Bearing assembly and fluid machine

Abstract

The utility model relates to a bearing assembly and a fluid machine. The bearing assembly comprises a bearing support, a static pressure gas radial bearing and a dynamic pressure gas radial bearing. The static pressure gas radial bearing is arranged in the bearing support and comprises at least one bearing section and at least two sealing sections in the axial direction of the static pressure gas radial bearing. Each bearing section is located between every two adjacent sealing sections and provided with a throttling hole. The sealing section and the inner surface of the bearing support are arranged in a sealed mode, at least part of the inner surface of the sealing section is provided with an installation position, and the dynamic pressure gas radial bearing is arranged at the installation position. According to the bearing assembly, the dynamic pressure gas radial bearing is additionally arranged in the sealing section, so that the bearing assembly also has the bearing capacity at the sealing section without the throttling hole, and particularly, the bearing capacity is improved when the rotor inclines or is impacted by a load; the supporting force provided by the dynamic pressure gas radial bearing can reduce the possibility of rigid friction between the static pressure gas radial bearing and the rotor, reduce the sideband abrasion of the bearing assembly, improve the reliability and prolong the service life of the bearing assembly.

Description

Technical Field

[0001] The present application relates to the technical field of mechanical components, and in particular to a bearing assembly and a fluid machinery. Background Art

[0002] Gas lubrication technology was first proposed in the mid-19th century and developed rapidly in the mid-20th century. When working, gas bearings developed from gas lubrication technology use gas as a lubricant and utilize the characteristics of gas adsorption, transmission and compressibility. Under the action of fluid dynamic pressure effect, static pressure effect and extrusion effect, a layer of gas film is formed to support the load and reduce friction. Since gas bearings have a series of advantages such as low friction loss, good stability, low vibration and oil-free lubrication, they have very broad application prospects in the fields of high-speed turbines, machine tool manufacturing and space technology.

[0003] According to the different mechanisms of lubricating gas film generation, they are divided into dynamic pressure gas bearings, static pressure gas bearings and extrusion type gas bearings. Static pressure gas bearings provide gas with a certain pressure through an external gas supply system. The high-pressure gas is transported to the gap between the bearing and the rotor through the bearing throttle, and a gas film is formed in the gap to support the load.

[0004] In the related art, the two ends of the hydrostatic gas radial bearing are provided with O-rings for sealing and damping. Therefore, the two ends of the hydrostatic gas radial bearing cannot be processed with throttling holes, so the two ends have no load-bearing capacity. When working, if the rotor tilts or vibrates during rotation, it is easy to have rigid contact with the two ends of the hydrostatic gas radial bearing. In severe cases, adhesion occurs, resulting in sideband wear and even shaft seizure failure, reducing the reliability and life of the bearing. Utility Model Content

[0005] Based on this, it is necessary to provide a bearing assembly and a fluid machinery having the bearing assembly that can reduce sideband wear to improve its reliability and service life in order to address the above-mentioned problems.

[0006] A bearing assembly, comprising:

[0007] Bearing support;

[0008] A static pressure gas radial bearing is arranged in the bearing support and includes at least one bearing section and at least two sealing sections in its axial direction; each of the bearing sections is located between two adjacent sealing sections and has a throttle hole; the sealing section is sealed with the inner surface of the bearing support, and the inner surface of at least part of the sealing section has a mounting position; and

[0009] The dynamic pressure gas radial bearing is arranged at the installation position.

[0010] In one embodiment, the mounting position has a cooling groove, and the cooling groove extends from one end of the mounting position to the other end in the axial direction of the static pressure gas radial bearing.

[0011] In one of the embodiments, the sealing section also has an air outlet structure, which is located between the dynamic pressure gas radial bearing and the bearing section. The gap between the bearing section and the rotor matched with the bearing assembly is connected to one end of the dynamic pressure gas radial bearing and the cooling groove through the air outlet structure.

[0012] In one of the embodiments, the sealing section also has an annular groove, which is located at the mounting position in the axial direction of the static pressure gas radial bearing close to one end of the bearing section, and the annular groove is connected to the air outlet structure; each mounting position has a plurality of cooling grooves, and all of the cooling grooves are connected to the annular groove.

