An actively controlled aerostatic bearing and method of using the same

Abstract

The application provides an active control aerostatic bearing and a use method thereof, which comprises a bearing body, a plurality of independent installation cavities which are uniformly and circumferentially provided with a gas inlet channel, a movable piston arranged in the installation cavity, and an equalizing cavity formed between the piston and the installation cavity; a linear driving mechanism installed in the installation cavity, which drives the piston to move along the installation cavity to adjust the volume of the equalizing cavity; a variable-diameter throttling mechanism comprising a throttling hole communicated with the equalizing cavity, which adjusts the diameter of the throttling hole by adjusting the voltage to control the gas flow resistance of the bearing body; and a control mechanism for detecting the gas state in the bearing body and selecting the installation cavity to be adjusted according to the gas state; when the disturbance is high frequency, the control mechanism controls the throttling hole adjustment; when the disturbance is low frequency, the control mechanism controls the piston adjustment, and the control mechanism comprises a feedforward decoupling compensator which calculates the compensation voltage through the displacement of the piston and drives the throttling hole adjustment according to the compensation voltage.

Description

Technical Field

[0001] This invention relates to the field of ultra-precision equipment and intelligent fluid support technology, specifically to an actively controlled gas hydrostatic bearing and its usage method. Background Technology

[0002] Gas hydrostatic bearings are a type of precision support component that utilizes externally supplied compressed gas to form a stable gas film between relatively moving surfaces, thereby achieving non-contact support. Compared with traditional rolling bearings or liquid-lubricated bearings, gas hydrostatic bearings have advantages such as low friction loss, high motion accuracy, low temperature rise, low contamination, and suitability for high-speed operation. Therefore, they are widely used in ultra-precision machine tools, semiconductor manufacturing equipment, precision measurement platforms, optical processing equipment, and high-end rotating machinery.

[0003] Existing gas hydrostatic bearings are typically designed with fixed throttling structures and fixed cavity parameters. During operation, compressed gas enters the equalizing chamber through throttling orifices, throttling slots, or other throttling elements, and then flows out from the equalizing chamber to the bearing clearance, thus forming a gas film with a certain pressure distribution. This type of structure can achieve good load-bearing performance and support accuracy under specific design conditions. However, its throttling characteristics and cavity parameters remain essentially unchanged after manufacturing. When external loads, speeds, environmental disturbances, or installation postures change, the bearing cannot actively adjust the gas film state in a timely manner according to the actual operating conditions, resulting in limitations in load-bearing capacity, stiffness, damping, and stability.

[0004] To address the aforementioned issues, existing technologies employ methods that alter the bearing's operating state by adjusting the parameters of the equalizing chamber. For example, a piston can be moved using a motor, lead screw, voice coil motor, or other linear drive mechanism to change the height or volume of the equalizing chamber, thereby adjusting the pressure and film load capacity. These methods typically offer a wide adjustment range, making them suitable for handling low-frequency, high-amplitude load changes and facilitating operating point adjustment and static compensation. However, these adjustment methods often rely on mechanical actuators, resulting in relatively low system response speeds and difficulty in timely dynamic correction when facing high-frequency, low-amplitude disturbances.

[0005] On the other hand, existing technologies also include methods to adjust airflow resistance by changing the flow area of ​​the throttling orifice. For example, piezoelectric ceramics, flexible micro-actuators, or other fast-acting elements can be used to change the orifice diameter or equivalent flow area, thereby achieving rapid fine-tuning of the pressure in the equalizing chamber and the gas film state. This type of approach features fast response and good dynamic performance, making it suitable for high-frequency micro-vibration suppression and rapid compensation. However, because the stroke and output capacity of these actuators are typically limited, their adaptability to large-scale load variations and significant operational disturbances remains insufficient.

[0006] Therefore, the two existing schemes each have their own characteristics: the scheme based on equalizing chamber parameter adjustment is more suitable for large-range, low-frequency adjustment, but its dynamic response is relatively insufficient; the scheme based on orifice variation is more suitable for high-frequency, small-amplitude adjustment, but it has limitations in large-range load adjustment. Currently, there is a lack of a gas hydrostatic bearing structure and its control method that can organically combine the two adjustment methods and implement differentiated or coordinated control based on disturbance characteristics.

[0007] Furthermore, under complex operating conditions, gas static pressure bearings not only need to achieve active adjustment during normal operation, but also need to consider the issues of operational continuity and maintenance of basic support capacity in cases of actuator malfunction or local adjustment failure. Existing technologies for fault diagnosis, fault-tolerant monitoring, and degraded operation schemes for active adjustment systems of gas static pressure bearings are still relatively insufficient, making it difficult to meet the requirements of high-reliability precision equipment.

