TW202117189A - Turbo molecular pump and dustproof rotor element thereof - Google Patents

Abstract

A turbo molecular pump and a dustproof rotor element thereof are provided. The dustproof rotor element includes a rotor body, a plurality of rotor blade assembly and a dustproof cover. The rotor body has an exposed connection space. The dustproof cover is configured to seal the connection space and includes a cover body and a positioning structure. The cover body has two pressure-balancing holes that are in air communication with the connection space. The positioning structure extends from the cover body into the connection space, so as to seal the connection space. When the turbo molecular pump is in use, the dustproof cover can prevent particle substances from depositing in the connection space of the rotor body, and can eliminate the pressure difference between the inside and outside of the connection space.

Description

Turbo molecular pump and its dust-proof rotor element

The invention relates to a vacuum pump and its rotor, in particular to a turbomolecular pump and its dust-proof rotor.

At present, the main semiconductor manufacturing processes such as ion implantation, furnace tube, thin film sputtering, plasma etching, chemical mechanical polishing, etc., all need to be carried out in the cavity of the high vacuum process; therefore, the vacuum environment of the cavity is One of the key factors affecting the process yield, and a clean and stable vacuum environment helps to improve the process yield. As the heart of the vacuum system, the turbomolecular pump uses the rotor to rotate at a high speed relative to the stator to discharge the gas out of the process cavity to create a high vacuum environment.

However, some semiconductor manufacturing processes will generate a large number of particles in the pump. These particles are easy to accumulate in the gas-contacting places (such as the rotor and the exhaust port), which reduces the exhaust efficiency and affects the vacuum efficiency. In addition, these particles are also easy to accumulate in some exposed locking areas, and when the pressure changes, they move with the unstable airflow and return to the process cavity to cause pollution.

Therefore, how to improve the reliability of turbomolecular pumps and increase the process yield through structural design improvements has become one of the important issues that this business intends to solve.

The technical problem to be solved by the present invention is to provide a dust-proof rotor in view of the shortcomings of the prior art, which can take into account the process yield and the pressure balance inside the pump. In addition, a turbomolecular pump using the dust-proof rotor is provided.

In order to solve the above technical problems, one of the technical solutions adopted by the present invention is to provide a dust-proof rotor element, which includes a rotor seat, a plurality of rotor blade groups, and a dust cover. The rotor base has an exposed connecting chamber, a plurality of the rotor blade groups are connected to the rotor base and arranged at intervals, and the dust cover is used to seal the connecting chamber; wherein the dust cover includes a cover body And a positioning structure, the cover body has two pressure balance holes arranged oppositely and in gas communication with the connecting chamber, and the positioning structure extends from the bottom of the cover body into the connecting chamber and is connected to the connecting chamber. A seal is formed between the chambers.

In order to solve the above technical problem, another technical solution adopted by the present invention is to provide a turbomolecular pump, which includes a casing, a stator element, a dust-proof rotor element and a high-speed rotating shaft. The housing has a cavity, the stator element is arranged in the cavity, and includes a plurality of stator blade groups arranged at intervals, and the dust-proof rotor element is arranged in the cavity and includes a A rotor base, a plurality of rotor blade groups, and a dust cover, the high-speed rotating shaft is used to drive the dust-proof rotor element to rotate relative to the stator element; the rotor base has an exposed connecting chamber, and a plurality of the rotors The blade group is connected to the rotor seat and is arranged alternately up and down with a plurality of the stator blade groups. The dust cover is used to seal the connection chamber; wherein the dust cover includes a cover body and a positioning structure. The cover body has two gas pressure balance holes which are arranged oppositely and are in gas communication with the connecting chamber. The positioning structure extends from the bottom of the cover body into the connecting chamber and forms a seal with the connecting chamber.

