TWI828573B - Rotor cap for turbomolecular vacuum pump - Google Patents

Abstract

A rotor cap for a turbo molecular vacuum pump is disclosed. The rotor cap comprises a cover element and a connection element, wherein the side wall and the top surface of the cover element are curved smoothly, and the connection element comprises an extension rod and a hardness and weight adjusting element. The first end of the extension rod is connected to the bottom center of the cover element, the second end of the extension rod is extended in a direction away from the cover element to be adjacent to a rotor shaft, and the hardness and weight adjusting element is connected between the second end of the extension rod and the rotor shaft to reduce the hardness difference between the extension rod and the rotor shaft and to provide a counterweight effect to reduce the rotational vibration of the cover element.

Description

Rotor cover for turbomolecular vacuum pump

The present invention relates to a cover, and in particular to a rotor cover for a turbomolecular vacuum pump.

The current turbomolecular vacuum pump can drive the rotor connected to it to perform the vacuum pumping process. The center of the rotor is concave in the direction of the turbomolecular vacuum pump to form a locking space, so that the rotor and turbine can be assembled by fixing elements such as bolts. Molecular vacuum pump. However, when a turbomolecular vacuum pump is used in etching processes such as wafers or electronic substrates, the dust particles generated during the processing are easy to accumulate in the locking space, and the airflow generated by the rotor during the processing is easy to cause the locking space to accumulate. The dust particles in the machine float back to the processing area with the airflow, which may cause contamination of the wafers or electronic substrates in the processing area. Therefore, in order to prevent dust particles from accumulating in the locking chamber, U.S. Patent No. 3908977 discloses a product with a rotor cover designed to close the locking chamber above the rotor. The rotor cover penetrates from the outside to the inside and is locked in the locking chamber. Bolts on the bottom side. However, there is still a small amount of space for dust particles to accumulate in the bolt locking area, so the blocking connection of the cover is not perfect, and the bolt locking can easily overly force the rotor cover, causing the rotor cover to be deformed and broken after the rotor rotates at high speed.

In addition, in the traditional bolt locking technology, when the rotor cover rotates at high speed, rotational vibration is likely to occur, causing the rotor's center of gravity to shift or lose the sealing effect. If bolts extending from the bottom of the rotor cover are used to connect the bottom side of the locking chamber, the rotor cover will still produce rotational vibration and/or wear. In view of this, one object of the present invention is to provide a rotor cover for a turbomolecular vacuum pump, so as to overcome the above long-standing but unsolvable technical problems.

In order to achieve the above object, the present invention proposes a rotor cover for a turbomolecular vacuum pump. A rotating shaft is protruding above the turbomolecular vacuum pump. A rotor is set on the rotating shaft. There is a locking chamber recessed in the center of the rotor. The locking chamber is recessed in the center of the rotor. The center of the connecting chamber is fixed to the rotating shaft. The rotor cover includes: a covering element, the side wall and top surface of the covering element are smooth curved surfaces; and a connecting element including: an extension rod and a hardness and weight adjustment element, the extension A first end of the rod is connected to the center of the bottom surface of the covering element, a second end of the extension rod is extended in a direction away from the covering element to be adjacent to the rotation axis, and the hardness and weight adjustment element is connected to the extension rod between the second end and the rotating shaft, thereby reducing the hardness difference between the connecting element and the rotating shaft, and providing a counterweight effect to reduce the rotational vibration of the covering element.

Wherein, the first end of the extension rod is integrally connected to the center of the bottom surface of the covering element.

Wherein, the first end of the extension rod is screwed to the center of the bottom surface of the covering element.

Wherein, the top end of the rotating shaft is concave to form a first screw hole, the second end of the extension rod is concave to form a second screw hole, and the first end of the hardness and weight adjustment element is a first screw hole. Bolt, the second end of the hardness and weight adjustment element is a second bolt, the first bolt of the hardness and weight adjustment element is used to screw the first screw hole of the rotating shaft, the hardness and weight adjustment The second bolt of the component is used to screw the second screw hole of the extension rod.

Wherein, the diameter of the first bolt of the hardness and weight adjustment element is greater than the diameter of the second bolt, and the diameter of the first bolt corresponds to the diameter of the first screw hole of the rotating shaft, and the diameter of the second bolt Corresponding to the diameter of the second screw hole of the extension rod.

