CN114382775A

CN114382775A - Gas dynamic pressure radial bearing, compressor and engine

Info

Publication number: CN114382775A
Application number: CN202210044080.5A
Authority: CN
Inventors: 胡余生; 陈彬; 贾金信; 孔祥茹; 苏久展
Original assignee: Gree Electric Appliances Inc of Zhuhai
Current assignee: Gree Electric Appliances Inc of Zhuhai
Priority date: 2022-01-14
Filing date: 2022-01-14
Publication date: 2022-04-22
Also published as: WO2023134256A1

Abstract

The application provides a gas dynamic pressure radial bearing, a compressor and an engine. The gas dynamic pressure radial bearing comprises a bearing seat (1), a second layer of wave foil (4), a first layer of wave foil (3) and a flat foil, wherein the second layer of wave foil (4) and the first layer of wave foil (3) are overlapped and arranged between the bearing seat (1) and the flat foil, wave crests of the second layer of wave foil (4) and the first layer of wave foil (3) are correspondingly arranged, and a preset gap (203) is formed between the wave crests of the second layer of wave foil (4) and the first layer of wave foil (3). According to the gas dynamic pressure radial bearing, the damping of the bearing can be increased, the integral rigidity of the bearing is improved, and the bearing performance of the bearing is improved.

Description

Gas dynamic pressure radial bearing, compressor and engine

Technical Field

The application relates to the technical field of bearings, in particular to a gas dynamic pressure radial bearing, a compressor and an engine.

Background

The gas dynamic pressure radial bearing is an elastic supporting dynamic pressure gas bearing, the rotating shaft rotates at high speed to drive gas between the bearing and the rotating shaft to flow, viscous gas enters the wedge-shaped area to generate a fluid dynamic pressure effect to form a high-pressure gas film, and the rotating shaft rotating at high speed can be suspended when the pressure of the dynamic pressure gas film is large enough. When the rotating shaft rotates at a high speed, the high-pressure air film extrudes the bearing, the top foil and the supporting bump foil both generate elastic deformation, the air film gap is enlarged, and the stable operation of the bearing is ensured.

The prior art discloses a gas dynamic pressure radial bearing, which is composed of a single-layer arched foil and a single-layer flat foil, wherein the arched foil is of a three-section structure, two sides of the arched foil are high arched foils, the middle of the arched foil is a low arched foil, the high arched foils at two ends provide bearing capacity when load is small, and the three arched foils provide bearing capacity together when load is large. The design has an effective adjusting effect on the rigidity of the bearing. However, the segmentation results in a reduced contact area with the flat foil at low loads, only 2/3, resulting in a reduced overall load-bearing performance of the radial bearing.

Disclosure of Invention

Therefore, the technical problem to be solved by the application is to provide a gas dynamic pressure radial bearing, a compressor and an engine, which can increase the damping of the bearing, improve the overall rigidity of the bearing and improve the bearing performance of the bearing.

In order to solve the above problems, the present application provides a gas dynamic pressure radial bearing, which includes a bearing seat, a second layer of wave foil, a first layer of wave foil, and a flat foil, wherein the second layer of wave foil and the first layer of wave foil are stacked and disposed between the bearing seat and the flat foil, the wave peaks of the second layer of wave foil and the first layer of wave foil are disposed correspondingly, and a predetermined gap is provided between the wave peaks of the second layer of wave foil and the first layer of wave foil.

Preferably, the second layer of wave foil is arranged on the side close to the flat foil, the first layer of wave foil is arranged on the side close to the bearing seat, and the rigidity of the second layer of wave foil is smaller than that of the first layer of wave foil.

Preferably, the second layer of wave foils and the first layer of wave foils each comprise a flat section and an arc-shaped section, the flat section of the second layer of wave foils is supported on the flat section of the first layer of wave foils, the width of the flat section of the second layer of wave foils in the circumferential direction is smaller than that of the flat section of the first layer of wave foils, and the chord length of the arc-shaped section of the second layer of wave foils is larger than that of the arc-shaped section of the first layer of wave foils.

