A thrust foil bearing

Abstract

The application belongs to the technical field of bearings, and particularly relates to a thrust foil bearing. The thrust foil bearing comprises a flexible structure, a back plate and a movable structure which are connected in sequence. The flexible structure comprises a flat foil, a gasket and a wave foil assembly which are connected in sequence. The wave foil assembly is arranged on the back plate. The wave foil assembly comprises a first wave foil and a second wave foil which are arranged in sequence. The first wave foil comprises a first flat section and a first wave arch. The second wave foil comprises a second flat section and a second wave arch. The first flat section is connected with the back plate. The second flat section is connected with the back plate. The first flat section is provided with the first gasket. The second flat section is provided with the second gasket. The flat foil, the second gasket and the second flat section are connected in sequence. The first wave arch is free. The other end of the flat foil is in contact with the first wave arch. The back plate and the movable structure form a kinematic pair. The back plate can be freely inclined or swung. The one end of the flat foil is connected with the second gasket through a connecting plate. The application has the advantages of simple structure, low cost and strong applicability.

Description

Technical Field

[0001] This application belongs to the field of bearing technology, and in particular relates to a thrust foil bearing. Background Technology

[0002] With the development of high-speed turbines, aerospace, precision instruments and other fields, there are higher requirements for the speed and stability of bearings in rotating machinery. Hydrodynamic thrust bearings are widely used in rotor supports of high-speed rotating machinery. Among them, foil bearings occupy a major position in hydrodynamic bearings due to their simple structure, high speed, long service life, low power consumption, cleanliness and wide operating temperature range.

[0003] The high-precision dimensions of foil bearings require relatively stable operating conditions. However, due to factors such as installation errors, asymmetrical loads, and thermal deformation, rotor misalignment is an unavoidable fault in rotating machinery. Misalignment in the bearing-rotor system alters the bearing's operating state, generating a series of dynamic effects detrimental to the stable operation of rotating machinery. These include: reduced lubricating film thickness, decreased bearing capacity, stiffness, and damping; rotor deflection; excessive vibration of the rotor system; dry friction between the rotor system and bearing surfaces, damaging the coating and generating significant frictional heat; and rotor instability or even seizure. Rotor misalignment under high-speed, high-load conditions is one of the main reasons affecting the stability and reliability of high-speed rotating machinery.

[0004] Thrust foil bearings with elastic supports offer some deformation space and compensation for rotor misalignment due to their combination of low friction and high damping. However, for excessively high thrust disc eccentricity and misalignment, increasing the damping of the elastic support beneath the lubricated surface to increase local deflection is often ineffective. This is because traditional thrust foil bearings are integrally fixed and lack circumferential and radial degrees of freedom, making them unable to adapt well to rotor tilting and oscillation. Summary of the Invention

[0005] 1. Technical problems to be solved

[0006] Since traditional thrust foil bearings are fixed as a whole and lack circumferential and radial degrees of freedom, they cannot adapt well to the tilting and oscillation of the rotor. This application provides a thrust foil bearing.

[0007] 2. Technical Solution

[0008] To achieve the above objectives, this application provides a thrust foil bearing, comprising a flexible structure, a back plate, and a movable structure connected in sequence. The flexible structure includes a flat foil, a gasket, and a corrugated foil assembly connected in sequence. The corrugated foil assembly is disposed on the back plate. The corrugated foil assembly includes a first corrugated foil and a second corrugated foil arranged in sequence. The first corrugated foil includes a first straight section and a first corrugated arch connected to each other. The second corrugated foil includes a second straight section and a second corrugated arch connected to each other. The first straight section is connected to the back plate, and the second straight section is connected to the back plate. A first gasket is disposed on the first straight section, and a second gasket is disposed on the second straight section. One end of the flat foil, the second gasket, and the second straight section are connected in sequence. The first corrugated arch is free, and the other end of the flat foil contacts the first corrugated arch. The back plate and the movable structure form a kinematic pair, and the back plate can freely tilt or swing. One end of the flat foil is connected to the second gasket through a connecting plate.

