CN113217334A

CN113217334A - Linear compressor

Info

Publication number: CN113217334A
Application number: CN202110665892.7A
Authority: CN
Inventors: 唐明生; 汤鑫斌; 邹慧明; 田长青
Original assignee: Technical Institute of Physics and Chemistry of CAS
Current assignee: Technical Institute of Physics and Chemistry of CAS
Priority date: 2021-06-16
Filing date: 2021-06-16
Publication date: 2021-08-06

Abstract

The invention provides a linear compressor, which comprises a shell and a compressor core positioned in the shell, wherein the compressor core comprises a linear motor assembly and a piston assembly; the piston assembly comprises a cylinder and a piston, the piston is in contact with the cylinder through a gas bearing and is sleeved in the cylinder in a coaxial matching mode, and the gas bearing supplies gas for the cylinder through a gas storage cavity. When the mover in the linear compressor drives the piston to reciprocate in the cylinder, the gas bearing generates a stable gas lubricating film in a gap between the piston and the cylinder, and the gas lubricating film plays a good role in supporting and lubricating the cylinder and the piston in the process of matching reciprocating motion, so that the cylinder and the piston of the linear compressor run in a non-contact manner, and high-pressure gas in a compression cavity is effectively prevented from entering a back pressure cavity along a gas gap between the piston and the cylinder, so that the leakage of the high-pressure gas is prevented.

Description

Linear compressor

Technical Field

The invention relates to the technical field of compressors, in particular to a linear compressor.

Background

In the low temperature technical field, a refrigerating machine (such as a thermoacoustic refrigerator, a Stirling refrigerator, a pulse tube refrigerator and the like) which generates a refrigerating effect by utilizing alternating flow heat return of fluid mainly adopts a valveless linear compressor as a pressure wave generator so as to realize the periodic compression and expansion of refrigerating fluid. The linear compressor cancels a crank connecting rod mechanism of the traditional reciprocating piston compressor, directly adopts a linear motor for driving, reduces the intermediate motion transmission link, greatly improves the efficiency and the reliability of the compressor, and obtains wide attention and application.

At present, a linear oscillating motor applied to a pressure wave generator of an alternating flow regenerative refrigerator mainly has two structures of a moving coil type and a moving magnet type. Compared with a moving coil type linear motor, the moving magnet type linear motor has more advantages in the aspects of reliability and performance, the alternating magnetic field of the linear oscillating motor in the structural form is composed of the excitation coil and the magnetic conduction material, the rotor part adopts the permanent magnet to generate the constant magnetic field, and the linear motor in the structural form has the advantages of small magnetic circuit loss, large specific thrust and the like.

The low-temperature valveless linear compressor driven by the cylindrical linear oscillating motor applied in the prior art mostly adopts plate springs arranged on two sides of a core of the compressor as supports to realize the non-contact operation of a piston and a cylinder of the compressor. The arrangement of the resonant plate springs at two sides of the compressor movement requires the reservation of an axial dimension space at least larger than the running distance of the plate springs, resulting in a larger size of the compressor. Simultaneously because of the influence of spare part machining precision and workman installation accuracy, for guaranteeing compressor piston and the complete contactless operation of cylinder, need adopt the great cylinder of size and piston to carry out clearance fit, but this kind of cooperation mode leads to the high-pressure gas leakage of compression chamber to the backpressure chamber serious to lead to compressor operation pressure ratio can't further improve.

Disclosure of Invention

The invention provides a linear compressor, which is used for solving the defect that in the prior art, in order to ensure that a compressor piston and a cylinder operate in a completely non-contact manner, a large-size cylinder and a large-size piston are adopted to perform clearance fit, so that high-pressure gas from a compression cavity to a back pressure cavity is easy to leak seriously.

In order to solve the above problems, the present invention provides a linear compressor, comprising a casing and a compressor core located in the casing, wherein the compressor core comprises a linear motor assembly and a piston assembly;

the piston assembly comprises a cylinder and a piston, the piston is in contact with the cylinder through a gas bearing and coaxially sleeved in the cylinder in a matching manner, and the gas bearing supplies gas to the piston through a gas storage cavity;

the air storage cavity is provided with an air storage channel and an air supply channel, the air storage channel is connected to a second channel communicated with the air cylinder and a compression cavity formed by the piston, the air storage channel is provided with a control valve, and the air supply channel is connected with the air bearing.

