CN114688163A - Gas bearing and compressor - Google Patents

Abstract

The present disclosure relates to a gas bearing and a compressor. The gas bearing includes: a bearing housing (10) having an axially extending inner cavity comprising at least one static pressure mounting section (11b) and at least one dynamic pressure mounting section (11a) arranged in an axial direction; at least one porous material inner bushing (30) respectively arranged in the at least one static pressure mounting section (11 b); and at least one dynamic pressure foil group (20) respectively arranged in the at least one dynamic pressure mounting section (11a), wherein the inner diameter d2 of the at least one porous material inner shaft sleeve (30) is smaller than the inner diameter d1 of the at least one dynamic pressure foil group (20). The embodiment of the disclosure can provide good support for the rotor with a larger rotating speed range, and improve the service life and the working stability.

Description

Gas bearing and compressor

Technical Field

The disclosure relates to the field of bearings, in particular to a gas bearing and a compressor.

Background

Gas bearings are a type of bearing in which gas acts as a lubricating medium, and a lubricating gas film that supports a load is formed by utilizing the dynamic pressure effect or static pressure effect of a gas fluid. In the related art, gas bearings are classified into dynamic pressure gas bearings, static pressure gas bearings, and squeeze type gas bearings according to the mechanism of generation of a lubricating gas film. The gas bearing is often selected as an ideal substitute of the traditional oil bearing by virtue of a series of advantages of small friction loss, good stability, small vibration and the like, and particularly has very wide application prospect in the fields of high-speed turbine, precision machine tool manufacturing and space technology.

Disclosure of Invention

The inventor researches and discovers that both the dynamic pressure gas bearing and the static pressure gas bearing in the related art have certain limitations. The dynamic pressure gas bearing utilizes the wedge-shaped space formed between the rotor and the bearing surface to generate the wedge-shaped effect, and the ambient gas is continuously dragged into the wedge-shaped space due to the viscosity of the gas along with the continuous increase of the speed of the rotor, so that the air pressure in the wedge-shaped space is continuously increased. The dynamic pressure air film can be formed when the rotating speed of the bearing reaches a certain value. However, in the process of starting and stopping the rotor, due to insufficient rotating speed, an effective lubricating gas film cannot be formed between the dynamic pressure gas bearing and the rotor, so that serious dry friction exists between a top foil of the bearing and the surface of the rotor, the surface of the bearing is gradually seriously abraded under the action of the dry friction, the service life of the dynamic pressure gas bearing is influenced, and the situation that the foil and the rotor are seriously adhered and abraded in the later abrasion stage can even occur.

The static pressure gas bearing provides gas with certain pressure through an external gas supply system, then the gas is transmitted to a gap between the bearing and the rotor through a throttling structure, and then a gas film is formed in a matching gap between the rotor and the bearing to play a role in supporting the rotor. However, when the speed of the rotor is high, the static pressure gas bearing cannot effectively absorb and suppress the vibration of the rotor due to the lack of a damping mechanism, so that the stability of the bearing is reduced, and the use of the static pressure gas bearing in a high-speed and high-linear-speed working environment is limited.

In view of this, the embodiments of the present disclosure provide a gas bearing and a compressor, which can provide good support for a rotor with a larger rotation speed range, and improve the service life and the working stability.

In one aspect of the present disclosure, there is provided a gas bearing including:

the bearing comprises a bearing shell, a bearing sleeve and a bearing sleeve, wherein the bearing shell is provided with an inner cavity extending along the axial direction, and the inner cavity comprises at least one static pressure mounting section and at least one dynamic pressure mounting section which are arranged along the axial direction;

at least one porous material inner shaft sleeve respectively arranged in the at least one static pressure mounting section;

at least one dynamic pressure foil group respectively arranged in the at least one dynamic pressure mounting section,

wherein the inner diameter d2 of the at least one inner sleeve of porous material is smaller than the inner diameter d1 of the at least one dynamic pressure foil set.

