A gas radial bearing and electric machine

Abstract

The application provides a gas radial bearing and motor, the gas radial bearing comprising: a bearing seat, a top foil, a first layer of wave foil and a second layer of wave foil; the first layer of wave foil comprises a first wave foil located at an axial first position, the second layer of wave foil comprises a second wave foil located at an axial second position and a third wave foil located at an axial third position; the first wave foil comprises first wave foil supporting ends and first wave foil flat sections alternately arranged along a circumferential direction, the second wave foil also comprises second wave foil supporting ends and second wave foil flat sections alternately arranged along the circumferential direction, and the third wave foil also comprises third wave foil supporting ends and third wave foil flat sections alternately arranged along the circumferential direction; and the arch height of the first wave foil supporting end is less than the arch height of the second wave foil supporting end, and the arch height of the first wave foil supporting end is less than the arch height of the third wave foil supporting end. According to the application, the gas film thickness at the middle position is effectively increased, the bearing carrying stiffness is improved, the bearing end leakage is reduced, and the carrying capacity is improved.

Description

A gas radial bearing and an electric motor Technical Field

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

[0002] During operation, foil gas bearings experience high-speed motion between the rotor surface and the bearing's inner surface. Gas, due to viscosity, is drawn into the wedge-shaped gap, forming a hydrodynamic gas film between the bearing and the shaft. Under this hydrodynamic effect, a relative equilibrium is achieved, thus supporting the shaft structure. Foil gas bearings differ from traditional oil film and ball bearings due to their high load-carrying capacity, good damping characteristics, and low friction loss. Even so, the lack of high-load-carrying and high-damping foil gas hydrodynamic bearings remains a technical challenge for gas bearing development. Therefore, achieving high-load-carrying and high-damping bearing performance through optimizing the elastic structural profile and innovating the support structure is essential. Changing the foil shape and the gas film thickness are effective ways to improve bearing load-carrying performance.

[0003] Because existing hydrodynamic air-bearing radial bearings suffer from problems such as small air film thickness and low air film pressure in the bearing area, resulting in bearing end leakage, poor gas bearing capacity, and poor stability, this invention researches and designs a gas radial bearing and motor. Summary of the Invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the defect of the prior art in which the gas film thickness in the bearing area is small, resulting in leakage at the bearing end, thereby providing a gas radial bearing and a motor.

[0005] To address the above problems, the present invention provides a gas radial bearing, comprising:

[0006] The bearing housing, top foil, first layer corrugated foil, and second layer corrugated foil are provided, wherein the first layer corrugated foil and the second layer corrugated foil are both disposed between the bearing housing and the top foil, and the first layer corrugated foil is disposed between the second layer corrugated foil and the top foil;

[0007] The first layer of corrugated foil includes a first corrugated foil located at a first position in the axial direction, and the second layer of corrugated foil includes a second corrugated foil located at a second position in the axial direction and a third corrugated foil located at a third position in the axial direction, wherein the first position in the axial direction is located between the second position in the axial direction and the third position in the axial direction;

[0008] The first wave foil includes a first wave foil support end and a first wave foil flat section alternately arranged in the circumferential direction; the second wave foil also includes a second wave foil support end and a second wave foil flat section alternately arranged in the circumferential direction; and the third wave foil also includes a third wave foil support end and a third wave foil flat section alternately arranged in the circumferential direction.

[0009] Furthermore, the arch height of the first wave foil support end is less than the arch height of the second wave foil support end, and the arch height of the first wave foil support end is less than the arch height of the third wave foil support end.

[0010] In some embodiments, the first corrugated foil is disposed on the outer periphery of the top foil, and the first corrugated foil support end protrudes toward the second corrugated foil, the second corrugated foil is disposed on the outer periphery of the first corrugated foil, and the second corrugated foil support end protrudes toward the first corrugated foil, and the third corrugated foil support end protrudes toward the first corrugated foil.

[0011] In some embodiments, the first layer of corrugated foil further includes a first arched foil planar region, which is a cylindrical structure and is sleeved on the outer periphery of the top foil. The first corrugated foil flat section is disposed on the outer periphery of the first arched foil planar region or between two adjacent first arched foil planar regions, and the first corrugated foil support end is connected to the first corrugated foil flat section and protrudes radially outward.

