Ultra-precise air flotation motion platform deck

Abstract

The invention belongs to the technical field of precision technical equipment, and relates to an ultra-precision air flotation motion platform deck which comprises a granite base, and two Y-direction linear motors are arranged on the granite base in 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 rotor matched with the Y-direction linear motor stator; two Y-direction linear motor rotors are fixedly connected with first sliding seats respectively, an X-direction combination beam is arranged between the two first sliding seats, and two X-direction linear motors are arranged on the X-direction combination beam at intervals in the Y direction; according to the ultra-precision air-floating motion platform deck, the air-floating bottom plate is driven by the linear motor to drive the carrying plate to move on the granite base, coarse adjustment of movement is achieved, the carrying sliding block is pushed by the ball screw linear driving mechanism to move on the air-floating guide rail, fine adjustment of movement of the carrying plate is achieved, efficiency and precision are both considered, the adjustment range is large, and the precision is high.

Description

Technical Field

[0001] The invention belongs to the technical field of precision technical equipment and relates to an ultra-precision air-floating motion carrier. Background Art

[0002] A pneumatic stage utilizes the principle of air pressure transmission to carry, move, or position objects. High-end lithography systems, such as EUV lithography machines, require an air-bearing stage, a core technology for achieving nanometer-level precision and high-speed motion. The pneumatic stage operates by using a linear motor to drive the stage. Compressed air creates a micron-sized air film between the stage and the base, eliminating mechanical friction. The stator (coil array) in the linear motor is fixed to the base, while the mover (permanent magnet assembly) is mounted on the stage. When powered, electromagnetic thrust is generated, propelling the stage to achieve nanometer-level motion precision.

[0003] Pneumatic stages currently face technical challenges such as limited control accuracy and poor air supply pressure stability. In terms of control accuracy, pneumatic stages sometimes produce difficult-to-correct nonlinear control errors, making them unable to meet the precision requirements of certain applications requiring extremely high position control accuracy. The stability of the air supply pressure directly impacts the performance of the air film and overall motion accuracy. Excessive or insufficient air supply pressure can lead to a series of problems, affecting the load-bearing capacity, rigidity, stability, and even the lifespan of the pneumatic stage's guide rails.

[0004] Therefore, taking effective measures to optimize the mechanical structure of the carrier, reduce mechanical friction, equip a high-precision air source processing system, and further improve the accuracy and stability of the pneumatic carrier are still the directions that technical personnel in this field need to work hard to improve. Summary of the Invention

[0005] In order to solve the technical problems of the existing pneumatic carrier in the background technology, such as limited control accuracy, 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 rail, the present invention provides an ultra-precision air-floating motion carrier.

[0006] The present invention solves the above-mentioned technical problems through the following technical solutions, and provides an ultra-precision air-floating motion platform, comprising a granite base, on which two Y-direction linear motors are arranged at intervals along the X direction, the Y-direction linear motor comprising a Y-direction linear motor stator fixed on the granite base and a Y-direction linear motor mover cooperating with the Y-direction linear motor stator; the two Y-direction linear motor movers are respectively fixedly connected to a first slide, an X-direction combined beam is arranged between the two first slides, and 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 cooperating 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 respectively fixedly connected to a second slide, a first mounting plate and a second mounting plate are fixedly connected between the two second slides, and the air-floating motion platform is fixedly connected to the first mounting plate and the second mounting plate.

[0007] The air-floating mobile platform includes a track base, and the track base includes two opposite air-floating guide rails, each of which is slidably fitted with a loading slider, and a ball screw linear drive mechanism is arranged between the two air-floating 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 on the first mounting plate, the screw tail bearing is fixedly connected to the second mounting plate, the upper part of the screw nut is fixedly connected to the loading plate, and the two ends of the loading plate are respectively fixedly connected to the loading sliders on the two air-floating guide rails.

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

[0009] Furthermore, in the first stage of the position adjustment of the air-floating movable platform, the air-floating bottom plate drives the track base under the drive of two Y-axis linear motors and two X-axis linear motors, and drives the carrier plate fixed to the carrier slider to move on the granite base through the track base, thereby realizing coarse adjustment of the carrier plate movement; in the second stage of the position adjustment of the air-floating movable platform, an air-floating pair is formed between the carrier slider and the air-floating guide rail, and the carrier slider is pushed to move on the air-floating guide rail by the ball screw linear drive mechanism, thereby realizing fine adjustment of the carrier plate movement.

