Radial gas foil bearing with air gaps in four directions of circumference capable of being independently adjusted

Abstract

The utility model discloses a radial gas foil bearing capable of independently adjusting circumferential four-direction air gaps. The radial gas foil bearing structurally comprises a bearing sleeve, an air gap adjusting screw rod, a locking screw, a wedge-shaped push block, a supporting tile, a bump foil and a flat foil. The air gap adjusting screw drives the wedge-shaped push block to move axially, so that the position of the supporting tile is adjusted, the bump foil is pushed to be compressed or released, and accurate adjustment of the air gap is achieved; each air gap adjusting screw can independently control the corresponding push block, independent adjustment of air gaps in four directions is ensured, and high precision and flexibility are provided. According to the bearing structure, independent adjustment is achieved through an air gap adjusting mechanism formed by four sets of air gap adjusting screws, wedge-shaped push blocks, supporting tiles and bump foils, the performance of the bearing is optimized, load changes and air film rigidity are adapted, the stability and efficiency of a rotor system are improved, and the bearing structure adapts to various complex working conditions.

Description

A radial gas foil bearing with independently adjustable air gap in four directions around the circumference. Technical Field

[0001] This utility model belongs to the field of mechanical transmission technology, specifically relating to a radial gas foil bearing with independently adjustable air gap in four directions around the circumference. Background Technology

[0002] Among the many types of gas bearings, foil gas hydrodynamic bearings are widely used in high-speed rotating machinery due to their simple structure. These bearings consist of corrugated and flat foils, and their load-bearing capacity, preload, stiffness, and damping are key parameters for evaluating their performance, directly affecting the stability of the rotor system. The bearing's stiffness and damping are determined by the foil air gap structure and the gas film; therefore, rationally designing the bearing's support stiffness and increasing structural damping are crucial aspects of foil gas hydrodynamic bearing design.

[0003] However, existing foil bearings have some limitations. For example, Chinese patent application CN119288975A provides an adjustable stiffness foil gas hydrodynamic bearing. This bearing achieves active adjustment of bearing stiffness by rapidly adjusting the elastic modulus of the SMA (shape memory alloy) foil through an electrically controlled heating film and cooling plate. This solves to some extent the technical problem that existing foil gas hydrodynamic bearings cannot cross critical speeds and ultra-high speed instability. However, its adjustment mechanism relies on the electrically controlled heating film and cooling plate, which may increase the complexity and energy consumption of the system. Moreover, the response speed and adjustment range of the SMA foil may be limited by the material properties, making it impossible to achieve rapid and precise adjustment under all operating conditions.

[0004] It is evident that the performance of foil gas bearings is affected by the foil air gap structure and air film thickness. Once traditional foil bearings are assembled, the air gap cannot be adjusted according to load changes, resulting in the inability to actively adjust the air film thickness when the equipment operating conditions change. This affects the bearing's load-bearing capacity, stiffness, and damping, and consequently, the stability and performance of the rotor system. Summary of the Invention

[0005] In view of the above, this utility model provides a radial gas foil bearing with independently adjustable air gap in four directions around the circumference. This bearing can precisely adjust the air gap between itself and the rotor, actively adapt to changes in load and eccentricity, improve the bearing's load-bearing capacity, stiffness and damping, and optimize the dynamic performance of the bearing-rotor system.

[0006] A radial gas foil bearing with independently adjustable air gap in four directions around the circumference includes a bearing sleeve, an air gap adjusting screw, a push block, a support pad, corrugated foil, and flat foil, wherein:

[0007] The bearing sleeve adopts a hollow cylindrical structure. Four threaded holes are evenly distributed on the end face of the bearing sleeve for installing the air gap adjustment screw. Four threaded holes are distributed on the circumference of the bearing sleeve, and locking screws are installed in the holes to lock the position of the air gap adjustment screw. Four wedge-shaped grooves are evenly distributed inside the bearing sleeve for installing push blocks. Multiple slots are also evenly distributed on the inner side of the bearing sleeve for embedding corrugated foil and flat foil, ensuring the fixation of the foil and the precise realization of air gap adjustment.