[0013] In one embodiment, the gas outlet structure has an arc-shaped guide wall toward the dynamic pressure gas radial bearing, and in the axial projection of the static pressure gas radial bearing, the annular groove and the dynamic pressure gas radial bearing at least partially overlap with the arc-shaped guide wall.

[0014] In one embodiment, the cooling groove extends helically around the axial direction of the static pressure gas radial bearing.

[0015] In one embodiment, the radial clearance dimension G1 between the bearing segment and the rotor matched with the bearing assembly is smaller than the radial clearance dimension G2 between the dynamic pressure gas radial bearing and the rotor;

[0016] And / or, the length of the bearing segment is greater than the length of the sealing segment.

[0017] In one embodiment, the dynamic pressure gas radial bearing includes a bump foil and a top foil, wherein the bump foil is arranged at the installation position, and the top foil is arranged at the top of the bump foil away from the installation position.

[0018] In one embodiment, the bump foil includes a plurality of sub-foil segments, the plurality of sub-foil segments are sequentially arranged along the circumference of the dynamic pressure gas radial bearing, and adjacent sub-foil segments are spaced apart from each other.

[0019] In one embodiment, each of the sub-foil segments has a first folded edge, the mounting position has a first matching groove, and the first folded edge is inserted into the first matching groove.

[0020] In one embodiment, the top foil has a second folded edge, the mounting position has a second matching groove, and the second folded edge is inserted into the second matching groove.

[0021] A fluid machine comprises the bearing assembly as described above.

[0022] The above-mentioned bearing assembly and fluid machinery add a dynamic pressure gas radial bearing in the sealing section of the static pressure gas radial bearing, so that the bearing assembly has load-bearing capacity even in the sealing section without a throttle hole. Especially when the rotor is tilted or subjected to load impact, the supporting force provided by the dynamic pressure gas radial bearing can reduce the possibility of rigid friction between the static pressure gas radial bearing and the rotor, thereby achieving the purpose of reducing the sideband wear of the bearing assembly to improve the reliability and service life of the bearing assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0024] Figure 1 It is a cross-sectional schematic diagram of the cooperation between the bearing assembly and the rotor in one embodiment of the present application.

[0025] Figure 2 for Figure 1 An enlarged schematic diagram of the bearing assembly and rotor at point A is shown.

[0026] Figure 3 for Figure 1 A left side view of the bearing assembly and rotor is shown.

[0027] Figure 4 for Figure 1 Right side view of the bearing assembly and rotor shown.

[0028] Figure 5 for Figure 1 A schematic structural diagram of a sub-foil segment in a corrugated foil of a hydrodynamic gas radial bearing in a bearing assembly is shown.

[0029] Figure 6 for Figure 1 Schematic diagram of the top foil structure of the hydrodynamic gas radial bearing in the bearing assembly shown.

[0030] Figure 7 for Figure 1 A schematic diagram of the structure of a hydrostatic gas radial bearing in a bearing assembly is shown.

[0031] Figure 8 for Figure 7 Another angle structural schematic diagram of the static pressure gas radial bearing is shown.

[0032] Fig. 9 for Figure 7 Left side view of a hydrostatic gas journal bearing shown.

[0033] Fig.10 for Figure 7 Right side view of a hydrostatic gas journal bearing shown.

[0034] Fig.11 for Figure 7 A partial cross-sectional view of a static pressure gas journal bearing is shown.

[0035] Fig.12 for Figure 8 A schematic cross-sectional view of a static pressure gas journal bearing is shown.

[0036] Fig.13 for Fig.12 An enlarged schematic diagram of the static pressure gas radial bearing at point B is shown.

