Ultra-precision laser processing machine tool

Abstract

The invention relates to the technical field of high-end manufacturing equipment and machine tool functional parts and discloses an ultra-precision laser processing machine tool. The ultra-precision laser processing machine tool comprises a machine tool body, a portal frame, an X-axis air floatation moving mechanism, a Y-axis air floatation moving mechanism, an AC cradle rotary table and a Z-axis air floatation moving mechanism. The Z-axis air floatation moving mechanism is provided with a gravity balance unit and a partition air pressure regulation and control module, overturning torque is accurately offset through an independent air path, and air film failure is avoided; the AC cradle turntable adopts a main and auxiliary support and a coaxial coupling structure, so that the unbalance loading resistance is improved. According to the machine tool, through cooperation of all parts, the defects that a traditional gas static pressure guide rail is low in rigidity and the rotary table is weak in unbalance loading resistance are overcome, submicron-level movement precision is achieved, the bearing stability is improved, and the machine tool is suitable for high-end equipment such as precision machine tools and high-precision measuring instruments.

Description

Technical Field

[0001] This invention relates to the field of high-end manufacturing equipment and machine tool functional components, and in particular to an ultra-precision laser processing machine tool. Background Technology

[0002] In the field of ultra-precision laser processing, processing accuracy directly determines the core performance of products, and the vertical movement accuracy of the machine tool and the rotation accuracy of the workpiece-bearing turntable are key factors affecting the processing effect. In existing ultra-precision laser processing machine tools, the vertical movement mechanism mostly adopts a traditional mechanical guide rail structure. The friction between the metal contact surfaces leads to high movement resistance, which is prone to wear after long-term use, thereby reducing the movement and positioning accuracy and failing to meet the requirements of nanoscale processing.

[0003] For this purpose, the vertical moving mechanism adopts gas static pressure guide rails. With the significant advantages of high motion straightness and low friction coefficient brought by air film support, gas static pressure guide rail pairs have become the core key components of linear motion pairs in precision machine tools, high-precision measuring instruments and other equipment. By isolating the moving parts from the reference surface through the air film, it effectively avoids mechanical contact wear and provides a basic guarantee for the high-precision operation of the equipment.

[0004] However, due to the inherent physical property of the strong compressibility of air, the overall stiffness of the gas static pressure guide pair is relatively low. This deficiency is particularly prominent in vertical applications, which severely limits its applicability under heavy load and large eccentric load conditions. In practical applications, the slide of the vertical gas static pressure guide pair needs to support functional components such as machine tool tools, measuring instrument sensors or lasers. When these loads are heavy or the cantilever distance between the load center and the geometric center of the slide support is long, a significant overturning torque will inevitably be generated.

[0005] In existing technologies, gas static pressure guide rail pairs generally adopt an equal pressure or uniform gas supply mode. The load-bearing capacity of each point supporting the gas film on the slide is basically equal, or symmetrically distributed along the center of the slide. This design cannot accurately control the direction and magnitude of the overturning torque, causing the slide to tilt under the action of the overturning torque, specifically manifested as a deviation in attitude in the left-right or front-back direction. This results in direct contact between the throttle surface and the guide rail reference surface, destroying and failing the gas film structure, ultimately causing the guide rail pair to fail to achieve the normal linear motion function.

[0006] It is evident that existing technologies still need improvement and enhancement. Summary of the Invention

[0007] In view of the shortcomings of the prior art, the purpose of this invention is to provide an ultra-precision laser processing machine tool, which aims to solve the problems of low stiffness of gas hydrostatic guide rails, tilting caused by overturning torque and weak resistance to off-center loads of the turntable, thereby improving the positioning accuracy and stability of the ultra-precision laser processing machine tool.

[0008] To achieve the above objectives, the present invention adopts the following technical solution: An ultra-precision laser processing machine tool includes a bed, a gantry mounted on the bed, a Y-axis air-bearing mechanism mounted on the bed, an X-axis air-bearing mechanism mounted on the Y-axis air-bearing mechanism, and an AC cradle turntable mounted on the X-axis air-bearing mechanism. The X-axis air-bearing mechanism drives the AC cradle turntable to move left and right, and the Y-axis air-bearing mechanism drives the X-axis air-bearing mechanism and the AC cradle turntable to move back and forth. A Z-axis air-bearing mechanism is mounted on the gantry, and a downward-facing laser processing component is mounted on the Z-axis air-bearing mechanism. The Z-axis air-bearing mechanism drives the laser processing component to move up and down. The machining component is used to process workpieces on the AC cradle turntable; the Z-axis air-floating movement mechanism includes a gravity balance unit, a control device, and a gas static pressure guide rail pair electrically connected to the control device; the gas static pressure guide rail pair includes a linear guide rail pair, a slide assembly surrounding the outer periphery of the linear guide rail pair, and multiple air path control units, the air outlets of the multiple air path control units are respectively connected to the air inlet of the slide assembly, and the air outlet side of the slide assembly faces the linear guide rail pair; the control device is electrically connected to the multiple air path control units, and through independent control of each air path control unit, the zoned air pressure regulation of the gas static pressure guide rail pair is realized.

[0009] The slide assembly includes a main slide, a first side slide, a second side slide, a first back slide, and a second back slide. The main slide is disposed on the front side of the linear guide pair, with its air outlet facing the front reference plane of the linear guide pair. The first side slide and the second side slide are disposed opposite to each other on both sides of the linear guide pair, and are respectively fixedly connected to the left and right ends of the main slide. The air outlets of the first and second side slides face the side reference plane of the linear guide pair. The first back slide and the second back slide are respectively disposed on the back side of the linear guide pair, with the first back slide fixedly connected to the first side slide and the second back slide fixedly connected to the second side slide. The air outlets of the first and second back slides face the back reference plane of the linear guide pair.

[0010] The gas static pressure guide rail assembly includes twelve sets of air path control units. The air inlet end of the main slide is connected to four sets of air path control units, which are used to control the air pressure on the upper left, lower left, upper right, and lower right sides of the main slide, respectively. The air inlet ends of the first side slide, the second side slide, the first back slide, and the second back slide are each connected to two sets of air path control units. The eight sets of air path control units are used to control the air pressure on the upper and lower sides of the first side slide, the upper and lower sides of the second side slide, the upper and lower sides of the first back slide, and the upper and lower sides of the second back slide, respectively.

[0011] Each of the aforementioned air circuit control units has the same structure. The air circuit control unit includes an air circuit, a throttle, and a pressure regulating valve and a pressure gauge that are electrically connected to the control device. The output end of the air circuit is connected to the air inlet end of the slide assembly. The pressure regulating valve and the pressure gauge are respectively installed on the air circuit. The throttle is installed on the output side of the air circuit and is located at the air outlet end of the slide assembly.

[0012] The gravity balancing unit includes a first lifting ring, a second lifting ring, a fixed pulley, and a counterweight. The first lifting ring is fixedly connected to the slide assembly, and the first lifting ring is connected to the second lifting ring via a flexible metal wire. The fixed pulley is fixedly mounted on the top of the gantry frame, and the flexible metal wire slides in cooperation with the fixed pulley. The second lifting ring is fixedly connected to the counterweight, and the counterweight is slidably mounted on the back side of the gantry frame.

[0013] The AC cradle turntable includes a fixed base, an A-axis turntable mounted on the fixed base, and a C-axis turntable connected to the output end of the A-axis turntable. The A-axis turntable includes a first torque motor, a first main bearing housing located at the head of the first torque motor and connected to the fixed base, a first auxiliary bearing housing located at the tail of the first torque motor, a first output shaft connected to one end of the mover of the first torque motor, and a first extension shaft connected to the other end of the mover of the first torque motor. The first output shaft is rotatably connected to the first main bearing housing, and the first extension shaft is rotatably connected to the first auxiliary bearing housing. The first extension shaft, the mover of the first torque motor, and the first… The output shaft is coaxially coupled to form the A-axis axis; the C-axis turntable includes a second torque motor, a second main bearing housing disposed at the head of the second torque motor, a second auxiliary bearing housing disposed at the tail of the second torque motor, a second output shaft connected to one end of the mover of the second torque motor, and a second extension shaft connected to the other end of the mover of the second torque motor. The second output shaft is rotatably connected to the second main bearing housing, and the second extension shaft is rotatably connected to the second auxiliary bearing housing. The second extension shaft, the mover of the second torque motor, and the second output shaft are coaxially coupled to form the C-axis axis; the first output shaft is connected to the second main bearing housing through a transfer bracket.

[0014] The first output shaft includes a rear shaft, a middle shaft, and a front shaft connected in sequence. The middle shaft is rotatably connected to a first main bearing seat via a first bearing, and the rear shaft is connected to the mover of a first torque motor.

[0015] The central shaft is a hollow circular shaft structure. The rear shaft has an outer ring and a first recess that mates with the central shaft. One end face of the central shaft has a plurality of circumferentially arranged first threaded holes. The rear shaft has a first countersunk hole that corresponds to each of the first threaded holes. A first screw that connects to the corresponding first threaded hole is installed at each first countersunk hole. One end face of the mover of the first torque motor has a plurality of circumferentially arranged second threaded holes. The outer ring has a second countersunk hole that corresponds to each of the second threaded holes. A second screw that connects to the corresponding second threaded hole is installed at each second countersunk hole.

[0016] The front axle body is provided with an inner ring around its periphery. The front axle body is provided with an inner ring and has a second embedded recess that mates with the middle axle body. The other end face of the middle axle body is provided with a plurality of circumferentially arranged third threaded holes. The front axle body is provided with third countersunk holes that correspond one-to-one with the third threaded holes. Each third countersunk hole is provided with a third screw that connects to the corresponding third threaded hole. The inner ring is provided with a code disk. The first main bearing seat is provided with an encoding reader that works in conjunction with the code disk.

[0017] The first extension shaft is rotatably connected to the first secondary bearing seat through the second bearing and is provided with a stepped ring. The other end face of the mover of the first torque motor is provided with a plurality of circumferentially arranged fourth threaded holes. The stepped ring is provided with fourth countersunk holes corresponding to the fourth threaded holes one by one. A fourth screw connected to the corresponding fourth threaded hole is installed at each fourth countersunk hole.

[0018] Beneficial effects: This invention provides an improved Z-axis air-bearing movement mechanism for an ultra-precision laser processing machine tool. Through electrical connection between a control device and multiple air circuit control units, it achieves independent zoned air pressure regulation, overcoming the shortcomings of existing medium-pressure or uniform air supply modes that cannot specifically address overturning torques. Under heavy load or large eccentric load conditions, precise control of the air pressure in different zones can generate a reverse support force, effectively counteracting the overturning torque, preventing lateral or longitudinal displacement of the slide assembly, and preventing air film failure due to contact between the throttle surface and the guide rail reference surface. This ensures the stable realization of the linear motion function of the gas static pressure guide pair, significantly improving the applicability of the mechanism under heavy load and large eccentric load conditions, achieving sub-micron level motion accuracy, and simultaneously enhancing the mechanism's load-bearing capacity and operational stability. It is suitable for high-end equipment such as precision machine tools and high-precision measuring instruments, broadening the application range of gas static pressure guide pairs. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of the ultra-precision laser processing machine tool provided by the present invention.

