Description

LINEAR COMPRESSOR

Technical Field

[I] The present invention relates to a linear compressor and, more particularly, to a linear compressor mainly used for refrigerator and etc as an apparatus compressing a working fluid such as refrigerant and etc in a cylinder with a piston in the cylinder reciprocated by the rectilinear driving force of the linear motor.

Background Art [2] FIG. 1 is a cross-sectional view illustrating a linear compressor according to the conventional art, and FIG. 2 is a cross-sectional view along the line A-A of FIG. 1. [3] The linear compressor according to the conventional art as illustrated in FIGS. 1 and 2 comprises a shell 2 inhaling and discharging the working fluid and a compression unit compressing the working fluid as arranged in the shell 2. [4] The shell 2 includes a fluid suction pipe 4 inhaling the working fluid from outside to the compression unit, and a fluid discharge pipe 6 discharging the working fluid compressed in the compression unit to outside of the shell 2. [5] The compression unit includes a cylinder 10 inhaling the working fluid through the fluid suction pipe 4 as fixed in the inside of the shell 2, a piston 20 compressing the working fluid inhaled to the cylinder 10 with a prescribed pressure ratio as arranged in the cylinder 10 to be reciprocated, and a linear motor 30 reciprocating the piston 20. [6] The cylinder 10 has a discharge valve assembly 12 discharging the working fluid compressed in the cylinder 10 to the fluid discharge pipe 6. [7] The piston 20 has a fluid passing path 21 let the working fluid inhaled through the fluid suction pipe 4 pass to the cylinder 10, and a suction valve 22 let the working fluid in the fluid passing pipe 21 of the piston 20 inhaled to the cylinder 10 selectively. [8] The linear motor 30 is broadly composed of a stator 32 and a rotor 34 connected with the piston 20 and reciprocated by the electromagnetic interaction with the stator

32. [9] Reference will now be made in detail to the operation of the linear compressor according to the conventional art configured as above. [10] When the linear motor 30 is operated, the piston 20 is reciprocated in the cylinder

10 by the driving force of the linear motor 30. Further, the discharge valve assembly

12 and the suction valve 22 achieves the repetitive opening and shutting operation as interlocked with the reciprocating movement of the piston 20.

[I I] Then, the working fluid is inhaled to the inside of cylinder 10 through the fluid suction pipe 4 and the fluid passing path 21. The working fluid inhaled to the cylinder

10 is compressed with a high pressure by the piston 20. The fluid compressed in the cylinder 10 is discharged to outside of the shell 2 through the discharge valve assembly 12 and the fluid discharge pipe 6.

[12] The above processes of inhaling, compressing, discharging of the working fluid are continued and repeated in order while the linear motor 30 is operated.

[13] The linear compressor according to the conventional art, however, has a disadvantage that the floating noise and vibration are loud and big as the discharge pulsation of the working fluid discharged after compressed in the cylinder 10 is very high- Disclosure of Invention Technical Problem

[14] The present invention is contrived to overcome the above-mentioned conventional problems, and an object of the present invention is to provide a linear compressor minimizing the flow-induced noise and the vibration generated by the high discharge pulsation of the compressed working fluid as arranging a silencer on the discharging line of the working fluid compressed in the compression unit. Technical Solution

[15] For the technical problems, the present invention provides a linear compressor comprising a compression unit compressing the working fluid and a silencer connected with the compression unit for passing of the working fluid compressed in the compression unit.

[16] The compression unit and the silencer may be arranged in the inside of the shell inhaling and discharging the working fluid.

[17] The compression unit includes a discharge valve assembly discharging the working fluid compressed in the compression unit, and the silencer may be integrally combined with the discharge valve assembly.

[18] The silencer may comprise a silencer cover extended from the compression unit and silencer chamber combined with the silencer cover as capable of opened and shut on the silencer cover.

[19] At least a part of the connection pipe connecting the compression unit and the silencer may be inserted into the inside of the silencer.

[20] The compression unit includes a discharge cover outlet discharging the working fluid compressed in the compression unit, and the silencer may include a silencer intake inhaling the working fluid compressed in the compression unit and spaced apart the discharge cover outlet.

[21] The compression unit includes a discharge cover outlet discharging the working fluid compressed in the compression unit, and the silencer may include a silencer

intake inhaling the working fluid compressed in the compression unit and combined with the discharge cover outlet.