[0037] Explanation of the reference numerals in the accompanying drawings: 100, bearing assembly; 10, bearing support; 11, air inlet; 30, static pressure gas radial bearing; 31, bearing section; 311, throttle hole; 33, sealing section; 331, mounting position; 3311, first matching groove; 3313, second matching groove; 3315, cooling groove; 333, sealing groove; 335, air outlet structure; 3351, arc-shaped guide wall; 337, annular groove; 35, shaft cavity; 37, air storage cavity; 50, dynamic pressure gas radial bearing; 51, corrugated foil; 511, sub-foil section; 513, first folded edge; 53, top foil; 531, second folded edge; 70, sealing element; 200, rotor. DETAILED DESCRIPTION

[0038] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0039] In the description of the present application, it should be understood that if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, the orientation or position relationship indicated by these terms is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.

[0040] In addition, if the term "and / or" appears, "and / or" is merely a description of the association relationship of associated objects, indicating that three relationships may exist, for example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the objects associated before and after are in an "or" relationship. If the terms "first" and "second" appear, these terms are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, if the term "multiple" appears, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0041] In this application, unless otherwise clearly specified and limited, if the terms "installed", "connected", "connected", "fixed" and the like appear, these terms should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0042] In the present application, unless otherwise clearly specified and limited, if there is a description that a first feature is "above" or "below" a second feature, etc., or similar descriptions appear, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0043] It should be noted that if an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. If an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. If any, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in this application are for illustrative purposes only and do not represent the only implementation method.

[0044] See also Figures 1 to 4 The bearing assembly 100 provided in one embodiment of the present application includes a bearing support 10, a static pressure gas radial bearing 30, and a dynamic pressure gas radial bearing 50. The static pressure gas radial bearing 30 is arranged in the bearing support 10, and includes at least one bearing section 31 and at least two sealing sections 33 in its own axial direction. Each bearing section 31 is located between two adjacent sealing sections 33, and each has a throttle hole 311, and the number of throttle holes 311 is multiple and spreads throughout the entire bearing section 31. The sealing section 33 is sealed with the inner surface of the bearing support 10, and the inner surface of at least part of the sealing section 33 has a mounting position 331, and the dynamic pressure gas radial bearing 50 is arranged at the mounting position 331.

[0045] It can be understood that the bearing assembly 100 is used to support the rotor 200 while enabling it to rotate smoothly. The bearing support 10 provides support for the static pressure gas radial bearing 30 and can surround the static pressure gas radial bearing 30. The static pressure gas radial bearing 30 forms an axial cavity 35 (such as Figure 5 As shown in the figure), the rotor 200 matched with the bearing assembly 100 is arranged in the shaft cavity 35.

[0046] The static gas radial bearing 30 is divided into a bearing section 31 and a sealing section 33 in the axial direction, and the dynamic gas radial bearing 50 is located at the installation position 331, that is, between the sealing section 33 and the rotor 200. Taking the static gas radial bearing 30 including a bearing section 31 and two sealing sections 33, and both sealing sections 33 have installation positions 331 as an example, a sealing section 33, a bearing section 31 and another sealing section 33 are connected end to end to form the static gas radial bearing 30, and the two sealing sections 33 are respectively located at the two ends of the static gas radial bearing 30 in the axial direction, and both have installation positions 331, and the two dynamic gas radial bearings 50 are respectively located in the two ends of the static gas radial bearing 30, and the two are coaxially arranged. At the same time, the gap between the bearing section 31 and the rotor 200 is connected to the gap between the dynamic gas radial bearing 50 and the rotor 200.

[0047] In this way, when the bearing assembly 100 is used, high-pressure gas is introduced into the static-pressure gas radial bearing 30, and the high-pressure gas is blown toward the surface of the rotor 200 matched with the bearing assembly 100 through the throttle hole 311, forming an air film on the surface of the rotor 200 to support the suspension of the rotor 200. The sealing arrangement between the sealing section 33 and the inner surface of the bearing support 10 can improve the sealing performance of the static-pressure gas radial bearing 30 and reduce the probability of gas passing into the static-pressure gas radial bearing 30 overflowing. It can be understood that for the purpose of sealing, the sealing section 33 itself is not processed to form the throttle hole 311.

