KR20160000651A - A linear compressor and a suction apparatus of the linerar compressor - Google Patents

Abstract

According to the present invention, a suction apparatus of a linear compressor comprises: a piston comprising a suction hole in which a low pressure refrigerant flows; a suction valve provided to open and close the suction hole; and a mounting member to mount the suction valve on the piston. The suction valve comprises: a fixing unit mounted by the mounting member; and two or more port units which are symmetrically separated about the fixing unit, and open and close the suction hole. The two or more port units each comprises: a circumferential portion forming an outer covering in a radial direction from the port unit; a radial portion extended from the fixing unit in the radial direction to be separated from a different port unit; a connection portion connecting the circumferential portion and the radial portion; and a flow hole through which a fluid sucked into the suction hole in the port unit flows. According to the present invention, quick responsiveness and a large passage area of the suction valve are secured to secure a sufficient quantity of flow even when the compressor is operated at a high speed. The natural frequency of the suction valve is increased to eliminate a concern for noise, vibration and damage. Damage to the suction valve is suppressed to obtain sufficiently long life.

Description

Technical Field [0001] The present invention relates to a linear compressor and a suction apparatus for a linear compressor,

The present invention relates to a linear compressor and a suction device of a linear compressor.

The compressor is a mechanical device that receives power from an electric motor or turbine and receives various kinds of fluids such as air, refrigerant, working gas and various other fluids to increase the pressure. It is widely used in household appliances such as a refrigerator and an air conditioner, .

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

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

In the linear compressor, the piston is linearly reciprocated within the cylinder by a linear motor in the closed shell, and is configured to suck and compress the refrigerant, and then discharge the refrigerant.

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

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

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

In order to reduce the size of the linear compressor, components of a compressor such as a piston and a cylinder must be made small, but the compression capacity and performance of the compressor are deteriorated. In order to solve this problem, the operating frequency of the compressor must be increased.

On the other hand, as the operating frequency of the compressor increases, the gas should be sucked into the compression space through the suction device of the linear compressor for a short time. For example, if the operating frequency is doubled, then sufficient suction of gas should occur for half the time compared to the original.

With regard to the suction device, the applicant has proposed a suction valve structure of a linear compressor in the patent document 10-2008-0012713. According to the conventional suction apparatus of the linear compressor, when the suction valve 200 opens the port 102h of the piston 102, the fluid is sucked. In addition, the re-trainer 300 presses the suction valve 200 to prevent foreign matter from being caught, thereby preventing the suction valve from being broken.

The suction valve 200 is provided to connect the single port portion 220 and the fixing portion 210 with the long neck portion 230. Therefore, the response speed is low and it can not cope with a high operating frequency of 100 Hz or more. Here, the responsiveness indicates that the suction valve opens and closes quickly when there is a pressure difference between the front end and the rear end of the suction valve, so that even when the pressure difference is low in the suction stroke of the suction valve, It can be said that the response time is high when the suction time of the gas can be sufficiently secured.

Further, by providing only three ports 102h, it is not possible to secure a sufficient flow passage area for fluid flow. Therefore, sufficient fluid can not be sucked in during a short suction stroke.

On the other hand, in order to prevent noise, vibration, and damage caused by resonance, the natural frequency of the intake valve is set to be three times or more as compared with the operation frequency of the compressor. However, in the conventional structure in which the single port portion 220 is connected to the long neck portion 230 operated by the spring when the operating frequency of the compressor becomes 100 Hz or more, Obtaining frequency is practically impossible.

Further, in order to reduce the flow path resistance, the conventional suction valve provides the outer periphery of the suction valve concavely inward at a position corresponding to the port 120h. However, there is a fear that the recess concentrates stress on the concave portion as a portion striking the piston at the time of opening / closing operation of the suction valve, thereby damaging the suction valve. Such a phenomenon is more likely to occur when the operating frequency of the compressor is high .

The suction valve of the suction valve structure of the linear compressor and its related structure are disclosed in Japanese Patent Application Laid-open No. 10-2008-0012713.

