KR101499992B1 - Linear Compressor - Google Patents

Abstract

Since the linear compressor according to the present invention changes the structure of the linear motor, it can prevent the leakage of the magnetic force and is designed so as to reduce the mechanical spring constant in consideration of the magnetic spring constant as the linear motor structure is changed. It is possible to reduce the size of the springs supporting the springs and to eliminate the parts supporting the springs, thereby making it possible to reduce the size and weight of the springs, to reduce the influence of the scattering of the stroke due to the characteristics of the linear motor structure, There is an advantage that it becomes easy.

Linear compressor, linear motor, inner stator, outer stator, permanent magnet

Description

[0001] LINEAR COMPRESSOR [0002]

The present invention relates to a linear compressor capable of ensuring high efficiency in response to a demand for a low compression capacity and a small installation space, and a linear motor applied thereto. More particularly, the present invention can prevent leakage of magnetic force, And a linear motor applied to the linear compressor.

BACKGROUND ART Generally, a reciprocating compressor is constituted such that a compression space in which a working gas is sucked and discharged is formed between a piston and a cylinder so that the piston linearly reciprocates in the cylinder and compresses the refrigerant.

In recent years, since a conventional reciprocal compressor includes a component such as a crankshaft in order to convert the rotational force of the driving motor into the reciprocating linear motion force of the piston, To solve these problems, many linear compressors have been developed.

In particular, the linear compressor is directly connected to a linear motor in which the piston reciprocates linearly, so that there is no mechanical loss due to the switching of the motion, so that the compression efficiency is improved and the structure is simple. Since the operation can be controlled, the noise is smaller than that of other compressors, and thus it is widely applied to home appliances such as refrigerators used indoors.

FIG. 1 is a cross-sectional view illustrating an example of a linear compressor according to the related art, and FIG. 2 is a side sectional view of an example of a linear motor applied to a conventional linear compressor.

1, the conventional linear compressor includes a frame 2, a cylinder 3, a piston 4, a suction valve 5, a discharge valve assembly 6, a motor cover (not shown) 7, the supporter 8, the back cover 9, the muffler assembly 10, the eight springs 20, and the linear motor 30 are elastically supported. Of course, the closed container 1 is provided with a suction pipe 1a through which refrigerant is sucked and a discharge pipe 1b through which the compressed refrigerant is discharged.

The springs 20 are installed such that the pistons 4 are elastically supported in the axial direction and four first springs 21 are provided between the motor cover 7 and the supporter 8, (22) is provided between the supporter (8) and the back cover (9). Therefore, when the piston 4 moves in the direction of compressing the refrigerant, the first springs 21 compress and elastically support the piston 4. On the other hand, when the piston 4 moves in the direction of sucking the refrigerant, The second springs 22 are compressed and the piston 4 is elastically supported.

The linear motor 30 maintains an air gap between the inner stator 31 and the outer stator 32 as shown in Figs. 1 and 2, and a permanent magnet 33 is disposed between the inner stator 31 and the outer stator 32, And the piston 4 is reciprocally driven as the permanent magnet 33 is connected to the piston 4 by the connecting member 34. [ One end of the inner stator 31 is in contact with one surface of the frame 2 and the other end of the inner stator 31 in the axial direction is in contact with the inner surface of the frame 2. The inner stator 31 is formed in a cylindrical shape in which lamination is laminated in the circumferential direction. And is fixed to the outer peripheral surface of the cylinder 3 by a retaining ring (not shown). The outer stator 32 is coupled to a plurality of cores 32B and 32B 'at regular intervals in the circumferential direction of the coil winding body 32A. The cores 32B and 32B' And the cores 32B and 32B 'are provided so as to surround the outer circumferential surface of the coil winding body 32A in the axial direction of the coil winding body 32A so as to surround a part of the inner circumferential surface of the coil winding body 32A The pawls 32a and 32b are provided. Of course, the outer stator 32 is installed so as to maintain a clearance with the outer circumferential surface of the inner stator 31. The outer stator 32 is positioned so as to abut the frame 2 and the motor cover 7 in the axial direction, (7) is bolted to the frame (2). The permanent magnet 33 is provided so that the poles NS are located on the surface facing the inner stator 31 and the surface facing the outer stator 32 and the connecting member 34 And is connected to the piston (4). Therefore, the permanent magnet 33 reciprocates linearly by the mutual electromagnetic force between the inner stator 31, the outer stator 32 and the permanent magnet 33 to operate the piston 4.

Therefore, the moving member composed of the piston 4 and the permanent magnet 33 moves the mechanical spring 20 from both sides with respect to the linear motion direction with respect to the fixed member composed of the cylinder 3 and the stator 31, The MK resonance frequency defined by the mass (mass) M of the moving member and the spring constant K of the springs supporting the mass M is calculated, and the power frequency Is designed to follow the MK resonant frequency, it is possible to optimize the efficiency of the linear compressor.

