US20150004021A1 - Linear compressor - Google Patents

Linear compressor Download PDF

Info

Publication number
US20150004021A1
US20150004021A1 US14/316,908 US201414316908A US2015004021A1 US 20150004021 A1 US20150004021 A1 US 20150004021A1 US 201414316908 A US201414316908 A US 201414316908A US 2015004021 A1 US2015004021 A1 US 2015004021A1
Authority
US
United States
Prior art keywords
piston
surface area
cylinder
linear compressor
compressor according
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US14/316,908
Other languages
English (en)
Inventor
Kyoungseok KANG
Wonhyun JUNG
Chulgi Roh
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
LG Electronics Inc
Original Assignee
LG Electronics Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by LG Electronics Inc filed Critical LG Electronics Inc
Assigned to LG ELECTRONICS INC. reassignment LG ELECTRONICS INC. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: Jung, Wonhyun, Kang, Kyoungseok, ROH, CHULGI
Publication of US20150004021A1 publication Critical patent/US20150004021A1/en
Abandoned legal-status Critical Current

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B17/00—Pumps characterised by combination with, or adaptation to, specific driving engines or motors
    • F04B17/03—Pumps characterised by combination with, or adaptation to, specific driving engines or motors driven by electric motors
    • F04B17/04—Pumps characterised by combination with, or adaptation to, specific driving engines or motors driven by electric motors using solenoids
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B35/00—Piston pumps specially adapted for elastic fluids and characterised by the driving means to their working members, or by combination with, or adaptation to, specific driving engines or motors, not otherwise provided for
    • F04B35/04—Piston pumps specially adapted for elastic fluids and characterised by the driving means to their working members, or by combination with, or adaptation to, specific driving engines or motors, not otherwise provided for the means being electric
    • F04B35/045—Piston pumps specially adapted for elastic fluids and characterised by the driving means to their working members, or by combination with, or adaptation to, specific driving engines or motors, not otherwise provided for the means being electric using solenoids
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B35/00—Piston pumps specially adapted for elastic fluids and characterised by the driving means to their working members, or by combination with, or adaptation to, specific driving engines or motors, not otherwise provided for
    • F04B35/04—Piston pumps specially adapted for elastic fluids and characterised by the driving means to their working members, or by combination with, or adaptation to, specific driving engines or motors, not otherwise provided for the means being electric
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B39/00—Component parts, details, or accessories, of pumps or pumping systems specially adapted for elastic fluids, not otherwise provided for in, or of interest apart from, groups F04B25/00 - F04B37/00
    • F04B39/0005—Component parts, details, or accessories, of pumps or pumping systems specially adapted for elastic fluids, not otherwise provided for in, or of interest apart from, groups F04B25/00 - F04B37/00 adaptations of pistons
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B39/00—Component parts, details, or accessories, of pumps or pumping systems specially adapted for elastic fluids, not otherwise provided for in, or of interest apart from, groups F04B25/00 - F04B37/00
    • F04B39/12—Casings; Cylinders; Cylinder heads; Fluid connections
    • F04B39/122—Cylinder block
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B51/00—Testing machines, pumps, or pumping installations
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K41/00—Propulsion systems in which a rigid body is moved along a path due to dynamo-electric interaction between the body and a magnetic field travelling along the path
    • H02K41/02—Linear motors; Sectional motors
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
    • F05C—INDEXING SCHEME RELATING TO MATERIALS, MATERIAL PROPERTIES OR MATERIAL CHARACTERISTICS FOR MACHINES, ENGINES OR PUMPS OTHER THAN NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES
    • F05C2253/00—Other material characteristics; Treatment of material
    • F05C2253/12—Coating