[0008] Therefore, it is necessary to provide an actively controlled gas hydrostatic bearing and its application method to balance the load adjustment requirements under low-frequency large disturbances and the rapid dynamic suppression requirements under high-frequency small disturbances, and improve the stability, adaptability and reliability of the system under complex working conditions. Summary of the Invention

[0009] This invention provides an actively controlled gas static pressure bearing and its usage method. Its main purpose is to solve the fundamental problems of fixed performance of gas static pressure bearings and the isolation and inability to coordinate existing active adjustment schemes in the prior art. The gas static pressure bearing provided by this invention can systematically solve the contradiction between the long-standing "fixed performance" and "variable operating condition requirements" of gas static pressure bearings, and ultimately achieve online dynamic optimization and comprehensive improvement of key performances such as stiffness, damping, and stability of gas static pressure bearings.

[0010] To achieve the above objectives, the present invention employs the following technical solution: This invention provides an actively controlled gas hydrostatic bearing, comprising: The bearing body has multiple mounting cavities that are evenly distributed around its circumference and communicate with the air intake channel. The mounting cavities are independently arranged, and a movable piston is arranged in each mounting cavity. The piston and the mounting cavity form a pressure equalization cavity. A linear drive mechanism is installed in the mounting cavity to drive the piston to move along the mounting cavity and adjust the volume of the pressure equalization cavity; The variable diameter throttling mechanism includes a throttling orifice communicating with the equalizing chamber. The diameter of the throttling orifice is adjusted by voltage to control the gas flow resistance of the bearing body. A control mechanism is used to detect the gas state inside the bearing body and select the appropriate mounting cavity based on the gas state. When there is a high-frequency disturbance, the control mechanism adjusts the throttle orifice by controlling the voltage. When there is a low-frequency disturbance, the control mechanism controls the piston adjustment. The control mechanism includes a feedforward decoupling compensator. The feedforward decoupling compensator calculates the compensation voltage based on the displacement of the piston and drives the throttle orifice adjustment according to the compensation voltage.

[0011] This invention controls a linear drive mechanism and a variable-diameter throttling mechanism through a control mechanism to adjust the position of the equalizing chamber and the airflow resistance. It solves the problem of "high force, slow change" by adjusting the piston and copes with the disturbance of "low force, rapid change" by adjusting the throttling orifice. It organically integrates macro-adjustment and micro-adjustment, static compensation and dynamic suppression. At the same time, a feedforward decoupling compensator is set to couple the transient effects generated during adjustment, so as to avoid affecting the stability of the bearing. This invention achieves online dynamic optimization and comprehensive improvement of key performance of gas static pressure bearings such as stiffness, damping and stability.

[0012] In one specific implementation, the variable diameter throttling mechanism includes a module housing, a piezoelectric ceramic actuator tube, and a lead hole; The throttling orifice is formed inside the piezoelectric ceramic actuator tube, the throttling orifice is connected to the piston, and the piston is connected to the air intake passage of the bearing body; The piezoelectric ceramic actuator is disposed inside the module housing, which is connected to the piston via threads. The lead hole is opened on the module housing, and an electrical lead is disposed inside the lead hole. One end of the electrical lead is connected to the piezoelectric ceramic actuator, and the other end of the electrical lead is connected to a drive circuit.

[0013] In one specific implementation, the linear drive mechanism includes a motor, a push plate, and an elastic buffer element; The motor is fixedly connected to the bearing body, and the push plate is movably mounted on the bearing body. One end of the push plate is connected to the output end of the motor, and the other end of the push plate is connected to the piston. The end of the piston near the push plate is provided with the elastic buffer element.

[0014] In one specific implementation, the control mechanism further includes at least one sensing system, a central controller, and a driver; The central controller is connected to the sensing system, the driver, and the feedforward decoupling compensator. The driver is connected to the linear drive mechanism and the throttle orifice. The sensing system detects the gas inside the bearing body. Based on the data detected by the sensing system, the central controller controls the driver to drive the linear drive mechanism and / or the throttle orifice to operate.

[0015] The present invention also provides a method for using the above-mentioned actively controlled gas hydrostatic bearing, which includes the following steps: The control mechanism detects the gas state inside the bearing body; The control mechanism adjusts the diameter of the flow orifice and regulates the airflow resistance based on the detection results; The control mechanism controls the linear drive mechanism to drive the piston to move according to the detection results, and adjusts the volume of the equalizing chamber. The feedforward decoupling compensator calculates the compensation voltage based on the displacement of the piston, and drives the throttle orifice to adjust according to the compensation voltage.

[0016] In one specific implementation, the control mechanism detects the gas state within the bearing body by the following steps: The sensing system detects the gas state of the bearing body, and the detected gas state includes one or more combinations of gas film thickness, gas film pressure and equalization chamber pressure. The sensing system sends the detection results to the central controller; The central controller receives the detection results, runs the control algorithm, and outputs control commands; The driver receives control commands and selects to drive the motor and / or drive circuit.

