CN210637202U - Linear compressor - Google Patents

Abstract

The utility model provides a linear compressor, which comprises a shell; a cylinder defining a first compression chamber and provided with a first exhaust valve; the first piston is arranged in the first compression cavity, is provided with a first air suction hole and is provided with a first air suction valve; the connecting rod is connected with the first piston and drives the first piston to reciprocate under the driving of the rotor, and the connecting rod is provided with a second compression cavity communicated with the first air suction hole; the second piston is inserted into the second compression cavity, is provided with a second air suction hole and is provided with a second air suction valve; the linear compressor is configured to gradually move the second piston away from the first piston when the first piston moves towards the first exhaust valve, so that gas in the second suction hole pushes the second suction valve away to enter the second compression cavity; and when the first piston moves away from the first exhaust valve, the second piston gradually approaches the first piston, so that the gas in the second compression cavity is compressed by the second piston and pushes the first air suction valve away to enter the first compression cavity. The utility model discloses a linear compressor has promoted the air-breathing volume through multistage compression.

Description

Linear compressor

Technical Field

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

Background

The linear compressor is a piston compressor using a linear motor, and is mainly applied to low-temperature refrigeration systems such as refrigerators and freezers.

However, the energy efficiency of the linear compressor with the conventional structure is still not high enough, and the popularization and the application of the linear compressor in the refrigeration field are greatly limited.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a linear compressor with higher efficiency of breathing in to promote the efficiency of compressor.

Another object of the present invention is to make the multistage compression structure of the linear compressor simpler and more reliable.

The utility model discloses a further purpose makes the compression power of second piston stronger.

In particular, the present invention provides a linear compressor, which includes:

a housing;

the cylinder is arranged in the shell, defines a first compression cavity and is provided with a first exhaust valve;

the first piston is arranged in the first compression cavity, provided with a first air suction hole and provided with a first air suction valve;

the connecting rod is connected with the first piston and drives the first piston to reciprocate under the drive of a rotor of the linear motor, and the connecting rod is of a hollow structure to form a second compression cavity communicated with the first air suction hole;

the second piston is inserted into the second compression cavity, is provided with a second air suction hole and is provided with a second air suction valve; the linear compressor is configured to:

when the first piston moves towards the first exhaust valve, the second piston gradually moves away from the first piston to promote the gas in the second suction hole to push the second suction valve away and enter the second compression cavity; and is

When the first piston moves away from the first exhaust valve, the second piston gradually approaches the first piston, so that the gas in the second compression cavity is compressed by the second piston and pushes the first intake valve away to enter the first compression cavity.

Optionally, the linear compressor further comprises: the plurality of resonant springs are connected with the second piston and the rotor to jointly form a resonant system; the resonant system is configured to: and under the excitation of the reciprocating motion of the rotor, the second piston and the rotor move in opposite directions.

Optionally, the plurality of resonant springs comprises a plurality of first springs, a plurality of second springs and a plurality of third springs extending in the second piston movement direction; two ends of the first spring are respectively fixed on the machine shell and the second piston directly or indirectly; two ends of the second spring are respectively fixed on the second piston and the rotor directly or indirectly; two ends of the third spring are respectively and directly or indirectly fixed on the rotor and the stator of the linear motor, so that the resonance system forms a two-degree-of-freedom vibration system; the linear compressor is configured to vibrate the resonant system in a second order mode under excitation of the mover to cause the second piston to move in a direction opposite to the direction of movement of the mover.

Optionally, the number of the first springs, the second springs and the third springs is the same, and each first spring is coaxially arranged with one second spring and one third spring.

Optionally, the plurality of first springs, the plurality of second springs and the plurality of third springs are all evenly distributed on a circumference coaxial with the cylinder.

Optionally, the second piston comprises: the piston head is used for being matched with the peripheral wall of the second compression cavity; the piston rod part is connected to the piston head part and extends out of the connecting rod in the direction away from the first piston; and the center of the connecting plate part is connected with the extending end of the piston rod part, two sides of the connecting plate part are respectively connected with the first spring and the second spring, and the second air suction hole penetrates through the piston head part, the piston rod part and the connecting plate part.