[22] The silencer may have a silencer intake connected with the compression unit, and a silencer outlet arranged on the upper part of the silencer to be close with the silencer intake and connected with the fluid discharge pipe.

[23] Furthermore, the present invention to overcome the above-mentioned technical problems provides a linear compressor comprises a shell; a cylinder arranged in the shell, and inhaling and discharging the working fluid; a piston combined with the cylinder to be capable of reciprocating into the cylinder; a linear motor reciprocating the piston; a discharge valve assembly discharging the working fluid compressed in the cylinder as coupled with the cylinder; and a silencer connected with the discharge valve assembly for the passage of the compressed working fluid.

[24] The discharge valve assembly may have a discharge plenum connected with the opening of the cylinder, and having a discharge plenum outlet; a discharge cover arranged on the outside of the discharge plenum to be connected with the discharge plenum outlet, and having a discharge cover outlet; a discharge valve opening and shutting the outlet of the cylinder as positioned in the discharge plenum; and the discharge plenum may have a discharge plenum flange unit to be combined with the silencer as extended to outside of the discharge cover.

[25] The silencer includes a silencer cover extended from the discharge valve assembly and a silencer chamber opened and shut by the silencer cover.

[26] The silencer may be arranged in the inside of the shell.

[27] At least, a part of the connection pipe connecting the discharge valve assembly and the silencer may be inserted in the silencer.

[28] The silencer may have a silencer intake connected with the compression unit, and a silencer outlet arranged on the upper part of the silencer to be close with the silencer intake and connected with the fluid discharge pipe.

Advantageous Effects

[29] The linear compressor according to the present invention has an effective advantage that the flow-induced noise and the vibration generated by the discharge pulsation of the working fluid are minimized as the discharge pulsation of the compressed working fluid is reduced by the organization that the working fluid compressed in the compressor is discharged as passing through the silencer as compared with the operation without silencer. Brief Description of the Drawings

[30] FIG. 1 is a cross-sectional view showing a linear compressor according to the conventional art,

[31] FIG. 2 is a cross-sectional view along the line A-A of FIG. 1,

[32] FIG. 3 is a cross-sectional showing the reversing state of the piston of the linear compressor according to the first preferred embodiment of the present invention, [33] FIG. 4 is a cross-sectional view showing the advancing state of the piston of the linear compressor according to the first preferred embodiment of the present invention, [34] FIG. 5 is a view magnifying a part of FIG. 4,

[35] FIG. 6 is a cross-sectional view along the line B-B of FIG. 5,

[36] FIG. 7 is a graph showing the pulsation timely compared in accordance with the presence of the silencer in the linear compressor according to the present invention, [37] FIG. 8 is a pulsation FFT graph in accordance with the presence of the silencer in the linear compressor according to the present invention, [38] FIG. 9 is a cross-sectional view of the linear compressor according to the second preferred embodiment of the present invention. [39] <REFERENCE NUMERALS FOR THE PRINCIPLE PARTS OF THE

DRAWINGS>

[40] 50: SHELL 56: FLUID SUCTION PIPE

[41] 58: FLUID DISCHARGE PIPE 60: CYLINDER BLOCK

[42] 62: BACK COVER 62': FLUID SUCTION PATH

[43] 70: CYLINDER 80: PISTON

[44] 81 : FLUID PASSING PATH 84: SUCTION VALVE

[45] 86: FIRST PISTON SPRING 87: SECOND PISTON SPRING

[46] 90: LINEAR MOTOR 92: MAGNET

[47] 94: MAGNET FRAME 95: OUTER STATOR

[48] 96: COIL 98: INNER STATOR

[49] 100: OIL SUPPLY UNIT 102: LUBRICATING OIL SUCTION PATH

[50] 104: LUBRICATING OIL DISCHARGE PATH 106: LUBRICATING OIL PUMP

[51] 110: DISCHARGE VALVE ASSEMBLY 112: DISCHARGE PLENUM

[52] 114: DISCHARGE COVER 116: DISCHARGE VALVE

[53] 120: SILENCER 122: SILENCER COVER

[54] 124: SILENCER CHAMBER 130: CONNECTION PIPE

Best Mode for Carrying Out the Invention [55] FIG. 3 is a cross-sectional showing the reversing state of the piston of the linear compressor according to the first preferred embodiment of the present invention, FIG.