[0008] The air gap adjusting screw is installed in the threaded hole on the end face of the bearing sleeve and faces the push block. The air gap adjusting screw drives the axial movement of the push block by rotation, changes the position of the push block, and then changes the radial position of the support tile to adjust the air gap between the corrugated foil and the flat foil.

[0009] The pusher block has a wedge-shaped structure and is axially embedded in the wedge groove. It is driven to move axially by the air gap adjusting screw. The axial movement of the pusher block causes the support plate to move radially, thereby compressing or releasing the corrugated foil and adjusting the air gap between it and the rotor.

[0010] The support tile is an arc-shaped tile structure located between the push block and the corrugated foil. As the push block moves axially, the support tile moves radially, pushing the corrugated foil to compress or release. The movement of the support tile enables precise adjustment of the air gap.

[0011] The corrugated foil is fixed in a slot inside the bearing sleeve. The corrugated foil is compressed or released by the radial movement of the support bearing to adjust the air gap with the rotor. The compression and release of the corrugated foil directly affects the thickness of the air film and the bearing capacity.

[0012] The flat foil is embedded in the slot inside the bearing sleeve. One side of the flat foil is in contact with the corrugated foil, and the other side forms an adjustable air gap with the rotor. The flat foil can move slightly in the radial and axial directions within the slot to adapt to the air gap adjustment. The flat foil and the corrugated foil work together to ensure the stability of the air film and optimize the load-bearing capacity.

[0013] Furthermore, the inner side of the bearing sleeve has 8 corrugated foil slots and 1 flat foil slot. The corrugated foil slots are used to fix 4 corrugated foils, which are evenly distributed circumferentially. The two ends of each corrugated foil are respectively embedded in the corresponding corrugated foil slot. One end of the flat foil is embedded in the flat foil slot. The width of the corrugated foil slot and the flat foil slot are respectively matched with the thickness of the corrugated foil and the end of the flat foil, ensuring that the foil is firmly fixed in the slot, reducing structural gaps, and ensuring precise adjustment.

[0014] Furthermore, the flat foil is supported by four corrugated foils. The radial compression movement of the flat foil can change the air gap with the rotor. The compression of the four corrugated foils is driven radially by four independent support tiles. The four support tiles are installed in corresponding wedge-shaped grooves and are driven radially by independent push blocks.

[0015] Furthermore, the corrugated foil has an overall arc-shaped structure, and the side that is in contact with the flat foil has a wavy structure. The two ends of the corrugated foil are embedded in the bearing sleeve and move slightly along the radial direction of the corrugated foil groove. The corrugated foil is attached between the support tile and the flat foil, providing elastic support force and ensuring that the bearing operates smoothly and efficiently by relying on air buoyancy without mechanical contact.

[0016] Furthermore, the flat foil is a planar structure that is a complete circle, with its fixed end embedded in the flat foil slot, enabling limited axial and radial movement, while the free end is suspended.

[0017] Furthermore, the axial length of the corrugated foil and the flat foil is less than the axial length of the bearing sleeve, and one side of the corrugated foil and the flat foil is aligned with the bearing sleeve.

[0018] Furthermore, the flat foil, corrugated foil, support tile, and push block are tightly fitted together in sequence along the radial direction of the bearing sleeve, and are combined with the corresponding air gap adjusting screw to form four sets of air gap adjusting mechanisms, thereby realizing independent air gap adjustment in four directions.

[0019] This invention aims to solve the problem of the inability to adjust the air gap in the prior art. Through structural innovation, it achieves independent adjustment of the air gap in four directions, improves the adjustment accuracy, response speed and stability of the bearing, thereby accurately controlling the air film thickness, improving bearing performance, and adapting to the dynamic adjustment requirements of the air film thickness under different working conditions. It is particularly suitable for air gap adjustment applications in ultra-high speed rotor systems.

