JP2000097152A - Linear compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a linear compressor realizable of miniaturizing the device, reducing the number of part items and making the device highly efficient and long lasting. SOLUTION: The linear compressor is provided with a cylindrical first and a second cylinders 2, 3 provided on both sides inside a housing 1, a cylindrical piston 6 fitted on the outer circumferential surface of the first and the second cylinders 2, 3 and including an inside wall 8 for partitioning and forming a first and a second compression chambers 4, 5, and a linear motor 13 for reciprocatingly driving the piston 6 by impressing alternating voltage of a specific frequency, and it alternately compresses gas inside the first and the second compression chambers 4, 5 and feeds it outside by reciprocating the piston 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a linear compressor for producing a compressed gas.

[0002]

2. Description of the Related Art In recent years, a linear compressor has been developed as a mechanism for compressing and supplying a refrigerant gas in a refrigeration system. For example, as shown in FIG. 4, a housing 101 having a bottomed cylindrical body, a magnetic frame 102 made of low carbon steel formed at an upper end opening of the housing 101, and a cylinder 103 formed at the center of the magnetic frame 102 When,
Reciprocally fitted in the cylinder 103, the cylinder 10
Piston 105 for forming compression chamber 104 in inner space 3
And a linear motor 106 as a drive source for driving the piston 105 back and forth.

In the linear motor 106, an annular permanent magnet 107 is arranged concentrically outside the cylinder 103 and is fixed to the housing 101. This magnet 10
A magnetic field B is generated in a cylindrical gap 108 concentric with the center of the cylinder 103 by a magnetic circuit including the magnetic frame 7 and the magnetic frame 102. The gap 105 has a piston 105 at the center.
Cylindrical movable body 10 made of resin integrally fixed to
A coil spring 110 for elastically supporting the movable body 109 and the piston 105 so as to reciprocate is fixed to the housing 101.

A magnet 107 is mounted on the outer periphery of the movable body 109.
The electromagnetic coil 111 is wound at a position facing the
By passing an alternating current of a predetermined frequency through a lead wire (not shown), the coil 111 and the movable body 109 are driven by the action of a magnetic field passing through the gap 108, and the piston 10
5 is reciprocated in the cylinder 103 to generate a gas pressure in a predetermined cycle in the compression chamber 104.

On the other hand, as a typical refrigeration system, FIG.
As shown in FIG. 1, a hermetic refrigeration system in which a linear compressor 121 (compressor), a condenser 122, an expansion valve 123, and an evaporator 124 are connected by a gas flow path pipe 125 is known. The refrigerant gas vaporized by the condenser 124 is sucked through a gas flow pipe 125 and compressed to a high pressure, and the high pressure refrigerant gas is discharged to the condenser 122 through the gas flow pipe 125.

For this reason, as shown in FIG.
4 includes a valve mechanism 1 provided at the upper end of the cylinder 103.
12, a gas flow path pipe 12 outside the housing 101.
5 is connected. The valve mechanism 112 is connected to the gas flow pipe 1
The suction valve 112a allows only the suction of the refrigerant gas from the evaporator 124 via the inlet 25, and the discharge valve 112b allows only the discharge of the refrigerant gas to the condenser 122 via the gas flow pipe 125. You. The suction valve 112 a is a valve that causes a gas to flow in the direction of the compression chamber 104 by the pressure difference between the refrigerant gas in the gas passage pipe 125 on the low pressure side and the compression chamber 104. The discharge valve 112b is opened by the pressure difference of the refrigerant gas between the compression chamber 104 and the gas passage pipe 125 on the high pressure side so that the discharge valve 112b opens when the refrigerant gas pressure in the compression chamber 104 becomes equal to or higher than a predetermined pressure. This is a valve that allows gas to flow out in the direction of the gas flow pipe 125. The suction valve 112a and the discharge valve 112b are both valves that are biased by leaf springs.

With the above arrangement, in the conventional apparatus, the suction valve 1
After the refrigerant gas sucked from 12a is compressed to a high pressure in the compression chamber 104, it is supplied to the condenser 122 via the discharge valve 112b.

Recently, as shown in FIG. 6, compression chambers 63 and 64 are provided on both sides of a housing 61 by one linear motor 62, and two pistons 65 and
It has been proposed to operate the device 66 to improve the efficiency of the device.

[0009]

However, in the conventional apparatus shown in FIG. 6, since the two pistons 65 and 66 are connected by the piston shaft 67, there is a problem that the compressor becomes large.

