CN114688072A - Gas bearing, bearing assembly and compressor - Google Patents

Abstract

The present disclosure relates to a gas bearing, a bearing assembly and a compressor. The gas bearing (30) comprises: a bearing housing (31) having at least one groove (314) on an outer peripheral surface thereof configured to form a pressure chamber (316); at least one bottom foil (32) disposed inside an inner circumferential surface of the bearing housing (31) and corresponding to the at least one groove (314), respectively; at least one bump foil (33) respectively arranged on one side of the at least one bottom foil (32) far away from the bearing shell (31) and respectively corresponding to the at least one groove (314); a top foil (34) arranged on a side of the at least one bump foil (33) facing away from the bearing housing (31), wherein a groove bottom of the groove (314) has a plurality of through holes (313), the plurality of through holes (313) being configured to let pressure gas within the pressure chamber (316) enter between the bearing housing (31) and the corresponding bottom foil (32) and act on a surface of the bottom foil (32). The embodiment of the disclosure can quickly form a dynamic pressure air film of the bearing in the starting and stopping stages of the rotor.

Description

Gas bearings, bearing assemblies and compressors

technical field

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

Background technique

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 dominance of liquid lubrication technology and made a qualitative leap in lubrication technology. The gas bearing is a new type of bearing based on this new lubrication technology. It has a series of advantages such as low friction loss, good stability, low vibration, and oil-free lubrication. It has a wide range of high-speed turbines, machine tool manufacturing and space technology. application prospects.

Gas bearing refers to the use of gas as a lubricant, and the use of gas adsorption, transmission (diffusion, viscosity and thermal conductivity) and compressibility characteristics, based on fluid dynamic pressure effect, static pressure effect and extrusion during friction. The effect is to form a layer of gas film to support the load and reduce friction.

According to the different generating mechanism of lubricating gas film, gas bearing can be divided into dynamic pressure gas bearing, static pressure gas bearing and extruded gas bearing. Foil dynamic pressure gas radial bearing is a gas bearing with the most research literature available at present, and its typical structure is generally composed of bearing shell, top foil and corrugated foil. The corrugated foil is an elastic foil with a special waveform. During operation, the elastic change of the waveform generates a supporting force to provide the main stiffness and partial damping for the bearing; the top foil is a long cylindrical foil, and in the radial direction, the top foil is uniform on one side The ground overlaps the top of each corrugated foil, and provides another part of the damping for the bearing through the friction force generated by the contact with the corrugated foil; the other side of the top foil is clearance fit with the rotor to form the air film required for the dynamic pressure effect space.

The rotating shaft is eccentric relative to the bearing under the action of gravity, forming a wedge-shaped gap with the inner surface of the bearing. When the rotating shaft rotates at high speed, the gas with a certain viscosity is continuously brought into the wedge-shaped gap, and the continuous entry of the gas makes the gas film generate a certain pressure. When the air film force is sufficient to balance the shaft load, the shaft and the bearing are completely separated, and the process of the above air film generation is called the dynamic pressure effect.

Hydrostatic gas bearing refers to the supply of gas with a certain pressure through the external gas supply system, and then the gas is delivered to the gap between the bearing and the rotor through the bearing restrictor, thereby forming a gas film at the gap to support the external load. The air film pressure in the bearing clearance can be adjusted by the bearing restrictor and air supply system. According to the different restrictors, there are common small hole static pressure gas bearings and porous static pressure gas bearings.

SUMMARY OF THE INVENTION

The research found that in the process of starting and stopping the rotor, due to insufficient rotation speed, the gas film could not be formed quickly through the principle of dynamic pressure. At this time, the top foil of the dynamic pressure gas bearing had dry friction with the rotor, which affected the bearing life. In addition, the force of the rotor is not static, especially in high-speed turbocentrifuges, the working conditions often change with the actual application of the end, and the dynamic pressure gas bearing in the related art is difficult to adjust the bearing capacity according to the working conditions.