Definitions

  • a linear compressor is disclosed herein.
  • compressors may be mechanisms that receive power from power generation devices, such as electric motors or turbines, to compress air, refrigerants, or other working gases, thereby increasing a pressure of the working gas.
  • power generation devices such as electric motors or turbines
  • Compressors are widely used in home appliances or industrial machineries, such as refrigerators and air-conditioners.
  • Compressors may be largely classified into reciprocating compressors, in which a compression space, into and from which a working gas, such as a refrigerant, is suctioned and discharged, is defined between a piston and a cylinder to compress the refrigerant while the piston is linearly reciprocated within the cylinder; rotary compressors, in which a compression space into and from which a working gas, such as a refrigerant, is suctioned and discharged, is defined between a roller, which is eccentrically rotated, and a cylinder to compress the refrigerant while the roller is eccentrically rotated along an inner wall of the cylinder; and scroll compressors, in which a compression space, into and from which a working gas, such as a refrigerant, is suctioned and discharged, is defined between an orbiting scroll and a fixed scroll to compress the refrigerant while the orbiting scroll is rotated along the fixed scroll.
  • reciprocating compressors in which a compression space, into and from which a working gas,
  • linear compressors having a simple structure in which a piston is directly connected to a drive motor, which is linearly reciprocated, to improve compression efficiency without mechanical loss due to switching in moving, are being actively developed.
  • a linear compressor is configured to suction and compress a refrigerant while a piston is linearly reciprocated within a cylinder by a linear motor in a sealed shell, thereby discharging the compressed refrigerant.
  • the linear motor has a structure in which a permanent magnet is disposed between an inner stator and an outer stator.
  • the permanent magnet may be linearly reciprocated by a mutual electromagnetic force between the permanent magnet and the inner (or outer) stator. Also, as the permanent magnet is operated in a state in which the permanent magnet is connected to the piston, the refrigerant may be suctioned and compressed while the piston is linearly reciprocated within the cylinder and then be discharged.
  • a linear compressor according to the related art is disclosed in Korean Patent Publication No. 10-2010-0010421.
  • the piston repeatedly moves within the cylinder, interference between the cylinder and the piston may occur causing abrasion of the cylinder or piston. More particularly, when a predetermined pressure (a coupling pressure) acts on the piston causing deformation of the piston due to the pressure, interference between the cylinder and the piston may occur. Also, if a slight error occurs when the piston is assembled with the cylinder, a compression gas may leak to the outside, and thus, abrasion between the cylinder and the piston may occur.
  • a predetermined pressure a coupling pressure
  • the interference between the cylinder and the piston may occur causing interference between the permanent magnet and the inner and outer stators, thereby damaging components.
  • the cylinder and/or the piston may be formed of a magnetic material. Thus, a large amount of flux generated in the linear motor may leak to the outside through the cylinder and the piston, deteriorating efficiency of the compressor.
  • FIG. 1 is a cross-sectional view of a linear compressor in accordance with an embodiment
  • FIG. 2 is a cross-sectional view illustrating a coupling state between a cylinder and a piston according to an embodiment
  • FIG. 3 is a cross-sectional view illustrating a state in which the piston of FIG. 2 is moved in one direction;
  • FIG. 4 is a cross-sectional view illustrating a state in which a piston and a cylinder are coupled with each other according to an embodiment
  • FIG. 5 is a graph illustrating change in abrasion ratio of the cylinder or the piston according to a difference in hardness between first and second surface areas according to an embodiment.
  • FIG. 1 is a cross-sectional view of a linear compressor in accordance with an embodiment.
  • the linear compressor 10 may include a cylinder 120 disposed in a shell 100 , a piston 130 that linearly reciprocates in the cylinder 120 , and a motor assembly 200 that provides a drive force to the piston 130 .
  • the shell 100 may include an upper shell and a lower shell.
  • the shell 100 may further include an inlet 101 , through which a refrigerant may flow into the shell 100 , and an outlet 105 , through which the refrigerant compressed in the cylinder 120 may be discharged from the shell 100 .
  • the refrigerant sucked in through the inlet 101 may flow into the piston 130 through a suction muffler 140 . While the refrigerant passes through the suction muffler 140 , noise may be reduced.
  • a compression space P in which the refrigerant may be compressed by the piston 130 , may be provided in the cylinder 120 .
  • a suction hole 131 a through which the refrigerant may be introduced to the compression space P, may be provided at the piston 130 , and a suction valve 132 may be provided at a side of the suction hole 131 a to selectively open the suction hole 131 a.
  • a discharge valve assembly 170 , 172 , and 174 may be provided at a side of the compression space P to discharge the refrigerant compressed in the compression space P. That is, the compression space P may be defined between an end of the piston 130 and the discharge valve assembly 170 , 172 , and 174 .
  • the discharge valve assembly 170 , 172 , 174 may include a discharge cover 172 , which may define a discharge space for the refrigerant, a discharge valve 170 , which may be opened so that the refrigerant may be introduced into the discharge space when a pressure of the compression space P is more than a discharge pressure, and a valve spring 174 , which may be provided between the discharge valve 170 and the discharge cover 172 so as to provide an elastic force in an axial direction.
  • the term “axial direction” may refer to a reciprocating direction of the piston 130 , that is, a transverse direction in FIG. 1 .
