CN103047349B - Magnetic suspension planar-drive positioning vibration isolator with coplanar air floatation orthogonal decoupling function and angular decoupling function by aid of sliding joint bearing - Google Patents

Abstract

The invention discloses a magnetic suspension planar-drive positioning vibration isolator with a coplanar air floatation orthogonal decoupling function and an angular decoupling function by the aid of a sliding joint bearing, and belongs to the technical field of precision vibration isolation. Space between a sleeve of a vibration isolator body and a lower mounting plate is carried under a magnetic suspension effect of a magnetic suspension planar motor, space between a piston barrel and the sleeve is lubricated and supported via an air floatation plane, the degree of freedom of horizontal linear movement between an upper mounting plate and the lower mounting plate is decoupled by coplanar orthogonal air floatation guide rails, the degree of freedom of angular movement between the upper mounting plate and the lower mounting plate is decoupled by the sliding joint bearing, and motors, displacement sensors, limit switches, a controller and a driver form a position closed-loop feedback control system to precisely control relative positions of the upper mounting plate and the lower mounting plate. The magnetic suspension planar-drive positioning vibration isolator has the advantages of approximately zero three-dimensional stiffness, high positioning precision and capabilities of decoupling the degree of freedom of linear movement and decoupling the degree of freedom of angular movement, and can effectively realize high-performance vibration isolation for ultra-precision measuring instruments and processing equipment, and particularly for step-scan lithography machines.

Description

Orthogonal decoupling of coplanar air bearings and angular decoupling of sliding joint bearings for magnetic suspension planar drive positioning vibration isolators

technical field

The invention belongs to the technical field of precision vibration isolation, and mainly relates to a magnetic suspension plane drive positioning vibration isolator for coplanar air bearing orthogonal decoupling and sliding joint bearing angle decoupling. the

Background technique

With the continuous improvement of ultra-precision machining and measurement accuracy, environmental vibration has become an important factor restricting the improvement of the accuracy and performance of ultra-precision machining equipment and measuring instruments. In particular, the ultra-large-scale integrated circuit processing equipment represented by the step-scan lithography machine is extremely technically intensive and complex, and the key technical indicators have reached the limit of the existing technology, representing the highest level of ultra-precision processing equipment. Precision vibration isolation has become the core key technology in this type of equipment; the line width of the step-and-scan lithography machine has reached 22nm and below, the positioning accuracy and overlay accuracy of silicon wafers have reached several nanometers, and the movement speed of the workpiece table has reached 1m/s Above, the acceleration of the workpiece table reaches dozens of times of the acceleration of gravity, which poses a new challenge to the existing vibration isolation technology. First of all, the lithography machine needs to provide an "ultra-quiet" working environment for the metrology system and the lithography objective lens, and at the same time needs to drive the workpiece table to move at high speed and high acceleration, which poses extremely strict requirements on the vibration isolation performance of the vibration isolation system. It is required that the natural frequencies in the three directions must be below 1Hz; secondly, the relative position between the various components of the lithography machine, such as the distance between the lithography objective lens and the surface of the silicon wafer, has very strict requirements and is in a position closed loop Under the control of the feedback control system, the relative position accuracy between the upper and lower mounting plates of the vibration isolator is required to reach the order of 10 μm, and the positioning accuracy of the traditional vibration isolator is far from meeting the requirements. the

According to the vibration isolation theory, the natural frequency of a passive vibration isolator is proportional to the stiffness and inversely proportional to the load mass. Therefore, under the premise of a certain load mass, reducing the stiffness of the vibration isolator is to reduce the natural frequency and improve low frequency and ultra-low frequency vibration isolation. efficient way to perform. Vibration isolators in the form of traditional air springs have an inherent contradiction between static load capacity and stiffness. At the same time, they are constrained by factors such as material properties and structural stiffness. It is very difficult to further reduce their stiffness, especially the horizontal stiffness. In response to this problem, the researchers introduced the "pendulum" structure into the air spring vibration isolator to achieve the purpose of reducing the horizontal stiffness of the vibration isolator (1. Nikon Corporation. Vibration Isolator With Low Lateral Stiffness. US Patent Publication No.: US20040065517A1 ; 2. U.S.Philips Corporation. Positioning Device with a Force Actuator System for Compensating Center-of-gravity Displacements, and Lithographic Device Provided with Such APositioning Device. U.S. Patent No.: US005844664A). This method can reduce the horizontal stiffness of the air spring isolator to a certain extent and improve its low-frequency vibration isolation performance. The problems of this method are: 1) Constrained by the material properties and structural stiffness, the vertical and horizontal stiffness of the vibration isolator can be reduced to a limited extent; 2) The vertical and horizontal positioning accuracy of the air spring vibration isolator is very poor, It cannot meet the requirements of the photolithography process; 3) To achieve a lower horizontal stiffness requires a larger pendulum length, resulting in excessive height of the vibration isolator, prone to string-membrane resonance, and poor stability. the