Hereinafter, the operation of the conventional art will be described.

When the power is input to the coil winding body 32A, the inner stator 31 and the outer stator 32 are ignited alternately with the N / S poles, and the permanent magnet 33 positioned therebetween is interposed between the inner stator 31 And reciprocatingly linearly moves while being moved by an attractive force or a repulsive force according to the pole change of the outer stator 32. At this time, if the center of the permanent magnet 33 deviates from the ends of the two pawls 32a and 32b of the outer stator 32, the attractive force is not applied to the permanent magnet 33 or the external divergence of the electromagnetic field becomes large. Is detached between the inner stator 31 and the outer stator 32 or is magnetized by the electromagnetic field radiated to the outside to magnetize the other components in the hermetically sealed container 1 or the hermetically sealed container 1, The stroke of the piston 4 or the moving distance of the permanent magnet 33 has been strictly limited so that the center of the permanent magnet 33 reaches the ends of the two poles 32a and 32b of the outer stator 32, Several mechanical springs 20 made of a spring steel of high rigidity have been used to elastically support the moving member as shown in Fig.

When the linear motor 30 is operated as described above, the piston 3 and the muffler assembly 10 connected thereto are linearly reciprocated, and as the pressure in the compression space P changes, the suction valve 5 and the discharge valve assembly The refrigerant flows through the suction holes 1a of the closed container 1, the openings of the back cover 9, the muffler assembly 10 and the pistons 3 through the inlets of the piston 3, And is discharged to the outside through the discharge valve assembly 6, the loop pipe (not shown) and the discharge pipe 1b of the closed container 1. [

Recent linear compressors are being developed not only to be easily applied to low capacity but also to be easily installed in a small space. The conventional linear compressor and the linear motor applied thereto are arranged such that the center of the permanent magnet 33 is reciprocated between the two pawls 32a and 32b of the outer stator 32 because of the above- This is strictly limited by the distance of linear motion and is not suitable for use in a low-capacity simple structure because it uses several springs 20 for this purpose.

An object of the present invention is to provide a linear compressor capable of reducing the size or size of a linear compressor by integrating or eliminating component parts by changing the linear motor structure. It is another object of the present invention to provide a linear motor that enables integration, lightening, and downsizing of component parts.

Another object of the present invention is to provide a linear compressor capable of optimizing efficiency by using a magnetic spring constant (K _magnet ) by changing a linear motor structure, and a linear motor applied thereto.

According to an aspect of the present invention, there is provided a stator comprising: a cylinder having a compression space therein; an inner stator disposed outside the cylinder; and a stator including an inner stator and an outer stator forming a pole in a gap; A piston for compressing a working fluid introduced into the compression space while linearly reciprocating to the compression space of the cylinder and a permanent magnet for reciprocating linear motion together with the piston by the mutual electromagnetic force in the gap between the inner stator and the outer stator Wherein a plurality of permanent magnets are arranged along a direction of reciprocating linear motion, and N poles and S poles of the respective permanent magnets are formed to face the inner stator and the outer stator.

Preferably, the plurality of permanent magnets arranged along the direction of reciprocating linear motion are arranged so that the poles contact with each other.

Alternatively, a plurality of permanent magnets arranged along the direction of reciprocating linear motion may be arranged so that the poles are adjacent to each other.

And a mechanical spring elastically supporting the movable member with respect to the stationary member at both sides in the reciprocating linear motion direction, and as the center of the at least one permanent magnet moves away from the center of the pole of the outer stator in the reciprocating linear motion, Between the inner stator and the outer stator and the at least one permanent magnet, an electromagnetic restoring force can act in the same direction as the restoring force of the mechanical spring in the compressed direction.

Here, between the inner stator and the outer stator and the at least one permanent magnet, the magnetic spring constant K (K) compatible with the _mechanical spring constant (K _mechanical ) is obtained from the maximum electromagnetic repulsive force acting in the same direction as the restoring force of the mechanical spring in the compression direction _magnet can be obtained.

In this case, the mass M of the movable member, the mechanical spring constant (K _mechanical ) obtained by the restoring force of the mechanical spring, the defined gas spring constant (K _gas ) obtained by the working fluid pressure flowing into the compression space, the resonance frequency (f _o) by a (K _magnet) can be obtained.

In this case, preferably, the magnetic spring constant (K _magnet ) has a proportional relation with the motor characteristic value (alpha) calculated by the magnetic flux density (B) and the coil length (l), and the stroke (S) (α) and has a proportional relationship with the magnetic spring constant (K _magnet ).

Further, it is preferable that the inner stator and the outer stator are formed to abut one side and have one pole only on the other side.

The outer stator is disposed on the outer peripheral surface of the inner stator and has a connecting portion connected to one end in the axial direction of the inner stator and a connecting portion connected to one axial end of the inner stator in the direction of the reciprocating linear motion. And the permanent magnets are positioned between the inner stator and the pole of the outer stator and can linearly reciprocate by mutual electromagnetic force.

