An air foil bearing with interlocking function

Abstract

The present invention provides an air foil bearing with an interlocking function, relating to the field of turbomachinery technology. The bearing comprises a bearing sleeve, a corrugated foil, and a top foil. The bearing sleeve comprises a hollow portion into which a rotating shaft is inserted and several groups of keyways formed on the inner circumferential surface of the hollow portion, with the same group of keyways located within a countersunk hole on the end face of the bearing sleeve. The corrugated foil is disposed on the inner circumferential surface of the hollow portion and is provided with a first engaging portion for engaging with the keyway. The top foil is disposed on the inner side of the corrugated foil and is provided with second and third engaging portions for engaging with the keyway. The second and third engaging portions are disposed on opposite sides of the top foil. The present invention achieves interlocking with the keyway through the first, second, and third engaging portions. Compared with conventional foil bearings fixed by welding or pinning, the present invention reduces the requirements for foil molding, thereby increasing the service life of the bearing.

Description

Technical Field

[0001] The present invention relates to the technical field of turbomachinery, and in particular to an air foil bearing with an interlocking function. Background Art

[0002] Common air foil bearings are dynamic pressure bearings with a flexible surface consisting of one or more layers of corrugated foil and top foil. Relying on the relative motion between the shaft and the bearing surface, the shaft draws a viscous gas into the wedge-shaped space between the shaft and the bearing top foil, squeezing it to form a lubricating gas film with a certain pressure, thereby suspending the shaft. Figure 1 As shown in the figure, when there is a wedge-shaped space between two relatively moving surfaces, the surfaces moving against each other continuously drive the gas into the wedge-shaped groove, so that a dynamic pressure air film with a certain pressure is formed in the wedge-shaped groove. When the air film pressure is large enough to support the load, the shaft is floated and the friction force disappears.

[0003] Air foil bearings have a series of advantages such as low friction loss, almost no friction at extremely high speeds, good high-temperature stability, low vibration, and no need for lubricating oil. They are widely used in air cycle machines, air blowers, fuel cell air compressors, micro gas turbines and other machinery, and have very broad application prospects in low-temperature and high-temperature technology, high-speed turbines, space technology and other fields.

[0004] However, the foil of the foil bearing is usually fixed to the bearing sleeve by welding, such as Figure 1 As shown, or fixed with pins, such as Figure 2 As shown, whether it is fixed by welding or pin, both are fastening methods with one end fixed and the other end free. This fixing method has high requirements for forming. When the curvature radius of the top foil and the wave foil forming does not meet the design, it will cause the bearing to wear more severely with the rotor during operation, thereby reducing the service life of the bearing. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide an air foil bearing with an interlocking function to solve the technical problem in the prior art that the foil of the foil bearing is fixed on the bearing sleeve by welding or pins, which has high requirements for foil forming and the curvature radius of the foil does not meet the design, resulting in increased wear between the bearing and the rotor during operation, thereby reducing the service life of the bearing.

[0006] In order to achieve the above-mentioned objectives, the present invention provides an air foil bearing with an interlocking function, comprising a bearing sleeve, a wave foil and a top foil, wherein the bearing sleeve comprises a hollow portion for inserting a rotating shaft and several groups of key grooves formed on the inner circumferential surface of the hollow portion, and the same group of key grooves is located in a countersunk hole on the end face of the bearing sleeve, the wave foil is arranged on the inner circumferential surface of the hollow portion, and is provided with a first coupling portion for coupling to the key groove, the top foil is arranged on the inner side of the wave foil, and is provided with a second coupling portion and a third coupling portion for coupling to the key groove, and the second coupling portion and the third coupling portion are arranged on opposite sides of the top foil.

[0007] According to an optional embodiment, the corrugated foil is composed of three parts, each part has the same shape, and the end parts correspond to each other to form a ring structure, and each part is provided with the first connecting portion.

[0008] According to an optional embodiment, the top foil is also composed of three parts, each part has the same shape, and the end parts echo each other to form a ring structure, and each part is provided with the second connecting portion and the third connecting portion.

[0009] According to an optional embodiment, the countersunk holes include three, and the corresponding keyways include three groups, each group of keyways includes a first keyway adapted to the first combining portion, a second keyway adapted to the second combining portion, and a third keyway adapted to the third combining portion.

[0010] According to an optional embodiment, the extension depths of the first key groove, the second key groove and the third key groove decrease in sequence.

[0011] According to an optional embodiment, it is characterized in that the extension direction of the first keyway is perpendicular to the tangent line of the connection point between the first keyway and the inner circumferential surface of the bearing sleeve.

[0012] According to an optional embodiment, the extending depths of the first keyway, the second keyway and the third keyway from the inner circumferential surface of the bearing sleeve into the countersunk hole decrease in sequence.

[0013] According to an optional embodiment, a threaded hole is provided between the first keyway and the second keyway. The threaded hole is provided at both ends of the bearing sleeve and is a blind hole.

[0014] According to an optional embodiment, a pin hole is further provided in the countersunk hole, the pin hole is located at the end of the second keyway, and the pin hole is configured as a through hole.

[0015] According to an optional embodiment, the bump foil is an elastic support structure or a mesh support structure.

[0016] The air foil bearing with interlocking function provided by the present invention has the following technical effects:

[0017] This type of air foil bearing is similar to traditional foil bearings in that it includes a bearing sleeve, a wave foil and a top foil. Unlike traditional foil bearings, the inner circumferential surface of the hollow portion in the bearing sleeve of the present invention has several groups of key slots, the wave foil has a first coupling portion coupled to the key slot, and the top foil has a second coupling portion and a third coupling portion coupled to the key slot, that is, interlocking with the key slot is achieved through the first coupling portion, the second coupling portion and the third coupling portion. Compared with traditional foil bearings that are fixed by welding or pins, the requirements for foil forming are reduced, thereby increasing the service life of the bearing.

[0018] In addition, the top foil of the present invention is fixed by the second and third joints at both ends to the keyways on the bearing sleeve, thereby constraining and fixing the top foil, so that the top foil forms an arc surface structure without the need for heat treatment or curling processing, thereby reducing the bearing manufacturing process and processing difficulty.

[0019] Furthermore, since both ends of the top foil of the present invention are constrained, wedge-shaped spaces can be formed at both ends, so that the foil bearing can work normally in both clockwise and counterclockwise rotations. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0021] Figure 1 It is a cross-sectional view of an air foil bearing fixed by welding in the prior art;

[0022] Figure 2 is a cross-sectional view of an air foil bearing fixed with pins in the prior art;

[0023] Figure 3 Schematic diagram of the exploded structure of the air foil bearing according to Example 1 of the present invention;

[0024] Figure 4 yes Figure 3 Enlarged view of point A of the hollow foil bearing;

[0025] Figure 5 yes Figure 3 Transverse cross-section of a hollow air foil bearing;

[0026] Figure 6 is a cross-sectional view of an air foil bearing according to embodiment 2 of the present invention;

[0027] Figure 7 is a transverse cross-sectional view of the air foil bearing of Example 1 and Example 2 without the bump foil;

[0028] Figure 8 1 is a cross-sectional view of the air foil bearing of Example 1 and Example 2, excluding the bump foil and the top foil.

[0029] in, Figures 1-8 :

[0030] 100. Air foil bearing;

[0031] 1. Bearing sleeve; 11. Hollow portion; 12. Countersunk hole; 13. First keyway; 14. Second keyway; 15. Third keyway; 16. Pin hole; 17. Threaded hole;

[0032] 2. a wave foil; 21. a first joint;

[0033] 3. Top foil; 31. Second joint; 32. Third joint; 4. Pin; 5. Screw. DETAILED DESCRIPTION

[0034] To make the objectives, technical solutions, and advantages of the present invention more apparent, the technical solutions of the present invention will be described in detail below. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other implementations obtained by those of ordinary skill in the art without inventive effort are within the scope of protection of the present invention.

[0035] In the description of the present invention, it should be noted that, unless otherwise specified, "plurality" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," "front end," "rear end," "head," "tail," etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings and are intended only to facilitate the description of the present invention and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific direction, be constructed, or operate in a specific direction, and therefore should not be construed as limiting the present invention. Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0036] It should also be noted that, in the description of the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood broadly. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; and direct or indirect connections through an intermediary. Those skilled in the art will understand the specific meanings of the above terms in the present invention depending on the specific circumstances.

[0037] As described in the background art, the foil of the foil bearing in the prior art is usually fixed to the bearing sleeve by welding, such as Figure 1 As shown, or fixed with pins, such as Figure 2 As shown, whether it is fixed by welding or pin, both are fastening methods with one end fixed and the other end free. This fixing method has high requirements for forming. When the curvature radius of the top foil and the wave foil forming does not meet the design, it will cause the bearing to wear more severely with the rotor during operation, thereby reducing the service life of the bearing.

[0038] Based on this, the present invention provides an air foil bearing. Unlike traditional foil bearings, the inner circumferential surface of the hollow portion in the bearing sleeve of the present invention has several groups of key slots, the wave foil has a first coupling portion coupled to the key slot, and the top foil has a second coupling portion and a third coupling portion coupled to the key slot, that is, the first coupling portion, the second coupling portion and the third coupling portion are interlocked with the key slot. Compared with traditional foil bearings fixed by welding or pins, the requirements for foil forming are reduced, thereby improving the service life of the bearing.

[0039] The following is combined with specific Figure 3-8 The technical solution of the present invention is described in detail.

[0040] Figure 3 An exploded structural diagram of an air foil bearing 100 according to embodiment 1 of the present invention is shown. The air foil bearing 100 according to the exemplary embodiment of the present invention is configured in a rotating mechanical device having a rotating shaft (also referred to as a "rotor" in the art) as a rotating body.

[0041] The air foil bearing 100 supports the weight of a rotating shaft and a load applied to the rotating shaft in a rotating machine and rotatably supports the rotating shaft. Furthermore, the air foil bearing 100 according to an exemplary embodiment of the present invention supports a radial load perpendicular to the axial direction of the rotating shaft in the rotating machine.

[0042] The air foil bearing 100 described above effectively supports a rotating shaft rotating at high speed. For example, the air foil bearing 100 can be applied to rotating shafts rotating at high speed in rotating machinery such as turbo compressors, turbo coolers, turbo generators, air compressors, and blowers installed in vehicles. However, the scope of the present invention should not be construed as limited to rotating machinery in the automotive field, and the technical concepts of the air foil bearing 100 according to the present invention can be applied to rotating machinery of various types and applications.

[0043] In the exemplary embodiment of the present invention, the axial direction of the rotating shaft is defined as the front-to-rear direction, the direction perpendicular to the axial direction is defined as the radial direction, the surface located on the front side is defined as the front surface, and the surface located on the rear side is defined as the rear surface. The definition of the direction is relative and may vary depending on the reference position of the rotating shaft and the assembly position of the bearing assembly. Therefore, the reference direction is not particularly limited to the reference direction of the exemplary embodiment.

[0044] An air foil bearing 100 according to an exemplary embodiment of the present invention may include a bearing sleeve 1 , a bump foil 2 , and a top foil 3 .

[0045] The bearing sleeve 1 may include a front surface and a rear surface to be assembled to the rotating mechanical device and may include a hollow portion 11 into which a rotating shaft of the rotating mechanical device may be rotatably inserted. The bearing sleeve 1 may further include several groups of key grooves in the front-rear direction, i.e., the axial direction, on the inner circumferential surface of the hollow portion 11 to mount the bump foil 2 and the top foil 3, which will be further described below.

[0046] The front end of the keyway can be open on the front surface of the bearing sleeve 1, and the rear end of the keyway can be open on the rear surface of the bearing sleeve 1. Regardless of whether it is open on the front surface or the rear surface, the countersunk hole 12 is utilized, that is, the countersunk hole 12 is located on the front surface and the rear surface of the bearing sleeve 1, and the front end face and the rear end face of the keyway are both located in the countersunk hole 12.

[0047] In an exemplary embodiment of the present invention, the bump foil 2 can be arranged on the inner side of the hollow portion 11 of the bearing sleeve 1. In addition, the bump foil 2 can be an elastic support structure, a mesh support structure, or other support structures. As long as it can achieve support and can be deformed, it is within the protection scope of the present invention.

[0048] like Figure 3 and Figure 5 As shown, it is a schematic diagram of the wave foil 2 as a mesh support structure, such as Figure 6As shown, it is a schematic diagram of the bump foil 2 as an elastic support structure. Regardless of whether it is a mesh support structure or an elastic support structure, it is composed of three parts. Each part has the same shape and echoes each other from beginning to end to form a ring structure. Each part is provided with a first connecting portion 21. The first connecting portion 21 can be formed as a flat plate (for example, a strip or a belt) that bends radially outward at one end of the bump foil 2.

[0049] In addition, if Figure 3 and Figure 5-8 As shown, the top foil 3 can be installed on the inner side of the corrugated foil 2. The top foil 3 is also composed of three parts. Each part has the same shape and echoes each other from beginning to end to form a ring structure. Each part is provided with a second connecting portion 31 and a third connecting portion 32.

[0050] The top foil 3 of each part can be rolled into an arc shape and arranged close to the wave foil 2. The second combining portion 31 and the third combining portion 32 are located on opposite sides of the top foil 3 of each part. The arc shape changes of the second combining portion 31 and the third combining portion 32 and the main structure of the top foil 3 of each part are not much different. The second combining portion 31 and the third combining portion 32 are both used to be combined into the keyway.

[0051] In an exemplary embodiment of the present invention, there are three countersunk holes 12, which are respectively distributed in an array on the front surface and the rear surface of the bearing sleeve 1. The countersunk holes 12 are blind holes. Figure 3-8 As shown, the corresponding keyways also include three groups, each group of keyways includes a first keyway 13 adapted to the first coupling portion 21, a second keyway 14 adapted to the second coupling portion 31, and a third keyway 15 adapted to the third coupling portion 32, the first keyway 13, the second keyway 14 and the third keyway 15 are all located in the countersunk hole 12, wherein the extension depths of the first keyway 13, the second keyway 14 and the third keyway 15 from the inner circumferential surface of the bearing sleeve 1 to the countersunk hole 12 decrease successively.

[0052] Among them, such as Figure 5-8 As shown, the extension direction of the first keyway 13 is perpendicular to the tangent of the connection point with the first keyway 13 on the inner circumferential surface of the bearing sleeve 1, and the width and depth of the first keyway 13 are slightly larger than the width and length of the first coupling portion 21, so as to facilitate the insertion of the first coupling portion 21 into the first keyway 13.

[0053] The second keyway 14 and the third keyway 15 extend from opposite sides of the inner circumferential surface of the bearing sleeve 1 into the countersunk hole 12, and the second keyway 14 and the third keyway 15 form an approximately "human"-shaped structure. However, it should be noted that there is no conduction between the second keyway 14 and the third keyway 15. The width of the second keyway 14 is greater than the width of the second combining portion 31, which facilitates the insertion of the second combining portion 31 into the second keyway 14. The width of the third keyway 15 is greater than the width of the third combining portion 32, which facilitates the insertion of the third combining portion 32 into the third keyway 15.

[0054] In addition, a pin hole 16 is provided in the countersunk hole 12. The pin hole 16 is set as a through hole, that is, it extends from the front surface to the rear surface of the bearing sleeve 1. The pin hole 16 is close to the inner edge of the countersunk hole 12. The pin hole 16 is located at the end of the second keyway 14 and is connected to the second keyway 14.

[0055] A threaded hole 17 is further provided between the first keyway 13 and the second keyway 14 . The threaded hole 17 is located at the center of the countersunk hole 12 . Both ends of the bearing sleeve 1 have threaded holes 17 . The threaded holes 17 are blind holes.

[0056] The installation process of the air foil bearing 100 of the present invention is as follows:

[0057] When installing the bump foil 2, the first coupling portion 21 of the bump foil 2 is inserted into the first keyway 13 of the bearing sleeve 1. When installing the top foil, first insert the second coupling portion 31 of the top foil 3 into the second keyway 14 through the space margin of the pin hole 16, and then curl the top foil 3 out of the pin hole 16 by squeezing, and insert the pin 4 to form an interlocking; finally, lock the screw 5 to form an axial limit for the bump foil 2 and the top foil 3.

[0058] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. An air foil bearing with interlocking function, comprising a bearing sleeve, a wave foil and a top foil, characterized in that: The bearing sleeve includes a hollow portion for inserting a rotating shaft and a plurality of key grooves formed on the inner circumferential surface of the hollow portion, wherein the same group of key grooves is located in a countersunk hole on the end surface of the bearing sleeve. The bump foil is provided on the inner circumferential surface of the hollow portion and is provided with a first coupling portion for coupling to the key groove. The top foil is provided on the inner side of the bump foil and is provided with a second coupling portion and a third coupling portion for coupling to the key groove. The second coupling portion and the third coupling portion are provided on opposite sides of the top foil. There are three countersunk holes, and the corresponding key slots include three groups. Each group of key slots includes a first key slot adapted to the first combining portion, a second key slot adapted to the second combining portion, and a third key slot adapted to the third combining portion.

2. The air foil bearing with interlocking function according to claim 1, characterized in that: The corrugated foil is composed of three parts, each part has the same shape, and the end parts correspond to each other to form a ring structure, and each part is provided with the first connecting portion.

3. The air foil bearing with interlocking function according to claim 2, characterized in that: The top foil is also composed of three parts, each part has the same shape, and the end parts echo each other to form a ring structure, and each part is provided with the second connecting part and the third connecting part.

4. The air foil bearing with interlocking function according to claim 1, characterized in that: The extending depths of the first key groove, the second key groove and the third key groove from the inner circumferential surface of the bearing sleeve into the countersunk hole decrease in sequence.

5. The air foil bearing with interlocking function according to claim 1, characterized in that: The extending direction of the first key groove is perpendicular to a tangent line on the inner circumferential surface of the bearing sleeve at a connection point with the first key groove.

6. The air foil bearing with interlocking function according to claim 1, characterized in that: The second keyway and the third keyway extend from opposite sides of the inner circumferential surface of the bearing sleeve into the countersunk hole.

7. The air foil bearing with interlocking function according to claim 1, characterized in that: A threaded hole is provided between the first keyway and the second keyway. The threaded holes are provided at both ends of the bearing sleeve and are blind holes.

8. The air foil bearing with interlocking function according to claim 1, characterized in that: A pin hole is further provided in the countersunk hole. The pin hole is located at the end of the second keyway and is configured as a through hole.

9. The air foil bearing with interlocking function according to any one of claims 1 to 8, characterized in that: The corrugated foil is an elastic support structure or a mesh support structure.

Images