molecular pump

Abstract

The present application relates to the technical field of vacuum equipment, in particular to a molecular pump, which comprises a shell, a blade stage, a drag stage and a first Tesla valve structure, the shell is provided with an air inlet and an air outlet, the blade stage is arranged in the shell and is communicated with the air inlet, the drag stage is arranged in the shell and is located downstream of the blade stage, the drag stage is communicated with the air outlet, the drag stage comprises a static traction disc arranged on the inner wall of the shell and a drag disc in transmission connection with a rotating shaft, the drag disc and the static traction disc are alternately arranged along the axial direction of the rotating shaft, and the first Tesla valve structure is arranged on the surface of the static traction disc to guide the gas flowing forward from the drag disc and block the gas flowing backward from the air outlet. The present application can guide the gas flowing forward from the drag disc, ensure the flowing direction and path of the gas, block the gas flowing backward from the air outlet, enhance the drag effect on the gas, reduce the gas backflow phenomenon, and improve the reliability and stability of the molecular pump.

Description

Technical Field

[0001] This invention relates to the field of vacuum equipment measurement technology, specifically to molecular pumps. Background Technology

[0002] A molecular pump is a high-speed rotating vacuum generating device, consisting of a moving impeller, stationary blades, a high-speed motor, and rolling bearings. The molecular pump comprises a turbine section and a traction section. The turbine section, composed of multiple sets of moving impellers and stationary blades, achieves high pumping speed. The traction section consists of a rotor drive plate and a stationary traction plate. Several grooves are cut into the stationary traction plate according to a specific pattern. Several stationary traction plates are then connected in series. The grooves can be Archimedean spirals, logarithmic spirals, or circular arcs. During pumping, the high-speed rotating rotor drive plate "drags" the gas molecules, causing them to flow in a directional manner along the grooves of the stationary traction plate, reciprocating from the inside out and from the outside in, ultimately reaching the fore-stage port (exhaust port), thus achieving the pumping purpose.

[0003] However, due to the inevitable gap between the rotor drive plate and the stationary traction plate, a small amount of gas molecules will flow back from the fore-stage port to the molecular pump inlet, thus affecting the pumping effect of the molecular pump. Summary of the Invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the defect of gas backflow in the molecular pump of the prior art, thereby providing a molecular pump that can reduce gas backflow and ensure pumping effect.

[0005] To address the aforementioned problems, the present invention provides a molecular pump, comprising: a housing having an inlet and an outlet; a blade stage disposed within the housing, the blade stage communicating with the inlet; a drive stage disposed within the housing and downstream of the blade stage, the drive stage communicating with the outlet, the drive stage including a stationary traction disc disposed on the inner wall of the housing and a drive disc drivenly connected to a rotating shaft, the drive disc and the stationary traction disc being alternately arranged along the axial direction of the rotating shaft; and a first Tesla valve structure disposed on the surface of the stationary traction disc to guide gas flowing in from the drive disc in the forward direction and to obstruct gas flowing in from the outlet in the reverse direction.

[0006] As a preferred technical solution of the molecular pump of the present invention, the first Tesla valve structure includes: a spiral flow channel, which is formed on the surface of the stationary traction disk, wherein the inlet end of the spiral flow channel is connected to the upper adjacent traction disk, and the outlet end of the spiral flow channel is connected to the lower adjacent traction disk; and a Tesla valve flow channel, which is formed on the surface of the stationary traction disk and connected to the spiral flow channel, wherein the Tesla valve flow channel is arranged on the reverse tangent of the spiral flow channel along the gas flow direction in the spiral flow channel, and the Tesla valve flow channel can guide the gas flowing in the forward direction along the spiral flow channel and can block the gas flowing in the reverse direction along the spiral flow channel.

[0007] As a preferred embodiment of the molecular pump of the present invention, the Tesla valve channel is an ear-shaped groove.

[0008] As a preferred embodiment of the molecular pump of the present invention, the Tesla valve flow channel is provided in multiple intervals along the winding direction of the spiral flow channel.

[0009] As a preferred technical solution of the molecular pump of the present invention, the surface of the static traction disk is further provided with a drag gas inlet area, the drag gas inlet area is connected to the air inlet end of the spiral flow channel, the drag gas inlet area corresponds to the gap between the upper adjacent drag disk and the outer shell sidewall, and the width of the drag gas inlet area is greater than the width of the spiral flow channel.

[0010] As a preferred technical solution of the molecular pump of the present invention, the outer casing includes a pump housing and a pump base arranged vertically, the blade stage is disposed inside the pump housing, the drive stage is located between the blade stage and the pump base, the rotating shaft is rotatably mounted on the pump base, the air inlet is disposed on the pump housing, and the exhaust port is disposed on the pump base.