[0009] Another embodiment provided in this application is as follows: the movable structure is connected to the back plate through a movable joint. The movable structure includes a pressure plate and a first bearing seat that are connected to each other. One end of the movable joint is connected to the back plate, and the other end of the movable joint passes through the pressure plate. The other end of the movable joint is disposed in the first bearing seat. The back plate 4 can freely tilt or swing around the movable joint.

[0010] Another embodiment provided in this application is as follows: an elastic washer is provided between the pressure plate and the first bearing seat, and the pressure plate, the elastic washer and the first bearing seat are connected by fastening screws.

[0011] Another embodiment provided in this application is: the movable joint is a spherical structure, the spherical structure includes a boss, and the plane of the boss is fixedly connected to the back plate.

[0012] Another embodiment provided in this application is that the pressure plate has a disc-shaped structure.

[0013] This application provides a thrust foil bearing, comprising a flexible structure, a back plate, and a movable structure connected in sequence. The flexible structure includes a flat foil, a gasket, and a corrugated foil assembly connected in sequence. The corrugated foil assembly is disposed on the back plate. The corrugated foil assembly includes a first corrugated foil and a second corrugated foil arranged in sequence. The first corrugated foil includes a first straight section and a first corrugated arch connected to each other. The second corrugated foil includes a second straight section and a second corrugated arch connected to each other. The first straight section is connected to the back plate, and the second straight section is connected to the back plate. A first gasket is disposed on the first straight section, and a second gasket is disposed on the second straight section. One end of the flat foil, the second gasket, and the second straight section are connected in sequence. The first corrugated arch is free, and the other end of the flat foil is in contact with the first corrugated arch. The back plate and the movable structure form a kinematic pair, and the back plate can tilt or swing freely. One end of the flat foil is connected to the second gasket through a connecting plate. The movable structure includes a second bearing seat. One side of the disc-shaped structure is a plane, and the corrugated foil is disposed on the plane. The other side of the disc-shaped structure is a curved surface, and the curved surface cooperates with the second bearing seat. The back plate and the second bearing seat are connected through a contact point, and the back plate can tilt or swing freely around the contact point.

[0014] Another embodiment provided in this application is: the back plate is a disc-shaped structure, and the second bearing seat is a split semi-circular structure.

[0015] This application provides a thrust foil bearing, comprising a flexible structure, a back plate, and a movable structure connected in sequence. The flexible structure includes a flat foil, a gasket, and a corrugated foil assembly connected in sequence. The corrugated foil assembly is disposed on the back plate. The corrugated foil assembly includes a first corrugated foil and a second corrugated foil arranged in sequence. The first corrugated foil includes a first straight section and a first corrugated arch connected to each other. The second corrugated foil includes a second straight section and a second corrugated arch connected to each other. The first straight section is connected to the back plate, and the second straight section is connected to the back plate. A first gasket is disposed on the first straight section, and a second gasket is disposed on the second straight section. One end of the flat foil, the second pad, and the second straight section are connected in sequence. The first corrugated section is free, and the other end of the flat foil is in contact with the first corrugated section. The back plate and the movable structure form a kinematic pair, and the back plate can tilt or swing freely. One end of the flat foil is connected to the second pad through a connecting plate. The movable structure includes a fixed ring and a third bearing seat that are connected to each other. The fixed ring is connected to the back plate. The back plate, the fixed ring, and the third bearing seat are coaxially arranged circular ring structures. The back plate and the fixed ring form a sliding friction pair, and the back plate can tilt around the axis of the third bearing seat.

[0016] Another embodiment provided in this application is that the back plate is provided with a plurality of slits, which are distributed radially.

[0017] Another embodiment provided in this application is that the flexible structure includes a planar region, a wedge-shaped region, and a fixed region connected in sequence.

