CN113250929A

CN113250929A - Linear compressor

Info

Publication number: CN113250929A
Application number: CN202010085014.3A
Authority: CN
Inventors: 唐明生; 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: 2020-02-10
Filing date: 2020-02-10
Publication date: 2021-08-13

Abstract

The invention relates to the technical field of compressors, and discloses a linear compressor, comprising a stator, a mover, a piston and a cylinder arranged coaxially, and a leaf spring arranged at one or both ends of the stator, the leaf spring comprising a plurality of free The first end of the piston is connected to the mover, and the second end is inserted into the cylinder; the middle of the leaf spring is connected to the piston, each free end of the leaf spring is connected to the corresponding end of the stator, or at least one free end of the leaf spring is connected to the piston , the other free ends of the leaf springs are connected to the corresponding ends of the stator; the invention has a simple structure, and the piston is radially positioned and installed through a low-cost leaf spring, which effectively avoids the radial displacement of the piston and realizes the contactless reciprocation of the piston in the cylinder. Therefore, the oil-free or oil-lubricated linear compressor can be realized, the working noise of the linear compressor is reduced, and its axial size is greatly reduced.

Description

Linear compressor

Technical Field

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

Background

The linear compressor is a piston type compressor using a linear motor, and has advantages of compact structure, light weight, no oil or less lubricant, excellent capacity-variable characteristic, etc., and thus has been increasingly widely used, and has become a main development direction of a high-efficiency compressor for a small-sized refrigeration apparatus.

The linear motor comprises a stator and a rotor, and the rotor makes linear reciprocating motion along the axial direction. The moving magnet type linear oscillating motor is a linear motor with a typical structure, and the structure is that a magnetic conductive material is arranged on the circumference of an excitation coil to form a magnetic circuit structure of a cylindrical air gap concentric with the excitation coil, the cylindrical inner stator and the cylindrical outer stator form the air gap, and a cylindrical permanent magnet which is magnetized in the radial direction reciprocates in the air gap. The linear motor has the advantages of optimized magnetic circuit structure and small magnetic circuit loss, is widely used as a driver of a linear compressor, and realizes the reciprocating motion of a piston in a cylinder by arranging a resonance spiral spring between the cylinder and the piston of the linear compressor in an oil lubrication mode.

However, since the resonant coil spring has a large axial installation dimension, it greatly increases the axial dimension of the linear compressor; meanwhile, because resonance coil spring sets up between cylinder and piston along the axial, this makes the piston when along axial reciprocating motion, still can produce great radial skew at reciprocating motion's in-process because of the vibration, and then produces great contact sliding friction between piston and cylinder, must inject lubricating oil into the cylinder from this to carry out oil lubrication, and the use of lubricating oil can worsen refrigerating system heat exchange efficiency, and the compressor is scrapped the back, the aftertreatment of lubricating oil also can bring serious environmental protection problem.

Disclosure of Invention

The embodiment of the invention provides a linear compressor, which is used for solving the problems that the existing linear compressor has large axial size, large contact type sliding friction exists between a piston and a cylinder of the existing linear compressor, and oil lubrication treatment is required.

In order to solve the technical problem, an embodiment of the present invention provides a linear compressor, including a stator, a mover, a piston, and a cylinder, which are coaxially arranged, wherein the piston is inserted into the cylinder and reciprocates in an axial direction under the driving of the mover, and further including a leaf spring disposed at one end or both ends of the stator; the leaf spring includes a plurality of free ends; the first end of the piston is connected with the rotor, and the second end of the piston is inserted into the cylinder; the middle part of the leaf spring is connected with the piston, and each free end of the leaf spring is connected with the corresponding end of the stator, or at least one free end of the leaf spring is connected with the piston, and other free ends of the leaf spring are connected with the corresponding ends of the stator.

The plurality of leaf springs are sequentially stacked at intervals along the axial direction to form a leaf spring group; and/or the leaf springs are elastic members distributed in the same plane or nearby the same plane, and the leaf springs further comprise elastic transition parts used for connecting all free ends, the elastic transition parts are formed by sequentially connecting a plurality of straight line sections or curve sections end to form a first combined shape, and the free ends are arranged at two ends of the first combined shape respectively; or the elastic transition part is in a second combined shape formed by integrally connecting one ends of a plurality of straight line sections or curved line sections, and the other ends of the corresponding straight line sections or curved line sections in the second combined shape are respectively provided with the free ends.

The stator comprises an inner stator and an outer stator which are coaxially arranged, and a cylindrical air gap is formed between the inner stator and the outer stator; the rotor is embedded in the cylindrical air gap and comprises a rotor framework and an annular permanent magnet which are coaxially connected; the piston is coaxially positioned on the inner side of the rotor, and the first end of the piston is connected with one end, far away from the annular permanent magnet, of the rotor framework; and/or the stator further comprises a first fixing seat and a second fixing seat which are coaxially arranged at two ends of the stator, and the cylinder is arranged on the first fixing seat or the second fixing seat.