[0017] In one specific implementation scheme, the central controller receives the detection results, runs the control algorithm, and outputs control commands, including the following steps: The central controller receives the detection results and makes a judgment on the detection results: Compare the real-time main frequency and real-time amplitude with the frequency threshold and amplitude threshold: When the real-time main frequency is less than the frequency threshold and the real-time amplitude is greater than the amplitude threshold, it is judged as a low-frequency, large-amplitude disturbance. When the real-time main frequency is greater than the frequency threshold and the real-time amplitude is less than the amplitude threshold, it is determined to be a high-frequency, small-amplitude disturbance. Otherwise, it is determined to be a composite disturbance; When the detection result is a low-frequency, large-amplitude disturbance or a complex disturbance, the central controller determines that the position of the equalizing chamber should be adjusted, the central controller calculates the required piston displacement, and issues a control command. When the detection result is a high-frequency, small-amplitude disturbance, the central controller determines that the diameter of the throttling orifice should be adjusted, and the central controller generates an orifice adjustment command and issues a control command.

[0018] In one specific implementation, the driver receiving control commands to select the operation of the motor and / or drive circuit includes the following steps: When the motor is running, it drives the piston to move precisely, changing the volume of the equalizing chamber. When the volume increases, the pressure and bearing capacity of the equalizing chamber decrease; when the volume increases, the pressure and bearing capacity of the equalizing chamber increase. When the driving circuit is running, the voltage of the driving circuit drives the piezoelectric ceramic actuator tube to deform slightly, changing the diameter of the throttling orifice. When the diameter increases, the pressure equalization chamber and the load-bearing capacity increase instantaneously; when the diameter decreases, the pressure equalization chamber and the load-bearing capacity decrease instantaneously.

[0019] In one specific implementation, the adjustment of the throttle orifice based on the compensation voltage includes the following steps: The feedforward decoupling compensator calculates a compensation voltage based on the precise movement of the piston, and superimposes it onto the drive circuit. The voltage of the drive circuit drives the throttling orifice to adjust the orifice diameter.

[0020] In one specific implementation, the method of use further includes the following steps: Real-time monitoring of the operating current and impedance characteristics of multiple sets of motors and drive circuits; Determine whether the detection data exceeds the safety threshold or whether the response times out abnormally; After determining the fault, lock the current orifice diameter and trigger an alarm; The central controller initiates a degraded operation optimization algorithm, reallocates control weights, updates the coordination strategy, and runs until maintenance is required.

[0021] Compared with the prior art, the present invention has at least the following advantages: 1. This invention addresses the shortcomings of existing technologies by providing a complete system solution encompassing hardware architecture, control algorithms, and fault-tolerant management. It directly addresses the fundamental contradiction between "fixed performance" and "variable operating conditions." By simultaneously incorporating a pressure equalization chamber adjustment mechanism and a variable diameter throttling adjustment mechanism within the same gas static pressure bearing unit, the bearing simultaneously possesses a wide range of load-bearing adjustment capabilities and high dynamic response capabilities. This facilitates the consideration of both the operating point adjustment requirements under low-frequency large-amplitude disturbance conditions and the rapid vibration suppression requirements under high-frequency small-amplitude disturbance conditions, thereby achieving online dynamic optimization and comprehensive improvement of key performance characteristics such as stiffness, damping, and stability of the gas static pressure bearing.

[0022] 2. This invention uses a linear drive mechanism to drive the piston to move axially, thereby changing the volume of the pressure equalization chamber and thus achieving active adjustment of the pressure and load-bearing capacity of the pressure equalization chamber. It is suitable for adjustment scenarios with large load changes or slow operating conditions, and is beneficial to improving the adaptability of bearings under variable load conditions.

[0023] 3. By setting up a variable diameter throttling mechanism, the present invention uses a piezoelectric ceramic actuator to drive the flow diameter of the throttling orifice to change, thereby rapidly adjusting the airflow resistance entering the equalizing chamber. This enables rapid fine-tuning of the gas film state, which is beneficial to improving the bearing's ability to suppress high-frequency vibrations and minor disturbances. Meanwhile, the modular design allows the variable diameter throttling mechanism to be disassembled and replaced separately, making maintenance convenient; the feedforward decoupling compensator effectively solves the most challenging dynamic interference problem in engineering integration, ensuring the stability of the gas static pressure bearing in actual operation; the complete fault-tolerant process makes the product more suitable for the application requirements of high-reliability equipment.

[0024] 4. This invention analyzes the operating parameters collected by the sensing system through the control mechanism, and determines the control mode based on the disturbance frequency characteristics and amplitude characteristics, thereby performing equalization chamber regulation, throttling regulation or coordinated regulation respectively. This helps to improve the matching between the control strategy and the actual disturbance type, and enhances the control effect of the system under complex operating conditions.