[0018] 3. Beneficial effects

[0019] Compared with the prior art, the beneficial effects of the thrust foil bearing provided in this application are as follows:

[0020] The thrust foil bearing provided in this application grants it a certain degree of radial and circumferential freedom, allowing the back plate 4 to tilt or swing freely within a certain angle. This improves the thrust foil bearing's adaptability to thrust disc eccentricity and rotor misalignment. It ensures the working performance of the gas thrust foil bearing under high-speed, high-load conditions and enhances the stability of the rotor system.

[0021] The thrust foil bearing provided in this application has a simple structure, low cost, and strong applicability; it can be widely used in the application fields of gas foil bearings.

[0022] The thrust foil bearing provided in this application is a thrust foil bearing with tilting freedom. Attached Figure Description

[0023] Figure 1 This is an exploded schematic diagram of the thrust foil bearing structure of this application;

[0024] Figure 2 This is a cross-sectional schematic diagram of the thrust foil bearing structure of this application;

[0025] Figure 3 This is a partial structural diagram of the thrust foil bearing of this application;

[0026] Figure 4 This is a second exploded schematic diagram of the thrust foil bearing structure of this application;

[0027] Figure 5 This is a second cross-sectional schematic diagram of the thrust foil bearing structure of this application;

[0028] Figure 6 This is a schematic diagram of the second partial structure of the thrust foil bearing of this application;

[0029] Figure 7 This is a third exploded view of the thrust foil bearing structure of this application;

[0030] Figure 8 This is a third cross-sectional schematic diagram of the thrust foil bearing structure of this application;

[0031] Figure 9 This is a schematic diagram of the third part of the thrust foil bearing structure of this application;

[0032] Figure 10 This is a schematic diagram of the fourth partial structure of the thrust foil bearing of this application.

[0033] 1. Flat foil; 2. Gasket; 3. Corrugated foil; 4. Backing plate; 5. Fastening screw; 6. Pressure plate; 7. Elastic washer; 8. Movable joint; 9. Bearing seat; 10. Retaining ring; 11. Second bearing seat; 12. Third bearing seat. Detailed Implementation

[0034] In the following, specific embodiments of this application will be described in detail with reference to the accompanying drawings. Based on these detailed descriptions, those skilled in the art will be able to clearly understand and implement this application. Without departing from the principles of this application, features from various embodiments can be combined to obtain new implementations, or certain features from some embodiments can be substituted to obtain other preferred implementations.

[0035] See Figures 1-10 This application provides a thrust foil bearing, comprising a flexible structure, a back plate 4, and a movable structure connected in sequence. The flexible structure includes a flat foil 1, a gasket 2, and a corrugated foil 3 assembly connected in sequence. The corrugated foil 3 assembly is disposed on the back plate 4. The corrugated foil 3 assembly includes a first corrugated foil 3 and a second corrugated foil 3 arranged in sequence. The first corrugated foil 3 includes a first straight section and a first corrugated arch connected to each other. The second corrugated foil 3 includes a second straight section and a second corrugated arch connected to each other. The first straight section is connected to the back plate 4, and the second straight section is connected to the back plate 4. A first gasket 2 is disposed on the first straight section, and a second gasket 2 is disposed on the second straight section. One end of the flat foil 1, the second gasket 2, and the second straight section are connected in sequence. The first corrugated arch is free, and the other end of the flat foil 1 contacts the first corrugated arch. The back plate 4 and the movable structure form a kinematic pair, and the back plate 4 can tilt or swing freely. One end of the flat foil is connected to the second gasket 2 through a connecting plate.