In some embodiments, the at least one static pressure mounting section comprises at least two static pressure mounting sections, a portion of the at least two static pressure mounting sections being located axially on one side of the at least one dynamic pressure mounting section and another portion of the at least two static pressure mounting sections being located axially on the other side of the at least one dynamic pressure mounting section.

In some embodiments, the at least one inner sleeve of porous material comprises at least two inner sleeves of porous material respectively disposed within the at least two static pressure mounting sections, the at least two static pressure mounting sections are identical in structure and size, and the at least two inner sleeves of porous material are identical in structure and size.

In some embodiments, the at least one porous material inner sleeve comprises two porous material inner sleeves, and the at least one dynamic pressure foil set comprises one dynamic pressure foil set, and the one dynamic pressure foil set is located between the two porous material inner sleeves.

In some embodiments, the difference between the inner diameter of the at least one dynamic pressure foil set and the inner diameter of the at least one porous material inner shaft sleeve is 5-8 μm.

In some embodiments, the dynamic compression foil set comprises:

the supporting wave foils are connected with the inner wall of the dynamic pressure mounting section of the bearing shell, each supporting wave foil is integrally arc-shaped, and a plurality of arc-shaped ripples are arranged along the extending direction of the supporting wave foils;

the first top foil is connected with the inner wall of the dynamic pressure mounting section of the bearing shell, is positioned on one side, adjacent to the axis of the bearing shell, of the supporting wave foil and supports the supporting wave foil in the radial direction;

a second top foil connected to an inner wall of the dynamic pressure mounting section of the bearing housing, the second top foil being located on a side of the first top foil adjacent to an axis of the bearing housing and supporting the first top foil in a radial direction,

wherein the inner diameter d1 of the set of dynamic pressure foils is the inner diameter of the second top foil.

In some embodiments, the inner wall of the dynamic pressure mounting section of the bearing housing has a plurality of sets of the linear grooves corresponding to the plurality of the supporting wave foils, the first end of the supporting wave foil corresponding to each set of the linear grooves is fixed in the set of the linear grooves, the first end of the first top foil is fixed in one set of the linear grooves, the first end of the second top foil is fixed in one set of the linear grooves, the second end of the supporting wave foil corresponding to each set of the linear grooves extends in a direction opposite to the first end of the second top foil, and the second end of the supporting wave foil corresponding to each set of the linear grooves extends in the same direction as the first end of the second top foil.

In some embodiments, each group of the wire slots includes a non-pin hole wire slot, the first end of the supporting bump foil corresponding to each group of the wire slots is inserted and fixed in the non-pin hole wire slot, at least one group of the wire slots includes a pin hole wire slot, and the first end of the first top foil and the first end of the second top foil are inserted and fixed in the pin hole wire slot through a pin.

In some embodiments, the first end of the first top foil and the first end of the second top foil are both plugged within the same pin hole slot.

In some embodiments, a height h1 of at least one of the plurality of arcuate corrugations of the supporting wave foil is 0.4 to 0.6mm, and/or a diameter d3 of at least one of the plurality of arcuate corrugations of the supporting wave foil is 4 to 5mm, and/or an angular difference α of every two adjacent arcuate corrugations of the plurality of corrugations of the supporting wave foil with respect to an axis of the bearing shell is 3 to 5 °.

In some embodiments, the outer wall of the bearing shell has at least one first annular groove and an air supply inlet hole, each static pressure mounting section of the bearing shell has an air supply outlet hole, the body of the bearing shell has an air supply flow passage communicating the air supply inlet hole and the air supply outlet hole, and the at least one first annular groove is configured as an annular seal ring fixedly sleeved in the first annular groove.

In some embodiments, the outer circumferential surface of the porous material inner sleeve has a plurality of air flow grooves arranged at intervals in the axial direction, a flow opening is provided between adjacent air flow grooves, and the air supply outlet hole faces at least one of the air flow grooves.

In some embodiments, at least one of the plurality of air flow slots has a depth of 0.3 to 0.5 mm.

