Hydrostatic gas-lubricated bearings supported by metal-rubber damping elements

Abstract

This invention relates to the field of gas-lubricated bearings, and discloses a hydrostatic gas-lubricated bearing supported by a metal-rubber damping element, comprising a bearing sleeve, an annular metal-rubber damping element, and a top foil. The bearing sleeve has symmetrically arranged annular grooves of the same specifications at both ends, and four air supply channels are arranged at equal angles along the circumference of its central part. Two annular metal-rubber damping elements of the same specifications are symmetrically installed within the annular grooves. The top foil provides a lubrication surface for the bearing, and has four air inlets arranged at equal angles along its central circumference. The air inlets and air supply channels are coaxially arranged with the same diameter, and the inner side of the top foil is designed with a surface microtexture with a depth of 0.005 mm to 0.01 mm to improve friction and generate a secondary pressure boosting effect. This invention employs hydrostatic hybrid lubrication and a metal-rubber elastic support, resulting in a simple structure, high stiffness and damping characteristics, improved load-bearing capacity and operational stability, and reduced frictional power consumption during start-up, shutdown, and stable operation.

Description

Technical Field

[0001] This invention relates to the field of gas-lubricated bearings for aerospace and defense industries, and more specifically to hydrostatic gas-lubricated bearings supported by metal-rubber damping elements. Background Technology

[0002] Gas-lubricated bearings, with their unique advantages such as high speed, low frictional power consumption, high precision, and no pollution, are widely used in modern advanced turbine machinery such as centrifuges, gyroscopes, turbine blowers, air circulators, and turbine compressors in aerospace equipment. However, traditional foil-type gas hydrodynamic bearings suffer from large nonlinear deformation of the elastic support structure during operation, resulting in poor load-bearing capacity and shaft system stability, making it difficult to meet the urgent performance requirements of the aerospace field for key components, such as high load-bearing capacity, high speed, and high precision.

[0003] Using ambient air with low viscosity as the lubricating medium and employing an elastic support surface design severely limits the load-bearing capacity of gas hydrodynamic bearings, a long-standing global challenge for researchers. To address this, numerous scholars have been continuously developing and improving gas-lubricated bearing technology. After decades of tackling technical difficulties, gas-lubricated bearing technology has made breakthrough progress. However, the improved bearings still suffer from low load-bearing capacity, poor shaft system stability, and high frictional power consumption during operation. Therefore, seeking new support structures for gas-lubricated bearings with the goal of improving bearing load-bearing capacity and enhancing shaft system stability is particularly important. Summary of the Invention

[0004] This invention addresses the problems of limited load-bearing capacity, poor shaft system stability, and severe frictional wear of the top foil in traditional foil-type gas lubricated bearings. It provides a hydrostatic gas lubricated bearing supported by a metal-rubber damping element to achieve stable operation, high load-bearing capacity, and reduced frictional power consumption.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a hydrostatic gas-lubricated bearing supported by a metal-rubber damping element, comprising: a bearing sleeve, an annular metal-rubber damping element, and a top layer foil. The bearing sleeve has symmetrically arranged annular grooves of the same specification at both ends, and four air supply channels are arranged at equal angles along the circumferential direction of its central part, with a narrow through slot on its inner side. The annular metal-rubber damping element is coaxially arranged with the bearing sleeve, and two annular metal-rubber damping elements of the same specification are symmetrically installed in the annular grooves at both ends of the bearing sleeve to provide structural stiffness and damping. The top layer foil is coaxially arranged with the bearing sleeve, providing a lubrication surface for the hydrostatic gas-lubricated bearing, and has four air inlets at equal angles along its central circumferential direction. The air inlets and air supply channels are coaxially arranged with the same diameter. The present invention simultaneously possesses hydrostatic and hydrodynamic effects, and employs a metal-rubber elastic support form, enabling the gas-lubricated bearing to obtain high stiffness and damping characteristics, improving the bearing's load-bearing capacity and shaft system operational stability, and reducing frictional power consumption during start-up, shutdown, and stable operation.

