Composite air floating bearing structure for precision rotary table

Abstract

This invention discloses a composite air bearing structure for a precision turntable, relating to the field of air bearing turntable technology. This composite air bearing structure for a precision turntable, by setting a first air bearing, a second air bearing, and an air bearing ring, in conjunction with an adjustable transmission plate structure, achieves flexible adjustment of the air bearing gap and on-demand adaptation of axial load capacity. The first and second air bearings apply opposite air bearing thrusts to the two transmission plates from the upper and lower sides, respectively. Combined with the radial support of the air bearing ring on the surface of the transmission shaft tube, a "air bearing preload" effect is formed, precisely clamping the transmission shaft tube between the two air bearing surfaces, effectively eliminating axial movement and significantly improving the axial positioning accuracy and rotational stability of the turntable. Rotating the bidirectional threaded rod by the internal hexagonal nut drives the two moving plates to move closer or further apart along the guide rod, and through the connecting plate, drives the two transmission plates to move synchronously, achieving precise adjustment of the air film gap.

Description

Technical Field

[0001] This invention relates to air bearing turntable technology, specifically to a composite air bearing structure for a precision turntable. Background Technology

[0002] Precision rotary stages are core components in ultra-precision machining, semiconductor manufacturing, and optical inspection, and their rotational accuracy and load-bearing capacity directly determine machining quality and inspection reliability. Air bearings are widely used as support elements for precision rotary stages due to their advantages such as no mechanical contact, low frictional resistance, smooth movement, and long theoretical life. Existing air bearing rotary stages typically employ a fixed clearance structure, meaning the air film thickness between the air bearing and the rotary stage's transmission components is fixed after design and manufacturing, and cannot be adjusted according to actual working conditions.

[0003] However, in practical applications, precision rotary tables face complex and varied operating conditions: heavy-duty machining requires high rigidity and strong load-bearing capacity to ensure machining accuracy, while light-duty or high-speed scanning conditions prioritize low air consumption and dynamic response speed. Traditional fixed-clearance air bearing structures cannot simultaneously meet the requirements of rigidity and load-bearing capacity—too small a clearance can improve rigidity but consumes a lot of air and is prone to rubbing, while too large a clearance results in insufficient rigidity to meet heavy-duty requirements. Therefore, there is an urgent need for a composite air bearing structure that can flexibly adjust the air bearing clearance to adapt to different operating conditions. Summary of the Invention

[0004] The purpose of this invention is to provide a composite air bearing structure for precision turntables, in order to solve the problem that the air film gap of existing air bearings is fixed and cannot be adjusted as needed, resulting in difficulty in balancing rigidity and load-bearing capacity and inability to adapt to different working conditions.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a composite air bearing structure for a precision turntable, comprising a mounting tube, a mounting shaft rotatably connected inside the mounting tube, a drive mechanism for driving the mounting shaft to rotate about its own axial direction connected to the outer surface of the mounting shaft, a spline shaft fixedly connected to the bottom end of the mounting shaft, a transmission shaft tube slidably connected to the outer surface of the spline shaft, a transmission groove slidably connected to the spline shaft on the transmission shaft tube, two transmission plates slidably connected to the outer surface of the transmission shaft tube, and an adjustment mechanism provided on the transmission shaft tube, the adjustment mechanism being connected to the transmission plates;

[0006] A first air bearing is fixedly connected inside the mounting tube. A second air bearing is fixedly connected to the mounting tube above the first air bearing. An air bearing ring fixedly connected to the mounting tube is provided between the first air bearing and the second air bearing. A turntable plate is fixedly connected to the top end of the drive shaft tube.

[0007] Furthermore, the adjusting mechanism includes a bidirectional threaded rod rotatably connected to the transmission shaft tube, and two movable plates are threadedly fitted on the outer surface of the bidirectional threaded rod. The movable plates are slidably connected to the transmission shaft tube, and a connecting plate that is fixedly connected to the transmission plate is fixedly connected to the outer surface of the movable plates.

[0008] Furthermore, a guide rod that is fixedly connected to the transmission shaft tube is slidably connected to the movable plate.

[0009] Furthermore, the driving mechanism includes a rotating driving component fixedly connected inside the mounting tube, and a first driving gear is fixedly connected to the output end of the rotating driving component. A second driving gear, which is fixedly sleeved with the mounting shaft, is meshed with the outer surface of the first driving gear.

