KR101978964B1 - Linear compressor - Google Patents

Abstract

A linear compressor according to the present invention comprises: a cylinder in which a compression space for compressing a refrigerant is formed; A piston reciprocating in an axial direction within the cylinder; A mover coupled to the piston and transmitting driving force to the piston; A stator for generating a driving force together with the mover; A frame for axially supporting the stator; A discharge valve inserted into a cylinder space of the stator to selectively open and close the compression space; And a cylinder holder inserted into the cylinder space, one end of which is coupled to the stator, and the other end of which is longer than the axial length of the cylinder and axially supports the cylinder.

Description

[0001] Linear compressor [0002]

The present invention relates to a linear compressor.

Generally, a compressor is a device that receives power from a power generating device such as a motor or a turbine and compresses a working fluid such as air or refrigerant. Compressors are widely applied to industrial and household appliances, especially vapor compression refrigeration cycles (hereinafter referred to as " refrigeration cycles ").

Such a compressor can be classified into a reciprocating compressor, a rotary compressor, and a scroll compressor according to a method of compressing a refrigerant. The reciprocating compressor is a system in which a compression space is formed between a piston and a cylinder, and a piston reciprocates linearly to compress the fluid. The rotary compressor compresses the fluid by a roller eccentrically rotated in the cylinder. The scroll compressor is a spiral type And the fluid is compressed.

BACKGROUND ART [0002] Reciprocating compressors are known as a crank system that compresses a refrigerant by converting a rotational force of a rotary motor into a linear motion, and a vibration system that compresses a refrigerant by using a linear motor that performs linear reciprocating motion. The oscillating type reciprocating compressor is referred to as a linear compressor. The linear compressor has no mechanical loss in converting the rotational motion into a linear reciprocating motion, thereby improving the efficiency and simplifying the structure.

On the other hand, the linear compressor can be divided into an oil-lubricated linear compressor and a gas-type linear compressor according to the lubrication system. The oil-lubricated linear compressor is configured to store a predetermined amount of oil in the casing and lubricate the cylinder and the piston using the oil, as disclosed in Patent Document 1 (Korean Patent Laid-Open Publication No. KR10-2015-0040027). On the other hand, as disclosed in Patent Document 2 (Korean Patent Laid-Open Publication No. KR10-2016-0024217), the gas-lubricated linear compressor has a structure in which a part of the refrigerant discharged from the compression space without guiding oil into the casing is guided between the cylinder and the piston And is configured to lubricate between the cylinder and the piston by the gas force of the refrigerant.

The oil-lubricated linear compressor can prevent the cylinder and the piston from being overheated by the heat of the motor, the heat of compression, etc., as the oil of relatively low temperature is supplied between the cylinder and the piston. As a result, the oil-lubricated linear compressor can prevent the suction loss from being generated by suppressing the rise of the refrigerant heated by the suction passage of the refrigerant passing through the suction passage of the piston into the compression chamber of the cylinder.

However, in the oil-lubricated linear compressor, when the oil discharged to the refrigeration cycle apparatus together with the refrigerant is not smoothly recovered to the compressor, oil shortage may occur in the casing of the compressor. Which may cause the reliability to deteriorate.

On the other hand, the gas-lubricated linear compressor is advantageous in that it can be downsized as compared with the oil-lubricated linear compressor and lubricates between the cylinder and the piston with the refrigerant, so that the reliability of the compressor is not lowered due to oil shortage.

In the conventional linear compressor as described above, both the outer stator and the inner stator, which constitute the stator of the linear motor as well as the oil lubrication type, are supported by the frame so that the gap between the outer stator and the inner stator, It is kept constant. Simultaneously, an inner stator is inserted into the outer circumferential surface of the frame, and a cylinder is inserted into the inner circumferential surface of the frame, thereby supporting the radial and axial directions of the inner stator and the cylinder.

Further, in the case of the gas lubricating type, the frame and the cylinder are assembled so as to secure a certain gap so that a coolant passage forming a gas bearing is formed between the inner peripheral surface of the frame and the outer peripheral surface of the cylinder.

However, in the conventional linear compressor, since the frame is formed in a complicated shape and the dimension of the frame is precisely controlled, the processing cost for the frame is greatly increased.

In addition, since the conventional linear compressor is formed to support both the stator and the cylinder with an expensive frame, there is a problem that the material cost for the frame increases. That is, as the frame supports the stator, a material having a relatively low permeability such as aluminum is used in consideration of magnetic flux leakage, but this may cause a rise in material cost of the frame.

In the conventional linear compressor, since the front end of the cylinder is axially supported at the front end of the frame, the length of the cylinder becomes long, so that the material cost for the cylinder increases and the length of the compressor becomes long there was.

In addition, in the conventional linear compressor, since the discharge valve for opening and closing the discharge side of the compression space is provided outside the linear motor, the axial length of the linear compressor is increased and the length of the piston is increased. There was a problem that the loss also increased.

In addition, in the conventional linear compressor, as the discharge valve is provided outside the linear motor, the discharge cover, which accommodates the discharge valve, is assembled to one side surface in the axial direction of the frame, There was also a problem.

In the conventional linear compressor, when the refrigerant passage that guides the refrigerant between the cylinder and the piston is not sealed in the process of simplifying the structure of the frame in the case of the gas lubricating type, the refrigerant leaks and the performance of the gas bearing may be significantly deteriorated.

