Ultra-precision air-floating motion platform

Abstract

The application belongs to the technical field of precision technology equipment, and relates to an ultra-precision air floating movement platform, which comprises a granite base, two Y-direction linear motors are arranged on the granite base along the X direction at intervals, the Y-direction linear motor comprises a Y-direction linear motor stator fixed on the granite base and a Y-direction linear motor mover matched with the Y-direction linear motor stator, the two Y-direction linear motor movers are respectively fixedly connected with first sliding seats, an X-direction combined beam is arranged between the two first sliding seats, two X-direction linear motors are arranged on the X-direction combined beam along the Y direction at intervals, the ultra-precision air floating movement platform moves the object plate on the granite base under the driving of the linear motor, realizes the coarse adjustment of movement, the object sliding block is pushed to move on the air floating guide rail by the ball screw linear driving mechanism, realizes the fine adjustment of movement of the object plate, and the efficiency and the precision are considered, the adjustment range is large, and the precision is high.

Description

Technical Field

[0001] This invention belongs to the field of precision technology equipment technology, and relates to an ultra-precision air-bearing motion platform. Background Technology

[0002] A pneumatic stage is a device that uses pneumatic transmission to support, move, or position objects. In high-end lithography machines, such as EUV lithography machines, air-bearing motion stages are essential, as this is one of the core technologies for achieving nanometer-level precision and high-speed motion. Its working principle involves using a linear motor to drive the air-bearing motion stage. The driving method is as follows: compressed air forms a micron-level air film between the stage and the base, eliminating mechanical friction. The stator (coil array) of the linear motor is fixed to the base, while the mover (permanent magnet assembly) is mounted on the air-bearing motion stage. When energized, it generates electromagnetic thrust, propelling the air-bearing motion stage to achieve nanometer-level motion precision.

[0003] Currently, pneumatic platforms still suffer from technical challenges such as limited control precision and poor stability of air source pressure. Regarding control precision, pneumatic platforms sometimes exhibit nonlinear control errors that are difficult to correct, failing to meet accuracy requirements in applications demanding extremely high position control precision. Furthermore, the stability of the air supply pressure directly affects the performance of the air film and the overall motion accuracy. Excessive or insufficient air supply pressure can lead to a series of problems, impacting the load-bearing capacity, stiffness, stability, and even lifespan of the pneumatic platform's guide rails.

[0004] Therefore, taking effective measures to optimize the mechanical structure of the platform, reduce mechanical friction, equip it with a high-precision air source processing system, and further improve the accuracy and stability of the pneumatic platform remains a direction that those skilled in the art need to strive to improve. Summary of the Invention

[0005] To address the technical problems of limited control precision, poor air source pressure stability, inability to meet extremely high precision requirements, and impact on the load-bearing capacity, rigidity, and stability of the guide rails in the existing pneumatic platforms described in the background art, this invention provides an ultra-precision air-bearing motion platform.

[0006] This invention solves the above-mentioned technical problems by providing an ultra-precision air-bearing motion platform, comprising a granite base, on which two Y-axis linear motors are spaced apart along the X direction. Each Y-axis linear motor includes a stator fixed to the granite base and a mover cooperating with the stator. The two movers are respectively fixedly connected to first slides. An X-axis composite beam is provided between the two first slides, and two X-axis linear motors are spaced apart along the Y direction on the X-axis composite beam. Each X-axis linear motor includes a cooperating stator and mover. The two stators are fixed to the X-axis composite beam, and the two movers are respectively fixedly connected to second slides. A first mounting plate and a second mounting plate are fixedly connected between the two second slides. An air-bearing moving platform is fixedly connected to the first and second mounting plates.

[0007] The air-bearing mobile platform includes a track base, which includes two opposing air-bearing guide rails. A load-carrying slider is slidably fitted on each air-bearing guide rail. A ball screw linear drive mechanism is provided between the two air-bearing guide rails. The ball screw linear drive mechanism includes a servo motor, a screw nut, and a screw tail bearing. The servo motor is fixed to a first mounting plate, and the screw tail bearing is fixedly connected to a second mounting plate. A load-carrying plate is fixedly connected to the upper part of the screw nut, and the two ends of the load-carrying plate are respectively fixedly connected to the load-carrying sliders on the two air-bearing guide rails.

