Compound multi-compression mechanism vacuum pump with high compression ratio and large pumping speed

Abstract

The present invention provides a composite multi-compression mechanism vacuum pump with a high compression ratio and high pumping speed. The multi-compression mechanism includes three types: a turbine, a traction wheel, and a vortex blade array. The traction wheel is divided into a first-stage traction wheel and a second-stage traction wheel. A first-stage exhaust port and a second-stage exhaust port are respectively provided on the base, and a valve is provided on the first-stage exhaust port. In the first pumping stage, the valve is opened, and most of the gas flows through the turbine and the first-stage traction wheel and is discharged from the first-stage exhaust port. A small part of the gas flows through the turbine, the first-stage traction wheel, the second-stage traction wheel, and the vortex blade array in sequence and is discharged from the second-stage exhaust port. In the second pumping stage, the valve is closed, and the gas flows through the turbine, the first-stage traction wheel, the second-stage traction wheel, and the vortex blade array and is discharged from the second-stage exhaust port. The present invention solves the problem that high pumping speed and high vacuum cannot be achieved at the same time and that the molecular pump must be equipped with a pre-stage pump by using multiple compression mechanisms in series. The present invention can replace a traditional set of multiple vacuum pumps with a single vacuum pump, significantly reducing costs.

Description

Technical Field

[0001] The present invention relates to the technical field of vacuum pumps, and in particular to a composite multi-compression mechanism vacuum pump with high compression ratio and high pumping speed. Background Art

[0002] As a key infrastructure in industry and scientific research, vacuum pumps rely on a combination of high pumping speed and high compression ratio. In existing technologies, turbine compression, traction wheel compression, and scroll compression structures often combine in pairs for compound pumps due to their different characteristics. However, these structures still have significant limitations. Compound pumps in existing technologies have the following technical issues:

[0003] 1. Turbine-traction wheel compound pump;

[0004] This type of compound pump features a turbine stage and a traction wheel stage connected in series, similar to the design of some molecular pumps. The turbine stage achieves gas compression through a layered design of rotors and stators, while the traction wheel stage further increases the compression ratio through momentum transfer. However, the overall compression ratio of the turbine-traction wheel compound pump is still insufficient, and it cannot exhaust directly into the atmosphere, requiring a pre-vacuuming mechanism using a fore-stage mechanical pump / dry pump. This limitation limits its application scenarios, especially in operating conditions that require rapid startup and shutdown or frequent exposure to the atmosphere. An additional fore-stage pump set is required, increasing system complexity and cost.

[0005] 2. Traction wheel-vortex compound pump;

[0006] This type of compound pump combines a traction wheel stage with a scroll stage, leveraging the high compression ratio of the scroll stage to achieve direct atmospheric exhaust. However, due to the inherent limitations of the traction wheel, its pumping speed and compression ratio are far lower than those of the turbine stage. Furthermore, because the scroll stage relies on the principle of volumetric compression, its gas handling capacity decreases sharply with increasing pressure. When the two are connected in series, the overall pumping speed and compression ratio are insufficient to meet the rapid extraction requirements of large cavities, and the vacuum level is also unsatisfactory.

[0007] Therefore, there is an urgent need in this field for a vacuum pump that can exhaust directly to the atmosphere and has both a high pumping speed and a high compression ratio. Summary of the Invention

[0008] In view of the defects in the prior art, the object of the present invention is to provide a composite multi-compression mechanism vacuum pump with high compression ratio and high pumping speed.

[0009] The composite multi-compression mechanism vacuum pump with high compression ratio and high pumping speed provided by the present invention comprises a base, a motor, a rotor, a casing and a main shaft;

[0010] The base is fixedly mounted inside the casing, the rotor is rotatably sleeved on the outside of the base, the main shaft is rotatably mounted inside the base and coaxially connected to the rotor, and the motor is fixedly mounted inside the base for driving the main shaft to rotate;

[0011] The rotor includes a rotor body, a main shaft, a turbine structure, a traction wheel, and a vortex blade row. The turbine structure is arranged on the air inlet end of the rotor body and forms a turbine compression structure with the stator inside the pump body. The traction wheel and the vortex blade row are arranged in sequence on the rotor body until the air outlet end.

[0012] A vortex compression structure is formed between the vortex blade row and the vortex guide groove of the casing. The traction wheel compression structure includes a primary traction wheel located on the outside and a secondary traction wheel located on the inside. The base is provided with a primary exhaust port and a secondary exhaust port.