According to the linear compressor provided by the invention, the linear motor assembly is composed of a stator and a rotor;

the stator comprises an inner stator and an outer stator which are coaxially arranged, and an air gap exists between the inner stator and the outer stator;

the rotor is embedded in the air gap and comprises a rotor framework and an annular permanent magnet which are coaxially arranged, and the rotor framework is integrally arranged or assembled; the piston is coaxially arranged on the inner side of the rotor and connected with the rotor framework.

According to the linear compressor provided by the invention, the two ends of the stator are respectively provided with the first fastening seat and the second fastening seat, and the air cylinder is arranged on the second fastening seat.

According to the linear compressor provided by the invention, an anti-collision structure is arranged between the piston and the shell and is used for preventing rigid collision between the piston and the shell.

According to the linear compressor provided by the invention, the air storage cavity is arranged on the shell, the air cylinder, the second fastening seat or the anti-collision structure;

the air supply channel and the air storage channel are respectively and correspondingly arranged on the shell, the air cylinder, the second fastening seat or the anti-collision structure.

According to the linear compressor provided by the invention, at least a first channel is arranged on the shell, and the first channel is connected with the compression cavity through the second channel.

According to the linear compressor provided by the invention, the rotor framework is formed by assembling the first permanent magnet fastener and the second permanent magnet fastener, and the annular permanent magnet is coaxially arranged in the rotor framework formed by the first permanent magnet fastener and the second permanent magnet fastener.

According to the linear compressor provided by the invention, the first fastening seat is connected with a leaf spring assembly, and the leaf spring assembly is also connected with the piston;

the flat spring assembly is formed by sequentially stacking a plurality of flat springs at intervals along the axial direction;

the leaf springs are elastic members distributed in or near the same plane and comprise free ends and elastic transition parts for connecting the free ends.

According to the linear compressor provided by the invention, one side, opposite to the compression cavity, of the piston in the shell is a back pressure cavity, and a vibration damping structure is arranged in the back pressure cavity;

the vibration reduction structure comprises a vibration reduction spring and a vibration reduction block, and the vibration reduction spring and the piston are coaxially arranged;

the damping block is arranged in the middle of the damping spring, one end of the damping spring is connected with the leaf spring assembly, and the other end of the damping spring is connected with the casing.

According to the linear compressor provided by the invention, one group of compressor cores or two groups of compressor cores are arranged in the shell, and the two groups of compressor cores are symmetrically arranged.

According to the linear compressor provided by the invention, the gas bearing is coaxially arranged or embedded with the cylinder, the gas storage cavity is formed in the shell and is used as a stable high-pressure gas supply source of the gas bearing, and high-pressure gas is supplied to the gas bearing through the gas supply channel, so that when a rotor in the linear compressor drives the piston to reciprocate in the cylinder, the gas bearing generates a stable gas lubricating film in a gap between the piston and the cylinder, the gas lubricating film plays a good role in supporting and lubricating in the process of matching reciprocating motion of the cylinder and the piston, the non-contact operation of the cylinder and the piston of the linear compressor is realized, and the high-pressure gas in the compression cavity is effectively prevented from entering the back pressure cavity along the air gap between the piston and the cylinder, so that the leakage of the high-pressure gas is prevented.

And then adopt gas bearing cooperation leaf spring subassembly to provide the cooperative support for the piston to realize linear compressor's oil-free lubrication, reduce the clearance that high-pressure gas produced between cylinder and piston and leak, avoid linear compressor because of the pollution that the mechanical wear of contact operation produced, ensure linear compressor's high efficiency and reliability of operation, and can effectively reduce the axial dimensions of compressor because of the structure of leaf spring subassembly itself.

Drawings

In order to more clearly illustrate the technical solutions of the present invention or the prior art, the drawings needed for the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and those skilled in the art can also obtain other drawings according to the drawings without creative efforts.