[0048] The support of the rotor 200 by the dynamic pressure gas radial bearing 50 does not require a throttling hole 311. When the rotor 200 is eccentric relative to the bearing, a wedge-shaped gap is formed with the inner surface of the bearing. At this time, when the rotor 200 rotates at high speed, gas with a certain viscosity is continuously brought into the wedge-shaped gap. The continuous entry of gas causes the gas film to generate a certain pressure, thereby generating a supporting force.

[0049] The above-mentioned bearing assembly 100 is provided with a dynamic pressure gas radial bearing 50 in the sealing section 33 of the static pressure gas radial bearing 30, so that the bearing assembly 100 has load-bearing capacity even in the sealing section 33 without the throttle hole 311. Especially when the rotor 200 is tilted or subjected to load impact, the supporting force provided by the dynamic pressure gas radial bearing 50 can reduce the possibility of rigid friction between the static pressure gas radial bearing 30 and the rotor 200, thereby achieving the purpose of reducing the sideband wear of the bearing assembly 100 and improving the reliability and service life of the bearing assembly 100.

[0050] In addition, the bearing support 10 and the bearing section 31 are spaced apart in the radial direction to form an air storage chamber 37, and the air storage chamber 37 is connected to the throttle hole 311, and the throttle hole 311 extends radially along the rotor 200. The bearing support 10 is also provided with an air inlet 11 connected to the air storage chamber 37, and high-pressure gas enters the air storage chamber 37 through the air inlet 11. The air storage chamber 37 can store part of the gas from the air inlet 11, and transfer the high-pressure gas to the throttle hole 311, and finally blow it to the surface of the rotor 200. The sealing section 33 is located at both ends of the air storage chamber 37, and the sealing arrangement between the sealing section 33 and the inner surface of the bearing support 10 can reduce the probability of gas overflowing from the air storage chamber 37.

[0051] The bearing assembly 100 may further include a seal 70, and the seal section 33 and the inner surface of the bearing support 10 are sealed by the seal 70. The seal 70 may be specifically but not limited to a seal ring, and the outer surface of the seal section 33 is configured with a seal groove 333, and the seal ring is arranged in the seal groove 333, and contacts with the inner surface of the bearing support 10, and is squeezed and deformed to form a seal. Among them, the outer surface of the seal section 33 is the surface thereof facing the bearing support 10, and the inner surface of the seal section 33 is the surface thereof facing the rotor 200.

[0052] Please also read Figures 5 to 8 In some embodiments, the dynamic pressure gas radial bearing 50 includes a bump foil 51 and a top foil 53. The bump foil 51 is disposed at the mounting position 331, and the top foil 53 is disposed at the top of the bump foil 51 away from the mounting position 331. In other words, the dynamic pressure gas radial bearing 50 is a foil dynamic pressure gas bearing.

[0053] The corrugated foil 51 is an elastic foil with a special corrugation. The bottom of the corrugation is located on the mounting position 331 of the sealing section 33, and the top of the corrugation supports the top foil 53. When working, the corrugated foil 51 generates a supporting force through the elastic change of the corrugation, providing the main stiffness and partial damping for the dynamic pressure gas radial bearing 50. The top foil 53 is a cylindrical foil. In the radial direction, one side of the top foil 53 is evenly overlapped on the top of each corrugation of the corrugated foil 51, and the friction force generated by the contact with the corrugated foil 51 provides another part of the damping for the bearing. The other side of the top foil 53 is in clearance fit with the rotor 200 to form the air film space required for the dynamic pressure effect.

[0054] In this way, the bearing assembly 100 can utilize the flexible fit and wear resistance of the foil dynamic pressure gas bearing to position the dynamic pressure gas radial bearing 50 between the sealing section 33 and the rotor 200, and adapt to the changes of the rotor 200 through the deformation of its wave foil 51, thereby avoiding rigid friction between the static pressure gas radial bearing 30 and the rotor 200.

[0055] Furthermore, the bump foil 51 includes a plurality of sub-foil segments 511 , which are arranged in sequence along the circumferential direction of the dynamic pressure gas radial bearing 50 , and adjacent sub-foil segments 511 are spaced apart from each other.