[0012] The second layer of corrugated foil also includes a second arched foil planar region, which is a cylindrical structure and is sleeved on the outer periphery of the first layer of corrugated foil. The second corrugated foil flat section is disposed on the inner periphery of the second arched foil planar region or between two adjacent second arched foil planar regions. The second corrugated foil support end is connected to the second corrugated foil flat section and protrudes radially inward. The third corrugated foil flat section is disposed on the inner periphery of the second arched foil planar region or between two adjacent second arched foil planar regions. The third corrugated foil support end is connected to the third corrugated foil flat section and protrudes radially inward.

[0013] In some embodiments, the area of ​​the first arch foil plane region opposite to the second axial position is not provided with corrugated foil, the area of ​​the first arch foil plane region opposite to the third axial position is not provided with corrugated foil, the second corrugated foil support end is opposite to the first arch foil plane region without corrugated foil, and the third corrugated foil support end is opposite to the first arch foil plane region without corrugated foil.

[0014] The area of ​​the second arched foil plane opposite to the first axial position is not provided with corrugated foil, and the first corrugated foil support end is opposite to the second arched foil plane area where no corrugated foil is provided.

[0015] In some embodiments, when the force on the radially inner side of the top foil is 0 or less than a first preset force, there is a first gap between the first wave foil support end and the second arch foil plane area, a second gap between the second wave foil support end and the first arch foil plane area, and a third gap between the third wave foil support end and the first arch foil plane area, wherein the first gap is greater than the second gap and the first gap is greater than the third gap.

[0016] In some embodiments, when the force on the radially inner side of the top foil is greater than a first preset force and less than a second preset force, the second wave foil support end contacts the first arch foil plane area and deforms, the third wave foil support end contacts the first arch foil plane area and deforms, and there is still a gap between the first wave foil support end and the second arch foil plane area, wherein the second preset force is greater than the first preset force.

[0017] In some embodiments, when the force on the radially inner side of the top foil is greater than the second preset force, the second wave foil support end contacts the first arch foil plane area and deforms, the third wave foil support end contacts the first arch foil plane area and deforms, and the first wave foil support end contacts the second arch foil plane area and deforms.

[0018] In some embodiments, the first corrugated foil occupies 1 / 3 of the total axial length of the first layer of corrugated foil, the area of ​​the first arched foil plane opposite to the second axial position where no corrugated foil is provided occupies 1 / 3 of the total axial length of the first layer of corrugated foil, and the area of ​​the first arched foil plane opposite to the third axial position where no corrugated foil is provided occupies 1 / 3 of the total axial length of the first layer of corrugated foil.

[0019] The second wave foil occupies 1 / 3 of the total axial length of the second layer of wave foil in the axial direction, the third wave foil occupies 1 / 3 of the total axial length of the second layer of wave foil in the axial direction, and the area without wave foil opposite to the first arch foil plane region and the second axial position occupies 1 / 3 of the total axial length of the second layer of wave foil.

[0020] In some embodiments, the arch height of the second corrugated foil support end is equal to that of the third corrugated foil support end, and the structure of the second corrugated foil flat section is the same as that of the third corrugated foil flat section.

[0021] In some embodiments, a bottom foil is also included, which is a cylindrical structure and disposed between the second corrugated foil and the bearing seat, and the bottom foil is a flat foil structure.

[0022] The present invention also provides an electric motor comprising the aforementioned gas radial bearing.

[0023] The gas radial bearing and motor provided by this invention have the following beneficial effects:

[0024] 1. This invention provides a first and second corrugated foil layer between the bearing housing and the top foil. The first corrugated foil support end of the first corrugated foil layer is located at a first axial position, forming a single-layer corrugated foil support structure for the top foil at the first axial position of the bearing housing. The second corrugated foil layer, located at a second axial position, also forms a single-layer corrugated foil support structure for the top foil at the second axial position. The third corrugated foil layer, located at a third axial position, also forms a single-layer corrugated foil support structure for the top foil at the third axial position. Furthermore, the arch height of the first corrugated foil support end is smaller than that of the second and third corrugated foil support ends, effectively increasing the gas film thickness in the middle position while the gas film thickness at both axial ends is lower. This effectively seals the gas film in the middle, thereby improving the bearing stiffness, reducing bearing end leakage, and enhancing the bearing capacity.

