Radial gas foil bearing

Abstract

The utility model provides a radial gas foil bearing. The radial gas foil bearing comprises a bearing sleeve, a bump foil and a flat foil, the bearing sleeve is provided with an open groove penetrating through the wall thickness in the radial direction. A bump foil radial extension section is arranged at the fixed end of the bump foil piece, the bump foil radial extension section is arranged in the open groove in a penetrating mode, a bent bump foil clamping hook is arranged at the end, away from the bump foil piece, of the bump foil radial extension section, and the bump foil clamping hook is used for being arranged on the peripheral wall of the bearing sleeve in a hooking mode; the fixed end of the flat foil piece is provided with a flat foil radial extension section, the flat foil radial extension section is arranged in the open groove in a penetrating mode, the end, away from the flat foil piece, of the flat foil radial extension section is provided with a bent flat foil clamping hook, and the flat foil clamping hook is used for being arranged on the peripheral wall of the bearing sleeve in a hooked mode. According to the bearing, reliable connection of the bump foil and the flat foil on the bearing sleeve is realized, welding or additional fasteners are not needed, so that the assembly process is simplified, the connection reliability and the overall performance of the bearing are improved, and the bearing has the advantages of simple structure, convenience in assembly, firmness and reliability in connection, stable performance and long service life.

Description

TECHNICAL FIELD

[0001] The utility model relates to bearing technical field, specifically, a radial gas foil bearing. BACKGROUND

[0002] The commonly used radial air foil bearing fixes the wave foil and the flat foil in the inner wall of the bearing sleeve by welding or fasteners. These two fixing methods have their own disadvantages. Although the welding method has firm initial connection, the firmness of the connection will gradually decrease after long-term use, which may lead to performance degradation or failure of the bearing. Although the fastener method can realize detachable connection, the assembly process is relatively complex, which increases the difficulty of production and maintenance. These problems not only affect the service life and reliability of the bearing, but also may increase the maintenance cost and downtime.

[0003] In addition, the welding points or fasteners may cause local stress concentration, affecting the uniformity and stability of the bearing. At the same time, these fixing methods also limit the application range of the bearing under high speed, high temperature or other extreme working conditions.

[0004] Considering the wide application of radial gas foil bearings in high-end equipment such as aerospace, the performance and reliability of the radial gas foil bearings are directly related to the safety and efficiency of the entire system. Therefore, developing a new type of more reliable and efficient fixing method to improve the performance and service life of the radial gas foil bearing has become an urgent need for current technical development. SUMMARY

[0005] The purpose of the present application is to provide a radial gas foil bearing with the advantages of simple structure, convenient assembly, firm and reliable connection, stable performance and long service life.

[0006] The present application provides a radial gas foil bearing, comprising a bearing sleeve and a wave foil and a flat foil coaxially installed on the inner wall of the bearing sleeve, the flat foil is arranged on the inner side of the wave foil; the bearing sleeve is provided with a slot penetrating the wall thickness in the radial direction; the fixed end of the wave foil is provided with a wave foil radial extension section, the wave foil radial extension section is arranged in the slot, and the end of the wave foil radial extension section away from the wave foil is provided with a curved wave foil hook, the wave foil hook is used for hooking on the outer peripheral wall of the bearing sleeve; the fixed end of the flat foil is provided with a flat foil radial extension section, the flat foil radial extension section is arranged in the slot, and the end of the flat foil radial extension section away from the flat foil is provided with a curved flat foil hook, the flat foil hook is used for hooking on the outer peripheral wall of the bearing sleeve.

[0007] Compared with the prior art, the radial air foil bearing has the following advantages: the wave foil and the flat foil are simply and reliably fixed by arranging the through-wall slot on the bearing sleeve and designing the corresponding radial extension and the curved hook structure on the wave foil and the flat foil. The design avoids the shortcomings of traditional welding or the use of fasteners, improves the stability and reliability of the bearing, and simplifies the assembly process.

