Gas bearing assemblies and compressors

Abstract

The present disclosure relates to a gas bearing assembly and a compressor. The gas bearing assembly comprises: a first rotor (10), comprising an air storage chamber (11) located inside the first rotor (10) and a throttling structure (12) located radially outside the air storage chamber (11), wherein the air storage chamber (11) is configured to convey static pressure gas to the outside of the throttling structure (12) through the throttling structure (12); a bearing housing (20), which is sleeved on the outer peripheral surface of the first rotor (10) and has a static pressure radial bearing section (21) and a dynamic pressure radial bearing section (22) arranged in the axial direction, wherein the throttling structure (12) and the static pressure radial bearing section (21) have at least a partially overlapping length range in the axial direction, and the distance between the static pressure fitting surface of the throttling structure (12) and the static pressure radial bearing section (21) is smaller than the distance between the first rotor (10) and the dynamic pressure radial bearing section (22). The embodiment of the present disclosure can avoid the collision between the gas bearing and the rotor as much as possible during operation.

Description

Technical Field

[0001] The present disclosure relates to the field of bearings, and in particular to a gas bearing assembly and a compressor. Background Art

[0002] Gas lubrication technology was first proposed in the mid-19th century and developed rapidly in the mid-20th century. The emergence of this technology broke the dominant position of liquid lubrication technology and made a qualitative leap in lubrication technology. Gas bearings are new bearings based on this new lubrication technology. They have a series of advantages such as low friction loss, good stability, low vibration, and oil-free lubrication. They have broad application prospects in the fields of high-speed turbines, machine tool manufacturing, and space technology.

[0003] Gas bearings use gas as a lubricant and take advantage of the gas's adsorption, transport (diffusivity, viscosity and thermal conductivity) and compressibility characteristics. Based on the fluid dynamic pressure effect, static pressure effect and extrusion effect, a gas film is formed during friction to support the load and reduce friction.

[0004] According to the different mechanisms of lubricating gas film generation, gas bearings can be divided into dynamic pressure gas bearings, static pressure gas bearings and extrusion type gas bearings. The foil dynamic pressure gas radial bearing is the type of gas bearing with the most research literature available. Its typical structure is generally composed of a bearing shell, a top foil and a corrugated foil. The corrugated foil is an elastic foil with a special waveform. When working, it generates a supporting force through the elastic change of the waveform, providing the main stiffness and partial damping for the bearing; the top foil is a long cylindrical foil. In the radial direction, one side of the top foil is evenly overlapped on the top of each corrugation of the corrugated foil, and the friction generated by the contact with the corrugated foil provides another part of the damping for the bearing; the other side of the top foil cooperates with the rotor gap to form the air film space required for the dynamic pressure effect.

[0005] Under the action of gravity, the shaft becomes eccentric relative to the bearing, forming a wedge-shaped gap with the inner surface of the bearing. When the shaft is rotating at high speed, it continuously brings gas with a certain viscosity into the wedge-shaped gap, and the continuous entry of gas causes the gas film to generate a certain pressure. When the gas film force is sufficient to balance the shaft load, the shaft and the bearing are completely separated. The process of generating the above gas film is called the dynamic pressure effect.

[0006] A hydrostatic gas bearing is a bearing that uses an external gas supply system to provide gas with a certain pressure, and then the gas is transported to the gap between the bearing and the rotor through the bearing throttle, thereby forming an air film in the gap to support the external load. The air film pressure in the bearing gap can be adjusted by the bearing throttle and the gas supply system. According to the different throttles, the common ones are small-hole hydrostatic gas bearings and porous hydrostatic gas bearings. Summary of the invention

[0007] The inventors have found through research that the bearing stiffness of the gas bearing in the related art is much lower than that of the oil bearing, so the rotor-bearing system using the gas bearing often operates transcritically. When the rotor speed is near the mode (such as the first-order mode and the second-order mode), the rotor is prone to resonance. When the rotor amplitude is too large, so that it is greater than the bearing clearance, it will cause the bearing and the rotor to collide.

[0008] In view of this, an embodiment of the present disclosure provides a gas bearing assembly and a compressor, which can minimize the collision between the gas bearing and the rotor during operation.