[0025] 5. This invention introduces a feedforward compensation mechanism during the equalizing chamber adjustment process, which couples the transient effects caused by piston displacement adjustment to the variable diameter throttling mechanism for compensation, thereby reducing pressure fluctuations in the equalizing chamber and improving the stability and smoothness of the coordinated control process. Through hardware integration and intelligent control, H adjustment (position adjustment of the equalizing chamber) and d adjustment (diameter adjustment of the throttling orifice) produce a synergistic effect of "1+1>2". The organic combination of macro-adjustment and micro-adjustment enables the gas static pressure bearing to simultaneously possess strong anti-interference capability and precise dynamic adjustment capability, which cannot be achieved by any single adjustment scheme. 6. This technology platform can be used to develop various product configurations, such as pure H-adjustment type (suitable for heavy loads), pure d-adjustment type (suitable for high speeds), and full-function composite type, to meet the diverse needs of different fields and cost budgets, such as ultra-precision machine tools, semiconductor equipment, optical instruments, and high-end measurement platforms.

[0026] 7. The multiple electrical / drive circuits in this invention can be controlled independently. In addition to being used for adjusting the total load capacity, they can also be used to compensate for the attitude error of the support components through differential adjustment, which is beneficial to improving the support accuracy and operational stability of the bearing system.

[0027] 8. The present invention further includes a fault diagnosis and degraded operation mechanism. When a local execution channel is abnormal, the current state or safe state of the faulty channel can be locked, and the control parameters of the remaining normal channels can be adjusted to maintain the basic support function of the system, which is conducive to improving the reliability of the device and its engineering applicability. Attached Figure Description

[0028] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0029] Figure 1 This is a schematic diagram of the overall structure of the gas hydrostatic bearing provided by the present invention; Figure 2 This is a cross-sectional view of the gas hydrostatic bearing provided by the present invention; Figure 3 This is a schematic diagram of the pressure equalization chamber of the gas static bearing provided by the present invention; Figure 4 This is an isometric view of the variable diameter throttling mechanism in the gas static pressure bearing provided by the present invention.

[0030] in: 1-Bearing body; 2-Variable diameter throttling mechanism; 21-Module housing; 211-External thread; 212-Mounting cavity; 22-Piezoelectric ceramic actuator tube; 23-Throttle orifice; 24-Structural adhesive layer; 25-Lead wire hole; 26-Sealing ring; 27-Throttle tube; 3-Linear drive mechanism; 4-Piston; 5-Equalizing chamber; 6-Air film; 7-Sensing system; 8-Inlet channel; 9-Air chamber; 10-Central controller; 11-Driver; 12-Elastic buffer element. Detailed Implementation

[0031] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings and specific embodiments. However, those skilled in the art will understand that the embodiments described below are some embodiments of the present invention, but not all embodiments, and are only used to illustrate the present invention, and should not be regarded as limiting the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall be followed. Where the manufacturers of reagents or instruments are not specified, they are all conventional products that can be purchased commercially.

[0032] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0033] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "connected," and "connected" should be interpreted broadly. For example, they can refer to fixed connection, detachable connection, or integral connection; they can refer to mechanical connection or electrical connection; they can refer to direct connection or indirect connection through an intermediate medium; and they can refer to the connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0034] To more clearly illustrate the technical solutions in this invention, specific embodiments are described below.

[0035] Example 1 like Figures 1-4 As shown, this embodiment provides an actively controlled gas static pressure bearing. The gas static pressure bearing has multiple mounting cavities 212, which are evenly arranged in a circumferential shape on the gas static pressure bearing. Each mounting cavity 212 is independently equipped with an adjustment component. The multiple adjustment components work together to achieve real-time, active and precise control of the pressure field of the gas film 6 inside the gas static pressure bearing.

[0036] In this embodiment, taking a single adjustment component as an example, it includes a piston 4, a linear drive mechanism 3, a variable diameter throttling mechanism 2, and a control mechanism. The piston 4 is axially movable and is installed in the mounting cavity 212 on the bearing body 1. Specifically, the piston 4 has a hollow structure and an air inlet is provided on the piston 4. The air inlet is connected to the air inlet channel 8 through the air chamber 9. The piston 4 is movably installed in the mounting cavity 212. The gap between the piston 4 and the bearing body 1 (the cavity wall of the mounting cavity 212) forms a pressure equalization cavity 5. The linear drive mechanism 3 drives the piston 4 to move, adjusts the position of the pressure equalization cavity 5, and changes the volume of the pressure equalization cavity 5 to cope with low-frequency, large-amplitude load changes, and performs operating point setting and coarse adjustment. The variable diameter throttling mechanism 2 is located at the lower end of the piston 4. The variable diameter throttling mechanism 2 includes a throttling orifice 23. By adjusting the diameter of the throttling orifice 23, high-frequency, small-amplitude dynamic vibrations are suppressed, and fine adjustment and compensation are performed. The two work together to achieve adaptive suppression of full-spectrum disturbances.

