US20080213108A1 - Linear Compressor - Google Patents

Linear Compressor Download PDF

Info

Publication number
US20080213108A1
US20080213108A1 US11/660,732 US66073204A US2008213108A1 US 20080213108 A1 US20080213108 A1 US 20080213108A1 US 66073204 A US66073204 A US 66073204A US 2008213108 A1 US2008213108 A1 US 2008213108A1
Authority
US
United States
Prior art keywords
movable member
load
spring constant
pressure
linear compressor
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
US11/660,732
Other languages
English (en)
Inventor
Bong-Jun Choi
Chang-Yong Jang
Man-Seok Cho
Shin-Hyun Park
Hyun Kim
Jong-Min Shin
Young-Hoan Jeon
Chul-Gi 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
Family has litigation
First worldwide family litigation filed litigation Critical https://patents.darts-ip.com/?family=36000240&utm_source=google_patent&utm_medium=platform_link&utm_campaign=public_patent_search&patent=US20080213108(A1) "Global patent litigation dataset” by Darts-ip is licensed under a Creative Commons Attribution 4.0 International License.
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: CHO, MAN SEOK, CHOI, BONG JUN, JANG, CHANG YONG, JEON, YOUNG HOAN, KIM, HYUN, PARK, SHIN HYUN, ROH, CHUL GI, SHIN, JONG MIN
Publication of US20080213108A1 publication Critical patent/US20080213108A1/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
    • 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
    • F04B2201/00—Pump parameters
    • F04B2201/08—Cylinder or housing parameters
    • F04B2201/0806—Resonant frequency
    • 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
    • F04B2207/00—External parameters
    • F04B2207/04—Settings
    • F04B2207/045—Settings of the resonant frequency of the unit motor-pump