The frame may further include a frame integrally formed with the cylinder, the frame having an inner stator and an outer stator connected to each other in a reciprocating linear motion direction.

Further, it is preferable to further include a motor cover which supports the outer stator in the die-cutting direction and bolts the outer stator to the frame, and the inner stator is preferably fixed by an outer stator.

In this case, it is preferable that the mechanical spring is a first spring and a second spring that support the piston on both sides in the reciprocating linear motion direction.

The first spring is installed between the cylinder and the flange of the piston, and the second spring is installed between the flange of the piston and the back cover. .

According to another aspect of the present invention, there is provided a stator comprising: a cylinder having a compression space therein; an inner stator provided outside the cylinder; and a stator including an inner stator which abuts against the inner stator at one side and forms a pole between the gaps at the other side; A piston which compresses a working fluid introduced into the compression space while linearly moving back and forth to a compression space of the cylinder, and a piston reciprocating linearly with the piston by mutual electromagnetic force in a gap between the inner stator and the outer stator, A movable member including a plurality of permanent magnets arranged so that N poles and S poles of the respective permanent magnets face each other with the poles thereof contacting each other, the permanent magnets facing the inner stator and the outer stator; As the center of one or more permanent magnets moves away from the center of the pole of the outer stator in the reciprocating linear motion, the mechanical springs move in the direction of reciprocating linear motion from the center of the pole of the outer stator, An electromagnetic compressor is provided between an inner stator and an outer stator and one or more permanent magnets, in which an electromagnetic restoring force acts in the same direction as the restoring force of a mechanical spring in a compression direction.

Here, between the inner stator and the outer stator and the at least one permanent magnet, a magnetic spring constant (K _magnet ) compatible with the _mechanical spring constant (K _mechanical ) is calculated from the maximum electromagnetic restoring force acting in the same direction as the restoring force of the mechanical spring in the compressed direction And the magnetic spring constant K _magnet has a proportional relationship with the motor characteristic value alpha calculated by the magnetic flux density B and the coil length l and the stroke S of the movable member is the motor characteristic value α) and at the same time, it is preferably proportional to the magnetic spring constant (K _magnet ).

In the linear motor according to the present invention configured as described above, since two permanent magnets connected in the direction of motion between one pole of the inner stator and the pole of the outer stator are reciprocatingly linearly moved, not only the magnetic spring constant is increased, Since the compressor adopting such a linear motor can design the mechanical spring constant (K _mechanical ) by designing the resonance frequency in consideration of the magnetic spring constant (K _magnet ), the two springs Since the two springs can elastically support the piston directly, it is possible to omit the supporter or to simplify the shape of the motor cover, which is advantageous in that the capacity, the weight and the size can be reduced .

In the linear compressor according to the present invention, as the structure of the linear motor is changed, a magnetic spring constant (K _magnet ) in addition to the mechanical spring constant (K _mechanical ) and the gas spring constant (K _gas ) is considered in the overall spring constant Since the cooling force is determined by the magnetic spring constant K _magnet and the motor characteristic value alpha, the magnetic spring constant K _magnet can cancel the influence of the motor characteristic value alpha, There is an advantage to reduce disparity.

In the linear compressor according to the present invention, an electromagnetic force is generated only at one pole of the stator. Therefore, as the stroke S increases, the motor characteristic value alpha and the magnetic spring constant K _magnet are sharply reduced. The spring constant k is reduced as the magnetic spring constant _Kmagnet decreases as the amount of stroke Δx of the piston is increased by the influence of the spring K _gas and the stroke S is increased, There is an advantage that the compression capacity corresponding to the load can be easily enlarged as the total amount of stroke S further increases because the amount of thrusting (DELTA x) becomes larger.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 3 is a plan view showing an example of a linear compressor according to the present invention, and FIG. 4 is a side sectional view showing an example of a structure of a linear compressor according to the present invention.

3 and 4, the linear compressor according to the present invention includes a hermetically sealed container 101 having a suction pipe 101a and a discharge pipe 101b through which a refrigerant is sucked / discharged, The valve assembly 100 includes a frame 102, a cylinder 103, a piston 104, a suction valve 105 and a discharge valve assembly 106, a motor cover 107, a back cover 108, a suction muffler 110, 120: 121, 122) and the linear motor 130 are elastically supported.

The frame 102 and the cylinder 103 are integrally formed. However, the frame 102 and the cylinder 103 may be formed of a magnetic material due to the characteristics of the linear motor 130 according to the present invention. That is, in the conventional linear compressor, as described above, there are two pawls in the linear motor, and since the magnetic flux leaks through the gap existing in the pole on the cylinder side, the frame is magnetized and therefore one of the frame, cylinder, Should be made of a non-magnetic material such as aluminum. However, in the linear motor 130 according to the present invention, the inner stator 131 and the outer stator 132 of the linear motor 130 abut against each other on the side of the frame 102 and the cylinder 103 It is not necessary to form the frame 102 or the cylinder 103 as a nonmagnetic material and the frame 102 and the cylinder 103 are made of cast iron or the like because there is no fear that the magnetic flux leaks to the outside as a closed loop is formed therebetween. Can be integrally cast.