[0010] Furthermore, multiple first air inlet pipes are fixedly connected to both the first air bearing and the second air bearing, and the first air inlet pipes are fixedly connected to the mounting pipe.

[0011] Furthermore, a plurality of second air inlet pipes are fixedly connected to the air bearing ring, and the second air inlet pipes are fixedly connected to the mounting pipe.

[0012] Furthermore, an internal hexagonal nut is fixedly connected to the top end of the bidirectional threaded rod.

[0013] Furthermore, a mounting plate is fixedly connected to the bottom of the mounting pipe, a cooler is fixedly connected to the mounting plate, an air supply pipe is fixedly connected to the air outlet of the cooler and fixedly connected to the mounting pipe, a blower coil tube is fixedly connected to one end of the air supply pipe and fixedly connected to the mounting pipe, multiple air blowing covers are fixedly connected to the outer surface of the blower coil tube, and multiple air outlet pipes are fixedly connected to the outer surface of the mounting pipe.

[0014] Compared with the prior art, the composite air bearing structure for precision turntables provided by the present invention has the following advantages:

[0015] By incorporating a first air bearing, a second air bearing, and an air bearing ring, along with an adjustable transmission plate structure, flexible adjustment of the air bearing gap and on-demand adaptation of axial load capacity are achieved. The first and second air bearings apply opposite air bearing thrusts to the two transmission plates from the top and bottom, respectively. Combined with the radial support of the air bearing ring on the surface of the transmission shaft tube, an "air bearing preload" effect is created, precisely clamping the transmission shaft tube between the two air bearing surfaces. This effectively eliminates axial movement and significantly improves the axial positioning accuracy and rotational stability of the turntable. Rotating the double-threaded rod with an internal hexagonal nut drives the two moving plates to move closer or further apart along the guide rod. The connecting plate then drives the two transmission plates to move synchronously, achieving precise adjustment of the air film gap. When the two transmission plates move further apart, the air film gap decreases, the air bearing thrust increases, and the axial stiffness and load-bearing capacity are significantly improved, meeting the requirements of heavy-duty processing. When they move closer together, the air film gap increases, stiffness decreases, but air consumption decreases, making it suitable for light-load, high-speed operation. This invention completely solves the contradiction between rigidity and load-bearing capacity in traditional fixed-gap structures, enabling a single turntable to cover a wide speed range from low-speed heavy load to high-speed precision. At low speeds, the small gap ensures stable floating without the risk of bottoming out, while at high speeds, the large gap provides space for thermal expansion to prevent collisions and abrasions, significantly improving the overall performance of the equipment.

[0016] A cooler blower cools the outside air, creating a low-temperature airflow. This airflow is then delivered through a supply pipe into a blower coil surrounding the bottom of the mounting tube. Multiple blower hoods, evenly distributed on the inner surface of the blower coil, cover the rotating drive component housing and heat dissipation fins at multiple angles, achieving efficient forced convection heat transfer. Simultaneously, the cool air spreads upwards along the gaps at the bottom of the mounting tube, providing additional cooling to the lower end of the mounting shaft and the spline shaft connection area. After heat exchange, the heated airflow is smoothly discharged from the outlet pipe under the impeller of fresh cool air, forming a complete circulating heat dissipation path. Through this circulating cooling, the operating temperature of the rotating drive component is consistently controlled below the threshold value, effectively suppressing thermal disturbances to the internal thermal environment of the mounting tube caused by temperature rise. This prevents fluctuations in the air film thickness caused by changes in the fit clearance due to thermal expansion of the air bearing, ensuring that the air bearing system operates in a stable temperature field. This significantly improves the turntable's ability to maintain geometric accuracy and dynamic response consistency under long-term continuous high-speed operation, extending the equipment's service life.