The present invention proposes a linear compressor and a suction device for a linear compressor capable of sucking a sufficient amount of fluid by ensuring sufficient response even when the compressor is operated at a high operating frequency .

Further, there is proposed a linear compressor and a suction device of a linear compressor which can ensure a sufficient flow area and suck a large amount of fluid in a short time.

Further, there is proposed a suction device of a linear compressor and a linear compressor in which the natural frequency of the suction valve is made sufficiently high so that the fear of noise, vibration, and breakage can be improved.

Further, the present invention proposes a linear compressor and a suction device of a linear compressor, which distribute the impact of the suction valve against the piston evenly to suppress stress concentration and suppress breakage of the suction valve.

The suction device of the linear compressor according to the present invention includes: a piston provided with a suction hole through which a low-pressure refrigerant flows; A suction valve provided to open and close the suction hole; And a fastening member provided to fasten the suction valve to the piston, wherein the suction valve includes: a fastening part fastened by the fastening member; And at least two port portions spaced apart from each other by a symmetrical structure around the fixed portion and opening and closing the suction hole, wherein the port portion includes a circumferential portion forming an outer angle in a radial direction outside the port portion; A radial upper portion extending radially in the fixing portion to be spaced apart from other adjacent port portions; A connecting portion connecting the circumferential portion and the radial portion; And a flow hole through which the fluid sucked into the suction hole passes within the port portion.

According to another aspect of the present invention, there is provided a suction device for a linear compressor, comprising: a piston provided with a suction hole through which a low-pressure refrigerant flows; A suction valve provided to open and close the suction hole; And a fastening member provided to fasten the suction valve to the piston; Wherein the suction valve is provided with a fixing part which is fastened by the fastening member; And at least two port portions in the radial direction when the fixed portion is the center, and the thickness of the suction valve is 40 to 50 mu m.

According to another aspect of the present invention, there is provided a linear compressor comprising: a shell; A cylinder disposed inside the shell and forming a compression space for the refrigerant; A piston provided to be axially reciprocable within the cylinder; A motor assembly for operating the piston; A suction valve that is coupled to an end of the piston and intermittently sucks the refrigerant into the compression space; And a discharge valve provided at one side of the cylinder for selectively discharging the refrigerant compressed in the compression space of the refrigerant, wherein the suction valve is arranged radially to have a high natural frequency corresponding to the high- Wherein at least two port portions provided are provided, and the thickness of the suction valve is 40 to 50 mu m.

According to the present invention, there is an effect that a quick response of the suction valve and a wide passage area are ensured, and a sufficient flow rate can be ensured even when the compressor is operated at high speed.

According to the present invention, there is no fear of noise, vibration, and breakage by raising the natural frequency of the intake valve.

INDUSTRIAL APPLICABILITY According to the present invention, breakage of a suction valve can be suppressed and a sufficient life can be obtained.

1 is a sectional view showing a linear compressor according to an embodiment;
Fig. 2 is an enlarged view of a portion A in Fig. 1; Fig.
3 is an exploded perspective view of the suction device.
4 is a plan view of a suction valve according to an embodiment.
5 is an enlarged view of a port portion;
6 is a view showing a stress distribution of a suction valve.
7 is a PV diagram of a refrigerant in a linear compressor.
8 is a cross-sectional view showing a fastening state of a fastening member, a suction valve, and a washer.
9 is a side view of an integral fastening member in which a fastening member and a washer are integrally provided.

Hereinafter, specific embodiments of the present invention will be described with reference to the drawings. However, the spirit of the present invention is not limited to the embodiments shown, and those skilled in the art of the present invention who intend to understand the spirit of the present invention can readily suggest other embodiments included within the scope of the same idea, .

Although the following embodiment describes a refrigerant as a fluid to be compressed by a linear compressor, it is obviously possible to use it for various kinds of fluid compression including working gas, and it is included in the idea of the present invention.

1 is a sectional view showing a linear compressor according to an embodiment.

Referring to FIG. 1, a linear compressor 100 according to the embodiment includes a substantially cylindrical shell 101, a first cover 102 coupled to one side of the shell 101, A cover 103 is included. For example, the linear compressor 100 is laid in a lateral direction, and the first cover 102 is coupled to the right side of the shell 101, and the second cover 103 is coupled to the left side of the shell 101 .

