Turntable mechanism

Abstract

The present invention relates to a turntable mechanism, comprising a flat plate and a rotating device for driving the flat plate to rotate, wherein the flat plate rotates to generate negative pressure between the lower surface of the flat plate and the surface of the adsorbed object, and the flat plate and the adsorbed object are adsorbed together by the adsorption force generated by the negative pressure, and at this time, a gap is left between the lower surface of the flat plate and the surface of the adsorbed object. The present invention forms a continuous, consistent, and stable fluid film between the rotating flat plate and the adsorbed object, and is not prone to secondary flow, so that the adsorption force between the rotating flat plate and the adsorbed object is more stable.

Description

Technical Field

[0001] The present invention relates to the technical field of negative pressure adsorption, and in particular to a turntable mechanism. Background Art

[0002] Adsorption technology is a widely used basic technology. A typical application scenario is to adsorb and move workpieces on an automated production line. For example, the patent with application number CN201310366707.X discloses an object adsorption device, which has a shell with fan blades arranged inside the shell. The motor drives the fan blades to rotate, forming a rotating airflow inside the shell. Under the action of the centrifugal force of the rotating airflow, a concave negative pressure distribution is formed inside the shell. Therefore, the device can suck up the workpiece. The patent with application number JP2009298331A discloses a contactless adsorption device, which adds an air suction hole on the shell, inhales air and discharges air from the lower end surface of the shell, so that the workpiece can be adsorbed and a certain distance is maintained with the workpiece, thereby realizing contactless adsorption. However, the above two patented technologies have the following defects:

[0003] (1) The rotating airflow formed by the fan blades driving the air is a discontinuous rotating airflow. Figure 1 As shown in the (top view cross-sectional view), the fan blade 1' rotates counterclockwise in the shell 2'. In the circumferential direction, there is a significant velocity gradient in the air speed between the two fan blades 1', that is, the air next to the A surface of the fan blade maintains the same speed as the fan blade. However, the air between the A surface and the B surface is not directly driven by the fan blades. At the same time, it is also slowed down by the viscosity of the stationary wall surface C of the shell 2', which causes the rotation speed of the air to gradually decrease from the A surface to the B surface. The inconsistent speed inside the rotating airflow causes the negative pressure at the same radius to change in the rotation direction. Therefore, as the fan blade 1' rotates, the suction force on any area of ​​the workpiece surface fluctuates periodically, which brings about serious vibration problems.

[0004] (2) Surface A, surface B, surface C, the top surface of the housing 2' and the surface of the object to be adsorbed ( Figure 1 The space is composed of multiple surfaces, including two moving surfaces (surface A and surface B) and three fixed surfaces (surface C, the top surface of the shell 2' and the surface of the adsorbed object). For the air in the space, this is a complex multi-interface constrained flow. Such a flow is very likely to form a secondary flow. The secondary flow will weaken the rotational flow, thereby weakening the negative pressure distribution and reducing the adsorption force. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a turntable mechanism, which forms a continuous, consistent and stable fluid film between the turntable and the adsorbed object, is not easy to generate secondary flow, and makes the adsorption force between the turntable and the adsorbed object more stable.

[0006] The present invention is implemented in this way. A turntable mechanism is provided, including a flat plate and a rotating device driving the flat plate to rotate. The rotation of the flat plate generates negative pressure between the lower surface of the flat plate and the surface of the adsorbed object. The flat plate and the adsorbed object are adsorbed together by the adsorption force generated by the negative pressure. At this time, a gap is left between the lower surface of the flat plate and the surface of the adsorbed object.

[0007] Furthermore, the turntable mechanism also includes a push rod, which is connected and fixed to the rotating device through a connecting piece. The front end of the push rod extends to the surface of the adsorption object and contacts the surface of the object, so that a gap is maintained between the lower surface of the plate and the surface of the adsorption object.

[0008] Furthermore, a height adjustment device is provided on the push rod, and the height adjustment device can adjust the extension position of the front end of the push rod, thereby adjusting the gap size between the lower surface of the flat plate and the surface of the adsorption object.

[0009] Furthermore, the height adjustment device is a push rod device, which is connected and fixed to the rotating device. After the push rod device is actuated, the extension position of the front end of the push rod is adjusted, thereby adjusting the gap size between the lower surface of the flat plate and the surface of the adsorption object.

[0010] Furthermore, a through hole is provided on the plate, and the through hole communicates with the fluids on the upper and lower sides of the plate.

[0011] Furthermore, the rotating device includes a motor and a rotating shaft, the rotating shaft is connected to the flat plate, and the motor drives the flat plate to rotate by driving the rotating shaft.

