A radial load bearing gas bearing and motor

Abstract

The application provides a radial load gas bearing and motor, the radial load gas bearing comprising: a bearing seat, a first layer top foil, a second layer top foil and a wave foil layer, the first layer top foil, the second layer top foil, the wave foil and the bearing seat being sequentially arranged along a radial direction from inside to outside; the wave foil layer comprises a first wave foil at an axial first position, the first wave foil comprising first wave foil supporting ends and first wave foil flat sections alternately arranged along a circumferential direction, the second layer top foil comprises a first top foil also at the axial first position, the first top foil being a flat foil structure; and the first top foil is located between the first wave foil supporting ends and the first layer top foil. According to the application, the double-layer top foil plus one layer of wave foil can effectively increase the stiffness of the bearing, prevent the bearing from failing due to large deformation under large load, and improve the load-carrying performance of the bearing.

Description

Technical Field

[0001] This invention relates to the field of bearing technology, specifically to a radial load-bearing gas bearing and an electric motor. Background Technology

[0002] A gas hydrodynamic bearing is a type of elastically supported hydrodynamic gas bearing, such as... Figure 1 As shown, the high-speed rotation of the shaft 101 drives the gas flow between the bearing 102 and the shaft 101. The viscous gas enters the wedge-shaped region, generating a hydrodynamic pressure effect and forming a high-pressure gas film 103. When the pressure of the hydrodynamic gas film 103 is sufficiently high, it can suspend the high-speed rotating shaft 101. During high-speed rotation of the shaft, the high-pressure gas film 103 compresses the bearing 102, causing elastic deformation in both the top foil and the supporting corrugated foil, increasing the gas film gap and ensuring stable operation of the bearing 102.

[0003] Patent number CN 112648283 A discloses a hydrodynamic radial gas bearing, see Figures 2-3 The system includes a bearing housing 1, a top foil 2 is provided on the inner circumference of the bearing housing, and a plurality of wave foil groups 3 are provided between the bearing housing 1 and the top foil 2. Each wave foil group 3 includes two high arch foils 31 and one low arch foil 32. The distance from the foil arch of the high arch foil 31 to the top foil 2 is less than the distance from the foil arch of the low arch foil 32 to the top foil 2.

[0004] The main defects of the original technical structure are as follows: 1. Low radial bearing stiffness and poor load-bearing capacity. This radial bearing consists of a single-layer arched foil and a single-layer top foil. The arched foil has a three-section structure, with high arched foils on both sides and a low arched foil in the middle. Under small loads, the high arched foils at both ends provide load-bearing capacity first, while under large loads, all three arched foils provide load-bearing capacity together. This design effectively adjusts the bearing stiffness. However, the segmentation reduces the contact area with the top foil under low loads, to only 2 / 3 of the contact area. This design flaw leads to a decrease in the overall load-bearing capacity of the radial bearing. 2. Low bearing stiffness, low damping, and easy wear. This hydrodynamic radial bearing consists of a single-layer arched foil and a single-layer top foil structure. The single-layer top foil has low damping under large loads and is prone to wear. Top foil wear also includes wear during bearing start-up and shutdown, resulting in a reduction in the overall load-bearing range of the bearing and a decrease in its overall load-bearing capacity.

[0005] In summary, the original technical solution of hydrodynamic air-bearing radial bearing has problems such as low bearing stiffness, low damping, easy wear, and poor load-bearing performance.

[0006] Because existing hydrodynamic air-bearing radial bearings suffer from problems such as low bearing stiffness leading to poor load-bearing performance and low damping leading to easy wear, this invention studies and designs a radial load-bearing gas bearing and a motor. Summary of the Invention

[0007] Therefore, the present application aims to solve the technical problem of overcoming the poor load capacity caused by small bearing stiffness of the dynamic pressure gas floating radial bearing in the prior art, thereby providing a radial load gas bearing and motor.

[0008] To solve the above problems, the present application provides a radial load gas bearing, which comprises:

[0009] a bearing seat, a first layer of top foil, a second layer of top foil and a wave foil layer, the first layer of top foil, the second layer of top foil, the wave foil layer and the bearing seat are sequentially arranged along the direction from inside to outside in the radial direction;

[0010] The wave foil layer comprises a first wave foil located at an axial first position, the first wave foil comprises first wave foil supporting ends and first wave foil flat sections alternately arranged along the circumferential direction, the second layer of top foil comprises a first top foil also located at the axial first position, the first top foil is a flat foil structure; the first top foil is located between the first wave foil supporting end and the first layer of top foil.