It is an object of the present invention to provide a linear compressor which can simplify the frame structure and reduce the processing cost for the frame.

It is another object of the present invention to provide a linear compressor capable of reducing the size of a frame, which is a relatively expensive material, to reduce the material cost.

Another object of the present invention is to provide a linear compressor capable of reducing the length of a cylinder by separately providing a member for axially supporting the cylinder in addition to the frame, thereby reducing the material cost for the cylinder and reducing the size of the compressor I am trying to provide.

Another object of the present invention is to provide a linear compressor capable of reducing the axial length of the compressor and reducing the length of the piston by providing the discharge valve inside the linear motor, I am trying to provide.

Another object of the present invention is to provide a linear compressor which can smoothly supply the refrigerant between the cylinder and the piston while simplifying the structure of the frame when lubricating between the cylinder and the piston using the refrigerant.

In order to achieve the object of the present invention, there is provided a stator comprising: a frame for supporting an outer stator and an inner stator; And a cylinder holder inserted in the inner stator and supporting the cylinder in the axial direction, wherein the cylinder holder is formed to have a longer axial length than the cylinder.

Here, the cylinder holder may be supported on the side surface of the inner stator, or may be fixedly supported on the inner circumferential surface of the inner stator.

Further, in order to achieve the object of the present invention, there is provided a compressor comprising: a cylinder in which a compression space for compressing a refrigerant is formed; A piston reciprocating in an axial direction within the cylinder; A mover coupled to the piston and transmitting driving force to the piston; A stator for generating a driving force together with the mover; A frame for axially supporting the stator; A discharge valve inserted into a cylinder space of the stator to selectively open and close the compression space; And a cylinder holder which is formed to be longer than an axial length of the cylinder and inserted in the cylinder space, one end of which is coupled to the stator and the other end that supports the cylinder in the axial direction.

Here, the first bent portion may be bent outward so that one end of the cylinder holder is supported by the stator, and the other end of the cylinder holder may be bent inward to support the end face of the cylinder in the axial direction have.

The first bent portion may be axially supported on one side of the stator from the outside of the stator.

The first bent portion may be fixed by one side of the frame.

An annular fixing groove is formed in the inner circumferential surface of the cylinder space, and the first bending portion is inserted into the fixing groove to be supported in the axial direction.

The radial thickness of the cylinder holder may be made thinner than the axial thickness of the frame.

The cylinder holder may be formed of a material having higher stiffness than the frame.

The cylinder space may include at least one discharge space for receiving the refrigerant discharged from the compression space.

A discharge cover for covering the cylinder space may be coupled to the frame.

The cover may be integrally formed with the frame to cover the cylinder space.

The at least one discharge space communicates with the inner circumferential surface of the cylinder and the outer circumferential surface of the piston so that a part of the refrigerant discharged to the discharge space is guided between the inner circumferential surface of the cylinder and the outer circumferential surface of the piston.

Further, in order to achieve the object of the present invention, there is provided a compressor comprising: a cylinder in which a compression space for compressing a refrigerant is formed; A piston reciprocating in an axial direction within the cylinder; A mover coupled to the piston and transmitting driving force to the piston; A stator for generating a driving force together with the mover; At least one frame supporting the stator in the axial direction; And a cylinder holder fixed to one axial side surface of the stator and axially supporting one end of the cylinder.

Here, a discharge valve for opening and closing the compression space may be provided in the cylinder holder.

A discharge valve for opening and closing the compression space may be provided outside the cylinder holder.

In the linear compressor according to the present invention, the outer stator and the inner stator constituting the driving unit are supported by the frame, while the cylinder is inserted into the inner stator and supported by the cylinder, so that the structure of the frame can be simplified, The manufacturing cost can be reduced.

In the linear compressor according to the present invention, since the frame contacts the outer stator and the inner stator, the frame is made of a non-magnetic material having a high cost. However, since the frame supports only one side of the stator, the size of the frame can be minimized . Accordingly, even if the frame is made of a nonmagnetic material, which is an expensive material, the material cost due to the frame can be lowered.

Further, in the linear compressor according to the present invention, since the cylinder is supported by the separate cylinder holder in a state of being inserted into the inner stator, the length of the cylinder can be reduced. This can reduce the material cost for the cylinder and reduce the compressor weight.

Further, according to the linear compressor of the present invention, as the discharge valve is inserted into the inner stator forming the cylinder space, the axial length of the compressor is reduced and the axial length of the piston is shortened. .

In the linear compressor according to the present invention, since the discharge valve is inserted into the inner stator constituting the cylinder space, the discharge cover can be formed integrally with the frame, thereby reducing the number of assembling steps and lowering the manufacturing cost of the compressor .