[0009] In one aspect of the present disclosure, there is provided a gas bearing assembly comprising:

[0010] a first rotor, comprising an air storage cavity located inside the first rotor and a throttling structure located radially outside the air storage cavity, wherein the air storage cavity is configured to transport static pressure gas to the outside of the throttling structure through the throttling structure;

[0011] The bearing housing is sleeved on the outer peripheral surface of the first rotor and has at least one static pressure radial bearing section and at least one dynamic pressure radial bearing section arranged in the axial direction.

[0012] The throttling structure and the at least one static pressure radial bearing segment have at least partially overlapping axial length ranges, and the distance between the static pressure fitting surface of the throttling structure and the at least one static pressure radial bearing segment is smaller than the distance between the first rotor and the at least one dynamic pressure radial bearing segment.

[0013] In some embodiments, the first rotor further comprises:

[0014] An air inlet chamber, located at one end of the first rotor along the axial direction and connected with the air storage chamber inside the first rotor;

[0015] The assembly portion is located at the other end of the first rotor along the axial direction and is configured to be fixedly connected to a second rotor coaxial with the first rotor.

[0016] In some embodiments, the first rotor further comprises:

[0017] A plurality of axial flow fan blades are circumferentially located on the inner wall of the air inlet cavity and are configured to draw the airflow outside the first rotor into the air inlet cavity when the first rotor rotates.

[0018] In some embodiments, there is a partition wall between the air inlet cavity and the air storage cavity, and an air inlet hole is provided on the partition wall.

[0019] In some embodiments, the air inlet hole is located at the center of the isolation wall, and the axis of the first rotor passes through the air inlet hole.

[0020] In some embodiments, a surface of the isolation wall adjacent to the air inlet cavity is tapered and concave toward the air inlet hole.

[0021] In some embodiments, the air inlet cavity and the air storage cavity both include a cylindrical hollow portion.

[0022] In some embodiments, the assembly portion includes:

[0023] The assembly cavity is located inside the first rotor and communicated with the air storage cavity. The assembly cavity is configured to accommodate the end of the second rotor and to be interference fit with the end of the second rotor.

[0024] In some embodiments, the throttling structure includes a first annular shell, the first annular shell having a plurality of static pressure micropores, the plurality of static pressure micropores respectively passing through the solid part of the first annular shell to connect the air storage chamber with the outside of the static pressure mating surface, the at least one static pressure radial bearing segment includes a second annular shell, and the distance between the static pressure mating surface of the throttling structure and the at least one static pressure radial bearing segment is the distance between the outer wall of the first annular shell and the inner wall of the second annular shell.

[0025] In some embodiments, the plurality of static pressure micro holes are arranged in an array along the circumferential direction and the axial direction of the first annular shell.

[0026] In some embodiments, the throttling structure includes a porous material ring, or the throttling structure includes an annular shell and a plurality of porous material blocks circumferentially spaced apart from each other on the annular shell.

[0027] In some embodiments, the at least one dynamic pressure radial bearing segment includes two dynamic pressure radial bearing segments, which are axially located on both sides of the at least one static pressure radial bearing segment.

[0028] In some embodiments, each hydrodynamic radial bearing segment comprises:

[0029] A third annular housing, connected to the second annular housing along the axial direction;

[0030] At least one supporting corrugated foil connected to the inner wall of the third annular shell, each supporting corrugated foil being in an arc shape as a whole and having a plurality of arc-shaped corrugations along the extension direction of the supporting corrugated foil;

[0031] a top foil connected to the inner wall of the third annular shell and located at a side of the bump foil away from the third annular shell, and configured to support the support bump foil in a radial direction,

[0032] The distance between the first rotor and the at least one dynamic pressure radial bearing segment is the distance between the outer circumferential surface of the first rotor and the inner circumferential surface of the top foil.

[0033] In some embodiments, the outer diameter of the first annular housing is greater than the outer diameter of other parts of the first rotor.

[0034] In some embodiments, the gas bearing assembly further comprises:

[0035] The second rotor is coaxial with the first rotor and fixedly connected to the assembly portion of the first rotor.

[0036] In one aspect of the present disclosure, a compressor is provided, comprising: the aforementioned gas bearing assembly.