[0011] As a preferred technical solution of the molecular pump of the present invention, the pump base is provided with an annular groove on the end face facing the drive stage, and the molecular pump further includes a second Tesla valve structure. The second Tesla valve structure is disposed on the bottom wall of the annular groove. The inlet end of the second Tesla valve structure is connected to the outlet end of the adjacent first Tesla valve structure on the upper layer, and the gas outlet of the second Tesla valve structure is connected to the exhaust port.

[0012] As a preferred technical solution of the molecular pump of the present invention, it further includes a cover plate, which is disposed in the annular groove and covers the top of the second Tesla valve structure. There is a flow gap between the cover plate and the inner sidewall of the annular groove. The flow gap is connected to the air inlet end of the second Tesla valve structure and the air outlet end of the adjacent first Tesla valve structure on the upper layer.

[0013] As a preferred technical solution of the molecular pump of the present invention, a traction guide groove is provided on the static traction disk near the blade stage, and the first Tesla valve structure is provided on the static traction disk near the exhaust port.

[0014] As a preferred technical solution of the molecular pump of the present invention, the blade stage includes stationary blades spaced circumferentially along the inner wall of the housing and moving blades spaced circumferentially along the shaft, wherein the moving blades and the stationary blades are alternately arranged along the axial direction of the shaft.

[0015] The present invention has the following advantages:

[0016] 1. In the molecular pump of the present invention, when the pump is started, gas enters the blade stage from the inlet, flows into the drive stage through the blade stage, and then into the stationary traction plate by the rotating drive plate in the drive stage. The gas can then enter the first Tesla valve structure and flow along the first Tesla valve structure. This cycle continues until the gas is introduced into the exhaust port and flows out. Therefore, by setting the first Tesla valve structure on the stationary traction plate, the present invention can guide the gas flowing in from the drive plate in the forward direction according to the characteristics of the Tesla valve, ensuring its flow direction and path. It can also block the gas flowing in from the exhaust port in the reverse direction, which not only enhances the dragging effect of the gas, but also reduces the gas backflow phenomenon. That is, the setting of the first Tesla valve structure can act as a one-way valve. In addition, when the exhaust port pressure is too high, the first Tesla valve structure can also slow down the speed at which the high pressure at the exhaust port diffuses into the molecular pump, providing the molecular pump with time to decelerate, thereby improving the reliability and stability of the molecular pump.

[0017] 2. The molecular pump of the present invention includes a first Tesla valve structure comprising a spiral flow channel and a Tesla valve flow channel. The spiral flow channel is formed on the surface of the stationary traction disk. The inlet end of the spiral flow channel is connected to the adjacent upper traction disk, and the outlet end of the spiral flow channel is connected to the adjacent lower traction disk. The Tesla valve flow channel is formed on the surface of the stationary traction disk and connected to the spiral flow channel. Along the flow direction of the gas in the spiral flow channel, the Tesla valve flow channel is set on the reverse tangent of the spiral flow channel. The Tesla valve flow channel can guide the gas flowing in the forward direction along the spiral flow channel and can block the gas flowing in the reverse direction along the spiral flow channel. In the above configuration, when gas is dragged into the stationary traction plate by the drag plate, the gas enters the spiral flow channel from the inlet end of the spiral flow channel and flows along the spiral flow channel. When the gas flows through the Tesla valve flow channel, due to the characteristics of the Tesla valve flow channel, the gas flow resistance is small, which facilitates the gas to flow through in the forward direction. However, when gas flowing in the reverse direction from the exhaust port flows into the spiral flow channel and passes through the Tesla valve flow channel, since the tangents of the Tesla valve flow channel and the spiral flow channel are opposite, that is, the tangent direction of the Tesla valve flow channel and the reverse flow gas are consistent, the reverse flow gas will preferentially enter the Tesla valve flow channel, thereby hindering the reverse flow gas through the Tesla valve flow channel, reducing the amount of gas flowing in the reverse direction through the spiral flow channel, and reducing backflow.

[0018] 3. In the molecular pump of the present invention, multiple Tesla valve channels are spaced apart along the winding direction of the spiral channel, thereby providing a stronger resistance to the reverse flow of gas in the spiral channel and reducing gas backflow to a greater extent.

[0019] 4. In the molecular pump of the present invention, the surface of the static traction disc is further provided with a drag gas inlet area. The drag gas inlet area is connected to the air inlet end of the spiral flow channel and corresponds to the gap between the upper adjacent drag disc and the outer shell sidewall. The width of the drag gas inlet area is greater than the width of the spiral flow channel. The wider drag gas inlet area can guide the gas flowing out from the gap between the upper adjacent drag disc and the outer shell sidewall to receive as much gas as possible, so as to guide the gas into the narrower spiral flow channel, so that the gas flows along the spiral flow channel as much as possible, improving the accuracy of gas movement.

