Gas bearings

Abstract

The present application relates to the field of bearing technology, and provides a gas bearing, including a bearing sleeve, a top foil arranged in the bearing sleeve, and a plurality of sections of supporting foil elastically supported between the top foil and the bearing sleeve; the inner peripheral wall of the top foil includes a plurality of sections of first curved surfaces connected in sequence along the circumferential direction, the distance from a point on each first curved surface to the central axis of the bearing sleeve first decreases and then increases along the circumferential direction, and each first curved surface can form a convergent wedge gap and a divergent wedge gap with the outer peripheral wall of the rotor located at the center of the bearing sleeve; the number of supporting foils is the same as the number of first curved surfaces, and each supporting foil is supported one by one at the position of the top foil corresponding to each first curved surface. The gas bearing provided by the present application forms the inner peripheral wall of the top foil by means of a plurality of sections of first curved surfaces, and forms a plurality of groups of convergent wedge gaps and divergent wedge gaps, thereby improving the load-bearing capacity of the gas bearing and improving the stability against interference and impact.

Description

Technical Field

[0001] The present application belongs to the technical field of bearings, and more specifically, relates to a gas bearing. Background Art

[0002] Gas bearings have the characteristics of extremely low friction during operation, no need to add liquid lubricants, no pollution to the environment, and low noise when running at high speeds. Compared with traditional oil-lubricated bearings, they are more suitable for high-speed and light-load conditions.

[0003] Gas bearings are divided into two categories according to the load-bearing mechanism: hydrodynamic bearings and hydrostatic bearings. Compared with hydrostatic bearings, hydrodynamic bearings do not require additional high-pressure gas and have advantages such as simple structure and small size. Therefore, hydrodynamic bearings are widely used in engine auxiliary power systems, air cycle machines, micro gas turbines, and micro turbojet engines. However, the load-bearing capacity and load-bearing stability of hydrodynamic bearings are still relatively weak, especially when the rotor is disturbed or impacted, it is likely to cause damage to the hydrodynamic bearing. Summary of the invention

[0004] The purpose of the embodiments of the present application is to provide a gas bearing to solve the technical problems of low load-bearing capacity and poor load-bearing stability of hydrodynamic bearings in the prior art.

[0005] To achieve the above-mentioned purpose, the technical solution adopted in the present application is: to provide a gas bearing, including a bearing sleeve, a top foil arranged in the bearing sleeve, and a plurality of supporting foils elastically supported between the top foil and the bearing sleeve; the inner peripheral wall of the top foil includes a plurality of first curved surfaces connected in sequence along the circumferential direction, the distance from each point on the first curved surface to the central axis of the bearing sleeve first decreases and then increases along the circumferential direction, and each first curved surface can form a convergent wedge gap and a divergent wedge gap with the outer peripheral wall of the rotor located at the center of the bearing sleeve; the number of the supporting foils is the same as the number of the first curved surfaces, and each of the supporting foils is supported one by one at the position of the top foil corresponding to each of the first curved surfaces.

[0006] In one embodiment, the first curved surface is an arc surface; or, the first curved surface is a curved surface whose curvature changes according to a preset rule.

[0007] In one embodiment, the angle between two adjacent first curved surfaces is less than 180 degrees.

[0008] In one embodiment, the outer peripheral wall of the top foil includes multiple sections of second curved surfaces connected in sequence along the circumferential direction, and the inner peripheral wall of the bearing sleeve includes multiple sections of third curved surfaces connected in sequence along the circumferential direction, and each of the first curved surfaces, each of the second curved surfaces, each of the supporting foils and each of the third curved surfaces are arranged one by one from the inside to the outside.

[0009] In one embodiment, the first curved surface, the second curved surface and the third curved surface corresponding to each other from the inside to the outside are arranged to be geometrically similar.

[0010] In one embodiment, the top foil is formed with an opening along the circumferential direction, and the opening is arranged at the junction of two of the first curved surfaces; the top foil is interrupted by the opening to form two ends, one of which is fixed on the bearing sleeve, and the other end is suspended.

