CN214304255U

CN214304255U - Double-piston opposed air suction piston for valve linear compressor

Info

Publication number: CN214304255U
Application number: CN202120176479.XU
Authority: CN
Inventors: 刘政; 任道顺
Original assignee: Shanghai Langdan Technology Group Co Ltd
Current assignee: Shanghai Langdan Technology Group Co Ltd
Priority date: 2021-01-23
Filing date: 2021-01-23
Publication date: 2021-09-28
Anticipated expiration: 2031-01-23

Abstract

The utility model provides a two pistons opposed type have valve linear compressor with piston of breathing in, piston are the column solid of revolution, including leaf spring cooperation portion, permanent magnet support cooperation portion, cylinder cooperation portion, valve block cooperation portion and working medium runner portion. The plate spring matching part is a related structure which is in rigid connection with the plate spring, the permanent magnet support matching part is a related structure which is in rigid connection with the permanent magnet support, the air cylinder matching part is a related structure which forms clearance seal with the air cylinder, the valve plate matching part is a related structure which is in rigid connection with the air suction valve plate, and the working medium flow channel part is a related structure which forms a working medium gas flow channel. The utility model discloses a piston processing of breathing in is made conveniently, has guaranteed the clearance seal of compressor piston and cylinder, has reduced the friction loss of compressor operation, has improved the efficiency of compressor.

Description

Double-piston opposed air suction piston for valve linear compressor

Technical Field

The utility model belongs to the refrigeration field, concretely relates to double-piston opposed type has valve linear compressor with piston of breathing in.

Background

For a vapor compression refrigeration system, a compressor is a core component and can directly determine the refrigerating capacity and the performance of the whole refrigeration system. At present, the traditional reciprocating compressor is adopted in most refrigeration compressors, the technology is relatively mature, the processing cost is relatively low, but due to the existence of a crank connecting rod mechanism, the whole system structure of the compressor is huge, meanwhile, all parts can rub against each other in the power transmission process, the transmission efficiency is low, and the noise and the vibration are also relatively large. In order to reduce friction, conventional reciprocating compressors generally use lubricating oil, which is decomposed when the temperature is relatively high, and the compressor may overheat in a severe working environment, which affects the stability of the refrigeration system.

In view of the above problems with conventional compressors, a linear compressor is a good alternative. The linear compressor is driven by a linear motor, is mostly used for a pressure wave generator of an aerospace low-temperature refrigerator from research and development to date, and can realize oil-free lubrication through gap sealing and gas bearing technologies. The opposed double-piston valve linear compressor adopts one air suction piston and one non-air suction piston to oppositely compress working medium gas in a compression cavity in a cylinder, has the advantages of symmetrical structure, low vibration, low noise, high reliability and the like, and becomes an important research direction in the field of the research of the existing valve linear compressor.

The compression piston is one of main parts of the valve linear compressor, the compression piston performs reciprocating resonant motion in the cylinder to compress working medium gas in the compression cavity to the exhaust pipeline, and other parts such as a plate spring, a permanent magnet support and the like are matched with the compression piston in a rigid connection mode to ensure the normal operation of the compression piston. At present, most research works are concentrated on the directions of the design of a magnetic circuit structure of a linear motor in a linear compressor, and the influence of a compression piston structure on the operation condition of the linear compressor is ignored. In the performance test of the valve linear compressor prototype, the low pressure ratio of the compressor and the serious overheating of the compressor are caused because the structural design of the compression piston is not reasonable. The high-frequency collision between the compression piston and the air cylinder, the unreasonable gap arrangement between the piston and the air cylinder, and the design structure defects of low-precision shaft hole matching between the piston and other parts can cause the unstable operation of the linear compressor, reduce the efficiency of the linear motor and influence the refrigeration performance of the refrigeration system.

Disclosure of Invention

In order to solve the problem, the utility model discloses a structure is through simplifying, ensures the stable double piston opposed type of compressor compression, exhaust, inflation and the thermodynamic cycle process of breathing in simultaneously and has the piston of breathing in for the valve linear compressor.

The utility model provides a two pistons opposed type have valve linear compressor with piston of breathing in, the piston is the column solid of revolution, has such characteristic, include: the permanent magnet valve comprises a plate spring matching part, a permanent magnet support matching part, a cylinder matching part, a valve block matching part and a working medium flow channel part. The plate spring matching part is a related structure which is in rigid connection with the plate spring, the permanent magnet support matching part is a related structure which is in rigid connection with the permanent magnet support, the air cylinder matching part is a related structure which forms clearance seal with the air cylinder, the valve plate matching part is a related structure which is in rigid connection with the air suction valve plate, and the working medium flow channel part is a related structure which forms a working medium gas flow channel.

