Aerodynamic bearing

Abstract

The invention provides a gas dynamic pressure bearing. The gas dynamic pressure bearing comprises a top foil, a fixed foil piece, a first supporting foil piece, a second supporting foil piece and a bearing sleeve, wherein the fixed foils are composed of fixed foil arc foils and fixed foil flat foils, the fixed foils distributed in the circumferential direction are fixed to the outer surface of the top foil through the flat foils, the first supporting foil and the second supporting foil are arranged in the space defined by the two adjacent fixed foil arc foils and the top foil, the second supporting foil is arranged in the first supporting foil, and the first supporting foil and the second supporting foil are arranged on the outer surface of the top foil. And the fixed foil and the first supporting foil jointly support the top foil, and the arc-shaped foil of the fixed foil is arranged in the arc-shaped groove of the bearing sleeve to limit the circumferential movement of all the foils. The arc-shaped foil of the fixed foil surrounds the supporting foil to jointly support the top foil, and the flat foil of the fixed foil is fixed on the outer surface of the top foil, so that the processing technology of the foil gas dynamic pressure bearing is simplified; meanwhile, the multi-layer structure can provide good rigidity and damping characteristics for the bearing.

Description

Technical Field

[0001] The present invention relates to the technical field of hydrodynamic bearings, and in particular to a gas hydrodynamic bearing, which is particularly suitable for high-speed rotating mechanical equipment, such as air compressors or air cycle machines, blowers, micro gas turbines, etc. Background Art

[0002] The foil gas dynamic pressure bearing is generally composed of a top foil, an elastic foil and a bearing sleeve. There is a convergence domain between the top foil and the air film surrounding the rotor, forming a carrier for the high-pressure gas to support the rotor. The elastic foil is compressed and deformed, and a relative displacement is generated between the top foil and the bearing sleeve, providing stiffness and damping for the bearing. Therefore, the foil gas dynamic pressure bearing with gas as the lubricating medium has the advantages of low friction loss, no pollution, and high speed, and is widely used in air cycle machines, air blowers, fuel cell air compressors, micro gas turbines and other machinery.

[0003] However, the elastic foil is usually fixed to the inner surface of the bearing sleeve by welding or pinning, which places high demands on the welding or processing equipment of the radial bearing. In addition, the contact area between the wavy elastic foil and the top foil and the bearing sleeve is small, and the friction damping provided by the bearing is small, which cannot consume the vibration energy generated by the rotor at high speed, aggravates the wear of the top foil, reduces the service life, and limits the development of the rotor system to a higher speed. Summary of the invention

[0005] In view of the above-mentioned technical deficiencies, the present application provides a gas hydrodynamic bearing, which limits the circumferential movement of the bearing support foil by cooperating the fixed foil arc foil with the two bearing sleeve arc grooves, and replaces the welding fixation of the foil and the inner surface of the bearing sleeve in the traditional bearing with the welding fixation of the fixed foil and the top foil, thereby improving the processing technology of the bearing; at the same time, a plurality of support foils are arranged in the space surrounded by the fixed foil and the top foil, and the interaction of the multi-layer structure increases the friction damping of the bearing, or adds eddy current damping based on coils and iron cores to increase the rotor damping or bearing damping. The many technical effects that can be produced by the preferred technical scheme among the many technical schemes provided by the present invention are described below.

[0006] To achieve the above technical objectives, the present invention provides the following technical solutions: A gas dynamic pressure bearing comprises: a top foil, a fixed foil, a first supporting foil, a second supporting foil, and a bearing sleeve.

[0007] Furthermore, the top foil is in the shape of an arc with a notch, and the outer surface of the top foil is fixed to the fixed foil by welding, and the welding position of the top foil is selected according to actual needs.

