Air suspension compressor

Abstract

The present disclosure relates to an air suspension compressor, comprising: a casing (10); a motor rotor (30) arranged in the casing (10); an impeller (41, 42) connected to the end of the motor rotor (30) in the axial direction, and the air intake part is located on the side of the impeller (41, 42) away from the motor rotor (30); a diffuser (51, 52) arranged on the side of the impeller (41, 42) adjacent to the motor rotor (30); and a gas thrust bearing (21, 22) arranged on the diffuser (51, 52); wherein an axial gap is provided between the part of the impeller (41, 42) adjacent to the motor rotor (30) and the gas thrust bearing (21, 22), for forming a pressure gas film (90) located in the axial gap as a first sealing structure. The embodiment of the present disclosure can reduce the leakage of working gas in the compressor to the motor cavity.

Description

Technical Field

[0001] The present disclosure relates to the field of compressors, and in particular to an air suspension compressor. Background Art

[0002] The hydrodynamic gas suspension compressor is a compressor that uses hydrodynamic gas bearings to support the rotor. It is very popular due to its high limit speed, adaptive stability and other advantages. The hydrodynamic gas suspension compressor technology has become the research frontier in the compressor field.

[0003] The dynamic pressure air suspension compressor realizes the process of gas compression through the impeller, diffuser, volute and other structures. The dynamic pressure air suspension compressor has the problem of gas leakage during operation, and the gas leakage problem comes from the axial gap behind the impeller. There are many tiny axial gaps behind the impeller leading to the motor cavity, and the leaked gas will eventually flow into the motor cavity. The leaked gas will increase the power consumption of the compressor and reduce the efficiency.

[0004] In order to solve the above leakage problem, some related technologies use a comb-tooth structure for sealing (also known as a comb-tooth sealing method). When the leaked gas passes through the comb-tooth structure, the gas is throttled multiple times in the process of passing through the comb-tooth structure, thereby losing energy and reducing pressure. In this way, the comb-tooth structure can achieve a sealing effect by multiple decompressions, but the sealing effect of the comb-tooth structure can only reduce gas leakage to a certain extent. Summary of the invention

[0005] In view of this, an embodiment of the present disclosure provides an air suspension compressor, which can reduce the leakage of working gas into the motor cavity.

[0006] In one aspect of the present disclosure, there is provided an air suspension compressor, comprising:

[0007] chassis;

[0008] A motor rotor is arranged in the housing;

[0009] An impeller connected to the end of the motor rotor in the axial direction, and an air inlet portion is located on a side of the impeller away from the motor rotor;

[0010] a diffuser disposed on a side of the impeller adjacent to the motor rotor; and

[0011] a gas thrust bearing, disposed on the diffuser;

[0012] There is an axial gap between the portion of the impeller adjacent to one side of the motor rotor and the gas thrust bearing, which is used to form a pressure gas film as a first sealing structure in the axial gap.

[0013] In some embodiments, the gas thrust bearing comprises a hydrodynamic gas thrust bearing.

[0014] In some embodiments, the air suspension compressor further includes a volute, and a gas passage between the volute and the diffuser and the air inlet portion of the impeller is in communication with the axial gap.

[0015] In some embodiments, the axial gap is 20-50 μm.

[0016] In some embodiments, a groove which is concave inwardly along the axial direction of the motor rotor is provided on a side surface of the diffuser adjacent to the impeller, and the gas thrust bearing is fixedly disposed at the bottom of the groove.

[0017] In some embodiments, the bottom of the groove is in a circular ring shape, the inner diameter of the bottom of the groove is larger than the diameter of the connection portion between the motor rotor and the impeller, and the outer diameter of the bottom of the groove is larger than the diameter of the impeller.

[0018] In some embodiments, the gas thrust bearing is annular, the outer diameter of the gas thrust bearing is less than or equal to the outer diameter of the bottom of the groove, and the inner diameter of the gas thrust bearing is larger than the diameter of the connection portion between the motor rotor and the impeller.

[0019] In some embodiments, a surface of the gas thrust bearing adjacent to the bottom of the groove is in close contact with the bottom of the groove and is fixedly connected to the diffuser via a connecting member.

[0020] In some embodiments, a portion of the diffuser radially adjacent to the motor rotor has a second sealing structure.

[0021] In some embodiments, the second sealing structure includes a plurality of comb teeth arranged at intervals along the axial direction of the motor rotor.