[0037] Therefore, according to the embodiment of the present disclosure, an air storage chamber is set in the rotor, so that the air storage chamber can transport static pressure gas to the static pressure radial bearing section of the bearing housing through the throttling structure, and the distance between the throttling structure and the static pressure radial bearing section is smaller than the distance between the rotor and the dynamic pressure radial bearing section. In this way, the dynamic pressure radial bearing section in the gas bearing assembly of the embodiment of the present disclosure can form a dynamic pressure gas film with the rotor to support the rotation of the rotor when the rotor reaches the design speed, and the static pressure gas discharged through the air storage chamber and the throttling structure can flow to the gap of the dynamic pressure radial bearing section, which is called the gas source for forming the dynamic pressure gas film; when the rotor speed is near the critical mode, the rotor amplitude increases due to resonance, and when it approaches the gap of the static pressure radial bearing section, the static pressure gas film can participate in supporting the rotor, provide additional support force, and suppress the vibration of the rotor, so as to avoid the collision between the gas bearing and the rotor during operation as much as possible. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] 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.

[0039] The present disclosure may be more clearly understood from the following detailed description with reference to the accompanying drawings, in which:

[0040] Figure 1 is a partially cutaway schematic diagram of a mounting structure according to some embodiments of a gas bearing assembly of the present disclosure;

[0041] Figure 2 yes Figure 1 A schematic longitudinal section diagram of the installation structure;

[0042] Figure 3 yes Figure 2 Structural diagram from perspective A;

[0043] Figure 4 yes Figure 2 Schematic diagram of the structure from the perspective of middle B;

[0044] Figure 5 yes Figure 3 A partial enlarged schematic diagram of the portion indicated by the middle circle I;

[0045] Figure 6 is a schematic diagram of the installation structure of the first rotor and the second rotor in some embodiments of the gas bearing assembly according to the present disclosure;

[0046] Figure 7 yes Figure 6 A schematic longitudinal section diagram of the installation structure;

[0047] Figure 8 is a schematic structural diagram of a bearing housing in some embodiments of a gas bearing assembly according to the present disclosure;

[0048] Fig. 9 yes Figure 8 Schematic diagram of the longitudinal section.

[0049] 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

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] refer to Figure 1-Figure 9 In some embodiments, the present disclosure provides a gas bearing assembly. The gas bearing assembly includes: a first rotor 10 and a bearing housing 20. The first rotor 10 includes an air storage chamber 11 located inside the first rotor 10 and a throttling structure 12 located radially outside the air storage chamber 11, and the air storage chamber 11 is configured to transport static pressure gas to the outside of the throttling structure 12 through the throttling structure 12.

[0056] The bearing housing 20 is sleeved on the outer circumferential surface of the first rotor 10 and has at least one static pressure radial bearing segment 21 and at least one dynamic pressure radial bearing segment 22 arranged in the axial direction. The throttling structure 12 and the at least one static pressure radial bearing segment 21 have at least a partially overlapping axial length range. Figure 1 and Figure 2 In the embodiment, the axial length range of the throttling structure 12 is substantially completely overlapped with the axial length range of the hydrostatic radial bearing section 21. In other embodiments, the axial length ranges of the two can be partially staggered and partially overlapped, or the axial length range of one of the two includes the axial length range of the other.

[0057] The gas in the air storage chamber 11 comes from the outside of the first rotor 10. After passing through the throttling structure 12 and entering the gap between the bearing housing 20 and the throttling structure 12, it can flow into the dynamic pressure radial bearing section 22 to provide an air source for forming a dynamic pressure air film in the dynamic pressure gap.

[0058] The spacing θ1 between the static pressure mating surface of the throttling structure 12 and the at least one static pressure radial bearing segment 21 is smaller than the spacing θ2 between the first rotor 10 and the at least one dynamic pressure radial bearing segment 22. In this way, the dynamic pressure radial bearing segment in the gas bearing assembly of this embodiment can form a dynamic pressure gas film with the rotor to support the rotation of the rotor when the rotor reaches the design speed, and the static pressure gas discharged through the air storage chamber and the throttling structure can flow to the gap of the dynamic pressure radial bearing segment, which is called the gas source for forming the dynamic pressure gas film. When the rotor speed is near the critical mode (such as the first-order mode or the second-order mode), the rotor amplitude increases due to resonance. When it approaches the gap of the static pressure radial bearing segment, the static pressure gas film can participate in supporting the rotor and provide additional support force, and suppress the vibration of the rotor.