[0011] In some embodiments, the first wave foil flat section is in contact with the bearing seat, and the first wave foil supporting end protrudes towards the first top foil relative to the first wave foil flat section; when the force borne by the first layer of top foil on the inner side in the radial direction is 0 or less than a first preset force, the first wave foil supporting end and the first top foil are spaced apart or in contact.

[0012] In some embodiments, the wave foil layer further comprises a second wave foil arranged at an axial second position, the second wave foil comprises second wave foil supporting ends and second wave foil flat sections alternately arranged along the circumferential direction, the second wave foil flat section is in contact with the bearing seat, and the second wave foil supporting end protrudes towards the first layer of top foil relative to the second wave foil flat section; the second layer of top foil is not provided with a top foil at the axial second position; when the force borne by the first layer of top foil on the inner side in the radial direction is 0 or less than the first preset force, the minimum distance between the second wave foil supporting end and the first layer of top foil is greater than the minimum distance between the first wave foil supporting end and the first top foil.

[0013] In some embodiments, in the axial direction of the bearing seat, the second wave foil supporting end is opposite to the first wave foil flat section, and the second wave foil flat section is opposite to the first wave foil supporting end; in the radial direction of the bearing seat, the second wave foil supporting end is opposite to the first layer of top foil.

[0014] In some embodiments, when the force borne by the first layer of top foil on the inner side in the radial direction is greater than the first preset force and less than a second preset force, the first wave foil supporting end is in contact with the first top foil and deformed, and the second wave foil supporting end is still spaced apart from the first layer of top foil, wherein the second preset force is greater than the first preset force.

[0015] In some embodiments, when the force borne by the radially inner side of the first layer top foil is greater than the second preset force, the first wave foil supporting end is deformed in contact with the first layer top foil, and the second wave foil supporting end is deformed in contact with the first layer top foil.

[0016] In some embodiments, the wave foil layer further comprises a third wave foil located at an axially third position, the third wave foil comprising third wave foil supporting ends and third wave foil flat sections alternately arranged along a circumferential direction, the axially first position, the axially second position and the axially third position being arranged in sequence along an axial direction; the second layer top foil comprises a second top foil also located at the axially third position, the second top foil being a flat foil structure; the second top foil is located between the third wave foil supporting end and the first layer top foil.

[0017] In some embodiments, the third wave foil flat section is in contact with the bearing seat, and the third wave foil supporting end protrudes towards the second top foil relative to the third wave foil flat section; when the force borne by the radially inner side of the first layer top foil is 0 or less than the first preset force, the third wave foil supporting end is spaced apart from or in contact with the second top foil, and the minimum distance between the second wave foil supporting end and the first layer top foil is greater than the minimum distance between the third wave foil supporting end and the second top foil.

[0018] In some embodiments, in the axial direction of the bearing seat, the third wave foil supporting end is opposite to the second wave foil flat section, and the third wave foil flat section is opposite to the second wave foil supporting end.

[0019] In some embodiments, when the second preset force and the third preset force are further included:

[0020] When the force borne by the radially inner side of the first layer top foil is greater than the first preset force and less than the second preset force, the third wave foil supporting end is deformed in contact with the second top foil, and the second wave foil supporting end is still spaced apart from the first layer top foil.

[0021] When the force borne by the radially inner side of the first layer top foil is greater than the second preset force, the third wave foil supporting end is deformed in contact with the second top foil, and the second wave foil supporting end is deformed in contact with the first layer top foil.

[0022] In some embodiments, when the force borne by the radially inner side of the first layer top foil is 0 or less than the first preset force, the minimum distance between the third wave foil supporting end and the second top foil is equal to the minimum distance between the first wave foil supporting end and the first top foil.

[0023] In some embodiments, the wave foil layer further comprises a wave foil fixed end that fixes the circumferential same side of the first wave foil, the second wave foil and the third wave foil as a whole, the second layer top foil further comprises a top foil fixed end that fixes the circumferential one end of the first top foil and the second top foil, the bearing seat is provided with a bearing clamping groove, the wave foil fixed end, the top foil fixed end and the first layer top foil are integrally fixed into the bearing clamping groove and are fixed by locking pins.

[0024] The application further provides an electric machine comprising the aforementioned radial load gas bearing.