Further, the pistons 65 and 66 are reciprocated while being in sliding contact with the cylinders 68 and 69 by the driving of the linear motor 62, and a kind of sliding bearing is formed between the piston and the cylinder. However, when the length of the piston shaft 67 is increased, a force (radical force) in a direction perpendicular to the piston moving direction is generated due to a problem of machining accuracy or distortion of the electromagnetic force of the electromagnetic coil, and the radical force is large. There is a possibility that the operating efficiency may be reduced due to friction loss, the life of the device may be reduced due to wear of the gas seal portions provided on the pistons 65 and 66, and the refrigerant may be contaminated by abrasion powder.

The present invention has been made in view of the above points, and provides a linear compressor which achieves miniaturization of an apparatus, reduction of the number of parts, and high efficiency and long life of the apparatus. It is.

[0012]

SUMMARY OF THE INVENTION The present invention comprises first and second cylindrical cylinders provided on both sides of a housing;
A cylindrical piston fitted to the outer peripheral surfaces of the first and second cylinders and having an intermediate wall portion for defining the first and second compression chambers; A linear motor for reciprocatingly driving the piston, and by reciprocating the piston, alternately compresses gas in the first and second compression chambers and supplies the compressed gas to the outside.

By using this configuration, the piston shaft is eliminated, and the first piston is reciprocated by one piston.
Further, since the gas can be compressed in the second compression chamber, the external dimensions of the apparatus can be made smaller than before, and the number of parts can be reduced.

The linear motor is wound around the outer periphery of the piston so as to be disposed in a magnetic circuit comprising a magnet and a magnetic frame provided in a housing and disposed in a gap formed in a part of the magnetic circuit. And a reciprocating drive of the piston by supplying alternating current of a predetermined frequency to the electromagnetic coil.

By using this configuration, the role of the movable body conventionally required can be shared by the piston, and the movable body can be omitted.

[0016] More specifically, the piston has a substantially H-shaped longitudinal section. In addition, it has a bearing for regulating the position of the piston in the moving axis direction.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the linear compressor according to the present invention will be described below with reference to the drawings.

As shown in FIG. 5, the linear compressor of the present invention is used as a compressor of a closed type refrigeration system. As a linear compressor, as shown in FIG.
And holds the linear compressor as an enclosed space. The housing 1 is provided with cylindrical first and second cylinders 2 and 3 on both sides thereof, which are fitted on the outer peripheral surfaces of the cylinders 2 and 3, respectively.
Piston 6 for partitioning first compression chamber 4 and second compression chamber 5
Is provided.

The piston 6 has a cylindrical non-magnetic member 7
An inner wall portion 8 for defining the first compression chamber 4 and the second compression chamber 5 is provided inside the center of the cylindrical member, and has a substantially H-shaped vertical section. In this embodiment, an aluminum alloy is used as the non-magnetic member 7, but other non-magnetic members, such as PEEK and PP, may be used.
Engineered plastics such as S may be used.

The housing 1 and the first and second cylinders 2 and 3 are integrally formed to form a magnetic frame (yoke) made of low carbon steel. An annular permanent magnet 10 is provided between the housing 1 and an inner side surface (cylinder outer peripheral surface) 12 on an outer side surface 11 of an annular concave portion formed between the first and second cylinders 2 and 3. The magnet 10 and the yoke constitute a magnetic circuit 14 of the linear motor 13.
4 generates a magnetic field having a predetermined strength in the gap between the magnet 10 and the inner side surface 12. The piston 6 is disposed in a gap formed in a part of the magnetic circuit 14 including the magnet 10 and the yoke, and supplies an alternating current of a predetermined frequency to the electromagnetic coil 9 wound around the outer periphery of the piston 6 to thereby provide a piston. 6 is reciprocated in the first cylinder 2 and the second cylinder 3 to generate a gas pressure of a predetermined cycle in the first compression chamber 4 and the second compression chamber 5. Here, the resonance frequency during the reciprocating movement of the piston 6 is determined by the weight of the piston 6 and the spring constant of the gas spring between the piston 6 and the housing 1. Although no mechanical spring is provided in this embodiment, a coil spring or the like located outside the first and second cylinders 2 and 3 may be arranged between the piston 6 and the housing 1 if necessary. I do not care.

The first and second compression chambers 4 and 5 have a gas passage outside the housing 1 via valve mechanisms 15 and 16 provided at the upper ends of the first and second cylinders 2 and 3 respectively. The pipe 125 is connected. Valve mechanisms 15, 16
Suction valves 15a and 16a that allow only the suction of the refrigerant gas from the evaporator 124 through the gas flow pipe 125, and discharge that allows only the discharge of the refrigerant gas to the condenser 122 through the gas flow pipe 125. The valves 15b and 16b are both urged by leaf springs.