The hydrostatic bearing in the related art has the advantages of large bearing capacity, stable operation and long life. However, when the rotor speed is high, the hydrostatic bearing cannot effectively absorb and suppress the rotor vibration due to the lack of a damping mechanism.

In view of this, embodiments of the present disclosure provide a gas bearing, a bearing assembly, and a compressor, which can rapidly form a dynamic pressure gas film of the bearing during the start-stop stage of the rotor.

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

a bearing housing having at least one groove on an outer peripheral surface configured to form a pressure chamber;

at least one bottom foil, disposed on the inner side of the inner peripheral surface of the bearing housing, and corresponding to the at least one groove respectively;

at least one corrugated foil, respectively disposed on the side of the at least one bottom foil away from the bearing housing, and corresponding to the at least one groove respectively;

a top foil, disposed on the side of the at least one corrugated foil away from the bearing housing,

Wherein, the groove bottom of the at least one groove has a plurality of through holes, and the plurality of through holes are configured to allow the pressure gas in the pressure chamber to enter between the bearing housing and the corresponding bottom foil, and Act on the surface of the bottom foil.

In some embodiments, the at least one groove includes a plurality of grooves spaced circumferentially of the bearing housing.

In some embodiments, the plurality of through holes include at least two through hole groups, the at least two through hole groups are distributed along the circumference of the bearing housing, and the at least two through hole groups are configured The pressure gradually increases in the direction of rotation of the rotor supported by the gas bearing.

In some embodiments, the number of through holes of the at least two through hole groups is configured to increase along the direction of rotation of the rotor supported by the gas bearing, and/or each of the at least two through hole groups The diameters of the through holes in the through hole group are configured to increase in the direction of rotation of the rotor supported by the gas bearing.

In some embodiments, the at least two through-hole groups include a first through-hole group, a second through-hole group, and a third through-hole group arranged in a circumferential direction of the bearing housing, the first through-hole group The diameters of the plurality of through holes respectively included in the hole group, the second through hole group and the third through hole group are the same, and the number of through holes in the first through hole group is less than that in the second through hole group The number of through holes in the second through hole group is less than the number of through holes in the third through hole group.

In some embodiments, the at least one groove includes at least two scalloped annular grooves, each scalloped annular groove having two first groove walls opposed along the circumference of the bearing housing and along the bearing housing The axially opposite two second groove walls.

In some embodiments, the at least one bottom foil includes:

Arc plate, the cross-section is arc-shaped;

At least three hemming plates are connected to at least three edges of the circular arc plate and extend radially outward relative to the circular arc plate,

Wherein, the inner wall of the bearing housing has at least three embedding grooves, and the at least three edge-folding plates are respectively embedded in the at least three embedding grooves.

In some embodiments, each bottom foil has two hemming plates arranged opposite to each other in the circumferential direction and one hemming plate arranged in the axial direction, which are respectively embedded in the three embedding grooves of the inner wall of the bearing housing, So that the bottom foil and the inner wall of the bearing housing form an axially open gas outflow end.

In some embodiments, each bottom foil has two hem plates disposed opposite to each other in the circumferential direction and two hem plates disposed in the axial direction, which are respectively embedded in the four embedding grooves of the inner wall of the bearing housing. , so that the bottom foil and the inner wall of the bearing housing form a closed air cavity.

In some embodiments, the top foil includes:

a first top foil, located on a side of the at least one corrugated foil away from the bearing housing, supporting the at least one corrugated foil in a radial direction;

The second top foil, located on the side of the first top foil away from the bearing housing, supports the first top foil in the radial direction,

Wherein, the first end of the first top foil and the first end of the second top foil are both connected to the inner wall of the bearing housing through a fixing pin and a first pin hole wire groove located on the inner wall of the bearing housing , the extension direction of the second end of the first top foil is opposite to that of the second top foil.

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

a bearing support having a cavity and a ventilation hole communicating with the cavity;

The aforementioned gas bearing, located in the cavity,

Wherein, at least one groove of the bearing housing and the cavity wall of the cavity form a pressure cavity.

