CN214533416U - Linear compressor - Google Patents

Abstract

The utility model relates to a compressor technical field discloses a linear compressor, include: compressor core, compressor core include linear electric motor, cylinder, piston and flat spring assembly, and in linear electric motor's the drum of inner stator was located to the cylinder, the piston was located in the cylinder, and cylinder, inner stator and piston set up coaxially, and linear electric motor's both ends are fixed respectively and are equipped with flat spring assembly, and the cylinder support connection is worn out respectively in the both ends of piston in the flat spring assembly that corresponds for the piston suspends in the inside of cylinder. The cylinder and the piston are arranged in the cylinder of the linear motor inner stator, so that the internal space of the motor can be effectively utilized, and the size of the compressor can be reduced; in addition, the piston is supported by the double-side plate spring assembly and suspended in the cylinder, so that non-contact reciprocating motion of the piston and the cylinder is realized, the reliability of the piston in motion is improved, the vibration of the compressor is reduced, and the vibration noise is reduced.

Description

Linear compressor

Technical Field

The utility model relates to a compressor technical field especially relates to a linear compressor.

Background

In the cryogenic field, the compressor used to drive stirling coolers and pulse tube coolers is primarily a valveless linear compressor. The linear compressor is directly driven by a linear motor, a crank link mechanism of the traditional reciprocating piston type compressor is eliminated, a motion conversion device is reduced, the efficiency of the compressor is greatly improved, and therefore the linear compressor is widely concerned and applied.

The moving magnet type linear oscillating motor with the Redlich-type structure is widely applied at present, the moving magnet type linear oscillating motor with the structure is a magnetic circuit structure which is provided with a magnetic conductive material on the circumference of an excitation coil to form 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 does reciprocating motion in the air gap. The Redlich type structure linear motor has the advantages of better design of a magnetic circuit structure and small magnetic circuit loss.

In the prior art, a cylindrical linear oscillating motor with a Redlich structure is mainly used as a driver, and a low-cost spiral spring or a vortex arm plate spring is mostly used as a support. The existing compressor has the problems of large occupied installation size and large whole machine vibration, thereby limiting the application range.

SUMMERY OF THE UTILITY MODEL

The utility model provides a linear compressor for solve or partially solve current compressor and exist to occupy great mounting dimension and complete machine vibration great, thereby restricted range of application's problem.

The utility model provides a linear compressor, include: the compressor core comprises a linear motor, a cylinder, a piston and a flat spring assembly, wherein the cylinder is arranged in a cylinder of an inner stator of the linear motor, the piston is arranged in the cylinder, the inner stator and the piston are coaxially arranged, the flat spring assembly is fixedly arranged at each of two ends of the linear motor, and the two ends of the piston penetrate out of the cylinder respectively to be supported and connected to the corresponding flat spring assemblies, so that the piston is suspended in the cylinder.

According to the linear compressor provided by the utility model, the inside of the cylinder is provided with a step-shaped through channel along the axial direction, and the part with smaller cross-sectional dimension of the through channel is arranged at the first end of the cylinder; the piston is constructed in a way that the middle section of the piston is larger in size, and the sections of the two ends of the piston are smaller in size; the middle part of the piston is matched with the part with the larger cross-sectional dimension of the through passage in the cylinder, and the first end of the piston is matched with the through passage at the first end of the cylinder.

According to the utility model provides a pair of linear compressor, the second end of piston is connected in piston support, piston support connect in corresponding leaf spring assembly, just piston support with linear electric motor's active cell links to each other.

According to the utility model provides a linear compressor, the leaf spring assembly comprises a plurality of layers of elastic components which are arranged along the axial direction in a laminated way, and a flat gasket is arranged between two adjacent layers of elastic components; the elastic component is provided with two free ends and is of a bent structure integrally or is provided with at least three free ends, and the free ends are distributed at the edge part; the middle part of the elastic component is connected with the piston.

According to the utility model provides a pair of linear compressor, linear motor's both ends are equipped with the fixing base respectively, the leaf spring subassembly with the cylinder connect respectively in the fixing base.

According to the utility model provides a pair of linear compressor, the middle part of piston with form the compression chamber between the first end of cylinder, be equipped with at least one intercommunication along circumference on the first end wall of cylinder the exhaust hole in compression chamber.