In an embodiment of the present invention, a partition is provided inside the rotor base to define the connecting chamber, and a connecting passage communicating with the connecting chamber is provided on the partition; the high-speed rotating shaft It includes a shaft body and an extension part extending from the shaft body, and the position of the extension part corresponds to the connecting channel; the dust-proof cover also includes a connecting structure, which is arranged on the inner side of the positioning structure, and The connecting structure is fixed together with the extension part of the high-speed rotating shaft.

In an embodiment of the present invention, the shaft body has a central area and a peripheral area surrounding the central area, and the extension portion extends from the central area into the connecting passage.

In an embodiment of the present invention, the cover is closed on the connecting chamber.

In an embodiment of the present invention, each of the two air pressure balance holes has a columnar body, and the two columnar bodies can be applied with external force to make the dust cover rotate relative to the rotor base.

In an embodiment of the present invention, the dust cover further includes an elastic sealing ring, which is arranged on the positioning structure.

In an embodiment of the present invention, the positioning structure has a groove, and the elastic sealing ring is fixed on the positioning structure by the groove.

In an embodiment of the present invention, the cover has an outer surface, the positioning structure has an inner surface opposite to the outer surface, and the two air pressure balance holes extend from the outer surface to the outer surface. Mentioned inner surface.

In an embodiment of the present invention, the cover body further has two counterweight holes arranged oppositely.

In an embodiment of the present invention, the positioning structure has an undercut portion, a gap exists between the undercut portion and the cover, and a guide surface facing the boundary of the connecting chamber; The guiding surface is an inclined surface.

One of the beneficial effects of the present invention is that the dust-proof rotor element provided by the present invention can be connected to a high-speed rotating shaft through a connecting chamber of the rotor base. The dust-proof cover includes a cover body and a positioning structure, wherein the cover body There are two pressure balance holes arranged oppositely and connected to the connecting chamber. The positioning structure extends from the bottom of the cover into the connecting chamber and forms a seal with the connecting chamber to prevent the particles generated in the process from being deposited on the connecting chamber. Make sure that the pressure of the connecting chamber is consistent with the internal pressure of the pump to avoid generating unstable airflow to bring the particles back into the process cavity and cause pollution.

In order to further understand the features and technical content of the present invention, please refer to the following detailed description and drawings about the present invention. However, the drawings provided are only for reference and description, and are not used to limit the present invention.

In the semiconductor manufacturing process, many process stages have the problem of yield loss caused by random particle defects. Therefore, the present invention provides a turbomolecular pump for vacuuming the process cavity. The improvement lies in the use of dust-proof rotor elements. ; When in use, the dust-proof rotor element can not only prevent the particles generated by the process from being deposited in the connecting chamber with the shaft, but also ensure that the pressure in the connecting chamber is balanced with the internal pressure of the pump to prevent the particles from flying and moving back to the process cavity Pollution in the body.

The following is a specific embodiment to illustrate the implementation of the “turbomolecular pump and its dust-proof rotor element” disclosed in the present invention. Those skilled in the art can understand the advantages and effects of the present invention from the content disclosed in this specification. The present invention can be implemented or applied through other different specific embodiments, and various details in this specification can also be based on different viewpoints and applications, and various modifications and changes can be made without departing from the concept of the present invention. In addition, the drawings of the present invention are merely schematic illustrations, and are not drawn according to actual dimensions, and are stated in advance. The following embodiments will further describe the related technical content of the present invention in detail, but the disclosed content is not intended to limit the protection scope of the present invention.

It should be understood that although terms such as "first", "second", and "third" may be used herein to describe various elements or signals, these elements or signals should not be limited by these terms. These terms are mainly used to distinguish one element from another, or one signal from another signal. In addition, the term "or" used in this document may include any one or a combination of more of the associated listed items depending on the actual situation.