Definitions

  • the present invention relates to a linear compressor which can actively handle load and efficiently perform an operation, by synchronizing an operation frequency with a natural frequency of a movable member varied by the load.
  • a compressor that is a mechanical apparatus for increasing a pressure, by receiving power from a power unit system such as an electric motor or turbine and compressing air, refrigerants or other various operation gases has been widely used for home appliances such as a refrigerator and an air conditioner or in the whole industrial fields.
  • the compressors are roughly divided into a reciprocating compressor having a compression space through which operation gases are sucked or discharged between a piston and a cylinder, so that the piston can be linearly reciprocated inside the cylinder to compress refrigerants, a rotary compressor having a compression space through which operation gases are sucked or discharged between an eccentrically-rotated roller and a cylinder, so that the roller can be eccentrically rotated on the inner walls of the cylinder to compress refrigerants, and a scroll compressor having a compression space through which operation gases are sucked or discharged between an orbiting scroll and a fixed scroll, so that the orbiting scroll can be rotated with the fixed scroll to compress refrigerants.
  • a linear compressor has been mass-produced because it has high compression efficiency and simple structure by removing mechanical loss by motion conversion by directly connecting a piston to a driving motor performing linear reciprocation.
  • the linear compressor which sucks, compresses and discharges refrigerants by using a linear driving force of the motor includes a compression unit consisting of a cylinder and a piston for compressing refrigerant gases, and a driving unit consisting of a linear motor for supplying a driving force to the compression unit.
  • the cylinder in the linear compressor, the cylinder is fixedly installed in a closed vessel, and the piston is installed in the cylinder to perform linear reciprocation.
  • the piston When the piston is linearly reciprocated inside the cylinder, refrigerants are sucked into a compression space in the cylinder, compressed and discharged.
  • a suction valve assembly and a discharge valve assembly are installed in the compression space, for controlling suction and discharge of the refrigerants according to the inside pressure of the compression space.
  • the linear motor for generating a linear motion force to the piston is installed to be connected to the piston.
  • An inner stator and an outer stator formed by stacking a plurality of laminations at the periphery of the cylinder in the circumferential direction are installed on the linear motor with a predetermined gap.
  • a coil is coiled inside the inner stator or the outer stator, and a permanent magnet is installed at the gap between the inner stator and the outer stator to be connected to the piston.
  • the permanent magnet is installed to be movable in the motion direction of the piston, and linearly reciprocated in the motion direction of the piston by an electromagnetic force generated when a current flows through the coil.
  • the linear motor is operated at a constant operation frequency f c , and the piston is linearly reciprocated by a predetermined stroke S.
  • various springs are installed to elastically support the piston in the motion direction even though the piston is linearly reciprocated by the linear motor.
  • a coil spring which is a kind of mechanical spring is installed to be elastically supported by the closed vessel and the cylinder in the motion direction of the piston.
  • the refrigerants sucked into the compression space serve as a gas spring.
  • the coil spring has a constant mechanical spring constant K m
  • the gas spring has a gas spring constant K g varied by load.
  • a natural frequency f n of the piston (or linear compressor) is calculated in consideration of the mechanical spring constant K m and the gas spring constant K g .
  • the thusly-calculated natural frequency f n of the piston determines the operation frequency f c of the linear motor.
  • the linear motor improves efficiency by equalizing its operation frequency f c to the natural frequency f n of the piston, namely, operating in the resonance state.
  • the linear compressor when a current is applied to the linear motor, the current flows through the coil to generate an electromagnetic force by interactions with the outer stator and the inner stator, and the permanent magnet and the piston connected to the permanent magnet are linearly reciprocated by the electromagnetic force.
  • the linear motor is operated at the constant operation frequency f c .
  • the operation frequency f c of the linear motor is equalized to the natural frequency f n of the piston, so that the linear motor can be operated in the resonance state to maximize efficiency.
  • the inside pressure of the compression space is changed.
  • the refrigerants are sucked into the compression space, compressed and discharged according to changes of the inside pressure of the compression space.
  • the linear compressor is formed to be operated at the operation frequency f c identical to the natural frequency f n of the piston calculated by the mechanical spring constant K m of the coil spring and the gas spring constant K g of the gas spring under the load considered in the linear motor at the time of design. Therefore, the linear motor is operated in the resonance state merely under the load considered on design, to improve efficiency.
  • the operation frequency f c of the linear motor is determined to be identical to the natural frequency f n of the piston in a middle load area at the time of design. Even if the load is varied, the linear motor is operated at the constant operation frequency f c . But, as the load increases, the natural frequency f n of the piston increases.
  • f n represents the natural frequency of the piston