[0008] In a possible implementation, the bending directions of the wave foil hook and the flat foil hook are arranged in opposite directions along the circumference of the bearing sleeve. Compared with the prior art, the mutual interference between the two hooks is effectively avoided, and the arrangement not only improves the convenience of installation, but also enhances the stability of the overall structure.

[0009] In a possible implementation, two hook slots are arranged on the outer circumferential wall of the bearing sleeve, and the wave foil hook and the flat foil hook are arranged in the two hook slots respectively, and the slot is arranged between the two hook slots. Compared with the prior art, the flat foil hook and the wave foil hook are arranged in the special hook slots arranged on the outer circumferential wall of the bearing sleeve, which effectively solves the problem of mutual interference between the hooks; and by arranging the slot between the two hook slots, the overall structural layout is further optimized, and the stability and reliability of the bearing are improved.

[0010] In a possible implementation, the wave foil is a ring-shaped wave foil, the ring-shaped wave foil has an opening, and the wave foil radial extension is arranged at the opening of the ring-shaped wave foil. Compared with the prior art, the ring-shaped wave foil passes through the slot of the bearing sleeve through the wave foil radial extension at the opening, and is then hooked on the outer circumferential wall of the bearing sleeve by the wave foil hook, thereby realizing reliable fixation of the wave foil.

[0011] In a possible implementation, the wave foil, the wave foil radial extension and the wave foil hook are integrally formed. Compared with the prior art, by manufacturing the wave foil, the wave foil radial extension and the wave foil hook as a whole, the number of parts can be reduced, the assembly difficulty can be reduced, and the stability and reliability of the overall structure can be improved.

[0012] In a possible implementation, the flat foil is a ring-shaped flat foil, the ring-shaped flat foil has an opening, and the flat foil radial extension is arranged at the opening of the ring-shaped flat foil. Compared with the prior art, the ring-shaped flat foil passes through the slot of the bearing sleeve through the flat foil radial extension at the opening, and is then hooked on the outer circumferential wall of the bearing sleeve by the flat foil hook, thereby realizing reliable fixation of the flat foil.

[0013] In a possible implementation, the flat foil, the flat foil radial extension and the flat foil hook are integrally formed. Compared with the prior art, by integrally forming the flat foil, the flat foil radial extension and the flat foil hook, the overall structural strength and stability of the flat foil can be effectively improved.

[0014] In a possible implementation, the circumferential width of the slot is greater than the sum of the thicknesses of the wave foil radial extension and the flat foil radial extension. Compared with the prior art, it ensures that the wave foil and the flat foil can smoothly pass through the slot and will not be stuck or deformed during installation.

[0015] In a possible implementation, the wave foil hook is provided with first limiting flanges at both axial ends, and the two first limiting flanges are used to abut against the axial end faces on both sides of the bearing sleeve. Compared with the prior art, axial limiting of the wave foil is achieved, traditional welding or use of fasteners is avoided, the assembly process is simplified, and axial limiting reliability is improved.

[0016] In a possible implementation, the flat foil hook is provided with second limiting flanges at both axial ends, and the two second limiting flanges are used to abut against the axial end faces on both sides of the bearing sleeve. Compared with the prior art, axial limiting of the flat foil is achieved, traditional welding or use of fasteners is avoided, the assembly process is simplified, and axial limiting reliability is improved. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is a structural schematic view of the present application;

[0018] Figure 2 is a partial enlarged view of Figure 1 ;

[0019] Figure 3 is a structural schematic view of the bearing sleeve;

[0020] Figure 4 is a structural schematic view of the wave foil;

[0021] Figure 5 is a structural schematic view of the flat foil;

[0022] BRIEF DESCRIPTION OF DRAWINGS

[0023] 1, bearing sleeve; 11, slot; 12, hook slot; 2, wave foil; 21, wave foil radial extension; 22, wave foil hook; 23, first limiting flange; 3, flat foil; 31, flat foil radial extension; 32, flat foil hook; 33, second limiting flange. DETAILED DESCRIPTION

[0024] First of all, those skilled in the art should understand that these implementations are only used to explain the technical principles of the embodiments of the present application, and are not intended to limit the protection scope of the embodiments of the present application. Those skilled in the art can adjust them as needed in order to adapt to specific application occasions.