In some embodiments, the bearing housing outer wall and the cavity have a radial interference fit.

In some embodiments, the bearing assembly further includes:

A rotor amplitude detection unit, arranged on the bearing support and located on one side of the gas bearing along the axial direction of the gas bearing, is configured to detect the amplitude of the rotor supported by the gas bearing during rotation,

Wherein, the vent hole is configured to be connected to an external air supply device, and the amount of air supply received is adjusted according to the amplitude.

In some embodiments, the rotor amplitude detection unit includes:

At least two eddy current displacement sensors are distributed at different angular positions along the circumferential direction of the gas bearing.

In some embodiments, the rotor amplitude detection unit includes two eddy current displacement sensors that differ by 90 degrees in the circumferential direction of the gas bearing.

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

Therefore, according to the embodiment of the present disclosure, by arranging the bottom foil between the inner peripheral surface of the bearing housing and the corrugated foil, static pressure is applied to the bottom foil through the groove on the bearing housing and the through hole at the bottom of the groove, thereby In the rotor start-stop stage, the static pressure air film formed on the outside of the bottom foil is used to quickly form a dynamic pressure air film between the top foil and the rotor, thereby reducing the wear between the top foil and the rotor.

Description of drawings

The accompanying drawings, which form 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.

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

FIG. 1 is a schematic diagram of the mating structure between some embodiments of a bearing assembly and a rotor according to the present disclosure;

Fig. 2 is the structural representation of Fig. 1 after partial cutaway;

Fig. 3 is the structural representation of the longitudinal section of Fig. 1;

Fig. 4 is the structural representation of Fig. 1 under the axial viewing angle;

Fig. 5 is the structural representation of AA section in Fig. 3;

Fig. 6 is the enlarged schematic diagram of the area indicated by circle B in Fig. 5;

Fig. 7 is the enlarged schematic diagram of the area indicated by circle C in Fig. 6;

8 is a schematic structural diagram of a bearing housing in some embodiments of a gas bearing according to the present disclosure;

Fig. 9 is the structural schematic diagram of Fig. 8 under the axial viewing angle;

Fig. 10A is the structural representation of DD section in Fig. 9;

10B is a schematic cross-sectional view of a partial structure of a bearing housing in some embodiments of a gas bearing according to the present disclosure;

11A is a schematic structural diagram of the bottom foil in some embodiments of the gas bearing according to the present disclosure in an axial view;

FIG. 11B is a schematic three-dimensional structure diagram of FIG. 11A .

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

Detailed ways

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 illustrative only, and in no way limits the disclosure, its application or uses in any way. The present disclosure may be implemented 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 unless specifically stated otherwise, the relative arrangements of parts and steps, compositions of materials, numerical expressions and numerical values set forth in these embodiments are to be interpreted as illustrative only and not as limiting.

As used in this disclosure, "first," "second," and similar words do not denote any order, quantity, or importance, but are merely used to distinguish the different parts. "Comprising" or "comprising" and similar words mean that the elements preceding the word cover the elements listed after the word, and do not exclude the possibility that other elements are also covered. "Up", "Down", "Left", "Right", etc. are only used to indicate the relative positional relationship. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

In this disclosure, when a particular device is described as being between a first device and a second device, there may or may not be an intervening device between the particular device and the first device or the second device. When it is described that a particular device is connected to other devices, the particular device may be directly connected to the other devices without intervening devices, or may not be directly connected to the other devices but have intervening devices.

All terms (including technical or scientific terms) used in this disclosure have the same meaning as understood by one of ordinary skill in the art to which this disclosure belongs, unless specifically defined otherwise. It should also be understood that terms defined in, for example, general-purpose dictionaries should be construed to have meanings consistent with their meanings in the context of the related art, and not to be construed in an idealized or highly formalized sense, unless explicitly stated herein. Defined like this.

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

As shown in FIGS. 1-11B , the embodiments of the present disclosure provide a gas bearing, a bearing assembly and a compressor, which can rapidly form a dynamic pressure gas film of the bearing during the start-stop stage of the rotor.

