CN215860794U

CN215860794U - Eccentric main shaft mounting structure of dry-type scroll vacuum pump

Info

Publication number: CN215860794U
Application number: CN202121823025.3U
Authority: CN
Inventors: 谭波; 董仁军; 朱跃
Original assignee: Linhai Tan Vacuum Equipment Co ltd
Current assignee: Linhai Tan Vacuum Equipment Co ltd
Priority date: 2021-08-05
Filing date: 2021-08-05
Publication date: 2022-02-18
Anticipated expiration: 2031-08-05

Abstract

The utility model provides an eccentric main shaft mounting structure of a dry-type scroll vacuum pump, and belongs to the technical field of pumps. It has solved the problem that current dry-type vortex vacuum pump eccentric spindle has the rotational stability low. The mounting structure of the eccentric main shaft of the dry-type scroll vacuum pump comprises a movable scroll plate connecting structure of the eccentric main shaft and a scroll air pumping assembly and a rotary connecting structure between the eccentric main shaft and a pump body assembly; the eccentric main shaft is provided with an eccentric section, a first bearing mounting section, a rotor mounting section and a second bearing mounting section from one end to the other end; the eccentric section is connected with the movable scroll plate, and the first bearing mounting section and the second bearing mounting section are connected with the pump body assembly through first bearings; a motor rotor is fixed on the rotor mounting section, a motor stator is sleeved outside the motor rotor, and the motor stator is fixedly connected with the pump body assembly; the structure realizes the improvement of the running efficiency and the running stability of the dry-type vortex vacuum pump.

Description

Eccentric main shaft mounting structure of dry-type scroll vacuum pump

Technical Field

The utility model belongs to the technical field of vacuum pumps, and relates to a dry-type scroll vacuum pump, in particular to an eccentric main shaft mounting structure of the dry-type scroll vacuum pump.

Background

The dry type vortex vacuum pump mainly comprises a pair of vortex plates consisting of a fixed vortex plate and a movable vortex plate, and a vortex oil-free vacuum basic air exhaust mechanism is formed by the pair of vortex plates. The scroll is a scroll-type structure formed by one or more involute spirals connected at one end to a flat surface. The movable and static vortex plates move relatively to form a crescent vacuum cavity with constantly changing volume, so that air is sucked from the air suction port and exhausted from the air exhaust port to complete the exhaust circulation.

Many documents are available on dry scroll vacuum pumps, such as oil-free scroll vacuum pumps (application No. 97109681.3) and full-scroll dry vacuum pumps (application No. 200810139527.7). The applicant also provides a scroll vacuum pump (application number 201320121796.7), which has some disadvantages, wherein 1, the eccentric main shaft is connected with the pump shell only through a group of bearings, the main shaft of the motor is connected with the eccentric main shaft through a coupling, and the eccentric main shaft has low rotation stability, so that the operation stability of the scroll vacuum pump is influenced; 2. the heating of the running scroll pair of the vacuum pump is objective, so that the starting and the static scroll are induced to generate heat and deform, the air extraction efficiency is influenced, and even the actuating and the static scroll are locked; 3. a small gap is usually formed between the movable vortex plate and the fixed vortex plate, so that the sealing property is influenced, and the ultimate vacuum degree is insufficient; 4. steam is easily condensed at the exhaust port, thereby affecting exhaust efficiency.

Disclosure of Invention

The utility model provides a dry type scroll vacuum pump, and aims to solve the technical problem of improving the running stability of the dry type scroll vacuum pump.

The technical problem to be solved by the utility model can be realized by the following technical scheme: the dry-type scroll vacuum pump eccentric main shaft mounting structure comprises a pump body assembly and a scroll air exhaust assembly mounted on the pump body assembly, and the dry-type scroll vacuum pump eccentric main shaft mounting structure comprises an eccentric main shaft and movable scroll plate connecting structure of the scroll air exhaust assembly and a rotating connecting structure between the eccentric main shaft and the pump body assembly; the eccentric main shaft is provided with an eccentric section, a first bearing mounting section, a rotor mounting section and a second bearing mounting section from one end to the other end; the eccentric section is connected with the movable scroll plate, and the first bearing mounting section and the second bearing mounting section are connected with the pump body assembly through first bearings; and a motor rotor is fixed on the rotor mounting section, a motor stator is sleeved outside the motor rotor, and the motor stator is fixedly connected with the pump body assembly.