[0008] Furthermore, the fixed foil is pressed from a flat foil, and consists of two fixed foil arc foils and one fixed foil flat foil. The two arc foils of the fixed foil are placed in the arc groove of the bearing sleeve. The concave part formed by the two fixed foil arc foils matches the convex part formed by the two bearing sleeve arc grooves. The fixed foil and the bearing sleeve do not need to be fixed, and the circumferential movement of the bearing support foil can also be limited. All or part of the fixed foil is fixed on the outer surface of the top foil by flat foil welding. The radius of the flat foil is smaller than the radius of the inner surface of the bearing sleeve, allowing the top foil and the fixed foil to have a certain radial deformation at the fixed position. A deformation space is left between two adjacent fixed foils distributed circumferentially. Multiple support foils are placed in the "crescent-shaped" space surrounded by the two adjacent fixed foil arc foils and the top foil.

[0009] Furthermore, the first supporting foil is similar to the second supporting foil in structure, the circumferential size of the first supporting foil is slightly larger than that of the second supporting foil, the first supporting foil is composed of an inner arc foil of the first supporting foil and two outer arc foils of the first supporting foil, the inner arc foil of the first supporting foil and the outer arc foil of the first supporting foil are connected via an arc foil, a part or all of the outer surface of the inner arc foil of the first supporting foil fits the outer surface of the top foil, a part or all of the outer surface of the outer arc foil of the first supporting foil fits the arc foil surface of the fixed foil, a part or all of the outer surface of the second supporting foil fits the inner surface of the first supporting foil, and the second supporting foil and the first supporting foil jointly support the top foil.

[0010] Furthermore, an arc-shaped groove of the bearing sleeve is processed on the inner surface of the bearing sleeve, and the bearing sleeve is used to limit the circumferential movement of the supporting foil and provide a radial support foundation.

[0011] Furthermore, the top foil may be made into an integral top foil, one end of which is pressed and processed, overlapped with the other end and placed outside the other end to avoid free vibration of the end.

[0012] Furthermore, the top foil can be made into a thick top foil, which is composed of a thick top foil arc foil and a thick top foil hinge. The thick top foil hinge is obtained by removing part of the material at a certain position of the thick top foil arc foil. The stiffness of the thick top foil hinge is lower than that of other thick top foil arc foils. When the thick top foil arc foil is subjected to uneven force, it deflects around the thick top foil hinge, and at the same time drives the thick top foil arc foil at other positions to deform, which has an effect similar to a tilting pad bearing and reduces the continuity of the air film dynamic pressure effect. The relative position of the thick top foil hinge facing the first supporting foil or placed between two adjacent first supporting foils can be determined according to actual needs.

[0013] Furthermore, the first supporting foil and the second supporting foil can be directly fixed on the thick top foil, and the fixing foil is removed, and two adjacent first supporting foils cooperate with the arc groove of the bearing sleeve to limit the circumferential movement of the thick foil.

[0014] Furthermore, a plurality of fixing foils are connected at their ends to form an integrated fixing foil, and the number of fixing positions of the integrated fixing foil and the top foil is greater than or equal to one.

[0015] Furthermore, no supporting foil or one or more supporting foils may be placed in the "crescent-shaped" space surrounded by the fixed foil, the arc foil and the top foil.

[0016] Furthermore, the first supporting foil can be changed into a hollow first supporting foil, wherein the inner arc foil of the first supporting foil and the outer arc foil of the first supporting foil are processed with circumferentially or axially distributed holes to reduce the friction between the supporting foils and between the supporting foil and the fixed foil, thereby avoiding plastic deformation caused by contact friction.

[0017] Furthermore, the fixing foil may be changed into a hollow fixing foil.

[0018] Furthermore, the first supporting foil may be changed into a short-side first supporting foil, wherein the outer arc foil of the first supporting foil is shorter and does not contact the second supporting foil, and the outer arc foil of the second supporting foil contacts the fixed foil.

[0019] Furthermore, the fixed foil arc can be changed into a short-side fixed foil, wherein the length of the fixed foil arc is shorter, and the outer surfaces of the fixed foil, the first supporting foil and the second supporting foil are all in contact with the arc groove of the bearing sleeve.