Optionally, the diameter of the piston rod is smaller than the diameter of the piston head.

Optionally, the linear compressor further comprises: the framework is fixed in the shell; the stator is fixed in the framework, and the cylinder is directly or indirectly fixed with the framework at one axial side of the stator; the connecting rod penetrates through the central through hole of the stator from one axial side of the stator to the other axial side of the stator; the rotor comprises an annular magnetic part inserted into the annular gap of the stator from the other axial side of the stator and a connecting part radially and inwardly extending to the connecting rod from the end part of the annular magnetic part and fixed on the connecting rod; the end part of the first spring is fixed on the end plate part of the framework, which is far away from one axial end of the cylinder; the two sides of the connecting part are respectively fixedly connected with the second spring and the third spring. Optionally, the second suction hole communicates with the inner space of the casing to suck low-pressure gas; and the exhaust gas flow of the first compression cavity is communicated with the exhaust pipe of the shell so as to exhaust high-pressure gas.

Optionally, the second piston is directly or indirectly fixed to the housing.

The utility model discloses a linear compressor has realized multistage compression, and the cylinder inspiratory gas has been compressed by the second piston for the suction pressure increase of cylinder, the density of breathing in increases, thereby makes the inspiratory capacity increase, has finally promoted linear compressor's efficiency. And, the utility model discloses set up the second compression chamber in the connecting rod, do not occupy extra space for linear compressor's overall structure is compacter, and this makes the technical scheme of the utility model more does benefit to leading-in actual product.

Further, the utility model discloses a linear compressor relies on the motion of resonance system drive second piston based on the vibration principle, makes the direction of motion of second piston opposite with active cell direction of motion (the direction of motion of first piston promptly) to cooperate first piston to accomplish the two-stage compression process just. This is equivalent to providing additional power for the compression process of the second piston, so that the compression capacity is stronger, and the increment of the air suction amount of the cylinder is larger. And because the second piston is driven to move away from the first piston in an absolute manner when the first piston is compressed, the air suction amount of the second air suction hole is larger, and finally, the air suction amount increase value of the cylinder is also improved.

Further, the utility model discloses a linear compressor has set up first spring, second spring and third spring and has counted three resonant spring of group altogether, makes it constitute a two degree of freedom vibration system with second piston and active cell to through the excitation of control active cell, make resonant system with the vibration of second order mode, realize the reverse motion of second piston and active cell, this kind of structure is very ingenious, controls very accurately.

The above and other objects, advantages and features of the present invention will become more apparent to those skilled in the art from the following detailed description of specific embodiments thereof, taken in conjunction with the accompanying drawings.

Drawings

Some specific embodiments of the present invention will be described in detail hereinafter, by way of illustration and not by way of limitation, with reference to the accompanying drawings. The same reference numbers in the drawings identify the same or similar elements or components. Those skilled in the art will appreciate that the drawings are not necessarily drawn to scale. In the drawings:

fig. 1 is a schematic cross-sectional view of a linear compressor according to an embodiment of the present invention, with the cylinder in the exhaust phase;

fig. 2 is a schematic view of a compression structure in the linear compressor shown in fig. 1;

fig. 3 is a schematic cross-sectional view of a linear compressor according to an embodiment of the present invention, with the cylinder in the suction phase;

fig. 4 is a schematic view of a compression structure in the linear compressor shown in fig. 3.

Detailed Description

Fig. 1 is a schematic cross-sectional view of a linear compressor according to an embodiment of the present invention, with the cylinder in the exhaust phase; fig. 2 is a schematic view of a compression structure in the linear compressor shown in fig. 1; fig. 3 is a schematic cross-sectional view of a linear compressor according to an embodiment of the present invention, with the cylinder in the suction phase; fig. 4 is a schematic view of a compression structure in the linear compressor shown in fig. 3. Fig. 2 and 4 illustrate the flow of the gas flow by hollow arrows.

