A combined gas thrust foil bearing device

Abstract

The application provides a combined gas thrust foil bearing device, which comprises a bottom plate assembly, a gasket arranged on the bottom plate assembly, and a plurality of top foils and combined wave foils clamped on the gasket and the bottom plate assembly; the gasket comprises an annular gasket body, and a gasket radial slot is annularly arranged on the inner side of the circumference of the annular gasket body; the end of the top foil and the combined wave foil of the device is provided with a bending part clamped in the radial slot and fixed on the gasket and the bottom plate, so that the top foil and the combined wave foil are in a natural state, the fixed end does not generate an additional mechanical effect on the top foil and the wave foil, and the thickness of the gasket can be adjusted to adjust the angle between the top foil and the combined wave foil; the combined wave foil can be composed of segmented wave foils and segmented flat foils with different widths; the rigidity and the carrying capacity of the entire combined wave foil can be changed through the combination of the segmented wave foils and the segmented flat foils with different widths, so that the specific requirements under different working conditions can be met.

Description

Technical Field

[0001] This invention relates to the field of hydrodynamic gas bearings, and more particularly to a combined gas thrust foil bearing device. Background Technology

[0002] In the 1970s, aerodynamic foil bearings were first applied in military fields such as aerospace, especially the corrugated foil bearings from the United States. In the 1980s and 90s, they were widely used in airborne turbines, turbine refrigeration units, and automotive turbochargers in civilian aircraft such as Boeing and fighter jets like the Mirage. South Korea also applied aerodynamic foil bearings to high-speed centrifugal blowers, developing various centrifugal blowers and compressors. However, to date, theoretical research on aerodynamic foil bearings is incomplete, and there are no universal design guidelines, making standardization and serialization difficult. Each bearing structure and design parameter requires individual research, development, and testing. The manufacturing process is complex, requiring significant investment and high-level technical expertise. Therefore, in recent years, several countries have been dedicated to developing their own unique foil bearings, hoping for successful applications in various high-speed turbine machinery. Currently, among the foil-type pressure gas bearings used in high-speed turbine machinery, the corrugated foil structure from the United States remains the most widely used. Most existing patents related to gas thrust foil bearings are of integral structure. For example, patent publication number CN105202027B discloses a hybrid hydrodynamic gas thrust bearing, which has the following disadvantages: 1. The outer and inner discs work together to fix the foil, which is fixed at one end to the inner end face of the outer disc. Then the inner and outer discs press the foil to be fixed for positioning. This integral structure has additional force at the fixing points of the corrugated foil and the top foil, and is not in a natural state, which affects the performance of the gas thrust foil bearing; 2. The corrugated foil is an integral fixed structure, and its stiffness and damping cannot be adjusted, so it is impossible to achieve the best performance according to actual needs. Summary of the Invention

[0003] To solve the above-mentioned technical problems, the present invention proposes a combined gas thrust foil bearing device, including a base plate assembly, on which a gasket is provided, and a plurality of top foils and combined wave foils are engaged on the gasket and the base plate assembly; the gasket includes an annular sheet body, and radial grooves of the gasket are arranged in annularly on the inner side of the annular sheet body.

[0004] The top foil includes an arc-shaped top foil sheet, and the end of the arc-shaped top foil sheet is provided with a top foil bending portion;

[0005] The combined corrugated foil has a corrugated foil bending portion at its end, the corrugated foil bending portion extends into the top foil bending portion, and the top foil bending portion is engaged in the radial groove. The corrugated foil bending portion is located at the lower part of the gasket, and the gasket is located between the top foil and the combined corrugated foil.

[0006] Preferably, the cylindrical pin passes through the gasket and connects the gasket and the base plate assembly.

[0007] Preferably, the base plate assembly includes a supporting base plate and a base plate layer located below the supporting base plate. The base plate layer and the supporting base plate are connected by a plurality of cylindrical pins. The supporting base plate is provided with a base plate radial groove corresponding to the gasket radial groove, and the base plate layer is provided with a groove or through hole corresponding to the gasket radial groove.

[0008] Preferably, the top foil bend and the corrugated foil bend pass through the radial groove of the bottom plate.

[0009] Preferably, the combined wave foil includes at least one set of staggered segmented flat foils and segmented wave foils, wherein the segmented flat foils and segmented wave foils are arranged axially.

[0010] Preferably, the top foil and the combined wave foil are arranged circumferentially on the gasket and the base plate assembly.

[0011] Preferably, the top foil bending portion and the corrugated foil bending portion are L-shaped.

[0012] Preferably, the upper surface of the top foil is provided with a wear-resistant coating.