Wherein, the first bolt of the hardness and weight adjustment element and the extension rod have a length ratio, and the length ratio is between 1:7 and 7:1.

Wherein, the first bolt of the hardness and weight adjustment element and the extension rod have a length ratio, and the length ratio is 1:7.

Wherein, the diameters of the second end of the extension rod and the first end of the hardness and weight adjustment element are substantially the same.

Wherein, the top end of the rotating shaft is recessed to form a first screw hole, and the hardness and weight adjustment element covers the second end of the extension rod to jointly form a first bolt to screw the rotating shaft. First screw hole.

It further includes a fixture, one end of which is concave to form a clamping space, and a clamping element is provided in the clamping space, wherein when the covering element is placed in the clamping space of the fixture When in position, the clamping element holds the surface of the covering element and drives the rotor cover to rotate by rotating the jig.

Wherein, the side or top surface of the covering element is a completely curved surface, and when the covering element is placed in the clamping space of the jig, the clamping element holds the completely curved surface of the covering element by rotating The jig is used to drive the rotor cover to rotate, wherein the clamping element is a plate body, a rod body or a ring body.

Wherein, the side or top surface of the covering element has a flat area or a recessed area, and when the covering element is placed in the clamping space of the jig, the clamping element holds the flat area of the covering element. The surface area or the recessed area drives the rotor cover to rotate by rotating the jig, wherein the clamping element is a plate body, a rod body or a ring body.

Wherein, when the turbomolecular vacuum pump is running, the rotational vibration changes of the top surface and the bottom surface of the covering element are both less than a target value.

Among them, the target value is 15μm.

Wherein, the hardness of a first end of the hardness and weight adjustment element is substantially the same as the hardness of the rotating shaft, and the hardness of a second end of the hardness and weight adjustment element is substantially the same as the hardness of the extension rod.

Wherein, the hardness of a first end of the hardness and weight adjustment element is substantially the same as the hardness of the rotating shaft, and the hardness of a second end of the hardness and weight adjustment element is substantially different from the hardness of the extension rod.

Wherein, when the rotor cover covers the locking chamber of the rotor, the rotor cover is connected to the rotating shaft only with a first end of the hardness and weight adjustment element of the connecting element.

Based on the above, the rotor cover for a turbomolecular vacuum pump according to the present invention can not only keep the locking chamber of the turbomolecular vacuum pump sealed, but also can produce a counterweight effect through the connecting element with the hardness and weight adjustment element. The rotational vibration phenomenon of the covering element of the rotor cover is reduced, and by reducing the hardness difference, the wear of the connecting element when connecting the rotating shaft can be reduced.

In order to enable Jun Shen to have a further understanding of the technical features and technical effects of the present invention, preferred embodiments and accompanying detailed descriptions are provided below.

10:Rotor cover

20: Covering components

22: Plane area

24:Sag area

30:Connection component

32:Extension rod

32a: first end

32b:Second end

33:Second screw hole

34: Hardness and weight adjustment components

34a: first end

34b:Second end

35:First bolt

37:Second bolt

38: Clamping area

60:Jig

62: Clamping space

64: Clamping components

100: Turbomolecular vacuum pump

102:Rotation axis

104:First screw hole

110:Rotor

112:Lock room

Figure 1 is a schematic diagram of the appearance of the rotor cover used in the turbomolecular vacuum pump of this invention.

Figure 2 is a cross-sectional exploded view of the rotor cover used in the turbomolecular vacuum pump of this invention.

Figure 3 is a schematic cross-sectional view of the rotor cover for the turbomolecular vacuum pump of the present invention installed on the turbomolecular vacuum pump.

Figure 4 is a schematic top view of the rotor cover used in the turbomolecular vacuum pump of this invention, the side of which is completely curved.

Figure 5 is a schematic top view of a rotor cover for a turbomolecular vacuum pump with a flat area on its side.

Figure 6 is a schematic top view of the rotor cover of the present invention with a recessed area on its side.

Figure 7 is a schematic bottom perspective view of the ring-shaped clamp used for the rotor cover of the turbomolecular vacuum pump of this invention.

Figure 8 is a schematic bottom perspective view of the rod used for the rotor cover of the turbomolecular vacuum pump of this invention.

