Axial gas bearings, compressors and air conditioning units

Abstract

The present invention relates to an axial gas bearing, a compressor and an air conditioning unit, wherein the axial gas bearing comprises a bearing shell (21), a bump foil (22) and a top foil (23), the bump foil (22) and the top foil (23) are both arranged on the side of the same axial end face of the bearing shell (21), and the bump foil (22) is located between the bearing shell (21) and the top foil (23), the bump foil (22) comprises a first pressure-bearing area (221) and a second pressure-bearing area (222) arranged along the circumference of the bearing shell (21), the first pressure-bearing area (221) and the second pressure-bearing area (222) are configured to at least partially absorb the force transmitted from the top foil (23), and the first pressure-bearing area (221) and the second pressure-bearing area (222) have different pressure resistance. The axial gas bearing of the present invention has different bearing stiffnesses, can adapt to different rotation speeds of the rotor, and has high reliability.

Description

Technical Field

[0001] The invention relates to the technical field of bearings, and in particular to an axial gas bearing, a compressor and an air conditioning unit. Background Art

[0002] Bearings are essential basic components in rotating machinery. Common bearings include rolling bearings, sliding bearings, and magnetic bearings. With the development of science and technology, people have put forward higher requirements for bearings in terms of oil-free and high precision, and new air bearings have emerged.

[0003] Air bearings are divided into static gas bearings and dynamic gas bearings according to the different mechanisms of lubricating gas film generation. The corrugated foil type dynamic gas thrust bearing is a type of dynamic gas bearing, which is mainly composed of a bearing housing, corrugated foil and top foil, etc., and provides axial stiffness and damping for the rotor system. Similar to lubricating oil thrust bearings, the top foil of the corrugated foil type dynamic gas thrust bearing can act as a pad of the thrust bearing. The corrugated foil under the top foil has a special corrugated structure, which plays an elastic support role and is the main source of stiffness and damping of the thrust bearing.

[0004] One end of the wave foil and the top foil is fixed on the bearing seat, and the other end is free. There is a convergence angle between the front end of the top foil and the bearing housing, and the rear end of the top foil is parallel to the bearing housing. When the rotor rotates at high speed, a dynamic pressure air film is formed under the action of the above-mentioned convergence angle to support the rotor.

[0005] The key to the working of the corrugated foil type hydrodynamic gas thrust bearing is to form a hydrodynamic gas film, but the rotation speed of the rotor is variable, and sometimes the hydrodynamic gas film cannot be formed, resulting in dry friction between the bearing and the rotor, which greatly affects the life of the bearing.

[0006] It should be noted that the information disclosed in the background technology section of the present invention is only intended to increase the understanding of the overall background of the present invention, and should not be regarded as acknowledging or suggesting in any form that the information constitutes prior art already known to those skilled in the art. Summary of the invention

[0007] The purpose of the present invention is to provide an axial gas bearing, a compressor and an air conditioning unit, so as to improve the adaptability of the axial gas bearing.

[0008] To achieve the above object, the present invention provides an axial gas bearing, comprising:

[0009] Bearing housing;

[0010] The bump foil and the top foil are both arranged on the side surfaces of the same axial end surface of the bearing housing, and the bump foil is located between the bearing housing and the top foil. The bump foil includes a first pressure-bearing area and a second pressure-bearing area arranged along the circumference of the bearing housing. The first pressure-bearing area and the second pressure-bearing area are configured to at least partially absorb the force transmitted from the top foil, and the first pressure-bearing area and the second pressure-bearing area have different pressure resistance.

[0011] In some embodiments, the top foil includes a third pressure-bearing area and a fourth pressure-bearing area, the third pressure-bearing area is located at a side of the first pressure-bearing area and contacts the first pressure-bearing area, and the fourth pressure-bearing area is located at a side of the second pressure-bearing area and contacts the second pressure-bearing area.