According to the utility model provides a pair of linear compressor, the inside of shell is located to the compressor core, along circumference on the inner wall of shell with the exhaust hole correspondence is connected with at least one boss, the inside of boss is equipped with the intermediate channel with the exhaust hole intercommunication that corresponds, exhaust passage has still been arranged to the inside of shell, exhaust passage with the intermediate channel intercommunication, be equipped with on the wall of shell at least one with the gas vent of exhaust passage intercommunication.

According to the utility model provides a pair of linear compressor, the inside of shell is equipped with two symmetric distributions the compressor core, two the exhaust hole of compressor core all communicate in exhaust passage.

According to the utility model provides a pair of linear compressor, two are located to the boss between the compressor core, two the exhaust hole that corresponds on the compressor core communicates in the inside intermediate channel of boss that corresponds simultaneously.

According to the utility model provides a pair of linear compressor, the surface of piston is scribbled and is equipped with the lubricant coating.

The cylinder and the piston are arranged in the cylinder of the linear motor inner stator, so that the internal space of the motor can be effectively utilized, the size of the compressor is favorably reduced, and the system volume is reduced; in addition, the piston is supported by the double-side plate spring assembly and suspended in the cylinder, so that non-contact reciprocating motion of the piston and the cylinder is realized, the coaxiality of the piston and the cylinder is guaranteed, meanwhile, friction between the piston and the cylinder can be reduced, the compressor can run without oil, the reliability of the piston during motion is improved, the vibration of the compressor is reduced, and the vibration noise is reduced.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be 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 for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

Fig. 1 is a schematic cross-sectional view of a linear compressor provided by the present invention;

fig. 2 is an external schematic view of a linear compressor provided by the present invention;

fig. 3 is one of the schematic diagrams of the elastic member provided by the present invention;

fig. 4 is a second schematic view of the elastic member provided by the present invention;

fig. 5 is a third schematic view of the elastic member provided by the present invention;

fig. 6 is a fourth schematic view of the elastic member provided by the present invention;

fig. 7 is a fifth schematic view of the elastic member provided by the present invention;

fig. 8 is a detailed connection diagram of the fifth embodiment of the elastic member according to the present invention.

Reference numerals:

1. a cylinder; 2. a central axis; 3. a first fixed seat; 4. an inner stator; 5. a piston; 6. a piston holder; 7. a second fixed seat; 8. a field coil; 9. an outer stator; 10. a cylindrical air gap; 11. an annular permanent magnet; 12. a rotor framework; 13. a leaf spring assembly; 14. a compression chamber; 15. a flat washer; 16. a right linear arm; 17. a left linear arm; 18. a lower linear arm; 19. a clamp arm shaped portion; 20. a clip arm-shaped portion through hole; 21. a central through hole; 22. a left end housing; 23. a right end housing; 24. a middle housing; 25. a left exhaust port; 26. a right exhaust port; 27. a boss; 28. a middle channel; 29. an exhaust passage; 30. and (4) exhausting holes.

Detailed Description

To make the objects, technical solutions and advantages of the present invention clearer, the drawings of the present invention are combined to clearly and completely describe the technical solutions of the present invention, and obviously, the described embodiments are some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.

The linear compressor of the present invention will be described with reference to fig. 1 to 8.

Referring to fig. 1, the present embodiment provides a linear compressor including: compressor core. The compressor core comprises a linear motor, a cylinder 1, a piston 5 and a leaf spring assembly 13; the linear motor provides linear reciprocating motion. The cylinder 1 is arranged in a cylinder of an inner stator 4 of the linear motor, the piston 5 is arranged in the cylinder 1, and the cylinder 1, the inner stator 4 and the piston 5 are coaxially arranged; and the two ends of the linear motor are respectively and fixedly provided with a leaf spring assembly 13. The leaf spring assembly 13 is of a leaf structure and is fixed outside two axial ends of the linear motor. Two ends of the piston 5 respectively penetrate through the cylinder 1 and are supported and connected to the corresponding leaf spring assemblies 13, so that the piston 5 is suspended inside the cylinder 1.