Figure 9 is a schematic bottom perspective view of the clamp used for the rotor cover of the turbomolecular vacuum pump of this invention as a plate body.

In order to facilitate understanding of the technical features, content and advantages of this creation and the effects it can achieve, this creation is described in detail below with the drawings and in the form of expressions of embodiments, and the terms used therein are described below. The purpose of the drawings is only for illustration and auxiliary instruction, and may not represent the actual proportions and precise configurations of this creation after implementation. Therefore, the proportions and configuration relationships of the attached drawings should not be interpreted or limited to the actual implementation of this creation. scope of rights. In addition, to facilitate understanding, the same elements in the following embodiments are labeled with the same symbols for explanation.

Please refer to Figures 1 and 2 together. Figure 1 is a schematic diagram of the appearance of the rotor cover used in the turbomolecular vacuum pump of the present invention. Figure 2 is a cross-sectional exploded schematic diagram of the rotor cover used in the turbomolecular vacuum pump of the present invention. The invention is a rotor cover 10 for a turbomolecular vacuum pump 100. As shown in Figure 3, a rotating shaft 102 is protruding above the turbomolecular vacuum pump 100. There is a locking chamber 112 recessed in the center of the rotor 110. The rotor 110 is sleeved on the rotating shaft 102, and the rotating shaft 102 is fixed to the center of the locking chamber 112 of the rotor 110, so that the rotor 110 is sleeved on the rotating shaft 102. . The rotating shaft 102 may be fixed to the center of the locking chamber 112 of the rotor 110 by, for example, threaded fitting or other components. Wherein, the outer surface of the rotating shaft 102 has threads, for example, and the other components mentioned above can be, for example, nuts. The rotating shaft 102 is locked to the locking chamber 112 of the rotor 110 by screwing the nut into the thread. Alternatively, bolts (not shown) may be passed from top to bottom through the locking chamber 112 of the rotor 110 and screwed into a screw hole (not shown) formed in the concave top surface of the rotating shaft 102 . In other words, this invention is not limited to the method used to fix the rotating shaft 102 to the locking chamber 112 of the rotor 110. As long as the rotating shaft 102 can drive the rotor 110 to rotate, it is applicable to this invention and falls within the scope of the protection claimed by this invention. .

The rotor cover 10 of the present invention includes a covering component 20 and a connecting component 30 . The covering element 20 is used to cover the lock chamber 112 of the rotor 110 to prevent process particles in the process chamber of the gas extracted by the turbomolecular vacuum pump 100 from being deposited or accumulated in the lock chamber 112 . The top shape of the covering element 20 of the rotor cover 10 of the present invention is, for example, conical, hemispherical or flat, but is not limited thereto. The side walls and top surface of the covering element 20 are preferably smooth curved surfaces to effectively guide the airflow and stabilize it. In addition, coverage The side walls and top surface of the component 20 are not limited to completely curved surfaces, that is, the side walls or top surfaces covering the component 20 may also have flat areas or recessed areas, for example. The bottom shape of the covering element 20 may be, for example, conical, hemispherical or flat. In addition, the top surface and the bottom surface of the covering element 20 are not limited to substantially corresponding to each other, but have the same shape. For example, the top surface and the bottom surface of the covering element 20 may not correspond to each other and have different shapes. In other words, as long as the rotor cover 10 can guide airflow and the center of its bottom surface can be connected to the rotating shaft 102 of the turbomolecular vacuum pump 100 through the connecting element 30, it is applicable to this invention and falls within the scope of protection claimed by this invention.

The two ends of the connecting element 30 of the rotor cover 10 of the present invention are used to connect the bottom center of the covering element 20 of the rotor cover 10 and the top center of the rotating shaft 102 of the turbomolecular vacuum pump 100 respectively, so that the covering element 20 can be detachably covered. The locking chamber 112 of the turbomolecular vacuum pump 100. In addition, the bottom surface of the rotor cover 10 of the present invention may, for example, have a sealing gasket (not shown). When the covering element 20 covers the locking chamber 112 of the rotor 110, the sealing gasket is located between the covering element 20 and the locking chamber 112 of the rotor 110. in order to enhance the air sealing effect.