[0017] By adding an active cooling airflow system, the problem of thermal deformation of the air bearing caused by the heat generated by the rotating drive components during long-term continuous operation of the turntable is effectively solved, significantly improving the thermal stability and long-term precision maintenance capability of the turntable. Specifically, after the air cooler is started, it cools the outside air to form a low-temperature dry airflow. The low-temperature airflow is sent through the air supply pipe into the air blowing ring tube surrounding the bottom of the mounting tube. The air blowing ring tube is distributed in a ring shape, and multiple air blowing hoods are evenly arranged on its inner surface. The air outlet of each air blowing hood faces the housing of the rotating drive component and the heat dissipation fins, realizing forced convection heat exchange with multi-angle and all-round coverage, which greatly improves the heat dissipation efficiency. At the same time, the cold air spreads upward along the opening gap at the bottom of the mounting tube, forming an auxiliary airflow from bottom to top, which also cools the lower end of the mounting shaft and the spline shaft connection area, further expanding the heat dissipation coverage. The heated airflow after heat exchange is smoothly discharged from multiple air outlets on the outer surface of the mounting tube under the continuous input of fresh cold air, forming a complete circulation heat dissipation path of "forced intake - directional delivery - precise injection - forced discharge", ensuring that the heat dissipation process is continuous, stable and efficient. Through the aforementioned cyclic cooling, the operating temperature of the rotating drive components can be consistently controlled below the set threshold, effectively suppressing thermal disturbances caused by temperature rise to the internal thermal environment of the mounting tube. This prevents the first air bearing, the second air bearing, and the air bearing ring from changing their original fit clearance with the transmission plate and transmission shaft tube due to thermal expansion, avoiding fluctuations in air film thickness. This ensures the air bearing system operates in a stable temperature field, significantly reducing thermal error sources, greatly improving the turntable's geometric accuracy retention and dynamic response consistency under long-term continuous high-speed operation, extending equipment lifespan, and reducing maintenance costs. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0019] Figure 1 This is a perspective view of the external structure of the present invention;

[0020] Figure 2 This is a first perspective view of the internal structure of the present invention;

[0021] Figure 3 This is a second perspective view of the internal structure of the present invention;

[0022] Figure 4 This is a third perspective view of the internal structure of the present invention.

[0023] Explanation of reference numerals in the attached figures:

[0024] 1. Mounting tube; 2. Mounting shaft; 3. Splined shaft; 4. Drive shaft tube; 5. Drive groove; 6. Drive plate; 7. First air bearing; 8. Second air bearing; 9. Air bearing ring; 10. Turntable plate; 21. Double-sided threaded rod; 22. Moving plate; 23. Connecting plate; 24. Guide rod; 31. Rotation drive component; 32. First drive gear; 33. Second drive gear; 41. First air inlet pipe; 51. Second air inlet pipe; 61. Hex socket nut; 71. Mounting plate; 72. Air cooler; 73. Air supply pipe; 74. Blower coil tube; 75. Blower hood; 76. Air outlet pipe. Detailed Implementation

[0025] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0026] Example 1

[0027] Please see Figures 1 to 4 As shown, the present invention provides a composite air bearing structure for a precision turntable, including a mounting tube 1, a mounting shaft 2 rotatably connected inside the mounting tube 1, a drive mechanism for driving the mounting shaft 2 to rotate around its own axial direction connected to the outer surface of the mounting shaft 2, a spline shaft 3 fixedly connected to the bottom end of the mounting shaft 2, a transmission shaft tube 4 slidably connected to the outer surface of the spline shaft 3, a transmission groove 5 slidably connected to the spline shaft 3 on the transmission shaft tube 4, two transmission plates 6 slidably connected to the outer surface of the transmission shaft tube 4, and an adjustment mechanism provided on the transmission shaft tube 4, the adjustment mechanism being connected to the transmission plates 6;

[0028] A first air bearing 7 is fixedly connected inside the mounting tube 1. A second air bearing 8, which is fixedly connected to the mounting tube 1, is provided above the first air bearing 7. An air bearing ring 9, which is fixedly connected to the mounting tube 1, is provided between the first air bearing 7 and the second air bearing 8. A turntable plate 10 is fixedly connected to the top end of the drive shaft tube 4.

[0029] The adjustment mechanism includes a bidirectional threaded rod 21 that is rotatably connected to the drive shaft tube 4. The outer surface of the bidirectional threaded rod 21 is threaded with two movable plates 22. The movable plates 22 are slidably connected to the drive shaft tube 4. The outer surface of the movable plates 22 is fixedly connected to a connecting plate 23 that is fixedly connected to the drive plate 6.

[0030] A guide rod 24, which is fixedly connected to the transmission shaft tube 4, is slidably connected to the movable plate 22.