[0008] An air-floating base plate is installed on the lower surface of the track base. Four air-floating holes are symmetrically arranged at the four corners of the geometric edge of the air-floating base plate. Each air-floating hole is independently connected to a positive pressure air passage arranged inside the air-floating base plate. The inlet of each positive pressure air passage is threaded with a dedicated positive pressure connector, and the other end of the dedicated positive pressure connector is connected to an air compressor. A vacuum hole is provided at the geometric center of the air-floating base plate. The vacuum hole is connected to a vacuum passage arranged inside the air-floating base plate. The inlet of the vacuum passage is threaded with a dedicated negative pressure connector, and the other end of the dedicated negative pressure connector is connected to a vacuum pump. A first pressure sensor is installed inside the dedicated positive pressure connector and the dedicated negative pressure connector. The first pressure sensor is electrically connected to a controller. The controller is electrically connected to the air compressor, the vacuum pump, a first regulating valve assembly arranged between the dedicated positive pressure connector and the air compressor, and a second regulating valve assembly arranged between the dedicated negative pressure connector and the vacuum pump.

[0009] Furthermore, in the first stage of adjusting the position of the air-floating moving platform, the air-floating base plate, driven by two Y-axis linear motors and two X-axis linear motors, drives the track base, and through the track base, drives the load plate, which is fixed together with the load slider, to move on the granite base, thereby achieving coarse adjustment of the load plate's movement; in the second stage of adjusting the position of the air-floating moving platform, an air-floating pair is formed between the load slider and the air-floating guide rail, and the load slider is pushed by a ball screw linear drive mechanism to move on the air-floating guide rail, thereby achieving fine adjustment of the load plate's movement.

[0010] Furthermore, a Y-guide rail assembly is provided below the two first slide blocks. The Y-guide rail assembly includes a Y-guide rail laid along the Y direction on the granite base and a Y-axis slider that slides with the Y-guide rail. An X-guide rail assembly is provided below the two second slide blocks. The X-guide rail assembly includes an X-guide rail laid along the X direction on the granite base and an X-axis slider that slides with the X-guide rail. Both the Y-guide rail assembly and the X-guide rail assembly adopt the form of air-bearing guide rails.

[0011] Furthermore, the air compressor is connected to an air storage tank, which is connected to a first distribution valve via a pipeline. Each outlet of the first distribution valve is sequentially connected to a positive pressure dedicated combination connector on the air float base plate via a positive pressure branch pipeline. The inlet of the first regulating valve assembly is connected to the air storage tank, and the outlet is connected to the positive pressure branch pipeline via a three-way valve. The electrical control terminal of the first regulating valve assembly is connected to a controller. A second pressure sensor is installed in the positive pressure branch pipeline between the first distribution valve and the positive pressure dedicated combination connector, and the second pressure sensor is electrically connected to the controller. A third pressure sensor is installed on the air storage tank, and the third pressure sensor is electrically connected to the controller. The controller controls the operation of the air compressor based on the pressure signal from the third pressure sensor in the air storage tank, controls the first regulating valve assembly based on the signal from the first pressure sensor in the positive pressure air passage connected to the air float orifice and the signal from the second pressure sensor in the positive pressure branch pipeline, and controls the air supply to each positive pressure air passage through the first regulating valve assembly, thereby adjusting the air supply pressure of each air float orifice.

[0012] Furthermore, the vacuum pump is connected to a vacuum tank, which is connected to a second distribution valve via a pipe. One outlet of the second distribution valve is connected to a negative pressure dedicated combination connector on the air-float base plate via a pipe. The outlet of the second regulating valve assembly is connected to the vacuum tank, and the inlet is connected to the negative pressure branch pipe via a three-way valve. The electrical control end of the second regulating valve assembly is electrically connected to a controller. A second pressure sensor is installed in the negative pressure branch pipe between the second distribution valve and the negative pressure dedicated combination connector, and the second pressure sensor is electrically connected to the controller. A third pressure sensor is installed on the vacuum tank, and the third pressure sensor is electrically connected to the controller. The controller controls the operation of the vacuum pump based on the pressure signal from the third pressure sensor in the vacuum tank, and controls the second regulating valve assembly based on the signals from the first pressure sensor in the vacuum passage connected to the vacuum hole and the second pressure sensor in the negative pressure branch pipe. The controller then controls the pressure in the vacuum passage through the second regulating valve assembly, thereby adjusting the vacuum pressure at the vacuum hole.

[0013] In a preferred embodiment, the air flotation hole is a small hole with a fixed throttling orifice structure for throttling air supply.

[0014] As another preferred embodiment, the bottom of the air flotation hole is a stepped mounting hole, and an air foot structure element is detachably installed in the stepped mounting hole of the air flotation hole. The air foot structure element is a variety of standard parts made according to porous air foot structure, small hole throttling air foot structure and grooved air foot structure, and can be selectively installed according to the needs of the applicable scenario.