[0020] Figure 2 This is a schematic diagram of the Z-axis air-float moving mechanism provided by the present invention.

[0021] Figure 3 This is a schematic diagram of the linear guide pair and slide assembly provided by the present invention.

[0022] Figure 4 This is a schematic diagram of the gas circuit control unit provided by the present invention.

[0023] Figure 5 This is a schematic diagram of the gravity balance unit provided by the present invention.

[0024] Figure 6 This is a schematic diagram of the slide assembly and throttle provided by the present invention.

[0025] Figure 7 This is a perspective view of the AC cradle turntable provided by the present invention.

[0026] Figure 8 This is a cross-sectional view of the AC cradle turntable provided by the present invention.

[0027] Figure 9 for Figure 8 A magnified view of a portion of region A in the middle.

[0028] Figure 10 This is an exploded view of the first output shaft.

[0029] Figure 11 The explosion of the transfer support Figure 1 .

[0030] Figure 12 The explosion of the transfer support Figure 2 .

[0031] Key component symbols: 1-Gantry frame, 2-Gravity balance unit, 21-First lifting ring, 22-Second lifting ring, 23-Fixed pulley, 24-Counterweight, 25-Flexible metal wire, 3-Gas static pressure guide rail pair, 31-Main slide, 32-First side slide, 33-Second side slide, 34-First back slide, 35-Second back slide, 361-Air passage, 362-Throttle, 363-Air pressure regulating valve, 364-Air pressure gauge, 37-Linear guide rail pair, 38-Z-axis linear motor magnetic rail, 39-Z 391-Z-axis linear motor coil, 4-bed, 51-Y-axis air-bearing moving mechanism, 52-X-axis air-bearing moving mechanism, 6-Z-axis air-bearing moving mechanism, 7-AC cradle turntable, 71-fixed seat, 711-L-shaped support, 712-base plate, 72-A-axis turntable, 721-first torque motor, 722-first main bearing seat, 7221-lower leg, 7222-first mounting slot, 723-first auxiliary bearing seat, 724-first output shaft, 7241-rear shaft body, 724 11-Outer ring, 72412-First embedded recess, 72413-First countersunk hole, 72414-Second countersunk hole, 7242-Central shaft, 72421-First threaded hole, 7243-Front shaft, 72431-Inner ring, 72432-Second embedded recess, 72433-Third countersunk hole, 725-First extension shaft, 7251-Stepped ring, 7252-Second bearing, 726-First bearing, 727-Code disk, 728-Brake mechanism, 7291-Front cover, 7292-Rear cover, 7 293-Sealing ring, 73-C-axis turntable, 731-Second torque motor, 732-Second main bearing seat, 7321-Support arm, 7322-Second mounting slot, 733-Second auxiliary bearing seat, 734-Second output shaft, 735-Second extension shaft, 736-Upper cover, 737-Lower cover, 738-Clamping platform, 74-Transfer bracket, 741-Positioning disc, 7411-Circular positioning protrusion, 742-Vertical plate, 743-Upright arm, 744-Positioning block, 745-Positioning groove, 8-Laser processing component. Detailed Implementation

[0032] This invention provides an ultra-precision laser processing machine tool. To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining the invention and are not intended to limit the invention.

[0033] In the description of this invention, it should be understood that the terms "upper," "lower," "left," and "right," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or a specific orientational structure and operation. Therefore, they should not be construed as limitations on the invention. Furthermore, "first" and "second" are only for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "multiple" means two or more.

[0034] Please see Figures 1 to 6 As shown, this invention provides an ultra-precision laser processing machine tool, including a bed 4, a gantry 1 mounted on the bed 4, a Y-axis air-bearing moving mechanism 51 mounted on the bed 4, an X-axis air-bearing moving mechanism 52 mounted on the Y-axis air-bearing moving mechanism 51, and an AC cradle turntable 7 mounted on the X-axis air-bearing moving mechanism 52. The X-axis air-bearing moving mechanism 52 is used to drive the AC cradle turntable 7 to move left and right, and the Y-axis air-bearing moving mechanism 51 is used to drive the X-axis air-bearing moving mechanism 52 and the AC cradle turntable 7 to move back and forth. A Z-axis air-bearing moving mechanism 6 is provided on the gantry 1, and a downward-facing laser processing component 8 is provided on the Z-axis air-bearing moving mechanism 6. The Z-axis air-bearing moving mechanism 6 is used to drive the laser processing component. The laser processing component 8 moves up and down and is used to process the workpiece on the AC cradle turntable 7. The Z-axis air-floating moving mechanism 6 includes a gravity balance unit 2, a control device, and a gas static pressure guide rail pair 3 electrically connected to the control device. The gas static pressure guide rail pair 3 includes a linear guide rail pair 37, a slide assembly surrounding the outer periphery of the linear guide rail pair 37, and multiple air path control units. The air outlets of the multiple air path control units are respectively connected to the air inlet of the slide assembly, and the air outlet side of the slide assembly faces the linear guide rail pair 37. The control device is electrically connected to the multiple air path control units and achieves zoned air pressure regulation of the gas static pressure guide rail pair 3 by independently regulating each air path control unit.

[0035] Before processing, the staff clamps the workpiece on the AC cradle turntable 7. The Y-axis air-bearing moving mechanism 51 drives the X-axis air-bearing moving mechanism 52 and the AC cradle turntable 7 to adjust their positions in the front and back directions. At the same time, the X-axis air-bearing moving mechanism 52 drives the AC cradle turntable 7 to adjust its positions in the left and right directions. Through the coordinated movement of the longitudinal and lateral directions, the workpiece on the AC cradle turntable 7 is accurately transported to the processing area directly below the laser processing component 8.

[0036] During the processing stage, the Z-axis air-bearing moving mechanism 6 drives the downward-facing laser processing component 8 to move up and down to adapt to the processing requirements of workpieces of different thicknesses and complete precise vertical processing feed. Specifically, the gravity balance unit 2 starts working first, and through the cooperation of the flexible metal wire 25 and the fixed pulley, the weight of the counterweight 24 is transferred to the slide assembly, accurately offsetting the vertical gravity of the slide assembly itself and the load such as the laser processing component 8 it carries. In this process, the connection method of the flexible metal wire 25 can effectively isolate the error generated during the movement of the counterweight 24, avoid interfering with the movement accuracy of the gas static pressure guide pair 3, and significantly reduce the bearing pressure of the gas film, providing a stable foundation for the subsequent formation of a stable gas film. The control device is electrically connected to multiple air circuit control units of the gas static pressure guide pair 3. After starting, the control device first obtains the gas film gap data of the gas static pressure guide pair 3 in various dimensions through the laser interferometer, and at the same time, combined with the actual weight of the load such as the laser processing component 8, accurately calculates the magnitude and direction of the possible overturning torque. Based on preset calibration information, the control device determines the air pressure difference and specific adjustment values ​​for each zone according to the calculated overturning moment parameters, and then issues precise control commands to the corresponding air circuit control units. Each air circuit control unit independently adjusts its output air pressure according to the commands, delivering gas of appropriate pressure to the outlet side of the slide assembly through the inlet end of the slide assembly, and finally outputting gas to the corresponding reference surface of the linear guide pair 37, forming a stable supporting air film and achieving non-contact isolation between the slide assembly and the linear guide pair 37. When the load center of gravity shifts, causing an overturning moment, the control device responds quickly, selectively adjusting the air circuit control units of the corresponding zones, increasing the pressure in the zone opposite to the direction of the overturning moment and decreasing the pressure in the zone in the same direction. By forming an asymmetrical and precise supporting force, the influence of the overturning moment is quickly offset, ensuring that the slide assembly always maintains a vertical posture. Based on this, the linear guide 37 of the gas static pressure guide 3 achieves high-precision relative linear motion with the slide assembly, driving the laser processing assembly 8 to complete stable and precise vertical movement. In conjunction with the work of the laser processing assembly 8, the ultra-precision machining of the workpiece on the AC cradle turntable 7 is finally achieved.

[0037] The ultra-precision laser processing machine tool provided by this invention features a significant improvement to the Z-axis air-bearing movement mechanism 6. Through electrical connection between the control device and multiple air circuit control units, it achieves independent control of zoned air pressure, overcoming the shortcomings of existing medium-pressure or uniform air supply modes that cannot specifically address overturning torques. Under heavy load or large eccentric load conditions, precise control of the air pressure in different zones can generate a reverse support force, effectively counteracting the overturning torque and preventing left-right or front-back attitude deviations in the slide assembly. This prevents the throttle surface 362 from contacting the guide rail reference surface, thus preventing air film failure and ensuring the stable linear motion of the gas static pressure guide rail pair 3. This significantly improves the applicability of the mechanism under heavy load and large eccentric load conditions, achieving sub-micron level motion accuracy. Simultaneously, it enhances the load-bearing capacity and operational stability of the mechanism, making it suitable for high-end equipment such as precision machine tools and high-precision measuring instruments, thus broadening the application range of the gas static pressure guide rail pair 3.

[0038] In this embodiment, the control device is fixed to the side of the gantry 1 or in a separate control box. It is electrically connected to each gas path control unit of the gas static pressure guide rail pair 3 via a cable to realize signal transmission and control command issuance. In the gas static pressure guide rail pair 3, the slide assembly surrounds the outer periphery of the linear guide rail pair 37. An initial gap is reserved between each slide and the linear guide rail pair 37. Multiple gas path control units are sealed to the air inlet end of the slide assembly through air pipes to ensure that there is no leakage in the air pressure transmission.

[0039] Furthermore, the gas static pressure guide rail pair 3 also includes a Z-axis linear motor magnetic rail 38, a Z-axis linear motor coil 39, and an adjustment pad for the Z-axis linear motor coil 39; the linear guide rail pair 37 is fixedly installed on the front of the gantry frame 1 by bolts, serving as the reference rail for the movement of the slide assembly and providing a stable guiding foundation. The slide assembly surrounds the outer periphery of the linear guide rail pair 37, with air film gaps reserved between it and each reference surface of the linear guide rail pair 37; when the air circuit control unit adjusts the air pressure of each zone, a stable and uniform air film is formed between the slide assembly and each reference surface of the linear guide rail pair 37, enabling the slide assembly to move smoothly along the extension direction of the linear guide rail pair 37. At the same time, the stable support of the air film ensures the straightness and posture stability during the movement; the Z-axis linear motor magnetic rail 38 is fixed in the concave groove of the linear guide rail pair 37, using an embedded installation method to ensure that it is parallel to the central axis of the linear guide rail pair 37, and its position is fixed after installation, not moving with the slide. The component moves; the Z-axis linear motor coil 39 is fixedly connected to the Z-axis linear motor coil 39 adjustment pad, and the two form an integral component. The Z-axis linear motor coil 39 adjustment pad is fixed to the back of the main slide plate 31 by bolts, so that the Z-axis linear motor coil 39 and the main slide plate 31 move synchronously. A preset air gap is maintained between the Z-axis linear motor coil 39 and the Z-axis linear motor magnetic rail 38 to avoid mechanical contact during movement. The Z-axis linear motor magnetic rail 38 and the Z-axis linear motor coil 39 constitute the core component of the linear drive. When three-phase AC power is applied to the Z-axis linear motor coil 39, a traveling wave magnetic field is generated along the extension direction of the Z-axis linear motor magnetic rail 38. The traveling wave magnetic field interacts with the magnetic field generated by the Z-axis linear motor magnetic rail 38 to form an electromagnetic thrust. This thrust directly drives the main slide plate 31, which is fixedly connected to the Z-axis linear motor coil 39, and drives the entire slide plate assembly to move in a vertical linear direction along the linear guide pair 37.