[0025] 2. The height of the first wave foil support end located in the middle section of the axial direction of the present invention is less than the height of the second and third wave foil support ends at both ends. This allows for the formation of a larger gas film thickness in the middle section, resulting in a structure with a smaller gas film thickness at both ends and a larger gas film thickness in the middle. The middle gas film effectively supports the top foil, and the smaller gas film thickness at both ends effectively prevents gas leakage from both ends, improving the gas leakage phenomenon and enhancing the bearing load-bearing performance.

[0026] 3. The height of the first corrugated foil support end in the axial middle section of the present invention is less than the height of the second and third corrugated foil support ends at both ends. This allows the top foil to be supported by an air film as the load force on the shaft gradually increases during high-speed rotation. Then, it is supported by the deformation of the second and third corrugated foil support ends combined with the air film, and finally by the deformation of the second and third corrugated foil support ends combined with the deformation of the third corrugated foil support end in the axial middle section combined with the air film. This allows the appropriate corrugated foil to be used for support adaptively according to different loads, providing sufficient elastic deformation, reducing wear, preventing excessive deformation, improving load-bearing performance, and enhancing the versatility of the bearing. Attached Figure Description

[0027] Figure 1 is an axial structural diagram of the gas radial bearing of the present invention;

[0028] Figure 2 is a three-dimensional structural diagram of the first layer of corrugated foil in the gas radial bearing of the present invention;

[0029] Figure 3 is a three-dimensional structural diagram of the second layer of corrugated foil in the gas radial bearing of the present invention;

[0030] Figure 4 is an enlarged view of the corrugated foil structure at the first and second axial positions in Figure 1 (partial enlarged view of part A).

[0031] The attached figures are labeled as follows:

[0032] 1. Bearing housing; 2. Bottom foil; 3. First layer of corrugated foil; 31. First raised edge; 32. First arched foil planar area; 33. First corrugated foil; 331. First corrugated foil support end; 332. First corrugated foil flat section; 4. Second layer of corrugated foil; 41. Second raised edge; 42. Second arched foil planar area; 43. Second corrugated foil; 431. Second corrugated foil support end; 432. Second corrugated foil flat section; 44. Third corrugated foil; 441. Third corrugated foil support end; 442. Third corrugated foil flat section; 5. Top foil; 6. Bearing housing groove. Detailed Implementation

[0033] As shown in Figures 1-4, the present invention provides a gas radial bearing, which includes:

[0034] The bearing housing 1, top foil 5, first layer corrugated foil 3, and second layer corrugated foil 4 are provided. The first layer corrugated foil 3 and the second layer corrugated foil 4 are both disposed between the bearing housing 1 and the top foil 5, and the first layer corrugated foil 3 is disposed between the second layer corrugated foil 4 and the top foil 5.

[0035] The first layer of corrugated foil 3 includes a first corrugated foil 33 located at a first position in the axial direction, and the second layer of corrugated foil 4 includes a second corrugated foil 43 located at a second position in the axial direction and a third corrugated foil 44 located at a third position in the axial direction, wherein the first position in the axial direction is located between the second position in the axial direction and the third position in the axial direction.

[0036] The first wave foil 33 includes a first wave foil support end 331 and a first wave foil flat section 332 alternately arranged in the circumferential direction; the second wave foil 43 also includes a second wave foil support end 431 and a second wave foil flat section 432 alternately arranged in the circumferential direction; and the third wave foil 44 also includes a third wave foil support end 441 and a third wave foil flat section 442 alternately arranged in the circumferential direction.

[0037] Furthermore, the arch height of the first corrugated foil support end 331 is less than the arch height of the second corrugated foil support end 431, and the arch height of the first corrugated foil support end 331 is less than the arch height of the third corrugated foil support end 441. Preferably, the arch heights of the second and third corrugated foil support ends are the same.