[0006] Furthermore, the radial angle between the radial axis of the air supply channel, which is close to the narrow groove on the inner side of the bearing sleeve, and the radial axis of the narrow groove on the inner side is 45°.

[0007] Furthermore, the annular metal-rubber damping element is a three-dimensional elastic mesh structure formed by cold stamping after winding, stretching, laying, and coiling metal wires made of GH2696 or GH3030 raw materials. It has the dual characteristics of metal and rubber and can maintain good structural stiffness and damping characteristics even under high and low temperature and high pressure environments.

[0008] Furthermore, the annular metal rubber damping element is symmetrically installed in the annular groove on the end face of the bearing sleeve, and its opening matches the narrow through groove on the inner side of the bearing sleeve.

[0009] Furthermore, there is a gap between the two identical annular metal-rubber damping elements, and the gap accounts for 25% to 35% of the axial length of the bearing.

[0010] Furthermore, the inner surface of the top foil is uniformly coated with a PS304 coating using a high-temperature resistant spraying technology.

[0011] Furthermore, one end of the top foil is fixed in the narrow groove inside the bearing sleeve, and the other end is freely overlapped on the inner surface of the annular metal rubber damping element.

[0012] Furthermore, the air inlet on the top foil and the air supply channel on the bearing sleeve housing are arranged coaxially with the same diameter.

[0013] Furthermore, the air inlet and air supply channel are connected to an external air source.

[0014] Furthermore, the inner side of the top foil is designed with a surface microtexture with a depth of 0.005 mm to 0.01 mm to improve friction and generate a secondary pressure boosting effect.

[0015] The technical solution adopted in this invention achieves the following effects: This invention employs both hydrostatic and dynamic lubrication methods. During the operation of the hydrostatic gas-lubricated bearing, the combined effect of the gas pressure provided by the external air supply device and the dynamic pressure generated by the high-speed rotation of the rotor greatly increases the bearing's load-bearing capacity. It exhibits excellent load-bearing capacity and dynamic performance under both low-speed and high-speed operating conditions. Simultaneously, the top foil undergoes flexural deformation under gas film pressure, forcing the annular metal-rubber damping element to undergo radial elastic deformation, thereby providing elastic support to the journal. This significantly increases the operational stability of the hydrostatic gas-lubricated bearing. Furthermore, the inner surface of the top foil is uniformly coated with a PS304 coating using high-temperature spraying technology, which greatly reduces frictional power consumption during start-up, shutdown, and stable operation. Additionally, the 0.005mm to 0.01mm deep surface microtexture on the inner side of the top foil generates a secondary pressurization effect, further enhancing the gas film load-bearing capacity and reducing frictional wear. Compared with existing gas-lubricated bearings, the hydrostatic gas-lubricated bearing supported by metal rubber damping elements provided by this invention combines the advantages of gas static bearings and gas dynamic bearings. It has both static pressure effect and dynamic pressure effect, and has good load-bearing capacity and dynamic operation stability whether the bearing is running at low speed or high speed. It significantly improves the load-bearing capacity of the bearing and the operation stability of the shaft system, and can reduce the friction power consumption and impact vibration of the bearing during start-up, shutdown and stable operation. Attached Figure Description

[0016] Figure 1 A schematic diagram of a hydrostatic gas-lubricated bearing supported by a metal-rubber damping element;

[0017] Figure 2 An exploded view of a hydrostatic gas-lubricated bearing supported by a metal-rubber damping element;

[0018] Figure 3 This is a schematic diagram of the bearing sleeve structure;

[0019] Figure 4 This is a schematic diagram of a metal-rubber damping element.

[0020] Figure 5 This is a schematic diagram of the top foil structure;

[0021] Figure 6 This is a schematic diagram showing the unfolded inner surface of the top foil.

