KR20180094291A - Linear compressor - Google Patents

Abstract

The present invention relates to a linear compressor. The linear compressor according to the present invention comprises: a piston reciprocating in a shaft direction; a frame accommodating the piston and a cylinder accommodating the piston; a linear motor arranged at the outside of a radial direction of the frame so as to provide driving force of the piston; and a motor cover arranged at one side of the shaft direction of the linear motor so as to fix the linear motor, wherein the linear motor comprises: an interior stator coupled to the frame; and an exterior stator coupled to the outside of a radial direction of the interior stator so as to form an air gap. The motor cover includes a cover supporting portion contacting to one surface of the exterior stator forming the air gap, thereby capable of preventing damage to parts.

Description

[0001] Linear compressor [0002]

The present invention relates to a linear compressor.

A compressor is a mechanical device that receives power from an electric motor or a power generating device such as a turbine and compresses air, refrigerant or various other operating gases to increase the pressure, and is widely used in the household appliances or industry .

Such compressors are broadly classified into a reciprocating compressor that compresses the refrigerant while linearly reciprocating the piston inside the cylinder so that a compression space in which the working gas is sucked or discharged is formed between the piston and the cylinder, A rotary compressor for compressing the refrigerant while the roller is eccentrically rotated along the cylinder inner wall and a compression space in which a working space is sucked or discharged between the cylinder and the cylinder is formed between the eccentrically rotated roller and the cylinder, a scroll compressor in which a compression space in which an operating gas is sucked or discharged is formed between a fixed scroll and a fixed scroll and the orbiting scroll rotates along the fixed scroll to compress the refrigerant, .

In recent years, a linear compressor has been developed in which the piston is directly connected to a driving motor that reciprocates linearly in the reciprocating compressor, and the compression efficiency can be improved without mechanical loss due to motion switching, and is configured with a simple structure.

Normally, in a linear compressor, a piston is linearly reciprocated in a cylinder by a linear motor in a closed shell, and sucks the refrigerant, compresses it, and then discharges it.

The linear motor includes a stator and a mover or rotor. The stator includes an inner stator and an outer stator, and a coil for generating an induction magnetic field is provided on one of the inner stator and the outer stator.

And the mover is driven to reciprocate linearly in accordance with the direction of the magnetic flux generated when a current flows through the coil. As the mover is driven in the state of being connected to the piston, the piston reciprocates linearly in the cylinder while sucking the refrigerant, compressing the refrigerant, and discharging the refrigerant.

Regarding a conventional linear compressor, the present applicant has been registered by applying a patent application (hereinafter referred to as a prior art document).

[Prior Art]

1. Application No. 10-2014-0078762, filed on June 26, 2014, entitled " Linear compressor

2. Application No. 10-2014-0091881, filed on July 21, 2014, entitled " Linear compressor

As in the above-described [Prior Art], the linear compressor is generally driven such that the magnet disposed between the inner stator and the outer stator reciprocates linearly. That is, the magnet was driven as a mover.

Recently, a linear compressor has been introduced in which the magnet is installed in the stator and is driven by a separate mover reciprocating. At this time, the mover reciprocates in an air gap between the inner stator and the outer stator.

However, there is a problem that the gap is reduced or uneven due to the magnetic force of the magnet. In the case where the voids are reduced or uneven, there is a problem that the efficiency decreases and breakage of the mover or the like occurs.

It is an object of the present invention to provide a linear compressor which maintains a gap between an inner stator and an outer stator uniformly.

Another object of the present invention is to provide a linear compressor that is easy to manufacture by using a simple device that keeps the gap uniform.

The present invention also provides a linear motor capable of reducing the weight of the mover and capable of high-speed operation, and a linear compressor equipped with the same.

According to an aspect of the present invention, there is provided a linear compressor including a piston reciprocating in an axial direction, a frame accommodating the piston and a cylinder accommodating the piston, a linear motor disposed radially outward of the frame to provide a driving force of the piston, And a motor cover disposed on one axial side of the linear motor so as to fix the linear motor, wherein the linear motor includes an inner stator coupled to the frame, And an outer stator coupled to a radially outer side of the stator, wherein the motor cover includes a cover supporting portion contacting the one surface of the outer stator forming the gap.

That is, the cover supporting portion supports one surface of the outer stator to maintain the interval of the gap.

The motor cover may further include a fastening hole formed in the cover body such that a ring-shaped cover body and a cover fastening member connected to the frame are inserted, and the cover supporting portion may be disposed radially inward of the fastening hole have.

