Thrust gas foil bearings and bearing assemblies

Abstract

The present invention provides a thrust gas foil bearing and a bearing assembly, which relates to the technical field of air bearings, and solves the technical problem that the thrust gas foil bearing in the prior art is only allowed to work in a single direction and is prone to wear when it is reversed. The device includes a top foil, a top foil gasket and a top foil bottom plate, the top foil foil and the top foil bottom plate clamp the top foil gasket and the top foil foil is connected to the top foil bottom plate; the top foil includes a foil ring of an annular structure and a multi-petal foil support plate, the inner ring of the foil ring is fixedly connected to the foil support plate, and the foil support plate is distributed along the circumferential direction of the foil ring; the foil support plate includes a first welding area, a first wedge area, a pressure plate area, a second wedge area and a second welding area, both ends of the pressure plate area are connected to the upper end faces of the first wedge area and the second wedge area, the lower end face of the first wedge area is connected to the first welding area, and the lower end face of the second wedge area is connected to the second welding area.

Description

Technical Field

[0001] The invention relates to the technical field of air bearings, and in particular to a thrust gas foil bearing and a bearing assembly. Background Art

[0002] Gas foil bearing is a kind of dynamic pressure gas bearing. It is widely used in turbomachinery such as air compressors, air cycle machines, micro gas turbines, etc. due to its high temperature resistance, high speed, oil-free lubrication, and low friction loss. Gas foil bearing uses the wedge effect. As the speed of the supporting rotor increases, the gas with a certain viscosity in the surrounding environment is dragged into the wedge-shaped air cavity formed by the rotor and the bearing support surface by the high-speed rotating rotor. When the speed of the rotor rises to a certain speed, the gas pressure in the wedge-shaped supporting air cavity increases to support the rotor.

[0003] At present, the most common and widely used is the wave foil type thrust gas foil bearing, which has good stiffness and damping characteristics. Usually, the wave foil type thrust gas foil bearing includes three layers: top foil, wave foil and supporting base plate. The top foil and wave foil include multi-lobed top foil and wave foil respectively. Each lobe of wave foil is fixed on the supporting base plate by welding. Each lobe of top foil is also fixed on the wave foil or supporting base plate by welding, forming a structure in which the supporting base plate supports the wave foil, and the wave foil supports the top foil. During operation, the rotor and the top foil form a wedge-shaped space. After the rotor rotates, the top foil needs to overcome the starting friction torque. The rotor drags the gas with a certain viscosity in the surrounding environment into the wedge for compression. When the speed increases to a certain level, the rotor is suspended. During operation, the direction of the wedge is the direction of rotation of the rotor.

[0004] The applicant has found that the prior art has at least the following technical problems:

[0005] In the prior art, when the top foil of the thrust gas foil bearing is worn, the thrust gas foil bearing cannot be used and is treated as scrapped, and the undamaged foil and supporting base plate cannot be used either, wasting resources. In addition, the existing thrust gas foil bearing is only allowed to work in a single direction, and reversal often occurs from time to time during assembly and debugging, which can easily cause wear of the thrust gas foil bearing. Summary of the invention

[0006] The purpose of the present invention is to provide a thrust gas foil bearing and a bearing assembly to solve the technical problem that the thrust gas foil bearing in the prior art is only allowed to work in one direction and is prone to wear when it is reversed. The preferred technical solution among the many technical solutions provided by the present invention can produce many technical effects as described below.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] A thrust gas foil bearing provided by the present invention comprises a top foil, a top foil gasket and a top foil bottom plate, wherein the top foil, the top foil gasket and the top foil bottom plate are arranged in sequence, the top foil and the top foil bottom plate clamp the top foil gasket and the top foil is connected to the top foil bottom plate;

[0009] The top foil comprises a foil ring of an annular structure and a multi-petal foil support plate, the inner ring of the foil ring is fixedly connected to the foil support plate, and the foil support plates are distributed along the circumferential direction of the foil ring;

[0010] The foil support plate includes a first welding area, a first wedge-shaped area, a pressure plate area, a second wedge-shaped area and a second welding area. The first welding area, the first wedge-shaped area, the pressure plate area, the second wedge-shaped area and the second welding area are connected in sequence. Both ends of the pressure plate area are connected to the upper end surfaces of the first wedge-shaped area and the second wedge-shaped area. The lower end surface of the first wedge-shaped area is connected to the first welding area, and the lower end surface of the second wedge-shaped area is connected to the second welding area.

