Screw vacuum pump

Abstract

The utility model discloses a screw vacuum pump, and belongs to the technical field of liquid crystal panel processing. The screw vacuum pump comprises a pump shell and an air exhaust assembly, an air exhaust inlet and an air exhaust outlet are formed in the two ends, in the first direction, of the pump shell correspondingly, and the air exhaust inlet communicates with a part to be vacuumized; the air exhaust assembly comprises a working chamber and a pair of rotors which are arranged in the working chamber side by side in a reverse rotation mode, each rotor comprises a rotating shaft and a spiral blade spirally arranged on the rotating shaft, and the two ends of each rotating shaft are rotationally arranged in the working chamber. The multiple air exhaust assemblies are arranged in the pump shell at intervals in the first direction and communicate with one another in sequence. In the first direction, the screw pitches of the spiral blades of the rotors in all the working cavities are sequentially reduced, and the rotating speeds of the rotors in all the working cavities are sequentially reduced. According to the screw vacuum pump, energy consumption can be reduced, horsepower is saved, the use cost is reduced, and the service life is long.

Description

Technical Field

[0001] The utility model relates to the technical field of liquid crystal panel processing, in particular to a screw vacuum pump. Background Art

[0002] A vacuum pump is a device or equipment that uses mechanical, physical, chemical or physicochemical methods to evacuate the container to obtain a vacuum. In other words, a vacuum pump is a device that uses various methods to improve, generate and maintain a vacuum in a closed space. It is widely used in metallurgy, chemical industry, food, electronic coating and other industries.

[0003] Dry screw vacuum pumps are a widely used type of vacuum pump, primarily used in high-purity vacuum processes. They are adaptable to harsh operating conditions, capable of extracting condensable and particulate gases, and are particularly well-suited for clean environments. They are also easily treated for corrosion and are widely used in electronics, chemicals, biomedicine, metalworking, food processing, and other fields. While dry screw vacuum pumps operate smoothly and quietly, they do have high energy consumption, resulting in higher operating costs and a shortened service life.

[0004] Therefore, a screw vacuum pump is urgently needed to solve the above problems. Utility Model Content

[0005] The purpose of the utility model is to provide a screw vacuum pump which can reduce energy consumption, save horsepower, reduce use costs and has a long service life.

[0006] In order to achieve the above objectives, the present invention adopts the following technical solutions:

[0007] A screw vacuum pump, comprising:

[0008] A pump housing, wherein an air extraction inlet and an air exhaust outlet are respectively provided at two ends of the pump housing along the first direction, and the air extraction inlet is connected to the part to be vacuumed;

[0009] The exhaust assembly includes a working chamber and a pair of rotors arranged side by side and rotating in opposite directions in the working chamber, each of the rotors including a rotating shaft and a spiral blade spirally arranged on the rotating shaft, and both ends of the rotating shaft are rotatably arranged in the working chamber;

[0010] Several of the vacuum components are arranged in the pump housing at intervals along the first direction and are connected in sequence; along the first direction, the pitch of the spiral blades of the rotor in each working chamber decreases in sequence, and the rotation speed of the rotor in each working chamber decreases in sequence.

[0011] As a preferred solution, the pitch of the spiral blades of the rotor is 5 mm to 40 mm.

[0012] As a preferred solution, the pitch M of the spiral blades of the rotor in each working chamber satisfies:

[0013] M N-1 / 2≤M N <M N-1 , N is an integer greater than 1;

[0014] Among them, M N M is the pitch of the helical blade of the rotor in the Nth working chamber along the first direction; N-1 is the pitch of the spiral blade of the rotor in the N-1th working chamber along the first direction.

[0015] As a preferred solution, the rotation speed of the rotor is 600 r / min to 4500 r / min.

[0016] As a preferred solution, the rotational speed V of the rotor in each working chamber satisfies:

[0017] V N-1 / 2≤V N <V N-1 , N is an integer greater than 1;

[0018] Among them, V N V is the rotational speed of the rotor in the Nth working chamber along the first direction; N-1 is the rotational speed of the rotor in the N-1th working chamber along the first direction.

[0019] As a preferred solution, along the first direction, the length of the rotating shaft of the rotor in each of the working chambers increases successively.

[0020] As a preferred solution, the length of the rotor shaft is 300 mm to 2400 mm.