Preferably, the flat foils are used for contacting with the rotating shaft, and the flat foils include a first layer of flat foil, a second layer of flat foil and a third layer of flat foil which are sequentially attached along the radial direction from outside to inside, the circumferential extending direction of the first layer of flat foil and the second layer of flat foil is opposite to the rotating direction of the rotating shaft, and the circumferential extending direction of the second layer of flat foil is the same as the rotating direction of the rotating shaft.

Preferably, the first, second and third layers of flat foils are all of a full-circumference surrounding structure.

Preferably, the circumferential extension of the second layer of flat foil is 3/5-4/5 of the whole circumference.

Preferably, the circumferential extension of the second layer of flat foil is 2/3 of the entire circumference.

Preferably, the circumferential end of the second layer of flat foil is in a slope structure, and the inclined surface of the slope structure faces the third layer of flat foil.

Preferably, the second layer of wave foil and the first layer of wave foil each include at least three wave foil sections sequentially arranged along the axial direction, wherein the flat sections and the arc sections of the wave foil sections located at the two axial ends are correspondingly arranged along the circumferential direction, and the wave crests of the wave foil section located in the middle and the wave crests of the wave foil sections located at the two axial ends are staggered in the circumferential direction.

Preferably, the wave foil sections include a first wave foil section, a second wave foil section, a third wave foil section and a fourth wave foil section, wherein the first wave foil section and the fourth wave foil section are located at two axial ends of the bearing seat, the second wave foil section and the third wave foil section are located between the first wave foil section and the fourth wave foil section, a flat section and an arc section of the first wave foil section and the fourth wave foil section are correspondingly arranged along the circumferential direction, a flat section and an arc section of the second wave foil section and the third wave foil section are correspondingly arranged along the circumferential direction, and peaks of the first wave foil section and the second wave foil section are staggered along the circumferential direction.

Preferably, the first, second, third and fourth wave foil sections are sequentially arranged at intervals along the axial direction, the first, second, third and fourth wave foil sections include fixed ends and free ends, the fixed ends of the first, second, third and fourth wave foil sections are commonly connected to the bearing seat, the circumferential lengths of the first and fourth wave foil sections are greater than the circumferential lengths of the second and third wave foil sections, the free ends of the first and fourth wave foil sections are fixedly connected through a connecting rod, and the free ends of the second and third wave foil sections are fixedly connected through a connecting rod.

Preferably, the inner surface of the flat foil is sprayed with a high temperature resistant lubricating coating.

According to another aspect of the present application, there is provided a compressor including a gas dynamic pressure radial bearing which is the above gas dynamic pressure radial bearing.

According to another aspect of the present application, there is provided an engine comprising the above-described aerodynamic radial bearing or the above-described compressor.

The application provides a gas dynamic pressure radial bearing, including bearing frame, second floor wave foil, first floor wave foil and flat foil, second floor wave foil and the superpose of first floor wave foil to set up between bearing frame and flat foil, the wave crest of second floor wave foil and first floor wave foil corresponds the setting, and has preset clearance between the wave crest of second floor wave foil and first floor wave foil. This gas dynamic pressure radial bearing adopts the stack formula structure to form double-deck ripples paper tinsel, and double-deck ripples paper tinsel is in the same place as the flat section laminating of trough, form common support, it has preset clearance to have between the arc section as the crest, thereby provide bearing capacity by the top layer ripples paper tinsel with the flat contact in first layer ripples paper tinsel and the second floor ripples paper tinsel earlier when low load, because whole top layer ripples paper tinsel homoenergetic with the flat contact of paper tinsel, consequently, the area of contact of ripples paper tinsel and flat paper tinsel has been guaranteed, the bearing capacity of single ripples tinsel has been guaranteed, along with load increases, the top layer ripples tinsel takes place after certain deformation and bottom ripples tinsel contact, two-layer ripples tinsel provides bearing capacity jointly, thereby further improve gas dynamic pressure bearing's bearing performance and bearing system's stability.