Referring to FIGS. 1-7 , in some embodiments, the present disclosure provides a bearing assembly including: a bearing support 20 and a gas bearing 30 . The bearing support 20 has a cavity and a vent hole 21 communicating with the cavity. The gas bearing 30 is located in the cavity, and can support the rotor 10 which is located in the gas bearing 30 and rotates.

The vent hole 21 of the bearing support 20 can be connected to an external air supply device, and the high-pressure gas provided by the external air supply device can reach the outside of the gas bearing 30 through the vent hole 21. The external air supply can be an active air supply such as a pump, or a higher pressure air path in the equipment where the bearing assembly is applied.

Referring to FIG. 6 , in some embodiments, the gas bearing 30 includes a bearing housing 31 , at least one bottom foil 32 , at least one corrugated foil 33 and a top foil 34 . The outer peripheral surface of the bearing housing 31 has at least one groove 314 configured to form a pressure chamber 316. The pressure chamber 316 may be formed by at least one groove 314 of the bearing housing 31 and the cavity wall of the cavity of the bearing support 20 .

At least one bottom foil 32 is disposed inside the inner peripheral surface of the bearing housing 31, and corresponds to the at least one groove 314, respectively. At least one corrugated foil 33 is respectively disposed on the side of the at least one bottom foil 32 away from the bearing housing 31, and also corresponds to the at least one groove 314, respectively. The top foil 34 is disposed on the side of the at least one corrugated foil 33 away from the bearing housing 31 . When the rotor 10 rotates, a dynamic pressure air film may be formed between the top foil 34 and the rotor 10 .

In order to enable the gas in the pressure chamber 316 to reach between the bearing housing 31 and the corresponding bottom foil 32, a plurality of through holes 313 may be respectively provided at the bottom of the at least one groove 314. These through holes 313 enable the pressurized gas in the pressure chamber 316 to enter between the bearing housing 31 and the corresponding bottom foil 32 and act on the surface of the bottom foil 32 .

The functions of the plurality of through holes on the bearing housing 31 are equivalent to small-hole static pressure gas bearings. The static pressure air film is used to quickly form a dynamic pressure air film between the top foil and the rotor during the start-stop stage of the rotor, thereby reducing the wear between the top foil and the rotor.

In the bearing assembly, the bottom foil and the bearing housing and between the bottom foil and the corrugated foil can move relative to each other, and friction is generated, and part of the vibration of the rotor can be consumed by this friction, and part of the damping of the gas bearing can be realized.

In some embodiments, only one groove 314 (eg, annular groove) and corresponding one bottom foil 32 may be provided on the bearing housing 31 . Referring to FIGS. 5 and 8 , in some embodiments, the bearing housing 31 may include a plurality of grooves 314 , such as the three grooves 314 shown in FIGS. 5 and 8 , each groove 314 corresponding to one bottom foil 32 and a wave foil 33.

A plurality of grooves 314 may be spaced apart along the circumference of the bearing housing 31, ie each groove 314 may be located at a different angular position. In some embodiments, each groove is of equal length and is equally angularly spaced in order to create a more uniform hydrostatic film.

In some embodiments, the outer wall of the bearing housing 31 is a radial interference fit with the cavity of the bearing support 20. For example, a protruding structure may be formed between the aforementioned two adjacent grooves 314 , and the protruding structure may be used for interference fit with the inner wall of the cavity of the bearing support 20 in the radial direction. In other embodiments, the bearing housing 31 can also be fixed in the cavity of the bearing support 20 by means of clamping, bonding, welding, screw connection or screw bolt connection.

6, 8, 10A and 10B, in some embodiments, the plurality of through holes 313 includes at least two through hole groups. Each through hole group may include at least one through hole. The at least two through-hole groups are distributed along the circumferential direction of the bearing housing 31, in other words, each through-hole group occupies a circumferential extent within the groove. In some embodiments, at least two sets of through holes may be configured to gradually increase the pressure exerted on the bottom foil along the direction of rotation ω of the rotor 10 supported by the gas bearing 30.

