A multi-orifice molecular pump with adjustable orifice

Abstract

The present invention relates to a multi-flow port molecular pump with adjustable flow ports, the molecular pump comprising a base, a pump casing and a drag stage, the pump casing being detachably connected or rotatably connected to the base; the drag stage being arranged in the pump casing, the drag stage comprising a cylindrical drag stage stator, a plurality of first flow ports being axially spaced apart on the peripheral wall of the drag stage stator, the plurality of first flow ports being staggered with each other in the circumferential direction of the drag stage stator, a first connecting port being provided on the pump casing, the first connecting port being a strip-shaped opening that can cover all the first flow ports in the axial direction of the drag stage stator, and being suitable for connecting the first connecting port with any first flow port by rotating the pump casing. By adopting the above-mentioned design, during use, the pump casing can be rotated according to the requirements of the actual working conditions so that the connecting port thereon corresponds to the target flow port, thereby realizing the selection and adjustment of flow ports of different positions and performances, the adjustment method is simple and convenient, and there is no need to reprocess and assemble the pump casing and the stator in the pump, thus saving manpower and material resources.

Description

Technical Field

[0001] The present invention relates to the technical field of molecular pumps, and in particular to a multi-orifice molecular pump with adjustable orifices. Background Art

[0002] With the booming development of molecular pumps in industries such as semiconductors and industrial coatings, their application is becoming increasingly common. A molecular pump is a vacuum pump that uses a high-speed rotating rotor to transfer momentum to gas molecules, giving them a directional velocity. This allows them to be compressed and driven toward the exhaust port, where they are then pumped away by the forestage. The specific working principle of a molecular pump is as follows: Before use, the gas enters through the molecular pump inlet, moves under the drive of the molecular pump's rotor and stator, and is finally discharged through the forestage port. Molecular pumps are all equipped with orifices, and orifices located in different positions result in different pumping speeds and compression ratios. Currently, multi-orifice molecular pumps are widely used in scientific research and mass spectrometry. The orifice location requirements for multi-orifice molecular pumps vary depending on the working environment.

[0003] In existing multi-orifice molecular pumps, a single pump housing corresponds to only one set of orifices with specific performance. Once the components of the multi-orifice molecular pump are machined, the orifice positions are fixed, and the performance of each orifice in the multi-orifice pump is determined. To meet different performance requirements, the original molecular pump must be disassembled, the housing and corresponding components re-machined, and then the newly machined components assembled into the new pump. This repeated machining and assembly process is a waste of time and materials, and repeated disassembly and assembly can damage the precision molecular pump. Summary of the Invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the defect of the prior art multi-orifice molecular pump that parts need to be disassembled and reprocessed when the orifice position needs to be adjusted, which wastes time and materials while damaging the molecular pump, thereby providing a multi-orifice molecular pump with adjustable orifice that is easy to adjust the orifice position.

[0005] In order to solve the above problems, the present invention provides a multi-orifice molecular pump with adjustable orifices, comprising:

[0006] base;

[0007] A pump housing is detachably connected or rotatably connected to the base, wherein the pump housing has a rotating state in which it can rotate relative to the base and a fixed state in which it is maintained at a set position;

[0008] The drag stage is arranged in the pump casing, and the drag stage includes a cylindrical drag stage stator. A plurality of first flow ports are axially spaced apart on the peripheral wall of the drag stage stator. The plurality of first flow ports are staggered with each other in the circumferential direction of the drag stage stator. A first connecting port is provided on the pump casing. The first connecting port is a strip-shaped opening that can cover all the first flow ports in the axial direction of the drag stage stator, and is suitable for connecting the first connecting port with any first flow port by rotating the pump casing.

[0009] Optionally, the pump housing is detachably connected and fixed to the base, and is adapted to be rotated by disassembling the pump housing and the base so that the first communication port can be connected to the preset first flow port;

[0010] The base is provided with a first connecting structure suitable for connecting to the pump casing, and the bottom of the pump casing is provided with a second connecting structure suitable for detachably connecting to the first connecting structure; the first connecting structure and / or the second connecting structure are multiple and spaced apart along the circumferential direction, and the spacing angles of the multiple first connecting structures and / or the second connecting structures in the circumferential direction match the spacing angles of the multiple first flow ports in the circumferential direction.