[0015] Furthermore, the positive pressure dedicated combination connector includes a connector seat and a fish-scale threaded end. The threaded end of the fish-scale threaded end is connected to the internal threaded hole of the connector seat, and the fish-scaled end of the fish-scale threaded end is connected to the positive pressure branch pipeline (not shown in the figure). The connector seat is connected to the positive pressure air passage on the air float base plate through an external thread. The connector seat includes an internal hexagonal mounting hole, an internal threaded through hole that is connected to the internal hexagonal mounting hole, a sensor seat hole parallel to the internal threaded through hole, and a pressure measuring through hole that connects the internal threaded through hole and the sensor seat hole. The outer port of the sensor seat hole is connected to a special-shaped plug with a through hole through an internal thread. The special-shaped plug seals the outer port of the sensor seat hole. The first air pressure sensor is installed inside the sensor seat hole. The data line of the first air pressure sensor passes through the through hole on the special-shaped plug. A sealing ring is also provided between the bottom of the special-shaped plug and the data line of the first air pressure sensor. The outer port of the pressure measuring through hole is sealed by a universal plug. The shape and structure of the negative pressure dedicated combination connector are exactly the same as those of the positive pressure dedicated combination connector.

[0016] Furthermore, the first pressure sensor is a miniature pressure sensor, which is wirelessly connected to the controller; the second and third pressure sensors are ordinary pressure sensors, and their circuits are connected to the controller.

[0017] Furthermore, under operating conditions, the air pressure in the positive pressure branch pipe between the air compressor and the air flotation base plate is 0.4 MPa; the air pressure in the negative pressure branch pipe between the vacuum pump and the air flotation base plate is -60 kPa to -70 kPa.

[0018] Beneficial effects

[0019] 1. Compared with the prior art, the ultra-precision air-bearing motion stage of the present invention has an air-bearing base plate that drives the load plate to move on a granite base under the drive of a linear motor, realizing coarse adjustment of movement. The load slider is pushed by a ball screw linear drive mechanism to move on the air-bearing guide rail, realizing fine adjustment of the load plate movement. It takes into account both efficiency and precision, with a large adjustment range and high precision. During the movement of the air-bearing motion stage, the air-bearing base plate and the air-bearing guide rail are present at the same time, and the superimposed movement effect of the air-bearing pair improves the stability of movement, reduces nonlinear control error, and further improves the positioning accuracy and working efficiency of the air-bearing motion stage.

[0020] 2. The air flotation port and vacuum port are connected to an external air compressor or vacuum equipment through separate branch pipes. Each branch pipe is equipped with a pressure sensor and a pressure regulating device. Miniature pressure sensors are also installed in the air chambers inside the air flotation port and vacuum port. The miniature pressure sensors are connected to a controller, which is connected to the air compressor, vacuum pump, and pressure regulating device to further regulate the pressure of the air foot in the air flotation base plate. This changes the current situation where the dynamic characteristics of the air film are simply regulated by the air compressor and vacuum pump, avoiding repeated over-adjustment of the air pressure. This makes the pressure of the air foot in the air flotation base plate stable and the air film thickness moderate, avoiding air film fluctuations, improving the performance of the air film and the overall motion accuracy, and greatly improving the load-bearing capacity, rigidity, stability, and lifespan of the pneumatic platform guide rail.

[0021] 3. The structural design of the dedicated positive pressure and negative pressure combination connectors ensures the installation of the miniature pressure sensor in the positive and negative pressure air channels on the air float base plate, and ensures the reliability of pressure measurement in the air float hole and vacuum hole, creating favorable conditions for precise control of the internal pressure of the air foot.

[0022] 4. The structural design of the air float hole and air foot structure components allows the air float hole to select the appropriate air foot structure according to different equipment application scenarios, thereby improving the working adaptability of the ultra-precision air float motion platform of the present invention. Attached Figure Description

[0023] Figure 1This is a schematic diagram of the overall structure of the ultra-precision air-bearing motion platform according to an embodiment of the present invention;

[0024] Figure 2 yes Figure 1 A magnified view of point A in the image;

[0025] Figure 3 yes Figure 1 BB-direction sectional view in the middle;

[0026] Figure 4 This is a schematic diagram of the track base structure according to an embodiment of the present invention;

[0027] Figure 5 This is a bottom view of the track base according to an embodiment of the present invention;

[0028] Figure 6 This is a front view of the air-floating base plate component according to an embodiment of the present invention;

[0029] Figure 7 This is a top view of an air-floating base plate component with a fixed throttling orifice according to an embodiment of the present invention;

[0030] Figure 8 This is a top view of an air-floating base plate component with air foot structural elements installed according to an embodiment of the present invention;

[0031] Figure 9 These are schematic diagrams of two air-foot structural elements according to embodiments of the present invention;

[0032] Figure 10 This is a schematic diagram of a positive pressure-specific combination joint component according to an embodiment of the present invention;

