An air flotation device

Abstract

An air flotation device of the present invention relates to the technical field of air flotation support, and aims to overcome the problem of insufficient static and dynamic performance of existing air static pressure bearings, comprising a base platform and an air flotation bearing; the base platform is located at the air film generating surface of the air flotation bearing; the air flotation bearing comprises a sliding block, a plurality of first throttles, a first high-pressure gas pipeline and a suction regulating device; the plurality of first throttles are fixed inside the sliding block, and the plurality of first throttles are centrally symmetrically arranged with the center point of the air film generating surface as the symmetrical point; the first high-pressure gas pipeline is arranged inside the sliding block; and one end of the first high-pressure gas pipeline is connected to the air inlet end of the throttle pipeline of all the first throttles, and the other end is used to introduce the first high-pressure gas; the pressure chambers of the plurality of first throttles are all arranged on the air film generating surface and connected to the outside of the sliding block; the suction regulating device is arranged on the air flotation bearing, and is used to generate suction between the air flotation bearing and the base platform.

Description

Technical Field

[0001] The invention belongs to the technical field of air floating support, and in particular relates to an air floating device for intelligent control and measurement. Background Art

[0002] Air-floating hydrostatic bearings have the advantages of high precision, no friction, cleanliness and no pollution, and are widely used in ultra-precision machine tools, photolithography machines and other precision instruments and manufacturing fields.

[0003] Due to its unique advantages of low friction and small temperature rise, it greatly reduces the errors caused by friction, heat and deformation between moving parts, and realizes the improvement of the accuracy of the motion mechanism from the micron level to the nanometer level. It has become the mainstream support method for precision and ultra-precision machining equipment.

[0004] When the thickness of the working air film of the air static pressure bearing reaches several microns, the gas flow pattern in the air film changes, and the load-bearing capacity, stiffness and stability of the air bearing change accordingly. The vibration caused by the internal gas flow of the air static pressure bearing cannot be ignored, and the air floating preload problem has always restricted the high-speed motion process of the air floating bearing. Therefore, the static and dynamic performance of the existing air static pressure bearing has always restricted the further improvement and development of the bearing. Summary of the invention

[0005] In order to solve the problems existing in the above background technology, the present invention discloses an air flotation device which overcomes the problem of insufficient static and dynamic performance of the existing air static pressure bearing.

[0006] The technical solution adopted by the present invention to solve its technical problems is: an air flotation device, including an air flotation bearing and a base platform arranged relatively to each other up and down; a throttle structure is arranged in the air flotation bearing, and high-pressure gas provided by the air source passes through the throttle structure to form an air film between the air flotation bearing and the base platform; a suction adjustment structure is arranged on the air flotation bearing, and the thickness of the air film is adjusted by the suction adjustment structure.

[0007] The air bearing includes a rectangular block-shaped sliding block, and a throttle structure and a suction adjustment structure arranged on the sliding block. The air outlet end of the throttle structure passes through the working surface of the sliding block toward the base platform, and the air inlet end of the throttle structure is connected to an air source. The air source provides high-pressure gas to pass through the throttle structure to form an air film between the sliding block and the air bearing. The suction adjustment structure includes a pneumatic component and a magnetic component. The pneumatic component and the magnetic component work together to adjust the thickness of the air film, thereby adjusting the suction generated between the air bearing and the base platform.

[0008] Beneficial effects of the present invention: The present invention effectively controls the working air film thickness of the air bearing by adding a suction regulating device, and can actively improve the static and dynamic characteristics of the air bearing. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] In the attached picture:

[0010] Figure 1 It is a schematic diagram of the bottom surface structure of the air bearing of the present invention;

[0011] Figure 2 yes Figure 1 The middle air membrane is a schematic diagram of the AA cross-sectional structure of the small air membrane;

[0012] Figure 3 yes Figure 1 The middle air membrane is a schematic diagram of the cross-sectional structure of the large air membrane in the BB direction;

[0013] Figure 4 yes Figure 1 The middle air membrane is a schematic diagram of the CC section structure of the large air membrane;

[0014] Figure 5 yes Figure 1 The middle air membrane is a schematic diagram of the DD-direction cross-sectional structure of the large air membrane. DETAILED DESCRIPTION

[0015] The present invention is now described in further detail with reference to the accompanying drawings. The accompanying drawings are simplified schematic diagrams, which only illustrate the basic structure of the present invention in a schematic manner, and therefore only show the components related to the present invention.