[0025] The radial load gas bearing and the electric machine provided by the application have the following beneficial effects:

[0026] 1. The application can form a double-layer top foil + one-layer wave foil support structure for the rotating shaft at the axial first position of the bearing seat by arranging the second layer top foil and the wave foil layer between the bearing seat and the first top foil, and arranging the first wave foil at the axial first position, wherein the first wave foil comprises a first wave foil support end, and the second top foil comprises a first top foil (flat foil structure) at the axial first position, the first top foil is located between the first wave foil support end and the first layer top foil, thereby effectively increasing the stiffness of the bearing, preventing large deformation under large load, especially at the axial first position, and causing the bearing to fail, improving the stiffness of the bearing and the load carrying performance of the bearing; and the second wave foil is arranged at the axial second position, and the minimum distance between the second wave foil support end and the first layer top foil is greater than the minimum distance between the first wave foil support end and the first top foil when the second wave foil support end is not stressed or is stressed less than the first preset force, thereby making the stiffness of the arch foil + top foil at both ends small and the deformation large, the support stiffness of the second wave foil support end in the middle large and the deformation small, effectively supporting the first layer top foil by the second wave foil support end, effectively preventing the small gas film gap at both ends from causing severe wear, adjusting the axial stiffness of the foil, coordinating the deformation of the bearing, improving the impact resistance of the bearing and avoiding bearing wear.

[0027] 2. The height of the second wave foil support end at the middle section of the axial direction is less than the height of the first and third wave foil support ends at both ends, thereby forming a large gas film thickness at the middle section, forming a structure with small gas film thickness at both ends of the axial direction and large gas film thickness in the middle, effectively supporting the top foil by the middle gas film, effectively preventing gas leakage from both ends by the small gas film thickness at both ends, improving the gas end leakage phenomenon and improving the load carrying performance of the bearing.

[0028] 3. The height of the second wave foil supporting end of the axial middle section is less than the height of the first and second wave foil supporting ends of the two ends, which can enable the top foil to be supported by the gas film first, then by the deformation of the first and third wave foil supporting ends + the gas film, and then by the deformation of the first and third wave foil supporting ends + the deformation of the second wave foil supporting end of the axial middle section + the gas film, according to the different loads, so as to adaptively support the corresponding wave foil, have sufficient elastic deformation amount, reduce wear, prevent excessive deformation, improve the bearing performance, and enhance the versatility of the bearing. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 is a structural diagram of background technology 1;

[0030] The reference signs thereof are: 101, shaft; 102, bearing; 103, high-pressure gas film.

[0031] Figure 2 is a structure of background technology 2 Figure 1 ;

[0032] Figure 3 is a partial enlarged view of Figure 2 ;

[0033] Figures 2-3 The reference signs of are: 1, bearing seat; 2, top foil; 3, wave foil group; 31, high-arch foil; 32, low-arch foil.

[0034] Figure 4 is an axial structural diagram of the radial load gas bearing of the application;

[0035] Figure 5 is an unfolded plane structural diagram of the wave foil layer of the radial load gas bearing of the application;

[0036] Figure 6 is an unfolded plane structural diagram of the second layer top foil of the radial load gas bearing of the application;

[0037] Figure 7 is an unfolded plane structural diagram of the first layer top foil of the radial load gas bearing of the application;

[0038] Figure 8 is a structural enlarged view of Figure 4 about I;

[0039] Figure 9 is a three-dimensional structural diagram of the radial load gas bearing of the application.

[0040] Figures 4-9 The reference signs of are:

[0041] 1 bearing seat; 2 locking pin; 3 wave foil layer; 301 first wave foil; 31 first wave foil supporting end; 32 first wave foil flat section; 302 second wave foil; 33 second wave foil supporting end; 34 second wave foil flat section; 303 third wave foil; 35 third wave foil supporting end; 36 third wave foil flat section; 304 wave foil fixed end; 4 second layer top foil; 401 first top foil; 402 top foil fixed end; 403 second top foil; 5 first layer top foil; 6 rotating shaft. DETAILED DESCRIPTION

[0042] As shown in Figures 4-9 The present application provides a radial load bearing gas bearing, which comprises:

[0043] The bearing seat 1, the first layer top foil 5, the second layer top foil 4 and the wave foil layer 3 are sequentially arranged along the radial direction from inside to outside.

[0044] The wave foil layer 3 comprises a first wave foil 301 located at an axial first position, the first wave foil 301 comprises first wave foil supporting ends 31 and first wave foil flat sections 32 alternately arranged along the circumferential direction, the second layer top foil 4 comprises a first top foil 401 also located at the axial first position, the first top foil 401 is a flat foil structure; the first top foil 401 is located between the first wave foil supporting end 31 and the first layer top foil 5.