[0031] The drive mechanism includes a rotating drive component 31 fixedly connected inside the mounting tube 1. The rotating drive component 31 is a servo motor, which is controlled by a PLC programming program. The servo motor can be controlled to rotate forward and backward and rotate at different angles. A first drive gear 32 is fixedly connected to the output end of the rotating drive component 31. A second drive gear 33 is meshed with the outer surface of the first drive gear 32 and fixedly sleeved with the mounting shaft 2. The rotating drive component 31 drives the first drive gear 32 to rotate, and the first drive gear 32 drives the second drive gear 33 and the mounting shaft 2 to rotate.

[0032] Multiple first air inlet pipes 41 are fixedly connected to both the first air bearing 7 and the second air bearing 8, and the first air inlet pipes 41 are fixedly connected to the mounting pipe 1.

[0033] Multiple second air inlet pipes 51 are fixedly connected to the air bearing ring 9, and the second air inlet pipes 51 are fixedly connected to the mounting pipe 1.

[0034] The top end of the double-threaded rod 21 is fixedly connected to an internal hex nut 61.

[0035] Air is supplied to the first air bearing 7 and the second air bearing 8 through the first air inlet pipe 41. At this time, the first air bearing 7 discharges gas through multiple throttling orifices at its top, blowing air onto the transmission plate 6 on the drive shaft tube 4, generating an upward thrust on the transmission plate 6. Simultaneously, the second air bearing 8 discharges gas through multiple throttling orifices at its bottom, blowing air downward onto the transmission plate 6 above the drive shaft tube 4. This creates an air film between both the first and second air bearings 7 and the transmission plate 6, achieving axial positioning of the drive shaft tube 4. Meanwhile, the second air inlet pipe 51 supplies air to the air bearings... Gas is supplied to ring 9, and the air bearing ring 9 blows air onto the surface of the drive shaft tube 4. The two air buoyancy forces are in opposite directions, forming an "air buoyancy preload" effect, which clamps the drive shaft tube 4 between the two air buoyancy surfaces, thereby accurately limiting the axial position of the drive shaft tube 4 and preventing it from moving under the action of gravity or external axial force. This allows the drive shaft tube 4 to rotate stably. Subsequently, the drive mechanism drives the mounting shaft 2 to rotate, and the mounting shaft 2 drives the drive shaft tube 4 to rotate through the spline shaft 3. The drive shaft tube 4 drives the turntable plate 10 to rotate, thereby driving the turntable plate 10 to rotate stably.

[0036] During operation, the bidirectional threaded rod 21 rotates in both directions, causing the two moving plates 22 to move away from or towards each other along the guide rod 24. The moving plates 22, via the connecting plate 23, cause the two transmission plates 6 to move away from or towards each other. When the two transmission plates 6 approach each other, the air film gap between each transmission plate 6 and the first air bearing 7 and the second air bearing 8 increases. When the two transmission plates 6 move away from each other, the air film gap decreases, thus adjusting the air film gap. When the two transmission plates 6 move away from each other, the air film gap decreases, the air film is compressed more, and the air bearing thrust of the first air bearing 7 and the second air bearing 8 on the transmission plates 6 is simultaneously enhanced, significantly improving axial stiffness and load-bearing capacity, meeting the requirements of heavy-duty high-precision machining. When the two transmission plates 6 approach each other, the air film gap increases, stiffness decreases, but air consumption decreases, making it suitable for light-duty or high-speed scanning conditions. This design completely resolves the inherent contradiction between rigidity and load-bearing capacity in traditional fixed-gap structures. Simultaneously, during low-speed rotation, the two transmission plates 6 are spaced further apart, creating a smaller film gap to achieve high starting rigidity and ensure the turntable floats smoothly without the risk of bottoming out. During high-speed operation, the two transmission plates 6 are adjusted in the opposite direction, bringing them closer together to increase the film gap. This provides sufficient space for the rotor's centrifugal expansion and thermal elongation, preventing excessively small effective gaps that could lead to rubbing. A single turntable can cover a wide speed range, from low-speed heavy-load to high-speed precision, overcoming the shortcomings of traditional solutions in terms of poor speed adaptability.

[0037] Example 2

[0038] Based on Example 1, please refer to Figure 2 and Figure 4 As shown, a mounting plate 71 is fixedly connected to the bottom of the mounting pipe 1. A cooler 72 is fixedly connected to the mounting plate 71. An air supply pipe 73, which is fixedly connected to the mounting pipe 1, is fixedly connected to the air outlet end of the cooler 72. A blower coil pipe 74, which is fixedly connected to the mounting pipe 1, is fixedly connected to one end of the air supply pipe 73. Multiple air blowing covers 75 are fixedly connected to the outer surface of the blower coil pipe 74. Multiple air outlet pipes 76 are fixedly connected to the outer surface of the mounting pipe 1.