The first cylinder 2 is provided with communication holes 17a and 17b which allow the suction gas 15a and the discharge valve 15b to communicate with the gas flow path pipe 125 and allow the passage of the refrigerant gas. 3, communication holes 18a and 18b are provided, which allow the suction valve 16a and the discharge valve 16b to communicate with the gas flow path pipe 125 and allow the passage of the refrigerant gas.

Further, a material having a low coefficient of friction is coated on a facing portion of the piston 6 which is in sliding contact with the cylinders 2 and 3,
It constitutes a bearing part that regulates the axial direction when the piston 6 reciprocates. Thereby, the shaft 6 of the piston 6 is prevented from shaking. In this embodiment, a bearing alloy material such as white metal or kelmet is used as the coating material.

Next, FIGS. 2 and 3 are cross-sectional views showing states when gas is discharged from the first compression chamber 4 and the second compression chamber 5, respectively. Here, the arrows in the figure indicate the flow of the refrigerant gas in the first compression chamber 4 and the second compression chamber 5 as the piston 6 moves.

As is apparent from the figure, as the piston 6 moves to the vicinity of the top dead center on the first cylinder 2 side, a part of the compressed gas in the first compression chamber 4 passes through the discharge valve 15b. The liquid is discharged to the outside through the communication passage 17b, and
A part of the refrigerant gas is supplied to the second compression chamber 5 through the suction valve 16a through the suction valve 16a (see FIG. 2). Conversely, with the movement of the piston 6 near the top dead center on the second cylinder 3 side,
A part of the compressed gas in the second compression chamber 5 is discharged to the outside through the communication passage 18b through the discharge valve 16b, and a part of the refrigerant gas is discharged through the communication passage 17a through the suction valve 15a. And supplied to the first compression chamber 4 (see FIG. 3).

As described above, the piston shaft and the movable body conventionally required are eliminated, and the gas can be compressed in the first and second compression chambers 4 and 5 by one piston 6 reciprocating.

The description of the above embodiment is for the purpose of describing the present invention, and should not be construed as limiting the invention described in the claims or reducing the scope thereof. Also, the configuration of each part of the present invention is not limited to the above-described embodiment,
It goes without saying that various modifications are possible within the technical scope described in the claims.

For example, in the description of the above embodiment, the case where the housing 1, the magnetic frame, and the cylinders 2 and 3 are constituted by the same body has been described, but they may be constituted by separate bodies.

[0029]

As described above, according to the present invention, since the piston shaft is eliminated and gas compression in the first and second compression chambers can be performed by reciprocating one piston, the apparatus can be reduced in size and parts can be reduced. The points can be reduced.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a linear compressor showing one embodiment of the present invention.

FIG. 2 is a cross-sectional view for explaining the operation performed by moving a piston 6 of the apparatus of FIG. 1 to a position near a top dead center on a first cylinder 2 side.

FIG. 3 is a cross-sectional view for explaining the contents of an operation by moving a piston 6 of the apparatus in FIG. 1 to a position near a top dead center on a second cylinder 3 side.

FIG. 4 is a sectional view of a conventional linear compressor.

FIG. 5 is a conceptual diagram showing a configuration of a closed type refrigeration system.

FIG. 6 is a sectional view of a conventional two-piston linear compressor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Housing 2 1st cylinder 3 2nd cylinder 4 1st compression chamber 5 2nd compression chamber 6 Piston 7 Non-magnetic member 8 Middle wall part 9 Electromagnetic coil 10 Permanent magnet 13 Linear motor 14 Magnetic circuit 15, 16 Valve mechanism 17, 18 Communication hole

Claims (4)

[Claims] 1. A linear compressor for generating a compressed gas, comprising first and second columnar cylinders provided on both sides in a housing.
A cylinder; a cylindrical piston fitted to the outer peripheral surfaces of the first and second cylinders and having a middle wall for defining the first and second compression chambers; and applying an AC voltage having a predetermined frequency. A linear motor for reciprocatingly driving the piston, and by reciprocating the piston, alternately compresses gas in the first and second compression chambers and supplies the compressed gas to the outside. . 2. The linear motor is wound around an outer periphery of the piston so as to be disposed in a magnetic circuit including a magnet and a magnetic frame provided in a housing and disposed in a gap formed in a part of the magnetic circuit. The linear compressor according to claim 1, further comprising an electromagnetic coil, wherein the piston is reciprocated by supplying an alternating current having a predetermined frequency to the electromagnetic coil. 3. The linear compressor according to claim 1, wherein the piston has a substantially H-shaped vertical cross section. 4. The linear compressor according to claim 1, wherein the piston has a bearing for regulating a position of the piston in a movement axis direction.