Figure 1 is a cross-sectional view, in axial direction, of a compressor movement according to a first embodiment of the linear compressor of the present invention;

figure 2 is a radial cross-sectional view of a compressor core of a first embodiment of the linear compressor according to the invention;

figure 3 is a cross-sectional view, in axial direction, of two compressor movements of a first embodiment of the linear compressor according to the invention;

figure 4 is a cross-sectional view, in axial direction, of a compressor movement according to a second embodiment of the linear compressor of the present invention;

figure 5 is a cross-sectional view, in axial direction, of two compressor movements of a second embodiment of the linear compressor according to the invention;

FIG. 6 is a cross-sectional view of two compressor cartridges in another embodiment of the linear compressor of the present invention taken along the axial direction;

fig. 7 is a schematic sectional view of the linear compressor shown in fig. 6 in a radial direction thereof;

fig. 8 is a cross-sectional view of two compressor movements in an axial direction in still another embodiment of the linear compressor of the present invention.

Reference numerals:

1: a housing; 11: a housing; 12: a first end cap;

13: a second end cap; 2: a compressor core; 21: a linear motor assembly;

211: an inner stator; 212: outer stator 213: a rotor framework;

2131: a first permanent magnet fastener; 2132: a second permanent magnet fastener; 214: an annular permanent magnet;

215: a field coil; 22: a piston assembly; 221: a cylinder;

222: a piston; 223: a gas bearing; 224: a gas storage cavity;

225: a gas storage channel; 226: a gas supply channel; 227: a compression chamber;

228: a second channel; 229: a back pressure chamber; 230: a first channel;

23: a first fastening seat: 24: a second fastening seat; 25: an anti-collision structure;

26: a leaf spring assembly; 27: a vibration reduction structure; 271: a damping spring;

272: a vibration damping block;

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings, and it is obvious that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Embodiments of the present invention will be described below with reference to fig. 1 to 8. It should be understood that the following description is only exemplary embodiments of the present invention and is not intended to limit the present invention in any way.

Referring to fig. 1 to 3 in detail, as a first embodiment of the present invention, the present invention provides a linear compressor, which includes a casing 1, and a compressor movement 2 located in the casing 1, wherein the compressor movement 2 includes a linear motor assembly 21 and a piston assembly 22.

The piston assembly 22 comprises a cylinder 221 and a piston 222, wherein the piston 222 is in contact with the cylinder 221 through a gas bearing 223 and coaxially sleeved inside the cylinder 221 in a matching manner; the gas bearing 223 is supplied with gas through a gas storage cavity 224, the gas storage cavity 224 is provided with a gas storage channel 225 and a gas supply channel 226, the gas storage channel 225 is connected to a second channel 228 communicated with a compression cavity 227 formed by the cylinder 221 and the piston 222, the gas storage channel 225 is provided with a control valve (not shown), and the gas supply channel 226 is connected with the gas bearing 223.

Specifically, the piston 222 has a first end and a second end, and the cylinder 221 is coaxially fitted and sleeved outside the second end of the piston 222. As shown in fig. 1 and 2, the air storage cavity 224 is disposed near the second end of the piston 222, and may be opened inside any one of the fastening seat of the compressor core 2, the air cylinder 221, or the casing 1, and any position capable of accommodating the air storage cavity 224, and the air supply channel 226 and the air storage channel 225 are respectively disposed in the fastening seat of the compressor core 2, the air cylinder 221, and the casing 1; the gas bearing 223 is coaxially connected with the cylinder 221 and is embedded on the inner side wall of the cylinder 221; the gas storage cavity 224 collects high-pressure gas through a gas storage channel 225 and is communicated with the outer side surface of the gas bearing 223 through a gas supply channel 226 to supply gas to the gas bearing 223.

In addition, the second end of the piston 222, the cylinder 221 and the sealing surface of the casing 1 together form a compression chamber 227, and a back pressure chamber 229 is formed in the casing 1 on the side of the piston 222 opposite to the compression chamber 227.