[0045] The present application can form a double-layer top foil + one layer of wave foil support structure for the rotating shaft at the axial first position of the bearing seat by arranging the second layer top foil and the wave foil layer between the bearing seat and the first top foil, and the wave foil layer has a first wave foil at the axial first position, the first wave foil comprises a first wave foil supporting end, the second top foil has a first top foil (flat foil structure) at the axial first position, and the first top foil is located between the first wave foil supporting end and the first layer top foil. By adopting the double-layer top foil + one layer of wave foil, the stiffness of the bearing can be effectively increased, the deformation under large load conditions, especially at the axial first position, can be prevented, the bearing failure can be avoided, the stiffness of the bearing can be improved, and the load bearing performance of the bearing can be improved.

[0046] The present application provides a large load bearing radial gas bearing and motor, the radial gas bearing structure can increase the bearing damping, the bearing is not easy to wear, can ensure that the bearing dynamic adaptability under the premise of increasing the bearing load performance range, small load and large load can provide load, increase the bearing damping, reduce the radial bearing end leakage, improve the bearing end leakage phenomenon, improve the gas film stability, improve the bearing stiffness of the radial bearing, improve the anti-vibration, wear resistance, stability and load bearing performance of the bearing.

[0047] The present application provides a large load bearing radial gas bearing and motor, the radial gas bearing structure can increase the bearing damping, the bearing is not easy to wear, can ensure that the bearing dynamic adaptability under the premise of increasing the bearing load performance range, small load and large load can provide load, increase the bearing damping, reduce the radial bearing end leakage, improve the bearing end leakage phenomenon, improve the gas film stability, improve the bearing stiffness of the radial bearing, improve the anti-vibration, wear resistance, stability and load bearing performance of the bearing.

[0048] 1. The double-layer top foil is used to increase the stiffness and damping of the bearing, the gas film thickness is small on both sides and large in the middle, which improves the gas end leakage phenomenon and improves the bearing carrying capacity;

[0049] 2. The three-section structure arch foil is used, the arch foils are staggered and the arch heights are inconsistent, the support stiffness of the two side arch foils is small and the deformation is large, the support stiffness of the middle region arch foil is large and the deformation is small, the axial stiffness of the foil is adjusted, the axial deformation of the bearing is coordinated, and the bearing carrying capacity is improved;

[0050] 3. The radial bearing has a three-section structure in the axial direction, the two ends are a layer of arch foil + two layers of top foil structure, and the middle section is a layer of arch foil + a layer of top foil structure. The height of the middle section arch foil is greater than the height of the two end arch foils and less than the sum of the height of the two end arch foils plus the thickness of one layer of top foil (that is, the minimum distance between the middle arch foil and the first layer of top foil is greater than the minimum distance between the two end arch foils and the second layer of top foil).

[0051] As shown in Figure 4 , during the initial stage of operation of the high-speed motor, the eccentric motion of the rotating shaft 6 before high-speed rotation causes the gap between the rotating shaft 6 and the foil radial gas bearing to form a wedge-shaped area, and the viscous gas entering the wedge-shaped area forms a high-pressure lubricating gas film to provide bearing-rotating shaft system carrying capacity.

[0052] As shown in Figure 4 , the entire circumference of the foil radial gas bearing is composed of three one-third circular arcs, each one-third circular arc structure is composed of a locking pin 2, a wave foil layer 3, a second layer of top foil 4, and a first layer of top foil 5. The wave foil layer 3 is formed by pressing and pressure forming Figure 5 of the metal foil through the corresponding mold of the structure, and then winding and heat treatment forming Figure 4 through a specially designed tool to ensure that the flat sections between each arch fit the inner surface of the bearing seat 1, thereby ensuring the consistency and feasibility of bearing preparation.

[0053] In some embodiments, the first wave foil flat section 32 is connected to the bearing seat 1, and the first wave foil supporting end 31 protrudes towards the first top foil 401 relative to the first wave foil flat section 32, and when the force borne by the radial inner side of the first layer of top foil 5 is 0 or less than the first preset force, the first wave foil supporting end 31 is spaced apart from or in contact with the first top foil 401.