[0038] This invention provides a first and second corrugated foil layer between the bearing housing and the top foil. The first corrugated foil support end is located at a first axial position, forming a single-layer corrugated foil support structure for the top foil at the first axial position of the bearing housing. The second corrugated foil, located at a second axial position, also forms a single-layer corrugated foil support structure for the top foil at the second axial position. The third corrugated foil, located at a third axial position, also forms a single-layer corrugated foil support structure for the top foil at the third axial position. Furthermore, the arch height of the first corrugated foil support end is smaller than that of the second and third corrugated foil support ends, effectively increasing the gas film thickness in the middle position while the gas film thickness at both axial ends is lower. This effectively seals the gas film in the middle, thereby improving the bearing's load-bearing stiffness, reducing bearing end leakage, and enhancing load-bearing capacity.

[0039] This invention enables the bearing to adapt to changes in axial stiffness, coordinate deformation, and improve stability; it also increases the thickness of the high-pressure lubricating gas film in the middle region, reduces bearing end leakage, and enhances load-bearing capacity.

[0040] The height of the first wave foil support end located in the middle section of the axial direction of the present invention is less than the height of the second and third wave foil support ends at both ends. This allows for the formation of a thicker gas film in the middle section, resulting in a structure with a smaller gas film thickness at both ends and a larger gas film thickness in the middle. The middle gas film effectively supports the top foil, and the smaller gas film thickness at both ends effectively prevents gas leakage from both ends, improving the gas leakage phenomenon and enhancing the bearing load-bearing performance.

[0041] This invention provides a hydrodynamic radial bearing structure in which two layers of supporting corrugated foil are placed opposite each other. By using a structural form with different arch heights along the axial direction, the thickness of the gas film in the load-bearing area is increased, the gas film pressure is enhanced, and the gas load-bearing capacity and stability are improved. Furthermore, the radial bearing structure provided by this invention can homogenize the pressure in the axial direction of the radial bearing, improve bearing end leakage, increase the thickness of the gas film in the main load-bearing area, and improve the overall load-bearing performance of the gas hydrodynamic radial bearing.

[0042] Specifically: 1. The present invention adopts a concave-convex double-layer foil form with different stiffness along the axial direction, which can easily form a wedge-shaped area in the bearing area; 2. When the bearing is working, the top foil of the two layers of foil is concave downward to form a gas retention area, which increases the thickness of the gas film, improves the bearing bearing stiffness, reduces bearing end leakage, and improves the bearing capacity.

[0043] In some embodiments, the first corrugated foil 3 is disposed on the outer periphery of the top foil 5, and the first corrugated foil support end 331 protrudes toward the second corrugated foil 4. The second corrugated foil 4 is disposed on the outer periphery of the first corrugated foil 3, and the second corrugated foil support end 431 protrudes toward the first corrugated foil 3. The third corrugated foil support end 441 protrudes toward the first corrugated foil 3. This is a preferred structural form of the first corrugated foil support end, the second corrugated foil support end, and the third corrugated foil support end of the present invention. That is, the first corrugated foil support end and the second corrugated foil support end protrude in opposite directions, so that an air film can be formed between the first corrugated foil support end and the planar portion of the second corrugated foil, and an air film can be formed between the second corrugated foil support end and the planar portion of the first corrugated foil, thereby providing different support forces to the top foil. The air film thickness of the first corrugated foil support end in the middle is greater than that at both ends, which can effectively prevent gas leakage from both ends.

[0044] In some embodiments, the first layer of corrugated foil 3 further includes a first arched foil planar region 32, which is a cylindrical structure and is sleeved on the outer periphery of the top foil 5. The first corrugated foil flat section 332 is disposed on the outer periphery of the first arched foil planar region 32 or between two adjacent first arched foil planar regions 32. The first corrugated foil support end 331 is connected to the first corrugated foil flat section 332 and protrudes radially outward.

