Silencing structure and oxygen generator

Abstract

The invention relates to a silencing structure and an oxygen generator, and relates to the field of oxygen generation equipment. The noise elimination structure comprises a shell, and a first noise elimination unit and a second noise elimination unit are arranged in the shell; a sound absorption piece is arranged in the first silencing unit; the second silencing unit comprises at least two stages of expansion cavities, and corresponding air holes are formed between every two adjacent expansion cavities to form a gas bending flow channel; gas enters from the first silencing unit, passes through the sound absorption part, enters the expansion cavities of all stages, passes through the gas bending flow channel and then is discharged out of the shell. The sound absorption piece is arranged in the first silencing unit, so that the sound absorption piece conducts resistive silencing on airflow; at least two stages of expansion cavities are formed in the second silencing unit and are used for reducing the wind resistance of airflow flowing in the gas bending flow channel, and resistant silencing is carried out on the airflow; the noise elimination structure realizes impedance composite noise elimination, reduces nitrogen exhaust noise, and solves the technical problem of poor effect of the existing nitrogen exhaust noise elimination structure.

Description

Technical Field

[0001] The present invention relates to the field of oxygen production equipment, and in particular to a sound-absorbing structure and an oxygen production machine. Background Art

[0002] The existing oxygen concentrators are noisy, and the noise mainly comes from the suction and closing sound of the compressor and solenoid valve and the sound of nitrogen exhaust.

[0003] The inventors have found that the exhaust nitrogen is discharged into the compressor compartment or the bottom of the compressor compartment through the muffler. Such a structural design causes poor sealing of the expansion chamber, and the air inlet and outlet are large in size, which cannot effectively cause reflection and interference of sound waves to perform noise reduction, resulting in poor noise reduction effect and high noise.

[0004] Based on the above technical problems, it is urgent to design a silencer structure and an oxygen generator. Summary of the invention

[0005] The object of the present invention is to provide a silencer structure and an oxygen concentrator to solve the technical problem that the silencer structure used for nitrogen emission of the existing oxygen concentrator has poor silencer effect.

[0006] The embodiment of the present invention is achieved as follows:

[0007] In the first aspect, the present invention proposes a sound-absorbing structure, including a shell, in which a first sound-absorbing unit and a second sound-absorbing unit are arranged; the first sound-absorbing unit is provided with a sound-absorbing component; the second sound-absorbing unit includes at least two levels of expansion chambers, and corresponding air holes are arranged between each adjacent expansion chamber to form a gas bending flow channel; wherein, the gas enters from the first sound-absorbing unit and passes through the sound-absorbing component, then enters the expansion chambers of each level and is discharged from the shell after passing through the gas bending flow channel.

[0008] Optionally, the at least two-stage expansion chamber includes a primary expansion chamber and at least one secondary expansion chamber which are connected in sequence, and the at least one secondary expansion chamber is at least arranged at the end of the primary expansion chamber.

[0009] Optionally, the first muffler unit comprises a first expansion chamber;

[0010] The primary expansion chamber comprises a second expansion chamber and a third expansion chamber which are connected in sequence, and the second expansion chamber is connected to the first expansion chamber;

[0011] The secondary expansion chambers include two, and the two secondary expansion chambers are symmetrically arranged on both sides of the third expansion chamber.

[0012] Optionally, one of the secondary expansion chambers comprises a fourth expansion chamber and a fifth expansion chamber which are connected in sequence, the fourth expansion chamber is connected to the third expansion chamber, and the fifth expansion chamber is provided with an air outlet;

[0013] Another of the second muffler units includes a sixth expansion chamber and a seventh expansion chamber which are connected in sequence, the sixth expansion chamber is connected to the third expansion chamber, and the seventh expansion chamber is provided with an air outlet.

[0014] Optionally, the air outlet includes a plurality of exhaust holes arranged in a matrix or annular arrangement;

[0015] The sound absorbing member is a porous sound absorbing material or a sound absorbing structure.

[0016] In a second aspect, the present invention further proposes an oxygen generator, comprising the muffler structure described in any one of the above items and a molecular sieve, wherein the molecular sieve is provided with a nitrogen exhaust port, and the nitrogen exhaust port is connected to the first muffler unit.