[0020] 5. In the molecular pump of the present invention, a traction guide groove is provided on the stationary traction disc near the blade stage, and a first Tesla valve structure is provided on the stationary traction disc near the exhaust port. In the driven stage, the gas density at the stationary traction disc near the exhaust port is greater than the gas density at the stationary traction disc near the blade stage. Therefore, by placing the first Tesla valve structure on the stationary traction disc with the higher gas density, when the gas passes through the traction guide grooves of the blade stage, the driven disc, and the traction disc in sequence and reaches the first Tesla valve structure, the gas is in a transitional flow or viscous flow state, which can effectively enhance the flow resistance effect.

[0021] 6. The molecular pump of the present invention further includes a second Tesla valve structure. An annular groove is provided on the end face of the pump base facing the drive stage. The second Tesla valve structure is disposed on the bottom wall of the annular groove. The inlet end of the second Tesla valve structure is correspondingly connected to the outlet end of the adjacent first Tesla valve structure on the upper layer. The gas outlet of the second Tesla valve structure is connected to the exhaust port. With this configuration, when gas flows out of the drive stage, the gas flows from the outlet end of the adjacent first Tesla valve structure on the upper layer of the pump base into the second Tesla valve structure, and then flows through the gas outlet of the second Tesla valve structure into the exhaust port for discharge. The second Tesla valve structure further impedes the backflow of gas at the exhaust port, further improving the pressure resistance of the molecular pump pre-stage (exhaust port). Attached Figure Description

[0022] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0023] Figure 1 A schematic diagram of the overall structure of the molecular pump according to an embodiment of the present invention is shown;

[0024] Figure 2 A three-dimensional exploded structural diagram of a molecular pump according to an embodiment of the present invention is shown;

[0025] Figure 3 An overall cross-sectional view of the molecular pump according to an embodiment of the present invention is shown;

[0026] Figure 4 A partially exploded structural diagram of the molecular pump according to an embodiment of the present invention is shown;

[0027] Figure 5 A schematic diagram of the pump base according to an embodiment of the present invention is shown;

[0028] Figure 6 A schematic diagram of the static traction disc with a first Tesla valve structure according to an embodiment of the present invention is shown.

[0029] Figure 7 A schematic diagram of the structure of forward gas flow on the static traction disc according to an embodiment of the present invention is shown;

[0030] Figure 8 A schematic diagram of the reverse flow of gas on the static traction disc according to an embodiment of the present invention is shown.

[0031] Explanation of reference numerals in the attached figures:

[0032] 1. Outer casing; 11. Pump housing; 111. Air inlet; 12. Pump base; 121. Exhaust port; 122. Annular groove; 123. Second Tesla valve structure; 1231. Gas outlet; 124. Pump bottom cover; 2. Vane stage; 21. Stationary vane; 22. Moving vane; 23. Spacer ring; 3. Drive stage; 31. Stationary traction disc; 311. Spiral flow channel; 312. Tesla valve flow channel; 313. Driven gas inlet area; 32. Drive disc; 4. Motor; 5. Shaft; 6. Turbine rotor; 7. Cover plate; 71. Flow gap; 8. First sealing ring; 9. Second sealing ring. Detailed Implementation

[0033] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0035] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0036] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0037] like Figures 1 to 6As shown, this embodiment discloses a molecular pump, including a housing 1, a blade stage 2, a drive stage 3, and a first Tesla valve structure. The housing 1 is provided with an inlet 111 and an outlet 121. The blade stage 2 is disposed inside the housing 1 and communicates with the inlet 111. The drive stage 3 is disposed inside the housing 1 and located downstream of the blade stage 2. The drive stage 3 communicates with the outlet 121. The drive stage 3 includes a stationary traction disk 31 disposed on the inner wall of the housing 1 and a drive disk 32 that is drivenly connected to the rotating shaft 5. The drive disk 32 and the stationary traction disk 31 are alternately arranged along the axial direction of the rotating shaft 5. The first Tesla valve structure is disposed on the surface of the stationary traction disk 31 to guide the gas flowing in from the drive disk 32 in the forward direction and to block the gas flowing in from the outlet 121 in the reverse direction.

[0038] When the molecular pump in this embodiment starts, gas enters the blade stage 2 through the inlet 111 and flows into the drive stage 3. In the drive stage 3, the rotating drive disk 32 drags the gas into the stationary traction disk 31, allowing the gas to enter the first Tesla valve structure and flow along it. This cycle continues until the gas is introduced into the exhaust port 121 and flows out. Therefore, by setting the first Tesla valve structure on the stationary traction disk 31, this invention can guide the gas flowing in from the drive disk 32 in the forward direction, ensuring its flow direction and path, and can also block the gas flowing in from the exhaust port 121 in the reverse direction. This enhances the dragging effect of the gas and reduces the backflow phenomenon. In other words, the first Tesla valve structure acts as a one-way valve. In addition, when the pressure at the exhaust port 121 is too high, the first Tesla valve structure can also slow down the rate at which the excessive pressure at the exhaust port 121 diffuses into the molecular pump, providing time for the molecular pump to decelerate and improving its reliability and stability.