[First Embodiment]

1 to 4, the turbomolecular pump Z of the present invention mainly includes a housing 1, a stator element 2, a dust-proof rotor element 3, and a high-speed rotating shaft 4. The housing 1 has a cavity 100. The stator element 2, the dust-proof rotor element 3 and the high-speed rotating shaft 4 are all arranged in the cavity 100, and the dust-proof rotor element 3 can be driven by the high-speed rotating shaft 4 to rotate at a high speed relative to the stator element 2 . The turbomolecular pump Z can be connected to a processing chamber (not shown in the figure) of a semiconductor process equipment through a pipeline to pump the processing chamber to the vacuum required for a specific semiconductor process (such as an etching process), but the present invention is not limited Here.

In practical applications, the turbomolecular pump Z also includes a base 5 for assembling the housing 1, the stator element 2, the dust-proof rotor element 3, and the high-speed rotating shaft 4. An exhaust port 500 is provided on the base 5, and the base 5 includes a bearing mechanism 51 and a driving unit 52 (such as a motor). The high-speed rotating shaft 4 is arranged on the bearing mechanism 51. The bearing mechanism 51 can generate magnetic force to support the high-speed rotating shaft 4. The driving unit 52 can drive the high-speed rotating shaft 4 for high-speed rotation. The composition of the bearing mechanism 51, including mechanical bearings, radial magnetic bearings, axial magnetic bearings, etc., is well known to those skilled in the art, so it will not be repeated here.

The housing 1 is a two-piece housing, which includes a first housing 11 and a second housing 12; the first housing 11 is, for example, an upper housing, the second housing 12 is, for example, a lower housing, and the first housing The body 11 and the second shell 12 can be combined into one body by a locking method; the main parts of the first shell 11 and the second shell 12 are cylindrical, and they jointly form a cavity body 100. Furthermore, the first housing 11 and the second housing 12 have a gas guiding function, wherein the first housing 11 defines an upstream area of the cavity 100, and the first housing 11 has a communication with the cavity In addition, the second housing 12 defines the downstream area of the cavity 100, and the inner wall of the second housing 12 is provided with a threaded air guide groove 121. However, these details are only for describing possible embodiments of the housing 1 and are not intended to limit the present invention. In some embodiments, the housing 1 may also be a one-piece housing according to actual needs.

When the turbomolecular pump Z is evacuated, the gas will flow into the cavity 100 from the air inlet 111, and flow through the passage between the housing 1, the stator element 2 and the dust-proof rotor element 3, and then enter the air guide groove 121 After being compressed, it is discharged from the exhaust port 500.

Referring to Figures 1 to 4, in conjunction with Figures 5 and 6, the stator element 2 corresponds to the position of the dust-proof rotor element 3. The stator element 2 includes a plurality of spacers 21 and a plurality of stator blade groups 22. The stator blade group 22 extends in the radial direction, and is connected to the inner wall of the first housing 11 by a plurality of spacers 21 respectively, and is arranged in layers up and down; the spacers 21 may be ring-shaped, but are not limited thereto. The dust-proof rotor element 3 includes a rotor seat 31, a plurality of rotor blade groups 32, and a dust cover 33, wherein the rotor seat 31 has an exposed connecting chamber 300 for assembling the high-speed rotating shaft 4; the plurality of rotor blade groups 32 are connected In the rotor seat 31, a plurality of rotor blade groups 32 also extend in the radial direction and are alternately arranged with the plurality of stator blade groups 22; the dust cover 33 is used to seal the connecting chamber 300.

Furthermore, each stator blade group 22 includes a plurality of stator blades 221, and each rotor blade group 32 includes a plurality of rotor blades 321; the inclination direction of the plurality of rotor blades 321 is opposite to the inclination direction of the plurality of stator blades 221, and The inclination angle of the upper stator blades 221 is greater than or equal to the inclination angle of the lower stator blades 221, and the inclination angle of the upper rotor blades 321 is greater than or equal to the inclination angle of the lower rotor blades 321. Thereby, it can be ensured that the gas molecules irreversibly flow from the air inlet 111 to the air outlet 500. However, the number and the inclination angle of the stator blades 221 included in each stator blade group 22 and the number and the inclination angle of the rotor blades 321 included in each rotor blade group 32 are not particularly limited. In some embodiments, depending on the level of the stator blade group 22, the number of stator blades 221 can be selected from 16 to 48, and the inclination angle of the stator blades 221 can be between 13 degrees and 45 degrees. Adjustment; similarly, according to the different levels of the rotor blade group 32, the number of rotor blades 321 can be selected from 25 to 56, and the inclination angle of the rotor blades 321 can be adjusted between 13 degrees and 45 degrees .