[0021] As a preferred solution, the length of the rotating shaft of the rotor in each working chamber satisfies:

[0022] L N-1 <L N ≤2L N-1 , N is an integer greater than 1;

[0023] Among them, L N L is the length of the rotating shaft of the rotor in the Nth working chamber along the first direction; N-1 is the length of the rotating shaft of the rotor in the N-1th working chamber along the first direction.

[0024] As a preferred solution, the number of the air extraction components is three.

[0025] As a preferred solution, the screw vacuum pump further includes a driving mechanism, each of the working chambers corresponds to one driving mechanism, and each driving mechanism is used to drive a pair of rotors in the corresponding working chamber to rotate synchronously and in opposite directions.

[0026] The beneficial effects of the present invention are:

[0027] The screw vacuum pump provided by the present invention rotates synchronously in opposite directions in the working chamber when the pump is started, causing the size of the multiple enclosed spaces formed between each rotor and the working chamber, as well as between the two rotors, to continuously change, thereby achieving the process of gas intake, transmission, and exhaust. When the gas in the vacuumed member enters the first-stage working chamber from the air extraction inlet of the pump housing, the speed of the rotor in the working chamber is the highest, but the pitch of the spiral blades of the inner rotor is the highest. As the gas is transmitted, the speed of the rotor in each stage of the working chamber decreases successively, and the pitch of the spiral blades of the rotor in each stage of the working chamber decreases successively, so that the speed of the rotor in each working chamber matches the pitch of the corresponding spiral blade, thereby reducing the air load on each rotor and reducing energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following is a brief introduction to the drawings required for use in the description of the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the contents of the embodiments of the present invention and these drawings without paying any creative work.

[0029] Figure 1 This is a partial cross-sectional schematic diagram of a screw vacuum pump provided in Example 1 of the present utility model;

[0030] Figure 2 This is a relationship diagram between the power consumption and air resistance of the rotor of the screw vacuum pump provided in the first embodiment of the present invention;

[0031] Figure 3 It is a partial cross-sectional schematic diagram of the screw vacuum pump provided in the second embodiment of the present utility model.

[0032] Reference numerals:

[0033] 100. Air extraction assembly;

[0034] 110, working chamber; 111, primary chamber; 112, secondary chamber; 113, tertiary chamber;

[0035] 120, rotor; 121, shaft; 122, spiral blade;

[0036] 130. Bearings;

[0037] 200. Vacuum tube. DETAILED DESCRIPTION

[0038] Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the foregoing drawings.

[0039] In this utility model, the terms "comprises," "includes," "has," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes the element.

[0040] In this utility model, the term "and / or" describes an association between related objects, indicating that three possible relationships exist. For example, "A and / or B" can represent: A exists alone, A and B exist simultaneously, or B exists alone. Furthermore, the character " / " in this utility model generally indicates that the related objects are in an "and / or" relationship.

[0041] In this utility model, the terms "connect," "combine," "couple," and "install" may refer to direct connection, combination, coupling, or installation, or indirect connection, combination, coupling, or installation. For example, a direct connection refers to two parts or components being connected together without the presence of an intermediary, while an indirect connection refers to two parts or components being connected to at least one intermediary, with the two parts or components being connected via the intermediary. Furthermore, "connect" and "couple" are not limited to physical or mechanical connections or couplings and may also include electrical connections or couplings.

[0042] In the present invention, it will be understood by those skilled in the art that relative terms (e.g., "about," "approximately," "substantially," etc.) used in conjunction with quantities or conditions include the values ​​and have the meaning indicated by the context. For example, the relative terms include at least the degree of error associated with the measurement of a specific value, the tolerance caused by manufacturing, assembly, and use associated with a specific value, and the like. Such terms should also be considered to disclose a range defined by the absolute values ​​of the two endpoints. Relative terms may refer to plus or minus a certain percentage (e.g., 1%, 5%, 10% or more) of the indicated value. Numerical values ​​that do not employ relative terms should also be disclosed as specific values ​​with tolerances. In addition, "substantially" may refer to plus or minus a certain degree (e.g., 1 degree, 5 degrees, 10 degrees or more) on the basis of the indicated angle when expressing a relative angular position relationship (e.g., substantially parallel, substantially perpendicular).

[0043] In the present invention, it will be understood by those skilled in the art that the function performed by an assembly can be performed by one assembly, multiple assemblies, one part, or multiple parts. Similarly, the function performed by a part can also be performed by one part, one assembly, or a combination of multiple parts.