[0010] Furthermore, a Y-guide rail assembly is provided below the two first slides, and the Y-guide rail assembly includes a Y-guide rail laid on a granite base along the Y direction and a Y-direction slider that slides with the Y-guide rail; an X-guide rail assembly is provided below the two second slides, and the X-guide rail assembly includes an X-guide rail laid on a granite base along the X direction and an X-direction slider that slides with the X-guide rail; the Y-guide rail assembly and the X-guide rail assembly both adopt the form of air-floating guide rails.

[0011] Furthermore, the air compressor is connected to an air storage tank, which is connected to a first distributing valve through a pipeline, and each outlet of the first distributing valve is connected to the positive pressure dedicated combination joint on the flotation bottom plate in turn through a positive pressure branch pipe; the air inlet end of the first regulating valve assembly is connected to the air storage tank, and the air outlet end is connected to the positive pressure branch pipe through a three-way valve, and the electrical control end circuit of the first regulating valve assembly is connected to the controller; a second air pressure sensor is installed in the positive pressure branch pipe between the first distributing valve and the positive pressure dedicated combination joint, and the second air pressure sensor is electrically connected to the controller; a third air pressure sensor is installed on the air storage tank, and the third air pressure sensor is electrically connected to 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 air storage tank, controls the first regulating valve assembly according to the first air pressure sensor signal in the positive pressure air channel connected to the flotation hole and the second air pressure sensor signal in the positive pressure branch pipe, and controls the air supply entering each positive pressure air channel through the first regulating valve assembly, thereby adjusting the air supply pressure of each flotation hole.

[0012] Furthermore, the vacuum pump is connected to a vacuum tank, which is connected to a second distribution valve through a pipeline, and one outlet of the second distribution valve is connected to a negative pressure special combination joint on the air flotation bottom plate through a pipeline; the air outlet end of the second regulating valve assembly is connected to the vacuum tank, and the air inlet end is connected to the negative pressure branch pipe through a three-way valve, and the electrical control end of the second regulating valve assembly is electrically connected to the controller; a second air pressure sensor is installed in the negative pressure branch pipe between the second distribution valve and the negative pressure special combination joint, and the second air pressure sensor is electrically connected to the controller; a third air pressure sensor is installed on the vacuum tank, and the third air pressure sensor is electrically connected to 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 duct connected to the vacuum hole and the second air pressure sensor signal in the negative pressure branch pipe, and controls the pressure of the vacuum air duct through the second regulating valve assembly, thereby adjusting the vacuum pressure at the vacuum hole.

[0013] As a preferred embodiment, the air flotation hole is a small hole throttling air foot with a fixed throttling hole structure.

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

[0015] Furthermore, the positive-pressure dedicated combination joint includes a joint seat and a fish-scale thread head, the thread head end of the fish-scale thread head is cooperatively connected with the inner thread hole of the joint seat, the fish-scale end of the fish-scale thread head is connected to the positive-pressure branch pipe (not shown in the figure), and the joint seat is connected to the positive-pressure airway on the flotation bottom plate through an external thread; the joint seat includes an internal hexagonal mounting hole, an internal threaded through hole connected to the internal hexagonal mounting hole, a sensor seat hole parallel to the internal threaded through hole, and a pressure measuring through hole connecting the internal threaded through hole and the sensor seat hole, the outer port of the sensor seat hole is connected to a special-shaped thread plug with a through hole through an internal thread, the special-shaped thread plug closes 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 thread plug, and a sealing ring is also provided between the bottom of the special-shaped thread plug and the data line of the first air pressure sensor, and the outer port of the pressure measuring through hole is sealed by a universal thread plug; the shape and structure of the negative-pressure dedicated combination joint are exactly the same as those of the positive-pressure dedicated combination joint.

[0016] Furthermore, the first air pressure sensor is a micro pressure sensor, which is wirelessly connected to the controller; the second air pressure sensor and the third air pressure sensor are ordinary air pressure sensors, which are circuit-connected to the controller.