The linear compressor according to the present invention can prevent the refrigerant from leaking between the stator sheets constituting the inner stator by inserting the cylinder holder into the inner circumferential surface of the inner stator while inserting the cylinder into the inner stator constituting the cylinder space . As a result, the refrigerant discharged into the cylinder space is guided smoothly between the cylinder and the piston, so that the piston can be stably lubricated.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a cross-sectional view of the inside of a linear compressor according to the present invention,
Fig. 2 is a schematic view for explaining a magnetic resonance spring of a linear motor in the linear compressor according to Fig. 1,
Fig. 3 is a perspective view of the compressor shown in Fig. 1,
FIG. 4 is a perspective view showing a front part of the compressor body in FIG. 3,
FIG. 5 is a cross-sectional view of a part of the compressor main body shown in FIG. 3,
Fig. 6 is a perspective view showing the rear side of the frame and the cylinder holder in Fig. 5,
FIG. 7 is a cross-sectional view showing a coupling relationship between the frame, the inner stator, and the cylinder holder in FIG. 5,
FIG. 8 is a cross-sectional view showing another embodiment of the cylinder holder in the compressor according to FIG. 1;
FIG. 9 is a sectional view showing another embodiment of the frame in the linear compressor according to FIG. 1;
FIG. 10 is a cross-sectional view showing another embodiment of the frame in the linear compressor according to FIG. 1;
11 is a sectional view showing a state in which a discharge cover is coupled to a frame in FIG. 10,
12 is a sectional view showing another embodiment of a frame and a discharge cover in the linear compressor according to the present invention.

Hereinafter, a linear compressor according to the present invention will be described in detail with reference to an embodiment shown in the accompanying drawings.

The linear compressor according to the present invention performs an operation of sucking and compressing a fluid, and discharging a compressed fluid. The linear compressor according to the present invention may be a constituent of a refrigeration cycle. Hereinafter, the fluid will be described by taking a refrigerant circulating in a refrigeration cycle as an example.

1 is a cross-sectional view illustrating an embodiment of a linear compressor according to the present invention. As shown, the linear compressor 100 according to the present embodiment includes a casing 110, a driving unit 120, and a compression unit 130.

The casing 110 forms a space in which the internal space is sealed. The closed internal space may be a suction space 101 filled with the refrigerant to be sucked and a suction pipe 111 may be connected to the casing 110 such that the refrigerant is sucked into the suction space 101. Also, the discharge tube 113 may be connected to the casing 110 so that the refrigerant is discharged from the discharge space 104, which will be described later, to the outside.

A linear motor constituting a drive unit 130 may be supported by a support spring (not shown) in a resilient manner in the suction space 101 of the casing 110. The support spring may be a leaf spring or a coil spring.

The casing 110 may be elongated in the transverse direction or elongated in the longitudinal direction depending on the arrangement of the driving unit 120 and the compression unit 130. In addition, the casing 110 may be formed by covering the upper housing with the lower housing, or by covering both ends of the cylindrical shell with the caps. Fig. 1 shows an example in which the cap is folded at both ends of a cylindrical shell and is elongated in the transverse direction.

Meanwhile, the driving unit 120 may include a stator 120a and a movers 120b reciprocating with respect to the stator 120a.

The stator 120a may include an outer stator 121 and an inner stator 122 disposed inside the outer stator 121 by a predetermined gap 120c. The outer stator 121 and the inner stator 122 are closely attached to the front and rear surfaces of the stator by the assembly bolts 143 by the frame 141 and the stator cover 142 which will be described later, .

The movers 120b may be composed of a core holder 123a and a magnetic core 123b supported by the core holder 123a.

The core holder 123a is formed in a cylindrical shape and has one end coupled to a piston 132 to be described later and the other end inserted into a gap 120c between the outer stator 121 and the inner stator 122 .

The magnetic material core 123b may be formed by stacking a plurality of magnetic material sheets or may be press-fitted into the core holder 123a. However, the magnetic substance core 123b may be adhered to the outer circumferential surface of the core holder 123a and fixed thereto, or may be fixed using a separate fixing ring (not shown). The magnetic core 123b can reciprocate linearly together with the core holder 123a by the mutual electromagnetic force formed between the outer stator 121 and the inner stator 122. [

On the other hand, the compression unit 130 sucks the refrigerant in the suction space 101 into the compression space 103, compresses it, and discharges it to the discharge space 104. The compression unit 130 can be located in the center of the casing 110 inside the inner stator 122 and includes a cylinder 131 and a piston 132. The cylinder 131 is inserted and supported in the cylinder space 122a of the inner stator 122, and a compression space 103 can be formed therein.

The cylinder 131 may be formed in a cylindrical shape having both ends opened to receive the refrigerant and the piston 132 therein. The cylinder 131 can be inserted and fixed in the cylinder space 122a of the inner stator 122 to be described later. The cylinder 131 is formed to be shorter than the axial length of the inner stator 122 and can be disposed on the rear side with respect to the middle of the cylinder space 122a. This will be explained later.

One end of the cylinder 131 (hereinafter referred to as the front end) can be closed by a discharge valve 134 to be described later and is provided at the opposite side of the compression space 103 with respect to the discharge valve 134 in the compression space 103 The discharge space 104 may be formed to accommodate the discharged refrigerant. One discharge space 104 may be formed, but a plurality of discharge spaces 104 may be formed in order to effectively attenuate discharge noises.

The discharge space 104 can be formed with the first discharge space 104a in the inner stator 122, i.e., the cylinder space 122a, and the second discharge space 104b outside the inner stator 122 . When the second discharge space 104b is formed outside the inner stator 122, the second discharge space 104b is exposed in the suction space 101 of the casing 110, and the temperature of the discharged refrigerant is lowered, The efficiency can be increased.