[0044] In the present invention, the terms "upper", "lower", "left", "right", "front", "back" and other directional words are described based on the orientation and positional relationship shown in the accompanying drawings, and should not be understood as limiting the embodiments of the present invention. In addition, in the context, it is also necessary to understand that when it is mentioned that an element is connected to another element "upper" or "lower", it can not only be directly connected to the other element "upper" or "lower", but also be indirectly connected to the other element "upper" or "lower" through an intermediate element. It should also be understood that directional words such as upper side, lower side, left side, right side, front side, back side, etc. not only represent the positive orientation, but can also be understood as the lateral orientation. For example, below can include directly below, lower left, lower right, lower front, and lower back, etc.

[0045] Example 1

[0046] Figure 1 A partial cross-sectional schematic diagram of the screw vacuum pump provided in this embodiment is shown. Figure 1As shown, this embodiment provides a screw vacuum pump, which includes a pump housing and an air extraction assembly 100. The pump housing is provided with an air extraction inlet and an exhaust outlet at both ends along a first direction, respectively. The air extraction inlet is connected to the part to be vacuumed. The air extraction assembly 100 includes a working chamber 110 and a pair of rotors 120 arranged side by side and rotating in opposite directions in the working chamber 110. Each rotor 120 includes a rotating shaft 121 and a spiral blade 122 spirally arranged on the rotating shaft 121. Both ends of the rotating shaft 121 are rotatably arranged in the working chamber 110. When the screw vacuum pump is started, the pair of rotors 120 in the working chamber 110 rotate synchronously in opposite directions, so that the sizes of the multiple enclosed spaces formed between each rotor 120 and the working chamber 110 and between the two rotors 120 are continuously changed, thereby realizing the process of gas intake, transmission and exhaust.

[0047] However, in the prior art, screw vacuum pumps consume a lot of energy during use, resulting in high operating costs and shortened service life. To address this issue, in this embodiment, a plurality of vacuum assemblies 100 are provided, spaced apart within the pump housing along the first direction and sequentially connected. Along the first direction, the pitch of the helical blades 122 of the rotor 120 in each working chamber 110 decreases sequentially, and the rotational speed of the rotor 120 in each working chamber 110 decreases sequentially.

[0048] It needs to be explained that, when the pitch of the spiral blades 122 of the rotor 120 is the same, the greater the rotational speed of the rotor 120, the greater the air resistance it encounters and the greater the load it loads, that is, the greater the energy consumption; when the rotational speed of the rotor 120 is the same, the smaller the pitch of the spiral blades 122 of the rotor 120, the greater the air resistance it encounters and the greater the load it loads, that is, the greater the energy consumption.

[0049] In the screw vacuum pump provided in this embodiment, when the gas in the vacuumed part enters the first-stage working chamber 110 from the exhaust inlet of the pump housing, the rotation speed of the rotor 120 in the working chamber 110 is the largest, but the pitch of the spiral blades 122 of the inner rotor 120 is the largest. As the gas is transmitted, the rotation speed of the rotor 120 in each stage of the working chamber 110 decreases successively, and the pitch of the spiral blades 122 of the rotor 120 in each stage of the working chamber 110 decreases successively, so that the rotation speed of the rotor 120 in each working chamber 110 matches the pitch of the corresponding spiral blade 122, thereby reducing the air load on each rotor 120 and reducing energy consumption.

[0050] Furthermore, when the rotor 120 has the same rotational speed, the greater the pitch of the helical blades 122 of the rotor 120, the greater the friction between the rotor 120 and the gas during operation, and the greater the heat generated. Therefore, by sequentially decreasing the rotational speed of the rotor 120 in each working chamber 110 along the first direction, this embodiment can also reduce the overall heat generated by the screw vacuum pump during operation, thereby reducing damage to the rotor 120 caused by heat and further extending the service life of the screw vacuum pump.

[0051] Of course, in other embodiments, the screw vacuum pump may further include a heat dissipation mechanism. Each working chamber 110 may be provided with a heat dissipation mechanism to dissipate heat from the rotor 120 to prevent damage due to excessive heat generation during operation. This embodiment does not limit the specific structure of the heat dissipation mechanism, and any heat dissipation mechanism applicable to screw vacuum pumps in the prior art may be adopted.