[0056] The corrugated foil 51 can be evenly divided into multiple sub-foil segments 511 in the circumferential direction. Compared with the traditional structure which is a whole in the circumferential direction, the corrugated foil 51 with a multi-segment structure has a reduced force-bearing area of ​​each sub-foil segment 511 and lower rigidity. When the rotor 200 tilts in a certain direction, the elastic deformation of the corresponding compressed sub-foil segment 511 is larger, and the intervals between adjacent sub-foil segments 511 provide space for their deformation.

[0057] The following example illustrates that when the rotor 200 is subjected to a 1000N impact force and tilts in a certain direction and vibrates, the elastic deformation of the conventional structure is 5um, while the position of a sub-foil segment 511 in the multi-segment structure is in the direction of the impact force. Since it has lower rigidity and more sufficient deformation space, its elastic deformation may be 15um. Obviously, the latter has a greater degree of deformation, and the impact force vibration is absorbed by the deformation of the wave foil 51. The deformed wave foil 51 itself is elastic, and the recovery process releases energy in the form of heat energy.

[0058] In this way, the corrugated foil 51 can better adapt to the rotor 200 tilting at different angles. The tilt range of the rotor 200 is 360°, so theoretically the more sub-foil segments 511 the better. However, considering the processing and assembly processability, the number of sub-foil segments 511 is preferably 3 to 8.

[0059] Please also read Fig. 9 and Fig.10 In some embodiments, each sub-foil segment 511 has a first folded edge 513 , the mounting position 331 has a first matching groove 3311 , and the first folded edge 513 is inserted into the first matching groove 3311 .

[0060] It can be understood that the first matching grooves 3311 on the installation position 331 correspond to the sub-foil segments 511 one by one, and each sub-foil segment 511 is matched with a first matching groove 3311 through its first folded edge 513. The sub-foil segment 511 forms a first folded edge 513 at one end in the longitudinal direction thereof, which matches the installation position 331, and the other end can be a free end, which moves with the deformation of the sub-foil segment 511.

[0061] In this way, each sub-foil segment 511 can be accurately positioned by means of the cooperation between the first folded edge 513 and the first matching groove 3311, reducing the probability of movement and improving the reliability of the dynamic pressure gas radial bearing 50. At the same time, the sub-foil segment 511 can be positioned only by one end, so that it has good deformation ability.

[0062] In some embodiments, the top foil 53 has a second folded edge 531 , the mounting position 331 has a second matching groove 3313 , and the second folded edge 531 is inserted into the second matching groove 3313 .

[0063] In this way, the top foil 53 can be accurately positioned by means of the cooperation between the second folded edge 531 and the second matching groove 3313, thereby reducing the probability of movement and improving the reliability of the dynamic pressure gas radial bearing 50.

[0064] Please also read Figures 11 to 13 In some embodiments, the mounting position 331 has a cooling groove 3315 , and the cooling groove 3315 extends from one end to the other end of the mounting position 331 in the axial direction of the static pressure gas radial bearing 30 .

[0065] It can be understood that the cooling groove 3315 is used to pass a cooling medium, and the cooling medium can be, but is not limited to, a gas. After the cooling medium is passed through the cooling groove 3315 on the mounting position 331, the cooling medium can flow around the circumference of the dynamic pressure gas radial bearing 50 provided on the mounting position 331, specifically, flow at the bottom of the corrugated foil 51, and take away the heat of the dynamic pressure gas radial bearing 50 from the circumference.

[0066] When the rotor 200 is running at high speed, the heat generated by the bearing is proportional to the square of the rotation speed of the rotor 200. If the heat is not removed in time, the bearing is prone to thermal failure. Among them, the bearing section 31 of the static pressure gas radial bearing 30 forms a high-pressure gas film at the gap with the rotor 200, which supports the suspension of the rotor 200 and also takes away the heat of the bearing section 31. The cooling groove 3315 can improve the heat dissipation effect of the dynamic pressure gas radial bearing 50 and reduce the probability of its thermal failure.

[0067] In some embodiments, the sealing section 33 also has an air outlet structure 335, which is located between the dynamic pressure gas radial bearing 50 and the bearing section 31. The gap between the bearing section 31 and the rotor 200 is connected to one end of the dynamic pressure gas radial bearing 50 and the cooling groove 3315 through the air outlet structure 335.