[0013] The gas outlet of the turbine compression structure is connected to the gas inlet of the first-stage traction wheel, the gas outlet of the first-stage traction wheel is connected to the first-stage exhaust port and the gas inlet of the second-stage traction wheel, the gas outlet of the second-stage traction wheel is connected to the gas inlet of the vortex compression structure, and the gas outlet of the vortex compression structure is connected to the second-stage exhaust port;

[0014] A valve is installed on the first-stage exhaust port. When in the first exhaust stage, the valve is opened, and most of the gas passes through the turbine compression structure and the first-stage traction wheel in sequence and is discharged from the first-stage exhaust port. A small part of the gas passes through the turbine compression structure, the first-stage traction wheel, the second-stage traction wheel and the vortex compression structure in sequence and is discharged from the second-stage exhaust port.

[0015] In the second exhaust stage, the valve is closed, and the remaining gas passes through the turbine compression structure, the first-stage traction wheel, the second-stage traction wheel and the vortex compression structure in sequence, and is discharged from the second-stage exhaust port.

[0016] Preferably, the turbine structure includes a plurality of stacked turbine blades, and a plurality of stacked stators are fixedly mounted inside the base via a pressure ring. The stators and turbine blades are alternately mounted in sequence to form a turbine compression structure.

[0017] Preferably, a vertical cylindrical partition is provided in the middle of the traction wheel compression structure, a first spiral structure is provided on the outer side of the vertical cylindrical partition to form a primary traction wheel, and a second spiral structure is provided on the inner side of the vertical cylindrical partition to form a secondary traction wheel;

[0018] The primary traction wheel is used to guide the gas molecules from the gas path inlet of the primary traction wheel to the gas path outlet along a first direction by rotating, and the secondary traction wheel is used to guide the gas molecules from the gas path inlet of the secondary traction wheel to the gas path outlet along a second direction opposite to the first direction by rotating.

[0019] Preferably, the gas path inlet of the first-stage traction wheel is directly connected to the turbine compression structure;

[0020] The air path outlet of the first-stage traction wheel is communicated with the air path inlet of the second-stage traction wheel through the gap between the vertical cylindrical partition and the base.

[0021] Preferably, a radial magnetic suspension unit is fixedly installed inside the base, and the radial magnetic suspension unit is sleeved outside the main shaft.

[0022] Preferably, the rotor includes a first rotor and a second rotor, and the first rotor and the second rotor are installed in pairs at both ends of the main shaft;

[0023] The turbine structure, traction wheel and vortex blade row of the first rotor have mechanical rotation directions opposite to those of the turbine structure, traction wheel and vortex blade row of the second rotor.

[0024] Preferably, the first rotor and the second rotor are installed face to face;

[0025] The air outlet ends of the rotor bodies of the first rotor and the second rotor are arranged opposite to each other, and the air inlet ends of the rotor bodies are arranged opposite to each other and respectively face the two ends of the base. The two ends of the base are provided with openings, which serve as air inlets for the first turbine structure in the first rotor and the second turbine structure in the second rotor, respectively.

[0026] A first traction wheel and a second traction wheel are provided on the top of the first rotor, and the first traction wheel and the second traction wheel serve as a primary traction wheel and a secondary traction wheel respectively. A second vortex blade row is provided on the top of the first rotor, and is used to form a first vortex compression structure with the vortex guide groove of the base;

[0027] A third traction wheel and a fourth traction wheel are provided at the bottom of the second rotor, and the third traction wheel and the fourth traction wheel serve as a secondary traction wheel and a primary traction wheel respectively. A first vortex blade row is provided at the bottom of the second rotor, which is used to form a second vortex compression structure with the vortex guide groove of the base;

[0028] The base is provided with a first exhaust port, a second exhaust port and a third exhaust port in the middle thereof, wherein the first exhaust port serves as a secondary exhaust port and is connected to the gas path outlets of the first scroll compression structure and the second scroll compression structure respectively;

[0029] The second exhaust port and the third exhaust port are respectively provided with a first valve and a second valve. The second exhaust port and the third exhaust port serve as primary exhaust ports and are respectively connected to the air outlet of the first traction wheel and the air outlet of the fourth traction wheel.

[0030] Preferably, the first rotor and the second rotor are installed back to back;

[0031] The air outlet ends of the rotor bodies of the first rotor and the second rotor are arranged in opposite directions, and the air inlet ends of the rotor bodies are arranged opposite to each other and respectively face the middle part of the base. The middle part of the base is provided with an air inlet, which serves as the air inlet of the first turbine structure in the first rotor and the second turbine structure in the second rotor respectively;

[0032] A first traction wheel and a second traction wheel are provided at the bottom of the first rotor, the first traction wheel and the second traction wheel serving as a primary traction wheel and a secondary traction wheel respectively. A second vortex blade row is provided at the bottom of the first rotor for forming a first vortex compression structure with the vortex guide groove of the base.