In addition, the present invention provides a suction piston for a double-piston opposed valve linear compressor, which can further have the following features: the front end of the plate spring matching portion is provided with two sections of cylinder structures with different diameters so as to form a circular ring surface for placing the plate spring, a section of fine-tooth external threads are distributed on the outer cylindrical surface of the tail end of the plate spring matching portion, and a circular ring groove serving as a tool withdrawal groove for thread machining is formed in the cylindrical surface of the middle section of the plate spring matching portion.

In addition, the present invention provides a suction piston for a double-piston opposed valve linear compressor, which can further have the following features: the rear end of the permanent magnet support matching part is uniformly distributed with 4-8 circular through holes for fastening and connecting the piston and the permanent magnet support through screws.

In addition, the present invention provides a suction piston for a double-piston opposed valve linear compressor, which can further have the following features: wherein, the disk-shaped structure at the rear end of the permanent magnet support matching part can be provided with a counterweight plate.

In addition, the present invention provides a suction piston for a double-piston opposed valve linear compressor, which can further have the following features: the outer diameter of the columnar structure at the front end of the matching part of the permanent magnet support is consistent with the central aperture of the permanent magnet support used in a matched mode, and a close clearance matching relation is formed.

In addition, the present invention provides a suction piston for a double-piston opposed valve linear compressor, which can further have the following features: the valve plate matching part is provided with a groove opening, a threaded blind hole is formed in the center of the front end face of the valve plate matching part, and the matched air suction valve plate and the air suction piston are locked through screws.

In addition, the present invention provides a suction piston for a double-piston opposed valve linear compressor, which can further have the following features: wherein, the cylinder cooperation portion surface plates the abrasionproof cladding material of a layer teflon material.

In addition, the present invention provides a suction piston for a double-piston opposed valve linear compressor, which can further have the following features: the working medium runner part is in stepped distribution with a front section, a middle section and a rear section, the rear section runner is a circular ring-shaped runner, the middle section runner is three uniformly distributed kidney-shaped groove runners, and the front section runner is a cylindrical runner.

In addition, the present invention provides a suction piston for a double-piston opposed valve linear compressor, which can further have the following features: the outer diameter of the circular ring-shaped runner at the rear section of the working medium runner part is not smaller than the outer diameter of the runner of the kidney-shaped groove, the inner diameter of the circular ring-shaped runner at the rear section of the working medium runner part is not larger than the inner diameter of the runner of the kidney-shaped groove, and the outer diameter of the circular ring-shaped runner at the front section is larger than the inner diameter of the runner of the kidney-shaped groove so as to ensure that the runner is communicated.

The function and effect of the utility model

According to the utility model relates to a two pistons opposed type have valve linear compressor with piston of breathing in, this piston is emphatically in cooperation and the fastening design between piston and the relevant spare part, and the piston after the simplification adopts the rigid connection mode between three and other parts, and the structure is retrencied, and manufacturing is convenient. Meanwhile, the piston optimizes a working medium gas flow passage, and the three-section gas flow passages with different shapes and the design of the groove openings of the valve plate matching part are beneficial to the stable operation of the compressor in the air suction and exhaust process, so that the gas flow resistance loss in the air suction and exhaust process is reduced, and the probability of the bad phenomena of vibration, delayed closing and the like in the movement of the valve plate is reduced. In addition, the piston, the plate spring and the permanent magnet support are in precise shaft hole matching relation to ensure stable operation of the piston, and collision does not occur between the piston and the cylinder, so that friction loss of operation of the compressor is reduced, and efficiency of the compressor is improved.

Drawings

FIG. 1 is an isometric illustration of an intake piston in the present embodiment;

FIG. 2 is a schematic sectional view of the suction piston in the present embodiment;

FIG. 3 is a schematic view of the suction piston in this embodiment in cooperation with a leaf spring;

FIG. 4 is a schematic view of the suction piston in this embodiment in cooperation with a permanent magnet holder;

FIG. 5 is a schematic view of the intake piston and cylinder assembly of the present embodiment;

FIG. 6 is a schematic view of the intake piston and the valve plate in this embodiment;

FIG. 7 is a schematic view of the cooperation between the intake piston and the cylinder in the second embodiment;

fig. 8 is a schematic view of the cooperation between the suction piston and the weight plate in the third embodiment.