[0012] In some embodiments, the first pressure-bearing area includes a first upstream end located upstream, the third pressure-bearing area includes a third upstream end located upstream, the first upstream end and the third upstream end gradually approach the bearing housing along the direction from downstream to upstream, the second pressure-bearing area includes a second upstream end located upstream, the fourth pressure-bearing area includes a fourth upstream end located upstream, the second upstream end and the fourth upstream end gradually approach the bearing housing along the direction from downstream to upstream, the lengths of the first upstream end and the third upstream end are different from the lengths of the second upstream end and the fourth upstream end; and / or, the inclination angle of the third upstream end relative to the bearing housing is different from the inclination angle of the fourth upstream end relative to the bearing housing.

[0013] In some embodiments, the first pressure-bearing area includes a plurality of first pressure-bearing segments arched toward the top foil, the second pressure-bearing area includes a plurality of second pressure-bearing segments arched toward the top foil, and the axial distance between the first pressure-bearing segments and the bearing shell is different from the axial distance between the second pressure-bearing segments and the bearing shell.

[0014] In some embodiments, the first pressure-bearing area includes a plurality of first pressure-bearing segments arched toward the top foil, and the second pressure-bearing area includes a plurality of second pressure-bearing segments arched toward the top foil, and the projection lengths of the first pressure-bearing segments on the circumferential inner side surface of the bearing shell and the projection lengths of the second pressure-bearing segments on the circumferential inner side surface of the bearing shell are different.

[0015] In some embodiments, the first pressure-bearing area includes a plurality of first pressure-bearing segments arched toward the top foil, and the first pressure-bearing segments extend in a direction deviating from the center of the bearing housing; and / or, the second pressure-bearing area includes a plurality of second pressure-bearing segments arched toward the top foil, and the second pressure-bearing segments extend in a direction deviating from the center of the bearing housing.

[0016] In some embodiments, the first pressure-bearing area and / or the second pressure-bearing area is fan-shaped.

[0017] In some embodiments, the number of the first pressure-bearing region and the number of the second pressure-bearing region are both plural, and the first pressure-bearing region and the second pressure-bearing region are arranged at intervals.

[0018] In some embodiments, the number of first pressure-bearing regions and the number of second pressure-bearing regions are equal.

[0019] In some embodiments, the number of the first pressure-bearing regions and the number of the second pressure-bearing regions are both even numbers.

[0020] To achieve the above object, the present invention also provides a compressor, comprising the above axial gas bearing.

[0021] To achieve the above object, the present invention also provides an air conditioning unit, comprising the above compressor.

[0022] Based on the above technical solution, the wave foil in the embodiment of the present invention includes two pressure-bearing areas with different pressure resistance arranged along the circumference of the bearing shell. In this way, the bearing can have different load-bearing stiffness, improve the bearing's adaptability to different rotor speeds, improve the bearing's reliability, avoid dry friction between the bearing and the rotor, and help to increase the service life of the bearing. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0024] Figure 1 It is a front view of an embodiment of an axial gas bearing of the present invention.

[0025] Figure 2 It is a partial cross-sectional view of an embodiment of an axial gas bearing of the present invention.

[0026] Figure 3 It is a schematic diagram of the structure of the corrugated foil in one embodiment of the axial gas bearing of the present invention.

[0027] Figure 4 This is a schematic diagram from another angle of the corrugated foil in one embodiment of the axial gas bearing of the present invention.

[0028] Figure 5 It is a schematic diagram of the structure of the top foil in one embodiment of the axial gas bearing of the present invention.

[0029] Figure 6 This is a schematic diagram from another angle of the top foil in one embodiment of the axial gas bearing of the present invention.

[0030] Figure 7 for Figure 1 Cross-sectional view along the AA direction.

[0031] Figure 8 for Figure 7 A partial enlarged view of the structure.

[0032] Fig. 9 for Figure 1 Cross-sectional view along the BB direction.

[0033] Fig.10 for Figure 8 A partial enlarged view of the structure.