[0037] In this embodiment, the linear drive mechanism 3 includes a push plate and a motor, wherein the motor is a servo electric cylinder or a voice coil motor. In actual operation, any motor or device that can drive the push plate to reciprocate can be used. The output end of the motor is connected to one end of the push plate, and the other end of the push plate is connected to the piston 4. When the motor is running, the piston 4 is driven to move through the push plate to adjust the position of the pressure equalization chamber 5.

[0038] Meanwhile, the linear drive mechanism 3 also includes an elastic buffer element 12. The elastic buffer element 12 is an elastic element or elastomer material such as a spring or rubber. The elastic buffer element 12 is installed on the upper end of the piston 4 and is located between the upper end of the piston 4 and the bearing body 1, so as to play a pre-tightening role.

[0039] In this embodiment, to better adjust the position of the equalizing chamber 5, the piston 4 is configured as an inverted U-shape, including a cylindrical upper end and a lower end, wherein the diameter of the upper end is larger than the diameter of the lower end. The upper end cooperates with the precision guide hole on the bearing body 1 to ensure the straightness of the movement. The outer cylindrical surface of the lower end forms an annular lateral space with the mounting cavity 212 of the bearing body 1. This space and the lower end surface together form the equalizing chamber 5. When the motor drives the piston 4 to move, the height of the annular lateral space formed between the lower end and the bearing body 1 will also change accordingly, and the volume of the equalizing chamber 5 will also change accordingly. The position of the equalizing chamber 5 will also change, thereby coping with low-frequency, large-amplitude load changes.

[0040] This embodiment also provides a variable-diameter throttling structure to cope with high-frequency, low-amplitude dynamic vibrations, which includes a module housing 21, a piezoelectric ceramic actuator tube 22, and a lead hole 25. The module housing 21 has an external thread 211, and the lower end of the piston 4 has an internal thread. The module housing 21 is connected to the lower end of the piston 4 via the thread. A sealing ring 26 is also provided to ensure the sealing of the connection. The piezoelectric ceramic actuator tube 22 is fixed inside the module housing 21 by a structural adhesive layer 24. Additionally, the module housing 21 also has... A throttling tube 27, made of flexible material, has a throttling orifice 23 formed on the piezoelectric ceramic actuator 22. The throttling tube 27 is disposed within the throttling orifice 23. An electrical lead is disposed within a lead hole 25, with one end connected to the piezoelectric ceramic actuator 22 and the other end connected to a drive circuit. The drive circuit supplies power; upon receiving voltage, the piezoelectric ceramic actuator 22 alters the diameter of the throttling orifice 23, thereby changing the diameter of the throttling tube 27 and controlling the airflow resistance within the bearing body 1. Specifically, the drive circuit applies a driving voltage to the piezoelectric ceramic actuator 22, causing radial deformation and further altering the equivalent flow diameter of the throttling tube 27, thus changing the flow area of ​​the throttling orifice 23 and adjusting the airflow resistance entering the equalizing chamber 5.

[0041] The control mechanism includes a feedforward decoupling compensator, which can couple the transient effects generated during piston adjustment to the orifice adjustment for compensation. Specifically, during piston adjustment, the feedforward decoupling compensator calculates the compensation voltage based on the piston displacement and drives the orifice adjustment according to the compensation voltage.

[0042] In this embodiment, the control mechanism further includes a sensing system 7, a central controller 10, and a driver 11. The central controller 10 is connected to the sensing system 7 and the driver 11. The central controller 10 receives signals from the sensing system 7 and controls the driver 11 to drive the motor and / or drive circuit to operate, thereby adjusting the position of the equalizing chamber 5 and / or the diameter of the throttling orifice 23.

[0043] The sensing system 7 is used to detect the operating status parameters of the bearing body 1. The detected items are one or a combination of the thickness of the air film 6, the pressure of the equalizing chamber 5, and the pressure of the air film 6. In this embodiment, a displacement sensor for measuring the thickness of the air film 6 and a pressure sensor for measuring the pressure of the equalizing chamber 5 are provided.

[0044] In summary, the gas path of the gas static pressure bearing provided in this application is as follows: external high-pressure gas enters the gas chamber 9 through the inlet channel 8 and is stabilized, and then passes through the piston 4, the throttle orifice 23, and the pressure equalization chamber 5, and finally overflows from the periphery of the pressure equalization chamber 5 to form a gas film 6 with load-bearing function. The circuit is as follows: the sensor system 7 collects signals and transmits them to the central controller 10. After processing, the central controller 10 outputs control commands to the driver 11. The driver 11 drives the motor and / or the drive circuit to operate, thus forming a complete measurement-decision-execution closed loop.