[0011] In one embodiment, the thickness between the first curved surface and the second curved surface is in the range of 0.5-3 mm; and a groove is formed on the peripheral wall of the top foil at the connection between the two second curved surfaces.

[0012] In one embodiment, the groove penetrates the top foil along the axial direction of the bearing sleeve, and the groove is in an arc shape or an irregular curve shape along a cross section perpendicular to the axial direction of the bearing sleeve; the depth of the groove is 0.4-0.6 times the thickness of the top foil.

[0013] In one embodiment, the length of each supporting foil along the circumferential direction is smaller than the length of the third curved surface along the circumferential direction; one end of the supporting foil is fixed on the bearing sleeve, and the other end of the supporting foil is suspended.

[0014] In one embodiment, the supporting foil comprises a plurality of arched segments and a flat segment connected between the bottoms of two adjacent arched segments; the flat segment is used to fit with the third curved surface of the bearing sleeve, and the top of the arched segment is used to contact and connect with the second curved surface of the top foil.

[0015] The beneficial effect of the gas bearing provided by the present application is that: the gas bearing provided by the embodiment of the present application, by dividing the inner circumferential wall of the top foil into multiple first curved surfaces connected in sequence along the circumferential direction, and the distance from the point on each first curved surface to the central axis of the bearing sleeve first decreases and then increases along the circumferential direction, that is, the inner circumferential wall of the top foil is not a complete cylindrical surface, so that when the rotor is not eccentric, each first curved surface can form a convergent wedge gap and a divergent wedge gap with the outer circumferential wall of the rotor located at the center of the bearing sleeve. Compared with the general hydrodynamic bearing that can only form a convergent wedge gap and a divergent wedge gap when the rotor is eccentric, the present application can reduce the offset of the rotor during operation, thereby improving the rotation accuracy of the rotor. At the same time, the rate of change of the convergent wedge gap and the divergent wedge gap of the present application in the circumferential direction can be changed according to the design of the first curved surface, thereby improving the bearing capacity of the gas bearing. In addition, the gas bearing of the present application can form multiple groups of convergent wedge gaps and divergent wedge gaps between the gas bearing and the rotor, so that the span of the bearing area of ​​the gas bearing is greatly increased, which improves the bearing capacity of the rotor on the one hand, and improves the bearing stability of the gas bearing on the rotor when it is disturbed or impacted on the other hand. Finally, the present application arranges multiple sections of supporting foil between the bearing sleeve and the top foil, which reduces the difficulty of manufacturing and assembling the supporting foil on the one hand, and reduces the mutual influence between the bearing areas on the other hand. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application, 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 labor.

[0017] Figure 1 A three-dimensional schematic diagram of a gas bearing provided in an embodiment of the present application;

[0018] Figure 2 for Figure 1 Exploded diagram of the gas bearing;

[0019] Figure 3 for Figure 1 Axial schematic diagram of the gas bearing;

[0020] Figure 4 for Figure 1 Schematic diagram of the structure of the middle top foil;

[0021] Figure 5 for Figure 1 Schematic diagram of the structure of the middle support foil;

[0022] Figure 6 for Figure 1Schematic diagram of the structure of the middle bearing sleeve.

[0023] Among them, the reference numerals in the figure are:

[0024] 100, gas bearing; 10, bearing sleeve; 11, third curved surface; 12, first fixed groove; 13, second fixed groove; 20, supporting foil; 21, arched section; 22, flat section; 23, second fixed block; 30, top foil; 31, first curved surface; 32, second curved surface; 33, opening; 34, groove; 35, first fixed block; M, convergent wedge gap; N, divergent wedge gap; 200, rotor. DETAILED DESCRIPTION

[0025] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0026] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0027] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do 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 should not be understood as a limitation on the present application.

[0028] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0029] See also Figures 1 to 3 , the gas bearing 100 provided in the embodiment of the present application is now described.