As shown in fig. 1 to 2, an embodiment of the present invention provides a linear compressor, which can be applied to a vapor compression refrigeration cycle system, such as a refrigerator or a freezer. The linear compressor may generally include a casing 100, a linear motor 700, a cylinder 200, a first piston 300, a connecting rod 400, and a second piston 500.

The casing 100 defines a receiving chamber and is mounted with a suction pipe (not shown) and a discharge pipe 110. The linear motor 700 is installed in the cabinet 100, and includes a stator 720 and a mover 710. The stator 720 is directly or indirectly fixed to the casing 100. When the linear motor 700 is powered on, the mover 710 linearly reciprocates relative to the stator 720 by an electromagnetic force.

The cylinder 200 is disposed in the casing 100, and defines a first compression chamber 201 therein, and the first compression chamber 201 may be cylindrical. The cylinder 200 is also provided with a first exhaust valve 210. The first piston 300 is disposed in the first compression chamber 201, has a first air suction hole 301 formed therein, and is provided with a first air suction valve 310. The first piston 300 may have a circular ring shape, and a central through-hole portion constitutes the first suction hole 301. The connecting rod 400 is connected to the first piston 300 and is connected to the mover 710 to be driven by the mover 710. The connecting rod 400 is driven by the mover 710 to drive the first piston 300 to reciprocate, thereby completing the processes of air suction, compression and air exhaust in the first compression cavity 201 in the cylinder 200. The linear compressor of the present embodiment has a horizontal type structure in which the central axis of the cylinder 200 extends in a horizontal direction.

The rod 400 has a hollow structure to define a second compression chamber 401, the second compression chamber 401 having a cylindrical shape, and the second compression chamber 401 communicating with the first suction hole 301. For example, the connecting rod 400 may be a hollow cylinder shape having both axial ends open. The second piston 500 is inserted into the inside (fully or partially inserted) of the connecting rod 400, that is, into the second compression chamber 401. The second piston 500 has a second suction hole 501 and a second suction valve 510. The first exhaust valve 210, the first suction valve 310 and the second suction valve 510 are all elastic valve plates commonly used in the compressor field, and the detailed structure is not described again.

The linear compressor is configured to: when the first piston 300 moves towards the first exhaust valve 210 (i.e. moves in the positive direction along the x-axis) to compress the gas in the first compression chamber 201 and when the gas pressure in the first compression chamber 201 is large enough to push open the first exhaust valve 210 for exhaust, the second piston 500 is gradually moved away from the first piston 300 to cause the gas in the second suction hole 501 to push open the second suction valve 510 into the second compression chamber 401, referring to fig. 1 and 2. That is, while the first compression chamber 201 is in the compression or exhaust process, the second compression chamber 401 is in the suction process.

When the first piston 300 moves away from the first exhaust valve 210 (i.e. moves in the negative x-axis direction), the gas pressure in the first compression chamber 201 decreases (or forms a negative pressure), so that the first exhaust valve 210 is forced to close and the first intake valve 310 opens, and when the first compression chamber 201 performs an intake operation, the second piston 500 gradually approaches the first piston 300, so that the gas in the second compression chamber 401 is compressed by the second piston 500, and then pushes the first intake valve 310 away into the first compression chamber 201, referring to fig. 3 and 4. That is, when the first compression chamber 201 is in the suction process, the second compression chamber 401 is put into the compression and discharge processes, and the discharged gas having a higher pressure enters the first compression chamber 201.

In a word, the embodiment of the utility model provides a realize gaseous doublestage compression, the gas that cylinder 200 inhaled is the gas after second compression chamber 401 has been compressed, this makes the suction pressure increase of cylinder 200, and the density of breathing in increases to make the volume of breathing in increase (because cylinder 200 is carminative gas volume unchangeable at every turn, gas density increases the back, makes the discharge gas quality of the gas increase at every turn), promoted linear compressor's the efficiency of breathing in, and then promoted its efficiency.

Furthermore, because the embodiment of the utility model provides a set up second compression chamber 401 in connecting rod 400, do not occupy extra space for linear compressor's overall structure is compacter, and the spare part that needs the change is less, makes this technical scheme more do benefit to leading-in actual product.