When the piston 222 reciprocates in the cylinder 221 under the action of the working magnetic field, a gas pressure wave is formed in the compression cavity 227, and the pulsating high-pressure gas gradually enters the second channel 228 along with the increase of the pressure in the compression cavity 227 and is discharged to the outside of the compressor; upon passing through the second passage 228, a portion of the high pressure gas is directed into the gas storage chamber 224 through the control valve.

During the process that the piston 222 continuously reciprocates relative to the cylinder 221, the high-pressure gas buffered in the gas storage cavity 224 supplies gas to the gas bearing 223 through the gas supply channel 226, so as to provide a continuous and stable high-pressure gas source for the gas bearing 223, so that the gas bearing 223 generates a stable gas lubricating film in a gap between the cylinder 221 and the piston 222, not only can the cylinder 221 and the piston 222 realize good gas floating supporting and lubricating effects during the matching reciprocating motion process, but also can prevent the high-pressure gas in the compression cavity 227 from entering the back pressure cavity 229 along an air gap between the piston 222 and the cylinder 221, so as to prevent the high-pressure gas from leaking.

In an embodiment, the air receiver 224 is illustrated as being provided on the casing 1, and at least one first passage 230 is provided on the casing 1, and the first passage 230 is communicated with the compression chamber 227 through a second passage 228, so that the high-pressure air in the compression chamber 227 passes through the second passage 228 and the first passage 230 in sequence, and the high-pressure air in the compression chamber 227 is discharged to the outside of the compressor.

Specifically, the first channel 230 and the second channel 228 are both opened on the casing 1, and the first channel 230 and the second channel 228 are connected in series. In setting the positional relationship of the first passage 230 and the second passage 228, a positional relationship perpendicular to each other may be set with the object of reducing the size of the compressor. Other positional relationships may also be provided according to the use requirement, and are not limited herein.

In one embodiment, the control valve is a one-way valve for controlling the high-pressure gas in the compression chamber 227 to be directed into the gas storage chamber 224 through the second passage 228 and the gas storage passage 225, so as to prevent the high-pressure gas in the gas storage chamber 224 from flowing out reversely.

In one embodiment, the linear motor assembly 21 is composed of a stator and a mover; the stator comprises an inner stator 211 and an outer stator 212 which are coaxially arranged, and a cylindrical air gap is formed between the inner stator 211 and the outer stator 212; the mover is embedded in the cylindrical air gap, the mover includes a mover frame 213 and an annular permanent magnet 214 coaxially disposed, and the annular permanent magnet 214 is fixedly installed in the mover frame 213.

Specifically, the mover frame 213 may be integrally disposed or assembled, and the specific disposition is determined according to the use environment, for example, when the linear compressor of the present invention is used in a refrigerator, the mover frame 213 may be assembled, for a specific reason, see the following modified embodiments.

The piston 222 is coaxially disposed inside the mover, and is coupled to the mover frame 213 via a piston 222 holder so that the piston 222 reciprocates with the mover relative to the cylinder 221 when the mover moves.

Further, the cores of the inner stator 211 and the outer stator 212 are hollow cylindrical, and the excitation coil 215 is disposed on the outer sidewall of the core of the inner stator 211 or the inner sidewall of the core of the outer stator 212 in the circumferential direction.

Specifically, the inner side wall of the iron core of the outer stator 212 is further provided with a plurality of protrusions arranged along the circumference, and each protrusion is wound with one excitation coil 215.

The linear motor assembly 21 has a structure in which a magnetic conductive material is installed on the circumference of the exciting coil 215 to form a magnetic circuit structure having a cylindrical air gap concentric with the exciting coil 215, the cylindrical inner stator 211 and the cylindrical outer stator 212 form the air gap, and the radially magnetized cylindrical permanent magnet reciprocates in the air gap.

In one embodiment, the stator is provided at both ends with a first fastening seat 23 and a second fastening seat 24, respectively, for fixedly mounting the stator and/or the cylinder 221, respectively.

Wherein the first fastening seat 23 is installed adjacent to the back pressure chamber 229, the second fastening seat 24 is installed adjacent to the compression chamber 227, and the cylinder 221 is installed on the second fastening seat 24.