The configuration and arrangement are provided so as to occupy at least a space in the machine room of the refrigerator. For example, it is possible to reduce the height of the machine room by placing the cylinder in a narrow and narrow space, compared to the spherical shape.

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

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

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

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

The piston 130 may be made of an aluminum material (aluminum or aluminum alloy) which is a non-magnetic material. The piston 130 is made of an aluminum material to prevent the magnetic flux generated in the motor assembly 140 from being transmitted to the piston 130 and leaking to the outside of the piston 130. The piston 130 may be formed by a forging method. The cylinder 120 may be made of an aluminum material (aluminum or aluminum alloy) which is a non-magnetic material. The material composition ratio of the cylinder 120 and the piston 130, that is, kind and composition ratio, may be the same. Since the cylinder 120 is made of an aluminum material, the magnetic flux generated in the motor assembly 200 can be prevented from being transmitted to the cylinder 120 and leaking to the outside of the cylinder 120. The cylinder 120 may be formed by an extrusion rod processing method. Since the piston 130 and the cylinder 120 are made of the same material (aluminum), the coefficients of thermal expansion become equal to each other. Since the piston 130 and the cylinder 120 have the same thermal expansion coefficient during the operation of the linear compressor 100 and the inside of the shell 100 has a high temperature (about 100 ° C) And the cylinder 120 can be thermally deformed by the same amount. As a result, since the piston 130 and the cylinder 120 are thermally deformed in different sizes or directions, interference between the piston 130 and the cylinder 120 can be prevented.

The cylinder (120) is configured to receive at least a portion of the suction muffler (150) and at least a portion of the piston (130). A compression space P in which the refrigerant is compressed by the piston 130 is formed in the cylinder 120. A suction hole 133 for introducing a refrigerant into the compression space P is formed in a front portion of the piston 130. The suction hole 133 is selectively provided in front of the suction hole 133, A suction valve 135 is provided. At a substantially central portion of the suction valve 135, a fastening hole to which a predetermined fastening member is coupled is formed.

A discharge cover 160 for forming a discharge space or a discharge path for the refrigerant discharged from the compression space P and a discharge cover 160 coupled to the discharge cover 160 and disposed in front of the compression space P, A discharge valve assembly (161, 162, 163) for selectively discharging compressed refrigerant is provided.

The discharge valve assembly 161 is provided with a discharge valve 161 that opens when the pressure in the compression space P becomes equal to or higher than the discharge pressure and causes the refrigerant to flow into the discharge space of the discharge cover 160, A valve spring 162 provided between the discharge cover 161 and the discharge cover 160 for applying an elastic force in the axial direction and a stopper 163 for limiting the amount of deformation of the valve spring 162. Here, the compression space P is understood as a space formed between the suction valve 135 and the discharge valve 170.

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

The stopper 163 may be seated in the discharge cover 160 and the valve spring 162 may be seated in the rear of the stopper 163. The discharge valve 161 is coupled to the valve spring 162 and the rear or rear surface of the discharge valve 161 is positioned to be supported on the front surface of the cylinder 120. The valve spring 162 may include a plate spring, for example.

The suction valve 135 is formed on one side of the compression space P and the discharge valve 161 may be provided on the other side of the compression space P, that is, on the opposite side of the suction valve 135.

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

In this case, the responsiveness can be determined according to the degree of time when the pressure in the compression space P becomes lower than the suction pressure and the opening timing of the suction valve 135 is earlier. Specifically, when the pressure in the compression space P is slightly lower than the suction pressure, the suction valve 135 is quickly opened so that responsiveness can be increased and more refrigerant can be sucked. On the contrary, when the responsiveness is low, a relatively small amount of refrigerant can be sucked. In this case, since the vacuum state of the compression space P must be further increased in view of the stroke of the piston 130, It is not preferable because consumption is increased.