[0036] The flat foil 1, gasket 2, and corrugated foil 3 are arranged sequentially from top to bottom on the bearing seat, and have the same number, generally 4 to 8 pieces. The corrugated foil 3 is a regular fan shape, and the flat foil 1 differs from the corrugated foil 3 in shape and size. The corrugated foil 3 is fixed to the back plate 4, and its fixed end is flush with the positioning groove on the back plate 4. The gasket 2 is fixed to the planar section of the corrugated foil 3, and one end is flush with its leading edge. The flat foil 1 is fixed to the gasket 2, and its fixed end is flush with the other end of the gasket 2. The flat foil 1 and the corrugated foil 3 are arranged in a staggered manner in the circumferential direction, and the directions from their fixed ends to their free ends are opposite.

[0037] The overlapping of the flat foil 1, shim 2, and corrugated foil 3 naturally forms a converging wedge-shaped gap, eliminating the need for pre-deformation of the flat foil 1. In typical thrust foil bearings, the flat foil requires stamping to create the required wedge-shaped gap. However, with the shim, the height difference between the shim and the corrugated foil allows the flat foil to naturally form a converging gap, which can be adjusted by adjusting the shim height.

[0038] This structure gives the thrust foil bearing a certain degree of tilting freedom, allowing the back plate 4 to tilt or swing freely. This improves the thrust foil bearing's adaptability to thrust disc eccentricity and rotor misalignment, ensures the working performance of the gas thrust foil bearing under high-speed and high-load conditions, and improves the stability of the rotor system.

[0039] In foil bearings, the foils are generally fan-shaped. One end of the flat foil 1 completely overlaps with the shape of the straight washer. In this application, the shape adjustment of the flat foil 1 is to achieve the forward and reverse mounting of the flat foil 1 and the corrugated foil 3 without changing the fan shape of the corrugated foil. (The processing difficulty of the fan-shaped corrugated foil is low, while the processing difficulty of the corrugated foil is much greater than that of the flat foil.)

[0040] Furthermore, the movable structure is connected to the back plate 4 via a movable joint 8. The movable structure includes a pressure plate 6 and a first bearing seat that are connected to each other. One end of the movable joint 8 is connected to the back plate 4, and the other end of the movable joint 8 passes through the pressure plate 6. The other end of the movable joint 8 is disposed in the first bearing seat. The back plate 4 can freely tilt or swing around the movable joint 8.

[0041] The thrust foil bearing consists of a flexible structure and a movable structure. The flexible structure includes a flat foil 1, a gasket 2, and a corrugated foil 3. The movable structure includes a back plate 4, a fastening screw 5, a pressure plate 6, an elastic washer 7, a movable joint 8, and a bearing housing 9, or the back plate 4 and the bearing housing, or the retaining ring 10 and the bearing housing. The flat foil 1, gasket 2, and corrugated foil 3 are fixed to the movable structure from top to bottom, and the flat foil 1 and corrugated foil 3 are oriented in opposite directions from their fixed ends to their free ends. The movable structure and the back plate 4 form a kinematic pair, allowing the back plate 4 to tilt or swing freely around its pivot.

[0042] The movable joint 8 is a spherical structure with a boss, and the back plate 4 is a disc structure. The boss plane of the movable joint 8 is fixedly connected to the back plate 4. The bearing seat 9 is a disc structure with an annular boss on its outer edge that mates with the pressure plate 6, and screw holes for fixing are opened along its circumferential direction. A spherical hole that mates with the movable joint 8 is opened on its upper surface. The pressure plate 6 is a disc structure with a circular boss that mates with the bearing seat 9, and spherical holes and circular holes that mate with the movable joint 8 are opened concentrically. The elastic washer 7 is placed between the pressure plate 6 and the bearing seat, and the three are coaxially configured and fixedly connected by the fastening screw 5. The movable joint 8 is installed in the spherical hole between the pressure plate 6 and the bearing seat 9, forming a kinematic pair. The back plate 4 is hinged through the movable joint 8, and there is a certain gap between the lower surface of the back plate 4 and the upper surface of the pressure plate 6. The back plate 4 can freely tilt or swing around the center of the sphere of the movable joint 8.

