Piezoceramic based variable restriction aerostatic bearing

Abstract

The application discloses a piezoelectric ceramic-based variable throttling aerostatic bearing, which comprises a bearing base, a cover and a thrust plate; the bearing base is provided with an elastic throttler; the elastic throttler comprises a throttler main body and a gas inlet channel; the gas inlet channel is arranged on the throttler main body; the outer surface of the gas inlet channel is conical; a gas inlet hole is arranged in the center of the gas inlet channel; the bottom of the gas inlet channel is provided with a throttling hole which is in communication with the gas inlet hole; a base conical hole is arranged on the bearing base and matched with the gas inlet channel; a piezoelectric ceramic driver is arranged in the cover and used for driving the elastic throttler, so that the cross-sectional shape of the throttling hole is changed and the throttling area is changed; the application can effectively realize the adjustment of the throttling area of the aerostatic thrust bearing and provide a new method for adjusting the bearing stiffness, load capacity and stability in the use stage.

Description

Technical Field

[0001] This invention relates to the field of bearing construction technology, and specifically to a variable throttling gas hydrostatic bearing based on piezoelectric ceramics. Background Technology

[0002] Gas static pressure bearings have advantages such as high precision, long service life, and no pollution, and are widely used in ultra-precision machining and measurement equipment. However, the lubricating medium of gas static pressure bearings is air. The compressibility of air results in relatively low stiffness and load-bearing capacity, which are major factors limiting the further application of gas static pressure bearings.

[0003] The throttling area of ​​the orifice is closely related to the performance of gas static pressure bearings. Generally, after the bearing is designed and manufactured, the shape of its orifice does not change, meaning the throttling area typically remains constant, which to some extent affects the control of bearing performance. Literature research indicates that using variable throttling in gas static pressure bearings can improve and control their performance.

[0004] For variable throttling of small-orifice throttling gas hydrostatic bearings, the throttling area is generally adjusted by changing the cross-sectional shape of the throttling orifice (e.g., Kodnyanko V, Shatokhin S, Kurzakov A, et al. Theoretical analysis of compliance and dynamics quality of a lightly loaded aerostatic journalbearing with elastic orifices. Precision Engineering, 2021, 68: 72-81.) or by changing the orifice diameter (e.g., patent number ZL201810200469.8, titled "Gas Hydrostatic Spindle Throttling Orifice Diameter Adjustment Device"), thereby changing the throttling effect. However, the method of changing the orifice diameter has some shortcomings in practical implementation. Taking the aforementioned "Gas Hydrostatic Spindle Throttling Orifice Diameter Adjustment Device" as an example, it uses an electrically actuated flexible material body to drive the inner ring flexible material to achieve the adjustment of the orifice diameter. However, in actual adjustment, it cannot be guaranteed that the axis of the reduced-diameter orifice will completely coincide with that of the original orifice. Furthermore, the inner wall surface formed by contraction or expansion may not be smooth enough, thus affecting the actual throttling area. Therefore, from a control perspective, there are certain accuracy issues. Considering the current research status, changing the cross-sectional shape of the orifice to adjust the throttling area is a more controllable method.

[0005] For variable throttling bearings that use altered orifice cross-sectional shapes, the deformation of the throttling area is mainly due to the pressure difference between the orifice inlet and outlet. Although the degree of deformation is very small, it still has a certain impact on bearing performance.

[0006] This invention provides a novel variable throttling gas hydrostatic bearing based on piezoelectric ceramics. The piezoelectric ceramic actuator controls the cross-sectional shape of the throttling orifice, thereby achieving active control of the throttling area and thus actively regulating the bearing performance. Summary of the Invention

[0007] To overcome the shortcomings of current technology, this invention provides a variable throttling gas hydrostatic bearing based on piezoelectric ceramics, which can conveniently, quickly and effectively adjust the throttling area.

[0008] The technical solution of the present invention is as follows: A variable throttling gas hydrostatic bearing based on piezoelectric ceramics includes a bearing base, a cover, and a thrust plate. The bearing base is equipped with an elastic throttling device, which includes a throttling device body and an air inlet channel. The air inlet channel is disposed on the throttling device body, and its outer surface is tapered with an air inlet hole at its center. A throttling hole communicating with the air inlet hole is located at the bottom of the air inlet channel. The bearing base has a tapered hole that mates with the air inlet channel. The cover contains a piezoelectric ceramic actuator for driving the elastic throttling device, thereby changing the cross-sectional shape of the throttling hole and altering the throttling area.

[0009] Furthermore, the diameter of the throttling orifice is smaller than the diameter of the intake orifice at the center of the intake channel.

[0010] Furthermore, the top of the flexible throttle is provided with a pressure plate, and the pressure plate has a pressure plate opening at a position corresponding to the air inlet of the flexible throttle.