[0011] Optionally, the first connection structure includes at least two first screw holes symmetrically opened on the base;

[0012] The second connection structure includes a plurality of second screw holes spaced apart along the circumference of the bottom connection end surface of the pump housing;

[0013] Wherein, the first screw hole is a through stepped through hole, and the second screw hole is a threaded countersunk hole.

[0014] Optionally, the pump housing includes an upper housing and a lower housing, the lower housing is detachably connected or rotatably connected between the base and the upper housing, the drag stage is disposed in the lower housing, the first flow port is opened on the lower housing, and the multi-flow port molecular pump further includes:

[0015] The blade stage comprises a plurality of isolation rings disposed in the upper shell and arranged in sequence along the axial direction of the upper shell, each of the isolation rings being provided with a second flow opening, and the second flow openings on the plurality of isolation rings being staggered in the circumferential direction;

[0016] A second connecting port is provided on the pump casing, which is a strip-shaped opening that can cover the second flow ports on all isolation rings in the axial direction of the pump casing, and is suitable for connecting the second connecting port with the second flow port on any isolation ring by rotating the upper casing.

[0017] Optionally, the upper shell is detachably connected and fixed to the lower shell, and is adapted to be rotated by disassembling the upper shell and the lower shell so that the second communication port can be connected to the preset second flow port;

[0018] The bottom of the upper shell is provided with a third connecting structure suitable for connecting to the lower shell, and the top of the lower shell is provided with a fourth connecting structure suitable for detachably connecting to the third connecting structure. The third connecting structure and / or the fourth connecting structure are multiple and spaced apart along the circumferential direction, and the spacing angle of the multiple first connecting structures and / or second connecting structures in the circumferential direction matches the spacing angle of the multiple second flow ports in the circumferential direction.

[0019] Optionally, the third connection structure includes a plurality of third screw holes spaced apart along the circumference of the upper shell;

[0020] The fourth connection structure includes at least two fourth screw holes symmetrically opened on the upper connection end surface of the lower shell;

[0021] Wherein, the third screw hole is a through stepped through hole, and the fourth screw hole is a threaded countersunk hole.

[0022] Optionally, a plurality of the first flow ports are evenly spaced along the circumferential direction of the drag stage stator, a plurality of the second connection structures are evenly spaced on the top of the lower shell, and an interval angle of the first flow ports is an integer multiple of an interval angle of the second connection structures;

[0023] And / or, a plurality of the second flow ports are evenly spaced along the circumference of the drag stage stator, there are a plurality of the fourth connection structures, and a plurality of the fourth connection structures are evenly spaced on the top of the lower shell, and the spacing angle of the second flow ports is an integer multiple of the spacing angle of the fourth connection structure.

[0024] Optionally, a first sealing structure is provided between the lower shell and the base for sealing a fitting gap therebetween;

[0025] And / or, a second sealing structure for sealing a fitting gap between the upper shell and the lower shell is provided between the upper shell and the lower shell.

[0026] Optionally, a plurality of screw holes suitable for connecting with the outlet end of an external air intake device are provided at intervals on the outer wall of the lower shell located at the periphery of the first communication port and on the upper shell located at the periphery of the second communication port.

[0027] And / or, sealing grooves are respectively formed on the outer wall of the lower shell body located at the periphery of the first communicating port and the upper shell body located at the periphery of the second communicating port, and the sealing grooves are respectively filled with elastic sealing rings.

[0028] Optionally, the width of the plurality of first flow openings is greater than the width of the first communication hole;

[0029] And / or, the opening width of the plurality of second flow ports is greater than the opening width of the second communication hole.