[0017] Optionally, the oxygen concentrator further comprises a compressor cabin and a base, and the compressor cabin is arranged on the top of the base;

[0018] The compressor compartment is provided with a sealed installation cavity and a first opening and a second opening communicating with the installation cavity, the compressor compartment is provided with the muffler structure, and the air outlet of the muffler structure is communicated with the installation cavity;

[0019] The first opening is used for air intake, and the installation cavity is connected with the base through the second opening for exhaust.

[0020] Optionally, a pipeline structure is provided outside the compressor compartment, one end of the pipeline structure is used for air intake, and the other end is connected with the installation cavity through the first opening;

[0021] An exhaust member is also provided in the pipeline structure, and the exhaust member is arranged at the first opening.

[0022] Optionally, the molecular sieve is arranged on the outer wall of the compressor compartment, and the silencer structure is arranged on the inner wall of the compressor compartment and close to the molecular sieve.

[0023] Optionally, the oxygen concentrator further comprises a compressor and a muffler compartment, and the compressor shock absorber is arranged in the compressor compartment;

[0024] The air outlet of the compressor is connected to the air inlet of the molecular sieve through a pipeline;

[0025] The silencer chamber is arranged on the compressor compartment, and the air inlet end of the compressor is connected to the outside through the silencer chamber.

[0026] The beneficial effects of the embodiments of the present invention are:

[0027] The silencer structure and oxygen generator proposed in the present invention provide a sound absorbing component in the first silencer unit so that the sound absorbing component performs resistive silence on the airflow; provide at least two expansion chambers in the second silencer unit, at least two expansion chambers are used to reduce the wind resistance of the airflow entering the gas bending flow channel, and resistive silence is performed on the airflow entering the gas bending flow channel; the silencer structure provided in this way combines the first silencer unit and the second silencer unit, realizes impedance composite silencer, reduces nitrogen exhaust noise, and solves the technical problem of poor effect of existing nitrogen exhaust silencer structures. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0029] Figure 1 This is a schematic diagram of the structure of an oxygen concentrator according to an embodiment of the present invention;

[0030] Figure 2 It is a structural schematic diagram of the sound-absorbing structure of an embodiment of the present invention;

[0031] Figure 3 A top view of a sound-absorbing structure according to an embodiment of the present invention;

[0032] Figure 4 It is a schematic diagram of the lower shell of the sound-absorbing structure according to an embodiment of the present invention.

[0033] Icons: 010-oxygen generator; 100-silencing structure; 101-shell; 1011-upper shell; 1012-lower shell; 102-air inlet; 103-air outlet; 104-sound absorbing element; 110-first silencer unit; 111-first expansion chamber; 120-second silencer unit; 121-expansion chamber; 122-second expansion chamber; 123-third expansion chamber; 124-fourth expansion chamber; 125-fifth expansion chamber; 126-sixth expansion chamber; 127-seventh expansion chamber; 128-connecting port; 200-molecular sieve; 300-compressor; 310-inlet pipe; 320-outlet pipe; 400-compressor cabin; 410-installation cavity; 420-pipeline structure; 430-exhaust element; 440-silencing chamber; 500-base. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0035] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0037] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or the positions or positional relationships in which the product of the invention is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0038] In addition, the terms "horizontal", "vertical" and the like do not mean that the components are required to be absolutely horizontal or suspended, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0039] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0040] This embodiment provides an oxygen generator 010, in which a silencer structure 100 is directly built into a compressor compartment 400, and impedance composite silencer is used to solve the technical problem that the existing nitrogen exhaust silencer structure has a poor effect.

[0041] Please refer to Figure 1 The oxygen generator 010 proposed in this embodiment includes a muffler structure 100 and a molecular sieve 200. The molecular sieve 200 is provided with a nitrogen exhaust port, which is connected to the air inlet 102 of the first muffler unit 110.

[0042] It is understandable that the nitrogen exhaust port of the molecular sieve 200 is connected to the air inlet 102 of the silencer structure 100 to reduce the noise of nitrogen exhaust sound from the nitrogen exhaust port, thereby solving the technical problem of poor effect of the existing nitrogen exhaust silencer structure.

[0043] Please refer to Figure 1 In this embodiment, the oxygen concentrator 010 includes a compressor 300 .