[0068] It can be understood that, in the axial projection of the static pressure gas radial bearing 30, the gas outlet structure 335 at least partially overlaps with the dynamic pressure gas radial bearing 50. Specifically, the gas outlet structure 335 at least partially overlaps with the corrugated foil 51 of the dynamic pressure gas radial bearing 50. In addition, the gas outlet structure 335 is connected to the cooling groove 3315, and part of the gas discharged through the gas outlet structure 335 enters the inside of the dynamic pressure gas radial bearing 50, and part of the gas enters the cooling groove 3315 as a cooling medium.

[0069] In this way, the gas flowing out from the gap between the bearing section 31 and the rotor 200 is finally discharged outwardly through the gas outlet structure 335, and part of it is discharged toward the dynamic pressure gas radial bearing 50, and can flow toward the inside of the dynamic pressure gas radial bearing 50, flowing axially along the various waveforms of the wave foil 51 to dissipate the heat of the dynamic pressure gas radial bearing 50, and part of it is discharged into the cooling groove 3315, flowing through the bottom of the waveform, and dissipating the heat of the dynamic pressure gas radial bearing 50 on the circumferential side.

[0070] In some embodiments, the sealing section 33 further has an annular groove 337, which is located at one end of the mounting position 331 close to the bearing section 31 in the axial direction of the static pressure gas radial bearing 30, and the annular groove 337 is connected to the gas outlet structure 335. Each mounting position 331 has a plurality of cooling grooves 3315, and all cooling grooves 3315 are connected to the annular groove 337.

[0071] In this way, the gas discharged from the gas outlet structure 335 can flow into the cooling groove 3315 from one end of the cooling groove 3315 through the annular groove 337 , and it is ensured that each cooling groove 3315 can flow with gas.

[0072] In some embodiments, the air outlet structure 335 has an arc-shaped guide wall 3351 facing the dynamic pressure gas radial bearing 50 , and in the axial projection of the static pressure gas radial bearing 30 , the annular groove 337 and the dynamic pressure gas radial bearing 50 at least partially overlap with the arc-shaped guide wall 3351 .

[0073] In this way, after the gas enters the gas outlet structure 335 , it can flow toward the annular groove 337 and the dynamic pressure gas radial bearing 50 under the guidance of the arc-shaped guide wall 3351 .

[0074] The cooling groove 3315, the annular groove 337, the arc-shaped guide wall 3351 and other structures are integrated on the sealing section 33 of the static pressure gas radial bearing 30 to reduce the impact on the design of the throttle hole 311 of the bearing section 31 and the uniformity of the flow field.

[0075] In some embodiments, the cooling groove 3315 spirally extends around the axial direction of the static pressure gas radial bearing 30. It can be understood that in the direction around the axial direction of the static pressure gas radial bearing 30, the extension arc of the cooling groove 3315 can be, but not limited to, π / 4, π / 3, π / 2, π, 2π, etc., which is not specifically limited here.

[0076] In this way, the spirally extending cooling groove 3315 can cover a wider range of the circumference of the dynamic pressure gas radial bearing 50 in the axial direction of the dynamic pressure gas radial bearing 50, thereby improving the heat dissipation effect.

[0077] Specifically, all cooling grooves 3315 can be divided into multiple groups, and each group of cooling grooves 3315 is respectively arranged corresponding to one sub-foil segment 511. In other words, each group of cooling grooves 3315 is located between two adjacent first matching grooves 3311, and each group of cooling grooves 3315 includes at least one cooling groove 3315.

[0078] In this way, each group of cooling grooves 3315 cools one sub-foil segment 511 without being blocked by the first matching groove 3311. When processing economy permits, the more cooling grooves 3315 are distributed, the more uniform the circumferential cooling of the dynamic pressure gas radial bearing 50 is.

[0079] In some embodiments, the radial clearance size G1 (eg, Figure 2 ) is smaller than the clearance size G2 between the dynamic pressure gas radial bearing 50 and the rotor 200 in the radial direction (as shown in Figure 2 Specifically, the ratio of the gap size G1 to the gap size G2 may be x:1, where 0.9≤x<1.

