) and the second port group (516b) may each include six ports.

[0209] If the number of ports constituting the first port group (516a) and the second port group (516b) is too large, the opening amount of the suction valve (550) becomes excessive, increasing stress on the suction valve (550) and consequently, the valve may break.

[0210] On the other hand, if the number of ports is too small and the size of the ports is formed too large, the bulging of the valve into the port may increase due to high pressure during the compression process of the compression space (P), and the valve may break.

[0211] And, if the location of the port constituting the first and second port groups (516a, 516b) is formed at an eccentric location of the shear wall (513), the opening amount at a specific point of the suction valve (550) becomes excessive in response, and the valve may break.

[0212] Accordingly, the number and location of the ports provided in the first and second port groups (516a, 516b) according to the embodiment of the present invention can be determined to prevent excessive opening of the suction valve (550), thereby reducing the stress applied to the suction valve (550) and securing a sufficient safety factor relative to the material fatigue limit of the suction valve (550).

[0213] That is, since the plurality of suction ports (516) are evenly distributed on both sides based on the center of the valve wall (513), the amount of refrigerant that must be sucked through a single port may not be large.

[0214] In addition, by providing multiple ports, the pressure of the suction refrigerant is distributed over the entire surface area of ​​the suction valve (550), so the opening amount of the suction valve (550) can be reduced, and accordingly, the stress acting on the suction valve (550) can be reduced.

[0215] The valve wall (513) may include a first wall part (513a) forming the front portion of the piston (500). The first wall part (513a) may form at least one surface of the compression space (P).

[0216] The first wall part (513a) forms the front perimeter of the valve wall (513) and may have a ring shape.

[0217] The valve wall (513) may include a valve seating surface (514a) on which the suction valve (550) is placed. The valve seating surface (514a) is provided on the outside of the plurality of suction ports (516) and may extend in the outer circumference. For example, the valve seating surface (514a) may have a ring shape.

[0218] A port shield (560) of the suction valve (550) may be placed on the valve seating surface (514a).

[0219] The valve seating surface (514a) may be formed with a step relative to the first wall part (513a). Specifically, the valve wall (513) may include a first stepped portion (514) extending axially from the first wall part (513a).

[0220] The first stepped portion (514) extends backward in a stepped manner from the inner circumference of the first wall part (513a) and can be connected to the valve seating surface (514a).

[0221] The axial depth of the first step portion (514) may correspond to the axial thickness of the suction valve (550). Accordingly, when the suction valve (550) is placed on the valve seating surface (514a), the suction valve (550) may be restricted from protruding forward beyond the first wall part (513a), or the amount of protrusion may be reduced.

[0222] Ultimately, when the piston (500) is at the top dead center (TDC) during the process of reciprocating motion, the phenomenon in which the suction valve (550) is struck by the discharge valve (410) due to abnormal operation of the compressor can be prevented.

[0223] The valve wall (513) may include a second wall part (513b) that forms the fastening hole (517). The second wall part (513b) forms the central portion of the valve wall (513) and may be formed on the inner side of the valve seating surface (514a). For example, the front portion of the second wall part (513b) may have a circular shape.

[0224] The second wall part (513b) can form the same height as the valve seating surface (514a) based on the axial direction. That is, the shear surface of the second wall part (513b) and the valve seating surface (514a) can form the same plane.

[0225] Accordingly, at least a portion of the suction valve (550) is seated on the second wall part (513b), and the front surface of the second wall part (513b) may form another valve seating surface. For convenience of explanation, the front surface of the second wall part (513b) may be named the "first seating surface," and the valve seating surface (514a) may be named the "second seating surface."

[0226] The front surface of the second wall part (513b) and the valve seating surface (514a) may be worn out or damaged by impact during the process of the suction valve (550) being repeatedly opened and closed. To prevent such problems, the material and coating of the piston (500) may be proposed.

[0227] The above piston (500) may be made of aluminum or an aluminum alloy.

[0228] In order to prevent wear or damage caused by the suction valve (550), a coating portion may be provided on the shear surface of the second wall part (513b) and the valve seating surface (514a). For example, the coating portion may include a nickel-phosphorus (Ni-P) coating portion.

[0229] The valve wall (513) may include a port surface (518) on which the plurality of suction ports (516) are formed. The port surface (518) may be understood as a surface forming a first region (A1) of the first port group (516a) and a second region (A2) of the second port group (516b).