[0011] Optionally, an annular groove is provided between the foil ring and the foil support plate.

[0012] Optionally, two adjacent foil support plates are fixedly connected, and a strip groove is provided between the two adjacent foil support plates.

[0013] Optionally, the top foil gasket includes a gasket ring with an annular structure and a multi-petal gasket support plate, the inner ring of the gasket ring is fixedly connected to the gasket support plate, the gasket support plate is distributed along the circumferential direction of the gasket ring, a welding groove is arranged between two adjacent gasket support plates, the first welding area and the second welding area pass through the welding groove to contact and weld with the top foil bottom plate, and the pressure plate area is in contact with the gasket support plate.

[0014] Optionally, pin holes are arranged on the outer circles of the top foil, the top foil gasket and the top foil bottom plate.

[0015] Optionally, connecting shaft holes are provided on the inner circles of the top foil, the top foil gasket and the top foil bottom plate.

[0016] Optionally, it also includes an elastic support module and a bearing seat, the elastic support module and the bearing seat are in contact, the elastic support module is in contact with the top foil bottom plate, and the bearing seat, the elastic support module and the top foil bottom plate are connected in sequence through pins; or, the elastic support module is embedded in the bearing seat, the bearing seat is in contact with the top foil bottom plate, and the bearing seat and the top foil bottom plate are connected through the pins.

[0017] Optionally, the elastic support module is made of metal rubber or asbestos rubber.

[0018] Optionally, connecting shaft holes are provided on the inner rings of both the elastic support module and the bearing seat.

[0019] A bearing assembly comprises a rotor and a thrust gas foil bearing, wherein the rotor is connected to the thrust gas foil bearing via a connecting shaft, and there are two thrust gas foil bearings, which are respectively located on opposite sides of the rotor.

[0020] The present invention provides a thrust gas foil bearing, wherein the wedge directions of a first wedge area and a second wedge area are different. At the same time, when working, the rotor can form a wedge space with the first wedge area, and the rotor can also form a wedge space with the second wedge area. Therefore, whether the rotor rotates forward or reversely, the gas with a certain viscosity in its surrounding environment will be dragged into the wedge space for compression. When the rotation speed increases to a certain level, the rotor is suspended, and thus it is not easy to cause wear of the thrust gas foil bearing. The top foil, the top foil gasket and the top foil bottom plate form a top foil module. The top foil module is contact-connected with the elastic support module. When the top foil module is worn, only the top foil module needs to be replaced. When the elastic support module is damaged, only the elastic support module needs to be replaced. It is not necessary to treat the entire thrust gas foil bearing as scrapped, thereby saving resources. The thrust gas foil bearing in the prior art is solved in that the thrust gas foil bearing is only allowed to work in a single direction and is prone to wear when it is reversed. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 is a schematic structural diagram of a thrust gas foil bearing provided by an embodiment of the present invention;

[0023] Figure 2 is an exploded view of a top foil, a top foil gasket and a top foil bottom plate of a thrust gas foil bearing provided by an embodiment of the present invention;

[0024] Figure 3 is a top view of a top foil, a top foil gasket and a top foil bottom plate of a thrust gas foil bearing provided by an embodiment of the present invention;

[0025] Figure 4is a cross-sectional view of the connection between a top foil, a top foil gasket and a top foil bottom plate of a thrust gas foil bearing provided by an embodiment of the present invention;