In some embodiments, the width of the vent is the same as the width of each of the plurality of airflow slots.

In some embodiments, the gas supply channel is a straight line channel penetrating through the body of the bearing housing, the gas supply channel is parallel to the axis of the bearing housing, and sealing plugs are arranged at both ends of the gas supply channel.

In one aspect of the present disclosure, there is provided a compressor comprising the aforementioned gas bearing.

Therefore, according to the embodiment of the disclosure, at least one inner sleeve made of porous material and at least one dynamic pressure foil set are respectively arranged on at least one static pressure mounting section and at least one dynamic pressure mounting section which are arranged in the inner cavity of the bearing shell along the axial direction, and the inner diameter of the inner sleeve made of porous material is smaller than that of the dynamic pressure foil set. The gas bearing provided by the embodiment of the disclosure can realize reliable supporting effect on the rotor through the static pressure radial bearing section corresponding to the porous material inner shaft sleeve when the rotor is at a lower speed, and can provide supporting effect with higher rigidity and damping for the rotor through the dynamic pressure radial bearing section corresponding to the dynamic pressure foil set when the rotor is at a higher speed, so that the gas bearing provided by the embodiment of the disclosure can provide good support for the rotor in a larger rotating speed range, and the service life and the working stability are improved.

In addition, the integrated bearing shell can ensure the coaxiality of the gas bearing more easily during processing of the gas bearing, so that the mounting precision of the bearing is ensured, the quality of a gas film formed by the gas bearing is improved, and higher structural strength can be obtained.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and together with the description, serve to explain the principles of the disclosure.

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

FIG. 1 is a schematic structural view of some embodiments of a gas bearing according to the present disclosure;

FIG. 2 is a longitudinal cross-sectional schematic view of a mounting structure in an axial direction according to some embodiments of the gas bearing of the present disclosure;

FIG. 3 is a schematic longitudinal cross-sectional view of an exploded structure in an axial direction according to some embodiments of the gas bearing of the present disclosure;

FIG. 4 is a schematic structural view of a dynamic pressure bearing segment from an axial perspective in accordance with some embodiments of the gas bearing of the present disclosure;

FIG. 5 is an enlarged schematic view of circle A in FIG. 4;

FIG. 6 is a perspective view of an inner sleeve of porous material in accordance with some embodiments of the gas bearing of the present disclosure.

It should be understood that the dimensions of the various parts shown in the drawings are not drawn to scale. Further, the same or similar reference numerals denote the same or similar components.

Detailed Description

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 disclosure, its application, or uses. The present disclosure may be embodied in many different forms and is not limited to the embodiments described herein. These embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. It should be noted that: the relative arrangement of parts and steps, the composition of materials, numerical expressions and numerical values set forth in these embodiments are to be construed as merely illustrative, and not as limitative, unless specifically stated otherwise.

The use of "first," "second," and similar terms in this disclosure is not intended to indicate any order, quantity, or importance, but rather are used to distinguish one element from another. The word "comprising" or "comprises", and the like, means that the element preceding the word covers the element listed after the word, and does not exclude the possibility that other elements are also covered. "upper", "lower", "left", "right", and the like are used merely to indicate relative positional relationships, and when the absolute position of the object being described is changed, the relative positional relationships may also be changed accordingly.

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 intervening devices between the specific device and the first device or the second device. When a particular device is described as being coupled to other devices, that particular device may be directly coupled to the other devices without intervening devices or may be directly coupled to the other devices with intervening devices.

All terms (including technical or scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs unless specifically defined otherwise. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail but are intended to be part of the specification where appropriate.

FIG. 1 is a schematic structural view of some embodiments of a gas bearing according to the present disclosure. FIG. 2 is a longitudinal cross-sectional schematic view of a mounting structure in an axial direction according to some embodiments of the gas bearing of the present disclosure. FIG. 3 is a schematic longitudinal cross-sectional view of an exploded structure in an axial direction according to some embodiments of the gas bearing of the present disclosure.