[0039] The structure of the molecular pump in this embodiment will be described in detail below with reference to the accompanying drawings.

[0040] In this embodiment, the outer casing 1 includes a pump housing 11 and a pump base 12 arranged vertically. The pump housing 11 is provided with an air inlet 111 and the pump base 12 is provided with an exhaust port 121. Gas enters the pump housing 11 from the air inlet 111 and then flows through the exhaust port 121 of the pump base 12 and is discharged.

[0041] In terms of specific shape, the pump housing 11 is conical, with the smaller end of the pump housing 11 serving as the air inlet 111, and the larger end of the pump housing 11 connected and fixed to the pump base 12. The pump base 12 is cylindrical, matching the shape of the larger end of the pump housing 11. An annular groove 122 is provided on the end face of the pump base 12 facing the drive stage 3, and the annular groove 122 communicates with the exhaust port 121.

[0042] To improve the sealing performance between the pump housing 11 and the pump base 12, the molecular pump also includes a first sealing ring 8. The first sealing ring 8 elastically abuts against the pump housing 11 and the pump base 12 to seal the connection between them. Specifically, the outer wall of the pump base 12 is provided with a sealing ring groove, and the first sealing ring 8 is installed in the sealing ring groove and elastically abuts against the inner wall of the pump housing 11. The sealing ring groove facilitates the installation and positioning of the first sealing ring 8, reduces displacement of the first sealing ring 8 during use, and also protects the first sealing ring 8 from being squeezed, deformed, or failing.

[0043] In this embodiment, the blade stage 2 is disposed inside the pump housing 11, the drive stage 3 is located between the blade stage 2 and the pump base 12, and the rotating shaft 5 is rotatably mounted on the pump base 12. Gas flows into the pump housing 11 from the inlet 111, then flows through the blade stage 2 and the drive stage 3, and then flows out from the exhaust port 121 of the pump base 12.

[0044] Specifically, blade stage 2 includes stationary blades 21 and moving blades 22. The stationary blades 21 are spaced circumferentially along the inner wall of the outer casing 1, and the moving blades 22 are spaced circumferentially along the rotating shaft 5. The moving blades 22 and stationary blades 21 are alternately arranged axially along the rotating shaft 5. When the molecular pump pumps gas, the gas undergoing random thermal motion enters through the inlet 111 of the pump casing 11. The high-speed rotating moving blades 22 collide with the gas molecules, giving the gas molecules an additional velocity component in the direction of motion of the moving blades 22. After being superimposed with the original thermal motion velocity component of the gas molecules, the gas molecules form a tendency to move towards the stationary blades 21. The arrangement of the stationary blades 21 can maintain the tendency of the gas molecules to move. After passing through multiple layers of moving blades 22 and stationary blades 21, the gas molecules are pressurized layer by layer and reach the drive stage 3.

[0045] It is understood that the structure and principle of the moving blade 22 and the stationary blade 21 in blade stage 2 are existing technologies, and will not be described in detail in this embodiment.

[0046] In terms of quantity, in this embodiment, both the moving blade 22 and the stationary blade 21 are provided in three layers at intervals along the axial direction of the rotating shaft 5.

[0047] To support and position the stationary blades 21, the blade stage 2 in this embodiment also includes a spacer ring 23. The spacer ring 23 is disposed inside the housing 1 and located between two adjacent layers of stationary blades 21, thereby providing axial support and positioning for the stationary blades 21 and improving installation stability. It is understood that a gap exists between the spacer ring 23 and the corresponding moving blade 22 to facilitate gas passage.

[0048] In this embodiment, the rotating shaft 5 is rotatably mounted on the pump base 12. Specifically, one end of the rotating shaft 5 is connected to the motor 4 for transmission, and the other end of the rotating shaft 5 is connected to the turbine rotor 6. The turbine rotor 6 is located inside the upper housing 1, and the moving blades 22 are disposed on the turbine rotor 6. The rotating shaft 5 is driven to rotate by the motor 4, which in turn drives the turbine rotor 6 to rotate, thereby driving the moving blades 22 to rotate, thus realizing air extraction.

[0049] The drive disk 32 is a circular disk, and it is fixedly connected to the turbine rotor 6. That is, both the moving blade 22 and the drive disk 32 are integrated on the turbine rotor 6 and rotate with the turbine rotor 6. Specifically, the drive disk 32 is located near the pump base 12, and the moving blade 22 is located near the air inlet 111. That is, the gas first flows through the moving blade 22 and the stationary blade 21 before reaching the drive stage 3.

[0050] Accordingly, the stationary traction disk 31 is a circular disk, and there is a gap between the stationary traction disk 31 and the adjacent drag disk 32 to allow gas to pass through without obstructing the rotational movement of the drag disk 32. A mounting hole is provided at the center of the circular disk, through which the stationary traction disk 31 is fitted onto the outer periphery of the turbine rotor 6. Specifically, the diameter of the mounting hole in the stationary traction disk 31 is larger than the outer diameter of the turbine rotor 6, so that gas from the upper drag disk 32 can flow to the lower drag disk 32 through the gap between the stationary traction disk 31 and the turbine rotor 6.

