A split-type independent foil air bearing

Abstract

The present invention discloses a split independent foil air bearing, which includes a bearing seat and a foil ring. The foil ring includes a jellyfish-shaped multi-stiffness foil and a plurality of arched multi-stiffness foils. The jellyfish-shaped multi-stiffness foil mainly includes a bearing part and two symmetrically arranged deformation support parts. The arched multi-stiffness foil includes an arched bearing part and two symmetrically arranged arched bearing support parts. A slot is provided on the bearing seat, and the jellyfish-shaped multi-stiffness foil and the arched multi-stiffness foil are snap-connected to the slot. The jellyfish-shaped multi-stiffness foil is at the bottom of the foil ring, and the jellyfish-shaped multi-stiffness foil is symmetrically arranged with the diameter in the vertical direction of the bearing seat as the center. Compared with the traditional integral foil ring, the newly designed independent foil ring of the present invention has good deformation space. The shape of the foil ring deforms rapidly following the transfer of the central rotor and the air film. The foil ring is not easily collided with the rotor, improving the service life of the foil bearing and expanding the application scenarios of the bearing.

Description

Technical Field

[0001] The present invention relates to the field of using foil bearings, and specifically to a split independent foil air bearing. Background Art

[0002] Air bearings have a wide range of applications in the industrial field. For conventional mechanical contact rolling bearings, the higher the rotational speed, the higher the requirements for bearing accuracy, lubrication, etc., and the shorter the service life. The air bearing suspends the spindle in the air without mechanical contact, uses clean air as the lubricant, and reduces the wear to the lowest level. Therefore, it can provide extremely high radial and axial rotational accuracies and shows unique advantages in high-speed, low-friction, high-temperature, low-temperature, and radioactive occasions.

[0003] However, the requirements for air bearings vary greatly in different application scenarios. Due to the external vibration added to mobile machinery and the large difference in operating conditions between mobile and non-mobile machinery, especially in the automotive field, the vehicle vibration caused by road unevenness will give a strong external excitation to the air bearing through the tires and the vehicle body. This excitation is relatively complex, and its load spectrum is related to the road conditions, vehicle conditions, and vehicle operating conditions. This excitation often causes changes in the gap between the foil of the air bearing and the shaft, resulting in changes, fluctuations, and breakage of the bearing load gas film, and further causing damage or even failure of the air bearing.

[0004] The problem to be solved by the present invention is that due to the large difference in operating conditions during the operation of mobile rotating machinery, the external excitation vibration transmitted to the existing foil bearings due to harsh road environments, human factors, etc. has a large range of changes in vibration acceleration and very large changes in vibration frequency. The maximum value of the vibration acceleration often exceeds the maximum bearing capacity of the existing foil bearings. The foil itself is composed of a very thin elastic metal sheet, and this metal sheet is very susceptible to the influence of vibration force and generates deformation. The deformation of the thin foil under external excitation vibration causes the deformation of the "gas film formation boundary", and this deformation is uneven circumferentially along the rotation axis, resulting in changes, fluctuations, and breakage of the gas film, and unable to maintain a continuous, regular, and stable structure, thereby causing the shaft to not rotate normally. It is necessary to ensure that the deformation of the gas film boundary meets the requirements of hydrodynamics from aspects such as structural design and foil stiffness to ensure the normal and efficient operation of the gas film. Summary of the Invention

[0005] The purpose of the present invention is to improve the poor stress response and easy damage problems of existing foil bearings, and provide a split independent foil air bearing and a multi-stiffness foil system to adapt to the excited vibration under different working conditions, so that the foil can generate uniform deformation around the continuously vibrating shaft, enabling the gas film to be regular, continuous, and follow the rotation axis to move, ensuring the stable operation of the bearing system.

[0006] To achieve the above purpose, the present invention adopts the following technical solutions:

[0007] A split independent foil air bearing includes a bearing seat and a foil ring. The foil ring includes a jellyfish-shaped multi-stiffness foil and several arched multi-stiffness foils. The jellyfish-shaped multi-stiffness foil mainly includes a bearing part and two symmetrically arranged deformation support parts. The arched multi-stiffness foil includes an arched bearing part and two symmetrically arranged arched bearing support parts. A slot is provided on the bearing seat, and the jellyfish-shaped multi-stiffness foil and the arched multi-stiffness foil are snap-connected to the slot. The jellyfish-shaped multi-stiffness foil is at the bottom of the foil ring, and the jellyfish-shaped multi-stiffness foil is symmetrically arranged with the diameter of the bearing seat in the vertical direction as the center. Compared with the traditional integral foil ring, this newly designed independent foil ring has good deformation space. The shape of the foil ring deforms rapidly following the transfer of the central rotor and the air film. The foil ring is not easy to collide with the rotor, improving the service life of the foil bearing and expanding the application scenarios of the bearing.