[0040] Furthermore, see Figure 3As shown, the slide assembly includes a main slide 31, a first side slide 32, a second side slide 33, a first back slide 34, and a second back slide 35. The main slide 31 is disposed on the front side of the linear guide pair 37, with the air outlet side of the main slide 31 facing the positive reference plane of the linear guide pair 37. The first side slide 32 and the second side slide 33 are disposed opposite to each other on both sides of the linear guide pair 37, and the first side slide 32 and the second side slide 33 are respectively fixedly connected to the left and right ends of the main slide 31. The air outlet end of the first side slide plate 32 and the air outlet side of the second side slide plate 33 face the side reference surface of the linear guide pair 37; the first back slide plate 34 and the second back slide plate 35 are respectively disposed on the back side of the linear guide pair 37, the first back slide plate 34 is fixedly connected to the first side slide plate 32, and the second back slide plate 35 is fixedly connected to the second side slide plate 33, and the air outlet end of the first back slide plate 34 and the air outlet end of the second back slide plate 35 face the back reference surface of the linear guide pair 37.

[0041] In this embodiment, the main slide plate 31 has a plate-like structure, with its back side facing the positive reference surface of the linear guide pair 37. Connecting flanges are provided at both ends of the main slide plate 31, which are fixedly connected to one end of the first side slide plate 32 and the second side slide plate 33 by bolts. The connecting surfaces are precision machined to ensure perpendicularity and flatness after connection. The first side slide plate 32 and the second side slide plate 33 are symmetrically structured and located on the left and right sides of the linear guide pair 37, respectively. Their inner sides are facing the side reference surface of the linear guide pair 37, and their outer sides are provided with connecting ears, which are fixedly connected to the first back slide plate 34 and the second back slide plate 35 by bolts. The first back slide plate 34 and the second back slide plate 35 are symmetrically structured and located at the left and right ends of the back side of the linear guide pair 37, respectively. Their inner sides are facing the back reference surface of the linear guide pair 37. Each slide plate has multiple throttle valve 362 mounting holes on its outlet side. The throttle valve 362 is fixed in the mounting holes by threads or interference fit to ensure sealing performance.

[0042] During the actual operation of the slide assembly, the main slide 31 corresponds to the positive reference plane of the linear guide pair 37, and the throttle 362 on its outlet side outputs air pressure to form a front air film, mainly responsible for adjusting the tilt in the front and rear directions; the first side slide 32 and the second side slide 33 correspond to the left and right reference planes of the linear guide pair 37, and the throttle 362 on its outlet side outputs air pressure to form left and right air films, responsible for adjusting the tilt in the left and right directions; the first back slide 34 and the second back slide 35 correspond to the back reference plane of the linear guide pair 37, and the throttle 362 on its outlet side outputs air pressure to form left and right air films, responsible for adjusting the tilt in the left and right directions; the first back slide 34 and the second back slide 35 correspond to the back reference plane of the linear guide pair 37, and the throttle 362 on its outlet side outputs air pressure to form a front air film, mainly .... 2. The output air pressure forms a back air film to assist in the adjustment of the tilt in the front and rear directions. When the control device issues an air pressure adjustment command, the air circuit control unit corresponding to each slide adjusts the air pressure so that the corresponding throttle 362 outputs the preset pressure. The pressure difference of the air film generates a supporting force to counteract the overturning torque and adjust the attitude of the slide assembly. This ensures that the air film between the slide assembly and the linear guide pair 37 is uniform and stable, improving the comprehensiveness and accuracy of attitude adjustment, realizing high-precision linear motion, and effectively avoiding air film failure caused by local pressure concentration.

[0043] Furthermore, the gas static pressure guide rail assembly 3 includes twelve sets of air path control units. The air inlet end of the main slide plate 31 is connected to four sets of the air path control units. The four sets of air path control units are respectively used to control the air pressure on the upper left side, lower left side, upper right side, and lower right side of the main slide plate 31. The air inlet ends of the first side slide plate 32, the second side slide plate 33, the first back slide plate 34, and the second back slide plate 35 are respectively connected to two sets of the air path control units. The eight sets of air path control units are respectively used to control the air pressure on the upper and lower sides of the first side slide plate 32, the upper and lower sides of the second side slide plate 33, the upper and lower sides of the first back slide plate 34, and the upper and lower sides of the second back slide plate 35.

[0044] In this embodiment, the distribution of the 12 sets of air path control units corresponds one-to-one with the partitions of the slide assembly, forming a precise air pressure control system. When the load center of gravity is shifted to the left, the two sets of air path control units corresponding to the second side slide 33 increase the air pressure, while the two sets of air path control units corresponding to the first side slide 32 decrease the air pressure. The pressure difference between the left and right side air films generates a rightward supporting force to counteract the overturning torque in the left and right directions. When the load center of gravity is shifted to the front, the four sets of air path control units corresponding to the first back slide 34 and the second back slide 35 increase the air pressure, while the four sets of air path control units corresponding to the main slide 31 decrease the air pressure. The pressure difference between the front and rear side air films generates a backward supporting force to counteract the overturning torque in the front and rear directions. When a combined tilting condition occurs, the air path control units in the corresponding directions adjust synchronously to form corresponding pressure differences, thereby counteracting the overturning torque in both directions and ensuring that the air film is uniform and stable.

[0045] The distributed design of 12 air circuit control units achieves precise coverage of each zone of the slide assembly. The independent control capability of each air circuit 361 allows the air pressure adjustment to accurately match the overturning torque of different directions and magnitudes, avoiding the limitations of the traditional uniform air supply mode. The air circuit control units corresponding to the front and rear and left and right directions can achieve synchronous control under compound tilting conditions without the need for step-by-step adjustment, thus improving control efficiency. The independent control of air pressure in each zone ensures the uniformity of the air film gap, effectively avoiding air film failure caused by local tilting. At the same time, this distribution method is adapted to the center of gravity shift conditions of different loads, improving the adaptability and flexibility of the mechanism, providing structural protection for sub-micron level motion accuracy, and greatly improving the attitude adjustment capability and motion accuracy of the mechanism.

[0046] Furthermore, the structures of each of the air circuit control units are identical. Each air circuit control unit includes an air circuit 361, a throttle valve 362, and a pressure regulating valve 363 and a pressure gauge 364, which are electrically connected to the control device. The output end of the air circuit 361 is connected to the air inlet end of the slide assembly. The pressure regulating valve 363 and the pressure gauge 364 are respectively disposed on the air circuit 361. The throttle valve 362 is disposed on the output side of the air circuit 361 and is located at the air outlet end of the slide assembly.

[0047] In this embodiment, the air passage 361 uses a high-strength metal pipe or a high-pressure hose. Its input end is connected to the air source, and its output end is fixedly connected to the air inlet end of the slide assembly through a sealing joint to ensure the sealing and stability of the air pressure transmission. The air pressure regulating valve 363 is connected in series with the air passage 361 and fixed to the mounting bracket by bolts. Its control end is electrically connected to the control device through a cable to receive the command signal from the control device. The air pressure gauge 364 is connected in parallel with the air passage 361 and is located between the air pressure regulating valve 363 and the slide assembly. It is sealed to the air passage 361 through a threaded interface to monitor the air pressure value output by the air passage 361 in real time. The throttle 362 is fixed to the air outlet end of the slide assembly by thread or interference fit. Its air inlet is connected to the air passage inside the slide assembly, and its air outlet faces the reference surface of the linear guide pair 37 to ensure that the air pressure can directly act on the reference surface to form an air film.

[0048] During the actual operation of the air circuit control unit, the control device sends a control command to the air pressure regulating valve 363 according to the preset zone air pressure adjustment value. After receiving the command, the air pressure regulating valve 363 adjusts the valve core opening, changes the gas flow rate of the air circuit 361, and thus adjusts the air pressure value output by the air circuit 361. The air pressure gauge 364 detects the air pressure value output by the air circuit 361 in real time and feeds the detection data back to the control device, forming a closed-loop control to ensure that the air pressure value accurately reaches the preset value. The gas is transmitted through the air circuit 361 to the air passage inside the slide assembly, and then, through the flow restriction effect of the throttle 362, it is ejected from the outlet at a stable air pressure. The reference plane acting on the linear guide pair 37 forms a stable air film between itself and the end face of the slide assembly. When the attitude needs to be adjusted, the control device adjusts the air pressure regulating valve 363 of the corresponding air circuit control unit to change the output air pressure of the throttle 362, causing the air film pressure to change and generating a support force difference, thereby realizing the attitude adjustment of the slide assembly. The structure of the air circuit control unit can accurately execute the control device's control commands, enabling the air pressure of each zone to respond and adjust quickly, forming a stable air film support, offsetting the overturning torque, ensuring the motion accuracy and operational reliability of the mechanism, while also being simple in structure, easy to maintain, and reducing the operating cost of the mechanism.

[0049] Furthermore, the gravity balancing unit 2 includes a first lifting ring 21, a second lifting ring 22, a fixed pulley 23, and a counterweight 24. The first lifting ring 21 is fixedly connected to the slide assembly, and the first lifting ring 21 is connected to the second lifting ring 22 via a flexible metal wire 25. The fixed pulley 23 is fixedly mounted on the top of the gantry frame 1, and the flexible metal wire 25 is slidably engaged with the fixed pulley 23. The second lifting ring 22 is fixedly connected to the counterweight 24, and the counterweight 24 is slidably disposed on the back side of the gantry frame 1.

[0050] In this embodiment, the first lifting ring part 21 includes two first lifting rings, which are respectively fixed to the top of the slide assembly by welding or bolts, and the two first lifting rings are also fixedly connected to the flexible metal wire 25. The flexible metal wire 25 is made of high-strength stainless steel wire rope, which has good flexibility and tensile strength. Its other end passes through the fixed pulley part 23 and is fixedly connected to the second lifting ring part 22. The fixed pulley part 23 consists of four fixed pulleys, which are fixed to the top of the gantry frame 1 by brackets. The four fixed pulleys are arranged in different positions to ensure that the traction direction of the flexible metal wire 25 is consistent with the movement direction of the slide assembly, thereby reducing frictional resistance. The second lifting ring part 22 includes two second lifting rings, which are respectively fixedly connected to the counterweight 24 by bolts. The counterweight 24 has sliders on both sides, which cooperate with the guide rail set on the back side of the gantry frame 1. The sliders and the guide rail adopt a rolling friction or sliding friction structure to ensure that the counterweight 24 can slide smoothly in the vertical direction without jamming.