[0022] In the figure: 1. Bearing sleeve, 2. Annular metal rubber damping element, 3. Top layer foil, 4. Air inlet, 5. Air supply channel, 6. Narrow channel, 7. Surface microtexture. Detailed Implementation

[0023] like Figure 1 , Figure 2 As shown, a hydrostatic gas-lubricated bearing supported by a metal-rubber damping element includes: a bearing sleeve (1), an annular metal-rubber damping element (2), and a top foil (3). This invention adopts a hydrostatic mixed lubrication method, that is, the bearing is jointly supported by the external air source and the dynamic pressure generated by the bearing. This invention adopts an elastic support scheme of an annular metal-rubber damping element (2), which has a simple structure and easy clearance adjustment, enabling the gas-lubricated bearing to obtain excellent stiffness and damping characteristics, improving the bearing load capacity and shaft system operation stability, and reducing the frictional power consumption of the bearing during start-up, shutdown, and stable operation. The bearing sleeve (1) has annular grooves of the same specification symmetrically arranged at both ends, and four air supply channels (5) are arranged at equal angles along the circumferential direction of the middle part of its housing. The annular metal-rubber damping element (2) is coaxially arranged with the bearing sleeve (1), and two annular metal-rubber damping elements (2) of the same specification are symmetrically installed in the annular grooves on the end face of the bearing sleeve (1) to provide structural stiffness and damping, and to provide elastic support for the journal. The top foil (3) is coaxially arranged with the bearing sleeve (1), which can provide a lubrication surface for the dynamic and static pressure gas lubricated bearing, and four air inlets (4) are arranged at equal angles along the central circumferential direction.

[0024] like Figure 3 As shown, the bearing sleeve (1) serves to support and protect the bearing. The bearing sleeve (1) has symmetrically arranged annular grooves of the same specifications at both ends, and four air supply channels (5) are arranged at equal angles along the circumference of its housing. The radial axis of the air supply channel (5), which is close to the narrow through groove (6) on the inner side of the bearing sleeve (1), is at an angle of 45° with the radial axis of the narrow through groove (6). When the hydrostatic pressure gas-lubricated bearing is not started, lubricating gas is supplied by an external air supply device through the air supply channel (5) until the bearing stops operating. This scheme can reduce friction during the bearing start-up and shutdown phases. During the stable operation phase of the bearing, the journal is supported by the external air source and the dynamic pressure generated by the high-speed rotation of the rotor.

[0025] like Figure 4As shown, the annular metal-rubber damping element (2) is a three-dimensional elastic mesh structure formed by cold stamping after winding, stretching, laying, and coiling metal wire made of GH2696 or GH3030 raw materials. It has the dual characteristics of metal and rubber, and can provide excellent structural stiffness and damping under high temperature, low temperature and high pressure environments. The annular metal-rubber damping element (2) is coaxially arranged with the bearing sleeve (1). Two annular metal-rubber damping elements (2) of the same specification are symmetrically installed in the annular grooves at both ends of the bearing sleeve (1), and their openings are matched with the narrow through grooves (6) on the inner side of the bearing sleeve (1). There is a gap between the two annular metal-rubber damping elements (2) of the same specification, which accounts for 25% to 35% of the axial length of the bearing. This specific gap ratio design is to ensure that the metal rubber provides excellent radial structural stiffness when the rotor is under extreme conditions of high speed and high load, and to leave sufficient margin for fretting wear and thermal expansion of the contact surface between the top foil and the metal rubber under high frequency operation, so as to ensure the stability of the shaft system during long-term operation. During the operation of the bearing, the dynamic pressure generated by the high-speed rotation of the journal will cause the top foil (3) to flex and deform, which in turn causes the annular metal rubber damping element (2) to undergo radial elastic deformation. That is, the annular metal rubber damping element (2) provides elastic support for the journal, which can improve the operating stability of the bearing-rotor system.

[0026] like Figure 5 As shown, the top foil (3) is coaxially arranged with the bearing sleeve (1) to provide a lubricating surface for the bearing. The top foil (3) has four air inlets (4) at equal angles along the central circumference. The air inlets (4) are coaxially arranged with the air supply channel (5) of the same diameter and connected to an external air source. One end of the top foil (3) is fixed in the narrow through groove (6) inside the bearing sleeve (1), and the other end is freely overlapped on the inner surface of the annular metal rubber damping element (2). Its inner surface is uniformly coated with PS304 using high-temperature spraying technology, which can reduce the frictional power consumption of the bearing during operation.

