An elliptical pad radial gas foil bearing based on double-layer corrugated foils

Abstract

The application discloses an elliptical shoe radial gas foil bearing based on double-layer corrugated foils and relates to the technical field of air bearings, and solves the problem that the traditional aerodynamic pressure radial foil bearing cannot support the shaft system to stably work at a higher rotating speed due to the limitation of the circular shoe structure, mainly comprises a bearing sleeve, double-layer corrugated foils and top foils, the two ends of the top foils are fixed by dovetail grooves, the circular shoe of the bearing is changed into an elliptical shoe, the stability of the bearing is improved, the double-layer corrugated foils are composed of two layers of corrugated foils with different corrugation numbers, the corrugation number of the upper corrugated foil is less than that of the lower corrugated foil, the top foil of the bearing changes in the arc at the position where the upper corrugated foil lacks corrugations, the proportion of the elliptical shoe is increased, a better wedge surface is obtained, and the proportion of the elliptical shoe of the top foil is more accurately adjusted by adjusting the difference between the corrugation numbers of the upper and lower foils, and the stability of the bearing is further improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of air bearings, in particular to an elliptical shoe radial gas foil bearing based on double-layer corrugated foils. BACKGROUND

[0002] Air bearings use air as the medium and have the advantages of high precision, good working reliability, small friction, high rotation precision, and no oil, so that the proportion of rotary machines equipped with air bearings gradually increases in the fields of energy and chemical industry, and people have higher requirements for the rotation speed of rotary machines. However, with the increasing demand for rotation speed of rotary machines, the traditional aerodynamic pressure radial foil bearing is limited by its circular shoe structure, and low-frequency components are generated in the shaft system at high speed, which has poor stability and cannot support the shaft system to work stably at a higher rotation speed, thereby limiting the application of aerodynamic pressure radial gas foil bearings in high-speed working conditions. SUMMARY

[0003] In view of the above problems, the purpose of the present application is to provide an elliptical shoe radial gas foil bearing based on double-layer corrugated foils, which can effectively compensate for the lack of stability of the bearing at high speed by controlling the difference in the number of corrugations between the upper and lower corrugated foils of the double-layer corrugated foils to control the elliptical proportion of the bearing shoe.

[0004] In order to achieve the above-mentioned purpose, the technical scheme adopted by the present application is as follows:

[0005] An elliptical shoe radial gas foil bearing based on double-layer corrugated foils, comprising: a top foil 1, double-layer corrugated foils 2, and a bearing sleeve 3, each double-layer corrugated foil 2 comprises: an upper corrugated foil 21 and a lower corrugated foil 22 connected to each other, the upper corrugated foil 21 is arranged close to the inner wall of the bearing sleeve 3, the inner wall of the bearing sleeve 3 is provided with two center-symmetric straight grooves 4 and two center-symmetric dovetail grooves 5, the two straight grooves 4 are located in the horizontal direction, and the two dovetail grooves 5 are located in the vertical direction, four double-layer corrugated foils 2 form a circumferentially unclosed first ring, two top foils 1 form a circumferentially unclosed second ring, the first ring is arranged between the inner wall of the bearing sleeve 3 and the second ring, both ends of each top foil 1 are respectively installed in two dovetail grooves 5, and one end of each double-layer corrugated foil 2 is installed in one straight groove 4.

[0006] An elliptical tile radial gas foil bearing based on double-layer corrugated foils, comprising: top foils 1, double-layer corrugated foils 2 and a bearing sleeve 3, each double-layer corrugated foil 2 comprises: an upper corrugated foil 21 and a lower corrugated foil 22 connected to each other, the upper corrugated foil 21 is arranged close to the inner wall of the bearing sleeve 3, a plurality of straight grooves 4 and a plurality of dovetail grooves 5 are arranged on the inner wall of the bearing sleeve 3 at equal intervals, each straight groove 4 is arranged between any two adjacent dovetail grooves 5, a plurality of double-layer corrugated foils 2 form a circumferentially non-closed first ring, a plurality of top foils 1 form a circumferentially non-closed second ring, the first ring is arranged between the inner wall of the bearing sleeve 3 and the second ring, and the two ends of each top foil 1 are respectively arranged in any two adjacent dovetail grooves 5, and one end of each double-layer corrugated foil 2 is arranged in a straight groove 4.