Through the analysis of the technical scheme of the existing air spring isolator, it can be seen that the existing air spring isolator is difficult to meet the requirements of ultra-low stiffness and high positioning accuracy of the lithography machine. The German IDE company proposed a vibration isolator technology solution that abandons the traditional rubber air spring (1. Integrated Dynamics Engineering GmbH. Isolatorgeometrie Eines Schwingungsisolationssystem. European Patent No.: EP1803965A2; 2. Integrated Dynamics Engineering GmbH. Schwingungsisolationssystem Mit Pneumatischemil. European Patent No.: filter Tiefpass EP1803970A2; 3. Integrated Dynamics Engineering GmbH. Air Bearing with Consideration of High-Frequency Resonances. US Patent Publication No.: US20080193061A1). The solution uses vertical and horizontal air bearings to decouple and isolate vibrations in all directions, which can achieve extremely low stiffness and natural frequency. The problems of this solution are: 1) In the disclosed technical solution, the vibration isolator cannot achieve precise positioning; 2) In the patent EP1803965A2, there is no degree of freedom of angular movement around the horizontal axis between the upper and lower mounting plates. The angular stiffness and natural frequency are very high; patents EP1803970A2 and US20080193061A1 use rubber blocks to provide angular freedom of rotation around the horizontal axis for the upper and lower mounting plates, but due to the high angular stiffness of the rubber blocks, the angular freedom of motion cannot be effectively achieved High degree of decoupling, there is friction between the components of the decoupling mechanism, which introduces a large additional stiffness, which restricts the natural frequency and low frequency vibration isolation performance. the

Netherlands ASML company also proposed a similar vibration isolator technical scheme (1. U.S.Philips Corp, ASM Lithography B.V. Pneumatic Support Device with A Controlled Gas Supply, and Lithographic Device Provided with Such A Support Device. U.S. Patent No.: US006144442A; 2 .Koninklijke Philips ElectronicsN.V.，ASM Lithography B.V.Lithographic Pneumatic Support Device with Controlled Gas Supply.国际专利公开号：WO99/22272；3.ASML Netherlands B.V.Support Device，LithographicApparatus，and Device Manufacturing Method Employing A Supporting Device，and A PositionControl System Arranged for Use in A Supporting Device.美国专利号：US007084956B2；4.ASML Netherlands B.V.Support Device，Lithographic Apparatus，and Device ManufacturingMethod Employing A Supporting Device and A Position Control System Arranged for Use in ASupporting Device.欧洲专利号： EP1486825A1). In patent US006144442A and WO99/22272, closed-loop feedback control is performed on the air source pressure to achieve the purpose of improving the stability and performance of the vibration isolator; in patent US007084956B2 and EP1486825A1, a vibration sensor is installed on the upper mounting plate, and a reference vibration system is introduced at the same time. The vibration isolation performance of the vibration isolator is improved through the control algorithm. However, the proposed technical solution still does not effectively solve the problem of precise positioning of the vibration isolator and decoupling of the angular motion degrees of freedom of the upper and lower mounting plates. the