And a cover connecting portion connecting the cover body and the cover supporting portion, and the outer stator may include an outer fixed end received between the cover connecting portion and the cover supporting portion.

The outer fixed end may include an inner surface which is in surface contact with the cover supporting portion and an outer surface which is connected to the inner surface and is at least partially separated from the cover connecting portion.

The outer stator can be effectively supported as the cover supporting portion comes into surface contact with the outer fixed end, that is, the outer stator. In addition, the cover connecting portion and the outer stator may be spaced apart from each other to prevent the fastening force of the motor cover from being transmitted to the outer stator.

The linear motor may further include a magnet provided on one of the inner stator and the outer stator forming the gap, and the cover supporting portion may be disposed axially rearward of the magnet.

Wherein the outer stator includes a magnet fixing surface on which the magnet is installed and a single piece portion formed on one side of the magnet fixing surface and protruding radially inwardly from the magnet fixing surface, And may be installed on the magnet fixing surface so as to be in contact with the cover supporting portion.

Accordingly, the installation position of the magnet can be easily grasped, and the magnet can be prevented from being separated.

The linear motor is provided with a coil wound around the inner stator and the outer stator, a magnet provided on one of the inner stator and the outer stator forming the gap, and a magnet disposed on the gap A movable core may be included.

The magnet, the motor cover, and the outer stator in the axial direction, and the outer stator, the magnet, the movable core, and the inner stator in order in the radial direction.

With this arrangement, the volume of the linear motor can be reduced as compared with the conventional one.

And a fastening ring disposed between the coil and the magnet in the axial direction and between the outer stator and the inner stator in the radial direction. It is possible to more effectively maintain the interval of the gap with the cover supporting portion.

Wherein the gap is formed axially rearward of the outer stator and the inner stator, the motor cover is disposed on an axially rear side of the outer stator, and the cover supporting portion is axially forward Can be extended.

That is, the cover support portion is merely a modification of the shape of the motor cover, not a separate member, and has an advantage of being relatively easy to manufacture.

According to the present invention, the gap between the outer stator and the inner stator is uniformly maintained, thereby increasing the efficiency of the compressor and preventing the parts from being damaged.

Further, since the gap can be maintained by deforming the shape of the motor cover, which has been conventionally used for fixing the position of the stator, the manufacturing is relatively easy.

Further, not only the motor cover, but also the clamping ring is further included in the gap, so that the interval of the gap can be maintained more effectively.

In addition, since the mover is resonated by the magnetic resonance spring, there is no need for a mechanical resonance spring for resonating the piston, so that the structure of the linear compressor is simplified, and the use frequency is prevented from being restricted within the operation frequency.

Further, since the magnets are provided on the stator, the weight of the mover can be reduced, and high-speed operation can be performed.

Further, according to the present invention, the length of the mover is increased as compared with the prior art, and the operation stroke of the mover can be increased.

In addition, since the mechanical resonance spring is reduced, the weight and size of the linear compressor can be reduced.

In addition, in the resonance motion of the piston, the support device guides the movement of the piston, and the resonance motion of the piston is stable, and the sagging phenomenon of the compressor body can be prevented.

1 is a schematic view illustrating an internal configuration of a linear compressor according to an embodiment of the present invention.
2 and 3 are views showing a linear motor and a motor cover of a linear compressor according to an embodiment of the present invention.
4 and 5 are views showing a motor cover according to an embodiment of the present invention.
6 is a view showing a linear motor, a motor cover, and a spacing ring of a linear compressor according to an embodiment of the present invention.

Hereinafter, specific embodiments of the present invention will be described with reference to the drawings. It is to be understood, however, that the spirit of the invention is not limited to the embodiments shown and that those skilled in the art, upon reading and understanding the spirit of the invention, may easily suggest other embodiments within the scope of the same concept.

1 is a schematic view illustrating an internal configuration of a linear compressor according to an embodiment of the present invention.

Referring to FIG. 1, the linear compressor 10 according to the present embodiment may include a shell 101 forming an outer shape and having an inner space. Both sides of the shell 101 are configured to be opened, and shell covers 102 and 103 can be coupled to both sides of the opened shell 101. [ In a broad sense, the shell covers 102 and 103 can be understood as one configuration of the shell 101. [

Specifically, the shell covers 102 and 103 are provided with a first shell cover 102 coupled to one side of the shell 101 that is open, and a second shell cover 102 coupled to the other side of the shell 101, (103). By the shell covers 102 and 103, the inner space of the shell 101 can be sealed.