[0043] With axial stiffness and radial and circumferential degrees of freedom, the thrust foil bearing structure can tilt and swing freely, exhibiting good adaptability and self-balancing ability to thrust disc eccentricity and rotor misalignment, thereby improving the stability and reliability of the bearing-rotor system.

[0044] The back plate 4, pressure plate 6, elastic washer 7, movable joint 8, bearing seat 9 or fixing ring 10 provided in this application are split structures, which reduces processing costs and processing difficulty, makes disassembly and assembly convenient, and has low precision requirements.

[0045] Furthermore, an elastic washer 7 is provided between the pressure plate 6 and the first bearing seat, and the pressure plate 6, the elastic washer 7 and the first bearing seat are connected by fastening screws 5.

[0046] Furthermore, the movable joint 8 has a spherical structure, which includes a boss, and the plane of the boss is fixedly connected to the back plate 4.

[0047] Furthermore, the pressure plate 6 has a disc-shaped structure.

[0048] Furthermore, the movable structure includes a second bearing seat 11, one side of the disc-shaped structure is a plane, the corrugated foil 3 is disposed on the plane, the other side of the disc-shaped structure is a curved surface, the curved surface cooperates with the second bearing seat 11, the back plate 4 is connected to the second bearing seat 11 through a contact point, and the back plate 4 can freely tilt or swing around the contact point.

[0049] The back plate 4 has a disc-shaped structure with a curved lower surface. The second bearing seat 11 has a split semi-circular structure with grooves on its surface that mate with the curved surface of the back plate 4. The curvature of the grooves is greater than that of the back plate 4, and the groove diameter is slightly smaller than the maximum diameter of the curved surface of the back plate 4. The back plate 4 can swing around the contact point.

[0050] Furthermore, the back plate 4 has a disc-shaped structure, and the second bearing seat 11 has a split semi-circular structure.

[0051] Furthermore, the movable structure includes a fixed ring 10 and a third bearing seat 12 connected to each other. The fixed ring 10 is connected to the back plate 4. The back plate 4, the fixed ring 10 and the third bearing seat 12 are coaxially arranged circular ring structures. The back plate 4 and the fixed ring 10 form a sliding friction pair. The back plate 4 can tilt around the axis of the third bearing seat 12.

[0052] The back plate 4, the fixing ring 10, and the third bearing seat 12 are coaxially arranged circular ring structures. The inner ring is fixed to the third bearing seat 12. The outer ring of the back plate 4 and the inner ring of the fixing ring 10 are a pair of mating spherical surfaces, forming a sliding friction pair. The back plate 4 can tilt within a certain angle range around the axis of the third bearing seat 12.

[0053] Furthermore, the back plate 4 is provided with a plurality of slits distributed radially. The slits are used for positioning foil sheets when assembling them on the back plate, so that the foil sheets can be evenly arranged on the back plate.

[0054] Furthermore, the flexible structure includes a planar region, a wedge-shaped region, and a fixed region connected in sequence.

[0055] One end of the flat foil 1 is fixedly mounted on the gasket 2, and the other end is freely overlapped on the corresponding next corrugated foil 3. The corrugated foil 3 and the gasket 2 have a slight height difference, generally 50 to 100 μm. After the flat foil 1 is installed, it will naturally form a planar area and a wedge-shaped area.