The eccentric main shaft and the pump body assembly in the dry type scroll vacuum pump are connected through two groups of first bearings, so that the load capacity of the eccentric main bearing is improved, and the rotation stability of the eccentric main shaft is improved. The motor rotor is directly fixed on the eccentric main shaft, and the motor stator is directly installed on the pump body assembly, so that unnecessary loss and vibration generated by transmission between the motor and the eccentric main shaft are avoided. The structure not only improves the efficiency and the operation stability of the dry-type vortex vacuum pump; the structure of the dry type vortex vacuum pump is also improved, the structure is simplified, and the manufacturing cost is reduced.

In the above eccentric main shaft mounting structure of the dry-type scroll vacuum pump, the pump body assembly includes a main pump body and a bearing seat, and the bearing seat is fixedly connected with the main pump body; the first bearing mounting section is connected with the main pump body through a first bearing, and the second bearing mounting section is connected with the bearing seat through a first bearing.

In the above eccentric main shaft mounting structure of the dry scroll vacuum pump, the main pump body has a tubular bearing mounting part; the first bearing mounting section is connected with the bearing mounting part of the main pump body through a first bearing.

In the above-mentioned dry-type scroll vacuum pump eccentric main shaft mounting structure, the rotation connection structure between the first bearing mounting section and the bearing mounting portion can restrict the eccentric main shaft from moving towards the direction of the scroll air extraction assembly.

In the above eccentric main shaft mounting structure of the dry-type scroll vacuum pump, the bearing seat includes an outer ring portion fixedly connected to the main pump body and an inner ring portion connected to the first bearing, and the outer ring portion and the inner ring portion are connected by a spoke portion.

In the above eccentric main shaft mounting structure of the dry-type scroll vacuum pump, the pump body assembly further includes an end cover fixedly connected with the main pump body, and the bearing seat is arranged between the main pump body and the end cover.

In the above-mentioned dry-type scroll vacuum pump eccentric main shaft mounting structure, an elastic member is provided between the inner ring part of the bearing seat and the end cover.

In the above-mentioned dry-type scroll vacuum pump eccentric main shaft mounting structure, the inner ring portion is connected with the eccentric main shaft through a limit bolt.

In the above-mentioned dry-type scroll vacuum pump eccentric main shaft mounting structure, the eccentric main shaft and movable scroll plate connecting structure includes the second bearing, and the eccentric section is connected with the movable scroll plate through the second bearing.

In the eccentric main shaft mounting structure of the dry-type scroll vacuum pump, the inner ring part of the second bearing is fixed on the eccentric section through the pressing cap and the bolt, the movable scroll plate is provided with the screwing operation hole, and the movable scroll plate is detachably provided with the plug for plugging the screwing operation hole.

Drawings

Fig. 1 is a schematic perspective view of a dry scroll vacuum pump.

Fig. 2 is a left side view schematically showing the structure of the dry scroll vacuum pump.

Fig. 3 is a schematic sectional structure view of a-a in fig. 2.

Fig. 4 is a schematic sectional structure view of B-B in fig. 3.

Fig. 5 is a schematic sectional structure view of C-C in fig. 4.

FIG. 6 is an exploded view of the end cap region of the dry scroll vacuum pump.

FIG. 7 is a schematic cross-sectional view of the gasket area between the pump block assembly and the scroll pumping assembly.

Fig. 8 is a schematic perspective view of the pump body assembly and the orbiting scroll.

Figure 9 is a perspective view of the fixed scroll and fan assembly.

In the figure, 1, a pump body assembly; 1a, a main pump body; 1a1, air inlet chamber; 1a2, motor cavity; 1a3, intake; 1a4, bearing mounting part; 1b, end covers; 1c, a bearing seat; 1c1, outer ring portion; 1c2, inner race part; 1c3, spoke parts; 2. a vortex air extraction assembly; 2a, a movable scroll; 2a1, dynamic spiral sheet; 2a2, moving spiral groove; 2b, a fixed scroll; 2b1, static spiral sheet; 2b2, static spiral groove; 2c, a check valve; 2d, gas ballast valve; 2d1, valve core seat; 2d2, control channel; 2d3, first spool; 2d4, a first spring; 2d5, valve stem; 2d6, second spool; 2d7, second spring; 2d8, handle; 2e, moving a sealing strip; 2f, static sealing strips; 2g, an exhaust channel; 2h, gas ballast channel; 2i, a heat dissipation sheet part; 3. an eccentric main shaft; 4. a motor rotor; 5. a motor stator; 6. a fan assembly; 6a, a flow guide cover; 6b, a fan; 6c, passing a wind channel; 7. a first bearing; 8. a second bearing; 9. an elastic member; 10. a gasket; 11. a counterbalance; 12. a bellows; 13. a limit bolt; 14. a rubber member; 15. and (7) a plug.