Drawings

FIG. 1 is a schematic view of a gas dynamic radial bearing according to an embodiment of the present application;

FIG. 2 is a schematic view of a load bearing configuration of a gas dynamic radial bearing according to an embodiment of the present application;

FIG. 3 is an enlarged schematic view of FIG. 2 at I;

FIG. 4 is a schematic view of a first wave foil of an embodiment of a gas dynamic radial bearing of the present application;

fig. 5 is a schematic perspective view of a bump foil of a gas dynamic pressure radial bearing according to an embodiment of the present application.

The reference numerals are represented as:

1. a bearing seat; 2. locking the pin; 3. a first layer of corrugated foil; 4. a second layer of corrugated foil; 5. a first layer of flat foil; 6. a second layer of flat foil; 7. a third layer of flat foil; 8. a rotating shaft; 101. a first bump foil segment; 102. a second bump foil segment; 103. a third band of foil; 104. a fourth band of foils; 201. a gas film; 202. a wedge-shaped region; 203. a gap.

Detailed Description

Referring to fig. 1 to 5 in combination, according to an embodiment of the present application, a gas dynamic pressure radial bearing includes a bearing housing 1, a second layer of wave foil 4, a first layer of wave foil 3, and a flat foil, wherein the second layer of wave foil 4 and the first layer of wave foil 3 are stacked and disposed between the bearing housing 1 and the flat foil, the second layer of wave foil 4 and the first layer of wave foil 3 are disposed in correspondence with each other, and a predetermined gap 203 is provided between the second layer of wave foil 4 and the first layer of wave foil 3.

This gas dynamic pressure radial bearing adopts the superimposed structure to form double-deck ripples paper tinsel, and the flat section laminating of the double-deck ripples paper tinsel as the trough is in the same place, form common support, it predetermines clearance 203 to have between the arc section as the crest, thereby provide bearing capacity by the top layer ripples paper tinsel with the flat contact in first layer ripples paper tinsel 3 and the second floor ripples paper tinsel 4 earlier when low load, because whole top layer ripples paper tinsel homoenergetic with the flat contact, consequently, the area of contact of ripples paper tinsel with the flat paper tinsel has been guaranteed, the bearing capacity of single ripples tinsel has been guaranteed, along with the load increases, the top layer ripples tinsel takes place after certain deformation and bottom ripples tinsel contact, two-layer ripples tinsel provides bearing capacity jointly, thereby further improve gas dynamic pressure bearing's bearing capacity and bearing system's stability. In this embodiment, the top wave foil is the wave foil close to the flat foil, and the bottom wave foil is the wave foil far from the flat foil.

In one embodiment, the second layer of wave foil 4 is arranged on the side close to the flat foil, the first layer of wave foil 3 is arranged on the side close to the bearing support 1, and the second layer of wave foil 4 has a stiffness smaller than the stiffness of the first layer of wave foil 3. In this embodiment, because there is the difference in height between the two layers of wave foils, the crest position has the clearance 203, and the rigidity of top layer wave foil is less than the rigidity of bottom layer wave foil, so can utilize top layer wave foil to provide low load bearing capacity, when the load is great, then can utilize double-layer wave foil to provide bearing capacity, because the rigidity of bottom layer wave foil is bigger simultaneously, consequently can bear bigger load, can form better supporting role to top layer wave foil, utilize the difference of both rigidity to provide better bearing capacity, further improve bearing system's stability.

In one embodiment, the height of the gap 203 is 20% to 35% of the height of the peak of the second layer of wave foil 4, and as a preferred embodiment, the height of the gap 203 is 27% of the height of the peak of the second layer of wave foil 4.

In one embodiment, the second layer of wave foils 4 and the first layer of wave foils 3 each include a flat section and an arc-shaped section, the flat section of the second layer of wave foils 4 is supported on the flat section of the first layer of wave foils 3, the width of the flat section of the second layer of wave foils 4 in the circumferential direction is smaller than the width of the flat section of the first layer of wave foils 3 in the circumferential direction, and the chord length of the arc-shaped section of the second layer of wave foils 4 is larger than the chord length of the arc-shaped section of the first layer of wave foils 3.