  • K m and K g represent the mechanical spring constant and the gas spring constant, respectively
  • M represents a mass of the piston.
  • the gas spring constant K g has a small ratio in the total spring constant K t , the gas spring constant K g is ignored or set to be a constant value.
  • the mass M of the piston and the mechanical spring constant K m are also set to be constant values. Therefore, the natural frequency f n of the piston is calculated as a constant value by the above Formula 1.
  • the operation frequency f c of the linear motor and the natural frequency f n of the piston are identical in the middle load area, so that the piston can be operated to reach a top dead center (TDC), thereby stably performing compression.
  • the linear motor is operated in the resonance state, to maximize efficiency of the linear compressor.
  • the natural frequency f n of the piston gets smaller than the operation frequency f c of the linear motor in a low load area, and thus the piston is transferred over the TDC, to apply an excessive compression force. Moreover, the piston and the cylinder are abraded by friction. Since the linear motor is not operated in the resonance state, efficiency of the linear compressor is reduced.
  • the natural frequency f n of the piston becomes larger than the operation frequency f c of the linear motor in a high load area, and thus the piston does not reach the TDC, to reduce the compression force.
  • the linear motor is not operated in the resonance state, thereby decreasing efficiency of the linear compressor.
  • the conventional linear compressor varies the operation frequency f c of the linear motor by controlling an input current in proportion to the load.
  • the linear compressor controls the operation frequency f c of the linear motor to be more lowered in the low load area.
  • compression is not performed in the resonance state, which seriously reduces efficiency of the linear compressor. Nevertheless, because efficiency of the whole refrigeration cycle increases, the whole efficiency is not much changed.
  • the conventional linear compressor In order to perform compression in the resonance state even in the low load area, the conventional linear compressor is intended to be operated in the low frequency area so that the operation frequency f c of the linear motor can be equalized to the natural frequency f n of the piston.
  • the linear compressor having the large mechanical spring constant K m it is difficult to control the operation frequency f c of the linear motor to the low frequency by adjusting the input current. Furthermore, the linear compressor cannot efficiently vary the compression capacity.
  • An object of the present invention is to provide a linear compressor which can be operated in the resonance state regardless of variations of load, by synchronizing an operation frequency of a linear motor with a natural frequency of a piston, even if the natural frequency of the piston is varied by the load.
  • Another object of the present invention is to provide a linear compressor which can efficiently vary a compression capacity, by enabling a linear motor to simultaneously or individually vary an operation frequency by load and control a stroke of a piston.
  • a linear compressor including: a fixed member having a compression space inside; a movable member linearly reciprocated in the fixed member in the axial direction, for sucking refrigerants into the compression space and compressing the refrigerants; one or more springs installed to elastically support the movable member in the motion direction of the movable member, spring constants of which being varied by load; and a linear motor installed to be connected to the movable member, for linearly reciprocating the movable member in the axial direction, and synchronizing its operation frequency with a natural frequency of the movable member.
  • the spring constants of the springs are varied in proportion to the load, and the operation frequency of the linear motor is varied in proportion to the load.
  • the linear compressor is installed in a refrigeration/air conditioning cycle, and the load is calculated in proportion to a difference between a pressure of condensing refrigerants (condensing pressure) and a pressure of evaporating refrigerants (evaporating pressure) in the refrigeration/air conditioning cycle. More preferably, the load is additionally calculated in proportion to a pressure that is an average of the condensing pressure and the evaporating pressure (average pressure).
  • the springs include a mechanical spring being installed to support the movable member at both sides of the motion direction of the movable member, and having a constant mechanical spring constant, and a gas spring having a gas spring constant varied by the load of the refrigerants sucked into the compression space.
  • the mechanical spring and the gas spring are formed so that the ratio of the mechanical spring constant to the total spring constant obtained by adding up the mechanical spring constant and the gas spring constant can be below 90%, and the mechanical spring constant and the gas spring constant are determined so that the natural frequency of the movable member can be set in a low frequency area between 30 and 55 Hz.
  • the mechanical spring constant and the gas spring constant of the mechanical spring and the gas spring are set so that a stroke that is a linear reciprocation distance of the movable member can be varied by the load. More preferably, the mechanical spring constant and the gas spring constant of the mechanical spring and the gas spring are set so that the movable member can be linearly reciprocated to reach a top dead center even if the stroke of the movable member is varied.
  • an initial position of the movable member is closer to the top dead center according to decrease of the mechanical spring constant, so that the movable member can be stably elastically supported by the mechanical spring and the gas spring.