  • the suction valve 132 may be provided at a first side of the compression space P, and the discharge valve 170 may be provided at a second side of the compression space P, that is, at an opposite side to the suction valve 132 .
  • the suction valve 132 may be opened, and the refrigerant may be suctioned into the compression space P.
  • the suction valve 132 may be closed and the refrigerant in the compression space P compressed.
  • the valve spring 174 may be deformed so as to open the discharge valve 170 , and the refrigerant discharged from the compression space P to the discharge space of the discharge cover 172 .
  • the refrigerant in the discharge space may be introduced into a loop pipe 178 through a discharge muffler 176 .
  • the discharge muffler 176 may reduce a flow noise of the compressed refrigerant, and the loop pipe 178 may guide the compressed refrigerant to the outlet 105 .
  • the loop pipe 178 may be coupled to the discharge muffler 176 and curvedly extended to be coupled to the outlet 105 .
  • the linear compressor 10 may further include a frame 110 .
  • the frame 110 may serve to fix the cylinder 200 within the shell 100 .
  • the frame 110 may be integrally provided with the cylinder 200 or may be fastened to the cylinder 200 by a separated fastening member, for example.
  • the discharge cover 172 and the discharge muffler 176 may be coupled to the frame 110 .
  • the motor assembly 200 may include an outer stator 210 , which may be fixed to the frame 110 and disposed to enclose or surround the cylinder 120 , an inner stator 220 , which may be disposed inside the outer stator 210 to be spaced apart from the outer stator 210 , and a permanent magnet 230 , which may be disposed at or in a space between the outer and inner stators 210 and 220 .
  • the permanent magnet 230 may be linearly reciprocated by an electromagnetic force between the outer and inner stators 210 and 220 .
  • the permanent magnet 230 may be a single magnet having one pole, or may be formed by coupling a plurality of magnets having three poles. More specifically, in a case of the permanent magnet 230 having three poles, one surface thereof may have a polar distribution of a N-S-N type, and the other surface thereof may have a polar distribution of a S-N-S type.
  • the permanent magnet 230 may be coupled to the piston 130 by a connection member 138 .
  • the connection member 138 may extend from an end of the piston 130 to the permanent magnet 130 .
  • the piston 130 may be linearly reciprocated together with the permanent magnet 230 in the axial direction.
  • the outer stator 210 may include a bobbin 213 , a coil 215 , and a stator core 211 .
  • the coil 215 may be wound in a circumferential direction of the bobbin 213 .
  • the coil 215 may have a polygonal shape, for example, a hexagonal shape.
  • the stator core 211 may be configured by stacking a plurality of laminations in the circumferential direction, and may be disposed so as to enclose the bobbin 213 and the coil 215 .
  • a current is applied to the motor assembly 200 , the current may flow through the coil 215 , and a magnetic flux may be generated around the coil 215 .
  • the magnetic flux may form a closed circuit and flow along the outer and inner stators 210 and 220 .
  • the magnetic flux flowing along the outer and inner stators 210 and 220 may interact with a magnetic flux of the permanent magnet 230 , and thus, a force to move the permanent magnet 230 may be generated.
  • a stator cover 240 may be provided at a side of the outer stator 210 .
  • a first side end of the outer stator 210 may be supported by the frame 110 , and a second side end thereof may be supported by the stator cover 240 .
  • the inner stator 220 may be fixed to an outer circumference of the cylinder 120 .
  • the inner stator 220 may be configured by stacking a plurality of laminations in a circumferential direction at an outside of the cylinder 120 .
  • the linear compressor 10 may further include a supporter 135 that supports the piston 130 , and a back cover 115 that extends from the piston 130 toward the inlet 101 .
  • the back cover 115 may be disposed so as to cover at least a portion of the suction muffler 140 .
  • the linear compressor 10 may include a plurality of springs 151 and 155 , a natural frequency of which may be controlled so as to enable a resonant motion of the piston 130 .
  • the plurality of springs 151 and 155 may include a plurality of first springs 151 , which may be disposed between the supporter 135 and the stator cover 240 , and a plurality of second springs 155 , which may be disposed between the supporter 135 and the back cover 115 .
  • the plurality of first springs 151 may be provided at both sides of the cylinder 120 or the piston 130
  • the plurality of second springs 155 may be provided at a front side of the cylinder 120 or the piston 130 .
  • the term a “front side” may refer to a direction from the piston 130 toward the inlet 101 .
  • the term a “rear side” may refer to a direction from the inlet 101 toward the discharge valve assembly 170 , 172 , and 174 . These terms may also be used in the below description.
  • a predetermined amount of oil may be stored at or in an internal bottom surface of the shell 100 , and an oil supplying device 160 may be provided at a lower side of the shell 100 to pump the oil.
  • the oil supplying device 160 may be operated by vibration generated when the piston 130 is linearly reciprocated, so as to pump the oil upwardly.
  • the linear compressor 10 may further include an oil supply pipe 165 that guides oil flow from the oil supplying device 160 .
  • the oil supply pipe 165 may extend from the oil supplying device 160 to a space between the cylinder 120 and the piston 130 .
  • the oil pumped from the oil supplying device 160 may be supplied to the space between the cylinder 120 and the piston through the oil supply pipe 165 , and perform cooling and lubricating functions.
  • FIG. 2 is a cross-sectional view illustrating a coupling state between a cylinder and a piston according to an embodiment.
  • FIG. 3 is a cross-sectional view illustrating a state in which the piston of FIG. 2 is moved in one direction.
  • FIG. 4 is a cross-sectional view illustrating a state in which a piston and a cylinder are coupled with each other according to an embodiment.