[0045] Specifically, when external high-pressure gas enters the bearing body 1 through the above-mentioned gas path, static pressure is generated at the gas film 6, causing the thrust disc or shaft to float. Next, the sensing system 7 detects the real-time operating status parameters of the bearing body 1, and simultaneously transmits the detection signals to the central controller 10. The algorithm within the central controller 10 processes the detection signals and identifies disturbance characteristics. If a low-frequency, large-amplitude disturbance (such as load change) is detected, it is determined that the height (H) of the equalizing chamber 5 needs to be adjusted: The central controller 10 (through MPC algorithm) calculates the required displacement of piston 4 (ΔH_cmd) and sends it to the corresponding motor. The motor pushes piston 4 to move precisely, adjusts the position of equalizing chamber 5, and changes the volume (i.e., height H) of equalizing chamber 5. When H increases, the pressure and load-bearing capacity of equalizing chamber 5 decreases, and vice versa. The motor has a large operating range and is relatively slow, which is suitable for setting the working point or compensating for large loads. If high-frequency and small-amplitude disturbances (such as vibrations) are detected, it is determined that the aperture (d) of the throttle hole 23 needs to be adjusted: the central controller 10 generates an aperture adjustment command (Δd_cmd), sends it to the drive circuit, and the drive circuit releases voltage to the piezoelectric ceramic actuator tube 22. The piezoelectric ceramic actuator tube 22 undergoes micro-deformation under voltage drive, changing the aperture d of the throttle hole 23. When d increases, the air flow resistance decreases, and the pressure and bearing capacity of the pressure equalizing chamber 5 increase; conversely, they instantaneously drop. The circuit drive has a very fast response and high precision, and is used for dynamic fine adjustment and vibration suppression. Key decoupling action: When issuing the H adjustment command, the feedforward decoupling compensator in the central controller 10 calculates a compensation voltage (V_ff) according to the change amount or change rate of ΔH_cmd and superimposes it on the d adjustment command to offset the instantaneous interference caused by the movement of the piston 4 on the pressure of the pressure equalizing chamber 5.

[0046] In this embodiment, multiple adjustment components (motors / drive circuits) are independently controllable. They can not only adjust the total bearing capacity but also generate a correction torque through differential adjustment to control the attitude of the thrust disk. At the same time, during the operation of the system, the central controller 10 continuously detects the states of each adjustment component. When a certain adjustment component fails, the aperture value of its throttle hole 23 is determined, and the central controller 10 is triggered to re-optimize the algorithm, and more adjustment tasks are assigned to the H adjustment mechanism of this adjustment component and other normal adjustment components, enabling the system to enter the downgraded operation mode and maintaining the basic functions.

[0047] This embodiment also provides a method for using the above active control aerostatic bearing. A central controller 10 controls the motors and drive circuits in multiple gas channels arranged in a circular shape, and it includes the following steps: 1. Acquisition of real-time working condition parameters: Through the sensing system 7, signals of the air film 6 thickness h(t) and the pressure p(t) of the pressure equalizing chamber 5 are acquired in real time at a sampling frequency not lower than 1 kHz. Other state parameters such as the air film 6 pressure can also be acquired according to needs. 2. Analysis of disturbance characteristics and decision-making of control modes: The central controller 10 filters and performs real-time spectrum analysis (such as fast Fourier transform FFT) on the signals transmitted by the sensing system 7 to extract the real-time main frequency f and real-time amplitude A of the current disturbance. Compare the real-time main frequency f and real-time amplitude A with the preset frequency threshold f_th and amplitude threshold A_th: If f < f_th and A > A_th, it is determined as a low-frequency large-amplitude disturbance, and enter the "H main adjustment mode".

[0048] If f > f_th and A < A_th, it is determined as a high-frequency small-amplitude disturbance and enters the "d main control mode".

[0049] In other cases (if the signal components satisfy both or are between them), it enters the "composite disturbance".

[0050] 3. Generate and execute control instructions: a. H main control mode (low-frequency large-amplitude disturbance) or composite disturbance: The central controller 10 (such as the model predictive controller MPC) calculates the required pressure regulation amount in the next several control cycles according to the thickness deviation of the air film 6, and decomposes it into the basic volume regulation instruction ΔH_cmd for each pressure equalizing chamber 5, and transmits the instruction to the corresponding motor through the driver 11; The feedforward decoupling compensator calculates the compensation voltage according to the real-time change rate of ΔH_cmd according to the formula V_ff = K * d(ΔH_cmd) / dt (K is the feedforward gain coefficient identified by the system identification), and superimposes it on the drive circuit; b. d main control mode (high-frequency small-amplitude disturbance): The high-frequency vibration suppression module in the central controller 10 generates the dynamic instruction Δd_cmd for adjusting the diameter of the throttle hole 23 in the opposite phase according to the identified vibration frequency and phase; The central controller 10 converts ΔH_cmd into the drive signal for the motor; converts Δd_cmd + V_ff into the drive voltage for the piezoelectric ceramic in the drive circuit; and adopts high-speed PID control to ensure accurate tracking.