[0026] Figure 5 is a schematic structural diagram of an elastic support module of a thrust gas foil bearing provided in an embodiment of the present invention;

[0027] Figure 6 It is a structural schematic diagram of another elastic support module of a thrust gas foil bearing provided in an embodiment of the present invention;

[0028] Figure 7 yes Figure 6 A side cross-sectional view of

[0029] Figure 8 is a structural schematic diagram of a bearing assembly provided by an embodiment of the present invention;

[0030] In the figure, 1, top foil; 11, foil ring; 12, foil support plate; 121, first welding area; 122, first wedge area; 123, pressure plate area; 124, second wedge area; 125, second welding area; 13, annular groove; 14, strip groove; 2, top foil gasket; 21, gasket ring; 22, gasket support plate; 23, welding groove; 3, top foil bottom plate; 4, pin hole; 5, connecting shaft hole; 6, elastic support module; 7, bearing seat; 8, rotor; 9, connecting shaft. DETAILED DESCRIPTION

[0031] To make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described in detail below. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other implementation methods obtained by ordinary technicians in this field without creative work belong to the scope of protection of the present invention.

[0032] In the description of the present invention, it should be noted that, unless otherwise specified, the meaning of "plurality" is two or more; the orientations or positional relationships indicated by the terms "upper", "lower", "left", "right", "inner", "outer", "front end", "rear end", "head", "tail", etc. are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0033] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "installation", "connection", and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0034] The present invention provides a thrust gas foil bearing, comprising a top foil 1, a top foil gasket 2 and a top foil bottom plate 3, wherein the top foil 1, the top foil gasket 2 and the top foil bottom plate 3 are arranged in sequence, the top foil 1 and the top foil bottom plate 3 clamp the top foil gasket 2, and the top foil 1 and the top foil bottom plate 3 are welded and connected;

[0035] The top foil 1 comprises a foil ring 11 of an annular structure and a multi-petal foil support plate 12, the inner ring of the foil ring 11 is fixedly connected to the foil support plate 12, and the foil support plates 12 are distributed along the circumferential direction of the foil ring 11;

[0036] The foil support plate 12 includes a first welding area 121, a first wedge-shaped area 122, a pressure plate area 123, a second wedge-shaped area 124 and a second welding area 125. The first welding area 121, the first wedge-shaped area 122, the pressure plate area 123, the second wedge-shaped area 124 and the second welding area 125 are connected in sequence. Both ends of the pressure plate area 123 are connected to the upper end surfaces of the first wedge-shaped area 122 and the second wedge-shaped area 124. The lower end surface of the first wedge-shaped area 122 is connected to the first welding area 121, and the lower end surface of the second wedge-shaped area 124 is connected to the second welding area 125. The slope length of the first wedge-shaped area 122 is greater than the slope length of the second wedge-shaped area 124. The present invention provides a thrust gas foil bearing, wherein the wedge directions of the first wedge area 122 and the second wedge area 124 are different. At the same time, when working, the rotor 8 can form a wedge space with the first wedge area 122, and the rotor 8 can also form a wedge space with the second wedge area 124. Therefore, whether the rotor 8 rotates forward or reversely, it will drag the gas with a certain viscosity in its surrounding environment into the wedge space for compression. When the rotation speed increases to a certain level, the rotor 8 is suspended, and thus it is not easy to cause wear of the thrust gas foil bearing. The top foil 1, the top foil gasket 2 and the top foil bottom plate 3 form a top foil module. The top foil module is contact-connected with the elastic support module 6. When the top foil module is worn, only the top foil module needs to be replaced. When the elastic support module 6 is damaged, only the elastic support module 6 needs to be replaced. There is no need to treat the entire thrust gas foil bearing as scrapped, thereby saving resources and reducing production costs, so as to solve the technical problem that the thrust gas foil bearing in the prior art is only allowed to work in a single direction and is prone to wear when it is reversed.

