Sealing assembly for multi-stage roots pump and multi-stage roots pump

Abstract

The utility model relates to the technical field of sealing of multi-stage roots pumps, in particular to a sealing assembly for a multi-stage roots pump and the multi-stage roots pump, the sealing assembly for the multi-stage roots pump comprises two sealing strips, the sealing strips are provided with a plurality of arc-shaped protrusions, the arc-shaped protrusions comprise first protrusions and second protrusions, and the first protrusions and the second protrusions are arranged on the sealing strips. The opening direction of the first bulge is opposite to that of the second bulge; the multistage roots pump comprises a pump shell, a pump body and the sealing assembly, the pump body is arranged in the pump shell, and the pump shell is provided with a first containing groove and a second containing groove; due to the fact that the arc-shaped protrusions comprise the first protrusion and the second protrusion, and the opening direction of the first protrusion is opposite to the opening direction of the second protrusion, after the sealing strip is arranged in the first containing groove, at least part of the sealing strip can abut against the inner wall of the first containing groove, positioning is achieved, a positioning groove does not need to be additionally formed in the pump shell, and the sealing effect is improved. No positioning piece needs to be additionally arranged on the sealing strip.

Description

Technical Field

[0001] This disclosure relates to the field of sealing technology for multistage Roots pumps, and in particular to a sealing assembly for a multistage Roots pump and the multistage Roots pump itself. Background Technology

[0002] Roots vacuum pumps evolved from Roots blowers and include high-vacuum multistage Roots pumps, medium-vacuum Roots booster pumps, and dry Roots pumps that discharge directly to the atmosphere. They are widely used in industries such as chemical, papermaking, metallurgy, thin film preparation, and food, and are also a commonly used vacuum pump in the IC equipment industry.

[0003] The working principle of a Roots pump is similar to that of a Roots blower. Because the space between the rotor and the pump casing is completely closed after air intake, the gas in the pump chamber does not undergo compression or expansion. Therefore, a Roots pump is a vacuum pump without internal compression, and typically has a very low compression ratio. To improve the ultimate vacuum of the pump, Roots pumps can be used in series.

[0004] Patent No. 2021800118092 discloses a pump and a sealing assembly for the stator component of this pump. The sealing assembly includes two longitudinal sealing elements, each with a square annular structure for positioning. A larger square positioning groove needs to be additionally formed on the pump housing, within which the square annular structure is positioned. This necessitates the creation of the positioning groove during pump housing manufacturing, and the size of the positioning groove must be compatible with the square annular structure on the longitudinal sealing elements. This significantly increases the manufacturing difficulty of both the sealing assembly and the pump housing. Utility Model Content

[0005] In view of the shortcomings or problems existing in the prior art, this disclosure provides a sealing assembly for a multi-stage Roots pump and a multi-stage Roots pump. The sealing assembly is easy to operate during assembly and has a good sealing effect.

[0006] The technical solution adopted by this disclosure to solve the above-mentioned technical problem is as follows: a sealing assembly for a multi-stage Roots pump, comprising two sealing strips, wherein the sealing strips are provided with a plurality of arc-shaped protrusions, the arc-shaped protrusions including a first protrusion and a second protrusion, wherein the opening orientation of the first protrusion is opposite to the opening orientation of the second protrusion.

[0007] In a preferred embodiment, it further includes two sealing rings, two sealing strips are disposed parallel between the two sealing rings, and the two ends of the two sealing strips are respectively connected to the two sealing rings.

[0008] In a preferred embodiment, the sealing strip includes a first segment and a second segment connected to each other, the length of the first segment being greater than the length of the second segment, a first protrusion being disposed on the first segment, and a second protrusion being disposed on the second segment.

[0009] In a preferred embodiment, the first segment is provided with at least two first protrusions, and the second segment is provided with at least one second protrusion.

[0010] Another object of this disclosure is to provide a multi-stage Roots pump, including a pump housing, a pump body, and the sealing assembly described above, wherein the pump body is disposed in the pump housing, and the pump housing is provided with a first receiving groove and a second receiving groove, the first receiving groove being used to receive a sealing strip, and the second receiving groove being used to receive a sealing ring.

[0011] In a preferred embodiment, the pump housing includes an upper housing and a lower housing, two sealing strips for sealing between the upper housing and the lower housing, and two sealing rings for sealing the two end faces of the pump housing.

[0012] In a preferred embodiment, there are two first receiving grooves, which are respectively disposed on both sides of the upper shell or the lower shell. The first receiving grooves are respectively provided with a first mounting groove adapted to the first protrusion and a second mounting groove adapted to the second protrusion.

[0013] In a preferred embodiment, the outer side of the first protrusion contacts the inner wall of the first mounting groove, and the outer side of the second protrusion contacts the inner wall of the second mounting groove.

[0014] In a preferred embodiment, the length of the first mounting groove is greater than the distance between two adjacent first protrusions.

[0015] In a preferred embodiment, the length of the sealing strip in its natural state is 1-8 mm shorter than the length of the first receiving groove.