[0007] The elliptical tile radial gas foil bearing based on double-layer corrugated foils, wherein the number of corrugations of the upper corrugated foil 21 is less than that of the lower corrugated foil 22, one end of the upper corrugated foil 21 and one end of the lower corrugated foil 22 are connected and provided with a bending part, and the bending part is arranged in a straight groove 4.

[0008] The elliptical tile radial gas foil bearing based on double-layer corrugated foils, wherein each dovetail groove 5 comprises two symmetrical cutouts, and each cutout is used for connecting the end of a top foil 1.

[0009] The elliptical tile radial gas foil bearing based on double-layer corrugated foils, wherein the top foil 1 is in the shape of an elliptical arc.

[0010] The elliptical tile radial gas foil bearing based on double-layer corrugated foils, wherein the number of corrugations of each lower corrugated foil 22 is one more than that of the upper corrugated foil 21 connected thereto.

[0011] The elliptical tile radial gas foil bearing based on double-layer corrugated foils, wherein the number of corrugations of each lower corrugated foil 22 is at least two more than that of the upper corrugated foil 21 connected thereto.

[0012] The present application has the following advantages over the prior art due to the use of the above-mentioned technology:

[0013] (1) The present application realizes that the tile in the bearing is changed from a circular tile to an elliptical tile by arranging a dovetail groove on the relative position of the bearing sleeve of the dynamic pressure radial gas foil bearing and fixing the two ends of the top foil in the two dovetail grooves, thereby effectively improving the high-speed stability of the bearing.

[0014] (2) The application adopts double-layer corrugated foils, changes the oval proportion of the tile by controlling the corrugation number of the upper corrugated foil of the double-layer corrugated foils to be less than the corrugation number of the lower corrugated foil, and further improves the high-speed stability of the bearing. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 is a structure schematic diagram of an oval tile radial gas foil bearing based on double-layer corrugated foils of the application.

[0016] Figure 2 is an assembly schematic diagram of an oval tile radial gas foil bearing based on double-layer corrugated foils of the application.

[0017] Figure 3 is a structure schematic diagram of a bearing sleeve of an oval tile radial gas foil bearing based on double-layer corrugated foils of the application.

[0018] Figure 4 is a structure schematic diagram of a top foil of an oval tile radial gas foil bearing based on double-layer corrugated foils of the application.

[0019] Figure 5 is a structure schematic diagram of an upper corrugated foil of an oval tile radial gas foil bearing based on double-layer corrugated foils of the application, in which the corrugation number of the upper corrugated foil is one less than the corrugation number of the lower corrugated foil.

[0020] Figure 6 is a structure schematic diagram of an upper corrugated foil of an oval tile radial gas foil bearing based on double-layer corrugated foils of the application, in which the corrugation number of the upper corrugated foil is two less than the corrugation number of the lower corrugated foil.

[0021] Figure 7 is an installation schematic diagram of an oval tile radial gas foil bearing based on double-layer corrugated foils of the application.

[0022] In the drawings: 1, top foil; 2, double-layer corrugated foil; 21, upper corrugated foil; 22, lower corrugated foil; 3, bearing sleeve; 4, straight groove; 5, dovetail groove. DETAILED DESCRIPTION

[0023] The application will be further described below in conjunction with the drawings and specific embodiments, but not as a limitation of the application.

[0024] Please refer to Figures 1 to 7As shown, it shows a kind of elliptical radial gas foil bearing based on double-layer corrugated foil, wherein, including: top foil 1, double-layer corrugated foil 2 and bearing sleeve 3, each double-layer corrugated foil 2 includes: upper layer corrugated foil 21 and lower layer corrugated foil 22 connected with each other, upper layer corrugated foil 21 is arranged close to the inner wall of bearing sleeve 3, a plurality of straight grooves 4 and a plurality of dovetail grooves 5 are arranged at equal intervals on the inner wall of bearing sleeve 3, each straight groove 4 is arranged between any two adjacent dovetail grooves 5, a plurality of double-layer corrugated foils 2 form a circumferentially unclosed first ring, a plurality of top foils 1 form a circumferentially unclosed second ring, the first ring is arranged between the inner wall of bearing sleeve 3 and the second ring, and the two ends of each top foil 1 are respectively mounted in any two adjacent dovetail grooves 5, and one end of each double-layer corrugated foil 2 is mounted in a straight groove 4.