[0054] This is the preferred connection relationship and position relationship of the first wave foil and the first top foil of the application, that is, the first wave foil flat section is connected with the bearing seat, the first wave foil supporting end is arranged on the first wave foil flat section, the first top foil is formed between the first wave foil supporting end and the first layer top foil, when the top foil is not under force or under small force, the first preset force is greater than 0, the first wave foil supporting end is not deformed or is slightly deformed, a gap is formed between the first wave foil supporting end and the first top foil, gas can be contained in the gap to form a gas film, the first top foil and the first layer top foil are supported, a double support structure is formed, the support capacity of the top foil and even the shaft is improved, the first top foil is deformed downward to contact the first wave foil supporting end according to the increase of the force, the first wave foil supporting end is deformed, different elastic support forces can be applied according to the size of the load, and the application can be suitable for working conditions with larger loads and higher rotating speeds.

[0055] In some embodiments, the wave foil layer 3 further comprises a second wave foil 302 arranged at an axial second position, the second wave foil 302 comprises second wave foil supporting ends 33 and second wave foil flat sections 34 arranged alternately in the circumferential direction, the second wave foil flat sections 34 are connected with the bearing seat 1, the second wave foil supporting ends 33 protrude towards the first layer top foil 5 relative to the second wave foil flat sections 34, no top foil is arranged at the axial second position of the second layer top foil 4, when the force borne by the radial inner side of the first layer top foil 5 is 0 or less than a first preset force, the minimum distance between the second wave foil supporting ends 33 and the first layer top foil 5 is greater than the minimum distance between the first wave foil supporting ends 31 and the first top foil 401.

[0056] The application further comprises the second wave foil arranged at the axial second position, and the minimum distance between the second wave foil supporting ends and the first layer top foil is greater than the minimum distance between the first wave foil supporting ends and the first top foil when the second wave foil supporting ends are not under force or under force less than the first preset force, the rigidity of the arch foil + top foil at both ends is small and the deformation is large, the supporting rigidity of the second wave foil supporting ends in the middle is large and the deformation is small, the first layer top foil is effectively supported by the second wave foil supporting ends, the situation that the gap between the gas films at both ends is small and the wear is serious is effectively prevented, the axial rigidity of the foil piece is adjusted, the bearing deformation is coordinated, the impact resistance of the bearing is improved, and the wear of the bearing is avoided.

[0057] The height of the second wave foil supporting ends in the middle section is less than the height of the first and third wave foil supporting ends at both ends, a gas film with a large thickness can be formed in the middle section, a structure with small gas film thickness at both ends and large gas film thickness in the middle is formed, the top foil is effectively supported by the middle gas film, the gas leakage from both ends is effectively prevented by the small gas film thickness at both ends, the gas leakage phenomenon is improved, and the bearing carrying capacity is improved.

[0058] The structure of the second layer top foil 4 is shown in Figure 6 The structure of the second layer top foil 4 is shown in The structure of the second layer top foil 4 is shown in

[0059] The structure of the second layer top foil 4 is shown in The structure of the second layer top foil 4 is shown in

[0060] The structure of the second layer top foil 4 is shown in The structure of the second layer top foil 4 is shown in

[0061] The structure of the second layer top foil 4 is shown in

[0062] In some embodiments, when the force on the radially inner side of the first top foil 5 is greater than the second preset force, the first wave foil support end 31 contacts and deforms with the first top foil 401, and the second wave foil support end 33 contacts and deforms with the first top foil 5. In this invention, when the force on the first top foil further increases to greater than the second preset force, the first wave foil support end deforms, and the first top foil deforms to form contact with the second wave foil support end. The second wave foil support end also deforms. At this time, through the respective deformations of the first and second wave foil support ends and the air film supporting the top foil, a further increased supporting force can be provided by the deformation of the second wave foil support end.

[0063] In some embodiments, the corrugated foil layer 3 further includes a third corrugated foil 303 located at a third position in the axial direction. The third corrugated foil 303 includes a third corrugated foil support end 35 and a third corrugated foil flat section 36 alternately arranged in the circumferential direction. The first axial position, the second axial position, and the third axial position are arranged sequentially in the axial direction. The second top foil 4 includes a second top foil 403 also located at the third axial position. The second top foil 403 is a flat foil structure. The second top foil 403 is located between the third corrugated foil support end 35 and the first top foil 5.

[0064] The present invention also provides a third corrugated foil at the third axial end, which provides almost the same support as the first axial end. The third axial end also forms a support structure of double top foil + single corrugated foil, which can effectively increase the stiffness of the bearing and prevent large deformation, especially under heavy load at the third axial position, from causing bearing failure. This further improves the stiffness and load-bearing capacity of the bearing.