The rotor seat 31 includes a first seat body 311 and a second seat body 312. The position of the first seat body 311 corresponds to the first housing 11, and the position of the second seat body 312 corresponds to the second housing 12; 300 is formed by being recessed downward from the top of the first seat body 311, and the position corresponds to the air inlet 111 of the first housing 11, and a plurality of rotor blades 321 are formed by extending from the outer wall of the first seat body 311. In this embodiment, the plurality of rotor blade groups 32, the first seat body 311, and the second seat body 312 are integrally formed; the first seat body 311 is tapered toward the air inlet 111, and the second seat body 312 is cylindrical. However, these details are only to describe possible implementations of the stator element 2 and the dust-proof rotor element 3 and are not intended to limit the present invention.

5 to 8, the dust cover 33 includes a cover 331, a positioning structure 332 and a connecting structure 333, wherein the cover 331 covers the connecting chamber 300, and has at least two oppositely arranged and connected with The gas pressure balance holes H1 of the chamber 300 are preferably two or four; the positioning structure 332 extends from the bottom of the cover 331 into the connecting chamber 300 and forms a seal with the connecting chamber 300; the connecting structure 333 is arranged in the positioning structure The inner side of 332 is used to connect the high-speed shaft 4 and make the high-speed shaft 4 in an upright state. It is worth noting that when the dustproof rotor element 3 rotates at high speed, the dustproof cover 33 can effectively block the process particles from entering the connecting chamber 300, and keep the pressure of the connecting chamber 300 consistent with the internal pressure of the pump through the air pressure balance hole H1 to avoid An unstable air flow is generated to bring the particles back into the process cavity and cause pollution.

In addition, the air pressure balance hole H1 can also achieve the effect of adjusting the rotor's dynamic balance weight, that is, the air pressure balance hole H1 can reduce the weight to improve the dynamic balance accuracy of the rotor. According to actual needs, the cover 331 may have at least two counterweight holes H2 opposite to the position where the air balance hole H1 is located, as shown in FIG. 5. In this embodiment, the air pressure balance hole H1 penetrates the outer surface S1 of the cover 331 and the inner surface S2 of the positioning structure 332, that is, extends from the outer surface S1 of the cover 331 to the inner surface S2 of the positioning structure 332, as shown in FIG. Shown, but not limited to this. In practical applications, the counterweight hole H2 may or may not penetrate the outer surface S1 of the cover 331 and the inner surface S2 of the positioning structure 332, as long as it does not affect the high-speed dynamic balance of the rotor.

Furthermore, the positioning structure 332 may be an annular rib, and the connecting structure 333 may include a cylindrical portion 3331 and a connecting portion 3332 coupled to the cylindrical portion 3331; the cylindrical portion 3331 and the connecting portion 3332 may be two separate parts. In this way, the dust cover 33 can adapt to different types of shafts and increase the structural strength of the rotor. The cylindrical portion 3331 and the connecting portion 3332 can be combined by screwing, that is, the cylindrical portion 3331 has an internal thread and the connecting portion 3332 has an external thread, but the present invention is not limited to this. In some embodiments, the cylindrical portion 3331 and the connecting portion may be integrally formed. It is worth noting that the cover 331 has a central highest point T, and the height of the cover 331 gradually decreases from the central highest point T outwards with a specific slope or curvature; thereby, the cover 331 can perform the function of guiding gas. That is, the gas flowing in from the air inlet 111 of the first housing 11 can flow along the upper surface of the cover 331 to the area where the rotor and stator blades 321 and 221 are located, and particles are prevented from being deposited on the cover 331.