1, the first shell cover 102 is located on the right side of the linear compressor 10 and the second shell cover 103 is located on the left side of the linear compressor 10 . In other words, the first and second shell covers 102 and 103 may be arranged to face each other.

A structure may be provided on the outer side of the shell 101 so as to be coupled to the base of the product in which the linear compressor 10 is installed. For example, the product may include a refrigerator, and the base may include a machine room base of the refrigerator. As another example, the product may include an outdoor unit of the air conditioner, and the base may include a base of the outdoor unit.

The linear compressor 10 further includes a pipe provided in the shell 101 or the shell covers 102 and 103 for sucking, discharging or injecting refrigerant.

The pipe includes a suction pipe (104) for allowing refrigerant to be sucked into the linear compressor (10). Further, a discharge pipe (not shown) may be included to allow the compressed refrigerant to be discharged from the linear compressor 10.

For example, the suction pipe 104 may be coupled to the first shell cover 102. The refrigerant can be sucked into the linear compressor (10) along the axial direction through the suction pipe (104). Accordingly, the inner space of the shell 101 may be filled with the refrigerant to be sucked to form a suction pressure.

In addition, the refrigerant sucked through the suction pipe 104 can be compressed while flowing in the axial direction. The compressed refrigerant can be discharged through the discharge pipe. At this time, the discharge pipe may be disposed at a position closer to the second shell cover 103 than the first shell cover 102.

A plurality of supporting devices 500 and 600 for supporting the compressor main body 100 and the compressor main body 100 are provided inside the shell 101. Here, the compressor main body 100 refers to various components provided inside the shell 101.

The plurality of supporting devices 500 and 600 may include a first supporting device 500 connected to one side of the compressor body 100 and a second supporting device 500 connected to the other side of the compressor body 100 600). Each of the supporting devices 500 and 600 can absorb axial vibration and radial vibration of the compressor body 100.

The compressor main body 100 is provided with a cylinder 120 provided inside the shell 101, a piston 130 linearly reciprocating in the cylinder 120, and a driving force applied to the piston 130 And a linear motor 200 is provided.

FIG. 1 is a schematic view of the linear compressor 10, and the compressor body 100 may further include various devices. For example, the compressor main body 100 may further include a suction muffler (not shown) for reducing noise generated from the refrigerant sucked in.

Hereinafter, a direction is defined.

The term "axial direction" can be understood as a direction in which the piston 130 reciprocates, that is, a lateral direction in FIG. In the "axial direction", the direction in which the refrigerant flows is referred to as "forward", and the opposite direction is defined as "rearward". At this time, the piston 130 can reciprocate in the Z-axis direction in the drawing.

On the other hand, "radial direction" can be understood as a direction perpendicular to the direction in which the piston 130 reciprocates, and in the longitudinal direction of Fig.

A compression space P in which the refrigerant is compressed by the piston 130 is formed in the cylinder 120. A suction valve 132 for opening and closing the suction side of the compression space P is disposed in the front portion of the piston 130.

A discharge cover 150 is formed in front of the compression space P and forms a discharge space 151 through which the refrigerant discharged from the compression space P flows. There is provided a discharge valve assembly 140, 142 for selectively discharging the refrigerant compressed in the space P.

The discharge space 151 includes a plurality of spaces defined by inner walls of the discharge cover 150. The plurality of space portions are arranged in the front-rear direction and can communicate with each other.

The discharge valve assembly 140 or 142 is provided with a discharge valve 140 that opens when the pressure of the compression space P becomes equal to or higher than the discharge pressure and allows the refrigerant to flow into the discharge space 151, And a valve spring 142, which is provided between the discharge cover 150 and provides an elastic force in the axial direction.

For example, the rear portion or the rear surface of the discharge valve 140 is positioned so as to be supported on the front surface of the cylinder 120. When the discharge valve 140 is supported on the front surface of the cylinder 120, the compression space P is maintained in a closed state. When the discharge valve 140 is separated from the front surface of the cylinder 120, The space P is opened so that the compressed refrigerant in the compression space P can be discharged.

Therefore, the compression space P is understood as a space formed between the suction valve 132 and the discharge valve 140. The suction valve 132 is formed on one side of the compression space P and the discharge valve 140 is disposed on the other side of the compression space P, Can be provided.

When the pressure in the compression space P is lower than the discharge pressure and the suction pressure is lower than the suction pressure in the reciprocating linear motion of the piston 130 in the cylinder 120, the suction valve 132 is opened, And sucked into the compression space (P). On the other hand, when the pressure in the compression space P becomes equal to or higher than the suction pressure, the refrigerant in the compression space P is compressed while the suction valve 132 is closed.