[0033] A third traction wheel and a fourth traction wheel are provided on the top of the second rotor, and the third traction wheel and the fourth traction wheel serve as a secondary traction wheel and a primary traction wheel respectively. A first vortex blade row is provided on the top of the second rotor, which is used to form a second vortex compression structure with the vortex guide groove of the base;

[0034] A first-stage exhaust port and a second-stage exhaust port are provided at both ends of the base. The second-stage exhaust ports at both ends are respectively connected to the air outlets of the first scroll compression structure and the second scroll compression structure. Valves are provided on the first-stage exhaust ports at both ends, and are respectively connected to the air outlets of the first traction wheel and the fourth traction wheel.

[0035] Preferably, a thrust plate, an axial magnetic suspension unit and an axial sensor are coaxially mounted on one end of the main shaft in sequence;

[0036] The axial magnetic suspension unit is connected to the main shaft end through a thrust plate, and the thrust plate, the axial magnetic suspension unit and the axial sensor form an axial magnetic suspension bearing.

[0037] Preferably, the outer sleeve of the main shaft is provided with a first protection bearing and a second protection bearing;

[0038] The first protective bearing is arranged between the main shaft and the base, and the second protective bearing is arranged between the main shaft and the axial magnetic suspension unit.

[0039] Compared with the prior art, the present invention has the following beneficial effects:

[0040] 1. The present invention adopts the series use of a turbine compression structure, a traction wheel compression structure, and a vortex compression structure, and timely controls the valve action of the first-stage exhaust port, thereby achieving a high pumping speed and a high compression ratio. This solves the problem that a vacuum pump cannot achieve both high pumping speed and high vacuum degree, and that a molecular pump must be equipped with a set of fore-stage pumps. A single vacuum pump can replace several traditional vacuum pumps, greatly reducing the production and use costs.

[0041] 2. The present invention divides the vacuuming process into two stages by equipping the first-level exhaust port with a valve opening and closing action. In the first stage, most of the gas is discharged through the first-level exhaust port, which can quickly reduce the air pressure to the kilopascal level or even the hectopascal level. In the second stage, the valve is closed to force the remaining gas in the vacuum chamber to be discharged through the second-level exhaust port, thereby achieving high vacuum or even ultra-high vacuum.

[0042] 3. The present invention uses a turbine compression structure, a traction wheel compression structure and a vortex compression structure in series. The maximum pumping speed in the low vacuum stage can reach tens of thousands of cubic meters per hour, and the maximum pumping speed in the high vacuum stage can reach tens of thousands of liters per second, or even higher. The ultimate vacuum can be directly discharged from the atmosphere to 10 －6 Pa~10 －7 Pa. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Other features, objects and advantages of the present invention will become more apparent upon reading the detailed description of non-limiting embodiments with reference to the following drawings:

[0044] Figure 1 This is a schematic diagram of the overall structure of Example 1 of the present invention;

[0045] Figure 2 for Figure 1 A partial enlarged schematic diagram of part A in the middle;

[0046] Figure 3 This is a schematic diagram of the overall structure of Example 2 of the present invention;

[0047] Figure 4 for Figure 3 A partial enlarged schematic diagram of part A in the middle.

[0048] The figure shows:

[0049] DETAILED DESCRIPTION

[0050] The present invention will be described in detail below with reference to specific embodiments. The following examples will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those skilled in the art, several changes and improvements can be made without departing from the scope of the present invention. These all fall within the scope of protection of the present invention.

[0051] The present invention discloses a composite multi-compression mechanism vacuum pump with high compression ratio and high pumping speed. The vacuum pump has the excellent performance of high pumping speed and high compression ratio by serial operation of turbine compression, traction wheel compression, and scroll blade pair compression and timely control of exhaust port valve action. The maximum pumping speed in the low vacuum stage can reach tens of thousands of cubic meters per hour, and the maximum pumping speed in the high vacuum stage can reach tens of thousands of liters per second, or even higher; the ultimate vacuum can be directly discharged from the atmosphere to 10 －5 Pa~10 －6 Pa, and even higher ultimate vacuum can be achieved, such as 10 －6 Pa~10 －7 Pa can meet the needs of most industrial production and experimental equipment, thus avoiding the complex system of using a series combination of a molecular pump and a backing pump. It is not only more efficient but also can significantly reduce costs. In short, it achieves the goal of using only a vacuum pump to evacuate from atmospheric state to high vacuum or even ultra-high vacuum, which has incomparable advantages in terms of cost saving, simplified structure, and reduced life cycle cost.