[0065] Corrugated foil layer 3 Figure 5 and Figure 8 As shown in the enlarged view of the foil radial gas bearing, the corrugated foil layer 3 is divided into three sections (first corrugated foil 301, second corrugated foil 302, and third corrugated foil 303). The arch height, pitch, and horizontal section parameters of each arch in the first corrugated foil 301 and third corrugated foil 303 are identical, meaning the arched foil structures at both ends of the foil radial gas bearing have the same structural stiffness. The designed arch height of the second corrugated foil 302 in the middle section of the foil radial gas bearing is greater than that of the first and third corrugated foils, and its structural stiffness is greater than that at both ends. The first and third corrugated foils 301 and 303 at the ends of the foil radial gas bearing have low support stiffness and large deformation, while the second corrugated foil 302 in the middle section has high support stiffness and small deformation. Adjusting the axial stiffness of the foils coordinates the axial deformation of the bearing and improves its load-bearing performance.

[0066] In some embodiments, the third wave foil flat section 36 is connected to the bearing seat 1, and the third wave foil supporting end 35 protrudes towards the second top foil 403 relative to the third wave foil flat section 36; when the force borne by the radially inner side of the first layer top foil 5 is 0 or less than a first preset force, the third wave foil supporting end 35 is spaced apart from or in contact with the second top foil 403, and the minimum distance between the second wave foil supporting end 33 and the first layer top foil 5 is greater than the minimum distance between the third wave foil supporting end 35 and the second top foil 403.

[0067] The height of the second wave foil supporting end in the middle axial section is less than the height of the first and third wave foil supporting ends at both ends, which can form a larger gas film thickness in the middle section, form a structure with small gas film thickness at both ends and large gas film thickness in the middle, effectively support the top foil through the middle gas film, and effectively prevent gas leakage from both ends through the small gas film thickness at both ends, improve the gas end leakage phenomenon, and improve the bearing carrying capacity;

[0068] The height of the second wave foil supporting end in the middle axial section is less than the height of the first and third wave foil supporting ends at both ends, which can make the top foil first supported by the gas film, then supported by the deformation of the first and third wave foil supporting ends + gas film, and finally supported by the deformation of the first and third wave foil supporting ends + deformation of the second wave foil supporting end in the middle axial section + gas film, according to the different loads, the corresponding wave foil is adaptively supported, has sufficient elastic deformation amount, reduces wear, prevents excessive deformation, improves the carrying capacity, and enhances the versatility of the bearing.

[0069] In some embodiments, in the axial direction of the bearing seat 1, the third wave foil supporting end 35 is opposite to the second wave foil flat section 34, and the third wave foil flat section 36 is opposite to the second wave foil supporting end 33. This is the preferred positional relationship between the third wave foil and the second wave foil of the present application, which can effectively support the top foil at different axial positions and different circumferential positions through the circumferential interlacing of the third wave foil supporting end and the second wave foil supporting end, and improve the support effect on the top foil and even the shaft.

[0070] When the motor runs at high speed, a high-pressure lubricating gas film is formed in the gap between the foil radial gas bearing and the rotating shaft 6, the gas pressure in the central region of the radial bearing is higher than that at both ends of the radial bearing, and the integral radial wave foil arch structure causes the top foil to produce a through deformation against the direction of the arch, resulting in leakage of the high pressure in the center to both ends, which is an end leakage phenomenon. The wave crests of the first wave foil 301 and the third wave foil 303 at both axial ends of the wave foil layer 3 and the second wave foil 302 in the middle section are staggered, forming a variable stiffness arch foil, which can effectively improve the end leakage phenomenon of the radial bearing and improve the carrying capacity of the foil radial gas bearing.

[0071] In some embodiments, when the second preset force and the third preset force are also included:

[0072] When the force borne by the first layer top foil 5 on the radial inner side is greater than the first preset force and less than the second preset force, the third wave foil supporting end 35 is deformed in contact with the second top foil 403, and there is still a gap between the second wave foil supporting end 33 and the first layer top foil 5.

[0073] When the force borne by the first layer top foil 5 on the radial inner side is greater than the second preset force, the third wave foil supporting end 35 is deformed in contact with the second top foil 403, and the second wave foil supporting end 33 is deformed in contact with the first layer top foil 5.

[0074] When the force borne by the top foil gradually increases to be greater than the first preset force, the first and third wave foil supporting ends are deformed, and there is a deformation + gas film between them to support, and at this time the second wave foil supporting end is not deformed or has less deformation, and there is a gas film between the second wave foil supporting end and the first layer top foil, which supports the top foil through the gas film.