[0030] The gas bearing 100 includes a bearing sleeve 10, a top foil 30 and a plurality of support foils 20. The top foil 30 is disposed in the bearing sleeve 10, and each support foil 20 is elastic and elastically supported between the top foil 30 and the bearing sleeve 10. The inner circumferential wall of the top foil 30 includes a plurality of first curved surfaces 31, and each first curved surface 31 is sequentially connected along the circumferential direction, that is, the inner circumferential wall of the top foil 30 is composed of a plurality of first curved surfaces 31 sequentially connected along the circumferential direction. The distance from each point on the first curved surface 31 to the central axis of the bearing sleeve 10 first decreases and then increases along the circumferential direction, that is, the central axis of the bearing sleeve 10 is not the center line of each first curved surface 31, please refer to Figure 3 When the rotor 200 is arranged in the top foil 30 with the central axis of the bearing sleeve 10 as the center line, the inner circumferential wall of the top foil 30 and the outer circumferential wall of the rotor 200 form an air film gap, and the thickness of the air film gap at the intersection of two adjacent first curved surfaces 31 is the largest, and the thickness of the air film gap at the middle position of each first curved surface 31 along the circumferential direction is the smallest. In this way, when the rotor 200 is initially set, each first curved surface 31 can form a convergent wedge gap M and a divergent wedge gap N with the outer circumferential wall of the rotor 200 located at the center of the bearing sleeve 10.

[0031] The convergent wedge gap M is a gradually decreasing wedge gap formed between the first curved surface 31 and the outer peripheral wall of the rotor 200, and the divergent wedge gap N is a gradually increasing wedge gap formed between the first curved surface 31 and the outer peripheral wall of the rotor 200. Both the convergent wedge gap M and the divergent wedge gap N are air film gaps between the gas bearing 100 and the rotor 200. When the rotor 200 rotates at high speed, these air film gaps generate dynamic pressure, thereby providing load bearing for the high-speed rotating rotor 200.

[0032] It should be noted that the outer peripheral wall of the rotor 200 refers to the outer side wall of the rotor 200 along the circumferential direction, the inner peripheral wall of the top foil 30 refers to the inner side wall of the top foil 30 along the circumferential direction, and the outer peripheral wall of the top foil 30 refers to the outer side wall of the top foil 30 along the circumferential direction.

[0033] See also Figure 1 and Figure 3 The number of the supporting foils 20 is the same as the number of the first curved surfaces 31 , and each supporting foil 20 is supported one by one at the position of the top foil 30 corresponding to each first curved surface 31 , that is, each section of the supporting foil 20 is used to support a corresponding section of the top foil 30 , and the supporting foils 20 do not affect each other.

[0034] The gas bearing 100 in this embodiment is formed by dividing the inner peripheral wall of the top foil 30 into multiple first curved surfaces 31 connected in sequence along the circumferential direction, and the distance from each point on the first curved surface 31 to the central axis of the bearing sleeve 10 decreases first and then increases along the circumferential direction, that is, the inner peripheral wall of the top foil 30 is not a complete cylindrical surface. In this way, when the rotor 200 is not eccentric, each first curved surface 31 can form a convergent wedge gap M and a divergent wedge gap N with the outer peripheral wall of the rotor 200 located at the center of the bearing sleeve 10. Compared with the general hydrodynamic bearing that can only form a convergent wedge gap M and a divergent wedge gap N when the rotor 200 is eccentric, the present application can reduce the offset of the rotor 200 during operation, thereby improving the rotation accuracy of the rotor 200. At the same time, the change rate of the convergent wedge gap M and the divergent wedge gap N in the present application along the circumferential direction can be changed according to the design of the first curved surface 31, thereby improving the bearing capacity of the gas bearing 100. In addition, the gas bearing 100 of the present application can form multiple groups of convergent wedge gaps M and divergent wedge gaps N between the rotor 200, so that the span of the bearing area of ​​the gas bearing 100 is greatly increased, which improves the bearing capacity of the rotor 200 on the one hand, and improves the bearing stability of the gas bearing 100 on the rotor 200 when it is disturbed or impacted on the other hand. Finally, the present application arranges multiple sections of support foil 20 between the bearing sleeve 10 and the top foil 30, which reduces the difficulty of manufacturing and assembling the support foil 20 on the one hand, and reduces the mutual influence between the bearing areas on the other hand.