[0051] When the gravity balancing unit 2 is working, the weight of the counterweight 24 is transferred to the first lifting ring 21 through the flexible metal wire 25, and then acts on the slide assembly. Its weight is balanced with the total weight of the slide assembly and the load, so that the slide assembly is in a state of force balance in the vertical direction. This greatly reduces the vertical gravity that the air film needs to bear, improves the stability and rigidity of the air film, and prevents the air film from failing due to excessive load. The fixed pulley 23 changes the traction direction of the flexible metal wire 25, so that the vertical movement of the counterweight 24 is converted into a vertical pulling force on the slide assembly. At the same time, the rolling characteristics of the fixed pulley reduce the frictional resistance during the traction process, ensuring the efficiency of gravity transmission. The flexibility of the flexible metal wire 25 allows it to adapt to the vertical movement of the slide assembly, while isolating the slight tilting, vibration and other errors during the movement of the counterweight 24, preventing these errors from being transmitted to the slide assembly and affecting the movement accuracy of the gas static pressure guide rail pair 3. The counterweight 24, through the cooperation of the slider and the guide rail, ensures the perpendicularity of its movement direction and avoids the generation of lateral force, further ensuring the stability of gravity balance.

[0052] The following details the air pressure control method for the Z-axis air-bearing moving mechanism 6, including: 101. Obtain the real-time center of gravity offset information of the load, wherein the real-time center of gravity offset information includes the offset direction and offset amount; In this embodiment, the offset direction refers to the deviation of the center of gravity from the geometric center of the support mechanism, including four cases: the center of gravity is offset forward, backward, left, and right; the offset amount is the actual distance difference between the coordinates of the center of gravity and the coordinates of the geometric center of the support mechanism.

[0053] 102. Obtain the load weight, and calculate the corresponding overturning torque based on the load weight and the real-time center of gravity offset information; In this embodiment, the overturning torque is derived from the product of the load weight and the offset, that is, the overturning torque in the left and right direction is the load weight multiplied by the left and right offset, and the overturning torque in the front and back direction is the load weight multiplied by the front and back offset; the overturning torque is the core force that causes the slide assembly to tilt.

[0054] 103. Obtain preset calibration information, determine the pressure difference value based on the overturning torque, and calculate the zone pressure adjustment value by combining the calibration information and the pressure difference value; In this embodiment, the preset calibration information is a set of key parameters determined through prior experiments. In this preset calibration information, the standard air-film gap is set to 10 micrometers, which is the optimal value to ensure air-film stiffness and motion accuracy. The reference air pressure is the initial air supply pressure under the standard air-film gap. The calibration curve is a curve showing the relationship between the overturning torque and the air pressure difference, plotted through multiple experiments. For example, per 100 Newtons... millimeters ( The overturning torque corresponds to a pressure difference of 0.01 MPa; the pressure difference is the pressure difference required to balance the overturning torque; the zoned pressure adjustment value is the specific adjustment parameter of each zone calculated based on the reference pressure and the pressure difference; the zone of the mechanism is based on the structural layout of the slide assembly, specifically divided into the front zone corresponding to the main slide 31, the left and right side zones corresponding to the first side slide 32 and the second side slide 33, and the back zone corresponding to the first back slide 34 and the second back slide 35. Each zone corresponds to an independent air path control unit, and a total of 12 air path control units are set to achieve full-dimensional control.

[0055] 104. Based on the offset direction and the partition air pressure adjustment value, adjust the air pressure of each partition of the Z-axis air-float moving mechanism 6; In this embodiment, according to the offset direction, the partition opposite to the offset direction is pressurized, and the partition in the same direction is depressurized, ultimately forming a reverse torque to counteract the overturning torque; thus forming a stable and uniform 10-micron standard air film between each reference surface of the slide assembly and the throttle 362, preventing the loss of motion function due to air film failure.

[0056] The air pressure control method disclosed in this application adopts a closed-loop control logic of real-time center of gravity offset sensing, quantification calculation of overturning torque, and dynamic adjustment of zoned air pressure, replacing the traditional uniform air supply mode. This makes the air pressure control more closely match the dynamic changes of the load, significantly improving the operating accuracy and stability of the Z-axis air-bearing moving mechanism 6. By acquiring real-time center of gravity offset information of the load, calculating the overturning torque in combination with the load weight, and then determining the air pressure difference and adjusting the zoned air pressure based on the calibration information, the overturning torque can be accurately quantified and offset. This effectively solves the defect of existing technologies that cannot control the direction and magnitude of the overturning torque, greatly improving the applicability of the mechanism under heavy load and large eccentric load conditions. Furthermore, by adjusting the corresponding zoned air pressure according to the offset direction, the slide attitude can be corrected in real time, avoiding mechanical contact, ensuring the stability of the air film structure to prevent loss of motion function due to air film failure, and ensuring that the mechanism achieves sub-micron level motion accuracy under heavy load and large eccentric load conditions, significantly expanding its application range and enhancing operational reliability.

[0057] Furthermore, in this embodiment of the invention, the Z-axis air-bearing moving mechanism 6 includes a laser interferometer; the acquisition of real-time center of gravity offset information of the load includes: 201. Obtain the front gap, left gap, right gap, and back gap fed back by the laser interferometer; In this embodiment, the front gap is the distance between the main slide plate 31 and the positive reference surface of the linear guide pair 37, the left gap is the distance between the first side slide plate 32 and the left reference surface, the right gap is the distance between the second side slide plate 33 and the right reference surface, and the back gap is the distance between the back slide plate and the back reference surface.

[0058] 202. Compare the front gap and the back gap, and compare the left gap and the right gap to determine the offset direction, which includes the center of gravity shifting forward, the center of gravity shifting backward, the center of gravity shifting to the left, and the center of gravity shifting to the right. In this embodiment, the offset direction is determined by comparing the gaps. If the gap on the front is smaller than the gap on the back, it means that the center of gravity is shifted forward, and vice versa. If the gap on the left is smaller than the gap on the right, it means that the center of gravity is shifted to the left, and vice versa.

[0059] 203. Obtain the center of gravity coordinates of the load and the support geometric center coordinates of the Z-axis air-bearing moving mechanism 6, and calculate the offset based on the center of gravity coordinates and the support geometric center coordinates; In this embodiment, the offset is calculated by the coordinates of the center of gravity and the geometric center coordinates of the support. The center of gravity coordinates are the coordinates of the center of gravity after the load and the slide assembly are combined. When obtaining the center of gravity coordinates, a combination of weighing and coordinate measurement methods can be used. First, the approximate location of the center of gravity is determined by the weighing method, and then the coordinate values ​​are accurately measured by the coordinate measuring instrument. The geometric center coordinates of the support are the geometric center coordinates formed by the various support points of the slide assembly. The geometric center coordinates of the support are fixed values ​​preset during the mechanism design stage. After assembly, they can be calibrated by a laser tracker to ensure consistency with the design values. The difference between the center of gravity coordinates and the geometric center coordinates of the support is the offset.

[0060] In this embodiment, multi-dimensional gap data is acquired using a laser interferometer, which can intuitively reflect the tilting trend of the slide and provide a real-time and accurate basis for determining the offset direction. The offset is calculated by combining the coordinates of the center of gravity and the coordinates of the support geometric center, realizing the quantitative acquisition of the center of gravity offset information. This avoids the subjectivity and error of relying on experience judgment in traditional methods, and lays a reliable foundation for subsequent calculation of overturning torque and determination of air pressure difference. It effectively improves the accuracy and operability of the entire air pressure control method and ensures that the control measures can accurately match the actual load conditions.

[0061] Further, in this embodiment of the invention, the step of obtaining preset calibration information, determining the pressure difference value based on the overturning torque, and calculating the zone pressure adjustment value by combining the calibration information and the pressure difference value includes: 301. Obtain preset calibration information, the calibration information including standard air film gap, reference air pressure corresponding to the standard air film gap and calibration curve, the calibration curve being used to characterize the relationship between overturning torque and air pressure difference; In this embodiment, the standard air film gap is set to 10 micrometers. This gap is the optimal value verified by a large number of tests. It can ensure the rigidity of the air film and prevent the throttle 362 from contacting the guide rail reference surface. The reference air pressure is the initial air supply pressure of each air circuit control unit under the standard air film gap. It ensures the stability of the air film in the initial state. The reference air pressure is usually set between 0.3-0.5 MPa. The specific value needs to be adjusted according to the actual mechanism parameters. The calibration curve is drawn from the test data under different load weights and different offsets. The drawing needs to cover the rated load range and maximum offset range of the mechanism to clearly characterize the linear or nonlinear relationship between the overturning torque and the air pressure difference.

[0062] 302. Based on the overturning torque and the calibration curve, determine the air pressure difference value; In this embodiment, based on the calculated overturning moment, the corresponding pressure difference value is found on the calibration curve. This pressure difference value is the minimum pressure difference value required to balance the overturning moment.

[0063] 303. Calculate the zone pressure adjustment value based on the reference air pressure and the air pressure difference; In this embodiment, when calculating the zone air pressure adjustment value, the reference air pressure is used as the basis. The air pressure adjustment value for the pressurized object is the reference air pressure plus half of the air pressure difference, and the air pressure adjustment value for the depressurized object is the reference air pressure minus half of the air pressure difference. This avoids excessive pressurization leading to excessively large air film gaps or excessively low pressure leading to excessively small air film gaps.

[0064] In this embodiment, preset calibration information provides a quantitative basis for air pressure regulation, avoiding blind adjustment in traditional regulation methods. The air pressure difference is determined based on the overturning torque and calibration curve, ensuring the targeted nature of air pressure adjustment. Combined with the reference air pressure, the zone air pressure adjustment value is calculated, realizing precise quantitative control of air pressure in each zone. This allows the air film gap to be stably maintained at the 10-micron standard value, effectively balancing different sizes of overturning torque, improving the efficiency and accuracy of air pressure regulation, and ensuring the consistency and stability of the mechanism under different load conditions, thus extending the service life of the mechanism.

[0065] Furthermore, in this embodiment of the invention, the Z-axis air-bearing moving mechanism 6 includes multiple independent air path control units, which are used to realize tilt attitude adjustment. Adjusting the air pressure of each zone of the Z-axis air-bearing moving mechanism 6 based on the offset direction and the zone air pressure adjustment value includes: 401. Determine the air circuit control unit opposite to the offset direction as the pressure boosting target, and determine the air circuit control unit in the same direction as the offset direction as the pressure reduction target; In this embodiment, when determining the pressurization target and the depressurization target, the pressurization target is the air path control unit facing the offset direction. That is, when the center of gravity is shifted to the left, the air path control unit on the right is the pressurization target; when the center of gravity is shifted forward, the air path control unit on the back is the pressurization target. The depressurization target is the air path control unit in the same direction as the offset direction. That is, when the center of gravity is shifted to the left, the air path control unit on the left is the depressurization target; when the center of gravity is shifted forward, the air path control unit on the front is the depressurization target.