  • a linear compressor includes: a fixed member having a compression space inside; a movable member linearly reciprocated in the fixed member in the axial direction, for compressing refrigerants sucked into the compression space; a mechanical spring being installed to elastically support the movable member at both sides of the motion direction of the movable member, and having a constant mechanical spring constant; a gas spring having a gas spring constant varied by load of the refrigerants sucked into the compression space; and a linear motor installed to be connected to the movable member, for linearly reciprocating the movable member in the axial direction, wherein the mechanical spring constant and the gas spring constant of the mechanical spring and the gas spring are set so that a stroke that is a linear reciprocation distance of the movable member can be varied by the load.
  • the linear compressor is installed in a refrigeration/air conditioning cycle, and the load is calculated in proportion to a difference between a pressure of condensing refrigerants (condensing pressure) and a pressure of evaporating refrigerants (evaporating pressure) in the refrigeration/air conditioning cycle. More preferably, the load is additionally calculated in proportion to a pressure that is an average of the condensing pressure and the evaporating pressure (average pressure).
  • the mechanical spring constant and the gas spring constant of the mechanical spring and the gas spring are set so that the movable member can be linearly reciprocated to reach a top dead center even if the stroke of the movable member is varied.
  • an initial position of the movable member is closer to the top dead center according to decrease of the mechanical spring constant, so that the movable member can be stably elastically supported by the mechanical spring and the gas spring.
  • FIG. 1A is a graph showing a stroke by load in a conventional linear compressor
  • FIG. 1B is a graph showing efficiency by the load in the conventional linear compressor
  • FIG. 2 is a cross-sectional view illustrating a linear compressor in accordance with the present invention
  • FIG. 3A is a graph showing a stroke by load in the linear compressor in accordance with the present invention.
  • FIG. 3B is a graph showing efficiency by the load in the linear compressor in accordance with the present invention.
  • FIG. 4 is a graph showing changes of a gas spring constant by the load in the linear compressor in accordance with the present invention.
  • FIG. 5 is a graph showing changes of the gas spring constant by variations of an ambient temperature, a mass of a piston, a mechanical spring constant and a natural frequency in the linear compressor in accordance with the present invention
  • FIG. 6 is a structure view illustrating the stroke by the load in part of the linear compressor in accordance with the present invention.
  • FIGS. 7A to 7C are side-sectional views illustrating an operation state of the linear compressor in accordance with the present invention.
  • an inlet tube 2 a and an outlet tube 2 b through which refrigerants are sucked and discharged are installed at one side of a closed vessel 2
  • a cylinder 4 is fixedly installed inside the closed vessel 2
  • a piston 6 is installed inside the cylinder 4 to be linearly reciprocated to compress the refrigerants sucked into a compression space P in the cylinder 4
  • various springs are installed to be elastically supported in the motion direction of the piston 6 .
  • the piston 6 is connected to a linear motor 10 for generating a linear reciprocation driving force. As depicted in FIGS.
  • the linear motor 10 controls its operation frequency f c to be synchronized with the natural frequency f n of the piston 6 , so that the resonance operation can be performed in the whole load areas to improve compression efficiency.
  • a suction valve 22 is installed at one end of the piston 6 contacting the compression space P
  • a discharge valve assembly 24 is installed at one end of the cylinder 4 contacting the compression space P.
  • the suction valve 22 and the discharge valve assembly 24 are automatically controlled to be opened or closed according to the inside pressure of the compression space P, respectively.
  • the top and bottom shells of the closed vessel 2 are coupled to hermetically seal the closed vessel 2 .
  • the inlet tube 2 a through which the refrigerants are sucked and the outlet tube 2 b through which the refrigerants are discharged are installed at one side of the closed vessel 2 .
  • the piston 6 is installed inside the cylinder 4 to be elastically supported in the motion direction to perform the linear reciprocation.
  • the linear motor 10 is connected to a frame 18 outside the cylinder 4 .
  • the cylinder 4 , the piston 6 and the linear motor 10 compose an assembly.
  • the assembly is installed on the inside bottom surface of the closed vessel 2 to be elastically supported by a support spring 29 .
  • the inside bottom surface of the closed vessel 2 contains oil, an oil supply device 30 for pumping the oil is installed at the lower end of the assembly, and an oil supply tube 18 a for supplying the oil between the piston 6 and the cylinder 4 is formed inside the frame 18 at the lower side of the assembly. Accordingly, the oil supply device 30 is operated by vibrations generated by the linear reciprocation of the piston 6 , for pumping the oil, and the oil is supplied to the gap between the piston 6 and the cylinder 4 along the oil supply tube 18 a , for cooling and lubrication.
  • the cylinder 4 is formed in a hollow shape so that the piston 6 can perform the linear reciprocation, and has the compression space P at its one side.
  • the cylinder 4 is installed on the same straight line with the inlet tube 2 a in a state where one end of the cylinder 4 is adjacent to the inside portion of the inlet tube 2 a.