Meanwhile, in order to improve the working performance of the piston 222, a wear-resistant self-lubricating coating may be coated on the surface of the piston 222, and the wear-resistant self-lubricating coating includes a graphite-like coating (GLC), a polyether ether copper coating (PEEK), a polyimide resin coating (PI), a diamond-like carbon coating (DLC), a Teflon coating (Teflon), and a molybdenum disulfide coating (MoS)₂) Tungsten disulfide coating (WS)₂) Graphite coating (C), chromium nitride Coating (CRN), titanium aluminum silicon nitride coating (TiAlSiN), titanium aluminum nitride coatingLayer (AlTiN), titanium nitride coating (TiN), alumina ceramic coating (Al)₂O₃) And a phosphate coating (P) or a combination of at least two thereof.

Referring to fig. 4 to 8 in detail, as a second embodiment of the present invention, on the basis of the above embodiment, an anti-collision structure 25 is disposed between the piston 222 and the casing 1, specifically, the anti-collision structure 25 is disposed between the second end of the piston 222 and the casing 1, and the air storage cavity 224 is disposed in the anti-collision structure 25.

When the linear compressor runs in a cylinder collision mode, that is, when the mover in the linear compressor runs over the stroke, the piston 222 is likely to collide with the sealing surface of the casing 1 rigidly. The anti-collision structure 25 is additionally arranged to prevent the piston 222 from rigidly colliding with the sealing surface of the casing 1, so that the operation reliability and stability of the linear compressor are improved, and the service life of the linear compressor is further prolonged.

Specifically, the anti-collision structure 25 is an exhaust gasket, and the air storage cavity 224 may be provided on the exhaust gasket, or the air storage cavity 224 has a housing directly placed in the exhaust gasket, and a middle through hole is formed in the exhaust gasket, which is equivalent to the second channel 228 in the first embodiment, and the air storage channel 225 is equivalent to the air storage channel 225 in the first embodiment.

Referring to fig. 1, fig. 3 and fig. 8 in detail, a third embodiment of the present invention is a modification of the first embodiment, that is, a mover frame 213 is assembled by a first permanent magnet fastener 2131 and a second permanent magnet fastener 2132, and an annular permanent magnet 214 is coaxially installed inside the mover frame 213 formed by the first permanent magnet fastener 2131 and the second permanent magnet fastener 2132.

The assembly method effectively avoids the problem that the annular permanent magnet 214 needs to be bonded on the rotor framework 213 through glue in the prior art. After the glue is bonded, due to the existence of volatile gas impurities, when the linear compressor is used for a refrigerator, the heat exchange performance of the refrigerator is affected. In addition, the assembly method increases the overall mass of the linear compressor compared to the integrated mover frame 213, and effectively reduces the natural frequency of the linear compressor when the linear compressor reciprocates in the axial direction at the same time.

It should be noted that the annular permanent magnet 214 is coaxially installed inside the first permanent magnet fastener 2131 and the second permanent magnet fastener 2132, which can be understood as a fixed installation or a detachable installation of the annular permanent magnet 214, and the specific installation form should be broadly understood, and when a fixed installation form is selected, the annular permanent magnet 214 may be welded to the first permanent magnet fastener 2131 or the second permanent magnet fastener 2132.

When a detachable mounting mode is selected, the annular permanent magnet 214 can be assembled on the first permanent magnet fastener 2131 and the second permanent magnet fastener 2132, and the two permanent magnet fasteners are fixed through threaded connection; or a clip connection is used to assemble the annular permanent magnet 214 to the first and second

permanent magnet fasteners

2131, 2132.

Referring to fig. 8 in detail, as a fourth embodiment of the present invention, the inner stator 211 is mounted on the body of the piston 222, such that the inner stator 211 and the piston 222 form an integrated assembly, and further connected to the mover frame 213 through the piston 222 support.

Because the piston 222 and the inner stator 211 are integrally installed, the total mass of the rotor is increased, and when the rotor reciprocates axially at the same time, the natural frequency of the linear compressor is effectively reduced, so that the radial displacement caused by the increase of the mass of the rotor is reduced, and meanwhile, the lower operating frequency is more favorable for matching the linear compressor with a cold head of a low-temperature refrigerator, so that the overall performance of the low-temperature refrigerator is improved.