[0052] The composite multi-compression mechanism vacuum pump with a high compression ratio and high pumping speed provided by the present invention includes a base, a motor 37, a rotor, a radial magnetic suspension unit, and a main shaft 10; the radial magnetic suspension unit 40 and the motor 37 are fixedly mounted inside the base, the rotor is rotatably mounted outside the radial magnetic suspension unit 40 and the motor 37, the main shaft 10 is rotatably mounted inside the radial magnetic suspension unit 40 and the motor 37, and is coaxially connected to the rotor; the motor 37 is fixedly mounted inside the base to drive the main shaft 10 to rotate;

[0053] The rotor includes a rotor body, a turbine structure, a traction wheel, and a vortex blade row. The turbine structure is arranged on the air inlet end of the rotor body and forms a turbine compression structure with the stators of each stage inside the base. The traction wheel and the vortex blade row are arranged on the air outlet end of the rotor body in sequence from the outside to the inside.

[0054] A vortex compression structure is formed between the vortex blade row and the vortex guide groove of the base. The traction wheel compression structure includes a first-stage traction wheel located on the outside and a second-stage traction wheel located on the inside. The base is provided with a first-stage exhaust port and a second-stage exhaust port. The air outlet of the turbine compression structure is connected to the air inlet of the first-stage traction wheel. The air outlet of the first-stage traction wheel is simultaneously connected to the first-stage exhaust port and the air inlet of the second-stage traction wheel. The air outlet of the second-stage traction wheel is connected to the air inlet of the vortex compression structure. The air outlet of the vortex compression structure is connected to the second-stage exhaust port.

[0055] A valve is installed on the first-stage exhaust port. When in the first exhaust stage, the valve is opened, and most of the gas passes through the turbine compression structure and the first-stage traction wheel in sequence and is discharged from the first-stage exhaust port; a small part of the gas passes through the turbine compression structure, the first-stage traction wheel, the second-stage traction wheel and the vortex compression structure in sequence and is discharged from the second-stage exhaust port; when in the second exhaust stage, the valve is closed, and the remaining gas in the vacuum chamber passes through the turbine compression structure, the first-stage traction wheel, the second-stage traction wheel and the vortex compression structure in sequence and is discharged from the second-stage exhaust port.

[0056] Specifically, the turbine structure includes a plurality of stacked turbine blades. A plurality of stacked stators are fixedly mounted within the base via a pressure ring. The stators and turbine blades are alternately mounted to form a turbine compression structure. A vertical cylindrical baffle is disposed in the middle of the traction wheel compression structure. A first helical structure is disposed on the outer side of the vertical cylindrical baffle, forming a primary traction wheel. A second helical structure is disposed on the inner side of the vertical cylindrical baffle, forming a secondary traction wheel. The primary traction wheel is configured to guide gas molecules from the gas path inlet to the gas path outlet of the primary traction wheel via rotation. The secondary traction wheel is configured to guide gas molecules from the gas path inlet to the gas path outlet of the secondary traction wheel via rotation in a second direction, opposite to the first direction. The gas inlet of the first-stage traction wheel is directly connected to the turbine compression structure, that is, the gas directly enters the first-stage traction wheel after passing through the turbine compression structure; the gas outlet of the first-stage traction wheel is connected to the gas inlet of the second-stage traction wheel through the gap between the vertical cylindrical partition and the base; the radial magnetic suspension unit 40 and the motor stator 37 are fixedly installed inside the base, and the radial magnetic suspension unit 40 and the motor stator 37 are sleeved on the outside of the main shaft 10.

[0057] The above is a basic embodiment of the present invention, and its working principle is as follows:

[0058] by Figure 1 Taking the rotor in the middle and upper part as an example, the pumped gas is first compressed layer by layer in the second turbine structure 42. The second turbine structure 42 can be designed with compression levels as needed, and then enters the fourth traction wheel 39 for further compression. After being compressed by the fourth traction wheel 39, most of the gas is directly discharged from the third exhaust port 36, and a small part passes through the gap between the second rotor 9 and the base and enters the third traction wheel 38 for compression. The compressed gas is then sent to the first vortex blade row 8 for the fourth compression, and finally discharged from the pump through the first exhaust port 11.

[0059] There is a key point that has been overlooked in the art and remains a technical challenge. If the vacuum pump is directly activated to pump air under relatively high pressure, the mismatch between the scroll compression structure and the turbine compression structure can easily lead to air holding, which significantly affects work efficiency. The present invention provides a second valve 35 at the third exhaust port 36. In the initial stage of pumping, when the gas is compressed by the second turbine structure 42 and the fourth traction wheel 39, the chamber pressure drops to a certain level—for example, the kilopascals or even the hectopascals level. When the compression ratio reaches the limit of the second turbine structure 42 and the fourth traction wheel 39, the chamber pressure stops decreasing or decreases slowly. The second valve 35 can be closed, forcing the gas to be discharged from the pump body along the path of "second turbine structure 42 → fourth traction wheel 39 → third traction wheel 38 → first scroll blade row pair → first exhaust port 11." In this way, after the vacuum chamber has been largely exhausted, the amount of remaining gas is minimal. Thanks to the compression ratio of the third traction wheel 38 and the first scroll blade row pair, the gas can be quickly pumped out and the ideal ultimate vacuum degree can be achieved.