Contents of the invention

The purpose of the present invention is to provide a coplanar air conditioning system for the urgent requirements of ultra-precision measuring instruments and processing equipment, especially ultra-large-scale integrated circuit processing equipment such as step-scan lithography machines, for vibration isolators with low natural frequency and high positioning accuracy. Floating orthogonal decoupling and sliding joint bearing angle decoupling magnetic levitation planar drive positioning vibration isolator, the vibration isolator has three-dimensional approximately zero stiffness and extremely low natural frequency, and can perform precise positioning and three-dimensional linear motion between the upper and lower mounting plates The decoupling of degrees of freedom and angular motion degrees of freedom can effectively solve the problem of precision vibration isolation in ultra-precision measuring instruments and processing equipment, especially in step-and-scan lithography machines. the

The purpose of the present invention is achieved like this:

A magnetic levitation planar drive positioning vibration isolator with coplanar air bearing orthogonal decoupling and sliding joint bearing angle decoupling. The main body of the isolator is installed between the upper mounting plate and the lower mounting plate, and the clean compressed air source is connected to the main body of the vibration isolator through the air pipe. The magnetic levitation gap formed by the magnetic levitation effect of the magnetic levitation bearing is carried. The piston barrel is installed in the sleeve with an inverted buckle, and is lubricated and supported with the sleeve through the radial bearing cylindrical air bearing surface. The sliding joint bearing is installed between the piston barrel and the upper mounting plate. The sleeve The cylinder and the X-direction air-floating guide rail are lubricated and guided by the air-floating surface of the X-direction guide rail. The X-direction air-flotation guide rail and the lower mounting plate are lubricated and supported by the Z-direction bearing air-floating surface. The two ends of the air bearing guide rail and the Y direction air bearing guide rail are lubricated and guided by the air bearing surface of the Y guide rail; the Z direction voice coil motor, the Z direction displacement sensor and the Z direction limit switch are installed between the piston cylinder and the sleeve, and the X direction The displacement sensor, the X-direction limit switch and the Y-direction displacement sensor and the Y-direction limit switch are installed between the sleeve and the lower mounting plate. The direction of the driving force of the Z-direction voice coil motor and the X-direction driving force and Y The direction of the driving force is perpendicular to each other, the direction of the action line of the Z-direction displacement sensor and the Z-direction limit switch is consistent with the direction of the driving force of the Z-direction voice coil motor, and the direction of the action line of the X-direction displacement sensor and X-direction limit switch is consistent with The X-direction driving force of the magnetic levitation planar motor is consistent, and the action line direction of the Y-direction displacement sensor and the Y-direction limit switch is consistent with the Y-direction driving force direction of the magnetic levitation planar motor; X, Y, Z direction displacement sensors and X, Y, Z The direction limit switches are respectively connected to the signal input terminals of the controller, the signal output terminals of the controller are connected to the signal input terminals of the driver, and the signal output terminals of the driver are respectively connected to the magnetic levitation planar motor and the Z direction voice coil motor. the

A gas pressure sensor is arranged inside the piston barrel, an air inlet and a solenoid valve are arranged on the piston barrel, the gas pressure sensor is connected to the signal input end of the controller, and the signal output end of the driver is connected to the solenoid valve. the

The configuration of the magnetic levitation planar motor is to install a magnetic levitation planar motor mover without wire connection on the side wall of the bottom surface of the sleeve, and to equip the magnetic levitation planar motor stator on the upper surface side wall of the lower mounting plate. the

The Z-direction voice coil motor is a cylindrical voice coil motor or a flat voice coil motor. the

The X-direction air-floating guide rail and the Y-direction air-floating guide rail have a single guide rail structure or a double guide rail structure. the

The X, Y, and Z direction displacement sensors are grating scales, magnetic scales, capacitive scales or linear potentiometers. the

The X-, Y-, and Z-direction limit switches are mechanical limit switches, Hall-type limit switches or photoelectric limit switches. the

The gas pressure in the piston barrel is 0.1MPa-0.8MPa. the

The magnetic suspension gap between the mover of the magnetic suspension planar motor and the stator of the magnetic suspension planar motor is 0.01 mm to 1 mm. the

The technical innovation of the present invention and the good effect produced are:

(1) The present invention abandons the traditional vibration isolator technical scheme based on elastic elements/mechanisms, adopts the magnetic levitation effect of the magnetic levitation planar motor, and the radial bearing cylinder air bearing surface to decouple and isolate the horizontal and vertical vibrations respectively, and the magnetic levitation The magnetic levitation effect of the planar motor has no friction with the air bearing surface, and the stiffness is approximately zero, which enables the vibration isolator to obtain approximately zero stiffness characteristics and outstanding ultra-low frequency vibration isolation performance, which solves the limitations of the existing technology due to structural stiffness and material properties. It is difficult to further reduce the problem that stiffness and stability cannot be balanced. This is one of the innovative points that the present invention is different from the prior art. the

(2) The present invention adopts a displacement sensor, a limit switch, a controller, a driver and a motor to form a position closed-loop feedback control system to precisely control the relative position between the upper and lower mounting plates, and the positioning accuracy can reach 10 μm level and above. The invention can effectively solve the problems of low positioning accuracy and inability to balance positioning accuracy, stiffness, and vibration isolation performance in the existing technical solutions. This is the second innovative point that the present invention is different from the prior art. the

(3) The present invention uses coplanar orthogonal air-floating guide rails and sliding joint bearings to decouple the degrees of freedom of horizontal linear motion and angular motion between the upper and lower mounting plates of the vibration isolator, and the air-floating rails have no friction and wear , the sliding joint bearing introduces a small friction force and has a large load-carrying capacity, which can fully decouple the freedom of movement between the upper and lower mounting plates, that is, the vibration isolator and the load, and effectively solve the existing elastic body decoupling. Technical solutions such as introducing larger additional stiffness, restricting natural frequency and low-frequency vibration isolation performance and other issues. This is the third innovative point that the present invention is different from the prior art. the

(4) The present invention adopts a gas pressure sensor, a solenoid valve, a controller, a driver, etc. to form a pressure closed-loop feedback control system to accurately control the gas pressure in the sleeve, and perform gravity balance and compensation for the axial load of the vibration isolator. Under the action of the air bearing surface of the bearing cylinder, the piston cylinder bearing the load gravity can slide up and down freely along the sleeve with zero stiffness, so as to achieve the ideal gravity balance and zero stiffness vibration isolation effect. This is the fourth innovative point that the present invention is different from the prior art. the

(5) The present invention uses an active actuator to actively control the relative position between the upper and lower mounting plates and the gas pressure in the piston cylinder, and the parameters of the vibration isolator can be adjusted in real time according to the characteristics of the vibration-isolated object and the change of the working environment, so that Adapt to different working conditions, with good flexibility, adaptability and stability. This is the fifth innovative point that the present invention is different from the prior art. the

Description of drawings

Fig. 1 is a schematic diagram of the structure of the magnetic levitation planar drive positioning vibration isolator with coplanar air bearing orthogonal decoupling and sliding joint bearing angle decoupling after the upper mounting plate is removed;

Fig. 2 is a schematic cross-sectional structure diagram of the magnetic levitation planar drive positioning vibration isolator with coplanar air bearing orthogonal decoupling and sliding joint bearing angle decoupling;

Figure 3 is a schematic diagram of the maglev gap, the air bearing surface of the radial bearing cylinder, the air bearing surface of the X-direction guide rail and the bearing air bearing surface of the Z direction;

Figure 4 is a schematic diagram of the Y-guided air bearing surface;

Figure 5 is a schematic diagram of the sleeve structure;

Figure 6 is a schematic structural diagram of a sliding joint bearing;

Fig. 7 is a block diagram of the control structure of the magnetic levitation plane driven positioning vibration isolator with coplanar air bearing orthogonal decoupling and sliding joint bearing angle decoupling;

Fig. 8 is a schematic diagram of the orifice on the cylindrical air bearing surface on the piston barrel. the