[0035] See also Figure 3 and Figure 4 The inner circumferential wall of the top foil 30 includes three sections of first curved surfaces 31, which are connected in sequence along the circumferential direction, and the three sections of the first curved surfaces 31 extend along the axial direction of the bearing sleeve 10, and three groups of convergent wedge gaps M and divergent wedge gaps N are formed between the three sections of the first curved surfaces 31 and the rotor 200. Correspondingly, the gas bearing 100 includes three sections of supporting foils 20, which are respectively supported at positions of the top foil 30 corresponding to the three sections of the first curved surfaces 31. It can be understood that in other embodiments of the present application, according to actual design conditions and specific requirements, the top foil 30 may also have two, four or more sections of the first curved surfaces 31, and correspondingly, the number of sections of the supporting foil 20 may also be two, four or more sections, which is not limited here.

[0036] In the specific embodiment, please see Figure 3 and Figure 4, the first curved surface 31 is an arc surface, the curvature of each first curved surface 31 is the same, and the axial direction of each first curved surface 31 is parallel to the axial direction of the bearing sleeve 10. By setting each first curved surface 31 as an arc surface, the convergent wedge gap M and the divergent wedge gap N change evenly, and the inner peripheral wall processing technology of the top foil 30 is simple, and the processing cost is low; at the same time, the designer can set the first curved surface 31 to be an arc surface with different curvatures as needed to improve the bearing capacity of the gas bearing 100. It can be understood that in other embodiments of the present application, according to actual design conditions and specific requirements, the above-mentioned first curved surface 31 can also be set to be not an arc surface, but a curved surface whose curvature changes according to a preset rule. For example, according to multiple tests, when the curvature of the first curved surface 31 changes according to a certain rule, the gas bearing 100 can obtain a higher bearing capacity. In this case, the curvature of the first curved surface 31 can be designed according to the rule when designing the first curved surface 31.

[0037] In the specific embodiment, please see Figure 3 , the angle between two adjacent first curved surfaces 31 is less than 180 degrees, so that the radius of the inscribed circle of each first curved surface 31 is smaller than the radius of each first curved surface 31, and the radius of the rotor 200 is also smaller than the radius of each first curved surface 31. The convergent wedge-shaped gaps M and the divergent wedge-shaped gaps N are alternately arranged in sequence, so that the span of the bearing area of ​​the gas bearing 100 is greatly increased, which on the one hand improves the bearing capacity of the rotor 200, and on the other hand also improves the bearing stability of the gas bearing 100 on the rotor 200 when it is disturbed or impacted.

[0038] In the specific embodiment, please see Figures 3 to 6 , the outer peripheral wall of the top foil 30 includes multiple sections of second curved surfaces 32, and each second curved surface 32 is connected in sequence along the circumferential direction. The inner peripheral wall of the bearing sleeve 10 includes multiple sections of third curved surfaces 11, and each third curved surface 11 is connected in sequence along the circumferential direction. Each first curved surface 31, each second curved surface 32, each supporting foil 20 and each third curved surface 11 are arranged one by one from the inside to the outside. Specifically, the outer peripheral wall of the top foil 30 refers to the outer side wall of the top foil 30 along the circumferential direction, and the inner peripheral wall of the bearing sleeve 10 refers to the inner side wall of the bearing sleeve 10 along the circumferential direction. In order to adapt to each first curved surface 31, the present application forms the second curved surface 32 and the third curved surface 11 accordingly, so that the bearing position of each first curved surface 31 can be supported by the corresponding top foil 30, supporting foil 20 and bearing sleeve 10, and the bearing is more targeted, thereby improving the bearing capacity and bearing effectiveness of the entire gas bearing 100.