  • the piston 6 is installed inside one end of the cylinder 4 adjacent to the inlet tube 2 a to perform linear reciprocation, and the discharge valve assembly 24 is installed at one end of the cylinder 4 in the opposite direction to the inlet tube 2 a.
  • the discharge valve assembly 24 includes a discharge cover 24 a for forming a predetermined discharge space at one end of the cylinder 4 , a discharge valve 24 b for opening or closing one end of the cylinder 4 near the compression space P, and a valve spring 24 c which is a kind of coil spring for applying an elastic force between the discharge cover 24 a and the discharge valve 24 b in the axial is direction.
  • An O-ring R is inserted onto the inside circumferential surface of one end of the cylinder 4 , so that the discharge valve 24 a can be closely adhered to one end of the cylinder 4 .
  • An indented loop pipe 28 is installed between one side of the discharge cover 24 a and the outlet tube 2 b , for guiding the compressed refrigerants to be externally discharged, and preventing vibrations generated by interactions of the cylinder 4 , the piston 6 and the linear motor 10 from being applied to the whole closed vessel 2 .
  • a refrigerant passage 6 a through which the refrigerants supplied from the inlet tube 2 a flows is formed at the center of the piston 6 .
  • the linear motor 10 is directly connected to one end of the piston 6 adjacent to the inlet tube 2 a by a connection member 17 , and the suction valve 22 is installed at one end of the piston 6 in the opposite direction to the inlet tube 2 a .
  • the piston 6 is elastically supported in the motion direction by various springs.
  • the suction valve 22 is formed in a thin plate shape.
  • the center of the suction valve 22 is partially cut to open or close the refrigerant passage 6 a of the piston 6 , and one side of the suction valve 22 is fixed to one end of the piston 6 a by screws.
  • the suction valve 22 is opened so that the refrigerants can be sucked into the compression space P, and if the pressure of the compression space P is over the predetermined suction pressure, the refrigerants of the compression space P are compressed in the close state of the suction valve 22 .
  • the piston 6 is installed to be elastically supported in the motion direction.
  • a piston flange 6 b protruded in the radial direction from one end of the piston 6 adjacent to the inlet tube 2 a is elastically supported in the motion direction of the piston 6 by mechanical springs 8 a and 8 b such as coil springs.
  • the refrigerants included in the compression space P in the opposite direction to the inlet tube 2 a are operated as gas spring due to an elastic force, thereby elastically supporting the piston 6 .
  • the mechanical springs 8 a and 8 b have constant mechanical spring constants K m regardless of the load, and are preferably installed side by side with a support frame 26 fixed to the linear motor 10 and the cylinder 4 in the axial direction from the piston flange 6 b . Also, preferably, the mechanical spring 8 a supported by the support frame 26 and the mechanical spring 8 a installed on the cylinder 4 have the same mechanical spring constant K m .
  • the gas spring has a gas spring constant K g varied by the load.
  • K g gas spring constant
  • the load can be measured in various ways. Since the linear compressor is installed in a refrigeration/air conditioning cycle for compressing, condensing, expanding and evaporating refrigerants, the load can be defined as a difference between a condensing pressure which is a pressure of condensing refrigerants and an evaporating pressure which is a pressure of evaporating refrigerants. In order to improve accuracy, the load is determined in consideration of an average pressure of the condensing pressure and the evaporating pressure.
  • the load is calculated in proportion to the difference between the condensing pressure and the evaporating pressure and the average pressure.
  • the load increases.
  • the gas spring constant K g increases according to the load.
  • a condensing temperature proportional to the condensing pressure and an evaporating temperature proportional to the evaporating pressure are measured, and the load is calculated in proportion to a difference between the condensing temperature and the evaporating temperature and an average temperature.
  • the mechanical spring constant K m and the gas spring constant K g can be determined by various experiments. Referring to FIG. 5 , when the mechanical spring constant K m decreases, the ratio of the gas spring constant K g to the total spring constant K T obtained by adding up the mechanical spring constant K m and the gas spring constant K g increases. In addition, the higher the ambient temperature is, namely, the more the load increases, the higher the ratio of the gas spring constant K g to the total spring constant K T is. When the ratio of the gas spring constant K g to the total spring constant K T increases, the natural frequency f n is remarkably changed.
  • the ratio of the gas spring constant K g to the total spring constant K T is set below 90%.
  • the ratio of the gas spring constant K g to the total spring constant K T exceeds 10% by setting the mechanical spring constant K m below 35.5 kN/m, the natural frequency f n is remarkably varied due to changes of the ambient temperature. Therefore, the operation frequency f c of the linear motor 10 is easily controlled, so that the linear motor 10 can be operated in the resonance state. Moreover, the load is rapidly overcome, to reduce power consumption.
  • the linear motor 10 is operated in the resonance state, thereby maximizing efficiency. Furthermore, even if the operation frequency f c of the linear motor 10 is operated in the low frequency area, the load can be rapidly overcome by high efficiency, which results in low power consumption.
  • the natural frequency f n of the piston 6 is determined at the time of design by the mechanical spring constant K m , the gas spring constant K g and the mass M of the piston 6 . If the natural frequency f n of the piston 6 is set in the low frequency area ranging from 30 to 55 Hz, which is lower than the general natural frequency f n of the piston 6 , the linear compressor can be efficiently operated, rapidly overcoming the load.