[0059] refer to Figure 1 , Figure 2 , Figure 6 and Figure 7 In some embodiments, the first rotor 10 further includes: an air inlet cavity 13 and an assembly portion 15. The air inlet cavity 13 is located at one end of the first rotor 10 in the axial direction and is connected to the air storage cavity 11 inside the first rotor 10. The gas entering the air inlet cavity 13 may be driven by a gas drive device outside the rotor or inside the rotor. For example, an air inlet pipe for filling the air inlet cavity 13 with high-pressure gas is provided at the end of the first rotor 10, or a structure capable of sucking external air, such as a fan blade, is provided at the end of the first rotor 10.

[0060] The assembly portion 15 is located at the other end of the first rotor 10 along the axial direction, and is configured to be fixedly connected to the second rotor 30 coaxial with the first rotor 10 . Figure 1 and Figure 2 Only a portion of the second rotor 30 is shown. The second rotor 30 may be a part of the gas bearing assembly or may be provided independently of the gas bearing assembly. The assembly portion 15 and the second rotor 30 may be fixed by various connection methods, such as interference fit formed by shrink fitting, bonding, threaded connection, welding, etc.

[0061] Since the air storage chamber is located inside the first rotor, the assembly part is provided to facilitate the processing of the air storage chamber and the throttling structure of the first rotor. In other words, before the assembly part is connected to the second rotor, the air storage chamber and the throttling structure are first processed on one side of the assembly part. In other embodiments, the air storage chamber and the throttling structure are formed by other means, and the assembly parts on the second rotor and the first rotor can also be omitted.

[0062] refer to Figure 2-Figure 7In some embodiments, the first rotor 10 further includes a plurality of axial flow blades 14. The plurality of axial flow blades 14 are circumferentially disposed on the inner wall of the air inlet cavity 13 and are configured to draw the airflow outside the first rotor 10 into the air inlet cavity 13 when the first rotor 10 rotates.

[0063] During operation, the first rotor 10 and the second rotor 30 can move along the Figure 3 and Figure 4 The first rotor 10 rotates at high speed in the direction indicated by the arrows, and the axial fan blades 14 rotate synchronously with the first rotor 10, and the gas on the left side of the first rotor 10 is continuously sucked into the air inlet cavity 13, and then enters the air storage cavity 11, so that the gas pressure in the air storage cavity 11 increases. The gas in the air storage cavity 11 then passes through the throttling structure 12 to reach the static pressure matching surface outside the throttling structure 12, so as to form a static pressure gas support effect.

[0064] Compared with the method of supplying air from the outside of the bearing housing in the related art, the air supply method implemented in this embodiment greatly simplifies the structure of the static pressure air supply system, eliminating components such as the air supply pump, air supply pipe, and corresponding pipe joints.

[0065] refer to Figure 1 , Figure 2 and Figure 7 In some embodiments, there is a partition wall 131 between the air inlet cavity 13 and the air storage cavity 11, and an air inlet hole 132 is provided on the partition wall 131. The axial flow blade 14 can extend from the inlet of the air inlet cavity 13 to the partition wall 131 or a position adjacent to the partition wall 131. In some embodiments, the air inlet hole 132 is located at the center of the partition wall 131, and the axis of the first rotor 10 passes through the air inlet hole 132. This is conducive to avoiding the additional centrifugal force caused by the eccentric airflow when the airflow enters.

[0066] exist Figure 2 and Figure 7 In the embodiment, the surface of the partition wall 131 adjacent to the air inlet cavity 13 is conical and concave toward the air inlet hole 132. In this way, the partition wall can achieve the function of guiding the gas flow, guiding the gas to transition from the axial flow blades to the air inlet hole in the air inlet cavity, improving the uniformity of the flow field, and avoiding noise at high speed.

[0067] refer to Figure 1 and Figure 6 The air inlet chamber 13 and the air storage chamber 11 both include a cylindrical hollow portion, which is conducive to more uniform air intake and exhaust to the outside through the throttling structure 12. In other embodiments, the air inlet chamber 13 and the air storage chamber 11 may also include hollow portions of other shapes, such as a prism, a cone, etc.