A part of the gas bearing that guides the refrigerant between the cylinder 131 and the piston 132 may be formed in the cylinder 131. [ That is, a plurality of bearing holes 131a may be formed which penetrate from the outer circumferential surface to the inner circumferential surface of the cylinder 131 and form a part of the gas bearing. A part of the compressed refrigerant is supplied to the space between the cylinder 131 and the piston 132 via the bearing hole 131a to gas-lub between the cylinder 131 and the piston 132. [

The bearing hole 131a may be formed as a fine hole so that the inlet is wide and the outlet is a nozzle. And a filter (not shown) for blocking foreign matter from entering the bearing hole 131a. The filter may be a metal mesh filter or may be formed by winding a member such as a cecile. Therefore, the inlet and outlet of the bearing hole 131a may be formed individually so as to communicate with each other independently, and the inlet may be formed as an annular groove and the outlet may be formed with a plurality of bearing holes at regular intervals along the annular groove have.

The bearing hole 131a may be formed only on the side adjacent to the compression space 103 (hereinafter referred to as the front side) with respect to the axial center of the cylinder 131, Or may be formed on the rear side.

The piston 132 may have a cylindrical shape such that the piston 132 has a suction passage 102 therein and the front end thereof is partially opened while the rear end thereof is completely opened. The rear end of the piston 132, which is an open end, is connected to the core holder 123a and can reciprocate together with the core holder 123a as described above.

A plurality of suction ports 132a communicating between the suction passage 102 and the compression space 103 are formed at the front end of the piston 132. A plurality of suction ports 132a are formed in the front surface of the piston 132, And a suction valve 133 for selectively opening and closing the valve 132a. The refrigerant sucked into the inner space 101 of the casing 110 is discharged through the suction passage 102 and the suction port 132a of the piston 132 while opening the suction valve 133, As shown in FIG.

The suction valve 133 may be formed in a disc shape so that the plurality of suction ports 132a can be opened or closed at a time, or may be formed in a petal shape having a plurality of opening and closing parts so that the suction ports 132a can be individually opened and closed. .

The suction valve 134 is fixed depending on the position of the suction port 132a. For example, when the suction port 132a is formed at the edge, the central portion of the suction valve 134 may be bolted or riveted to the center of the front surface of the piston 132. [

The discharge valve 134 is resiliently supported by a valve spring 135 so as to open and close the compression space 103 on the front surface of the cylinder 131. The valve spring 135 is supported by a valve stopper 150 Can be supported. The valve stopper 150 may be provided with a spring support member 136 for stably supporting the valve spring 135. The spring support member 136 may be formed in a disk shape to form a plurality of first discharge holes 136a.

Reference numeral 112 denotes a loop pipe, reference numeral 144 denotes a back cover, reference numeral 151 denotes a body portion of the valve stopper, reference numeral 151a denotes a bearing communication hole forming a gas bearing, reference numeral 152 denotes a baffle portion of the valve stopper, and reference numeral 152a denotes a second discharge hole.

The linear compressor according to this embodiment operates as follows.

That is, when a current is applied to the drive unit 120, a magnetic flux is formed in the stator 120a, and the electromagnetic force generated by the magnetic flux causes the movers 120b having the magnetic substance cores 123b to contact the outer stator 121, And can be linearly reciprocated at the air gap 120c between the inner stator 122.

Then, as the piston 132 connected to the mover 120b reciprocates linearly in the cylinder 131, the volume of the compression space 103 is increased or decreased. At this time, when the piston 132 moves backward and the volume of the compression space 103 increases, the suction valve 133 opens and the refrigerant in the suction passage 102 is sucked into the compression space 103 through the suction port 132a On the other hand, when the piston 132 moves forward and the volume of the compression space 103 decreases, the piston 132 compresses the refrigerant in the compression space 103. [ The compressed refrigerant is discharged into the first discharge space 104a while opening the discharge valve 134. [

A part of the refrigerant discharged into the first discharge space 104a flows through the bearing hole 131a of the cylinder 131 through the bearing communicating hole 151a forming the gas bearing and the inner peripheral surface of the cylinder 131 and the piston 132 so as to support the piston 132 with respect to the cylinder 131. The remaining refrigerant discharged to the first discharge space 104a moves to the second discharge space 104b through the second discharge hole 152a and then flows through the loop pipe 112 and the discharge pipe 113, The refrigerant is discharged to the outside, and the refrigerant is returned to the condenser of the refrigeration cycle. At this time, the refrigerant passes through the first discharge space 104a and the second discharge space 104b in order, and the noise of the refrigerant can further be attenuated.

On the other hand, in the drive unit according to the present embodiment, when a current is applied to a winding coil to be described later, a magnetic flux is formed in the stator, and a magnetic flux formed by applying a current and a magnetic flux Interaction can generate forces that the mover can move in the left and right direction of the drawing. Thus, the driving unit of the linear compressor according to the present invention can perform the function of a magnetic resonance spring as a substitute for a mechanical resonance spring. A process in which the driving unit performs the function of the magnetic resonance spring is as follows.

Referring to FIGS. 1 and 2, the driving unit according to the present embodiment may include a stator 120a and a movers 120b reciprocating with respect to the stator 120a. The stator 120a may include an outer stator 121 and an inner stator 122 disposed inside the outer stator 121 with a predetermined gap 120c.

The outer stator 121 includes a stator core 126 laminated so as to surround the coil winding body 125 and the coil winding body 125. The coil winding body 125 includes a bobbin 125a and a bobbin 125a A winding coil 125b wound in the circumferential direction may be included. The end face of the winding coil 125b may be formed in a circular or polygonal shape, and may have a hexagonal shape, for example.