4 is a cross-sectional view showing the advancing state of the piston of the linear compressor according to the first preferred embodiment of the present invention, FIG.

5 is a view magnifying a part of FIG. 4, and FIG. 6 is a cross-sectional view along the line B-B of FIG. 5.

[56] The linear compressor according to the first preferred embodiment of the present invention is composed of a shell 50 filled with the lubricating oil, inhaling and discharging the working fluid, and composed of a compression unit arranged in the shell 50, and discharging the working fluid inhaled into the shell 50 after compressing with a predetermined pressure.

[57] The shell 50 may be composed of a lower container 52 that the upper part is opened and an upper cover 54 covering the upper part of the lower container 52. The inside of the shell 50 may be filled with the lubricating oil G for lubricating and refrigerating.

[58] A fluid suction pipe 56 inhaling the working fluid into the shell 50 from outside of the shell 50 is connected with the shell 50. Further, A fluid discharge pipe 58 leading the working fluid compressed in the compression unit to be discharged to outside of the shell 50 is connected with the shell.

[59] The compression unit may be arranged at between the cylinder block 60 arranged on a side in the shell 50 and the back cover 62 arranged on the other side in the shell 50.

[60] A fluid suction path 62' inhaling the working fluid passed through the fluid suction pipe 56 as connected with the fluid suction pipe may be arranged on the back cover 62. The back cover 62 may be supported by a damper spring 64 arranged between the back cover 62 and the shell 50.

[61] The compression unit may comprises a cylinder 70 fixed on the cylinder block 60 and having a compression chamber C where the working fluid is compressed, a piston 80 compressing the working fluid in the compression chamber C with a predetermined pressure ratio as reciprocated in the cylinder 70, a linear motor 90 reciprocating the piston 80 connected to be interlocked with the piston 80, and the oil supply unit 100 for lubricating and refrigerating of the cylinder 70 and the piston 80.

[62] The cylinder 70 is composed as a cylindrical shape that the both ends are opened for inserting the piston 80 into the inlet and for discharging the working fluid compressed in the compression chamber C.

[63] The piston 80 has a passing path 81 inhaling the working fluid passed through the back cover 62 and the fluid suction path 62' in the inside.

[64] A suction valve 84 is installed on the fluid passing path 81 of the piston 80 for connecting the fluid passing path 81 and the compression chamber C selectively as interlocked with the reciprocating movement of the piston 80 to inhale the working fluid in the fluid passing path 81 of the piston 80 into the compression chamber C from the discharging direction of the working fluid.

[65] The piston 80 is supported by the first and second springs 86 and 87 providing elastic force in the reciprocating direction of the piston 80 to reverse the reciprocating force during the reciprocating of the piston 80.

[66] The first piston spring 86 is supported by the piston 80 and cylinder block 60 as located between the cylinder 70 and the linear motor 90. The second piston spring 87 is arranged in a row with the first piston spring 86 as arranged between the piston 80 and the back cover 62.

[67] The linear motor 90 is broadly composed of a rotor connected with the piston 80 to be interlocked, and a stator interacted with the rotor electro magnetically for reciprocating the rotor.

[68] The rotor is positioned on the outer side of the cylinder 70 in the radius direction, and is composed of a magnet 92 installed to be reciprocated in the stator and, a magnet frame 94 on which the magnet is fixed and transferring the reciprocating force of the linear motor 90 to the piston 80 as connected to be interlocked with the piston 90.

[69] The stator is composed of a ring-shaped outer stator 95 fixed between the cylinder block 60 and the back cover 62 as positioned on the outside of the cylinder 70 in the radius direction, a coil 96 forming magnetic field as arranged in the outer stator 95, and a ring-shaped inner stator 98 pressurized on the outer side of the cylinder 70.

[70] A rotor is arranged on a gap between the outer stator 95 and the inner stator 98.

[71] The oil supply unit 100 is composed of a lubricating oil suction path 102 leading the lubricating oil G in the shell 50 to be inhaled into a gap between the cylinder 70 and the piston 80, a lubricating oil discharge path 104 leading the lubricating oil G inhaled into the gap between the cylinder 70 and the piston 80 to be discharged into the shell 50, and a lubricating oil pump 106 arranged on the lubricating oil suction path 102.