[0068] refer to Figure 7In some embodiments, the assembly portion 15 includes an assembly cavity 151. The assembly cavity 151 is located inside the first rotor 10 and is in communication with the air storage cavity 11. It is configured to accommodate the end of the second rotor 30 and to have an interference fit with the end of the second rotor 30. The assembly cavity 151 may include a cylindrical hollow portion to facilitate processing. In other embodiments, a prismatic hollow portion may also be included to better transmit torque. The assembly cavity 151 may be formed before the air storage cavity 11, so that the processing tool can pass through the assembly cavity 151 to process the air storage cavity 11. In other embodiments, the assembly cavity and the air storage cavity may be formed together by integral molding.

[0069] refer to Figure 6 and Figure 7 In some embodiments, the throttling structure 12 includes a first annular shell 122, the first annular shell 122 has a plurality of static pressure micropores 121, and the plurality of static pressure micropores 121 respectively penetrate the solid part of the first annular shell 122 to connect the air storage cavity 11 with the outer side of the static pressure matching surface. Figure 2 and Figure 8 The at least one hydrostatic radial bearing segment 21 includes a second annular housing 211. The distance θ1 between the hydrostatic mating surface of the throttling structure 12 and the at least one hydrostatic radial bearing segment 21 is the distance θ1 between the outer wall of the first annular housing 122 and the inner wall of the second annular housing 211.

[0070] exist Figure 6 and Figure 7 In the embodiment, the plurality of static pressure micropores 121 are arranged in an array along the circumferential and axial directions of the first annular shell 122. The spacing between rows in the array may be the same, and the spacing between columns may also be the same. The size and number of the static pressure micropores 121 may be selected according to the static pressure requirements. The shape of the static pressure micropores 121 is preferably a circular cross-section, and may also be an elliptical cross-section or a polygonal cross-section. In terms of size, the pore diameter of the circular cross-section static pressure micropores 121 is 10 to 50 microns, for example, 20 microns.

[0071] In other embodiments, other forms of throttling structures 12 may also be used, for example, the throttling structure 12 includes a porous material ring. The porous material ring may be a ring body formed of a porous graphite material. Alternatively, the throttling structure 12 includes an annular shell and a plurality of porous material blocks arranged on the annular shell at intervals along the circumferential direction. The porous material blocks may be blocks formed of a porous graphite material.

[0072] No matter what form of throttling structure is used, as long as the sum of the diameters of the throttling channels or pores is much smaller than the diameter of the air inlet, the gas pressure in the air storage cavity can be effectively increased. After the high-pressure gas reaches the static pressure matching surface through the throttling effect of the throttling structure, it can play a role in static pressure gas support for the rotor.

[0073] In addition to supporting the rotor, the gas that reaches the static pressure fitting surface also flows along the axial flow channel between the dynamic pressure radial bearing section and the rotor, thus providing a source of gas for dynamic pressure support. This can also clean up the impurities in the dynamic pressure radial bearing section, avoid impurity accumulation, and reduce the wear of the dynamic pressure radial bearing section caused by impurity accumulation.

[0074] refer to Figure 1-Figure 5 as well as Figure 8-Figure 9 In some embodiments, at least one hydrodynamic radial bearing segment 22 includes two hydrodynamic radial bearing segments 22, which are axially located on both sides of at least one hydrostatic radial bearing segment 21. This is conducive to balancing the loads of the rotor by each segment of the gas bearing assembly in the axial direction, and reduces the risk of the rotor tilting during operation. In other embodiments, the hydrodynamic radial bearing segment may be provided only on one side of the hydrostatic radial bearing segment to reduce the bearing size.

[0075] refer to Figure 3-Figure 5 In some embodiments, each dynamic pressure radial bearing segment 22 includes: a third annular shell 221, at least one supporting bump foil 222 and a top foil 223. The third annular shell 221 is axially connected to the second annular shell 211. At least one supporting bump foil 222 is connected to the inner wall of the third annular shell 221. Figure 3 and Figure 4 In the embodiment, the dynamic pressure radial bearing section 22 includes three support wave foils 222. Each support wave foil 222 is in an arc shape as a whole, and has a plurality of arc-shaped corrugations along the extension direction of the support wave foil 222. The top foil 223 is connected to the inner wall of the third annular shell 221, and is located on the side of the wave foil away from the third annular shell 221, and is configured to support the support wave foil 222 in the radial direction. The spacing θ2 between the first rotor 10 and the at least one dynamic pressure radial bearing section 22 is the spacing θ2 between the outer circumferential surface of the first rotor 10 and the inner circumferential surface of the top foil 223.