Meanwhile, when the pressure in the compression space P becomes equal to or higher than the discharge pressure, the valve spring 142 is compressed forward to open the discharge valve 140, and the refrigerant is discharged from the compression space P , And is discharged to the discharge space 151. When the discharge of the refrigerant is completed, the discharge valve 140 closes the compression space P by the restoring force of the valve spring 142.

The linear compressor 10 further includes a discharge guide pipe 152 coupled to the discharge cover 150 and discharging the refrigerant discharged from the discharge space 151 of the discharge cover 150. The refrigerant discharged from the discharge space 151 may flow along the discharge guide pipe 152 and then be discharged to the outside of the shell 101 through the discharge pipe.

In addition, some of the refrigerant gas discharged into the discharge space 151 may be supplied between the cylinder 120 and the piston 130. This refrigerant gas is understood to be a refrigerant used as a gas bearing of the linear compressor 10.

In addition, the compressor body 100 may further include a frame 110.

The cylinder 120 and the piston 130 are disposed inside the frame 110 and the linear motor 200 is disposed outside the frame 110. The discharge cover 150 may be coupled to the front surface of the frame 110.

The frame 110 is disposed to surround the cylinder 120. That is, the cylinder 120 may be positioned to be received inside the frame 110. In addition, the cylinder 120 and the frame 110 may be made of aluminum or an aluminum alloy.

The linear motor 200 includes a stator 210, a magnet 410 mounted on the stator 210, and a mover 400 moving with respect to the stator 210.

The stator 210 includes an inner stator 220 and an outer stator 230 coupled to the outer side of the inner stator 220 in the radial direction. The inner stator 220 and the outer stator 230 may be made of a magnetic material or a conductive material.

A coil 300 may be wound between the inner stator 220 and the outer stator 230. For example, the coil 300 may be coupled to the inner stator 220 while the outer stator 230 is wound on the inner stator 220. Alternatively, the outer stator 230 may be coupled with the inner stator 220 in a state where the coil 300 is previously wound in a ring shape so as to surround the inner stator 220.

The magnet 410 may be installed on at least one of the outer surface of the inner stator 220 and the inner surface of the outer stator 230. At this time, the surface on which the magnet 410 is installed is referred to as a magnet fixing surface 232.

1, the magnet 410 is installed on the outer stator 230 and the magnet fixing surface 232 is formed on the outer stator 230. Hereinafter, this case will be described as an example, but the same applies to the case where the magnet 410 is installed in the inner stator 230.

At this time, the magnet 410 may be spaced apart from the coil 300 in the axial direction. That is, the magnet 410 and the coil 300 may be arranged so as not to overlap each other in the radial direction.

Conventionally, the magnet 410 and the coil 300 have to overlap in the radial direction of the stator 210, and the diameter of the linear motor has to be increased accordingly. On the other hand, in the present invention, since the magnet 410 and the coil 300 are spaced apart from each other in the axial direction, the diameter of the linear motor 200 can be reduced.

For example, the magnet 410 may be cylindrical. In addition, the magnet 410 may have an arc-shaped cross section when viewed from the axial direction. That is, a plurality of magnets 410 may be disposed on the outer circumferential surface of the inner stator 220 or the inner circumferential surface of the outer stator 230 in the circumferential direction.

In addition, the magnet 410 may be formed such that different magnetic poles are arranged in the axial direction. For example, the magnet 410 includes a first pole portion 412 and a second pole portion 414, and the first pole portion 412 and the second pole portion 414 are aligned in an axial direction .

The mover 400 includes a connection part 402 connected to the piston 130 and a movable core 404 installed in the connection part 402.

The connection portion 402 supports the movable core 404 and connects the piston 130 to the movable core 404. At this time, a part of the connection portion 402 may be positioned between the stator 210. For example, at least a part of the connection portion 402 may be formed in a cylindrical shape.

The movable core 404 may be disposed on the connection portion 402 so as to face the magnet 410. 1 shows the movable core 404 installed on the outer circumferential surface of the connection portion 402 so as to face the magnet 410 installed on the inner circumferential surface of the outer stator 230. [ When the magnet 410 is installed on the inner stator 220, the movable core 404 may be installed on the inner circumferential surface of the connection part 402 so as to face the magnet 410.

The movable core 404 is made of a magnetic material and reciprocates with respect to the stator 210 and the magnet 410. Since the piston 130 and the mover 400 are connected by the connection part 402, the piston 130 can reciprocate as the movable core 404 reciprocates.