[0016] In a preferred embodiment, the length of the sealing strip in its natural state is 3-5 mm shorter than the length of the first receiving groove.

[0017] Compared with existing products, since the arc-shaped protrusion includes a first protrusion and a second protrusion, and the opening orientation of the first protrusion is opposite to that of the second protrusion, the sealing strip is positioned after the first receiving groove, and at least a portion of the sealing strip can abut against the inner wall of the first receiving groove, thereby achieving positioning. Therefore, there is no need to open an additional positioning groove on the pump housing, nor is there a need to add a positioning component to the sealing strip. The sealing component in this application has a simple structure, is easy to manufacture and process, and effectively avoids compression and stretching problems during assembly. Attached Figure Description

[0018] The present application will be described in further detail below with reference to the accompanying drawings and preferred embodiments. However, those skilled in the art will understand that these drawings are drawn only for the purpose of explaining the preferred embodiments and therefore should not be construed as limiting the scope of the present application. Furthermore, unless specifically indicated, the drawings are only schematic representations of the composition or structure of the described objects and may contain exaggerated depictions, and the drawings are not necessarily drawn to scale.

[0019] Figure 1 This is one of the structural schematic diagrams of a sealing assembly for a multi-stage Roots pump disclosed herein;

[0020] Figure 2 This is the second schematic diagram of a sealing assembly for a multi-stage Roots pump disclosed herein;

[0021] Figure 3 This is one of the structural schematic diagrams of the pump casing disclosed herein;

[0022] Figure 4 This is the second schematic diagram of the pump casing disclosed herein.

[0023] Explanation of reference numerals in the attached figures:

[0024] 1. Sealing strip; 11. First protrusion; 12. Second protrusion; 2. Sealing ring; 3. Pump housing; 31. First receiving groove; 311. First mounting groove; 312. Second mounting groove. Detailed Implementation

[0025] To enable those skilled in the art to better understand the technical solutions of this disclosure, the following detailed, clear, and complete description of this disclosure is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of this disclosure and are not intended to limit it.

[0026] Those skilled in the art should understand that in the disclosure of this utility model, the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying 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, the above terms should not be construed as a limitation of this utility model.

[0027] Please refer to Figure 1 and Figure 2As shown, this application provides a sealing assembly for a multi-stage Roots pump, including two sealing strips 1. Each sealing strip 1 has multiple arc-shaped protrusions, including a first protrusion 11 and a second protrusion 12. The opening orientation of the first protrusion 11 is opposite to that of the second protrusion 12. This allows the sealing strip 1 to be positioned after the first receiving groove 31, with at least a portion of the sealing strip 1 abutting against the inner wall of the first receiving groove 31 on the pump housing 3, thus achieving positioning. Therefore, no additional positioning groove is needed on the pump housing 3, and no additional positioning element is required on the sealing strip 1. The sealing assembly provided by this application eliminates the need for additional positioning elements, and the corresponding position on the pump housing 3 does not require an additional positioning groove, simplifying the processing of the sealing assembly and the pump housing 3 and avoiding compression and stretching problems during assembly.

[0028] Furthermore, it also includes two annular sealing rings 2, and two sealing strips 1 are arranged parallel between the two sealing rings 2, with the two ends of the two sealing strips 1 respectively connected to the two sealing rings 2.

[0029] In one embodiment of this disclosure, the sealing strip 1 includes a first segment and a second segment connected to each other. The length of the first segment is greater than the length of the second segment. A first protrusion 11 is disposed on the first segment, and a second protrusion 12 is disposed on the second segment. Specifically, two first protrusions 11 are disposed on the first segment, and one second protrusion 12 is disposed on the second segment. The first protrusion 11 and the second protrusion 12 have the same curvature.

[0030] Please refer to Figure 3 and Figure 4 As shown, another embodiment of this application provides a multi-stage Roots pump, including a pump housing 3, a pump body, and the sealing assembly described in the above embodiment. The pump body is disposed within the pump housing 3, and the pump housing 3 is provided with a first receiving groove 31 and a second receiving groove. The first receiving groove 31 is used to receive a sealing strip 1, and the second receiving groove is used to receive a sealing ring 2. Specifically, the pump housing 3 includes an upper housing and a lower housing, two sealing strips 1 are used for sealing between the upper housing and the lower housing, and two sealing rings 2 are used for sealing the two end faces of the pump housing 3.

[0031] Furthermore, there are two first receiving grooves 31, respectively disposed on both sides of the upper or lower housing. Each first receiving groove 31 has a first mounting groove 311 adapted to the first protrusion 11 and a second mounting groove 312 adapted to the second protrusion 12. The first protrusion 11 and the second protrusion 12, with openings facing opposite directions, are located in the first mounting grooves 311 and 312. This allows the sealing strip 1 to expand under heat, and under the pressure of the upper and lower housings, the first protrusion 11 and the second protrusion 12 deform to both sides, filling the first mounting grooves 311 and 312, thus achieving a better sealing effect. If the openings of the first protrusion 11 and the second protrusion 12 face the same direction, they will deform in the same direction after thermal expansion and pressure from the upper and lower housings. Multiple first protrusions 11 and second protrusions 12 deforming in the same direction can easily cause the entire sealing strip 1 to deform excessively in the same direction, leading to sealing failure.