In this embodiment, the first layer of corrugated foil 3 and the second layer of corrugated foil 4 are formed by pressing and pressure maintaining metal foils through corresponding dies of the structure as shown in fig. 4, and then the structure as shown in fig. 5 is formed by winding and heat treatment through a special tool, so as to ensure that the flat section between each arch is attached to the inner surface of the bearing seat 1, thereby ensuring the consistency and feasibility of bearing preparation. Design parameter chord lengths and band values of the first layer of wave foil 3 and the second layer of wave foil 4 are different, and reasonable setting can be carried out according to design positions of the first layer of wave foil 3 and the second layer of wave foil 4, so that flat sections of the first layer of wave foil 3 and the second layer of wave foil 4 are partially attached, and meanwhile, interference phenomenon is not generated. In addition, the arch height of the second layer of wave foil 4 is larger than that of the first layer of wave foil 3, and a gap 203 exists in each arch section, so that the arc sections of the first layer of wave foil 3 and the second layer of wave foil 4 are overlapped, and interference caused by unreasonable design of the width of the flat section can be avoided. The implementation of the design scheme of the two layers of wave foils can increase the damping of the bearing and the deformation degree of the arched foils and improve the bearing performance of the arched foils.

In one embodiment, the flat foils are used for contacting with the rotating shaft 8, and the flat foils comprise a first layer of flat foil 5, a second layer of flat foil 6 and a third layer of flat foil 7 which are sequentially attached from outside to inside in the radial direction, the circumferential extension direction of the first layer of flat foil 5 and the second layer of flat foil 6 is opposite to the rotating direction of the rotating shaft 8, and the circumferential extension direction of the second layer of flat foil 6 is the same as the rotating direction of the rotating shaft 8.

The first layer of flat foil 5, the second layer of flat foil 6 and the third layer of flat foil 7 are all of a whole-circle surrounding structure, so that the structural consistency of all the foils can be guaranteed in the preparation and bending processes of the bearing, the consistency of the overall structure of the gas dynamic pressure bearing is guaranteed, the installation consistency of the gas dynamic pressure bearing is further guaranteed, and the bearing performance of the gas dynamic pressure bearing is improved.

In one embodiment, the second layer of flat foil 6 has a circumferential extension of 3/5-4/5 of the entire circumference. As a preferred embodiment the circumferential extension of the second layer of flat foil 6 is 2/3 of the entire circumference. The circumferential tail end of the second layer of flat foil 6 is of a slope structure, and the inclined surface of the slope structure faces the third layer of flat foil 7.

In the present embodiment, the winding directions of the second layer of flat foil 6 are opposite to the winding directions of the first layer of flat foil 5 and the third layer of flat foil 7, the design of the reverse winding is determined based on the running direction of the rotating shaft 8, a wedge-shaped area 202 is formed when the rotating shaft 8 starts running, the design shape and the winding manner of the middle layer are designed based on the point, when the rotating shaft 8 starts running, the top layer of flat foil starts along with the rotating shaft 8, and a micro-deformation is generated at the slope structure of the middle layer, and the damping of the radial bearing can be increased by designing the micro-deformation, so that the overall rigidity is improved, and the bearing performance is increased.

In the initial stage of the operation of the high-speed motor, the eccentric motion in the high-speed rotation advancing process of the rotating shaft 8 causes the rotating shaft 8 and the pneumatic radial bearing to form a wedge-shaped area at the intersection position of the first layer of flat foil 5, the second layer of flat foil 6 and the third layer of flat foil 7, and the viscous gas enters the wedge-shaped area to form a high-pressure lubricating gas film so as to provide bearing capacity for a bearing-rotating shaft system. The second layer of flat foil 6 rotates along with the rotating shaft 8, the contact area between the wedge angle at the tail end of the second layer of flat foil 6 and the third layer of flat foil 7 generates wedge-shaped deformation as shown in fig. 3, and 202 is a wedge-shaped area formed after the third layer of flat foil 7 generates elastic deformation along with the rotation of the rotating shaft 8. And 201 is a gas film between the rotating shaft and the radial gas dynamic pressure bearing. The structure can increase the bearing damping for the radial gas dynamic pressure bearing, improve the abrasion and impact resistance of the bearing in the start-stop stage, and increase the self-applicability of the bearing.