[72] The lubricating oil pump 106 is composed of a lubricating oil cylinder 106a connected with the lubricating oil suction path 102 as positioned on the lower side of the compression unit, a lubricating oil piston 106b arranged in the lubricating oil cylinder 106a to be capable of reciprocating in the lubricating oil cylinder 106a, and a pair of lubricating oil springs 106c and 106d reciprocating the lubricating oil piston 106a as resonated with the vibration generated by the operation of the linear compressor as arranged on the both sides of the lubricating oil piston 106b in the lubricating oil cylinder 106a.

[73] On the other hand, a discharge valve assembly 110 may be arranged on the outlet discharging the working fluid compressed in the compression chamber C in the cylinder 70.

[74] The discharge valve assembly 110 is arranged to cover the outlet of the cylinder 70, and is composed of a discharge plenum 112 communicated with the outlet of the cylinder 70 and having a discharge plenum outlet 112a to inhale and discharge the working fluid, a discharge cover 114 arranged on the outer side of the discharge plenum 112 and having a discharge cover outlet 114a to inhale and discharge the

working fluid, and a discharge valve 116 arranged in the discharge plenum 112 and opening and shutting the outlet of the cylinder 70.

[75] The part of the discharge plenum 112 faced with the outlet of the cylinder 70 is opened to be communicated with the outlet of the cylinder 70, and the discharge plenum 112 is formed as cap-shaped having a predetermined inner space to discharge the working fluid compressed in the cylinder 70 as well as having a discharge valve 116 in the inside. The cap-shaped discharge plenum 112 has a discharge plenum flange unit 112' extended to outside of the discharge cover to be adhered closely on the cylinder 70 and combined with the silencer 120 illustrated on the following.

[76] The discharge plenum flange unit 112' may be brazed on the cylinder 70 to combine the discharge plenum 112 with the cylinder 70 as a single organization.

[77] One or more of the plenum outlet 112a is arranged on the discharge plenum 112.

[78] It is desirable for the discharge plenum outlet 112a to be apart as far as it can be from the outlet 114a to minimize the discharge pulsation of the working fluid discharged after compressed in the cylinder 70.

[79] Therefore, in case that a plurality of the discharge plenum outlet 112a is arranged, all of the plural discharge plenum outlet 112a may be arranged on a side of the discharge plenum 112 to be positioned on the opposite side of the discharge cover outlet 114a.

[80] A part of the discharge cover 114 faced with the discharge plenum 112 is opened to inhale the working fluid of the discharge plenum 112, and the discharge cover 114 is formed as a cap shape to have a predetermined space with between the discharge plenum 112.

[81] The cap-shaped discharge cover 114 has a discharge cover flange unit 114' protruded to outside of the discharge cover 114 on a part faced with the discharge plenum 112 to be adhered closely to the discharge plenum flange unit 112'.

[82] The discharge cover flange unit 114' may be brazed on the discharge plenum flange unit 112' to combine the discharge cover 114 with the discharge plenum 112 as a single organization.

[83] The discharge cover 114 is planed as a geometric structure to minimize the noise of the pulsation of the working fluid discharged after compressed in the cylinder 70, and to maximize the capacity of the linear compressor.

[84] The discharge valve 116 is composed a discharge valve body 116a arranged as capable of retreated and advanced to the outlet of the cylinder 70 and a discharge valve spring 116b supporting the discharge valve body 116a elastically as positioned on the opposite side of the cylinder 70 as centering around the discharge valve body 116a.

[85] The discharge valve assembly 110 configured as above is connected with the silencer 120 for reducing the discharge pulsation of the working fluid discharged

through the discharge valve assembly 110 after compressed in the cylinder 70.

[86] The silencer 120 is arranged as a sort of mufflers having a noise reducing space of a predetermined size and a volume to reduce the discharge pulsation of the working fluid discharged through the discharge valve assembly 110 after compressed in the cylinder 70.

[87] The silencer 120 is arranged in the shell 50 to pass the working fluid discharged through the discharge assembly 110 after compressed in the cylinder 70.

[88] Especially, the silencer 120 may be composed as a single organization with the discharge valve assembly 110 to pass the working fluid discharged through the discharge valve assembly 110 immediately after compressed in the cylinder 70.