In detail, when the mover 400 reciprocates with respect to the stator 210 and the magnet 410, the piston 130 inserted into the cylinder 120 moves to the movable core 404 And reciprocates in the axial direction together.

The movable core 404 may be spaced apart from the coil 300 in the axial direction. That is, the movable core 404 and the coil 300 may be arranged so as not to overlap each other in the radial direction.

Conventionally, the movable core 404 and the coil 300 have to overlap in the radial direction of the stator 210, and the diameter of the linear motor has to be increased accordingly. On the other hand, in the present invention, since the movable core 404 and the coil 300 are spaced apart from each other in the axial direction, the diameter of the linear motor 200 can be reduced.

For example, the magnet 410 may be cylindrical. In addition, the magnet 410 may have an arc-shaped cross section when viewed from the axial direction. That is, a plurality of magnets 410 may be disposed on the outer circumferential surface of the inner stator 220 or the inner circumferential surface of the outer stator 230 in the circumferential direction.

For example, the movable core 404 may be circular. The movable core 404 may be formed at least partially in an arc shape when viewed from the axial direction. That is, the movable core 404 may be formed in a ring shape, or may be provided with a plurality of movable cores 404 having arc-shaped cross-sections and spaced circumferentially.

The compressor main body 100 further includes a motor cover 700 disposed on one side of the linear motor 200. The motor cover 700 is fastened to the frame 110 by a cover fastening member 702.

Hereinafter, the linear motor 200 and the motor cover 700 will be described in detail.

2 and 3 are views showing a linear motor and a motor cover of a linear compressor according to an embodiment of the present invention. For convenience of explanation, one side cross-sectional view is shown, and the cover fastening members 702 and the like are omitted and shown.

The outer stator 230 is coupled to the radially outer side of the inner stator 220 and the coil 300 is wound between the inner stator 220 and the outer stator 230 .

2 and 3, the outer stator 230 and the inner stator 220 are connected at one side and the other side is spaced apart at a predetermined interval. More specifically, the inner stator 220 and the outer stator 230 are disposed to be in contact with each other at the front portion in the axial direction, and the inner stator 220 and the outer stator 230 are spaced apart from each other at the rear portion.

At this time, a part of the front part disposed such that the inner stator 220 and the outer stator 230 are in contact with each other may be generated. The inner stator 220 and the outer stator 230 are in close contact with each other. The inner stator 220 and the outer stator 230 are formed according to the shape or the shape of the inner stator 220 and the outer stator 230, respectively.

The air gap A is formed at the rear portion where the inner stator 220 and the outer stator 230 are spaced apart from each other. The air gap A means a space formed by radially separating the inner stator 220 and the outer stator 230 and may be referred to as an air gap.

In the gap A, the magnet 410 is installed. That is, the magnet fixing surface 232 may be formed on one of the mutually facing surfaces of the inner stator 220 and the outer stator 230 to form the gap A '.

2 and 3 illustrate that the magnet 410 is installed on the outer stator 230. So that the magnet fixing surface 232 is formed on the outer stator 230.

In addition, the magnet fixing surface 232 may include a stepped portion 232a for mounting the magnet 410. The stepped portion 232a is formed between the coil and the magnet 410 in the axial direction.

As shown in FIGS. 2 and 3, the step 232a is protruded inwardly in the axial direction from the magnet fixing surface 232. Further, when the magnet fixing surface 232 is formed on the inner stator 230, the step portion 232a protrudes outward in the axial direction.

Accordingly, one end of the magnet 410 is in contact with the step portion 232a, and the other end of the magnet 410 is in contact with the magnet fixing surface 232. That is, the mounting position of the magnet 410 can be easily recognized by the stepped portion 232a, and the convenience of the operation can be improved.

In addition, the movable core 404 is movably arranged in the gap A. As shown in FIGS. 2 and 3, the movable core 404 moves in the axial direction inside the gap A. In particular, the movable core 404 is positioned in the gap A in which the magnet 410 is exposed. That is, the magnet 410 is moved at a portion where the magnet 410 is installed.

Also, in the present invention, the length of the magnet 410 may be two or more times the maximum stroke of the movable core 404. The reason for limiting the length of the magnet 410 is taking into consideration the inflection of the stiffness of the motor spring. Therefore, the length of the magnet 410 is required to be longer than the maximum stroke of the movable core 404.

Also, in the present invention, the axial length of the movable core 404 may be greater than half the length of the magnet 410. In this case, rigidity of the motor spring can be secured.

Hereinafter, the operation of the linear motor 200 will be briefly described.