[0076] At least one mounting slit 224 may be provided on the inner wall of the third housing 221, and one end of the top foil 223 and the bump foil 222 may be fixed in the mounting slit 224 by a fixing pin 225. In the related art, the rotor supported by the dynamic pressure bump foil gas bearing needs to rotate in the direction from the free end of the supporting bump foil to the fixed end so that the supporting bump foil is in a "tight" state, otherwise the bearing will fail. However, this embodiment allows the rotor to reverse because when the rotor reverses, the static pressure air film formed by the static pressure radial bearing segment and the rotor can support the rotor, thereby protecting the rotor.

[0077] refer to Figure 5-Figure 7 In some embodiments, the outer diameter of the first annular housing 122 is larger than the outer diameter of other parts of the first rotor 10. That is, a step 16 is formed at the position of the first annular housing 122. Figure 5 It can be seen that the spacing θ1 is formed between the larger diameter outer periphery of the first rotor and the bearing housing, and the spacing θ2 is formed between the smaller diameter outer periphery of the first rotor and the top foil. Such a structure of the first rotor is conducive to forming the effect of θ1<θ2.

[0078] In the above embodiment, the bearing housing can be made by casting or machining, and the support foil and the top foil are assembled on the bearing housing. The first rotor can be made by casting or machining. For the embodiment using a porous material ring or a porous material block, the porous material ring or the porous material block can be assembled on the first rotor.

[0079] The various embodiments of the gas bearing assembly described above can be applied to various equipment or facilities that need to support a rotor, such as a compressor. Therefore, the embodiment of the present disclosure also provides a compressor, including any embodiment of the gas bearing assembly described above.

[0080] refer to Figure 1-Figure 9 , when the rotor operates normally at a certain speed, the dynamic pressure radial bearing section can support the rotor through the dynamic pressure air film formed by the top foil and the rotor surface. The strength of the dynamic pressure air film is positively correlated with the speed. Under high speed conditions, the dynamic pressure radial bearing section provides the main bearing capacity. However, when the rotor speed runs near the critical mode, the rotor amplitude inevitably increases due to resonance. When the amplitude is close to the spacing θ1 of the static pressure radial bearing section, the static pressure air film formed on the surface of the throttling structure participates in supporting the rotor and provides additional bearing capacity, and suppresses the vibration of the rotor. When the rotor runs at a high speed (speed greater than 15000rpm), the rotor requires a greater bearing capacity of the bearing. In addition, sometimes the required bearing capacity suddenly increases due to the airflow impact caused by the operating environment. At this time, the bearing capacity of the dynamic pressure radial bearing section is insufficient, and the thickness of the dynamic pressure air film is reduced. At this time, the static pressure air film will also participate and provide additional bearing capacity to support the rotor.

[0081] 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.

[0082] 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. A gas bearing assembly, characterized in that: include: A first rotor (10), comprising an air storage chamber (11) located inside the first rotor (10) and a throttling structure (12) located radially outside the air storage chamber (11), wherein the air storage chamber (11) is configured to transport static pressure gas to the outside of the throttling structure (12) through the throttling structure (12); A bearing housing (20) is sleeved on the outer peripheral surface of the first rotor (10) and comprises at least one static pressure radial bearing section (21) and at least one dynamic pressure radial bearing section (22) arranged in the axial direction. The throttling structure (12) and the at least one static pressure radial bearing segment (21) have at least partially overlapping length ranges in the axial direction, and the distance between the static pressure fitting surface of the throttling structure (12) and the at least one static pressure radial bearing segment (21) is smaller than the distance between the first rotor (10) and the at least one dynamic pressure radial bearing segment (22); the first rotor (10) further comprises an air inlet cavity (13), the air inlet cavity (13) being located at one end of the first rotor (10) in the axial direction and being connected to the air storage cavity (11) inside the first rotor (10), and the gas entering the air inlet cavity (13) is driven by a gas driving device outside or inside the first rotor (10).