The stator core 126 may be laminated with a plurality of lamination sheets radially, and a plurality of lamination blocks may be laminated along the circumferential direction. The present embodiment describes an example in which a plurality of lamination blocks are stacked along the circumferential direction. Accordingly, the assembly bolts 143 pass between the lamination blocks 126a as shown in FIG. 1, And may be coupled to the frame 141 and the stator cover 142.

The inner stator 122 can be formed into a cylindrical shape by stacking a plurality of lamination sheets 127 radially. The plurality of lamination sheets 127 can be press-fitted into the fixing grooves 127a formed on both the front and rear sides to hold the cylindrical shape.

Thus, a cylinder-shaped cylinder space 122a is formed in the center of the inner stator 122, and a cylinder 131, which will be described later, is inserted into the cylinder space 122a and fixed. As described above, a part of the first discharge space 104a and the second discharge space 104b may be formed in the remaining space of the cylinder space 122a where the cylinder 131 is inserted.

The outer stator 121 and the inner stator 122 may be formed so as to have a plurality of voids (not shown) spaced apart from each other with the coil winding body 125 interposed therebetween, 125 may be spaced apart from each other to form an air gap 120c while the other may be connected to each other to have one air gap. In this case, the magnets 124a and 124b may be coupled to the mover 120b or may be coupled to the stator 120a. The present embodiment describes a linear motor having one cavity and a magnet coupled to the stator as an example.

As shown in FIG. 1, magnets 124a and 124b, which are permanent magnets, may be attached to the pole portion 121a of the outer stator 121 forming the gap 120c. The pole portion 121a may be formed to be equal to or longer than the length of the magnets 124a and 124b. The stiffness of the magnetic spring, the alpha value (the thrust constant or the induced voltage constant of the motor), the alpha value variation rate, and the like can be determined by the combination of the stator as described above. The stator 120a may have a length or a shape in various ranges depending on the design of the product to which the linear motor is applied.

The magnets 124a and 124b may be disposed so as not to overlap with the winding coils 125b in the radial direction. Thus, the diameter of the motor can be reduced.

The magnets 124a and 124b may be arranged such that the first magnet 124a and the second magnet 124b having different polarities are reciprocated in the direction of the mover 120b. Accordingly, the magnets 124a and 124b may be formed of a 2-pole magnet having N poles and S poles formed to have the same length on both sides.

In this embodiment, the magnets 124a and 124b are shown to be provided only in the outer stator 121, but the present invention is not limited thereto. For example, the magnets 124a and 124b may be provided only in the inner stator 122 and may be provided in both the outer stator 121 and the inner stator 122.

The stator 120a and the movers 120b of the driving unit 120 according to the present embodiment are formed to provide thrust and restoring force for the reciprocating motion of the piston 132. [ Here, the thrust refers to a force that pushes the mover 120b in the direction of motion, and more specifically acts toward the top dead center in the compression stroke and toward the bottom dead center in the suction stroke. On the other hand, the restoring force means a force pushing the mover 120b toward the reference position (or the initial position). That is, the restoring force may be zero at the reference position (0), and may be increased or decreased toward the top dead center or bottom dead center, respectively, away from the reference position.

2, two kinds of magnetic fluxes may be formed in the stator 120a and the movers 120b of the present embodiment. One is a magnetic flux A that forms a magnetic path for connecting the winding coils 125b, and can perform the role of generating the above-described thrust. That is, one loop may be formed along the outer and inner stator 121 and 122 by the current applied to the winding coil 125b, which generates a thrust for the compression and intake stroke of the mover 120c .

The other magnetic flux B is formed to surround the magnets 124a and 124b of the present embodiment, that is, the first and second magnets 124a and 124b. In this embodiment, Lt; / RTI > The magnetic flux which rotates the magnets 124a and 124b is larger than the amount that the magnetic core 123b of the movers 120b is exposed to the side surface of the pole portion of the stator 120a forming the gap 120c Can be increased. Therefore, the restoring force formed by the magnetic fluxes surrounding the magnets 124a and 124b tends to increase as the distance from the reference position 0 increases.

Accordingly, the drive unit 120 of the present embodiment is capable of generating a reciprocating centering force between the stator 120a and the movers 120b, that is, a magnetic energy when the movers 120b move in the magnetic field , Magnetoresistance) is generated. This force is called the reciprocating direction center force, and this force forms a magnetic resonance spring. Therefore, when the mover 120b reciprocates by the magnetic force, the mover 120b accumulates a force for returning to the center direction by the magnetic resonance spring, and this force causes the mover 120b to perform the resonance motion And it is possible to continue the reciprocating motion.

In the gas lubricating linear compressor according to the present embodiment, on the inner circumferential surface of the inner stator 122, that is, on the inner circumferential surface of the cylinder space 122a, the refrigerant in the first discharge space 104a is laminated with the lamination sheets A sealing portion may be formed to prevent leakage to a gap between the first and second electrodes 127a and 127b.

The sealing portion can also be formed by forming a coating layer (not shown) with a metal powder or a ceramic powder on the inner circumferential surface of the cylinder space 122a, or by inserting a cylinder holder made of a thin cylindrical body. Hereinafter, a case in which the sealing portion is formed of a cylinder holder will be described as an example.