Part number description in the figure: 1 upper mounting plate, 2 lower mounting plate, 3 clean compressed air source, 4 vibration isolator main body, 5 piston cylinder, 6 sleeve, 7 sliding joint bearing, 7a bearing body, 7b bearing seat, 10Z Voice coil motor, 10a Z-direction motor iron yoke, 10b Z-direction motor magnetic steel, 10c Z-direction motor coil bobbin, 10d Z-direction motor coil, 10e Z-direction motor transition piece, 11X-direction displacement sensor, 11a X-direction grating reading head Transition piece, 11b X-direction grating reading head, 11c X-direction glass scale, 12Y-direction displacement sensor, 13Z-direction displacement sensor, 13a Z-direction grating reading head transition piece, 13b Z-direction grating reading head, 13c Z-direction glass scale, 14X-direction limit switch, 14a X-direction limit block, 14b X-direction Hall switch, 14c X-direction limit switch transition piece, 14d X-direction limit block transition piece, 15Y-direction limit switch, 16Z-direction limit switch, 16a Z-direction limit block, 16b Z-direction Hall switch, 16c Z-direction limit switch transition piece, 17 Gas pressure sensor, 18 Solenoid valve, 19 Controller, 20 Driver, 21 Magnetic suspension gap, 22 Radial bearing cylindrical air bearing surface , 23 air inlet, 24 maglev planar motor, 24a maglev planar motor mover, 24b maglev planar motor stator, 25 cylindrical air bearing surface throttle hole, 26 air pipe, 29X air bearing guide rail, 30Y air bearing guide rail, 31X guide rail Air bearing surface, 32Y guide rail air bearing surface, 33Z bearing air bearing surface. the

Detailed ways

Specific embodiments of the present invention are given below in conjunction with the accompanying drawings. the

A magnetically suspended plane-driven positioning vibration isolator with coplanar air bearing orthogonal decoupling and sliding joint bearing angle decoupling, consisting of an upper mounting plate 1, a lower mounting plate 2, a clean compressed air source 3, an air pipe 26 and a vibration isolator main body 4 components, the vibration isolator main body 4 is installed between the upper mounting plate 1 and the lower mounting plate 2, the clean compressed air source 3 is connected to the vibration isolator main body 4 through the air pipe 26, the structure of the vibration isolator main body 4 is: sleeve The lower surface of the cylinder 6 and the lower mounting plate 2 are carried by the magnetic suspension gap 21 formed by the magnetic suspension of the magnetic suspension plane motor 24, and the piston cylinder 5 is installed in the sleeve 6 with an undercut, and is carried by the sleeve 6 through the radial bearing cylindrical air bearing surface. 22 Lubrication and support, the sliding joint bearing 7 is installed between the piston cylinder 5 and the upper mounting plate 1, the sleeve 6 and the X-direction air bearing guide rail 29 are lubricated and guided by the X-direction guide air bearing surface 31, and the X-direction air bearing guide rail 29 and the The lower mounting plate 2 is lubricated and supported by the bearing air bearing surface 33 in the Z direction, the air bearing guide rail 30 in the Y direction is rigidly connected with the lower mounting plate 2, and the two ends of the air bearing guide rail 29 in the X direction and the air bearing guide rail 30 in the Y direction pass through the air bearing guide rail 30 in the Y direction. The floating surface 32 is lubricated and guided; the Z-direction voice coil motor 10, the Z-direction displacement sensor 13 and the Z-direction limit switch 16 are installed between the piston cylinder 5 and the sleeve 6, and the X-direction displacement sensor 11, the X-direction limit switch 14 and The Y direction displacement sensor 12 and the Y direction limit switch 15 are installed between the sleeve 6 and the lower mounting plate 2. The directions are perpendicular to each other, the direction of the action line of the Z-direction displacement sensor 13 and the Z-direction limit switch 16 is consistent with the direction of the driving force of the Z-direction voice coil motor 10, and the action line of the X-direction displacement sensor 11 and the X-direction limit switch 14 The direction is consistent with the X-direction driving force of the magnetic levitation planar motor 24, and the action line direction of the Y-direction displacement sensor 12 and the Y-direction limit switch 15 is consistent with the Y-direction drive force direction of the magnetic levitation planar motor 24; X, Y, and Z direction displacement sensors 11, 12, 13 and X, Y, Z limit switches 14, 15, 16 are connected with the signal input end of controller 19 respectively, and the signal output end of controller 19 is connected with the signal input end of driver 20, and the signal input end of driver 20 The signal output ends are respectively connected with the magnetic levitation planar motor 24 and the Z direction voice coil motor 10 . the