[0025] Further, in a preferred embodiment, the number of corrugations of upper layer corrugated foil 21 is less than the number of corrugations of lower layer corrugated foil 22, one end of upper layer corrugated foil 21 and one end of lower layer corrugated foil 22 are connected and provided with a bending portion, and the bending portion is mounted in a straight groove 4.

[0026] Further, in a preferred embodiment, each dovetail groove 5 includes two symmetrical cutouts, and each cutout is used to connect with the end of a top foil 1.

[0027] Further, in a preferred embodiment, top foil 1 is in the shape of elliptical arc.

[0028] Further, in a preferred embodiment, the number of corrugations of each lower layer corrugated foil 22 is one more than the number of corrugations of the upper layer corrugated foil 21 connected therewith.

[0029] Further, in a preferred embodiment, the number of corrugations of each lower layer corrugated foil 22 is at least two more than the number of corrugations of the upper layer corrugated foil 21 connected therewith.

[0030] The above is only a preferred embodiment of the present application, and does not limit the implementation and protection scope of the present application.

[0031] The present application further has the following implementation based on the above:

[0032] In a further embodiment of the present application, an elliptical tile radial gas foil bearing based on double-layer corrugated foils comprises a top foil 1, double-layer corrugated foils 2, and a bearing sleeve 3, each double-layer corrugated foil 2 comprises an upper corrugated foil 21 and a lower corrugated foil 22 connected to each other, the upper corrugated foil 21 is arranged close to the inner wall of the bearing sleeve 3, the inner wall of the bearing sleeve 3 is provided with two center-symmetrical straight grooves 4 and two center-symmetrical dovetail grooves 5, the two straight grooves 4 are located in the horizontal direction, and the two dovetail grooves 5 are located in the vertical direction, the four double-layer corrugated foils 2 form a circumferentially non-closed first ring, the two top foils 1 form a circumferentially non-closed second ring, the first ring is arranged between the inner wall of the bearing sleeve 3 and the second ring, and the two ends of each top foil 1 are respectively arranged in the two dovetail grooves 5.

[0033] In a further embodiment of the present application, an elliptical tile radial gas foil bearing based on double-layer corrugated foils is provided, by fixing the two ends of the top foil 1 in the two dovetail grooves 5, the tile in the bearing is changed from a circular tile to an elliptical tile, the high-speed stability of the bearing is effectively improved, and by controlling the number of corrugations of the upper corrugated foil 21 of the double-layer corrugated foil 2 to be less than the number of corrugations of the lower corrugated foil 22, the elliptical proportion of the tile is changed, and the high-speed stability of the bearing is further improved.

[0034] In a further embodiment of the present application, an elliptical tile radial gas foil bearing based on double-layer corrugated foils is disclosed, mainly comprising a bearing sleeve 3, double-layer corrugated foils 2, and top foils 1. The elliptical tile radial gas foil bearing based on double-layer corrugated foils adopts dovetail grooves 5 to fix the two ends of the top foil 1, so that the circular tile of the bearing is changed to an elliptical tile, and the stability of the bearing is improved. In addition, the double-layer corrugated foils 2 used in the present application are composed of two layers of corrugated foils with different numbers of corrugations, the number of corrugations of the upper corrugated foil 21 is less than the number of corrugations of the lower corrugated foil 22, through such a structure, the top foil 1 of the bearing changes in curvature at the position where the upper corrugated foil 21 lacks corrugations, the proportion of the elliptical tile is increased, a better wedge surface is obtained, and by adjusting the difference in the number of corrugations between the upper and lower foils, the elliptical tile proportion of the top foil 1 is more accurately adjusted, and the effect of further improving the stability of the bearing is finally achieved.

[0035] In a further embodiment of the present application, an elliptical tile radial gas foil bearing based on double-layer corrugated foils comprises a top foil 1, double-layer corrugated foils 2, and a bearing sleeve 3.

[0036] In a further embodiment of the present application, a straight groove 4 is formed at a relative position on the inner wall of the bearing sleeve 3, and a dovetail groove 5 is formed at a relative position 90 degrees apart from the straight groove 4.