In one embodiment, the second layer of wave foil 4 and the first layer of wave foil 3 each include at least three wave foil segments sequentially arranged along the axial direction, wherein the flat segments and the arc segments of the wave foil segments located at the two axial ends are correspondingly arranged along the circumferential direction, and the wave peaks of the wave foil segment located in the middle and the wave peaks of the wave foil segments located at the two axial ends are staggered along the circumferential direction.

In one embodiment, the bump foil section comprises three sections, wherein the first section and the third section are located at two ends, the second section is located in the middle, the lengths of the first section and the third section in the axial direction are the same, and the length of the second section in the axial direction is the same as the sum of the lengths of the first section and the third section in the axial direction, so that the minimum top foil deformation in the axial direction is generated at the axial edge position of the bearing, the rigidity of the bump foil at the axial edge of the top foil can be reduced, that is, the local deformation at the axial edge of the top foil can be increased, and therefore, the bearing is allowed to have a larger eccentricity and the bearing performance of the bearing is improved.

In one embodiment, the wave foil segments include a first wave foil segment 101, a second wave foil segment 102, a third wave foil segment 103, and a fourth wave foil segment 104, where the first wave foil segment 101 and the fourth wave foil segment 104 are located at two axial ends of the bearing housing 1, the second wave foil segment 102 and the third wave foil segment 103 are located between the first wave foil segment 101 and the fourth wave foil segment 104, a flat section and an arc section of the first wave foil segment 101 and the fourth wave foil segment 104 are correspondingly arranged along a circumferential direction, a flat section and an arc section of the second wave foil segment 102 and the third wave foil segment 103 are correspondingly arranged along a circumferential direction, and peaks of the first wave foil segment 101 and the second wave foil segment 102 are staggered along the circumferential direction.

In one embodiment, the first, second, third and fourth

wave foil sections

101, 102, 103 and 104 are sequentially arranged at intervals along the axial direction, the first, second, third and fourth

wave foil sections

101, 102, 103 and 104 include fixed ends and free ends, the fixed ends of the first, second, third and fourth

wave foil sections

101, 102, 103 and 104 are commonly connected to the bearing block 1, the circumferential lengths of the first and fourth

wave foil sections

101 and 104 are greater than the circumferential lengths of the second and third

wave foil sections

102 and 103, the free ends of the first and fourth

wave foil sections

101 and 104 are fixedly connected by a connecting rod, and the free ends of the second and third

wave foil sections

102 and 103 are fixedly connected by a connecting rod.

When the motor runs at high speed, a high-pressure lubricating gas film 201 is formed in a gap 203 between the aerodynamic radial bearing and the rotating shaft 8, the gas pressure in the central area of the radial bearing is higher than the gas pressure at two ends of the radial bearing, and the integral radial bump foil arch structure can lead the top foil to generate penetrating deformation against the arch direction, so that the high pressure in the center leaks to the two ends, and the phenomenon is an end leakage phenomenon.

In the present embodiment, as shown in fig. 4 and 5, the first and second layers of corrugated foils 3 and 4 are designed to have a four-stage structure, i.e., a first corrugated foil stage 101, a second corrugated foil stage 102, a third corrugated foil stage 103, and a fourth corrugated foil stage 104. The first wave foil section 101 and the fourth wave foil section 104 are connected together, the middle second wave foil section 102 and the middle third wave foil section 103 are connected together to form a supporting arch foil similar to a 'return' type structure, and wave foil units of the first wave foil section 101 and the fourth wave foil section 104 are staggered with wave foil units of the second wave foil section 102 and the third wave foil section 103 to form a variable-stiffness arch foil. One end of each of the first, second, third and fourth

