Equal-diameter variable-pitch multistage roots vacuum pump

Abstract

The utility model relates to an equal-diameter variable-pitch multistage roots vacuum pump. The utility model discloses a motor, bearing, gear, sealing structure, left rotor, right rotor and shell, left rotor and right rotor both pass through the bearing rotatingly install in the shell, said motor with left rotor front end connection, left rotor rear end and right rotor rear end both are fixed with gear, its characterized in that: left rotor and right rotor both consist of five sub-rotor, and left rotor and right rotor both consist of five sub-rotor. The five sub-rotors in the left rotor and the five sub-rotors in the right rotor are in one-to-one correspondence and form five sections of sub-rotors, each of the left rotor and the right rotor is provided with three teeth, the sum of the addendum circle radius and the root circle radius of each section of sub-rotor is equal, and in the direction from the air suction side to the air exhaust side of the equal-diameter variable-pitch multistage roots vacuum pump, the number of the sub-rotors in the left rotor and the number of the sub-rotors in the right rotor are equal. The addendum circle radiuses of the branch rotors on the left rotor and the right rotor are sequentially reduced, and the corresponding dedendum circle radiuses are sequentially increased. According to the utility model, the scraping risk of the end plate can be reduced, and dust discharge is facilitated.

Description

Technical Field

[0001] This utility model relates to the field of vacuum pump technology, specifically to a constant diameter variable pitch multistage Roots vacuum pump. Background Technology

[0002] Multistage Roots vacuum pumps are widely used in industrial fields requiring high efficiency and stable performance, such as petroleum, chemical, metallurgy, and textile industries. Multistage Roots vacuum pumps can provide vacuum pumping capabilities in these fields, meeting the needs of various industries.

[0003] Currently, commonly used multistage Roots vacuum pumps have the following problems when in use: because the tooth profiles of the rotors are consistent, the rotor diameter and tooth height on the exhaust side are large, resulting in a large amount of thermal deformation of the end plate of the casing, which easily leads to scraping between the end plate and the rotor; in addition, this type of tooth profile is not conducive to dust discharge. Utility Model Content

[0004] The purpose of this utility model is to overcome the above-mentioned shortcomings in the existing technology and provide a multi-stage Roots vacuum pump with equal diameter and variable pitch that has a reasonable structural design, can reduce the risk of end plate scratching, and is conducive to dust discharge.

[0005] The technical solution adopted by this utility model to solve the above problems is as follows: The equal-diameter variable-pitch multistage Roots vacuum pump includes a motor, bearings, gears, sealing structures, a left rotor, a right rotor, and a housing. The left and right rotors are rotatably mounted in the housing through bearings. Sealing structures are provided at both ends of the left and right rotors. The motor is fixed to the front end of the housing and connected to the front end of the left rotor. Gears are fixed to the rear ends of the left and right rotors. The gears on the left and right rotors mesh with each other. Its structural feature is that the left and right rotors are each composed of 5 sub-rotors. The 5 sub-rotors in the left rotor and the 5 sub-rotors in the right rotor correspond one-to-one and form 5 segments of sub-rotors. Each sub-rotor in the left and right rotors has three teeth. The sum of the tooth tip circle radius and the tooth root circle radius of each segment of the sub-rotor is equal. From the suction side to the exhaust side of the equal-diameter variable-pitch multistage Roots vacuum pump, the tooth tip circle radius of each sub-rotor on the left and right rotors decreases sequentially, and the corresponding tooth root circle radius increases sequentially.

[0006] Preferably, in this invention, from the intake side to the exhaust side of the equal-diameter variable-pitch multistage Roots vacuum pump, the diameter of the rotor holes on the inner wall of the housing at the locations of the sub-rotors on the left and right rotors decreases sequentially.

[0007] Preferably, the thickness of each sub-rotor on the left and right rotors of this invention is the same.

[0008] Preferably, the housing of this utility model includes a front cover and a rear cover, and the front and rear ends of the housing are respectively fixed with the front cover and the rear cover.

[0009] Preferably, the sealing structure described in this utility model is a labyrinth sealing structure or a dynamic-static combined sealing structure.

[0010] Preferably, the motor described in this utility model is a water-cooled motor or an air-cooled motor.

[0011] Preferably, the motor described in this invention is a water-cooled direct-drive motor, which is directly connected to the left rotor.