It will be appreciated by those skilled in the art that the embodiments shown in fig. 1 to 4 may be further modified to achieve a multi-stage linear compressor scheme of three and more stages. For example, the second suction hole 501 in the second piston 500 may be used as a third compression chamber, and a third piston may be provided in the third compression chamber so that the gas compressed by the third piston is sucked into the second compression chamber 401.

In some embodiments, as shown in fig. 1, the linear compressor further includes a plurality of resonant springs (e.g., a plurality of first springs 810, a plurality of second springs 820, and a plurality of third springs 830). A plurality of resonant springs are coupled to the second piston 500 and the mover 710 to collectively form a resonant system 800. The resonant spring applies a flexible support to the mover 710 when the mover 710 reciprocates. Also, the natural frequency of the resonant system 800 is kept identical to the operating frequency of the linear compressor, so that the linear compressor can obtain the highest energy efficiency. The resonant system 800 is widely used in linear compressors and its principle will not be described too much here.

In an embodiment of the present invention, the resonance system 800 is particularly configured to: the second piston 500 and the mover 710 are moved in opposite directions by the reciprocating motion excitation of the mover 710. For example, the plurality of resonant springs may include a plurality of first springs 810, a plurality of second springs 820, and a plurality of third springs 830 extending in the moving direction of the second piston 500 (i.e., a direction parallel to the x-axis). The first spring 810, the second spring 820 and the third spring 830 are sequentially arranged in the moving direction of the second piston 500. A first end of each first spring 810 (the end of the spring herein refers to the end in the length direction) is directly or indirectly fixed to the housing 100, and the position thereof is maintained, and a second end is directly or indirectly fixed to the second piston 500. Each of the second springs 820 has a first end directly or indirectly fixed to the second piston 500 and a second end directly or indirectly fixed to the mover 710. Each third spring 830 has a first end directly or indirectly fixed to the mover 710 and a second end directly or indirectly fixed to the stator 720, and is positionally fixed. In this manner, the resonant system 800 forms a two degree of freedom vibration system. And, the linear compressor is configured to: the resonant system 800 is caused to vibrate in the second order mode when the mover 710 is excited, which may cause the second piston 500 to move in a direction opposite to the moving direction of the mover 710. The specific principle of the two-degree-of-freedom vibration system vibrating in the second-order mode so that the two masses move in opposite directions is not described herein again.

The present invention is provided in the above embodiments, the linear compressor drives the second piston 500 to move by the resonance system 800 based on the vibration principle, so that the moving direction of the second piston 500 is opposite to the moving direction of the mover 710 (i.e. the moving direction of the first piston 300), and the two-stage compression process is completed by just matching the first piston 300. This is equivalent to providing additional power to the compression process of the second piston 500, so that the compression capacity is stronger and the increase of the suction amount of the cylinder 200 is larger. Further, since the second piston 500 is driven to move away from the first piston 300 in an absolute motion when the first piston 300 is compressed, the suction amount of the second suction hole 501 is made larger, and finally the suction amount increase value of the cylinder 200 is also increased. And, through controlling the excitation of the mover 710, the resonant system 800 vibrates in a second-order mode, so that the reverse motion of the second piston 500 and the mover 710 is realized, the structure is ingenious, and the control is accurate.

Further, the number of the first springs 810, the second springs 820 and the third springs 830 is preferably the same, for example, 10. And each first spring 810 is coaxially disposed with one second spring 820 and one third spring 830. Further, the plurality of first springs 810, the plurality of second springs 820, and the plurality of third springs 830 may be uniformly distributed on a circumference (with the x-axis as a central axis) coaxial with the cylinder 200. This allows the resonant springs to more uniformly and dispersedly support the second piston 500 and the mover 710, and reduces unnecessary deformation of the springs and unnecessary displacement of the mover 710 and the second piston 500, making the movement thereof more accurate.