[0037] In a further embodiment of the present application, the top foil 1 and the double-layer corrugated foil 2 are both hollow cylindrical structures that are not closed in the circumferential direction. The double-layer corrugated foil 2 is placed inside the bearing sleeve 3, with the outer surface of the double-layer corrugated foil 2 being attached to the inner surface of the bearing sleeve 3. The top foil 1 is placed inside the double-layer corrugated foil 2, with the outer surface of the top foil 1 being attached to the inner surface of the double-layer corrugated foil 2. The folded corner end of the double-layer corrugated foil 2 is fixed by being inserted into the straight slot 4 on the bearing sleeve 3. The two ends of the top foil 1 are inserted into the dovetail slot 5 for fixation.

[0038] In a further embodiment of the present application, the top foil 1 is two pieces, the double-layer corrugated foil 2 is four pieces, and the bearing sleeve 3 is one piece.

[0039] In a further embodiment of the present application, the material of the top foil 1 is stainless steel, nickel-based alloy, copper, aluminum, graphite, or other metal or polytetrafluoroethylene or other non-metallic material.

[0040] In a further embodiment of the present application, the double-layer corrugated foil 2 is composed of an upper corrugated foil 21 and a lower corrugated foil 22. The number of corrugations of the upper corrugated foil 21 is less than the number of corrugations of the lower corrugated foil. The missing corrugations are present in the tail of the non-fixed end of the double-layer corrugated foil 2. The fixed end of the double-layer corrugated foil 2 is bent to a certain extent, so that the folded corner end is inserted into the straight slot 4 to fix the double-layer corrugated foil 2.

[0041] In a further embodiment of the present application, the beneficial effects of the present application are as follows. The present application realizes the following effects by providing a dovetail slot 5 on the relative position of the bearing sleeve of the dynamic pressure radial gas foil bearing. The two ends of the top foil are fixed in the two dovetail slots 5. The pad inside the bearing is changed from a circular pad to an elliptical pad, effectively improving the high-speed stability of the bearing. The double-layer corrugated foil is used to change the elliptical ratio of the pad by controlling the number of corrugations of the upper corrugated foil of the double-layer corrugated foil to be less than the number of corrugations of the lower corrugated foil, further improving the high-speed stability of the bearing.

[0042] In a further embodiment of the present application, as shown in Figure 1 , a kind of based on double-layer corrugated foil's elliptical pad radial gas foil bearing, including top foil 1 double-layer corrugated foil 2, bearing sleeve 3;Wherein bearing sleeve 3 as a basic "frame" of overall structure, its schematic diagram as shown in Figure 3 , double-layer corrugated foil 2 is placed in the inside of bearing sleeve 3, as shown in Figure 5 , its number is four, the folded corner of the fixed end of upper and lower two corrugated foils is fixed in the straight slot 4 of bearing sleeve 3;Top foil 1 as shown in Figure 4As shown, the two ends of the top foil are fixed in the dovetail groove 5; the double-layer corrugated foil 2 is placed inside the bearing sleeve 3, the outer surface of the double-layer corrugated foil 2 is attached to the inner surface of the bearing sleeve 3, the top foil 1 is placed inside the double-layer corrugated foil 2, the outer surface of the top foil 1 is attached to the inner surface of the double-layer corrugated foil 2, because the upper corrugated foil 21 has less corrugations than the lower corrugated foil, so the outer surface of the top foil 1 will change from a round tile to an oval tile after being attached to the last corrugation of the free end of the upper corrugated foil 21, therefore, by controlling the number of corrugations of the upper corrugated foil 21 to be less than that of the lower corrugated foil 22, the proportion of the bearing oval tile can be controlled. An assembly can be formed, such as Figure 2 As shown.

[0043] In further embodiments of the present application, the oval tile can make the wedge-shaped dynamic pressure effect of the bearing better, because when the gas radial foil bearing is working, the rotor will make the rotor axis trajectory elliptical due to gravity, at this time the stability of the rotor is higher, therefore, the oval tile compared to the round tile will make the shafting more stable, the greater the oval proportion, the higher the stability of the shafting.

[0044] The above is only the preferred embodiment of the present application, and does not limit the implementation and protection scope of the present application. For those skilled in the art, it should be realized that any equivalent replacement and obvious changes made according to the content of the present application should be included in the protection scope of the present application.