[0039] See also Figure 3 and Figure 5The bearing sleeve 10 is cylindrical as a whole, and its inner circumferential wall is formed by multiple sections of third curved surfaces 11 connected end to end. The bearing sleeve 10, each supporting foil 20 and the top foil 30 extend along the axial direction of the bearing sleeve 10, and the bearing sleeve 10, each supporting foil 20 and the top foil 30 have the same axial length along the bearing sleeve 10. The center line of the inner circumferential wall of the top foil 30, the center line of the outer circumferential wall of the top foil 30, the center line of each supporting foil 20 and the center line of the inner circumferential wall of the bearing sleeve 10 all coincide with the central axis of the entire bearing sleeve 10. In addition, the number of second curved surfaces 32 and the number of third curved surfaces 11 are both 3. Of course, the number of second curved surfaces 32 and the number of third curved surfaces 11 in other embodiments can also be changed accordingly according to the change of the number of first curved surfaces 31.

[0040] In the specific embodiment, please see Figure 3 , each first curved surface 31, second curved surface 32 and third curved surface 11 are set to be geometrically similar, that is, the second curved surface 32 is formed by the first curved surface 31 being offset outward by an appropriate distance, and the third curved surface 11 is also formed by the first curved surface 31 being offset outward by an appropriate distance, so that the thickness of the top foil 30 is evenly distributed along the circumferential direction, the force distribution on the top foil 30 is even, and the manufacturing process of the top foil 30 is simple, and at the same time, the gap between the outer circumferential wall of the top foil 30 and the inner circumferential wall of the bearing sleeve 10 is evenly distributed along the circumferential direction, so that when any position on the top foil 30 is subjected to force, it can be deformed by the supporting foil 20 to bear the load, and the supporting foil 20 has high load-bearing efficiency.

[0041] Specifically, each of the first curved surface 31, the second curved surface 32 and the third curved surface 11 is an arc surface, and the first curved surface 31, the second curved surface 32 and the third curved surface 11 corresponding to each other from the inside to the outside are coaxially arranged. It can be understood that in other embodiments of the present application, each of the first curved surface 31, the second curved surface 32 and the third curved surface 11 can also be set as a curved surface whose curvature changes according to a preset rule, which is not the only limitation here.

[0042] In the specific embodiment, please see Figure 3 and Figure 4 The top foil 30 is formed with an opening 33 along the circumferential direction, and the opening 33 is arranged at the junction of two of the first curved surfaces 31; the top foil 30 is interrupted by the opening 33 to form two ends, one of which is fixed on the bearing sleeve 10, and the other end is suspended. The setting of the opening 33 makes the elastic deformation ability of the top foil 30 better, and when subjected to a loading force, it can quickly bear the load through deformation, and at the same time, it can transmit the loading force to the supporting foil 20 through deformation, and bear and consume the loading force through the elastic deformation of the supporting foil 20. By fixing one end of the top foil 30 on the bearing sleeve 10, the top foil 30 is prevented from circumferentially moving in the bearing sleeve 10 due to the force, and the other end of the top foil 30 is suspended, so that the elastic deformation ability of the top foil 30 can be improved.

[0043] See also Figure 3 , Figure 4 and Figure 6 , a first fixing block 35 bent toward the bearing sleeve 10 is provided on one end of the top foil 30, a first fixing groove 12 is recessed on the inner peripheral wall of the bearing sleeve 10, the first fixing block 35 and the first fixing groove 12 both extend along the axial direction of the bearing sleeve 10, and when installing, the first fixing block 35 is inserted into the first fixing groove 12 along the axial direction to be fixed. It can be understood that in other embodiments of the present application, one end of the top foil 30 can also be directly fixed to the bearing sleeve 10 by welding, riveting, and screw locking, which is not the only limitation here.

[0044] In a specific embodiment, the thickness between the first curved surface 31 and the second curved surface 32 is 0.5-3 mm; see Figure 3 and Figure 4 The outer peripheral wall of the top foil 30 is provided with a groove 34, and the groove 34 is specifically provided at the connection between the two second curved surfaces 32. Figure 3 It can be seen that the load-bearing area of ​​the top foil 30 is mainly in the middle of the first curved surface 31, and less load is required at the junction of the two first curved surfaces 31. Therefore, the overall thickness of the top foil 30 is set to be thicker, and the rigidity of the load-bearing area of ​​the top foil 30 is greater, which can reduce the collapse phenomenon between the vertices of the supporting foil 20. The rigidity is smaller at the intersection of the second curved surfaces 32. When the supporting foil 20 is deformed, the top foil 30 can have better adaptability and adaptive deformation.