[0012] Compared with the prior art, the turntable mechanism of the present invention includes a flat plate and a rotating device for driving the flat plate to rotate. The rotating flat plate drives the fluid film to rotate through the fluid viscosity, so that negative pressure is generated between the lower surface of the flat plate and the surface of the adsorbed object. Because the flat plate is a continuous surface, the rotation state of the fluid in the fluid film is continuous and consistent in the circumferential direction, and the negative pressure distribution and suction force formed are also continuous and stable; on the other hand, the fluid film is only constrained by the surface of the flat plate and the surface of the adsorbed object, and the number of interfaces constraining the flow of the fluid is small, which is a simple and stable flow and is not easy to generate secondary flow. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a top view cross-sectional view of an existing adsorption device;

[0014] Figure 2 It is a schematic diagram of the structural principle of the turntable mechanism embodiment 1 of the present invention;

[0015] Figure 3 It is a schematic diagram of the structural principle of the turntable mechanism embodiment 2 of the present invention;

[0016] Figure 4 It is a schematic diagram of the structural principle of the turntable mechanism embodiment 3 of the present invention;

[0017] Figure 5 It is a schematic diagram of the structural principle of the turntable mechanism embodiment 4 of the present invention. DETAILED DESCRIPTION

[0018] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0019] Please refer to Figure 2 As shown, a preferred embodiment of the turntable mechanism of the present invention includes a flat plate 1 and a rotating device 2 for driving the flat plate 1 to rotate. The rotation of the flat plate 1 generates a negative pressure between the lower surface of the flat plate 1 and the surface of the adsorbed object 3. The flat plate 1 and the adsorbed object 3 are adsorbed together by the adsorption force generated by the negative pressure. At this time, a gap 4 is left between the lower surface of the flat plate 1 and the surface of the adsorbed object 3.

[0020] The specific structure of the turntable mechanism of the present invention is further described below in conjunction with specific embodiments.

[0021] Example 1

[0022] A first embodiment of the turntable mechanism of the present invention.

[0023] like Figure 2 As shown, the rotating device 2 is a motor, and the flat plate 1 is fixedly mounted on the motor shaft 5. The motor drives the flat plate 1 to rotate through the motor shaft 5. There is an adsorption object 3 under the rotating flat plate 1. A certain distance is maintained between the flat plate 1 and the surface of the adsorption object 3 to form a fluid film. Taking the air environment as an example, the fluid film is an air film. Under the action of the viscosity of the air fluid, the rotating flat plate 1 drives the air film below it to rotate. Centrifugal force is generated inside the rotating air film, so that the air inside the air film is thrown out, thereby forming a negative pressure distribution between the flat plate 1 and the surface of the adsorption object 3. The negative pressure distribution applies suction between the flat plate 1 and the adsorption object 3, so that the flat plate 1 and the adsorption object 3 are adsorbed together by the adsorption force generated by the negative pressure. At this time, a gap 4 is left between the lower surface of the flat plate 1 and the surface of the adsorption object 3.

[0024] Example 2

[0025] The second embodiment of the turntable mechanism of the present invention. Further analysis of the structure of embodiment 1 shows that the flat plate 1 drives the fluid film to rotate through the viscous effect, and the distance between the flat plate 1 and the surface of the adsorption object 3 has a great influence on the viscous effect of the fluid. When the spacing is small, the viscous effect is strong, and the rotation of the fluid film is more sufficient; when the spacing is large, the viscous effect is weak, and the rotation of the fluid film is weakened. A fully rotating fluid film can form a lower negative pressure and a greater suction force, while the negative pressure distribution of an insufficiently rotating fluid film is relatively weak, and the suction force will also become weak. It can be seen that we can set the adsorption force between the flat plate 1 and the surface of the adsorption object 3 by setting the size of the spacing between the flat plate 1 and the surface of the adsorption object 3.

[0026] like Figure 3 As shown, in this embodiment, a plurality of push rods 6 are added to the rotating device. The push rods 6 are fixedly connected to the rotating device 2. In this example, the push rods 6 are fixedly connected to the rotating device 2 by a connecting member 8. The front end of the push rod 6 is lower than the lower end surface of the flat plate 1 and contacts the surface of the adsorption object 3. The height difference between the front end of the push rod 6 and the flat plate 1 is the distance between the flat plate 1 and the surface of the adsorption object 3. Therefore, we can set the length of the push rod 6 to set the gap between the flat plate 1 and the surface of the adsorption object 3. When the rotation speed of the flat plate 1 is constant, we can obtain a greater suction force by reducing the height difference between the front end of the push rod 6 and the lower surface of the flat plate 1, or we can weaken the suction force by increasing the height difference between the front end of the push rod 6 and the lower surface of the flat plate 1.