In order to enable the at least two through-hole groups to gradually increase the pressure along the direction ω, referring to FIG. 10A , in some embodiments, the number of through-holes of the at least two through-hole groups can be configured to be supported along the gas bearing 30 The rotation direction ω of the rotor 10 increases. For example, in FIGS. 10A and 10B , the at least two through hole groups include a first through hole group 313 a , a second through hole group 313 b and a third through hole group arranged along the circumferential direction of the bearing housing 31 313c. The first through hole group 313a, the second through hole group 313b and the third through hole group 313c respectively include a plurality of through holes 313 with the same diameter, and the through holes of the first through hole group 313a The number is less than the number of through holes in the second through hole group 313b, and the number of through holes in the second through hole group 313 is less than the number of through holes in the third through hole group 313c.

By increasing the number of through holes, the air pressure input to the outside of the bottom foil can be increased, and by arranging different numbers of through holes at different circumferential positions in a groove, multiple different pressures between the bottom foil and the bearing housing can be achieved. Area. Different pressure zones can form wedge-shaped gaps of different sizes. Referring to FIG. 10B , along the rotation direction ω of the rotor 10, the first through hole group 313a, the second through hole group 313b and the third through hole group 313c correspond to the low pressure area, the medium pressure area and the high pressure area, respectively. The action of the air pressure in the pressure zone can change the wedge-shaped gap formed between different positions of the rotor 10 and the top foil 34 .

The low pressure region can form a wedge-shaped gap X3 between the rotor 10 and the top foil 34 , the medium pressure region can form a wedge-shaped gap X2 between the rotor 10 and the top foil 34 , and the high-pressure region can form a wedge-shaped gap between the rotor 10 and the top foil 34 . X1. Among them, the wedge-shaped gap X1 is smaller than the wedge-shaped gap X2, and the wedge-shaped gap X2 is smaller than the wedge-shaped gap X3. In this way, along the rotation direction ω of the rotor 10, the wedge-shaped gap is changed from large to small. This allows the gas bearing to form a dynamic pressure gas film faster during the start-stop phase or low-speed phase of the rotor.

In other embodiments, the diameter of the through hole 313 in each of the at least two through hole groups is configured to increase along the rotation direction ω of the rotor 10 supported by the gas bearing 30. By increasing the diameter of the through holes, an effect similar to increasing the number of through holes can also be achieved. In other words, assuming that each through-hole group has the same number of through-holes, through-hole groups with different through-hole diameters can realize multiple pressure zones with different pressures between the bottom foil and the bearing housing, while through-hole groups with larger through-hole diameters can realize multiple pressure zones with different pressures between the bottom foil and the bearing housing. Orifice groups allow for higher pressure zones.

Of course, for the designer, the number of through holes and the diameter of the through holes in each through hole group can be set correspondingly according to actual needs to realize the division of different pressures.

5 and 6, in some embodiments, at least one groove 314 includes at least two scalloped grooves. For example, in FIG. 5, the bearing housing 31 may have three scalloped annular grooves. The fan ring here refers to the shape of the groove on the cross section of the bearing housing 31, wherein the outer ring of the fan ring is the outer ring of the bearing housing 31, and the inner ring is the bottom of the groove.

In FIG. 8 , each sector annular groove has two first groove walls 314 a opposite along the circumferential direction of the bearing housing 31 and two second groove walls 314 b opposite along the axial direction of the bearing housing 31 . These four groove walls may form a closed pressure chamber 316 with the inner wall of the cavity of the bearing support 20.

Referring to FIGS. 8 , 11A and 11B , in some embodiments, at least one bottom foil 32 includes a circular arc plate 321 and at least three hemming plates 322 . The arc-shaped plate 321 has an arc-shaped cross-section, and the cross-section is perpendicular to the axis of the gas bearing 30 . At least three hemming plates 322 are connected to at least three edges of the circular arc plate 321 and extend radially outward relative to the circular arc plate 321. The inner wall of the bearing housing 31 has at least three inserting grooves 315, and the at least three flanging plates 322 are respectively embedded in the at least three inserting grooves 315.