  • the piston 130 may be provided in the cylinder 120 to be reciprocated.
  • the piston 130 may be made of an aluminum material, for example, aluminum or an aluminum alloy, which is a non-magnetic material.
  • the piston 130 may be made of the aluminum material, magnetic flux generated at the motor assembly 200 may be prevented from being transferred to the piston 130 and then leaked to an outside of the piston 130 .
  • the piston 130 may be formed by forging, for example.
  • the piston 130 may include a piston body 131 , which may have an approximately cylindrical shape and may be disposed in the cylinder 120 , and a flange 136 , which may be radially expanded from a side end of the piston body 131 and coupled to the permanent magnet 230 .
  • the inlet 131 a may be provided at a first surface of the piston body 131 .
  • the first surface of the piston body 131 may be a surface facing the discharge valve 170 , for example, a rear surface thereof.
  • the piston body 131 may include an outer circumferential surface on which a first surface area 310 , which may be in the form of a predetermined layer or film, may be provided.
  • the first surface area 310 may be provided on the outer circumferential surface of the piston body 131 in a surface treatment manner. By providing the first surface area 310 , it is possible to improve abrasion resistance, lubricity, and heat resistance of the piston body 131 .
  • the first surface area 310 may be a “first coating layer”.
  • the first surface area 310 may be made of one of polytera fluoroethylene (PTFE), diamond like carbon (DLC), a nickel-phosphorus alloy, or an anodizing layer.
  • the flange 136 may include a plurality of holes 137 a and 137 b .
  • the plurality of holes 137 a and 137 b may include one or more coupling holes 137 a , in which a fastening member coupled with the supporter 135 and the connection member 138 may be inserted, and one or more through-holes 137 b , which may reduce flow resistance generated around the piston 130 .
  • the cylinder 120 may be made of an aluminum material, for example, aluminum or an aluminum alloy, which is a non-magnetic material.
  • a material composition ratio that is, a kind and composition of the material in each of the cylinder 120 and the piston 130 may be the same.
  • the cylinder 120 may be made of the aluminum material, magnetic flux generated at the motor assembly 200 may be prevented from being transferred to the cylinder 120 and then leaked to an outside of the cylinder 120 . Further, the cylinder 120 may be formed by extruded rod processing, for example.
  • the piston 130 and the cylinder 120 may be made of the same material, for example, aluminum, the piston 130 and the cylinder 120 may have a same thermal expansion coefficient. While the linear compressor 10 is operated, a high temperature environment approximately (100° C.) is created in the shell 100 . As the piston 130 and the cylinder 120 have the same thermal expansion coefficient, the piston 130 and the cylinder 120 may be equally thermally deformed. As the piston 130 and the cylinder 120 may be thermally deformed in different sizes or directions, the piston 130 may be prevented from interfering with the cylinder 120 , while the piston 130 is reciprocated.
  • the cylinder 120 may have the hollow cylindrical shape, and the piston body 131 may be movably received therein.
  • the cylinder 120 may include an inner circumferential surface disposed opposite to an outer circumferential surface of the piston body 131 .
  • a second surface area 320 which may be in the form of a predetermined layer or film, may be provided on the inner circumferential surface of the cylinder 120 .
  • the second surface area 320 may be provided using a different surface treatment from that of the first surface area 310 . By providing the second surface area 320 , it is possible to improve abrasion resistance, lubricity, and heat resistance of the piston body 131 .
  • the second surface area 320 may be a “second coating layer”.
  • the second surface area 320 may be made of one of Teflon (PTFE), diamond like carbon (DLC), a nickel-phosphorus alloy, or a anodizing layer.
  • a certain difference in hardness between the outer circumferential surface of the piston 130 and the inner circumferential surface of the cylinder 120 may be generated. If the difference in hardness therebetween is too small, one of the piston 130 or the cylinder 120 may be stuck to the other one, that is, the surface thereof may be worn, while the piston 130 is reciprocated in the cylinder 120 .
  • each of the piston 130 having the first surface area 310 and the cylinder 120 having the second surface area 320 may have a hardness greater than a predetermined value, and thus, the abrasion resistance of the piston 130 and the cylinder 120 may be improved.
  • the first surface area 310 or the second surface area 320 may include polytera fluoroethylene (PTFE).
  • PTFE is a fluorinate polymer, which is referred to as “Teflon”.
  • the PTFE may be sprayed on the outer circumferential surface of the piston 130 or the inner circumferential surface of the cylinder 120 , and treated by heating and plastic working at a predetermined temperature, thereby providing an inactive coating layer.
  • the PTFE may be coated on the outer circumferential surface of the piston 130 or the inner circumferential surface of the cylinder 120 , to enhance lubricity and abrasion resistance of the surface.
  • the hardness of the PTFE is very small, and may be measured by a measuring method of pencil hardness.
  • the hardness of the PTFE may be more than a pencil hardness of HB.
  • the PTFE may have approximately 0 to approximately 30Hv (referring to Table 1).
  • the first surface area 310 or the second surface area 320 may include a film prepared by an anodizing technique, that is, an anodizing layer.
  • the anodizing technique is a kind of aluminum painting, in which, when current is applied in a state in which aluminum is used as an anode, an aluminum surface is oxidized by oxygen generated at the anode, and thus, an oxidized aluminum layer is provided.
  • the anodizing layer has excellent corrosion resistance and electrical breakdown resistance.
  • the hardness of the anodizing layer may be changed according to a state or a composition of a material (a basic material) to be coated, and may be approximately 300 to 500Hv (referring to Table 1).