[0012] Compared with existing technologies, this invention has the following advantages and effects: The structural design is reasonable. From the suction side to the exhaust side of the equal-diameter variable-pitch multistage Roots vacuum pump, the tooth tip circle radius of each sub-rotor on the left and right rotors decreases sequentially, while the corresponding tooth root circle radius increases sequentially, which is beneficial for dust discharge. The thickness of the five sub-rotors in the left rotor and the five sub-rotors in the right rotor is the same. By changing the tooth tip circle radius of the sub-rotors, the suction volume is changed, resulting in stronger rotor rigidity. From the suction side to the exhaust side of the equal-diameter variable-pitch multistage Roots vacuum pump, the rotor hole diameter on the inner wall of the housing at the location of each sub-rotor section on the left and right rotors decreases sequentially. This results in greater strength of the rotor cavity end plate and less deformation under stress and heat, reducing the risk of end plate scratching. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of this utility model and / or the prior art, the drawings used in the description of the embodiments and / or the prior art 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.

[0014] Fig. 1 This is a schematic diagram of the internal structure of the equal-diameter variable-pitch multistage Roots vacuum pump according to an embodiment of the present invention.

[0015] Fig. 2 This is a three-dimensional structural diagram of the five sub-rotors in the left rotor and the five sub-rotors in the right rotor of this utility model embodiment, which correspond one-to-one and form five sub-rotor segments.

[0016] In the diagram: 1-Motor; 2-Front end cover; 3-Rear end cover; 4-Bearing; 5-Gear; 6-Sealing structure; 7-Left rotor; 8-Right rotor; 9-Housing. Detailed Implementation

[0017] The present invention will be further described in detail below with reference to the accompanying drawings and through embodiments. The following embodiments are explanations of the present invention, but the present invention is not limited to the following embodiments.

[0018] Example

[0019] See Figs. 1-2 The equal diameter variable pitch multistage Roots vacuum pump in this embodiment includes a motor 1, a bearing 4, a gear 5, a sealing structure 6, a left rotor 7, a right rotor 8, and a housing 9. The housing 9 includes a front cover 2 and a rear cover 3, and the front cover 2 and the rear cover 3 are fixed at the front and rear ends of the housing 9, respectively.

[0020] In this embodiment, the left rotor 7 and the right rotor 8 are rotatably mounted in the housing 9 via bearings 4. Both ends of the left rotor 7 and the right rotor 8 are provided with sealing structures 6. The motor 1 is fixed to the front end of the housing 9 and is connected to the front end of the left rotor 7. Gears 5 are fixed to the rear end of the left rotor 7 and the rear end of the right rotor 8, and the gears 5 on the left rotor 7 and the right rotor 8 mesh with each other.

[0021] In this embodiment, both the left rotor 7 and the right rotor 8 are composed of 5 sub-rotors. The 5 sub-rotors in the left rotor 7 and the 5 sub-rotors in the right rotor 8 correspond one-to-one and form 5 sub-rotor segments. Each sub-rotor in the left rotor 7 and the right rotor 8 has three teeth. The sum of the tooth tip circle radius and the tooth root circle radius of each sub-rotor segment is equal, ensuring that the meshing center distance of all sub-rotors is equal.

[0022] From the intake side to the exhaust side of the equal-diameter variable-pitch multistage Roots vacuum pump, the tooth tip circle radius of each sub-rotor on the left rotor 7 and the right rotor 8 decreases sequentially, while the corresponding tooth root circle radius increases sequentially, ensuring that the intake volume of the sub-rotors decreases sequentially, thus achieving a larger compression ratio of 4 to 7 times.

[0023] From the suction side to the exhaust side of the equal-diameter variable-pitch multistage Roots vacuum pump, the diameter of the rotor holes on the inner wall of the housing 9 where each segment of the sub-rotor is located on the left rotor 7 and the right rotor 8 decreases sequentially. The rotor cavity end plate has greater strength and less deformation after being subjected to force and heat, which can reduce the risk of end plate scratching.

[0024] In this embodiment, the thickness of each sub-rotor on the left rotor 7 and the right rotor 8 is the same. By changing the radius of the tooth tip circle of the sub-rotors, the intake volume is changed, making the rotor more rigid.

[0025] In this embodiment, the sealing structure 6 can be a labyrinth seal or a dynamic-static combined seal, and the motor 1 can be a water-cooled motor or an air-cooled motor. If the motor 1 is a water-cooled direct-drive motor, it can be directly connected to the left rotor 7, resulting in a simple structure, high transmission efficiency, and convenient use.