[0037] As an optional embodiment, an annular groove 13 is provided between the foil ring 11 and the foil support plate 12. Two adjacent foil support plates 12 are fixedly connected, and a strip groove 14 is provided between the two adjacent foil support plates 12. The annular groove 13 and the strip groove 14 are to facilitate the deformation of the foil support plate 12 and reduce the rigidity of the top foil 1.

[0038] As an optional implementation, the top foil gasket 2 includes a gasket ring 21 of an annular structure and a multi-petal gasket support plate 22. The inner ring of the gasket ring 21 is fixedly connected to the gasket support plate 22. The gasket support plate 22 is distributed along the circumferential direction of the gasket ring 21. A welding groove 23 is arranged between two adjacent gasket support plates 22. Each welding groove 23 is connected to the connecting shaft hole 5. The welding groove 23 is for facilitating the first welding area 121 and the second welding area 125 to be welded to the top foil bottom plate 3. The first welding area 121 and the second welding area 125 pass through the welding groove 23 to contact and weld with the top foil bottom plate 3. The pressure plate area 123 contacts the gasket support plate 22 by clamping the top foil bottom plate 3.

[0039] As an optional implementation, the outer rings of the top foil 1, the top foil gasket 2 and the top foil bottom plate 3 are all provided with pin holes 4, the outer rings of the top foil 1, the top foil gasket 2 and the top foil bottom plate 3 have the same diameter and the pins pass through the pin holes 4 of the three in sequence. The inner rings of the top foil 1, the top foil gasket 2 and the top foil bottom plate 3 are all provided with connecting shaft holes 5, and the connecting shaft holes 5 are for connecting the top foil 1, the top foil gasket 2 and the top foil bottom plate 3 to the connecting shaft 9. The top foil 1, the top foil gasket 2 and the top foil bottom plate 3 can be cut by laser cutting or wire cutting process, with good consistency and stable quality, which is conducive to mass production.

[0040] As an optional implementation, it also includes an elastic support module 6 and a bearing seat 7, the elastic support module 6 and the bearing seat 7 are in contact, the elastic support module 6 is in contact with the top foil bottom plate 3, the bearing seat 7, the elastic support module 6, the top foil bottom plate 3, the top foil gasket 2 and the top foil 1 are connected in sequence through pins; or, the elastic support module 6 is embedded in the bearing seat 7, the bearing seat 7 is also in contact with the top foil bottom plate 3, the elastic support module 6 is in contact with the top foil bottom plate 3, the diameter of the elastic support module 6 is smaller than the diameter of the top foil bottom plate 3, and the bearing seat 7 is connected to the top foil module through pins.

[0041] As an optional embodiment, the material used for the elastic support module 6 can be metal rubber or asbestos rubber. Metal rubber is a homogeneous elastic porous material. It is formed by placing a certain mass of stretched, spiral metal wires in a stamping (or rolling) mold in an orderly manner using a certain process method, and then using a cold stamping method. Its raw material is metal wire, which has both the inherent properties of the selected metal and the elasticity of rubber. It is particularly suitable for solving damping and vibration reduction in environments such as high and low temperatures, large temperature differences, high pressure, high vacuum, strong radiation, severe vibration and corrosion.

[0042] As an optional implementation, a connecting shaft hole 5 is provided on the inner ring of both the elastic support module 6 and the bearing seat 7 , and the connecting shaft hole 5 is for connecting the elastic support module 6 and the bearing seat 7 to the connecting shaft 9 .

[0043] A bearing assembly includes a rotor 8 and a thrust gas foil bearing. The rotor 8 is connected to the thrust gas foil bearing via a connecting shaft 9. There are two thrust gas foil bearings. The two thrust gas foil bearings are located on opposite sides of the rotor 8, respectively. The two thrust gas foil bearings are symmetrical structures. The two thrust gas foil bearings are also connected via pins. The bearing assembly is arranged with the rotor 8 in the middle, and the arrangement direction from the middle to the two sides is top foil 1, top foil gasket 2, top foil bottom plate 3, elastic support module 6 and bearing seat 7 in sequence.