FIG. 3 is a perspective view of the compressor shown in FIG. 1, and FIG. 4 is a perspective view of the compressor shown in FIG. 3, Fig. 6 is a perspective view of the frame and the cylinder holder shown in Fig. 5, viewed from the rear side. Referring to these figures, the cylinder holder 145 is formed in a cylindrical shape and can be inserted into the inner peripheral surface of the inner stator 122. The cylinder holder 145 may be made of a magnetic material as it is in close contact with the inner circumferential surface of the cylinder space 122a, but it may be more preferable that the cylinder holder 145 is formed of a nonmagnetic material in consideration of motor efficiency.

The cylinder holder 145 may be formed by sheet metal processing by a drawing method or may be formed by using a metal mold. Accordingly, the radial thickness of the cylinder holder 145 can be made thinner than the axial thickness of the frame 141.

The cylinder holder 145 may be formed of a thin metal, but may be made of a rigid plastic material such as an engineer plastic.

A first bent portion 145a extending outwardly may be formed at the front end of the cylinder holder 145 so as to be axially supported on the front surface of the inner steyer 122. [ 3 and 6, the first bending portion 145a is pushed by the rear surface of the frame 141 to be described later and is supported on the front surface of the inner stator 122, And can be inserted and supported in the groove 141a1. 5, the front side of the cylinder holder 145 protrudes from the front side of the inner stator 122 so that the axial length L2 of the cylinder holder 145 is smaller than the axial length L2 of the inner stator 122 And may be formed to be slightly larger than the length L1. Also in this case, the axial length L2 of the cylinder holder 145 may be longer than the axial length of the cylinder 131 at least.

However, the first bent portion 145a of the cylinder holder 145 may be inserted and supported on the front side of the inner stator 122. 7, a holder insertion groove 122b is formed on the front surface of the inner stator 122 and a first bent portion 145a of the cylinder holder 145 is inserted into the holder insertion groove 122b . In this case, the depth of the holder insertion groove 122b can be the same as the depth of the first bending portion 145a of the cylinder holder 145, as well as the bending portion 152b provided on the front side of the baffle portion 152 As shown in FIG. Thus, it is not necessary to form a separate holder insertion groove on the rear surface of the frame 141, so that the frame 141 can be easily processed.

The rear end of the cylinder holder 145 may form a second bent portion 145b extending inward to support the rear end of the cylinder 131 in the axial direction. The second bending portion 145b closely contacts the rear surface of the cylinder 131 and is sealed to form a gas bearing between the outer circumferential surface of the cylinder 131 and the inner circumferential surface of the cylinder holder 145. [

On the other hand, the cylinder holder may be supported on the front surface of the inner stator at the first bent portion at the front end thereof as in the above embodiment, but may be inserted into the inner circumferential surface of the cylinder space, have.

8, an annular fixed groove 122c is formed in the inner peripheral surface of the inner stator 122 and a first bent portion 145a of the cylinder holder 145 is inserted into the fixing groove 122c. . In this case, considering the strength of the cylinder holder 145, it is more preferable to stack the stator cores of the inner stator 122 in the cylinder holder 145 rather than to insert the cylinder holder 145 after stacking the inner stator 122 Lt; / RTI > The first bending portion 145a of the cylinder holder 145 is inserted into the first bending portion 145a of the cylinder holder 145 so that the fixing groove 122c of the inner stator 122 is inserted into the first bending portion 145a of the cylinder holder 145, (Not shown).

A baffle portion 152 of a valve stopper 150, which will be described later, may be inserted and coupled to the front space of the cylinder holder 145. The depth of the holder insertion groove 141b1 can be reduced because only the front side bent portion 152b of the baffle portion 152 to be described later is inserted into the holder insertion groove 141b1 formed on the rear surface of the frame 141 Or depending on the fixing method of the baffle portion 152, the holder insertion groove itself may not be necessary. Then, the shape of the frame 141 can be further simplified.

The outer circumferential surface of the baffle portion 152 is directly contacted and fixed to the inner circumferential surface of the cylinder space 122a or the inner circumferential surface of the inner stator 122 so that the volume of the second discharge space 104b formed by the baffle portion 152 The noise reduction effect can be enhanced.

 Meanwhile, the frame 141 may be made of a material having a certain strength even when the magnetic permeability is low, that is, aluminum or the like, so as to minimize leakage of magnetic flux as the rear surface comes into contact with the stator 120 .

The frame 141 may be formed in a disc shape so as to support one side of the stator 120a and cover the cylinder space 122a of the stator 120a as described above.

3 and 4, the frame 141 includes a support portion 141a formed at the edge portion to be engaged with one axial side surface of the stator 120a and a support portion 141b extending from the inside of the support portion 141a as a single body And a cover portion 141b formed at the center portion to cover the cylinder space 122a.

At least one or more terminal holes 141a2 may be formed in the support portion 141a so that a terminal portion for connecting the winding coil 125b to the external power source passes through the support portion 141a. At least one or more (three in the drawing) fastening holes or fastening grooves 141a3 may be formed in the support portion 141a to fasten the assembly bolts 143 described above.

A third discharge hole 141b1 for connecting the loop pipe 112 may be formed in the cover portion 141b.

As described above, the cover portion 141b is integrally formed from the inside of the support portion 141a. The cover portion 141b is protruded to a predetermined height toward the outside (front side) of the stator 120a as shown in Fig. . The outer space 141b2 forming part of the second discharge space 104b is formed outside the cylinder space 122a so that the volume or the number of the second discharge space 104b increases so that the discharge noise can be effectively Can be reduced.