[0022] In some embodiments, the air suspension compressor comprises:

[0023] The two impellers, serving as a primary impeller and a secondary impeller, are respectively connected to two ends of the motor rotor along the axial direction;

[0024] The two diffusers, as a first-stage diffuser and a second-stage diffuser, are respectively located on one side of the first-stage impeller and the second-stage impeller adjacent to the motor rotor, and are respectively fixedly connected to two ends of the casing;

[0025] The two gas thrust bearings, as a primary gas thrust bearing and a secondary gas thrust bearing, are respectively arranged on the primary diffuser and the secondary diffuser;

[0026] The two volutes serve as a primary volute and a secondary volute and are connected through a pipeline so that the working gas output from the primary volute is input into the secondary volute for secondary work.

[0027] In some embodiments, the air suspension compressor also includes: a casing, a motor stator, a bearing seat and a radial bearing, the motor stator and the bearing seat are fixed in the casing, the motor rotor is arranged at the center of the motor stator, and the radial bearing is connected between the motor rotor and the bearing seat, and the volute is fixedly connected to the casing.

[0028] Therefore, according to the embodiment of the present disclosure, an axial gap is set between the part of the impeller adjacent to the motor rotor side and the gas thrust bearing, and a pressure gas film is formed in the axial gap when the compressor is working. The pressure gas film is used as the first sealing structure to achieve sealing, thereby reducing the amount of gas leaking into the motor cavity, thereby improving the sealing effect between the impeller side and the motor cavity. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The accompanying drawings, which constitute a part of the specification, illustrate embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0030] The present disclosure may be more clearly understood from the following detailed description with reference to the accompanying drawings, in which:

[0031] Figure 1 is a schematic structural diagram of some embodiments of the air suspension compressor according to the present disclosure;

[0032] Figure 2 yes Figure 1 A partial enlarged schematic diagram of the middle circle A;

[0033] Figure 3 yes Figure 1 A partial enlarged schematic diagram of the middle circle B.

[0034] It should be understood that the size of each part shown in the accompanying drawings is not drawn according to the actual proportional relationship. In addition, the same or similar reference numerals represent the same or similar components. DETAILED DESCRIPTION

[0035] Various exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. The description of the exemplary embodiments is merely illustrative and is in no way intended to limit the present disclosure and its application or use. The present disclosure can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided to make the present disclosure thorough and complete and to fully express the scope of the present disclosure to those skilled in the art. It should be noted that unless otherwise specifically stated, the relative arrangement of the components and steps, the composition of the materials, the numerical expressions and the numerical values ​​set forth in these embodiments should be interpreted as being merely exemplary and not as limiting.

[0036] The words "first", "second" and similar words used in this disclosure do not indicate any order, quantity or importance, but are only used to distinguish different parts. The words "include" or "comprise" and similar words mean that the elements before the word include the elements listed after the word, and do not exclude the possibility of including other elements. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0037] In the present disclosure, when a specific device is described as being located between a first device and a second device, there may or may not be an intermediate device between the specific device and the first device or the second device. When a specific device is described as being connected to other devices, the specific device may be directly connected to the other device without an intermediate device, or may not be directly connected to the other device but have an intermediate device.

[0038] All terms (including technical terms or scientific terms) used in the present disclosure have the same meanings as those understood by ordinary technicians in the field to which the present disclosure belongs, unless otherwise specifically defined. It should also be understood that terms defined in general dictionaries, such as general dictionaries, should be interpreted as having meanings consistent with their meanings in the context of the relevant technology, and should not be interpreted in an idealized or extremely formal sense, unless explicitly defined herein.

[0039] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered as part of the specification.

[0040] like Figure 1 , which is a schematic diagram of the structure of some embodiments of the air suspension compressor according to the present disclosure. Figure 1 , and combined with reference Figure 2 and Figure 3 In some embodiments, the air suspension compressor includes: a casing 10, a motor rotor 30, an impeller, a diffuser and a gas thrust bearing. The casing 10 may be an irregular cavity part, which may be formed by casting and play the role of support, protection, shock absorption and the like. The motor rotor 30 is arranged in the casing 10. In order to drive the motor rotor 30 to rotate, a motor stator 60 including a winding may be arranged in the casing 10 of the air suspension compressor, which can provide a magnetic field to the motor rotor, so that the motor rotor rotates at high speed in the magnetic field. The motor stator and the motor rotor may be cooled by refrigerant gas inside the casing 10.