X, Y, and Z direction displacement sensors 11, 12, and 13 measure the displacement output by X, Y, and Z direction voice coil motors 8, 9, and 10, and X, Y, and Z direction limit switches 14, 15, and 16 are for X , Y, and Z direction voice coil motors 8,9,10 movement stroke limit; 16 feedback signals to control the X, Y, Z direction voice coil motors 8, 9, 10 to accurately control the relative position between the upper and lower mounting plates 1, 2. the

A gas pressure sensor 17 is provided in the piston barrel 5, an air inlet 23 and a solenoid valve 18 are arranged on the piston barrel 5, the gas pressure sensor 17 is connected with the signal input end of the controller 19, and the signal output end of the driver 20 is connected with the electromagnetic valve. Valve 18 is connected. the

The configuration of the magnetic levitation planar motor 24 is to install a magnetic levitation planar motor mover 24a without wire connection on the side wall of the bottom surface of the sleeve 6, and a magnetic levitation planar motor stator 24b is relatively equipped on the upper surface side wall of the lower mounting plate. the

The Z-direction voice coil motor 10 is a cylindrical voice coil motor or a flat plate voice coil motor. the

The X-direction air-floating guide rail 29 and the Y-direction air-floating guide rail 30 have a single guide rail structure or a double guide rail structure. the

The X, Y, Z direction displacement sensors 11, 12, 13 are grating scales, magnetic scales, capacitive scales or linear potentiometers. the

Described X, Y, Z direction limit switches 14,15,16 are mechanical limit switches, Hall type limit switches or photoelectric limit switches. the

The gas pressure in the piston barrel 5 is 0.1MPa-0.8MPa. the

The magnetic levitation gap 21 between the magnetic levitation planar motor mover 24a and the magnetic levitation planar motor stator 24b is 0.01mm˜1mm. the

An embodiment of the present invention is given below with reference to FIG. 1 to FIG. 5 and FIG. 7 . In this embodiment, when the vibration isolator is working, the lower mounting plate 2 is rigidly connected to the foundation, the base of the instrument or the foundation frame, etc., and the upper mounting plate 1 is rigidly connected to the load or platform. The Z-direction voice coil motor 10 adopts a cylindrical voice coil motor, which is mainly composed of a Z-direction motor iron yoke 10a, a Z-direction motor magnet 10b, a Z-direction motor coil frame 10c, and a Z-direction motor coil 10d. The Z-direction motor iron yoke 10a and the Z-direction motor bobbin 10c are cylindrical, the Z-direction motor magnet 10b is cylindrical, and the Z-direction motor coil 10d is wound on the Z-direction motor coil bobbin 10c. The Z-direction motor iron yoke 10a and the Z-direction motor magnetic steel 10b constitute the motor stator, the Z-direction motor coil frame 10c and the Z-direction motor coil 10d constitute the motor mover, and the Z-direction motor transition piece 10e provides the installation structure of the Z-direction motor coil frame 10c . When the motor is working, a current is passed through the coil. According to the electromagnetic theory, the energized coil will be affected by the Lorentz force in the magnetic field. By controlling the magnitude and direction of the current, the magnitude and direction of the motor output driving force can be controlled. the

X, Y, and Z direction displacement sensors 11, 12, 13 adopt grating rulers. Taking the Z-direction displacement sensor 13 as an example, it mainly includes a Z-direction grating reading head transition piece 13a, a Z-direction grating reading head 13b, and a Z-direction glass scale 13c. The Z-direction grating readhead transition piece 13a provides a mounting structure for the Z-direction grating readhead 13b. When the grating ruler is working, the Z-direction grating reading head 13b can detect the relative displacement between it and the Z-direction glass grating ruler 13c, and send it to the controller 19 through the signal wire. the

X, Y, Z direction limit switches 14, 15, 16 adopt Hall type limit switches. Taking the Z-direction limit switch 16 as an example, it mainly includes components such as a Z-direction limit block 16a, a Z-direction Hall switch 16b, and a Z-direction limit switch transition piece 16c. The two Z-direction Hall switches 16b are installed back to back, and the two Z-direction limit blocks 16a are made of metal materials, and are installed opposite to the sensitive end of the Z-direction Hall switch 16b. The Z-direction limit switch transition piece 16c provides a mounting structure for the Z-direction Hall switch 16b. When the limit switch is working, when the Z-direction Hall switch 16b is close to the Z-direction limit block 16a, the Z-direction Hall switch 16b gives a limit signal and sends it to the controller 19 through the signal wire. the