An alternating current is applied to the coil 300 and an alternating magnetic flux is formed between the inner stator 220 and the outer stator 230 in a state where the magnetic flux by the magnet 410 is formed.

Accordingly, the movable core 404 continuously reciprocates while moving in both directions along the direction in which the magnetic flux is increased by the magnet 410 and the stator 210.

In detail, a magnetic spring is formed between the movable core 404, the stator 210, and the magnet 410 to induce the resonant motion of the movable core 404.

For example, the magnet 410 may be fixed to the outer stator 220, and an alternating current may be applied to the coil 300 in a state where the magnetic flux generated by the magnet 410 flows in a clockwise direction in the figure . Here, the magnet 410 is illustratively a case where the first pole portion 412 is an N pole and the second pole portion 414 is an S pole.

2, when the magnetic flux by the coil 300 flows in the clockwise direction in the figure, the magnetic flux generated by the coil 300 and the magnetic flux of the magnet 410 are increased in the right direction of the drawing, 404) (see arrow M1).

At this time, a reciprocating center force (hereinafter, referred to as " reciprocating center force ") for returning to the left side of the drawing, which is the lower side of the magnetic energy (i.e., magnetic potential energy or magnetic resistance), is generated between the movable core 404, the stator 210, and the magnet 410 Centering force (F1) is accumulated.

In this state, when the direction of the current applied to the coil 300 is changed as shown in FIG. 3, the magnetic flux generated by the coil 300 flows counterclockwise in the drawing. Then, the magnetic flux of the coil 300 and the magnetic flux of the magnet 410 are increased in a direction opposite to the previous direction, that is, leftward in the drawing.

At this time, the movable core 404 is moved by the accumulated centering force F1 and the magnetic force generated by the magnetic fluxes of the coil 300 and the magnet 410 in the left direction of the drawing (See arrow M2).

In this process, the movable core 404 is moved to the left side of the drawing through the center of the magnet 410, that is, the boundary line between the first pole portion 412 and the second pole portion 414 by an inertial force and a magnetic force . At this time, the right end of the magnet 410 is located on the right side of the boundary line between the first pole 412 and the second pole 414.

At this time as well, a centering force F2 for returning to the right side of the drawing is accumulated between the movable core 404, the stator 210, and the magnet 410.

When the direction of the current applied to the coil 300 is changed as shown in FIG. 2, the stored centering force F2 and the magnetic force generated by the magnetic fluxes of the coil 300 and the magnet 410 The movable core 404 is moved in the right direction.

At this time as well, the movable core 404 is further moved to the right side of the drawing through the boundary line between the first pole portion 412 and the second pole portion 414, which is the center of the magnet 410, by inertial force and magnetic force . At this time, the left end of the magnet 410 is positioned to the left of the boundary line between the first pole portion 412 and the second pole portion 414.

A centering force F1 for returning to the left side of the drawing is accumulated between the movable core 404, the stator 210, and the magnet 410.

In this manner, the movable core 404 can continuously repeat the reciprocating movement in which the right and left sides of the movable core 404 alternately move, as in the case of the mechanical resonance spring. That is, the movable core 404 reciprocates in the axial direction.

In this way, since the movable core 404 is moved inside the gap A, it is important to keep the gap of the gap A constant. The gap between the outer stator 230 and the inner stator 220 is spaced apart in the radial direction.

If the spacing of the air gaps A is not uniform, a uniform force can not be transmitted and relatively strong force can be generated. As a result, the efficiency decreases, and as the gap A narrows, breakage of devices such as the movable core 404 may occur.

However, even if the gap of the gap A is constant, the surrounding magnetic bodies are urged by the magnetic force to the magnet 410 installed in the gap A. In detail, the stator 410 spaced by the attraction force of the magnet 410 may be affected.

In particular, the outer stator 230 is generally divided into several blocks, and each block is formed by stacking a plurality of laminations in the circumferential direction. Accordingly, the outer stator 230 receives a relatively large influence by the attracting force of the magnet 410.

At this time, the motor cover 700 may be provided to support the outer stator 230.

As described above, the motor cover 700 is disposed at one side of the linear motor 200 and is fastened to the frame 110 by the cover fastening member 702. Accordingly, the motor cover 700 includes a cover fastening hole 704 into which the cover fastening member 702 is inserted.

The motor cover 700 includes a cover supporting portion 710 which is in contact with the outer stator 230. The cover supporting portion 710 is provided radially inward of the cover fastening hole 704.