[0041] The impeller is connected to the end of the motor rotor 30 in the axial direction, and the air inlet portion is located on the side of the impeller away from the motor rotor 30. The diffuser is arranged on the side of the impeller adjacent to the motor rotor 30. The gas thrust bearing is arranged on the diffuser. An axial gap is provided between the portion of the impeller adjacent to the motor rotor 30 and the gas thrust bearing, which is used to form a pressure gas film 90 (at the first sealing structure) located in the axial gap. Figure 2 and Figure 3 The ellipse in the figure is used to schematically represent the internal circulating pressure gas flow. The size of the axial gap is preferably 20 to 50 μm, that is, the distance from the gas thrust bearing to the back of the impeller along the axis of the motor rotor.

[0042] In this embodiment, a pressure gas film is formed in the axial gap when the compressor is working, and the pressure gas film is used as the first sealing structure to achieve sealing, so that the gas leaked behind the impeller enters the motor cavity less, thereby improving the sealing effect between the axial gap behind the impeller and the motor cavity. On the other hand, in this embodiment, the thrust plate can be eliminated, and the function of the thrust plate can be achieved by the impeller. When the motor rotor moves axially, the pressure gas film can act on the impeller to offset the axial force causing the axial movement, so that the motor rotor remains balanced in the axial direction.

[0043] refer to Figure 1 In some embodiments, the gas thrust bearing includes a hydrodynamic gas thrust bearing. A better sealing effect can be achieved through the characteristics of the hydrodynamic gas thrust bearing. For the hydrodynamic gas thrust bearing, a wedge-shaped space can be formed between it and the back of the impeller. When the rotor rotates at high speed, it drives the gas to move, and continuously presses the gas into the wedge-shaped space, so that a high-pressure hydrodynamic gas film is formed in the tiny axial gap between the rotating impeller and the thrust bearing. This pressure gas film 90 can greatly reduce the leakage of gas from the back side of the impeller to the motor cavity, thereby reducing the power consumption of the compressor caused by leakage and improving the efficiency of the compressor.

[0044] exist Figure 1 In the embodiment, the air suspension compressor further comprises a volute. The gas passage between the volute and the air inlet portion of the diffuser and the impeller can be communicated with the axial gap, so that when the motor rotor rotates at a high speed relative to the dynamic pressure gas thrust bearing, the gas in the gas passage between the volute and the air inlet portion of the diffuser and the impeller is introduced into the axial gap between the dynamic pressure gas thrust bearing and the back of the impeller to form a pressure gas film.

[0045] refer to Figure 1In some embodiments, the air suspension compressor may include: the two impellers 41 and 42 as the first-stage impeller and the second-stage impeller, the two diffusers 51 and 52 as the first-stage diffuser and the second-stage diffuser, the two diffusers 51 and 52 as the first-stage diffuser and the second-stage diffuser, the two gas thrust bearings 21 and 22 as the first-stage gas thrust bearing and the second-stage gas thrust bearing, and the two volutes 11 and 12 as the first-stage volute and the second-stage volute.

[0046] The impellers 41 and 42 are respectively connected to the two ends of the motor rotor 30 in the axial direction, and can respectively do work on the working gas entering the volutes 11 and 12. The impellers 41 and 42, which serve as the first-stage impeller and the second-stage impeller, can be used as thrust plates to maintain the axial position of the motor rotor 30. When the motor rotor moves axially, the high-pressure dynamic pressure film formed between the impeller and the dynamic pressure gas thrust bearing can act on the impeller to adjust the axial position of the motor rotor so that the motor rotor maintains a balanced state. In other embodiments, the thrust plate can be eliminated at one end of the motor rotor and the impeller can be used as the thrust plate, while the thrust plate is still used at the other end to cooperate with the impeller to keep the motor rotor in a balanced state.

[0047] The diffusers 51 and 52 are respectively located on one side of the first-stage impeller and the second-stage impeller adjacent to the motor rotor 30, and are respectively fixedly connected to both ends of the housing 10 along the axis direction of the motor rotor 30. The diffusers 51 and 52 can respectively diffuse the working gas that has been worked by the impellers 41 and 42 to form a working gas with a higher pressure.

[0048] The gas thrust bearings 21 and 22 are respectively arranged on the first-stage diffuser and the second-stage diffuser. When the impellers 41 and 42 are driven by the motor rotor 30 to rotate at high speed, a pressure gas film 90 can be formed between the gas thrust bearing 21 and the impeller 41 and between the gas thrust bearing 22 and the impeller 42, and the axial gap between the adjacent gas thrust bearings and the impeller is blocked by the pressure gas film 90, thereby achieving a certain sealing effect.

