A hydrostatic gas thrust bearing

Abstract

The present invention discloses a hydrostatic gas thrust bearing, which comprises a throttling component, a gas supply component, a vibration damping component and a load-bearing plate arranged in sequence. The throttling component includes a plurality of porous arc-shaped blocks arranged at circumferential intervals, the arc centers of the porous arc-shaped blocks coincide, and the outer surfaces of the front ends of the porous arc-shaped blocks in the circumferential direction are all inclined towards the gas supply component to form inclined surfaces. This hydrostatic gas thrust bearing has the advantages of simple structure and good load-bearing capacity, etc.

Description

Technical Field

[0001] The present invention relates to the technical field of air bearings, and particularly to a hydrostatic gas thrust bearing. Background Art

[0002] A gas hydrostatic bearing is a sliding bearing that uses gas as a lubricant. Its principle is that a fluid forms a thin film under the action of an external pressure to support an external load. The pressure thin film in the bearing has a homogenizing effect. The bearing has the advantages of high rotational accuracy, wide speed range, low friction coefficient, low driving power consumption, no creep at low-speed feeding, high positioning accuracy, excellent damping characteristics, no friction and wear, and long service life.

[0003] Existing gas hydrostatic bearings include porous tiles (throttling elements), air supply blocks, and vibration damping elements, and have the following deficiencies:

[0004] 1) The porous tile is a plane, and the gas film thickness formed between the porous tile and the thrust disk is the same. The bearing capacity of the bearing is related to the gas film pressure. When the rotational speed increases, the gas flow in the gas film layer speeds up, the resistance of the porous tile as a throttle to the gas flow decreases, the gas consumption increases, and the gas film pressure generated by the hydrostatic effect of the bearing will decrease, resulting in a certain reduction in the overall bearing capacity of the bearing;

[0005] 2) Since the load of the bearing is constantly changing, the gas flow rate flowing into the bearing and the pressure of the gas in the gas film layer also change continuously, resulting in bearing vibration and causing an unstable situation of "gas hammer";

[0006] 3) For high-speed rotating machinery, the rotor will have axial rotation and lateral swing, resulting in uneven bearing forces, and a larger force will occur on the outer or inner side of the bearing. Therefore, the existing bearings are prone to damage and have a low service life when used in this environment;

[0007] 4) The overall structure design is unreasonable and it is not convenient to disassemble and assemble. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a hydrostatic gas thrust bearing with a simple structure and good bearing capacity.

[0009] To solve the above technical problem, the present invention adopts the following technical solutions:

[0010] A hydrostatic gas thrust bearing includes a throttling assembly, an air supply member, a vibration damping member, and a load-bearing plate arranged in sequence. The throttling assembly includes a plurality of porous arc-shaped blocks arranged at circumferential intervals, the arc centers of the porous arc-shaped blocks coincide, and the outer surfaces of the front ends of the porous arc-shaped blocks in the circumferential direction are all inclined towards the air supply member to form inclined surfaces.

[0011] As a further improvement of the above technical solution:

[0012] The proportion of the inclined surface on the outer surface of the porous arc block is less than or equal to 50%.

[0013] The inclined depth h of the inclined surface is less than 30 μm.

[0014] One side of the air supply member facing the throttling assembly is provided with a damping chamber and an air supply groove, and the open end of the damping chamber is in close contact with the porous arc block.

[0015] The air supply member includes a plurality of arc-shaped air supply blocks, and each of the arc-shaped air supply blocks is arranged at a circumferential interval with the center of the arc of the porous arc block as the center, and is fixedly integrated with each throttling assembly in one-to-one correspondence. One side of each arc-shaped air supply block facing the porous arc block is provided with a damping chamber and an air supply groove, and an air inlet is provided on the circumferential side of the arc-shaped air supply block, and the air inlet is communicated with the air supply groove.

[0016] Plugging grooves are provided at positions of the porous arc block corresponding to the damping chamber, and the open end of the damping chamber is inserted into the corresponding plugging groove.

[0017] The vibration damping member includes a plurality of arc-shaped vibration damping sheets, and each of the arc-shaped vibration damping sheets is arranged at a circumferential interval with the center of the arc of the porous arc block as the center and is arranged in one-to-one correspondence with each porous arc block. The stiffness of the inner and outer parts of the arc-shaped vibration damping sheet is greater than that of the middle part.