  • the first surface area 310 or the second surface area 320 may include diamond-like carbon (DLC).
  • DLC is an amorphous carbon-based new material which is a thin film-shaped material prepared by electrically accelerating carbon ions in plasma or activated hydrocarbon molecules and smashing them on the surface.
  • DLC has similar physical properties to diamond, and thus, has high hardness and abrasion resistance, excellent electrical breakdown resistance, a low frictional coefficient, and excellent lubricity.
  • the hardness of the DLC may be approximately 1,500 to 1,800 (referring to Table 1).
  • the first surface area 310 or the second surface area 320 may include a nickel-phosphorus alloy material.
  • the nickel-phosphorus alloy material may be provided on the outer circumferential surface of the piston 130 or the inner circumferential surface of the cylinder 120 by an electroless nickel plating manner, such that nickel and phosphorus are surface-segregated in a uniform thickness.
  • the nickel-phosphorus alloy material may have a chemical composition in which nickel content is approximately 90 to 92%, phosphorus content is approximately 9 to 10%.
  • the nickel-phosphorus alloy material may improve corrosion resistance and abrasion resistance of the surface and also provide excellent lubricity.
  • the hardness of the nickel-phosphorus alloy material may be approximately 500 to 600Hv. (referring to Table 1).
  • the first surface area 310 or the second surface area 320 may be provided by one of the four coating materials (methods), for example.
  • first surface area 310 and the second surface area 320 may be provided by different coating materials (methods) from each other. Therefore, the outer circumferential surface of the piston 130 and the inner circumferential surface of the cylinder 120 may have a hardness difference, which is more than a predetermined value.
  • a hardness valve of the first surface area 310 may be referred to as a “first hardness value”
  • a hardness value of the second surface area 320 may be referred to as a “second hardness value”.
  • the above four materials may be selected to provide the hardness difference which is more than the predetermined value.
  • a change in an abrasion ratio of the cylinder or the piston according to the hardness difference between the first and second surface areas will be described.
  • FIG. 5 is a graph illustrating change in abrasion ratio of the cylinder or the piston according to a hardness difference between first and second surface areas in accordance with an embodiment.
  • a predetermined surface area was provided on each of the outer circumferential surface of the piston 130 and the inner circumferential surface of the cylinder 120 , and an abrasion ratio occurring at the piston or the cylinder according to a hardness difference between surface area was experimentally measured and organized.
  • the predetermined surface area was prepared using various materials or methods other than the four methods described in Table 1.
  • the surface areas were provided so that the hardness difference between the first surface area 310 of the piston 130 and the second surface area 320 of the cylinder 120 was approximately 50Hv, and then, for example, reciprocation of the piston 130 was performed for approximately 100 hours or more.
  • the abrasion ratio of the piston 130 or the cylinder 120 was approximately 5 ⁇ m
  • the abrasion ratio of the piston 130 or the cylinder 120 was approximately 4 ⁇ m.
  • the abrasion ratio of the piston 130 or the cylinder 120 was approximately 3 ⁇ m.
  • P1 is formed around approximately 150Hv. In a range in which the hardness difference is P1 or more, the abrasion ratio is maintained at 3 ⁇ m or less. As the hardness difference is increased, the abrasion ratio may be gradually decreased.
  • each surface treatment or area may be selected so that the hardness difference between the first surface area 310 of the piston 130 and the second surface area 320 of the cylinder 120 is approximately 150Hv or more.
  • Table 2 shows hardness difference values calculated by using an average hardness value of each coating material. More specifically, when the anodizing layer is provided at or on one of the first surface area 310 or the second surface area 320 , and the Ni—P alloy is provided at or on the other one, the hardness difference is approximately 150Hv. However, when the DLC is provided at or on one of the first surface area 310 or the second surface area 320 , and the PTFE is provided at or on the other one, the hardness difference is approximately 1,635Hv.
  • the hardness difference is approximately 385Hv.
  • the hardness difference is approximately 535Hv.
  • the hardness difference is approximately 1,250Hv.
  • the hardness difference is approximately 1,100Hv.
  • the hardness difference value between the piston 130 and the cylinder 120 is approximately minimum 150Hv and approximately maximum 1,635Hv. That is, the hardness difference value may be at least approximately 150Hv or more.
  • the hardness difference which is a reference for determining abrasion resistance
  • the hardness difference may be maintained at approximately 150Hv or more.
  • abrasion resistance of the piston 130 or the cylinder 120 may be maintained at a predetermined level. Therefore, during reciprocation of the piston 130 , it is possible to secure operation reliability of the piston 130 or the cylinder 120 .
  • the hardness difference between the first and second surface areas 310 and 320 may be approximately 385Hv, and thus, it is possible to satisfy the required hardness difference value.
  • the hardness difference between the first and second surface areas 310 and 320 may be approximately 150 to 385Hv, approximately 150 to 535Hv, approximately 150 to 1,100Hv, approximately 150 to 1250Hv, or approximately 150 to approximately 1,635Hv.
  • the PTFE coating layer may be provided on the piston 130 which is reciprocated, and thus, it is possible to improve lubricity.
  • the anodizing layer may be provided on the cylinder 120 , and thus, it is possible to improve corrosion resistance and electrical breakdown resistance, and also, it is possible to secure operation reliability of the piston 130 and the cylinder 120 .