On the other hand, when the pressure in the compression space P becomes equal to or higher than the discharge pressure, the valve spring 162 is deformed to open the discharge valve 161. The refrigerant is discharged from the compression space P, And is discharged into the discharge space of the cover 160. The refrigerant flowing in the discharge space of the discharge cover 160 flows into the loop pipe 165. The loop pipe 165 is coupled to the discharge cover 160 and extends to the discharge part 105 to guide the compressed refrigerant in the discharge space to the discharge part 105. For example, the loop pipe 178 has a round shape extending in a predetermined direction, and is coupled to the discharge unit 105.

The linear compressor (100) further includes a frame (110). The frame 110 is configured to fix the cylinder 120 and may be fastened to the cylinder 200 by a separate fastening member. The frame 110 is disposed to surround the cylinder 120. That is, the cylinder 120 may be positioned to be received inside the frame 110. The discharge cover 172 may be coupled to the front surface of the frame 110.

On the other hand, at least a portion of the gaseous refrigerant in the high-pressure gas refrigerant discharged through the opened discharge valve 161 flows through the space of the portion where the cylinder 120 and the frame 110 are coupled to the outer peripheral surface side of the cylinder 120 Can be introduced. The introduced refrigerant flows into the space between the piston 130 and the cylinder 120 so that the outer circumferential surface of the piston 130 is spaced from the inner circumferential surface of the cylinder 120. Accordingly, the introduced refrigerant can function as a "gas bearing " which reduces friction with the cylinder 120 during reciprocation of the piston 130. [

The motor assembly 140 includes outer stator 141, 143 or 145 fixed to the frame 110 and arranged to surround the cylinder 120, an inner stator 148 (not shown) And permanent magnets 146 positioned in the space between the outer stator 141, 143, 145 and the inner stator 148. The permanent magnets 146 can reciprocate linearly by mutual electromagnetic forces between the outer stator 141, 143, 145 and the inner stator 148. The permanent magnets 146 may be formed of a single magnet having one pole or a plurality of magnets having three poles. The permanent magnet 146 may be coupled to the piston 130 by a connecting member 138. In detail, the connecting member 138 may be coupled to the piston flange portion 132 and may be bent and extended toward the permanent magnet 146. As the permanent magnet 146 reciprocates, the piston 130 can reciprocate axially together with the permanent magnet 146.

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

The outer stator 141, 143, 145 includes the coil winding bodies 143, 145 and the stator core 141. The coil winding bodies 143 and 145 include a bobbin 143 and a coil 145 wound around the bobbin 143 in the circumferential direction. The end face of the coil 145 may have a polygonal shape, and may have a hexagonal shape, for example. The stator core 141 is formed by stacking a plurality of laminations in a circumferential direction, and may be arranged to surround the coil winding bodies 143 and 145. A stator cover 149 is provided at one side of the outer stator 141, 143, 145. One side of the outer stator 141, 143, 145 may be supported by the frame 110 and the other side may be supported by the stator cover 149.

The inner stator 148 is fixed to the outer periphery of the cylinder 120. The inner stator 148 is formed by laminating a plurality of laminations in the circumferential direction from the outside of the cylinder 120.

The linear compressor 100 further includes a supporter 137 for supporting the piston 130 and a back cover 170 spring-coupled to the supporter 137. The supporter 137 is coupled to the piston flange portion 132 and the connecting member 138 by a predetermined fastening member. A suction guide portion 155 is coupled to the front of the back cover 170. The suction guide part 155 guides the refrigerant sucked through the suction part 104 into the suction muffler 150.

The linear compressor 100 includes a plurality of springs 176 whose natural frequencies are adjusted so that the piston 130 can resonate. The plurality of springs 176 include a first spring supported between the supporter 137 and the stator cover 149 and a second spring supported between the supporter 137 and the back cover 170 do. The linear compressor 100 further includes leaf springs 172 and 174 which are provided on both sides of the shell 101 to allow the internal parts of the compressor 100 to be supported by the shell 101. The leaf springs 172 and 174 include a first leaf spring 172 coupled to the first cover 102 and a second leaf spring 174 coupled to the second cover 103. For example, the first leaf spring 172 can be fitted to a portion where the shell 101 and the first cover 102 are coupled, and the second leaf spring 174 can be engaged with the shell 101, 2 cover 103 is engaged.