  • the mechanical spring constant K m is set relatively small, and the ratio of the gas spring constant K g to the total spring constant K T is set high.
  • the operation frequency f c of the linear motor 10 is equalized to the natural frequency f n of the piston 6 even in the low load, so that the linear motor 10 can be operated in the resonance state to improve efficiency of the linear compressor. Since the linear motor 10 is operated in the low frequency area, efficiency of the whole refrigeration cycle can be improved.
  • the linear motor 10 includes an inner stator 12 formed by stacking a plurality of laminations 12 a in the circumferential direction, and fixedly installed outside the cylinder 4 by the frame 18 , an outer stator 14 formed by stacking a plurality of laminations 14 b at the periphery of a coil wound body 14 a in the circumferential direction, and installed outside the cylinder 4 by the frame 18 with a predetermined gap from the inner stator 12 , and a permanent magnet 16 positioned at the gap between the inner stator 12 and the outer stator 14 , and connected to the piston 6 by the connection member 17 .
  • the coil wound body 14 a can be fixedly installed outside the inner stator 12 .
  • the permanent magnet 16 when a current is applied to the coil wound body 14 a to generate an electromagnetic force, the permanent magnet 16 is linearly reciprocated by interactions between the electromagnetic force and the permanent magnet 16 , and the piston 6 connected to the permanent magnet 16 is linearly reciprocated inside the cylinder 4 .
  • the linear motor 10 can vary the compression capacity by changing the operation frequency f c .
  • the linear motor 10 can vary the compression capacity by changing a stroke S which is a linear reciprocation distance of the piston 6 into first and second strokes S 1 and S 2 according to the load, by adjusting the externally-inputted current.
  • the piston 6 While linearly reciprocated inside the cylinder 4 , the piston 6 forms the compression space P.
  • the piston 6 is linearly reciprocated to a point in which the piston 6 is completely compressed in the cylinder 4 not to form the compression space P, namely, a top dead center (TDC), to prevent compression efficiency from being reduced by the short stroke S.
  • TDC top dead center
  • the linear motor 10 can increase both the operation frequency f c and the stroke S of the piston 6 or only the stroke S of the piston 6 according to increase of the load.
  • the piston 6 is installed to be separated from the TDC at a predetermined interval.
  • the linear compressor is designed to increase the ratio of the gas spring constant K g to the total spring constant K T by decreasing the mechanical spring constant K m
  • the initial position of the piston 6 is set to be closer to the TDC according to decrease of the mechanical spring constant K m , so that the piston 6 can completely reach the TDC.
  • the permanent magnet 16 is linearly reciprocated by interactions between the electromagnetic force generated at the periphery of the coil wound body 14 a and the permanent magnet 16 , and the piston 6 connected to the permanent magnet 16 by the connection member 17 is linearly reciprocated inside the cylinder 4 .
  • the piston 6 is linearly reciprocated inside the cylinder 4 , the compression space P in the cylinder 4 is changed, and the refrigerants are sucked into the compression space P, compressed and discharged.
  • the inside pressure of the compression space P is reduced lower than a predetermined suction pressure, to open the suction valve 22 .
  • the refrigerants sucked through the inlet tube 2 a are sucked into the compression space P via the refrigerant passage 6 a of the piston 6 .
  • the inside pressure of the compression space P is higher than a predetermined discharge pressure. Accordingly, the valve spring 24 c is compressed to open the discharge valve 24 b , and the refrigerants compressed in the compression space P are externally discharged through the loop pipe 28 and the outlet tube 2 b via the discharge space.
  • the linear compressor compresses the refrigerants by repeating the above procedure.
  • the linear compressor performs the operation in the resonance state to improve efficiency, by synchronizing the operation frequency f c of the linear motor 10 with the natural frequency f n of the piston 6 calculated in consideration of the gas spring constant K g varied by the load.
  • the linear compressor varies the compression capacity by controlling the stroke S of the piston 6 by adjusting the current supplied to the linear motor 10 according to increase of the load, thereby rapidly handling the load and remarkably reducing power consumption.
  • the gas spring has greater influences than the general gas spring.
  • the influences of the gas spring increase, when the load increases, the natural frequency of the piston automatically increases.
  • the natural frequency of the piston is remarkably varied by the load, and the operation frequency of the linear motor is easily synchronized with the natural frequency of the piston.
  • the linear motor is operated in the resonance state to maximize efficiency and rapidly overcome the load. Furthermore, the operation in the low frequency area reduces power consumption.
  • the stroke of the piston is controlled by adjusting the external current applied to the linear motor, thereby actively handling and rapidly overcoming the load and reducing power consumption.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Compressors, Vaccum Pumps And Other Relevant Systems (AREA)
US11/660,732 2004-08-30 2004-08-30 Linear Compressor Abandoned US20080213108A1 (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/KR2004/002177 WO2006025617A1 (en) 2004-08-30 2004-08-30 Linear compressor