[0018] A plurality of arc-shaped grooves with the same center of the arc are provided on one side of the arc-shaped vibration damping sheet facing the bearing plate, and the center of the arc of the arc-shaped groove coincides with the center of the arc of the arc-shaped vibration damping sheet. The arc-shaped grooves in the inner and outer parts of the arc-shaped vibration damping sheet are smaller than those in the middle part.

[0019] The air supply member and the vibration damping member are fixed on the bearing plate by screws.

[0020] The throttling assembly and the air supply member are adhesively connected.

[0021] Compared with the prior art, the advantages of the present invention are as follows:

[0022] In the static pressure gas thrust bearing of the present invention, due to the existence of the inclined surface, the gas flows along the rotation direction of the thrust disk, that is, forward along the circumferential direction of the circle where each porous arc block is located. In this direction, the gap between the inclined surface and the thrust disk (hereinafter referred to as the gas film gap) gradually decreases. The lubricant flows from the large gas film gap to the small gas film gap, forming a convergent gap, and the cross-sectional area of the gas flow gradually decreases. According to the law of conservation of mass of the gas, the gas should follow the continuity condition, and a relatively high pressure distribution will be formed in the convergent gap area. This pressure distribution will reduce the gas inflow at the inlet of the large gas film gap and increase the gas inflow at the outlet of the small gas film gap to keep the flow rate equal at each interface. The gas flowing along the convergent gap will generate a positive pressure, producing a hydrodynamic effect and increasing the bearing capacity of the bearing. Therefore, the structure of this static pressure gas thrust bearing is simple and has good bearing capacity. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a three-dimensional structural schematic diagram of the static pressure gas thrust bearing of the present invention.

[0024] Figure 2 is a front view structural schematic diagram of the static pressure gas thrust bearing of the present invention.

[0025] Figure 3 is Figure 2 a sectional structural schematic diagram taken along A-A in

[0026] Figure 4 is a top view structural schematic diagram of the static pressure gas thrust bearing of the present invention.

[0027] Figure 5 is Figure 4 a sectional structural schematic diagram taken along B-B in

[0028] Figure 6 is an exploded view of the static pressure gas thrust bearing of the present invention.

[0029] Figure 7 is a three-dimensional structural schematic diagram of the porous arc block of the static pressure gas thrust bearing of the present invention.

[0030] Figure 8 is a front view structural schematic diagram of the porous arc block of the static pressure gas thrust bearing of the present invention.

[0031] Figure 9 is a three-dimensional structural schematic diagram of the arc-shaped gas supply block of the static pressure gas thrust bearing of the present invention.

[0032] Figure 10 is a top view structural schematic diagram of the arc-shaped vibration damping piece of the static pressure gas thrust bearing of the present invention.

[0033] Figure 11 is a front view structural schematic diagram of the arc-shaped vibration damping piece of the static pressure gas thrust bearing of the present invention.

[0034] Each label in the figure indicates:

[0035] 1. Throttle component; 11. Porous arc block; 12. Inclined surface; 13. Plugging groove; 2. Gas supply component; 21. Arc-shaped gas supply block; 211. Air inlet; 3. Vibration damping component; 31. Arc-shaped vibration damping sheet; 4. Load-bearing plate; 5. Damping chamber; 6. Gas supply groove; 7. Arc-shaped groove; 8. Screw. Specific implementation mode

[0036] The present invention will be further described in detail below with reference to the specification drawings and specific embodiments.

[0037] As shown in the present disclosure and the claims, unless the context clearly indicates otherwise, words such as "a", "an", "one" and / or "the" are not specifically singular and may also include plural. The terms "first", "second" and similar terms used in the present disclosure do not denote any order, quantity or importance, but are only used to distinguish different components. Similarly, words such as "comprising" or "including" mean that the elements or objects appearing before this word cover the elements or objects listed after this word and their equivalents, without excluding other elements or objects. "Connection" or "connected" and similar terms are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect.

[0038] Figures 1 to 11 An embodiment of the hydrostatic gas thrust bearing of the present invention is shown. The hydrostatic gas thrust bearing of this embodiment includes a throttle component 1, a gas supply component 2, a vibration damping component 3 and a load-bearing plate 4 arranged in sequence. The throttle component 1 includes a plurality of porous arc blocks 11 arranged at circumferential intervals. The arc centers of the porous arc blocks 11 coincide, and the outer surfaces of the front ends of the porous arc blocks 11 in the circumferential direction are all inclined towards the gas supply component 2 to form an inclined surface 12.