[0080] In some embodiments, the length of the bearing segment 31 is greater than the length of the sealing segment 33 .

[0081] The static pressure gas radial bearing 30 has a continuous flow of external high-pressure gas to take away the heat, while the dynamic pressure gas radial bearing 50 is self-priming, and the surrounding gas flows into the bearing by the rotation speed, so the dynamic pressure gas radial bearing 50 is not as good as the static pressure gas radial bearing 30 in terms of heat dissipation effect. In order to make the structure compact and reduce the heat generated by the bearing, the length of the bearing section 31 is designed to be greater than the length of the sealing section 33.

[0082] In this way, in the bearing assembly 100, the main load-bearing role is played by the static pressure gas radial bearing 30, while the dynamic pressure gas radial bearing 50 mainly protects the static pressure gas radial bearing 30 from sideband wear. Under normal circumstances, it is mainly the static pressure gas radial bearing 30 that provides a supporting air film for the rotor 200, and the dynamic pressure gas radial bearings 50 at both ends hardly work. When the rotor 200 tilts or is impacted by a load, the maximum tilt displacement of the rotor 200 is located at the dynamic pressure gas radial bearing 50. After the inclination reaches the gap difference, the dynamic pressure gas radial bearing 50 and the rotor 200 form a match to form a dynamic pressure air film to support the rotor 200 to float. At this time, the corrugated foil 51 can adapt well to the tilt of the rotor 200 or absorb the vibration energy of the rotor 200 through deformation.

[0083] The bearing assembly 100 includes a static pressure gas radial bearing 30 and a dynamic pressure gas radial bearing 50. The static pressure gas radial bearing 30 has a bearing section 31 and sealing sections 33 located at both ends of the bearing section 31. The sealing sections 33 each have a mounting position 331, and the mounting position 331 is formed with a spirally extending cooling groove 3315. The dynamic pressure gas radial bearing 50 is arranged at the mounting position 331. The length of the dynamic pressure gas radial bearing 50 is less than the length of the bearing section 31, and the gap between the dynamic pressure gas radial bearing 50 and the rotor 200 is larger. The corrugated foil 51 of the dynamic pressure gas radial bearing 50 is composed of a plurality of sub-foil sections 511 arranged at intervals, and each sub-foil section 511 is matched with the first matching groove 3311 of the mounting position 331 through its first folded edge 513, and the top foil 53 is matched with the second matching groove 3313 of the mounting position 331 through the second folded edge 531. In addition, the sealing section 33 also forms an annular groove 337 at one end of all the cooling grooves 3315, and forms an air outlet structure 335 between the annular groove 337 and the bearing section 31. The annular groove 337 connects all the cooling grooves 3315 and is connected to the air outlet structure 335. The air outlet structure 335 is connected to the gap between the bearing section 31 and the rotor 200, and is connected to one end of the dynamic pressure gas radial bearing 50.

[0084] When the bearing assembly 100 is working, the gas introduced into the bearing section 31 flows out from the throttle hole 311, forms a supporting gas film on the surface of the rotor 200, and flows into the gas outlet structure 335 along the gap between the bearing section 31 and the rotor 200. Part of the gas is blown into the dynamic pressure gas radial bearing 50 by the gas outlet structure 335, flows in the axial direction, and cools the dynamic pressure gas radial bearing 50. Part of the gas is blown into the cooling groove 3315, flows in a spiral along the cooling groove 3315, and cools the dynamic pressure gas radial bearing 50 on its peripheral side.

[0085] Thus, during normal operation, the rotor 200 is mainly supported by the air film provided by the static pressure gas radial bearing 30. When the rotor 200 tilts or is impacted by a load, the dynamic pressure gas radial bearing 50 cooperates with the rotor 200 to form a dynamic pressure air film to provide support force, thereby reducing the possibility of rigid friction between the static pressure gas radial bearing 30 and the rotor 200. In addition, the cooling of the bearing assembly 100 by the airflow can also improve its reliability and service life.