Claims

1. An elliptical radial gas foil bearing based on double-layer corrugated foil, characterized in that, include: The top foil (1), double-layer corrugated foil (2) and bearing sleeve (3) are provided. Each double-layer corrugated foil (2) includes an upper corrugated foil (21) and a lower corrugated foil (22) connected to each other. The upper corrugated foil (21) is located close to the inner wall of the bearing sleeve (3). The inner wall of the bearing sleeve (3) is provided with two centrally symmetrical straight grooves (4) and two centrally symmetrical dovetail grooves (5). The two straight grooves (4) are located in the horizontal direction, and the two dovetail grooves (5) are located in the vertical direction. The four double-layer corrugated foils (2) are arranged together to form a first ring that is not closed in the circumferential direction. The two top foils (1) are arranged together to form a second ring that is not closed in the circumferential direction. The first ring is located between the inner wall of the bearing sleeve (3) and the second ring. The two ends of each top foil (1) are respectively installed in the two dovetail grooves (5), and one end of each double-layer corrugated foil (2) is installed in one of the straight grooves (4). The upper corrugated foil (21) has fewer corrugations than the lower corrugated foil (22). One end of the upper corrugated foil (21) is connected to one end of the lower corrugated foil (22) and is provided with a bending part. The bending part is installed in one of the straight grooves (4). The number of corrugations in each lower corrugated foil (22) is one more than the number of corrugations in the upper corrugated foil (21) to which it is connected, or the number of corrugations in each lower corrugated foil (22) is at least two more than the number of corrugations in the upper corrugated foil (21) to which it is connected; With this structure, the bearing top foil (1) undergoes an arc change at the point where the upper corrugated foil (21) lacks corrugations, increasing the proportion of elliptical tiles and obtaining a better wedge-shaped surface. Furthermore, by adjusting the difference in the number of corrugations between the upper and lower foils, the proportion of elliptical tiles in the top foil (1) can be adjusted more accurately, further improving the bearing stability.

2. An elliptical radial gas foil bearing based on double-layer corrugated foil, characterized in that, include: The top foil (1), double-layer corrugated foil (2) and bearing sleeve (3) are provided. Each double-layer corrugated foil (2) includes an upper corrugated foil (21) and a lower corrugated foil (22) connected to each other. The upper corrugated foil (21) is located close to the inner wall of the bearing sleeve (3). The inner wall of the bearing sleeve (3) is provided with a plurality of straight grooves (4) and a plurality of dovetail grooves (5) at equal intervals. Each straight groove (4) is located between any two adjacent dovetail grooves (5). The plurality of double-layer corrugated foils (2) are arranged together to form a first ring that is not closed in a circumferential direction. The plurality of top foils (1) are arranged together to form a second ring that is not closed in a circumferential direction. The first ring is located between the inner wall of the bearing sleeve (3) and the second ring. The two ends of each top foil (1) are respectively installed in any two adjacent dovetail grooves (5). One end of each double-layer corrugated foil (2) is installed in a straight groove (4). The upper corrugated foil (21) has fewer corrugations than the lower corrugated foil (22). One end of the upper corrugated foil (21) is connected to one end of the lower corrugated foil (22) and is provided with a bending part. The bending part is installed in one of the straight grooves (4). The number of corrugations in each lower corrugated foil (22) is one more than the number of corrugations in the upper corrugated foil (21) to which it is connected, or the number of corrugations in each lower corrugated foil (22) is at least two more than the number of corrugations in the upper corrugated foil (21) to which it is connected; With this structure, the bearing top foil (1) undergoes an arc change at the point where the upper corrugated foil (21) lacks corrugations, increasing the proportion of elliptical tiles and obtaining a better wedge-shaped surface. Furthermore, by adjusting the difference in the number of corrugations between the upper and lower foils, the proportion of elliptical tiles in the top foil (1) can be adjusted more accurately, further improving the bearing stability.

3. The elliptical tile radial gas foil bearing based on double-layer corrugated foil according to claim 1 or claim 2, characterized in that, Each of the dovetail grooves (5) includes two symmetrically arranged cuts, each cut being used to connect to the end of a top foil (1).

4. The elliptical tile radial gas foil bearing based on double-layer corrugated foil according to claim 1 or claim 2, characterized in that, The top foil (1) is elliptical in shape.

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