[0020] Further, the first supporting foil can be changed into a first supporting foil on the opposite short side, which is composed of two inner arc foils of the first supporting foil on the opposite short side and one outer arc foil of the first supporting foil on the opposite short side. The circumferential length of the inner arc foils of the two first supporting foils on the opposite short side is shorter, the inner arc foil of the first supporting foil on the opposite short side does not contact the inner arc foil of the second supporting foil on the opposite short side, and the inner arc foil of the first supporting foil on the opposite short side and the inner arc foil of the second supporting foil on the opposite short side are both in contact with the top foil; or the inner arc foil of the first supporting foil on the opposite short side is in contact with the top foil, the second supporting foil on the opposite short side is placed inside the first supporting foil on the opposite short side, and the first supporting foil on the opposite short side and the second supporting foil on the opposite short side jointly support the top foil.

[0021] Furthermore, the first supporting foil and the second supporting foil can be replaced by a plurality of C-shaped supporting foils with different diameters, wherein the C-shaped supporting foil is formed by curling a flat foil; the circumferentially distributed C-shaped supporting foils are placed in a "crescent-shaped" space surrounded by the arc groove of the bearing sleeve and the top foil, and are used to support the top foil.

[0022] Furthermore, a spring of corresponding size may be placed in the C-shaped supporting foil to increase the rigidity of the C-shaped supporting foil.

[0023] Furthermore, an electromagnetic device consisting of a coil and an iron core may be placed in the first supporting foil to generate a controllable magnetic field, which directly acts on the rotor to increase rotor damping. This structure can be used for radial gas dynamic pressure bearings and thrust gas dynamic pressure bearings; Furthermore, the bearing sleeve may not be processed with an arc groove, the inner surface of the annular bearing sleeve is directly in partial contact with the outer surface of the fixed foil, a limit block is installed on the inner surface of the bearing sleeve, and the limit block is placed between two adjacent fixed foils to limit the circumferential movement of the fixed foil.

[0024] Further, a T-shaped foil may be placed above the first supporting foil of the opposite short side and the second supporting foil of the opposite short side, or a T-shaped foil may be placed above the hollow first supporting foil and the hollow second supporting foil to support the top foil; Furthermore, coils and iron cores can be added to both sides of the T-shaped foil, and the coils and iron cores are fixed inside the second supporting foil on the opposite short side. The controllable electromagnetic field they form is directly opposite to the vertical part of the T-shaped foil. The T-shaped foil vibrates with the bearing structure, cutting the magnetic lines of force and improving the damping characteristics of the bearing.

[0025] Due to the adoption of the above technology, the present invention has the following positive effects compared with the prior art: the present invention provides a gas hydrodynamic bearing, in which the cooperation between the arc foil of the fixed foil and the arc grooves of the two bearing sleeves limits the circumferential movement of the bearing support foil, and the welding fixation of the fixed foil and the top foil replaces the welding fixation of the foil and the inner surface of the bearing sleeve in the traditional bearing, thereby improving the processing technology of the gas hydrodynamic bearing; at the same time, a plurality of support foils are arranged in the "crescent-shaped" space surrounded by the fixed foil and the top foil, and the interaction of the multi-layer structure increases the friction damping of the bearing, or a coil and an iron core are added in the "crescent-shaped" space, and the magnetic flux lines generated by them are directly opposite to the rotor, thereby realizing the damping requirements of the rotor system under different working conditions; or a T-shaped foil, a coil and an iron core are added, and the vertical part of the T-shaped foil is directly opposite to the iron core and the coil, thereby increasing the damping characteristics of the bearing. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] 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.

[0027] Figure 1 An exploded diagram of a gas hydrodynamic bearing provided by the present invention.

[0028] Figure 2 This is a front view of a gas dynamic pressure bearing provided by the present invention.