[0033] Figure 11 This is a schematic diagram of the air pressure regulation and control process according to an embodiment of the present invention;

[0034] Figure 12 This is a schematic diagram of the Y-guide rail assembly structure according to an embodiment of the present invention;

[0035] In the diagram: 1. Granite base; 2. Y-axis linear motor; 21. Y-axis linear motor stator; 22. Y-axis linear motor mover; 23. First slide; 3. X-axis linear motor; 31. X-axis linear motor stator; 32. X-axis linear motor mover; 33. Second slide; 34. First mounting plate; 35. Second mounting plate; 4. X-axis composite beam; 5. Air-bearing moving platform; 6. Positive pressure special combination joint; 60. Joint seat; 61. Fish scale thread end; 62. Hexagonal mounting hole; 63. Internal threaded through hole; 64. Sensor seat hole; 65. Pressure measuring through hole; 66. Special-shaped plug; 67. Universal plug; 68. Sealing ring; 7. Air-bearing base plate; 71. Air-bearing hole; 711. Air supply structural element; 72. Positive pressure air passage; 73. Vacuum hole; 74. Vacuum passage; 8. Y-axis guide rail assembly; 81. Y-axis guide rail. 82. Y-axis slider; 9. Track base; 91. Air-bearing guide rail; 10. Load slider; 11. Ball screw linear drive mechanism; 111. Servo motor; 112. Screw nut; 113. Screw tail bearing; 12. Load plate; 13. X-axis guide rail assembly; 131. X-axis guide rail; 132. X-axis slider; 14. Fixed throttling orifice; 15. Air compressor; 150. First regulating valve assembly; 151. Air tank; 152. First distribution valve; 153. Positive pressure branch pipeline; 16. Negative pressure special combination joint; 17. Vacuum pump; 170. Second regulating valve assembly; 171. Vacuum tank; 172. Second distribution valve; 173. Negative pressure branch pipeline; 18. Controller; 181. First air pressure sensor; 182. Second air pressure sensor; 183. Third air pressure sensor; 19. Three-way valve. Detailed Implementation

[0036] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0037] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0038] 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. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0039] Please see Figures 1 to 12 An ultra-precision air-bearing motion platform includes a granite base 1. Two Y-axis linear motors 2 are spaced apart along the X-direction on the granite base 1. Each Y-axis linear motor 2 includes a Y-axis linear motor stator 21 fixed on the granite base 1 and a Y-axis linear motor mover 22 that cooperates with the Y-axis linear motor stator 21. The two Y-axis linear motor movers 22 are respectively fixedly connected to first slides 23. An X-axis composite beam 4 is arranged between the two first slides 23. Two X-axis linear motors 3 are spaced apart along the Y-direction on the X-axis composite beam 4. Each X-axis linear motor 3 includes a mutually cooperating X-axis linear motor stator 31 and an X-axis linear motor mover 32. The two X-axis linear motor stators 31 are fixed on the X-axis composite beam 4. The two X-axis linear motor movers 32 are respectively fixedly connected to second slides 33. A first mounting plate 34 and a second mounting plate 35 are fixedly connected between the two second slides 33. An air-bearing moving platform 5 is fixedly connected to the first mounting plate 34 and the second mounting plate 35.

[0040] The air-floating mobile platform 5 includes a track base 9, which includes two opposing air-floating guide rails 91. Each air-floating guide rail 91 is slidably fitted with a load slider 10. A ball screw linear drive mechanism 11 is provided between the two air-floating guide rails 91. The ball screw linear drive mechanism 11 includes a servo motor 111, a screw nut 112, and a screw tail bearing 113. The servo motor 111 is fixed on a first mounting plate 34, and the screw tail bearing 113 is fixedly connected to a second mounting plate 35. A load plate 12 is fixedly connected to the upper part of the screw nut 112, and the two ends of the load plate 12 are respectively fixedly connected to the load sliders 10 on the two air-floating guide rails 91.

[0041] An air-floating base plate 7 is mounted on the lower surface of the track base 9. Four air-floating holes 71 are symmetrically arranged at the four corners of the geometric edge of the air-floating base plate 7. Each air-floating hole 71 is independently connected to a positive pressure air passage 72 located inside the air-floating base plate 7. A positive pressure dedicated combination connector 6 is threaded onto the inlet of each positive pressure air passage 72, and the other end of the positive pressure dedicated combination connector 6 is connected to an air compressor 15. A vacuum hole 73 is located at the geometric center of the air-floating base plate 7. The vacuum hole 73 connects to a vacuum passage 74 located inside the air-floating base plate 7. The inlet of the vacuum passage 74 is threaded... A negative pressure dedicated combination connector 16 is installed, and the other end of the negative pressure dedicated combination connector 16 is connected to a vacuum pump 17. A first pressure sensor 181 is installed inside the positive pressure dedicated combination connector 6 and the negative pressure dedicated combination connector 16. The first pressure sensor 181 is electrically connected to a controller 18. The controller 18 is electrically connected to an air compressor 15, a vacuum pump 17, a first regulating valve assembly 150 located between the positive pressure dedicated combination connector 6 and the air compressor 15, and a second regulating valve assembly 170 located between the negative pressure dedicated combination connector 16 and the vacuum pump 17.