On the one hand, the embedded structure of the hemming plate and the embedded groove can realize the limited and movable connection between the bottom foil and the bearing shell, and the distance between the arc plate and the bearing shell can be adjusted by the gas pressure acting on the arc plate. , and use the folded plate to achieve the effect of gas accumulation. On the other hand, the friction between the folded plate and the embedded groove during relative movement can consume part of the vibration of the rotor and achieve part of the damping of the gas bearing.

In FIGS. 11A and 11B , each bottom foil 32 has two hemming plates 322 arranged opposite to each other in the circumferential direction and one hemming plate 322 arranged in the axial direction, which are respectively embedded in the inner wall of the bearing housing 31 . Three are embedded in the grooves 315 , so that the bottom foil 32 and the inner wall of the bearing housing 31 form an axially open gas outflow end. This prevents gas from leaking from these three directions by the three hem plates, thereby building up pressure between the bottom foil and the bearing housing, and the gas outflow end facilitates the flow of high-pressure gas.

In other embodiments, each bottom foil 32 has two hem plates 322 arranged opposite to each other in the circumferential direction and two folded plates 322 arranged in the axial direction, which are respectively embedded in the inner wall of the bearing housing 31 . Four are embedded in the grooves 315 , so that the bottom foil 32 and the inner wall of the bearing housing 31 form a closed air cavity. The static pressure effect is improved through the cooperation of the four hemming plates and the four embedding grooves, and the static pressure gas can flow out from the gap between the hemming plates and the embedding grooves.

5 and 6 , one end of each corrugated foil 33 can be connected to the inner wall of the bearing housing 31 through a fixing pin and a second pin hole slot 312 located on the inner wall of the bearing housing 31. In some embodiments, the top foil 34 includes a first top foil 341 and a second top foil 342 . The first top foil 341 is located on the side of the at least one corrugated foil 33 away from the bearing housing 31, and supports the at least one corrugated foil 33 in the radial direction. The second top foil 342 is located on the side of the first top foil 341 away from the bearing housing 31, and supports the first top foil 341 in the radial direction. The first end of the first top foil 341 and the first end of the second top foil 342 are connected to the bearing housing through a fixing pin and a first pin hole slot 311 located on the inner wall of the bearing housing 31 . 31 is connected to the inner wall, and the extension direction of the second end of the first top foil 341 and the second end of the second top foil 342 is opposite.

By arranging the first top foil and the second top foil with opposite extension directions, relative motion can be generated between the two top foils when the rotor rotates, thereby generating friction, which can consume part of the vibration of the rotor and form a part of the gas bearing damping.

1-4, in some embodiments, the bearing assembly further includes a rotor amplitude detection unit. The rotor amplitude detection unit is provided on the bearing support 20 and is located on one side of the gas bearing 30 along the axial direction of the gas bearing 30 . The rotor amplitude detection unit can detect the amplitude of the rotor 10 supported by the gas bearing 30 when rotating. And the ventilation hole 21 can be connected with an external air supply device, and the air supply volume it receives can be adjusted according to the amplitude.

In FIGS. 1-4 , the rotor amplitude detection unit includes at least two eddy current displacement sensors 40 . At least two eddy current displacement sensors 40 are distributed at different angular positions along the circumference of the gas bearing 30. For example, the eddy current displacement sensor 40 is fastened to the bearing support 20 by means of threads.

In order to reduce the number of sensors, it is preferable that the rotor amplitude detection unit includes two eddy current displacement sensors 40 that differ by 90 degrees in the circumferential direction of the gas bearing 30 . When the rotor 10 is at rest, the two eddy current displacement sensors 40 can detect the initial position of the rotor 10. When the rotor 10 rotates, the amplitude of the rotor is different under the action of different rotational speeds and external forces. By comparing with the initial position, the measured rotor amplitude can reflect the position of the rotor in real time on the one hand, and feedback the air film of the rotor on the other hand. Is the thickness appropriate. Appropriate air film thickness can make the rotor amplitude small and stable.