[0029] Figure 3 A schematic diagram of a top foil of a gas hydrodynamic bearing provided by the present invention.

[0030] Figure 4 A schematic diagram of a fixed foil of a gas hydrodynamic bearing provided by the present invention.

[0031] Figure 5 A schematic diagram of a first supporting foil of a gas hydrodynamic bearing provided by the present invention.

[0032] Figure 6 A schematic diagram of a bearing sleeve of a gas hydrodynamic bearing provided by the present invention.

[0033] Figure 7 A schematic diagram of an integrated top foil of a gas hydrodynamic bearing provided by the present invention.

[0034] Figure 8 An exploded view of a thick top foil gas dynamic pressure bearing of a gas dynamic pressure bearing provided by the present invention.

[0035] Fig. 9 A front view of a thick top foil gas dynamic pressure bearing provided by the present invention.

[0036] Fig.10 A partial enlarged view of a thick top foil of a gas dynamic pressure bearing provided by the present invention.

[0037] Fig.11 A front view of a non-fixed gas dynamic pressure bearing of a gas dynamic pressure bearing provided by the present invention.

[0038] Fig.12 An exploded diagram of an integrated fixed gas dynamic pressure bearing of a gas dynamic pressure bearing provided by the present invention.

[0039] Fig.13 An exploded view of a single supporting foil gas dynamic pressure bearing of a gas dynamic pressure bearing provided by the present invention.

[0040] Fig.14 A front view of a single supporting foil gas dynamic pressure bearing provided by the present invention.

[0041] Fig.15 An exploded diagram of a hollow supporting foil gas dynamic pressure bearing of a gas dynamic pressure bearing provided by the present invention.

[0042] Fig.16 An exploded view of a short-side supporting foil gas dynamic pressure bearing provided by the present invention.

[0043] Fig.17 A front view of a short-side supporting foil gas dynamic pressure bearing provided by the present invention.

[0044] Fig.18 An exploded view of a gas dynamic pressure bearing with reverse short side support foil provided by the present invention.

[0045] Fig.19 A front view of a gas dynamic pressure bearing provided by the present invention, which is a reverse short side support foil gas dynamic pressure bearing.

[0046] Fig. 20 An exploded view of a C-shaped supporting foil gas dynamic pressure bearing of a gas dynamic pressure bearing provided by the present invention.

[0047] Fig.21 A front view of a C-shaped supporting foil gas dynamic pressure bearing of a gas dynamic pressure bearing provided by the present invention.

[0048] Fig. 22 A schematic diagram of a C-shaped supporting foil and spring of a gas hydrodynamic bearing provided by the present invention.

[0049] Fig.23 An exploded diagram of an adjustable damping gas dynamic pressure bearing of a gas dynamic pressure bearing provided by the present invention.

[0050] Fig.24 An exploded view of an annular bearing sleeve type gas dynamic pressure bearing of a gas dynamic pressure bearing provided by the present invention.

[0051] Fig.25 An exploded diagram of a T-shaped foil gas dynamic pressure bearing of a gas dynamic pressure bearing provided by the present invention.

[0052] Fig.26 A front view of a T-shaped foil gas dynamic pressure bearing of a gas dynamic pressure bearing provided by the present invention.

[0053] Among them, the marks of the figures in the figure are: 1-top foil, 2-fixed foil, 3-first supporting foil, 4-bearing sleeve, 5-second supporting foil, 6-C-shaped supporting foil, 7-spring, 8-coil, 9-iron core, 10-limiting block, 11-thick top foil, 12-integrated top foil, 13-T-shaped foil, 21-fixed foil arc foil, 22-fixed foil flat foil, 23-integrated fixed foil, 31-first supporting foil inner arc foil, 32-first supporting foil outer arc foil, 33-short side first supporting foil, 34-opposite short side first supporting foil, 35-hollow first supporting foil, 41-bearing sleeve arc groove, 42-bearing sleeve inner surface, 43-annular bearing sleeve, 51-opposite short side second supporting foil, 111-thick top foil arc foil, 112-thick top foil hinge. DETAILED DESCRIPTION

[0054] 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.