[0052] Figure 2 FIG. 1 shows a relationship between power consumption and air resistance of the rotor 120 of the screw vacuum pump provided in this embodiment. Figure 2 Combined with Figure 1 As shown in FIG, the energy-saving principle and experimental data show that during the operation of the motor driving the rotor 120, the power consumption increases with the increase of the air resistance on the rotor 120. However, when the air resistance on the rotor 120 increases to a preset value ( Figure 2 In view of this, when designing the rotors 120 in each level of the working chambers 110, designers can adapt the pitch of the spiral blades 122 to their rotational speed to ensure that the air resistance experienced by the rotors 120 in each level of the working chambers 110 is less than a preset value, thereby avoiding excessive motor power consumption.

[0053] like Figure 1 As shown, in this embodiment, the number of the air pumping components 100 is three, and the three air pumping components 100 are arranged in sequence along the first direction. Of course, in other embodiments, the number of the air pumping components 100 can also be four, five, six, etc., and this embodiment does not limit this. The structure of the screw vacuum pump provided in this embodiment is introduced below by taking three air pumping components 100 as an example. For the convenience of description, the air pumping component 100 close to the air pumping inlet of the pump housing is defined as the first air pumping component, and the working chamber 110 of the first air pumping component is defined as the first chamber 111; the air pumping component 100 close to the exhaust outlet of the pump housing is defined as the third air pumping component, and the working chamber 110 of the third air pumping component is defined as the third chamber 113; the air pumping component 100 located between the first air pumping component and the third air pumping component is defined as the second air pumping component, and the working chamber 110 of the second air pumping component is defined as the second chamber 112.

[0054] Optionally, the first-stage chamber 111 is provided with a first air inlet and a first air outlet that are connected to each other, and the first air inlet is connected to the air extraction inlet of the pump housing; the second-stage chamber 112 is provided with a second air inlet and a second air outlet that are connected to each other, and the second air inlet of the second-stage chamber 112 is connected to the first air outlet of the first-stage chamber 111 through the vacuum tube 200; the third-stage chamber 113 is provided with a third air inlet and a third air outlet that are connected to each other, and the third air inlet of the third-stage chamber 113 is connected to the second air outlet of the second-stage chamber 112 through the vacuum tube 200, and the third air outlet of the third-stage chamber 113 is connected to the exhaust outlet of the pump housing, thereby realizing the transmission and discharge of gas. Figure 1 As shown, the air inlet and the air outlet of each stage of the working chamber 110 are respectively located at the two ends of the axial direction of the rotor 120 in the corresponding working chamber 110, so as to extend the flow path of the gas in each stage of the working chamber 110; and the first air outlet of the first-stage chamber 111 is arranged opposite to the second air inlet of the second-stage chamber 112, and the second air outlet of the second-stage chamber 112 is arranged opposite to the third air inlet of the tertiary chamber 113, so as to reduce the length of the corresponding vacuum tube 200, thereby reducing the production cost.

[0055] In some embodiments, the pitch of the helical blades 122 of the rotor 120 is 5 mm to 40 mm. The pitch M of the helical blades 122 of the rotor 120 in each working chamber 110 satisfies: M N-1 / 2≤M N <M N-1 , N is an integer greater than 1; where M N M is the pitch of the spiral blade 122 of the rotor 120 in the Nth working chamber 110 along the first direction; N-1 is the pitch of the spiral blades 122 of the rotor 120 in the N-1th working chamber 110 along the first direction. Taking this embodiment as an example, the pitch of the spiral blades 122 of the rotor 120 in the first chamber 111 is 20 mm to 40 mm; the pitch of the spiral blades 122 of the rotor 120 in the second chamber 112 is 10 mm to 20 mm; and the pitch of the spiral blades 122 of the rotor 120 in the third chamber 113 is 5 mm to 10 mm.

[0056] In some embodiments, the rotational speed of the rotor 120 is 600 rpm to 4500 rpm. The rotational speed V of the rotor 120 in each working chamber 110 satisfies: V N-1 / 2≤V N <V N-1 , N is an integer greater than 1; where V N V is the rotation speed of the rotor 120 in the Nth working chamber 110 along the first direction; N-1is the rotational speed of the rotor 120 in the N-1th working chamber 110 along the first direction. Taking this embodiment as an example, the rotational speed of the rotor 120 in the first chamber 111 is 3000 r / min to 4500 r / min; the rotational speed of the rotor 120 in the second chamber 112 is 1500 r / min to 3000 r / min; and the rotational speed of the rotor 120 in the third chamber 113 is 600 r / min to 1500 r / min.