[0045] See also Figure 3 and Figure 4 Due to the setting of the opening 33, two grooves 34 are provided in the present application, that is, the number of grooves 34 is one less than the number of second curved surfaces 32. Thus, when the number of second curved surfaces 32 increases, the number of grooves 34 will also increase accordingly.

[0046] In the specific embodiment, please see Figure 4 , the groove 34 penetrates the top foil 30 along the axial direction of the bearing sleeve 10, and the groove 34 is in an arc shape along the cross section perpendicular to the axial direction of the bearing sleeve 10. The arc-shaped design of the groove 34 can reduce the concentrated stress at the groove 34 when the top foil 30 is subjected to force. It can be understood that in other embodiments of the present application, the groove 34 along the cross section perpendicular to the axial direction of the bearing sleeve 10 can also be in other irregular curve shapes, specifically formed by connecting multiple curved surfaces. Similarly, the curved surface can also reduce the concentrated stress of the groove 34, which is not limited here.

[0047] The depth of the groove 34 along the thickness direction of the top foil 30 is 0.5 times the thickness of the top foil 30, so that not only the adaptive deformation ability of the top foil 30 between two adjacent second curved surfaces 32 can be improved, but also the basic rigidity of the top foil 30 at the groove 34 can be ensured. It can be understood that in other embodiments of the present application, the depth of the groove 34 can also be 0.4 times, 0.45 times, 0.55 times or 0.6 times the thickness of the top foil 30, which is not limited here.

[0048] In the specific embodiment, please see Figure 3 The circumferential length of each supporting foil 20 is smaller than the circumferential length of the third curved surface 11. On the one hand, it is convenient to bend each supporting foil 20 and install it into the bearing sleeve 10. On the other hand, it also reserves space between two adjacent supporting foils 20 at the groove 34 of the top foil 30, which is convenient for the sliding deformation of the supporting foil 20 and the adaptive deformation of the top foil 30.

[0049] One end of the support foil 20 is fixed to the bearing sleeve 10, and the other end of the support foil 20 is suspended. Specifically, one end of the support foil 20 is bent and extended toward the bearing sleeve 10 to form a second fixing block 23, and the inner peripheral wall of the bearing sleeve 10 is provided with a second fixing groove 13. The second fixing block 23 and the second fixing groove 13 both extend along the axial direction of the bearing sleeve 10. When installing, the second fixing block 23 is axially inserted into the second fixing groove 13 for fixing. It can be understood that in other embodiments of the present application, one end of the support foil 20 can also be directly fixed to the bearing sleeve 10 by welding, riveting, and screw locking, which is not the only limitation here.

[0050] See also Figure 6 One of the second fixing grooves 13 is connected to the first fixing groove 12, that is, the first fixing block 35 and one of the corresponding second fixing blocks 23 are fixed in the same groove, so that the number of grooves on the inner wall of the bearing sleeve 10 can be reduced.

[0051] In the specific embodiment, please see Figure 3 and Figure 5The supporting foil 20 includes a plurality of arched segments 21 and a plurality of flat segments 22. The arched segments 21 are arched, and the flat segments 22 are flat. The flat segments 22 are connected between the bottoms of two adjacent arched segments 21. The bottom of the arched segment 21 is the position where the opening 33 of the arched segment 21 is the largest, and the top is the vertex of the arched segment 21. During installation, the flat segment 22 is used to fit the third curved surface 11 of the bearing sleeve 10, and the top of the arched segment 21 is used to contact and connect with the second curved surface 32 of the top foil 30. During operation, when the top foil 30 is subjected to a loading force, it will squeeze the top of the arched segment 21, the arched segment 21 will be squeezed and deformed, and the bottom opening 33 of the arched segment 21 will become larger, thereby driving the flat segment 22 to slide on the third curved surface 11. Therefore, the setting of the top of the arched segment 21 can reduce the mutual wear between the arched segment 21 and the top foil 30 due to squeezing, and the setting of the flat segment 22 can increase the contact area between the supporting foil 20 and the bearing sleeve 10, thereby improving the load-bearing capacity.