[0045] The second layer of corrugated foil 4 further includes a second arched foil planar region 42, which is a cylindrical structure and is sleeved on the outer periphery of the first layer of corrugated foil 3. The second corrugated foil flat section 432 is disposed on the inner periphery of the second arched foil planar region 42 or between two adjacent second arched foil planar regions 42. The second corrugated foil support end 431 is connected to the second corrugated foil flat section 432 and protrudes radially inward. The third corrugated foil flat section 442 is disposed on the inner periphery of the second arched foil planar region 42 or between two adjacent second arched foil planar regions 42. The third corrugated foil support end 441 is connected to the third corrugated foil flat section 442 and protrudes radially inward.

[0046] This is a further preferred structural form of the first and second corrugated foil layers of the present invention. The first arched foil planar region facilitates the placement of the first corrugated foil support end and the first corrugated foil flat section thereon, and the first arched foil planar region can be opposite to the second and third corrugated foil support ends to form an air film between them. When the load-bearing capacity increases, contact will occur to generate an elastic support force. The second arched foil planar region facilitates the placement of the second corrugated foil support end, the second corrugated foil flat section, the third corrugated foil support end, and the third corrugated foil flat section thereon, and the second arched foil planar region can be opposite to the first corrugated foil support end to form an air film between them. When the load-bearing capacity increases, contact will occur to generate an elastic support force.

[0047] In some embodiments, the area of ​​the first arched foil plane region 32 opposite to the second axial position is not provided with corrugated foil, the area of ​​the first arched foil plane region 32 opposite to the third axial position is not provided with corrugated foil, the second corrugated foil support end 431 is opposite to the first arched foil plane region 32 without corrugated foil, and the third corrugated foil support end 441 is opposite to the first arched foil plane region 32 without corrugated foil.

[0048] The second arched foil plane region 42, which is opposite to the first axial position, is not provided with corrugated foil, and the first corrugated foil support end 331 is opposite to the second arched foil plane region 42, which is not provided with corrugated foil.

[0049] This is a further preferred structural form of the first arched foil planar region and the second arched foil planar region of the present invention, such that the first, second and third wave foil support ends are all opposite to the planar region, so as to effectively form an air film for supporting the rotating shaft, and when the load increases, the support force can be provided by the elastic deformation of the second and third wave foil support ends, and further support force can be provided by the elastic deformation of the first wave foil support end, thereby improving the adaptive bearing function to the working conditions and increasing the range of support load.

[0050] In some embodiments, when the force borne radially inward by the top foil 5 is 0 or less than a first preset force, there is a first gap between the first corrugated foil support end 331 and the second arched foil planar region 42, a second gap between the second corrugated foil support end 431 and the first arched foil planar region 32, and a third gap between the third corrugated foil support end 441 and the first arched foil planar region 32, wherein the first gap is greater than the second gap and the third gap is greater than the third gap. Preferably, the second gap is equal to the third gap.

[0051] This is the gap structure between the first wave foil support end, the second and third wave foil support ends and the opposite planar regions of the present invention. The first spacing of the first wave foil support end is greater than the second and third spacing, which makes the gas film thickness in the middle part greater than the gas film thickness at both ends in the axial direction, thereby effectively preventing end leakage.

[0052] In some embodiments, when the force on the radially inner side of the top foil 5 is greater than a first preset force and less than a second preset force, the second wave foil support end 431 contacts and deforms with the first arched foil plane region 32, and the third wave foil support end 441 contacts and deforms with the first arched foil plane region 32. A gap still exists between the first wave foil support end 331 and the second arched foil plane region 42, wherein the second preset force is greater than the first preset force. In this invention, when the force on the top foil gradually increases, the second and third wave foil support ends deform but fail to contact the first arched foil plane region. An air film still exists between them for support. At this time, the first wave foil support end does not deform or deforms only slightly. An air film exists between the first wave foil support end and the second arched foil plane region, which supports the top foil.