[0056] Example 1

[0057] This embodiment provides a multi-layer thrust foil bearing structure. For example... Figure 1 , Figure 2 and Figure 3As shown, the structure, from top to bottom, includes: flat foil 1, gasket 2, corrugated foil 3, back plate 4, fastening screw 5, pressure plate 6, elastic washer 7, movable joint 8, and bearing seat 9. Flat foil 1, gasket 2, and corrugated foil 3 are segmented structures and have the same number; a single thrust foil bearing typically contains 4 to 8 pieces. Flat foil 1, gasket 2, and corrugated foil 3 are fixedly mounted on the back plate 4 from top to bottom. The back plate 4 is a smooth, circular sheet with an axially oriented circular groove in its inner ring, the diameter of which is the same as the inner diameter of flat foil 1, gasket 2, and corrugated foil 3. It also has multiple radially arranged slits, the number of which is the same as the number of flat foil 1. The movable joint 8 is a spherical structure with a planar boss; the lower surface of the back plate 4 and the boss plane of the movable joint 8 are fixedly connected, serving as a carrier for flat foil 1, gasket 2, and corrugated foil 3. The movable joint 8 is installed in the spherical hole in the bearing housing 9, having the same curvature, and can slide freely around its center. The pressure plate 6, elastic washer 7, and bearing housing 9 are coaxially arranged and connected and fixed by fastening screws 5. The pressure plate 6 and bearing housing 9 have mating positioning bosses. The circular hole on the pressure plate 6 mates with the movable joint, and the planar boss of the movable joint protrudes above the upper surface of the pressure plate 6, creating a certain movable clearance between the back plate 4 and the pressure plate 6, which can be adjusted by adjusting the fastening screws 5. When the bearing is working, the movable joint 8 provides axial stiffness to the thrust foil bearing, while simultaneously giving the back plate 4 circumferential and radial degrees of freedom, allowing the back plate 4 to tilt or swing freely around the center of the movable joint 8. This improves the thrust foil bearing's adaptability to thrust disc eccentricity and rotor misalignment, ensuring the working performance of the gas thrust foil bearing under high-speed and high-load conditions.

[0058] Example 2

[0059] This embodiment provides a thrust foil bearing structure with a disc-shaped backplate. For example... Figure 4 , Figure 5 and Figure 6As shown, the structure includes: a flat foil 1, a gasket 2, a corrugated foil 3, a back plate 4, and a second bearing seat 11. Similar to Embodiment 1, the flat foil 1, gasket 2, and corrugated foil 3 are segmented structures and have the same quantity. The flat foil 1, gasket 2, and corrugated foil 3 are sequentially fixed on the back plate 4 from top to bottom. The back plate 4 has a dish-shaped structure with a curved lower surface. Similar to Embodiment 1, its inner ring has a circular groove along the axial direction and multiple slits arranged radially. The second bearing seat 11 is a split semi-circular structure. A pair of second bearing seats 11 are concentrically fixed and connected to the back plate 4. The second bearing seat 11 has a groove that matches the curved surface of the back plate 4. The curvature of the groove is greater than the curvature of the back plate, and the groove diameter is slightly smaller than the maximum diameter of the curved surface of the back plate. When the bearing is working, a certain arc-shaped gap is formed between the back plate 4 and the second bearing housing 11, which can freely tilt or swing around the contact point and restrict the axial displacement of the back plate. This can improve the adaptability of the thrust foil bearing to thrust disc eccentricity and rotor misalignment, and ensure the working performance of the gas thrust foil bearing under high speed and high load conditions.

[0060] Example 3

[0061] This embodiment provides a collar-type thrust foil bearing structure. For example... Figure 7 , Figure 8 and Figure 9 As shown, the structure includes: a flat foil 1, a gasket 2, a corrugated foil 3, a back plate 4, a third bearing seat 12, and a retaining ring 10. Similar to Embodiment 1, the flat foil 1, gasket 2, and corrugated foil 3 are segmented structures and have the same quantity. The flat foil 1, gasket 2, and corrugated foil 3 are sequentially fixed on the back plate 4 from top to bottom. The inner diameter of the back plate 4 is the same as that of the flat foil 1, and multiple slits are arranged radially. The third bearing seat 12, retaining ring 10, and back plate 4 are coaxially arranged ring structures. The back plate retaining ring 10 and bearing seat 9 are interference-fitted. The outer edge of the third bearing seat 12 has screw holes for fixing, thus fixing the retaining ring 10 and the third bearing seat 12 to the housing. The outer ring of the back plate 4 and the inner ring of the retaining ring 10 are a pair of mating spherical surfaces, forming a sliding friction pair. The back plate 4 can tilt within a certain angle range around the axis of its third bearing seat 12.