[89] That is, the silencer 120 may be composed of a silencer cover coupled with the discharge plenum flange unit 112', and a silencer chamber 124 that a part faced with the silencer cover is opened and having a predetermined space to reduce the discharge pulsation.

[90] The discharge plenum flange unit 112' maybe extended to be a silencer cover.

[91] The silencer cover and the silencer chamber 124 may be combined in a single organization.

[92] The silencer chamber 124 may be planned in a geometric organization for maximizing the reduction of the discharge pulsation of the working fluid discharged through the discharge valve assembly 110 after compressed in the cylinder 70.

[93] A silencer intake 124a inhaling the working fluid discharged through the discharge valve assembly 110 after compressed in the cylinder is formed on a side of the silencer chamber 124.

[94] The silencer intake 124a may be positioned on the center of the silencer 120 to maximize the reduction of the discharge pulsation of the working fluid discharged through the discharge valve assembly 110 after compressed in the cylinder 70 in a condition that the shape and the size of the silencer 120 are decided.

[95] A connection pipe 130 through which the working fluid discharged through the discharge valve assembly 110 after compressed in the cylinder 70 passes is arranged between the silencer intake 124a and the discharge cover outlet 114a.

[96] The connection pipe 130 may be brazed on the silencer chamber 124 and the discharge cover 114. A part of the connection pipe 130 is inserted into the silencer 120. At this time, the connection pipe 130 is planned to be inserted into the silencer 120 as a predetermined length in accordance with the special quality of the discharge pulsation of the working fluid discharged through the discharge valve assembly 110 after compressed in the cylinder 70, as the special quality of the discharge pulsation of the working fluid is changed in accordance with the inserted length of the connection pipe 130.

[97] Further, a silencer outlet 124b is positioned on the upper part of the silencer 120 to maximize the reduction of the discharge pulsation of the working fluid discharged through the discharge valve assembly 110 after compressed in the cylinder 70, and may be positioned to be close to the connection pipe 130. The discharge pipe 58 may be combined with the silencer outlet 124b as brazed.

[98] Reference will now be made in detail to operation of the linear compressor according to the first preferred embodiment of the present invention configured as above.

[99] When the linear motor 90 is operated, the magnet 92 is reciprocated with the magnet frame 94 with the electro magnetic interaction between the stator and the rotor, the reciprocating movement of the linear motor 90 is transferred to the piston 80 connected with the magnet frame 94, and the process inhaling and discharging the working fluid as the piston 80 is reciprocated in the cylinder 70 continually is repeated. That is, when the piston 80 is moved toward outside of the cylinder 70 as illustrated in FIG. 3, the suction valve 84 opens the fluid intake 82 of the piston 80 in accordance with the pressure difference between the fluid passing path 81 of the piston and the cylinder 70.

[100] Therefore, the working fluid is inhaled into the cylinder 70 as passing through the fluid suction pipe 56, the fluid suction path 62', the fluid passing path 81, and the fluid intake 82 of the piston 80 in order.

[101] At this time, the discharge valve 116 shuts the outlet of the cylinder 70 in accordance with the force balancing relation between the inner pressure of the cylinder 70 and the discharge valve spring 116b.

[102] On the other hand, when the piston 80 is moved toward the inside of the cylinder

70, the opposite direction of the above, as illustrated in FIGS. 4 and 5, the suction valve 84 shuts the fluid intake 82 of the piston 80 in accordance with the pressure difference between the fluid passing path 81 and the cylinder 70.

[103] Further, the working fluid 70 in the cylinder 70 is compressed by the piston 80 moved toward inside of the cylinder 70 with a predetermined pressure difference, and the discharge valve 116 opens the outlet of the cylinder 70 in accordance with the pressure in the cylinder 70 in accordance with the force balancing relation between the inner pressure of the cylinder 70 and the discharge valve spring 116b. Then, the working fluid compressed in the cylinder 70 is discharged as passing through the discharge plenum 112, the discharge cover 114, the connection pipe 130, the silencer 120, and the fluid discharge pipe 58 in order.

[104] At this time, when the working fluid is discharged after compressed in the cylinder

70, the discharge pulsation is reduced as the working fluid is passed through the silencer 120.