[0066] 402. Based on the partition air pressure adjustment value, adjust the air pressure of the pressurized object and the depressurized object respectively, so as to regulate the air pressure of the corresponding partition of the Z-axis air float moving mechanism 6; In this embodiment, when adjusting the air pressure based on the zoned air pressure adjustment value, it is necessary to operate through the air pressure regulating valve 363 in the air path control unit to increase the air pressure of the pressurized object and decrease the air pressure of the depressurized object, so that each zone forms a preset air pressure distribution, thereby generating a reverse torque to counteract the overturning torque. The correspondence between the grouping of the air path control units and the offset direction is preset in the control device. For example, the four groups of air path control units of the main slide 31 correspond to the four zones on the front, and the two groups of air path control units of the first side slide 32 correspond to the upper and lower zones on the left, ensuring that each offset direction has a corresponding air path control unit for regulation. When adjusting the air pressure, it is necessary to ensure the synchronization of the adjustment of each air path control unit to avoid sudden changes in the slide posture due to some air paths 361 adjusting too quickly. For compound tilting conditions, that is, when there is both forward and backward tilting and left and right tilting, it is necessary to simultaneously determine the corresponding pressurized object and depressurized object and adjust the air pressure synchronously.

[0067] In this embodiment, by clearly defining the principles for determining the pressurization and depressurization targets, the air pressure adjustment becomes more targeted, avoiding ineffective adjustments and improving control efficiency. Precise adjustments are made based on the zone air pressure adjustment values, ensuring that the air pressure in each zone reaches the preset value, forming a stable asymmetric support force, effectively offsetting the overturning torque, and preventing air film failure caused by slide tilt. At the same time, the independent control characteristics of each air circuit control unit enable the mechanism to adapt to offset conditions in different directions, including single-direction tilt and compound-direction tilt, improving the adaptability and control flexibility of the mechanism, and ensuring the accuracy and stability of linear motion.

[0068] Further, in this embodiment of the invention, adjusting the air pressure of the pressurized object and the depressurized object based on the partition air pressure adjustment value to regulate the air pressure of the corresponding partition of the Z-axis air-float moving mechanism 6 includes: 501. The air pressure of the corresponding partition of the Z-axis air-float moving mechanism 6 is adjusted by adopting a phased fine-tuning mode. Based on the partition air pressure adjustment value, the air pressure of the pressurized object is increased and the air pressure of the depressurized object is decreased to form a reverse torque. The reverse torque is used to counteract the overturning torque. In this embodiment, when using the phased fine-tuning mode, the pressure adjustment range does not exceed 0.005 MPa each time. By gradually adjusting, the air film gap slowly approaches the standard value, avoiding sudden gap changes caused by excessive single adjustment range. During the process of increasing the pressure of the pressurized object and decreasing the pressure of the depressurized object, the change of the air film gap is monitored in real time to ensure that the adjustment direction is correct.

[0069] 502. After one adjustment is completed, obtain the real-time center of gravity change and offset information of the Z-axis air-bearing moving mechanism 6; In this embodiment, a laser interferometer is used to collect gap data in various dimensions in real time, calculate the changes in the center of gravity position, and form real-time center of gravity shift information.

[0070] 503. Combining the real-time center of gravity offset information with the center of gravity change offset information, determine the gap change result of the Z-axis air-bearing moving mechanism 6; In this embodiment, by combining real-time center of gravity offset information and center of gravity change offset information, the changing trend and adjustment effect of the air film gap are judged, and the gap change result is determined, such as whether the gap is approaching the 10-micrometer standard value and whether the approaching speed is reasonable.

[0071] 504. Determine whether a fine-tuning operation needs to be performed based on the gap change result; if it is determined to be yes, then determine the air circuit control unit corresponding to the fine-tuning operation based on the gap change result, as the fine-tuning object; In this embodiment, the need for fine-tuning is determined based on the gap change results. If the gap has stabilized within the range of 10 micrometers ± 0.1 micrometers, no fine-tuning is required. If the standard is not met, the gas path control unit that needs fine-tuning is identified as the fine-tuning target.

[0072] 505. Obtain a preset fine-tuning pressure value, and fine-tune the pressure of the object to be fine-tuned based on the fine-tuning pressure value; In this embodiment, a small fine-tuning is performed based on a preset fine-tuning air pressure value. The preset fine-tuning air pressure value is determined based on a large amount of experimental data and is usually set to 0.001-0.002 MPa. The specific value needs to be adjusted according to the sensitivity of the mechanism. The number of fine-tunings needs to be determined according to the actual adjustment effect, generally 3-5 times. After each adjustment, it is necessary to pause for 1-2 seconds to wait for the air film to stabilize before making the next adjustment, until the gap meets the standard.

[0073] In this embodiment, the phased fine-tuning mode effectively avoids abrupt changes in the air film gap caused by excessive single adjustment, reducing instability during the control process. The acquisition of real-time center of gravity shift information and the judgment of gap change results enable timely feedback and dynamic adjustment of the control process, improving the accuracy of control. The fine-tuning operation further optimizes the air film gap, ensuring that it is stably maintained within a high-precision range of 10 micrometers ± 0.1 micrometers, effectively offsetting dynamic interference during operation and ensuring the reliability and accuracy stability of the mechanism in long-term operation. At the same time, this control mode adapts to different load change conditions, improving the mechanism's anti-interference ability and adaptability.

[0074] For details, see Figures 7 to 12 As shown, the AC cradle turntable 7 includes a fixed base 71, an A-axis turntable 72 mounted on the fixed base 71, and a C-axis turntable 73 connected to the output end of the A-axis turntable 72. The A-axis turntable 72 includes a first torque motor 721, a first main bearing housing 722 mounted at the head of the first torque motor 721 and connected to the fixed base 71, a first auxiliary bearing housing 723 mounted at the tail of the first torque motor 721, a first output shaft 724 connected to one end of the mover of the first torque motor 721, and a first extension shaft 725 connected to the other end of the mover of the first torque motor 721. The first output shaft 724 is rotatably connected to the first main bearing housing 722, and the first extension shaft 725 is rotatably connected to the first auxiliary bearing housing 723. The first extension shaft 725, the mover of the first torque motor 721, and the first main bearing housing 722 are connected together. An output shaft 724 is coaxially coupled to form the A-axis axis; the C-axis turntable 73 includes a second torque motor 731, a second main bearing housing 732 disposed at the head of the second torque motor 731, a second auxiliary bearing housing 733 disposed at the tail of the second torque motor 731, a second output shaft 734 connected to one end of the mover of the second torque motor 731, and a second extension shaft 735 connected to the other end of the mover of the second torque motor 731. The second output shaft 734 is rotatably connected to the second main bearing housing 732, and the second extension shaft 735 is rotatably connected to the second auxiliary bearing housing 733. The second extension shaft 735, the mover of the second torque motor 731, and the second output shaft 734 are coaxially coupled to form the C-axis axis; the first output shaft 724 is connected to the second main bearing housing 732 through a transfer bracket 74.

[0075] During operation, after the first torque motor 721 of the A-axis rotary table 72 starts, its mover drives the first output shaft 724 and the first extension shaft 725, which are coaxially connected at both ends, to rotate synchronously, forming an integrated rotational motion along the A-axis. Similarly, the mover of the second torque motor 731 of the C-axis rotary table 73 drives the second output shaft 734 and the second extension shaft 735 to rotate synchronously, forming a rotational motion along the C-axis. Since the first output shaft 724 of the A-axis rotary table 72 is fixedly connected to the second main bearing seat 732 of the C-axis rotary table 73 through the intermediate bracket 74, the rotation of the A-axis rotary table 72 can drive the entire C-axis rotary table 73 to deflect around the A-axis. The C-axis rotary table 73 independently drives the workpiece to rotate around the C-axis. The two work together to achieve two-dimensional rotation of the workpiece in space, accurately reproducing the machining trajectory of complex curved surfaces.

[0076] The first main bearing seat 722 of the A-axis rotary table 72 is fixed to the mounting frame and supports the first output shaft 724. The first auxiliary bearing seat 723 supports the first extension shaft 725 from the tail of the first torque motor 721, forming a bidirectional positioning support for the A-axis shaft system. Similarly, the second main bearing seat 732 and the second auxiliary bearing seat 733 of the C-axis rotary table 73 provide bidirectional support for the C-axis shaft system from both ends of the second torque motor 731. Simultaneously, the coaxial coupling design of the first output shaft 724, the mover of the first torque motor 721, and the first extension shaft 725, as well as the coaxial coupling design of the second output shaft 734, the mover of the second torque motor 731, and the second extension shaft 735, ensures that the shaft system maintains axial consistency throughout rotation, effectively suppressing radial runout and angular wobble.

[0077] During machining, the workpiece load is transferred to the second output shaft 734 and the second extension shaft 735 via the C-axis rotary table 73. It is then distributed to the intermediate support 74 via the second main bearing housing 732 and the second auxiliary bearing housing 733, and from there transferred to the first output shaft 724 of the A-axis rotary table. Finally, it is transferred to the fixed frame via the first main bearing housing 722 and the first auxiliary bearing housing 723. This bidirectional support structure achieves uniform load distribution, avoids force concentration at a single support point, and improves the shaft system's resistance to eccentric loads.

[0078] Compared to the redundant layout of existing double-sided support turntables, this solution adopts a single-sided support design, significantly reducing the turntable's space occupancy and perfectly adapting to the compact layout requirements of modern precision machine tools. It also avoids the material and structural redundancy inherent in double-sided support, laying the foundation for lightweight design. Addressing the weakness of traditional single-sided support in resisting eccentric loads, this solution employs a collaborative design of the main bearing housing, the secondary bearing housing, and the coaxially coupled shaft system: the main bearing housing bears the core load, the secondary bearing housing provides auxiliary restraint for the extension shaft, and the output shaft and extension shaft provide bidirectional coaxial fixation for the torque motor's actuator. This effectively suppresses shaft movement and sway under single-sided support, solving the problem of traditional single-sided support being susceptible to uneven workpiece weight distribution and improving the turntable's adaptability to complex loads.

[0079] Understandably, the coaxial coupling integrated design of the output shaft, torque motor mover, and extension shaft significantly improves the overall torsional stiffness of the shaft system compared to the existing one-piece continuously formed hollow shaft. At the same time, the addition of the extension shaft solves the problem of unbalanced force on one side of the torque motor rotor, further optimizes the rotational stability of the shaft system, and reduces end runout and static runout errors.

[0080] The main bearing housing and secondary bearing housing under single-sided support work together to constrain each other, and the load transmission path of multi-axis coupling makes the shaft system run more evenly, effectively suppressing the torsional deviation of the shaft. The reduction of this deviation directly ensures the reading accuracy of feedback components such as encoders, avoids positioning signal distortion, reduces the positioning error of machining trajectory, and improves the quality of ultra-precision machining. At the same time, it reduces the wear of moving parts and extends the service life of the turntable.