[0086] The present application also provides a fluid machine, including the above-mentioned bearing assembly 100. The fluid machine refers to a machine that uses fluid as a working medium for energy conversion, and may be, but is not limited to, a compressor, a pump, a steam turbine or a water turbine, etc., which is not specifically limited here.

[0087] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0088] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. A bearing assembly, characterized in that: The bearing assembly comprises: Bearing support (10); A static pressure gas radial bearing (30) is arranged in the bearing support (10) and comprises at least one bearing section (31) and at least two sealing sections (33) in its axial direction; each of the bearing sections (31) is located between two adjacent sealing sections (33) and has a throttle hole (311); a sealing arrangement is provided between the sealing section (33) and the inner surface of the bearing support (10), and the inner surface of at least part of the sealing section (33) has a mounting position (331); and The dynamic pressure gas radial bearing (50) is arranged at the installation position (331).

2. The bearing assembly according to claim 1, characterized in that: The mounting position (331) has a cooling groove (3315), and the cooling groove (3315) extends from one end of the mounting position (331) to the other end in the axial direction of the static pressure gas radial bearing (30).

3. The bearing assembly according to claim 2, characterized in that: The sealing section (33) further comprises an air outlet structure (335), wherein the air outlet structure (335) is located between the dynamic pressure gas radial bearing (50) and the bearing section (31), and a gap between the bearing section (31) and a rotor (200) matched with the bearing assembly is connected to one end of the dynamic pressure gas radial bearing (50) and the cooling groove (3315) via the air outlet structure (335).

4. The bearing assembly according to claim 3, characterized in that: The sealing section (33) further comprises an annular groove (337), the annular groove (337) being located at one end of the mounting position (331) in the axial direction of the static pressure gas radial bearing (30) close to the bearing section (31), and the annular groove (337) being connected to the gas outlet structure (335); each mounting position (331) comprises a plurality of cooling grooves (3315), and all of the cooling grooves (3315) are connected to the annular groove (337).

5. The bearing assembly according to claim 4, characterized in that The gas outlet structure (335) has an arc-shaped guide wall (3351) facing the dynamic pressure gas radial bearing (50), and a projection in the axial direction of the static pressure gas radial bearing (30), wherein the annular groove (337) and the dynamic pressure gas radial bearing (50) at least partially overlap with the arc-shaped guide wall (3351).

6. The bearing assembly according to claim 2, characterized in that: The cooling groove (3315) extends in a spiral around the axial direction of the static pressure gas radial bearing (30).

7. The bearing assembly according to claim 1, characterized in that A clearance dimension G1 in the radial direction between the bearing section (31) and the rotor (200) matched with the bearing assembly is smaller than a clearance dimension G2 in the radial direction between the dynamic pressure gas radial bearing (50) and the rotor (200); And / or, the length of the bearing segment (31) is greater than the length of the sealing segment (33).

8. The bearing assembly according to any one of claims 1 to 7, characterized in that: The dynamic pressure gas radial bearing (50) comprises a corrugated foil (51) and a top foil (53), wherein the corrugated foil (51) is arranged at the mounting position (331), and the top foil (53) is arranged at the top of the corrugated foil (51) away from the mounting position (331).

9. The bearing assembly according to claim 8, characterized in that The corrugated foil (51) comprises a plurality of sub-foil segments (511), the plurality of sub-foil segments (511) being arranged in sequence along the circumference of the dynamic pressure gas radial bearing (50), and adjacent sub-foil segments (511) being arranged at intervals from each other.

10. The bearing assembly according to claim 9, characterized in that Each of the sub-foil segments (511) has a first folded edge (513), the mounting position (331) has a first matching groove (3311), and the first folded edge (513) is inserted into the first matching groove (3311).

11. The bearing assembly according to claim 8, characterized in that The top foil (53) has a second folded edge (531), the mounting position (331) has a second matching groove (3313), and the second folded edge (531) is inserted into the second matching groove (3313).

12. A fluid machine, characterized in that: Comprising a bearing assembly as claimed in any one of claims 1 to 11.

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