Detailed Description

In order to make the technical means, creation characteristics, achievement purpose and efficiency of the present invention easy to understand, the following embodiments are combined with the accompanying drawings to specifically describe the suction piston for the double-piston opposed valve linear compressor of the present invention.

The first embodiment is as follows:

as shown in fig. 1 and 2, the suction piston for a double-piston opposed type valve linear compressor includes a plate spring fitting portion 100, a permanent magnet holder fitting portion 300, a cylinder fitting portion 500, a valve plate fitting portion 700, and a working medium flow path portion 900.

The plate spring matching part 100 is integrally divided into three parts, namely an external thread 101 at the tail end of the piston, a tool withdrawal groove 102 and a circular ring step surface 103.

In the embodiment, the tool withdrawal groove 102 abuts against the external thread 101, and the tool withdrawal groove 102 and the circular ring step surface 103 are separated by a section of columnar structure for realizing shaft hole matching with the central hole of the plate spring 200.

As shown in fig. 2 and 3, the diameter of the plate spring central hole 201 of the plate spring 200 is the same as the diameter of the annular step surface 103, the diameter of the plate spring central hole 201 is of the tolerance grade of H7 in a base hole system, the inner diameter of the annular step surface 103 is of the tolerance grade of g6, and a small gap is formed between the plate spring central hole 201 and the annular step surface 103, so that the coaxiality and the tight fit between the two parts can be ensured. The external thread 101 is a fine thread, the thread pitch of the fine thread is small, the diameter of the thread bottom is large, the wall thickness of the tail part of the piston is large, and the fatigue strength of the piston under high-frequency reciprocating motion is improved. The axial length of the relief groove 102 is slightly larger than the thread pitch of the external thread 101, and the depth is slightly larger than half of the thread pitch length of the external thread 101, so that the external thread 101 can be conveniently machined. The leaf spring 200 is fastened to the leaf spring fitting portion 100 by a nut fastener having the same pitch as the external thread 101.

As shown in fig. 2 and 4, the permanent magnet holder fitting portion 300 mainly includes two portions, a piston middle ring plate 301 and a piston middle shaft body 302. The piston middle ring disc 301 is provided with 4-8 piston middle ring disc circular through holes 303 which are uniformly distributed by taking the axis of the piston middle ring disc 301 as the center. Threaded blind holes are formed in the end faces of the permanent magnet supports 400 at corresponding positions, and the permanent magnet support matching portions 300 and the permanent magnet supports 400 are locked through screw fasteners. The end face of the permanent magnet support 400 is provided with a permanent magnet support center hole 401, the diameter of the permanent magnet support center hole 401 is consistent with the outer diameter of the piston middle shaft body 302, the diameter of the permanent magnet support center hole 401 is also in the H7 tolerance grade of a base hole system, the outer diameter of the piston middle shaft body 302 is in the g6 tolerance grade, and the matching precision is high.

As shown in fig. 5, the cylinder engaging portion 500 has a cylindrical structure, and an annular gap 601 is formed between the cylinder engaging portion and the cylinder 600, and the annular gap 601 serves as a gap seal. When fluid flows in the annular gap 601, the pressure of the airflow can be damaged due to the viscous friction effect of the fluid, so that throttling and pressure reduction are realized to achieve the effect of sealing. The axial length of the cylinder fitting 500 is the largest in proportion to the total axial length of the intake piston, and the longer cylinder fitting 500 is advantageous to improve the sealing effect of the annular gap 601.

As shown in fig. 6, the valve plate fitting part 700 includes a valve plate fixing cylinder 701, a rib 702, and a piston inner wall 704. During the suction process, most of the working medium gas enters the compression cavity through the annular groove formed by the inner wall 704 of the piston. The end face of the valve plate fixing cylinder 701 is provided with a threaded blind hole 703, and the air suction valve plate 800 is locked with the valve plate fixing cylinder 701 through a screw fastener. The number of the rib plates 702 is three, and the rib plates are uniformly distributed in the piston by taking the axis of the valve plate fixing cylinder 701 as the center, so that the function of supporting the valve plate fixing cylinder 701 is achieved. The front end face of the rib 702 does not contact the suction valve plate 800. The ribbed plate 702, the valve plate fixing cylinder 701 and the piston inner wall 704 form a working medium gas flow passage at the front end of the piston together. The valve plate fitting portion is provided with a notch 705 for discharging gas in the compression chamber.

