A flow field observation device and method for static pressure air flotation mechanism

Abstract

The present invention relates to a flow field observation device and method for a static pressure air flotation mechanism, the flow field observation device comprises a workbench, a support and a guide body; the guide body is fixed to the workbench through the support and is in a stationary state, and there is a gap between the guide body and the workbench in the vertical direction; the guide body comprises an abutment portion and a support portion, the abutment portion is used to closely adhere to a side surface of the air flotation mechanism having a throttling structure, the throttling structure is filled with a tracer medium, and the support portion and the abutment portion are arranged oppositely; an observation area connecting the support portion and the abutment portion is arranged inside the guide body, and the observation area, the support portion and the abutment portion are made of the same material and have a light transmittance greater than 85%; the present invention converts an observation channel from an air flotation slider in a dynamic process to a guide body in a stationary state, and directly observes the flow field morphology, streamline state and spatial distribution of the flow field within the air film support range under different working conditions or boundary conditions in real time through the highly transparent guide body, so as to facilitate the grasp of the air film characteristics.

Description

Technical Field

[0001] The present invention relates to the field of gas static pressure technology, and in particular to a flow field observation device and method for a static pressure air flotation mechanism. Background Art

[0002] The static pressure air flotation mechanism provides support and lubrication for the load through the static pressure air film in the gap. Due to the existence of the air film, the load does not directly contact the guide body during movement, and there is almost no friction, almost no wear, and a longer service life. In addition, due to the low viscosity coefficient of air, the friction and heat generated during movement can be effectively controlled. Based on the above advantages, the static pressure air flotation mechanism is widely used in precision moving parts in the fields of semiconductors, photolithography, and detection.

[0003] However, in closed field environments such as air bearings or air guides, due to the limitations of the space where the air film is located, the existing air flotation mechanism cannot directly observe the actual internal flow field and streamline state and change process, which directly affects the related research on the boundary condition setting of the air flotation mechanism. Summary of the invention

[0004] To this end, the technical problem to be solved by the present invention is to overcome the technical difficulty that the flow field and streamline state of the static pressure air flotation mechanism in the prior art cannot be directly observed in real time, and to provide a static pressure air flotation mechanism flow field observation device, which is convenient for real-time observation and recording of the flow field streamline morphology.

[0005] In a first aspect, in order to solve the above technical problems, the present invention provides a flow field observation device for a static pressure air flotation mechanism, which comprises:

[0006] Workbench;

[0007] A support, the support being located on the surface of the workbench;

[0008] A guide body, wherein the guide body is fixed to the support and is arranged in a stationary state, and a gap is provided between the guide body and the workbench in the vertical direction; the guide body comprises an abutment portion and a support portion, the abutment portion is used to closely adhere to a side surface of the air flotation mechanism having a throttling structure, the throttling structure is filled with a tracer medium, and the support portion is arranged opposite to the abutment portion; an observation area connecting the support portion and the abutment portion is arranged inside the guide body, and the observation area, the support portion and the abutment portion are made of the same material and have a light transmittance greater than 85%.

[0009] In one embodiment of the present invention, the guide body is configured as a prism, the axial direction of the guide body is parallel to the workbench surface, the support is supported at both ends of the axial direction of the guide body, and is staggered with the air flotation mechanism in the axial direction.

[0010] In one embodiment of the present invention, the guide body is a regular quadrangular prism, the abutment portion has two groups of side surfaces which are arranged adjacent to the guide body, and the support portion has two groups of side surfaces which are arranged adjacent to the guide body; when the guide body is fixed to the support, the abutment portion is located above the axis of the guide body, and the support portion is located below the axis and is arranged opposite to the abutment portion.

[0011] In one embodiment of the present invention, the guide body is configured as a truncated cone, and the side surface of the guide body matches the surface taper of the throttling structure of the air floating mechanism.

[0012] In one embodiment of the present invention, the guide body is configured as a plate-like structure, the abutting portion extends horizontally, and the supporting portion is configured parallel to and opposite to the abutting portion.