[0049] The volutes 11 and 12 are connected by a pipeline. The volute 11 as a primary volute can inhale working gas (such as gas refrigerant), and the primary impeller and the primary diffuser can work on the working gas to compress the working gas. The compressed working gas is input into the volute 12 as a secondary volute through a pipeline, and the secondary impeller and the secondary diffuser perform secondary work. The secondary volute can output the working gas after the secondary diffuser is expanded through its own outlet.

[0050] In addition, refer to Figure 1The air suspension compressor may further include: a motor stator 60, a bearing seat and a radial bearing. The motor stator 60 and the bearing seat are fixed in the housing 10, the motor rotor 30 is arranged at the center of the motor stator 60, and the radial bearing is connected between the motor rotor 30 and the bearing seat, and the volute and the diffuser are both fixedly connected to the housing 10. The bearing seat can play a role in fixing the radial bearing in the housing 10.

[0051] exist Figure 1 In the embodiment, for the motor rotor 30, two radial bearings 81 and 82 may be arranged in the axial direction thereof to achieve stable support of the motor rotor 30. The inner rings of the radial bearings 81 and 82 may be fixedly connected to the motor rotor 30. Accordingly, two bearing seats 71 and 72 may be provided to fix the outer rings of the radial bearings 81 and 82. The volutes 11 and 12 may be fixedly connected to the two ends of the housing 10 along the axial direction of the motor rotor 30, respectively.

[0052] refer to Figure 2 and Figure 3 In some embodiments, a side surface of the diffuser 51 adjacent to the impeller 41 is provided with a groove 51b that is concave in the axial direction of the motor rotor 30, and the concave direction is away from the impeller 41. A side surface of the diffuser 52 adjacent to the impeller 42 is provided with a groove 52b that is concave in the axial direction of the motor rotor 30, and the concave direction is away from the impeller 42. The gas thrust bearings 21 and 22 are fixedly disposed at the bottom of the grooves 51b and 52b, respectively.

[0053] In order not to affect the rotation of the motor rotor, the diffuser is provided with a through hole through which the power supply rotor passes. Accordingly, the bottom of the groove can be in the shape of a circular ring, and the through hole is the inner circle of the circular ring, and its diameter is larger than the diameter of the connection part between the motor rotor 30 and the impeller, so as to avoid interference with the rotation of the motor rotor 30. In addition, the outer diameter of the bottom of the groove is larger than the diameter of the impeller, so that the back of the impeller can partially enter the groove to control the appropriate size of the axial gap, and also can reduce the overall axial size including the impeller and the motor rotor.

[0054] In order to make the gas thrust bearing work more reliably, the surface of the gas thrust bearing adjacent to the bottom of the groove can be closely attached to the bottom of the groove, and fixedly connected to the diffuser through a connecting piece (such as a threaded piece). The gas thrust bearing can also be in a circular ring shape, and its outer diameter is less than or equal to the outer diameter of the bottom of the groove. The inner diameter of the gas thrust bearing is larger than the diameter of the connection part between the motor rotor 30 and the impeller. In some embodiments, the inner diameter of the gas thrust bearing can be the same as the diameter of the through hole of the diffuser to form a larger area of ​​pressure gas film and obtain better working stability. In other embodiments, the inner diameter of the gas thrust bearing can also be different from the through hole diameter of the diffuser.

[0055] To further improve the sealing performance, refer to Figure 2 and Figure 3 In some embodiments, the diffuser may further include a second sealing structure at a portion radially adjacent to the motor rotor 30. The second sealing structure may cooperate with the pressure gas film 90 as the first sealing structure to achieve a better sealing effect and reduce the leakage of the working gas into the motor cavity. In some embodiments, the second sealing structure may include a plurality of comb teeth arranged at intervals along the axial direction of the motor rotor 30. The comb teeth sealing structure may further reduce the leakage of the working gas into the motor cavity.

[0056] exist Figure 2 In the embodiment, the second sealing structure 51a is located at the portion of the diffuser 51 adjacent to the motor rotor 30 in the radial direction, that is, on the hole wall of the through hole of the diffuser 51. The second sealing structure 52b is located at the portion of the diffuser 52 adjacent to the motor rotor 30 in the radial direction, that is, on the hole wall of the through hole of the diffuser 52.

[0057] So far, various embodiments of the present disclosure have been described in detail. In order to avoid obscuring the concept of the present disclosure, some details known in the art are not described. Based on the above description, those skilled in the art can fully understand how to implement the technical solution disclosed here.

[0058] Although some specific embodiments of the present disclosure have been described in detail by way of examples, it should be understood by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present disclosure. It should be understood by those skilled in the art that the above embodiments may be modified or some technical features may be replaced by equivalents without departing from the scope and spirit of the present disclosure. The scope of the present disclosure is defined by the appended claims.