  • the cylinder and the piston may be made of a non-magnetic material, more particularly, an aluminum material, it is possible to prevent flux generated from the motor assembly from being leaked to the outside of the cylinder, and also, it is possible to improve efficiency of the compressor.
  • the surface treatment or area may be provided at or on each of opposite surfaces of the piston and the cylinder, more particularly, the outer circumferential surface of the piston and the inner circumferential surface of the cylinder, it is possible to increase abrasion resistance, and thus, to improve reliability of components of the compressor.
  • a hardness difference value between a first surface treatment or area provided on an outer circumferential surface of the piston and a second surface treatment or area provided on an inner circumferential surface of the cylinder may be provided within a predetermined range, it is possible to reduce an abrasion ratio of the cylinder or the piston. More particularly, as the difference value between the hardness of the first surface area and a hardness of the second surface area may be maintained at a predetermined value or more, it is possible to prevent the outer circumferential surface of the piston from being stuck to the inner circumferential surface of the cylinder, and thus, to prevent damage to the piston or the cylinder.
  • the permanent magnet provided at the motor assembly may be made of a ferrite material, which is relatively inexpensive, it is possible to reduce manufacturing costs of the compressor.
  • Embodiments disclosed herein provide a linear compressor that prevents abrasion or damage of internal components thereof.
  • Embodiments disclosed herein provide a linear compressor that may include a shell including a refrigerant inlet, an outer stator provided in the shell and including a coil, an inner stator disposed to be spaced apart from the outer stator, a permanent magnet disposed to be movable between the outer stator and the inner stator, a cylinder including a compression space in which a refrigerant sucked in through the refrigerant inlet is compressed, a piston coupled to the permanent magnet so as to be reciprocated in the cylinder, a first surface treatment part or first surface area provided at or on the piston so as to have a first hardness value, and a second surface area part or second surface treatment provide at or on the cylinder so as to have a second hardness value so that a difference value between the first and second hardness values is more than a preset value.
  • the preset value may be at least approximately 150Hv or more based on Vickers hardness.
  • the preset value may be determined, so that an abrasion amount generated at the piston or the cylinder, while the piston is repeatedly reciprocated for a predetermined period of time, may be approximately 3 ⁇ m or less.
  • the first surface treatment part or the second treatment part may be made of one of polytetra fluoroethylene (PTFE), diamond like carbon (DLC), an Ni—P alloy, and an anodizing layer.
  • the first surface treatment part may be made of one of the PTFE, the DLC, the Ni—P alloy, and the anodizing layer
  • the second treatment part may be made of another one of the PTFE, the DLC, the Ni—P alloy, and the anodizing layer, which is different from the first surface treatment part.
  • the first surface treatment part may be made of the PTFE
  • the second surface treatment part may be made of the anodizing layer.
  • the piston and the cylinder may be made of a non-magnetic material.
  • the piston and the cylinder may be made of aluminum or an aluminum alloy.
  • the aluminum or the aluminum alloy of the piston and the cylinder may be the same material.
  • the first surface treatment part may be provided on an outer circumferential surface of the piston.
  • the second surface treatment part may be provided on an inner circumferential surface of the cylinder, which is opposite to the outer circumferential surface of the piston.
  • the piston may include a piston body received in the cylinder, and a flange part or flange expanded in a radial direction of the piston body and coupled to the permanent magnet.
  • the first surface treatment part may be provided on an outer circumferential surface of the piston body.
  • Embodiments disclosed herein provide a linear compressor that may include a piston, which is reciprocated in a cylinder by a force generated by an interaction between a flux generated by a current applied to a coil and a flux of a permanent magnet, and which includes a first surface treatment part or first surface area provided on an outer circumferential surface of the piston, and a second surface treatment part or second surface area provided on an inner circumferential surface of the cylinder.
  • a hardness value measured at the first surface treatment part and a hardness value measured at the second surface treatment part may make a preset hardness difference.
  • Embodiments disclosed herein provide a linear compressor that may include a shell including a refrigerant inlet, an outer stator provided in the shell and including a coil, an inner stator disposed to be spaced apart from the outer stator, a permanent magnet disposed to be movable between the outer stator and the inner stator, a cylinder including a compression space in which a refrigerant sucked in through the refrigerant inlet may be compressed, a piston coupled to the permanent magnet so as to be reciprocated in the cylinder, a polytera fluroethylene (PTFE) coating layer, which may be surface-treated on an outer circumferential surface of the piston, and an anodizing layer which may be surface-treated on an inner circumferential surface of the cylinder.
  • PTFE polytera fluroethylene
  • any reference in this specification to “one embodiment,” “an embodiment,” “example embodiment,” etc. means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention.
  • the appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Electromagnetism (AREA)
  • Power Engineering (AREA)
  • Compressors, Vaccum Pumps And Other Relevant Systems (AREA)
  • Compressor (AREA)
  • Reciprocating, Oscillating Or Vibrating Motors (AREA)
US14/316,908 2013-06-28 2014-06-27 Linear compressor Abandoned US20150004021A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
KR1020130075514A KR101454550B1 (ko) 2013-06-28 2013-06-28 리니어 압축기
KR10-2013-075514 2013-06-28