Detailed Description

The following are specific embodiments of the present invention and are further described with reference to the drawings, but the present invention is not limited to these embodiments.

As shown in fig. 1 to 9, a dry scroll vacuum pump comprises a pump body assembly 1, a scroll pumping assembly 2, a fan assembly 6 and an eccentric main shaft 3.

The scroll pumping assembly 2 includes a orbiting scroll 2a, a fixed scroll 2b, a check valve 2c and a ballast valve 2 d. The movable scroll 2a is provided with a movable spiral piece 2a1 and a movable spiral groove 2a2, the fixed scroll 2b is provided with a fixed spiral piece 2b1 and a fixed spiral groove 2b2, the movable spiral piece 2a1 is embedded in the fixed spiral groove 2b2, and the fixed spiral piece 2b1 is embedded in the movable spiral groove 2a 2. A movable sealing groove is formed in the end face of the movable spiral piece 2a1 and is arranged along the spiral line direction of the movable spiral piece 2a1, and a movable sealing strip 2e is embedded in the movable sealing groove; the movable sealing strip 2e is leaned against the bottom surface of the static spiral groove 2b 2. A static sealing groove is formed in the end face of the static spiral piece 2b1 and is arranged along the spiral line direction of the static spiral piece 2b1, and a static sealing strip 2f is embedded in the static sealing groove; the static seal strip 2f is leaned against the bottom surface of the dynamic spiral groove 2a 2. The structure not only obviously improves the sealing performance between the movable scroll 2a and the fixed scroll 2b, but also realizes the improvement of the ultimate vacuum degree of the dry type scroll vacuum pump; still avoid moving the terminal surface wearing and tearing of vortex dish 2a and static vortex dish 2b to and showing the bottom surface wearing and tearing that reduce to move seal groove and static seal groove, move sealing strip 2e and static sealing strip 2f promptly and can be preferentially worn and torn, can change according to the wearing and tearing condition and move sealing strip 2e and static sealing strip 2f, realize improving dry-type scroll vacuum pump operating stability and life.

The dynamic sealing strip 2e and the static sealing strip 2f are made of polytetrafluoroethylene or graphite; the dynamic sealing strip 2e and the static sealing strip 2f can be made of the same material, the dynamic sealing strip 2e and the static sealing strip 2f not only have excellent sealing performance, but also avoid the obvious increase of the friction force between the dynamic vortex plate 2a and the static vortex plate 2b due to the self-lubricating property of the polytetrafluoroethylene and the graphite.

An exhaust passage 2g communicating with the inner end of the fixed spiral groove 2b2 is formed in the fixed scroll 2b, and a check valve 2c is installed in the exhaust passage 2 g. An air ballast channel 2h communicated with the inner end of the static spiral groove 2b2 is also formed in the static scroll 2b, and an air ballast valve 2d is installed in the air ballast channel 2 h.

The gas ballast valve 2d comprises a valve core seat 2d1 fixedly connected with the fixed scroll 2b, and a control channel 2d2 is arranged in the valve core seat 2d 1; the gas ballast channel 2h is internally provided with a first valve core 2d3 and a first spring 2d4, and the first valve core 2d3 can automatically abut against the valve core seat 2d1 under the action of the elastic force of the first spring 2d 4; when the first valve spool 2d3 abuts on the valve spool seat 2d1, the control passage 2d2 and the ballast passage 2h are in a cut-off state, and when the first valve spool 2d3 is separated from the valve spool seat 2d1, the control passage 2d2 and the ballast passage 2h are in a communication state. A valve rod 2d5 is further arranged on the fixed scroll 2b in a penetrating manner, a second valve core 2d6 is installed at the inner end of the valve rod 2d5, a second spring 2d7 is sleeved on the valve rod 2d5, and the second valve core 2d6 can automatically abut against the valve core seat 2d1 under the elastic force action of the second spring 2d 7; when the second valve spool 2d6 abuts against the valve spool seat 2d1, the control passage 2d2 is in a cut-off state with the outside; the handle 2d8 is installed at the outer end of the valve rod 2d5, and the second valve core 2d6 can be separated from the valve core seat 2d1 by operating the handle 2d8, and at the moment, the control channel 2d2 is in a communication state with the outside.