[0062] like Figure 10As shown, the assembly method of the flat foil 1, gasket 2, and corrugated foil 3 provided in this application is as follows: the flat foil 1, gasket 2, and corrugated foil 3 are fixed to the back plate 4 from bottom to top. The straight section of the corrugated foil 3 is welded to the back plate 4 and is flush with one end of the slit, while the other end of the corrugated foil 3 is free. One end of the gasket 2 is welded to the straight section of the corrugated foil 3 and is flush with the fixed end. The leading edge of the flat foil 1 is welded to the other end of the corresponding gasket 2 and is flush with the other end of the gasket 2. The other end of the flat foil 1 is freely overlapped on the corrugated arch of the next corrugated foil 3, that is, the directions of the flat foil 1 and the corrugated foil 3 from their fixed ends to their free ends are opposite. This structure ensures that the deformation directions of the flat foil 1 and the corrugated foil 3 in the circumferential direction are opposite when the thrust foil bearing is working, which is beneficial to improving the damping of the thrust foil bearing and improving the stability of the bearing-rotor system. Due to the height difference between the gasket 2 and the corrugated foil 3 in the axial direction, after installation, the flat foil 1 naturally forms three parts: a fixed area, a wedge-shaped area, and a flat area. The wedge-shaped region is used to generate the hydrodynamic effect, while the planar region is the working area for the high-pressure lubricating fluid, providing load-bearing capacity to the rotor. The advantage of this method is that it eliminates the need for additional stamping dies to pre-deform the flat foil 1, simplifying operation, reducing processing costs, and increasing efficiency.

[0063] When the bearing-rotor system is operating normally, the axis of the thrust foil bearing coincides with the rotor axis. The movable joint 8, bearing housing 9, or retaining ring 10 provides sufficient axial stiffness to the thrust foil bearing, preventing axial displacement. If the thrust disc becomes eccentric or the rotor misaligns, the bearing will change the shape of its lubricating film, causing an imbalance in the force on the back plate 4. The back plate 4 will then freely tilt or swing around the center of the bearing housing, restoring the lubrication surface of the thrust foil bearing to parallel with the surface of the thrust disc. Especially when the rotor axis trajectory is complex and fluctuates greatly, the back plate 4 can automatically and promptly adjust to align the bearing axis with the rotor axis, preventing premature contact between the thrust foil bearing lubrication surface and the rotor, thus improving the stability and reliability of the bearing-rotor system.

[0064] Although this application has been described above with reference to specific embodiments, those skilled in the art will understand that many modifications can be made to the configurations and details disclosed in this application within the principles and scope of the disclosure. The scope of protection of this application is determined by the appended claims, and the claims are intended to cover all modifications included in the literal meaning or scope of equivalents of the technical features in the claims.

Claims

1. A thrust foil bearing characterized by: The flexible structure, the back plate and the movable structure are sequentially connected, the flexible structure comprises a flat foil, a gasket and a wave foil assembly which are sequentially connected, the wave foil assembly is arranged on the back plate, the wave foil assembly comprises a first wave foil and a second wave foil which are sequentially arranged, the first wave foil comprises a first flat section and a first wave arch which are connected with each other, the second wave foil comprises a second flat section and a second wave arch which are connected with each other, the first flat section is connected with the back plate, the second flat section is connected with the back plate, the first flat section is provided with a first gasket, the second flat section is provided with a second gasket, one end of the flat foil, the second gasket and the second flat section are sequentially connected, the first wave arch is free, and the other end of the flat foil is in contact with the first wave arch; the back plate and the movable structure form a kinematic pair, and the back plate can be freely inclined or swung; one end of the flat foil is connected with the second gasket through a connecting plate. The movable structure is connected with the back plate through a movable joint, the movable structure comprises a pressing plate and a first bearing seat which are connected with each other, one end of the movable joint is connected with the back plate, the other end of the movable joint penetrates through the pressing plate, and the other end of the movable joint is arranged in the first bearing seat; and the back plate can be freely inclined or swung around the movable joint.