[0052] When installing the supporting foil 20, first, the supporting foil 20 needs to be bent to adapt to the shape of the third curved surface 11 on the inner circumferential wall of the bearing sleeve 10. This process can be achieved during the heat treatment process. Then, the supporting foil 20 is installed between the top foil 30 and the bearing sleeve 10, and the flat section 22 of the supporting foil 20 is in contact with the third curved surface 11 but not fixedly connected, and the top of the arched section 21 of the supporting foil 20 is in contact with the second curved surface 32 of the top foil 30 but not fixedly connected.

[0053] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A gas bearing, characterized in that: The invention comprises a bearing sleeve, a top foil arranged in the bearing sleeve, and a plurality of supporting foils elastically supported between the top foil and the bearing sleeve; the inner peripheral wall of the top foil comprises a plurality of first curved surfaces connected in sequence along the circumferential direction, the distance from a point on each first curved surface to the central axis of the bearing sleeve first decreases and then increases along the circumferential direction, each first curved surface can form a convergent wedge gap and a divergent wedge gap with the outer peripheral wall of the rotor located at the center of the bearing sleeve, each convergent wedge gap and each divergent wedge gap are alternately arranged in sequence, and the first curved surface is a curved surface whose curvature changes according to a preset rule; the number of the supporting foils is the same as the number of the first curved surfaces, and each of the first curved surfaces is a plurality of first curved surfaces connected in sequence along the circumferential direction, and the distance from a point on each first curved surface to the central axis of the bearing sleeve first decreases and then increases along the circumferential direction, and each first curved surface can form a convergent wedge gap and a divergent wedge gap with the outer peripheral wall of the rotor located at the center of the bearing sleeve, and each convergent wedge gap and each divergent wedge gap are alternately arranged in sequence, and the first curved surface is a curved surface whose curvature changes according to a preset rule; the number of the supporting foils is the same as the number of the first curved surfaces, and each of the first curved surfaces is a plurality of first curved surfaces connected in sequence. The supporting foils are supported one-to-one at positions of the top foil corresponding to the first curved surfaces. The outer peripheral wall of the top foil includes multiple sections of second curved surfaces connected in sequence along the circumferential direction. The inner peripheral wall of the bearing sleeve includes multiple sections of third curved surfaces connected in sequence along the circumferential direction. The first curved surfaces, the second curved surfaces, the supporting foils and the third curved surfaces are arranged one-to-one from the inside to the outside. The first curved surfaces, the second curved surfaces and the third curved surfaces corresponding to each other from the inside to the outside are arranged to be geometrically similar. The length of each supporting foil along the circumferential direction is less than the length of the third curved surface along the circumferential direction. One end of the supporting foil is fixed on the bearing sleeve, and the other end of the supporting foil is suspended.

2. The gas bearing according to claim 1, characterized in that: The angle between two adjacent first curved surfaces is less than 180 degrees.

3. The gas bearing according to claim 1 or 2, characterized in that: The top foil is formed with an opening along the circumferential direction, and the opening is arranged at the junction of two of the first curved surfaces; the top foil is interrupted by the opening to form two ends, one of which is fixed on the bearing sleeve, and the other end is suspended.

4. The gas bearing according to claim 1, characterized in that: The thickness between the first curved surface and the second curved surface ranges from 0.5 to 3 mm; a groove is formed on the peripheral wall of the top foil at the connection between the two second curved surfaces.

5. The gas bearing according to claim 4, characterized in that: The groove penetrates the top foil along the axial direction of the bearing sleeve, and the cross section of the groove perpendicular to the axial direction of the bearing sleeve is in the shape of an arc or an irregular curve; the depth of the groove is 0.4-0.6 times the thickness of the top foil.

6. The gas bearing according to claim 1, characterized in that: The supporting foil comprises a plurality of arched segments and a flat segment connected between the bottoms of two adjacent arched segments; the flat segment is used to fit with the third curved surface of the bearing sleeve, and the top of the arched segment is used to contact and connect with the second curved surface of the top foil.

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