[0025] In the description of the embodiments of the present application, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected", "connected" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0026] In the embodiments of the present application, unless otherwise explicitly specified and limited, the first feature is "on" or "under" the second feature can be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature "above", "above" and "above" the second feature can be that the first feature is directly above or obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "below" and "below" the second feature can be that the first feature is directly below or obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0027] Radial air foil bearing is an important mechanical component, which is widely used in high-speed rotating machinery. The commonly used radial air foil bearing fixes the wave foil and the flat foil on the inner wall of the bearing sleeve by welding or fasteners. However, these fixing methods have some technical problems. The welding method will reduce the connection firmness after long-term use, affecting the stability and reliability of the bearing. The method using fasteners has the problem of complex assembly, increasing the difficulty of production and maintenance. These problems directly affect the performance and service life of the bearing, and a better fixing scheme needs to be sought.

[0028] For example, in an aero-engine or a micro gas turbine, the application of radial air foil bearing is particularly critical. Specifically, the radial air foil bearing bears the important task of supporting the high-speed rotating shaft. In this application scenario, the bearing usually needs to operate stably for a long time at an extremely high speed of more than 100,000 revolutions per minute and a high temperature environment of more than 200℃. Under such harsh conditions, due to the repeated action of thermal stress and mechanical stress, the welding point is prone to fatigue cracking, which gradually reduces the fixing strength of the wave foil and the flat foil. The method of fixing by using fasteners becomes extremely complex and difficult to assemble due to the small size of the bearing and the limited installation space. This not only increases the production cost, but also may affect the performance of the bearing due to unstable assembly quality.

[0029] If these technical problems cannot be effectively solved, it will have a serious impact on the entire system. The reduction of bearing fixing strength may cause the wave foil and the flat foil to displace slightly during high-speed operation, destroy the stability of the air film, increase the friction and wear. This not only reduces the carrying capacity and damping performance of the bearing, but also may cause unstable vibration of the shaft system, and even may cause the whole machine to fail. In addition, the complex assembly process not only increases the production and maintenance cost, but also may cause inconsistent assembly quality due to human factors, affecting the reliability and consistency of the product. Therefore, it is of great significance to develop a new type of more reliable and convenient foil fixing scheme for improving the performance and reliability of the radial air foil bearing.

[0030] The application will be further described in detail below in combination with the drawings and specific embodiments.

[0031] Referring to Figures 1 to 5 The embodiment of the application discloses a radial air foil bearing, which comprises a bearing sleeve 1 and a wave foil 2 and a flat foil 3 coaxially installed on the inner wall of the bearing sleeve 1, the flat foil 3 is arranged on the inner side of the wave foil 2; the bearing sleeve 1 is provided with a slot 11 penetrating through the wall thickness in the radial direction; the fixed end of the wave foil 2 is provided with a wave foil radial extension section 21, the wave foil radial extension section 21 is arranged in the slot 11, and the end of the wave foil radial extension section 21 away from the wave foil 2 is provided with a curved wave foil hook 22, the wave foil hook 22 is used for hooking on the outer peripheral wall of the bearing sleeve 1; the fixed end of the flat foil 3 is provided with a flat foil radial extension section 31, the flat foil radial extension section 31 is arranged in the slot 11, and the end of the flat foil radial extension section 31 away from the flat foil 3 is provided with a curved flat foil hook 32, the flat foil hook 32 is used for hooking on the outer peripheral wall of the bearing sleeve 1.