[0016] An air flotation device comprises an air flotation bearing 2 and a base platform 1 which are arranged relatively to each other up and down; a throttle structure is arranged inside the air flotation bearing 2, and high-pressure gas provided by an air source passes through the throttle structure to form an air film 7 between the air flotation bearing 2 and the base platform 1; a suction adjustment structure is arranged on the air flotation bearing 2, and the thickness of the air film 7 is adjusted by the suction adjustment structure.

[0017] The air-floating bearing 2 includes a rectangular block-shaped sliding block body 2-1, and a throttle structure and a suction adjustment structure arranged on the sliding block body 2-1. The air outlet end of the throttle structure passes through the working surface of the sliding block body 2-1 facing the base platform 1, and the air inlet end of the throttle structure is connected to the air source. The air source provides high-pressure gas through the throttle structure to form an air film 7 between the sliding block body 2-1 and the air-floating bearing 2. The suction adjustment structure includes a pneumatic component and a magnetic component. The pneumatic component and the magnetic component work together to adjust the thickness of the air film 7, thereby adjusting the suction generated between the air-floating bearing 2 and the base platform 1.

[0018] A plurality of groups of throttle structures 1 are arranged inside the sliding block 2-1, and each group of the throttle structures 1 includes a first high-pressure gas pipeline 2-3 and n first throttles 2-2; the air inlet end of the first high-pressure gas pipeline 2-3 is ventilated with the gas source, and n first throttles 2-2 are arranged on the first high-pressure gas pipeline 2-3, where n is an even number greater than 0, and the air outlet end of each first throttle 2-2 is provided with a first pressure chamber on the working surface of the sliding block 2-1, and the air-floating bearing 2 can move horizontally on the base platform 1, and the vertical micro-motion height of the air-floating bearing 2 can be controlled by the first throttle 2-2 and the suction adjustment structure. The suction adjustment structure is introduced to effectively balance the air-floating bearing 2, and the static characteristics of the air-floating bearing 2 can be effectively improved by the suction adjustment structure.

[0019] A plurality of groups of compensating throttle structures 2 are also arranged inside the sliding block body 2-1, and each group of the throttle structures 2 includes a second high-pressure gas pipeline 2-5 and m second throttles 2-4; the air inlet end of the second high-pressure gas pipeline 2-5 is ventilated to the gas source, and m second throttles 2-4 are arranged on the second high-pressure gas pipeline 2-5, and the air outlet end of each second throttle 2-4 is provided with a second pressure chamber on the working surface of the sliding block body 2-1. Specifically, on the basis of the existing air-floating bearing 2, the performance of the air-floating bearing 2 can be improved by using the second throttle 2-4 as a compensating throttle.

[0020] Multiple first throttles 2-2 are symmetrically distributed about the center line of the front-to-back direction of the working surface of the sliding block body 2-1, and multiple second throttles 2-4 are symmetrically distributed about the center line of the front-to-back direction of the working surface of the sliding block body 2-1. A pressure equalizing groove 6 is provided at each of the first pressure chamber and the second pressure chamber.

[0021] The first throttles 2-2 or the second throttles 2-4 in the same arrangement position in the multiple groups of throttle structures 1 or throttle structures 2 are located on the same straight line, that is, multiple rows of pressure equalizing grooves 6 are formed on the working surface of the sliding block 2-1, such as Figure 1 As shown, from left to right in the figure there are six rows of pressure equalizing tanks 6 numbered one to six, wherein the first, third, fourth and sixth rows of pressure equalizing tanks 6 are connected to the first throttle 2-2, wherein the second and fifth rows of pressure equalizing tanks 6 are connected to the second throttle 2-4.

[0022] During use, the first high-pressure gas pipeline 2-3 or the second high-pressure gas pipeline 2-5 can be supplied with gas independently, so that multiple groups of throttle structures do not work at the same time. Among them, the throttle structure 1 is used first, that is, the first high-pressure gas pipeline 2-3 is supplied with gas first to ensure the rigidity of the air-floating bearing 2. When higher rigidity or load is required, the throttle structure 2 is activated, that is, the second high-pressure gas pipeline 2-5 is supplied with gas. That is, under normal working conditions, the gas source always passes through the first high-pressure gas pipeline 2-3 to the first throttle 2-2 and maintains high-pressure gas. When compensation gas is needed, the second throttle 2-4 is activated.