[0020] This invention utilizes an air gap adjustment mechanism consisting of four sets of "air gap adjusting screws, wedge-shaped pushers, support tiles, and corrugated foils" to achieve independent air gap adjustment in four directions. The wedge-shaped pushers are driven axially by the air gap adjusting screws, and this axial force is converted into radial movement of the support tiles via a wedge-shaped transmission structure. This, in turn, drives the corrugated foils to compress, adjusting the radial position of the corresponding flat foils. Each air gap adjusting screw can individually control its corresponding pusher, thereby precisely adjusting the air gap in each direction and ensuring the flexibility and high precision of the bearing. Therefore, this invention offers the following beneficial technical effects:

[0021] 1. The radial gas foil bearing proposed in this utility model has independently controllable air gaps in four directions. It can flexibly adjust the gas film thickness according to the load and working conditions in different directions, thereby optimizing the bearing's stiffness, damping and load-bearing capacity, breaking through the technical limitations of traditional foil bearings that rely on a fixed overall structure and passively adapt to the load.

[0022] 2. This utility model innovatively introduces an air gap adjustment mechanism. The four corrugated foils are independently supported by four support tiles. By controlling the in-and-out movement of the air gap adjustment screw, the wedge-shaped push block is pushed to move back and forth, and then the support tiles are radially squeezed. The support tiles radially squeeze the foils, thereby controlling the compression and release states of each corrugated foil and flat foil, and realizing the active dynamic adjustment of the air gap between the rotor and the rotor.

[0023] 3. The structure of this utility model is suitable for applications requiring high rigidity and dynamic adjustment capabilities, such as ultra-high speed motors and aero engines. The independent adjustment of the air gap in different directions can adapt to changes in load direction in real time. The gap is reduced in the heavy load direction to enhance the air film rigidity, and the gap is increased in the light load direction to reduce friction loss. It has the characteristics of high adjustment accuracy, fast response speed and compact structure. Attached Figure Description

[0024] Figure 1 is a front view of the axial side of the radial gas foil bearing in an embodiment of this utility model.

[0025] Figure 2 is a reverse side view of the radial gas foil bearing in an embodiment of this utility model.

[0026] Figure 3 is an axial cross-sectional view of the push block-support tile structure in an embodiment of this utility model.

[0027] Figure 4 is a radial cross-sectional view of the push block-support tile structure in an embodiment of this utility model.

[0028] Figure 5 is an axial view of the flat foil, corrugated foil, and push block-support tile structure in an embodiment of this utility model.

[0029] Figure 6 is a schematic diagram of the structure of the flat foil and the corrugated foil in the embodiment of this utility model.

[0030] In the figure: 1—bearing sleeve, 2—air gap adjusting screw, 3—push block, 4—support tile, 5—corrugated foil, 6—flat foil, 7—corrugated foil slot, 8—flat foil slot, 9—wedge groove, 10—locking screw. Detailed Implementation

[0031] To describe the present invention in more detail, the technical solution of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0032] This embodiment provides a radial gas foil bearing with independently adjustable air gaps in four directions. This bearing is mainly used in ultra-high speed motor systems. Through four independently adjustable air gaps, the bearing performance can be precisely adjusted under dynamic load changes, thereby improving the stability and performance of the rotor-bearing system.

[0033] In this embodiment, the bearing parameters are as follows: outer diameter 52mm, inner diameter 25mm, and length 29mm; corrugated foil parameters are as follows: thickness 0.2mm, height 0.9mm, and number of corrugations 7×4; flat foil parameters are as follows: thickness 0.25mm; and the maximum adjustable clearance of the bearing is 0.5mm (single side).