[0044] In this embodiment, the compressor 300 is used to compress air. The compressor 300 sucks in gas and compresses it, and introduces the compressed air into the molecular sieve 200 for separation.

[0045] Among them, the compressor 300 is arranged in the compressor cabin 400, and is connected to the bottom wall of the compressor cabin 400 for shock absorption through elastic parts; the compressor 300 includes at least one air inlet end and an air outlet end, the air inlet end of the compressor 300 is connected to the silencer chamber 440 through the air inlet pipe 310, and the air outlet end of the compressor 300 is connected to the air inlet end of the molecular sieve 200 through the air outlet pipe 320.

[0046] Please refer to Figure 1 In this embodiment, the oxygen generator 010 includes a molecular sieve 200 .

[0047] In this embodiment, the molecular sieve 200 includes at least one molecular sieve 200, which is arranged on the side wall of the compressor compartment 400; the molecular sieve 200 includes an air inlet end, a nitrogen outlet for discharging nitrogen, and an oxygen outlet for discharging oxygen. The nitrogen outlet is connected to the air inlet 102 of the muffler structure 100 through a pipeline, and the oxygen outlet is connected to the oxygen storage tank through a pipeline.

[0048] Specifically, the molecular sieve 200 is used to separate compressed air into oxygen and other gases. The air intake end of the compressor 300 extracts air and compresses it into high-pressure gas into the molecular sieve 200, and the molecular sieve 200 separates the air into oxygen and other gases, completes the oxygen production of the oxygen generator 010, and outputs the separated oxygen to the oxygen storage tank for storage, while other gases are discharged into the silencing structure 100 through the nitrogen exhaust port for noise reduction and then discharged.

[0049] Please refer to Figure 1In this embodiment, the oxygen concentrator 010 includes a compressor cabin 400 and a base 500 .

[0050] In this embodiment, a compressor compartment 400 is arranged on the top of the base 500, and the compressor compartment 400 is sealedly connected to the base 500 to ensure the sealing performance of the installation cavity 410 in the compressor compartment 400; it can be understood that the installation cavity 410 with better sealing performance can also further isolate the nitrogen exhaust noise.

[0051] In this embodiment, the compressor compartment 400 is a shell structure, which is sealed to form a sealed installation cavity 410, and a first opening and a second opening connected to the installation cavity 410 are provided on the shell structure; wherein the first opening is provided at the top of the compressor compartment 400 and is used for air intake in the installation cavity 410; wherein the second opening is provided at the bottom of the compressor compartment 400, and the installation cavity 410 is connected to the base 500 through the second opening for exhaust.

[0052] In this embodiment, a compressor 300 and a sound-absorbing structure 100 are arranged in the compressor compartment 400, and a molecular sieve 200 is arranged outside the compressor compartment 400; wherein the compressor 300 is installed in the installation cavity 410 of the compressor compartment 400 and is arranged in the compressor compartment 400 by means of a shock-absorbing spring. wherein the molecular sieve 200 is arranged on the outer side wall of the compressor compartment 400, and the sound-absorbing structure 100 is arranged on the inner side wall of the compressor compartment 400 and is arranged close to the molecular sieve 200.

[0053] Optionally, a pipe structure 420 is provided outside the compressor compartment 400. The pipe structure 420 is arranged along the outer wall of the compressor compartment 400 and forms a ventilation cavity inside to allow gas to pass through; one end of the pipe structure 420 is used for air intake, and the other end is connected to the installation cavity 410 through the first opening; at the same time, an exhaust piece 430 is also provided inside the pipe structure 420, and the exhaust piece 430 is arranged at the first opening.

[0054] Optionally, the exhaust member 430 may be a structure such as a blower or a fan that can drive the rapid flow of gas.

[0055] Optionally, the compressor compartment 400 is further provided with a third opening connected to the mounting cavity 410, and the third opening is provided at the top of the compressor compartment 400 and is used for the air intake pipe 310 of the compressor 300 to pass through. At the same time, a muffler chamber 440 is provided on the outer top wall of the compressor compartment 400, and the muffler chamber 440 is provided relative to the third opening, and the air intake end of the compressor 300 is connected to the outside through the muffler chamber 440.

