JP6190580B2 - Rotary part of vacuum pump and vacuum pump - Google Patents

Description

  The present invention relates to a vacuum pump rotor and a vacuum pump, and more particularly to a vacuum pump rotor and a vacuum pump that are optimal for use in exhausting a gas used in a semiconductor production line or the like.

  In a semiconductor manufacturing apparatus, a vacuum pump 51 such as a turbo molecular pump illustrated in FIG. 6 is used as means for exhausting process gas discharged from a process apparatus such as etching to the outside.

  The vacuum pump 51 includes a casing 42 having an intake port 44 and an exhaust port 46, a rotor shaft 47 rotated by a motor unit 45 provided in the casing 42, a rotor 48 attached to the rotor shaft 47, A concave portion 49 formed on the end surface of the rotor 48 on the intake port 44 side, and a base portion 43 that rotatably supports the rotor shaft 47 are provided. For example, a chamber (not shown) of a semiconductor manufacturing apparatus is connected to the intake port 44.

  A rotor shaft 47 having a mandrel 52 is provided on the intake port 44 side in the casing 42.

  The rotor 48 is fastened to the end of the mandrel 52 with bolts 55 and 55, and the fastening portion of the bolts 55 and 55 is provided on the bottom surface of the concave portion 49 of the rotor 48.

  In the above configuration, the process gas G that has flowed into the intake port 44 from the semiconductor manufacturing process is transferred to the upstream of the thread groove pump SP by being given a downward momentum by the rotating rotor 48. Next, the process gas G is compressed by the thread groove pump part SP and then exhausted to the outside from the exhaust port 46 (see Patent Document 1).

Japanese Patent No. 3974772

  When a vacuum pump such as a turbo molecular pump is used for a semiconductor manufacturing apparatus, there are many processes for causing various corrosive process gases to act on a semiconductor substrate (wafer). When exhausting the process gas to the outside of the cylinder, the process gas causes corrosion and rust on the surface of the bolt that fastens the mandrel and the rotor, or particles (fine particles due to physicochemical changes in the components in the process gas. , Dust).

  In addition, while the process gas containing foreign matter such as rust and particles repeatedly depressurizes and pressurizes, the foreign matter may flow back into the chamber connected to the intake port together with the process gas.

  In addition, if it is a normal stainless steel volt | bolt, there is little possibility of rusting in a vacuum, but depending on the component in process gas, rust may be generated in the bolt.

  Then, foreign matters such as rust and particles may flow back to the chamber side together with the process gas and enter the semiconductor manufacturing apparatus. In this case, there is a problem that foreign matters such as rust and particles adversely affect the semiconductor manufacturing process.

  For example, there is a problem that foreign matter such as rust and particles adheres to the semiconductor wafer and deteriorates the processing quality of the semiconductor wafer.

  Therefore, in view of the background art, technical problems to be solved in order to prevent deterioration of the processing quality of semiconductor wafers and the like due to corrosion and rusting of the fastening portion of the bolt or intrusion of the foreign matter into the manufacturing process. The present invention aims to solve this problem.

  As the above problem solving means, the gist of the present invention is that the means for preventing the occurrence of rust and corrosion at the fastening portion of the bolt for fixing the rotor to the mandrel and suppressing the outflow of foreign matter to the inlet side is adopted. To do.

According to a first aspect of the present invention, there is provided a rotor shaft having a mandrel at a shaft end on the intake port side in a casing having an intake port and an exhaust port, and a rotor fastened with a bolt to the mandrel of the rotor shaft. A vacuum pump comprising: a rotating part of a vacuum pump comprising: a cover disposed so as to cover a fastening part of the bolt; and the cover is attached to a central part of an end of the mandrel with a cover attaching bolt. Provides a rotating part.

  According to this configuration, by covering the fastening portion of the bolt (including the end portion of the mandrel) with the cover, corrosion and rusting at the fastening portion of the bolt due to contact with the process gas are suppressed. Further, the foreign matter such as rust and particles in the space formed by the cover and the rotor is prevented from flowing out to the intake port side, thereby preventing the entry of the foreign material into the apparatus chamber connected to the intake port.

According to a second aspect of the present invention, there is provided the rotating part of the vacuum pump according to the first aspect, wherein the cover is resistant to corrosion and rust.

  According to this configuration, the cover itself is made of a material having corrosion resistance and rust prevention, so that corrosion and rusting of the cover by the exhausted gas are suppressed.