Referring to fig. 1-3, in some embodiments, a gas bearing includes: the bearing comprises a bearing shell 10, at least one inner shaft sleeve 30 made of porous material and at least one movable pressing foil group 20. The bearing housing 10 has an axially extending inner cavity comprising at least one static pressure mounting section 11b and at least one dynamic pressure mounting section 11a arranged in the axial direction. At least one inner sleeve 30 of porous material is disposed within the at least one static pressure mounting section 11b, respectively. At least one dynamic pressure foil set 20 is respectively provided in the at least one dynamic pressure mounting section 11 a.

In the embodiment, at least one inner shaft sleeve made of porous material and at least one dynamic pressure foil set are respectively arranged on at least one static pressure mounting section and at least one dynamic pressure mounting section which are axially arranged in the inner cavity of the bearing shell, so that the respective short plates of the static pressure radial bearing and the static pressure radial bearing in the related art are compensated by utilizing the performance of the dynamic pressure radial bearing and the static pressure radial bearing under the condition of different rotating speeds of the rotor. The axial direction here refers to a direction parallel to the axis s of the gas bearing. In addition, the integrated bearing shell can ensure the coaxiality of the gas bearing more easily during processing of the gas bearing, so that the mounting precision of the bearing is ensured, the quality of a gas film formed by the gas bearing is improved, and higher structural strength can be obtained.

Referring to fig. 2, the inner diameter d2 of the at least one inner sleeve 30 of porous material is smaller than the inner diameter d1 of the at least one set of dynamic pressure foils 20. Compared with the dynamic pressure radial bearing in the related technology, the dynamic pressure radial bearing can avoid serious dry friction between the dynamic pressure radial bearing section and the surface of the rotor in the low-speed stage of the rotor. And moreover, the dynamic pressure foil group can support the rotor with higher rigidity and damping in the high-speed stage of the rotor, and compared with the static pressure radial bearing in the related art, the stability problem of the static pressure radial bearing section in the high-speed stage of the rotor can be avoided. Therefore, the suspension of the rotor in the full-speed working range can be further realized, and the service life of the gas bearing and the working stability and reliability are greatly prolonged.

In other words, by setting the inner diameter d2 of the porous material inner shaft sleeve 30 to be smaller than the inner diameter d1 of the dynamic pressure foil group 20, the action sequence of the static pressure radial bearing section corresponding to the porous material inner shaft sleeve and the dynamic pressure radial bearing section corresponding to the dynamic pressure foil group at different rotating speeds of the rotor can be realized, so that the performance of the dynamic pressure radial bearing and the static pressure radial bearing under different rotating speed conditions of the rotor respectively is fully realized, and the short plates of the static pressure radial bearing and the static pressure radial bearing in the related art are better compensated.

In some embodiments, the at least one static mount section 11b comprises at least two static mount sections 11 b. A portion of the at least two static pressure mounting sections 11b is located on one side of the at least one dynamic pressure mounting section 11a in the axial direction, and another portion of the at least two static pressure mounting sections 11b is located on the other side of the at least one dynamic pressure mounting section 11a in the axial direction. The arrangement mode is convenient for the assembly of the movable pressing foil group and the porous material inner shaft sleeve in the inner cavity of the bearing shell, reduces the assembly difficulty and is easy to ensure the bearing precision.

It should be noted that two adjacent dynamic pressure foil sets may also be regarded as one dynamic pressure foil set that is longer in the axial direction, and two adjacent porous material inner sleeves may also be regarded as one porous material inner sleeve that is longer in the axial direction. Thus, the above arrangement can be regarded as a gas bearing having a combination of static pressure-dynamic pressure-static pressure. In other embodiments, the gas bearing may also adopt a combination of dynamic pressure-static pressure, a combination of dynamic pressure-static pressure-dynamic pressure, and the like. The gas bearing based on the static pressure-dynamic pressure-static pressure combination mode of the integrated bearing shell has the advantages of lower assembly difficulty, more compact structure and easier guarantee of precision.