[0075] When the force borne by the top foil further increases to be greater than the second preset force, the first and third wave foil supporting ends are deformed, and the second wave foil supporting end is also deformed in contact, so that the top foil is supported by the deformation of the second wave foil supporting end and the respective deformations of the first and third wave foil supporting ends and the multiple gas films, and the support force can be further increased by the deformation of the second wave foil supporting end.

[0076] In some embodiments, when the force borne by the radially inner side of the first top foil 5 is 0 or less than the first preset force, the minimum distance between the third wave foil supporting end 35 and the second top foil 403 is equal to the minimum distance between the first wave foil supporting end 31 and the first top foil 401. This is the preferred relationship between the fifth wave foil supporting end and the second wave foil supporting end of the present application, i.e. the minimum distance between the two is preferably equal and equal to the minimum distance between the top foil, which can provide almost equal bearing force at the axial ends of the third wave foil, reduce end leakage, form a self-adaptive bearing, and provide the required bearing force according to the change of load such as speed, thereby improving the general performance.

[0077] In some embodiments, the wave foil layer 3 further comprises a wave foil fixing end 304 that fixes the circumferentially same side of the first wave foil 301, the second wave foil 302 and the third wave foil 303 into one body, the second layer top foil 4 also comprises a top foil fixing end 402 that fixes the circumferentially same end of the first top foil 401 and the second top foil 403, the bearing seat 1 is provided with a bearing clamping groove, and the wave foil fixing end 304, the top foil fixing end 402 and the first layer top foil 5 are fixed into the bearing clamping groove and fixed by the locking pin 2.

[0078] The present application can also fix the wave foil layer, the second layer top foil and the first layer top foil to the bearing seat through the setting of the wave foil fixing end and the top foil fixing end, and the bearing clamping groove of the present application is preferably 3, as shown in Figure 4 , i.e. the first layer wave foil, the second layer wave foil and the top foil are all 3, which are arranged uniformly in the circumferential direction. The load bearing performance of the rotating shaft is improved.

[0079] As shown in Figure 4 , the bearing seat 1 is used for installing and supporting the foil radial gas bearing. After the fixing end of the foil radial gas bearing is inserted into the clamping groove of the bearing seat 1, the locking pin 2 is used for fixing. The fixing mode is not limited to this. The axial fixing of the foil radial gas bearing avoids the axial movement of the foil radial gas bearing. The wave foil layer 3, the second layer top foil 4 and the first layer top foil 5 are fixed at one end and free at the other end, which ensures that the foil bearing has the space for deformation and sliding.

[0080] The first layer top foil 5 is surrounded by a metal foil in a whole circumference, and the surface is sprayed with a high-temperature-resistant lubricating coating, which plays a role of reducing friction and wear lubrication during the start-stop stage of high-speed operation of the motor.

[0081] The present application also provides a motor comprising the aforementioned radial load gas bearing.

[0082] The above merely describes preferred embodiments of the present application and is not used to limit the present application, and any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application. The above merely describes preferred embodiments of the present application and is not used to limit the present application, and any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A radial load bearing gas bearing characterized by: The radial load bearing gas bearing comprises a bearing seat (1), a first layer of top foil (5), a second layer of top foil (4) and a wave foil layer (3), the first layer of top foil (5), the second layer of top foil (4), the wave foil layer (3) and the bearing seat (1) are sequentially arranged along a radial direction from inside to outside; The wave foil layer (3) comprises a first wave foil (301) located at an axial first position, the first wave foil (301) comprises first wave foil supporting ends (31) and first wave foil flat sections (32) alternately arranged along a circumferential direction, the second layer of top foil (4) comprises a first top foil (401) also located at the axial first position, the first top foil (401) is a flat foil structure; the first top foil (401) is located between the first wave foil supporting end (31) and the first layer of top foil (5); The wave foil layer (3) further comprises a second wave foil (302) arranged at an axial second position, the second wave foil (302) comprises second wave foil supporting ends (33) and second wave foil flat sections (34) alternately arranged along the circumferential direction, the second wave foil flat section (34) is connected with the bearing seat (1), the second wave foil supporting end (33) protrudes towards the first layer of top foil (5) relative to the second wave foil flat section (34), the second layer of top foil (4) is not provided with a top foil at the axial second position, when the force borne by the radial inner side of the first layer of top foil (5) is 0 or less than a first preset force, the minimum distance between the second wave foil supporting end (33) and the first layer of top foil (5) is greater than the minimum distance between the first wave foil supporting end (31) and the first top foil (401); The wave foil layer (3) further comprises a third wave foil (303) located at an axial third position, the third wave foil (303) comprises third wave foil supporting ends (35) and third wave foil flat sections (36) alternately arranged along the circumferential direction, the axial first position, the axial second position and the axial third position are sequentially arranged along an axial direction; the second layer of top foil (4) comprises a second top foil (403) also located at the axial third position, the second top foil (403) is a flat foil structure; the second top foil (403) is located between the third wave foil supporting end (35) and the first layer of top foil (5).