[0013] In one embodiment of the present invention, the guide body is configured to be single crystal optical glass.

[0014] In one embodiment of the present invention, an industrial camera is further included, and the industrial camera and the abutting portion are respectively arranged on both sides of the observation area.

[0015] In a second aspect, the present invention further provides a flow field observation method for a static pressure air flotation mechanism, which is implemented by a flow field observation device for a static pressure air flotation mechanism in any of the above embodiments, and the flow field observation method comprises:

[0016] The shape of the guide body, the position of the guide body fixed to the support, and the gap between the guide body and the workbench are set according to the appearance of the air floating mechanism and the position of the throttling structure;

[0017] Placing the air flotation mechanism on the abutment portion of the guide body, and introducing gas from an external gas source, wherein the gas includes the tracer medium;

[0018] The movement track of the tracer medium is observed and recorded on the side where the support portion is located.

[0019] In one embodiment of the present invention, the air flotation mechanism includes an air flow channel and the throttling structure, and the throttling structure includes a throttling hole and a pressure chamber; the air flow channel connects the air source and one end of the throttling hole, and the other end of the throttling hole is connected to the pressure chamber, and the extension direction of the throttling hole is perpendicular to the plane where the abutment portion is located.

[0020] In one embodiment of the present invention, the tracer medium is configured as colored smoke.

[0021] The above technical solution of the present invention has the following beneficial effects compared with the prior art:

[0022] The flow field observation device and method for a static pressure air flotation mechanism described in the present invention converts an observation channel from an air flotation slider in a dynamic process to a guide body in a static state. The guide body can be used as a guide rail, platform or air flotation bearing seat when cooperating with the air flotation mechanism. It has a flexible shape and a simple structure, and has no built-in air circuits and external pipes, which will not hinder observation. By setting a highly transparent guide body, the flow field shape, streamline state and flow field change process of the moving load supported by the air film within the air film support range under different working conditions or boundary conditions can be directly observed and recorded in real time, which is convenient for grasping the dynamic and static characteristics of the air film, and further facilitates experimental demonstration or cross-verification with numerical simulation results, thereby improving the research and development efficiency and effect of the air flotation mechanism. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below according to specific embodiments of the present invention in conjunction with the accompanying drawings, wherein:

[0024] Figure 1 This is a schematic diagram of the use of the flow field observation device for the static pressure air flotation mechanism in the first embodiment of the present invention in conjunction with the air flotation mechanism;

[0025] Figure 2 It is a structural schematic diagram of a flow field observation device for a static pressure air flotation mechanism in Embodiment 1 of the present invention;

[0026] Figure 3 It is a structural schematic diagram of a support in Embodiment 1 of the present invention;

[0027] Figure 4 This is a schematic diagram of the principle of the flow field observation device in the first embodiment of the present invention;

[0028] Figure 5 It is a structural schematic diagram of a flow field observation device for a static pressure air flotation mechanism in the second embodiment of the present invention;

[0029] Figure 6 for Figure 5 Exploded view of;

[0030] Figure 7 It is an isometric cross-sectional view of the air-floating slider in the second embodiment of the present invention;

[0031] Figure 8 This is a schematic diagram of the principle of the flow field observation device in the second embodiment of the present invention;

[0032] Fig. 9 It is a structural schematic diagram of a flow field observation device for a static pressure air flotation mechanism in Embodiment 3 of the present invention;

[0033] Fig.10 It is an isometric cross-sectional view of the air-floating slider in the third embodiment of the present invention;

[0034] Fig.11 This is a schematic diagram of the principle of the flow field observation device in the third embodiment of the present invention;

[0035] Fig.12 for Fig.11 Enlarged schematic diagram of the throttle hole and pressure chamber.