[0032] Please continue reading. Figure 4 As shown, the outer side of the first protrusion 11 contacts the inner wall of the first mounting groove 311, and the outer side of the second protrusion 12 contacts the inner wall of the second mounting groove 312, thus positioning the sealing strip 1. This allows the first protrusion 11 and the second protrusion 12 to serve both a sealing and positioning function, facilitating the installation of the sealing assembly. It should be noted that gaps are provided between the other structures on the sealing strip 1, except for the first protrusion 11 and the second protrusion 12, and the first mounting groove 311 and the second mounting groove 312, providing space for the deformation of the sealing strip 1.

[0033] Preferably, the length of the first mounting groove 311 is greater than the distance between two adjacent first protrusions 11. This arrangement allows the two first protrusions 11 to be located in the same first mounting groove 311, making it easier to install the sealing strip 1.

[0034] Specifically, the length of the sealing strip 1 in its natural state is 1-8 mm shorter than the length of the first receiving groove 31. The sealing strip 1 expands and elongates when heated or compressed. If the initial length of the sealing strip 1 is set to be longer than or equal to the length of the first receiving groove 31, then after thermal expansion, the length of the sealing strip 1 will far exceed the length of the first receiving groove 31. The first receiving groove 31 cannot accommodate such a long sealing strip 1, which will cause the sealing strip 1 to arch, thus affecting the seal. Preferably, the length of the sealing strip 1 in its natural state is 3-5 mm shorter than the length of the first receiving groove 31. This setting ensures that the length of the sealing strip 1 after heating and compression is just compatible with the first receiving groove 31, thus achieving a better seal. Here, "natural state" refers to the natural extended state of the sealing strip 1 without tensile stress.

[0035] The present application has been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of the present application. The descriptions of the embodiments above are only for the purpose of helping to understand the present application and its core ideas. It should be noted that those skilled in the art can make several improvements and modifications to the present application without departing from the principles of the present application, and these improvements and modifications also fall within the protection scope of the claims of the present application.

Claims

1. A sealing assembly for a multi-stage Roots pump, characterized in that, It includes two sealing strips (1), and the sealing strips (1) are provided with multiple arc-shaped protrusions, including a first protrusion (11) and a second protrusion (12). The opening orientation of the first protrusion (11) is opposite to the opening orientation of the second protrusion (12).

2. The sealing assembly for a multi-stage Roots pump according to claim 1, characterized in that, It also includes two sealing rings (2), two sealing strips (1) are arranged in parallel between the two sealing rings (2), and the two ends of the two sealing strips (1) are respectively connected to the two sealing rings (2).

3. The sealing assembly for a multi-stage Roots pump according to claim 1, characterized in that, The sealing strip (1) includes a first segment and a second segment connected to each other. The length of the first segment is greater than the length of the second segment. A first protrusion (11) is provided on the first segment, and a second protrusion (12) is provided on the second segment.

4. The sealing assembly for a multi-stage Roots pump according to claim 3, characterized in that, The first segment is provided with at least two first protrusions (11), and the second segment is provided with at least one second protrusion (12).

5. A multi-stage Roots pump, characterized in that, The pump includes a pump housing (3), a pump body, and a sealing assembly as described in any one of claims 1-4. The pump body is disposed in the pump housing (3). The pump housing (3) is provided with a first receiving groove (31) and a second receiving groove. The first receiving groove (31) is used to receive a sealing strip (1), and the second receiving groove is used to receive a sealing ring (2).

6. The multi-stage Roots pump according to claim 5, characterized in that, The pump casing (3) includes an upper casing and a lower casing, two sealing strips (1) for sealing between the upper casing and the lower casing, and two sealing rings (2) for sealing the two end faces of the pump casing (3).

7. The multi-stage Roots pump according to claim 6, characterized in that, There are two first receiving grooves (31), which are respectively provided on both sides of the upper shell or the lower shell. The first receiving grooves (31) are respectively provided with a first mounting groove (311) adapted to the first protrusion (11) and a second mounting groove (312) adapted to the second protrusion (12).

8. The multi-stage Roots pump according to claim 7, characterized in that, The outer side of the first protrusion (11) contacts the inner wall of the first mounting groove (311), and the outer side of the second protrusion (12) contacts the inner wall of the second mounting groove (312).

9. The multi-stage Roots pump according to claim 7, characterized in that, The length of the first mounting groove (311) is greater than the distance between two adjacent first protrusions (11).

10. The multi-stage Roots pump according to claim 5, characterized in that, The length of the sealing strip (1) in its natural state is 1-8 mm shorter than the length of the first receiving groove (31).

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