CN114593051A

CN114593051A - Vacuum pump shaft structure and multistage vacuum pump

Info

Publication number: CN114593051A
Application number: CN202011410326.3A
Authority: CN
Inventors: 雷震霖; 孔祥玲; 王冰冰; 毕德龙; 张佳崎; 张军
Original assignee: Sky Development Co ltd Chinese Academy Of Sciences
Current assignee: Sky Development Co ltd Chinese Academy Of Sciences
Priority date: 2020-12-04
Filing date: 2020-12-04
Publication date: 2022-06-07

Abstract

The invention relates to a vacuum pump, in particular to a vacuum pump shaft structure and a multistage vacuum pump. The vacuum pump shaft structure comprises a vacuum pump shaft and a plurality of groups of rotor assemblies arranged on the vacuum pump shaft; the diameters and the thicknesses of the multiple groups of rotor assemblies are gradually reduced along the direction of air flow in the vacuum pump; the multiple groups of rotor assemblies and the vacuum pump shaft are of an integrated structure. The multistage vacuum pump comprises a shell, a motor and two vacuum pump shaft structures, wherein the motor and the two vacuum pump shaft structures are arranged in the shell; the two vacuum pump shaft structures are mutually meshed, the motor is coaxial with one vacuum pump shaft structure, and the motor rotor is arranged on the vacuum pump shaft of the vacuum pump shaft structure. The rotor and the shaft are integrated through processing, so that the integrity of the shaft is guaranteed, the strength of the shaft is improved, the rotor and the shaft do not need to be disassembled or assembled, the assembly efficiency is improved, the number of connecting pieces is reduced, the assembly difficulty is reduced, and the assembly precision is improved.

Description

Vacuum pump shaft structure and multistage vacuum pump

Technical Field

The invention relates to a vacuum pump, in particular to a vacuum pump shaft structure and a multistage vacuum pump.

Technical Field

A multi-stage roots pump generally comprises a pair of shafts each supporting a plurality of rotors in a cavity which provides a stator component for the pump. A pair of shafts is divided into a driving shaft and a driven shaft, and a motor rotor is arranged on a motor shaft, so that the axial size of the vacuum pump is larger, and the volume of the pump is increased. In the semiconductor industry, the field space is limited, the used equipment is various, the occupied area is large, and the space utilization rate is low, so that a pump shaft structure and a vacuum pump which are miniaturized and lightened are urgently needed for improving the space utilization rate of a semiconductor factory.

Disclosure of Invention

In view of the above problems, an object of the present invention is to provide a vacuum pump shaft structure and a multi-stage vacuum pump, so as to achieve miniaturization and light weight of the vacuum pump and improve the utilization rate of the space of a semiconductor factory.

In order to achieve the purpose, the invention adopts the following technical scheme:

a vacuum pump shaft structure comprises a vacuum pump shaft and a plurality of groups of rotor assemblies arranged on the vacuum pump shaft;

the diameters of the multiple groups of rotor assemblies are gradually reduced along the direction of the air flow in the vacuum pump;

the thicknesses of the multiple groups of rotor assemblies are gradually reduced along the direction of the air flow in the vacuum pump;

the multiple groups of rotor assemblies and the vacuum pump shaft are of an integrated structure.

The multi-group rotor assembly comprises a rotor group I and a rotor group II, and the diameter of the rotor group I is larger than that of the rotor group II; the thickness of the rotor set I is larger than that of the rotor set II.

The rotors of each stage of the rotor set I are equal in diameter, and the thickness of the rotors of each stage is gradually reduced along the direction close to the rotor set II.

The diameters of the rotors of each stage of the rotor set II are equal, and the thicknesses of the rotors of each stage are gradually reduced along the direction far away from the rotor set II.

The stage number of the rotor group I is smaller than that of the rotor group II; the stage number of the rotor set I is 1-3, and the stage number of the rotor set II is 2-4.

Each stage of rotor in the rotor set I and the rotor set II is of a blade-shaped structure and comprises a plurality of blade-shaped parts which are uniformly distributed along the circumferential direction.

A multi-stage vacuum pump comprises a shell, a motor and two vacuum pump shaft structures, wherein the motor is arranged in the shell; the two vacuum pump shaft structures are mutually meshed, the motor is coaxial with the vacuum pump shaft structure, and the motor rotor is arranged on the vacuum pump shaft of the vacuum pump shaft structure.

The volume of a chamber formed between the two vacuum pump shaft structures and the housing is gradually reduced from the air inlet end to the air outlet end.

The rotor set I of the vacuum pump shaft structure is close to the air inlet end, and the rotor set II is close to the air outlet end.

The wall thickness of the shell corresponding to the rotor set I is smaller than that of the shell corresponding to the rotor set II.