A special feature of this creation is that the connecting element 30 includes an extension rod 32 and a stiffness and weight adjustment element 34 . The first end 32a of the extension rod 32 is integrally connected or detachably connected to the bottom center of the covering element 20. The above-mentioned integral connection method can be, for example, integrally formed, but is not limited to this. If the first end 32a of the extension rod 32 is integrally formed and connected to the center of the bottom surface of the covering element 20, then the materials of the extension rod 32 and the covering element 20 are the same. If the first end 32a of the extension rod 32 is detachably connected to the bottom center of the covering element 20, the materials of the extension rod 32 and the covering element 20 may be the same or different. The above-mentioned detachable connection method can be, for example, screw connection, but is not limited to this. The two ends of the connecting element 30 are respectively connected to the covering element 20 and the rotating shaft 102 via the extension rod 32 and the hardness and weight adjustment element 34 . In one embodiment, the second end 32b of the extension rod 32 is provided with a hardness and weight adjustment element 34, wherein the hardness and weight adjustment element 34 can For example, the second end 32 b of the extension rod 32 is covered to form a first bolt 35 , wherein the connecting element 30 is connected to the rotating shaft 102 with the first bolt 35 . Or, in another embodiment, the second end 34b of the hardness and weight adjustment element 34 is connected to the second end 32b of the extension rod 32 via a second bolt 37, and the first end 34a of the hardness and weight adjustment element 34 has a third A bolt 35, wherein the connecting element 30 is connected to the rotating shaft 102 through the first bolt 35. Or, in another embodiment, the second end 34b of the hardness and weight adjustment element 34 is screwed into the second screw hole 33 of the second end 32b of the extension rod 32 through the second bolt 37, and the hardness and weight adjustment The first end 34a of the element 34 has a first bolt 35, wherein the connecting element 30 is connected to the rotating shaft 102 through the first bolt 35. The first bolt 35 may, for example, have a clamping area 38 , which may be a flat surface. The user may clamp the clamping area 38 , for example, with a clamp, thereby adjusting the second part of the hardness and weight adjustment component 34 . The bolt 37 is screwed into the second screw hole 33 of the second end 32b of the extension rod 32 .

In order to prevent the rotor cover 10 from shaking or swinging due to a high center of gravity when the turbomolecular vacuum pump 100 rotates at high speed, the covering element 20 and the connecting element 30 are preferably made of lightweight materials such as aluminum or aluminum alloy. The rotating shaft 102 of the turbomolecular vacuum pump 100 is usually made of corrosion-resistant and high-hardness materials such as stainless steel or nickel plating. However, because the hardness of aluminum or aluminum alloy is lower than stainless steel, if the extension rod 32 made of aluminum or aluminum alloy is directly screwed The rotating shaft 102 made of stainless steel or nickel plating is prone to wear and tear, chipping, and other wear phenomena. Therefore, another feature of this creation is that the connecting element 30 has an extension rod 32 and a hardness and weight adjustment element 34. The extension rod 32 is preferably made of a material with lighter weight but lower hardness such as aluminum or aluminum alloy. The hardness and The weight adjustment element 34 is preferably made of nickel-plated metal (such as nickel-plated aluminum or nickel-plated aluminum alloy) or stainless steel and other high-hardness materials. Therefore, the present invention can avoid the occurrence of rotational vibration of the covering element 20 and the occurrence of rotational vibration of the connecting element 30 at the same time. Wear phenomena such as loss or chipping. The length ratio of the hardness and weight adjustment element 34 to the extension rod 32 ranges from, but is not limited to, 1:7 to 7:1, and is preferably 1:7. The hardness and weight adjustment element 34 of the connecting element 30 of the present invention is It is connected between the second end 32b of the extension rod 32 and the rotation shaft 102, thereby reducing the hardness difference between the extension rod 32 and the rotation shaft 102 of the connecting element 30, and providing a counterweight effect to reduce the impact of the covering element 20 when rotating at high speed. Vibration occurs.