[0056] In this embodiment, a cavity structure for silencing is provided in the base 500, and the base 500 is connected to the installation cavity 410 of the compressor compartment 400 through a second opening; it can be understood that the gas in the pipeline structure 420 is passed into the compressor compartment 400 through the exhaust piece 430 and dissipates heat and cools the compressor 300 in the compressor compartment 400, and the cooled gas enters the base 500 through the second opening for silencing and noise reduction before being discharged.

[0057] Please refer to Figure 1 In this embodiment, the oxygen concentrator 010 includes a sound-absorbing structure 100 .

[0058] Please refer to Figure 2-Figure 4 A sound-absorbing structure 100 proposed in this embodiment includes a shell 101, in which a first sound-absorbing unit 110 and a second sound-absorbing unit 120 are arranged; a sound-absorbing member 104 is arranged in the first sound-absorbing unit 110; the second sound-absorbing unit 120 includes at least two levels of expansion chambers 121, and corresponding air holes are arranged between each adjacent expansion chamber 121 to form a gas bending flow channel; wherein, the gas enters from the first sound-absorbing unit 110 and passes through the sound-absorbing member 104, then enters each level of expansion chamber 121 and is discharged from the shell 101 through the gas bending flow channel.

[0059] Further, refer to Figure 1 , Figure 1 The arrow in the figure indicates the direction of air flow. The first muffler unit 110 is connected to the exhaust port of the external device. The airflow enters the second muffler unit 120 after the first muffler unit 110, and then enters the expansion chambers 121 at each level and is discharged from the housing 101 after passing through the gas bending channel. The exhaust port of the external device is the nitrogen outlet of the molecular sieve 200 of the oxygen generator 010.

[0060] It can be understood that by arranging the sound absorbing member 104 in the first silencer unit 110, the sound absorbing member 104 can perform resistive silence on the airflow; by arranging at least two stages of expansion chambers 121 in the second silencer unit 120, at least two stages of expansion chambers 121 can reduce the wind resistance of the airflow entering the gas bending flow channel, and resistive silence is performed on the airflow entering the gas bending flow channel; the silencer structure 100 arranged in this way combines the first silencer unit 110 and the second silencer unit 120, realizes impedance composite silencer, reduces nitrogen exhaust noise, and solves the technical problem of poor effect of existing nitrogen exhaust silencer structures.

[0061] In this embodiment, the sound absorption structure 100 includes a shell 101 .

[0062] In this embodiment, please refer to Figure 2 The shell 101 includes an upper shell 1011 and a lower shell 1012 , and the upper shell 1011 and the lower shell 1012 are installed to form an internal cavity; the cavity forms a first muffler unit 110 and at least two second muffler units 120 .

[0063] Among them, an air inlet 102 is provided at one end of the first sound-absorbing unit 110, at least two second sound-absorbing units 120 are respectively connected to at least two connecting ports 128 and are connected to the first sound-absorbing unit 110, and an air outlet 103 is provided at one end of the second sound-absorbing unit 120 away from the connecting port 128; at the same time, at least two levels of expansion chambers 121 are formed in the second sound-absorbing unit 120, and corresponding air holes are arranged between each adjacent expansion chamber 121 to form a gas bending flow channel.

[0064] Wherein, an air intake pipe 310 structure is provided at the air intake port 102 .

[0065] Optionally, the at least two-stage expansion chamber 121 includes a first-stage expansion chamber and at least one second-stage expansion chamber which are connected in sequence, and the at least one second-stage expansion chamber is at least arranged at the end of the first-stage expansion chamber; the first-stage expansion chamber and the at least one second-stage expansion chamber form a gas bending flow channel, and the gas flows in the gas bending flow channel and the wind resistance of the gas gradually decreases, thereby realizing the resistance to silencing of the airflow.

[0066] The expansion chamber 121 can be provided with two or three stages, etc., and can be specifically provided according to the model of the oxygen concentrator 010 to achieve the best noise reduction effect. Accordingly, the expansion chambers 121 are connected through the connection port 128 .

[0067] In this embodiment, please refer to Figure 3 and Figure 4 A first expansion chamber 111 is formed in the first muffler unit 110; the expansion chamber 121 in the second muffler unit 120 includes a primary expansion chamber and two secondary expansion chambers, and the two secondary expansion chambers are symmetrically arranged on both sides of the end of the primary expansion chamber.