[0011] Furthermore, the throttle body has a throttle groove in the circumference of the intake channel, thereby providing space for the up and down movement of the flexible throttle.

[0012] Furthermore, the cover is provided with a lead wire hole, and the piezoelectric ceramic actuator is connected to the control device via a circuit lead wire passing through the lead wire hole. A lead wire sealing ring is provided at the lead wire hole to maintain the airtightness of the bearing.

[0013] Furthermore, the piezoelectric ceramic actuator is connected to the cover at the top and to the pressure plate at the bottom.

[0014] Furthermore, a pressure sensor for detecting the air film pressure is installed on the bearing base, and the pressure sensor is distributed in a circumferential array on the bearing base.

[0015] Furthermore, the bearing base and the cover are sealed together by a sealing ring.

[0016] Furthermore, the upper and lower surfaces of the elastic throttle are respectively bonded to the pressure plate and the bearing base with sealant.

[0017] Furthermore, the external high-pressure gas enters the gap between the bearing base and the thrust plate through the air inlet on the cover, the pressure plate opening on the pressure plate, and the air inlet on the elastic throttle, forming a high-pressure gas film.

[0018] The beneficial effects of this invention are as follows: 1) This invention has a simple structure, is easy to use, and has wide applicability; 2) This invention employs an active control method to adjust the throttling area; 3) This invention can effectively adjust the throttling area of ​​the gas static pressure thrust bearing, providing a new means for adjusting the bearing stiffness, load-bearing capacity and stability during the service stage. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is an enlarged schematic diagram of the throttle section; In the diagram: 1. Bearing base; 101. Base conical hole; 2. Sealing ring; 3. Cover; 301. Air inlet; 302. Lead wire hole; 4. Flexible throttle; 401. Air inlet channel; 402. Throttling orifice; 403. Throttling base mating surface; 404. Throttling pressure plate mating surface; 405. Throttling groove; 5. Pressure plate; 501. Pressure plate opening; 6. Piezoelectric ceramic actuator; 7. Circuit lead; 8. Lead wire sealing ring; 9. Control device; 10. Air pressure sensor; 11. Thrust plate. Detailed Implementation

[0020] The present invention will be further described below with reference to the accompanying drawings.

[0021] like Figure 1-2 As shown: A variable throttling gas static pressure bearing based on piezoelectric ceramics, the bearing base 1 is airtightly connected to the cover 3 through the sealing ring 2; the bearing base 1 has a base tapered hole 101; the cover 3 has an air inlet hole 301 and a lead wire hole 302.

[0022] The flexible throttle 4 uses sealant to connect the throttle base mating surface 403 to the bearing base 1, and uses sealant to connect the throttle pressure plate mating surface 404 to the pressure plate 5; the flexible throttle 4 has an air intake channel 401, a throttle hole 402 and a throttle groove 405. The piezoelectric ceramic actuator 6 is located inside the cover 3 and is connected to the control device 9 via a circuit lead 7 passing through the lead hole 302; the lead sealing ring 8 is used to maintain the airtightness of the bearing; the top of the piezoelectric ceramic actuator 6 is connected to the cover 3, and the bottom is connected to the pressure plate 5; the control device 9 controls the output displacement of the piezoelectric ceramic actuator 6, thereby causing the pressure plate 5 to move up and down along the bearing axis under the drive of the piezoelectric ceramic actuator 6; because the elastic throttle 4 is made of elastic material, polyurethane is used in this embodiment, so under the drive of the pressure plate 5, as Figure 2 The structure shown can move up and down. Due to the restriction of the conical hole 101 on the base, the elastic throttle 4 deforms during the up and down movement, thereby changing the cross-sectional shape of the throttle hole 402 and ultimately changing the throttling area.

[0023] The throttle base mating surface 403 is bonded to the bearing base 1 with sealant, and the throttle pressure plate mating surface 404 is bonded to the pressure plate 5 with sealant, ensuring the airtightness of the bearing structure; the throttle groove 405 provides space for the up and down movement of the elastic throttle 4.

[0024] The pressure plate 5 has a pressure plate opening 501, an air inlet 301, an air inlet channel 401 (the air inlet on the air inlet channel 401), and a throttling orifice 402, which together form an overall gas flow channel. External high-pressure gas passes through the air inlet 301, the pressure plate opening 501, and the air inlet channel 401 (the air inlet on the air inlet channel 401), and finally enters the gap between the bearing base 1 and the thrust plate 11 through the throttling orifice 402, forming a high-pressure gas film.

[0025] A pressure sensor 10 for detecting air film pressure is installed on the bearing base 1; the pressure sensor 10 is distributed in a circumferential array on the bearing base 1.