[0039] Since the bearing capacity of the bearing is mainly determined by the pressure of the gas film, the bearing capacity of the gas hydrostatic bearing is mainly determined by the pressure formed in the gas film layer between the throttle component 1 and the thrust disk after the compressed gas passes through the throttle component 1. The smaller the thickness of the gas film, the more obvious the throttling effect of the throttle component 1 on the gas flow, the greater the pressure of the gas film layer, and the greater its bearing capacity. Conversely, the greater the thickness of the gas film, the smaller the bearing capacity of the bearing. At the same time, the greater the gas supply pressure, the greater the bearing capacity. In high-speed rotating machinery, due to the high rotational speed of the rotor, the gas flow velocity in the gas film layer increases, a large amount of gas flows out from the edge of the throttle component 1, the throttling effect of the bearing weakens, the gas consumption increases, the gas film layer pressure drops, and the bearing capacity drops.

[0040] Due to the existence of the inclined surface 12, the gas flows along the rotation direction of the thrust disk, that is, forward along the circumferential direction where each porous arc block 11 is located. In this direction, the gap between the inclined surface 12 and the thrust disk (hereinafter referred to as the gas film gap) gradually decreases. The lubricant flows from the large gas film gap to the small gas film gap, forming a converging gap, and the cross-sectional area through which the gas flows gradually decreases. According to the law of conservation of mass of the gas, the gas should follow the condition of continuity, and a relatively high pressure distribution will be formed in the converging gap area. This pressure distribution will reduce the gas inflow at the inlet of the large gas film gap and increase the gas inflow at the outlet of the small gas film gap to keep the flow rate at each interface equal. The gas flowing along the converging gap will generate a positive pressure, producing a hydrodynamic pressure effect and increasing the bearing capacity. Therefore, the structure of this hydrostatic gas thrust bearing is simple and has good bearing capacity.

[0041] In this embodiment, the proportion of the inclined surface 12 on the outer surface of the porous arc block 11 is less than or equal to 50%. Through theoretical calculation, the area of the inclined surface 12 is not the larger the better. For a hydrostatic gas thrust bearing using a gas such as air as the lubricating medium, the inclined surface 12 should not exceed 50% of the outer surface of the porous arc block 11.

[0042] In this embodiment, as Figure 3 and Figure 8 shown, the inclined depth h of the inclined surface 12 is less than 30 μm. Through theoretical calculation, the influence of the inclined depth h of the inclined surface 12 on the bearing capacity is also relatively obvious. For a hydrostatic gas thrust bearing using a gas such as air as the lubricating medium, the inclined depth h of the inclined surface 12 should be controlled within 30 μm, and the bearing capacity of the hydrostatic gas thrust bearing is better.

[0043] In this embodiment, as Figure 6 and Figure 9 shown, one side of the air supply member 2 facing the throttle assembly 1 is provided with a damping chamber 5 and an air supply groove 6, and the open end of the damping chamber 5 is in close contact with the porous arc block 11.

[0044] In order to eliminate the "air hammer" instability phenomenon, a damping chamber 5 is provided on one side of the air supply member 2 facing the throttle assembly 1. Both the throttle assembly 1 and the damping chamber 5 are made of porous materials, and the wall thickness of the damping chamber 5 is set to be less than the thickness of the porous arc block 11, and the ability to obstruct the gas flow is weaker than that of the porous arc block 11. Therefore, when a pressure is formed in the gas film gap, a part of the gas will flow into the damping chamber 5. Under the throttling effect of the throttle assembly 1, the pressure in the damping chamber 5 is less than the pressure in the gas film gap. When the bearing vibrates and causes a change in the pressure in the gas film gap, the gas will flow into or out of the damping chamber 5, weakening the vibration of the bearing and avoiding the occurrence of "air hammer" instability. Except for the open end, the other sides of the damping chamber 5 are sealed, so it will not affect the static bearing capacity and static stiffness of the bearing.

[0045] In this embodiment, asFigure 6 As shown, the air supply member 2 includes a plurality of arc-shaped air supply blocks 21. The arc-shaped air supply blocks 21 are arranged at circumferential intervals with the center of the arc of the porous arc block 11 as the center, and are fixedly integrated with each throttle assembly 1 in one-to-one correspondence. On the side of each arc-shaped air supply block 21 facing the porous arc block 11, a damping chamber 5 and an air supply groove 6 are provided. An air inlet 211 is provided on the circumferential side of the arc-shaped air supply block 21, and the air inlet 211 communicates with the air supply groove 6. The air supply member 2 includes a plurality of arc-shaped air supply blocks 21, which is convenient for disassembly and assembly. The arc-shaped air supply block 21 is arc-shaped, and the air supply groove 6 is also arc-shaped. The center of the arc of the air supply groove 6 coincides with the center of the arc of the arc-shaped air supply block 21.