[0081] For details, see Figure 9 and Figure 10 As shown, the first output shaft 724 includes a rear shaft body 7241, a middle shaft body 7242, and a front shaft body 7243 connected in sequence. The middle shaft body 7242 is rotatably connected to the first main bearing seat 722 via a first bearing 726, and the rear shaft body 7241 is connected to the mover of the first torque motor 721. The first output shaft 724 adopts a segmented coaxial design of the rear shaft body 7241, the middle shaft body 7242, and the front shaft body 7243. Combined with the rigid coupling with the mover of the first torque motor 721 and the first extension shaft 725, the overall torsional stiffness of the A-axis shaft system is greatly improved, solving the problem of the torsional weakness of traditional hollow shafts. The first bearing 726 (high-precision ball bearing or angular contact bearing) matched with the central shaft 7242, with its small size and high rigidity, reduces the space occupied in the installation while further controlling the runout of the central shaft 7242 through preload damping. Even when faced with dynamic inertial impact or slight load eccentricity, it can maintain the smooth rotation of the shaft system through the stress dispersion effect of the bearing, thus ensuring high-precision transmission.

[0082] The central shaft 7242 of the first output shaft 724 forms a single-sided main support with the first bearing 726 and the first main bearing seat 722. Together with the auxiliary support of the first extension shaft 725, it forms a bidirectional positioning support for the A-axis system, avoiding the defect of stress concentration at a single load point in traditional single-sided support. The segmented design of the output shaft and bearings allows the load to be evenly transmitted to the fixed seat 71 through the front shaft 7243, central shaft 7242, rear shaft 7241 and bearings, dispersing the stress concentration caused by off-center loading, improving the adaptability of the turntable to scenarios with uneven workpiece weight distribution, and suppressing posture deviation during processing.

[0083] Furthermore, the central shaft 7242 is a hollow circular shaft structure. The rear shaft 7241 is provided with an outer ring 72411 and has a first embedded recess 72412 that mates with the central shaft 7242. A plurality of circumferentially arranged first threaded holes 72421 are provided on one end face of the central shaft 7242. The rear shaft 7241 is provided with first countersunk holes 72413 that correspond one-to-one with the first threaded holes 72421. A first screw connected to the corresponding first threaded hole 72421 is installed at each first countersunk hole 72413. A plurality of circumferentially arranged second threaded holes are provided on one end face of the mover of the first torque motor 721. A second countersunk hole 72414 that corresponds one-to-one with the second threaded holes is provided on the outer ring 72411. A second screw connected to the corresponding second threaded hole is installed at each second countersunk hole 72414.

[0084] The rear axle 7241 achieves precise docking with one end of the central axle 7242 through its own first embedded recess 72412. The embedded structure directly limits the radial displacement of the two, providing a basic guarantee for coaxiality. At the same time, the multiple first threaded holes 72421 arranged circumferentially on the end face of the central axle 7242 correspond one-to-one with the first countersunk holes 72413 on the rear axle 7241. The first screw passes through the countersunk hole and is screwed into the threaded hole to form a rigid connection that is evenly distributed circumferentially, further locking the relative position of the rear axle 7241 and the central axle 7242, ensuring that the two rotate synchronously as a whole. In addition, the outer ring 72411 of the rear axle 7241 is in contact with the end face of the mover of the first torque motor 721. The second countersunk hole 72414 on the outer ring 72411 corresponds one-to-one with the second threaded hole on the end face of the mover. After being tightened by the second screw, the rear axle 7241 and the mover of the torque motor are rigidly connected. The circumferentially arranged connection structure ensures that the force is balanced during power transmission and avoids shaft misalignment caused by local stress concentration.

[0085] After the first torque motor 721 starts, the torque generated by its mover is transmitted to the rear axle 7241 through the circumferential screw connection at the outer ring 72411. Since the rear axle 7241 and the middle axle 7242 are rigidly connected through the embedded recess and the circumferential screw, the torque is smoothly transmitted along the rear axle 7241 to the middle axle 7242, and then from the middle axle 7242 to the front axle 7243, forming a deviation-free torque transmission path. Among them, the middle axle 7242 adopts a hollow round shaft structure, which reduces its own weight without affecting the torque transmission efficiency, while reserving installation space for internal wiring, oil circuits or other functional components of the turntable, adapting to the structural layout requirements of precision machining.

[0086] Furthermore, the front axle body 7243 is provided with an inwardly folding ring 72431 around its periphery. The front axle body 7243 is provided with the inwardly folding ring 72431 and has a second embedded recess 72432 that mates with the middle axle body 7242. The other end face of the middle axle body 7242 is provided with a plurality of circumferentially arranged third threaded holes. The front axle body 7243 is provided with third countersunk holes 72433 that correspond one-to-one with the third threaded holes. A third screw that connects to the corresponding third threaded hole is installed at each third countersunk hole 72433. The inwardly folding ring 72431 is provided with a code disk 727. The first main bearing seat 722 is provided with an encoding reader that works in conjunction with the code disk 727.

[0087] The front axle 7243 achieves precise engagement with the other end of the middle axle 7242 through its own second recess 72432. This recess structure directly restricts the radial relative displacement of the two axles, providing a basic guarantee for the coaxiality of the two axles. The multiple third threaded holes arranged circumferentially on the other end face of the middle axle 7242 correspond one-to-one with the third countersunk holes 72433 on the front axle 7243. The third screw passes through the countersunk holes and is screwed into the threaded holes to form a rigid connection that is evenly distributed circumferentially. This further locks the relative position of the front axle 7243 and the middle axle 7242, ensuring that the two rotate synchronously and integrally with the torque motor mover and the rear axle 7241, forming a complete rigid shaft system of the A-axis.

[0088] The inner ring 72431 surrounding the front axle 7243 provides a coaxial mounting reference for the code disk 727. The code disk 727 is fixed on the inner ring 72431 and rotates synchronously with the front axle 7243. The encoder reading head, which cooperates with the code disk 727, is fixed to the first main bearing seat 722 and maintains a preset gap with the code disk 727, forming a non-contact signal acquisition structure. When the A-axis system rotates, the code disk 727 rotates synchronously with the front axle 7243. The encoder reading head acquires the angular displacement signal of the code disk 727 in real time and transmits the signal to the control system. The control system adjusts the operating parameters of the first torque motor 721 in real time according to the feedback signal, realizing closed-loop precise control of the A-axis rotation angle.

[0089] The torque generated by the first torque motor 721 is transmitted sequentially through the rear shaft 7241 and the middle shaft 7242 to the front shaft 7243, driving the front shaft 7243 to rotate the C-axis turntable 73 around the A-axis axis. During this process, the rigid connection between the front shaft 7243 and the middle shaft 7242 ensures that the torque is transmitted without lag. The real-time signal feedback from the code disk 727 and the encoding head can promptly capture minute attitude deviations during the rotation of the axis system. Through the dynamic adjustment of the control system, errors such as axis torsion and yaw are suppressed, ensuring high-precision stability of the A-axis rotation attitude.

[0090] In a preferred embodiment, the first extension shaft 725 is rotatably connected to the first auxiliary bearing seat 723 via a second bearing 7252 and is provided with a stepped ring 7251. The other end face of the mover of the first torque motor 721 has multiple circumferentially arranged fourth threaded holes. The stepped ring 7251 has fourth countersunk holes corresponding to the fourth threaded holes one-to-one. Each fourth countersunk hole is fitted with a fourth screw that connects to the corresponding fourth threaded hole, forming a circumferentially uniformly distributed rigid connection structure. This connection method, on the one hand, locks the relative position of the extension shaft and the mover, ensuring their coaxiality; on the other hand, it enables the extension shaft, the mover of the first torque motor 721, and the first output shaft 724 to form a complete integrated A-axis shaft system, laying a structural foundation for torque transmission and attitude stability.

[0091] The first extension shaft 725 rotates with the first auxiliary bearing housing 723 via the second bearing 7252 (such as a self-aligning bearing or angular contact bearing). The first auxiliary bearing housing 723, as an auxiliary support, works in conjunction with the first main bearing housing 722 (main support) to construct a main-auxiliary support system where the main support bears the core load and the auxiliary support limits and stabilizes the posture. The second bearing 7252, with its preload damping and stress dispersion characteristics, constrains the radial runout and axial movement of the extension shaft. Combined with the rigidity of the integrated shaft system, it effectively counteracts the attitude deviation caused by the unbalanced force on one side of the torque motor rotor, ensuring the consistency of the ideal axis during shaft rotation.

[0092] After the first torque motor 721 starts, the torque is synchronously transmitted to the first output shaft 724 and the extension shaft through rigid connections at both ends, causing the integrated shaft system to rotate as a whole. During this process, the first main bearing housing 722 supports the first output shaft 724 through the first bearing 726, and the first auxiliary bearing housing 723 supports the first extension shaft 725 through the second bearing 7252, forming a bidirectional force constraint, so that the force is evenly distributed when the shaft system is running. At the same time, the presence of the first extension shaft 725 balances the force state of the torque motor rotor, avoiding rotational imbalance caused by a single-sided connection shaft. Combined with the support logic of multi-axis coupling, it further suppresses shaft torsion and yaw, providing a stable attitude foundation for the accurate signal acquisition of the encoder reader.

[0093] A brake mechanism 728 for braking the first extension shaft 725 is also provided between the first secondary bearing housing 723 and the first torque motor 721. During normal ultra-precision machining, the brake mechanism 728 is in a de-energized or released state, and the braking actuator maintains a preset gap with the first extension shaft 725, without mechanical contact with the first extension shaft 725, and does not interfere with the normal rotational movement of the A-axis system, ensuring that the axis system operates smoothly along the preset trajectory without affecting machining accuracy and dynamic response performance.

[0094] When the cradle turntable encounters an emergency (such as the control system detecting abnormal signals like overtravel, overload, power failure, or machining malfunction), the control system immediately sends a braking command to the brake mechanism 728, triggering its rapid activation. The brake mechanism 728, through electromagnetic drive or mechanical linkage, causes the braking actuator (such as a brake caliper or brake disc friction pad) to quickly clamp the extension shaft. Utilizing the friction between the braking surface and the extension shaft, or the mechanical clamping force, a rigid braking constraint is formed, forcing the extension shaft to stop rotating. Since the first extension shaft 725, the mover of the first torque motor 721, and the first output shaft 724 form an integrated rigid shaft system, the braking of the extension shaft synchronously drives the entire A-axis shaft system to brake rapidly, preventing the shaft system from continuously rotating due to inertia and causing danger.

[0095] For details, see Figure 11 and Figure 12 As shown, the transfer bracket 74 includes a positioning disk 741 connected to the front axle 7243, a vertical plate 742 connected to the positioning disk 741, and two vertical arms 743 mounted on the vertical plate 742. The positioning disk 741 has multiple positioning blocks 744 arranged in a circular array. The back of the vertical plate 742 has positioning grooves 745 that mate with the positioning blocks 744. The transfer bracket 74 achieves precise docking with the front axle 7243 and the C-axis turntable 73 through a dual positioning structure. First, the circular positioning protrusion 7411 on the back of the positioning disc 741 and the circular groove on the front end face of the front axle 7243 form a radial positioning fit, directly limiting the radial relative displacement between the two, providing a core guarantee for the coaxiality of the positioning disc 741 and the front axle 7243. Second, the positioning blocks 744 arranged in a circumferential array on the positioning disc 741 and the positioning grooves 745 on the back of the vertical plate 742 fit together one by one, forming a circumferential positioning constraint, locking the relative angular position of the positioning disc 741 and the vertical plate 742, and preventing circumferential slippage during rotation. The dual positioning structure, together with bolts and other fastening components, makes the front axle 7243, the positioning disc 741, the vertical plate 742, and the upright arm 743 form an integrated rigid connection, ensuring that the power transmission is seamless and deformation-free.