[0030] The present invention has the following advantages:

[0031] 1. By utilizing the technical solution of the present invention, a plurality of first flow ports are axially spaced apart and opened on the drag stage stator, and a first connecting port is opened on the pump casing. When the pumping speed and compression ratio of the vacuum pump need to be adjusted, the first flow port corresponding to the adjusted pumping speed and compression ratio is selected, the pump casing is rotated so that the first connecting port is connected to the first flow port, and then the pump casing is fixed on the base. This enables different flow ports to be selected on the basis of the same molecular pump to adapt to actual working conditions. The pump casing can be rotated according to the needs of the actual working conditions so that the connecting port thereon corresponds to the target flow port, thereby realizing selection and adjustment of flow ports of different positions and performances. The adjustment method is simple and convenient, and there is no need to re-process and assemble the pump casing and the stator in the pump, thereby avoiding damage to the molecular pump caused by disassembly, and saving manpower and material resources.

[0032] 2. By utilizing the technical solution of the present invention, when the pump casing needs to be fixed on the base, the pump casing is rotated to connect the first connecting port with the first flow port of the corresponding performance, the first screw hole is opposite to the second screw hole, the screw passes through the first screw hole and is fixed in the second screw hole, the stepped through hole limits the end cap of the screw, and the screw fixes the position of the pump casing, realizing the ready-to-disassemble and ready-to-install function, and ensuring the convenience of positioning the pump casing.

[0033] 3. By utilizing the technical solution of the present invention, the second flow port is opened on the isolation rings arranged in sequence along the axial direction, and the second connecting port is opened on the upper shell. When the pumping speed and compression ratio of the vacuum pump need to be adjusted, the second flow port corresponding to the adjusted pumping speed and compression ratio is selected, and the upper shell is rotated so that the second connecting port is connected to the second flow port. Then, the upper shell is fixed to the lower shell, thereby realizing multi-performance adjustment of the vacuum pump. For different performances, it is only necessary to cancel the fixed state of the upper shell and rotate the second connecting port to connect to the corresponding second flow port that realizes the performance. The adjustment is convenient, and there is no need to reprocess and assemble the molecular pump, thus saving manpower and material resources.

[0034] 4. By utilizing the technical solution of the present invention, when the upper shell needs to be fixed on the lower shell, the upper shell is rotated to connect the second connecting port with the second flow port of corresponding performance, the third screw hole is opposite to the fourth screw hole, the screw passes through the third screw hole and is fixed in the fourth screw hole, the stepped through hole limits the end cap of the screw, and the screw fixes the position of the upper shell, realizing the ready-to-use and ready-to-disassemble and ready-to-use installation, and ensuring the convenience of positioning the upper shell.

[0035] 5. By utilizing the technical solution of the present invention, the first sealing structure provided between the lower shell and the base and the second sealing structure provided between the upper shell and the lower shell improve the overall airtightness of the molecular pump, thereby preventing air leakage after vacuuming from affecting the normal operation of the molecular pump.

[0036] 6. By utilizing the technical solution of the present invention, the external air intake device is mounted on the pump housing through the screw hole, and the elastic sealing ring improves the sealing of the connection between the external air intake device and the molecular pump, thereby improving the overall airtightness of the molecular pump.

[0037] 7. By utilizing the technical solution of the present invention, when the connecting port is rotated to connect with the flow port, in order to ensure that the actual ventilation width of the flow port is equal to the opening width of the connecting port, the angles of the two need to be carefully adjusted before positioning the pump casing. The opening width of the flow port is greater than the opening width of the connecting port, which increases the adjustment margin of the pump casing positioning and reduces the positioning error of the pump casing, so that the maximum ventilation volume of the flow port can be guaranteed while the position of the pump casing is fixed within some deviation, thereby ensuring the ventilation efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0039] Figure 1 Shows the overall structural diagram of the molecular pump;

[0040] Figure 2 A schematic diagram showing the internal structure of a molecular pump is shown;

[0041] Figure 3 A cross-sectional view showing the positional relationship between the first connection structure, the second connection structure, the third connection structure, and the fourth connection structure;

[0042] Figure 4 shows a top view of the molecular pump;

[0043] Figure 5 A cross-sectional view of the connection position between the lower shell and the base is shown.