[0026] The working principle of this invention is as follows: external high-pressure gas enters the gap between the bearing base 1 and the thrust plate 11 through the air inlet 301, the pressure plate opening 501, and the air inlet channel 401, and finally enters the gap between the bearing base 1 and the thrust plate 11 through the throttling hole 402, forming a high-pressure gas film; the output displacement of the piezoelectric ceramic actuator 6 can be quantitatively controlled by the control device 9, thereby quantitatively controlling the up and down movement of the pressure plate 5, realizing the change of the cross-sectional shape of the throttling hole 402, and finally realizing the change of the throttling area, thus realizing the active adjustment of the throttling area.

[0027] The air pressure sensor 10 measures the air film pressure field signal and simultaneously sends it to the control device 9. The control device 9 processes the air film pressure field signal with a preset throttling orifice cross-section model to obtain the optimal throttling area adjustment scheme. Before adjusting the throttling area, the output displacement of the piezoelectric ceramic actuator 6 and the deformation of the throttling orifice 402 cross-section are measured in advance, as well as the quantitative relationship between the deformation of the throttling orifice 402 cross-section and the change in throttling area.

[0028] Based on the throttling area at the current output displacement of the piezoelectric ceramic actuator 6 and the target throttling area value to be obtained through adjustment, the target output displacement of the piezoelectric ceramic actuator 6 is obtained, and the adjustment of the throttling area is finally realized.

[0029] The embodiments described in this specification are merely examples of implementations of the inventive concept. The scope of protection of this invention should not be considered as limited to the specific forms stated in the embodiments. The scope of protection of this invention also includes equivalent technical means that can be conceived by those skilled in the art based on the inventive concept.

Claims

1. A variable throttling gas hydrostatic bearing based on piezoelectric ceramics, comprising a bearing base (1), a cover (3), and a thrust plate (11); characterized in that, The bearing base (1) is provided with an elastic throttle (4). The elastic throttle (4) includes a throttle body and an air intake channel (401). The air intake channel (401) is set on the throttle body. The outer surface of the air intake channel (401) is conical, and an air intake hole is opened in the center. The bottom of the air intake channel (401) is provided with a throttle hole (402) that communicates with the air intake hole. The bearing base (1) is provided with a base conical hole (101), which cooperates with the air intake channel (401). The cover (3) is provided with a piezoelectric ceramic actuator (6) inside, which is used to drive the elastic throttle (4) to change the cross-sectional shape of the throttle hole and realize the change of the throttling area.

2. The variable throttling gas hydrostatic bearing based on piezoelectric ceramics according to claim 1, characterized in that, The diameter of the throttle orifice (402) is smaller than the diameter of the air inlet at the center of the air inlet channel (401).

3. A variable throttling gas hydrostatic bearing based on piezoelectric ceramics according to claim 1, characterized in that, The top of the flexible throttle (4) is provided with a pressure plate (5), and the pressure plate (5) has a pressure plate opening (501) at a position corresponding to the air inlet of the flexible throttle (4).

4. A variable throttling gas hydrostatic bearing based on piezoelectric ceramics according to claim 1, characterized in that, The throttle body has a throttle groove (405) circumferentially located in the intake channel (401), thereby providing space for the up and down movement of the elastic throttle (4).

5. A variable throttling gas hydrostatic bearing based on piezoelectric ceramics according to claim 1, characterized in that, The cover (3) has a lead hole (302), and the piezoelectric ceramic actuator (6) is connected to the control device via a circuit lead passing through the lead hole (302). A lead sealing ring (8) is provided at the lead hole (302) to maintain the airtightness of the bearing.

6. A variable throttling gas hydrostatic bearing based on piezoelectric ceramics according to claim 1, characterized in that, The piezoelectric ceramic actuator (6) is connected to the cover (3) at the top and to the pressure plate (5) at the bottom.

7. A variable throttling gas hydrostatic bearing based on piezoelectric ceramics according to claim 1, characterized in that, The bearing base (1) is equipped with a pressure sensor (10) for detecting air film pressure, and the pressure sensor (10) is arranged in a circumferential array on the bearing base (1).

8. A variable throttling gas hydrostatic bearing based on piezoelectric ceramics according to claim 1, characterized in that, The bearing base (1) and the cover (3) are sealed together by a sealing ring (2).

9. A variable throttling gas hydrostatic bearing based on piezoelectric ceramics according to claim 1, characterized in that, The upper and lower surfaces of the elastic throttle (4) are respectively bonded to the pressure plate (5) and the bearing base (1) by sealant.

10. A variable throttling gas hydrostatic bearing based on piezoelectric ceramics according to claim 3, characterized in that, External high-pressure gas enters the gap between the bearing base (1) and the thrust plate (11) through the air inlet (301) on the cover (3), the pressure plate opening (501) on the pressure plate (5), and the air inlet on the elastic throttle (4), forming a high-pressure gas film.

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