The outer side wall of the iron core of the inner stator or the inner side wall of the iron core of the outer stator is provided with a magnet exciting coil which is arranged along the circumferential direction; the rotor comprises a group of annular permanent magnets, and magnetic poles of the annular permanent magnets are arranged along the radial direction.

The inner stator is a hollow cylindrical iron core; the iron core of the outer stator is in a hollow cylindrical shape, a plurality of protrusions which are arranged along the circumference are further arranged on the inner side of the iron core, and each protrusion is wound with an excitation coil; the rotor comprises two groups of coaxially connected annular permanent magnets, and the magnetic poles of the two groups of annular permanent magnets are arranged along the radial direction and are arranged in opposite directions.

Wherein, an air suction channel which penetrates through the piston along the axial direction is arranged in the piston; a suction muffler is arranged in the suction channel, an outlet of the suction channel is positioned at the second end of the piston, and a suction control valve is arranged at the outlet; and an exhaust device is arranged at one end of the cylinder, which is far away from the rotor.

The first fixing seat, the second fixing seat or the cylinder is further provided with a gas bearing sleeve, and the gas bearing sleeve is sleeved outside the piston; the gas bearing sleeve is coaxially connected with the cylinder and is positioned at one end of the cylinder close to the rotor or embedded on the inner side wall of the cylinder, a gas supply channel used for communicating the gas bearing sleeve with the exhaust device is arranged in the side wall of the cylinder, the gas bearing sleeve is made of porous materials, the aperture of each porous material is 0.1 micron to 1000 microns, and the porous materials are made of metal powder such as iron, aluminum and copper or metal wire mesh such as iron, aluminum and copper or carbon powder, graphite powder, silicon dioxide powder, engineering plastic powder and other non-metal powder.

The oil injection device also comprises an oil pump and an oil injection channel; the oil pump and the cylinder are jointly installed on the first fixing seat or the second fixing seat, one end of the oil injection channel is communicated with the oil pump, and the other end of the oil injection channel sequentially penetrates through the corresponding first fixing seat or the corresponding second fixing seat and the side wall of the cylinder and is communicated with the inner cavity of the cylinder.

And a vibration damping structure arranged along the axial direction is further arranged between the piston and the first fixed seat or the second fixed seat.

The surface of the piston is coated with a wear-resistant self-lubricating coating, and the wear-resistant self-lubricating coating comprises any one or a combination of at least two of a graphite-like coating, a polyether ether copper coating, a polyimide resin coating, a diamond-like carbon coating, a Teflon coating, a molybdenum disulfide coating, a tungsten disulfide coating, a graphite coating, a chromium nitride coating, a titanium aluminum silicon nitride coating, a titanium aluminum nitride coating, a titanium nitride coating, an aluminum oxide ceramic coating and a phosphating coating.

According to the linear compressor provided by the embodiment of the invention, the leaf spring is arranged at one end or two ends of the stator to connect the corresponding end of the stator with the piston, so that under the action of an alternating electromagnetic field generated by the excitation coil, when the piston reciprocates along with the rotor connected with the piston, the leaf spring is used as an energy storage element, and a better resonance effect can be achieved. Compared with the built-in resonance spring of the existing linear compressor, the flat spring has smaller axial size, so that the axial size of the linear compressor can be greatly reduced; meanwhile, the leaf spring is low in manufacturing cost and has a larger radial-axial stiffness ratio, the piston is radially positioned and installed through the leaf spring, radial displacement of the piston in the axial reciprocating motion process can be effectively avoided, contact type sliding friction between the piston and the cylinder is effectively reduced, even the piston does non-contact type reciprocating motion in the cylinder, the stability and the reliability of the working operation of the linear compressor are further ensured, the linear compressor can be lubricated without oil or with oil when in working operation, and the diversified selection of working modes is realized; in addition, the interference between adjacent spring wires during the working of the existing resonance spring can be effectively avoided, and the noise of the linear compressor during the working is effectively reduced.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in 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.