Referring to fig. 2 and 3, in some embodiments, the at least one inner sleeve 30 of porous material comprises at least two inner sleeves 30 of porous material disposed within the at least two static pressure mounting sections 11b, respectively. The structure and the size of the at least two static pressure mounting sections 11b are the same, and the structure and the size of the at least two inner shaft sleeves 30 made of porous materials are the same. The structure can balance the stress of the gas bearing to obtain better working stability.

In fig. 2 and 3, the at least one inner sleeve 30 of porous material includes two inner sleeves 30 of porous material, the at least one dynamic pressure foil set 20 includes one dynamic pressure foil set 20, and the one dynamic pressure foil set 20 is located between the two inner sleeves 30 of porous material. The gas bearing has high structural working stability, and the assembly can be simplified due to the small number of stages. And, this kind of gas bearing section number is less for whole axial width is relatively less, thereby guarantees the assembly precision more easily and is difficult to be worn and torn.

In the above embodiment, the difference between the inner diameter of at least one dynamic pressure foil set 20 and the inner diameter of the at least one porous material inner sleeve 30 is preferably 5-8 μm. The value range can enable the dynamic pressure radial bearing section corresponding to the dynamic pressure foil group 20 to obtain a relatively proper air film thickness, so that on one hand, the abrasion risk of the rotor and the dynamic pressure radial bearing section can be reduced, and on the other hand, the risk of instability caused by vibration of the dynamic pressure radial bearing section when the rotor rotates at a high speed can be reduced.

FIG. 4 is a schematic structural view of a dynamic pressure bearing segment from an axial perspective in some embodiments of gas bearings according to the present disclosure. Fig. 5 is an enlarged schematic view of circle a in fig. 4. Referring to fig. 4 and 5, in some embodiments, the dynamic pressure foil set 20 includes: a plurality of supporting wave foils 21, a first top foil 22 and a second top foil 23. The plurality of supporting wave foils 21 are connected to the inner wall of the dynamic pressure mounting section 11a of the bearing housing 10, and each supporting wave foil 21 is formed in an arc shape as a whole and has a plurality of arc-shaped ripples along the extending direction of the supporting wave foil 21. In some embodiments, the plurality of supporting wave foils 21 includes three circular arc-shaped supporting wave foils 21 having substantially the same length.

Referring to FIG. 5, in some embodiments, at least one of the plurality of arcuate corrugations of the supporting bump foil 22 has a height h1 of 0.4 to 0.6 mm. In some embodiments, at least one of the plurality of arcuate corrugations of the supporting bump foil 22 has a diameter d3 of 4-5 mm. In some embodiments, the angular difference α between each two adjacent arcuate corrugations of the plurality of corrugations of the supporting bump foil 22 with respect to the axis of the first bearing sleeve 21 is 3 ° to 5 °.

The first top foil 22 is connected to the inner wall of the dynamic pressure mounting section 11a of the bearing housing 10, and the first top foil 22 is located on the side of the support wave foil 21 adjacent to the axis of the bearing housing 10 and supports the support wave foil 21 in the radial direction. A second top foil 23 is attached to an inner wall of the dynamic pressure mounting section 11a of the bearing housing 10, and the second top foil 23 is located on a side of the first top foil 22 adjacent to the axis of the bearing housing 10 and supports the first top foil 22 in a radial direction. In this embodiment, the inner diameter d1 of the dynamic pressure foil set 20 is the inner diameter of the second top foil 23.

In this embodiment, the dynamic pressure foil set 20 can obtain better rigidity and damping when the rotor is in a high-speed working condition through the above-mentioned single-wave foil double-top foil combined structure, so as to prevent the rotor from generating self-excited vibration, thereby effectively improving the working stability of the rotor in the high-speed working condition.