[0017] Furthermore, in the working state, the air pressure in the positive pressure branch pipe between the air compressor and the air floating bottom plate is 0.4 MPa; the air pressure in the negative pressure branch pipe between the vacuum pump and the air floating bottom plate is -60 kPa to -70 kPa.

[0018] Beneficial effects 1. Compared with the prior art, the ultra-precision air-floating motion platform of the present invention has an air-floating bottom plate driven by a linear motor to move the carrier plate on the granite base to achieve coarse adjustment of movement, and a carrier slider is pushed by a ball screw linear drive mechanism to move on the air-floating guide rail to achieve fine adjustment of the carrier plate movement, taking into account both efficiency and precision, with a large adjustment range and high precision. During the movement of the air-floating motion platform, the air-floating bottom plate and the air-floating guide rail exist at the same time, and the superimposed air-floating pair movement effect improves the stability of movement, reduces nonlinear control errors, and further improves positioning accuracy and the working efficiency of the air-floating motion platform.

[0019] 2. The air flotation holes and vacuum holes are separately connected to the external air compressor or vacuum equipment through different branch pipes. The branch pipes are equipped with air pressure sensors and pressure regulating devices. Miniature pressure sensors are also installed in the air cavities inside the air flotation holes and vacuum holes. The miniature pressure sensors are connected to the controller, and the controller is connected to the air compressor, vacuum pump and pressure regulating device to further adjust the pressure of the air in the air flotation base plate. This changes the current situation in the prior art of simply using air compressors and vacuum pumps to adjust the dynamic characteristics of the air film, avoids repeated overshoot of air pressure, makes the pressure of the air in the air flotation base plate stable, and the thickness of the air film moderate, avoids air film fluctuations, improves the performance of the air film and the overall motion accuracy, and greatly improves the load-bearing capacity, stiffness, stability and life of the pneumatic platform guide rail.

[0020] 3. The structural design of the positive pressure special combination joint and the negative pressure special combination joint ensures the installation of the micro pressure sensor in the positive pressure airway and negative pressure airway on the air flotation base plate, ensures the reliability of pressure measurement in the air flotation hole and vacuum hole, and creates favorable conditions for precise control of the internal pressure of the air foot.

[0021] 4. The structural design of the air flotation hole and the air foot structure enables the air flotation hole to select a suitable air foot structure according to different equipment application scenarios, thereby improving the working adaptability of the ultra-precision air flotation motion carrier of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1Schematic diagram of the overall structure of the ultra-precision air-floating motion stage according to an embodiment of the present invention; Figure 2 yes Figure 1 A local enlarged view of point A in FIG; Figure 3 yes Figure 1 BB section view in the figure; Figure 4 This is a schematic diagram of the track base structure according to an embodiment of the present invention; Figure 5 This is a bottom view of a track base according to an embodiment of the present invention; Figure 6 This is a front view of an air-floating bottom plate component according to an embodiment of the present invention; Figure 7 A top view of an air-floating bottom plate component with a fixed throttle hole according to an embodiment of the present invention; Figure 8 A top view of an air-floating bottom plate component equipped with an air-foot structural element according to an embodiment of the present invention; Figure 9 Schematic diagram of two gas-filled structural elements according to an embodiment of the present invention; Figure 10 This is a schematic diagram of a positive pressure dedicated combined joint component according to an embodiment of the present invention; Figure 11 This is a schematic diagram of the gas foot pressure regulation control flow in an embodiment of the present invention; Figure 12 This is a schematic structural diagram of a Y-direction guide rail assembly according to an embodiment of the present invention; In the figure: 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 combined beam, 5. Air-floating moving carrier, 6. Positive pressure special combined joint, 60. Joint seat, 61. Fish scale wire head, 62. Hexagonal mounting hole, 63. Internal thread through hole, 64. Sensor seat hole, 65. Pressure measuring through hole, 66. Special-shaped wire plug, 67. Universal wire plug, 68. Sealing ring, 7. Air-floating bottom plate, 71. Air-floating hole, 711. Air foot structural element, 72. Positive pressure airway, 73. Vacuum hole, 74. Vacuum airway, 8. Y-axis guide rail assembly, 81. Y-axis guide rail , 82, Y-axis slider, 9, track base, 91, air-floating guide rail, 10, loading slider, 11, ball screw linear drive mechanism, 111, servo motor, 112, lead screw nut, 113, lead screw tail bearing, 12, loading plate, 13, X-axis guide rail assembly, 131, X-axis guide rail, 132, X-axis slider, 14, fixed throttle hole, 15, air compressor, 150, first regulating valve assembly, 151, air storage tank, 152, first distributing valve, 153, positive pressure branch pipe, 16, negative pressure special combination joint, 17, vacuum pump, 170, second regulating valve assembly, 171, vacuum tank, 172, second distributing valve, 173, negative pressure branch pipe, 18, controller, 181, first air pressure sensor, 182, second air pressure sensor, 183, third air pressure sensor, 19, three-way valve. DETAILED DESCRIPTION