[0032] Among them, the bearing sleeve 1 refers to the shell structure for accommodating and supporting the wave foil 2 and the flat foil 3, which can be realized by a cylindrical structure made of metal materials such as stainless steel. The wave foil 2 refers to a thin metal sheet with a wave-shaped structure, which can be made of elastic metal materials such as beryllium copper or stainless steel, and provides elastic support and damping function through the wave-shaped structure. The flat foil 3 refers to a thin metal sheet with a smooth surface, which can be made of wear-resistant metal materials such as chromium steel or nickel-based alloy, and is used to form an air film and provide a smooth moving surface. The wave foil hook 22 and the flat foil hook 32 refer to the curved structure arranged at the end of the wave foil radial extension section 21 and the flat foil radial extension section 31 away from the foil, which can be realized by cold working methods such as bending forming.

[0033] As can be known from the above, the bearing sleeve 1 is provided with a through slot 11 in the wall thickness direction as the main structure; the wave foil 2 and the flat foil 3 are respectively arranged on the inner wall of the bearing sleeve 1, wherein the flat foil 3 is located on the inner side of the wave foil 2; the fixed ends of the wave foil 2 and the flat foil 3 are respectively provided with radial extension sections, and the extension sections pass through the slot 11 on the bearing sleeve 1; the ends of the extension sections are provided with curved hooks, and the hooks are hooked on the outer peripheral wall of the bearing sleeve 1, so as to realize the fixation of the wave foil 2 and the flat foil 3.

[0034] The core innovation of the present application is that the through-wall slot 11 is arranged on the bearing sleeve 1 to provide sufficient space for the wave foil radial extension section 21 and the flat foil radial extension section 31 to pass through; this design makes the radial extension section utilize the entire wall thickness of the bearing sleeve 1, thereby increasing the fixation strength; at the same time, the design of the slot 11 also facilitates installation and disassembly, thereby improving the maintainability of the bearing. The curved design of the wave foil hook 22 and the flat foil hook 32 is to increase the reliability of fixation; by hooking the hooks on the outer peripheral wall of the bearing sleeve 1, the radial displacement of the wave foil 2 and the flat foil 3 during high-speed operation can be effectively prevented; this design fully utilizes the structural characteristics of the bearing sleeve 1, and does not require additional fixing parts, thereby simplifying the overall structure.

[0035] Continuing to refer to Figure 2 In the present embodiment, the bending directions of the wave foil hook 22 and the flat foil hook 32 are arranged in opposite circumferential directions of the bearing sleeve 1. Specifically, the wave foil hook 22 can be bent in one circumferential direction of the bearing sleeve 1, while the flat foil hook 32 is bent in the opposite circumferential direction; this opposite bending direction makes the two hooks not hinder each other during installation, forms circumferential limiting, and can also better disperse stress, thereby improving the carrying capacity of the overall structure.

[0036] In this embodiment, the outer peripheral wall of the bearing sleeve 1 is provided with two hook grooves 12, respectively for accommodating the wave foil hook 22 and the flat foil hook 32, and the slot 11 is located between the two hook grooves 12. Specifically, the two hook grooves 12 on the outer peripheral wall of the bearing sleeve 1 are respectively used to accommodate the flat foil hook 32 and the wave foil hook 22; this design allows the two hooks to be fixed in their respective dedicated positions, avoiding direct contact and interference between them; the depth and shape of the hook groove 12 can be customized according to the specific size of the hook to ensure that the hook can be firmly fixed on the bearing sleeve 1. The slot 11 is located between the two hook grooves 12, and this layout design has multiple advantages: first, the slot 11 provides a passage for the wave foil radial extension 21 and the flat foil radial extension 31 to pass through the wall of the bearing sleeve 1, allowing the wave foil 2 and the flat foil 3 to extend from the inside to the outside of the bearing and be fixed; second, placing the slot 11 between the two hook grooves 12 can minimize the impact on the structural strength of the bearing sleeve 1, as the slot 11 and the hook groove 12 are staggered in position, avoiding excessive weakening of the bearing sleeve 1 wall at the same radial position. In addition, the edges of the slot 11 and the hook groove 12 can be designed with smooth transitions to reduce stress concentration and prolong the service life of the bearing.