The pump body assembly 1 comprises a main pump body 1a, an end cover 1b and a bearing seat 1 c; one end area of the inner cavity of the main pump body 1a is called as an air inlet cavity 1a1, and the other end area is called as a motor cavity 1a 2; an air inlet hole 1a3 is arranged on the side wall of the air inlet cavity 1a 1. A fixed scroll 2b of the scroll air extraction assembly 2 is fixed on one end face of a main pump body 1a through bolts, a movable scroll 2a is located in an air inlet cavity 1a1, and a movable spiral groove 2a2 and a fixed spiral groove 2b2 are connected with the air inlet cavity 1a 1.

The eccentric main shaft 3 is provided with an eccentric section, a first balance block mounting section, a first bearing mounting section, a second balance block mounting section, a rotor mounting section and a second bearing mounting section from one end to the other end; the center line of the eccentric section and the axis line of the eccentric main shaft 3 have an eccentricity e.

The rotor installation section is positioned in the motor cavity 1a2, the rotor installation section is fixed with a motor rotor 4, a motor stator 5 is sleeved outside the motor rotor 4, and the motor stator 5 is fixedly connected with the main pump body 1a of the pump body component 1; whereby both the motor rotor 4 and the motor stator 5 are located in the motor cavity 1a 2.

The intake chamber 1a1 of the main pump body 1a has a tubular bearing attachment portion 1a 4; the end cover 1b is used for covering the opening of the motor cavity 1a2, the bearing seat 1c is arranged between the main pump body 1a and the end cover 1b, and the bearing seat 1c is fixedly connected with the main pump body 1 a. The first bearing mounting section of the eccentric main shaft 3 is rotatably connected with the bearing mounting part 1a4 of the main pump body 1a, and the second bearing mounting section of the eccentric main shaft 3 is rotatably connected with the bearing seat 1c, namely the first bearing mounting section is connected with the bearing mounting part 1a4, and the second bearing mounting section is connected with the bearing seat 1c through the first bearing 7. The eccentric section is connected with the movable scroll 2a through a second bearing 8; the eccentric main shaft 3 rotates to drive the movable scroll 2a to move horizontally; the inner ring portion of the second bearing 8 is fixed on the eccentric section through a pressing cap and a bolt, a screwing operation hole is formed in the movable scroll plate, and a plug 15 for plugging the screwing operation hole is detachably mounted on the movable scroll plate. The bearing mounting part 1a4 not only increases the distance between the two first bearings 7, but also improves the rotation stability of the eccentric main shaft 3; and the distance between one bearing and the movable scroll 2a is reduced, and the translation stability of the movable scroll 2a is improved.

The rotation connection structure between the first bearing installation section and the bearing installation part 1a4 can limit the eccentric main shaft 3 to move towards the direction of the vortex air exhaust assembly 2, and the bearing seat 1c enables the eccentric main shaft 3 to move and deform towards the direction of the end cover 1b, so that the consistency of the distance between the movable vortex disc 2a and the fixed vortex disc 2b is improved, and the operation stability of the dry-type vortex vacuum pump is improved.

The bearing seat 1c comprises an outer ring part 1c1 fixedly connected with the main pump body 1a and an inner ring part 1c2 connected with the first bearing 7, and the outer ring part 1c1 is connected with the inner ring part 1c2 through a spoke part 1c3, so that the deformation of the inner ring part 1c2 of the bearing seat 1c is facilitated, and the eccentric main shaft 3 can move and deform towards the direction of the end cover 1 b. An elastic piece 9 is arranged between the inner ring part 1c2 of the bearing seat 1c and the end cover 1b, and the elastic piece 9 is an elastic washer; the inner ring part 1c2 is connected with the eccentric main shaft 3 through a limit bolt 13; elastic component 9 and spacing bolt 13 make inner circle portion 1c2 ability automatic re-setting, and then improve eccentric main shaft 3 rotational stability, realize improving dry-type scroll vacuum pump operating stability.