Namely, the piston 5 is supported and fixed by being connected with the flat spring assembly 13, and the cylinder 1 only plays a limiting role at the periphery of the piston and does not apply supporting acting force to the piston 5. The piston 5 is supported and connected to the leaf spring assembly 13 such that there is a gap between the piston 5 and the inner wall of the cylinder 1 in the circumferential direction. Thereby realize piston 5 and cylinder 1's non-contact reciprocating motion, when guaranteeing piston 5 and cylinder 1's axiality, can reduce the friction between piston 5 and the cylinder 1, make the compressor can the oil-free operation, reliability when increasing the piston motion, reduce compressor vibration.

According to the linear compressor provided by the embodiment, the cylinder and the piston are arranged in the cylinder of the inner stator of the linear motor, so that the inner space of the motor can be effectively utilized, the size of the compressor can be reduced, and the volume of a system can be reduced; in addition, the piston is supported by the double-side plate spring assembly and suspended in the cylinder, so that non-contact reciprocating motion of the piston and the cylinder is realized, the coaxiality of the piston and the cylinder is guaranteed, meanwhile, friction between the piston and the cylinder can be reduced, the compressor can run without oil, the reliability of the piston during motion is improved, the vibration of the compressor is reduced, and the vibration noise is reduced.

Furthermore, one end of the piston penetrates through the air cylinder and is connected with a rotor of the linear motor; for reciprocating movement under the drive of the mover.

On the basis of the above embodiment, further, referring to fig. 1, a step-shaped through channel is provided in the cylinder 1 along the axial direction, and a portion with a smaller cross-sectional dimension of the through channel is provided at the first end of the cylinder 1; the piston 5 is constructed such that the middle section size is large and the both ends section size is small; the middle part of the piston 5 is matched with the part with larger cross section size of the through passage in the cylinder 1, and the first end of the piston 5 is matched with the through passage at the first end of the cylinder 1. That is, the middle portion of the piston 5 and the portion of the cylinder 1 in which the cross-sectional dimension of the through passage is large can be sealed by a gap. The through passage of the first end of the piston 5 and the first end of the cylinder enables clearance sealing. Through setting up the inside through passage of cylinder 1 for the step form to and piston 5 is the step form equally, thereby make and form the compression chamber between the intermediate position of piston 5 and the first end of cylinder 1, guarantee the normal operating of cylinder 1 piston.

On the basis of the above embodiment, further, the second end of the piston 5 is connected to the piston support 6, the piston support 6 is connected to the corresponding leaf spring assembly 13, and the piston support 6 is connected to the mover of the linear motor.

Specifically, referring to fig. 1, the piston 5 is stepped and is formed by three cylinders with different diameters, and the diameter of the middle cylinder section is the largest; the maximum diameter cylinder section of the piston 5 is matched with the large end of the step cylinder 1, namely, the part with the larger cross section size of the through passage is matched with the large end of the step cylinder 1 and can be arranged in the cylinder 1 in a reciprocating manner, the middle cylinder section of the step piston 5 and the large end of the step cylinder 1 form a gas compression cavity 14, and one end of the piston 5 is matched with the small end of the cylinder 1, namely, the first end and penetrates out of the step cylinder 1. One end of the piston 5 extends out of the large end of the cylinder 1 and is connected with the piston bracket 6 through a screw, and the other end of the piston extends out of the small end of the cylinder 1 and is connected with the flat spring assembly 13 through a screw and the like.

On the basis of the above embodiment, further, the leaf spring assembly 13 includes a plurality of layers of elastic members stacked in the axial direction, and a flat washer 15 is disposed between two adjacent layers of elastic members; the elastic component is provided with two free ends and is of a bent structure integrally or is provided with at least three free ends, and the free ends are distributed at the edge part; the middle part of the elastic component is connected with the piston.

On the basis of the above embodiment, further, two ends of the linear motor are respectively provided with a fixing seat, and the leaf spring assembly 13 and the cylinder 1 are respectively connected to the fixing seats. Specifically, referring to fig. 1, the stator of the linear motor has a first fixing seat 3 and a second fixing seat 7, which are coaxially and fixedly installed through threads and the like. The leaf spring assembly may be connected to the holder at an edge portion and to the piston at a middle portion. The outer wall surface of the first end of the cylinder 1 can be in threaded connection with the second fixed seat 7; and a sealing ring is arranged at the joint.