[105] FIG. 7 is a graph showing the pulsation timely compared in accordance with the presence of the silencer in the linear compressor according to the present invention, and FIG. 8 is a pulsation FFT graph in accordance with the presence of the silencer in the linear compressor according to the present invention.

[106] Referring to FIGS. 7 and 8, the discharge pulsation of the working fluid is greatly reduced as compared with when the silencer is not presented, as a lot of the high frequency harmonic ingredient exists and the shapes and the sizes are irregular when the silencer is not presented, however, the high frequency harmonic ingredient are hardly existed and the shapes and the sizes are maintained as the shape similar to the sine wave when the silencer is presented.

[107] Furthermore, the damage of the path of the fluid discharge pipe 58 caused by the discharge pulsation when the working fluid is passed through the silencer 120 is prevented.

[108] FIG. 9 is a cross-sectional view of the linear compressor according to the second preferred embodiment of the present invention.

[109] The examples of the preferred embodiment of the present invention and the repeated descriptions may be omitted, as the other organizations and operations excepting the combine organization of the discharge valve assembly and the silencer of the linear compressor according to the present preferred embodiment may be executed as same to the linear compressor according to the above-mentioned first preferred embodiment of the present invention.

[110] The linear compressor according to the second preferred embodiment of the present invention comprises a cylinder 152 arranged in the shell 150 and inhaling the working fluid through the fluid suction pipe 151, a piston 156 compressing the working fluid in the cylinder 152 as reciprocated in the cylinder 152 with the reciprocating force of the linear motor 154, a discharge valve assembly 160 discharging the working fluid compressed in the cylinder 152 as arranged on the outlet of the cylinder 152, and a silencer 170 equipped as a single organization with the discharge valve assembly 160 and reducing the discharge pulsation of the working fluid. The discharge valve assembly 160 includes a discharge plenum 162, a discharge valve 164 arranged in the discharge plenum 162, and a discharge cover 166 arranged on the outer side of the discharge plenum 162 and arranged with the silencer in a single organization.

[I l l] A surface of the silencer 170 may be contacted to a side of the discharge cover 166.

A silencer intake 171 connected with the discharge cover 166 may be formed on the part of the silencer 170 contacted to the side of the discharge cover 166. The silencer intake 171 may be extended toward the inside of the silencer 170 with a predetermined length.

[112] Reference will now be made in detail to the operation of the linear compressor

according to the second preferred embodiment of the present invention configured as above.

[113] When the linear motor 154 is operated, the piston 156 is reciprocated by reciprocating force of the linear motor 154 in the cylinder 152. Then, the working fluid is inhaled into the cylinder 152 through the fluid suction pipe 151 and compressed by the piston 156 with a predetermined pressure, and is discharged to the discharge plenum 162 and the discharge cover 166 in order.

[114] The working fluid discharged into the discharge cover 166 is directly inhaled into the silencer 170 from the discharge cover 166 through the noise intake 171, and the working fluid inhaled into the silencer 170 is discharged into the fluid discharge pipe 158 as passing through the silencer 170.

[115] The linear compressor according to the second preferred embodiment of the present invention configured and operated as above has some advantageous effects in that the path damage of the fluid discharge pipe 158 caused by the discharge pulsation of the working fluid is prevented as well as the discharge pulsation of the working fluid is minimized, as it is composed as the working fluid is passed through the silencer 170 right after discharged after compressed in the cylinder 152. Industrial Applicability

[116] The linear compressor according to the present invention configured as above has an advantage in that the flow-induced noise and the vibration caused by the discharge pulsation of the working fluid are minimized as reducing the discharge pulsation of the working fluid greatly in the silencer as composed to compress the working fluid in the compression unit with a predetermined ratio and to discharge the compressed working fluid after passing through the silencer.

[117] Further, the linear compressor according to the present invention has an advantage in that the interference of the silencer with other compositions in the products such as a refrigerator having a linear compressor is minimized as the silencer is arranged in the shell composing the external appearance of the linear compressor.

[118] Furthermore, the linear compressor according to the present invention has an advantage in that the damage of the path of the fluid discharge pipe leading the discharge of the working fluid is prevented as reducing the discharge pulsation of the working fluid right after discharged after compressing of the working fluid as arranging the silencer in the shell and connecting with the discharge valve assembly discharging the working fluid compressed in the compression unit.