[0046] In this embodiment, as Figure 7 shown, plugging grooves 13 are provided at the positions of the porous arc block 11 corresponding to the damping chambers 5. The open ends of the damping chambers 5 are inserted into the corresponding plugging grooves 13. Because the damping chambers 5 protrude towards the side of the porous arc block 11, in order to make the opposite surfaces of the porous arc block 11 and the arc-shaped air supply block 21 close to each other after assembly, concave plugging grooves 13 are provided on the porous arc block 11 for the protruding ends of the damping chambers 5 to be inserted. The openings of the damping chambers 5 are arranged at the protruding ends.

[0047] In this embodiment, the vibration damping member 3 includes a plurality of arc-shaped vibration damping sheets 31. The arc-shaped vibration damping sheets 31 are arranged at circumferential intervals with the center of the arc of the porous arc block 11 as the center and are provided in one-to-one correspondence with each porous arc block 11. The stiffness of the inner and outer parts of the arc-shaped vibration damping sheet 31 is greater than that of the middle part. The inner side of the arc-shaped vibration damping sheet 31 is the side facing the center of the arc. Conversely, the outer side of the arc-shaped vibration damping sheet 31 is the side facing away from the center of the arc.

[0048] At high speeds, due to the high-speed flow of air, the damping of the hydrostatic gas thrust bearing is small, and subsynchronous vibration is likely to occur. In order to further improve the damping characteristics of the bearing, a vibration damping member 3 is provided on the side of the air supply member 2 away from the throttle assembly 1. Specifically, in use, the throttle assembly 1, the air supply member 2, the vibration damping member 3, and the load-bearing plate 4 are generally stacked from top to bottom.

[0049] At high speeds, the inner and outer parts of the arc-shaped vibration damping sheet 31 have to bear a large load caused by the deflection and swing of the rotor. Therefore, the inner and outer parts of the arc-shaped vibration damping sheet 31 are set to have a greater stiffness than the middle part to improve the service life of the bearing.

[0050] In this embodiment, as Figure 10 and Figure 11As shown, on the side of the arc-shaped damping piece 31 facing the load-bearing plate 4, there are a plurality of arc-shaped grooves 7 with the same center of the arc. The center of the arc of the arc-shaped groove 7 coincides with the center of the arc of the arc-shaped damping piece 31. The arc-shaped grooves 7 in the inner and outer parts of the arc-shaped damping piece 31 are smaller than those in the middle part. Specifically, the arc-shaped damping piece 31 is provided with a plurality of arc-shaped grooves 7 with the same center of the arc, forming a wavy shape. The radian of the arc-shaped grooves 7 in the inner and outer parts of the arc-shaped damping piece 31 is smaller and the density is larger than that of the arc-shaped grooves 7 in the middle part, that is, they are more densely distributed, so the stiffness coefficient is larger. The arc-shaped damping piece 31 is a metal piece, such as a foil.

[0051] In this embodiment, the air supply member 2 and the damping member 3 are fixed to the load-bearing plate 4 by screws 8. The overall structure is reasonably designed and convenient for disassembly and assembly.

[0052] In this embodiment, the throttle assembly 1 and the air supply member 2 are adhesively connected.

[0053] In this embodiment, the damping member 3 is divided into three arc-shaped damping pieces 31. Each arc-shaped damping piece 31 affects each other complementarily. The end of each arc-shaped damping piece 31 is fixed to the load-bearing plate 4 through a fixing block. The stiffness of the middle area of the arc-shaped damping piece 31 is the smallest, which is used to provide sufficient damping. The stiffness of the outer edge area and the inner edge area is larger, which is used to provide a higher load-bearing capacity to ensure that when the rotor swings or deflects during high-speed operation, there is sufficient load-bearing capacity. The magnitudes of the stiffness and damping coefficients in different regions are determined by the sizes of the corrugations thereon, and can be designed according to the actual use conditions to meet different requirements.

[0054] The air inlet 211 communicates with the air supply groove 6 at the outer edge of the arc-shaped air supply block 21. The widths of the air supply grooves 6 are the same, so as to ensure the same air supply pressure. The damping chamber 5 is a separate cavity. The main function of the air supply groove 6 is to provide air supply pressure for the porous arc-shaped block 11 and provide support.