The invention has the advantages and beneficial effects that:

the invention provides a vacuum pump shaft structure, which integrates a rotor and a shaft through processing, thereby ensuring the integrity of the shaft, improving the strength of the shaft, avoiding the need of dismounting between the rotor and the shaft, improving the assembly efficiency, saving the number of connecting pieces, reducing the assembly difficulty and improving the assembly precision.

The multistage vacuum pump provided by the invention adopts a multistage rotor combination, particularly seven stages, so that a higher volume ratio can be obtained, and the energy consumption is reduced; on the other hand, the motor rotor is arranged on the driving rotor shaft, and the shaft of the pump is used, so that parts such as a coupler, a motor shaft, a bearing and the like are omitted, the size of the pump is shortened in the axial direction, and the whole size of the pump is reduced.

Drawings

Fig. 1 is a schematic diagram of a vacuum pump shaft structure according to an embodiment of the present invention.

Fig. 2 is a schematic structural diagram of a multi-stage vacuum pump according to another embodiment of the present invention.

In the figure: the rotor comprises a shell 1, a first-stage rotor 10, a second-stage rotor 11, a third-stage rotor 12, a fourth-stage rotor 13, a fifth-stage rotor 14, a sixth-stage rotor 15, a seventh-stage rotor 16, a bearing I20, a bearing II 21, a vacuum pump shaft 30, a driving shaft 31, a driven shaft 32, a motor rotor 40 and a blade portion 100.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in detail with reference to the accompanying drawings and specific embodiments.

Example one

As shown in fig. 1, the vacuum pump shaft structure provided by the present invention includes a vacuum pump shaft 30 and a plurality of sets of rotor assemblies disposed on the vacuum pump shaft 30; the diameters of the multiple groups of rotor assemblies are gradually reduced along the direction of the air flow in the vacuum pump; the thicknesses of the multiple groups of rotor assemblies are gradually reduced along the direction of the air flow in the vacuum pump; the multiple sets of rotor assemblies are integral with the vacuum pump shaft 30.

In the embodiment of the invention, the multi-group rotor assembly comprises a rotor group I and a rotor group II, wherein the diameter of the rotor group I is larger than that of the rotor group II; the thickness of rotor group I is greater than the thickness of rotor group II. The rotors of each stage of the rotor set I are equal in diameter, and gradually reduced in thickness in a direction close to the rotor set II. The rotors of each stage of the rotor set II are equal in diameter, and gradually decrease in thickness in a direction away from the rotor set II.

Furthermore, the stage number of the rotor set I is smaller than that of the rotor set II, the stage number of the rotor set I is 1-3, and the stage number of the rotor set II is 2-4. Specifically, each stage of rotor in the rotor set i and the rotor set ii is a lobed structure, and includes a plurality of lobed portions 100 uniformly distributed along the circumferential direction. Specifically, each rotor has two to five lobes 100.

In this embodiment, a vacuum pump shaft structure is seven-stage rotor shaft structure, wherein rotor group i includes tertiary rotor, specifically includes first order rotor 10, second order rotor 11 and tertiary rotor 12, and the diameter of first order rotor 10, second order rotor 11 and tertiary rotor 12 equals, and thickness decreases progressively in proper order. The rotor set II comprises a four-stage rotor, specifically comprises a four-stage rotor 13, a five-stage rotor 14, a six-stage rotor 15 and a seven-stage rotor 16, the four-stage rotor 13, the five-stage rotor 14, the six-stage rotor 15 and the seven-stage rotor 16 are equal in diameter, and gradually reduced in thickness.

According to the vacuum pump shaft structure provided by the invention, the rotor and the vacuum pump shaft are processed into a whole, so that the integrity of the pump shaft structure is ensured, the strength of the pump shaft structure is improved, the rotor and the vacuum pump shaft do not need to be disassembled and assembled, the assembly efficiency is improved, the number of connecting pieces is saved, the assembly difficulty is reduced, and the assembly precision is improved.

Example two

As shown in fig. 2, the multi-stage vacuum pump provided by the present invention includes a casing 1, a motor disposed in the casing 1, and two vacuum pump shaft structures provided in the first embodiment; the two vacuum pump shaft structures are meshed with each other, the motor is coaxial with one vacuum pump shaft structure, and the motor rotor 40 is arranged on the vacuum pump shaft 30 of the vacuum pump shaft structure.

In this embodiment, two ends of the two vacuum pump shafts 30 are respectively supported by the bearing i 20 and the bearing ii 21. Wherein, the vacuum pump shaft 30 which is coaxial with the motor is a driving shaft 31, and the other vacuum pump shaft 30 is a driven shaft 32. The motor rotor 40 is arranged on the driving shaft 31, one end of the motor rotor is propped against the inner ring of the bearing I20, and the other end of the motor rotor is locked by a nut. The motor stator corresponding to the motor rotor 40 is connected to the housing 1 so that the motor is in a vacuum state during use.