In this embodiment, the Z-direction voice coil motor 10 , the Z-direction displacement sensor 13 and the Z-direction limit switch 16 are installed between the piston cylinder 5 and the sleeve 6 and inside the piston cylinder 5 . the

The load bearing of the vibration isolator is realized in the following manner: the clean compressed air source 3 delivers clean compressed air to the piston cylinder 5 through the air pipe 26 , the electromagnetic valve 18 and the air inlet 23 . The controller 19 controls the opening of the solenoid valve 18 according to the feedback signal from the gas pressure sensor 17, and adjusts the gas flow rate input into the piston cylinder 5, thereby adjusting the pressure of the clean compressed air in the piston cylinder 5, so that the clean compressed air acts on the piston cylinder. 5 The upward force is balanced with the gravity of the load, the piston cylinder 5 and other parts loaded on the piston cylinder 5, so as to realize the ideal gravity compensation and zero-stiffness vibration isolation effect. the

In this embodiment, the pressure of the clean compressed air in the piston cylinder 5 is 0.4Mpa, and the effective radius of the lower surface of the piston cylinder 5 is 100mm, so the mass carried by a single vibration isolator is: m=p×πr ² /g≈1282kg, Where p is the gas pressure, p=0.4Mpa, r is the effective radius of the lower surface of the piston barrel 5, r=100mm, g is the acceleration of gravity, g=9.8m/m ² .

FIG. 2 shows an embodiment of a plain spherical plain bearing. The sliding joint bearing 7 is mainly composed of a bearing body 7a and a bearing seat 7b. The concave spherical surface on the bearing seat 7b and the convex spherical surface on the bearing body 7a form a sliding motion pair, which is lubricated by liquid or solid lubricant, and the upper and lower mounting plates The degrees of freedom of angular motion between 1 and 2 are decoupled. the

FIG. 6 shows another embodiment of the sliding spherical plain bearing. The bearing seat 7b has a convex spherical surface, which forms a sliding motion pair with the concave spherical surface on the bearing body 7a, and is lubricated with a liquid or solid lubricant, decoupling the degrees of freedom of angular motion between the upper and lower mounting plates 1, 2. the

Figure 8 shows an embodiment of the orifice on the cylindrical air bearing surface on the piston cylinder. In this embodiment, two rows of orifice holes 25 on the cylindrical air-floating surface are evenly distributed along the circumferential direction on the side wall of the piston cylinder 5, and the number of orifice holes 25 on each row of cylindrical air-floating surface is 8, with a diameter of φ0.2mm. the

Claims (9)