The connection mode of the leaf spring assembly and the piston has various forms, for example, the middle part of the leaf spring assembly is connected with the piston, and each free end of the leaf spring assembly is connected with the stator or the fixed seat; or at least one free end of the flat spring is connected with the piston, and the other free end of the flat spring is connected with the corresponding end of the stator. The leaf spring assembly includes resilient members distributed in or near the same plane. The elastic component is a first combined shape formed by sequentially connecting a plurality of straight line sections or curve sections end to end, and two ends of the first combined shape are respectively provided with a free end; that is, the elastic member has two free ends, and the two free ends can be formed by connecting any straight line segment and any curved line segment in any bending mode. Or the elastic component is in a second combined shape formed by connecting one ends of a plurality of straight line segments and/or curved line segments into a whole, and the other ends of the corresponding straight line segments or curved line segments in the second combined shape are respectively provided with free ends; the elastic component has more than three free ends, and each free end is connected with the central part by any straight line segment and any curved line segment in a random bending mode. The connection mode of the leaf spring assembly and the piston in the embodiment can be selected from one for installation, the elastic component of the leaf spring assembly can also be selected from one shape for design, and multiple forms of connection and shape design can be freely arranged and combined.

It should also be noted that the first combined shape may be formed by bending the spring wire material multiple times in the same plane, and obviously, the shape of each bending section of the first combined shape includes a straight section, a curved section and a combination thereof, and the cross section of the spring wire material may be circular, oval, square or triangular, and is not limited in particular. Thus, the combined shape obtained by bending may be "S" -type, "C" -type, "Z" -type, "L" -type, "ㄥ" -type, "V" -type, "U" -type, "L" -type, "く" -type, "へ" -type, "J" -type, or the like.

As shown in fig. 3, the elastic member of the first combined shape 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, 4 sections of connecting transition arcs (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 elastic component can be connected with the edge part of the fixed seat, and the central position of the elastic component is connected with the corresponding end of the piston 5 so as to support the piston 5 to realize reciprocating motion in the cylinder 1.

As shown in fig. 4, the elastic member 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. 5, the elastic member 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. 6, the elastic member 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 elastic member of the first combination also includes other structures, which are not necessarily listed here.

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

Thus, the resilient members in this form are arranged radially and obviously comprise a plurality of free ends. As shown in fig. 7, fig. 7 discloses a centrosymmetric arrangement structure of three curved sections in an elastic member, 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 elastic component can be connected with the piston, and the sector annular structure corresponding to each radiation end of the elastic component is connected with the corresponding fixed seat so as to support the piston to realize reciprocating motion in the cylinder.

Further, a mounting hole penetrating the end face may be provided in the middle of both ends of the piston 5. The middle portion of the elastic member of the leaf spring assembly 13 may be connected to the piston 5 through the mounting hole. When the elastic member is in the first combination form, the middle portion of the elastic member may be fastened to the end of the piston 5 by a fastening member. When the elastic member is in the second combination form, the mounting hole may be a threaded hole, and the elastic member may be connected with the mounting hole of the piston by a bolt.

Further, a plurality of leaf springs are arranged at the corresponding ends of the stator, the leaf springs are sequentially stacked at intervals along the axial direction to form a leaf spring assembly, and a flat washer 15 is used for separating the leaf springs between every two leaf springs. The elastic components can be correspondingly arranged and are connected with the fixed seat at the same time.

In addition to the above-mentioned embodiments, a compression chamber 14 is formed between the middle portion of the piston 5 and the first end of the cylinder 1, and at least one exhaust hole 30 communicating with the compression chamber is circumferentially provided on the first end wall surface of the cylinder 1. The exhaust hole is used for outputting compression expansion energy of gas in the compression cavity.

On the basis of the above embodiment, further, referring to fig. 1, the compressor core is disposed inside the casing, at least one boss 27 is connected to the inner wall of the casing along the circumferential direction corresponding to the exhaust hole 30, an intermediate channel 28 communicated with the corresponding exhaust hole 30 is disposed inside the boss 27, an exhaust channel 29 is further disposed inside the casing, the exhaust channel 29 is communicated with the intermediate channel 28, and at least one exhaust port communicated with the exhaust channel 29 is disposed on the wall surface of the casing. That is, each exhaust hole on the compressor core is correspondingly communicated with an exhaust channel 29 through the middle channel 28 of one boss 27.

Further, the exhaust holes 30 on the compressor core may be evenly distributed in the circumferential direction. The fixed seat can be correspondingly provided with an air passage communicated with the exhaust hole 30 for air to enter and exit.