[0060] For ease of understanding, the present invention can be regarded as dividing the pumping process into two stages: in the first stage, in this stage, the second valve 35 is open, and most of the gas is compressed by the second turbine structure 42 and the fourth traction wheel 39 and discharged from the pump through the third exhaust port 36 and the second valve 35, and a small part is discharged from the pump body through the "second turbine structure 42 → fourth traction wheel 39 → third traction wheel 38 → first vortex blade row pair → first exhaust port 11" path. The pumping speed in the first stage is very high, and the pressure can be quickly reduced to the kiloPascal level or even the hectoPascal level; in the second stage, when the pressure of the pumped cavity drops to a certain level, such as the kiloPascal level or even the hectoPascal level, the second valve 35 is closed, forcing all the remaining gas to go through the "second turbine structure 42 → fourth traction wheel 39 → third traction wheel 38 → first vortex blade row pair → first exhaust port 11" path to be discharged from the pump body. In this stage, the compression ratio is very large, and the vacuum degree can be pumped to 10 －5 Pa~10 －6 Pa, even better.

[0061] Furthermore, the present invention adopts two mechanical structures, face-to-face design or back-to-back design, in which the two rotors run coaxially, but the mechanical rotation directions of the rotors are opposite. Please note: the rotation direction here does not refer to the direction of rotation, but to the processing rotation direction. If the upper rotor rotates to the left, the lower rotor must be right-handed, which not only offsets the unidirectional force of the compression effect, but also doubles the pumping speed compared with the same caliber. The difference between the two is that: the face-to-face design is to take in air from both ends of the pump body and discharge it through the exhaust port in the center of the pump body; the back-to-back design is to take in air from the center of the pump body and discharge it from both ends of the pump body, and the axial force deviation is compensated by the axial magnetic levitation bearing composed of the axial sensor 22, the thrust plate 23, and the axial magnetic levitation unit 24; the above two mechanical structures of face-to-face design and back-to-back design will be further specifically explained through Examples 1 and 2;

[0062] Example 1: Figure 1 、 Figure 2 As shown, this embodiment discloses a vacuum pump form that is installed face to face. Specifically, the first rotor 13 and the second rotor 9 are installed in pairs at both ends of the main shaft 10, and the turbine structure, traction wheel and vortex blade row pair of the first rotor 13 have a mechanical rotation direction opposite to that of the turbine structure, traction wheel and vortex blade row pair of the second rotor 9.

[0063] The air outlet ends of the rotor bodies of the first rotor 13 and the second rotor 9 are arranged opposite to each other, and the air inlet ends of the rotor bodies are arranged opposite to each other and face the two ends of the base respectively. The two ends of the base are provided with openings, which serve as air inlets for the first turbine structure 25 in the first rotor 13 and the second turbine structure 42 in the second rotor 9 respectively.

[0064] A first traction wheel 31 and a second traction wheel 32 are provided at the top of the first rotor 13. The first traction wheel 31 and the second traction wheel 32 serve as the primary traction wheel and the secondary traction wheel, respectively. A second vortex blade row 12 is provided at the top of the first rotor 13, which is a first vortex compression structure. A third traction wheel 38 and a fourth traction wheel 39 are provided at the bottom of the second rotor 9. The third traction wheel 38 and the fourth traction wheel 39 serve as the secondary traction wheel and the primary traction wheel, respectively. A first vortex blade row 8 is provided at the bottom of the second rotor 9, which is a second vortex compression structure.

[0065] A first exhaust port 11, a second exhaust port 33 and a third exhaust port 36 are provided in the middle of the base. The first exhaust port 11 serves as a secondary exhaust port and is connected to the air outlets of the first scroll compression structure and the second scroll compression structure respectively; the second exhaust port 33 and the third exhaust port 36 are respectively provided with a first valve 34 and a second valve 35. The second exhaust port 33 and the third exhaust port 36 serve as primary exhaust ports and are connected to the air outlet of the first traction wheel 31 and the air outlet of the fourth traction wheel 39 respectively.