2. The gas bearing assembly according to claim 1, characterized in that The first rotor (10) further comprises: The assembly portion (15) is located at the other end of the first rotor (10) along the axial direction and is configured to be fixedly connected to a second rotor (30) coaxial with the first rotor (10).

3. The gas bearing assembly according to claim 1, characterized in that The first rotor (10) further comprises: A plurality of axial flow blades (14) are circumferentially located on the inner wall of the air inlet cavity (13) and are configured to draw airflow outside the first rotor (10) into the air inlet cavity (13) when the first rotor (10) rotates.

4. The gas bearing assembly according to claim 1 or 3, characterized in that: A separation wall (131) is provided between the air inlet cavity (13) and the air storage cavity (11), and an air inlet hole (132) is provided on the separation wall (131).

5. The gas bearing assembly according to claim 4, characterized in that The air inlet hole (132) is located at the center of the isolation wall (131), and the axis of the first rotor (10) passes through the air inlet hole (132).

6. The gas bearing assembly according to claim 4, characterized in that The surface of the isolation wall (131) adjacent to the air inlet cavity (13) is conical and concave toward the air inlet hole (132).

7. The gas bearing assembly according to claim 1, characterized in that The air inlet chamber (13) and the air storage chamber (11) both comprise a cylindrical hollow portion.

8. The gas bearing assembly according to claim 2, characterized in that The assembly part (15) comprises: The assembly cavity (151) is located inside the first rotor (10) and is in communication with the air storage cavity (11), and is configured to accommodate an end portion of the second rotor (30) and to be interference-fitted with the end portion of the second rotor (30).

9. The gas bearing assembly according to claim 1, characterized in that The throttling structure (12) comprises a first annular shell (122), the first annular shell (122) having a plurality of static pressure micropores (121), the plurality of static pressure micropores (121) respectively penetrating a solid part of the first annular shell (122) to connect the air storage chamber (11) with the outer side of the static pressure fitting surface, the at least one static pressure radial bearing segment (21) comprises a second annular shell (211), and the distance between the static pressure fitting surface of the throttling structure (12) and the at least one static pressure radial bearing segment (21) is the distance between the outer wall of the first annular shell (122) and the inner wall of the second annular shell (211).

10. The gas bearing assembly according to claim 9, characterized in that The plurality of static pressure micropores (121) are arranged in an array along the circumferential and axial directions of the first annular shell (122).

11. The gas bearing assembly according to claim 1, characterized in that The throttling structure (12) comprises a porous material ring, or the throttling structure (12) comprises an annular shell and a plurality of porous material blocks arranged on the annular shell at intervals along the circumferential direction.

12. The gas bearing assembly according to claim 1, wherein: The at least one dynamic pressure radial bearing segment (22) comprises two dynamic pressure radial bearing segments (22) which are axially located on both sides of the at least one static pressure radial bearing segment (21).

13. The gas bearing assembly according to claim 9, wherein: Each hydrodynamic radial bearing segment (22) comprises: A third annular housing (221) connected to the second annular housing (211) along the axial direction; At least one supporting corrugated foil (222) connected to the inner wall of the third annular shell (221), each supporting corrugated foil (222) being in an arc shape as a whole and having a plurality of arc-shaped corrugations along the extension direction of the supporting corrugated foil (222); A top foil (223) is connected to the inner wall of the third annular shell (221) and is located on a side of the bump foil away from the third annular shell (221), and is configured to support the support bump foil (222) in a radial direction. The distance between the first rotor (10) and the at least one dynamic pressure radial bearing segment (22) is the distance between the outer circumferential surface of the first rotor (10) and the inner circumferential surface of the top foil (223).

14. The gas bearing assembly according to claim 9, wherein: The outer diameter of the first annular housing (122) is greater than the outer diameter of other parts of the first rotor (10).

15. The gas bearing assembly according to claim 2, wherein: Also includes: The second rotor (30) is coaxial with the first rotor (10) and fixedly connected to the assembly portion (15) of the first rotor (10).

16. A compressor, characterized in that: include: A gas bearing assembly as claimed in any one of claims 1 to 15.

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