A multi-stage roots vacuum pump structure

Abstract

The utility model discloses a kind of multistage roots vacuum pump structures, belong to vacuum pump technical field, including lower shell, the upper shell is set on lower shell, air inlet hole is set on the upper shell, front bearing seat is set on the side of lower shell and upper shell, motor is connected with the side of front bearing seat, exhaust plate is connected with the bottom of lower shell, exhaust hole is set on the side of exhaust plate, rear bearing seat is set on the other side of lower shell and upper shell, gear box is connected with the side of rear bearing seat, the inside of lower shell and upper shell is provided with mutually adapted male rotor and female rotor, the utility model, by adopting multistage rotor combination structure, effectively dispersed rotor axial stress, substantially reduce bearing wear, prolong the service life of equipment;By differentiating rotor diameter and line design, optimize stage pressure difference and sealing, significantly improve pumping efficiency and vacuum degree.

Description

Technical Field

[0001] This utility model relates to the field of vacuum pump technology, specifically to a multi-stage Roots vacuum pump structure. Background Technology

[0002] A Roots vacuum pump, or simply a Roots pump, is a type of variable displacement vacuum pump containing two synchronously rotating, oppositely rotating lobe-shaped rotors. The rotors and the pump casing have small gaps that prevent them from contacting each other. Roots vacuum pumps are widely used in industries such as petroleum, chemical, metallurgy, and textiles. Vacuum pump accessories are used as silencers to control noise levels. The working principle of a Roots pump is to move gas by the pushing action of a pair of synchronously rotating, oppositely rotating lobe-shaped rotors within the pump chamber. The rotors and the pump casing do not contact each other; the gap is typically 0.1-0.8 mm.

[0003] The above technical conditions also have shortcomings: when traditional single-stage Roots pumps operate at higher inlet pressures, the rotor bears a large axial load, which can easily lead to accelerated bearing wear and a shortened service life.

[0004] Based on this, the present invention designs a multi-stage Roots vacuum pump structure to solve the above problems. Utility Model Content

[0005] The purpose of this invention is to provide a multi-stage Roots vacuum pump structure to solve the above-mentioned technical problems.

[0006] To achieve the above objectives, this utility model provides the following technical solution: a multi-stage Roots vacuum pump structure, including a lower shell, an upper shell on the lower shell, an air inlet on the upper shell, a front bearing seat on one side of the lower and upper shells, a motor connected to one side of the front bearing seat, an exhaust plate connected to the bottom of the lower shell, an exhaust hole on one side of the exhaust plate, a rear bearing seat on the other side of the lower and upper shells, a gearbox connected to one side of the rear bearing seat, and mutually compatible male and female rotors arranged inside the lower and upper shells. One end of the male rotor is coaxially fixed to the output shaft of the motor, and a first gear and a second gear are respectively connected to the other ends of the male and female rotors, with the first gear and the second gear meshing. The male rotor includes a main shaft, a first-stage rotor fixedly arranged near the middle of the main shaft, and a second-stage rotor fixedly connected to the main shaft near the front bearing seat.

[0007] By adopting the above technical solutions, the multi-stage rotor structure can compress gas step by step, effectively reducing the axial load on a single-stage rotor, reducing bearing wear, and extending the service life of the pump body.

[0008] Preferably, a third-stage rotor, a fourth-stage rotor, and a fifth-stage rotor are sequentially connected to the main shaft on one side of the first-stage rotor, and the female rotor has the same multi-stage rotor as the male rotor.

[0009] By adopting the above technical solution, the multi-stage rotor working in tandem can significantly improve the pumping efficiency and ultimate vacuum of the vacuum pump.

[0010] Preferably, the outer circle diameters of the third-stage, fourth-stage, and fifth-stage rotors are smaller than the outer circle diameters of the first-stage and second-stage rotors.

[0011] By adopting the above technical solutions, reducing the rotor diameter of the high-pressure section helps to increase the interstage pressure difference, improve gas compression efficiency, and enhance the pumping performance of the pump.

[0012] Preferably, the concave curvature of the sides of the first-stage and second-stage rotors is greater than that of the third-stage, fourth-stage, and fifth-stage rotors.

[0013] By adopting the above technical solutions, the rotor profile design with different curvatures optimizes the sealing and meshing performance between rotors, reduces internal gas leakage, and improves volumetric efficiency.

[0014] Preferably, a frequency converter is provided on one side of the gearbox.