On the basis of the above embodiments, most of the existing linear compressors are of a single-cylinder structure, and the gas compression in a single cylinder is realized. The single-cylinder linear compressor has an insignificant effect of improving the energy utilization efficiency, and when the compressor is operated, the machine body generates a large amount of vibration, and when the refrigerator is driven, the cold head of the refrigerator vibrates a large amount, thereby limiting the application range of the compressor. In the linear compressor provided by this embodiment, two compressor cores symmetrically distributed are disposed inside the housing, and the exhaust holes 30 of the two compressor cores are both communicated with the exhaust channel 29. The energy utilization efficiency is improved, and the vibration is reduced.

On the basis of the above embodiment, further, the boss 27 is disposed between the two compressor cores, and the corresponding exhaust holes 30 on the two compressor cores are simultaneously communicated with the intermediate channel 28 inside the corresponding boss.

Further, the exhaust passage may be circular and arranged along a cross-section of the housing. Is convenient for being communicated with the middle channels in the bosses at different positions. And an exhaust port is conveniently arranged on the shell.

On the basis of the above embodiment, further, the outer surface of the piston is coated with a lubricating coating. The surface of the piston 5 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. This two linear compressor is through the material coating that has the wear-resisting antifriction performance of self-lubricating characteristic at 5 surface preparation of piston, can reduce the friction between piston 5 and the cylinder 1, makes the compressor can not have oil operation, reliability when increasing the piston motion, the life of extension compressor.

On the basis of the above embodiments, further, the embodiment provides a double-cylinder opposed linear compressor, which includes a compressor core composed of a housing, a linear motor, a cylinder, a piston, and a leaf spring assembly. Two identical linear compressor cores are symmetrically arranged. The linear motor mainly utilizes electromagnetic force to generate vibration, and then combines mechanical resonance to push the piston to vibrate back and forth to compress gas, and the linear motor can adopt a moving magnet type, a moving coil type or a moving iron type.

Referring to fig. 1, the cylinder 1 is stepped and is formed by two hollow cylinders with different diameters, and the small end of the cylinder 1, i.e. the part with the smaller cross-sectional dimension of the through passage, is fixed on the second fixed seat 7 through threads. The small end of the cylinder 1 is provided with a vent hole 30 for communicating the compression cavity 14 with a vent port of the compressor middle shell 24.

In this embodiment, the middle of the flat spring assembly 13 is connected to the piston 5, and each free end of the flat spring assembly 13 is connected to a corresponding end of the stator, and as shown in fig. 8, the elastic member includes: the left linear arm 17, the right linear arm 16, the lower linear arm 18 and the clamping arm-shaped part 19 are the same in thickness, and the specific thickness is determined by the axial rigidity and the radial rigidity which are actually required; the left linear arm 17, the right linear arm 16 and the lower linear arm 18 are identical in shape and size and are circumferentially distributed; the clamping arm-shaped part 19 is provided with 3 uniformly distributed clamping arm-shaped part through holes 20; the leaf spring center through hole 21 is located at the center of the leaf spring. The central through hole 21 of the leaf spring assembly 13 is connected with the piston bracket 6 and the piston 5 through threads, and each clamping arm-shaped part 19 of the leaf spring assembly 13 is fixedly connected with the first fixing seat 3 and the second fixing seat 7 through threads.

The first fixed seat 3 is fixedly connected with the clamping arm-shaped part through hole 20 of the first leaf spring assembly through a thread. The second fixing seat 7 is fixedly provided with the cylinder 1 through threads, and the second fixing seat 7 is provided with an exhaust channel for communicating an exhaust hole of the cylinder 1 with an exhaust port of the middle shell. In the embodiment, the flat spring assembly 13 is used as a support, the piston 5 is suspended in the cylinder 1, non-contact reciprocating motion of the piston 5 and the cylinder 1 is realized, and the radial stiffness and the axial stiffness of the compressor are ensured while the coaxiality of the piston 5 and the cylinder 1 is ensured.