[0023] In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limitations on the present 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.

[0024] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0025] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0026] See also Figures 1 to 12 , an ultra-precision air-floating motion platform, comprising a granite base 1, on which two Y-direction linear motors 2 are arranged at intervals along the X direction, the Y-direction linear motor 2 comprising a Y-direction linear motor stator 21 fixed on the granite base 1 and a Y-direction linear motor mover 22 matched with the Y-direction linear motor stator 21; the two Y-direction linear motor movers 22 are respectively fixedly connected to a first slide 23, an X-direction combined beam 4 is arranged between the two first slides 23, and two X-direction linear motors 3 are arranged at intervals along the Y direction on the X-direction combined beam 4; the X-direction linear motor 3 comprises an X-direction linear motor stator 31 and an X-direction linear motor mover 32 matched with each other, the two X-direction linear motor stators 31 are fixed on the X-direction combined beam 4, the two X-direction linear motor movers 32 are respectively fixedly connected to a second slide 33, a first mounting plate 34 and a second mounting plate 35 are fixedly connected between the two second slides 33, and an air-floating moving platform 5 is fixedly connected to the first mounting plate 34 and the second mounting plate 35.

[0027] The air-floating mobile platform 5 includes a track base 9, which includes two opposite air-floating guide rails 91. Each of the air-floating guide rails 91 is slidably fitted with a carrier slider 10. A ball screw linear drive mechanism 11 is arranged 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 the first mounting plate 34, and the screw tail bearing 113 is fixedly connected to the second mounting plate 35. The upper part of the screw nut 112 is fixedly connected to the carrier plate 12, and the two ends of the carrier plate 12 are respectively fixedly connected to the carrier sliders 10 on the two air-floating guide rails 91.

[0028] An air-floating bottom plate 7 is installed 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 bottom plate 7. Each air-floating hole 71 is independently connected to a positive-pressure air duct 72 arranged inside the air-floating bottom plate 7. The inlet of each positive-pressure air duct 72 is threadedly installed with a positive-pressure special combination joint 6. The other end of the positive-pressure special combination joint 6 is connected to the air compressor 15. A vacuum hole 73 is provided at the geometric center of the air-floating bottom plate 7. The vacuum hole 73 is connected to a vacuum air duct 74 arranged inside the air-floating bottom plate 7. The inlet of the vacuum air duct 74 is threadedly installed with a positive-pressure special combination joint 6. The other end of the positive-pressure special combination joint 6 is connected to the air compressor 15. A negative pressure dedicated combination joint 16 is installed in the groove, and the other end of the negative pressure dedicated combination joint 16 is connected to the vacuum pump 17; a first air pressure sensor 181 is installed inside the positive pressure dedicated combination joint 6 and the negative pressure dedicated combination joint 16, and the first air pressure sensor 181 is electrically connected to the controller 18, and the controller 18 is electrically connected to the air compressor 15, the vacuum pump 17, the first regulating valve assembly 150 arranged between the positive pressure dedicated combination joint 6 and the air compressor 15, and the second regulating valve assembly 170 arranged between the negative pressure dedicated combination joint 16 and the vacuum pump 17.