It should be further noted that, the inner stator 211 and the mover are integrally installed, and besides the inner stator 211 can be directly and coaxially sleeved with the body of the piston 222, the inner stator 211 can also be fixed on the body of the piston 222 through a connector, or the annular permanent magnet 214 and the inner stator 211 can be simultaneously installed on the body of the piston 222, which is not illustrated herein.

Referring to fig. 1 to 8 in detail, as a fifth embodiment of the present invention, on the basis of the above embodiments, and unlike the above embodiments, in order to reduce the radial displacement of the piston 222 in the cylinder 221 and achieve a better resonance effect, the first fastening seat 23 is connected with the flat spring assembly 26, both ends of the flat spring assembly 26 are connected to the first fastening seat 23, and the middle portion of the flat spring assembly 26 is fixed on the piston 222 bracket.

The flat spring assembly 26 cooperates with the gas bearing 223 to provide radial support for the piston 222 when the piston 222 reciprocates in the cylinder 221, so as to effectively reduce contact sliding friction between the piston 222 and the cylinder 221, so as to achieve non-contact reciprocating motion of the piston 222 in the cylinder 221, thereby achieving the purpose of oil-free lubrication of the linear compressor.

Specifically, the flat spring assembly 26 is formed by stacking a plurality of flat springs in sequence at intervals along the axial direction. A plurality of layers of mounting positions for fixing the leaf springs and flat washers (which are labeled in the figures) are correspondingly arranged on the first fastening seat 23, one leaf spring is correspondingly mounted on each layer of mounting position, and the spaced stacking of two adjacent leaf springs is beneficial to preventing the two adjacent leaf springs from interfering in the resonance process and generating noise. Moreover, the leaf spring assembly 26 formed by combining a plurality of leaf springs has better rigidity, can better realize energy storage, and provides radial support for the reciprocating motion of the piston 222.

More specifically, the leaf springs are elastic members distributed in or near the same plane, and include free ends, and elastic transition portions for connecting the respective free ends, whereby the leaf springs are not strictly limited as to whether their respective elastic transition portions are distributed in the same plane. The elastic transition part is formed by sequentially connecting a plurality of straight line sections or curve sections end to end.

It should be further noted that a shape of the flat spring may be formed by bending the spring wire in the same plane for a plurality of times, and obviously, a shape of the flat spring includes a straight line segment, a curved line segment and a combination thereof, and the cross section of the spring wire may be circular, oval, square or triangular, which is not limited herein. Thus, the shape of the bent leaf spring may be "S" -type, "C" -type, "Z" -type, "L" -type, "ㄥ" -type, "V" -type, "U" -type, "" angle "-type," "L" -type, "く" -type, "へ" -type, "J" -type, or the like. The leaf spring may also take other shapes, which are not described in detail herein.

In the embodiment, by disposing the plate spring assembly 26 at one end of the first fastening seat 23, that is, indirectly disposing the plate spring assembly 26 at one end of the stator, the piston 222 in the linear compressor of the present invention can perform a good resonance effect when the piston 222 reciprocates along with the mover connected thereto under the action of the alternating electromagnetic field generated by the exciting coil 215, and the plate spring assembly 26 serves as an energy storage element.

In addition, the leaf spring assembly 26 has a smaller axial dimension than a resonant spring built in a conventional linear compressor, so that the axial dimension of the linear compressor can be greatly reduced.

Meanwhile, the leaf spring is low in manufacturing cost and has a large radial-axial stiffness ratio, the piston 222 is radially positioned and installed through the leaf spring, radial displacement of the piston 222 in the axial reciprocating motion process can be effectively avoided, contact type sliding friction between the piston 222 and the cylinder 221 is effectively reduced, non-contact type reciprocating motion of the piston 222 in the cylinder 221 is achieved, stability and reliability of work operation of the linear compressor are further guaranteed, oil-free lubrication and oil-containing lubrication can be achieved when the linear compressor works, and diversified selection of work modes is achieved.

In addition, the flat spring assembly 26 can effectively avoid interference between adjacent spring wires when the existing resonance spring works, and effectively reduces noise when the linear compressor works.