[0053] In some embodiments, when the force on the radially inner side of the top foil 5 is greater than the second preset force, the second wave foil support end 431 contacts and deforms with the first arched foil plane region 32, the third wave foil support end 441 contacts and deforms with the first arched foil plane region 32, and the first wave foil support end 331 contacts and deforms with the second arched foil plane region 42. In this invention, when the force on the top foil further increases to greater than the second preset force, the second and third wave foil support ends deform and contact the first arched foil plane region, supported by elastic force and air film pressure. The first wave foil support end deforms and contacts the second arched foil plane region, supported by elastic force and air film pressure. The deformation of the first, second, and third wave foil support ends collectively supports the top foil. At this time, the deformation of the second and third wave foil support ends, as well as the deformation of the first wave foil support end, supports the top foil, with the deformation of the first wave foil support end providing a further increased supporting force.

[0054] In some embodiments, the first corrugated foil 33 occupies 1 / 3 of the total axial length of the first layer of corrugated foil 3, the area of ​​the first arched foil plane region 32 opposite to the second axial position where no corrugated foil is provided occupies 1 / 3 of the total axial length of the first layer of corrugated foil 3, and the area of ​​the first arched foil plane region 32 opposite to the third axial position where no corrugated foil is provided occupies 1 / 3 of the total axial length of the first layer of corrugated foil 3.

[0055] The second corrugated foil 43 occupies 1 / 3 of the total axial length of the second corrugated foil 4 in the axial direction, the third corrugated foil 44 occupies 1 / 3 of the total axial length of the second corrugated foil 4 in the axial direction, and the area of ​​the first arched foil plane region 32 that is not corrugated foil relative to the second axial position occupies 1 / 3 of the total axial length of the second corrugated foil 4.

[0056] This is a preferred structural form of the first and second wave foils of the present invention, namely, it is configured to be divided into three equal parts axially, with a large gas film thickness in the middle part and a small gas film thickness on both sides. The gas film in the middle provides gas film support under low load conditions, and the two ends provide elastic support through the wave foil support end to reduce end leakage at the shaft end.

[0057] In some embodiments, the second corrugated foil support end 431 and the third corrugated foil support end 441 have the same arch height, and the second corrugated foil flat section 432 and the third corrugated foil flat section 442 have the same structure.

[0058] In some embodiments, a bottom foil 2 is also included, which is a cylindrical structure and disposed between the second layer of corrugated foil 4 and the bearing seat 1, and the bottom foil 2 is a flat foil structure.

[0059] The present invention also provides an electric motor comprising the aforementioned gas radial bearing.

[0060] This invention enables the formation of a wedge-shaped region in the gap between the rotor and the radial bearing during the initial stage of high-speed shaft rotation in a high-speed motor. This wedge-shaped region is created by the eccentric motion of the shaft. Gas entering this wedge-shaped region forms a high-pressure lubricating film, providing load-bearing capacity to the bearing-shaft system. The specific implementation scheme is as follows:

[0061] As shown in Figure 1, the bearing housing is an overall annular structure. A radial bearing is fixedly installed on the inner surface. A through groove is opened above the inner surface. The width of the groove is narrow, just enough to fit the convex edge of the top foil and the arch foil, ensuring that the top foil and the arch foil will not undergo circumferential displacement.

[0062] As shown in Figure 1, the bottom foil 2 is made of a thin metal foil rolled up, with protruding edges extending outwards from both ends along the normal direction of the foil. The bottom foil is fixed to the groove of the bearing seat by the protruding edges. The distance between the two protruding edges is the sum of the thicknesses of the top foil and the corrugated foil protruding edges. The distance between the bottom foil protruding edges is larger than the sum of the thicknesses of the corrugated foil and the top foil protruding edges, which ensures that it can be inserted into the groove.