In some alternative embodiments, the second piston 500 may be directly or indirectly fixed to the casing 100. When the linear compressor is operated, the position of the second piston 500 is always kept constant, but the position of the second piston 500 relative to the first piston 300 is constantly changed due to the reciprocating motion of the first piston 300, so that the relative motion is generated, and the above-mentioned suction and compression processes of the second compression chamber 401 can be also completed. The details are not described.

In some embodiments, as shown in fig. 1 and 2, the second piston 500 includes a piston head 520, a piston rod 530, and a webbed portion 540. The second suction hole 501 penetrates the piston head 520, the piston rod 530, and the connecting plate 540. The piston head 520 is adapted to fit the peripheral wall of the second compression chamber 401, i.e. the diameter of the piston head 520 is slightly smaller than the inner diameter of the second compression chamber 401, with a thin layer of oil film between them. The piston rod portion 530 is coupled to the piston head portion 520 and extends the connecting rod 400 in a direction away from the first piston 300 (i.e., in the negative x-axis direction). The center of the web portion 540 is connected to the protruding end of the piston rod portion 530, which may be detachably connected for processing and installation. The first spring 810 and the second spring 820 are connected to both sides of the connection plate 540, respectively. The diameter of the piston rod 530 is smaller than that of the piston head 520 to avoid friction with the inner wall of the second compression chamber 401, thereby improving mechanical efficiency.

The linear compressor further includes a frame 900 fixedly provided in the casing 100 so as to fix the stator 720 and the cylinder 200. Specifically, the stator 720 includes a cylindrical outer stator 721 and a cylindrical inner stator 722. The inner stator 722 is positioned radially inward of the outer stator 721 and has a coil 723 provided thereon. An annular gap 701 is provided between the outer stator 721 and the inner stator 722.

The cylinder 200 is fixed to the frame 900 directly or indirectly on one axial side of the stator 720. For example, the cylinder 200 is indirectly fixed to the frame 900 via a flange 220. The flange 220 is secured within the framework 900 and has an internal bore. One axial end of the flange 220 abuts against one axial end of the stator 720, and the other axial end abuts against the inside of the end plate 920 of the bobbin 900. The cylinder 200 is fixed in the inner hole of the flange 220. The end plate 920 has an exhaust chamber 932 at the middle for accommodating the first exhaust valve 210, and the end plate 920 is externally disposed to enclose the exhaust chamber 932 with an end cap 930. The connecting rod 400 (extending negatively in the x-axis direction) passes through the central through hole of the stator 720 from one axial side of the stator 720 to the other axial side of the stator 720.

The mover 710 includes an annular magnetic attraction portion 712 and a coupling portion 711. The annular magnetic attraction part 712 is cylindrical and is inserted into the annular gap 701 of the stator 720 from the other axial side of the stator 720 (not completely inserted, but partially exposed to the outside). The whole or a part of the annular magnetic part 712 is a permanent magnet. The connecting portion 711 is bent and extended radially inward from an end (exposed end) of the annular magnetic portion 712 to the connecting rod 400, and is fixed to the connecting rod 400. A first end of the first spring 810 is fixed to an end plate portion 910 of the frame 900 at an end thereof in the axial direction away from the cylinder 200, and the end plate portion 910 has an opening 911 to allow air flow into and out of the frame 900. Both sides of the connecting portion 711 are fixedly connected with the second spring 820 and the third spring 830, respectively.

In some embodiments, the linear compressor has a low back pressure structure, and the second suction hole 501 communicates with the inner space of the casing 100 to suck low pressure gas. The discharge gas flow of the first compression chamber 201 communicates with the discharge pipe 110 of the casing 100 to discharge the high pressure gas. For example, as shown in FIG. 1, the exhaust pipe 110 is placed in communication with the exhaust conduit 931 of the end cap 930. In some alternative embodiments, the linear compressor may also be of a medium-back pressure or high-back pressure structure, and details are not repeated.

Thus, it should be appreciated by those skilled in the art that while a number of exemplary embodiments of the invention have been shown and described in detail herein, many other variations and modifications can be made, consistent with the principles of the invention, which are directly determined or derived from the disclosure herein, without departing from the spirit and scope of the invention. Accordingly, the scope of the present invention should be understood and interpreted to cover all such other variations or modifications.