[0034] In the figure:

[0035] 10. rotor; 11. rotating shaft; 12. thrust plate;

[0036] 20. bearing; 21. bearing housing; 22. corrugated foil; 23. top foil;

[0037] 221, first pressure-bearing area; 222, second pressure-bearing area; 2211, first upstream end; 2221, second upstream end;

[0038] 231, third pressure bearing area; 232, fourth pressure bearing area;

[0039] 30. First gap; 40. Second gap; 50. First wedge-shaped area; 60. Second wedge-shaped area. DETAILED DESCRIPTION

[0040] The technical solutions in the embodiments will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. 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.

[0041] In the description of the present invention, it should be understood that the terms "center", "lateral", "longitudinal", "front", "back", "left", "right", "up", "down", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the scope of protection of the present invention.

[0042] The inventors have conducted a careful analysis of the problem of poor adaptability of the bearing structure in the prior art to the rotor speed. The inventors found that the main reason for the above problems in the existing bearing structure is that it adopts a single corrugated foil and top foil structure. Once the bearing is assembled, its convergence angle is unique, and the strength adaptability of the formed dynamic pressure film is limited. In actual work, the working state of the rotor system is changing, which can be roughly divided into startup, operation, shutdown, etc. For the startup process, the dynamic pressure film has not been formed at this time, so dry friction between the rotor and the bearing will occur; for the operation process, the dynamic pressure film has been formed at this time, but for the machine, its operating speed is not constant. The bearing stiffness required by the rotor system generally increases with the speed change, especially when a variable frequency motor is used and it needs to run at a frequently variable speed. At this time, the bearing with a single corrugated foil and top foil structure will be difficult to adapt. The shutdown process is manifested as a gradual decrease in speed, which belongs to the variable speed situation. The situation is similar to the operation process, so there is also a matching transition problem between the bearing stiffness and the speed.

[0043] Based on the above analysis, the inventors have made structural improvements to the bearing.

[0044] refer to Figures 1 to 4 As shown, in one embodiment of the axial gas bearing provided by the present invention, the axial gas bearing includes a bearing shell 21, a top foil 23 and a bump foil 22, the top foil 23 and the bump foil 22 are both arranged on the side of the same axial end face of the bearing shell 21, and the bump foil 22 is located between the bearing shell 21 and the top foil 23, the bump foil 22 includes a first pressure-bearing area 221 and a second pressure-bearing area 222 arranged along the circumference of the bearing shell 21, the first pressure-bearing area 221 and the second pressure-bearing area 222 are configured to at least partially absorb the force transmitted from the top foil 23, and the first pressure-bearing area 221 and the second pressure-bearing area 222 have different pressure resistance.

[0045] In the above embodiment, the wave foil 22 includes two pressure-bearing areas with different pressure resistance arranged along the circumference of the bearing housing 21. In this way, the bearing can have different load-bearing stiffness, improve the bearing's adaptability to different rotor speeds, improve the bearing's reliability, avoid dry friction between the bearing and the rotor, and help to increase the service life of the bearing.

[0046] The bump foil 22 may also include more pressure-bearing areas with different pressure resistance capabilities to further improve the bearing's adaptability to complex operating conditions of the rotor.

[0047] like Figure 5 and Figure 6As shown, the top foil 23 includes two pressure-bearing areas corresponding to the first pressure-bearing area 221 and the second pressure-bearing area 222 of the bump foil 22, respectively. This makes it convenient to fix each pressure-bearing area of ​​the bump foil 22 separately, and also makes it convenient for each pressure-bearing area of ​​the bump foil 22 to effectively support the corresponding pressure-bearing area on the top foil 23.

[0048] like Figures 7-10 As shown, the top foil 23 includes a third pressure-bearing area 231 and a fourth pressure-bearing area 232 . The third pressure-bearing area 231 is located at the side of the first pressure-bearing area 221 and contacts the first pressure-bearing area 221 . The fourth pressure-bearing area 232 is located at the side of the second pressure-bearing area 222 and contacts the second pressure-bearing area 222 .