[0230] The above port surface (518) may include a first port surface (518a) forming the first region (A1) and a second port surface (518b) forming the second region (A2). The first and second port surfaces (518a, 518b) may be formed opposite each other with respect to the first extension line (ℓ1).

[0231] The above port surface (518) is formed on the outer side of the second wall part (513b) and can be arranged to surround the second wall part (513b). For example, the port surface (518) may have a ring shape.

[0232] The above port surface (518) may be formed with a step relative to the valve seating surface (514a) and the second wall part (513b). Specifically, the valve wall (513) may include a second stepped portion (515) extending axially from the valve seating surface (514a) and the second wall part (513b).

[0233] The second step portion (515) may include an outer step portion (515a) that extends backward in a stepped manner from the inner side of the valve seating surface (514a) and is connected to the port surface (518).

[0234] The second step portion (515) may include an inner step portion (515b) that extends backward from the outer side of the second wall part (513b) in a stepped manner and is connected to the port surface (518).

[0235] The above outer periphery step portion (515a) and the above inner periphery step portion (515b) may have the same depth with respect to the axial direction.

[0236] A recessed portion (519, see FIG. 15) is formed by the above port surface (518) and the above second step portion (515), and the recessed portion (519) can define the exit side flow path of the above suction port (516).

[0237] The radial width of the above port surface (518) can be formed to be larger than the diameter of the above suction port (516). Accordingly, when the refrigerant passing through the suction port (516) flows through the above recess (519), the flow cross-sectional area increases, thereby increasing the pressure area applied to the suction valve (550), and accordingly, the opening amount of the suction valve (550) can be increased.

[0238] The rear end of the valve wall (513) forms an inner wall portion (513c), and the inner wall portion (513c) can define the front end of the refrigerant path (511).

[0239] The suction port (516) may be formed to penetrate the valve wall (513). Specifically, the suction port (516) may be formed to penetrate from the inner wall portion (513c) to the port surface (518) of the valve wall (513).

[0240] An intake valve (550) may be installed on the piston (500). The intake valve (550) is seated on the valve wall (513) and may be fastened to the fastening hole (517) by the valve fastening member (590).

[0241] The suction valve (550) may include a port shielding part (560) that is movably raised to open and close the plurality of suction ports (516), a fastening part (570) that forms a through hole (573) through which the valve fastening member (590) passes, and a bridge (580) connecting the port shielding part (560) and the fastening part (570).

[0242] The thickness of the suction valve (550) can be designed to improve the opening amount and responsiveness while reducing breakage. If the thickness is too small, the opening amount may increase and responsiveness may be improved, but there is a risk of breakage due to bending and impact occurring during the opening and closing process.

[0243] On the other hand, if the thickness is too large, the possibility of fracture is reduced and the safety factor can be improved, but there is a problem in that the opening amount is reduced, the suction efficiency is lowered and the opening / closing responsiveness is reduced. Therefore, the suction valve (550) according to the embodiment of the present invention can be designed to have an appropriate level of thickness.

[0244] Below, the suction valve (550) will be described in more detail with reference to the drawings.

[0245] FIG. 12 is a perspective view of an intake valve according to an embodiment of the present invention, FIG. 13 is a front view of an intake valve according to an embodiment of the present invention, and FIG. 14 is a front view showing an intake valve installed on a piston according to an embodiment of the present invention.

[0246] Referring to FIGS. 12 to 14, the suction valve (550) according to an embodiment of the present invention may be connected to the piston (500) and provided to be movably capable of opening or closing the suction port (516) of the piston (500).

[0247] The suction valve (550) may include a port shielding part (560) that is placed on the valve mounting surface (514a) and opens and closes the plurality of suction ports (516). The port shielding part (560) may have an area greater than that of the suction port (516) and the port surface (518) so as to cover the suction port (516) and the port surface (518).

[0248] In detail, the port shielding portion (560) may have an area greater than the sum of the area of ​​the valve seating surface (514a) and the area of ​​the port surface (518).

[0249] At least a portion of the above port shielding portion (560) is seated on the valve seating surface (514a), and another portion is spaced apart from the front of the port surface (518) to cover the suction port (516) and the port surface (518).

[0250] For example, the port shielding portion (560) may have a ring shape. The port shielding portion (560) may form an outer surface portion (563a) and an inner surface portion (563b).