On the basis of the above embodiment, as shown in fig. 1, the stator part of the linear motor comprises an inner stator 4 and an outer stator 9 which are coaxially arranged, and a cylindrical air gap 10 is arranged between the inner stator 4 and the outer stator 9; the rotor is embedded in the cylindrical air gap 10 and comprises a rotor framework 12 and an annular permanent magnet 11 which are coaxially connected; the piston 5 is coaxially positioned at the inner side of the rotor, and one end of the piston 5, which is not matched with the cylinder 1, is connected with one end of the rotor framework 12, which is far away from the annular permanent magnet 11. The iron cores of the inner stator 4 and the outer stator 9 are both in a hollow cylinder shape, and the inner stator 4 and the outer stator 9 form a symmetrical magnetic circuit; the outer side wall of the iron core of the inner stator 4 or the inner side wall of the iron core of the outer stator 9 is provided with an excitation coil 8 which is arranged along the circumferential direction, and the excitation coil 8 is electrified with alternating current to generate a magnetic field; the rotor comprises a group of annular permanent magnets 11, the magnetic poles of the annular permanent magnets 11 are arranged along the radial direction, a magnetic field with alternating positive and negative directions is formed in the cylindrical air gap 10 through a symmetrical magnetic circuit, and the annular permanent magnets 11 generate axial reciprocating electromagnetic driving force under the action of the magnetic field so as to push the piston 5 in the cylinder 1 to compress gas.

Referring to fig. 1 and 2, in the present embodiment, the two-cylinder opposed oil-free linear compressor further includes a housing including a left end housing 22, a right end housing 23, and a middle housing 24. The end part shell is provided with a plurality of threaded holes which are uniformly distributed to realize the fixed connection with the middle part shell 24; the left side and the right side of the end part shell are respectively provided with an O-ring sealing groove, so that the whole compressor is sealed. The inner space of the middle shell 24 is similar to a cylinder shape, three bosses which are uniformly distributed on the circumference are arranged in the shell, and the bosses avoid the clamping arm-shaped part 19 of the leaf spring assembly, so that the clamping arm-shaped part 19 can be smoothly connected to the fixed seat. Each boss is provided with a middle channel, an O-ring sealing groove is arranged around the middle channel, and the middle channel of the boss is used for communicating the exhaust hole 30 of the cylinder 1 with the exhaust channel in the middle of the middle shell 24. The boss is fixedly connected with the second fixed seat 7 through threads. A middle exhaust channel is arranged at the position of the central axis 2 of the middle shell 24, and the middle shell 24 is provided with a left exhaust port 25, a right exhaust port 26 and a lower exhaust port corresponding to the exhaust hole 30 of the cylinder 1. The middle shell 24 is also provided with a power line wiring hole and a backpressure cavity through hole. The outer parts of the three exhaust ports of the middle shell 24 are hermetically connected with an exhaust pipeline for exhausting; the power supply wiring hole is used for connecting a power supply wire of the linear motor to a power supply after extending out of the middle shell 24. The back pressure chamber through hole is used to detect the air pressure inside the middle housing 24. The 2 compressor cores are symmetrically arranged inside two sides of the shell.

It can be seen from the above embodiments that the double-cylinder opposed oil-free linear compressor provided by the embodiment comprises a compressor core consisting of a shell, a linear motor, a cylinder, a piston and a leaf spring assembly. Because the two identical linear compressor cores are symmetrically arranged and the stepped piston adopts an installation mode of coaxially locating at the inner side of the rotor, the size is effectively reduced, the volume and the weight of the system are reduced, the lateral force generated by a moving part is reduced, and the vibration and the noise of the compressor are reduced. In the compression process of the linear compressor, a working medium is under the action of a linear motor, and when a piston assembly supported by a leaf spring assembly reciprocates, a piston is suspended in a cylinder, so that non-contact reciprocating motion of the piston and the cylinder is realized, the coaxiality of the piston and the cylinder is ensured, and the radial stiffness and the axial stiffness of the compressor are increased. And the surface of the piston is provided with a material coating with wear resistance and wear reduction performance and self-lubricating property, so that the friction between the piston and the cylinder can be reduced, the compressor can run without oil, and the reliability of the piston during motion is improved. The working medium forms periodic pressure fluctuation in the compression cavity, namely periodic compression-expansion, then the working medium sequentially passes through the air cylinder, the second fixing seat and the exhaust hole of the middle shell from the compression cavity, finally the working medium is exhausted out of the middle shell through the exhaust hole of the middle shell, and the pressure fluctuation enters the Stirling or pulse tube refrigerator assembly through an exhaust pipeline externally connected with the exhaust hole, so that the double-cylinder opposed oil-free linear compressor can be used for driving a refrigerator.