[0049] There are gaps between the first pressure-bearing area 221 and the second pressure-bearing area 222 as well as between the third pressure-bearing area 231 and the fourth pressure-bearing area 232 to form gas inlets.

[0050] The compressive resistance can be understood as the ability to absorb pressure, the ability to resist deformation or its own rigidity. In order to facilitate the realization of different compressive resistances of the first pressure-bearing area 221 and the second pressure-bearing area 222, a variety of methods can be used. Three feasible methods are introduced below.

[0051] First way:

[0052] The first pressure-bearing area 221 includes a plurality of first pressure-bearing segments arched toward the top foil 23 , and the second pressure-bearing area 222 includes a plurality of second pressure-bearing segments arched toward the top foil 23 , and the axial distance between the first pressure-bearing segment and the bearing housing 21 is different from the axial distance between the second pressure-bearing segment and the bearing housing 21 .

[0053] The cross-sectional shape of the first pressure-bearing section and the second pressure-bearing section may be an arch, in which case the axial distance between the first pressure-bearing section or the second pressure-bearing section and the bearing housing 21 is the axial distance between the highest point of the arch and the bearing housing 21. The cross-sectional shape of the first pressure-bearing section and the second pressure-bearing section may also be a square, that is, the top surface of the arch is a plane, in which case the axial distance between the first pressure-bearing section or the second pressure-bearing section and the bearing housing 21 is the axial distance between the top of the square and the bearing housing 21, and is not affected by the measurement position.

[0054] Of course, the cross-sectional shape of the first pressure-bearing section and the second pressure-bearing section may also be a triangle or a trapezoid.

[0055] Second way:

[0056] The first pressure-bearing area 221 includes a plurality of first pressure-bearing sections arched toward the top foil 23, and the second pressure-bearing area 222 includes a plurality of second pressure-bearing sections arched toward the top foil 23, and the projection length of the first pressure-bearing sections on the circumferential inner side surface of the bearing housing 21 is different from the projection length of the second pressure-bearing sections on the circumferential inner side surface of the bearing housing 21.

[0057] For example, when the cross-sectional shape of the first pressure-bearing section and the second pressure-bearing section is an arch, the projected length of the first pressure-bearing section or the second pressure-bearing section on the circumferential inner side surface of the bearing housing 21 is the span of the arch.

[0058] The third way:

[0059] The axial distance between the first pressure-bearing section and the bearing housing 21 is different from the axial distance between the second pressure-bearing section and the bearing housing 21, and the projection length of the first pressure-bearing section on the circumferential inner side of the bearing housing 21 is different from the projection length of the second pressure-bearing section on the circumferential inner side of the bearing housing 21. The larger the axial distance between the first pressure-bearing section or the second pressure-bearing section and the bearing housing 21, the smaller the rigidity thereof; the larger the projection length of the first pressure-bearing section or the second pressure-bearing section on the circumferential inner side of the bearing housing 21, the smaller the rigidity thereof.

[0060] like Figure 3 and Figure 4 As shown, the first pressure section extends in a direction deviating from the center of the bearing housing 21; and / or the second pressure section extends in a direction deviating from the center of the bearing housing 21. Such an arrangement is conducive to making the bearing load more uniform.

[0061] The plurality of first pressure-bearing sections are arranged in parallel and at equal intervals, and the plurality of second pressure-bearing sections may also be arranged in parallel and at equal intervals.

[0062] The first pressure-bearing area 221 and / or the second pressure-bearing area 222 are fan-shaped, which facilitates distribution and arrangement.

[0063] The number of the first pressure-bearing area 221 and the number of the second pressure-bearing area 222 are both multiple, and the first pressure-bearing area 221 and the second pressure-bearing area 222 are arranged at intervals, which is conducive to achieving uniform load bearing.

[0064] The number of the first pressure-bearing areas 221 and the number of the second pressure-bearing areas 222 are equal, so that a uniform arrangement can be achieved.