Referring to fig. 4 and 8 in detail, as a sixth embodiment of the present invention, on the basis of the above embodiment, and unlike the above embodiment, a damping structure 27 is installed in the back pressure chamber 229, one end of the damping structure 27 is connected to the middle of the leaf spring assembly 26, and the other end is connected to the casing 1.

Specifically, the damping structure 27 may be one or a combination of a spring, a spring plate, an elastic rod, and the like, and the damping structure 27 in this embodiment includes a damping spring 271 and a damping block 272; the damping spring 271 is arranged coaxially with the piston 222; the damping block 272 is installed at the middle of the damping spring 271, and one end of the damping spring 271 is connected to the middle of the leaf spring assembly 26, and the other end is connected to the cabinet 1.

Since the mover in the linear compressor is connected to the first fastening seat 23 through the leaf spring assembly 26, when the mover cooperates with the piston 222 to perform reciprocating motion, the body of the linear compressor may generate a small vibration due to resonance of the leaf spring assembly 26 and friction during the motion process, and at this time, an acting force opposite to the body of the linear compressor may be generated through the vibration of the vibration damping block 272, so as to counteract the vibration on the body of the linear compressor, thereby achieving the effect of damping the body of the linear compressor.

Referring to fig. 1, fig. 3, fig. 5, fig. 6 and fig. 8 in detail, as a seventh embodiment of the present invention, on the basis of the above embodiment, and different from the above embodiment, a compressor core 2 is disposed in a casing 1; alternatively, two compressor cores 2 are disposed in the casing 1, and the two compressor cores 2 are arranged along the axial direction of the piston 222 and are disposed in an opposite manner.

And, the second channel 228 that the compression chamber 227 of two compressor movements 2 communicates with first channel 230 that opens on the casing 1. And/or, a collision-proof structure 25 is arranged between the cylinder 221 and the machine shell 1, and a middle through hole is formed on the collision-proof structure 25 and communicated with a first channel 230 formed on the machine shell 1.

In addition, in each of the above embodiments, the structure that can be applied to one compressor core 2 or the improved structure is applied to two compressor cores 2 symmetrically arranged in the casing 1.

In order to achieve the technical solution of the present invention more clearly and completely, the following more detailed description of the linear compressor of the present invention is made based on the description of the above embodiments.

As shown in fig. 1 to 8, in an implementation process, the casing 1 includes a housing 11 and end caps, a cross-section of the housing 11 may be polygonal, and a shape of the end caps is adapted to a shape of the housing 11; the end covers comprise a first end cover 12 and a second end cover 13, the compressor movement 2 is located in the shell 11, and the first end cover 12 and the second end cover 13 are respectively and fixedly installed at two ends of the shell 11 to hermetically contain the compressor movement 2 in the shell 11.

In the present embodiment, the first channel 230, the second channel 228, the air storage cavity 224 and the air storage channel 225 are all disposed on the housing 11.

A cylindrical air gap is formed between the inner stator 211 and the outer stator 212, and a rotor formed by the rotor framework 213 and the annular permanent magnet 214 is embedded in the cylindrical air gap; wherein, the rotor frame 213 is in a cup-shaped structure; the piston 222 is coaxially located inside the mover, and a first end of the piston 222 is bracket-coupled to the mover frame 213 through the piston 222, whereby the piston 222 and the mover constitute an integrated moving member.

The iron cores of the inner stator 211 and the outer stator 212 are formed by laminating a plurality of silicon steel sheets with corresponding shapes. As shown in fig. 1, an exciting coil 215 arranged in a circumferential direction is provided at an inner sidewall of a core of the outer stator 212, and the inner stator 211 is provided with a pure core structure. Of course, the outer side wall of the core of the inner stator 211 may be provided with the field coils 215 arranged along the circumferential direction, and the outer stator 212 may be provided with a pure core structure, which is not particularly limited herein.