As shown in Figures 2 and 3, the cover support 710 extends axially forwardly. Accordingly, the cover supporting portion 710 is disposed such that an extended end thereof abuts against one end of the magnet 410, and an extended surface abuts against the outer stator 230.

Accordingly, the magnet 410 is disposed axially between the cover supporting portion 710 and the step portion 232a. In particular, the cover support 710 may press the magnet 410 toward the coil 300. [ Therefore, the magnet 410 can be prevented from being separated from the stator 210 by the motor cover 700.

A portion of the outer stator 230 contacting the extended surface of the cover supporter 710 is referred to as an outer fixed end 230a. The outer fixed end 230a is located at the axially rear end of the magnet fixing surface 232, that is, at the axially rear end of the magnet 410.

The outer fixed end portion 230a and the cover supporting portion 710 are disposed such that an inner side surface of the outer fixed end portion 230a and an outer side surface of the cover supporting portion 710 are in contact with each other. That is, the outer fixed end portion 230a and the cover supporting portion 710 are arranged so as to be in 'surface contact'.

Accordingly, a force applied to the outer stator 230 by the magnet 410 can be dispersed in the cover supporting portion 710. [ Particularly, as the cover supporting portion 710 supports the outer fixed end portion 230a where the most deformation can occur, the gap of the gap A can be kept constant.

Further, as described above, the outer stator 230 is formed of a plurality of laminations. As the outer fixed end portion 230a and the cover supporting portion 710 are in surface contact with each other, a plurality of laminations of the outer stator 230 can be supported by the cover supporting portion 710. [

Hereinafter, the shape of the cover member 700 will be described in detail with reference to an end surface of the cover member 700 shown in FIGS. 2 and 3. FIG.

4 and 5 are views showing a motor cover according to an embodiment of the present invention.

As shown in FIGS. 4 and 5, the motor cover 700 is entirely provided in a ring shape. Therefore, the inner side of the motor cover 700 is opened, and the mover 400 and the piston 130 can penetrate the inside of the motor cover 700.

The motor cover 700 includes a ring-shaped cover body 701 constituting an outer portion. The fastening hole 704 is formed in the cover body 701. The fastening holes 704 may be provided at a plurality of evenly spaced apart circumferentially with respect to the center.

For example, as shown in FIGS. 4 and 5, three fastening holes 704 may be formed. That is, the frame 110 and the motor cover 700 can be stably coupled by three-point coupling. The linear motor 200 disposed between the frame 110 and the motor cover 700 is supported at three points and stably fixed to the motor cover 700. [ .

In addition, the motor cover 700 includes the inner side portion, that is, the inside of the cover body 701. The cover supporting portion 710 is provided on the inner side.

In addition, a cover connecting portion 720 formed between the cover body 701 and the cover supporting portion 710 is included in the inner side of the motor cover 700. The cover connection portion 720 can be understood as a configuration that accommodates the outer fixed end portion 230a.

Specifically, the inside of the outside fixed end portion 230a is in contact with the cover supporting portion 710, and the outside of the outside fixed end portion 230a is accommodated in the cover connecting portion 720. Therefore, the cover connecting portion 720 may be formed to correspond to the outer shape of the outer fixed end 230a.

For example, with reference to FIGS. 2 and 3, the outer side of the outer fixed end 230a is formed to be narrowed toward the rear in the axial direction. Accordingly, the cover connecting portion 720 is provided with an inclined surface.

However, the cover connecting portion 720 is provided so as to contact at least a part of the outer side of the outer fixed end 230a. That is, when the outer side of the outer fixed end 230a is received, the cover connection part 720 is formed to generate a predetermined empty space. This is because the engagement strength between the frame 110 and the motor cover 700 So that it is prevented from being transmitted to the outer stator 230.

In detail, as the cover fastening member 702 is inserted into the fastening hole 704 and fastened to the frame 110, the periphery of the fastening hole 704 may be affected by fastening force. Accordingly, a slight deformation may occur, and the cover connecting portion 720 may also be deformed. However, since the cover connecting portion 720 and the outer fixed end 230a are not completely in contact with each other, deformation of the outer fixed end 230a can be prevented.

The motor cover 700 includes an auxiliary coupling portion 740 protruding in a direction opposite to the cover supporting portion 710. That is, the auxiliary coupling portion 740 extends axially rearward, as opposed to the cover supporting portion 710, which extends axially forward.

The auxiliary coupling portion 740 may be provided for coupling with structures disposed axially rearward of the linear motor 200. For example, a muffler for reducing noise or a structure for supporting the rear portion of the piston 130 and the like.