[0251] In detail, the port shielding portion (560) may include a first valve area (B1) having an area greater than or equal to the plurality of suction ports (516) and port surface (518) so as to cover the plurality of suction ports (516) and port surface (518). For example, the first valve area (B1) may have a ring shape.

[0252] The above port shielding portion (560) may include a second valve area (B2) having a shape corresponding to the valve seating surface (514a) so as to be placed on the valve seating surface (514a). The second valve area (B2) can be understood as an area surrounding the first valve area (B1). For example, the second valve area (B1) may have a ring shape.

[0253] The above port shielding portion (560) may include a third valve area (B3) having a shape corresponding to the edge of the second wall part (513b) so that it can be placed on the second wall part (513b). The third valve area (B3) can be understood as an inner area of ​​the first valve area (B1). For example, the second valve area (B1) may have a ring shape.

[0254] The third valve region (B3) can form the inner circumferential portion (563b) of the port shielding portion (560). The inner circumferential portion (563b) can form a circular shape.

[0255] The above port shielding portion (560) may include a first shielding portion (561) having an area greater than or equal to the first port surface (518a) and the first port group (516a) so as to cover the first port surface (518a) and the first port group (516a).

[0256] The above port shielding portion (560) may include a second shielding portion (562) having an area greater than or equal to the second port surface (518b) and the second port group (516b) so as to cover the second port surface (518b) and the second port group (516b).

[0257] The first shielding part (561) and the second shielding part (562) can be connected to each other. For example, the first and second shielding parts (561, 562) can be formed integrally.

[0258] The suction valve (550) may include a fastening portion (570) that forms a through hole (573) into which the valve fastening member (590) is fastened. The fastening portion (570) is positioned inside the port shielding portion (560), and the port shielding portion (560) may be positioned to surround the fastening portion (570).

[0259] The above-mentioned fastening portion (570) may include a fastening body (571) placed on the second wall part (513b) of the valve wall (513). At this time, the through hole (573) may be aligned with the fastening hole (517) of the piston (550). The through hole (573) may be formed in the center of the fastening body (571).

[0260] When the suction valve (550) is assembled to the piston (500), a problem may occur where it is assembled incorrectly. To prevent this problem, an assembly pin (not shown) may be used as an assembly device, and the assembly pin may guide the position of the suction valve (550).

[0261] In detail, the fastening portion (570) may include an assembly guide groove (572) in which the assembly pin is located. The assembly guide groove (572) may be formed by recessing at least a portion of the outer surface of the fastening body (571). During the assembly process of the suction valve (550), the assembly pin may be positioned to be inserted into the assembly guide groove (572).

[0262] In order to prevent shaking of the suction valve (550) during the assembly process of the suction valve (550), the assembly guide grooves (572) may be formed in multiple numbers on both sides of the fastening part (570). Multiple assembly pins may be positioned in the multiple assembly guide grooves (572).

[0263] The suction valve (550) may include a bridge (580) connecting the port shielding part (560) and the connecting part (570). The bridge (580) may extend from the outer surface of the connecting part (570) and be connected to the inner circumferential part (563b) of the port shielding part (560).

[0264] The above bridge (580) may include a plurality of bridges (581, 582). The plurality of bridges (581, 582) may include a first bridge (581) extending from a first point of the fastening part (570) to a first point of the inner surface part (563b) and a second bridge (582) extending from a second point of the fastening part (570) to a second point of the inner surface part (563b).

[0265] The outer surface of the above-mentioned fastening part (570) may include first to fourth surfaces. Two assembly guide grooves (572) may be formed on the first and second surfaces of the above-mentioned fastening part (570), and the first and second bridges (582) may be formed on the third and fourth surfaces of the above-mentioned fastening part (570).

[0266] When defining an extension line (ℓ5) that extends the center (C1) of the suction valve (550) in a first radial direction, the suction valve (550) may have a shape that is symmetrical with respect to the extension line (ℓ5). The extension line (ℓ5) can be understood as an extension line passing through the center (C1) and the first and second bridges (581, 582).

[0267] The above bridge (580) can be connected to the port shielding portion (560) in the area between the plurality of ports constituting the first port group (516a) and the plurality of ports constituting the second port group (517b).