[0013] The combined gas thrust foil bearing device proposed in this invention has the following advantages: 1. The ends of the top foil and the combined corrugated foil are provided with bent parts that are fixed to the gasket and the base plate by radial grooves, so that the top foil and the combined corrugated foil are in a natural state. The fixed end will not exert additional mechanical force on the top foil and the corrugated foil, and the thickness of the gasket can be adjusted to adjust the angle between the top foil and the combined corrugated foil; 2. The combined corrugated foil can be composed of segmented corrugated foil and segmented flat foil of different widths. By combining segmented corrugated foil and segmented flat foil of different widths, the stiffness and load-bearing capacity of the entire combined corrugated foil can be changed, so as to adapt to the specific needs under different working conditions. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below.

[0015] Figure 1 This is a three-dimensional schematic diagram of the present invention;

[0016] Figure 2 This is an exploded view of the present invention;

[0017] Figure 3 This is a schematic diagram of the top foil of the present invention;

[0018] Figure 4 This is a schematic diagram of the combined wave foil of the present invention;

[0019] Figure 5 This is a schematic diagram of the segmented flat foil of the present invention;

[0020] Figure 6 This is a schematic diagram of the segmented wave foil of the present invention;

[0021] Figure 7 This is a schematic diagram of the assembly of the combined corrugated foil, top foil, and gasket of the present invention;

[0022] Among them, 1. Top foil; 2. Combined corrugated foil; 3. Gasket; 4. Support base plate; 5. Base plate layer; 6. Segmented corrugated foil; 7. Segmented flat foil; 8. Cylindrical pin; 9. Radial groove of base plate; 10. Radial groove of gasket; 11. Groove or through hole; 12. Top foil arc sheet; 13. Top foil bending part; 14. Corrugated foil bending part. Detailed Implementation

[0023] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0024] like Figure 1 , Figure 2 As shown, this invention proposes a combined gas thrust foil bearing device, including a base plate assembly. A gasket 3 is provided on the base plate assembly. A plurality of top foils 1 and combined corrugated foils 2 are engaged on the gaskets 3 and the base plate assembly. The gasket 3 includes an annular sheet body with radial grooves 10 arranged circumferentially on its inner circumference. The top foils 1 and combined corrugated foils 2 are circumferentially arranged on the gasket 3 and the base plate assembly. The top foil 1 includes an arc-shaped piece 12. The ends of the arc-shaped piece 12... The composite corrugated foil 2 has a top foil bending section 13 and a corrugated foil bending section 14 at its end. The corrugated foil bending section 14 extends into the top foil bending section 13, and the top foil bending section 13 is engaged in the radial groove. The corrugated foil bending section 14 is located below the gasket 3, which is located between the top foil 1 and the composite corrugated foil 2. The top foil bending section 13 and the corrugated foil bending section 14 have the same structure, both being L-shaped. The corrugated foil bending section 14 is placed inside the top foil bending section 13. Figure 7As shown, the top foil bending portion 13 is inserted into the radial groove 10 of the gasket 3, while the corrugated foil bending portion 14 is side-locked into the lower part of the gasket 3. The gasket 3 has a certain thickness, which ensures that an angle is generated between the corrugated foils below the top foil arc-shaped piece 12 of the top foil 1. By using gaskets 3 of different thicknesses, the angle A between the top foil and the corrugated foil can be adjusted. The thrust plate of the rotating shaft works by being supported by the foil bearing. The foil bearing can support the thrust plate because a converging wedge-shaped gap is formed between the top foil and the thrust plate, forming an air film that can generate load-bearing capacity. Therefore, adjusting the tilt angle of the top foil can change the size of the wedge-shaped gap, change the thickness of the air film, and thus change the load-bearing capacity of the foil bearing. When the foil bearing cannot meet the load-bearing capacity requirements under specific working conditions, it is not necessary to replace the entire foil bearing. Only the top foil or the combined corrugated foil needs to be replaced to adapt to the load-bearing capacity requirements under that working condition and to adapt to different working conditions.

[0025] Additionally, the base plate assembly includes a supporting base plate 4 and a base plate reinforcement layer 5 located below the supporting base plate 4. The base plate reinforcement layer 5 and the supporting base plate 4 are connected by several cylindrical pins 8. The supporting base plate 4 has a base plate radial groove 9 corresponding to the gasket radial groove 10. The base plate reinforcement layer 5 has a groove or through hole 11 corresponding to the gasket radial groove 10. The cylindrical pins 8 can fix the base plate assembly and the gasket 3 axially. The cylindrical pins 8 can finally fix the gasket 3 and the base plate assembly to the base (not shown). Due to the setting of the bending part, the top foil bending part 13 and the corrugated foil bending part 14 both pass through the base plate radial groove 9 on the supporting base plate 4, and their bottoms are inserted into the groove or through hole 11 of the base plate reinforcement layer 5 to achieve circumferential and axial positioning. The upper surface of the top foil 1 is provided with a wear-resistant coating to increase the service life of the top.