[0044] Explanation of the accompanying drawings: 1. Base; 2. Pump casing; 21. Lower casing; 211. First connecting port; 22. Upper casing; 221. Second connecting port; 3. Drag stage; 31. Drag stage stator; 311. First flow port; 4. First connecting structure; 5. Second connecting structure; 6. Blade stage; 61. Isolation ring; 611. Second flow port; 7. Third connecting structure; 8. Fourth connecting structure; 9. Elastic sealing ring. DETAILED DESCRIPTION

[0045] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0046] In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limitations on the present 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.

[0047] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0048] In addition, 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.

[0049] like Figures 1 to 5As shown, an embodiment of the present application provides a multi-orifice molecular pump with adjustable orifice, which includes a base 1, a pump housing 2 and a drag stage 3. The pump housing 2 is detachably connected or rotatably connected to the base 1, and the pump housing 2 has a rotating state that can rotate relative to the base 1 and a fixed state that is maintained at a set position; the drag stage 3 is arranged in the pump housing 2, and the drag stage 3 includes a cylindrical drag stage stator 31, and a plurality of first orifices 311 are axially spaced apart on the circumferential wall of the drag stage stator 31. The plurality of first orifices 311 are staggered with each other in the circumferential direction of the drag stage stator 31, and each first orifice 311 has different performances. A first connecting port 211 is provided on the pump housing 2, and the first connecting port 211 is a strip opening that can cover all the first orifices 311 in the axial direction of the drag stage stator 31, and is suitable for connecting the first connecting port 211 with any first orifice 311 by rotating the pump housing 2.

[0050] A plurality of first flow ports 311 are provided on the drag stage stator 31 at intervals along the axial direction, and the first communication port 211 is provided on the pump housing 2. When the pumping speed and the compression ratio of the vacuum pump need to be adjusted, the first flow port 311 corresponding to the adjusted pumping speed and the compression ratio is selected, and the pump housing 2 is rotated so that the first communication port 211 is connected to the first flow port 311. The pump housing 2 is then fixed on the base 1. This enables different flow ports to be selected on the basis of the same molecular pump to adapt to actual working conditions. The pump housing 2 can be rotated according to the actual working conditions so that the communication port thereon corresponds to the target flow port, thereby enabling the selection and adjustment of flow ports of different positions and performances. The adjustment method is simple and convenient, and there is no need to re-process and assemble the pump housing 2 and the stator in the pump, thereby avoiding damage to the molecular pump caused by disassembly, and saving manpower and material resources.

[0051] Furthermore, in one embodiment of the above scheme, the pump housing 2 can be detachably connected by a connecting structure such as screws or snaps. When it is desired to adjust the position of the conductive first flow port 311, the pump housing 2 is disassembled from the base 1 so that the pump housing 2 is in a rotating state relative to the base 1. When the first communication port 211 on the pump housing 2 is adjusted to a position corresponding to the target first flow port 311, the pump housing 2 is fixed to the base 1 so that the pump housing 2 remains stably in this position. In another embodiment, the pump housing 2 is rotatably sealed and connected to the base 1, and the base 1 can be driven to rotate by a driving mechanism. A damping mechanism or a positioning mechanism is further provided between the pump housing 2 and the base 1. When the pump housing 2 rotates to a position where the first communication port 211 corresponds to the target first flow port 311, the pump housing 2 is maintained at the preset position by the damping mechanism or the positioning mechanism.

[0052] In consideration of cost, preferably, in this embodiment, the pump housing 2 and the base 1 are connected in the manner of the first embodiment described above.

[0053] like Figure 1 、 Figure 2 and Figure 3 As shown, the pump casing 2 is detachably connected and fixed to the base 1, and is suitable for disassembling the pump casing 2 and the base 1 to rotate the pump casing 2 so that the first connecting port 211 can be connected to the preset first flow port 311; the base 1 is provided with a first connecting structure 4 suitable for connecting to the pump casing 2, and the bottom of the pump casing 2 is provided with a second connecting structure 5 suitable for detachably connecting to the first connecting structure 4; the first connecting structure 4 and / or the second connecting structure 5 are multiple and spaced apart along the circumferential direction, and the spacing angles of the multiple first connecting structures 4 and / or the second connecting structures 5 in the circumferential direction match the spacing angles of the multiple first flow ports 311 in the circumferential direction.