[0037] Continuing to refer to Figure 4 In this embodiment, the wave foil 2 is a ring-shaped wave foil with an opening, and the wave foil radial extension 21 is arranged at the opening of the ring-shaped wave foil. The use of a ring-shaped wave foil structure and the arrangement of the wave foil radial extension 21 at the opening provides convenience for the installation and removal of the radial air foil bearing; at the same time, the ring-shaped structure also improves the overall stiffness of the wave foil 2, which helps to improve the stability and load capacity of the bearing.

[0038] In this embodiment, the wave foil 2, the wave foil radial extension 21, and the wave foil hook 22 are integrally formed. Specifically, the wave foil 2, the wave foil radial extension 21, and the wave foil hook 22 can be formed by stamping or molding; this integrated design not only simplifies the manufacturing process, but also ensures the precise alignment and connection between the components; for example, the wave foil radial extension 21 can seamlessly transition to the wave foil 2 body, avoiding the stress concentration problems that may be caused by traditional welding or mechanical connection. In addition, integral molding can also optimize the overall stiffness distribution of the wave foil 2, which helps to improve the dynamic characteristics and load capacity of the bearing.

[0039] Continuing to refer to Figure 5In this embodiment, the flat foil 3 is a ring-shaped flat foil with an opening, and the flat foil radial extension 31 is arranged at the opening of the ring-shaped flat foil. The structure of the ring-shaped flat foil can improve the overall strength and rigidity of the flat foil 3. Due to the good stress distribution characteristics of the ring-shaped structure, various forces and pressures generated during the operation of the bearing can be more evenly borne, thereby reducing the risk of deformation or damage of the flat foil 3. This structural design not only improves the service life of the flat foil 3, but also ensures the stable performance of the bearing during long-term operation. As a preferred embodiment, the inner wall of the ring-shaped flat foil is provided with a wear-resistant layer, which can effectively improve the wear resistance of the flat foil 3 and prolong the service life of the bearing.

[0040] In this embodiment, the flat foil 3, the flat foil radial extension 31 and the flat foil hook 32 are integrally formed. The integrally formed flat foil 3, flat foil radial extension 31 and flat foil hook 32 can optimize the stress distribution of the material. Since there is no connection point, stress can be more evenly distributed throughout the structure, reducing the risk of local stress concentration. This is particularly important for gas foil bearings that bear centrifugal forces generated by high-speed rotation and thermal expansion stresses. In addition, the integrally formed design can also improve the dynamic balance of the flat foil 3, reducing the vibration and noise that may occur during high-speed operation. That is, the integrally formed design eliminates the welding points or connection points in the traditional connection method, reducing potential stress concentration points and potential failure risks. This structural design not only simplifies the manufacturing process, but also improves the reliability of the flat foil 3 in high-speed rotation and high-temperature environments.

[0041] In this embodiment, the circumferential width of the slot 11 is greater than the sum of the thicknesses of the wave foil radial extension 21 and the flat foil radial extension 31. This design not only solves the problem of interference between the wave foil radial extension 21 and the flat foil radial extension 31, but also brings the following technical effects: First, it simplifies the assembly process of the bearing. Since the slot 11 has enough space, the operator can more easily pass the extensions of the wave foil 2 and the flat foil 3 through the slot 11 at the same time, reducing the difficulty and time in the installation process. Second, it reduces the risk of part damage. A wide enough slot 11 can avoid squeezing or scratching the wave foil 2 and the flat foil 3 during installation, thereby prolonging the service life of the bearing. Third, it improves the reliability of the bearing. A reasonable gap design can ensure that the wave foil 2 and the flat foil 3 do not generate excessive stress during operation due to factors such as thermal expansion, thereby improving the stability and durability of the bearing. Finally, this design also provides convenience for maintenance and replacement of the bearing. When the wave foil 2 or the flat foil 3 needs to be replaced, a wide enough slot 11 can make the disassembly and reinstallation process much simpler and faster.