[0029] In the first stage of position adjustment of the air-floating movable platform 5, the air-floating bottom plate 7 drives the track base 9 under the drive of two Y-axis linear motors 2 and two X-axis linear motors 3, and drives the carrier plate 12 fixed to the carrier slider 10 to move on the granite base 1 through the track base 9, thereby realizing coarse adjustment of the movement of the carrier plate 12; in the second stage of position adjustment of the air-floating movable platform 5, an air-floating pair is formed between the carrier slider 10 and the air-floating guide rail 91, and the carrier slider 10 is pushed to move on the air-floating guide rail 91 by the ball screw linear drive mechanism 11, thereby realizing fine adjustment of the movement of the carrier plate 12.

[0030] Please refer to Figures 1 to 3 ,as well as Figure 12 A Y-guide rail assembly 8 is provided below the two first slides 23. 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. An X-guide rail assembly 13 is provided below the two second slides 33. 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 are air-floating guide rails.

[0031] Please refer to Figure 11The air compressor 15 is connected to an air storage tank 151, which is connected to a first distribution valve 152 through a pipeline. The outlets of the first distribution valve 152 are connected to the positive pressure dedicated combination joint 6 on the air floating bottom plate 7 in sequence through the positive pressure branch pipe 153; the air inlet end of the first regulating valve assembly 150 is connected to the air storage tank 151, and the air outlet end is connected to the positive pressure branch pipe 153 through the three-way valve 19. The electric control end circuit of the first regulating valve assembly 150 is connected to the controller 18; a second air pressure sensor 182 is installed in the positive pressure branch pipe 153 between the first distribution valve 152 and the positive pressure dedicated combination joint 6. The second air pressure sensor 18 2 is electrically connected to the controller 18; a third air pressure sensor 183 is installed on the air storage tank 151 and is electrically connected to the controller 18; the controller 18 controls the operation of the air compressor 15 based on the air pressure signal from the third air pressure sensor 183 in the air storage tank 151, and controls the first regulating valve assembly 150 based on the signal from the first air pressure sensor 181 in the positive pressure air passage 72 connected to the air flotation hole 71 and the signal from the second air pressure sensor 182 in the positive pressure branch pipe 153. The controller 18 controls the air supply volume entering each positive pressure air passage 72 through the first regulating valve assembly 150, thereby adjusting the air supply pressure to each air flotation hole 71.

[0032] The vacuum pump 17 is connected to a vacuum tank 171, which is connected to a second distribution valve 172 through a pipeline. One outlet of the second distribution valve 172 is connected to the negative pressure dedicated combination joint 16 on the air flotation bottom plate 7 through a pipeline; the air outlet end of the second regulating valve assembly 170 is connected to the vacuum tank 171, and the air inlet end is connected to the negative pressure branch pipe 173 through the three-way valve 19. The electric control end of the second regulating valve assembly 170 is electrically connected to the controller 18; a second air pressure sensor 182 is installed in the negative pressure branch pipe 173 between the second distribution valve 172 and the negative pressure dedicated combination joint 16. The second air pressure sensor 182 is electrically connected to the negative pressure branch pipe 173. Connected to the controller 18; a third air pressure sensor 183 is installed on the vacuum tank 171, and the third air pressure sensor 183 is electrically connected to the controller 18; the controller 18 controls the operation of the vacuum pump 17 according to the air pressure signal of the third air pressure sensor 183 in the vacuum tank 171, and controls the second regulating valve assembly 170 according to the signal of the first air pressure sensor 181 in the vacuum air duct 74 connected to the vacuum hole 73 and the signal of the second air pressure sensor 182 in the negative pressure branch pipe 173, and controls the pressure of the vacuum air duct 74 through the second regulating valve assembly 170, thereby adjusting the vacuum pressure at the vacuum hole 73.

[0033] The flotation hole 71 and the vacuum hole 73 are separately connected to the external air compressor or vacuum equipment through different branch pipes. The branch pipes are equipped with air pressure sensors and pressure regulating devices. Miniature pressure sensors are also installed in the air cavities inside the flotation hole 71 and the vacuum hole 73. The miniature pressure sensors are connected to the controller 18. The controller 18 is connected to the air compressor 15, the vacuum pump 17 and the pressure regulating device to further adjust the pressure of the air in the flotation base plate 7, which changes the current situation of simply using air compressors and vacuum pumps to adjust the dynamic characteristics of the air film in the existing technology, avoids repeated overshoot of air pressure, makes the pressure of the air in the flotation base plate 7 stable, and the thickness of the air film moderate, avoids fluctuations in the air film, improves the performance of the air film and the overall movement accuracy, and greatly improves the load-bearing capacity, rigidity, stability and life of the pneumatic platform guide rail.