Referring to FIGS. 4 to 6, as shown in FIGS. 7 and 8, in order to improve or better maintain the sealing effect of the connecting chamber 300, it is preferable to provide an elastic sealing ring 34 on the positioning structure 332. Furthermore, the outer wall of the positioning structure 332 may be provided with a groove R, and the elastic sealing ring 34 is fixed on the outer wall of the positioning structure 332 by the groove R. In addition, in the presence of the elastic sealing ring 34, the positioning structure 332 will be constrained by the elastic force provided by the elastic sealing ring 34, so that the axis of the dust cover 33 is always maintained on the axis defined by the high-speed rotating shaft 4.

In order to assemble the dust-proof rotor element 3 and the high-speed rotating shaft 4, as shown in FIG. 6, a partition 3111 is provided inside the first seat body 311 of the rotor seat 31 to define the connecting chamber 300, and the partition 3111 is There is a connecting passage 3112 communicating with the connecting chamber 300, and its position corresponds to the connecting structure 333 of the dust cover 33; the high-speed rotating shaft 4 includes a shaft 41 and an extension 42 extending from the shaft 41, wherein the extension 42 is along the shaft The axis of 41 extends and its position corresponds to the connecting channel 3112 to be fixed with the connecting structure 333 of the dust cover 33. Furthermore, as shown in FIG. 4, the shaft 41 has a central area 411 and a peripheral area 412 surrounding the central area 411. The extension 42 extends from the central area 411 through the connecting passage 3112 into the connecting chamber 300; 42 and the connecting portion 3332 can be combined by screwing, that is, the extension portion 42 has an internal thread and the connecting portion 3332 has an external thread. However, these details are only for describing possible implementations of the high-speed rotating shaft 4 and are not intended to limit the present invention. In some embodiments, the extension 42 may only extend to the connection channel 3112 without entering the connection chamber 300.

Referring to FIG. 9, in the presence of the air pressure balance hole H1, the dust cover 33 can be directly connected to the rotor base 31 without using any tools. Furthermore, a cylindrical body 6 (such as a latch) can be respectively inserted into the two opposite air pressure balance holes H1, and an external force can be applied to the two cylindrical bodies 6 at the same time to make the dust cover 33 rotate relative to the rotor base 31 , And then insert the connecting portion 3332 into the extension portion 42 of the high-speed rotating shaft 4.

[Second Embodiment]

10 and 11, the difference between the second embodiment and the first embodiment is mainly that the positioning structure 332 of the dust cover 33 has an undercut portion 3321, wherein the undercut portion 3321 has a boundary facing the connecting chamber 300 There is a gap G between the undercut portion 3321 and the cover 331; the guiding surface S3 can be an inclined surface, but is not limited to this. Thereby, during the assembly process, the interference between the positioning structure 332 and the boundary of the connecting chamber 300 can be reduced, so that the dust cover 33 can be assembled on the rotor base 31 more easily. After the assembly is completed, the undercut portion 3321 can press against the inner surface (not labeled) of the connecting chamber 300 to produce a pressing effect, and at the same time, part of the undercut portion 332 will be squeezed into the gap G, so that the axis of the dust cover 33 It can always remain on the axis defined by the high-speed rotating shaft 4.

[Beneficial effects of the embodiment]

One of the beneficial effects of the present invention is that the dust-proof rotor element provided by the present invention can be connected to a high-speed rotating shaft through a connecting chamber of the rotor base. The dust-proof cover includes a cover body and a positioning structure, wherein the cover body There are two pressure balance holes arranged oppositely and connected to the connecting chamber. The positioning structure extends from the bottom of the cover into the connecting chamber and forms a seal with the connecting chamber to prevent the particles generated in the process from being deposited on the connecting chamber. Make sure that the pressure of the connecting chamber is consistent with the internal pressure of the pump to avoid generating unstable airflow to bring the particles back into the process cavity and cause pollution.