[0055] In the description of the present invention, it should be noted that, unless otherwise specified, “plurality” means two or more than two; the orientations or positional relationships indicated by terms such as “upper”, “lower”, “top”, “bottom”, “inner”, “outer”, “first”, and “second” are based on the orientations or positional relationships shown in the accompanying 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 a limitation to the present invention.

[0056] The gas dynamic pressure bearing provided in the embodiment of the present application is now described.

[0057] Reference Figures 1 to 6 As shown, a gas dynamic pressure bearing is shown, comprising: a top foil (1), a fixed foil (2), a first supporting foil (3), a second supporting foil (5), and a bearing sleeve (4).

[0058] Reference Figure 1 and Figure 3 As shown, the top foil (1) is in the shape of an arc with a notch, and the outer surface of the top foil (1) is welded and fixed to the fixed foil (2). The welding position of the top foil (1) is selected according to actual needs.

[0059] Reference Figure 1 and Figure 4 As shown, the fixed foil (2) is formed by pressing a flat foil, and is composed of two fixed foil arc foils (21) and a fixed foil flat foil (22). The two arc foils of the fixed foil (2) are placed in the arc groove (41) of the bearing sleeve. The concave part formed by the two fixed foil arc foils (21) cooperates with the convex part formed by the two bearing sleeve arc grooves (41). The fixed foil (2) and the bearing sleeve (4) do not need to be fixed, and the circumferential movement of the bearing support foil can also be limited. The whole or part of the fixed foil (2) is fixed on the outer surface of the top foil (1) by flat foil welding. The radius of the flat foil is smaller than the radius of the inner surface (42) of the bearing sleeve, allowing the top foil (1) and the fixed foil (2) to have a certain radial deformation at the fixed position. A deformation space is left between two adjacent fixed foils (2) distributed in the circumferential direction. A plurality of support foils are placed in a "crescent-shaped" space surrounded by the two adjacent fixed foil arc foils (21) and the top foil (1).

[0060] Reference Figure 1 and Figure 5 As shown, the first supporting foil (3) and the second supporting foil (5) are similar in structure, the circumferential size of the first supporting foil (3) is slightly larger than that of the second supporting foil (5), the first supporting foil (3) is composed of a first supporting foil inner arc foil (31) and two first supporting foil outer arc foils (32), the first supporting foil inner arc foil (31) and the first supporting foil outer arc foil (32) are connected via an arc foil, a part or all of the outer surface of the first supporting foil inner arc foil (31) is in contact with the outer surface of the top foil (1), a part or all of the outer surface of the first supporting foil outer arc foil (32) is in contact with the surface of the fixed foil arc foil (21), a part or all of the outer surface of the second supporting foil (5) is in contact with the inner surface of the first supporting foil (3), and the second supporting foil (5) and the first supporting foil (3) jointly support the top foil (1).

[0061] Reference Figure 1 and Figure 6 As shown, the inner surface of the bearing sleeve (4) is processed to form a bearing sleeve (4) arc groove (41), and the bearing sleeve (4) is used to limit the circumferential movement of the supporting foil and provide a radial support foundation.

[0062] Reference Figure 7 As shown, as an optional embodiment, the top foil (1) can be made into an integral top foil (12), one end of which is pressed and processed, overlapped with the other end and placed outside the other end to avoid free vibration of the end.