[0039] When the turntable is working, the rotating drive component 31 is the main heat source. Its continuous operation will generate a lot of heat. If the heat accumulates in the closed space at the bottom of the mounting tube 1, it will be transferred to the inside of the mounting tube 1 through heat conduction and heat radiation. This will cause the first air bearing 7, the second air bearing 8 and the air bearing ring 9 to change their original fit clearance with the transmission plate 6 and the transmission shaft tube 4 due to thermal expansion, which will cause fluctuations in the air film thickness and seriously affect the rotation accuracy and stability of the turntable. To this end, the present invention provides an active cooling airflow system: First, the air cooler 72 is started, which draws in external air and cools it to generate a low-temperature dry airflow. This low-temperature airflow is transported through the air supply pipe 73 to the air blowing ring pipe 74 that surrounds the bottom of the mounting pipe 1. The air blowing ring pipe 74 is arranged in a ring shape, and multiple air blowing hoods 75 are evenly arranged on its inner ring surface. The air outlet of each air blowing hood 75 faces the housing of the rotating drive component 31 and the heat dissipation fin plate, ensuring that the cold air can cover the surface of the rotating drive component 31 from multiple angles and in all directions, so as to achieve efficient convective heat transfer. At the same time, the cold air will also spread upward along the bottom opening gap of the mounting pipe 1 during the flow process, forming an auxiliary airflow from bottom to top, which will also cool the lower end of the mounting shaft 2 and the connection area of ​​the spline shaft 3. After heat exchange, the heated airflow, propelled by continuously supplied fresh cool air, is smoothly discharged from multiple exhaust pipes 76 fixedly connected to the outer surface of the mounting tube 1, forming a complete circulating heat dissipation path of "forced intake—directional delivery—precise injection—forced discharge". Through the above-mentioned circulating cooling process, the operating temperature of the rotating drive component 31 can always be controlled below the set threshold, effectively suppressing the thermal disturbance caused by temperature rise to the internal thermal environment of the mounting tube 1, ensuring that the air bearing system operates in a stable temperature field, thereby further reducing thermal error sources and significantly improving the turntable's ability to maintain geometric accuracy and dynamic response consistency under long-term continuous high-speed operation conditions.

[0040] Working principle:

[0041] During operation, air is supplied to the first air bearing 7 and the second air bearing 8 through the first air intake pipe 41. The gas discharged from the top throttling hole of the first air bearing 7 generates an upward thrust on the transmission plate 6, and the gas discharged from the bottom throttling hole of the second air bearing 8 generates a downward thrust on the transmission plate 6, so that the two bearings and the transmission plate 6 form an air film with opposite directions. At the same time, air is supplied to the air bearing ring 9 through the second air intake pipe 51. The air bearing ring 9 blows air onto the surface of the transmission shaft tube 4, forming an "air preload" effect, which clamps the transmission shaft tube 4 between the two air surfaces and achieves precise axial positioning. Then, the rotating drive component 31 drives the first drive gear 32 to rotate. The first drive gear 32 drives the mounting shaft 2 to rotate through the second drive gear 33. The mounting shaft 2 drives the transmission shaft tube 4 to rotate through the sliding fit between the spline shaft 3 and the transmission groove 5. The transmission shaft tube 4 drives the turntable plate 10 to rotate stably. During use, the double-threaded rod 21 is rotated by the internal hex nut 61. The double-threaded rod 21 drives the two moving plates 22 to move closer or further apart along the guide rod 24. The moving plates 22 drive the two transmission plates 6 to move synchronously through the connecting plate 23, thereby adjusting the air film gap between the transmission plate 6 and the first air bearing 7 and the second air bearing 8, so as to achieve flexible adaptation of axial stiffness and load-bearing capacity and meet the needs of different working conditions.