[0068] A first expansion chamber 111 is formed in the first muffler unit 110 , and an air inlet 102 is provided in the first expansion chamber 111 .

[0069] The first-stage expansion chamber in the second muffler unit 120 includes a second expansion chamber 122 and a third expansion chamber 123 which are connected in sequence; the second expansion chamber 122 is connected to the first expansion chamber 111; and the third expansion chamber 123 is provided with two connection ports 128. The two connection ports 128 are relatively symmetrically arranged on both sides of the third expansion chamber 123.

[0070] Among them, one of the second muffler units 120 is provided with a fourth expansion chamber 124 and a fifth expansion chamber 125 which are connected in sequence, the fourth expansion chamber 124 is connected with one of the third expansion chambers 123 through a connecting port 128, and the fifth expansion chamber 125 is provided with an air outlet 103.

[0071] Among them, another second muffler unit 120 is provided with a sixth expansion chamber 126 and a seventh expansion chamber 127 which are connected in sequence. The sixth expansion chamber 126 is connected with the third expansion chamber 123 through a connecting port 128 , and the seventh expansion chamber 127 is provided with an air outlet 103 .

[0072] In this embodiment, please refer to Figure 2 and Figure 3 , the air outlet 103 includes a plurality of exhaust holes arranged in a matrix. Of course, in other embodiments, the air outlet 103 includes a plurality of exhaust holes arranged in a ring shape.

[0073] In this embodiment, please refer to Figure 3 and Figure 4 The multiple expansion chambers 121 can be a rectangular structure or a cylindrical structure, and the multiple expansion chambers 121 are arranged at intervals; at the same time, the connecting port 128 can be set to a small-diameter pipe mouth structure, so as to achieve better resistance and soundproofing.

[0074] Among them, multiple expansion chambers 121 and small-diameter nozzle structures are formed by connecting the upper shell 1011 and the lower shell 1012.

[0075] Please refer to Figure 4 In this embodiment, the sound absorption structure 100 includes a sound absorbing member 104 .

[0076] Optionally, the sound absorbing member 104 is a porous sound absorbing material or a sound absorbing structure, the sound absorbing member 104. The porous sound absorbing material may be sound absorbing cotton, glass fiber, low carbon steel wire mesh, felt, etc. The sound absorbing structure may be a honeycomb structure, a multilayer board structure, etc. arranged in the cavity.

[0077] In this embodiment, please refer to Figure 4 , the sound absorbing member 104 is arranged in the first expansion chamber 111 .

[0078] The working principles of the noise elimination structure 100 and the oxygen generator 010 proposed in this embodiment are:

[0079] When the compressor 300 is working, the gas is sucked into the air inlet of the compressor 300 from the muffler chamber 440 and the air inlet pipe 310. The compressor 300 compresses the gas after sucking it in, and introduces the compressed air into the molecular sieve 200 from the air outlet of the compressor 300 for separation. The molecular sieve 200 separates the compressed air into oxygen and other gases, completes the oxygen production of the oxygen generator 010, and outputs the separated oxygen to the oxygen storage tank for storage, while other gases are discharged into the muffler structure 100 through the nitrogen exhaust port for noise reduction before being discharged.

[0080] The nitrogen exhaust port of the molecular sieve 200 discharges air flow, and the air flow enters the silencer structure 100 through the air inlet 102, and the air flow is in the first expansion chamber 111, and the sound absorbing member 104 in the first expansion chamber 111 performs resistive silence on the air flow; then the air flow flows from the first expansion chamber 111 to the second expansion chamber 122 and the third expansion chamber 123 in sequence, and the multiple expansion chambers 121 buffer and reduce noise for the air flow; the air flow is diverted in the third expansion chamber 123, and a part of the air flow is diverted to the fourth expansion chamber 124 and the fifth expansion chamber 125, and is discharged from the air outlet 103 at the fifth expansion chamber 125 to the installation cavity 410 of the compressor cabin 400; the other part of the air flow is diverted to the sixth expansion chamber 126 and the seventh expansion chamber 127, and is discharged from the air outlet 103 at the seventh expansion chamber 127 to the installation cavity 410 of the compressor cabin 400.