The suction device of the linear compressor will be described in more detail below.

2 is an enlarged view of a portion A in Fig.

Referring to Fig. 2, the suction device is a device for sucking low-pressure refrigerant into the compression space (P). The suction device includes a piston 130 provided with a suction hole 133 through which a low-pressure refrigerant flows, a suction valve 133 provided in a head portion of the piston 130 for intermittently opening and closing the suction hole 133 And a suction valve 135 and a piston 135 interposed between the coupling member 139 and the suction valve 135. The suction valve 135 is connected to the piston 130, A washer 136 may be included to improve the contact reliability between the outer ring 130 and the outer ring.

The suction device controls the opening of the suction valve 135 by the pressure difference between the compression space P and the suction pressure inside the suction hole 133 (the suction pressure refers to the low pressure before the gas is compressed) . For example, when the piston moves rearward (rightward in FIG. 2), the pressure in the compression space P becomes lower than the suction pressure, so that the suction valve 135 opens and the low- (P). Conversely, when the piston moves forward (leftward in FIG. 2), the pressure of the compression space P becomes higher than the suction pressure, so that the suction valve 135 closes and the refrigerant does not flow through the suction hole 133.

When the operation frequency of the linear compressor is high in performing the suction operation as described above, the suction device must also operate at a high speed. It is a main attainment target of the suction device that a high responsiveness can be ensured, a sufficient flow rate can be obtained, and there is no fear of noise / vibration / breakage even when the suction device operates at a high speed. The inventor has made various efforts and attempts to achieve this purpose, and the following contents are the results derived from such a background.

First, the shape of the suction valve is remarkably improved.

로 주어질 수 있다. 그리고, 리니어 압축기의 운전 주파수가 60Hz에서 120Hz로 증가하는 경우에는 흡입밸브의 고유 주파수도 그에 맞추어 두 배가 늘어나도록 하여야 한다. 이를 위하여 상기 m은 줄이고, 상기 k는 늘여야 한다. 상기 수학식에서 m과 k를 실시예의 흡입밸브와 대응시키면, m은 개폐되는 부분으로서 포트부(도 4의 1353참조)의 질량이고, k는 고정되는 부분으로서 고정부(도 4의 1352참조)와 상기 포트부(1353)을 연결하는 부분의 스프링 상수와 대응될 수 있다. Will be described in detail. In general, the natural frequency of the intake valve is

Lt; / RTI > When the operating frequency of the linear compressor increases from 60 Hz to 120 Hz, the natural frequency of the intake valve should also be doubled accordingly. To do this, m must be reduced and k should be increased. M is the mass of the port portion (see 1353 in Fig. 4) as a portion to be opened and closed, and k is a fixed portion as a fixed portion (see 1352 in Fig. 4) and And may correspond to a spring constant of a portion connecting the port 1353.

4 is a plan view of a suction valve according to an embodiment.

4, the suction valve 135 includes a fixing portion 1352 having a fixing hole 1351 in the center thereof, and two or more port portions 1352 in the radial direction around the fixing portion 1352 1353 are provided. The embodiment shows that four port portions 1353 are provided. The port 1353 can open and close three suction holes 133, respectively. The port portions 1353 may be spaced apart from each other at equal angles around the fixing portion 1352. The port portion 1353 may be symmetrical with respect to any straight line passing through the center of the fixing portion 1352. The port 1353 may be provided symmetrically with respect to the upper, lower, left, and right directions. The port portion 1353 extending from the fixing portion 1352 may be radially provided.

According to the above-described configuration, the port 1353 can open / close a plurality of suction holes 133. Therefore, a wider flow passage area can be ensured. Further, the port portion 1353 and the fixing portion 1352 can be approached as much as possible to obtain a high spring constant (k), and it is possible to cope with a high operating frequency of the linear compressor.

5 is an enlarged view of the port portion.