[0008] Preferably, in the jellyfish-shaped multi-stiffness foil: the cross-section of the deformation support part is S-shaped. The deformation support part includes a first stiffness support part, a first deformation bend part, a second stiffness support part, a second deformation bend part, and an insertion part connected in sequence. The stiffness of the first stiffness support part and the second stiffness support part is greater than that of the first deformation bend part and the second deformation bend part.

[0009] Preferably, the length of the bearing part is 20% - 60% of the length of the jellyfish-shaped multi-stiffness foil.

[0010] Preferably, in the jellyfish-shaped multi-stiffness foil: a connecting main bend part is provided between the bearing part and the deformation support part, and the length of the connecting main bend part is 3% - 5% of the length of the jellyfish-shaped multi-stiffness foil.

[0011] Preferably, the length of the first stiffness support part is 5% - 10% of the length of the jellyfish-shaped multi-stiffness foil.

[0012] Preferably, the length of the second stiffness support part is 5% - 10% of the length of the jellyfish-shaped multi-stiffness foil.

[0013] Preferably, each arched multi-stiffness foil includes an arched bearing part and two symmetrically arranged arched deformation support parts. The arched deformation support part includes an arched deformation part and an arched support part.

[0014] Preferably, the inner circle of the foil ring is circular.

[0015] Preferably, the jellyfish-shaped multi-stiffness foil is a double-layer superimposed structure, and the thickness of the jellyfish-shaped multi-stiffness foil is twice that of the arch-shaped multi-stiffness foil. When the annular air film is damaged under the action of external vibration excitation, the rotating shaft will first start to drop under the influence of gravity, increasing the pressure burden on the bottom jellyfish-shaped multi-stiffness foil ring. Compared with other arch-shaped multi-stiffness foils in the circumferential direction, the bottom jellyfish-shaped multi-stiffness foil ring also has to bear the gravity of the rotating shaft additionally. At the same time, increasing the stiffness of the jellyfish-shaped multi-stiffness foil ring reduces the deformation amount after being excited as a whole and recovers more quickly, reducing friction and impact damage. Extending the overall service life, such a double-layer structural design ensures that the foil rings deform uniformly, regularly, and continuously under different vibration forces, thereby ensuring the stability of the air film.

[0016] The distribution of the foil stiffness should consider both the deformation amplitude under different loads and different vibration frequencies, so that the foil ring has good followability and ensures that the air film can be evenly distributed along with the vibration of the shaft.

[0017] The beneficial technical effects of the present invention are as follows: After being excited by the outside world, the split independent foil ring has a good deformation space. The shape of the foil ring deforms rapidly following the transfer of the central rotor and the air film. The foil ring has good followability, ensuring that the air film can be evenly distributed along with the vibration of the shaft. The foil ring is not easy to collide with the rotor, improving the service life of the foil bearing and expanding the application scenarios of the air bearing. Description of the Drawings

[0018] Figure 1 is the structural schematic diagram of the present invention;

[0019] Figure 2 is the structural schematic diagram of the jellyfish-shaped multi-stiffness foil;

[0020] Figure 3 is the structural schematic diagram of the arch-shaped multi-stiffness foil;

[0021] Figure 4 is the normal working air domain diagram of the split independent foil air bearing;

[0022] Figure 5 is the structural diagram of the split independent foil air bearing after being excited by external vibration;

[0023] Figure 6 is the air domain diagram of the split independent foil air bearing after being excited by external vibration;

[0024] Figure 7 is the comparison diagram of the split independent foil air bearing before and after bearing excitation vibration;

[0025] In the figure: Foil ring 1, jellyfish-shaped multi-stiffness foil 11, load-bearing part 111, deformation support part 112, first stiffness support part 1121, first deformation bend part 1122, second stiffness support part 1123, second deformation bend part 1124, insertion foot part 1125, connecting main bend part 113, arched multi-stiffness foil 12, arched load-bearing part 121, arched deformation part 122, arched support part 123, bearing seat 2, slot 20, shaft 3, air domain 4. Detailed implementation manner

[0026] The present invention will be further described below in conjunction with the accompanying drawings. Through the description of the embodiments below, it will be more conducive to the public to understand the present invention. However, the specific embodiments given by the applicant should not be regarded as a limitation to the technical solution of the present invention. Any change in the definition of components or technical features or a formal rather than substantial transformation of the overall structure should be regarded as the protection scope defined by the technical solution of the present invention. Embodiment

[0027] As Figure 1 shown: A split-type independent foil air bearing includes a bearing seat 2 and a foil ring 1. The foil ring 1 includes a jellyfish-shaped multi-stiffness foil 11 and five arched multi-stiffness foils 12. The jellyfish-shaped multi-stiffness foil 11 and the arched multi-stiffness foils 12 are snap-connected to the slot 20.