[0063] As shown in Figure 1, the arched foil consists of a planar area, an arched area, a raised edge, and an opening slot. The upper surface of the first layer of corrugated foil 3 is in close contact with the lower surface of the top foil, and its lower surface mates with the second layer of corrugated foil 4. The arched area of ​​the second layer of corrugated foil 4 is tangent to the planar area of ​​the first layer of corrugated foil 3, but the arched area of ​​the second layer of corrugated foil 4 does not contact the planar area of ​​the first layer of corrugated foil 3. When the first layer of corrugated foil 3 is under pressure, the central bearing area sinks to form a high-pressure gas film, which increases the load-bearing capacity of the rotor. The raised edge is in contact with the right side surface of the top foil and the right inner surface of the bearing seat groove to fix the circumferential movement of the arched foil. The middle area of ​​the first layer of corrugated foil 3 is processed into an arch shape, with flat ends, and the arched area accounts for 1 / 3 of the foil width. The two ends of the second layer of corrugated foil 4 are processed into arch shapes, with a flat middle section, and the arched area occupies about 2 / 3 of the foil. The distance between the vertices of adjacent arched areas of the arched foil is between 3-5 mm, and the number of arched areas is between 25-30. When the rotor rotates, under the action of frictional torque, the pressure transmitted by the top foil to the arch foil causes deformation from the free end to the fixed end, eventually resulting in the formation of a wedge-shaped area between the rotor and the top foil.

[0064] As shown in Figure 1, the top foil 5 is an integral annular structure, consisting of a support and fixing area and a load-bearing area. The left surface of the convex edge of the support and fixing area is fitted with the left inner surface of the bearing seat groove, and the right surface is fitted with the left surface of the convex edge of the arched foil to fix the circumferential displacement of the top foil. The outer surface of the top foil is tangent to the arched area of ​​the arched foil, and its end should completely cover the arched end of the arched foil. The inner surface of the top foil is the main load-bearing area; when the rotor rotates at high speed, the high-pressure lubricating gas film between the top foil and the rotor provides load-bearing force to the bearing.

[0065] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention. The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the protection scope of the present invention.

Claims

1. A gas radial bearing, characterized in that: include: The bearing housing (1), top foil (5), first layer corrugated foil (3), and second layer corrugated foil (4) are provided. The first layer corrugated foil (3) and the second layer corrugated foil (4) are both disposed between the bearing housing (1) and the top foil (5), and the first layer corrugated foil (3) is disposed between the second layer corrugated foil (4) and the top foil (5). The first layer corrugated foil (3) includes a first corrugated foil (33) located at a first position in the axial direction. The second layer corrugated foil (4) includes a second corrugated foil (43) located at a second position in the axial direction and a third corrugated foil (44) located at a third position in the axial direction. The first position in the axial direction is located between the second position in the axial direction and the third position in the axial direction. The first corrugated foil (33) includes a first corrugated foil support end (331) and a first corrugated foil flat section (332) alternately arranged in the circumferential direction. The second corrugated foil (43) also includes a first corrugated foil support end (331) and a first corrugated foil flat section (332) alternately arranged in the circumferential direction. The second wave foil support end (431) and the second wave foil flat section (432) are alternately arranged. The third wave foil (44) also includes a third wave foil support end (441) and a third wave foil flat section (442) alternately arranged in the circumferential direction. The first wave foil support end of the first layer of the wave foil is located in the first axial position and can form a single-layer wave foil support structure for the top foil at the first axial position of the bearing seat. The second wave foil is arranged in the second axial position and can form a single-layer wave foil support structure for the top foil at the second axial position. The third wave foil is arranged in the third axial position and can form a single-layer wave foil support structure for the top foil at the third axial position. The arch height of the first wave foil support end (331) is less than the arch height of the second wave foil support end (431), and the arch height of the first wave foil support end (331) is less than the arch height of the third wave foil support end (441).

2. The gas radial bearing according to claim 1, characterized in that: The first layer of corrugated foil (3) is disposed on the outer periphery of the top foil (5), and the first corrugated foil support end (331) protrudes toward the second layer of corrugated foil (4). The second layer of corrugated foil (4) is disposed on the outer periphery of the first layer of corrugated foil (3), and the second corrugated foil support end (431) protrudes toward the first layer of corrugated foil (3). The third corrugated foil support end (441) protrudes toward the first layer of corrugated foil (3).