[0268] That is, the port shielding portion (560) includes a connection portion (567) provided between the first shielding portion (561) and the second shielding portion (562), and the bridge (580) can be connected to the connection portion (567).

[0269] In detail, two connection parts (567) are provided between both ends of the first shielding part (561) and both ends of the second shielding part (562), and the first bridge (581) and the second bridge (582) can be connected to the two connection parts (567).

[0270] The above extension line (ℓ5) passes through the above connection part (567) and may not pass through the first area of ​​the first port group (516a) and the second area of ​​the second port group (517b).

[0271] When defining an extension line (ℓ6) that extends the center (C1) of the suction valve (550) in a second radial direction, the suction valve (550) may have a shape that is symmetrical with respect to the extension line (ℓ6). The extension line (ℓ6) is understood as an extension line passing through the center (C1) and the two assembly guide grooves (572), and may be perpendicular to the extension line (ℓ5).

[0272] The above bridge (580) can be configured to have a radial width (w1, w2, w3).

[0273] The radial width of the bridge (580) may change in the direction from the fastening portion (570) toward the port shielding portion (560). For example, the width of the bridge (580) may be formed to decrease and then increase in the direction from the fastening portion (570) toward the port shielding portion (560).

[0274] In detail, the first width (w1) of the first point of the bridge (580) that is close to the fastening part (570) may be larger than the width (w2) of the second point between the first point and the inner circumferential part (563b) of the port shielding part (560). With this configuration, the width of the bridge (580) gradually decreases from the fixed fastening part (570) toward the port shielding part (560), so the responsiveness of the port shielding part (560) is improved and an opening amount greater than a set level can be secured.

[0275] The width (w3) of the third point between the second point of the bridge (580) and the inner surface portion (563b) of the port shielding portion (560) may be formed to be larger than the width (w2) of the second point. The third point may be a point adjacent to the inner surface portion (563b).

[0276] With this configuration, damage to the part connecting the bridge (580) and the port shield (560) can be prevented when the opening and closing operation of the port shield (560) is repeated.

[0277] The above bridge (580) guides the port shielding part (560) to move while supported by the fastening part (570) when the port shielding part (560) performs the operation of opening and closing the suction port (516).

[0278] Since the above bridge (580) is not a part that opens and closes the suction port (516), the movement of the above bridge (580) may not be large when the above port shielding part (560) performs an opening and closing operation. However, the opening amount of the above port shielding part (560) can be adjusted by the size of the radial width of the above bridge (580).

[0279] For example, if the width (w1, w2, w3) of the bridge (580) is too large, the rigidity of the bridge (580) and the suction valve (550) increases, which has the advantage of improving the safety factor of the valve and preventing damage, but there is a problem in that the opening amount of the port shield (560) is reduced, thereby reducing the suction efficiency.

[0280] On the other hand, if the width (w1, w2, w3) of the bridge (580) is too small, the opening amount of the bridge (580) and the suction valve (550) increases, which has the advantage of improving suction efficiency, but the bending amount and impact amount of the valve increase, which reduces the safety factor and causes damage to the valve.

[0281] In this embodiment, considering these problems, the minimum thickness of the bridge (580), that is, the thickness of the second point (w2), is formed in the range of 1.5 to 1.7 mm.

[0282] FIG. 15 is a schematic diagram showing the combined appearance of a piston and an intake valve according to an embodiment of the present invention, and FIG. 16 is a schematic diagram showing the appearance of an intake valve in an open state according to an embodiment of the present invention.

[0283] Referring to FIGS. 15 and 16, a refrigerant passage (511) is formed inside a piston (500) according to an embodiment of the present invention, and the refrigerant in the refrigerant passage (511) flows into a plurality of suction ports (516) and can be sucked into the compression space (P) of a cylinder through an open suction valve (550).

[0284] A groove, i.e., a recess (519), defined by a port surface (518) and a second stepped portion (515) may be formed between the suction port (516) and the suction valve (550). The recess (519) may be formed on the outlet side of the suction port (516) as a rear space of the suction valve (550).

[0285] That is, the recess (519) may be formed between the suction port (516) and the rear end of the suction valve (550). The refrigerant flowing through the suction port (516) may act on the suction valve (550) as it passes through the recess (519).