Fig. 1 is a schematic sectional view of a linear compressor according to embodiment 1 of the present invention, taken along an axial direction thereof;

FIG. 2 is a schematic side view of a linear compressor according to embodiment 1 of the present invention;

fig. 3 is a schematic sectional view of a linear compressor according to embodiment 2 of the present invention, taken along an axial direction thereof;

fig. 4 is a schematic sectional view of a linear compressor according to embodiment 3 of the present invention, taken along an axial direction thereof;

fig. 5 is a schematic sectional view of a linear compressor according to embodiment 4 of the present invention, taken along an axial direction thereof;

fig. 6 is a schematic sectional view of a linear compressor according to embodiment 4 of the present invention, taken along a radial direction thereof;

fig. 7 is a schematic sectional view of a linear compressor according to embodiment 5 of the present invention, taken along an axial direction thereof;

fig. 8 is a schematic sectional view of a linear compressor according to embodiment 6 of the present invention, taken along an axial direction thereof;

FIG. 9 is a schematic structural diagram of a first form of flat spring in accordance with an embodiment of the present invention;

FIG. 10 is a schematic structural diagram of a second form of flat spring in accordance with an embodiment of the present invention;

FIG. 11 is a schematic structural view of a third form of flat spring in accordance with an embodiment of the present invention;

FIG. 12 is a schematic structural diagram of a fourth form of flat spring in accordance with an embodiment of the present invention;

fig. 13 is a schematic structural view of a leaf spring of a fifth form according to an embodiment of the present invention.

Description of reference numerals: 1. a stator; 101. an inner stator; 102. an outer stator; 1021. an iron core; 1022. a field coil; 2. a mover; 3. a first fixed seat; 4. a second fixed seat; 5. a piston; 6. a cylinder; 7. a gasket; 8. a leaf spring set; 9. a first fastening seat; 10. an air suction passage; 11. a suction muffler; 12. an exhaust chamber; 13. an exhaust valve; 14. an exhaust spring; 15. an exhaust muffler; 16. a gas bearing housing; 17. an oil pump; 18. an oil injection channel; 19. a housing; 20. a damping spring; 21. a vibration damping block; 22. and a second fastening seat.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, 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.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; may be a mechanical connection; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

The embodiment of the invention provides a linear compressor, which comprises a stator, a rotor, a piston and a cylinder, wherein the stator, the rotor, the piston and the cylinder are coaxially arranged, the piston is inserted into the cylinder and driven by the rotor to reciprocate along the axial direction, the linear compressor also comprises a leaf spring arranged at one end or two ends of the stator, and the leaf spring comprises a plurality of free ends; the first end of the piston is connected with the rotor, and the second end of the piston is inserted into the cylinder; the middle part of the leaf spring is connected with the piston, and each free end of the leaf spring is connected with the corresponding end of the stator, or at least one free end of the leaf spring is connected with the piston, and the other free ends of the leaf spring are connected with the corresponding ends of the stator.

Specifically, in the linear compressor shown in this embodiment, the leaf spring is disposed at one end or both ends of the stator to connect the corresponding end of the stator with the piston, so that the leaf spring serves as an energy storage element when the piston reciprocates along with the mover connected thereto under the action of the alternating electromagnetic field generated by the excitation coil, thereby achieving a better resonance effect. Compared with the built-in resonance spring of the existing linear compressor, the flat spring has smaller axial size, thereby greatly reducing the axial size of the linear compressor. Meanwhile, the leaf spring is low in manufacturing cost and has a large radial-axial stiffness ratio, the piston is installed in a radial positioning mode through the leaf spring, radial displacement of the piston in the process of axial reciprocating motion can be effectively avoided, contact type sliding friction between the piston and the air cylinder is effectively reduced, even the piston does non-contact type reciprocating motion in the air cylinder, stability and reliability of work operation of the linear compressor are further guaranteed, the linear compressor can be lubricated without oil or with oil when working, and diversified selection of work modes is achieved. In addition, the interference between adjacent spring wires during the working of the existing resonance spring can be effectively avoided, and the noise of the linear compressor during the working is effectively reduced.

It should be noted herein that the leaf spring is provided at one or both ends of the stator, and it is understood that the leaf spring is provided at one end of the stator, so that the corresponding end of the stator is connected with one end of the piston through the leaf spring, and the other end of the piston is inserted into the cylinder at the other end of the stator, and this mounting structure can effectively reduce contact sliding friction between the piston and the cylinder when the piston performs reciprocating motion; or, it can be understood that the two ends of the stator are provided with the leaf springs at the same time, so that the corresponding ends of the stator and the piston can be correspondingly connected through the corresponding leaf springs at the two ends of the stator, and the piston can perform non-contact reciprocating motion in the cylinder.

At the same time, in order to improve the working performance of the piston, the piston can be movedThe surface of the plug is coated with a wear-resistant self-lubricating coating, and the wear-resistant self-lubricating coating comprises 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 coating (AlTiN), titanium nitride coating (TiN), and alumina ceramic coating (Al)₂O₃) And a phosphate coating (P) or a combination of at least two thereof.