[0023] The pneumatic components of the suction adjustment structure include a vacuum adsorption chamber 3-1-1 and a vacuum adsorption pipe 3-1-2; a plurality of the vacuum adsorption chambers 3-1-1 are arranged on the working surface of the sliding block 2-1, and the plurality of vacuum adsorption chambers 3-1-1 are symmetrically distributed about the center line of the front-back direction of the working surface of the sliding block 2-1; a plurality of branches are arranged at one end of the vacuum adsorption pipe 3-1-2, and the plurality of branches are respectively connected to the plurality of vacuum adsorption chambers 3-1-1; the other end of the vacuum adsorption pipe 3-1-2 is connected to an exhaust device,

[0024] The vacuum device operates to suck the gas constituting the air film 7 through the vacuum adsorption tube 3-1-2 and the vacuum adsorption chamber 3-1-1, and indirectly controls the thickness of the air film 7 by controlling the vacuum adsorption flow rate of the vacuum adsorption chamber 3-1-1.

[0025] When it is necessary to actively control the thickness of the air film 7 of the air floating bearing 2, if the thickness of the air film 7 needs to be changed, the air supply pressure of the first throttle 2-2 can be changed, the air supply of the second throttle 2-4 can be introduced as secondary compensation, and the suction generated by the pneumatic components of the suction regulating structure can be changed, so that the air floating bearing 2 can reach the required thickness of the air film 7.

[0026] Vacuum adsorption can reduce the thickness of the air film 7. When the pressure of the high-pressure gas entering the first throttle 2-2 and / or the second throttle 2-4 and the vacuum adsorption force are balanced, a relatively stable high-pressure air film 7 can be achieved. If the thickness of the air film 7 needs to be changed, the supply pressure of the high-pressure gas of the first throttle 2-2 and / or the second throttle 2-4 and the vacuum adsorption force can be changed to balance the applied force again.

[0027] A magnetic conductive layer 4 is provided on one side of the base platform 1 facing the air bearing 2, and the magnetic components of the magnetic force regulating structure include a plurality of electromagnetic blocks 3-2; the plurality of electromagnetic blocks 3-2 are fixedly arranged on the working surface of the sliding block 2-1, and the plurality of electromagnetic blocks 3-2 are also symmetrically distributed about the center line of the front-to-back direction of the working surface of the sliding block 2-1, and the plurality of electromagnetic blocks 3-2 can adsorb the magnetic conductive layer 4 when energized, and the electromagnetic blocks 3-2 generate adjustable electromagnetic force to adsorb the magnetic conductive layer 4 when energized.

[0028] The electromagnetic block 3-2 can reduce the thickness of the air film 7 through electromagnetic force. When the pressure of the high-pressure gas, the vacuum adsorption force and the electromagnetic force of the electromagnetic block 3-2 are balanced, a relatively stable high-pressure air film 7 can be achieved. If the thickness of the air film 7 needs to be changed, the gas supply pressure, vacuum adsorption pressure and / or magnetic force of the first throttle 2-2 and / or the second throttle 2-4 can be changed to balance the force again.

[0029] The air flotation device also includes two displacement detection devices 5; the two displacement detection devices 5 are fixedly mounted on the bottom surface of the sliding block 2-1 and arranged on the left and right center lines of the working surface of the sliding block 2-1. The layout of the displacement detection device 5 is mainly responsible for real-time monitoring of the thickness of the air film 7.

[0030] The first throttle 2-2 is composed of the first throttle airflow pipeline 2-2-3, the first throttle throttling hole 2-2-2 and the first throttle pressure chamber 2-2-1 in sequence along the gas flow direction. The air inlet end of the first throttle airflow pipeline 2-2-3 is ventilated and connected to the first high-pressure gas pipeline 2-3. The air outlet end of the first throttle airflow pipeline 2-2-3 is connected to the first throttle pressure chamber 2-2-1 by setting the first throttle throttling hole 2-2-2 with a reduced radial size. The first throttle pressure chamber 2-2-1 is transitionally connected to the pressure equalizing groove 6. The structural composition of each of the second throttles 2-4 is the same as that of the first throttle 2-2.

[0031] As the instruction manual Figures 1 to 5 As shown, in this embodiment, the number of first throttles 2-2 is 12, the number of second throttles 2-4 is 6, the number of vacuum adsorption chambers 3-1-1 is 6, and the number of electromagnetic blocks 3-2 is 8. The first throttles 2-2, the second throttles 2-4, the vacuum adsorption chambers 3-1-1 and the electromagnetic blocks 3-2 are symmetrically distributed on both sides of a center line of the working surface.

[0032] Working principle:

[0033] The working surface of the air bearing 2 is provided with six rows of throttles (the first throttle 22 and the second throttle 24). The high-pressure gas provided by the gas source is passed from the gas inlet through the first high-pressure gas pipeline 23 and the second high-pressure gas pipeline 25 to the throttle structure of the air bearing 2. The gas flows into the pressure chamber through the throttling holes and forms a high-pressure gas film 7 with the upper end surface of the base platform 1.