In fig. 2 to 4, the inner wall of the dynamic pressure mounting section 11a of the bearing housing 10 has a plurality of sets of linear grooves corresponding to the plurality of supporting bump foils 21, and the first ends of the supporting bump foils 21 corresponding to each set of linear grooves are fixed in the sets of linear grooves. The first end of the first top foil 22 is fixed in one of the plurality of sets of wire slots, and the first end of the second top foil 23 is fixed in one of the plurality of sets of wire slots. The supporting bump foil 21, the first top foil 22 and the second top foil 23 may be connected to the inside of the bearing housing 10 through a pin-hole wiring groove or a non-pin-hole wiring groove, respectively.

The extending direction of the second end of the supporting wave foil 21 corresponding to each group of the line grooves with respect to the first end is opposite to the extending direction of the second end of the first top foil 22 with respect to the first end, and the extending direction of the second end of the supporting wave foil 21 corresponding to each group of the line grooves with respect to the first end is the same as the extending direction of the second end of the second top foil 23 with respect to the first end. For example, in fig. 5, the extending direction of the supporting bump foil 21 is clockwise, the extending direction of the first top foil 22 is counterclockwise, and the extending direction of the second top foil 23 is clockwise.

Referring to fig. 5, in some embodiments, each of the plurality of sets of wire slots includes a non-pin hole wire slot 17a, the first end of the supporting bump foil 21 corresponding to each of the plurality of sets of wire slots is inserted and fixed in the non-pin hole wire slot 17a, at least one of the plurality of sets of wire slots includes a pin hole wire slot 17b, and the first end of the first top foil 22 and the first end of the second top foil 23 are inserted and fixed in the pin hole wire slot 17b by a pin. This fixing means produces a self-pretensioning effect by the bending tension of the first top foil 22 and the second top foil 23 and causes a pretensioning effect between the first top foil 22 and the supporting bump foil 21.

In fig. 4 and 5, the first end of the first top foil 22 and the first end of the second top foil 23 are both inserted into the same pin hole slot 17 b. This allows the first top foil 22 and the second top foil 23 to together enclose a closed ring shape for providing a reliable support for the respective supporting bump foil 21.

FIG. 6 is a perspective view of an inner sleeve of porous material in accordance with some embodiments of the gas bearing of the present disclosure. Referring to fig. 2, 3 and 6, in some embodiments, the outer wall of the bearing housing 10 has at least one first annular groove 12 and an air supply inlet hole 13, each static pressure mounting section 11b of the bearing housing 10 has an air supply outlet hole 15, the body of the bearing housing 10 has an air supply flow passage 14 communicating the air supply inlet hole 13 and the air supply outlet hole 15, and the at least one first annular groove 12 is configured as an annular seal ring fixedly fitted in the first annular groove 12. These first annular grooves 12 increase the damping of the gas bearing and may act as gas seals by means of the annular sealing rings. In some embodiments, the material of the bearing shell 10 comprises a relatively lightweight aluminum alloy material.

The porous material inner sleeve 30 is located radially inward of the static pressure mounting section 11b of the bearing housing 10. An external gas source can introduce high-pressure gas from the outside of the bearing housing 10 to the outside of the porous material inner sleeve 30 through the gas supply inlet holes 13 via the gas supply flow passage 14 and the gas supply outlet holes 15, and make the gas film uniformly act on the rotor inside the porous material inner sleeve 30 through the porous material. In some embodiments, the porous material comprises porous graphite.

Referring to fig. 2 and 3, the air supply channel 14 is a straight channel penetrating through the body of the bearing housing 10, the air supply channel 14 is parallel to the axis of the bearing housing 10, and both ends of the air supply channel 14 are provided with sealing plugs 16. The air channel structure of the bearing shell 10 is more convenient to process.

In fig. 6, the at least one first annular groove 12 includes a plurality of first annular grooves 12 arranged at intervals in the axial direction. A part and another part of the plurality of first annular grooves 12 are respectively located on both sides of the air supply inlet hole 13 in the axial direction. For example, two first annular grooves 12 may be provided on both sides of the gas feed hole 13 in the axial direction of the gas bearing, so that the gas bearing can be kept uniform in damping in the axial direction while improving the gas-tight effect.