Furthermore, in the presence of the air pressure balance hole, there is no need to use any tools, and the dust cover is directly connected to the rotor seat, so it is more convenient to use.

Furthermore, the positioning structure of the dust cover may have an elastic sealing ring to improve or better maintain the sealing effect of the connecting chamber. In addition, in the presence of the elastic sealing ring, the positioning structure will be restricted by the elastic force provided by the elastic sealing ring, so that the dust cover is always kept on the axis of the high-speed rotating shaft.

Furthermore, in order to make it easier to assemble the dust cover on the rotor base and keep the axis of the dust cover on the axis of the rotating shaft, the positioning structure of the dust cover may have an undercut part, wherein the undercut part has a facing The guide surface is connected to the boundary of the chamber, and there is a gap between the undercut part and the cover.

The content disclosed above is only the preferred and feasible embodiments of the present invention, and does not limit the scope of the patent application of the present invention. Therefore, all equivalent technical changes made by using the description and schematic content of the present invention are included in the application of the present invention. Within the scope of the patent.

Z: Turbomolecular pump 1: shell 100: cavity 11: The first shell 111: air inlet 12: The second shell 121: air guide groove 2: stator element 21: Spacer 22: Stator blade group 221: Stator blades 3: Dust-proof rotor element 300: connecting room 31: Rotor seat 311: First Block 3111: partition 3112: connection channel 312: Second Block 32: Rotor blade group 321: rotor blade 33: Dust cover 331: Lid H1: Air pressure balance hole H2: Counterweight hole S1: Outer surface T: The highest point in the center 332: positioning structure 3321: Barb S2: Inside surface S3: Guide surface R: card slot G: gap 333: connection structure 3331: Cylinder 3332: connecting part 34: Elastic sealing ring 4: High-speed shaft 41: Shaft 411: Central Area 412: Surrounding Area 42: Extension 5: Base 500: exhaust port 51: bearing mechanism 52: drive unit 6: Cylinder

FIG. 1 is a schematic diagram of the three-dimensional assembly of the turbomolecular pump according to the first embodiment of the present invention.

FIG. 2 is a three-dimensional exploded schematic diagram of the turbomolecular pump according to the first embodiment of the present invention.

FIG. 3 is another three-dimensional exploded schematic diagram of the turbomolecular pump according to the first embodiment of the present invention.

Fig. 4 is a schematic cross-sectional view of the IV-IV section of Fig. 1.

Fig. 5 is a three-dimensional schematic diagram of the dust-proof rotor element according to the first embodiment of the present invention.

Fig. 6 is a schematic plan view of the dust-proof rotor element of the first embodiment of the present invention.

FIG. 7 is a schematic diagram of one of the structures of the dust cover of the first embodiment of the present invention.

FIG. 8 is another schematic diagram of the structure of the dust cover of the first embodiment of the present invention.

Fig. 9 shows the assembly process of the dust cover with the rotor base and the high-speed rotating shaft according to the first embodiment of the present invention.

FIG. 10 is a schematic diagram of the structure of the dust cover of the second embodiment of the present invention.

Fig. 11 shows the assembly process of the dust cover and the rotor base of the second embodiment of the present invention.