[0063] Reference Figures 8 to 11 As shown, as an optional implementation, the top foil (1) can be made into a thick top foil (11), which is composed of a thick top foil arc foil (111) and a thick top foil hinge (112); the thick top foil hinge (112) is obtained by removing part of the material at a certain position of the thick top foil arc foil (111); the thick top foil hinge (112) has a lower stiffness than other thick top foil arc foils (111); when the thick top foil arc foil (111) is subjected to uneven force, it deflects around the thick top foil hinge (112), and at the same time drives the thick top foil arc foil (111) at other positions to deform, which has an effect similar to a tilting pad bearing, and reduces the continuity of the air film dynamic pressure effect; the relative position of the thick top foil hinge (112) facing the first supporting foil (3) or placed between two adjacent first supporting foils (3) can be determined according to actual needs.

[0064] As an optional implementation, the first supporting foil (3) and the second supporting foil (5) can be directly fixed on the thick top foil (11), and the fixing foil (2) is removed. The two adjacent first supporting foils (3) cooperate with the arc groove (41) of the bearing sleeve to limit the circumferential movement of the thick foil.

[0065] Reference Fig.12As shown, as an optional implementation, a plurality of fixing foils (2) are connected at their ends to form an integrated fixing foil (23), and the number of fixing positions of the integrated fixing foil (23) and the top foil (1) is greater than or equal to one.

[0066] Reference Fig.13 and Fig.14 As shown, as an optional implementation, the "crescent-shaped" space enclosed by the fixed foil arc foil (21) and the top foil (1) may contain no supporting foil or one or more supporting foils.

[0067] Reference Fig.15 As shown, as an optional embodiment, the first supporting foil (3) can be changed into a hollow first supporting foil (35), wherein the first supporting foil inner arc foil (31) and the first supporting foil outer arc foil (32) are processed with circumferentially or axially distributed holes, so as to reduce the friction between the supporting foils and between the supporting foil and the fixed foil (2), and avoid plastic deformation caused by contact friction.

[0068] As an optional implementation, the fixing foil (2) may be changed into a hollow fixing foil (2).

[0069] Reference Fig.16 and Fig.17 As shown, as an optional embodiment, the first supporting foil (3) can be changed into a short-side first supporting foil (33), wherein the outer arc foil (32) of the first supporting foil is shorter and does not contact the second supporting foil (5), and the outer arc foil of the second supporting foil contacts the fixed foil (2).

[0070] As an optional implementation, the fixed foil (2) arc can be changed into a short-side fixed foil (2), wherein the length of the fixed foil arc foil (21) is relatively short, and the outer surfaces of the fixed foil (2), the first supporting foil (3), and the second supporting foil (5) are all in contact with the arc groove (41) of the bearing sleeve (4).

[0071] Reference Fig.18 and Fig.19As shown, as an optional embodiment, the first supporting foil (3) can be changed into a reverse short side first supporting foil (34), which is composed of two reverse short side first supporting foil inner arc foils (31) and one reverse short side first supporting foil outer arc foil (32); the circumferential length of the reverse short side first supporting foil inner arc foil (31) is shorter, the inner arc foil of the reverse short side first supporting foil (34) is not in contact with the inner arc foil of the reverse short side second supporting foil (51), and the inner arc foil of the reverse short side first supporting foil (34) and the inner arc foil of the reverse short side second supporting foil (51) are both in contact with the top foil (1); or the inner arc foil of the reverse short side first supporting foil (34) is in contact with the top foil (1), the reverse short side second supporting foil (51) is placed inside the reverse short side first supporting foil (34), and the reverse short side first supporting foil (34) and the reverse short side second supporting foil (51) jointly support the top foil (1).

[0072] Reference Fig. 20 and Fig.21 As shown, as an optional implementation, the first supporting foil (3) and the second supporting foil (5) can be replaced by a plurality of C-shaped supporting foils (6) of different diameters, wherein the C-shaped supporting foil (6) is formed by curling a flat foil; the circumferentially distributed C-shaped supporting foils (6) are placed in a "crescent-shaped" space surrounded by the arc groove (41) of the bearing sleeve (4) and the top foil (1), and are used to support the top foil (1).