[0042] In the first stage of adjusting the position of the air-floating moving platform 5, the air-floating base plate 7 is driven by two Y-axis linear motors 2 and two X-axis linear motors 3 to drive the track base 9, and the track base 9 drives the load plate 12, which is fixed together with the load slider 10, to move on the granite base 1, thereby achieving coarse adjustment of the movement of the load plate 12; in the second stage of adjusting the position of the air-floating moving platform 5, an air-floating pair is formed between the load slider 10 and the air-floating guide rail 91, and the load slider 10 is pushed by the ball screw linear drive mechanism 11 to move on the air-floating guide rail 91, thereby achieving fine adjustment of the movement of the load plate 12.

[0043] Please refer to Figures 1 to 3 ,as well as Figure 12 Below the two first slide blocks 23, a Y-guide rail assembly 8 is provided. The Y-guide rail assembly 8 includes a Y-guide rail 81 laid on the granite base 1 along the Y direction and a Y-direction slider 82 that slides with the Y-guide rail 81. Below the two second slide blocks 33, an X-guide rail assembly 13 is provided. The X-guide rail assembly 13 includes an X-guide rail 131 laid on the granite base 1 along the X direction and an X-direction slider 132 that slides with the X-guide rail 131. Both the Y-guide rail assembly 8 and the X-guide rail assembly 13 adopt the form of air-bearing guide rails.

[0044] Please refer to Figure 11An air compressor 15 is connected to an air storage tank 151. The air storage tank 151 is connected to a first distribution valve 152 via a pipeline. Each outlet of the first distribution valve 152 is connected to a positive pressure dedicated combination connector 6 on the air float base plate 7 via a positive pressure branch pipeline 153. The inlet of the first regulating valve assembly 150 is connected to the air storage tank 151, and the outlet is connected to the positive pressure branch pipeline 153 via a three-way valve 19. The electrical control circuit of the first regulating valve assembly 150 is connected to a controller 18. A second pressure sensor 182 is installed in the positive pressure branch pipeline 153 between the first distribution valve 152 and the positive pressure dedicated combination connector 6. 2. Electrically connected to controller 18; A third pressure sensor 183 is installed on the air tank 151, and the third pressure sensor 183 is electrically connected to controller 18; Controller 18 controls the operation of air compressor 15 according to the pressure signal of the third pressure sensor 183 in air tank 151, controls the first regulating valve assembly 150 according to the signal of the first pressure sensor 181 in the positive pressure air passage 72 connected to the air float orifice 71 and the signal of the second pressure sensor 182 in the positive pressure branch pipeline 153, and controls the air supply to each positive pressure air passage 72 through the first regulating valve assembly 150, thereby regulating the air supply pressure of each air float orifice 71.

[0045] Vacuum pump 17 is connected to vacuum tank 171. Vacuum tank 171 is connected to second distribution valve 172 via a pipe. One outlet of second distribution valve 172 is connected to negative pressure dedicated combination connector 16 on air flotation base plate 7 via a pipe. The outlet of second regulating valve assembly 170 is connected to vacuum tank 171, and the inlet is connected to negative pressure branch pipeline 173 via three-way valve 19. The electrical control end of second regulating valve assembly 170 is electrically connected to controller 18. A second pressure sensor 182 is installed in negative pressure branch pipeline 173 between second distribution valve 172 and negative pressure dedicated combination connector 16. The second pressure sensor 182 is electrically... A third pressure sensor 183 is installed on the vacuum tank 171 and is electrically connected to the controller 18. The controller 18 controls the operation of the vacuum pump 17 according to the pressure signal of the third pressure sensor 183 in the vacuum tank 171, controls the second regulating valve assembly 170 according to the signal of the first pressure sensor 181 in the vacuum passage 74 connected to the vacuum hole 73 and the signal of the second pressure sensor 182 in the negative pressure branch pipe 173, and controls the pressure of the vacuum passage 74 through the second regulating valve assembly 170, thereby adjusting the vacuum pressure at the vacuum hole 73.