[0055] The porous arc-shaped block 11 can be a gas throttle made of isostatic graphite. The surface of the porous arc-shaped block 11 is evenly covered with many small holes, which is an ideal throttle element and can provide a uniform gas film for the bearing. The porous arc-shaped block 11 is bonded to the arc-shaped gas supply block 21 with glue. The porous arc-shaped block 11 generally has a uniform thickness. In order to increase the hydrodynamic pressure effect of the bearing during high-speed operation and improve its load-bearing capacity, an inclined surface 12 is provided. The part of the inclined surface 12 corresponding to the porous arc-shaped block 11 is a wedge-shaped area, which is achieved by precision machining of the porous arc-shaped block 11. The inlet height of the wedge-shaped area should be equivalent to the size of the gas film gap during operation, and generally should be less than 30 microns. The proportion of the wedge-shaped area is controlled within half of the porous arc-shaped block 11. The place where the porous arc-shaped block 11 cooperates with the damping chamber 5 is formed by removing materials on the porous arc-shaped block 11 to form a plugging groove 13, and the damping chamber 5 is embedded in the plugging groove 13. By changing the thickness of the porous arc-shaped block 11 above the damping chamber 5, the throttling effect of the porous arc-shaped block 11 is weakened, which is equivalent to opening a channel for gas to flow into the damping chamber 5.

[0056] Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make many possible changes and modifications to the technical solution of the present invention by using the technical content disclosed above, or modify it into an equivalent embodiment with equivalent changes. Therefore, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the technical solution of the present invention shall fall within the scope of protection of the technical solution of the present invention.

Claims

1. A hydrostatic gas thrust bearing, comprising a throttling component (1), a gas supply component (2), a vibration damping component (3) and a load-bearing plate (4) arranged in sequence, characterized in that: The throttle component (1) includes a plurality of porous arc-shaped blocks (11) arranged at circumferential intervals, the centers of arcs of each of the porous arc-shaped blocks (11) coincide, and the outer surfaces of the front ends of each of the porous arc-shaped blocks (11) in the circumferential direction are inclined towards the air supply member (2) to form an inclined surface (12); the air supply member (2) includes a plurality of arc-shaped air supply blocks (21), each of the arc-shaped air supply blocks (21) is arranged at circumferential intervals with the center of the arc of the porous arc-shaped block (11) as the center, and is fixedly integrated with each throttle component (1) in one-to-one correspondence, and a damping chamber (5) and an air supply groove (6) are provided on the surface of each of the arc-shaped air supply blocks (21) facing the porous arc-shaped block (11), an air inlet (211) is provided on the peripheral side of the arc-shaped air supply block (21), and the air inlet (211) is communicated with the air supply groove (6); plugging grooves (13) are provided at positions of the porous arc-shaped blocks (11) corresponding to the damping chambers (5), and the open end of the damping chamber (5) is inserted into the corresponding plugging groove (13) and is in close contact with the porous arc-shaped block (11); the wall thickness of the damping chamber (5) is smaller than the thickness of the porous arc-shaped block (11).

2. The aerostatic thrust bearing according to claim 1, wherein: The proportion of the inclined surface (12) on the outer surface of the porous arc-shaped block (11) is less than or equal to 50%.

3. The aerostatic thrust bearing according to claim 1, wherein: The inclined depth h of the inclined surface (12) is less than 30 μm.

4. The aerostatic thrust bearing according to any one of claims 1 to 3, characterized in that: The vibration damping member (3) includes a plurality of arc-shaped vibration damping sheets (31), each of the arc-shaped vibration damping sheets (31) is arranged at circumferential intervals with the center of the arc of the porous arc-shaped block (11) as the center and is provided in one-to-one correspondence with each of the porous arc-shaped blocks (11), and the stiffness of the inner and outer parts of the arc-shaped vibration damping sheet (31) is greater than that of the middle part.

5. The aerostatic thrust bearing according to claim 4, characterized in that: A plurality of arc-shaped grooves (7) with the same center of the arc are provided on the side of the arc-shaped vibration damping sheet (31) facing the load-bearing plate (4), the center of the arc of the arc-shaped groove (7) coincides with the center of the arc of the arc-shaped vibration damping sheet (31), and the arc-shaped grooves (7) of the inner and outer parts on the arc-shaped vibration damping sheet (31) are smaller than the arc-shaped grooves (7) of the middle part.

6. The aerostatic thrust bearing according to any one of claims 1 to 3, characterized in that: The air supply member (2) and the vibration damping member (3) are fixed on the load-bearing plate (4) by screws (8).

7. The aerostatic thrust bearing according to any one of claims 1 to 3, characterized in that: The throttle component (1) and the air supply member (2) are adhesively connected.

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