As mentioned above, different wedge-shaped gaps corresponding to different pressure zones are realized through multiple through-hole groups. With the increase of the pressure of the high-pressure gas passing into the outer side of the bottom foil, the changes of the above-mentioned wedge-shaped gaps can be more obvious. increase. As the pressure of the high-pressure gas introduced into the outer side of the bottom foil decreases, the difference between the above-mentioned wedge-shaped gaps can be reduced. In this way, the static pressure can be adjusted by controlling the high-pressure gas entering the pressure chamber, so as to adjust the wedge-shaped gap, thereby forming a dynamic pressure gas film of different thicknesses, so that the bearing can adapt to the change of working conditions and provide corresponding bearing capacity.

For example, when the rotor rotates at high speed, the rotor needs a larger bearing support force. By reducing the thickness of the dynamic pressure gas film, the bearing support force can be provided. At this time, the pressure of the high-pressure gas introduced in is reduced, so that the corresponding wedge-shaped The difference between the gaps (eg, wedge-shaped gaps X3, X2, X1) becomes smaller, and the eddy current displacement sensor 40 detects the amplitude of the rotor in real time, and adjusts different pressures until a stable and small rotor amplitude is obtained.

The various embodiments of the bearing assemblies described above are applicable to various types of equipment having rotors, such as compressors. Accordingly, the present disclosure also provides a compressor comprising any of the foregoing embodiments of the bearing assembly.

So far, the various embodiments of the present disclosure have been described in detail. Some details that are well known in the art are not described in order to avoid obscuring the concept of the present disclosure. Those skilled in the art can fully understand how to implement the technical solutions disclosed herein according to the above description.

While some specific embodiments of the present disclosure have been described in detail by way of examples, those skilled in the art will appreciate that the above examples are for illustration only and not for the purpose of limiting the scope of the present disclosure. It should be understood by those skilled in the art that, without departing from the scope and spirit of the present disclosure, the above embodiments may be modified or some technical features may be equivalently replaced. The scope of the present disclosure is defined by the appended claims.

Claims (16)

1. A gas bearing (30), comprising:

a bearing housing (31) having at least one groove (314) on an outer peripheral surface thereof configured to form a pressure chamber (316);

at least one bottom foil (32) disposed inside an inner circumferential surface of the bearing housing (31) and corresponding to the at least one groove (314), respectively;

at least one bump foil (33) respectively arranged on one side of the at least one bottom foil (32) far away from the bearing shell (31) and respectively corresponding to the at least one groove (314);

a top foil (34) arranged on a side of the at least one bump foil (33) facing away from the bearing housing (31),

wherein a groove bottom of the at least one groove (314) has a plurality of through holes (313), the plurality of through holes (313) being configured to let pressure gas within the pressure chamber (316) enter between the bearing housing (31) and the corresponding bottom foil (32) and act on a surface of the bottom foil (32).

2. The gas bearing (30) of claim 1, wherein the at least one groove (314) comprises a plurality of grooves (314) spaced circumferentially along the bearing housing (31).

3. The gas bearing (30) of claim 1, wherein the plurality of through holes (313) comprises at least two through hole groups distributed along a circumferential direction of the bearing housing (31) and configured to gradually increase in pressure along a rotational direction (ω) of a rotor (10) supported by the gas bearing (30).

4. A gas bearing (30) according to claim 3, wherein the number of through holes of the at least two groups of through holes is configured to increase in the direction of rotation (ω) of the rotor (10) supported by the gas bearing (30) and/or the diameter of the through holes (313) in each of the at least two groups of through holes is configured to increase in the direction of rotation (ω) of the rotor (10) supported by the gas bearing (30).