According to the double-cylinder opposed oil-free linear compressor provided by the embodiment, the axial rigidity and the radial rigidity of the compressor can be effectively improved while the gap sealing and oil-free lubrication technology is ensured, the high-frequency resonance operation is realized, and the operation efficiency is improved; the internal space of the motor can be effectively utilized, the size of the compressor is reduced, the volume of the system is reduced, and the miniaturization of the compressor is realized; the service life and the reliability of the linear compressor are improved, the miniaturization of the compressor is realized, the vibration noise of the conventional linear compressor is reduced, and the characteristic matching of the linear compressor and the cold head of the low-temperature refrigerator is realized.

According to the embodiment, the linear motor rotor is supported by the springs on the two sides, the stepped piston is located in the mounting mode of the inner side of the rotor, the compression cavity is arranged on the inner side of the motor, the inner space of the motor can be effectively utilized, the size of the compressor is reduced, and the size of the system is reduced. In order to overcome the defects of large vibration and short service life of the linear compressor, the core bodies of the two identical linear compressors are symmetrically arranged, and the piston assembly supported by the leaf spring assembly suspends the piston in the cylinder through reciprocating motion, so that the non-contact reciprocating motion of the piston and the cylinder is realized, the coaxiality of the piston and the cylinder is ensured, and the radial stiffness and the axial stiffness of the compressor are increased.

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

Claims (10)

1. A linear compressor, comprising: the compressor core comprises a linear motor, a cylinder, a piston and a flat spring assembly, wherein the cylinder is arranged in a cylinder of an inner stator of the linear motor, the piston is arranged in the cylinder, the inner stator and the piston are coaxially arranged, the flat spring assembly is fixedly arranged at each of two ends of the linear motor, and the two ends of the piston penetrate out of the cylinder respectively to be supported and connected to the corresponding flat spring assemblies, so that the piston is suspended in the cylinder.

2. The linear compressor of claim 1, wherein a stepped through channel is axially formed in the cylinder, and a portion of the through channel having a smaller cross-sectional dimension is formed at the first end of the cylinder; the piston is constructed in a way that the middle section of the piston is larger in size, and the sections of the two ends of the piston are smaller in size; the middle part of the piston is matched with the part with the larger cross-sectional dimension of the through passage in the cylinder, and the first end of the piston is matched with the through passage at the first end of the cylinder.

3. The linear compressor of claim 2, wherein the second end of the piston is connected to a piston supporter, the piston supporter is connected to the corresponding leaf spring assembly, and the piston supporter is connected to a mover of the linear motor.

4. The linear compressor of claim 1, wherein the leaf spring assembly includes a plurality of layers of resilient members arranged in an axial stack with a flat washer disposed between adjacent layers of resilient members; the elastic component is provided with two free ends and is of a bent structure integrally or is provided with at least three free ends, and the free ends are distributed at the edge part; the middle part of the elastic component is connected with the piston.

5. The linear compressor of claim 1, wherein fixing seats are respectively provided at both ends of the linear motor, and the leaf spring assembly and the cylinder are respectively connected to the fixing seats.

6. The linear compressor of claim 2, wherein a compression chamber is formed between the middle portion of the piston and the first end of the cylinder, and at least one exhaust hole communicated with the compression chamber is formed in the first end wall surface of the cylinder along the circumferential direction.

7. The linear compressor according to claim 6, wherein the compressor core is disposed inside the housing, at least one boss is connected to an inner wall of the housing along a circumferential direction corresponding to the exhaust hole, an intermediate channel communicated with the corresponding exhaust hole is disposed inside the boss, an exhaust channel is further disposed inside the housing, the exhaust channel is communicated with the intermediate channel, and at least one exhaust port communicated with the exhaust channel is disposed on a wall surface of the housing.

8. The linear compressor of claim 7, wherein two symmetrically distributed compressor cores are arranged inside the housing, and exhaust holes of the two compressor cores are communicated with the exhaust channel.

9. The linear compressor of claim 8, wherein the boss is disposed between the two compressor cores, and the corresponding exhaust holes on the two compressor cores are simultaneously communicated with the intermediate channel inside the corresponding boss.

10. A linear compressor as claimed in any one of claims 1 to 9 wherein the outer surface of the piston is coated with a lubricating coating.

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