[0051] In terms of quantity, in this embodiment, there are two of each of the drag disk 32 and the stationary traction disk 31 arranged at intervals along the axial direction of the rotating shaft 5. The first drag disk 32 is connected to the downstream stationary blade 21, and the second stationary traction disk 31 is connected to the exhaust port 121 on the pump base 12.

[0052] In this embodiment, the first Tesla valve structure is disposed on the surface of the stationary traction disk 31 facing the blade stage 2, so that the drag disk 32 can drag the gas from the blade stage 2 into the first Tesla valve structure on the stationary traction disk 31.

[0053] In this embodiment, the first Tesla valve structure includes a spiral flow channel 311 and a Tesla valve flow channel 312. The spiral flow channel 311 is formed on the surface of the stationary traction disk 31. The air inlet end of the spiral flow channel 311 is connected to the upper adjacent drag disk 32, and the air outlet end of the spiral flow channel 311 is connected to the lower adjacent drag disk 32. The Tesla valve flow channel 312 is formed on the surface of the stationary traction disk 31 and is connected to the spiral flow channel 311. Along the flow direction of the gas in the spiral flow channel 311, the Tesla valve flow channel 312 is set on the reverse tangent of the spiral flow channel 311. The Tesla valve flow channel 312 can guide the gas flowing in the forward direction along the spiral flow channel 311 and can block the gas flowing in the reverse direction along the spiral flow channel 311.

[0054] In the above configuration, when gas is dragged into the stationary traction disk 31 by the drag disk 32, the gas enters the spiral flow channel 311 from the inlet end of the spiral flow channel 311 and flows along the spiral flow channel 311. When the gas flows through the Tesla valve flow channel 312, due to the characteristics of the Tesla valve flow channel 312, the gas flow resistance is small, which facilitates the forward flow of the gas. However, when gas flowing in the opposite direction from the exhaust port 121 flows into the spiral flow channel 311 and passes through the Tesla valve flow channel 312, since the tangents of the Tesla valve flow channel 312 and the spiral flow channel 311 are opposite, that is, the tangent direction of the Tesla valve flow channel 312 and the reverse flow of the gas are consistent, the reverse flow of the gas will preferentially enter the Tesla valve flow channel 312, thereby hindering the reverse flow of the gas through the Tesla valve flow channel 312, reducing the amount of gas flowing in the opposite direction through the spiral flow channel 311, and reducing backflow.

[0055] In this embodiment, the spiral channel 311 is an Archimedean spiral, which is a type of equidistant spiral. Each rotation cycle of the spiral channel 311 expands outward at equal distances.

[0056] Regarding the specific location of the Tesla valve flow channel 312, such as Figure 7 and Figure 8 As shown, Figure 7 This is a schematic diagram of the forward flow of gas within the spiral channel 311. Figure 8 This is a schematic diagram of gas flowing in reverse within the spiral channel 311. In this embodiment, since the direction of the Tesla valve channel 312 is opposite to the tangential direction of the gas flowing in along the self-driving disk 32 within the spiral channel 311, the inlet and outlet of the Tesla valve channel 312 are opposite to the tangential direction of the gas flowing in the forward direction within the spiral channel 311. This means that most of the gas flowing in the forward direction within the spiral channel 311 will not flow through the Tesla valve channel 312. Only a small portion of the gas will be rotated through the Tesla valve channel 312, and the direction of the rotated gas movement will be consistent with the direction of the gas flowing in the forward direction within the spiral channel 311. This allows the gas to merge together and continue to flow in the forward direction along the spiral channel 311. Therefore, the Tesla valve channel 312 has relatively low resistance to the gas flowing in the forward direction within the spiral channel 311, ensuring the smoothness of the gas flow in the forward direction.

[0057] Conversely, such as Figure 2 , Figure 3 and Figure 8As shown, since the orientation of the Tesla valve flow channel 312 is opposite to the tangential direction of the gas flowing into the spiral flow channel 311 along the self-driving disk 32, the inlet and outlet of the Tesla valve flow channel 312 are both consistent with the tangential direction of the gas flowing in the opposite direction within the spiral flow channel 311. When the gas flows back from the exhaust port 121 into the spiral flow channel 311, the gas flows in the opposite direction along the spiral flow channel 311. Most of the gas flows into the Tesla valve flow channel 312 in the tangential direction and rotates. After rotating, the gas movement direction is opposite to the gas movement direction flowing in the opposite direction within the spiral flow channel 311, which causes gas molecule collisions and hinders further reverse flow of the gas. At the same time, the gas movement direction after rotating is the same as the gas movement direction flowing in the forward direction within the spiral flow channel 311, and then follows the forward-flowing gas to the exhaust port 121, thereby reducing the gas backflow at the exhaust port 121.