[0027] like Figure 6As shown, the inner surface of the top foil (3) is uniformly coated with a PS304 coating, and a surface microtexture (7) with a depth of 0.005 mm to 0.01 mm (preferably 0.005 mm in this embodiment) is designed on the surface of the coating. The surface microtexture (7) forms a regularly arranged micron-level pit or groove structure on the inner surface of the top foil (3). During the operation of the bearing, when the gas flows through these surface microtextures (7), local eddies and secondary flows will be generated in the pits. This secondary flow can redirect and compress some of the gas to the main bearing area of ​​the gas film, thereby generating a secondary pressurization effect. Specifically, the depth, shape and distribution density of the surface microtexture (7) are optimized to effectively improve the uniformity of the gas film pressure distribution, increase the minimum gas film thickness, and thus significantly improve the bearing capacity and anti-disturbance stability of the bearing. At the same time, the surface microtexture (7) can also store lubricating gas and capture wear debris, further reducing the friction coefficient between the top foil (3) and the journal, and reducing dry friction wear during the start-up and shutdown phases.

Claims

1. A hydrostatic gas-lubricated bearing supported by a metal-rubber damping element, characterized in that, include: The bearing sleeve (1), the annular metal rubber damping element (2), and the top foil (3) are provided. The bearing sleeve (1) has annular grooves of the same specifications symmetrically arranged at both ends. Four air supply channels (5) are arranged at equal angles along the circumferential direction of the middle part of its shell. A narrow through groove (6) is opened on the inner side of the bearing sleeve (1). Two annular metal rubber damping elements (2) of the same specifications are coaxially arranged with the bearing sleeve (1) and symmetrically installed in the annular grooves on the end face of the bearing sleeve (1). The top foil (3) is coaxially arranged with the bearing sleeve (1) and has four air inlets (4) arranged at equal angles along the circumferential direction of its middle part. The air inlets (4) and the air supply channels (5) are coaxially arranged with the same diameter.

2. The hydrostatic gas-lubricated bearing supported by a metal-rubber damping element according to claim 1, characterized in that, The radial axis of the air supply channel (5) which is close to the narrow groove (6) on the inner side of the bearing sleeve (1) is 45° with the radial axis of the narrow groove (6) on the inner side.

3. The hydrostatic gas-lubricated bearing supported by a metal-rubber damping element according to claim 1, characterized in that, The annular metal rubber damping element (2) is a three-dimensional elastic mesh structure formed by cold stamping after the metal wire made of raw material GH2696 or GH3030 is wound, stretched, laid and rolled.

4. The hydrostatic gas-lubricated bearing supported by a metal-rubber damping element according to claim 1, characterized in that, There is a gap between the two identical annular metal-rubber damping elements (2), and the gap accounts for 25% to 35% of the axial length of the bearing.

5. The hydrostatic gas-lubricated bearing supported by a metal-rubber damping element according to claim 1 or 3, characterized in that, The annular metal rubber damping element (2) has an opening that mates with a narrow through groove (6) inside the bearing sleeve (1).

6. The hydrostatic gas-lubricated bearing supported by a metal-rubber damping element according to claim 1, characterized in that, The inner surface of the top foil (3) is uniformly coated with PS304 using high-temperature spraying technology.

7. The hydrostatic gas-lubricated bearing supported by a metal-rubber damping element according to claim 1, characterized in that, The air inlet (4) and air supply channel (5) are connected to an external air source.

8. The hydrostatic gas-lubricated bearing supported by a metal-rubber damping element according to claim 1, characterized in that, One end of the top foil (3) is fixed in the narrow through groove (6) inside the bearing sleeve (1), and the other end is freely attached to the inner surface of the annular metal rubber damping element (2).

9. The hydrostatic gas-lubricated bearing supported by a metal-rubber damping element according to claim 1, characterized in that, The inner surface of the top foil (3) is coated with a PS304 coating, and a surface microtexture (7) with a depth of 0.005mm-0.01mm is processed on the surface of the coating. The surface microtexture (7) is used to improve friction and generate a secondary pressure boosting effect.

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