[0015] By adopting the above technical solution, the motor speed can be adjusted, thereby flexibly controlling the pumping performance and energy consumption of the vacuum pump to meet the needs of different working conditions.

[0016] In summary, this application has the following beneficial technical effects: by adopting a multi-stage rotor combination structure, the axial force on the rotor is effectively dispersed, bearing wear is significantly reduced, and the service life of the equipment is extended; through differentiated rotor diameter and profile design, the interstage pressure difference and sealing performance are optimized, significantly improving pumping efficiency and vacuum level; the addition of a frequency converter further enhances the equipment's adaptability to operating conditions and its energy-saving potential; the overall structure is compact and reasonable, easy to maintain, and suitable for high-performance vacuum acquisition applications. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of this utility model, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the overall structure of this embodiment; Figure 2 This is a schematic diagram of the connection between the male and female rotors and the upper and lower shells in this embodiment; Figure 3 This is a schematic diagram of the male and female rotors in this embodiment; Figure 4 This is a schematic diagram of the male and female rotors and the front bearing housing in this embodiment; Figure 5 This is a schematic left view of the rotor structure in this embodiment; Figure 6 The right view is a schematic diagram of the rotor structure in this embodiment.

[0019] The attached diagram lists the components represented by each number as follows: 1. Lower housing; 2. Upper housing; 3. Air inlet; 4. Front bearing housing; 5. Motor; 6. Exhaust plate; 7. Exhaust port; 8. Rear bearing housing; 9. Gearbox; 10. Frequency converter; 11. Male rotor; 111. Main shaft; 112. First-stage rotor; 113. Second-stage rotor; 114. Third-stage rotor; 115. Fourth-stage rotor; 116. Fifth-stage rotor; 12. Female rotor; 13. Gear No. 1; 14. Gear No. 2. Detailed Implementation

[0020] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0021] The following is in conjunction with the appendix Figure 1-6 This application will be described in further detail.

[0022] A multi-stage Roots vacuum pump structure includes a lower housing 1, an upper housing 2 mounted on the lower housing 1, forming a cavity between the lower housing 1 and the upper housing 2, an air inlet 3 on the upper housing 2 for connecting an air inlet pipe, a front bearing seat 4 on one side of the lower housing 1 and the upper housing 2, a motor 5 connected to one side of the front bearing seat 4, an exhaust plate 6 connected to the bottom of the lower housing 1, and an exhaust port 7 on one side of the exhaust plate 6. Gas extracted by the vacuum pump is transported through the lower housing 1 to the exhaust plate 6 and finally discharged from the pump body through the exhaust port 7. A rear bearing seat 8 on the other side of the lower housing 1 and the upper housing 2, a gearbox 9 connected to one side of the rear bearing seat 8, and a male rotor 11 and a female rotor 12, which are adapted to each other, are arranged inside the lower housing 1 and the upper housing 2. One end of the male rotor 11 is coaxially fixed to the output shaft of the motor 5. A first gear 13 and a second gear 14 are respectively connected to the other ends of the male rotor 11 and the female rotor 12. The first gear 13 and the second gear 14 mesh with each other, thereby enabling the two rotors to rotate synchronously. The male rotor 11 includes a main shaft 111. A first-stage rotor 112 is fixedly installed on the main shaft 111 near the middle position. A second-stage rotor 113 is fixedly connected on the main shaft 111 near the front bearing seat 4. When gas is drawn in, it is drawn into the chamber where the first-stage rotor 112 is located and compressed by the first-stage rotor 112 into the chamber where the second-stage rotor 113 is located, which effectively reduces the axial pressure on the rotor, reduces the wear on the bearing, and thus increases the service life of the vacuum pump.

[0023] Furthermore, a third-stage rotor 114, a fourth-stage rotor 115, and a fifth-stage rotor 116 are sequentially connected on the main shaft 111 and on one side of the first-stage rotor 112. The female rotor 12 has the same multi-stage rotor as the male rotor 11. The first-stage rotor 112, the third-stage rotor 114, and the fourth-stage rotor 115 rotate in the cavity formed by the lower shell 1 and the upper shell 2. The second-stage rotor 113 rotates in the internal cavity of the front bearing seat 4, and the fifth-stage rotor 116 rotates in the internal cavity of the rear bearing seat 8. The absorption effect is improved by using multi-stage rotors.