[0036] Explanation of the markings in the figure in the specification: 1. workbench surface; 11. gap; 2. support; 21. mounting groove; 3. guide body; 31. abutment portion; 32. supporting portion; 33. observation area; 4. air floating slider; 41. air flow channel; 42. throttle hole; 43. pressure chamber; 51. first surface; 52. second surface; 53. third surface; 54. fourth surface; 55. fifth surface; 56. sixth surface. DETAILED DESCRIPTION

[0037] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention. Embodiment 1

[0038] Reference Figure 1~Figure 4 As shown, embodiment 1 of the present invention provides a flow field observation device for a static pressure air flotation mechanism, which can be used to observe the flow field distribution of the air flotation mechanism in a static state, or to observe the real-time flow field state of a transparent medium flowing in the air flotation mechanism; it is convenient to set different gas boundary conditions and to cross-verify with numerical simulation results, and it can also provide demonstration and teaching diagrams for the air flotation mechanism; the flow field observation device includes a workbench, a support 2 and a guide body 3, the structure is simple and easy to implement, the imaging is clear, and the accuracy and precision are high.

[0039] Specifically, refer to Figure 2 As shown, the support 2 and the guide body 3 are both placed on the workbench, and the support 2 is placed on the workbench surface 1 and is used to support the guide body 3; preferably, the workbench surface 1 extends horizontally to ensure that the guide body 3 is placed more stably and is not easy to slip. With the support of the support 2, a certain gap 11 is provided between the guide body 3 and the workbench in the vertical direction, and the gap 11 provides an escape space for observing the flow field and streamline morphology.

[0040] Specifically, the guide body 3 includes an abutment portion 31 and a supporting portion 32, the abutment portion 31 is used to closely adhere to the side surface of the flotation mechanism having a throttling structure, the throttling structure is filled with a tracer medium, and the supporting portion 32 is arranged opposite to the abutment portion 31; an observation area 33 connecting the supporting portion 32 and the abutment portion 31 is arranged inside the guide body 3, and the observation area 33, the supporting portion 32 and the abutment portion 31 are made of the same material and are all set to highly transparent materials with a transmittance greater than 85%, so that the support portion 32 can observe the flow field state and streamline shape around the throttling structure on one side of the abutment portion 31 through the observation area 33.

[0041] It should be noted that, in a preferred embodiment of the present invention, the throttling structure includes a throttling hole 42 and a pressure chamber 43, and the air film of the flotation mechanism is formed between the pressure chamber 43 and the guide surface of the guide body 3. The pressure chamber 43 is usually located on the side surface of the flotation slider 4 that abuts against the matching mechanism such as the guide rail, platform or bearing seat, so it is difficult to observe from the outside of the flotation slider 4; limited by the spatial size of the pressure chamber 43, it is difficult to design an observation window, and thus it is impossible to obtain the morphological information of the flow field and streamlines by direct observation, and simulation can only be performed by numerical calculation. On the one hand, the boundary condition setting and grid pre-processing will have a great influence on the accuracy of the simulation results. On the other hand, the simulation results are difficult to be effectively verified by experimental data, which brings many inconveniences to related research. The inventor of this case has found that if the air-floating slider 4 is set to a high-transmittance material for observation, due to the need for driving, a plurality of air holes and air channels are usually set in the air-floating slider 4. The interface reflection in the air holes and air channels will cause light distortion, affecting the final observation result. If a color tracer medium is injected into the air path, the flow field and streamline morphology in the air film gap cannot be directly observed. Therefore, setting the air-floating slider 4 to a high-transmittance material cannot obtain real and effective flow field and streamline information.

[0042] Accordingly, in the first embodiment of the present invention, at least the observation area 33, the abutment portion 31 and the support portion 32 are provided as a guide body 3 made of a highly permeable material, and through the tracer medium in the pressure chamber 43, the flow field morphology and streamline morphology under different boundary conditions can be directly observed in real time; the guide body 3 is always in a stationary state, and the observation result is more stable and clear.