[0034] As shown in Figures 1-4, the radial gas foil bearing in this embodiment includes a bearing sleeve 1, an air gap adjusting screw 2, a push block 3, a support plate 4, a corrugated foil 5, and a flat foil 6, wherein:

[0035] The bearing sleeve 1 has a hollow cylindrical structure. Four threaded holes are evenly distributed on the end face of the bearing sleeve for installing the air gap adjusting screw 2. Four threaded holes are distributed on the radial circumferential surface for installing locking screws 10 to lock the position of the air gap adjusting screw. Four wedge-shaped grooves 9 are evenly distributed inside the bearing sleeve for installing push blocks 3. Each air gap adjusting screw 2 cooperates with the push block 3. By rotating the air gap adjusting screw 2, the push block 3 moves back and forth axially (X-axis). The push block 3 has a wedge-shaped structure, embedded in the wedge-shaped groove 9, and its axial displacement is achieved by rotating the air gap adjusting screw 2. The axial movement of the push block drives the support plate 4 to move radially (Y-axis), which in turn drives the corrugated foil 5 to compress or release, adjusting the air gap between the corrugated foil and the rotor.

[0036] Eight corrugated foil slots 7 and one flat foil slot 8 are evenly distributed on the inner side of the bearing sleeve. The corrugated foil slots 7 are used to install corrugated foil pieces 5, and the flat foil slots 8 are used to install flat foil pieces 6. As shown in Figure 6, the corrugated foil piece 5 is a wavy arc-shaped piece, and its two ends are fixed in the bearing sleeve through the corrugated foil slots, while the wavy surface is in close contact with the flat foil piece 6; the flat foil piece 6 has a planar structure, with its fixed end embedded in the flat foil slot, its free end suspended, and an air gap formed between it and the rotor surface.

[0037] The axial length of the flat foil 6 is less than that of the bearing sleeve 1, so during the air gap adjustment process, the flat foil 6 can move slightly radially (Y-axis) and axially (X-axis) within the slot. In particular, the thickness of the fixed end of the corrugated foil 5 and the flat foil 6 matches the width of the corrugated foil slot 7 and the flat foil slot 8, thereby ensuring that the foils are firmly assembled within the slot and reducing structural gaps.

[0038] The working principle of this embodiment is as follows: by rotating the air gap adjusting screw 2, the push block 3 is controlled to move back and forth. Since the push block 3 is a wedge-shaped structure, the axial movement is converted into the radial movement of the support tile 4 through the wedge-shaped transmission structure, thereby driving the wave foil 5 to be compressed or released radially, thereby adjusting the air gap between the flat foil 6 and the rotor.

[0039] As shown in Figure 5, the air gap adjustment mechanism formed by four sets of "air gap adjusting screws 2-wedge push blocks 3-support tiles 4-corrugated foil 5" allows the air gaps in the four directions of the flat foil 6 to be adjusted independently. Each air gap adjusting screw 2 can achieve precise control of the air gaps in the four directions by individually controlling its corresponding push block 3.

[0040] When an ultra-high-speed motor is running, the air gap of the bearing needs to be adjusted in real time according to parameters such as speed and load under different loads and operating conditions. Assuming the system is operating at high speed, due to factors such as centrifugal force and vibration, the load in some directions may be relatively heavy. In this case, the air gap in these directions can be adjusted to increase the stiffness of the air film and enhance the load-bearing capacity. For the light load directions, the air gap can be increased to reduce friction loss and further improve system efficiency.

[0041] For example, if the system is under light load during startup, adjusting the air gap adjusting screw increases the air gap of the flat foil to reduce friction; while when the speed increases to a high load, adjusting the air gap adjusting screw decreases the air gap to enhance the support of the air film and maintain the stability and operating accuracy of the system.

[0042] The above description of the embodiments is provided to enable those skilled in the art to understand and apply the present invention. Those skilled in the art can readily make various modifications to the above embodiments and apply the general principles described herein to other embodiments without creative effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made to the present invention by those skilled in the art based on the disclosure of the present invention should be within the protection scope of the present invention.