Claims

1. An air suspension compressor, characterized in that: include: Housing (10); A motor rotor (30) is arranged in the casing (10); An impeller (41, 42) connected to an end of the motor rotor (30) in the axial direction, and an air intake portion is located on a side of the impeller (41, 42) away from the motor rotor (30); A diffuser (51, 52) is arranged on a side of the impeller (41, 42) adjacent to the motor rotor (30); volute (11, 12); and A gas thrust bearing (21, 22) arranged on the diffuser (51, 52); An axial gap is provided between a portion of the impeller (41, 42) adjacent to one side of the motor rotor (30) and the gas thrust bearing (21, 22), for forming a pressure gas film (90) located in the axial gap as a first sealing structure; a gas passage between the volute (11, 12) and the diffuser (51, 52) and the air inlet portion of the impeller (41, 42) is connected to the axial gap, so that gas in the gas passage between the volute (11, 12) and the diffuser (51, 52) and the air inlet portion of the impeller (41, 42) is introduced into the axial gap between the gas thrust bearing (21, 22) and the back of the impeller (41, 42), so as to form the pressure gas film (90).

2. The air suspension compressor according to claim 1, characterized in that: The gas thrust bearing (21, 22) comprises a dynamic pressure gas thrust bearing.

3. The air suspension compressor according to claim 2, characterized in that: The axial gap is 20-50 μm.

4. The air suspension compressor according to claim 1, characterized in that: A groove (51b, 52b) concave inwardly along the axial direction of the motor rotor (30) is provided on a side surface of the diffuser (51, 52) adjacent to the impeller (41, 42), and the gas thrust bearing (21, 22) is fixedly arranged at the bottom of the groove (51b, 52b).

5. The air suspension compressor according to claim 4, characterized in that: The bottom of the groove (51b, 52b) is in the shape of a ring, the inner diameter of the bottom of the groove (51b, 52b) is larger than the diameter of the connection portion between the motor rotor (30) and the impeller (41, 42), and the outer diameter of the bottom of the groove (51b, 52b) is larger than the diameter of the impeller (41, 42).

6. The air suspension compressor according to claim 5, characterized in that: The gas thrust bearing (21, 22) is in the form of a circular ring, the outer diameter of the gas thrust bearing (21, 22) is less than or equal to the outer diameter of the bottom of the groove (51b, 52b), and the inner diameter of the gas thrust bearing (21, 22) is greater than the diameter of the connection portion between the motor rotor (30) and the impeller (41, 42).

7. The air suspension compressor according to claim 4, characterized in that: The surface of the gas thrust bearing (21, 22) adjacent to the bottom of the groove (51b, 52b) is in close contact with the bottom of the groove (51b, 52b) and is fixedly connected to the diffuser (51, 52) via a connecting piece.

8. The air suspension compressor according to claim 1, characterized in that: The diffuser (51, 52) has a second sealing structure (51a, 52a) at a portion radially adjacent to the motor rotor (30).

9. The air suspension compressor according to claim 8, characterized in that: The second sealing structure (51a, 52a) comprises a plurality of comb teeth arranged at intervals along the axial direction of the motor rotor (30).

10. The air suspension compressor according to claim 1, characterized in that: The air suspension compressor comprises: The two impellers (41, 42), serving as a primary impeller and a secondary impeller, are respectively connected to two ends of the motor rotor (30) along the axial direction; The two diffusers (51, 52), serving as a first-stage diffuser and a second-stage diffuser, are respectively located on one side of the first-stage impeller and the second-stage impeller adjacent to the motor rotor (30), and are respectively fixedly connected to two ends of the casing (10); The two gas thrust bearings (21, 22) serve as a first-stage gas thrust bearing and a second-stage gas thrust bearing, and are respectively arranged on the first-stage diffuser and the second-stage diffuser; The two volutes (11, 12) serve as a primary volute and a secondary volute and are connected via a pipeline so that the working gas output from the primary volute is input into the secondary volute to perform secondary work.

11. The air suspension compressor according to claim 1, characterized in that: Also includes: A motor stator (60), a bearing seat (71, 72) and a radial bearing (81, 82), wherein the motor stator (60) and the bearing seat (71, 72) are fixed in the casing (10), the motor rotor (30) is arranged at the center of the motor stator (60), and the radial bearing (81, 82) is connected between the motor rotor (30) and the bearing seat (71, 72), and the volute (11, 12) is fixedly connected to the casing (10).

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