Publications (1)

Publication Number Publication Date
US20080213108A1 true US20080213108A1 (en) 2008-09-04

Family

ID=36000240

Family Applications (1)

Application Number Title Priority Date Filing Date
US11/660,732 Abandoned US20080213108A1 (en) 2004-08-30 2004-08-30 Linear Compressor

Country Status (6)

Country Link
US (1) US20080213108A1 (zh)
JP (1) JP2008511789A (zh)
CN (1) CN100510395C (zh)
BR (1) BRPI0419019A (zh)
DE (1) DE112004002953T5 (zh)
WO (1) WO2006025617A1 (zh)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20110250083A1 (en) * 2008-10-28 2011-10-13 Lg Electronics Inc. Linear compressor
US20140241919A1 (en) * 2013-02-28 2014-08-28 Sangsub Jeong Motor for compressor and reciprocating compressor having the same
US20150226201A1 (en) * 2014-02-10 2015-08-13 General Electric Company Linear compressor

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100963742B1 (ko) * 2007-10-24 2010-06-14 엘지전자 주식회사 왕복동식 압축기
KR101982850B1 (ko) 2017-01-12 2019-05-29 엘지전자 주식회사 가동코어형 왕복동 모터 및 이를 구비한 왕복동식 압축기

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4140439A (en) * 1976-04-20 1979-02-20 Matsushita Electric Industrial Co., Ltd. Reciprocating compressor having a cut-off device operable within predetermined angular range
US4353220A (en) * 1980-06-17 1982-10-12 Mechanical Technology Incorporated Resonant piston compressor having improved stroke control for load-following electric heat pumps and the like
US4474537A (en) * 1980-06-11 1984-10-02 Doelz Heinrich Oscillating compressor
US20030017064A1 (en) * 2001-07-19 2003-01-23 Matsushita Electric Industrial Co., Ltd. Linear compressor
US6733245B2 (en) * 2001-11-19 2004-05-11 Lg Electronics Inc. Piston support structure of reciprocating compressor
US6746211B2 (en) * 2002-03-16 2004-06-08 Lg Electronics Inc. Operation control method utilizing resonance frequency of reciprocating compressor
US6960893B2 (en) * 2002-05-21 2005-11-01 Matsushita Electric Industrial Co., Ltd. Driving apparatus of a linear motor
US20060110259A1 (en) * 2003-04-23 2006-05-25 Empresa Brasilerira De Compressores S.A. Embraco System for adjusting resonance frequencies in a linear compressor

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1539201A (en) * 1976-01-09 1979-01-31 Mechanical Tech Inc Compressor
JP2902584B2 (ja) * 1995-11-24 1999-06-07 住友重機械工業株式会社 圧縮機及び圧縮機に使用されるコイルバネの設計方法
JP3762469B2 (ja) * 1996-01-18 2006-04-05 三洋電機株式会社 リニアコンプレッサの駆動装置
JP3737902B2 (ja) * 1999-02-25 2006-01-25 住友重機械工業株式会社 ガス圧縮機
JP2002122080A (ja) * 2000-10-17 2002-04-26 Matsushita Refrig Co Ltd リニアコンプレッサーの制御装置