According to a third aspect of the present invention, there is provided the rotating part of the vacuum pump according to the second aspect, wherein the cover is subjected to a coating process having corrosion resistance and rust resistance on the surface.

  According to this configuration, the surface of the cover is subjected to a corrosion-resistant and rust-proof coating treatment, so that the cover surface is effectively corroded and rusted by the process gas exhausted from the apparatus chamber. Can be prevented.

According to a fourth aspect of the present invention, the bolt and the mandrel are subjected to a coating treatment having corrosion resistance and rust resistance on the surface thereof. The rotary part of the vacuum pump is provided.

  According to this configuration, since the surface of the bolt and the mandrel is subjected to a corrosion-resistant and rust-proof coating treatment, the surface of the bolt and mandrel is corroded by the process gas exhausted from the apparatus chamber. Rusting can be effectively prevented.

According to a fifth aspect of the present invention, there is provided the rotating part of the vacuum pump according to the third or fourth aspect, wherein the coating process is a nickel coating process.

  According to this configuration, since the coating treatment according to claim 3 or 4, that is, the coating treatment applied to each surface of the cover, the bolt and the mandrel is a nickel coating treatment, Corrosion and rusting of the surfaces of the cover, bolt and mandrel due to gas can be more effectively prevented.

According to a sixth aspect of the present invention, there is provided a vacuum pump comprising the rotary part of the vacuum pump according to any of the first to fifth aspects.

  According to this configuration, the action of the rotor of the vacuum pump according to any one of claims 1 to 5, for example, corrosion or rusting at a bolt fastening portion is suppressed, and the inside of the apparatus chamber connected to the air inlet It is possible to achieve an effect such as preventing foreign matter from entering the body.

  According to the first aspect of the present invention, the fastening portion of the bolt is covered with a cover to prevent corrosion and rusting in the fastening portion, and occurs in the fastening portion region (including the periphery of the fastening portion) of the bolt. Since foreign substances such as rust and particles are configured not to flow out to the intake port side, entry of foreign substances into the apparatus chamber can be prevented. As a result, as in the prior art, it is possible to prevent adverse effects on the manufacturing process due to foreign matters such as rust and particles in the apparatus chamber, for example, deterioration of the processing quality of the semiconductor wafer.

  In addition to the effect of the invention described in claim 1, the invention described in claim 2 can suppress the corrosion and rusting of the cover by the corrosive gas, so that the durability of the cover is improved.

  In addition to the effect of the invention described in claim 2, the invention described in claim 3 can further reliably prevent corrosion and rusting of the surface of the cover by corrosive gas, thereby further improving the durability of the cover. be able to.

  In addition to the effect of the invention of any one of claims 1 to 3, the invention of claim 4 effectively prevents corrosion and rusting of each surface of the bolt and mandrel by corrosive gas. Therefore, the durability of the bolt and mandrel can be further improved.

  In addition to the effects of the invention of claim 3 or claim 4, the invention of claim 5 can more reliably prevent corrosion and rusting of the surfaces of the cover, bolt and mandrel due to corrosive gas, The durability of the cover can be further improved.

  Since the invention according to claim 6 can prevent the effect of the rotor of the vacuum pump according to any one of claims 1 to 5, for example, the entry of foreign matter into the apparatus chamber, rust in the apparatus chamber, The adverse effects on the manufacturing process due to foreign matters such as particles can be prevented, and excellent effects such as improvement of the processing quality of the semiconductor wafer or improvement of durability of the bolt and mandrel can be exhibited.

A sectional view showing a vacuum pump (turbo molecular pump) concerning an embodiment of the present invention. The upper part of the vacuum pump of FIG. 1 is shown, (a) is sectional drawing, (b) is a top view which shows a bolt fastening part. The vacuum pump (turbomolecular pump) which concerns on other embodiment of this invention is shown, (a) is sectional drawing, (b) is the A section detail drawing of (a). A sectional view showing a vacuum pump (drag pump) concerning an embodiment of the present invention. Sectional drawing which shows the vacuum pump (drag pump) which concerns on other embodiment of this invention. Sectional drawing which shows the vacuum pump which concerns on a prior art example.

The present invention achieves the purpose of preventing the deterioration of the processing quality of semiconductor wafers and the like due to the intrusion of foreign matter such as rust and particles generated from the bolt fastening portion, in the casing having the intake port and the exhaust port, A rotating part of a vacuum pump comprising a rotor shaft having a mandrel at the shaft end on the inlet side and a rotor fastened to the mandrel of the rotor shaft with a bolt so as to cover the fastening part of the bolt And the cover is attached to the center of the end of the mandrel with a cover mounting bolt.