wave foil sections

101, 102, 103 and 104 is fixed, and the other end is free, the free ends of the first and fourth

wave foil sections

101 and 104 are fixedly connected together, the free ends of the second and third

wave foil sections

102 and 103 are fixedly connected together, and the fixed ends of the first, second, third and fourth

wave foil sections

101, 102, 103 and 104 are commonly connected to the bearing pedestal 1 through a fixed mounting portion. The design parameters of the wave foils of the first wave foil section 101, the second wave foil section 102, the third wave foil section 103 and the fourth wave foil section 104 are the same, and the arch height, the chord length and the flat section are the same. The implementation scheme of the variable stiffness corrugated foil can effectively improve the end leakage phenomenon of the radial bearing and improve the bearing performance of the gas dynamic pressure radial bearing.

The four-section type corrugated foils of the gas dynamic pressure radial bearing comprise two sections of outer supporting corrugated foils positioned at two axial ends and two sections of inner supporting corrugated foils positioned in the middle, the rigidity difference between the middle and two ends can be designed according to the operation requirement of a motor, the impact resistance of the bearing is improved, and the bearing stability of a bearing system is favorably improved. The double-layer wave foil structure is designed, so that the rigidity and the bearing performance of the supporting wave foil can be effectively improved.

Referring to fig. 1 in combination, the bearing seat 1 is used for mounting and supporting a protective gas dynamic pressure radial bearing. In the present embodiment, the fixed end of the double-layer wave foil of the aerodynamic radial bearing is inserted into the notch of the bearing housing 1 and then fixed by the locking pin 2. The fixing manner of the double-layer wave foil is not limited to this. In addition, the gas dynamic pressure radial bearing needs to be axially fixed by the locking pin 2 or other structures, so that the gas dynamic pressure radial bearing is prevented from axially shifting.

One ends of the first layer of corrugated foil 3, the second layer of corrugated foil 4, the first layer of flat foil 5, the second layer of flat foil 6 and the third layer of flat foil 7 are fixed on the bearing seat 1, and the other ends are free, so that the foil bearing is ensured to have deformation and sliding spaces.

In one embodiment, the inner surface of the flat foil is sprayed with a high-temperature-resistant lubricating coating, so that the lubricating coating can play a role in friction reduction, wear resistance and lubrication in the start-stop stage of high-speed operation of the motor.

According to an embodiment of the present application, the compressor includes a gas dynamic pressure radial bearing, which is the above-described gas dynamic pressure radial bearing.

According to an embodiment of the application, the engine comprises a gas dynamic pressure radial bearing as described above or a compressor as described above.

It is readily understood by a person skilled in the art that the advantageous ways described above can be freely combined, superimposed without conflict.

The present invention is not intended to be limited to the particular embodiments shown and described, but is to be accorded the widest scope consistent with the principles and novel features herein disclosed. The foregoing is only a preferred embodiment of the present application, and it should be noted that, for those skilled in the art, several modifications and variations can be made without departing from the technical principle of the present application, and these modifications and variations should also be considered as the protection scope of the present application.

Claims

1. A gas dynamic pressure radial bearing is characterized by comprising a bearing seat (1), a second layer of wave foil (4), a first layer of wave foil (3) and a flat foil, wherein the second layer of wave foil (4) and the first layer of wave foil (3) are overlapped and arranged between the bearing seat (1) and the flat foil, the wave foils (4) of the second layer and the wave foils (3) of the first layer are correspondingly arranged, and a preset gap (203) is formed between the wave foils (4) of the second layer and the wave foils (3) of the first layer.

2. A gas dynamic pressure radial bearing according to claim 1, characterized in that the second wave foil (4) is arranged on the side close to the flat foil and the first wave foil (3) is arranged on the side close to the bearing housing (1), the second wave foil (4) having a stiffness smaller than the stiffness of the first wave foil (3).