[0034] Please refer to Figure 7 As a preferred embodiment, the air flotation hole 71 is a small hole throttling air foot with a fixed throttling hole 14 structure.

[0035] Please refer to Figure 8 、 Figure 9 As another preferred embodiment, the bottom of the air flotation hole 71 is a stepped mounting hole, and an air foot structural element 711 is detachably installed in the stepped mounting hole of the air flotation hole 71. The air foot structural element 711 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 can be selectively installed according to the needs of the applicable scenario.

[0036] The following are the application scenarios of 711 standard parts of gas foot structural components for reference. 1. Porous gas foot is a gas foot structural element made of 711 sintered metal or porous ceramic with a pore size of 5-20μm. It is characterized by gas seeping through evenly distributed micropores to form a continuous gas film with high stability and strong anti-interference ability. It is suitable for high-precision machine tools and optical platforms.

[0037] 2. Small hole throttling air foot: The surface of the air foot structural element 711 is distributed with multiple precision small holes (diameter 0.1-0.5mm), which control the airflow through the small holes. The characteristic is that the air film stiffness is relatively high, but it is easily affected by load fluctuations. It is suitable for heavy equipment or high dynamic load occasions.

[0038] 3. Grooved gas foot: annular or spiral grooves are engraved on the bottom of the gas foot structural element 711 to guide gas diffusion. The characteristics are controllable gas film distribution and strong bearing capacity.

[0039] Please refer to Figure 10, the positive pressure special combination joint 6 includes a joint seat 60 and a fish scale wire head 61, the wire head end of the fish scale wire head 61 is matched with the inner wire hole of the joint seat 60, and the fish scale end of the fish scale wire head 61 is connected to the positive pressure branch pipe 153 (not shown in the figure), and the joint seat 60 is connected to the positive pressure airway 72 on the air flotation bottom plate 7 through an external thread; the joint seat 60 includes an inner hexagonal mounting hole 62, an inner threaded through hole 63 connected to the inner hexagonal mounting hole 62, a sensor seat hole 64 parallel to the inner threaded through hole 63, and a pressure measuring through hole 65 connecting the inner threaded through hole 63 and the sensor seat hole 64, The outer port of the sensor seat hole 64 is connected to the special-shaped wire plug 66 with a through hole through an internal thread. The special-shaped wire plug 66 closes the outer port of the sensor seat hole 64. The first air pressure sensor 181 is arranged inside the sensor seat hole 64. The data line of the first air pressure sensor 181 passes through the through hole on the special-shaped wire plug 66. A sealing ring 68 is also provided between the bottom of the special-shaped wire plug 66 and the data line of the first air pressure sensor 181. The outer port of the pressure measuring through hole 65 is sealed by a universal wire plug 67; the shape and structure of the negative pressure dedicated combination joint 16 are exactly the same as the shape and structure of the positive pressure dedicated combination joint 6.

[0040] The first air pressure sensor 181 is a miniature pressure sensor wirelessly connected to the controller 18. The second and third air pressure sensors 182, 183 are standard air pressure sensors, each electrically connected to the controller 18. The structural design of the positive-pressure and negative-pressure combination connectors 6, 16 ensures the installation of the miniature pressure sensors within the positive-pressure and negative-pressure airways 72, respectively, on the air-floating baseplate 7. This ensures reliable pressure measurement within the air-floating holes 71 and vacuum holes 73, creating favorable conditions for precise control of the internal pressure of the air-floating baseplate.

[0041] In the working state, the air pressure in the positive pressure branch pipe 153 between the air compressor 15 and the air floating bottom plate 7 is 0.4 MPa; the air pressure in the negative pressure branch pipe 173 between the vacuum pump 17 and the air floating bottom plate 7 is -60 kPa to -70 kPa.