  Hereinafter, preferred embodiments of the present invention will be described. This embodiment is applied to a turbo molecular pump as an example of a vacuum pump.

  In this embodiment, the mandrel of the rotor shaft and the rotor are fastened with bolts, the fastening portion of the bolts is provided in a recess formed in the rotor, and a cover is attached in the recess of the rotor.

  It forms so that a bolt fastening part may be covered with the said cover, and, thereby, it is comprised so that the gas in a recessed part may not flow backward to the inlet side of a vacuum pump. Therefore, even if foreign matter such as rust or particles is contained in the gas in the recess, there is no possibility that the foreign matter will flow out together with the gas to the apparatus chamber connected to the intake port.

  The cover itself can be made of a material having corrosion resistance and rust prevention. According to this configuration, it is possible to more effectively suppress the corrosion and rusting of the cover due to the exhausted gas.

  FIG. 1 is a cross-sectional view showing the inside of a turbo molecular pump 1 according to an embodiment of the present invention. The turbo molecular pump 1 is a vacuum pump suitable for exhausting a vacuum chamber. For example, the turbo molecular pump 1 is provided on the exhaust port side of a vacuum device side chamber (referred to as “device chamber” in this embodiment) 21 in a semiconductor manufacturing process. Communication connection is established.

  The turbo molecular pump 1 includes a turbo molecular pump unit and a thread groove pump unit, and is preferably used when exhausting a process gas containing a corrosive or easily condensable gas.

  A casing 2 forming an exterior body of the turbo molecular pump 1 constitutes a casing of the turbo molecular pump 1 together with a substantially cylindrical aluminum base portion 3 provided on the lower side of the casing 2. A gas transfer mechanism that allows the turbo molecular pump 1 to perform an exhaust function is housed inside the casing, and the gas transfer mechanism is provided so as to be rotatable with respect to the fixed portion and the fixed portion. And a rotating part.

  An inlet 4 for introducing a process gas into the turbo molecular pump 1 is formed at one end side in the axial direction of the casing 2. A flange portion 5 is formed on the end surface of the casing 2 on the intake port 4 side so as to project to the outer peripheral side.

  Further, an exhaust port 6 for exhausting the process gas from the turbo molecular pump 1 is formed at the other axial end side of the base portion 3.

  The rotating part is provided on the rotor shaft 7, the rotor 8 attached to the rotor shaft 7, a plurality of rotor blades 15 provided on the rotor 8, and the exhaust port 6 side (screw groove pump part SP side). The cylindrical rotating member 10 is formed. A mandrel 22 having a smaller diameter than the rotor shaft 7 is formed at the shaft end of the rotor shaft 7 on the intake port 4 side. A motor portion 11 for rotating the rotor shaft 7 at a high speed is provided at an intermediate portion in the axial direction of the rotor shaft 7.

  The fixed portion is composed of a plurality of fixed blades 9 provided on the intake port 4 side, a thread groove spacer (cylindrical outer stator) 16 provided on the inner peripheral surface of the casing 2, and the like. The fixed blades 9 at each stage are separated from each other by a cylindrical spacer 17 and are formed in a plurality of stages so as to be staggered with respect to the rotary blade 9.

  A spiral groove is formed in the thread groove spacer 16 on the surface facing the cylindrical rotary member 10, and the thread groove spacer 16 faces the outer peripheral surface of the cylindrical rotary member 10 with a predetermined clearance. Further, the depth of the spiral groove is formed so as to become gradually shallower as it approaches the exhaust port 6, so that the process gas transported through the spiral groove is gradually compressed as it approaches the exhaust port 6 side. It is configured.

  As shown in FIG. 2A, a recess 23 is formed on the upper end surface of the rotor 8, and stainless steel rotor fastening bolts 24, 24 are fastened to the bottom surface of the recess 23. The rotor fastening bolts 24, 24 are for fastening the rotor 8 to the mandrel 22 of the rotor shaft 7 via a washer 25.

  Thus, the rotor fastening bolts 24 and 24 for fastening the mandrel 22 of the rotor shaft 7 are fastened to the bottom surface of the recess 23 formed in the rotor 8.

  Here, in the prior art, when foreign matter such as rust and particles exists in the recess as described above, the foreign matter flows back to the apparatus chamber 21 side together with the process gas, adversely affects the semiconductor manufacturing process, and the processing quality. There was a problem of lowering.