[0046] The air float hole 71 and vacuum hole 73 are connected to an external air compressor or vacuum equipment through different branch pipes. Each branch pipe is equipped with a pressure sensor and a pressure regulating device. Miniature pressure sensors are also installed in the air chambers inside the air float hole 71 and vacuum hole 73. The miniature pressure sensors are connected to the controller 18. The controller 18 is connected to the air compressor 15, vacuum pump 17 and pressure regulating device to further regulate the pressure of the air foot in the air float base plate 7. This changes the current situation where the dynamic characteristics of the air film are simply regulated by the air compressor and vacuum pump, avoiding repeated over-adjustment of the air pressure. This makes the pressure of the air foot in the air float base plate 7 stable and the air film thickness moderate, avoiding air film fluctuations, improving the performance of the air film and the overall motion accuracy, and greatly improving the load-bearing capacity, rigidity, stability and life of the pneumatic platform guide rail.

[0047] Please refer to Figure 7 In a preferred embodiment, the air flotation hole 71 is a small hole with a fixed throttling hole 14 structure for throttling air supply.

[0048] Please refer to Figure 8 , Figure 9 As another preferred embodiment, the bottom of the air flotation hole 71 is a stepped mounting hole. An air foot structure element 711 is detachably installed in the stepped mounting hole of the air flotation hole 71. The air foot structure element 711 is a standard part made of porous air foot structure, small hole throttling air foot structure and grooved air foot structure, which can be selectively installed according to the needs of the applicable scenario.

[0049] The following are application scenarios for the 711 standard part of the air-supported structural component for reference.

[0050] 1. Porous gas-supplemented structure: It is a sintered metal or porous ceramic with a pore size of 5-20μm. Its characteristic is that gas permeates through uniformly distributed micropores to form a continuous gas film, which has high stability and strong anti-interference ability. It is suitable for high-precision machine tools and optical platforms.

[0051] 2. Small-hole throttling with sufficient air: The surface of the air-sufficient structural element 711 is distributed with multiple precision small holes (0.1-0.5mm in diameter). The airflow is controlled through the small holes. It is characterized by high air film stiffness, but is easily affected by load fluctuations. It is suitable for heavy equipment or high dynamic load applications.

[0052] 3. Grooved air foot: The bottom of the air foot structural element 711 is engraved with annular or spiral grooves to guide gas diffusion. Its features include controllable gas film distribution and strong load-bearing capacity.

[0053] Please refer to Figure 10The positive pressure dedicated combination connector 6 includes a connector seat 60 and a fish-scale threaded end 61. The threaded end of the fish-scale threaded end 61 is connected to the internal threaded hole of the connector seat 60. The fish-scaled end of the fish-scale threaded end 61 is connected to the positive pressure branch pipe 153 (not shown in the figure). The connector seat 60 is connected to the positive pressure air passage 72 on the air flotation base plate 7 via an external thread. The connector seat 60 includes an internal hexagonal mounting hole 62, an internal threaded through hole 63 that is connected to the internal hexagonal mounting hole 62, a sensor seat hole 64 that is parallel to the internal threaded through hole 63, and a pressure measuring through hole 65 that connects the internal threaded through hole 63 and the sensor seat hole 64. The outer port of the sensor seat hole 64 is connected to a shaped plug 66 with a through hole via an internal thread. The shaped plug 66 seals the outer port of the sensor seat hole 64. The first pressure sensor 181 is disposed inside the sensor seat hole 64. The data line of the first pressure sensor 181 passes through the through hole on the shaped plug 66. A sealing ring 68 is also provided between the bottom of the shaped plug 66 and the data line of the first pressure sensor 181. The outer port of the pressure measuring through hole 65 is sealed by a universal plug 67. The shape and structure of the negative pressure dedicated combination connector 16 are exactly the same as those of the positive pressure dedicated combination connector 6.

[0054] The first pressure sensor 181 is a miniature pressure sensor, which is wirelessly connected to the controller 18. The second pressure sensor 182 and the third pressure sensor 183 are ordinary pressure sensors, which are electrically connected to the controller 18. The structural design of the dedicated positive pressure connector 6 and the dedicated negative pressure connector 16 ensures the installation of the miniature pressure sensors in the positive pressure channel 72 and the negative pressure channel on the air flotation base plate 7, and ensures the reliability of pressure measurement in the air flotation hole 71 and the vacuum hole 73, creating favorable conditions for precise control of the internal pressure of the air foot.

[0055] Under operating conditions, the air pressure in the positive pressure branch pipe 153 between the air compressor 15 and the air flotation base plate 7 is 0.4 MPa; the air pressure in the negative pressure branch pipe 173 between the vacuum pump 17 and the air flotation base plate 7 is -60 kPa to -70 kPa.