[0058] In terms of shape, the Tesla valve flow channel 312 is an ear-shaped groove. Furthermore, multiple Tesla valve flow channels 312 are spaced apart along the winding direction of the spiral flow channel 311, thereby providing a stronger obstruction effect on the reverse flow of gas within the spiral flow channel 311 and reducing gas backflow to a greater extent.

[0059] It should be noted that when gas enters the molecular pump, the gas at the blade stage 2 is in a molecular flow state, while the gas at the drive stage 3 is in a transitional or viscous flow state. The principle of the Tesla valve is to impede the reverse flow of gas molecules through the collision of gas molecules. Therefore, the better the flow obstruction effect, the more the first Tesla valve structure is placed at the part with higher gas molecule density. That is, the first Tesla valve structure should be placed as close as possible to the exhaust port 121 of the molecular pump. In this embodiment, the first Tesla valve structure is placed at the drive stage 3. When the gas reaches the drive stage 3 after passing through the blade stage 2, the gas density has been superimposed, ensuring that the first Tesla valve structure can play a good role in obstructing the reverse flow of gas.

[0060] In this embodiment, the surface of the static traction disk 31 is further provided with a drag gas inlet area 313. The drag gas inlet area 313 is connected to the air inlet end of the spiral flow channel 311. The drag gas inlet area 313 corresponds to the gap between the upper adjacent drag disk 32 and the side wall of the outer shell 1, and the width of the drag gas inlet area 313 is greater than the width of the spiral flow channel 311. The wider drag gas inlet area 313 can guide the gas flowing out from the gap between the upper adjacent drag disk 32 and the side wall of the outer shell 1, so as to receive as much gas as possible and guide the gas into the narrower spiral flow channel 311, so that the gas flows along the spiral flow channel 311 as much as possible, improving the accuracy of gas movement.

[0061] Specifically, the drag gas inlet area 313 is an arc-shaped groove on the surface of the stationary traction disc 31, and the arc-shaped groove is naturally connected and transitioned with the spiral flow channel 311.

[0062] In this embodiment, the drag gas inlet area 313 is located on the outer periphery of the spiral flow channel 311 to receive the guide gas. It should be noted that, during the process of the gas dragged by the upper drag disk 32 flowing to the adjacent static traction disk 31, the gas flows into the outer edge of the static traction disk 31 along the gap between the end of the drag disk 32 away from the turbine rotor 6 and the side wall of the outer casing 1. Then, the gas flows into the spiral flow channel 311 along the outer edge and gradually spirals towards the center of the static traction disk 31. Therefore, the drag gas inlet area 313 is located on the outer periphery of the spiral flow channel 311 in this embodiment, which is specially designed according to the gas flow direction.

[0063] Preferably, a traction guide groove is provided on the stationary traction disc 31 near the blade stage 2, and a first Tesla valve structure is provided on the stationary traction disc 31 near the exhaust port 121. In the drag stage 3, the gas density at the stationary traction disc 31 near the exhaust port 121 is greater than the gas density at the stationary traction disc 31 near the blade stage 2. Therefore, by placing the first Tesla valve structure on the stationary traction disc 31 with the higher gas density, when the gas passes through the blade stage 2, the drag disc 32, and the traction guide groove of the traction disc in sequence before reaching the first Tesla valve structure, the gas is in a transitional flow or viscous flow state, which can effectively enhance the flow resistance effect. Specifically, the traction guide groove is a spiral groove. The structure of providing a spiral groove on the stationary traction disc 31 is a well-known technology in the art and will not be elaborated here.

[0064] In this embodiment, since there are two static traction discs 31, one of them, which is close to the static blade 21, is provided with a traction guide groove, and the other static traction disc 31, which is connected to the pump base 12, is provided with a first Tesla valve structure.

[0065] As an optional technical solution in this embodiment, the molecular pump also includes a second Tesla valve structure 123. The second Tesla valve structure 123 is disposed on the bottom wall of the annular groove 122. The inlet end of the second Tesla valve structure 123 is connected to the outlet end of the adjacent first Tesla valve structure on the upper layer. The gas outlet 1231 of the second Tesla valve structure 123 is connected to the exhaust port 121. With this configuration, when gas flows out of the drive stage 3, the gas flows from the outlet end of the adjacent first Tesla valve structure on the upper layer of the pump base 12 into the second Tesla valve structure 123, and flows into the exhaust port 121 through the gas outlet 1231 of the second Tesla valve structure 123 before being discharged. The second Tesla valve structure 123 can further impede the backflow of gas at the exhaust port 121, further improving the pressure resistance of the molecular pump preamplifier (exhaust port 121).

[0066] Since the pump base 12 is closer to the pre-stage port (exhaust port 121) than the drive stage 3, this embodiment provides a second Tesla valve structure 123 on the pump base 12, which can further enhance the pressure resistance of the molecular pump pre-stage (exhaust port 121).