The volume of the chamber formed between the two vacuum pump shaft structures and the housing 1 becomes progressively smaller from the intake end to the exhaust end. Specifically, a rotor set I of the vacuum pump shaft structure is close to an air inlet end, and a rotor set II is close to an air outlet end. The wall thickness of the shell 1 corresponding to the rotor set I is smaller than that of the shell corresponding to the rotor set II.

In this embodiment, the volume of the space formed by the three rotors of the rotor set i and the pump cavity in the vacuum pump shaft structure is gradually reduced. In particular, it may be obtained by a gradually decreasing thickness of the rotor and of the chamber; the volume of the space of the four-stage chambers of the following rotor group ii is also gradually reduced, and in particular, can be obtained by reducing the diameter and thickness of the rotor and the thickness of the pump chamber.

In the embodiment, the seven-stage rotor shaft structure can obtain higher volume ratio and reduce energy consumption. Vacuum pump shaft 30 and rotor group I and rotor group II's rotor formula structure as an organic whole at each level, middle no key-type connection, draw-in groove connection, interference fit etc. integral type rotor shaft simple structure, convenient assembling has guaranteed the integrality of axle and has improved the intensity of axle, makes things convenient for the vacuum pump dismouting, and repeated dismouting can not lead to the fact the damage to counter shaft and rotor. The rotor and the shaft are integrated, so that the assembly precision and the assembly efficiency are improved, failures caused by interference hot-fitting, key connection and clamping groove connection are eliminated, and the assembly time is saved.

In the embodiment of the invention, the space formed by the rotor and the chamber on the air inlet side of the pump body is larger than the space formed by the rotor and the chamber on the air outlet side of the pump body, and the spaces are reduced in sequence, wherein the motor rotor is arranged on a driving shaft of the pump; the thickness of the exhaust side rotor is at least 14% smaller than that of the inlet side rotor, the volume formed by each stage of rotor and the chamber has a certain proportional relation, and the inlet side and the exhaust side are sequentially reduced to be 20:1 at most. The number of rotor stages may be three to seven, and to obtain a relatively high volume ratio, the highest number of stages may be seven.

In the embodiment of the invention, the rotor on the driving shaft and the motor rotor share one shaft, so that parts such as a coupler, a motor shaft, a bearing and the like and a lubricating system of a motor part are omitted, the axial space is more compact, and meanwhile, the motor is convenient to install and distribute. The motor rotor is arranged on the driving shaft of the vacuum pump, so that the axial size of the vacuum pump is shortened, and the axial volume of the pump is reduced. The motor is connected with the vacuum pump, so that the motor is in a vacuum state when working.

The above description is only an embodiment of the present invention, and is not intended to limit the scope of the present invention. Any modification, equivalent replacement, improvement, extension, etc. made within the spirit and principle of the present invention are included in the protection scope of the present invention.

Claims

1. A vacuum pump shaft structure is characterized by comprising a vacuum pump shaft (30) and a plurality of groups of rotor assemblies arranged on the vacuum pump shaft (30);

the multiple groups of rotor assemblies and the vacuum pump shaft (30) are of an integrated structure.

2. The vacuum pump shaft structure of claim 1, wherein the plurality of sets of rotor assemblies comprise a rotor set I and a rotor set II, and the diameter of the rotor set I is larger than that of the rotor set II; the thickness of the rotor set I is larger than that of the rotor set II.

3. The vacuum pump shaft structure of claim 2, wherein each stage of rotors of the rotor set i has an equal diameter and a thickness that gradually decreases in a direction approaching the rotor set ii.

4. The vacuum pump shaft structure of claim 2, wherein the rotors of each stage of the rotor set ii are equal in diameter and gradually decrease in thickness in a direction away from the rotor set ii.

5. The vacuum pump shaft structure of claim 2, wherein the number of stages of the rotor set i is smaller than the number of stages of the rotor set ii; the number of stages of the rotor set I is 1-3, and the number of stages of the rotor set II is 2-4.

6. The vacuum pump shaft structure of claim 1, wherein each stage of the rotors in the rotor group I and the rotor group II is a lobed structure comprising a plurality of lobes (100) uniformly distributed along a circumferential direction.

7. A multi-stage vacuum pump, comprising a housing (1) and an electric motor arranged in the housing (1) and two vacuum pump shaft arrangements according to any of claims 1-6; the two vacuum pump shaft structures are meshed with each other, the motor is coaxial with the vacuum pump shaft structure, and the motor rotor (40) is arranged on the vacuum pump shaft (30) of the vacuum pump shaft structure.

8. A multi-stage vacuum pump according to claim 7, wherein the volume of the chamber formed between the two vacuum pump shaft structures and the housing (1) tapers from the inlet end to the outlet end.

9. A multi-stage vacuum pump according to claim 8, wherein the rotor set i of the vacuum pump shaft arrangement is adjacent the inlet end and the rotor set ii is adjacent the outlet end.

10. A multi-stage vacuum pump according to claim 9, wherein the wall thickness of the housing (1) corresponding to the rotor set i is smaller than the wall thickness corresponding to the rotor set ii.