[0286] The radial width (w', diameter) of the above-mentioned recess (519) may be larger than the radial width (w, diameter) of the above-mentioned suction port (516). That is, since the cross-sectional area of ​​the above-mentioned recess (519) is larger than the cross-sectional area of ​​the above-mentioned suction port (516), the pressure of the refrigerant acting on the above-mentioned suction valve (550) increases, and thus the opening amount of the above-mentioned suction valve (550) may increase. Consequently, the suction efficiency may be improved.

[0287] The axial depth (h) of the above-mentioned recess (519) can be proposed within an appropriate range. If the axial depth of the above-mentioned recess (519) becomes too large, bulging occurs in which the suction valve (550) is pressed into the interior of the above-mentioned recess (519) by the pressure of the above-mentioned compression space (P) when compression occurs in the above-mentioned compression space (P), and consequently, stress increases and the valve may break.

[0288] In this embodiment, the axial depth (h) of the recess (519) may be formed to be equal to or slightly larger than the thickness (t) of the suction valve (550). For example, the thickness (t) of the suction valve (550) may be formed in the range of 0.1 to 0.11 mm, and the axial depth (h) of the recess (519) may be formed in the range of 0.11 to 0.13 mm.

[0289] Referring to FIG. 16, when the suction pressure in the refrigerant passage (511) exceeds the pressure of the compression space (P), the suction valve (550) is opened, and the refrigerant in the refrigerant passage (511) can be sucked into the compression space (P) of the cylinder (60) through the opened suction valve (550).

[0290] In detail, as the refrigerant flowing into the suction port (516) passes through the recess (519), its flow cross-sectional area increases, and since the pressure of the suction refrigerant acts over the entire area of ​​the suction valve (550), the opening amount of the suction valve (550) can be increased.

[0291] Meanwhile, as described above, the position and number of multiple suction ports (516) provided in the piston (500) can be optimally proposed to prevent the opening amount of the suction valve (550) from increasing excessively.

[0292] FIG. 17 is a cross-sectional view showing the flow of compressed refrigerant from the compression space of a cylinder to the discharge cover according to an embodiment of the present invention.

[0293] Referring to FIG. 17, when the suction pressure formed inside the piston (500) according to an embodiment of the present invention becomes greater than the pressure of the compression space (P), the suction valve (500) is opened and the refrigerant can be sucked into the compression space (P) through the suction port (516) of the piston (500).

[0294] When the pressure in the compression space (P) exceeds the discharge pressure during the process of the piston (500) reciprocating, the discharge valve (410) moves to open the compression space (P), and accordingly, the valve spring (430) can be deformed.

[0295] The above discharge cover assembly (100, 200, 300) may include a discharge chamber through which high-pressure discharge gas discharged from the discharge valve (410) flows.

[0296] When the discharge valve (410) is opened, the refrigerant compressed in the compression space (P) flows into the discharge room of the first discharge cover (100) and can be discharged from the first discharge cover (100) through the discharge hole (123).

[0297] The discharged refrigerant flows into the discharge chamber of the second discharge cover (200) and can flow into the discharge chamber of the second discharge cover (200) through the recess (140) of the first discharge cover (100). The refrigerant in the discharge chamber of the second discharge cover (200) is discharged to the outside of the second discharge cover (200) and can be discharged to the discharge pipe of the shell (11) through the loop pipe.

[0298] When the compression space (P) of the cylinder (60) becomes below the discharge pressure, the discharge valve (410) can move to close the compression space (P) by the restoring force of the valve spring (430). This opening and closing action of the compression space (P) of the discharge valve (410) can be repeated.

[0299] According to an embodiment of the present invention, the structure of the intake valve and piston is improved to increase intake efficiency and prevent damage to the valve. Therefore, industrial applicability is significant.

Claims

1. A cylinder forming a compression space; A piston inserted into the cylinder and reciprocating in the axial direction, forming a suction port for sucking refrigerant into the compression space; and It includes a suction valve installed on the above piston and opening or closing the above suction port, and The above piston is a linear compressor that includes a recess connected to the suction port and having a radial width greater than the radial width of the suction port.

2. In Paragraph 1, The above-mentioned recess is formed as a recess at the end of the piston where the suction valve is seated, in a linear compressor.

3. In Paragraph 1, A linear compressor in which the recess is formed between the suction valve and the suction port so that the refrigerant passing through the suction port flows into the recess.

4. In Paragraph 1, A linear compressor in which the axial depth of the above-mentioned depression is formed to be greater than the axial thickness of the above-mentioned suction valve.