[0057] It should be explained that the rotational speed of the rotor 120 in each working chamber 110 and the pitch of the spiral blade 122 of the rotor 120 in each working chamber 110 are not independent of each other. When designing the structure of the rotor 120 and adjusting its rotational speed during operation, the designer should consider the matching relationship between the two to ensure that the air resistance encountered by the rotor 120 during operation is less than Figure 2 The preset value indicated by the dashed line in the middle reduces the energy consumption of the entire screw vacuum pump. This embodiment does not limit the specific values ​​of the rotational speed of the rotor 120 in each working chamber 110 and the pitch of the spiral blades 122 of the rotor 120 in each working chamber 110. Designers can adjust the above values ​​according to actual needs.

[0058] Optionally, each air extraction assembly 100 further includes a bearing 130 , and the rotating shaft 121 of each rotor 120 is rotatably mounted in the corresponding working chamber 110 through the corresponding bearing 130 to ensure the stability of its rotation process.

[0059] Continue as Figure 1 As shown, the screw vacuum pump also includes a drive mechanism (not shown in the figure), each working chamber 110 corresponds to a drive mechanism, and each drive mechanism is used to drive a pair of rotors 120 in the corresponding working chamber 110 to rotate synchronously and in opposite directions. By setting a drive mechanism to drive the two rotors 120 to rotate synchronously, the number of drive mechanisms can be reduced, thereby reducing the processing cost of the screw vacuum pump, and can reduce the overall volume of the screw vacuum pump to a certain extent, thereby facilitating installation and use. Specifically, the drive mechanism includes a drive motor, a driving gear and a driven gear, the driving gear is sleeved on one of the two rotors 120 in the corresponding working chamber 110, and the driven gear is sleeved on the other of the two rotors 120 in the corresponding working chamber 110, and the driving gear is meshed with the driven gear; the output end of the drive motor is connected to the driving gear to drive the driving gear to rotate, thereby driving the driven gear meshed with it to rotate, thereby achieving synchronous and opposite rotation of the corresponding two rotors 120, so as to achieve the extraction, transmission and discharge of gas in the working chamber 110.

[0060] Example 2

[0061] This embodiment provides a screw vacuum pump, the specific structure of which is substantially the same as that of the screw vacuum pump provided in the first embodiment, except that the lengths of the rotors 100 in the working chambers 110 of each stage are different.

[0062] Figure 3 FIG. 1 shows a partial cross-sectional schematic diagram of the screw vacuum pump provided in this embodiment. Figure 3 As shown, in this embodiment, the length of the rotating shaft 121 of the rotor 120 in each working chamber 110 increases sequentially along the first direction. Specifically, the volume of the working chamber 110 is adapted to the length of the corresponding rotor 120 therein, that is, the volume of each working chamber 110 also increases sequentially along the first direction. When the screw vacuum pump is started, when the gas in the vacuumed part enters the primary chamber 111, its volume is minimum and the gas compression is maximum. When the secondary chamber 112 extracts the gas from the primary chamber 111 and the tertiary chamber 113 extracts the gas from the secondary chamber 112, it is equivalent to the same volume of gas entering from a smaller space into a larger space, reducing the degree of gas congestion, thereby reducing the force exerted by the gas on the rotor 120 in the corresponding working chamber 110 and gradually reducing the load on the rotor 120, thereby achieving the effect of reducing energy consumption of the entire screw vacuum pump. It should be explained that although the rotation speed of the rotor 120 in the first-stage chamber 111 is relatively high and the gas compression is relatively large, the pitch of the spiral blades 122 of the rotor 120 in the first-stage chamber 111 is relatively large, so that the load on the rotor 120 does not exceed Figure 2 Compared to the prior art solution that uses a single vacuum assembly with equal pitches of the spiral blades of the vacuum assembly's rotor, the screw vacuum pump provided in this embodiment can significantly reduce the energy consumption of the drive motor, thereby reducing its operating costs and extending the service life of the entire screw vacuum pump.