[0034] The air bearing 2 is introduced with high-pressure gas through the air source to form a layer of high-pressure air film 7 with bearing capacity with the base platform 1, so that the bottom surface of the air bearing 2 has an upward pressure, and the air bearing 2 is provided with an array of electromagnetic blocks 32, which are attracted to the magnetic conductive layer 4 at the upper end of the base platform 1 to reduce the thickness of the air film 7 in real time. In addition, the addition of a vacuum adsorption component can also achieve the effect of reducing the thickness of the air film 7.

[0035] The pressure of the high-pressure gas passing through the first throttle 22 and the second throttle 24, the electromagnetic force of the electromagnetic block 32, and the vacuum adsorption force of the vacuum adsorption component are balanced, and the thickness of the air film 7 is fixed. If the thickness of the air film 7 needs to be changed, the force can be balanced again by changing the gas supply pressure of the first throttle 22 and / or the second throttle 24, the magnetic force of the electromagnetic block 32, and / or the adsorption pressure of the vacuum adsorption component, so as to achieve a relatively stable high-pressure air film 7.

[0036] Working process 1: When it is necessary to actively control the thickness of the air film 7 of the air-floating bearing 2, if it is necessary to increase the thickness of the air film 7, the air supply pressure of the first throttle 22, the secondary compensation air supply pressure of the second throttle 24, the vacuum adsorption force of the vacuum adsorption component, and the current of the electromagnetic block 32 can be increased, so that the air-floating bearing 2 reaches the required thickness of the air film 7; conversely, if it is necessary to reduce the thickness of the air film 7, the air supply pressure of the first throttle 22 can be reduced, the secondary compensation air supply of the second throttle 24 can be closed, the vacuum adsorption force of the vacuum adsorption component can be reduced or closed, and the current of the electromagnetic block 32 can be increased. Figure 2 and Figure 3 The figure shows the change of the thickness of the air film. Specifically, when the thickness of the air film 7 of the air bearing 2 needs to be actively controlled, the electromagnetic block 32, the vacuum adsorption component and the second throttle 24 can be introduced, and any combination can ultimately achieve a suitable and stable thickness of the air film 7. Compared with the air bearing 2 structure without active control, the characteristics of the air bearing 2 in the present invention will change with the change of the thickness of the air film 7, and ultimately achieve the desired air film characteristics.

[0037] Working process 2: When it is necessary to actively control the horizontal movement of the air bearing 2, it is necessary to drive the air bearing 2 to slide on the base platform 1. Since the magnetic conductive layer 4 is evenly arranged on the upper end of the base platform 1, it is only necessary to drive the air bearing 2 to satisfy the control of the static and dynamic characteristics of the air bearing 2 during the movement. In addition, through the two displacement detection devices 5 on the bottom surface of the air bearing 2, the thickness of the air film 7 can be monitored in real time.

[0038] The present invention effectively improves the static and dynamic characteristics of the air bearing 2 and expands the application field of the air bearing 2 by introducing dual air supply (the first throttle 22 and the second throttle 24 ), the vacuum adsorption component and the electromagnetic block 32 .

[0039] When the compressed gas flows into the throttle through the small hole, it fills the entire bearing gap and finally flows into the atmosphere from the outlet. Due to the sudden change in the size of the flow channel inside the throttle, the gas flow rate increases rapidly. Due to the friction of the fluid in the pipeline, its kinetic energy is converted into internal energy, making the pressure at the outlet less than the pressure at the inlet. When the air static pressure bearing is subjected to a vertical downward force, due to the compressibility of the gas, the bearing will move downward for a distance. At this time, the thickness of the air film 7 becomes smaller, and the bearing capacity and stiffness of the air film 7 also increase accordingly. Therefore, based on the current technology and methods, the magnetic mixing method can effectively control the thickness of the air film in real time and improve the static and dynamic characteristics of the air floating bearing 2.

[0040] It is to be understood that the present invention is described by some embodiments, and it is known to those skilled in the art that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention. In addition, under the teachings of the present invention, these features and embodiments may be modified to adapt to specific circumstances and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the scope of protection of the present invention.