In addition, the leaf springs at the corresponding ends of the stator are provided with a plurality of leaf springs which are sequentially stacked at intervals along the axial direction to form a leaf spring group, wherein the plurality of leaf springs can be sequentially stacked at intervals by the first fastening seats 9 shown in the following embodiment, correspondingly, the corresponding ends of the stator are provided with the second fastening seats 22 for fastening the corresponding free ends of the leaf springs, as shown in fig. 2, in order to ensure that the plurality of leaf springs are sequentially stacked at intervals along the axial direction, a plurality of layers of corresponding mounting positions are correspondingly arranged on the first fastening seats 9 and the second fastening seats 22, one leaf spring is correspondingly mounted at each layer of mounting position, and the spaced stacking of two adjacent leaf springs is also beneficial to preventing the two adjacent leaf springs from interfering in the process of resonance and causing noise. Therefore, the leaf spring group 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.

Further, the leaf springs are elastic members distributed in or near the same plane, and further include 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 a first combined shape formed by sequentially connecting a plurality of straight line sections or curve sections end to end, and the two ends of the first combined shape are respectively provided with the free ends.

It should also be mentioned here that the first combination of shapes can be produced by bending the spring wire several times in the same plane, it being obvious that the shape of each bend of the first combination of shapes comprisesStraight line segments, curved line segments, and combinations thereof, the spring wire may be circular, elliptical, square, or triangular in cross-section, and is not particularly limited herein. Thus, the combined shape obtained by bending may be "S" -type, "C" -type, "Z" -type, "L" -type, "ㄥ" -type, "V" -type, "U" -type, ". or" angle "-type,

Type, "く" type, "へ" type, "J" type, and the like.

As shown in fig. 9, the leaf spring is formed by bending a spring wire rod with a circular cross section for at least 6 times; the shape of the device comprises 5 sections of straight lines (straight line sections), 4 sections of connecting transition arc lines (curve sections) and arc free ends which are positioned at the head end and the tail end and used for positioning and mounting; therefore, the corresponding free ends of the head end and the tail end of the leaf spring can be connected with the end part of one side of the stator, and the central position of the leaf spring is connected with the piston of the corresponding side of the stator or is connected with the piston through the first fastening seat shown in the following embodiment so as to support the piston to realize reciprocating motion in the cylinder.

As shown in fig. 10, the leaf spring is formed by bending a spring wire rod with a circular cross section for at least 4 times; the shape of the device comprises 3 sections of straight lines (straight line sections), 2 sections of connecting transition arc lines (curve sections) and arc-shaped free ends which are positioned at the head end and the tail end and used for positioning and mounting.

As shown in fig. 11, the leaf spring is formed by bending a spring wire rod with a circular cross section for at least 22 times; the shape of the device comprises 21 sections of straight lines (straight line sections), 20 sections of connecting transition arc lines (curve sections) and arc-shaped free ends which are positioned at the head end and the tail end and used for positioning and mounting.

As shown in fig. 12, the leaf spring is formed by bending a spring wire rod with a circular cross section for at least 12 times; the shape of the device comprises 10 arc sections (curve sections), 1 central connecting section (straight section) and arc free ends which are positioned at the head end and the tail end and used for positioning and installation.

Of course, the leaf spring may also include other configurations, which are not intended to be exhaustive.

Meanwhile, the elastic transition part can also be in a second combined shape formed by connecting one ends of a plurality of straight line sections or curve sections into a whole, and the other ends of the corresponding straight line sections or curve sections in the second combined shape are respectively provided with free ends.

Thus, the leaf springs of this form are arranged radially and obviously comprise a plurality of free ends. As shown in fig. 13, fig. 13 discloses a centrosymmetric arrangement structure of three curved sections in a leaf spring, wherein each curved section has a rectangular cross section, and one ends of the three curved sections are connected through a ring structure, while the other ends of the three curved sections are provided as corresponding free ends, the free ends are fan-shaped ring structures, and a plurality of fixing holes are opened on the fan-shaped ring structures. Therefore, the annular structure at the central position of the flat spring can be connected with the piston, and the fan-shaped annular structure corresponding to each radiation end of the flat spring is connected with the end part of the corresponding side of the stator so as to support the piston to realize reciprocating motion in the cylinder.

The following description will be made of a specific configuration of the linear compressor based on the solutions shown in the above embodiments.

In the case of the example 1, the following examples are given,

as shown in fig. 1 and fig. 2, the stator 1 in the present embodiment includes an inner stator 101 and an outer stator 102 coaxially arranged, and a cylindrical air gap is formed between the inner stator 101 and the outer stator 102; the rotor 2 is embedded in the cylindrical air gap and comprises a rotor framework and an annular permanent magnet which are coaxially connected, wherein the rotor framework is of a cup-shaped structure; the piston 5 is coaxially positioned at the inner side of the rotor 2, and the first end of the piston 5 is connected with one end of the rotor framework far away from the annular permanent magnet through a gasket 7, so that the piston 5 and the rotor 2 form an integrated moving part.