[0054] In the above solution, the first connection structure 4 and the second connection structure 5 can be screw connection structures or snap connection structures. Preferably, in order to ensure the stability of the connection between the base 1 and the pump housing 2, the first connection structure 4 and the second connection structure 5 are both screw connection structures.

[0055] like Figure 3 As shown, the first connecting structure 4 includes at least two first screw holes symmetrically opened on the base 1; the second connecting structure 5 includes a plurality of second screw holes circumferentially spaced along the bottom connecting end surface of the pump casing 2; wherein, the first screw hole is a through stepped through hole for limiting the end cap of the screw to be installed, and the second screw hole is a threaded countersunk hole.

[0056] When the pump casing 2 needs to be fixed on the base 1, the pump casing 2 is rotated to connect the first connecting port 211 with the corresponding performance first flow port 311. The first screw hole is opposite to the second screw hole. The screw passes through the first screw hole and is fixed in the second screw hole. The stepped through hole limits the end cap of the screw, and the screw fixes the position of the pump casing 2, realizing the ready-to-disassemble and ready-to-install function, and ensuring the convenience of positioning the pump casing 2.

[0057] like Figure 1 and Figure 2As shown, the pump casing 2 includes an upper casing 22 and a lower casing 21, and the lower casing 21 is detachably connected or rotatably connected between the base 1 and the upper casing 22. The drag stage 3 is arranged in the lower casing 21, and the first flow port 311 is opened on the lower casing 21. The multi-flow port molecular pump also includes a blade stage 6, including a multi-stage isolation ring 61 arranged in the upper casing 22 and arranged in sequence along the axial direction of the upper casing 22, each of the isolation rings 61 is provided with a second flow port 611, and the second flow ports 611 on the multiple isolation rings 61 are staggered with each other in the circumferential direction; a second connecting port 221 is provided on the pump casing 2, and the second connecting port 221 is a strip opening that can cover the second flow ports 611 on all isolation rings 61 in the axial direction of the pump casing 2, and is suitable for connecting the second connecting port 221 with the second flow port 611 on any isolation ring 61 by rotating the upper casing 22.

[0058] The second flow port 611 is opened on the isolation ring 61 arranged in sequence along the axial direction, and the second connecting port 221 is opened on the upper shell 22. When the pumping speed and compression ratio of the vacuum pump need to be adjusted, the second flow port 611 corresponding to the adjusted pumping speed and compression ratio is selected, and the upper shell 22 is rotated so that the second connecting port 221 is connected to the second flow port 611. Then the upper shell 22 is fixed to the lower shell 21, thereby realizing multi-performance adjustment of the vacuum pump. For different performances, it is only necessary to cancel the fixed state of the upper shell 22 and rotate the second connecting port 221 to connect to the corresponding second flow port 611 that realizes the performance. The adjustment is convenient and there is no need to reprocess and assemble the molecular pump, thus saving manpower and material resources.

[0059] Optionally, a standard flange port is provided on the top wall of the upper shell 22. The flange port is the outlet of the molecular pump and is connected to subsequent equipment. When the molecular pump is not in use, the flange port is blocked to prevent dust from entering.

[0060] like Figure 3 、 Figure 4 and Figure 5 As shown, the upper shell 22 is detachably connected and fixed to the lower shell 21, and is suitable for disassembling the upper shell 22 and the lower shell 21 to rotate the upper shell 22 so that the second connecting port 221 can be connected to the preset second flow port 611; the bottom of the upper shell 22 is provided with a third connecting structure 7 suitable for connecting to the lower shell 21, and the top of the lower shell 21 is provided with a fourth connecting structure 8 suitable for detachably connecting to the third connecting structure 7, and the third connecting structure 7 and / or the fourth connecting structure 8 are multiple and spaced apart in the circumferential direction, and the spacing angles of the multiple first connecting structures 4 and / or second connecting structures 5 in the circumferential direction match the spacing angles of the multiple second flow ports 611 in the circumferential direction.