[0051] In actual operation, the central controller 10 can use model predictive control, proportional integral differential control or other control algorithms suitable for this system to implement control instruction calculation; the feedforward compensation signal can set corresponding compensation parameters according to the system identification results.

[0052] 4. Fault diagnosis and degraded operation: a. Real-time monitor the working current I and impedance characteristics Z of the motor and the drive circuit; b. Judge whether the monitored value exceeds the preset safety threshold, or whether the response is abnormally overtime, and judge whether it is a fault; c. If it is judged as a fault, immediately lock the aperture of the throttle hole 23 corresponding to the motor / drive circuit at the current value or the safety value, and trigger an alarm; d. The central controller 10 starts the degraded operation optimization algorithm, redistributes the control weights of each motor / drive circuit (for example: increase the H regulation loop gain of the faulty motor / drive circuit, and fine-tune the H and d loop parameters of the remaining normal motor / drive circuits), and update the cooperation strategy; f. Continue to operate in a state where the performance degradation is safe and controllable until maintenance.

[0053] This invention has at least the following advantages: 1. This invention integrates macroscopic H adjustment and microscopic d adjustment within a bearing body 1, and coordinates and decouples them through intelligent algorithms, enabling the bearing to function like an "intelligent muscle," possessing both powerful "force adjustment" (load resistance) and agile "fine-tuning reflection" (vibration suppression) capabilities. This systematically solves the problem of traditional bearings having fixed dynamic performance and being unable to adapt to changing working conditions. 2. This invention fundamentally overcomes the defect of fixed dynamic characteristics of traditional bearings: through the coordinated adjustment of H and d, it can effectively suppress the full spectrum disturbance from low-frequency load fluctuations below 10Hz to high-frequency mechanical vibrations above 50Hz. Under typical working conditions, the gas static pressure bearing disclosed in this invention can suppress high-frequency micro-amplitude vibrations by more than 90%, and increases the critical speed of gas hammer instability by 20%-30%, significantly expanding the safe and stable working range of gas static pressure bearings. 3. When faced with large load changes, the present invention can quickly reconstruct the load-bearing capacity through H adjustment, and control the thickness change of the air film 6 within a very small range (for example, under a load change of hundreds of Newtons, the thickness fluctuation can be controlled within ±2μm, and the stiffness is improved several times). At the same time, combined with the dynamic micro-compensation of d adjustment, the comprehensive optimal balance between dynamic and static stiffness is achieved. 4. The fault diagnosis and degraded operation mechanism provided by this invention ensures that when a local component (such as a single motor / drive circuit) fails, the gas static pressure bearing will not suddenly become unstable and can automatically enter the degraded operation mode to maintain at least 70% of the core support function and trigger an early warning, realizing the transformation from a "fragile system" to a "resilient system" and greatly improving the availability of the gas static pressure bearing. 5. The multiple adjustment components (motor / drive circuit) in this invention can be independently closed-loop controlled, which can not only adjust the total load capacity, but also actively compensate for torque load through differential adjustment of each H and d, and correct the attitude errors such as tilt and sway of the thrust plate or main shaft in real time, so as to control the parallelism or rotation accuracy at a higher level.

[0054] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. The present invention is not limited to the exact structures described above and illustrated in the accompanying drawings, and it should not be considered that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various changes and modifications made without departing from the concept of the present invention should be considered to fall within the protection scope of the present invention.

Claims

1. An actively controlled gas hydrostatic bearing, characterized in that, include: The bearing body has multiple mounting cavities that are evenly distributed around its circumference and communicate with the air intake channel. The mounting cavities are independently arranged, and a movable piston is arranged in each mounting cavity. The piston and the mounting cavity form a pressure equalization cavity. A linear drive mechanism is installed in the mounting cavity to drive the piston to move along the mounting cavity and adjust the volume of the pressure equalization cavity; The variable diameter throttling mechanism includes a throttling orifice communicating with the equalizing chamber. The diameter of the throttling orifice is adjusted by voltage to control the gas flow resistance of the bearing body. A control mechanism is used to detect the gas state inside the bearing body and select the appropriate mounting cavity based on the gas state. When there is a high-frequency disturbance, the control mechanism controls the adjustment of the throttle orifice; When there is a low-frequency disturbance, the control mechanism controls the piston adjustment. The control mechanism includes a feedforward decoupling compensator. The feedforward decoupling compensator calculates the compensation voltage based on the displacement of the piston and drives the throttle orifice adjustment according to the compensation voltage.