[0043] Preferably, the guide body 3 is configured as a dense solid structure, without air passages, pores or electrical settings inside, and the guide body 3 is configured as a highly transparent material to avoid the internal structure unevenly changing the refractive index of some areas, resulting in distortion of the obtained morphological information. In a preferred embodiment of the present invention, the material of the guide body 3 is configured as single crystal optical glass. Single crystal optical glass has high light transmittance, which is convenient for observing subtle morphological changes in the flow field and streamline state, and for grasping the dynamic and static characteristics of the flow field; single crystal optical glass has fewer impurities and bubbles inside, a uniform and stable structure, and a high consistency of refractive index in each area. The image will only translate without causing shape distortion, which is convenient for obtaining real and stable image information; in addition, single crystal optical glass has a strong ability to resist thermal deformation, a stable dimensional structure, and is not easily affected by changes in temperature and humidity.

[0044] Specifically, the guide body 3 is configured as a prism, the axial direction of the guide body 3 is parallel to the workbench surface 1, the support 2 is supported at both ends of the axial direction of the guide body 3, and is staggered with the air floating mechanism in the axial direction to provide avoidance for observation and avoid blocking or obstructing the line of sight.

[0045] Further, refer to Figure 2~Figure 4 As shown, in the first embodiment of the present invention, the guide body 3 is set as a regular quadrangular prism, the support 2 is provided with a mounting groove 21 matching the regular quadrangular prism, the groove walls on both sides of the mounting groove 21 are set as a "V"-shaped structure to match the adjacent side surfaces of the regular quadrangular prism, and the groove bottom of the mounting groove 21 is set as an arc surface to accommodate the side edges of the regular quadrangular prism and facilitate placement and disassembly. In other embodiments of the present invention, when the guide body 3 is set as a prism structure, the number of its sides can be set according to the actual needs of the air flotation mechanism, and is not limited thereto.

[0046] Next, the abutment portion 31 has two groups of side surfaces that are adjacent to the guide body 3, and the support portion 32 has two groups of side surfaces that are adjacent to the guide body 3; when the guide body 3 is fixed to the support 2, the abutment portion 31 is located above the axis of the guide body 3, and the support portion 32 is located below the axis and is arranged opposite to the abutment portion 31 in the vertical direction.

[0047] Continue, refer to Figure 2 and Figure 4 As shown, when the air flotation mechanism is in close contact with one set of the abutment portions 31, observation is performed through the support portion 32 on the opposite side. At this time, the observation area 33 passes through the center of the prism, and the abutment portions 31 for abutment and the support portions 32 for observation are two non-adjacent side surfaces of a regular quadrangular prism; when the air flotation mechanism is located on the first surface 51, observation is performed from the side where the second surface 52 is located, and when the air flotation mechanism is located on the third surface 53, observation is performed from the side where the fourth surface 54 is located.

[0048] Specifically, the flow field observation device also includes an industrial camera (not shown in the figure), and the industrial camera and the abutment portion 31 are respectively arranged on both sides of the observation area 33; in some embodiments, the experimenter observes and records with the naked eye, and in some embodiments, the industrial camera is set to perform image recording and dynamic analysis to facilitate comparison with numerical simulation results. Embodiment 2

[0049] The second embodiment of the present invention provides a flow field observation device for a static pressure air flotation mechanism. The flow field observation device of the second embodiment differs from that of the first embodiment only in that the structure of the air flotation mechanism and the shape of the guide body 3 are different.

[0050] Specifically, refer to Figure 5~Figure 8 As shown, in the second embodiment of the present invention, the air flotation mechanism is configured as an air flotation turntable, the guide body 3 is configured as a truncated cone structure, and the side surface of the guide body 3 matches the surface taper of the pressure chamber 43 of the air flotation mechanism; observation is performed through the side where the upper bottom surface or the lower bottom surface of the truncated cone structure is located. Embodiment 3

[0051] Embodiment 3 of the present invention provides a flow field observation device for a static pressure air flotation mechanism. The flow field observation device of Embodiment 3 differs from Embodiments 1 and 2 only in that the specific structure of the air flotation mechanism and the shape of the guide body 3 are different.