[0065] The number of the first pressure-bearing regions 221 and the second pressure-bearing regions 222 is equal and even, so that the first pressure-bearing regions 221 and the second pressure-bearing regions 222 can be evenly arranged diagonally, so that the bearing load is relatively uniform.

[0066] The following is combined with Figures 1 to 10 The structure and working process of an embodiment of the axial gas bearing of the present invention are described as follows:

[0067] like Figure 1 and Figure 2 As shown, the axial gas bearing 20 is used to support the rotor 10, and the rotor 10 includes a rotating shaft 11 and a thrust plate 12, and the thrust plate 12 is arranged on the outer periphery of the rotating shaft 11 and extends in the radial direction of the rotating shaft 11. The bearing 20 is arranged on the side of the axial end surface of one side of the thrust plate 12, or a set of bearings 20 is respectively arranged on the side of the axial end surfaces of both sides of the thrust plate 12.

[0068] The bearing 20 includes a bearing housing 21, a bump foil 22 and a top foil 23. The bearing housing 21, the bump foil 22 and the top foil 23 are all provided with through holes in their centers, and the rotating shaft 11 passes through the central through holes of the bearing housing 21, the bump foil 22 and the top foil 23.

[0069] like Figure 3 and Figure 4 As shown, the corrugated foil 22 includes a first pressure-bearing area 221 and a second pressure-bearing area 222 arranged in the circumferential direction, the number of the first pressure-bearing area 221 and the second pressure-bearing area 222 are both 4, and the first pressure-bearing area 221 and the second pressure-bearing area 222 are arranged at intervals. The first pressure-bearing area 221 and the second pressure-bearing area 222 are both fan-shaped, and the first pressure-bearing area 221 is located upstream or downstream of the second pressure-bearing area 222 in the rotation direction.

[0070] like Figure 5 and Figure 6 As shown, the top foil 23 includes a third pressure-bearing area 231 and a fourth pressure-bearing area 232 arranged in the circumferential direction, the number of the third pressure-bearing area 231 and the fourth pressure-bearing area 232 are both 4, and the third pressure-bearing area 231 and the fourth pressure-bearing area 232 are arranged at intervals. The third pressure-bearing area 231 and the fourth pressure-bearing area 232 are both fan-shaped, and the third pressure-bearing area 231 is located upstream or downstream of the fourth pressure-bearing area 232 in the rotation direction.

[0071] from Figure 5 and Figure 6 It can be seen that the upstream ends of the third pressure-bearing area 231 and the fourth pressure-bearing area 232 are provided with inclined surfaces so that the upstream ends of the third pressure-bearing area 231 and the fourth pressure-bearing area 232 gradually approach the bearing housing 21 and are connected to the bearing housing 21. The middle parts and downstream ends of the third pressure-bearing area 231 and the fourth pressure-bearing area 232 are kept parallel to the bearing housing 21.

[0072] like Figure 7 and 8As shown, the first pressure-bearing area 221 is in contact with the third pressure-bearing area 231. A first gap 30 is formed between the third pressure-bearing area 231 and the thrust disc 12. The axial distance of the first gap 30 is L1. The first pressure-bearing area 221 includes a plurality of first pressure-bearing segments with an arched cross-section. The height of the first pressure-bearing segment is L2, and the span of the first pressure-bearing segment is L3. The arched height of the first upstream end 2211 of the first pressure-bearing area 221 gradually decreases so that the first pressure-bearing area 221 gradually approaches the bearing housing 21. The inclined surfaces of the first upstream end 2211 and the upstream end of the third pressure-bearing area 231 approach the bearing housing 21 together and are fixed on the bearing housing 21. The projected length of the inclined surfaces of the first upstream end 2211 and the upstream end of the third pressure-bearing area 231 on the bearing housing 21 is L4. A first wedge-shaped area 50 is formed between the inclined surface of the upstream end of the third pressure-bearing area 231 and the thrust disc 12. The included angle between the inclined surface of the upstream end of the third pressure-bearing area 231 and the thrust disc 12 is θ1.