2. The gas hydrostatic bearing according to claim 1, characterized in that, The variable diameter throttling mechanism includes a module housing, a piezoelectric ceramic actuator tube, and a lead wire hole; The throttling orifice is formed inside the piezoelectric ceramic actuator tube, and the throttling orifice is connected to the piston; The piezoelectric ceramic actuator is disposed inside the module housing, which is connected to the piston via threads. The lead hole is opened on the module housing, and an electrical lead is disposed inside the lead hole. One end of the electrical lead is connected to the piezoelectric ceramic actuator, and the other end of the electrical lead is connected to a drive circuit.

3. The gas hydrostatic bearing according to claim 1, characterized in that, The linear drive mechanism includes a motor, a push plate, and an elastic buffer element; The motor is fixedly connected to the bearing body, and the push plate is movably mounted on the bearing body. One end of the push plate is connected to the output end of the motor, and the other end of the push plate is connected to the piston. The end of the piston near the push plate is provided with the elastic buffer element.

4. The gas hydrostatic bearing according to claim 1, characterized in that, The control mechanism also includes at least one sensing system, a central controller, and a driver; The central controller is connected to the sensing system, the driver, and the feedforward decoupling compensator. The driver is connected to the linear drive mechanism and the throttle orifice. The sensing system detects the gas inside the bearing body. Based on the data detected by the sensing system, the central controller controls the driver to drive the linear drive mechanism and / or the throttle orifice to operate.

5. The method of using the actively controlled gas hydrostatic bearing according to any one of claims 1-4, characterized in that, Includes the following steps: The control mechanism detects the gas state inside the bearing body; The control mechanism adjusts the airflow resistance by regulating the diameter of the flow orifice through voltage adjustment based on the detection results; The control mechanism controls the linear drive mechanism to drive the piston to move according to the detection results, and adjusts the volume of the equalizing chamber. The feedforward decoupling compensator calculates the compensation voltage based on the displacement of the piston, and drives the throttle orifice to adjust according to the compensation voltage.

6. The method of use according to claim 5, characterized in that, The control mechanism detects the gas state inside the bearing body through the following steps: The sensing system detects the gas state of the bearing body, and the detected gas state includes one or more combinations of gas film thickness, gas film pressure and equalization chamber pressure. The sensing system sends the detection results to the central controller; The central controller receives the detection results, runs the control algorithm, and outputs control commands; The driver receives control commands and selects to drive the motor and / or drive circuit.

7. The method of use according to claim 6, characterized in that, The central controller receives the detection results, runs the control algorithm, and outputs control commands, including the following steps: The central controller receives the detection results and makes a judgment on the detection results: Compare the real-time main frequency and real-time amplitude with the frequency threshold and amplitude threshold: When the real-time main frequency is less than the frequency threshold and the real-time amplitude is greater than the amplitude threshold, it is judged as a low-frequency, large-amplitude disturbance. When the real-time main frequency is greater than the frequency threshold and the real-time amplitude is less than the amplitude threshold, it is determined to be a high-frequency, small-amplitude disturbance. Otherwise, it is determined to be a composite disturbance; When the detection result is a low-frequency, large-amplitude disturbance or a complex disturbance, the central controller determines that the position of the equalizing chamber should be adjusted, the central controller calculates the required piston displacement, and issues a control command. When the detection result is a high-frequency, small-amplitude disturbance, the central controller determines that the diameter of the throttling orifice should be adjusted, and the central controller generates an orifice adjustment command and issues a control command.

8. The method of use according to claim 6, characterized in that, The driver receives control commands and selects to drive the motor and / or drive circuit, including the following steps: When the motor is running, it drives the piston to move precisely, changing the volume of the equalizing chamber. When the volume increases, the pressure and bearing capacity of the equalizing chamber decrease; when the volume increases, the pressure and bearing capacity of the equalizing chamber increase. When the driving circuit is running, the voltage of the driving circuit drives the piezoelectric ceramic actuator tube to deform slightly, changing the diameter of the throttling orifice. When the diameter increases, the pressure equalization chamber and the load-bearing capacity increase instantaneously; when the diameter decreases, the pressure equalization chamber and the load-bearing capacity decrease instantaneously.

9. The method of use according to claim 8, characterized in that, The adjustment of the throttle orifice based on the compensation voltage includes the following steps: The feedforward decoupling compensator calculates a compensation voltage based on the precise movement of the piston, and superimposes it onto the drive circuit. The voltage of the drive circuit drives the throttling orifice to adjust the orifice diameter.

10. The method of use according to claim 6, characterized in that, It also includes the following steps: Real-time monitoring of the operating current and impedance characteristics of multiple sets of motors and drive circuits; Determine whether the detection data exceeds the safety threshold or whether the response times out abnormally; After determining the fault, lock the current orifice diameter and trigger an alarm; The central controller initiates a degraded operation optimization algorithm, reallocates control weights, updates the coordination strategy, and runs until maintenance is required.

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