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4140439A (en) * 1976-04-20 1979-02-20 Matsushita Electric Industrial Co., Ltd. Reciprocating compressor having a cut-off device operable within predetermined angular range
US4474537A (en) * 1980-06-11 1984-10-02 Doelz Heinrich Oscillating compressor
US4353220A (en) * 1980-06-17 1982-10-12 Mechanical Technology Incorporated Resonant piston compressor having improved stroke control for load-following electric heat pumps and the like
US20030017064A1 (en) * 2001-07-19 2003-01-23 Matsushita Electric Industrial Co., Ltd. Linear compressor
US6733245B2 (en) * 2001-11-19 2004-05-11 Lg Electronics Inc. Piston support structure of reciprocating compressor
US6746211B2 (en) * 2002-03-16 2004-06-08 Lg Electronics Inc. Operation control method utilizing resonance frequency of reciprocating compressor
US6960893B2 (en) * 2002-05-21 2005-11-01 Matsushita Electric Industrial Co., Ltd. Driving apparatus of a linear motor
US20060110259A1 (en) * 2003-04-23 2006-05-25 Empresa Brasilerira De Compressores S.A. Embraco System for adjusting resonance frequencies in a linear compressor

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20110250083A1 (en) * 2008-10-28 2011-10-13 Lg Electronics Inc. Linear compressor
US20140241919A1 (en) * 2013-02-28 2014-08-28 Sangsub Jeong Motor for compressor and reciprocating compressor having the same
US9537381B2 (en) * 2013-02-28 2017-01-03 Lg Electronics Inc. Motor for compressor and reciprocating compressor having the same
US20150226201A1 (en) * 2014-02-10 2015-08-13 General Electric Company Linear compressor
US9841012B2 (en) * 2014-02-10 2017-12-12 Haier Us Appliance Solutions, Inc. Linear compressor

Also Published As

Publication number Publication date
BRPI0419019A (pt) 2007-12-11
CN101010510A (zh) 2007-08-01
DE112004002953T5 (de) 2007-08-02
JP2008511789A (ja) 2008-04-17
CN100510395C (zh) 2009-07-08
WO2006025617A1 (en) 2006-03-09

Similar Documents

Publication Publication Date Title
US9243620B2 (en) Apparatus for controlling a linear compressor
US8708662B2 (en) Linear compressor
US20090304525A1 (en) Linear Drive and Linear Compressor with Adaptive Output
JP2005344708A (ja) 往復動圧縮機及びその駆動装置並びに制御方法
US9194386B2 (en) Linear compressor having a controller and method for controlling a linear compressor
US20090232666A1 (en) Linear Compressor
US8430642B2 (en) Controlling apparatus for linear compressor
US9217429B2 (en) Linear compressor
US7816873B2 (en) Linear compressor
KR101299548B1 (ko) 압축기 제어 장치 및 제어 방법
US20080213108A1 (en) Linear Compressor
KR100588717B1 (ko) 리니어 압축기
KR100690153B1 (ko) 리니어 압축기
KR100690164B1 (ko) 리니어 압축기의 제어방법
EP2503149B1 (en) Linear compressor
KR100648787B1 (ko) 리니어 압축기
KR101637441B1 (ko) 리니어 압축기의 제어 장치, 제어 방법, 및 이들을 구비한 냉동 시스템
KR100588718B1 (ko) 리니어 압축기
KR100648818B1 (ko) 리니어 압축기
KR100756721B1 (ko) 리니어 압축기의 제어장치
KR100597295B1 (ko) 리니어 압축기
KR20200054021A (ko) 왕복동식 압축기의 운전 제어 장치 및 방법

Legal Events

Date Code Title Description
AS Assignment

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

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:CHOI, BONG JUN;JANG, CHANG YONG;CHO, MAN SEOK;AND OTHERS;REEL/FRAME:019996/0141

Effective date: 20070921

STCB Information on status: application discontinuation

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