[0052] Specifically, refer to Figure 9~Figure 12 As shown, the guide body 3 is configured as a plate-like structure and has a fifth surface 55 and a sixth surface 56 that are arranged parallel and opposite to each other in the thickness direction; preferably, the thickness direction is parallel to the vertical direction, the fifth surface 55 is configured as the abutment portion 31 and extends horizontally, and the sixth surface 56 is configured as the support portion 32 for observation; in other embodiments, the placement of the plate-like structure can be set according to the actual needs of the air flotation mechanism, but the extension direction of the observation area 33 is still consistent with the thickness direction of the plate-like structure and is perpendicular to the abutment portion 31. Embodiment 4

[0053] A fourth embodiment of the present invention provides a flow field observation method for a static pressure air flotation mechanism, which is implemented by a flow field observation device for a static pressure air flotation mechanism in any of the above embodiments.

[0054] Reference Figure 7 , Figure 10~Figure 12As shown, the air flotation mechanism includes an air flow channel 41 and a throttling structure. In the first, second and third embodiments of the present invention, the throttling structure is preferably configured as the throttling hole 42 and the pressure chamber 43; the air flow channel 41 connects the air source and one end of the throttling hole 42, and the other end of the throttling hole 42 connects to the pressure chamber 43. The extension direction of the throttling hole 42 is perpendicular to the plane where the abutment portion 31 is located to form an air film. In other embodiments of the present invention, the throttling structure can also be configured in various forms such as a pressure equalizing groove, a slit, two relative planes and pits on their inner surfaces, and is not limited to the throttling structure in which the throttling hole is connected to the pressure chamber; when the throttling structure is configured as a structure other than the pressure chamber 43, the observation purpose can still be achieved through the guide body.

[0055] In the fourth embodiment of the present invention, the throttling structure takes the throttling hole 42 and the pressure chamber 43 as an example, wherein the pressure chamber 43 can be set as a cylindrical chamber as shown in embodiments one to three, or can be set as a rectangular chamber, a hemispherical chamber or a diamond chamber and other structures, but is not limited thereto.

[0056] Next, the gas enters the pressure chamber 43 through the throttle hole 42 with an extremely fine aperture, and forms a pressure air film between the abutment portion 31 and the cavity wall of the pressure chamber 43; in some embodiments, the aperture of the throttle hole 42 can be set to 0.15mm, and when the pressure chamber 43 is set to a cylindrical cavity, its generatrix length is 0.3mm~0.5mm, and its cross-sectional diameter is 5mm; after the gas enters the pressure chamber 43, a good air film gap is established after preloading by the gravity or additional magnetic force of the moving load of the air floating mechanism, or additional vacuum suction, thereby providing better thrust and stable stiffness in a basically frictionless state, thereby achieving smooth movement of the load.

[0057] Next, in order to explore the influence of different loads and boundary conditions generated by different air source pressures on the streamlines and flow field morphology in the air film formed in the pressure chamber 43, as well as the thrust of the air-floating slider 4, avoid air hammer vibration, and improve boundary conditions to obtain the optimal air film thrust and stiffness, it is necessary to observe the flow field morphology and streamline morphology.

[0058] The flow field observation method comprises:

[0059] The shape of the guide body 3, the position of the guide body 3 fixed to the support 2, and the gap 11 between the guide body 3 and the workbench are set according to the appearance of the air floating mechanism and the position of the pressure chamber 43; when the air floating mechanism includes a group of air floating sliders 4, the plate-shaped guide body 3 provided in the third embodiment can be set and placed horizontally; when the air floating mechanism includes multiple groups of air floating sliders 4, the prismatic guide body 3 provided in the first embodiment can be set to achieve simultaneous observation of the states of multiple groups of pressure chambers 43; when the pressure chamber 43 of the air floating mechanism is arranged in a surrounding manner, the truncated cone structure guide body 3 provided in the second embodiment can be set. Single crystal optical glass can be used as a guide body 3 of the air floating mechanism in various forms such as a guide rail, a support platform, and a bearing seat.