Taking the embodiment in which the hardness and weight adjustment element 34 is screwed to the extension rod 32 as an example, the first end 34a of the hardness and weight adjustment element 34 of the present invention is detachably connected to the rotating shaft 102 of the turbomolecular vacuum pump 100. The hardness and weight The second end 34b of the adjusting element 34 is detachably provided on the second end 32b of the extension rod 32. For example, the top end of the rotating shaft 102 of the turbomolecular vacuum pump 100 is concave to form a first screw hole 104, and the second end 32b of the extension rod 32 of the rotor cover 10 is concave to form a second screw hole 33. The hardness and weight The first end 34a of the adjustment element 34 is the first bolt 35, and the second end 34b of the hardness and weight adjustment element 34 is the second bolt 37. The first bolt 35 of the hardness and weight adjustment element 34 is used to screw into the first screw hole 104 of the rotating shaft 102 , and the second bolt 37 of the hardness and weight adjustment element 34 is used to screw into the second screw hole of the extension rod 32 33. The length ratio of the first bolt 35 of the hardness and weight adjustment element 34 to the extension rod 32 ranges from about 1:7 to about 7:1, and is preferably about 1:7.

Among them, the connecting element 30 of the present invention is, for example, a columnar rod. For example, the diameter of the extension rod 32 is substantially the same as the diameter of the hardness and weight adjustment element 34, thereby effectively avoiding increasing the weight of the connecting element 30. The diameter of the first bolt 35 of the hardness and weight adjustment element 34 is, for example, substantially larger than the diameter of the second bolt 37 , and the diameter of the first bolt 35 corresponds to the diameter of the first screw hole 104 of the rotating shaft 102 , and the diameter of the second bolt 37 Corresponds to the diameter of the second screw hole 33 of the extension rod 32 . The diameters of the second end 32b of the extension rod 32 and the first end 34a of the hardness and weight adjustment element 34 are, for example, substantially the same.

Since the first end 34a of the hardness and weight adjustment element 34 is screwed into the first screw hole 104 formed by the concave top of the rotating shaft 102, the hardness of the first end 34a of the hardness and weight adjustment element 34 is preferably approximately The hardness of the rotating shaft 102 is, and preferably is substantially the same, so as to reduce the friction between the extension rod 32 and the rotating shaft 102 . Difference in hardness between shafts 102. The hardness and weight adjustment element 34 is detachably screwed to the second end 32b of the extension rod 32 with the second end 34b. Therefore, the hardness of the second end 34b of the hardness and weight adjustment element 34 is preferably similar to the hardness of the extension rod 32. , and preferably are substantially the same, so as to reduce the hardness difference between the hardness and weight adjustment element 34 and the extension rod 32 . However, the invention is not limited thereto. The hardness of the second end 34b of the hardness and weight adjustment element 34 may also be different from, for example, greater than or less than, the hardness of the second end 32b of the extension rod 32, as long as the hardness of the second end 34b of the hardness and weight adjustment element 34 is The hardness of the one end 34a is similar to or the same as the hardness of the rotating shaft 102, which can reduce the hardness difference between the connecting element 30 and the rotating shaft 102 and reduce the occurrence of wear. Similarly, the hardness and weight adjustment element 34 of the present invention can also be replaced by adjustment elements with other physical properties, such as rigidity, volume, density or thermal expansion or magnetism, to reduce the physical friction between the connecting element 30 and the rotation axis 102 . Characteristic differences.

Thereby, when the rotating shaft 102 of the turbomolecular vacuum pump 100 rotates at high speed, the rotor cover 10 of the present invention can not only keep the locking chamber 112 of the turbomolecular vacuum pump 100 sealed, but also has the hardness of the connecting element 30 of the rotor cover 10 and weight adjustment element 34. Therefore, the hardness and weight adjustment element 34 can produce a counterweight effect to reduce the rotational vibration phenomenon of the covering element 20 of the rotor cover 10, and reduce the hardness difference to reduce the connection element 30 to the rotation axis. Wear occurs at 102.

The disassembly direction of the hardness and weight adjustment element 34 and the extension rod 32 is, for example, opposite to the rotation direction of the rotation axis 102 , and the installation direction of the hardness and weight adjustment element 34 and the extension rod 32 is, for example, the same as the rotation direction of the rotation axis 102 . The rotation direction can prevent the rotor cover 10 from deflecting when the rotating shaft 102 rotates. Similarly, the disassembly direction of the hardness and weight adjustment element 34 and the rotation shaft 102 is, for example, opposite to the rotation direction of the rotation shaft 102 , and the installation direction of the hardness and weight adjustment element 34 and the rotation shaft 102 is, for example, the same as the rotation shaft 102 . The rotation direction can prevent the rotor cover 10 from deflecting when the rotating shaft 102 rotates. However, the above disassembly and installation directions are only examples and are not intended to limit this creation.