The cylinder 103 is formed in a cylindrical shape in which the compression space P can be provided. Since the stroke length of the piston is shorter than that of the conventional linear compressor, the cylinder 103 is formed shorter in the axial direction than the conventional cylinder. Is shorter than the axial length of the stator (131, 132) of the linear motor (130).

The piston 104 has a head 104a provided at a closed end of the cylinder and provided with a suction port 104h for sucking the refrigerant into the compression space P, And a portion 104b. In order to prevent leakage of the magnetic force from the linear motor 130, a part of the linear motor 130 may be made of a non-magnetic material. This is because a pole exists in the linear motor 130 according to the present invention toward the flange portion 104b of the piston 104 as will be described later. The magnetic flux leaking through the gap of the pole causes the magnetic member It is because it magnetizes. The head portion 104a of the piston 104 is installed to be inserted into the cylinder 103 and the flange portion 104b of the piston 104 is inserted into the magnet portion 133 of the linear motor 130, And is elastically supported in the axial direction by two springs 120 (121, 122).

Of course, the suction valve 105 is mounted on the head 104a of the piston 104, the discharge valve assembly 106 is mounted on one end of the compression space P of the cylinder 103, And is operated to open and close in accordance with the pressure change.

The motor cover 107 fixes the linear motor 103 to be described later to the frame 102 so that one end in the axial direction of the linear motor 130 is supported on the frame 102, The other end of the motor cover 107 is covered with the motor cover 107, and then the motor cover 107 is bolted to the frame 102. At this time, the outer stator 132 of the linear motor 130 is fixed between the actual frame 102 and the motor cover 107, and the inner stator 131 is also rotated while fixing the outer stator 132 of the linear motor 130 And can be configured to be fixed together, an example of which will be described in detail below.

The back cover 108 is formed by bending the flat plate to accommodate the flange portion 104b of the piston 104 and the suction muffler 110 and has a motor cover 107, respectively. The cap 108a of the back cover 108 may be attached to the closed container 108. The cap 108a of the back cover 108 may protrude from the closed container 108a, It is preferable that the round or the corner portion is rounded so as to serve as a stopper. Of course, the cap 108a of the back cover 108 is provided with an opening 108h for allowing the refrigerant to flow into the suction muffler 110 and is positioned on the straight line with the suction pipe 101a of the closed container 101 desirable.

The suction muffler 110 is fixed to the flange portion 104b of the piston 104 and guides various kinds of noise spaces and noise pipes so that the refrigerant is sucked up to the head portion 104a of the piston 104, (105). Of course, the suction muffler 110 may be formed of a non-magnetic material in part or in whole in order to prevent magnetic leakage of the linear motor 130.

The springs 120 include a first spring 121 supported by the end of the cylinder 103 and the flange 104b of the piston 104 and a second spring 121 supported by the flange 104b of the piston 104 and the cap And a second spring 122 which is supported by the second spring 108b. The first spring 121 is compressed when the piston 104 is moved in the direction to compress the refrigerant while the second spring 122 is compressed when the piston 104 is moved in the direction in which the refrigerant is sucked, The 1,2 springs 121 and 122 behave opposite to each other. In the linear motor 130 described below, since the value of the magnetic spring constant (K _magnet ) can have a meaning, unlike the conventional linear motor, the K _mechanical value can be made relatively small, It is possible to reduce the spring constant, that is, to reduce the total number of springs or to reduce the spring constant of the individual springs, that is, to reduce the diameter D, the diameter d and the length l of the individual springs . Accordingly, only the two springs 120 (121, 122) can be applied. Furthermore, the supporter that has been provided for installing a large number of springs in a more effective space can be omitted, or the spring support portion provided in the motor cover can be eliminated, , It can be lightened.

FIG. 5 is a side cross-sectional view of an example of a linear motor applied to the linear compressor according to the present invention, and FIG. 6 is a perspective view illustrating one example of an inner stator and an outer stator applied to the linear compressor according to the present invention.

5 to 6, one end of the inner stator 131 and one end of the outer stator 132 in the axial direction are connected to each other, and the other part of the linear motor is maintained in a gap And the magnet portion 133 is disposed between the inner stator 131 and the outer stator 132 so as to reciprocate linearly by electromagnetic force.