[0063] Optionally, in this embodiment, the length of the rotating shaft 121 of the rotor 120 is 300 mm to 2400 mm. Specifically, the length of the rotating shaft 121 of the rotor 120 in each working chamber 110 satisfies: L N-1 <L N ≤2L N-1 , N is an integer greater than 1; where L N L is the length of the rotation shaft 121 of the rotor 120 in the Nth working chamber 110 along the first direction; N-1is the length of the rotating shaft 121 of the rotor 120 in the N-1th working chamber 110 along the first direction. Taking three vacuum assemblies 100 as an example, the length of the rotating shaft 121 of the rotor 120 in the first-stage chamber 111 is 300mm to 600mm; the length of the rotating shaft 121 of the rotor 120 in the second-stage chamber 112 is 600mm to 1200mm; and the length of the rotating shaft 121 in the third-stage chamber 113 is 1200mm to 2400mm. Of course, this embodiment does not limit the specific values ​​of the lengths of the rotating shaft 121 of the rotor 120 in each level of the working chamber 110. Designers can adjust the above values ​​according to actual needs to reduce the energy consumption of the drive motor while ensuring that the screw vacuum pump has a good vacuuming effect.

[0064] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the above embodiments do not limit the present invention in any form, and any technical solution obtained by equivalent replacement or equivalent transformation falls within the scope of protection of the present invention.

Claims

1. A screw vacuum pump, characterized in that: include: A pump housing, wherein an air extraction inlet and an air exhaust outlet are respectively provided at two ends of the pump housing along the first direction, and the air extraction inlet is connected to the part to be vacuumed; An air extraction assembly (100) comprises a working chamber (110) and a pair of rotors (120) arranged side by side and rotating in opposite directions in the working chamber (110), each of the rotors (120) comprising a rotating shaft (121) and a spiral blade (122) spirally arranged on the rotating shaft (121), and both ends of the rotating shaft (121) are rotatably arranged in the working chamber (110); A plurality of the air extraction components (100) are arranged in the pump housing at intervals along the first direction and are connected in sequence; along the first direction, the pitch of the spiral blades (122) of the rotor (120) in each of the working chambers (110) decreases in sequence, and the rotation speed of the rotor (120) in each of the working chambers (110) decreases in sequence.

2. The screw vacuum pump according to claim 1, characterized in that The pitch of the spiral blades (122) of the rotor (120) is 5 mm to 40 mm.

3. The screw vacuum pump according to claim 2, characterized in that The pitch M of the spiral blade (122) of the rotor (120) in each of the working chambers (110) satisfies: M N-1 / 2≤M N <M N-1 , N is an integer greater than 1; Among them, M N M is the pitch of the spiral blade (122) of the rotor (120) in the Nth working chamber (110) along the first direction; N-1 is the pitch of the spiral blade (122) of the rotor (120) in the N-1th working chamber (110) along the first direction.

4. The screw vacuum pump according to claim 1, characterized in that The rotation speed of the rotor (120) is 600 r / min to 4500 r / min.

5. The screw vacuum pump according to claim 4, characterized in that The rotational speed V of the rotor (120) in each of the working chambers (110) satisfies: V N-1 / 2≤V N <V N-1 , N is an integer greater than 1; Among them, V N V is the rotational speed of the rotor (120) in the Nth working chamber (110) along the first direction; N-1 is the rotational speed of the rotor (120) in the N-1th working chamber (110) along the first direction.

6. The screw vacuum pump according to any one of claims 1 to 5, characterized in that Along the first direction, the length of the rotating shaft (121) of the rotor (120) in each of the working chambers (110) increases sequentially.

7. The screw vacuum pump according to claim 6, characterized in that The length of the rotating shaft (121) of the rotor (120) is 300 mm to 2400 mm.

8. The screw vacuum pump according to claim 7, characterized in that The length of the rotating shaft (121) of the rotor (120) in each of the working chambers (110) satisfies: L N-1 <L N ≤2L N-1 , N is an integer greater than 1; Among them, L N L is the length of the rotating shaft (121) of the rotor (120) in the Nth working chamber (110) along the first direction; N-1 is the length of the rotation shaft (121) of the rotor (120) in the N-1th working chamber (110) along the first direction.

9. The screw vacuum pump according to any one of claims 1 to 5, characterized in that The number of the air extraction components (100) is three.

10. The screw vacuum pump according to any one of claims 1 to 5, characterized in that The screw vacuum pump further comprises a driving mechanism, each of the working chambers (110) corresponds to one driving mechanism, and each driving mechanism is used to drive a pair of rotors (120) in the corresponding working chamber (110) to rotate synchronously and in opposite directions.

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