In other words, the rotor cover 10 of the present invention can reduce the loss or chipping and other wear phenomena that may occur due to the difference in material hardness between the connecting element 30 and the rotating shaft 102, and through weight adjustment, such as reducing the height of the center of gravity of the connecting element 30, It can reduce the phenomenon of rotational vibration caused by the covering element 20 of the rotor cover 10 when the rotating shaft 102 of the turbomolecular vacuum pump 100 rotates at high speed, and for example, the vibration changes of the top and bottom surfaces of the covering element 20 can be less than a target value. In actual operation, when the rotational speed of the rotating shaft 102 reaches about 27,660rpm~27,780rpm, the above target value can be about 15 μm.

In addition, the rotor cover 10 for the turbomolecular vacuum pump of the present invention further includes a fixture 60 . The jig 60 is used to clamp the covering element 20 of the rotor cover 10. By rotating the jig 60, the covering element 20 can be driven to rotate. One end of the jig 60 is concave to form a clamping space 62 , and the clamping space 62 has a clamping element 64 . When the user covers the rotor cover 10 with the jig 60, and when the covering element 20 is placed in the clamping space 62 of the jig 60, the clamping element 64 of the jig 60 can hold the surface of the covering element 20, so by Rotating the fixture 60 clockwise or counterclockwise can drive the rotor cover 10 to rotate, so that the rotor cover 10 can be installed on the rotating shaft 102 or the rotor cover 10 can be removed. Wherein, the clamping element 64 is, for example, a plate body, a rod body or a ring body. In addition, the clamping element 64 can be fixedly or detachably arranged in the clamping space 62 of the jig 60 , or the clamping element 64 can also be resettly arranged in the clamping space 62 of the jig 60 . For example, the clamping element 64 can be repositionably disposed in the clamping space 62 of the jig 60 by the elastic force of a spring or the elastic force of the clamping element 64 itself, so as to hold the surface of the covering element 20 .

Among them, the side or top surface of the covering element 20 can be completely curved, that is, it does not have a flat area or a recessed area (see Figure 4). Alternatively, the curved surface of the side or top surface of the covering element 20 may further have a flat area 22 (see FIG. 5 ) or a recessed area 24 (see FIG. 6 ). When the cover element 20 is placed in the clamping space 62 of the jig 60, the clamping element 64 is used to hold the flat area 22 or the recessed area 24 of the cover element 20, and the rotor cover 10 is driven to rotate by rotating the jig 60. Wherein, the clamping element 64 is, for example, a plate body (see Figure 9) or a rod body (see Figure 8) Or ring body (see Figure 7). For example, the clamping element 64 can be a plate, a rod or a ring disposed on the inner surface of the clamping space 62 of the jig 60 , where the material of the plate, rod or ring is, for example, rubber or metal. The metal is, for example, aluminum, aluminum alloy or stainless steel. The fixture 60 can tighten the side wall of the covering element 20 by the fastening force of the rubber plate, rod or ring, so as to drive the rotor cover 10 to rotate. Alternatively, the shape of the plate, rod or ring on the inner surface of the clamping space 62 may, for example, correspond to the flat area 22 or the recessed area 24 on the curved surface of the side wall of the covering element 20, whereby the clamping element of the jig 60 64 can be close to the flat area 22 or the recessed area 24 on the curved surface of the covering element 20 to drive the rotor cover 10 to rotate.

To sum up, the rotor cover for a turbomolecular vacuum pump of the present invention can not only keep the locking chamber of the turbomolecular vacuum pump sealed, but also can produce a counterweight effect through the connecting element with the hardness and weight adjustment element to reduce the The rotational vibration phenomenon of the covering element of the rotor cover and by reducing the hardness difference can reduce the wear of the connecting element when connecting the rotating shaft.

The above is only illustrative and not restrictive. Any equivalent modifications or changes that do not depart from the spirit and scope of the present invention shall be included in the appended patent scope.