[0060] The air flotation mechanism is placed close to the abutment portion 31 of the guide body 3, and an external air source is connected to introduce gas, the gas includes the tracer medium. Preferably, the tracer medium is set as colored smoke, and the colored smoke includes particles with higher opacity. Compared with transparent gas, it can display the flow characteristics more clearly and intuitively, which is convenient for observation.

[0061] The movement trajectory of the tracer medium is observed and recorded by a manual or industrial camera on the side where the support portion 32 is located. The obtained flow field information results can be used as a teaching demonstration or compared with the fluid simulation results obtained by numerical calculation to improve boundary conditions and enhance the research and development efficiency and effect of the flotation mechanism.

[0062] Obviously, the above embodiments are merely examples for the purpose of clear explanation and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the present invention.

Claims

1. A flow field observation device for a static pressure air flotation mechanism, characterized in that: include, Workbench; A support, the support being located on the surface of the workbench; A guide body, wherein the guide body is fixed to the support and is arranged in a stationary state, and a gap is provided between the guide body and the workbench in the vertical direction; the guide body comprises an abutment portion and a support portion, the abutment portion is used to closely adhere to a side surface of the air flotation mechanism having a throttling structure, the throttling structure is filled with a tracer medium, and the support portion is arranged opposite to the abutment portion; an observation area connecting the support portion and the abutment portion is arranged inside the guide body, and the observation area, the support portion and the abutment portion are made of the same material and have a light transmittance greater than 85%.

2. The flow field observation device for a static pressure air flotation mechanism according to claim 1, characterized in that: The guide body is configured as a prism, the axial direction of the guide body is parallel to the surface of the workbench, the support is supported at both ends of the axial direction of the guide body, and is staggered with the air floating mechanism in the axial direction.

3. The flow field observation device for a static pressure air flotation mechanism according to claim 2, characterized in that: The guide body is a regular quadrangular prism, the abutment portion has two groups of side surfaces which are arranged adjacent to the guide body, and the support portion has two groups of side surfaces which are arranged adjacent to the guide body; when the guide body is fixed to the support, the abutment portion is located above the axis of the guide body, and the support portion is located below the axis and is arranged opposite to the abutment portion.

4. The flow field observation device for a static pressure air flotation mechanism according to claim 1, characterized in that: The guide body is configured as a truncated cone, and the side surface of the guide body matches the surface taper of the throttling structure of the air floating mechanism.

5. The flow field observation device for a static pressure air flotation mechanism according to claim 1, characterized in that: The guide body is configured as a plate-shaped structure, the abutting portion extends horizontally, and the supporting portion is configured parallel to and opposite to the abutting portion.

6. The flow field observation device for a static pressure air flotation mechanism according to any one of claims 1 to 5, characterized in that: The guide body is configured to be single crystal optical glass.

7. The flow field observation device for a static pressure air flotation mechanism according to claim 1, characterized in that: It also includes an industrial camera, and the industrial camera and the abutment portion are respectively arranged on both sides of the observation area.

8. A flow field observation method for a static pressure air flotation mechanism, implemented by the flow field observation device for a static pressure air flotation mechanism according to any one of claims 1 to 7, characterized in that: The flow field observation method comprises: The shape of the guide body, the position of the guide body fixed to the support, and the gap between the guide body and the workbench are set according to the appearance of the air floating mechanism and the position of the throttling structure; Placing the air flotation mechanism on the abutment portion of the guide body, and introducing gas from an external gas source, wherein the gas includes the tracer medium; The movement track of the tracer medium is observed and recorded on the side where the support portion is located.

9. The flow field observation method for a static pressure air flotation mechanism according to claim 8, characterized in that: The air flotation mechanism includes an air flow channel and a throttling structure, and the throttling structure includes a throttling hole and a pressure chamber; the air flow channel connects the air source and one end of the throttling hole, and the other end of the throttling hole connects to the pressure chamber, and the extension direction of the throttling hole is perpendicular to the plane where the abutment portion is located.

10. The flow field observation method for a static pressure air flotation mechanism according to claim 8, characterized in that: The tracer medium is configured as colored smoke.

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