1. A magnetic levitation planar drive positioning vibration isolator with coplanar air bearing orthogonal decoupling and sliding joint bearing angle decoupling, consisting of an upper mounting plate (1), a lower mounting plate (2), and a clean compressed air source (3) , air pipe (26) and the main body of the vibration isolator (4), the main body of the vibration isolator (4) is installed between the upper mounting plate (1) and the lower mounting plate (2), and the clean compressed air source (3) passes through the air pipe ( 26) Connect with the main body of the vibration isolator (4), characterized in that: the structure of the main body of the vibration isolator (4) is that the lower surface of the sleeve (6) and the lower mounting plate (2) pass through the magnetic levitation plane motor (24) The magnetic levitation gap (21) formed by the magnetic levitation effect of the magnetic levitation is carried, and the piston cylinder (5) is installed in the sleeve (6) with an undercut, and is lubricated and supported with the sleeve (6) through the radial bearing cylindrical air bearing surface (22). The sliding joint bearing (7) is installed between the piston cylinder (5) and the upper mounting plate (1), the sleeve (6) and the X-direction air bearing guide rail (29) are lubricated and guided through the X guide rail air bearing surface (31), The X-direction air bearing guide rail (29) and the lower mounting plate (2) are lubricated and supported by the Z bearing air bearing surface (33), the Y-direction air bearing guide rail (30) is rigidly connected to the lower mounting plate (2), and the X-direction air bearing The two ends of the guide rail (29) and the Y-direction air-floating guide rail (30) are lubricated and guided through the Y-direction guide air-floating surface (32); the Z-direction voice coil motor (10), the Z-direction displacement sensor (13) and the Z-direction limit The switch (16) is installed between the piston barrel (5) and the sleeve (6), the X-direction displacement sensor (11), the X-direction limit switch (14) and the Y-direction displacement sensor (12), the Y-direction limit switch (15) Installed between the sleeve (6) and the lower mounting plate (2), the Z-direction of the driving force of the voice coil motor (10) and the X-direction and Y-direction of the driving force of the magnetic levitation planar motor (24) Two pairs are perpendicular to each other, the direction of the action line of the Z-direction displacement sensor (13) and the Z-direction limit switch (16) is consistent with the direction of the driving force of the Z-direction voice coil motor (10), the X-direction displacement sensor (11), the X-direction The action line direction of the limit switch (14) is consistent with the X-direction driving force of the magnetic suspension planar motor (24), and the action line direction of the Y-direction displacement sensor (12) and the Y-direction limit switch (15) is consistent with the direction of the magnetic suspension planar motor (24). ) in the same direction as the Y-direction driving force; X, Y, Z-direction displacement sensors (11, 12, 13) and X, Y, Z-direction limit switches (14, 15, 16) respectively communicate with the signals of the controller (19) The input terminal is connected, the signal output terminal of the controller (19) is connected with the signal input terminal of the driver (20), and the signal output terminal of the driver (20) is respectively connected with the magnetic levitation planar motor (24) and the Z direction voice coil motor (10) . the 2. The magnetic levitation planar driven positioning vibration isolator according to claim 1, characterized in that: the piston cylinder (5) is provided with a gas pressure sensor (17), the piston barrel (5) is provided with an air inlet (23) and a solenoid valve (18), the gas pressure sensor (17) is connected to the signal input end of the controller (19), and the signal output of the driver (20) The terminal is connected with the solenoid valve (18). the 3. The magnetic levitation planar driven positioning vibration isolator according to claim 1, characterized in that: the configuration of the magnetic levitation planar motor (24) is in A magnetic levitation planar motor mover (24a) without wire connection is installed on the bottom side wall of the sleeve (6), and a magnetic levitation planar motor stator (24b) is equipped on the upper side wall of the lower mounting plate. the 4. The magnetic levitation planar drive positioning vibration isolator with coplanar air bearing orthogonal decoupling and sliding joint bearing angle decoupling according to claim 1, characterized in that: the Z-direction voice coil motor (10) is a cylinder type voice coil motor or flat type voice coil motor. the 5. The magnetic suspension planar drive positioning vibration isolator according to claim 1, wherein the coplanar air bearing orthogonal decoupling and the sliding joint bearing angle decoupling are characterized in that: the X-direction air bearing guide rail (29) and the Y-direction The air bearing guide rail (30) is a single guide rail structure or a double guide rail structure. the 6. The magnetic levitation plane driven positioning vibration isolator according to claim 1, wherein the coplanar air bearing orthogonal decoupling and the sliding joint bearing angle decoupling are characterized in that: the X, Y, Z direction displacement sensors (11, 12, 13) are grating scale, magnetic scale, capacitive scale or linear potentiometer. the 7. The magnetic levitation plane driven positioning vibration isolator according to claim 1, wherein the coplanar air bearing orthogonal decoupling and the sliding joint bearing angle decoupling are characterized in that: the X, Y, Z direction limit switches (14 , 15, 16) are mechanical limit switches, Hall-type limit switches or photoelectric limit switches. the 8. The magnetic levitation planar driven positioning vibration isolator according to claim 1, wherein the coplanar air bearing orthogonal decoupling and the sliding joint bearing angle decoupling are characterized in that: the gas pressure in the piston barrel (5) is 0.1 MPa ~0.8 MPa. the 9. The magnetic levitation plane drive positioning vibration isolator according to claim 3, characterized in that: the magnetic levitation plane motor mover (24a) and the magnetic levitation plane The magnetic suspension gap (21) between the motor stators (24b) is 0.01mm-1mm. the

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