[0026] Additionally, it should be noted that this embodiment uses a combined wave foil 2, such as... Figure 4 , Figure 5 , Figure 6As shown, the combined corrugated foil 2 includes at least one set of staggered segmented flat foils 7 and segmented corrugated foils 6. The segmented flat foils 7 and segmented corrugated foils 6 are arranged axially. The segmented flat foil 7 is a flat arc-shaped structure with a corrugated foil bending part at one end. The segmented corrugated foil 6 is an arc-shaped sheet with a wavy structure on the surface. The number of segmented flat foils 7 and segmented corrugated foils 6 is adjustable. Through the segmented structure, segmented corrugated foils 6 and segmented flat foils 7 of different widths can be selected to form the combination. The corrugated foil bending parts 14 of each segmented corrugated foil 6 and segmented flat foil 7 are aligned and arranged. After assembly, the other end is the free end, ensuring that no additional force is applied to the top foil 1 and the combined corrugated foil 2. The thickness of the top foil 1 (1) is 1.5mm-2.0mm, and the thickness of the combined corrugated foil 2 (2) is 0.8mm-1.0mm. By combining segmented corrugated foil 6 and segmented flat foil 7 of varying widths, the stiffness of the combined corrugated foil 2 can be altered through different combinations of segmented flat foil 7 and segmented corrugated foil 6. This facilitates optimized combination of corrugated foil performance to meet different stiffness requirements under various working conditions and adapt to practical needs. Different combinations of corrugated foil 2 expand the range of bearing stiffness variation, improve the stiffness characteristics of foil bearings, and make them more suitable for various working conditions with different stiffness requirements. Furthermore, the entire structure has no welded or fixed parts, making disassembly and assembly extremely convenient. In contrast, integral bearings cannot be adjusted; once manufactured, all parameters are fixed. This application allows for adjustment; the segmented corrugated foil can adjust not only its width but also the corrugation distance and the number of corrugations. The stiffness characteristics and load-bearing capacity of the segmented corrugated foil vary with width, corrugation distance, and the number of corrugations. Therefore, by changing the width of the segmented flat foil and the segmented corrugated foil, as well as the corrugation distance and number of corrugations, the stiffness characteristics and load-bearing capacity of the combined corrugated foil can be altered. Experiments can be conducted to determine the stiffness and load-bearing capacity of different combinations of segmented flat foil and segmented corrugated foil, allowing for a one-to-one correspondence with different working conditions. Knowing the corresponding stiffness and load-bearing capacity requirements, the appropriate combination of corrugated foil can be selected to meet different needs.

Claims

1. A combined gas thrust foil bearing device, comprising a base plate assembly, characterized in that, The base plate assembly is provided with a gasket, and a plurality of top foils and combined corrugated foils are engaged on the gasket and the base plate assembly; the gasket includes an annular sheet body, and radial grooves of the gasket are arranged in annular arrangement on the inner circumference of the annular sheet body. The top foil includes an arc-shaped top foil sheet, and the end of the arc-shaped top foil sheet is provided with a top foil bending portion; The combined corrugated foil has a corrugated foil bending portion at its end, the corrugated foil bending portion extends into the top foil bending portion, and the top foil bending portion is engaged in the radial groove. The corrugated foil bending portion is located at the lower part of the gasket, and the gasket is located between the top foil and the combined corrugated foil.

2. The combined gas thrust foil bearing device according to claim 1, characterized in that, The base plate assembly includes a supporting base plate and a base plate layer located below the supporting base plate. The base plate layer and the supporting base plate are connected by a plurality of cylindrical pins. The supporting base plate is provided with a base plate radial groove corresponding to the gasket radial groove, and the base plate layer is provided with a groove or through hole corresponding to the gasket radial groove.

3. The combined gas thrust foil bearing device according to claim 2, characterized in that, The cylindrical pin passes through the gasket and connects the gasket and the base plate assembly.

4. The combined gas thrust foil bearing device according to claim 2, characterized in that, The top foil bending section and the corrugated foil bending section pass through the radial groove of the bottom plate.

5. The combined gas thrust foil bearing device according to claim 1, characterized in that, The combined wave foil includes at least one set of staggered segmented flat foils and segmented wave foils, wherein the segmented flat foils and segmented wave foils are arranged axially.

6. The combined gas thrust foil bearing device according to claim 1, characterized in that, The top foil and the combined wave foil are arranged circumferentially on the gasket and the base plate assembly.

7. The combined gas thrust foil bearing device according to claim 1, characterized in that, The top foil bending section and the corrugated foil bending section are L-shaped.

8. The combined gas thrust foil bearing device according to claim 1, characterized in that, The upper surface of the top foil is provided with a wear-resistant coating.

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