[0061] like Figure 4 and Figure 5 As shown, the third connection structure 7 includes a plurality of third screw holes spaced apart along the circumference of the upper shell 22; the fourth connection structure 8 includes at least two fourth screw holes symmetrically opened on the upper connection end surface of the lower shell 21; wherein, the third screw hole is a through stepped through hole for limiting the end cap of the screw to be installed, and the fourth screw hole is a threaded countersunk hole.

[0062] Optionally, the second screw hole and the fourth screw hole are arranged in an alternating manner, so that the lower shell 21 can be detachably connected to the base 1 and the upper shell 22 respectively while ensuring the strength of the lower shell 21 itself.

[0063] When it is necessary to fix the upper shell 22 on the lower shell 21, rotate the upper shell 22 to connect the second connecting port 221 with the corresponding performance second flow port 611, the third screw hole is opposite to the fourth screw hole, the screw passes through the third screw hole and is fixed in the fourth screw hole, the stepped through hole limits the end cap of the screw, and the screw fixes the position of the upper shell 22, realizing the ready-to-use and ready-to-disassemble and ready-to-use, ensuring the convenience of positioning the upper shell 22.

[0064] like Figure 2 As shown, multiple first flow ports 311 are evenly spaced along the circumference of the drag stage stator 31. Multiple second connection structures 5 are evenly spaced on the top of the lower housing 21. The spacing angle of the first flow ports 311 is an integer multiple of the spacing angle of the second connection structures 5. For example, the spacing angle between two adjacent first flow ports 311 is 30 degrees, while the spacing angle of the second connection structures 5 can be 5°, 6°, 10°, 15°, 30°, etc.

[0065] Preferably, the interval angle of the first flow openings 311 is 1-3 times the interval angle of the second connection structure 5 .

[0066] More preferably, the interval angle of the first flow openings 311 is the same as the interval angle of the second connection structure 5 .

[0067] Optionally, multiple second flow ports 611 are evenly spaced along the circumference of the drag stage stator 31, multiple fourth connection structures 8 are evenly spaced on the top of the lower housing 21, and the spacing angle of the second flow ports 611 is an integer multiple of the spacing angle of the fourth connection structures 8. For example, if the spacing angle between two adjacent second flow ports 611 is 30 degrees, the spacing angle of the fourth connection structures 8 can be 5°, 6°, 10°, 15°, 30°, etc.

[0068] Preferably, the interval angle of the second flow openings 611 is 1-3 times the interval angle of the fourth connection structure 8 .

[0069] More preferably, the interval angle of the second flow ports 611 is the same as the interval angle of the fourth connection structure 8 .

[0070] Optionally, the upper shell 22 and the lower shell 21 can be rotated 18° and integer multiples of 18° for angle adjustment, and the corresponding two circumferentially adjacent first flow ports 311 or two circumferentially adjacent second flow ports 611 are spaced at an angle of 18° to ensure that the screws are simultaneously connected between the first connecting structure 4 and the second connecting structure 5, or simultaneously connected between the third connecting structure 7 and the fourth connecting structure 8, to ensure that at this time a certain first flow port 311 is connected to the first connecting port 211, or a certain second flow port 611 is connected to the second connecting port 221.

[0071] Optionally, eight second connection structures 5 and eight fourth connection structures 8 are provided.

[0072] In this embodiment, a drive component consisting of a turbine, pump body, and other structures is disposed within the base 1, and the drive shaft of the drive component extends into the pump housing 2. A drag-stage stator 31 is fixedly mounted on the base 1. A drag-stage rotor is disposed within the drag-stage stator 31, and is suitable for connection to the drive shaft. An isolation ring 61 is fixedly mounted above the drag-stage stator 31. The blade stage also includes rotors disposed on the drive shaft. A layer of static blades is disposed between two adjacent layers of rotor blades. The isolation ring 61 is used to securely mount the static blades.

[0073] In this solution, a first sealing structure for sealing the fitting gap between the lower shell 21 and the base 1 is provided; a second sealing structure for sealing the fitting gap between the upper shell 22 and the lower shell 21 is provided; the first sealing structure provided between the lower shell 21 and the base 1 and the second sealing structure provided between the upper shell 22 and the lower shell 21 improve the overall airtightness of the molecular pump, and avoid air leakage after vacuuming that affects the normal operation of the molecular pump.