[0073] As Fig. 9 and 10 shown, the second pressure-bearing area 222 is in contact with the fourth pressure-bearing area 232. A second gap 40 is formed between the fourth pressure-bearing area 232 and the thrust disc 12. The axial distance of the second gap 40 is L5, and L5 < L1; the second pressure-bearing area 222 includes a plurality of second pressure-bearing segments with an arched cross-section. The height of the second pressure-bearing segment is L6, and L6 > L2; the span of the second pressure-bearing segment is L7, and L7 > L3. The arched height of the second upstream end 2221 of the second pressure-bearing area 222 gradually decreases so that the second pressure-bearing area 222 gradually approaches the bearing housing 21. The inclined surfaces of the second upstream end 2221 and the upstream end of the fourth pressure-bearing area 232 approach the bearing housing 21 together and are fixed on the bearing housing 21. The projected length of the inclined surfaces of the second upstream end 2221 and the upstream end of the fourth pressure-bearing area 232 on the bearing housing 21 is L8, and L8 < L4; a second wedge-shaped area 60 is formed between the inclined surface of the upstream end of the fourth pressure-bearing area 232 and the thrust disc 12. The included angle between the inclined surface of the upstream end of the fourth pressure-bearing area 232 and the thrust disc 12 is θ2, and θ2 > θ1.

[0074] θ1 < θ2, L4 < L8. The second wedge-shaped area 60 realizes a large inclined plane structure by measures such as increasing the inclination angle and decreasing the convergence length, thereby improving the convergence speed, enhancing the hydrodynamic effect, and achieving the rapid formation of a hydrodynamic gas film during the startup process; the first wedge-shaped area 50 realizes a small inclined plane structure by measures such as decreasing the inclination angle and increasing the convergence length, thereby reducing the convergence speed, reducing the fluctuation of the hydrodynamic gas film during the variable speed process, and reducing the shafting vibration.

[0075] During operation, the rotor 10 rotates at a high speed under the action of the electromagnetic field. When the designed rotational speed is reached, dynamic pressure air films are formed in the first gap 30 and the second gap 40 under the action of the first wedge region 50 and the second wedge region 60 to support the operation of the rotor 10. When the rotational speed of the rotor 10 is relatively low and the required stiffness is small, since L1 < L5, the second gap 40 takes effect preferentially at this time, and the support is mainly provided by the second bearing region 222; when the rotational speed of the rotor 10 is relatively high and the required stiffness increases, the support force that the second bearing region 222 can provide is insufficient, the waveform is further deformed, L6 decreases, and when L6 decreases to L2, the first gap 30 starts to take effect, and the first bearing region 221 and the second bearing region 222 provide support together.

[0076] Through the description of multiple embodiments of the axial gas bearing of the present invention, it can be seen that the embodiments of the axial gas bearing of the present invention utilize the structure of alternately distributing double wave foils and double top foils in the circumferential direction, adopt different stiffness designs, and can adapt to the requirements of different rotational speeds for the bearing stiffness, improving the bearing capacity and load-bearing adaptability of the bearing.

[0077] Based on the above axial gas bearing, the present invention also proposes a compressor, which includes the above axial gas bearing. The compressor further includes a rotor 10. The axial gas bearing is used to support the rotor 10. An air film gap is formed between the top foil 23 of the axial gas bearing and the thrust disk 12 of the rotor 10. When the compressor operates, gas enters the air film gap to form a dynamic pressure air film, suspending the rotor 10.

[0078] Based on the above compressor, the present invention also proposes an air-conditioning unit, which includes the above compressor.

[0079] The positive technical effects of the axial gas bearing in the above respective embodiments are equally applicable to the compressor and the air-conditioning unit, and will not be elaborated here.

[0080] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that without departing from the principle of the present invention, modifications can still be made to the specific implementation manners of the present invention or equivalent substitutions can be made to some technical features, and these modifications and equivalent substitutions should all be covered by the scope of the technical solutions claimed by the present invention.