[0067] Specifically, the second Tesla valve structure 123 is configured identically to the first Tesla valve structure, except that when gas flows forward along the first Tesla valve structure, it spirals from the outside of the spiral channel 311 towards the center, while when gas flows forward along the second Tesla valve structure 123, it spirals from the center of the spiral channel 311 towards the outside. The gas outlet 1231 of the second Tesla valve structure 123 is located on the outside of the spiral channel 311. Furthermore, a dragging gas inlet area 313 is also provided on the bottom wall of the annular groove 122. The dragging gas inlet area 313 is located inside the second Tesla valve structure 123 and communicates with the inlet end of the second Tesla valve structure 123, used to guide the gas flowing out of the adjacent first Tesla valve structure and introduce it into the second Tesla valve structure 123.

[0068] Furthermore, the molecular pump in this embodiment also includes a cover plate 7, which is disposed within the annular groove 122 and covers the top of the second Tesla valve structure 123. A flow gap 71 exists between the cover plate 7 and the inner wall of the annular groove 122. The flow gap 71 is connected to both the inlet end of the second Tesla valve structure 123 and the outlet end of the adjacent upper-level first Tesla valve structure. The cover plate 7 can shield the second Tesla valve structure 123, placing it below the cover plate 7. Gas flows along the outlet end of the first Tesla valve structure through the flow gap 71 into the second Tesla valve structure 123 below the cover plate 7, and then flows through the gas outlet 1231 to the exhaust port 121. Therefore, the cover plate 7 can restrict and guide the gas flow, ensuring it only flows into the second Tesla valve structure 123 along the flow gap 71, reducing gas dispersion within the annular groove 122.

[0069] It should be noted that the inner wall of the annular groove 122 here refers to the side wall of the annular groove 122 near the rotating shaft 5.

[0070] Specifically, the pump base 12 is provided with a through hole located at the center of the annular groove 122. The rotating shaft 5 passes through the through hole. One end of the rotating shaft 5 is inserted into the pump base 12 and connected to the rotor of the motor 4. The other end of the rotating shaft 5, away from the motor 4, extends into the pump housing 11 and is connected and fixed to the turbine rotor 6, thereby driving the turbine rotor 6 to rotate, which in turn drives the moving blades 22 and the drag disk 32 to rotate.

[0071] In addition to the above structure, the molecular pump in this embodiment also includes a pump bottom cover 124, which is detachably connected to the pump base 12. The motor 4 is supported and mounted on the pump bottom cover 124 to support the motor 4, the rotating shaft 5 and other drive structures.

[0072] To improve the sealing performance of the connection between the pump bottom cover 124 and the pump base 12, the molecular pump also includes a second sealing ring 9, which elastically abuts against the connection between the pump bottom cover 124 and the pump base 12.

[0073] To facilitate understanding of the molecular pump in this embodiment, please refer to the appendix to the instruction manual. Figure 1 To be continued Figure 6 The usage process of this molecular pump is described as follows:

[0074] Gas enters the molecular pump through inlet 111, first flows into blade stage 2, and is driven by moving blade 22 to flow towards stationary blade 21. In this way, moving blade 22-stationary blade 21-moving blade 22 alternately circulate until the gas is delivered to drive stage 3.

[0075] The gas is dragged by the first drag plate 32 to an adjacent stationary traction plate 31, and flows through the traction guide groove on the stationary traction plate 31 to the adjacent second drag plate 32. Dragged by the drag plate 32, the gas flows to another adjacent stationary traction plate 31, and flows into the spiral flow channel 311 through the dragged gas inlet area 313. It flows spirally along the spiral flow channel 311. During this process, part of the gas does not flow through the Tesla valve flow channel 312. Only a small part of the gas rotates through the Tesla valve flow channel 312, and the direction of the rotated gas movement is consistent with the direction of the gas movement in the spiral flow channel 311, so that the gas can merge together and continue to flow along the spiral flow channel 311 to the outlet end. The gas flows into the flow gap 71 and the second Tesla valve structure 123 in sequence through the outlet end of the spiral flow channel 311. After spiraling through the second Tesla valve structure 123, it finally flows into the exhaust port 121 through the gas outlet 1231 of the second Tesla valve structure 123 and is discharged.

[0076] During the operation of the molecular pump, if gas flows in reverse from the exhaust port 121 into the second Tesla valve structure 123 and the first Tesla valve structure, the gas flows in reverse along the spiral channel 311. Most of the gas flows tangentially into the Tesla valve channel 312 and rotates. The direction of gas movement after rotation is opposite to the direction of gas movement in reverse flow within the spiral channel 311, resulting in gas molecule collisions and hindering further reverse flow. At the same time, the direction of gas movement after rotation is the same as the direction of gas movement in forward flow within the spiral channel 311, and it follows the forward flow of gas towards the exhaust port 121, thereby reducing gas backflow at the exhaust port 121.