The inner stator 131 can be manufactured in the form of lamination lamination in the circumferential direction as in the prior art. The inner stator 131 has a connecting portion 131a extending in the radial direction on the outer circumferential surface at one end in the axial direction so as to be connected to the outer stator 132 And a protrusion 131b having an axially extending outer peripheral surface at one end in the axial direction is provided to increase the electromagnetic force. In this case, since the inner stator 131 is formed to be longer than the axial length of the cylinder 103 (shown in FIG. 4), the inner stator is hardly fixed to the outer circumferential surface of the cylinder, And fixed by a stator 132, which will be described in detail below.

The outer stator 132 is provided so as to surround a portion of the coil winding body 132A in which the coil is wound in the circumferential direction and a portion of the coil winding body 132A except for the inner circumferential surface at regular intervals in the circumferential direction of the coil winding body 132A The core 132B is configured such that only a part of the lamination in the circumferential direction is laminated such that the side end face of the core 132B is in the shape of "┗┛". At this time, the core 132B has two ends positioned to face the connecting portion 131a and the protruding portion 131b of the inner stator 131, and one end of the core 132B has a connecting portion And a connecting portion 132a protruding in the direction of the inner stator 131 so as to overlap with the outer circumferential surface of the inner stator 131 and the protruding portion 131b of the inner stator 131 are provided at the other end of the core 132B. (132b). Further, the connecting portion 132a of the core 132B is formed so as to press the inner stator 131 by a fastening force that is formed, welded, or axially engaged with the connecting portion 131a of the inner stator 131, The ends of the inner stator 131 and the outer stator 132 are connected to each other to form a closed loop so that there is no possibility that the magnetic flux leaks from the connecting portion of the stator 131 or 132. The pawl 132b of the core 132B has protrusions 132b that are both extended in both axial directions to widen the area of the surface facing the inner stator 131 in order to increase the electromagnetic force like the protrusions 131b of the inner stator 131. [ ') Is preferably formed.

Of course, the core applied to the conventional outer stator is provided with two pawls. In order to increase the electromagnetic force, the area of the pawls facing the inner stator is formed to extend in the axial direction. And two laminated laminated laminated layers having a side cross-sectional shape of '┗' and '┛', respectively. Then, the two core blocks were combined with a coil winding body by using a complex joining member and a joining method The core 132B applied to the outer stator 132 of the present invention is formed of one core block laminated with laminations having a side cross-sectional shape of '┛┛' because only one pole 132b is provided, (132A), so that the manufacturing process can be simplified.

The magnet portion 133 is constituted by first and second permanent magnets 133a and 133b having an NS pole facing the inner stator 131 and the outer stator 132. The first and second permanent magnets 133a and 133b, Are arranged so as to be in contact with or adjacent to different poles in the axial direction, that is, the reciprocating linear motion direction. That is, since one end of the inner stator 131 and the outer stator 132 are connected to each other in the axial direction, an electromagnetic force is generated only between the inner stator 131 and the pole 132b of the outer stator 132, The magnet unit 133 itself is configured such that the two permanent magnets 133a and 133b are connected to each other in the axial direction so that the magnet unit 133 reciprocates linearly even if the pole is changed only in one pole 132b And the two permanent magnets 133a and 133b are connected to each other with mutually different poles.

Of course, the _magnet portion 133 located between the inner stator 131 and the pole 132b of the outer stator 132 may be formed to have the magnetic spring constant (K _magnet ) Can be variously configured by adjusting the number and arrangement of permanent magnets. For example, the first and second permanent magnets 133a and 133b have eight permanent magnets arranged at regular intervals in the circumferential direction, and eight first permanent magnets 133a and eight second permanent magnets 133b. Even if eight first permanent magnets 133a and eight second permanent magnets 133b are arranged in the axial direction, the first permanent magnets 133a and the second permanent magnets 133b are arranged such that different poles are adjacent to each other, And the second permanent magnets 133b may be disposed between the first permanent magnets 133a and the second permanent magnets 133a. In addition to the first and second permanent magnets 133a and 133b, the magnet portion 133 may further include a permanent magnet arranged in the axial direction.

Referring to FIGS. 4 to 6, the following will describe a process of assembling the linear motor constructed as above.

The inner stator 131 is fitted on the outer circumferential surface of the cylinder 103 and the axial stator of the inner stator 131 is engaged with the frame 102 and then the outer stator 132 is fitted on the outer circumferential surface of the inner stator 131 The connecting portion 132a of the outer stator 132 overlaps with the connecting portion 131a of the inner stator 131 and the pawl 132b of the outer stator 132 keeps the gap with the outer circumferential surface of the inner stator 131 . The motor cover 107 is engaged in the axial direction to cover the outer circumferential surface of the one end portion in the axial direction of the outer stator 132, and then the motor cover 107 is bolted to the frame 102. Of course, the bolt passes through the space between the cores 132B of the outer stator 132 to join the frame 102 and the motor cover 107, and the outer stator 132 And the connecting portion 132a of the outer stator 132 presses the connecting portion 131a of the inner stator 131 against the frame 102 by the fastening force acting on the outer stator 132, 131 can be fixed.