  In the present embodiment, means for solving this problem are taken. That is, a disc-shaped cover 26 illustrated in FIG. 2B is provided in the concave portion 23 of the rotor 8, and the outer periphery of the fastening portion of the rotor fastening bolts 24, 24 is hermetically covered by the cover 26. Yes.

  This prevents corrosion of the fastening portions (including the end portion of the mandrel 22) of the rotor fastening bolts 24, 24 against the process gas, and also prevents the occurrence of rust from the fastening portions, The foreign matter in the cover 26 is configured not to flow out to the inlet 4 side.

  Further, the cover 26 itself is made of a corrosion-resistant and rust-proof material, and as the material of the cover 26, a material such as titanium can be adopted in addition to aluminum. With this configuration, corrosion and rusting of the cover 26 due to the process gas can be effectively suppressed.

  The cover 26 has an outer diameter that is the same as the inner diameter of the recess 23, and the cover 26 is attached to the upper end surface of the mandrel 22 by a cover mounting bolt 27 with a washer 20 that passes through the center of the cover 26. ing. Thereby, the cover 26 is mounted and fixed in the recess 23 of the rotor 8, and the cover 26 is configured to be airtight so that no gap is formed between the cover 26 and the recess 23.

  As described above, the cover 26 and the recess 23 are hermetically sealed so as not to cause gas leakage between them, so that the process gas existing in the recess 23 does not flow backward to the inlet 4 side. It is configured.

  The washer 25 can be provided with a mass adding means (not shown) for balancing the rotating body. As the mass adding means, for example, a weight made up of a screw, a split pin or a bush can be adopted. . In this way, by balancing the rotating body, smooth high-speed rotation of the rotor 8 is ensured without causing stress concentration at the local portion of the rotor 8.

  According to the above configuration, the cover 26 covers the bottom side of the recess 23 in an airtight manner, so that the process gas existing inside the cover 26 (the bottom side space of the recess 23) leaks to the inlet 4 side. There is no fear.

  For this reason, even if foreign matter such as rust and particles is present together with the process gas inside the cover 26 (the space on the bottom surface of the recess 23), the foreign matter is brought into the apparatus chamber 21 side together with the process gas as in the conventional example. Backflow is prevented.

  In the present embodiment, the surface of the cover 26 is subjected to a coating process having corrosion resistance and rust resistance, for example, an electroless nickel plating process. For this reason, corrosion and rusting due to the process gas are effectively suppressed on the surface of the cover 26.

  Further, in this embodiment, the stainless steel protection collar 28 and the protection collar retaining ring 29 provided on the surfaces of the rotor fastening bolts 24, 24, the mandrel 22 and the cover mounting bolt 27, and the opening of the intake port 4. The surface is also subjected to electroless nickel plating.

  Therefore, the rotor fastening bolts 24, 24, the mandrel 22, the washers 20, 25, the cover mounting bolt 27, and the stainless steel protection collar 28 and the protection collar retaining ring provided at the opening of the air inlet 4. The surface 29 has a high anti-corrosion action and an anti-rust action.

Therefore, corrosion and rusting of the surfaces of the rotor fastening bolts 24, 24, the mandrel 22, the washers 20, 25 and the cover mounting bolt 27 due to the process gas can be effectively suppressed.
Furthermore, even if the process gas leaks from the cover 26 and flows back to the intake port 4 side, it is possible to suppress corrosion and rusting of the surfaces of the protective mesh 28 and the protective mesh retaining ring 29 due to the process gas.

  FIG. 3 shows another embodiment of the cover 26 attached to the recess 23, and FIG. 3 (b) is a detailed view of part A of FIG. 3 (a). The same components as those in FIG. 2 are denoted by the same reference numerals, and detailed description thereof will be omitted.

  As shown in FIG. 3 (b), a ring-shaped step portion 31 is provided on the inner wall of the recess 23, and the recess 23 is slightly larger in diameter than the lower portion with the step portion 31 as a boundary. Is formed. The outer peripheral edge portion of the cover 26 is placed and mounted on the upper surface of the step portion 31. Thereby, a more highly airtight seal structure is secured between the outer peripheral edge of the cover 26 and the inner peripheral wall surface of the recess 23.

  Accordingly, since the bottom side space in the recess 23 is covered more tightly by the cover 26, it is possible to more reliably suppress the process gas in the cover 26 from flowing backward to the intake port 4 side.