The motor cover 700 is fixed to the frame 110 to fix the linear motor 200 in the axial direction and has separate structures disposed in the axial rear portion of the linear motor 200 Can be combined.

Further, the outer stator 230 may be supported so that the gap of the gap A is maintained. In particular, the motor cover 700 is provided to prevent the outer fixed end 230a, which is the rear end portion of the outer stator 230, from being deformed radially inward.

In addition, various devices may be provided so that the gap of the gap A is maintained.

Hereinafter, one example of an apparatus provided so as to maintain the interval of the gap A will be described.

6 is a view showing a linear motor, a motor cover, and a spacing ring of a linear compressor according to an embodiment of the present invention. 6, the description of the same structure as the above-described structure will be omitted and the above description will be referred to.

As shown in FIG. 6, the compressor body 100 further includes a spacing ring 800 disposed in the linear motor 200.

The spacing ring 800 may be provided in a fully ringed condition or may be provided in a plurality of circumferentially spaced arcs. In addition, the gap ring 800 may be formed as a non-magnetic material so as not to affect the magnetic force.

The spacing ring 800 is disposed radially between the inner stator 220 and the outer stator 230. And is disposed between the coil 300 and the magnet 410 in the axial direction.

Specifically, the spacing ring 800 is disposed such that its outer surface is in contact with the outer stator 230 and its inner surface is in contact with the inner stator 220. The gap ring 800 may have a length corresponding to a distance between the outer stator 230 and the inner stator 220.

Accordingly, the front part of the outer stator 230 and the inner stator 220 are in contact with each other, the rear part is supported by the motor cover 700, and the center part is spaced apart by the spacing ring 800. Therefore, the gap of the gap A can be maintained better.

In summary, as the gap of the gap A is maintained by the motor cover 700, the gap ring 800, and other structures, a load applied to the peripheral device by the magnet 410 can be prevented have. As a result, the linear motor 200 is efficiently operated and the efficiency of the linear compressor 10 is increased.

10: Linear compressor 100: Compressor main body
200: Linear motor 210: Stator
220: inner stator 230: outer stator
300: Coil 400: Mover
410: Magnet 700: Motor cover
710: cover support part 800: fastening ring

Claims (10)

A piston reciprocating in the axial direction;
A frame receiving the piston and the piston;
A linear motor disposed radially outward of the frame to provide a driving force of the piston; And
And a motor cover disposed on one axial side of the linear motor to fix the linear motor,
In the linear motor,
An inner stator coupled to the frame; And
And an outer stator coupled to the radially outer side of the inner stator so as to form an air gap,
Wherein the motor cover includes a cover supporting portion that is in contact with one surface of the outer stator that forms the gap. The method according to claim 1,
In the motor cover,
A ring-shaped cover body; And
Further comprising a fastening hole formed in the cover body such that a cover fastening member for connecting the frame to the frame is inserted,
And the cover supporting portion is disposed radially inward of the coupling hole. 3. The method of claim 2,
And a cover connecting portion connecting the cover body and the cover supporting portion,
Wherein the outer stator includes an outer fixed end that is received between the cover connection portion and the cover support portion. The method of claim 3,
At the outer fixed end,
An inner surface in surface contact with the cover support portion,
And an outer side portion connected to the inner side surface and spaced apart from the cover connecting portion at least partially. The method according to claim 1,
The linear motor further includes a magnet provided on one of the inner stator and the outer stator forming the gap,
And the cover supporting portion is disposed axially rearward of the magnet. 6. The method of claim 5,
In the outer stator,
A magnet fixing surface on which the magnet is installed; And
A magnetically fixed surface formed on one side of the magnet fixing surface and having a radially inwardly projecting portion,
Wherein the magnet is installed on the magnet fixing surface such that both ends of the magnet contact with the end portion and the cover supporting portion. The method according to claim 1,
In the linear motor,
A coil wound between the inner stator and the outer stator;
A magnet provided on one of the inner stator and the outer stator forming the gap; And
And a movable core movably disposed in the gap. 8. The method of claim 7,
The coil, the magnet and the motor cover are arranged in order in the axial direction,
Wherein the outer stator, the magnet, the movable core, and the inner stator are arranged in order in the radial direction. 8. The method of claim 7,
And a fastening ring disposed between the outer stator and the inner stator in a radial direction between the coil and the magnet in the axial direction. The method according to claim 1,
Wherein the gap is formed axially rearward of the outer stator and the inner stator,
The motor cover is disposed on an axially rear side of the outer stator,
And the cover supporting portion extends axially forward from the motor cover toward the gap.

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