[0074] like Figure 1 As shown, a plurality of threaded countersunk holes suitable for connecting to the outlet end of an external air intake device are provided at intervals on the outer wall of the lower shell 21 located at the periphery of the first connecting port 211 and on the upper shell 22 located at the periphery of the second connecting port 221; when the molecular pump is in use, the threaded countersunk holes are connected to the external air intake device, and when the molecular pump is in an idle state, the threaded countersunk holes are connected to the sealing components for sealing the first connecting port 211 or the second connecting port 221 to prevent dust from entering.

[0075] Optionally, sealing grooves are formed on the outer wall of the lower shell 21 located at the periphery of the first connecting port 211 and the upper shell 22 located at the periphery of the second connecting port 221, and the sealing grooves are filled with elastic sealing rings 9 respectively; the external air intake device is installed on the pump housing 2 through a threaded countersunk hole, and the elastic sealing ring 9 improves the sealing at the connection between the external air intake device and the molecular pump, thereby improving the overall airtightness of the molecular pump.

[0076] like Figure 1 and Figure 2 As shown, the opening width of multiple first flow ports 311 is greater than the opening width of the first connecting hole; the opening width of multiple second flow ports 611 is greater than the opening width of the second connecting hole; when the connecting port is rotated to be connected with the flow port, in order to ensure that the actual ventilation width of the flow port is equal to the opening width of the connecting port, the angles of the two need to be carefully adjusted before positioning the pump casing 2. The opening width of the flow port is greater than the opening width of the connecting port, which increases the adjustment margin of the positioning of the pump casing 2 and reduces the positioning error of the pump casing 2, so that the maximum ventilation volume of the flow port can still be guaranteed when the position of the pump casing 2 is fixed within some deviations, thereby ensuring the ventilation efficiency.

[0077] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will readily appreciate that other variations or modifications based on the above descriptions are possible. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A multi-orifice molecular pump with adjustable orifice, characterized in that: include: Base (1); A pump housing (2) is detachably connected or rotatably connected to the base (1), and the pump housing (2) has a rotating state in which it can rotate relative to the base (1) and a fixed state in which it is maintained at a set position; A drag stage portion (3) is arranged in a pump housing (2), the drag stage portion (3) comprising a cylindrical drag stage stator (31), a plurality of first flow ports (311) being spaced apart along the axial direction on the peripheral wall of the drag stage stator (31), the plurality of first flow ports (311) being staggered and distributed with respect to each other in the circumferential direction of the drag stage stator (31), a first communication port (211) being provided on the pump housing (2), the first communication port (211) being a strip-shaped opening capable of covering all the first flow ports (311) in the axial direction of the drag stage stator (31), and being adapted to enable the first communication port (211) to communicate with any first flow port (311) by rotating the pump housing (2).

2. The multi-orifice molecular pump with adjustable orifice according to claim 1, characterized in that: The pump housing (2) is detachably connected and fixed to the base (1), and is adapted to rotate the pump housing (2) by disassembling the pump housing (2) and the base (1), so that the first communication port (211) can be connected to a preset first flow port (311); The base (1) is provided with a first connection structure (4) suitable for connection with the pump housing (2), and the bottom of the pump housing (2) is provided with a second connection structure (5) suitable for detachably connecting with the first connection structure (4); the first connection structure (4) and / or the second connection structure (5) are multiple and spaced apart along the circumferential direction, and the spacing angle of the multiple first connection structures (4) and / or the second connection structures (5) in the circumferential direction matches the spacing angle of the multiple first flow ports (311) in the circumferential direction.

3. The multi-orifice molecular pump with adjustable orifice according to claim 2, characterized in that: The first connection structure (4) comprises at least two first screw holes symmetrically arranged on the base (1); The second connection structure (5) comprises a plurality of second screw holes spaced apart along the circumference of the bottom connection end surface of the pump housing (2); Wherein, the first screw hole is a through stepped through hole, and the second screw hole is a threaded countersunk hole.