Claims

1. An axial gas bearing, characterized in that: include: Bearing housing (21); The bump foil (22) and the top foil (23) are both arranged on the side of the same axial end face of the bearing housing (21), and the bump foil (22) is located between the bearing housing (21) and the top foil (23), the bump foil (22) comprises a first pressure-bearing area (221) and a second pressure-bearing area (222) arranged along the circumference of the bearing housing (21), the first pressure-bearing area (221) and the second pressure-bearing area (222) being configured to at least partially absorb a force transmitted from the top foil (23), and the first pressure-bearing area (221) and the second pressure-bearing area (222) have different pressure resistances; The top foil (23) comprises a third pressure-bearing area (231) and a fourth pressure-bearing area (232), the third pressure-bearing area (231) being located on the side of the first pressure-bearing area (221) and in contact with the first pressure-bearing area (221), and the fourth pressure-bearing area (232) being located on the side of the second pressure-bearing area (222) and in contact with the second pressure-bearing area (222); The first pressure-bearing region (221) includes a first upstream end (2211) located upstream, the third pressure-bearing region (231) includes a third upstream end located upstream, the first upstream end (2211) and the third upstream end gradually approach the bearing housing (21) along a direction from downstream to upstream, the second pressure-bearing region (222) includes a second upstream end (2221) located upstream, the fourth pressure-bearing region (232) includes a fourth upstream end located upstream, the second upstream end (2221) and the fourth upstream end gradually approach the bearing housing (21) along a direction from downstream to upstream, the lengths of the first upstream end (2211) and the third upstream end are different from the lengths of the second upstream end (2221) and the fourth upstream end; and / or an inclination angle of the third upstream end relative to the bearing housing (21) is different from an inclination angle of the fourth upstream end relative to the bearing housing (21).

2. The axial gas bearing according to claim 1, characterized in that: The first pressure-bearing area (221) comprises a plurality of first pressure-bearing segments arched toward the top foil (23), the second pressure-bearing area (222) comprises a plurality of second pressure-bearing segments arched toward the top foil (23), and the axial distance between the first pressure-bearing segment and the bearing housing (21) is different from the axial distance between the second pressure-bearing segment and the bearing housing (21).

3. The axial gas bearing according to claim 1 or 2, characterized in that: The first pressure-bearing area (221) comprises a plurality of first pressure-bearing segments arched toward the top foil (23), and the second pressure-bearing area (222) comprises a plurality of second pressure-bearing segments arched toward the top foil (23), wherein a projection length of the first pressure-bearing segments on the circumferential inner side surface of the bearing housing (21) is different from a projection length of the second pressure-bearing segments on the circumferential inner side surface of the bearing housing (21).

4. The axial gas bearing according to claim 1, characterized in that: The first pressure-bearing area (221) comprises a plurality of first pressure-bearing sections arched toward the top foil (23), the first pressure-bearing sections extending in a direction deviating from the center of the bearing housing (21); and / or the second pressure-bearing area (222) comprises a plurality of second pressure-bearing sections arched toward the top foil (23), the second pressure-bearing sections extending in a direction deviating from the center of the bearing housing (21).

5. The axial gas bearing according to claim 1, characterized in that: The first pressure-bearing area (221) and / or the second pressure-bearing area (222) are fan-shaped.

6. The axial gas bearing according to claim 1, characterized in that: The number of the first pressure-bearing regions (221) and the number of the second pressure-bearing regions (222) are both plural, and the first pressure-bearing regions (221) and the second pressure-bearing regions (222) are arranged at intervals.

7. The axial gas bearing according to claim 1, characterized in that: The number of the first pressure-bearing areas (221) and the number of the second pressure-bearing areas (222) are equal.

8. The axial gas bearing according to claim 6 or 7, characterized in that: The number of the first pressure-bearing areas (221) and the number of the second pressure-bearing areas (222) are both even numbers.

9. A compressor, characterized in that: Comprising an axial gas bearing as described in any one of claims 1 to 8.

10. An air conditioning unit, characterized in that: Comprising the compressor of claim 9.

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