Specifically, a first fixing seat 3 and a second fixing seat 4 which are coaxially arranged are arranged at two ends of the stator 1, so that the inner stator 101, the mover 2 and the outer stator 102 are sequentially arranged along a radial direction, and the first fixing seat 3 and the second fixing seat 4 are correspondingly arranged at two ends of the inner stator 101 and the outer stator 102. Meanwhile, for the integrated moving component formed by the piston 5 and the mover 2, a first fastening seat 9 is further installed in the center of a gasket 7 corresponding to the end of the piston 5, wherein a plurality of vent holes may be opened on the gasket 7, the first fastening seat 9 is connected to the middle of the leaf spring set 8 shown in the above embodiment, two free ends of the leaf spring set 8 are correspondingly connected to the first fixing seat 3 through corresponding second fastening seats 22, so as to support the piston 5 to reciprocate in the cylinder 6, wherein the cylinder 6 is coaxially installed in the second fixing seat 4.

Further, the iron cores of the inner stator 101 and the outer stator 102 are both hollow cylindrical, and the iron cores of the inner stator 101 and the outer stator 102 are formed by laminating a plurality of silicon steel sheets with corresponding shapes. As shown in fig. 1, specifically illustrated in fig. 1, an exciting coil 1022 arranged in a circumferential direction is provided at an inner sidewall of a core 1021 of an outer stator 102, and an inner stator 101 is provided in a pure core structure. Of course, the outer side wall of the core of the inner stator 101 may be provided with a field coil arranged along the circumferential direction, and the outer stator 102 may be provided with a pure core structure, which is not particularly limited herein.

Correspondingly, the mover 2 includes a group of annular permanent magnets, and magnetic poles of the annular permanent magnets are arranged in the radial direction, that is, the magnetic pole inside the annular permanent magnet is an N pole, the magnetic pole outside the annular permanent magnet is an S pole, or the magnetic pole inside the annular permanent magnet is an S pole, and the magnetic pole outside the annular permanent magnet is an N pole, which is not specifically limited to this, wherein the annular permanent magnet may be an integrated structure, or may be formed by connecting a plurality of tile-shaped magnets arranged in the circumferential direction by a shaped material.

Meanwhile, the piston 5 in the embodiment is provided with an air suction channel 10 penetrating along the axial direction; a suction muffler 11 is arranged in the suction passage 10, the outlet of the suction passage 10 is positioned at the second end of the piston 5, and a suction control valve, which is a one-way valve, in particular a reed valve, is arranged at the corresponding outlet, which is not illustrated in fig. 1; and an exhaust device is arranged at one end of the cylinder 6 far away from the rotor 2.

Specifically, the air suction passage 10 includes a central passage section and an inclined passage section, one end of the central passage section extends to the first end of the piston 5, the other end of the central passage section communicates with one end of the inclined passage section, the inclined passage section includes a plurality of sections, the other end of each inclined passage section extends to the second end of the piston 5, wherein an air suction muffler 11 coaxially arranged with the central passage section is installed in the central passage section, an air suction control valve is installed at the other end of the inclined passage section, and the air suction control valve is a reed valve.

It should be noted here that the suction muffler 11 may be made of a foamed metal, the suction muffler 11 is a cylindrical body with a central shaft hole, the outer side wall of the suction muffler 11 is formed by sequentially staggering protrusions and recesses, a plurality of sets of vent holes are further provided on the side wall of the suction muffler 11, the vent holes in each set are arranged in a circumferential direction, and thus, noise generated by the linear compressor during suction can be effectively eliminated by the suction muffler 11.

In addition, the exhaust device comprises an exhaust cavity 12, an exhaust silencer 15, an exhaust spring 14 and an exhaust valve 13, wherein the exhaust cavity 12 is arranged in the exhaust cavity 12 in a covering mode and covers one end, far away from the rotor 2, of the cylinder 6; the exhaust valve 13 is a mushroom-shaped valve or a disc-shaped valve with a plane end part and is arranged at the port of one end of the cylinder 6 far away from the rotor 2; the exhaust spring 14 is disposed between the exhaust valve 13 and the exhaust muffler 15 in the axial direction; the exhaust silencer 15 is of a trumpet-shaped structure, one end of the exhaust silencer 15, which is far away from the exhaust spring 14, is a flared end, the flared end abuts against the side wall of the exhaust cavity 12, and the exhaust silencer 15 can also be made of foam metal.