Since the portions where the inner stator 131 and the outer stator 132 are connected to each other form a closed loop in this manner, even if the diathermal inner stator 131 and the outer stator 132 come into contact with the frame 102, The frame 102 and the cylinder 103 do not need to be made of a nonmagnetic material such as aluminum by injection molding or the like and can be easily formed into a casting body by a cast iron .

7A to 7B are views showing an example of the operation of the linear motor applied to the linear compressor according to the present invention.

As shown in FIGS. 7A and 7B, as power is input to the coil winding body 132A, the inner stator 131 and the pole 132b of the outer stator 132 mutually alternate N-S poles. 7A, when the pole 132b of the outer stator 132 has the N pole, the S pole of the magnet portion 133 is pulled out and at the same time the N pole of the magnet portion 133 is pushed out In the same manner, the inner stator 131 draws the N pole of the magnet portion 133 while pushing the S pole of the magnet portion 133 with the S pole spaced apart. In addition to the restoring force of the first spring 121, The center of the first permanent magnet 133a is shifted from the outer protrusion 132b 'of the outer stator 132 to the outer protrusion 132b' (BDC point) which does not deviate from the end. As a result, the second permanent magnet 133b completely separates the gap space between the inner stator 131 and the pole 132b of the outer stator 132 from the outer protrusion end 132b 'of the outer stator 132 I will escape. 7B, if the pole 132b of the outer stator 133 has the S pole, since the N pole of the magnet portion 133 is pulled out and the S pole of the magnet portion 133 is pushed out Similarly, the inner stator 131 draws the S pole of the magnet portion 133 while pushing the N pole of the magnet portion 133 with the N pole being spaced apart from the N pole.) In addition to the restoring force of the second spring 122, The center of the second permanent magnet 133b similarly moves away from the inner protruding portion 132b 'end of the outer stator 132 while the magnet portion 133 moves in the opposite direction (left) by pushing the permanent magnet 133a to the left, (TDC point). The first permanent magnet 133a completely separates the gap space between the inner stator 131 and the pole 132b of the outer stator 132 from the inner protrusion end 132b 'of the outer stator 132 I will escape. That is, the moving distance of the magnet portion 133, that is, the stroke of the piston 104 is set such that the center of the first permanent magnet 133a is located at the end of the outer protruding portion 132b 'of the outer stator 132, And the center of the inner protrusion 133b is located at the end of the inner protrusion 132b 'of the outer stator 132.

In the linear motor according to the present invention as described above, the magnet portion 133 provided with the permanent magnets 133a and 133b performs reciprocating linear motion, and another restoring force acts on the magnet portion 133 of the linear motor . This is because the permanent magnet of one of the magnet portions 133 is passed between the protruding portion 131b of the inner stator and the pole 132b of the outer stator as in Figs. 7A and 7B, and one of the permanent magnets 133 of the magnet portion 133 The electromagnetic striking force acts to return to the center of the pole 132b of the outer stator 132 by the electromagnetic force as the pole 132b of the outer stator 132 having the different polarity deviates from the center of the pole 132b. 7A, a restoring force is applied so that the first permanent magnet 133a is positioned between the inner stator 131 and the pole 132b of the outer stator 132. In Fig. 7B, the second permanent magnet 133b A restoring force is applied so as to be positioned between the inner stator 131 and the pawl 132b of the outer stator 132.

Since the electromagnetic restoring force acts in the same direction as the restoring force of the springs 120, 121, 122 supporting the moving member composed of the piston 104 and the magnet portion 133, magnet spring, and the spring constant obtained therefrom is expressed as a magnet spring constant (K _magnet ). Such a magnetic spring constant (K _magnet ) is expressed in the same unit as a mechanical spring constant (K _tmechanical ) that elastically supports the movable member on both sides of the reciprocating linear motion direction, and is compatible with any amount. This restoring force starts from the center of the pawl 132b of the outer stator 132 having the center of one of the permanent magnets 133 of the magnet portion 133 with different polarities and is applied to the end of the pole 132b of the outer stator 132 When it is located, it becomes maximum and becomes suddenly smaller. That is, the restoring force (electromagnetic restoring force) of the magnetic spring in the same direction as the restoring force of the second spring 122 is such that the center of the first permanent magnet 133a is positioned at the end of the outer protrusion 132b 'of the outer stator 132 The restoring force (electromagnetic restoring force) of the magnetic spring in the same direction as the restoring force of the first spring 121 becomes the largest when the center of the second permanent magnet 133b is the inner protrusion of the outer stator 132 (In the case of Fig. 7B). The magnetic spring constant can be obtained by the electromagnetic restoring force (maximum electromagnetic restoring force) at the above positions.