5. In Paragraph 1, The above piston includes a valve wall in which the suction port is formed, and A linear compressor comprising a valve wall, a first stepped portion extending axially from an end of the valve wall, and a valve seating surface connected to the first stepped portion and extending radially, on which the suction valve is seated.

6. In Paragraph 5, A linear compressor comprising a valve wall that includes a second stepped portion extending further in the axial direction from the valve seating surface and a port surface connected to the second stepped portion and having a suction port formed therein.

7. In Paragraph 6, The above-mentioned recess is a linear compressor defined by the second step portion and the port surface so as to be recessed from the valve seating surface.

8. In Paragraph 1, The above piston includes a second wall part forming a fastening hole to which a valve fastening member is coupled, and the second wall part provides a seating surface on which the suction valve is placed, in a linear compressor.

9. In Paragraph 8, A linear compressor further comprising a second stepped portion extending further in the axial direction from the second wall part, wherein the second stepped portion is connected to a port surface forming the suction port.

10. In Paragraph 1, The above suction port includes a first port group and a second port group, each having a plurality of ports, and A linear compressor in which the first port group and the second port group are arranged to face each other based on a radial extension line passing through the center of the valve wall.

11. In Paragraph 10, A linear compressor in which the first port group and the second port group are arranged symmetrically with respect to the radial extension line.

12. In Paragraph 10, The gap (S2) between the first port group and the second port group is, A linear compressor characterized by being larger than the spacing (S1) between multiple ports constituting the first port group or the spacing (S1) between multiple ports constituting the second port group.

13. In Paragraph 10, The piston comprises a piston body extending in the axial direction and three piston flanges extending radially from the piston body, and A linear compressor in which, among the three extension lines connecting the three piston flanges at the center of the piston, one extension line passes through the area (A1) of the first port group and the remaining two extension lines pass through the area (A2) of the second port group.

14. In Paragraph 10, A linear compressor configured such that the first port group and the second port group each include six ports.

15. In Paragraph 1, The above suction valve is, A linear compressor comprising a port shielding member movably provided to open and close the suction port, a fastening member connected to the piston, and two bridges connecting the shielding member and the fastening member.

16. A cylinder forming a compression space; A piston inserted into the cylinder and reciprocating in the axial direction, forming a plurality of suction ports for sucking refrigerant into the compression space; and It includes a suction valve installed on the above piston and opening or closing the plurality of suction ports, The above suction valve is, A linear compressor comprising a ring-shaped port shield provided to be movably provided to open and close a plurality of suction ports, a fastening part provided on the inner side of the port shield and coupled to a valve fastening member, and a bridge connecting the port shield and the fastening part.

17. In Paragraph 16, A linear compressor wherein the plurality of suction ports each comprise a first port group and a second port group composed of a plurality of ports, and the port shielding part comprises a first shielding part for opening and closing the first port group and a second shielding part for opening and closing the second port group.

18. In Paragraph 17, A linear compressor comprising a port shielding portion provided between the first shielding portion and the second shielding portion, and a connection portion to which the bridge is connected.

19. In Paragraph 16, A linear compressor in which the above bridge extends from the outer surface of the above-mentioned fastening portion toward the inner surface of the above-mentioned port shielding portion, and the radial width of the above-mentioned bridge varies in the direction toward the inner surface of the above-mentioned port shielding portion.

20. In Paragraph 19, A linear compressor in which the first radial width (w1) of a first point of a bridge adjacent to the above-mentioned connection part is larger than the second radial width (w2) of a second point between the first point and the inner circumference of the port shielding part.

21. In Paragraph 20, A linear compressor in which the radial third width (w3) of the third point between the second point and the inner circumference of the port shielding part is larger than the radial second width (w2).

22. In Paragraph 16, The outer surface of the above-mentioned fastening part includes first to fourth surfaces, and on the first and second surfaces, an assembly guide groove is formed in which an assembly pin is positioned to prevent misassembly of the suction valve. A linear compressor in which the bridge is connected to the third and fourth sides, respectively.

23. In Paragraph 16, The above piston is, A valve mounting surface on which the above-mentioned suction valve is seated; and A linear compressor comprising a recess formed with a step difference between the suction port and the valve seating surface, and having a cross-sectional area larger than the cross-sectional area of ​​the suction port.

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