[0066] Example 2: Figure 1 、 Figure 2 As shown, this embodiment discloses a vacuum pump type that is installed back-to-back. Specifically, the first rotor 13 and the second rotor 9 are installed in pairs at both ends of the main shaft 10, and the turbine structure, traction wheel and vortex blade pair of the first rotor 13 have a mechanical rotation direction opposite to that of the turbine structure, traction wheel and vortex blade pair of the second rotor 9.

[0067] The air outlet ends of the rotor bodies of the first rotor 13 and the second rotor 9 are arranged in opposite directions, and the air inlet ends of the rotor bodies are arranged opposite to each other and respectively face the middle of the base. The middle of the base is provided with an air inlet 43, which serves as an air path inlet for the first turbine structure 25 in the first rotor 13 and the second turbine structure 42 in the second rotor 9, respectively.

[0068] A first traction wheel 31 and a second traction wheel 32 are provided at the bottom of the first rotor 13. The first traction wheel 31 and the second traction wheel 32 serve as the first-stage traction wheel and the second-stage traction wheel, respectively. A second vortex blade row 12 is provided at the bottom of the first rotor 13, which is a first vortex compression structure. A third traction wheel 38 and a fourth traction wheel 39 are provided at the top of the second rotor 9. The third traction wheel 38 and the fourth traction wheel 39 serve as the second-stage traction wheel and the first-stage traction wheel, respectively. A first vortex blade row 8 is provided at the top of the second rotor 9, which is a second vortex compression structure.

[0069] Both ends of the pump body are provided with a first-level exhaust port and a second-level exhaust port. The first exhaust port 11 of the second-level exhaust port at both ends is respectively connected to the air outlet of the first scroll compression structure and the second scroll compression structure. The second exhaust port 33 and the third exhaust port 36 of the first-level exhaust port at both ends are respectively provided with a first valve 34 and a second valve 35, and are respectively connected to the air outlet of the first traction wheel 31 and the air outlet of the fourth traction wheel 39.

[0070] The above-mentioned designs of Example 1 and Example 2 can effectively offset the axial force of the compression effect, and the pumping speed is doubled compared with the same caliber;

[0071] In a preferred embodiment, in order to compensate for part of the axial force that cannot be offset by the two rotors and to achieve dynamic control, a thrust plate 23, an axial magnetic suspension unit 24 and an axial sensor 22 are coaxially installed in sequence at one end of the main shaft 10; the axial magnetic suspension unit 24 is connected to the end of the main shaft 10 through the thrust plate 23, and the thrust plate 23, the axial magnetic suspension unit 24 and the axial sensor 22 form an axial magnetic suspension bearing.

[0072] The main shaft 10 is externally sleeved with a first protective bearing 21 and a second protective bearing 41 ; the first protective bearing 21 is disposed between the main shaft 10 and the base, and the second protective bearing 41 is disposed between the main shaft 10 and the axial magnetic suspension unit 24 .

[0073] It should be pointed out that although the present embodiment adopts a magnetic levitation bearing, the magnetic levitation bearing is not the main invention point of the design, but only the bearing mechanism and axial force compensation mechanism of the rotor system. Therefore, the magnetic levitation bearing mechanism will not be described in detail. However, it should be emphasized that: since the present invention adopts a magnetic levitation bearing, 360-degree all-round installation can be achieved, and upright, inverted, horizontal and other installation methods are all within the scope of the present invention.

[0074] Furthermore, the present invention allows for flexible adjustments to the number of turbine compression stages (from one to dozens), the length of the traction wheel compression, the number of spiral heads and spiral angles, and the number of vortex blade pairs (from one to dozens) to suit actual user needs, including pumping speed and vacuum requirements. Even certain components can be eliminated, such as eliminating the traction wheel, leaving only the turbine and vortex blade pairs; or eliminating the turbine, leaving only the traction wheel and vortex blade pairs; or eliminating the vortex blade pairs, leaving only the turbine and traction wheel.

[0075] Even for relatively small models, such as turbines with diameters ≤350mm, a dual-rotor symmetrical offset design is unnecessary. Instead, a single rotor can be used with a larger axial magnetic bearing to generate sufficient axial magnetic force to stabilize the rotor. Therefore, whether a dual-rotor design or a single-rotor design is used should not be construed as a limitation on this application.