Claims

1. A radial gas foil bearing with independently adjustable four-dimensional air gap, characterized in that, The system includes a bearing sleeve, an air gap adjusting screw, a push block, a support pad, corrugated foil, and a flat foil. The bearing sleeve has a hollow cylindrical structure with four threaded holes evenly distributed on its end face for mounting the air gap adjusting screw. Four threaded holes are also distributed on the circumference of the bearing sleeve, each housing a locking screw to lock the air gap adjusting screw. Four wedge-shaped grooves are evenly distributed inside the bearing sleeve for mounting the push block. Multiple slots are also evenly distributed on the inner side of the bearing sleeve for embedding the corrugated foil and flat foil. The air gap adjusting screw is installed in the threaded hole on the end face of the bearing sleeve, directly opposite the push block. The screw rotates to drive the axial movement of the push block, changing its position and thus the radial position of the support pad, thereby adjusting the air gap between the corrugated foil and the flat foil. The push block... The structure is wedge-shaped, axially embedded in a wedge-shaped groove, and driven axially by an air gap adjusting screw. The axial movement of the push block drives the support plate to move radially, thereby compressing or releasing the corrugated foil and adjusting the air gap with the rotor. The support plate is an arc-shaped tile structure located between the push block and the corrugated foil. As the push block moves axially, the support plate moves radially, pushing the corrugated foil to compress or release. The corrugated foil is fixed in a slot on the inner side of the bearing sleeve. The corrugated foil is compressed or released by the radial movement of the support plate, adjusting the air gap with the rotor. The flat foil is embedded in a slot on the inner side of the bearing sleeve. One side of the flat foil is in contact with the corrugated foil, and the other side forms an adjustable air gap with the rotor. The flat foil can move slightly radially and axially within the slot to adapt to air gap adjustment.

2. The radial gas foil bearing with independently adjustable four-dimensional air gap according to claim 1, characterized in that: The bearing sleeve has 8 corrugated foil slots and 1 flat foil slot distributed on its inner side. The corrugated foil slots are used to fix 4 corrugated foil pieces, which are evenly distributed circumferentially. The two ends of each corrugated foil piece are respectively embedded in the corresponding corrugated foil slot. One end of the flat foil piece is embedded in the flat foil slot. The width of the corrugated foil slot and the flat foil slot are respectively matched with the thickness of the corrugated foil piece and the end of the flat foil piece, to ensure that the foil piece is firmly fixed in the slot.

3. The radial gas foil bearing with independently adjustable four-dimensional air gap according to claim 2, characterized in that: The flat foil is supported by four corrugated foils. The radial compression movement of the flat foil can change the air gap with the rotor. The compression of the four corrugated foils is driven radially by four independent support tiles. The four support tiles are installed in corresponding wedge grooves and are driven radially by independent push blocks.

4. The radial gas foil bearing with independently adjustable four-dimensional air gap according to claim 1, characterized in that: The corrugated foil has an overall arc-shaped structure, and the side that is in contact with the flat foil has a wavy structure. The two ends of the corrugated foil are embedded in the bearing sleeve and move slightly along the radial direction of the corrugated foil groove. The corrugated foil is attached between the support tile and the flat foil, providing elastic support force and ensuring that the bearing operates smoothly and efficiently by relying on air buoyancy without mechanical contact.

5. The radial gas foil bearing with independently adjustable four-dimensional air gap according to claim 1, characterized in that: The flat foil is a planar structure that is a complete circle. Its fixed end is embedded in the flat foil slot, which can achieve limited axial and radial movement, while the free end is suspended.

6. The radial gas foil bearing with independently adjustable four-dimensional air gap according to claim 1, characterized in that: The axial length of the corrugated foil and the flat foil is less than the axial length of the bearing sleeve, and one side of the corrugated foil and the flat foil is aligned with the bearing sleeve.

7. The radial gas foil bearing with independently adjustable four-dimensional air gap according to claim 1, characterized in that: The flat foil, corrugated foil, support tile, and push block are tightly fitted together in sequence along the radial direction of the bearing sleeve, and are combined with the corresponding air gap adjusting screw to form four sets of air gap adjusting mechanisms, so as to realize independent air gap adjustment in four directions.

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