2. The radial load bearing gas bearing according to claim 1, wherein: The first wave foil flat section (32) is connected with the bearing seat (1), the first wave foil supporting end (31) protrudes towards the first top foil (401) relative to the first wave foil flat section (32), when the force borne by the radial inner side of the first layer of top foil (5) is 0 or less than a first preset force, the first wave foil supporting end (31) and the first top foil (401) are spaced apart or in contact.

3. The radial load bearing gas bearing according to claim 1, wherein: ​ In the axial direction of the bearing seat (1), the second wave foil supporting end (33) is opposite to the first wave foil flat section (32), and the second wave foil flat section (34) is opposite to the first wave foil supporting end (31); in the radial direction of the bearing seat (1), the second wave foil supporting end (33) is opposite to the first layer top foil (5).

4. The radial load gas bearing of claim 1, wherein: when the force borne by the first layer top foil (5) on the radial inner side is greater than a first preset force and less than a second preset force, the first wave foil supporting end (31) is deformed by being in contact with the first top foil (401), and there is still a gap between the second wave foil supporting end (33) and the first layer top foil (5), wherein the second preset force is greater than the first preset force.

5. The radial load gas bearing of claim 4, wherein: when the force borne by the first layer top foil (5) on the radial inner side is greater than the second preset force, the first wave foil supporting end (31) is deformed by being in contact with the first top foil (401), and the second wave foil supporting end (33) is deformed by being in contact with the first layer top foil (5).

6. The radial load gas bearing of claim 1, wherein: the third wave foil flat section (36) is connected with the bearing seat (1), and the third wave foil supporting end (35) protrudes towards the second top foil (403) relative to the third wave foil flat section (36), when the force borne by the first layer top foil (5) on the radial inner side is 0 or less than the first preset force, the third wave foil supporting end (35) is spaced apart from or in contact with the second top foil (403), and the minimum distance between the second wave foil supporting end (33) and the first layer top foil (5) is greater than the minimum distance between the third wave foil supporting end (35) and the second top foil (403).

7. The radial load gas bearing of claim 6, wherein: in the axial direction of the bearing seat (1), the third wave foil supporting end (35) is opposite to the second wave foil flat section (34), and the third wave foil flat section (36) is opposite to the second wave foil supporting end (33).

8. The radial load gas bearing of claim 6, wherein: when a second preset force and a third preset force are further included: when the force borne by the first layer top foil (5) on the radial inner side is greater than the first preset force and less than the second preset force, the third wave foil supporting end (35) is deformed by being in contact with the second top foil (403), and there is still a gap between the second wave foil supporting end (33) and the first layer top foil (5); when the force borne by the first layer top foil (5) on the radial inner side is greater than the second preset force, the third wave foil supporting end (35) is deformed by being in contact with the second top foil (403), and the second wave foil supporting end (33) is deformed by being in contact with the first layer top foil (5).

9. The radial load gas bearing of claim 1, wherein: When the force borne by the radially inner side of the first top foil (5) is 0 or less than a first preset force, the minimum distance between the third wave foil supporting end (35) and the second top foil (403) is equal to the minimum distance between the first wave foil supporting end (31) and the first top foil (401).

10. The radial load gas bearing of claim 1, wherein: The wave foil layer (3) further comprises a wave foil fixed end (304) that fixes the circumferential same side of the first wave foil (301), the second wave foil (302) and the third wave foil (303) into one body, the second layer top foil (4) also comprises a top foil fixed end (402) that fixes the circumferential one end of the first top foil (401) and the second top foil (403), the bearing seat (1) is provided with a bearing clamping groove, the wave foil fixed end (304), the top foil fixed end (402) and the first layer top foil (5) are fixed into the bearing clamping groove integrally and are fixed by a locking pin (2).

11. An electric machine characterized by: The radial load gas bearing of any one of claims 1-10.

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