[0081] The airflow enters the installation cavity 410 , which can further isolate the nitrogen exhaust noise due to its good sealing performance; then the airflow enters the base 500 through the second opening and is exhausted.

[0082] In summary, the silencer structure 100 and the oxygen generator 010 proposed in the present invention perform resistive silence on the airflow by setting a sound absorbing member 104; and perform resistive silence on the airflow entering the cavity by setting a plurality of expansion chambers 121 that are spaced apart and connected to each other so as to reduce the wind resistance of the airflow entering the cavity; and the combination of the two realizes impedance composite silencer, reduces nitrogen exhaust noise, and solves the technical problem of poor effect of existing nitrogen exhaust silencer structures.

[0083] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A sound-absorbing structure, characterized in that: include: A shell, wherein a first muffler unit and a second muffler unit are arranged in the shell; A first sound-absorbing unit, wherein a sound-absorbing member is provided in the first sound-absorbing unit; A second muffler unit, the second muffler unit comprises at least two expansion chambers, and corresponding air holes are arranged between adjacent expansion chambers to form a gas bending flow channel; The gas enters from the first silencer unit and passes through the sound absorbing member, then enters the expansion chambers at each level and is discharged from the shell through the gas bending channel.

2. The sound-absorbing structure according to claim 1, characterized in that: The at least two-stage expansion chamber comprises a primary expansion chamber and at least one secondary expansion chamber which are connected in sequence, and the at least one secondary expansion chamber is at least arranged at the end of the primary expansion chamber.

3. The sound-absorbing structure according to claim 2, characterized in that: The first muffler unit includes a first expansion chamber; The primary expansion chamber comprises a second expansion chamber and a third expansion chamber which are connected in sequence, and the second expansion chamber is connected to the first expansion chamber; The secondary expansion chambers include two, and the two secondary expansion chambers are symmetrically arranged on both sides of the third expansion chamber.

4. The sound-absorbing structure according to claim 3, characterized in that: One of the secondary expansion chambers comprises a fourth expansion chamber and a fifth expansion chamber which are connected in sequence, the fourth expansion chamber is connected to the third expansion chamber, and the fifth expansion chamber is provided with an air outlet; Another of the second muffler units includes a sixth expansion chamber and a seventh expansion chamber which are connected in sequence, the sixth expansion chamber is connected to the third expansion chamber, and the seventh expansion chamber is provided with an air outlet.

5. The sound-absorbing structure according to claim 1, characterized in that: The air outlet comprises a plurality of exhaust holes arranged in a matrix or annular arrangement; The sound absorbing member is a porous sound absorbing material or a sound absorbing structure.

6. An oxygen concentrator, characterized in that: include: The sound-absorbing structure according to any one of claims 1 to 5; A molecular sieve is provided with a nitrogen exhaust port, and the nitrogen exhaust port is communicated with the first muffler unit.

7. The oxygen concentrator according to claim 6, characterized in that: The oxygen concentrator further comprises a compressor cabin and a base, wherein the compressor cabin is arranged on the top of the base; The compressor compartment is provided with a sealed installation cavity and a first opening and a second opening communicating with the installation cavity, the compressor compartment is provided with the muffler structure, and the air outlet of the muffler structure is communicated with the installation cavity; The first opening is used for air intake, and the installation cavity is connected with the base through the second opening for exhaust.

8. The oxygen concentrator according to claim 7, characterized in that: A pipeline structure is provided outside the compressor compartment, one end of the pipeline structure is used for air intake, and the other end is connected with the installation cavity through the first opening; An exhaust member is also provided in the pipeline structure, and the exhaust member is arranged at the first opening.

9. The oxygen concentrator according to claim 7, characterized in that: The molecular sieve is arranged on the outer side wall of the compressor compartment, and the muffler structure is arranged on the inner side wall of the compressor compartment and close to the molecular sieve.

10. The oxygen concentrator according to claim 7, characterized in that: The oxygen concentrator further comprises a compressor and a muffler compartment, wherein the compressor damping is arranged in the compressor compartment; The air outlet of the compressor is connected to the air inlet of the molecular sieve through a pipeline; The silencer chamber is arranged on the compressor compartment, and the air inlet end of the compressor is connected to the outside through the silencer chamber.

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