Therefore, in the linear compressor employing the linear motor of the present invention, the mechanical spring constant K _tmechanical can be designed to be relatively small considering the magnetic spring constant (K _magnet ), so that the rigidity of the springs (the number of springs, Length, line diameter, and the like) can be reduced. More specifically, in order to operate the linear compressor most efficiently, the power frequency f is designed to be adjusted to the resonance frequency (f _o ). When the linear compressor of the present invention is designed according to the linear motor characteristic of the present invention, It is preferable that the resonance design is performed in consideration of the magnetic spring constant (K _magnet ) as shown in the following equation.

That is, when the power supply frequency f supplied to the linear motor is determined, in order to adjust the power supply frequency f to the resonance point, the mass M of the moving member composed of the piston and the permanent magnet, resilient mechanical spring constant (K _mechanical), spring constant (K _gas), which is defined by the pressure of the gas sucked into the compression space which is defined by of, as described above, according to the center of the permanent magnets departing from the pole center of the stator The magnetic spring constant (K _magnet ) defined by the restoring force acting can be adjusted. In this case, the mass (M) of the moving member can be regarded as a constant value determined for each product, but the gas spring constant (K _gas ) varies depending on the type and load of the refrigerant. However, For this, it is necessary to increase the mass (M) of the movable member to reduce the influence of the gas spring, or to increase the rigidity of the mechanical spring, thereby reducing the relative influence of the gas spring . In order to increase the rigidity of the mechanical spring, a plurality of mechanical springs must be connected in parallel. Therefore, a separate supporting structure such as a supporter piston for supporting a plurality of mechanical springs in parallel was required. However, in the present invention, it is possible to consider a magnetic spring which provides a restoring force in the same direction as the mechanical spring in addition to the mechanical spring, so that the rigidity of the mechanical spring or the mechanical spring constant can be relatively reduced. Therefore, it is possible to design the number n of the springs, the diameter D, the diameter d and the length l of the pistons supporting the piston linearly reciprocating in the both axial directions to be small, So that it can be made lighter and smaller.

Further, the linear compressor employing the linear motor of the present invention has the effect of reducing the influence of the stroke dispersion. That is, the magnetic spring constant (K _magnet ) is proportional to the motor characteristic value (K _magnet α). Using this characteristic, the influence of the motor characteristic value (α) . More specifically, the cooling power is proportional to the stroke S (cooling power? S), and the characteristic value of the linear motor represented by? Can be calculated by the magnetic flux density B and the coil length l in the counter electromotive force The magnetic flux density B and the coil length l may be different depending on the model of the linear motor, so that each of the models has its own motor characteristic value [alpha]. However, while the motor characteristic value alpha has a relation (K _magnet alpha alpha) proportional to the magnetic spring, the stroke S is inversely proportional to the motor characteristic value alpha (S alpha 1 / alpha) (S? K _magnet ).

That is, in the linear compressor employing the linear motor having a large motor characteristic value?, Even if the stroke S becomes small due to the relatively large motor characteristic value?, A relatively large motor characteristic value? And this also leads to a relatively large stroke S, so that the reduction of the stroke caused by the relatively large motor characteristic value? Is canceled by the increase of the stroke by the increase of the magnetic spring constant value, It is possible to minimize the influence of the stroke dispersion and the cooling power scattering according to the motor characteristic value that varies depending on the model of the linear motor.

Alternatively, even if the stroke S becomes large due to a relatively small motor characteristic value? In a linear compressor employing a linear motor having a small motor characteristic value?, A relatively small motor characteristic value? And this also leads to a relatively small stroke S, so that the increase of the stroke caused by the relatively small motor characteristic value? Is canceled by the reduction of the stroke by the reduction of the magnetic spring constant value, It is possible to minimize the influence of the stroke dispersion and the cooling power scattering according to the motor characteristic value that varies depending on the model of the linear motor.

Further, in the linear motor of the present invention, since the rigidity of the mechanical spring is reduced compared with the conventional one, the influence of the gas spring acting on the load can be relatively increased. More specifically, in the conventional linear motor, an electromagnetic force is generated at two poles (2pole) of the stator, whereas the linear motor of the present invention generates an electromagnetic force at only one pole (1pole) of the stator. As the stroke S of the linear motor becomes larger than that of the conventional linear motor, the magnetic flux density B becomes sharply smaller, and the motor characteristic value? Affected by the magnetic flux density B becomes smaller. That is, as the stroke S increases in the linear compressor employing the linear motor of the present invention, the motor characteristic value? Is more sensitively reduced. In a linear motor, the motor characteristic value? And the magnetic spring constant K _magnet ) ≪ / RTI > exhibits a proportional characteristic as described above. 8, when the refrigerant is introduced into the compression space, the initial position (x _o ) of the piston 104 by the gas spring is reduced by a predetermined amount (? X) in the bottom dead center direction is pushed, this way was pressed in a piston 104, an initial position (x _o ') the center of the piston 104 is the top dead center (top dead center: TDC) and bottom dead center: the stroke between the (bottom dead center BDC) S And the stroke S is formed only by the mechanical spring and the gas spring since it is not affected by the magnetic spring. On the other hand, in the case of the present invention shown in the right side of FIG. 8, the mechanical spring constant value can be designed to be relatively small due to the influence of the magnetic spring as described above, The amount of the throttling amount? X 'increases in the bottom dead center direction from the initial position (x _o ) of the piston 104 even if a refrigerant having the same pressure as that of the motor 104 is introduced into the compression space. As the stroke S increases, ) is the smaller and the conventional case around the magnetic spring constant (K _magnet) value also becomes small as a whole spring constant (K) values small since with the piston 104 is pressed initial position (x _o '') which is proportional thereto It is possible to perform the reciprocating linear motion over the longer stroke S1. As a result, the compression capacity can be expanded more easily as a result.