Although not shown in the drawing, a discharge cover having a separate discharge space may be coupled to the outer surface of the frame opposite to the cylinder space. In this case, the third discharge space communicates with the second discharge space, and the loop pipe is coupled to the discharge cover and can communicate with the third discharge space.

Meanwhile, the valve stopper 150 may be inserted and fixed in the space formed in the front side of the cylinder 131 in the cylinder space 122a to receive the discharge valve 134. [

The valve stopper 150 includes a body 151 formed in a cylindrical shape to form a first discharge space 104a and coupled to an inner circumferential surface of the cylinder space 122a, And a baffle portion 152 coupled to the baffle portion.

The body part 151 may be formed of a nonmagnetic material to suppress magnetic flux leakage. However, a coating layer made of an insulating material may be formed on the inner circumferential surface of the inner stator 122, or a separate cylinder holder 145 may be inserted. It is not necessary to form the magnetic layer 151 as a non-magnetic material. However, the body part 151 may be formed of a heat insulating material so as to block the transfer of the motor heat to the refrigerant, which may be desirable to enhance the motor efficiency.

At least one or more bearing communicating holes 151a may be formed in the middle of the body portion 151 so that a part of the refrigerant discharged into the first discharge space 104a is guided to the gas bearing. The bearing communicating hole 151a is formed between the inner peripheral surface of the cylinder space 122a (or the inner peripheral surface of the cylinder holder) and the outer peripheral surface of the cylinder 131 through a passage provided on the outer peripheral surface of the body portion 151 And this refrigerant can be supplied to the space between the cylinder 131 and the piston 132 through the bearing hole 131a of the cylinder 131. [

The baffle portion 152 is disposed between the body portion 151 and the frame 141 so that at least one or more baffle portions 152 are arranged along the axial direction so as to partition the first discharge space 104a and the second discharge space 104b . At least one second discharge hole 152a is formed in the baffle portion 152 so that the refrigerant moving from the first discharge space 104a to the second discharge space 104b can move toward the loop pipe 112 . Accordingly, the valve stopper 150 can perform a function as a kind of discharge muffler.

Meanwhile, another embodiment of the frame in the linear compressor according to the present invention is as follows.

9 is a cross-sectional view showing another embodiment of the frame in the linear compressor according to FIG. As shown in the figure, the cover portion 141b may be formed flush with the support portion 141a at the same height. In this case, the second discharge space 104b having a predetermined volume is provided in the cylinder space 122a, but the cover portion 141b does not protrude forward, so that the length of the compressor can be reduced accordingly so that the compressor can be downsized.

Also in this case, a discharging cover having a separate third discharging space may be provided on the outer surface of the cover portion of the frame. In this case, the third discharge space communicates with the second discharge space, and the loop pipe is coupled to the discharge cover and can communicate with the third discharge space.

On the other hand, there may be another embodiment of the frame. FIG. 10 is a sectional view showing another embodiment of a frame in the linear compressor according to FIG. 1, and FIG. 11 is a sectional view showing a state in which a discharge cover is coupled to a frame in FIG.

10, the cover portion 141b may be recessed by a predetermined depth from the support portion 141a toward the cylinder space 122a. In this case, the second discharge space may not be formed in the cylinder space 122a, or may be formed small.

Here, as shown in FIG. 11, a discharge cover 148 having a separate second discharge space 104b on the outer surface of the cover portion 141b of the frame 141 may be provided. In this case, the second discharge space 104b communicates with the first discharge space 104a, and the loop pipe 112 is coupled to the discharge cover 148 and can communicate with the second discharge space 104b. Particularly, in this case, as the cover portion 141b of the frame 141 is inserted into the cylinder space 122a, the discharge cover 148 is formed in a flat plate shape so that the second discharge space 104b is formed in the cylinder space 122a in order to reduce the discharge noise and to reduce the size of the compressor.

Meanwhile, in the above-described embodiments, the frame is formed as the support portion and the cover portion, and the frame and the ejection cover are integrally formed. However, the frame and the discharge cover may be formed separately. In this case, a plurality of discharge covers can be formed, and the plurality of discharge covers can be formed so as to be successively communicated sequentially. Of course, the discharge covers can be formed in a single number, and the single discharge covers can be coupled to the frame.

When there are a plurality of discharge covers, the cylinder may be formed so as to have substantially the same axial length as the cylinder holder, so that the front surface of the cylinder and the front surface of the cylinder holder substantially coincide. Therefore, as the discharge space is not formed in the cylinder space, the discharge cover is protruded forward, and when there are a plurality of discharge spaces, a plurality of discharge covers for forming the discharge spaces must be formed.

On the other hand, in the case of a single discharge cover, the axial length of the cylinder is formed to be smaller than the axial length of the cylinder holder as in the embodiment of FIG. 5, so that it can be inserted almost to the middle of the rear end of the cylinder holder. Accordingly, as described above, the discharge space can be formed on the front side of the cylinder, so that even if only one discharge cover is formed, a plurality of discharge spaces can be formed together with the discharge space formed inside the cylinder holder.