[0042] In the ultra-precision air-floating motion stage of the present invention, an air-floating base plate 7, driven by a linear motor, moves the carrier plate 12 on a granite base for coarse movement adjustment. A ball screw linear drive mechanism propels the carrier slide along an air-floating guide rail for fine adjustment of the carrier plate 12. This achieves a balance of efficiency and precision, offering a wide adjustment range and high accuracy. The structural design of the air-floating holes 71 and the air-foot structure 711 allows the air-floating holes 71 to be used with the appropriate air-foot structure depending on the device's application scenario, enhancing the operational adaptability of the ultra-precision air-floating motion stage of the present invention.

[0043] The above embodiments and accompanying drawings are intended only 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 spirit and scope of the present invention do not depart from the spirit of the present invention and are intended to fall within the scope of the claims. Other related technical structures not fully disclosed in the present invention constitute prior art in the art.

Claims

1. An ultra-precision air-floating motion stage, characterized by: It includes a granite base, on which two Y-direction linear motors are arranged at intervals along the X direction, the Y-direction linear motor includes 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 to a first slide, an X-direction combined beam is provided between the two first slides, and two X-direction linear motors are arranged at intervals along the Y direction on the X-direction combined beam; the X-direction linear motor includes an X-direction linear motor stator and an X-direction linear motor mover that match 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 respectively fixedly connected to a second slide, a first mounting plate and a second mounting plate are fixedly connected between the two second slides, and an air-floating movable carrier is fixedly connected to the first mounting plate and the second mounting plate; The air-floating mobile carrier includes a track base, and the track base includes two opposite air-floating guide rails, each of which is slidably fitted with a loading slider, and a ball screw linear drive mechanism is provided between the two air-floating guide rails, and the ball screw linear drive mechanism includes a servo motor, a screw nut, and a screw tail bearing, the servo motor is fixed to the first mounting plate, the screw tail bearing is fixedly connected to the second mounting plate, the upper part of the screw nut is fixedly connected to the loading plate, and the two ends of the loading plate are respectively fixedly connected to the loading sliders on the two air-floating guide rails; An air-floating bottom plate is installed on the lower surface of the track base, and four air-floating holes are symmetrically arranged at the four corners of the geometric edge of the air-floating bottom plate. Each of the air-floating holes is independently connected to the positive-pressure air duct arranged inside the air-floating bottom plate, and the inlet of each positive-pressure air duct is threadedly installed with a positive-pressure dedicated combination joint, and the other end of the positive-pressure dedicated combination joint is connected to the air compressor; a vacuum hole is provided at the geometric center of the air-floating bottom plate, and the vacuum hole is connected to the vacuum air duct arranged inside the air-floating bottom plate, and the inlet of the vacuum air duct is threadedly installed with a negative-pressure dedicated combination joint, and the other end of the negative-pressure dedicated combination joint is connected to the vacuum pump; a first air pressure sensor is installed inside the positive-pressure dedicated combination joint and the negative-pressure dedicated combination joint, and the first air pressure sensor is electrically connected to a controller, and the controller is electrically connected to the air compressor, the vacuum pump, a first regulating valve assembly arranged between the positive-pressure dedicated combination joint and the air compressor, and a second regulating valve assembly arranged between the negative-pressure dedicated combination joint and the vacuum pump.

2. The ultra-precision air-floating motion stage according to claim 1, characterized in that: In the first stage of the position adjustment of the air-floating movable platform, the air-floating bottom plate drives the track base under the drive of two Y-axis linear motors and two X-axis linear motors, and drives the carrier plate fixed to the carrier slider to move on the granite base through the track base, thereby realizing coarse adjustment of the carrier plate movement; in the second stage of the position adjustment of the air-floating movable platform, an air-floating pair is formed between the carrier slider and the air-floating guide rail, and the carrier slider is pushed to move on the air-floating guide rail by the ball screw linear drive mechanism, thereby realizing fine adjustment of the carrier plate movement.