10:Rotor cover

20: Covering components

30:Connection component

32:Extension rod

32a: first end

32b:Second end

34: Hardness and weight adjustment components

34a: first end

34b:Second end

35:First bolt

38: Clamping area

Claims (10)

A rotor cover for a turbomolecular vacuum pump. A rotating shaft is protruding from the top of the turbomolecular vacuum pump. A rotor is set on the rotating shaft. There is a locking chamber recessed in the center of the rotor. The center of the locking chamber is fixedly connected to the rotating shaft. , the rotor cover includes: a covering element, the side wall and top surface of the covering element are smooth curved surfaces; and a connecting element, including: an extension rod and a hardness and weight adjustment element, a first end of the extension rod is connected The center of the bottom surface of the covering element, the first end of the extension rod and the covering element are made of the same material. When the covering element covers the locking chamber of the rotor, a second end of the extension rod faces away from the The direction of the covering element extends to be adjacent to the rotation axis, and a first end and a second end of the hardness and weight adjustment element are respectively detachably connected to the rotation axis and the second end of the extension rod, wherein the hardness and The hardness of the first end of the weight adjustment element is substantially the same as the hardness of the rotating shaft, and the hardness of the second end of the weight adjustment element is substantially the same as the hardness of the extension rod, thereby reducing the hardness of the extension rod and the hardness of the extension rod. The hardness difference between the weight adjustment element and the hardness difference between the hardness and weight adjustment element and the rotating shaft are reduced, and the second end of the hardness and weight adjustment element is compared with the third end of the hardness and weight adjustment element. One end is made of lightweight material. By reducing the height of the center of gravity of the connecting element, the rotational vibration phenomenon of the covering element is reduced when the turbomolecular vacuum pump is running, so that the vibration changes of the top and bottom surfaces of the covering element are both less than a target value. The rotor cover for a turbomolecular vacuum pump as claimed in claim 1, wherein the first end of the extension rod is integrally connected to the center of the bottom surface of the cover element. The rotor cover for a turbomolecular vacuum pump as claimed in claim 1, wherein the first end of the extension rod is screwed to the center of the bottom surface of the cover element. The rotor cover for a turbomolecular vacuum pump as described in claim 2 or 3, wherein the top end of the rotating shaft is concave to form a first screw hole, and the second end of the extension rod is concave to form a second screw hole. hole, the first end of the hardness and weight adjustment element is a first bolt, the second end of the hardness and weight adjustment element is a second bolt, and the first bolt of the hardness and weight adjustment element is used to The first screw hole of the rotating shaft is screwed, and the second bolt of the hardness and weight adjustment element is used to screw the second screw hole of the extension rod. The rotor cover for a turbomolecular vacuum pump as claimed in claim 4, wherein the diameter of the first bolt of the hardness and weight adjustment element is greater than the diameter of the second bolt, and the diameter of the first bolt corresponds to the rotation axis The diameter of the first screw hole and the diameter of the second bolt correspond to the diameter of the second screw hole of the extension rod. The rotor cover for a turbomolecular vacuum pump as claimed in claim 1, wherein the length ratio of the first end of the hardness and weight adjustment element to the extension rod is 1:7. The rotor cover for a turbomolecular vacuum pump as described in claim 1 further includes a fixture, one end of the fixture is concave to form a clamping space, and a clamping element is provided in the clamping space, wherein When the covering element is placed in the clamping space of the fixture, the clamping element holds the surface of the covering element and drives the rotor cover to rotate by rotating the fixture. The rotor cover for a turbomolecular vacuum pump as claimed in claim 7, wherein the side or top surface of the covering element is a completely curved surface, and when the covering element is placed in the clamping space of the fixture, the clamp The holding element holds the complete curved surface of the covering element, and drives the rotor cover to rotate by rotating the jig, wherein the holding element is a plate, a rod or a ring. The rotor cover for a turbomolecular vacuum pump as claimed in claim 7, wherein the side or top surface of the covering element has a flat area or a concave area, and when the covering element is placed on the fixture When in the clamping space, the clamping element holds the flat area or the recessed area of the cover element, and drives the rotor cover to rotate by rotating the jig, wherein the clamping element is a plate body or a rod body. or ring body. The rotor cover for a turbomolecular vacuum pump as claimed in claim 1, wherein the target value is 15 μm.