In the case of the linear compressor shown in the present embodiment, when the piston 5 moves leftward with respect to the cylinder 6 along with the mover 2 during suction, the suction control valve is opened and the discharge valve 13 is closed, and when the piston 5 moves rightward with respect to the cylinder 6 along with the mover 2 during compression, the suction control valve is closed and when the pressure in the compression chamber formed by the piston 5 and the cylinder 6 is higher than the discharge pressure, the discharge valve 13 is opened. Meanwhile, in the linear compressor, most compression components such as the piston 5 and the suction muffler 11 are arranged inside the linear motor formed by the stator 1 and the rotor 2, so that the internal space of the linear motor can be fully utilized, the space occupied by the linear compressor is greatly reduced, and the overall dimension of the linear compressor is reduced.

Further, in this embodiment, the second fixing seat 4 is further provided with a gas bearing sleeve 16, and the gas bearing sleeve 16 is sleeved on the outer side of the piston 5; the gas bearing sleeve 16 is coaxially connected with the cylinder 6 and is located at one end of the cylinder 6 close to the rotor 2, a gas supply channel for communicating the gas bearing sleeve 16 with an exhaust device is arranged in the side wall of the cylinder 6, the gas supply channel is not shown in fig. 1, it should be noted that the gas bearing sleeve 16 and the cylinder 6 can also be coaxially installed on the first fixing seat 3, or an annular groove is arranged on the inner side wall of the cylinder 6, the gas bearing sleeve 16 is embedded in the annular groove, and the gas bearing sleeve 16 is also ensured to be sleeved on the outer side of the piston 5.

Therefore, the high-pressure gas in the exhaust cavity 12 can directly lead to the gas bearing sleeve 16 through the gas supply channel, and the gas bearing sleeve 16 is a hollow cylinder made of porous material, so that the gas bearing sleeve 16 can uniformly provide radial pneumatic floating support for the outer side wall of the piston 5, and can cooperate with the radial support provided by the leaf spring for the piston 5, so that the contact type sliding friction between the piston 5 and the cylinder 6 can be greatly reduced, and even the piston 5 can perform non-contact type reciprocating motion in the cylinder 6, so as to realize the oil-free lubrication of the linear compressor.

It should be noted that the porous material shown in the present embodiment has a pore size of 0.1 to 1000 micrometers, and is an air-permeable porous metal foam, a porous air-permeable ceramic or a porous air-permeable plastic processed from metal powder such as iron, aluminum, and copper, or non-metal powder such as metal mesh, carbon powder, graphite powder, silicon dioxide powder, and engineering plastic powder.

In the case of the example 2, the following examples are given,

as shown in fig. 3, the present embodiment is based on a further improvement of embodiment 1, and is characterized in that the present embodiment is provided with leaf spring groups 8 on both sides of the stator 1, that is, the middle portion of the leaf spring group 8 on the left side of the stator 1 is connected to the piston 5 on the corresponding side, the free end of the leaf spring group 8 is connected to the first fixing seat 3, the middle portion of the leaf spring group 8 on the right side of the stator 1 is connected to the end portion of the piston 5 on the corresponding side, and the free end of the leaf spring group 8 is connected to the second fixing seat 4, wherein the cylinder 6 and its corresponding exhaust device may be provided on the first fixing seat 3 or the second fixing seat 4, which is not particularly limited.

Therefore, the two groups of leaf spring groups 8 jointly provide enough radial support for the piston 5 from two sides of the piston 5, the phenomenon of 'head hanging' at the end part of the piston 5 of the linear compressor is effectively avoided, the gas bearing sleeve 16 shown in the embodiment 1 is not required to be arranged in the linear compressor, and therefore the non-contact reciprocating motion and the oil-free lubrication of the piston 5 and the cylinder 6 can be realized.

In the case of the example 3, the following examples are given,

as shown in fig. 4, the present embodiment is based on a further improvement of embodiment 1, and is different in that the gas bearing housing 16 shown in embodiment 1 is not provided in the linear compressor shown in the present embodiment. Since the leaf spring assembly 8 is disposed at one side end of the stator 1 in embodiment 1 to provide better radial support for the piston 5 during the reciprocating motion in the cylinder 6, so as to greatly reduce the contact type sliding friction between the piston 5 and the cylinder 6, this embodiment may also adopt an oil lubrication manner to further reduce the contact type friction between the piston 5 and the cylinder 6 and ensure a longer service life of the linear compressor.

Therefore, in the design of a specific scheme, an oil pump 17 and an oil injection channel 18 can be arranged, the oil pump 17 and the cylinder 6 are installed on the second fixing seat 4 together, one end of the oil injection channel 18 is communicated with an oil delivery end of the oil pump 17, and the other end of the oil injection channel 18 sequentially penetrates through the corresponding side walls of the second fixing seat 4 and the cylinder 6 and is communicated with an inner cavity of the cylinder 6. Thus, lubricating oil can be injected into the cylinder 6 through the oil pump 17 and the corresponding oil injection passage 18 for lubricating and sealing the fit clearance between the piston 5 and the cylinder 6.