[0024] Furthermore, refer to Figure 5 In the figure, the outer circle diameters of the third-stage rotor 114, the fourth-stage rotor 115, and the fifth-stage rotor 116 are smaller than the outer circle diameters of the first-stage rotor 112 and the second-stage rotor 113, which effectively reduces their intake volume, thereby increasing the pressure difference and improving the intake effect.

[0025] Furthermore, refer to Figure 6 In the figure, the concave curvature of the sides of the first-stage rotor 112 and the second-stage rotor 113 is greater than that of the sides of the third-stage rotor 114, the fourth-stage rotor 115 and the fifth-stage rotor 116, which further reduces the intake volume of the third-stage rotor 114, the fourth-stage rotor 115 and the fifth-stage rotor 116.

[0026] Furthermore, sealing rings are installed at the joints of multiple housings to improve the overall sealing performance of the vacuum pump.

[0027] Furthermore, a frequency converter 10 is provided on one side of the gearbox 9 for controlling and adjusting the working status of the vacuum pump.

[0028] The implementation principle of this embodiment is as follows: Motor 5 drives the male rotor 11 to rotate, and through the meshing transmission of gear 13 and gear 14, drives the female rotor 12 to rotate synchronously in the opposite direction; gas enters the pump chamber from the air inlet 3, and after being initially compressed by the first-stage rotor 112, it enters the chambers containing the second-stage rotor 113, the third-stage rotor 114, the fourth-stage rotor 115, and the fifth-stage rotor 116 for multi-stage compression in sequence; finally, the compressed gas is collected by the exhaust plate 6 and discharged from the exhaust port 7. The multi-stage rotor structure not only realizes the step-by-step compression of gas and effectively reduces the single-stage load, but also optimizes the flow path and sealing performance inside the pump through the differentiated design of rotor diameter and profile parameters, thereby significantly improving the overall performance and working efficiency of the vacuum pump.

[0029] In the description of this utility model, it should be understood that the terms "coaxial", "bottom", "one end", "top", "middle", "other end", "upper", "side", "top", "inner", "front", "center", "both ends", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0030] In this utility model, unless otherwise explicitly specified and limited, the terms "installation", "setting", "connection", "fixing", "screw connection", etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components or the interaction between two components. Unless otherwise explicitly limited, those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0031] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A multi-stage Roots vacuum pump structure, comprising a lower housing (1), characterized in that: An upper shell (2) is provided on the lower shell (1), and an air inlet (3) is provided on the upper shell (2). A front bearing seat (4) is provided on one side of the lower shell (1) and the upper shell (2), and a motor (5) is connected to one side of the front bearing seat (4). An exhaust plate (6) is connected to the bottom of the lower shell (1), and an exhaust hole (7) is provided on one side of the exhaust plate (6). A rear bearing seat (8) is provided on the other side of the lower shell (1) and the upper shell (2), and a gearbox (9) is connected to one side of the rear bearing seat (8). A matching anode is provided inside the lower shell (1) and the upper shell (2). The rotor (11) and the female rotor (12) are coaxially fixed at one end on the output shaft of the motor (5). A first gear (13) and a second gear (14) are respectively connected to the other end of the male rotor (11) and the female rotor (12). The first gear (13) and the second gear (14) mesh with each other. The male rotor (11) includes a main shaft (111). A first-stage rotor (112) is fixedly installed on the main shaft (111) near the middle position. A second-stage rotor (113) is fixedly connected on the main shaft (111) near the front bearing seat (4).

2. The multi-stage Roots vacuum pump structure according to claim 1, characterized in that: The main shaft (111) and located on one side of the first-stage rotor (112) are connected in sequence a third-stage rotor (114), a fourth-stage rotor (115) and a fifth-stage rotor (116). The female rotor (12) has the same multi-stage rotor as the male rotor (11).

3. The multi-stage Roots vacuum pump structure according to claim 2, characterized in that: The outer circle diameters of the third-stage rotor (114), fourth-stage rotor (115), and fifth-stage rotor (116) are smaller than the outer circle diameters of the first-stage rotor (112) and second-stage rotor (113).

4. The multi-stage Roots vacuum pump structure according to claim 3, characterized in that: The concave curvature of the sides of the first-stage rotor (112) and the second-stage rotor (113) is greater than that of the third-stage rotor (114), the fourth-stage rotor (115) and the fifth-stage rotor (116).

5. The multi-stage Roots vacuum pump structure according to claim 1, characterized in that: A frequency converter (10) is provided on one side of the gearbox (9).

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