12 is a vertical cross-sectional view illustrating an example in which a plurality of discharge covers are sequentially coupled to a frame when the cylinder is formed to have a length substantially similar to that of the cylinder holder. The frame 141 is formed in an annular shape having an inner opening 141c and the first discharging cover 148a is formed larger than the inner opening 141c of the frame 141, As shown in FIG. The second discharge cover 148b may be sequentially coupled to the first discharge cover 148a and the third discharge cover 148c may be sequentially connected to the second discharge cover 148b.

In this case, the front surface of the cylinder 131 may be formed so as to protrude or be positioned more than the front surface of the frame 141, but the front surface of the cylinder 131 may be substantially coincident with the rear surface of the frame 141 It is possible to position the discharge cover on the inner side opening 141c of the frame 141 so that the size of the compressor can be reduced accordingly.

The inlet of the gas bearing may be formed on the front surface of the frame 141 and communicated with the discharge space 104a of the first discharge cover 148a, unlike the embodiment described above. Of course, the bearing inlet may communicate with the discharge space 104b of the second discharge cover 148b or may communicate with the discharge space 104c of the third discharge cover 148c.

As described above, even when the cylinder 131 has a length similar to that of the cylinder holder 145 or the inner stator 122, the stator 120a is supported by the frame 141 and the cylinder 131 is supported by the cylinder holder 145 The effect of reducing the material cost by reducing the size and the size of the frame 141 is the same. In addition, since a plurality of discharge covers 148 are formed, not only the discharge noise of the compressor can be reduced but also the efficiency of the compressor can be increased by lowering the temperature of the discharged refrigerant as the discharge space is located outside the motor.

However, in the present embodiment, the length of the cylinder is increased and the length of the piston is relatively increased as compared with the above-described embodiment. However, as the length of the piston becomes longer, the sealing length between the cylinder and the piston becomes longer, so that the behavior of the piston can be stabilized and the leakage of the refrigerant in the compression space can be reduced.

The embodiments according to the present invention may be modified in various ways within the scope of the basic technical idea and those having ordinary skill in the art, and the scope of the present invention should be interpreted based on the appended claims.

110: casing 101: inner space of the casing
103: compression space 104a, 104b: discharge space
120: Linear motor 120a:
120b: Movers 122: Inner stator
122a: cylinder space 130: compression unit
131: Cylinder 131a: Bearing hole
132: piston 133: suction valve
134: discharge valve 141: frame
141a: Support portion 141a1: Holder insertion groove
141a2: Terminal hole 141a3:
141b: Cover part 141b1: Discharge hole
141b2: outer space part 141c: inner opening
145: cylinder holder 141a: first bent portion
141b: second bent portion 148: discharge cover
150: Valve stopper

Claims (14)

A cylinder in which a compression space for compressing the refrigerant is formed;
A piston reciprocating in an axial direction within the cylinder;
A mover coupled to the piston and transmitting driving force to the piston;
A stator for generating a driving force together with the mover;
A frame for axially supporting the stator;
A discharge valve inserted into a cylinder space of the stator to selectively open and close the compression space; And
And a cylinder holder formed separately from the frame and longer than the axial length of the cylinder so as to be inserted into the cylinder space and having one end coupled to the stator and the other end supporting the cylinder axially, . The method according to claim 1,
Wherein the first bent portion is bent outwardly so that one end of the cylinder holder is supported by the stator and the other end of the cylinder holder is bent inward to support the end face of the cylinder in the axial direction. Linear compressor. 3. The method of claim 2,
And the first bent portion is axially supported on one side of the stator from the outside of the stator. The method of claim 3,
And the first bent portion is fixed by one side of the frame. 3. The method of claim 2,
Wherein an annular fixing groove is formed in an inner peripheral surface of the cylinder space,
And the first bending portion is inserted into the fixing groove and is supported in the axial direction. The method according to claim 1,
Wherein a thickness of the cylinder holder in the radial direction is thinner than an axial thickness of the frame. The method according to claim 6,
Wherein the cylinder holder is formed of a material having higher stiffness than the frame. The method according to claim 1,
Wherein at least one discharge space for accommodating the refrigerant discharged in the compression space is formed in the cylinder space. 9. The method of claim 8,
And a discharge cover for covering the cylinder space is coupled to the frame. 9. The method of claim 8,
Wherein the cover is formed integrally with the frame so as to cover the cylinder space. 9. The method of claim 8,
Wherein the at least one discharge space communicates with the inner circumferential surface of the cylinder and the outer circumferential surface of the piston so that a part of the refrigerant discharged to the discharge space is guided between the inner circumferential surface of the cylinder and the outer circumferential surface of the piston. compressor. A cylinder in which a compression space for compressing the refrigerant is formed;
A piston reciprocating in an axial direction within the cylinder;
A gas bearing for supplying a part of the refrigerant discharged from the compression space from the outer circumferential surface to the inner circumferential surface of the cylinder to lubricate between the cylinder and the piston;
A mover coupled to the piston and transmitting driving force to the piston;
A stator for generating a driving force together with the mover;
At least one frame supporting the stator in the axial direction; And
And an inner peripheral surface of the cylinder is formed in a cylindrical shape so as to form a refrigerant passage forming the gas bearing between the inner peripheral surface and the outer peripheral surface of the cylinder so as to be positioned between the stator and the cylinder, And the other end of the cylinder holder axially supporting one end of the cylinder. 13. The method of claim 12,
And a discharge valve for opening and closing the compression space is provided inside the cylinder holder. 13. The method of claim 12,
And a discharge valve for opening and closing the compression space is provided outside the cylinder holder.

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