5, a circumferential portion 1355 forming an outermost periphery of the port portion 1353 as a curved line having a single radius of curvature and having an outer periphery outside the port portion 1353 is formed in the port portion 1353, A radiating portion 1356 extending radially so as to be spaced apart from an adjacent port portion 1353 so that the radiating portion 1353 can perform an opening and closing action and a radiating portion 1356 that smoothly connects the radiating portion 1356 and the circumferential portion 1355 A connection portion 1357 is provided. A flow hole 1354 may be formed in the port 1353 to reduce the flow resistance of the refrigerant sucked through the suction hole 133.

The configuration of the port 1353 will be described in more detail.

The circumferential portion 1355 is provided as a curve having a single radius of curvature. Provided in such a shape is to prevent breakage of the outermost portion of the port portion 1353. More specifically, the circumferential portion 1355 of the port portion 1353 is largest when the piston 130 and the suction valve 135 are opened and closed. Therefore, when the circumferential portion 1355 is formed of a discontinuous curved line, the amount of the stress, that is, the stress is concentrated on the vertex of the discontinuous curve and the portion thereof may be broken. Furthermore, when the operating frequency of the linear compressor is high, it has a greater effect. In order to solve such a problem, the circumferential portion 1355 may be provided with a curve of a single curvature radius.

Also, the radiation top 1356 is provided parallel to the radiation top 1356 of the adjacent port portion 1353. The reason for this is to prevent the inner portion of the radiating portion 1356 from being broken. The stress distribution of the suction valve shown in Fig. 6 will be described in detail with reference to the drawings. 6, when the distance between the radial upper portions 1356 of the adjacent pair of the port portions 1353 becomes narrower toward the inner side (in the case of a), stress in the innermost portion of the radial upper portion 1356 So that the suction valve 135 may be broken or the like. When the gap between the radiating portions 1356 of the adjacent pair of the port portions 1353 widens toward the inner side, the distance between the radiating portion 1356 and the flow holes 1354 becomes narrow, It is undesirable because the part is weakened and may be damaged by itself. In addition, when it is widened, stress is concentrated on both corner portions bent from the inside, which is not preferable. Therefore, it is preferable that the intervals of the radiating portions 1356 of the pair of adjacent port portions 1353 are parallel to each other (in the case of b). In this case, since a large portion spreads stress, the strength against breakage is strong. On the other hand, in FIG. 6, the portion where the stress is concentrated is indicated by a hearing.

Referring to FIG. 5 again, it is already described that the flow hole 1354 is intended to reduce the flow resistance of the refrigerant flowing through the suction hole 133. The flow hole 1354 is provided in a substantially triangular shape similar to the approximate shape of the port portion 1353, and the stem is smoothly rounded to prevent stress concentration.

On the other hand, the outer portion of the flow hole 1354 is provided so as to approach each suction hole 133 so that the refrigerant flowing through each suction hole 133 is guided to the flow hole 1354 so that flow resistance is minimized. Furthermore, it should be prevented from being damaged by the amount of impact when the port portion 1353 collides with the piston 130. In order to achieve the above object, the distances w1 and w2 between the flow holes 1354 and the respective suction holes 133 are the same, and the outer shape of the flow hole 1354 corresponding to the middle suction hole among the three suction holes The radius of curvature R1 of the flow hole 1354 may be larger than the curvature radius R2 of the outer shape of the flow hole 1354 corresponding to the suction hole on the outer side.

On the other hand, by providing the flow holes 1354, the spring constant given when opening and closing the port portion 1353 can be adjusted. For example, when the size of the flow hole 1354 is increased, the effect of reducing the spring constant given to the operation of the port portion 1353 can be expected, and conversely, the same effect can be achieved.

The connection portion 1357 is a smoothly connected curve and may be provided to connect the radiating portion 1356 and the circumferential portion 1355 to each other. As a result, damage of the suction valve 135 can be prevented by stress concentration.