[0073] Reference Fig. 22 As shown, as an optional embodiment, a spring (7) of corresponding size can be placed in the C-shaped supporting foil (6) to increase the rigidity of the C-shaped supporting foil (6).

[0074] Reference Fig.23 As shown, as an optional embodiment, an electromagnetic device consisting of a coil (8) and an iron core (9) can be placed in the first supporting foil (3) to generate a controllable magnetic field that directly acts on the rotor to increase rotor damping. This structure can be used for radial gas hydrodynamic bearings and thrust gas hydrodynamic bearings.

[0075] Reference Fig.24 As shown, as an optional embodiment, the bearing sleeve (4) may not be processed with the arc groove (41) of the bearing sleeve (4), the inner surface of the annular bearing sleeve (41) is directly in partial contact with the outer surface of the fixed foil (2), and a limit block (10) is installed on the inner surface of the bearing sleeve (4), and the limit block (10) is placed between two adjacent fixed foils (2) to limit the circumferential movement of the fixed foil (2).

[0076] Reference Fig.25 and Fig.26As shown, as an optional embodiment, a T-shaped foil (13) may be placed above the first supporting foil (34) on the opposite short side and the second supporting foil (51) on the opposite short side, or a T-shaped foil (13) may be placed above the hollow first supporting foil (35) and the hollow second supporting foil (5) to support the top foil (1).

[0077] As an optional implementation, a coil (8) and an iron core (9) can be added to both sides of the T-shaped foil (13). The coil (8) and the iron core (9) are fixed inside the second supporting foil (51) on the opposite short side. The controllable electromagnetic field formed by the coil (8) and the iron core (9) is directly opposite to the vertical part of the T-shaped foil (13). The T-shaped foil (13) vibrates together with the bearing structure, cutting the magnetic flux lines and improving the damping characteristics of the bearing.