[0028] As Figure 2 shown: The jellyfish-shaped multi-stiffness foil 11 mainly includes a load-bearing part 111 and two symmetrically arranged deformation support parts 112. In the jellyfish-shaped multi-stiffness foil 11: The cross-section of the deformation support part is S-shaped. The deformation support part 112 includes a first stiffness support part 1121, a first deformation bend part 1122, a second stiffness support part 1123, a second deformation bend part 1124 and an insertion foot part 1125 connected in sequence. The stiffness of the first stiffness support part and the second stiffness support part is greater than that of the first deformation bend part and the second deformation bend part. The jellyfish-shaped multi-stiffness foil 11 is at the bottom of the foil ring, and the jellyfish-shaped multi-stiffness foils are symmetrically arranged with the diameter in the vertical direction of the bearing seat as the center.

[0029] The length of the load-bearing part 111 is 50% of the length of the jellyfish-shaped multi-stiffness foil 11.

[0030] In the jellyfish-shaped multi-stiffness foil 11: A connecting main bend part 113 is provided between the load-bearing part and the deformation support part 12. The length of the connecting main bend part is 3% of the length of the jellyfish-shaped multi-stiffness foil 11. The length of the first stiffness support part 1121 is 10% of the length of the jellyfish-shaped multi-stiffness foil 11.

[0031] The length of the second stiffness support part 1123 is 10% of the length of the jellyfish-shaped multi-stiffness foil 11.

[0032] The inner circle of the foil ring 1 is circular. The jellyfish-shaped multi-stiffness foil 11 has a double-layer stacked structure, and the thickness of the jellyfish-shaped multi-stiffness foil is twice that of the arched multi-stiffness foil 12. When the annular air film is damaged under the action of external vibration excitation, the rotating shaft will first start to drop under the influence of gravity, increasing the pressure burden on the jellyfish-shaped multi-stiffness foil ring at the bottom. Compared with other arched multi-stiffness foils in the circumferential direction, the jellyfish-shaped multi-stiffness foil ring at the bottom also has to bear the gravity of the rotating shaft additionally. At the same time, the stiffness of the jellyfish-shaped multi-stiffness foil ring is increased, and the deformation amount after being excited is reduced as a whole, and it recovers more quickly, reducing friction and impact damage. Extend the overall service life. Such a double-layer structural design ensures that the foil ring deforms uniformly, regularly, and continuously under different vibration forces, thereby ensuring the stability of the air film.

[0033] The distribution of the foil stiffness should consider both the deformation amplitude under different loads and different vibration frequencies, so that the foil ring has good followability and ensures that the air film can be evenly distributed along with the vibration of the shaft.

[0034] As Figure 3 shown: Each arched multi-stiffness foil 12 includes an arched bearing part 121 and two symmetrically arranged arched deformation support parts. The arched deformation support part includes an arched deformation part 122 and an arched support part 123. The length of the arched bearing part 121 is L1, accounting for 60% of the overall length, and the lengths of the arched deformation part 122 and the arched support part 123 respectively account for 10% of the overall length.

[0035] In summary: The stiffness of the arched bearing part is K1, the stiffness of the arched support part is K3, and the stiffnesses of the bearing part 111, the first stiffness support part 1121, the second stiffness support part 1123, and the insertion part 1125 are all made of high-stiffness materials, while the first deformation bent part, the second deformation bent part, and the arched deformation part 122 are made of low-stiffness, high-toughness, and strong-deformation-capability materials. Before actual production, the stiffness of each part of the foil should calculate both the deformation amplitude under different loads and different vibration frequencies, and finally determine the stiffness range so that the foil ring has good followability and ensures that the air film can be evenly distributed along with the vibration of the shaft.

[0036] As Figure 4 shown: It is the normal working air domain diagram of the split independent foil air bearing; it can be seen that there is no mutual extrusion between the foils. The foils are connected in sequence to jointly form an air domain 4 that is circular near the shaft but has sharp corners between the foils. The shaft 3 works more stably in the air domain closer to the circle. Therefore, in later production, the shape and stiffness of the foil can be changed through processes to make the sharp corner area smaller.