The working medium runner part 900 is in stepped distribution with a front section, a middle section and a rear section, the front section runner is a cylindrical runner 901, the middle section runner is three kidney-shaped runners 902 which are uniformly distributed, the rear section runner is an annular runner 903, and the three sections of runners share the same axis. The outer diameter of the working medium runner part rear section circular ring-shaped runner 903 is not smaller than the outer diameter of the kidney-shaped groove runner 902, the inner diameter of the working medium runner part rear section circular ring-shaped runner 903 is not larger than the inner diameter of the kidney-shaped groove runner 902, and the outer diameter of the front section cylindrical runner 901 is larger than the inner diameter of the kidney-shaped groove runner 902, so that the runner is communicated.

Preferably, when the axis of the outer cylindrical surface of the cylinder matching part 500 is taken as a reference, the coaxiality of the cylindrical surface of the piston middle shaft body 302 to the reference is less than 0.01, and the cylindricity of the cylindrical surface is less than 0.005; the axis of the outer cylindrical surface of the cylinder matching part 500 is used as a reference, the perpendicularity of the end surface of the valve plate fixing cylinder 701 and the circular ring step surface 103 to the reference is less than 0.01, and the two planeness degrees are less than 0.005.

The working process of the air suction piston for the double-piston opposed type valve linear compressor comprises the following steps:

the operation of the suction piston in the valved linear compressor is: when the moving position of the suction piston is at the bottom dead center, the interior of the cylinder 600 is filled with low-pressure vapor sucked from the suction pipe, and compression starts. The air suction piston moves to the top dead center under the action of the axial electromagnetic thrust generated by the motor and the axial reciprocating force of the plate spring 200, the air suction valve plate 800 is closed, the working volume of the cylinder 600 is gradually reduced, and the temperature of the working medium gas is gradually increased. The suction piston moves to a certain position in the cylinder 600, the pressure of the working medium steam rises to be slightly higher than the minimum opening pressure of the exhaust valve plate of the compressor, the exhaust valve plate is opened, and the compressor exhausts. When the air suction piston starts to move towards the bottom dead center after moving to the top dead center, the exhaust process is finished, and the exhaust valve plate is closed. As the volume inside the cylinder 600 is continuously increased, the working medium gas expands and the pressure is gradually reduced. When the low-pressure steam pressure is greater than the opening pressure of the air suction valve plate 800, the air suction valve plate 800 is opened, the compressor starts to suck air, and when the air suction piston returns to the bottom dead center, the air suction is completed, so that one cycle is completed. In the whole thermodynamic cycle process, the annular gap 601 between the cylinder matching part 500 and the cylinder 600 plays a role of gap sealing all the time, the plate spring 200 provides continuous radial supporting force and axial reciprocating force for the air suction piston through the screw rigid connection between the plate spring matching part 100 and the plate spring 200, the permanent magnet support matching part 300 transfers the axial electromagnetic thrust force borne by the permanent magnet to the air suction piston through the screw rigid connection with the permanent magnet support 400, the valve plate fixing cylinder 701 is in rigid connection with the air suction valve plate 800 through the screw rigid connection, and the rib plate 702 which is not in contact with the air suction valve plate 800 ensures that the air suction valve plate 800 is opened and closed in time.

Example two:

other structures of this embodiment are the same as those of the first embodiment, and in order to reduce friction during the reciprocating motion of the suction piston, a teflon coating 501 with a thickness of 0.1 to 0.3mm is coated on the surface of the compression piston, as shown in fig. 7. The Teflon coating material, namely polytetrafluoroethylene, has the characteristics of high temperature resistance and extremely low friction coefficient, is very suitable for being used as a lubricating material, and is beneficial to prolonging the service life of the air suction piston.

Example three:

the other structure of this embodiment is the same as the first embodiment, as shown in fig. 8, except that a weight plate 304 is added in this embodiment to change the overall mass of the mover and match the stiffness of the plate spring, so as to implement resonance. The counterweight plate 304 is circular and has small thickness, a plurality of counterweight plate circular through holes 305 are arranged on the end surface, and the through holes distributed in an array are consistent with the circular through holes 303 of the piston middle ring disc in size and position. The weight plate 304, the piston middle ring plate 301 and the permanent magnet holder 400 are locked together by screw fasteners.