[0027] Example 3

[0028] The third embodiment of the turntable mechanism of the present invention is based on the embodiment 2, and a height adjustment device is added to the turntable mechanism. The height adjustment device is arranged on the top rod 6, and the size of the gap 4 between the lower surface of the plate 1 and the surface of the adsorption object 3 is changed by adjusting the extension length of the top rod 6.

[0029] like Figure 4 As shown, in this embodiment, the height adjustment device is a plurality of push rod devices 7. The push rod device 7 is connected and fixed to the rotating device 2 through a connecting piece 8. The push rod device 7 adjusts the extension length of the push rod 6 to adjust the distance between the lower surface of the flat plate 1 and the surface of the adsorption object 3. The push rod device 7 can push the push rod 6 to move in the up and down directions. When it is necessary to increase the height difference between the front end of the push rod 6 and the lower surface of the flat plate 1, the push rod device 7 pushes the push rod 6 downward. When it is necessary to reduce the height difference between the front end of the push rod 6 and the lower surface of the flat plate 1, the push rod device 7 pushes the push rod 6 upward. In this way, the size of the adsorption force between the flat plate 1 and the adsorption object 3 is controlled.

[0030] Example 4

[0031] The fourth embodiment of the turntable mechanism of the present invention. When the surface of the adsorption object 3 is a workpiece surface, the turntable mechanism of embodiment 1 approaches the workpiece and applies adsorption force on the workpiece, the workpiece is sucked up and approaches the rotating flat plate 1 under the action of the suction force, and as the workpiece approaches the rotating flat plate 1, the air film between the flat plate 1 and the workpiece becomes thinner, and the suction force increases, so the workpiece is further approached to the rotating flat plate 1. Eventually, the workpiece collides with the rotating flat plate 1, causing the workpiece and the turntable mechanism to collide and be damaged.

[0032] like Figure 5 The cross-sectional view of the flat plate 1 shown in the figure shows that in order to solve the above-mentioned problem, some through holes 9 are provided on the flat plate 1. Negative pressure is formed between the flat plate 1 and the workpiece, and the negative pressure sucks air through the through holes 9. The sucked air is driven by the rotating flat plate 1 to rotate together, and flows to the periphery of the flat plate under the action of centrifugal force. This establishes a radial gap flow from the through hole 9 to the periphery in the rotating air film. The viscosity of the radial gap flow will establish a positive pressure component, and the smaller the gap 4, the stronger the viscosity, and the larger the positive pressure component. The positive pressure component is superimposed on the negative pressure distribution of the rotating air film, weakening the negative pressure distribution and suction. In the process of adsorbing the workpiece, when the workpiece approaches the rotating flat plate 1, the gap 4 becomes smaller, the positive pressure component is enhanced, and the suction is weakened, thereby preventing the workpiece from continuing to approach the rotating flat plate 1; when the workpiece moves away from the rotating flat plate 1, the gap 4 becomes larger, the positive pressure component becomes smaller, and the weakening effect on the suction is weakened, and the suction prevents the workpiece from continuing to move away from the rotating flat plate 1. Under the combined effect of the positive pressure component of the radial gap flow and the negative pressure of the rotating flow, the workpiece can be stably suspended below the rotating plate 1, maintaining a certain distance from the rotating plate 1. The design of the through hole 9 can avoid collision between the workpiece and the rotating plate 1, and realize contactless adsorption. The contactless adsorption of this structure can be applied to the handling of precision workpieces (semiconductor wafers, glass substrates, etc.), which can effectively avoid damaging the surface of the precision workpiece.

[0033] In the above-mentioned embodiment, air is used as the fluid medium for detailed description. The principle of this embodiment is applicable to all fluid media, such as water, oil, etc.

[0034] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A turntable mechanism, characterized in that: The device comprises a flat plate and a rotating device for driving the flat plate to rotate. The flat plate rotates so as to generate negative pressure between the lower surface of the flat plate and the surface of the adsorbed object. The flat plate and the adsorbed object are adsorbed together by the adsorption force generated by the negative pressure. At this time, a gap is left between the lower surface of the flat plate and the surface of the adsorbed object. A through hole is provided on the plate, and the through hole communicates with the fluids on the upper and lower sides of the plate; Negative pressure is formed between the plate and the adsorbed object, and the negative pressure sucks in air through the through hole; the sucked air is driven by the rotating plate to rotate together, and flows to the periphery of the plate under the action of centrifugal force; this establishes a radial gap flow from the through hole to the periphery in the rotating air film, and the viscosity of the radial gap flow will establish a positive pressure component, which is superimposed on the negative pressure distribution of the rotating air film, weakening the negative pressure distribution and suction; The rotating device comprises a motor and a rotating shaft.

2. The turntable mechanism according to claim 1, characterized in that: The rotating shaft is connected to the flat plate, and the motor drives the flat plate to rotate by driving the rotating shaft.

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