It should be noted here that, in practical design, the oil pump 17 and the cylinder 6 may also be mounted together on the first fixing seat 3, and accordingly, the leaf spring assembly 8 is used to connect the second fixing seat 4 and the piston 5, so that one end of the oil injection channel 18 communicates with the oil pump 17, and the other end thereof sequentially penetrates through the side walls of the corresponding first fixing seat 3 and the cylinder 6 and communicates with the inner cavity of the cylinder 6.

In the case of the example 4, the following examples are given,

as shown in fig. 5 and fig. 6, the present embodiment is based on a further improvement of embodiment 1, and is characterized in that in the present embodiment, the inner stator 101 is a hollow cylindrical iron core, and the inner stator 101 is not provided with an excitation coil; the iron core 1021 of the outer stator 102 is in a hollow cylindrical shape, a plurality of protrusions arranged along the circumference are further arranged on the inner side of the iron core 1021, each protrusion is wound with one excitation coil 1022, the number of the protrusions can be eight, correspondingly, the eight excitation coils arranged along the circumference are wound on the outer stator 102, and the iron cores of the inner stator 101 and the outer stator 102 are formed by laminating a plurality of silicon steel sheets in corresponding shapes; the mover 2 includes two sets of coaxially connected annular permanent magnets, magnetic poles of the two sets of annular permanent magnets are all arranged along the radial direction and are arranged in opposite directions, so that a magnetic pole on the inner side of one set of annular permanent magnet is set to be an N pole, a magnetic pole on the outer side is set to be an S pole, correspondingly, a magnetic pole on the inner side of the other set of annular permanent magnet is set to be an S pole, and a magnetic pole on the outer side is set to be an N pole.

In the case of the example 5, the following examples were conducted,

as shown in fig. 7, this embodiment is based on a further improvement of embodiment 4, and is distinguished in that the linear compressor shown in embodiment 4 is provided with a leaf spring set 8 at one side end of the stator to provide better radial support for the reciprocating motion of the piston 5 in the cylinder 6, and the outer side wall of the piston 5 is uniformly provided with pneumatic floating support in the radial direction by providing the gas bearing sleeve 16, and the linear compressor shown in this embodiment is not provided with the gas bearing sleeve 16 shown in embodiment 4, but adopts an oil lubrication manner to further reduce contact friction between the piston 5 and the cylinder 6 and ensure longer service life of the linear compressor.

Therefore, an oil pump 17 and an oil injection channel 18 can be arranged in the design of the specific scheme, the oil pump 17 and the cylinder 6 are installed on the second fixing seat 4 together, one end of the oil injection channel 18 is communicated with an oil delivery end of the oil pump 17, and the other end of the oil injection channel 18 sequentially penetrates through the corresponding side walls of the second fixing seat 4 and the cylinder 6 and is communicated with an inner cavity of the cylinder 6. Thus, lubricating oil can be injected into the cylinder 6 through the oil pump 17 and the corresponding oil injection passage 18 for lubricating and sealing the fit clearance between the piston 5 and the cylinder 6.

In the case of the example 6, it is shown,

the present embodiment is based on a further improvement of embodiment 1, and is characterized in that a vibration damping structure arranged along the axial direction is further provided between the piston 5 and the first fixed seat 3 or the second fixed seat 4 in the linear compressor shown in the present embodiment.

Specifically, as shown in fig. 8, a set of leaf spring set 8 is disposed on the left side of the stator 1, the middle of the leaf spring set 8 is connected to the end of the piston 5 on the corresponding side of the stator 1, two free ends of the leaf spring set 8 are connected to the first fixing seat 3, and the cylinder 6 and its corresponding exhaust device are disposed on the second fixing seat 4.

It should be noted here that a housing 19 is also provided on the side of the first fastening base 3 remote from the second fastening base 4. The damping structure shown in this embodiment may specifically include a damping spring 20 and a damping block 21, where the damping block 21 is installed in the middle of the damping spring 20, the damping spring 20 is axially disposed, one end of the damping spring 20 is connected to the end of the piston 5, and the other end is connected to the inner side wall of the housing 19. Because the mover 2 of the linear compressor is connected with the first fixing base 3 through the plate spring group 8, therefore, when the mover 2 cooperates with the piston 5 to perform reciprocating motion, the body (other parts except the mover 2) of the linear compressor generates a tiny vibration due to the resonance of the plate spring group 8 and the friction in the motion process, at the moment, through the arrangement of the vibration attenuation block 21 and the vibration attenuation spring 20, a force opposite to the body of the linear compressor can be generated through the vibration of the vibration attenuation block 21, so that the vibration on the body of the linear compressor is counteracted, and the effect of reducing the vibration of the body of the linear compressor is further achieved.