Referring again to FIG. 4, the port 1353 of the suction valve 135 is directly connected to the fixing portion 1352 in the radial direction. In other words, the port portion 1353, which performs the opening and closing action from the fixing portion 1352 fixed to the position, is directly connected in the radial direction without a separate neck portion interposed therebetween. Therefore, the portion providing elasticity for performing the opening / closing action of the port portion 1353 is short and has a high spring constant k. The thickness of the suction valve 135 should be adjusted to provide high response to the port 1353 even in such a shape. In other words, opening and closing operations of the suction valve 135 should be performed even at low pressure differences between the front and rear ends of the suction valve 135. In order to achieve such a purpose, the thickness of the suction valve 135 is preferably 40 to 50 μm as a stainless material. If the thickness of the suction valve 135 exceeds 50 탆, the responsiveness is low so that it can not cope with a high operating frequency of the linear compressor. When the thickness is less than 40 탆, the suction valve 135 can not withstand a high impact or its cost becomes high.

In other respects, the port 1353 is a part that is opened and closed, and it is possible to increase the natural frequency as high as possible by reducing the mass, so that it can positively cope with the high operating frequency of the linear compressor. However, when it is too thin, it is not preferable because it is weak against shock, expensive, difficult to handle, and difficult to work.

The results of performing experiments with different thicknesses of the suction valves will be described with reference to the P-V line of the refrigerant in the linear compressor shown in FIG.

Referring to FIG. 7, P _d is the pressure on the discharge side of the linear compressor P _s is the pressure on the suction side of the linear compressor. All other conditions are the same, and the case where the thickness of the intake valve is 50 탆 is shown in the diagram 1 and the case where it is 70 탆 is shown in the diagram 2.

In the case of the above-mentioned line 2, it can be seen that the internal area of the P-V line is larger and thus more work is done than in the case of the line 1. In other words, in the case of the line 2, since the responsiveness of the intake valve is low, the intake valve is opened later, the intake valve is not opened at the position where the intake valve should theoretically be opened, The suction valve is opened. Therefore, the motor is required to further apply the unused force to the piston 130. [0064] In addition, since the suction amount of the refrigerant is reduced, the operation efficiency of the linear compressor may be lowered. This undesirable effect causes a greater problem when the operating frequency of the compressor is high.

Therefore, preferably, the suction valve 135 is opened when the pressure is close to the suction side. In order to satisfy such a condition, a suction valve having a thickness of 40 to 50 mu m can be preferably proposed. More preferably, a thickness of 45 +/- 2 mu m can be proposed. This value is a numerical value that allows the suction valve to open at almost the suction pressure, and is proposed in order to operate the linear compressor with a minimum efficiency.

On the other hand, when the thickness of the suction valve is made thin as described above, the outer periphery of the suction valve may be heard when the suction valve 135 is mounted. For example, when the fixing portion 1352 located at the center of the suction valve 135 is pushed by the fastening member 139, the suction port 135 of the suction valve 135 may be raised. In such a case, there may arise a problem that the refrigerant becomes large during operation of the linear compressor or the suction valve is broken. The washer 136 may be used to solve this problem. 3 shows the washer and its related structure in more detail with reference to an exploded perspective view of the suction device.

3, the suction valve 135 is positioned so that the port portion 1353 is aligned with the suction hole 133, and a washer 136 is provided so that the fixing portion 1352 can be pressed more widely. The washer 136 is a dish washer and is provided with a bottom portion 1361 capable of gently pressing the fixed portion 1352 of the suction valve 135 and a raised portion 1362 with which the fastening member 139 abuts. According to such a configuration, when the fastening member 139 is fastened, the bottom portion 1361 can press the fixing portion 1352 of the suction valve 135 widely, so that the port portion 1353 can be prevented from being lifted up . In addition, since the fastening member 139 indirectly presses the suction valve 135 through the ridge 1362, no excessive force is applied to the suction valve 134. Therefore, it is possible to reduce tearing or breakage of the suction valve 135 when the fastening member 139 is fastened. Particularly, when the fastening member 139 is a bolt, the suction valve 135 is not damaged by the shear force.

8 is a sectional view showing a fastening state of the fastening member and the suction valve and the washer. Referring to FIG. 8, since the fastening member 139 indirectly presses the suction valve 135, . Further, since the washer 136 presses the suction valve 135 with a large area, the outside portion of the suction valve 135 is not heard.

The present invention can further include other embodiments included in the same concept in addition to the above embodiments. Hereinafter, another embodiment will be further described.