[0037] As Figure 5Shown: is the structural diagram of a split independent foil air bearing after being subjected to external excitation vibration; it can be seen that the shaft is significantly displaced downward. At this time, the space above the shaft becomes larger, and the two arched multi-stiffness foils above bulge towards the shaft under their own acting forces; the arched multi-stiffness foils on the left and right sides and the jellyfish-shaped multi-stiffness foil below the shaft are displaced to the sides and downward under pressure.

[0038] As Figure 6 Shown: is the air domain diagram of a split independent foil air bearing after being subjected to external excitation vibration; after being subjected to external excitation vibration, the air film can still maintain a nearly circular shape, and the insertion feet of the two jellyfish-shaped multi-stiffness foils below are closer to each other under extrusion, and the pointed air gap is narrower. However, on the contrary, the arched multi-stiffness foil above has a larger pointed air gap due to the reduced pressure.

[0039] As Figure 7 Shown: is the comparison diagram of a split independent foil air bearing before and after bearing excitation vibration; as shown in the figure, the dotted line is the position of the foil and the shaft during normal operation, and the solid line is the position of the foil and the shaft after being subjected to excitation vibration.

[0040] In this embodiment, after the split independent foil ring is subjected to external vibration excitation, it has good deformation space. The shape of the foil ring deforms rapidly following the transfer of the central rotor and the air film. The foil ring has good followability, ensuring that the air film can be evenly distributed along with the vibration of the shaft. The foil ring is not likely to collide with the rotor, improving the service life of the foil bearing and expanding the application scenarios of the air bearing.

[0041] Of course, the present invention can also have many other embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and deformations according to the present invention, but these corresponding changes and deformations should all fall within the protection scope of the appended claims of the present invention.

Claims

1. A split-type independent foil air bearing, characterized in that: It includes a bearing housing (2) and a foil ring (1). The foil ring (1) includes a jellyfish-shaped multi-stiffness foil (11) and several arch-shaped multi-stiffness foils (12). The jellyfish-shaped multi-stiffness foil (11) includes a bearing part (111) and two symmetrically arranged deformation support parts (112). A slot (20) is provided on the bearing housing (2). The jellyfish-shaped multi-stiffness foil (11) and the arch-shaped multi-stiffness foil (12) are snap-connected to the slot (20). The jellyfish-shaped multi-stiffness foil (11) is at the bottom of the foil ring, and the jellyfish-shaped multi-stiffness foils are symmetrically arranged with the diameter of the bearing housing in the vertical direction as the center. In the jellyfish-shaped multi-stiffness foil (11): The cross-section of the deformation support part is S-shaped. The deformation support part (112) includes a first stiffness support part (1121), a first deformation bend part (1122), a second stiffness support part (1123), a second deformation bend part (1124) and a plug-in part (1125) connected in sequence. The stiffness of the first stiffness support part and the second stiffness support part is greater than that of the first deformation bend part and the second deformation bend part.

2. The split-type independent foil air bearing according to claim 1, wherein The length of the bearing part (111) is 20% - 60% of the length of the jellyfish-shaped multi-stiffness foil (11).

3. The split independent foil air bearing according to claim 2, characterized in that, In the jellyfish-shaped multi-stiffness foil (11): A connecting main bend part (113) is provided between the bearing part and the deformation support part (12). The length of the connecting main bend part is 3% - 5% of the length of the jellyfish-shaped multi-stiffness foil (11).

4. A split-type independent foil air bearing according to claim 1, characterized in that, The length of the first stiffness support part (1121) is 5% - 10% of the length of the jellyfish-shaped multi-stiffness foil (11).

5. A split-type independent foil air bearing according to claim 1, characterized in that, The length of the second stiffness support part (1123) is 5% - 10% of the length of the jellyfish-shaped multi-stiffness foil (11).

6. The split-type independent foil air bearing according to claim 1, characterized in that: Each arch-shaped multi-stiffness foil (12) includes an arch-shaped bearing part (121) and two symmetrically arranged arch-shaped deformation support parts. The arch-shaped deformation support part includes an arch-shaped deformation part (122) and an arch-shaped support part (123).

7. The split independent foil air bearing according to claim 1, wherein, The inner circle of the foil ring (1) is circular.

8. A split-type independent foil air bearing according to claim 1, characterized in that, The jellyfish-shaped multi-stiffness foil (11) is a double-layer superimposed structure, and the thickness of the jellyfish-shaped multi-stiffness foil is twice that of the arch-shaped multi-stiffness foil (12).

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