3. The aerodynamic radial bearing according to claim 1, wherein the second wave foil layer (4) and the first wave foil layer (3) each include a flat section and an arc-shaped section, the flat section of the second wave foil layer (4) being supported on the flat section of the first wave foil layer (3), the flat section of the second wave foil layer (4) having a width in the circumferential direction smaller than the width of the flat section of the first wave foil layer (3) in the circumferential direction, and the arc-shaped section of the second wave foil layer (4) having a chord length larger than the arc-shaped section chord length of the first wave foil layer (3).

4. The aerodynamic radial bearing according to claim 1, wherein the flat foils are configured to contact a rotating shaft (8) and comprise a first layer of flat foil (5), a second layer of flat foil (6) and a third layer of flat foil (7) which are sequentially attached in a radial direction from outside to inside, the circumferential extension direction of the first layer of flat foil (5) and the second layer of flat foil (6) is opposite to the rotation direction of the rotating shaft (8), and the circumferential extension direction of the second layer of flat foil (6) is the same as the rotation direction of the rotating shaft (8).

5. Aerodynamic radial bearing according to claim 4, characterized in that the first (5), second (6) and third (7) layers of flat foil are all full-circumference encircling structures.

6. Aerodynamic radial bearing according to claim 5, characterized in that the circumferential extension of the second layer of flat foil (6) is 3/5-4/5 of the entire circumference.

7. Aerodynamic radial bearing according to claim 6, characterized in that the circumferential extension of the second layer of flat foil (6) is 2/3 of the entire circumference.

8. Aerodynamic radial bearing according to claim 6, characterized in that the circumferential ends of the flat foils (6) of the second layer are of a ramp structure with the inclined faces of the ramp structure facing the flat foils (7) of the third layer.

9. A gas dynamic pressure radial bearing according to any one of claims 1 to 8, characterized in that the second layer of wave foil (4) and the first layer of wave foil (3) each comprise at least three wave foil segments arranged in sequence in the axial direction, wherein the flat and arc segments of the wave foil segments at both axial ends are arranged in correspondence with each other in the circumferential direction, and the wave peaks of the wave foil segments in the middle are arranged in a staggered manner in the circumferential direction with respect to the wave peaks of the wave foil segments at both axial ends.

10. Aerodynamic radial bearing according to claim 9, wherein said wave foil segments comprise a first wave foil segment (101), a second wave foil segment (102), a third wave foil segment (103) and a fourth wave foil segment (104), wherein the first foil segment (101) and the fourth foil segment (104) are located at both axial ends of the bearing housing (1), the second wave foil segment (102) and the third wave foil segment (103) are located between the first wave foil segment (101) and the fourth wave foil segment (104), the flat sections and the arc sections of the first wave foil section (101) and the fourth wave foil section (104) are correspondingly arranged along the circumferential direction, the flat sections and the arc sections of the second wave foil section (102) and the third wave foil section (103) are correspondingly arranged along the circumferential direction, the wave crests of the first wave foil sections (101) and the second wave foil sections (102) are arranged in a staggered manner in the circumferential direction.

11. The aerodynamic radial bearing according to claim 10, wherein the first, second, third and fourth foil segments (101, 102, 103, 104) are sequentially arranged at intervals in an axial direction, the first, second, third and fourth foil segments (101, 102, 103, 104) include fixed ends and free ends, the fixed ends of the first, second, third and fourth foil segments (101, 102, 103, 104) are commonly connected to the bearing housing (1), the circumferential lengths of the first and fourth foil segments (101, 104) are greater than the circumferential lengths of the second and third foil segments (102, 103), the free ends of the first and fourth foil segments (101, 104) are fixedly connected by a connecting rod, the free ends of the second wave foil section (102) and the third wave foil section (103) are fixedly connected through a connecting rod.

12. A gas dynamic pressure radial bearing as claimed in claim 1, wherein the inner surface of the flat foil is coated with a high temperature resistant lubricating coating.

13. A compressor comprising a gas dynamic radial bearing, characterized in that the gas dynamic radial bearing is a gas dynamic radial bearing according to any one of claims 1 to 12.

14. An engine comprising a aerodynamic radial bearing according to any one of claims 1 to 12 or a compressor according to claim 13.