[0042] Simultaneously, when the turntable is working, the air cooler 72 is activated. The air cooler 72 cools the outside air to form a low-temperature airflow. The low-temperature airflow is sent through the air supply pipe 73 into the air blowing ring pipe 74 surrounding the bottom of the mounting tube 1, and then sprayed at multiple angles by multiple air blowing hoods 75 onto the housing of the rotating drive component 31 and the surface of the heat dissipation fin plate for forced convection heat exchange. At the same time, the cold air spreads upward along the bottom gap of the mounting tube 1, providing auxiliary cooling to the lower end of the mounting shaft 2 and the connection area of ​​the spline shaft 3. The heated airflow after heat exchange is smoothly discharged from multiple air outlet pipes 76 on the outer surface of the mounting tube 1 under the continuous input of fresh cold air, forming a complete circulating heat dissipation path. This effectively suppresses the thermal disturbance of the air bearing system inside the mounting tube 1 caused by the temperature rise, ensuring that the air bearing works in a stable temperature field and improving the accuracy maintenance capability of the turntable during long-term continuous operation.

[0043] The foregoing has only described certain exemplary embodiments of the present invention by way of illustration. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the foregoing drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A compound aerostatic bearing structure for a precision rotary table, characterized by, The device includes an installation tube (1), an installation shaft (2) is rotatably connected inside the installation tube (1), a drive mechanism for driving the installation shaft (2) to rotate around its own axis is connected to the outer surface of the installation shaft (2), a spline shaft (3) is fixedly connected to the bottom end of the installation shaft (2), a transmission shaft tube (4) is slidably connected to the outer surface of the spline shaft (3), a transmission groove (5) is opened on the transmission shaft tube (4) and slidably connected to the spline shaft (3), two transmission plates (6) are slidably connected to the outer surface of the transmission shaft tube (4), and an adjustment mechanism is provided on the transmission shaft tube (4) and the adjustment mechanism is connected to the transmission plate (6); A first air bearing (7) is fixedly connected inside the mounting tube (1). A second air bearing (8) is fixedly connected to the mounting tube (1) above the first air bearing (7). An air bearing ring (9) fixedly connected to the mounting tube (1) is provided between the first air bearing (7) and the second air bearing (8). A turntable plate (10) is fixedly connected to the top of the transmission shaft tube (4).

2. The hybrid air bearing structure for precision rotary tables according to claim 1, wherein, The adjustment mechanism includes a bidirectional threaded rod (21) rotatably connected to the transmission shaft tube (4). The outer surface of the bidirectional threaded rod (21) is threaded with two movable plates (22). The movable plates (22) are slidably connected to the transmission shaft tube (4). The outer surface of the movable plates (22) is fixedly connected to a connecting plate (23) that is fixedly connected to the transmission plate (6).

3. The composite air bearing structure for a precision turntable according to claim 1, characterized in that, The movable plate (22) is slidably connected to a guide rod (24) which is fixedly connected to the transmission shaft tube (4).

4. The composite air bearing structure for a precision turntable according to claim 1, characterized in that, The drive mechanism includes a rotating drive component (31) fixedly connected inside the mounting tube (1). The output end of the rotating drive component (31) is fixedly connected to a first drive gear (32). The outer surface of the first drive gear (32) is meshed with a second drive gear (33) fixedly sleeved with the mounting shaft (2).

5. The composite air bearing structure for a precision turntable according to claim 1, characterized in that, Multiple first air inlet pipes (41) are fixedly connected to both the first air bearing (7) and the second air bearing (8), and the first air inlet pipes (41) are fixedly connected to the mounting pipe (1).

6. The composite air bearing structure for a precision turntable according to claim 1, characterized in that, Multiple second air inlet pipes (51) are fixedly connected to the air bearing ring (9), and the second air inlet pipes (51) are fixedly connected to the mounting pipe (1).

7. The composite air bearing structure for a precision turntable according to claim 1, characterized in that, The top end of the bidirectional threaded rod (21) is fixedly connected to an internal hexagonal nut (61).

8. The composite air bearing structure for a precision turntable according to claim 1, characterized in that, The bottom of the mounting pipe (1) is fixedly connected to a mounting plate (71), a cooler (72) is fixedly connected to the mounting plate (71), the air outlet of the cooler (72) is fixedly connected to an air supply pipe (73) fixedly connected to the mounting pipe (1), one end of the air supply pipe (73) is fixedly connected to a blower coil pipe (74) fixedly connected to the mounting pipe (1), a plurality of blower hoods (75) are fixedly connected to the outer surface of the blower coil pipe (74), and a plurality of air outlet pipes (76) are fixedly connected to the outer surface of the mounting pipe (1).

Images