Publications (1)

Publication Number Publication Date
US20150004021A1 true US20150004021A1 (en) 2015-01-01

Family

ID=50732021

Family Applications (1)

Application Number Title Priority Date Filing Date
US14/316,908 Abandoned US20150004021A1 (en) 2013-06-28 2014-06-27 Linear compressor

Country Status (6)

Country Link
US (1) US20150004021A1 (ja)
EP (1) EP2818708B1 (ja)
JP (1) JP6469372B2 (ja)
KR (1) KR101454550B1 (ja)
CN (2) CN104251190B (ja)
BR (1) BR102014015672A2 (ja)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20170093918A1 (en) * 2015-09-30 2017-03-30 Symantec Corporation Automated construction of network whitelists using host-based security controls
US20170218931A1 (en) * 2013-06-28 2017-08-03 Lg Electronics Inc. Linear compressor
US20170284428A1 (en) * 2014-09-12 2017-10-05 Smc Corporation Hydraulic cylinder
US20170321673A1 (en) * 2016-05-03 2017-11-09 Lg Electronics Inc. Linear compressor and method for manufacturing a linear compressor
US20170321676A1 (en) * 2016-05-03 2017-11-09 Lg Electronics Inc. Linear compressor
US10890168B2 (en) * 2016-11-14 2021-01-12 Lg Electronics Inc. Linear compressor
US11384836B2 (en) * 2019-12-11 2022-07-12 Lg Electronics Inc. Piston for compressor

Families Citing this family (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN203906210U (zh) 2013-06-28 2014-10-29 Lg电子株式会社 线性压缩机
CN203867810U (zh) 2013-06-28 2014-10-08 Lg电子株式会社 线性压缩机
CN203835658U (zh) 2013-06-28 2014-09-17 Lg电子株式会社 线性压缩机
KR101454550B1 (ko) * 2013-06-28 2014-10-27 엘지전자 주식회사 리니어 압축기
CN104251196B (zh) 2013-06-28 2016-10-05 Lg电子株式会社 线性压缩机
CN204126840U (zh) 2013-06-28 2015-01-28 Lg电子株式会社 线性压缩机
DE102015001366A1 (de) * 2015-02-03 2016-08-04 Linde Aktiengesellschaft Zylinderlaufflächen in Fluidarbeitsmaschinen
KR102333982B1 (ko) 2015-07-01 2021-12-02 엘지전자 주식회사 리니어 압축기
KR101774012B1 (ko) * 2016-02-29 2017-09-01 엄현덕 골프 퍼팅용 방향 지시장치
KR101873002B1 (ko) * 2016-07-05 2018-07-02 박능출 코팅 리니어 피스톤 및 코팅 리니어 피스톤의 코팅 방법
CN108626099A (zh) * 2018-07-16 2018-10-09 蚌埠市昊源压缩机制造有限公司 一种压缩机活塞装置
US20200355176A1 (en) * 2019-05-08 2020-11-12 Haier Us Appliance Solutions, Inc. Linear compressor with oil splash shield
KR102324069B1 (ko) * 2020-02-05 2021-11-10 엘지전자 주식회사 압축기
KR102292633B1 (ko) 2020-02-20 2021-08-20 엘지전자 주식회사 피스톤의 베어링 구조 및 이를 적용한 리니어 압축기
KR102466986B1 (ko) 2020-03-27 2022-11-11 엘지전자 주식회사 리니어 모터 및 이를 적용한 리니어 압축기

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6328544B1 (en) * 1998-11-19 2001-12-11 Matsushita Electric Industrial Co., Ltd. Linear compressor
US6575716B1 (en) * 1998-12-01 2003-06-10 Matsushita Refrigeration Co. Linear compressor
US20050098031A1 (en) * 2001-11-08 2005-05-12 Hyung-Pyo Yoon Abrasion preventive structure of reciprocating compressor
US20080000348A1 (en) * 2004-12-23 2008-01-03 Bsh Bosch Und Siemens Hausgerate Gmbh Linear Compressor
US20130058815A1 (en) * 2011-09-06 2013-03-07 Donghan KIM Reciprocating compressor with gas bearing

Family Cites Families (23)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0028144A1 (en) * 1979-10-29 1981-05-06 Gordon Davey Support system for a reciprocating compressor piston
JPH04116278A (ja) * 1990-09-04 1992-04-16 Hitachi Ltd 冷媒圧縮用レシプロ型圧縮機
GB9021568D0 (en) * 1990-10-04 1990-11-21 Lucas Ind Plc Compressors for refrigeration apparatus
JPH05240156A (ja) * 1992-08-21 1993-09-17 Toshiba Corp 往復動型ピストンポンプ
JPH0819906B2 (ja) * 1992-09-04 1996-03-04 久男 北條 真空ポンプおよび真空排気装置
JP4156762B2 (ja) 1999-11-30 2008-09-24 本田技研工業株式会社 Ｓｉ系アルミニウム合金の表面処理方法
JP2001165044A (ja) * 1999-12-10 2001-06-19 Matsushita Refrig Co Ltd 摺動部材
JP2002031046A (ja) * 2000-07-17 2002-01-31 Zexel Valeo Climate Control Corp 斜板式圧縮機
JP2002138954A (ja) 2000-08-24 2002-05-17 Zexel Valeo Climate Control Corp 回転斜板式圧縮機
NL1019858C2 (nl) * 2002-01-29 2003-09-08 Thales Nederland Bv De onderhavige uitvinding heeft in het algemeen betrekking op cryogene koelers en in het bijzonder op de werkwijze voor de assemblage van de compressor van cryogene koelers en op middelen voor het in positie houden van de zuiger die in dergelijke cryogene koelers wordt gebruikt.
JP2004301074A (ja) * 2003-03-31 2004-10-28 Sanyo Electric Co Ltd 半密閉型多段圧縮機
JP2005155438A (ja) * 2003-11-26 2005-06-16 Matsushita Electric Ind Co Ltd 密閉型圧縮機
US7547643B2 (en) * 2004-03-31 2009-06-16 Applied Materials, Inc. Techniques promoting adhesion of porous low K film to underlying barrier layer
US7988430B2 (en) * 2006-01-16 2011-08-02 Lg Electronics Inc. Linear compressor
JP2008045493A (ja) * 2006-08-17 2008-02-28 Nachi Fujikoshi Corp ラジアルピストンポンプまたはモータ
JP2008144714A (ja) * 2006-12-12 2008-06-26 Ngk Spark Plug Co Ltd コンプレッサ、真空ポンプ、圧縮・真空複合機、及び酸素濃縮器
KR101343584B1 (ko) * 2007-10-19 2013-12-19 엘지전자 주식회사 왕복동식 압축기
WO2009054636A1 (en) * 2007-10-24 2009-04-30 Lg Electronics, Inc. Linear compressor
KR20100010421A (ko) * 2008-07-22 2010-02-01 엘지전자 주식회사 모터의 스테이터 및 이를 적용한 리니어 모터와 리니어압축기
KR100966132B1 (ko) * 2008-07-25 2010-06-25 주식회사 코미코 내 플라즈마성 갖는 세라믹 코팅체
KR101766242B1 (ko) * 2010-03-15 2017-08-08 엘지전자 주식회사 왕복동식 압축기
JP2013015092A (ja) 2011-07-05 2013-01-24 Daikin Industries Ltd 圧縮機
KR101454550B1 (ko) * 2013-06-28 2014-10-27 엘지전자 주식회사 리니어 압축기