First, the fastening member 139 and the washer 136 may be integrally provided, as well as being separated from each other as in the first embodiment. 9 is a side view of the integral fastening member. 9, the integral fastening member 1400 is provided with a head 1401 on which a fastening tool such as a driver acts, a washer 1402 capable of acting as a dish washer, A part 1403 may be included. The integral fastening member 1400 can be expected to be more convenient since the operator does not have to work separately by holding the washer separately. Of course, you can expect benefits that will help to reduce costs and cost.

According to the present invention, sufficient response can be ensured for a high operating frequency of the linear compressor, so that a sufficient amount of fluid can be sucked, and the operating efficiency of the linear compressor can be increased. In addition, since a sufficient flow area can be ensured and a large amount of fluid can be sucked in a short time, the operation efficiency of the compressor can be increased. Further, the natural frequency of the intake valve can be sufficiently increased, so that noise, vibration, and breakage can be prevented and the reliability of the product can be improved. In addition, it is possible to expect an advantage that the product reliability is improved by distributing the shock applied to the suction valve evenly to suppress stress concentration. Therefore, it is possible to realize a premium linear compressor with low noise, low weight and high speed operation.

135: Suction valve
1352:
1353:

Claims (13)

A piston provided with a suction hole through which a low-pressure refrigerant flows;
A suction valve provided to open and close the suction hole; And
And a fastening member provided to fasten the suction valve to the piston,
In the suction valve,
A fixing part which is fastened by the fastening member; And
At least two port portions spaced apart from each other in symmetry with respect to the fixed portion and opening / closing the suction hole,
In the port portion,
A circumferential portion forming a radially outward outer angle at the port portion;
A radial upper portion extending radially in the fixing portion to be spaced apart from other adjacent port portions;
A connecting portion connecting the circumferential portion and the radial portion; And
And a fluid hole through which the fluid sucked into the suction hole passes, in the port portion. The method according to claim 1,
Wherein the circumferential portion is provided as a curve having a single radius of curvature. The method according to claim 1,
Wherein the radial sections adjacent to each other in the radial upper portion are parallel to each other. The method according to claim 1,
Wherein at least one of the port portions is provided to open and close the three suction holes,
Wherein the curvature radius of the outer shape of the flow hole corresponding to the suction hole in the middle of the three suction holes is provided larger than the radius of curvature of the outer shape of the flow hole corresponding to the suction hole on the outer side. 5. The method of claim 4,
Wherein a distance between the flow hole and the suction hole is the same when the suction valve and the piston are fastened. The method according to claim 1,
Wherein the thickness of the suction valve is 40 to 50 占 퐉. The method according to claim 1,
Wherein the thickness of the suction valve is 45 +/- 2 mu m. The method according to claim 1,
And a washer interposed between the coupling member and the suction valve to improve contact reliability between the suction valve and the piston. 9. The method of claim 8,
Wherein the washer is a dish washer. 10. The method according to any one of claims 8 to 9,
Wherein the washer and the fastening member are provided as one body. A piston provided with a suction hole through which a low-pressure refrigerant flows;
A suction valve provided to open and close the suction hole; And
A fastening member provided to fasten the suction valve to the piston;
Wherein the suction valve is provided with a fixing part which is fastened by the fastening member; And
At least two port portions in the radial direction when the fixed portion is the center,
Wherein the thickness of the suction valve is 40 to 50 占 퐉. 12. The method of claim 11,
And a washer for improving contact reliability between the suction valve and the piston,
Wherein the washer is a dish type and is provided integrally with the fastening member. Shell;
A cylinder disposed inside the shell and forming a compression space for the refrigerant;
A piston provided to be axially reciprocable within the cylinder;
A motor assembly for operating the piston;
A suction valve that is coupled to an end of the piston and intermittently sucks the refrigerant into the compression space; And
A discharge valve provided on one side of the cylinder for selectively discharging compressed refrigerant in a compression space of the refrigerant,
The suction valve
At least two port portions provided radially so as to have a high natural frequency corresponding to the high-speed operation of the piston,
Wherein the thickness of the suction valve is 40 to 50 占 퐉.

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