Equal fixedly connected with balancing piece 11 on eccentric main shaft 3's the first balancing piece installation section and the second balancing piece installation section, first balancing piece installation section is located air intake chamber 1a1, the second balancing piece installation section is located motor chamber 1a2, a balancing piece 11 is located air intake chamber 1a1 from this, another balancing piece 11 is located motor chamber 1a2, but like this not only make full use of main pump body 1a in the finite space, avoid adjusting the structure of main pump body 1a because of balancing piece 11 size, shape and size, help improving eccentric main shaft 3 rotational stability simultaneously.

A plurality of gaskets 10 are arranged between the fixed scroll 2b and one end face of the main pump body 1a in a cushioning mode, the gaskets 10 are distributed along the circumferential direction of the axial lead of the eccentric main shaft 3, and the verticality between the end face of the fixed scroll 2b and the axial lead of the eccentric main shaft 3 can be adjusted by adjusting the thickness of the gaskets 10, so that the matching degree of the fixed scroll 2b and the movable scroll 2a is improved, the operation stability of the dry-type scroll vacuum pump is improved, and the ultimate vacuum degree is improved. The gasket 10 is provided with a first pre-installation hole, one end face of the main pump body 1a is provided with a second pre-installation hole, the rubber part 14 penetrates through the first pre-installation hole and is embedded into the second pre-installation hole, the position of the gasket 10 is pre-fixed, and the gasket 10 and the vortex air exhaust assembly 2 are convenient to install.

The corrugated pipe 12 is sleeved outside the bearing mounting part 1a4, one end of the corrugated pipe 12 is fixedly connected with the main pump body 1a in a sealing way, and the other end of the corrugated pipe 12 is fixedly connected with the movable scroll 2a in a sealing way; the bellows 12 not only supports the movable scroll 2a and improves the translation stability of the movable scroll 2a, but also separates the inside and the outside of the air inlet cavity 1a1, so that air is prevented from entering the outside area of the air inlet cavity 1a1 between the first bearing mounting section and the bearing mounting section 1a4, and the operation stability of the dry-type scroll vacuum pump is improved and the ultimate vacuum degree is improved.

The fan assembly 6 comprises a flow guide cover 6a and a fan 6b, the fan 6b is installed on the flow guide cover 6a, the flow guide cover 6a covers the fixed scroll 2b, the flow guide cover 6a is fixedly connected with the fixed scroll 2b, an air passing channel 6c is formed between the flow guide cover 6a and the fixed scroll 2b, when the fan 6b operates, air flows from one end of the air passing channel 6c to the other end, as shown by arrows in fig. 3, heat of the fixed scroll 2b is taken away, the highest temperature of the fixed scroll 2b is reduced, deformation of the fixed scroll 2b is controlled, and operation stability of the vortex air extraction assembly 2 is improved. The surface of the fixed scroll 2b is provided with a plurality of fin portions 2i, so that the heat of the fixed scroll 2b can be taken away by the airflow, and the highest temperature of the fixed scroll 2b can be further reduced.

By explaining the operation process of the dry type scroll vacuum pump and further explaining the functions and advantages of all parts, the air inlet hole 1a3 is communicated with a cavity to be extracted by a pipeline; the motor stator 5 is connected with a power supply, the motor rotor 4 rotates to drive the eccentric main shaft 3 to rotate, and the eccentric main shaft 3 drives the movable scroll 2a to translate; in the process, the corrugated pipe 12 swings, and the movable scroll 2a and the fixed scroll 2b move relatively to form a constant volume change, so that the gas in the chamber to be pumped is sucked into the outer area of the air inlet chamber 1a1 and is exhausted to the atmosphere from the exhaust passage 2 g. In the initial stage of operation of the dry type scroll vacuum pump, the handle 2d8 can be pulled and the handle 2d8 can be rotated to make the handle 2d8 abut against the outer side surface of the air guide sleeve 6a, and at the moment, the control channel 2d2 is in a communication state with the outside. Along with the increase of the operation time of the dry type scroll vacuum pump, the air pressure at the inner end of the static spiral groove 2b2 is continuously reduced, under the action of the air pressure difference, the first valve core 2d3 overcomes the elastic force of the first spring 2d4, the first valve core 2d3 is automatically separated from the valve core seat 2d1, the control channel 2d2 and the air ballast channel 2h are in a communicated state, air is automatically fed into the inner end of the static spiral groove 2b2, the air is mixed with the steam, and the steam is prevented from being condensed. Along with the further increase of the operation length of the dry type scroll vacuum pump, the air pressure of the air in the chamber to be pumped is reduced and the moisture content is reduced, the handle 2d8 is rotated again, the second valve core 2d6 automatically abuts against the valve core seat 2d1 under the elastic action of the second spring 2d7, and the control channel 2d2 is in a stop state with the outside; thereby preventing air from entering the inner end of the stationary spiral groove 2b 2. The dry type vortex vacuum pump continues to operate and the air pressure in the chamber to be pumped is continuously reduced.