2. The thrust foil bearing of claim 1 wherein: An elastic gasket is arranged between the pressing plate and the first bearing seat, and the pressing plate, the elastic gasket and the first bearing seat are connected through a fastening screw.

3. The thrust foil bearing of claim 2, wherein: The movable joint is a spherical structure, and the spherical structure comprises a boss, and the boss is fixedly connected with the back plate.

4. The thrust foil bearing of claim 2 wherein: The pressing plate is a disc-shaped structure.

5. The thrust foil bearing of claim 1 wherein: The flexible structure comprises a planar area, a wedge-shaped area and a fixed area which are sequentially connected.

6. A thrust foil bearing characterized by: The flexible structure, the back plate and the movable structure are sequentially connected, the flexible structure comprises a flat foil, a gasket and a wave foil assembly which are sequentially connected, the wave foil assembly is arranged on the back plate, the wave foil assembly comprises a first wave foil and a second wave foil which are sequentially arranged, the first wave foil comprises a first flat section and a first wave arch which are connected with each other, the second wave foil comprises a second flat section and a second wave arch which are connected with each other, the first flat section is connected with the back plate, the second flat section is connected with the back plate, the first flat section is provided with a first gasket, the second flat section is provided with a second gasket, one end of the flat foil, the second gasket and the second flat section are sequentially connected, the first wave arch is free, and the other end of the flat foil is in contact with the first wave arch; the back plate and the movable structure form a kinematic pair, and the back plate can be freely inclined or swung; one end of the flat foil is connected with the second gasket through a connecting plate. The movable structure comprises a second bearing seat, the back plate is a disc-shaped structure, one side of the disc-shaped structure is a plane, the wave foil is arranged on the plane, the other side of the disc-shaped structure is a curved surface, the curved surface is matched with the second bearing seat, the back plate and the second bearing seat are connected through a contact point, and the back plate can be freely inclined or swung around the contact point.

7. The thrust foil bearing of claim 6 wherein: The second bearing seat is a split half-circular structure.

8. The thrust foil bearing of claim 6, wherein: The flexible structure comprises a planar area, a wedge-shaped area and a fixed area which are sequentially connected.

9. A thrust foil bearing characterized by: The flexible structure, the back plate and the movable structure are sequentially connected, the flexible structure comprises a flat foil, a gasket and a wave foil assembly which are sequentially connected, the wave foil assembly is arranged on the back plate, the wave foil assembly comprises a first wave foil and a second wave foil which are sequentially arranged, the first wave foil comprises a first flat section and a first wave arch which are connected with each other, the second wave foil comprises a second flat section and a second wave arch which are connected with each other, the first flat section is connected with the back plate, the second flat section is connected with the back plate, the first flat section is provided with a first gasket, the second flat section is provided with a second gasket, one end of the flat foil, the second gasket and the second flat section are sequentially connected, the first wave arch is free, and the other end of the flat foil is in contact with the first wave arch; the back plate and the movable structure form a kinematic pair, the back plate can be freely inclined or oscillated; one end of the flat foil is connected with the second gasket through a connecting plate. The movable structure comprises a fixed ring and a third bearing seat which are connected with each other, the fixed ring is connected with the back plate, the back plate, the fixed ring and the third bearing seat are coaxially arranged in a ring structure, the back plate and the fixed ring form a sliding friction pair, and the back plate can be inclined around the axis of the third bearing seat.

10. The thrust foil bearing of claim 9, wherein: The back plate is provided with a plurality of slits which are distributed in the radial direction.

11. The thrust foil bearing of claim 9, wherein: The flexible structure comprises a flat area, a wedge-shaped area and a fixed area which are sequentially connected.

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