3. The gas radial bearing according to claim 2, characterized in that: The first layer of corrugated foil (3) further includes a first arched foil planar region (32), which is a cylindrical structure and is fitted around the outer periphery of the top foil (5). The first corrugated foil flat section (332) is disposed around the outer periphery of the first arched foil planar region (32) or between two adjacent first arched foil planar regions (32). The first corrugated foil support end (331) is connected to the first corrugated foil flat section (332) and protrudes radially outward. The second layer of corrugated foil (4) further includes a second arched foil planar region (42), which is a cylindrical structure and is fitted around the top foil (5). The outer periphery of the first layer of corrugated foil (3), the second corrugated foil flat section (432) is disposed on the inner periphery of the second arched foil plane area (42) or between two adjacent second arched foil plane areas (42), and the second corrugated foil support end (431) is connected to the second corrugated foil flat section (432) and protrudes radially inward, the third corrugated foil flat section (442) is disposed on the inner periphery of the second arched foil plane area (42) or between two adjacent second arched foil plane areas (42), and the third corrugated foil support end (441) is connected to the third corrugated foil flat section (442) and protrudes radially inward.

4. The gas radial bearing according to claim 3, characterized in that: The area of ​​the first arched foil plane region (32) opposite to the second axial position is not provided with corrugated foil, the area of ​​the first arched foil plane region (32) opposite to the third axial position is not provided with corrugated foil, the second corrugated foil support end (431) is opposite to the first arched foil plane region (32) without corrugated foil, and the third corrugated foil support end (441) is opposite to the first arched foil plane region (32) without corrugated foil; the area of ​​the second arched foil plane region (42) opposite to the first axial position is not provided with corrugated foil, and the first corrugated foil support end (331) is opposite to the second arched foil plane region (42) without corrugated foil.

5. The gas radial bearing according to claim 3, characterized in that: When the force on the radial inner side of the top foil (5) is 0 or less than the first preset force, there is a first gap between the first wave foil support end (331) and the second arch foil plane area (42), a second gap between the second wave foil support end (431) and the first arch foil plane area (32), and a third gap between the third wave foil support end (441) and the first arch foil plane area (32), and the first gap is greater than the second gap and the first gap is greater than the third gap.

6. The gas radial bearing according to claim 5, characterized in that: When the force on the radial inner side of the top foil (5) is greater than the first preset force and less than the second preset force, the second wave foil support end (431) contacts the first arch foil plane area (32) and deforms, the third wave foil support end (441) contacts the first arch foil plane area (32) and deforms, and there is still a gap between the first wave foil support end (331) and the second arch foil plane area (42), wherein the second preset force is greater than the first preset force.

7. The gas radial bearing according to claim 6, characterized in that: When the force on the radial inner side of the top foil (5) is greater than the second preset force, the second wave foil support end (431) contacts the first arch foil plane area (32) and deforms, the third wave foil support end (441) contacts the first arch foil plane area (32) and deforms, and the first wave foil support end (331) contacts the second arch foil plane area (42) and deforms.

8. The gas radial bearing according to claim 3, characterized in that: The first corrugated foil (33) occupies 1 / 3 of the total axial length of the first layer of corrugated foil (3) in the axial direction. The area of ​​the first arched foil plane region (32) opposite to the second axial position without corrugated foil occupies 1 / 3 of the total axial length of the first layer of corrugated foil (3). The area of ​​the first arched foil plane region (32) opposite to the third axial position without corrugated foil occupies 1 / 3 of the total axial length of the first layer of corrugated foil (3). The second corrugated foil (43) occupies 1 / 3 of the total axial length of the second layer of corrugated foil (4) in the axial direction. The third corrugated foil (44) occupies 1 / 3 of the total axial length of the second layer of corrugated foil (4). The area of ​​the second arched foil plane region (42) opposite to the first axial position without corrugated foil occupies 1 / 3 of the total axial length of the second layer of corrugated foil (4).

9. The gas radial bearing according to any one of claims 1-8, characterized in that: The arch height of the second wave foil support end (431) is equal to that of the third wave foil support end (441), and the structure of the second wave foil flat section (432) is the same as that of the third wave foil flat section (442).

10. The gas radial bearing according to any one of claims 1-8, characterized in that: It also includes a bottom foil (2), which is a cylindrical structure and is disposed between the second layer of corrugated foil (4) and the bearing seat (1). The bottom foil (2) is a flat foil structure.

11. An electric motor, characterized in that: Includes the gas radial bearing according to any one of claims 1-10.

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