[0056] The ultra-precision air-bearing motion stage of this invention features an air-bearing base plate 7 that, driven by a linear motor, moves a carrier plate 12 on a granite base for coarse adjustment. A carrier slider, propelled by a ball screw linear drive mechanism, moves along the air-bearing guide rail for fine adjustment, balancing efficiency and precision with a wide adjustment range and high accuracy. The structural design of the air-bearing holes 71 and the air-foot structural elements 711 allows for the selection of appropriate air-foot structures based on different equipment application scenarios, improving the adaptability of the ultra-precision air-bearing motion stage of this invention.

[0057] The above embodiments and accompanying drawings are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. The present invention has been described in detail with reference to preferred embodiments. Those skilled in the art should understand that any changes, modifications, additions, or substitutions made by those skilled in the art within the scope of the present invention do not depart from the spirit of the present invention and should also fall within the protection scope of the claims of the present invention. Other related technical structures not disclosed in detail in the present invention are existing technologies in the art.

Claims

1. An ultra-precision air-floating motion stage, characterized in that: The granite base is provided with two Y-direction linear motors which are arranged at intervals along the X direction on the granite base, the Y-direction linear motor comprises a Y-direction linear motor stator fixed on the granite base and a Y-direction linear motor mover matched with the Y-direction linear motor stator, the two Y-direction linear motor movers are fixedly connected with first sliding seats, an X-direction combined beam is arranged between the two first sliding seats, two X-direction linear motors are arranged at intervals along the Y direction on the X-direction combined beam, the X-direction linear motor comprises an X-direction linear motor stator and an X-direction linear motor mover which are matched with each other, the two X-direction linear motor stators are fixed on the X-direction combined beam, the two X-direction linear motor movers are fixedly connected with second sliding seats, the first and second mounting plates are fixedly connected between the two second sliding seats, and an air floating moving stage is fixedly connected on the first and second mounting plates. The air floating moving stage comprises a track base, the track base comprises two opposite air floating rails, each air floating rail is slidably matched with a load sliding block, a ball screw linear driving mechanism is arranged between the two air floating rails, the ball screw linear driving mechanism comprises a servo motor, a screw nut and a screw tail bearing, the servo motor is fixed on the first mounting plate, the screw tail bearing is fixedly connected with the second mounting plate, the screw nut is fixedly connected with a load plate at the upper portion, and the load plate is fixedly connected with the load sliding blocks on the two air floating rails at the two ends. A air floating bottom plate is mounted on the lower surface of the track base, four air floating holes are symmetrically arranged on the four corners of the geometric edge of the air floating bottom plate, each air floating hole is independently communicated with a positive pressure air duct arranged inside the air floating bottom plate, a positive pressure special combination joint is threadedly mounted at the inlet of each positive pressure air duct, and the other end of the positive pressure special combination joint is communicated with an air compressor; a vacuum hole is arranged at the geometric center of the air floating bottom plate, the vacuum hole is communicated with a vacuum air duct arranged inside the air floating bottom plate, a negative pressure special combination joint is threadedly mounted at the inlet of the vacuum air duct, and the other end of the negative pressure special combination joint is communicated with a vacuum pump; a first air pressure sensor is mounted inside the positive pressure special combination joint and the negative pressure special combination joint, the first air pressure sensor is electrically connected with a controller, the controller is electrically connected with the air compressor, the vacuum pump, a first adjusting valve assembly arranged between the positive pressure special combination joint and the air compressor, and a second adjusting valve assembly arranged between the negative pressure special combination joint and the vacuum pump.

2. The ultra-precision air floating motion platform according to claim 1, wherein: In the first stage of position adjustment of the air floating moving stage, the air floating bottom plate drives the track base under the driving of the two Y-direction linear motors and the two X-direction linear motors, and drives the load plate fixed with the load sliding blocks to move on the granite base, so as to realize the coarse adjustment of the load plate movement; in the second stage of position adjustment of the air floating moving stage, the air floating vice is formed between the load sliding blocks and the air floating rails, and the load sliding blocks are driven to move on the air floating rails by the ball screw linear driving mechanism, so as to realize the fine adjustment of the load plate movement.

3. The ultra-precision air floating motion platform according to claim 1, wherein: Y-direction guide rail assemblies are arranged below the two first sliding seats, and each Y-direction guide rail assembly comprises a Y-direction guide rail laid on the granite base in the Y direction and a Y-direction sliding block in sliding cooperation with the Y-direction guide rail; X-direction guide rail assemblies are arranged below the two second sliding seats, and each X-direction guide rail assembly comprises an X-direction guide rail laid on the granite base in the X direction and an X-direction sliding block in sliding cooperation with the X-direction guide rail; and each of the Y-direction guide rail assemblies and the X-direction guide rail assemblies is in the form of an air floating guide rail.