[0078] The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art can still modify the technical solutions described in the above embodiments, or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, modification, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A gas dynamic pressure bearing, characterized in that: The invention comprises: a top foil, a fixed foil, a first supporting foil, a second supporting foil, and a bearing sleeve; wherein the fixed foil is composed of a fixed foil arc foil and a fixed foil flat foil, two fixed foil arc foils are placed in the bearing sleeve arc groove, the concave parts formed by the two fixed foil arc foils cooperate with the convex parts formed by the two bearing sleeve arc grooves, the fixed foil and the bearing sleeve do not need to be fixed, and the circumferential movement of the bearing supporting foil can also be limited; all or part of the fixed foil is fixed on the outer surface of the top foil through a flat foil, the radius of the fixed foil flat foil is smaller than the radius of the inner surface of the bearing sleeve, a deformation space is left between two adjacent fixed foils distributed in the circumferential direction, and two adjacent fixed foil arc foils and the top foil The first supporting foil and the second supporting foil are placed in a "crescent-shaped" space; a plurality of the fixed foils are connected end to end to form an integrated fixed foil, and the number of fixed positions of the integrated fixed foil and the top foil is greater than or equal to one; the first supporting foil is similar to the second supporting foil in structure, the circumferential size of the first supporting foil is slightly larger than that of the second supporting foil, the first supporting foil is composed of an inner arc foil of a first supporting foil and two outer arc foils of the first supporting foil, the inner arc foil of the first supporting foil and the outer arc foil of the first supporting foil are connected by an arc foil, a partial or entire outer surface of the inner arc foil of the first supporting foil is in contact with the outer surface of the top foil, and a partial or entire outer surface of the outer arc foil of the first supporting foil is The second supporting foil is fitted with the curved foil surface of the fixed foil, and the outer surface of the second supporting foil is fitted with the inner part of the first supporting foil, and supports the top foil together with the first supporting foil; the first supporting foil can be changed into a hollow first supporting foil, wherein the inner arc foil of the first supporting foil and the outer arc foil of the first supporting foil are processed with circumferentially or axially distributed holes to reduce the friction between the supporting foils and between the supporting foil and the fixed foil, and avoid plastic deformation caused by contact friction; the first supporting foil can be changed into a short-side first supporting foil, wherein the outer arc foil of the first supporting foil is shorter and does not contact the second supporting foil, and the outer arc foil of the second supporting foil contacts the fixed foil; the first supporting foil can be changed into a reverse short-side first A supporting foil is composed of two inner arc foils of the first supporting foil of the opposite short side and one outer arc foil of the first supporting foil of the opposite short side, wherein the inner arc foil of the first supporting foil of the opposite short side is shorter in circumferential direction, the inner arc foil of the first supporting foil of the opposite short side is not in contact with the inner arc foil of the second supporting foil of the opposite short side, the inner arc foil of the first supporting foil of the opposite short side and the inner arc foil of the second supporting foil of the opposite short side are both in contact with the top foil, or the inner arc foil of the first supporting foil of the opposite short side is in contact with the top foil, the second supporting foil of the opposite short side is placed inside the first supporting foil of the opposite short side, and the first supporting foil of the opposite short side and the second supporting foil of the opposite short side jointly support the top foil; the first supporting foil and the second supporting foil can be directly fixed on the top foil, and the fixing foil is removed;The first supporting foil and the second supporting foil can be replaced by a plurality of C-shaped supporting foils with different diameters. The circumferentially distributed C-shaped supporting foils are placed in a "crescent-shaped" space surrounded by the arc groove of the bearing sleeve and the top foil to support the top foil; a spring of corresponding size can be placed in the C-shaped supporting foil to increase the supporting stiffness. ; 2. The gas dynamic pressure bearing according to claim 1, characterized in that: The top foil is in the shape of an arc with a notch, the outer surface of the top foil is welded and fixed to the fixed foil, and the inner surface of the arc surrounds the dynamic pressure air film to form a bearing force; the top foil can be made into an integrated top foil, one end of which is pressed and processed, overlapped with the other end and placed outside the other end to avoid free vibration of the end; the top foil can be made into a thick top foil, consisting of a thick top foil arc foil and a thick top foil hinge, and the thick top foil arc foil can deflect around the thick top foil hinge when the force is uneven, and at the same time drive the thick top foil arc foil at other positions to deform, which has an effect similar to a tilting pad bearing and reduces the continuity of the dynamic pressure effect of the air film; the first supporting foil and the second supporting foil can be directly fixed on the thick top foil, and the fixed foil is removed, and the two adjacent first supporting foils cooperate with the arc groove of the bearing sleeve to limit the circumferential movement of the thick foil.

3. The gas dynamic pressure bearing according to claim 1, characterized in that: The inner surface of the bearing sleeve is processed with an arc groove to limit the circumferential movement of the foil; the bearing sleeve may not be processed with the arc groove, the inner surface of the bearing sleeve is directly in partial contact with the outer surface of the fixed foil, and a limit block is installed on the inner surface of the bearing sleeve, and the limit block is placed between two adjacent fixed foils to limit the circumferential movement of the fixed foil.

4. The gas dynamic pressure bearing according to claim 1, characterized in that: An electromagnetic device consisting of a coil and an iron core can be placed in the first supporting foil to generate a controllable magnetic field, which directly acts on the rotor to increase rotor damping. This structure can be used for radial gas dynamic pressure bearings and thrust gas dynamic pressure bearings.

5. The gas dynamic pressure bearing according to claim 1, characterized in that: A T-shaped foil can be placed above the first supporting foil on the opposite short side and the second supporting foil on the opposite short side, or a T-shaped foil can be placed above the hollow first supporting foil and the hollow second supporting foil to support the top foil; coils and iron cores can be added on both sides of the T-shaped foil, and the controllable electromagnetic field composed of the coils and the iron core is directly opposite to the vertical part of the T-shaped foil. The T-shaped foil vibrates with the bearing structure, cuts the magnetic lines of force, and improves the damping characteristics of the bearing.

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