3. The ultra-precision air-floating motion stage according to claim 1, characterized in that: A Y-guide rail assembly is provided below the two first slides, and the Y-guide rail assembly includes a Y-guide rail laid on a granite base along the Y direction and a Y-direction slider that slides with the Y-guide rail; an X-guide rail assembly is provided below the two second slides, and the X-guide rail assembly includes an X-guide rail laid on a granite base along the X direction and an X-direction slider that slides with the X-guide rail; the Y-guide rail assembly and the X-guide rail assembly both adopt air-floating guide rails.

4. The ultra-precision air-floating motion stage according to claim 1, characterized in that: The air compressor is connected to an air storage tank, which is connected to a first distributing valve through a pipeline, and each outlet of the first distributing valve is connected to the positive pressure dedicated combination joint on the flotation bottom plate in turn through a positive pressure branch pipe; the air inlet end of the first regulating valve assembly is connected to the air storage tank, and the air outlet end is connected to the positive pressure branch pipe through a three-way valve, and the electrical control end circuit of the first regulating valve assembly is connected to the controller; a second air pressure sensor is installed in the positive pressure branch pipe between the first distributing valve and the positive pressure dedicated combination joint, and the second air pressure sensor is electrically connected to the controller; a third air pressure sensor is installed on the air storage tank, and the third air pressure sensor is electrically connected to 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 air storage tank, controls the first regulating valve assembly according to the first air pressure sensor signal in the positive pressure air channel connected to the flotation hole and the second air pressure sensor signal in the positive pressure branch pipe, and controls the air supply entering each positive pressure air channel through the first regulating valve assembly, thereby adjusting the air supply pressure of each flotation hole.

5. The ultra-precision air-floating motion stage according to claim 4, characterized in that: The vacuum pump is connected to a vacuum tank, which is connected to a second distribution valve through a pipeline, and one outlet of the second distribution valve is connected to a negative pressure special combination joint on the flotation bottom plate through a pipeline; the air outlet end of the second regulating valve assembly is connected to the vacuum tank, and the air inlet end is connected to the negative pressure branch pipe through a three-way valve, and the electrical control end of the second regulating valve assembly is electrically connected to the controller; a second air pressure sensor is installed in the negative pressure branch pipe between the second distribution valve and the negative pressure special combination joint, and the second air pressure sensor is electrically connected to the controller; a third air pressure sensor is installed on the vacuum tank, and the third air pressure sensor is electrically connected to 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 duct connected to the vacuum hole and the second air pressure sensor signal in the negative pressure branch pipe, and controls the pressure of the vacuum air duct through the second regulating valve assembly, thereby adjusting the vacuum pressure at the vacuum hole.

6. The ultra-precision air-floating motion stage according to claim 1, characterized in that: The air flotation hole is a small hole throttling air foot with a fixed throttling hole structure.

7. The ultra-precision air-floating motion stage according to claim 1, characterized in that: The bottom of the flotation hole is a stepped mounting hole, and an air foot structural element is detachably installed in the stepped mounting hole of the flotation hole. The air foot structural element is a standard part made according to a porous air foot structure, a small hole throttling air foot structure, and a groove-type air foot structure, and is selectively installed according to the needs of the applicable scenario.

8. The ultra-precision air-floating motion stage according to claim 1, characterized in that: The positive-pressure dedicated combination joint includes a joint seat and a fish-scale thread head, the thread head end of the fish-scale thread head is cooperated with the inner thread hole of the joint seat, the fish-scale end of the fish-scale thread head is connected to the positive-pressure branch pipe, and the joint seat is connected to the positive-pressure airway on the flotation bottom plate through an external thread; the joint seat includes an inner hexagonal mounting hole, an inner threaded through hole connected to the inner hexagonal mounting hole, a sensor seat hole parallel to the inner threaded through hole, and a pressure measuring through hole connecting the inner threaded through hole and the sensor seat hole, the outer port of the sensor seat hole is connected to a special-shaped wire plug with a through hole through an inner thread, the special-shaped wire plug closes 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 wire plug, and a sealing ring is also provided between the bottom of the special-shaped wire plug and the data line of the first air pressure sensor, and the outer port of the pressure measuring through hole is sealed by a universal wire plug; the shape and structure of the negative-pressure dedicated combination joint are exactly the same as those of the positive-pressure dedicated combination joint.

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

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

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