4. The multi-orifice molecular pump with adjustable orifice according to any one of claims 1 to 3, characterized in that: The pump housing (2) comprises an upper housing (22) and a lower housing (21); the lower housing (21) is detachably connected or rotatably connected between the base (1) and the upper housing (22); the drag stage (3) is arranged in the lower housing (21); the first flow port (311) is opened on the lower housing (21); and the multi-flow port molecular pump further comprises: The blade stage (6) comprises a plurality of isolation rings (61) disposed in the upper shell (22) and arranged in sequence along the axial direction of the upper shell (22), each isolation ring (61) being provided with a second flow opening (611), and the second flow openings (611) on the plurality of isolation rings (61) being staggered in the circumferential direction. The pump housing (2) is provided with a second communication port (221), which is a strip-shaped opening that can cover the second flow ports (611) on all isolation rings (61) in the axial direction of the pump housing (2), and is suitable for connecting the second communication port (221) with the second flow port (611) on any isolation ring (61) by rotating the upper housing (22).

5. The multi-orifice molecular pump with adjustable orifice according to claim 4, characterized in that: The upper shell (22) is detachably connected and fixed to the lower shell (21), and is suitable for disassembling the upper shell (22) and the lower shell (21) to rotate the upper shell (22), so that the second communication port (221) can be connected to the preset second flow port (611); The bottom of the upper shell (22) is provided with a third connecting structure (7) suitable for connecting to the lower shell (21), and the top of the lower shell (21) is provided with a fourth connecting structure (8) suitable for detachably connecting to the third connecting structure (7), and the third connecting structure (7) and / or the fourth connecting structure (8) are multiple and spaced apart along the circumferential direction, and the spacing angle of the multiple first connecting structures (4) and / or second connecting structures (5) in the circumferential direction matches the spacing angle of the multiple second flow ports (611) in the circumferential direction.

6. The multi-orifice molecular pump with adjustable orifices according to claim 5, characterized in that: The third connection structure (7) includes a plurality of third screw holes spaced apart along the circumference of the upper shell (22); The fourth connection structure (8) comprises at least two fourth screw holes symmetrically opened on the upper connection end surface of the lower shell (21); Wherein, the third screw hole is a through stepped through hole, and the fourth screw hole is a threaded countersunk hole.

7. The multi-orifice molecular pump with adjustable orifices according to claim 5, characterized in that: A plurality of first flow ports (311) are evenly spaced along the circumference of the drag stage stator (31); a plurality of second connection structures (5) are evenly spaced on the top of the lower shell (21); and an interval angle of the first flow ports (311) is an integer multiple of an interval angle of the second connection structures (5); And / or, a plurality of the second flow ports (611) are evenly spaced along the circumference of the drag stage stator (31), a plurality of the fourth connection structures (8) are evenly spaced on the top of the lower shell (21), and an interval angle of the second flow ports (611) is an integer multiple of an interval angle of the fourth connection structures (8).

8. The multi-orifice molecular pump with adjustable orifices according to claim 4, characterized in that: A first sealing structure for sealing the fitting gap between the lower shell (21) and the base (1) is provided between the lower shell (21) and the base (1); And / or, a second sealing structure for sealing the fitting gap between the upper shell (22) and the lower shell (21) is provided between the upper shell (22) and the lower shell (21).

9. The multi-orifice molecular pump with adjustable orifices according to claim 8, characterized in that: A plurality of screw holes suitable for connecting to the outlet end of an external air intake device are provided at intervals on the outer wall of the lower shell (21) located at the periphery of the first communication port (211) and on the upper shell (22) located at the periphery of the second communication port (221); And / or, sealing grooves are respectively formed on the outer wall of the lower shell (21) located at the periphery of the first communication port (211) and the upper shell (22) located at the periphery of the second communication port (221), and the sealing grooves are respectively filled with elastic sealing rings (9).

10. The multi-orifice molecular pump with adjustable orifices according to claim 4, characterized in that: The opening width of the plurality of first flow openings (311) is greater than the opening width of the first communicating hole; And / or, the opening width of the plurality of second flow openings (611) is greater than the opening width of the second communicating hole.

Images