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6328544B1 (en) * 1998-11-19 2001-12-11 Matsushita Electric Industrial Co., Ltd. Linear compressor
US6575716B1 (en) * 1998-12-01 2003-06-10 Matsushita Refrigeration Co. Linear compressor
US20050098031A1 (en) * 2001-11-08 2005-05-12 Hyung-Pyo Yoon Abrasion preventive structure of reciprocating compressor
US20080000348A1 (en) * 2004-12-23 2008-01-03 Bsh Bosch Und Siemens Hausgerate Gmbh Linear Compressor
US20130058815A1 (en) * 2011-09-06 2013-03-07 Donghan KIM Reciprocating compressor with gas bearing

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20170218931A1 (en) * 2013-06-28 2017-08-03 Lg Electronics Inc. Linear compressor
US10634127B2 (en) * 2013-06-28 2020-04-28 Lg Electronics Inc. Linear compressor
US20170284428A1 (en) * 2014-09-12 2017-10-05 Smc Corporation Hydraulic cylinder
US10480546B2 (en) * 2014-09-12 2019-11-19 Smc Corporation Hydraulic cylinder
US20170093918A1 (en) * 2015-09-30 2017-03-30 Symantec Corporation Automated construction of network whitelists using host-based security controls
US20170321673A1 (en) * 2016-05-03 2017-11-09 Lg Electronics Inc. Linear compressor and method for manufacturing a linear compressor
US20170321676A1 (en) * 2016-05-03 2017-11-09 Lg Electronics Inc. Linear compressor
US10495081B2 (en) * 2016-05-03 2019-12-03 Lg Electronics Inc. Linear compressor
US10941758B2 (en) * 2016-05-03 2021-03-09 Lg Electronics Inc. Linear compressor and method for manufacturing a linear compressor
US10890168B2 (en) * 2016-11-14 2021-01-12 Lg Electronics Inc. Linear compressor
US11384836B2 (en) * 2019-12-11 2022-07-12 Lg Electronics Inc. Piston for compressor

Also Published As

Publication number Publication date
CN203978749U (zh) 2014-12-03
BR102014015672A2 (pt) 2016-05-31
JP6469372B2 (ja) 2019-02-13
CN104251190A (zh) 2014-12-31
EP2818708A3 (en) 2015-10-07
EP2818708B1 (en) 2016-07-20
EP2818708A2 (en) 2014-12-31
CN104251190B (zh) 2016-12-07
KR101454550B1 (ko) 2014-10-27
JP2015010610A (ja) 2015-01-19

Similar Documents

Publication Publication Date Title
US20150004021A1 (en) Linear compressor
US10634127B2 (en) Linear compressor
US9695811B2 (en) Linear compressor
US9677553B2 (en) Linear compressor
US10871154B2 (en) Linear compressor having suction muffler
US10941758B2 (en) Linear compressor and method for manufacturing a linear compressor
US11415126B2 (en) Piston for compressor
US20170002808A1 (en) Compressor
US20160056699A1 (en) Linear compressor
US11225958B2 (en) Linear compressor
KR102148260B1 (ko) 리니어 압축기
US11384836B2 (en) Piston for compressor
JP6878443B2 (ja) ロータリ圧縮機および冷凍サイクル装置
KR20210080920A (ko) 압축기용 피스톤

Legal Events

Date Code Title Description
AS Assignment

Owner name: LG ELECTRONICS INC., KOREA, REPUBLIC OF

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:KANG, KYOUNGSEOK;JUNG, WONHYUN;ROH, CHULGI;REEL/FRAME:033193/0587

Effective date: 20140507

STCB Information on status: application discontinuation

Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION