CN217814534U

CN217814534U - Thrust air foil bearing and axial supporting structure

Info

Publication number: CN217814534U
Application number: CN202122055162.3U
Authority: CN
Inventors: 张彪; 毕刘新; 聂慧凡
Original assignee: Tianjin Feixuan Technology Co ltd
Current assignee: Tianjin Feixuan Technology Co ltd
Priority date: 2021-08-27
Filing date: 2021-08-27
Publication date: 2022-11-15
Anticipated expiration: 2031-08-27

Abstract

The utility model provides a thrust air foil bearing and an axial supporting structure, wherein the thrust air foil bearing comprises a back plate, a bump foil and a top foil; the wave foil comprises a fixed section and an arch wave section which are arranged along the circumferential direction of the back plate, the fixed section is attached to and fixedly connected with the back plate, a plurality of arch waves are arranged on the arch wave section, the arch waves are arranged in a V shape, and the tips of the arch waves are back to the fixed section; the top foil covers the side of the bump foil facing away from the back plate. The wave foil is provided with a plurality of V-shaped arch waves in the arch wave band, the top foil is supported at the arch waves when attached to the surface of the wave foil, V-shaped collapse is formed between two adjacent arch waves, and the V-shaped collapsed tip faces away from the fixed section. Because the rotation direction of the flying disc is the direction pointing to the arch wave band from the fixed band, the flying disc can drive external air flow to flow in from the two ends of the V-shaped collapse in the rotation process and collect at the tip of the V-shaped collapse, the lifting effect of the flying disc is better, and the bearing capacity of the thrust air foil bearing is enhanced finally.

Description

Thrust air foil bearing and axial supporting structure

Technical Field

The utility model relates to a thrust bearing field especially relates to a thrust air foil bearing and axial bearing structure.

Background

The thrust air foil bearing is a self-acting dynamic pressure flexible bearing taking a flexible surface as a support, is directly matched with a flying disc fixed on a rotating shaft, limits the axial displacement of the rotating shaft by supporting the load from the flying disc, and is widely applied to high-speed rotating machines such as oil-free turbines, low-temperature expanders, air cycle machines and the like.

Thrust air foil bearings are generally composed of three parts: a backsheet, a bump foil and a top foil. The top foil and the wave foil are positioned between the back plate and the flying disc, the top foil and the wave foil are fixed with the back plate together, and the top foil covers the wave foil and is opposite to the flying disc. When the system works, the two relative motion surfaces of the top foil surface and the flying disc surface are separated by the gas film, and under the action of pressure, the top foil and the wave foil are elastically deformed to form a convergent wedge to generate a fluid dynamic pressure effect for supporting the axial bearing force.

The known bump foil comprises a plurality of wave-shaped protrusions which are parallel to each other. After the dynamic pressure is formed, the top foil is pushed towards the bump foil. Despite the wave foil support, the top foil may locally collapse between two adjacent wave-like protrusions. The collapse extends along the length direction of the bulge, high-pressure gas between the top foil and the flying disc is leaked, the pressure is reduced, and finally the bearing capacity of the thrust air foil bearing is weakened.

SUMMERY OF THE UTILITY MODEL

In order to solve the problems existing in the prior art, one of the objects of the present invention is to provide a thrust air foil bearing.

The utility model provides a following technical scheme:

a thrust air foil bearing comprising a back plate, a bump foil, and a top foil;

the wave foil comprises a fixed section and an arch wave section which are arranged along the circumferential direction of the back plate, the fixed section is attached to and fixedly connected with the back plate, a plurality of arch waves are arranged on the arch wave section, the arch waves are arranged in a V shape, and the tips of the arch waves are back to the fixed section;

the top foil covers one side of the wave foil, which is back to the back plate.

As a further alternative to the thrust air foil bearing, the camber waves comprise outer and inner lobes;

one end of the outer bulge facing the outer edge of the back plate is close to the fixed section, and the other end of the outer bulge faces the inner bulge and is far away from the fixed section;

one end, facing the inner edge of the back plate, of the inner bulge is close to the fixed section, and the other end of the inner bulge faces the outer bulge and is far away from the fixed section.

As a further optional scheme for the thrust air foil bearing, a first through groove is formed in the arch wave section, and the outer protrusion and the inner protrusion are respectively located on two sides of the first through groove.

As a further optional scheme for the thrust air foil bearing, a second through groove and a third through groove are formed in the arch wave section, the second through groove and the third through groove are both arranged along the circumferential direction of the back plate, the second through groove penetrates through the outer protrusion, and the third through groove penetrates through the inner protrusion.

As a further alternative to the thrust air foil bearing, the top foil comprises a bearing section and an inclined section;

the supporting section covers one side of the arch wave section back to the back plate;

one end of the inclined section is connected with the supporting section, the other end of the inclined section is connected with the fixing section, and the inclined section is used for forming a wedge-shaped gap with the flying disc.

As a further alternative to the thrust air foil bearing, the fixing section is welded and fixed to the back plate, and the top foil is welded and fixed to the fixing section.

As a further optional scheme for the thrust air foil bearing, an installation groove is formed in one side of the back plate facing the bump foil, and the bump foil and the top foil are inserted into the installation groove.

As a further alternative to the thrust air foil bearing, a first connecting ring and a second connecting ring are pinned to the back plate;

the first connecting ring is arranged around the bump foil and fixedly connected with the fixed section;

the second connection ring is disposed around the top foil and is fixedly connected to the top foil.

As a further optional solution to the thrust air foil bearing, the wave foil is provided in plurality, the wave foils are arranged along the circumferential direction of the back plate, the fixed segments and the arch segments are alternately arranged, and the top foil is arranged corresponding to the wave foil.

Another object of the present invention is to provide an axial supporting structure.

The utility model provides a following technical scheme:

an axial bearing structure comprises a flying disc and the thrust air foil bearing, wherein the flying disc is positioned on one side, back to the bump foil, of the top foil, and the flying disc is used for being connected with a rotating shaft.

The embodiment of the utility model has the following beneficial effect:

when the flying disc rotates, a pressure air film is formed between the flying disc and the top foil, and the pressure air film presses the top foil to enable the top foil to be close to the wave foil and attached to the surface of the wave foil. A plurality of V-shaped arch waves are arranged on the arch wave section of the wave foil, the top foil is supported at the arch wave position when being attached to the surface of the wave foil, V-shaped collapse is formed between two adjacent arch waves, and the V-shaped collapsed tip end faces away from the fixed section. Because the rotation direction of the flying disc is the direction pointing to the arch wave section from the fixed section, the flying disc can drive external air flow to flow in from the two ends of the V-shaped collapse in the rotation process and collect at the tip of the V-shaped collapse, so that the air pressure at the position is increased, the lifting effect on the flying disc is better, and finally the pressure bearing capacity of the thrust air foil bearing is enhanced.

In order to make the aforementioned and other objects, features and advantages of the present invention more comprehensible and obvious, preferred embodiments accompanied with figures are described in detail below.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are required to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention, and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

Fig. 1 is a schematic diagram illustrating an overall structure of a thrust air foil bearing according to an embodiment of the present invention;

FIG. 2 illustrates a top view of a thrust air foil bearing provided by an embodiment of the present invention;

FIG. 3 illustrates a top view of a bump foil in a thrust air foil bearing according to an embodiment of the present invention;

fig. 4 is a schematic diagram illustrating an axial structure of a bump foil in a thrust air foil bearing according to an embodiment of the present invention;

FIG. 5 illustrates a front view of a thrust air foil bearing provided by an embodiment of the present invention;

fig. 6 shows a schematic structural diagram of a bump foil in a thrust air foil bearing according to another specific implementation manner provided by an embodiment of the present invention;

fig. 7 is a front view of an axial support structure provided in an embodiment of the present invention.

Description of the main element symbols:

100-a back plate; 110-a connecting plate; 200-wave foil; 210-a stationary section; 220-arch wave band; 221-bow wave; 221 a-outer lobe; 221 b-inner protrusion; 222-an outer channel; 223-an inner channel; 224-a first through slot; 225-a second through slot; 226-third through slot; 300-top foil; 310-a support section; 320-inclined section; 400-flying disc.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are exemplary only for the purpose of explaining the present invention, and should not be construed as limiting the present invention.

It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. In contrast, when an element is referred to as being "directly on" another element, there are no intervening elements present. The terms "vertical," "horizontal," "left," "right," and the like as used herein are for illustrative purposes only.

In the present invention, unless otherwise explicitly specified or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly, e.g., as being fixedly connected, detachably connected, or integrated; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically limited otherwise.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the templates herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Examples

Referring to fig. 1, the present embodiment provides a thrust air foil bearing for cooperating with a flying disc 400 (see fig. 7) on a rotating shaft to axially support the rotating shaft. The thrust air foil bearing includes a back plate 100, a bump foil 200, and a top foil 300, wherein the back plate 100 is a mounting base of the bump foil 200 and the top foil 300.

Specifically, the back plate 100 is circular, and a through hole in the middle thereof is used for the rotation shaft to pass through. Three connecting plates 110 are integrally formed on the outer edge of the back plate 100 and bolted and fixed on the bearing seat through the connecting plates 110, and the three connecting plates 110 are uniformly arranged along the circumferential direction of the back plate 100.

Referring to fig. 2 and 3 together, in particular, the bump foil 200 is composed of a fixed segment 210 and a bow wave segment 220. The fixed section 210 and the bow wave section 220 are arranged along the circumferential direction of the backplate 100, and the direction from the fixed section 210 to the bow wave section 220 is the rotation direction of the flying disc 400 relative to the backplate 100.

The fixing section 210 is attached to the back plate 100, and one end of the fixing section 210 away from the arch wave band 220 is fixed on the back plate 100 by spot welding. The arch wave section 220 is integrally formed with the fixing section 210, and is connected to the back plate 100 through the fixing section 210. Further, the arch wave section 220 is formed with a plurality of arch waves 221, and the plurality of arch waves 221 are arranged along the circumferential direction of the back plate 100. Each of the arch waves 221 is disposed in a V-shape, and the tip of the arch wave 221 faces away from the fixed section 210.

The arch wave 221 is composed of an outer protrusion 221a and an inner protrusion 221b, the outer protrusion 221a being opposite to the outer peripheral region of the rear plate 100, and the inner protrusion 221b being opposite to the inner peripheral region of the rear plate 100. Specifically, one end of the outer protrusion 221a facing the outer edge of the back plate 100 lags behind the other end in the circumferential direction of the back plate 100, and the other end of the outer protrusion 221a faces the inner protrusion 221b. One end of the inner protrusion 221b facing the inner edge of the back plate 100 lags the other end in the circumferential direction of the back plate 100, and the other end of the inner protrusion 221b faces the outer protrusion 221a. Finally, the outer projection 221a and the inner projection 221b together form a V-shaped bow wave 221.

In this embodiment, the outer protrusion 221a and the inner protrusion 221b both extend along a straight line, and the straight line of the outer protrusion 221a and the straight line of the inner protrusion 221b do not coincide with any radial line of the back plate 100. In another embodiment of the present application, the outer protrusion 221a and the inner protrusion 221b may also extend along a curve, and the concave surface of the curve faces the fixing section 210.

Referring to fig. 4, along the circumferential direction of the back plate 100, the area between two adjacent outer protrusions 221a is tightly attached to the back plate 100 to form an outer channel 222, and the area between two adjacent inner protrusions 221b is tightly attached to the back plate 100 to form an inner channel 223.

Referring to fig. 5, in particular, the top foil 300 is composed of a support section 310 and an inclined section 320. The supporting section 310 covers a side of the arch wave section 220 facing away from the backplate 100, and the inclined section 320 is located on a side of the fixing section 210 facing away from the backplate 100.

One end of the inclined section 320 is integrally formed with the supporting section 310, and the other end of the inclined section 320 is fixedly connected to the fixing section 210 by spot welding and is connected to the back plate 100 through the fixing section 210. The entire inclined section 320 is arranged obliquely with respect to back plate 100, forming a wedge-shaped gap with flying disc 400, and the tip of the wedge-shaped gap points in the rotation direction of flying disc 400.

The supporting section 310 is connected to the fixing section 210, and thus to the back plate 100, by the inclined section 320. When the flying disc 400 rotates, a pressure air film is formed between the flying disc 400 and the supporting section 310, and the pressure air film presses the supporting section 310, so that the supporting section 310 is close to the arch section 220 and attached to the surface of the arch section 220. The arch wave section 220 is provided with a plurality of V-shaped arch waves 221, the support section 310 is supported at the outer protrusion 221a and the inner protrusion 221b when being attached to the surface of the arch wave section 220, and is collapsed at the outer passage 222 and the inner passage 223 to form a V-shaped air inlet passage, and the tip of the air inlet passage faces away from the fixed section 210. Since the rotation direction of the flying disc 400 is the direction from the fixed section 210 to the arch wave section 220, the flying disc 400 drives the external air flow to flow in from the two ends of the air inlet channel during the rotation process, and the external air flow is collected at the tip of the air inlet channel, so that the air pressure at the position is increased, the lifting effect of the flying disc 400 is better, and the bearing capacity of the thrust air foil bearing is enhanced finally.

Referring again to fig. 4, further, during the process of processing the wave foil 200, the arch wave 221 on the arch wave section 220 is typically formed by stamping. In order to facilitate the punch forming of the obliquely intersecting outer protrusion 221a and inner protrusion 221b, a first through groove 224 is formed in the arch wave section 220. The first through groove 224 is provided along the circumferential direction of the back plate 100, and divides the outer protrusion 221a and the inner protrusion 221b, and the outer protrusion 221a and the inner protrusion 221b of each arch wave 221 are located on both sides of the first through groove 224, respectively. At this time, the outer protrusion 221a and the inner protrusion 221b do not interfere with each other in the press-forming process.

In addition, since the outer projection 221a and the inner projection 221b are obliquely intersected, when the outer projection 221a and the inner projection 221b are expanded to both sides or gathered to the middle, the moving directions of both side regions thereof are also different. After the first through groove 224 is provided to divide the outer protrusion 221a and the inner protrusion 221b, the outer protrusion 221a and the inner protrusion 221b can be freely deformed.

In another embodiment of the present application, the first through groove 224 may penetrate the entire wave foil 200 in the circumferential direction of the back plate 100 to form two sub-wave foils 200. The two sub-wave foils 200 are respectively formed and then fixed to the back plate 100 by spot welding.

Referring to fig. 6, further, since the bump foil 200 is disposed along the circumferential direction of the backplate 100, but the extending direction of the outer protrusion 221a and the inner protrusion 221b does not coincide with any radial line of the backplate 100, in order to make the outer protrusion 221a and the inner protrusion 221b better expand or contract along the circumferential direction of the backplate 100, the arch wave band 220 is further provided with a second through groove 225 and a third through groove 226.

The second through grooves 225 are disposed along the circumferential direction of the back plate 100 and penetrate the outer protrusions 221a, and the number thereof may be one or more. When the second through grooves 225 are provided in plurality, the second through grooves 225 are uniformly arranged in the radial direction of the backplate 100. The second through groove 225 divides the outer protrusion 221a into at least two sections, and the sections of the outer protrusion 221a are not affected by each other in the deformation process under pressure.

Similarly, the third through groove 226 is disposed along the circumferential direction of the back plate 100 and penetrates the inner protrusion 221b, and the number thereof may be one or more. When the third through grooves 226 are provided in plural, each of the third through grooves 226 is uniformly arranged in the radial direction of the backplate 100. The third through groove 226 divides the inner protrusion 221b into at least two sections, and the inner protrusions 221b of the sections are not affected by each other in the deformation process under pressure.

In another embodiment of the present application, the first through groove 224, the second through groove 225, and the third through groove 226 may penetrate through the entire bump foil 200 in the circumferential direction of the backplate 100 to form at least four sub-bump foils 200. Each of the sub-wave foils 200 is formed separately and then fixed to the back plate 100 by spot welding.

In the entire thrust air foil bearing, the number of the bump foils 200 is at least one, the number of the top foils 300 is the same as the bump foils 200, and the top foils 300 are disposed corresponding to the bump foils 200.

In the present embodiment, six wave foils 200 are provided, the six wave foils 200 are arranged along the circumferential direction of the backplate 100, and the respective fixed segments 210 and the arch segments 220 are alternately arranged. Six top foils 300 are respectively covered on the corresponding wave foils 200, and each pair of wave foils 200 and top foils 300 forms an independent thrust pad to support the flying disc 400.

In another embodiment of the present application, the back plate 100, the bump foil 200 and the top foil 300 may also be fixed together by other means. For example, a mounting groove is formed on the side of the backplate 100 facing the bump foil 200, the ends of the bump foil 200 and the top foil 300 are folded toward the backplate 100 to form a flange, and the flange is inserted into the mounting groove, so that the bump foil 200 and the top foil 300 can be fixed on the backplate 100. Alternatively, the bump foil 200 and the top foil 300 are fixed to the backplate 100 by disposing a first connection ring around the periphery of the bump foil 200, integrally molding or welding the first connection ring to the fixed section 210, disposing a second connection ring around the periphery of the top foil 300, integrally molding or welding the second connection ring to the inclined section 320, and then fixing the first connection ring and the second connection ring to the backplate 100 by pins.

In particular, when six top foils 300 are fixedly connected to the back plate 100 by the second connection rings, the top foils 300 and the second connection rings may be integrally stamped and formed for easy transportation, storage and assembly.

Referring to fig. 7, the present embodiment further provides an axial support structure, which includes a flying disc 400 and the above-mentioned thrust air foil bearing. The flying disc 400 surrounds the rotating shaft, and is bolted or welded to the rotating shaft and is opposite to the side of the top foil 300 facing away from the bump foil 200.

In operation, the two opposing surfaces of motion, the top foil 300 surface and the flying disc 400 surface, are separated by a thin film of gas. Under the action of pressure, the top foil 300 and the bump foil 200 are elastically deformed to form a convergent wedge, so that a hydrodynamic effect is generated to support the axial bearing force.

In all examples shown and described herein, any particular value should be construed as merely exemplary, and not as a limitation, and thus other examples of example embodiments may have different values.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures.

The above-described embodiments are merely illustrative of several embodiments of the present invention, which are described in detail and specific, but not intended to be construed as limiting the scope of the present invention. It should be noted that, for those skilled in the art, without departing from the spirit of the present invention, several variations and modifications can be made, which are within the scope of the present invention.

Claims

1. A thrust air foil bearing comprising a backing plate, a bump foil and a top foil;

the top foil covers one side of the wave foil, which is back to the back plate.

2. The thrust air foil bearing of claim 1, wherein the crowning includes an outer lobe and an inner lobe;

one end of the outer protrusion facing the outer edge of the back plate lags behind the other end along the circumferential direction of the back plate;

one end of the inner protrusion facing the inner edge of the back plate lags the other end in the circumferential direction of the back plate.

3. The thrust air foil bearing of claim 2, wherein said scalloped portion defines a first channel, and said outer bump and said inner bump are positioned on opposite sides of said first channel, respectively.

4. The thrust air foil bearing of claim 2, wherein said domeshaped segment is provided with a second through groove and a third through groove, said second through groove and said third through groove being disposed along a circumferential direction of said back plate, said second through groove extending through said outer protrusion, said third through groove extending through said inner protrusion.

5. The thrust air foil bearing of claim 1, wherein said top foil includes a bearing section and an angled section;

the supporting section covers one side of the arch wave section, which is back to the back plate;

6. The thrust air foil bearing of claim 1, wherein said stationary segment is welded to said backing plate and said top foil is welded to said stationary segment.

7. The thrust air foil bearing of claim 1, wherein a mounting groove is defined in a side of said back plate facing said bump foil, said bump foil and said top foil being inserted into said mounting groove.

8. The thrust air foil bearing of claim 1, wherein said back plate has a first connecting ring and a second connecting ring pinned thereto;

the second connection ring is arranged around the top foil and is fixedly connected with the top foil.

9. The thrust air foil bearing of claim 1, wherein the bump foil is provided in plurality, the bump foils are arranged in plurality along a circumferential direction of the back plate, the fixed segments and the arch segments are alternately arranged, and the top foil is arranged corresponding to the bump foils.

10. An axial support structure comprising a flying disc on a side of the top foil facing away from the bump foil, the flying disc being adapted for connection to a rotating shaft, and a thrust air foil bearing as claimed in any one of claims 1 to 9.