[0042] In the embodiment, the axial two ends of the wave foil hook 22 are integrally provided with first limiting flanges 23, and the two first limiting flanges 23 are used for abutting against the two side axial end faces of the bearing sleeve 1; the axial two ends of the flat foil hook 32 are integrally provided with second limiting flanges 33, and the two second limiting flanges 33 are used for abutting against the two side axial end faces of the bearing sleeve 1. The axial limiting of the foil on the bearing sleeve 1 is realized, the traditional welding or the use of fasteners is avoided, the assembly process is simplified, and the axial limiting reliability is improved.

[0043] In the description of the embodiments of the present application, it should be noted that in the description of the present application, the terms indicating the direction or position relationship are based on the direction or position relationship shown in the drawings, which is only for the convenience of description, and does not indicate or imply that the device or member must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.

[0044] In the description of the present application, the description of the terms "one embodiment", "some embodiments", "in the embodiment", "specific examples" or "some examples" means that the specific features, mechanisms, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, mechanisms, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. Furthermore, the skilled in the art can combine and combine the different embodiments or examples described in the specification and the features of the different embodiments or examples without contradiction.

[0045] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art can easily think of changes or replacements within the technical range disclosed in the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A radial air foil bearing, comprising a bearing sleeve (1) and a wave foil (2) and a flat foil (3) coaxially installed on the inner wall of the bearing sleeve (1), the flat foil (3) being arranged on the inner side of the wave foil (2), characterized in that: the bearing sleeve (1) is provided with a slot (11) penetrating the wall thickness in the radial direction; the fixed end of the wave foil (2) is provided with a wave foil radial extension section (21), the wave foil radial extension section (21) is arranged in the slot (11), and the end of the wave foil radial extension section (21) away from the wave foil (2) is provided with a curved wave foil hook (22) for hooking on the outer peripheral wall of the bearing sleeve (1); the fixed end of the flat foil (3) is provided with a flat foil radial extension section (31), the flat foil radial extension section (31) is arranged in the slot (11), and the end of the flat foil radial extension section (31) away from the flat foil (3) is provided with a curved flat foil hook (32) for hooking on the outer peripheral wall of the bearing sleeve (1). The bending directions of the wave foil hook (22) and the flat foil hook (32) are arranged in opposite directions in the circumferential direction of the bearing sleeve (1). The outer peripheral wall of the bearing sleeve (1) is provided with two hook grooves (12) for accommodating the wave foil hook (22) and the flat foil hook (32), respectively, and the slot (11) is located between the two hook grooves (12). The wave foil (2) is a ring-shaped wave foil, the ring-shaped wave foil has an opening, and the wave foil radial extension section (21) is arranged at the opening of the ring-shaped wave foil.

2. The radial air foil bearing of claim 1 wherein, The wave foil (2), the wave foil radial extension section (21) and the wave foil hook (22) are integrally formed.

3. The radial air foil bearing of claim 2 wherein, The flat foil (3) is a ring-shaped flat foil, the ring-shaped flat foil has an opening, and the flat foil radial extension section (31) is arranged at the opening of the ring-shaped flat foil.

4. The radial air foil bearing of claim 1 wherein, The flat foil (3), the flat foil radial extension section (31) and the flat foil hook (32) are integrally formed.

5. The radial air foil bearing of claim 4 wherein, The circumferential width of the slot (11) is greater than the sum of the thicknesses of the wave foil radial extension section (21) and the flat foil radial extension section (31).

6. The radial air foil bearing of claim 1 wherein, The axial ends of the wave foil hook (22) are each provided with a first limiting flange (23), and the two first limiting flanges (23) are used to abut against the two axial end faces of the bearing sleeve (1).

7. The radial air foil bearing of claim 6 wherein, The axial ends of the flat foil hook (32) are each provided with a second limiting flange (33), and the two second limiting flanges (33) are used to abut against the two axial end faces of the bearing sleeve (1).

8. The radial air foil bearing of claim 1 wherein, ​ 9. The radial air foil bearing of claim 1 wherein, ​ 10. The radial air foil bearing of claim 1 wherein, ​

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