Referring to fig. 6, in some embodiments, the outer circumferential surface of the inner sleeve 30 made of porous material has a plurality of airflow grooves 31, the airflow grooves 31 are arranged at intervals in the axial direction, a through-flow opening 32 is provided between adjacent airflow grooves 31, and the air supply outlet 15 faces at least one of the airflow grooves 31. These gas flow grooves 31 may form a plurality of gas flow passages with the bearing housing 10 so that high-pressure gas can be uniformly discharged along the inner surface of the sleeve 30 in the porous material, thereby providing a more uniform supporting function to the rotor.

In fig. 6, the width of the through-flow opening 32 is the same as the width of each of the plurality of gas flow grooves 31, so that the high-pressure gas is more uniformly distributed. In addition, the depth of at least one of the airflow grooves 31 is 0.3-0.5 mm.

Any of the embodiments of the gas bearing described above in this disclosure may be used in a variety of apparatuses that use rotors, such as compressors. Accordingly, embodiments of the present disclosure provide a compressor including any one of the gas bearings described above.

Thus far, various embodiments of the present disclosure have been described in detail. Some details that are well known in the art have not been described in order to avoid obscuring the concepts of the present disclosure. It will be fully apparent to those skilled in the art from the foregoing description how to practice the presently disclosed embodiments.

Although some specific embodiments of the present disclosure have been described in detail by way of example, it should be understood by those skilled in the art that the foregoing examples are for purposes of illustration only and are not intended to limit the scope of the present disclosure. It will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope and spirit of the present disclosure. The scope of the present disclosure is defined by the appended claims.

Claims (16)

1. A gas bearing, comprising:

a bearing housing (10) having an axially extending inner cavity comprising at least one static pressure mounting section (11b) and at least one dynamic pressure mounting section (11a) arranged in an axial direction;

at least one inner sleeve (30) made of porous material and respectively arranged in the at least one static pressure mounting section (11 b);

at least one dynamic pressure foil set (20) respectively arranged in the at least one dynamic pressure mounting section (11a),

wherein the inner diameter d2 of the at least one porous material inner sleeve (30) is smaller than the inner diameter d1 of the at least one movable pressing foil group (20).

2. The gas bearing according to claim 1, wherein the at least one static pressure mounting section (11b) comprises at least two static pressure mounting sections (11b), a portion of the at least two static pressure mounting sections (11b) being located axially on one side of the at least one dynamic pressure mounting section (11a) and another portion of the at least two static pressure mounting sections (11b) being located axially on the other side of the at least one dynamic pressure mounting section (11 a).

3. The gas bearing according to claim 2, wherein said at least one porous material inner sleeve (30) comprises at least two porous material inner sleeves (30) respectively disposed within said at least two static pressure mounting sections (11b), said at least two static pressure mounting sections (11b) being identical in structure and size, said at least two porous material inner sleeves (30) being identical in structure and size.

4. The gas bearing of claim 1, wherein said at least one porous material inner sleeve (30) comprises two porous material inner sleeves (30), and said at least one dynamic pressure foil set (20) comprises one dynamic pressure foil set (20), said one dynamic pressure foil set (20) being located between said two porous material inner sleeves (30).

5. The gas bearing according to claim 1, wherein the difference between the inner diameter of the at least one moving foil set (20) and the inner diameter of the at least one porous inner sleeve (30) is 5-8 μm.

6. Gas bearing according to claim 1, wherein the dynamic pressure foil set (20) comprises:

a plurality of supporting wave foils (21) connected to the inner wall of the dynamic pressure mounting section (11a) of the bearing housing (10), each supporting wave foil (21) being formed in an arc shape as a whole and having a plurality of arc-shaped ripples along the extending direction of the supporting wave foil (21);

a first top foil (22) connected to an inner wall of the dynamic pressure mounting section (11a) of the bearing housing (10), the first top foil (22) being located on a side of the supporting wave foil (21) adjacent to an axis of the bearing housing (10) and supporting the supporting wave foil (21) in a radial direction;

a second top foil (23) connected to an inner wall of the dynamic pressure mounting section (11a) of the bearing housing (10), the second top foil (23) being located on a side of the first top foil (22) adjacent to an axis of the bearing housing (10) and supporting the first top foil (22) in a radial direction,

wherein the inner diameter d1 of the dynamic pressure foil set (20) is the inner diameter of the second top foil (23).