[0044] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A thrust gas foil bearing, characterized in that: It comprises a top foil sheet (1), a top foil gasket (2) and a top foil bottom plate (3), wherein: The top foil sheet (1), the top foil gasket (2) and the top foil bottom plate (3) are arranged in sequence, the top foil sheet (1) and the top foil bottom plate (3) clamp the top foil gasket (2) and the top foil sheet (1) is connected to the top foil bottom plate (3); The top foil (1) comprises a foil ring (11) of an annular structure and a multi-petal foil support plate (12), the inner ring of the foil ring (11) is fixedly connected to the foil support plate (12), and the foil support plate (12) is distributed along the circumferential direction of the foil ring (11); The foil support plate (12) comprises a first welding area (121), a first wedge-shaped area (122), a pressure plate area (123), a second wedge-shaped area (124) and a second welding area (125); the first welding area (121), the first wedge-shaped area (122), the pressure plate area (123), the second wedge-shaped area (124) and the second welding area (125) are connected in sequence; both ends of the pressure plate area (123) are connected to the upper end surfaces of the first wedge-shaped area (122) and the second wedge-shaped area (124); the lower end surface of the first wedge-shaped area (122) is connected to the first welding area (121); and the lower end surface of the second wedge-shaped area (124) is connected to the second welding area (125).

2. The thrust gas foil bearing according to claim 1, characterized in that: An annular groove (13) is provided between the foil ring (11) and the foil support plate (12).

3. The thrust gas foil bearing according to claim 1, characterized in that: Two adjacent foil support plates (12) are fixedly connected, and a strip-shaped groove (14) is provided between the two adjacent foil support plates (12).

4. The thrust gas foil bearing according to claim 1, characterized in that: The top foil gasket (2) comprises a gasket ring (21) of an annular structure and a multi-petal gasket support plate (22); the inner ring of the gasket ring (21) is fixedly connected to the gasket support plate (22); the gasket support plates (22) are distributed along the circumferential direction of the gasket ring (21); a welding groove (23) is provided between two adjacent gasket support plates (22); the first welding area (121) and the second welding area (125) pass through the welding groove (23) to contact and be welded to the top foil bottom plate (3); and the pressure plate area (123) is in contact with the gasket support plate (22).

5. The thrust gas foil bearing according to claim 1, characterized in that: The top foil sheet (1), the top foil gasket (2) and the top foil bottom plate (3) are all provided with pin holes (4) on their outer circles.

6. The thrust gas foil bearing according to claim 1, characterized in that: Connecting shaft holes (5) are provided on the inner circles of the top foil sheet (1), the top foil gasket (2) and the top foil bottom plate (3).

7. The thrust gas foil bearing according to claim 1, characterized in that: It also includes an elastic support module (6) and a bearing seat (7), wherein the elastic support module (6) and the bearing seat (7) are in contact with each other, the elastic support module (6) is in contact with the top foil bottom plate (3), and the bearing seat (7), the elastic support module (6) and the top foil bottom plate (3) are sequentially connected via pins; or, the elastic support module (6) is embedded in the bearing seat (7), the bearing seat (7) is in contact with the top foil bottom plate (3), and the bearing seat (7) and the top foil bottom plate (3) are connected via the pins.

8. The thrust gas foil bearing according to claim 7, characterized in that: The material used for the elastic support module (6) is metal rubber or asbestos rubber.

9. The thrust gas foil bearing according to claim 7, characterized in that: The inner rings of both the elastic support module (6) and the bearing seat (7) are provided with connecting shaft holes (5).

10. A bearing assembly, characterized in that: It comprises a rotor (8) and a thrust gas foil bearing as described in any one of claims 1 to 9, wherein the rotor (8) is connected to the thrust gas foil bearing via a connecting shaft (9), and there are two thrust gas foil bearings, which are respectively located on opposite sides of the rotor (8).

Images