[0076] Adopting face-to-face or back-to-back installation methods can offset most of the axial forces generated during the compression process. It should be pointed out that whether it is face-to-face or back-to-back, the compression process and gas path direction are not essentially different, and it depends on actual needs;

[0077] Example 3: This example mainly describes the number of stages of turbine compression. Figure 1 or Figure 3As shown, the outer ring of the second turbine structure 42 is sequentially mounted with a first stator 1, a second stator 2, a third stator 3, a fourth stator 4, a fifth stator 5, a sixth stator 6, and a seventh stator 7, and the above stators are fixed to the inside of the base by a first pressure ring 26, a second pressure ring 27, a third pressure ring 28, a fourth pressure ring 29, and a fifth pressure ring 30 located in the gap. The outer ring of the first turbine structure 25 is sequentially mounted with an eighth stator 14, a ninth stator 15, a tenth stator 16, an eleventh stator 17, a twelfth stator 18, a thirteenth stator 19, and a fourteenth stator 20, and the above stators are fixed to the inside of the base by a first pressure ring 26, a second pressure ring 27, a third pressure ring 28, a fourth pressure ring 29, and a fifth pressure ring 30 located in the gap. The above stators cooperate with the turbine structure of the rotor to form a multi-stage turbine compression structure. It should be noted that the number of turbine compression stages is not fixed and is also set according to actual needs.

[0078] In the description of this application, it should be understood that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0079] The above describes specific embodiments of the present invention. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art may make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. The embodiments of this application and the features in the embodiments may be combined with each other in any manner unless there is a conflict.

Claims

1. A composite multi-compression mechanism vacuum pump with high compression ratio and high pumping speed, characterized in that: It includes a base, a motor (37), a rotor, a housing and a main shaft (10); The base is fixedly mounted inside the housing, the rotor is rotatably mounted outside the base, the main shaft (10) is rotatably mounted inside the base and is coaxially connected to the rotor, and the motor (37) is fixedly mounted inside the base for driving the main shaft (10) to rotate; The rotor includes a rotor body, a turbine structure, a traction wheel, and a vortex blade row. The turbine structure is arranged on the air inlet end of the rotor body and forms a turbine compression structure with the interior of the base. The traction wheel and the vortex blade row are arranged on the air outlet end of the rotor body in sequence from the outside to the inside. A vortex compression structure is formed between the vortex blade row and the vortex guide groove of the casing. The traction wheel includes a primary traction wheel located on the outside and a secondary traction wheel located on the inside. The base is provided with a primary exhaust port and a secondary exhaust port. The gas outlet of the turbine compression structure is connected to the gas inlet of the first-stage traction wheel, the gas outlet of the first-stage traction wheel is connected to the first-stage exhaust port and the gas inlet of the second-stage traction wheel, the gas outlet of the second-stage traction wheel is connected to the gas inlet of the vortex compression structure, and the gas outlet of the vortex compression structure is connected to the second-stage exhaust port; A valve is installed on the first-stage exhaust port. When in the first exhaust stage, the valve is opened, and most of the gas passes through the turbine compression structure and the first-stage traction wheel in sequence and is discharged from the first-stage exhaust port. A small part of the gas passes through the turbine compression structure, the first-stage traction wheel, the second-stage traction wheel and the vortex compression structure in sequence and is discharged from the second-stage exhaust port. In the second exhaust stage, the valve is closed, and the remaining gas passes through the turbine compression structure, the first-stage traction wheel, the second-stage traction wheel and the vortex compression structure in sequence, and is discharged from the second-stage exhaust port; The turbine structure includes a plurality of stacked turbine blades, and a plurality of stacked stators are fixedly mounted inside the base via a pressure ring. The stators and turbine blades are alternately mounted in sequence to form a turbine compression structure.

2. The compound multi-compression mechanism vacuum pump with high compression ratio and high pumping speed according to claim 1, characterized in that: A vertical cylindrical partition is provided in the middle of the traction wheel, a first spiral structure is provided on the outer side of the vertical cylindrical partition to form a primary traction wheel, and a second spiral structure is provided on the inner side of the vertical cylindrical partition to form a secondary traction wheel; The primary traction wheel is used to guide the gas molecules from the gas path inlet of the primary traction wheel to the gas path outlet along a first direction by rotating, and the secondary traction wheel is used to guide the gas molecules from the gas path inlet of the secondary traction wheel to the gas path outlet along a second direction opposite to the first direction by rotating.

3. The compound multi-compression mechanism vacuum pump with high compression ratio and high pumping speed according to claim 2, characterized in that: The air path inlet of the first-stage traction wheel is directly connected to the turbine compression structure; The air path outlet of the first-stage traction wheel is communicated with the air path inlet of the second-stage traction wheel through the gap between the vertical cylindrical partition and the base.

4. The compound multi-compression mechanism vacuum pump with high compression ratio and high pumping speed according to claim 1, characterized in that: A radial magnetic suspension unit (40) is fixedly installed inside the base, and the radial magnetic suspension unit (40) is sleeved outside the main shaft (10).