In summary, the leaf spring shown in the above embodiment can be formed by bending a spring wire with low cost or processing a high-elasticity strip-shaped plate or strip, so that a single resonant leaf spring can be manufactured at low cost and has a large radial-to-axial stiffness ratio, and therefore, the linear compressor assembled based on the structure shown in the above embodiment can effectively reduce the axial size of the linear compressor required by installing the resonant spring in the prior art, effectively avoid the radial displacement of the piston 5, omit a support bearing corresponding to the piston 5 in the conventional linear compressor, and realize the non-contact reciprocating motion of the piston 5 in the cylinder 6; meanwhile, the linear compressor can be lubricated without oil or with oil, the problem of interference between adjacent spring wires of the conventional resonant spring can be avoided, and the problem of noise of the linear compressor caused by the resonant spring is effectively solved.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.

Claims

1. A linear compressor comprises a stator, a rotor, a piston and a cylinder which are coaxially arranged, wherein the piston is inserted into the cylinder and reciprocates along the axial direction under the driving of the rotor;

the first end of the piston is connected with the rotor, and the second end of the piston is inserted into the cylinder;

the middle part of the leaf spring is connected with the piston, and each free end of the leaf spring is connected with the corresponding end of the stator, or at least one free end of the leaf spring is connected with the piston, and other free ends of the leaf spring are connected with the corresponding ends of the stator.

2. Linear compressor according to claim 1,

a plurality of leaf springs are arranged at the corresponding ends of the stator, and are sequentially stacked at intervals along the axial direction to form a leaf spring group;

and/or the leaf springs are elastic members distributed in the same plane or nearby the same plane, and the leaf springs further comprise elastic transition parts used for connecting the free ends;

the elastic transition part is a first combined shape formed by sequentially connecting a plurality of straight line sections or curve sections end to end, and the two ends of the first combined shape are respectively provided with the free ends; or the elastic transition part is in a second combined shape formed by integrally connecting one ends of a plurality of straight line sections or curved line sections, and the other ends of the corresponding straight line sections or curved line sections in the second combined shape are respectively provided with the free ends.

3. Linear compressor according to claim 1 or 2,

the stator comprises an inner stator and an outer stator which are coaxially arranged, and a cylindrical air gap is formed between the inner stator and the outer stator;

the rotor is embedded in the cylindrical air gap and comprises a rotor framework and an annular permanent magnet which are coaxially connected;

the piston is coaxially positioned on the inner side of the rotor, and the first end of the piston is connected with one end, far away from the annular permanent magnet, of the rotor framework;

and/or the stator further comprises a first fixing seat and a second fixing seat which are coaxially arranged at two ends of the stator, and the cylinder is arranged on the first fixing seat or the second fixing seat.

4. Linear compressor according to claim 3,

the iron cores of the inner stator and the outer stator are both in a hollow cylinder shape, and the outer side wall of the iron core of the inner stator or the inner side wall of the iron core of the outer stator is provided with excitation coils arranged along the circumferential direction; the rotor comprises a group of annular permanent magnets, and magnetic poles of the annular permanent magnets are arranged along the radial direction.

5. Linear compressor according to claim 3,

the inner stator is a hollow cylindrical iron core;

the iron core of the outer stator is in a hollow cylindrical shape, a plurality of protrusions which are arranged along the circumference are further arranged on the inner side of the iron core, and each protrusion is wound with an excitation coil;

the rotor comprises two groups of coaxially connected annular permanent magnets, and the magnetic poles of the two groups of annular permanent magnets are arranged along the radial direction and are arranged in opposite directions.

6. Linear compressor according to claim 3,

an air suction channel which penetrates through the piston along the axial direction of the piston is arranged in the piston;

a suction muffler is arranged in the suction channel, an outlet of the suction channel is positioned at the second end of the piston, and a suction control valve is arranged at the outlet;

and an exhaust device is arranged at one end of the cylinder, which is far away from the rotor.

7. Linear compressor according to claim 6,

the first fixed seat or the second fixed seat or the cylinder is also provided with a gas bearing sleeve, and the gas bearing sleeve is sleeved outside the piston;

the gas bearing sleeve is coaxially connected with the cylinder and is positioned at one end, close to the rotor, of the cylinder or embedded on the inner side wall of the cylinder, and a gas supply channel used for communicating the gas bearing sleeve with the exhaust device is arranged in the side wall of the cylinder.

8. Linear compressor according to claim 3,

the oil injection device also comprises an oil pump and an oil injection channel;

the oil pump and the cylinder are jointly installed on the first fixing seat or the second fixing seat, one end of the oil injection channel is communicated with the oil pump, and the other end of the oil injection channel sequentially penetrates through the corresponding first fixing seat or the corresponding second fixing seat and the side wall of the cylinder and is communicated with the inner cavity of the cylinder.

9. Linear compressor according to claim 3,

10. Linear compressor according to claim 1,