Claims (10)

1. A linear compressor, characterized by comprising:

a housing;

the cylinder is arranged in the shell, defines a first compression cavity and is provided with a first exhaust valve;

the first piston is arranged in the first compression cavity, is provided with a first air suction hole and is provided with a first air suction valve in a matching way;

the connecting rod is connected with the first piston and drives the first piston to reciprocate under the drive of a rotor of the linear motor, and the connecting rod is of a hollow structure to form a second compression cavity communicated with the first air suction hole;

the second piston is inserted into the second compression cavity, is provided with a second air suction hole and is provided with a second air suction valve in a matching mode; the linear compressor is configured to:

moving the second piston gradually away from the first piston as the first piston moves toward the first exhaust valve to cause gas in the second suction port to push open the second suction valve into the second compression chamber; and is

And when the first piston moves away from the first exhaust valve, the second piston gradually approaches the first piston, so that the gas in the second compression cavity is compressed by the second piston and then pushes the first air suction valve away to enter the first compression cavity.

2. The linear compressor of claim 1, further comprising:

the resonant springs are connected with the second piston and the rotor to jointly form a resonant system;

the resonant system is configured to: and under the excitation of the reciprocating motion of the rotor, the second piston and the rotor are moved in opposite directions.

3. Linear compressor according to claim 2,

the plurality of resonant springs includes a plurality of first springs, a plurality of second springs, and a plurality of third springs extending in the second piston movement direction;

two ends of the first spring are respectively and directly or indirectly fixed on the shell and the second piston;

two ends of the second spring are respectively and directly or indirectly fixed on the second piston and the rotor;

two ends of the third spring are respectively and directly or indirectly fixed on the rotor and the stator of the linear motor, so that the resonance system forms a two-degree-of-freedom vibration system;

the linear compressor is configured to vibrate the resonant system in a second order mode under excitation of the mover to cause a movement direction of the second piston to be opposite to a movement direction of the mover.

4. Linear compressor according to claim 3,

the number of the plurality of first springs, the number of the plurality of second springs and the number of the plurality of third springs are the same, and each of the first springs is coaxially arranged with one of the second springs and one of the third springs.

5. Linear compressor according to claim 3,

the plurality of first springs, the plurality of second springs and the plurality of third springs are all uniformly distributed on a circumference coaxial with the cylinder.

6. A linear compressor as claimed in claim 3, wherein said second piston comprises:

the piston head is used for being matched with the peripheral wall of the second compression cavity;

the piston rod part is connected to the piston head part and extends out of the connecting rod in the direction away from the first piston; and

the center of the connecting plate part is connected to the extending end of the piston rod part, two sides of the connecting plate part are respectively connected with the first spring and the second spring, and the second air suction hole penetrates through the piston head part, the piston rod part and the connecting plate part.

7. Linear compressor according to claim 6,

the diameter of the piston rod part is smaller than that of the piston head part.

8. The linear compressor of claim 3, further comprising:

the framework is fixed in the shell;

the stator is fixed in the framework, and the cylinder is directly or indirectly fixed with the framework on one axial side of the stator;

the connecting rod penetrates through the central through hole of the stator from one axial side of the stator to the other axial side of the stator;

the rotor comprises an annular magnetic suction part inserted into the annular gap of the stator from the other axial side of the stator and a connecting part which is bent inwards from the end part of the annular magnetic suction part to the connecting rod and is fixed on the connecting rod;

the end part of the first spring is fixed on an end plate part of the framework, which is far away from one axial end of the cylinder;

and two sides of the connecting part are respectively fixedly connected with the second spring and the third spring.

9. Linear compressor according to claim 1,

the second air suction hole is communicated with the inner space of the shell so as to suck low-pressure air; and is

And the exhaust gas flow of the first compression cavity is communicated with the exhaust pipe of the shell so as to exhaust high-pressure gas.

10. Linear compressor according to claim 1,

the second piston is directly or indirectly fixed to the housing.

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