7. The gas bearing according to claim 6, wherein the inner wall of the dynamic pressure mounting section (11a) of the bearing housing (10) has a plurality of sets of linear grooves corresponding to the plurality of supporting bump foils (21), the first end of the supporting wave foil (21) corresponding to each group of the wire slots is fixed in the group of the wire slots, the first end of the first top foil (22) is fixed in one group of the wire slots in the plurality of groups of the wire slots, a first end of the second top foil (23) is fixed in one of the sets of wire slots, the second end of the supporting bump foil (21) corresponding to each group of the wire grooves extends in the opposite direction to the first end of the supporting bump foil and the second end of the first top foil (22) extends in the opposite direction to the first end of the supporting bump foil, the extension direction of the second end of the supporting bump foil (21) corresponding to each group of the wire grooves relative to the first end is the same as the extension direction of the second end of the second top foil (23) relative to the first end.

8. The gas bearing of claim 7, wherein each set of wire grooves comprises a non-pin hole wire groove (17a), the first end of the supporting bump foil (21) corresponding to each set of wire grooves is inserted and fixed in the non-pin hole wire groove (17a), at least one set of wire grooves in the plurality of sets of wire grooves comprises a pin hole wire groove (17b), and the first end of the first top foil (22) and the first end of the second top foil (23) are inserted and fixed by a pin in the pin hole wire groove (17 b).

9. Gas bearing according to claim 8, wherein the first end of the first top foil (22) and the first end of the second top foil (23) are plugged into the same pin hole slot (17 b).

10. The gas bearing according to claim 6, wherein the height h1 of at least one of the plurality of arcuate corrugations of the supporting wave foil (21) is 0.4-0.6 mm, and/or the diameter d3 of at least one of the plurality of arcuate corrugations of the supporting wave foil (21) is 4-5 mm, and/or the angular difference α of every two adjacent arcuate corrugations of the plurality of corrugations of the supporting wave foil (21) with respect to the axis of the bearing shell (10) is 3-5 °.

11. The gas bearing according to claim 1, characterized in that the outer wall of the bearing housing (10) has at least one first annular groove (12) and a gas supply inlet hole (13), each static pressure mounting section (11b) of the bearing housing (10) has a gas supply outlet hole (15), the body of the bearing housing (10) has a gas supply flow channel (14) communicating the gas supply inlet hole (13) and the gas supply outlet hole (15), the at least one first annular groove (12) is configured as an annular sealing ring fixedly fitted in the first annular groove (12).

12. The gas bearing according to claim 11, wherein the outer circumferential surface of the porous material inner sleeve (30) has a plurality of gas flow grooves (31), the plurality of gas flow grooves (31) are arranged at intervals in the axial direction, flow openings (32) are provided between adjacent gas flow grooves (31), and the gas supply hole (15) faces at least one of the plurality of gas flow grooves (31).

13. A gas bearing according to claim 12, wherein at least one of the plurality of gas flow grooves (31) has a depth of 0.3-0.5 mm.

14. The gas bearing of claim 12, wherein the width of the flow opening (32) is the same as the width of each of the plurality of gas flow slots (31).

15. The gas bearing as claimed in claim 11, characterized in that the gas supply channel (14) is a straight channel running through the body of the bearing housing (10), the gas supply channel (14) is parallel to the axis of the bearing housing (10), and a sealing plug screw (16) is provided at both ends of the gas supply channel (14).

16. A compressor, comprising:

a gas bearing according to any one of claims 1 to 15.

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