5. The gas bearing (30) according to claim 4, wherein the at least two through hole groups include a first through hole group (313a), a second through hole group (313b), and a third through hole group (313c) arranged in a circumferential direction of the bearing housing (31), the first through hole group (313a), the second through hole group (313b), and the third through hole group (313c) respectively include a plurality of through holes (313) having the same diameter, and the number of through holes of the first through hole group (313a) is smaller than the number of through holes of the second through hole group (313b), and the number of through holes of the second through hole group (313) is smaller than the number of through holes of the third through hole group (313 c).

6. The gas bearing (30) of claim 1, wherein the at least one groove (314) comprises at least two sector-shaped annular grooves, each sector-shaped annular groove having two first groove walls (314a) opposing in a circumferential direction of the bearing housing (31) and two second groove walls (314b) opposing in an axial direction of the bearing housing (31).

7. Gas bearing (30) according to claim 1, wherein the at least one bottom foil (32) comprises:

the cross section of the arc plate (321) is arc-shaped;

at least three flange plates (322) connected to at least three edges of the circular arc plate (321) and extending outward in a radial direction with respect to the circular arc plate (321),

wherein the inner wall of the bearing housing (31) is provided with at least three embedded grooves (315), and the at least three folding plates (322) are respectively embedded in the at least three embedded grooves (315).

8. Gas bearing (30) according to claim 7, wherein each bottom foil (32) has two crimping plates (322) arranged opposite to each other in the circumferential direction and one crimping plate (322) arranged in the axial direction, respectively embedded in three embedding grooves (315) of the inner wall of the bearing housing (31), such that the bottom foil (32) forms an axially open gas outflow end with the inner wall of the bearing housing (31).

9. The gas bearing (30) as claimed in claim 7, wherein each bottom foil (32) has two folding plates (322) arranged opposite in the circumferential direction and two folding plates (322) arranged in the axial direction, which are respectively inserted into four insertion grooves (315) of the inner wall of the bearing housing (31) so that the bottom foil (32) forms a closed gas chamber with the inner wall of the bearing housing (31).

10. The gas bearing (30) of claim 1, wherein the top foil (34) comprises:

a first top foil (341) located on a side of the at least one bump foil (33) remote from the bearing housing (31) radially supporting the at least one bump foil (33);

a second top foil (342) on a side of the first top foil (341) facing away from the bearing housing (31) radially supporting the first top foil (341),

wherein the first end of the first top foil (341) and the first end of the second top foil (342) are connected with the inner wall of the bearing housing (31) through a fixed pin and a first pin hole line groove (311) positioned on the inner wall of the bearing housing (31), and the second end of the first top foil (341) and the second end of the second top foil (342) extend in the opposite direction.

11. A bearing assembly, comprising:

a bearing support (20) having a cavity and a vent hole (21) communicating with the cavity;

the gas bearing (30) of any of claims 1 to 10, located within the cavity,

wherein the at least one groove (314) of the bearing housing (31) forms a pressure chamber (316) with a wall of the cavity.

12. A bearing assembly according to claim 11, characterized in that the bearing housing (31) outer wall is a radially interference fit with the cavity.

13. The bearing assembly of claim 11, further comprising:

a rotor amplitude detection unit provided on the bearing holder (20) and located on one side of the gas bearing (30) in an axial direction of the gas bearing (30), configured to detect an amplitude of a rotor (10) supported by the gas bearing (30) when rotating,

wherein the vent hole (21) is configured to be connected to an external air supply device, and the amount of air supplied to be received is adjusted according to the amplitude.

14. The bearing assembly of claim 13, wherein the rotor amplitude detection unit comprises:

at least two eddy current displacement sensors (40) distributed at different angular positions along the circumference of the gas bearing (30).

15. A bearing assembly according to claim 14, characterized in that the rotor amplitude detection unit comprises two eddy current displacement sensors (40) which are 90 degrees apart in the circumferential direction of the gas bearing (30).

16. A compressor, comprising:

a bearing assembly according to any of claims 11 to 15.

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