5. The compound multi-compression mechanism vacuum pump with high compression ratio and high pumping speed according to claim 1, characterized in that: The rotor comprises a first rotor (13) and a second rotor (9), wherein the first rotor (13) and the second rotor (9) are mounted in pairs at both ends of the main shaft (10); The turbine structure, traction wheel and vortex blade array of the first rotor (13) have mechanical rotation directions opposite to those of the turbine structure, traction wheel and vortex blade array of the second rotor (9).

6. The compound multi-compression mechanism vacuum pump with high compression ratio and high pumping speed according to claim 5, characterized in that: The first rotor (13) and the second rotor (9) are mounted face to face; The air outlet ends of the rotor bodies of the first rotor (13) and the second rotor (9) are arranged opposite to each other, and the air inlet ends of the rotor bodies are arranged in opposite directions and respectively face the two ends of the base. The two ends of the base are provided with openings, which respectively serve as air inlets for the first turbine structure (25) in the first rotor (13) and the second turbine structure (42) in the second rotor (9); A first traction wheel (31) and a second traction wheel (32) are provided on the top of the first rotor (13), the first traction wheel (31) and the second traction wheel (32) serving as a first-stage traction wheel and a second-stage traction wheel, respectively. A second vortex blade row (12) is provided on the top of the first rotor (13) for forming a first vortex compression structure with the vortex guide groove of the base. A third traction wheel (38) and a fourth traction wheel (39) are provided at the bottom of the second rotor (9), and the third traction wheel (38) and the fourth traction wheel (39) serve as a secondary traction wheel and a primary traction wheel, respectively. A first vortex blade row (8) is provided at the bottom of the second rotor (9) for forming a second vortex compression structure with the vortex guide groove of the base; A first exhaust port (11), a second exhaust port (33), and a third exhaust port (36) are provided in the middle of the base, wherein the first exhaust port (11) serves as a secondary exhaust port and is communicated with the gas path outlets of the first scroll compression structure and the second scroll compression structure, respectively; The second exhaust port (33) and the third exhaust port (36) are provided with a first valve (34) and a second valve (35), respectively. The second exhaust port (33) and the third exhaust port (36) serve as primary exhaust ports and are communicated with the gas outlet of the first traction wheel (31) and the gas outlet of the fourth traction wheel (39), respectively.

7. The compound multi-compression mechanism vacuum pump with high compression ratio and high pumping speed according to claim 5, characterized in that: The first rotor (13) and the second rotor (9) are installed back to back; The air outlet ends of the rotor bodies of the first rotor (13) and the second rotor (9) are arranged in opposite directions, and the air inlet ends of the rotor bodies are arranged opposite to each other and respectively face the middle of the base. The middle of the base is provided with an air inlet (43), which serves as the air inlet of the first turbine structure (25) in the first rotor (13) and the second turbine structure (42) in the second rotor (9). A first traction wheel (31) and a second traction wheel (32) are provided at the bottom of the first rotor (13), the first traction wheel (31) and the second traction wheel (32) serving as a first-stage traction wheel and a second-stage traction wheel, respectively. A second vortex blade row (12) is provided at the bottom of the first rotor (13) for forming a first vortex compression structure with the vortex guide groove of the base. A third traction wheel (38) and a fourth traction wheel (39) are provided on the top of the second rotor (9), and the third traction wheel (38) and the fourth traction wheel (39) serve as a secondary traction wheel and a primary traction wheel, respectively. A first vortex blade row (8) is provided on the top of the second rotor (9) for forming a second vortex compression structure with the vortex guide groove of the base; Both ends of the base are provided with a first-stage exhaust port and a second-stage exhaust port, the second-stage exhaust ports at both ends are respectively connected to the gas outlets of the first scroll compression structure and the second scroll compression structure, and valves are provided on the first-stage exhaust ports at both ends, and are respectively connected to the gas outlets of the first traction wheel (31) and the gas outlet of the fourth traction wheel (39).

8. The compound multi-compression mechanism vacuum pump with high compression ratio and high pumping speed according to claim 1, characterized in that: A thrust plate (23), an axial magnetic suspension unit (24), and an axial sensor (22) are coaxially mounted in sequence on one end of the main shaft (10); The axial magnetic suspension unit (24) is connected to the end of the main shaft (10) via a thrust disc (23); the thrust disc (23), the axial magnetic suspension unit (24) and the axial sensor (22) form an axial magnetic suspension bearing.

9. The compound multi-compression mechanism vacuum pump with high compression ratio and high pumping speed according to claim 7, characterized in that: The outer sleeve of the main shaft (10) is provided with a first protective bearing (21) and a second protective bearing (41); The first protective bearing (21) is arranged between the main shaft (10) and the base, and the second protective bearing (41) is arranged between the main shaft (10) and the axial magnetic suspension unit (24).

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