As a modification, the weight plates 304 may be configured with multiple plates to achieve a wide range of mover mass adjustment.

Action and effect of the examples:

according to the air suction piston for the double-piston opposed type valve linear compressor, the air suction piston emphasizes the matching and fastening design between the piston and related parts, the simplified piston adopts a rigid connection mode between three parts and other parts, the structure is simplified, and the processing and the manufacturing are convenient. Meanwhile, the piston optimizes a working medium gas flow passage, the three-section gas flow passages with different shapes and the design of the groove openings of the valve plate matching part are favorable for stable operation of the suction and exhaust processes of the compressor, the gas flow resistance loss in the suction and exhaust processes is reduced, and the probability of undesirable phenomena such as trembling and delayed closing of the valve plate during movement is reduced.

In addition, a gap seal is adopted between the air suction piston and the cylinder, and when fluid flows in the annular gap, the air flow pressure can be damaged due to the viscous friction effect of the fluid, so that the throttling and pressure reduction effects are realized, and the sealing effect is achieved.

Furthermore, the air suction piston is matched with the plate spring and the permanent magnet bracket through a precise shaft hole so as to ensure the stable operation of the piston and avoid collision with the cylinder.

The above embodiments are preferred examples of the present invention, and are not intended to limit the scope of the present invention.

Claims

1. The air suction piston is characterized by comprising a plate spring matching part, a permanent magnet support matching part, an air cylinder matching part, a valve plate matching part and a working medium flow passage part; the plate spring matching part is a related structure which is in rigid connection with the plate spring, the permanent magnet support matching part is a related structure which is in rigid connection with the permanent magnet support, the air cylinder matching part is a related structure which forms clearance seal with the air cylinder, the valve plate matching part is a related structure which is in rigid connection with the air suction valve plate, and the working medium flow channel part is a related structure which forms a working medium gas flow channel.

2. An intake piston for a double piston opposed valve linear compressor according to claim 1, wherein: the front end of the plate spring matching portion is provided with two sections of cylinder structures with different diameters so as to form a circular ring surface for placing the plate spring, a section of fine-tooth external threads are distributed on the outer cylindrical surface of the tail end of the plate spring matching portion, and a circular ring groove serving as a tool withdrawal groove for thread machining is formed in the middle cylindrical surface of the plate spring matching portion.

3. An intake piston for a double piston opposed valve linear compressor according to claim 1, wherein: circular through holes are uniformly distributed on the circular ring disc-shaped structure at the rear end of the matching part of the permanent magnet support, and the number of the through holes is 4-8.

4. An intake piston for a double piston opposed valve linear compressor according to claim 1, wherein: and a counterweight plate can be placed on the disc-shaped structure at the rear end of the matching part of the permanent magnet support.

5. The suction piston for a double-piston opposed valve linear compressor according to claim 1, wherein the outer diameter of the cylindrical structure at the front end of the permanent magnet support fitting part is consistent with the central aperture of the permanent magnet support used in cooperation, so that a close clearance fit relation is formed.

6. An intake piston for a double piston opposed valve linear compressor according to claim 1, wherein: the center of the front end face of the valve plate matching part is provided with a threaded blind hole, and the matched air suction valve plate and the air suction piston are locked through a screw.

7. An intake piston for a double piston opposed valve linear compressor according to claim 1, wherein: the surface of the cylinder matching part can be plated with an anti-abrasion coating made of Teflon material.

8. An intake piston for a double piston opposed valve linear compressor according to claim 1, wherein: the working medium runner part is in stepped distribution with a front section, a middle section and a rear section, the front section runner is a cylindrical runner, the middle section runner is three uniformly distributed kidney-shaped groove runners, and the rear section runner is a circular ring-shaped runner.

9. An intake piston for a double piston opposed valve linear compressor according to claim 8, wherein: the outer diameter of the circular ring-shaped runner at the rear section of the working medium runner part is not smaller than the outer diameter of the runner of the kidney-shaped groove, the inner diameter of the circular ring-shaped runner at the rear section of the working medium runner part is not larger than the inner diameter of the runner of the kidney-shaped groove, and the outer diameter of the cylindrical runner at the front section is larger than the inner diameter of the runner of the kidney-shaped groove so as to ensure that the runner is communicated.