In the foregoing, the present invention has been described in detail by way of examples on the basis of the embodiments of the present invention and the accompanying drawings. However, the scope of the present invention is not limited by the above embodiments and drawings, and the scope of the present invention will be limited only by the content of the following claims.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a plan sectional view showing an example of a linear compressor according to the prior art; Fig.

2 is a side cross-sectional view partially showing an example of a linear motor applied to a linear compressor according to the related art.

3 is a plan sectional view showing an example of a linear compressor according to the present invention.

4 is a side sectional view showing an example of a structure of a linear compressor according to the present invention.

5 is a side cross-sectional view of a portion of an example of a linear motor applied to a linear compressor according to the present invention.

6 is a perspective view showing an example of an inner stator and an outer stator applied to the linear compressor according to the present invention.

7A to 7B are diagrams illustrating an example of operation of a linear motor applied to a linear compressor according to the present invention.

8 is a graph showing an initial position, a throttle amount, a TDC point, and a bottom dead center BDC of a piston in a linear compressor according to the present invention, as compared with the prior art.

Claims (15)

A stationary member including a cylinder provided with a compression space therein, an inner stator provided outside the cylinder, and an outer stator forming an inner stator and a pole in a gap; A piston which compresses a working fluid introduced into the compression space while linearly reciprocating to a compression space of the cylinder and a permanent magnet including a permanent magnet reciprocating linearly together with the piston by an electromagnetic force in a gap between the inner stator and the outer stator; And, And a mechanical spring elastically supporting the movable member with respect to the fixed member on both sides in the reciprocating linear motion direction, A plurality of permanent magnets are arranged along a direction of reciprocating linear motion, and N poles and S poles of the respective permanent magnets are formed to face the inner stator and the outer stator, As the center of the at least one permanent magnet moves away from the center of the pole of the outer stator in the direction of reciprocating linear motion, between the inner stator and the outer stator and the at least one permanent magnet, Miraculous restoring force works, Between the inner stator and the outer stator and the at least one permanent magnet, a magnetic spring constant (K _magnet ) compatible with the _mechanical spring constant (K _mechanical ) from the maximum electromagnetic restoring force acting in the same direction as the restoring force of the mechanical spring in the compressed direction Is obtained. The method according to claim 1, And the plurality of permanent magnets arranged along the direction of the reciprocating linear motion are arranged so that different poles contact each other. The method according to claim 1, And a plurality of permanent magnets arranged along the direction of reciprocating linear motion are arranged such that the poles are adjacent to each other. The method according to claim 1, The mass M of the movable member, the mechanical spring constant K _mechanical obtained by the restoring force of the mechanical spring, the defined gas spring constant K _gas and the magnetic spring constant K _magnet obtained by the working fluid pressure flowing into the compression space, (F _o ) can be obtained by the following equation. 5. The method according to any one of claims 1 to 4, Wherein the inner stator and the outer stator are formed so as to abut on one side and have only one pole on the other side. 6. The method of claim 5, The inner stator is prolonged in the reciprocating linear motion direction on the outer peripheral surface of the cylinder, The outer stator is disposed on the outer circumferential surface of the inner stator and has a connecting portion connected to one axial end of the inner stator and a pole for holding the other axial end portion and the gap space portion of the inner stator, Wherein the permanent magnets are located between the inner stator and the outer stator and are reciprocatingly linearly moved by mutual electromagnetic forces. The method according to claim 6, And a frame which is integrally formed with the cylinder and in which a portion where the inner stator and the outer stator are connected is supported in a reciprocating linear motion direction. 8. The method of claim 7, And a motor cover which axially supports the outer stator and bolts the outer stator to the frame, Wherein the inner stator is fixed by an outer stator. The method according to claim 1, Wherein the mechanical spring is a first spring and a second spring that support the piston on both sides of the reciprocating linear motion direction. 10. The method of claim 9, Further comprising a back cover installed to maintain an axial gap with the piston, The first spring is installed between the cylinder and the flange of the piston, And the second spring is installed between the flange of the piston and the back cover. delete delete delete delete delete

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