  Further, as described above, the cover 26 itself can be made of a corrosion-resistant and rust-proof material, such as aluminum or titanium, and this structure suppresses corrosion and rusting of the cover 26 due to process gas. it can.

  FIG. 4 shows an embodiment in which the present invention is applied to a vacuum pump (drag pump). In addition, the same code | symbol is attached | subjected to the component similar to the said embodiment, and the detailed description shall be abbreviate | omitted.

  As shown in FIG. 4, in the vacuum pump (drag pump) 1 </ b> A according to the present embodiment, a cylindrical rib 32 having an upper opening projects from the upper end surface of the rotor 8 </ b> A. A recess 33 is formed on the inner side. Stainless steel rotor fastening bolts 24, 24 are fastened to the bottom surface of the recess 33.

  With the rotor fastening bolts 24, 24, the mandrel 22 of the rotor shaft 7 is fastened to the rotor 8 </ b> A via a washer 25. Thus, the rotor fastening bolts 24 and 24 for fastening the mandrel 22 of the rotor shaft 7 are fastened to the bottom surface of the cylindrical rib 32 formed on the top surface of the rotor 8A.

  In addition, a disc-shaped cover 26 is attached to the recess 33 inside the cylindrical rib 32, and the outer periphery of the fastening portions (including the mandrel 22) of the rotor fastening bolts 24, 24 is hermetically covered by the cover 26. ing.

  That is, the cover 26 has an outer diameter that is the same as the inner diameter of the cylindrical rib 32, and the cover 26 is attached to the upper end surface of the mandrel 22 by a cover mounting bolt 27 that passes through the center of the cover 26. .

  Accordingly, since the inner wall surface of the cylindrical rib 32 and the outer peripheral side surface of the cover 26 are configured so that no gap is generated between them, the process gas in the cover 26 is sucked into the intake port (see reference numeral 4 in FIG. 1). ) It is configured not to leak to the side.

  As a result, even if foreign matter such as rust or particles is contained in the process gas in the recess 33 covered with the cover 26, the foreign matter is included in the apparatus chamber (see reference numeral 21 in FIG. 1) together with the process gas. Backflow is prevented in advance.

  Similarly to the above, the cover 26 itself can be made of a corrosion-resistant and rust-proof material, such as aluminum or titanium, and this structure suppresses the corrosion and rusting of the cover 26 due to process gas. it can.

  Further, the surface of the cover 26, the washer 20 and the cover mounting bolt 27 is subjected to a coating process having high corrosion resistance and rust resistance, for example, an electroless nickel plating process.

  For this reason, corrosion and rusting of the surfaces of the cover 26, the washer 20, and the cover mounting bolt 27 due to the process gas can be effectively suppressed.

  Further, since the surfaces of the rotor fastening bolts 24, 24, the washer 25, and the mandrel 22 are also subjected to a coating treatment having high corrosion resistance and rust resistance, for example, nickel coating treatment, as described above. There is no risk of corrosion and rust on each surface by the process gas.

  FIG. 5 shows another embodiment in which the present invention is applied to a vacuum pump (drag pump). In addition, the same code | symbol is attached | subjected to the component similar to the said embodiment, and the detailed description shall be abbreviate | omitted.

  As shown in FIG. 5, stainless steel rotor fastening bolts 24, 24 are fastened to the center of the upper end face of the rotor 8A of the vacuum pump (drag pump) 1A. With the rotor fastening bolts 24, 24, the mandrel 22 of the rotor shaft 7 is fastened to the rotor 8 </ b> A via a washer 25.

  Thus, the rotor fastening bolts 24 and 24 for fastening the mandrel 22 of the rotor shaft 7 are fastened to the central portion of the upper end surface of the rotor 8A.

  A short cylindrical cover 26A having a top surface portion on the upper side is attached to the center of the upper end surface of the rotor 8A, and the fastening portions of the rotor fastening bolts 24 and 24 (including the end surface of the mandrel 22 are included) by this cover 26A. ) Is airtightly covered.

  That is, the cover 26A is fixed to the upper end surface of the mandrel 22 by a cover mounting bolt 27 that passes through the center of the cover 26A, and there is a gap between the lower end of the cover 26A and the upper end surface of the rotor 8A. It is configured not to occur.

  Further, as described above, the cover 26A itself can be made of a material having corrosion resistance and rust resistance, for example, aluminum, titanium, and the like, thereby effectively suppressing corrosion and rusting on the surface of the cover 26A. it can.