[0077] It is understood that the above descriptions are the optimal technical solutions for this embodiment. Furthermore:

[0078] In other embodiments, the spiral channel 311 may also be configured as a logarithmic spiral, a circular arc, etc.

[0079] In other embodiments, a first Tesla valve structure may be provided on all static traction discs 31 in the drag stage 3 so as to impede the flow when the gas flows in the opposite direction through each static traction disc 31.

[0080] In other embodiments, the first Tesla valve structure and the second Tesla valve structure 123 may be provided as needed, and the reverse-flowing gas can be blocked by either the first Tesla valve structure or the second Tesla valve structure 123 alone.

[0081] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A molecular pump, characterized in that, include: The outer casing (1) is provided with an air inlet and an exhaust outlet (121). The blade stage (2) is disposed inside the housing (1) and is connected to the air inlet; The drag stage (3) is disposed inside the housing (1) and located downstream of the blade stage (2). The drag stage (3) is connected to the exhaust port (121). The drag stage (3) includes a stationary traction disc (31) disposed on the inner wall of the housing (1) and a drag disc (32) that is drivenly connected to the rotating shaft (5). The drag disc (32) and the stationary traction disc (31) are alternately arranged along the axial direction of the rotating shaft (5). A first Tesla valve structure is disposed on the surface of the stationary traction disc (31) to guide the gas flowing in from the drag disc (32) in the forward direction and to obstruct the gas flowing in from the exhaust port (121) in the reverse direction. The first Tesla valve structure includes a spiral flow channel (311) and a Tesla valve flow channel (312). The spiral flow channel (311) is opened on the surface of the stationary traction disc (31), and the air inlet end of the spiral flow channel (311) is correspondingly connected to the upper adjacent drag disc (32). The air outlet end of the spiral flow channel (311) is... The end is connected to the lower adjacent drag disk (32), the Tesla valve channel (312) is opened on the surface of the static traction disk (31) and connected to the spiral channel (311). Along the flow direction of gas in the spiral channel (311), the Tesla valve channel (312) is set on the reverse tangent of the spiral channel (311). The Tesla valve channel (312) can guide the gas flowing in the forward direction along the spiral channel (311) and can block the gas flowing in the reverse direction along the spiral channel (311).

2. The molecular pump according to claim 1, characterized in that, The Tesla valve flow channel (312) is an ear-shaped groove.

3. The molecular pump according to claim 1, characterized in that, The Tesla valve flow channel (312) is provided in multiple intervals along the winding direction of the spiral flow channel (311).

4. The molecular pump according to claim 1, characterized in that, The surface of the static traction disc (31) is also provided with a drag gas inlet area (313), which is connected to the air inlet end of the spiral flow channel (311). The drag gas inlet area (313) corresponds to the gap between the upper adjacent drag disc (32) and the side wall of the outer shell (1), and the width of the drag gas inlet area (313) is greater than the width of the spiral flow channel (311).

5. The molecular pump according to any one of claims 1 to 4, characterized in that, The outer casing (1) includes a pump housing (11) and a pump base (12) arranged vertically. The blade stage (2) is disposed inside the pump housing (11). The drive stage (3) is located between the blade stage (2) and the pump base (12). The rotating shaft (5) is rotatably mounted on the pump base (12). The air inlet is disposed on the pump housing (11). The exhaust port (121) is disposed on the pump base (12).

6. The molecular pump according to claim 5, characterized in that, The pump base (12) has an annular groove (122) on the end face facing the drive stage (3). The molecular pump also includes a second Tesla valve structure (123). The second Tesla valve structure (123) is disposed on the bottom wall of the annular groove (122). The air inlet of the second Tesla valve structure (123) is connected to the air outlet of the adjacent first Tesla valve structure on the upper layer. The gas outlet (1231) of the second Tesla valve structure (123) is connected to the exhaust port (121).

7. The molecular pump according to claim 6, characterized in that, It also includes a cover plate (7), which is disposed in the annular groove (122) and covers the top of the second Tesla valve structure (123). There is a flow gap (71) between the cover plate (7) and the inner wall of the annular groove (122). The flow gap (71) is connected to the air inlet of the second Tesla valve structure (123) and the air outlet of the adjacent first Tesla valve structure on the upper layer.

8. The molecular pump according to any one of claims 1 to 4, characterized in that, A traction guide groove is provided on the stationary traction disc (31) near the blade stage (2), and the first Tesla valve structure is provided on the stationary traction disc (31) near the exhaust port (121).

9. The molecular pump according to any one of claims 1 to 4, characterized in that, The blade stage (2) includes stationary blades (21) spaced circumferentially along the inner wall of the outer shell (1) and moving blades (22) spaced circumferentially along the rotating shaft (5), wherein the moving blades (22) and the stationary blades (21) are alternately arranged along the axial direction of the rotating shaft (5).

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