Claims

1. The dry-type scroll vacuum pump eccentric main shaft mounting structure comprises a pump body assembly (1) and a scroll air extraction assembly (2) mounted on the pump body assembly (1), and comprises a connecting structure of an eccentric main shaft (3) and a movable scroll (2 a) of the scroll air extraction assembly (2) and a rotating connecting structure between the eccentric main shaft (3) and the pump body assembly (1); the eccentric spindle is characterized in that an eccentric section, a first bearing mounting section, a rotor mounting section and a second bearing mounting section are arranged from one end to the other end of the eccentric spindle (3); the eccentric section is connected with the movable scroll (2 a), and the first bearing mounting section and the second bearing mounting section are connected with the pump body assembly (1) through a first bearing (7); and a motor rotor (4) is fixed on the rotor mounting section, a motor stator (5) is sleeved outside the motor rotor (4), and the motor stator (5) is fixedly connected with the pump body assembly (1).

2. The eccentric main shaft mounting structure of a dry scroll vacuum pump according to claim 1, wherein the pump body assembly (1) comprises a main pump body (1 a) and a bearing seat (1 c), and the bearing seat (1 c) is fixedly connected with the main pump body (1 a); the first bearing mounting section is connected with the main pump body (1 a) through a first bearing (7), and the second bearing mounting section is connected with the bearing seat (1 c) through the first bearing (7).

3. The eccentric main shaft mounting structure of a dry scroll vacuum pump according to claim 2, wherein the main pump body (1 a) has a bearing mounting portion (1 a 4) having a tubular shape therein; the first bearing mounting section is connected with a bearing mounting part (1 a 4) of the main pump body (1 a) through a first bearing (7).

4. A dry scroll vacuum pump eccentric main shaft mounting arrangement according to claim 3, wherein the rotational connection between the first bearing mounting section and the bearing mounting portion (1 a 4) is such as to restrict movement of the eccentric main shaft (3) towards the scroll pumping assembly (2).

5. The eccentric main shaft mounting structure of the dry scroll vacuum pump according to claim 2, wherein the bearing housing (1 c) comprises an outer ring portion (1 c 1) fixedly connected with the main pump body (1 a) and an inner ring portion (1 c 2) connected with the first bearing (7), and the outer ring portion (1 c 1) and the inner ring portion (1 c 2) are connected with each other through a spoke portion (1 c 3).

6. A dry scroll vacuum pump eccentric main shaft mounting structure according to claim 5, wherein the pump body assembly (1) further comprises an end cap (1 b) fixedly connected with the main pump body (1 a), and the bearing seat (1 c) is provided between the main pump body (1 a) and the end cap (1 b).

7. The eccentric main shaft mounting structure of a dry scroll vacuum pump according to claim 6, wherein an elastic member (9) is provided between the inner ring portion (1 c 2) of the bearing housing (1 c) and the end cover (1 b).

8. The eccentric main shaft mounting structure of a dry scroll vacuum pump according to claim 6, wherein the inner ring portion (1 c 2) is connected to the eccentric main shaft (3) by a stopper bolt (13).

9. A dry scroll vacuum pump eccentric main shaft mounting structure according to any one of claims 1 to 8, wherein the connecting structure of the eccentric main shaft (3) and the orbiting scroll (2 a) comprises a second bearing (8), and the eccentric section and the orbiting scroll (2 a) are connected by the second bearing (8).

10. The eccentric main shaft mounting structure of the dry scroll vacuum pump according to claim 9, wherein the inner ring portion of the second bearing (8) is fixed to the eccentric section by a pressing cap and a bolt, the orbiting scroll (2 a) is provided with a screwing operation hole, and a plug (15) for plugging the screwing operation hole is detachably mounted on the orbiting scroll (2 a).