Claims

1. An air flotation device, characterized in that: The invention comprises an air-floating bearing (2) and a base platform (1) which are arranged opposite to each other in the upper and lower parts; a throttle structure is arranged in the air-floating bearing (2); high-pressure gas provided by an air source passes through the throttle structure to form an air film (7) between the air-floating bearing (2) and the base platform (1); a suction force regulating structure is arranged on the air-floating bearing (2); the thickness of the air film (7) is regulated by the suction force regulating structure; the air-floating bearing (2) comprises a rectangular block-shaped sliding block (2-1), and the throttle structure and the suction force regulating structure are arranged on the sliding block (2-1); The invention relates to a force regulating structure, wherein the air outlet end of the throttle structure is connected to the working surface of the sliding block (2-1) facing the base platform (1), and the air inlet end of the throttle structure is connected to the gas source. The gas source provides high-pressure gas to pass through the throttle structure to form an air film (7) between the sliding block (2-1) and the air bearing (2). The suction force regulating structure comprises a pneumatic component and a magnetic component. The pneumatic component and the magnetic component cooperate to adjust the thickness of the air film (7), thereby adjusting the suction force generated between the air bearing (2) and the base platform (1).

2. An air flotation device according to claim 1, characterized in that: A plurality of groups of throttle structures (1) are arranged inside the sliding block body (2-1), and each group of the throttle structures (1) comprises a first high-pressure gas pipeline (2-3) and n first throttles (2-2); an air inlet end of the first high-pressure gas pipeline (2-3) is ventilatedly connected to a gas source, and n first throttles (2-2) are ventilatedly arranged on the first high-pressure gas pipeline (2-3), and a first pressure chamber is provided at an air outlet end of each of the first throttles (2-2) on a working surface of the sliding block body (2-1).

3. An air flotation device according to claim 2, characterized in that: A plurality of groups of throttle structures 2 for compensating purposes are also arranged inside the sliding block body (2-1), and each group of the throttle structures 2 comprises a second high-pressure gas pipeline (2-5) and m second throttles (2-4); the air inlet end of the second high-pressure gas pipeline (2-5) is ventilated to a gas source, and m second throttles (2-4) are arranged on the second high-pressure gas pipeline (2-5), and the air outlet end of each second throttle (2-4) is provided with a second pressure chamber on the working surface of the sliding block body (2-1).

4. An air flotation device according to claim 3, characterized in that: A plurality of first throttles (2-2) are symmetrically distributed about the front-to-back center line of the working surface of the sliding block body (2-1), a plurality of second throttles (2-4) are symmetrically distributed about the front-to-back center line of the working surface of the sliding block body (2-1), and each of the first pressure chamber and the second pressure chamber is provided with a pressure equalizing groove (6).

5. An air flotation device according to claim 1 or 4, characterized in that: The pneumatic component of the suction force regulating structure comprises a vacuum adsorption chamber (3-1-1) and a vacuum adsorption pipe (3-1-2); a plurality of the vacuum adsorption chambers (3-1-1) are arranged on the working surface of the sliding block body (2-1), and the plurality of vacuum adsorption chambers (3-1-1) are symmetrically distributed about the center line of the front-rear direction of the working surface of the sliding block body (2-1); a plurality of branches are arranged at one end of the vacuum adsorption pipe (3-1-2), and the plurality of branches are respectively connected to the plurality of vacuum adsorption chambers (3-1-1); and a vacuum device is connected to the other end of the vacuum adsorption pipe (3-1-2).

6. An air flotation device according to claim 5, characterized in that: A magnetic conductive layer (4) is provided on one side of the base platform (1) facing the air bearing (2); the magnetic component of the magnetic force regulating structure comprises a plurality of electromagnetic blocks (3-2); the plurality of electromagnetic blocks (3-2) are fixedly arranged on the working surface of the sliding block (2-1); the plurality of electromagnetic blocks (3-2) are also symmetrically distributed about the front-rear center line of the working surface of the sliding block (2-1); and the plurality of electromagnetic blocks (3-2) can adsorb the magnetic conductive layer (4) when energized.

7. An air flotation device according to claim 1 or 6, characterized in that: The air flotation device also includes two displacement detection devices (5); the two displacement detection devices (5) are fixedly mounted on the bottom surface of the sliding block (2-1) and arranged on the left-right center line of the working surface of the sliding block (2-1).

8. An air flotation device according to claim 4 or 7, characterized in that: The first throttle (2-2) comprises a first throttle airflow pipeline (2-2-3), a first throttle throttling hole (2-2-2) and a first throttle pressure chamber (2-2-1) in sequence along the gas flow direction; the air inlet end of the first throttle airflow pipeline (2-2-3) is ventilated and connected to the first high-pressure gas pipeline (2-3); the air outlet end of the first throttle airflow pipeline (2-2-3) is connected to the first throttle pressure chamber (2-2-1) by providing a first throttle throttling hole (2-2-2) with a reduced radial size; the first throttle pressure chamber (2-2-1) is transitionally connected to the pressure equalizing groove (6); and the structural structure of each second throttle (2-4) is the same as that of the first throttle (2-2).

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