Z: Turbomolecular pump

1: shell

11: The first shell

111: air inlet

12: The second shell

33: Dust cover

5: Base

500: exhaust port

Claims (18)

A dust-proof rotor element, which includes: A rotor seat with an exposed connecting chamber; A plurality of rotor blade groups connected to the rotor base and arranged at intervals; and A dustproof cover for sealing the connecting chamber, wherein the dustproof cover includes a cover body and a positioning structure, the cover body has two pressure balance holes arranged oppositely and in gas communication with the connecting chamber, the The positioning structure extends from the bottom of the cover body into the connecting chamber, and forms a seal with the connecting chamber. According to the dust-proof rotor element described in item 1 of the scope of patent application, the cover body is closed on the connecting chamber. The dust-proof rotor element described in item 2 of the scope of patent application, wherein each of the two air pressure balance holes has a columnar body, and the two columnar bodies can be applied with external force to make the dust cover face each other. Rotate on the rotor base. According to the dust-proof rotor element described in item 2 of the scope of patent application, the dust-proof cover further includes an elastic sealing ring arranged on the positioning structure. According to the dust-proof rotor element described in item 4 of the scope of patent application, the positioning structure has a groove, and the elastic sealing ring is fixed on the positioning structure by the groove. According to the dust-proof rotor element described in claim 1, wherein the cover has an outer surface, the positioning structure has an inner surface opposite to the outer surface, and two air pressure balance holes Extending from the outer surface to the inner surface. According to the dust-proof rotor element described in item 1 of the scope of patent application, the cover body further has two counterweight holes arranged oppositely. The dust-proof rotor element according to the first item of the scope of patent application, wherein the positioning structure has an undercut portion, a gap exists between the undercut portion and the cover, and there is a connection facing the The guiding surface of the boundary of the chamber; wherein the guiding surface is an inclined surface. A turbomolecular pump, which includes: A shell with a cavity; The stator element is arranged in the cavity and includes a plurality of stator blade groups arranged at intervals; A dust-proof rotor element arranged in the cavity, wherein the dust-proof rotor element includes: A rotor seat with an exposed connecting chamber; A plurality of rotor blade groups are connected to the rotor base and are alternately arranged up and down with the plurality of stator blade groups; and A dustproof cover for sealing the connecting chamber, wherein the dustproof cover includes a cover body and a positioning structure, the cover body has two pressure balance holes arranged oppositely and in gas communication with the connecting chamber, the The positioning structure extends from the bottom of the cover body into the connecting chamber and forms a seal with the connecting chamber; and A high-speed rotating shaft is used to drive the dust-proof rotor element to rotate relative to the stator element. The turbomolecular pump according to item 9 of the scope of patent application, wherein a partition is provided inside the rotor base to define the connecting chamber, and the partition is provided with a connecting chamber that communicates with the connecting chamber The connecting passage; the high-speed shaft includes a shaft body and an extension formed from the shaft body, and the location of the extension corresponds to the connecting passage; the dust cover also includes a connecting structure, which is arranged in The inner side of the positioning structure, and the connecting structure and the extension part of the high-speed rotating shaft are fixed together. The turbomolecular pump according to claim 10, wherein the shaft body has a central area and a peripheral area surrounding the central area, and the extension portion extends from the central area into the Connect the channel. The turbomolecular pump according to item 9 of the scope of patent application, wherein the cover is covered on the connecting chamber. The turbomolecular pump described in item 12 of the scope of patent application, wherein each of the two air pressure balance holes has a columnar body, and the two columnar bodies can be applied with external force to make the dust cover face each other. Rotate on the rotor base. According to the turbomolecular pump described in item 12 of the scope of patent application, the dust cover further includes an elastic sealing ring disposed on the positioning structure. According to the turbomolecular pump described in claim 14, wherein the positioning structure has a groove, and the elastic sealing ring is fixed on the positioning structure by the groove. The turbomolecular pump according to claim 9, wherein the cover has an outer surface, the positioning structure has an inner surface opposite to the outer surface, and two air pressure balance holes Extending from the outer surface to the inner surface. The turbomolecular pump according to item 9 of the scope of patent application, wherein the cover body further has two counterweight holes arranged opposite to each other. The turbomolecular pump according to item 9 of the scope of patent application, wherein the positioning structure has an undercut portion, and there is a gap between the undercut portion and the cover, and has a connection facing the The guiding surface of the boundary of the chamber; wherein the guiding surface is an inclined surface.

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