4. The ultra-precision air floating motion platform according to claim 1, wherein: The air compressor is connected with a gas storage tank, the gas storage tank is connected with a first distribution valve through a pipeline, each outlet of the first distribution valve is connected with a positive pressure special combination joint on the air floating bottom plate through a positive pressure branch pipeline in sequence; the air inlet end of a first regulating valve assembly is communicated with the gas storage tank, the air outlet end is communicated with the positive pressure branch pipeline through a three-way valve, and the electric control end circuit of the first regulating valve assembly is connected with a controller; a second air pressure sensor is installed in the positive pressure branch pipeline between the first distribution valve and the positive pressure special combination joint, and the second air pressure sensor is electrically connected with the controller; a third air pressure sensor is installed on the gas storage tank, and the third air pressure sensor is electrically connected with the controller; the controller controls the operation of the air compressor according to the air pressure signal of the third air pressure sensor in the gas storage tank, controls the first regulating valve assembly according to the first air pressure sensor signal in the positive pressure air channel communicated with the air floating hole and the second air pressure sensor signal in the positive pressure branch pipeline, and controls the air supply amount into each positive pressure air channel through the first regulating valve assembly, so as to adjust the air supply pressure of each air floating hole.

5. The ultra-precision air floating motion platform according to claim 4, wherein: The vacuum pump is connected with a vacuum tank, the vacuum tank is connected with a second distribution valve through a pipeline, one outlet of the second distribution valve is connected with a negative pressure special combination joint on the air floating bottom plate through a pipeline; the air outlet end of a second regulating valve assembly is communicated with the vacuum tank, the air inlet end is communicated with a negative pressure branch pipeline through a three-way valve, and the electric control end of the second regulating valve assembly is electrically connected with a controller; a second air pressure sensor is installed in the negative pressure branch pipeline between the second distribution valve and the negative pressure special combination joint, and the second air pressure sensor is electrically connected with the controller; a third air pressure sensor is installed on the vacuum tank, and the third air pressure sensor is electrically connected with the controller; the controller controls the operation of the vacuum pump according to the air pressure signal of the third air pressure sensor in the vacuum tank, controls the second regulating valve assembly according to the first air pressure sensor signal in the vacuum air channel communicated with the vacuum hole and the second air pressure sensor signal in the negative pressure branch pipeline, and controls the pressure of the vacuum air channel through the second regulating valve assembly, so as to adjust the vacuum pressure at the vacuum hole.

6. The ultra-precision air floating motion platform according to claim 1, wherein: The air floating hole is a small hole throttling air foot with a fixed throttling hole structure.

7. The ultra-precision air floating motion platform according to claim 1, wherein: The bottom of the air floating hole is a stepped mounting hole, and an air foot structure element is detachably mounted in the stepped mounting hole of the air floating hole, the air foot structure element is a standard part made of a porous air foot structure, a small hole throttling air foot structure and a groove type air foot structure, and is selectively mounted according to the application scene.

8. The ultra-precision air floating motion platform according to claim 1, wherein: The positive pressure special combination joint comprises a joint seat and a fish scale thread, the thread end of the fish scale thread is connected with the inner thread hole of the joint seat, the end with fish scale of the fish scale thread is connected with the positive pressure branch pipeline, and the joint seat is connected with the positive pressure air duct on the air floating bottom plate through external threads; the joint seat comprises an inner hexagonal mounting hole, an inner thread through hole connected with the inner hexagonal mounting hole, a sensor seat hole parallel to the inner thread through hole, and a pressure measurement through hole connecting the inner thread through hole and the sensor seat hole, the outer port of the sensor seat hole is connected with a special-shaped plug with a through hole through inner threads, the special-shaped plug seals the outer port of the sensor seat hole, the first air pressure sensor is arranged inside the sensor seat hole, the data line of the first air pressure sensor passes through the through hole on the special-shaped plug, a sealing ring is further arranged between the bottom of the special-shaped plug and the data line of the first air pressure sensor, and the outer port of the pressure measurement through hole is sealed through a general plug; the shape and structure of the negative pressure special combination joint are completely same as those of the positive pressure special combination joint.

9. The ultra-precision air floating motion platform according to claim 5, wherein: The first air pressure sensor is a micro pressure sensor, the micro pressure sensor is wirelessly connected with the controller; the second air pressure sensor and the third air pressure sensor are ordinary air pressure sensors, and the second air pressure sensor and the third air pressure sensor are circuit-connected with the controller.

10. The ultra-precision air floating motion platform according to claim 9, wherein: In the working state, the air pressure in the positive pressure branch pipeline between the air compressor and the air floating bottom plate is 0.4 MPa, and the air pressure in the negative pressure branch pipeline between the vacuum pump and the air floating bottom plate is-60 kpa to-70 kpa.

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