[0096] When the A-axis rotary table 72 is running, the rotational torque of the front shaft 7243 is transmitted to the vertical plate 742 through the rigid connection of the positioning disk 741. The vertical plate 742 then distributes the torque to the two symmetrically arranged vertical arms 743, and finally, through the vertical arms 743, it is transmitted to the second main bearing seat 732 of the C-axis rotary table 73, driving the entire C-axis rotary table 73 to rotate synchronously around the A-axis axis. Simultaneously, the workpiece load carried by the C-axis rotary table 73 is transmitted to the two vertical arms 743 through the second main bearing seat 732, and then evenly distributed to the front shaft 7243 via the vertical plate 742 and the positioning disk 741. From the front shaft 7243, the load is transmitted to the first main bearing seat 722 through the first bearing 726, and finally guided to the fixed seat 71. The symmetrically arranged vertical arms 743 and the circumferentially distributed positioning blocks 744 form a multi-point uniform force path, ensuring balanced load transmission and avoiding localized stress concentration.

[0097] The intermediate support 74 serves as a rigid connection bridge between the A-axis turntable 72 and the C-axis turntable 73, achieving stable torque transmission from the A-axis to the C-axis without interfering with the independent rotational motion of the C-axis turntable 73 around its own C-axis axis. Its integrated rigid structure and precise positioning design ensure the perpendicularity accuracy of the A-axis and C-axis axes, making the trajectory controllable during coordinated movement of the two axes and effectively reproducing complex surface machining paths. Simultaneously, the rigid structure reduces elastic deformation during multi-axis motion, providing support for axis posture stability and accurate coding feedback.

[0098] The fixed base 71 includes a base plate 712 and two L-shaped supports 711. The bottom of the first main bearing seat 722 forms two lower legs 7221. The lower legs 7221 are provided with first mounting slots 7222 that fit into the L-shaped supports 711. The L-shaped supports 711 and the lower legs 7221 are fastened together by screws. The second main bearing seat 732 forms two horizontally extending support arms 7321. The support arms 7321 are provided with second mounting slots 7322 that fit into the upright arms 743. The support arms 7321 and the upright arms 743 are fastened together by screws.

[0099] The two L-shaped supports 711 of the fixed base 71 provide a single-sided core support reference for the A-axis rotary table 72. The two lower legs 7221 at the bottom of the first main bearing housing 722 adapt and fit with the L-shaped supports 711 through their own first mounting slots 7222. The fitting structure directly limits the radial and circumferential relative displacement of the two, and quickly completes the initial positioning. Then, by passing screws through the corresponding mounting holes of the L-shaped supports 711 and the lower legs 7221 and tightening them, the first main bearing housing 722 and the fixed base 71 are locked into an integrated rigid structure, forming a stable main support system that reliably bears the core load of the A-axis rotary table 72, the C-axis rotary table 73 and the workpiece, providing a stable installation foundation for the rotation of the shaft system.

[0100] Two horizontally extending support arms 7321 on the second main bearing seat 732 of the C-axis rotary table 73 are fitted with the two vertical arms 743 of the intermediate support 74 through their own second mounting slots 7322. The fitting structure achieves circumferential positioning and radial limiting, preventing circumferential slippage or radial offset at the connection point. After being tightened with screws, the intermediate support 74 and the second main bearing seat 732 form a gapless rigid connection. When the A-axis rotary table 72 is running, the rotational torque of the front shaft 7243 is transmitted to the support arms 7321 of the second main bearing seat 732 through the positioning disc 741, vertical plate 742, and vertical arms 743, driving the C-axis rotary table 73 to rotate smoothly around the A-axis axis. At the same time, the workpiece load carried by the C-axis rotary table 73 is transmitted evenly in the reverse direction to the A-axis output shaft through the support arms 7321, vertical arms 743, vertical plate 742, and positioning disc 741, and finally guided to the fixed seat 71 through the first main bearing seat 722, forming a closed-loop and uniform load transmission path.

[0101] Preferably, the first main bearing housing 722 is provided with a front cover 7291, the front shaft body 7243 is provided with a sealing ring 7293 that mates with the front cover 7291, and the first secondary bearing housing 723 is provided with a rear cover 7292. The closed protective structure formed by the front cover 7291 and the sealing ring 7293 isolates the code disk 727 and the encoding reader from the external processing environment, effectively preventing dust, oil, coolant and other impurities from wearing or contaminating the grating pattern of the code disk 727, preventing dirt accumulation at the signal acquisition end of the encoding reader, ensuring the accuracy of angular displacement signal acquisition, avoiding positioning signal distortion caused by impurities, and providing reliable signal protection for closed-loop control of ultra-precision machining. The closed cavity reduces the impact of external airflow and temperature fluctuations on the working state of the code disk 727 and the encoding reader, avoids signal transmission instability caused by environmental factors, and further improves the A-axis positioning accuracy and repeatability.

[0102] The rear cover 7292 provides sealing protection for the interior of the first bearing housing 723, preventing components such as the raceway of the second bearing 7252, the stepped ring 7251 of the extension shaft, and the fourth screw from being corroded or worn by impurities. This reduces the risk of failures such as bearing jamming and loose connections, and extends the service life of the connection structure between the second bearing 7252 and the shaft system. The dynamic sealing design between the sealing ring 7293 and the front cover 7291 avoids mechanical wear between the code disk 727 and the encoding head. Compared with no protective structure, this significantly reduces the replacement frequency of core sensing components, thereby reducing maintenance costs and downtime.

[0103] The specific structure and working principle of the C-axis rotary table 73 can be set with reference to the A-axis rotary table 72 described above, and will not be repeated here. The second main bearing seat 732 is provided with an upper cover 736, the second auxiliary bearing seat 733 is provided with a lower cover 737, and a clamping platform 738 is installed on the top of the second output shaft 734 on the C-axis rotary table 73.

[0104] The C-axis rotary table 73 is designed with the main and auxiliary supports and multi-axis coupling of the A-axis rotary table 72 as a reference. After the second torque motor 731 starts, its mover drives the second output shaft 734 and the second extension shaft 735, which are coaxially connected at both ends, to rotate synchronously, forming an integrated C-axis rotational motion. Its specific structure and working principle will not be described in detail here. The upper cover 736 on the second main bearing seat 732 and the lower cover 737 on the second auxiliary bearing seat 733 respectively encapsulate the top and tail core components of the C-axis rotary table 73, forming a double-sealed protection structure to prevent the intrusion of external dust, oil, coolant and other impurities, and to avoid wear or jamming of internal components. At the same time, the upper cover 736 and the lower cover 737 are made of lightweight materials, which does not affect the rotational smoothness and dynamic response performance of the C-axis system.

[0105] The clamping table 738 is fixedly installed on top of the second output shaft 734, serving as the direct bearing and positioning reference for the workpiece. Rigid clamping of the workpiece is achieved through bolt tightening and chuck clamping, ensuring that the workpiece is coaxial with the C-axis. When the C-axis system rotates, the second output shaft 734 drives the clamping table 738 and the workpiece to rotate synchronously around the C-axis. Simultaneously, the A-axis rotary table 72 drives the entire C-axis rotary table 73 to deflect around the A-axis via the intermediate support 74. Together, these two components achieve two-dimensional rotational motion of the workpiece in space, accurately reproducing the machining trajectory of complex curved surfaces.

[0106] The fixed base 71, front cover 7291, rear cover 7292, upper cover 736, and lower cover 737 can be made of lightweight aluminum alloy or high-performance ceramic materials. Using lightweight aluminum alloy or high-performance ceramic materials significantly reduces the weight of non-core load-bearing components of the turntable. Aluminum alloy has a density only about one-third that of steel, and high-performance ceramics have a specific strength more than twice that of aluminum alloy. Combined with the differentiated design of the main support component (45 steel), this ensures that the overall machine weight is stably controlled within 100kg, significantly reducing the inertial force of the kinematic pairs. This characteristic directly improves the dynamic response speed of the turntable, perfectly matching the ultra-precision machining requirements of high-frequency attitude changes and avoiding machining trajectory lag; at the same time, it reduces the load pressure on linear kinematic pairs, ensuring the smoothness and response accuracy of linear motion, thus optimizing the overall machining efficiency and trajectory control accuracy.

[0107] Aluminum alloys possess excellent corrosion resistance, while high-performance ceramics offer even greater advantages, including high wear resistance, corrosion resistance, and a low coefficient of thermal expansion. This allows components such as the mounting base 71 and various cover plates to effectively resist corrosion, wear, and thermal deformation in complex environments such as aerospace component processing and precision mold manufacturing (facing dust, coolant spray, and temperature fluctuations). On one hand, this reduces the aging and wear of the components themselves, extending their service life. On the other hand, it prevents changes in sealing gaps and support positioning misalignment caused by component deformation and corrosion, thereby protecting internal core components (code disk 727, encoder head, bearings, and connecting screws) from contamination or damage, indirectly extending the maintenance cycle and service life of the turntable's core components.

[0108] The low coefficient of thermal expansion of high-performance ceramics allows for further reduction in thermal deformation of components in high and low temperature processing environments compared to aluminum alloys. Aluminum alloys can also significantly reduce the risk of thermal deformation of traditional steel parts. Both can avoid the offset of the positioning reference of the fixed seat 71, the change of the sealing clearance between the front cover 7291 and the rear cover 7292 and the shaft system, and the constraint deviation of the upper cover 736 and the lower cover 737 on the C-axis system caused by temperature changes. This feature effectively ensures the coaxiality and perpendicularity accuracy of the A-axis and C-axis axes, reduces the interference of temperature fluctuations on the encoder reading accuracy, avoids the amplification of axis torsional errors, and ensures that the turntable maintains stable positioning accuracy and repeatability during long-cycle ultra-precision machining tasks.

[0109] Understandably, the Z-axis air-bearing moving mechanism 6 achieves sub-micron-level vertical linear motion accuracy through zoned air pressure closed-loop control, gravity balance to offset the load gravity, and real-time feedback from a laser interferometer. The AC cradle turntable 7 ensures A / C axis rotational positioning accuracy and axis perpendicularity through multi-axis coaxial coupling, main and auxiliary support collaborative constraints, and closed-loop control of the encoder reader. The synergy of these two mechanisms enables precise and controllable motion trajectories in complex machining scenarios involving vertical feed and two-dimensional workpiece rotation, effectively suppressing linear deviation and rotational runout errors, providing core assurance for ultra-precision machining of complex curved surfaces. The synergistic improvement of the Z-axis air-bearing moving mechanism 6 and the AC cradle turntable 7 breaks through the accuracy and stability bottlenecks of traditional ultra-precision laser machining tools from the two core dimensions of linear and rotational motion, forming a synergistic advantage of multi-dimensional precise control and high rigidity load-bearing, significantly improving the overall performance of the machine tool.