[0026] In this embodiment, when the equal-diameter variable-pitch multistage Roots vacuum pump is running, the motor 1 drives the left rotor 7 to rotate, and the left rotor 7 drives the right rotor 8 to rotate at high speed through the gear 5. The housing 9 is equipped with a bearing 4 and a sealing structure 6 to support and fix the two screws. The bearing 4 enables the left rotor 7 and right rotor 8 to rotate at high speed, and the sealing structure 6 effectively isolates cooling and lubricating oil from entering the housing 9, sealing the housing 9 and ensuring that the rotor cavity of the housing 9 is dry. Small gaps are left between the left rotor 7 and right rotor 8, and between the pump housing 3 and the left rotor 7 and right rotor 8, so that scratching does not occur when the rotors rotate at high speed. When the motor 1 is working, it drives the left rotor 7 and right rotor 8 to rotate at high speed, drawing the medium in through the inlet, compressing it at the large-pitch intake end of the rotor, and discharging it through the small-pitch exhaust end of the rotor from the exhaust port.

[0027] Furthermore, it should be noted that the specific embodiments described in this specification may differ in the shape and name of their components. The above description is merely illustrative of the structure of this utility model. All equivalent or simple variations made based on the structure, features, and principles described in this utility model patent concept are included within the protection scope of this utility model patent. Those skilled in the art to which this utility model pertains may make various modifications or additions to the described specific embodiments or use similar methods to replace them, as long as they do not deviate from the structure of this utility model or exceed the scope defined in these claims, all of which should fall within the protection scope of this utility model.

Claims

1. A constant-diameter variable-pitch multi-stage Roots vacuum pump, comprising a motor (1), a bearing (4), a gear (5), a sealing structure (6), a left rotor (7), a right rotor (8) and a housing (9), the left rotor (7) and the right rotor (8) are rotatably installed in the housing (9) through the bearing (4), both ends of the left rotor (7) and the right rotor (8) are provided with the sealing structure (6), the motor (1) is fixed at the front end of the housing (9), the motor (1) is connected with the front end of the left rotor (7), the rear end of the left rotor (7) and the rear end of the right rotor (8) are both fixed with the gear (5), the gears (5) on the left rotor (7) and the right rotor (8) are engaged, characterized in that: The left rotor (7) and the right rotor (8) are each composed of five sub-rotors, the five sub-rotors in the left rotor (7) and the five sub-rotors in the right rotor (8) are one-to-one corresponding and constitute five sub-rotors, each sub-rotor in the left rotor (7) and the right rotor (8) has three teeth, the sum of the addendum circle radius and the root circle radius of each sub-rotor is equal, and from the suction side to the exhaust side of the equal-diameter variable-pitch multi-stage Roots vacuum pump, the addendum circle radius of each sub-rotor on the left rotor (7) and the right rotor (8) decreases in turn, and the corresponding root circle radius increases in turn.

2. A multi-stage equal-diameter variable-pitch Roots vacuum pump according to claim 1, characterized in that: From the suction side to the exhaust side of the equal-diameter variable-pitch multi-stage Roots vacuum pump, the rotor hole diameter of the inner wall of the shell (9) at the position of each sub-rotor on the left rotor (7) and the right rotor (8) decreases in turn.

3. A multi-stage equal-diameter variable-pitch Roots vacuum pump according to claim 1, characterized in that: The thickness of each sub-rotor on the left rotor (7) and the right rotor (8) is consistent.

4. The equal-angle variable-pitch multi-stage Roots pump according to claim 1, characterized in that: The shell (9) comprises a front end cover (2) and a rear end cover (3), and the front end cover (2) and the rear end cover (3) are respectively fixed at the front end and the rear end of the shell (9).

5. The equal-angle variable-pitch multi-stage Roots pump according to claim 1, characterized in that: The sealing structure (6) is a labyrinth sealing structure or a dynamic and static combined sealing structure.

6. The equal-angle variable-pitch multi-stage Roots pump according to claim 1, characterized in that: The motor (1) is a water-cooled motor or an air-cooled motor.

7. The equal-angle variable-pitch multi-stage Roots pump according to claim 1, characterized in that: The motor (1) is a water-cooled direct-drive motor, and the motor (1) is directly connected with the left rotor (7).

Images