  Each surface of the cover 26A, the washer 20, and the cover mounting bolt 27 is subjected to a coating process having high corrosion resistance and rust prevention, for example, an electroless nickel plating process. For this reason, corrosion and rust on each surface can be suppressed.

  Further, the surfaces of the rotor fastening bolts 24, 24, the washer 25, and the mandrel 22 are also subjected to a coating treatment having high corrosion resistance and rust prevention, for example, a nickel coating treatment. For this reason, there is no possibility of causing corrosion and rust on each surface of the rotor fastening bolts 24, 24 and the like.

  In this embodiment, the lower end surface of the cover 26A and the upper end surface of the rotor 8A are configured such that no gap is generated between them. Accordingly, there is no possibility that the process gas staying in the cover 26A leaks to the intake port (see reference numeral 4 in FIG. 1) side. Therefore, even if foreign matter such as rust or particles is included in the process gas in the cover 26A, the foreign matter is prevented from flowing out toward the apparatus chamber (see reference numeral 21 in FIG. 1).

  As described above, according to the present invention, the cover is configured to cover the fastening portion of the bolt, so that even if the exhaust gas is a highly corrosive process gas, the fastening portion of the bolt by the process gas is used. While preventing corrosion, it is possible to prevent rusting at the fastening portion of the bolt.

  In addition, there is no possibility that foreign matter such as rust and particles (fine particles, dust) existing in the cover will flow out to the inlet side together with the process gas, so that the foreign matter can be prevented from entering the device chamber. it can.

  Thus, it is possible to prevent an adverse effect on the semiconductor manufacturing process due to the entry of foreign matter into the apparatus chamber, and to improve the processing quality of, for example, a semiconductor wafer.

  In addition, by making the cover itself from corrosion-resistant and rust-proof materials, it is possible to suppress cover corrosion and rusting due to process gas, improve the durability of the cover, and extend the life of the cover. Can do.

  Furthermore, if the cover surface is coated with corrosion and rust prevention, corrosion and rusting of the cover surface due to the corrosive process gas can be effectively prevented, further enhancing the durability of the cover. Can be improved.

  Furthermore, in the present invention, the bolt and mandrel can also be subjected to a coating treatment having corrosion resistance and rust resistance on their surfaces, thereby further improving the durability of the bolt and mandrel. it can.

  In addition, when the coating treatment applied to each surface of the cover, bolt and mandrel is a nickel coating treatment, corrosion and rusting of the surfaces of the cover, bolt and mandrel by the corrosive process gas are more reliably prevented. Thus, the lifetime of these members can be further extended.

  It should be noted that the present invention can be variously modified without departing from the spirit of the present invention, and the present invention naturally extends to the modified ones.

1 Turbo molecular pump (vacuum pump)
1A Drag pump (vacuum pump)
2 Casing 3 Base 4 Inlet 5 Flange 6 Exhaust 7 Rotor Shaft 8 Rotor 8A Rotor 9 Rotor Blade 10 Cylindrical Rotating Member 11 Motor Unit 15 Fixed Blade 16 Thread Groove Spacer (Cylinder Outer Stator)
21 Equipment chamber 22 Mandrel 23 Recess 24 Rotor fastening bolt 25 Washer 26 Cover 26A Cover 28 Protective mesh 29 Protective mesh retaining ring 31 Stepped portion 32 Cylindrical rib 33 Recess

Claims (6)

In a rotary part of a vacuum pump comprising a rotor shaft having a mandrel at a shaft end on the intake port side and a rotor fastened with a bolt to the mandrel of the rotor shaft in a casing having an intake port and an exhaust port ,
A rotating part of a vacuum pump, wherein a cover is disposed so as to cover a fastening part of the bolt, and the cover is attached to a central part of an end part of the mandrel with a cover attaching bolt.   The rotating part of the vacuum pump according to claim 1, wherein the cover has corrosion resistance and rust prevention.   The rotating part of the vacuum pump according to claim 2, wherein the cover is subjected to a coating process having corrosion resistance and rust prevention on the surface.   The rotating part of the vacuum pump according to any one of claims 1 to 3, wherein the bolt and the mandrel are subjected to a coating process having corrosion resistance and rust resistance on the surface.   The rotary part of the vacuum pump according to claim 3 or 4, wherein the coating process is a nickel coating process.   A vacuum pump comprising the rotary part of the vacuum pump according to any one of claims 1 to 5.

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