[0110] The Y-axis air-bearing moving mechanism 51 includes a first air-bearing seat fixed on the bed 4, a Y-axis slide saddle slidably disposed on the first air-bearing seat, and a Y-axis linear motor for driving the Y-axis slide saddle to move. The X-axis air-bearing moving mechanism 52 includes a second air-bearing seat disposed on the Y-axis slide saddle, an X-axis slide slidably disposed on the second air-bearing seat, and an X-axis linear motor for driving the X-axis slide saddle to move. The AC cradle turntable 7 is disposed on the X-axis slide saddle.

[0111] The first air float is fixed to the bed 4 with high-precision positioning, serving as the reference carrier for Y-axis movement. An external air source supplies air to the first air float through a sealed air passage. The airflow is ejected through the throttle 362 inside the Y-axis slide saddle, forming a uniform air film of 0.008-0.012mm between the Y-axis slide saddle and the guide rail surface of the first air float, so that the Y-axis slide saddle is suspended on the first air float without mechanical contact.

[0112] The magnetic rail of the Y-axis linear motor is embedded in the side of the first air float, and the coil is fixed at the corresponding position of the Y-axis slide saddle (the two maintain a stable air gap of 0.3-0.5mm). After the mover is supplied with three-phase AC power, a traveling wave magnetic field is generated between the stator and the mover, forming an electromagnetic thrust along the Y direction, which directly drives the Y-axis slide saddle to move linearly along the first air float.

[0113] The grating ruler is fixed to the first air bearing seat, and the reading head moves synchronously with the Y-axis sliding saddle to collect Y-axis position data in real time and feed it back to the control device. The control device compares the target position with the actual position and dynamically adjusts the linear motor thrust to achieve high-precision closed-loop positioning in the Y-axis.

[0114] The second air float is fixed to the top surface of the Y-axis slide saddle (maintaining an orthogonal accuracy of ≤2μm / 1000mm with the Y direction); an external air source supplies air to the second air float through an independent air passage 361, and the airflow is ejected through the throttle 362 on the inner side of the X-axis slide saddle, forming a uniform air film between the X-axis slide saddle and the guide rail surface of the second air float, so that the X-axis slide saddle is suspended without contact.

[0115] The magnetic track of the X-axis linear motor is embedded in the side of the second air float, and the coil is fixed to the X-axis slide saddle. When energized, it generates an electromagnetic thrust along the X direction, driving the X-axis slide saddle to move along the second air float. At the same time, the Y-axis movement of the Y-axis slide saddle can synchronously drive the second air float, the X-axis slide saddle and the AC cradle turntable above to move. The two work together to realize the XY two-dimensional plane movement of the AC cradle turntable.

[0116] The X-axis grating ruler collects position data in real time and feeds it back to the control device. Together with the Y-axis positioning data, it achieves ultra-precise planar positioning of the AC cradle turntable.

[0117] It is understood that those skilled in the art can make equivalent substitutions or modifications to the technical solution and inventive concept of the present invention, and all such substitutions or modifications should fall within the protection scope of the appended claims.

Claims

1. An ultra-precision laser machining machine tool, characterized by, The application relates to a laser processing machine, which comprises a machine bed, a gantry arranged on the machine bed, a Y-axis air-floating moving mechanism arranged on the machine bed, an X-axis air-floating moving mechanism arranged on the Y-axis air-floating moving mechanism, an AC cradle rotary table arranged on the X-axis air-floating moving mechanism, the X-axis air-floating moving mechanism being used for moving the AC cradle rotary table leftward and rightward, and the Y-axis air-floating moving mechanism being used for moving the X-axis air-floating moving mechanism and the AC cradle rotary table forward and backward; a Z-axis air-floating moving mechanism is arranged on the gantry, a downward laser processing assembly is arranged on the Z-axis air-floating moving mechanism, the Z-axis air-floating moving mechanism is used for moving the laser processing assembly upward and downward, and the laser processing assembly is used for processing a workpiece on the AC cradle rotary table; the Z-axis air-floating moving mechanism comprises a gravity balance unit, a control device and a gas static pressure guide rail pair which is electrically connected with the control device; the gas static pressure guide rail pair comprises a linear guide rail pair, a slide plate assembly which is arranged on the outer circumferential side of the linear guide rail pair and a plurality of gas path control units, the gas outlet ends of the plurality of gas path control units are respectively connected with the gas inlet ends of the slide plate assembly, and the gas outlet side of the slide plate assembly faces the linear guide rail pair; the control device is electrically connected with the plurality of gas path control units, the independent regulation and control of each gas path control unit is realized, and the partitioned gas pressure regulation and control of the gas static pressure guide rail pair is realized.

2. The ultra-precision laser machining machine tool according to claim 1, characterized in that, The slide plate assembly comprises a main slide plate, a first side slide plate, a second side slide plate, a first back slide plate and a second back slide plate; the main slide plate is arranged on the front side of the linear guide rail pair, the gas outlet side of the main slide plate faces the normal reference surface of the linear guide rail pair; the first side slide plate and the second side slide plate are oppositely arranged on the two sides of the linear guide rail pair, the first side slide plate and the second side slide plate are respectively fixedly connected with the left and right ends of the main slide plate, the gas outlet end of the first side slide plate and the gas outlet side of the second side slide plate face the side reference surface of the linear guide rail pair; the first back slide plate and the second back slide plate are respectively arranged on the back side of the linear guide rail pair, the first back slide plate is fixedly connected with the first side slide plate, the second back slide plate is fixedly connected with the second side slide plate, and the gas outlet end of the first back slide plate and the gas outlet end of the second back slide plate respectively face the back reference surface of the linear guide rail pair.

3. The ultra-precision laser machining machine tool according to claim 2, wherein, The gas static pressure guide rail pair comprises twelve groups of gas path control units, the gas inlet end of the main slide plate is connected with four groups of the gas path control units, the four groups of the gas path control units are respectively used for controlling the left upper side gas pressure, the left lower side gas pressure, the right upper side gas pressure and the right lower side gas pressure of the main slide plate; the gas inlet end of the first side slide plate, the gas inlet end of the second side slide plate, the gas inlet end of the first back slide plate and the gas inlet end of the second back slide plate are respectively connected with two groups of the gas path control units, and the eight groups of the gas path control units are respectively used for controlling the upper and lower side gas pressures of the first side slide plate, the upper and lower side gas pressures of the second side slide plate, the upper and lower side gas pressures of the first back slide plate and the upper and lower side gas pressures of the second back slide plate.

4. The ultra-precision laser machining machine tool according to claim 1, wherein, The structure of each gas path control unit is consistent, and the gas path control unit comprises a gas path, a throttle, and a gas pressure regulating valve and a gas pressure gauge respectively electrically connected with the control device; the output end of the gas path is connected with the air inlet end of the slide plate assembly, and the gas pressure regulating valve and the gas pressure gauge are respectively arranged on the gas path; the throttle is arranged on the output side of the gas path and located at the air outlet end of the slide plate assembly.

5. The ultra-precision laser machining machine tool according to claim 1, wherein, The gravity balance unit comprises a first lifting ring part, a second lifting ring part, a fixed pulley part and a counterweight, the first lifting ring part is fixedly connected with the slide plate assembly, the first lifting ring part is connected with the second lifting ring part through a flexible metal wire, the fixed pulley part is fixedly arranged on the top of the portal frame, the flexible metal wire is in sliding fit with the fixed pulley part, the second lifting ring part is fixedly connected with the counterweight, and the counterweight is slidably arranged on the back side of the portal frame.

6. The ultra-precision laser machining machine tool according to claim 1, wherein, The AC cradle rotary table comprises a fixed seat, an A-axis rotary table arranged on the fixed seat, and a C-axis rotary table connected with the output end of the A-axis rotary table, the A-axis rotary table comprises a first torque motor, a first main bearing seat arranged on the head of the first torque motor and connected with the fixed seat, a first auxiliary bearing seat arranged at the tail of the first torque motor, a first output shaft connected with one end of the rotor of the first torque motor, and a first extension shaft connected with the other end of the rotor of the first torque motor, the first output shaft is rotationally connected with the first main bearing seat, the first extension shaft is rotationally connected with the first auxiliary bearing seat, and the first extension shaft, the rotor of the first torque motor and the first output shaft are coaxially coupled and form an A-axis axis; The C-axis rotary table comprises a second torque motor, a second main bearing seat arranged on the head of the second torque motor, a second auxiliary bearing seat arranged at the tail of the second torque motor, a second output shaft connected with one end of the rotor of the second torque motor, and a second extension shaft connected with the other end of the rotor of the second torque motor, the second output shaft is rotationally connected with the second main bearing seat, the second extension shaft is rotationally connected with the second auxiliary bearing seat, and the second extension shaft, the rotor of the second torque motor and the second output shaft are coaxially coupled and form a C-axis axis; The first output shaft is connected with the second main bearing seat through a transfer support.

7. The ultra-precision laser machining machine tool according to claim 6, wherein, The first output shaft comprises a rear shaft body, a middle shaft body and a front shaft body connected in sequence, the middle shaft body is rotationally connected with the first main bearing seat through a first bearing, and the rear shaft body is connected with the rotor of the first torque motor.

8. The ultra-precision laser machining machine tool according to claim 7, wherein, The middle shaft body is a hollow circular shaft structure, the rear shaft body is provided with an outer ring and is provided with a first embedded recess position in abutment with the middle shaft body, a plurality of first threaded holes arranged in a circumferential direction are formed in one end face of the middle shaft body, a first countersunk hole corresponding to each first threaded hole is formed in the rear shaft body, a first screw connected with the corresponding first threaded hole is arranged at each first countersunk hole, a plurality of second threaded holes arranged in a circumferential direction are formed in one end face of the rotor of the first torque motor, a second countersunk hole corresponding to each second threaded hole is formed in the outer ring, and a second screw connected with the corresponding second threaded hole is arranged at each second countersunk hole.

9. The ultra-precision laser machining machine tool according to claim 8, wherein, The periphery of the front shaft body is provided with an inrolling ring, the front shaft body is provided with the inrolling ring and is provided with a second embedded recess position which is connected with the middle shaft body, a plurality of third threaded holes which are arranged in a circumferential direction are arranged on the other end surface of the middle shaft body, a third countersunk hole which corresponds to the third threaded hole is arranged on the front shaft body, a third screw which is connected with the corresponding third threaded hole is arranged at each third countersunk hole, a code disc is arranged on the inrolling ring, and the first main bearing seat is provided with a code reading head which cooperates with the code disc.

10. The ultra-precision laser machining machine tool of claim 6, wherein, The first extension shaft is rotatably connected with the first auxiliary bearing seat through the second bearing and is provided with a stepped ring, a plurality of fourth threaded holes which are arranged in a circumferential direction are arranged on the other end surface of the rotor of the first torque motor, a fourth countersunk hole which corresponds to the fourth threaded hole is arranged on the stepped ring, and a fourth screw which is connected with the corresponding fourth threaded hole is arranged at each fourth countersunk hole.

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