Correspondingly, the mover includes a set of annular permanent magnets 214, and magnetic poles of the annular permanent magnets 214 are arranged in the radial direction, that is, the magnetic pole inside the annular permanent magnets 214 is an N pole, the magnetic pole outside the annular permanent magnets 214 is an S pole, or the magnetic pole inside the annular permanent magnets 214 is an S pole, and the magnetic pole outside the annular permanent magnets 214 is an N pole, which is not specifically limited, wherein the annular permanent magnets 214 may be an integrated structure, or a plurality of tile-shaped magnets arranged in the circumferential direction are connected by a shaped material, which is not specifically limited herein.

It should also be noted herein that the gas bearing 223 housing is a hollow cylinder of porous material such that the gas bearing 223 housing may uniformly provide radial gas floating support for the outer sidewall of the piston 222 and, in cooperation with the radial support provided by the leaf spring assembly 26 to the piston 222.

The porous material has a pore diameter of 0.1-1000 microns, and is air-permeable porous foam metal, porous air-permeable ceramic or porous air-permeable plastic processed from metal powder such as iron, aluminum, copper and the like or metal wire mesh such as iron, aluminum, copper and the like or non-metal powder such as carbon powder, graphite powder, silicon dioxide powder, engineering plastic powder and the like.

In summary, according to the present invention, the gas bearing 223 is installed or embedded coaxially with the cylinder 221, the gas storage cavity 224 is formed in the casing 1, the gas storage cavity 224 serves as a stable high-pressure gas supply source for the gas bearing 223, and high-pressure gas is supplied to the gas bearing 223 through the gas supply channel 226, so that when the mover in the linear compressor drives the piston 222 to reciprocate in the cylinder 221, the gas bearing 223 generates a stable gas lubrication film in a gap between the piston 222 and the cylinder 221, and the gas lubrication film plays a good role in supporting and lubricating during the reciprocating motion of the cylinder 221 and the piston 222, so as to realize non-contact operation of the cylinder 221 and the piston 222 of the linear compressor, and effectively prevent the high-pressure gas in the compression cavity 227 from entering the back pressure cavity 229 along the air gap between the piston 222 and the cylinder 221, so as to prevent the high-pressure gas from leaking.

It can be seen from this that, set up gas storage chamber 224 and provide stable high-pressure gas source for gas bearing 223, and then adopt gas bearing 223 cooperation leaf spring subassembly 26 to provide the cooperative support for piston 222, can realize linear compressor's oil-free lubrication, reduce the clearance leakage that high-pressure gas produced between cylinder 221 and piston 222, avoid linear compressor because of the pollution that the mechanical wear of contact operation produced, ensured linear compressor's high efficiency and reliability of operation, and can effectively reduce the axial dimensions of compressor because of the structure of leaf spring subassembly 26 itself.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.

Claims

1. A linear compressor is characterized by comprising a shell and a compressor movement positioned in the shell, wherein the compressor movement comprises a linear motor assembly and a piston assembly;

2. The linear compressor of claim 1, wherein the linear motor assembly is comprised of a stator and a mover;

3. The linear compressor of claim 2, wherein a first fastening seat and a second fastening seat are respectively provided at both ends of the stator, and the cylinder is mounted on the second fastening seat.

4. The linear compressor of claim 3, wherein an anti-collision structure is provided between the piston and the casing to prevent a rigid collision between the piston and the casing.

5. The linear compressor of claim 4, wherein the air reservoir is open on the casing, the cylinder, the second fastening seat, or the anti-collision structure;

6. The linear compressor of claim 5 wherein said housing defines at least a first passage, said first passage being connected to said compression chamber by said second passage.

7. The linear compressor of claim 2, wherein the rotor frame is assembled by a first permanent magnet fastener and a second permanent magnet fastener, and the annular permanent magnet is coaxially installed inside the rotor frame formed by the first permanent magnet fastener and the second permanent magnet fastener.

8. The linear compressor of claim 3, wherein a leaf spring assembly is connected to the first fastening seat, the leaf spring assembly further being connected to the piston;

9. The linear compressor of claim 8, wherein a back pressure chamber is formed in the casing on a side of the piston opposite to the compression chamber, and a vibration damping structure is arranged in the back pressure chamber;

10. The linear compressor of any one of claims 1 to 9, wherein one or two sets of the compressor cores are provided in the casing, the two sets of the compressor cores being symmetrically provided.