A sealing structure of a roots pump

Abstract

The utility model belongs to roots pump technical field relates to a sealing structure of roots pump, including motor, pump body, pivot, rotor blade and end cover, the pivot is fixed with the shaft sleeve on rotor blade both ends, the shaft sleeve with the central hole rotation cooperation of end cover, the outer wall of shaft sleeve is provided with first annular groove and second annular groove at intervals, be provided with in first annular groove, the shaft sleeve and end cover form piston type sealing through cooperation, be provided with steel cover in second annular groove, the outside of end cover is provided with third annular groove, the sealing ring of inner wall with sealing lip is fixed in third annular groove, end cover forms lip seal type sealing through sealing lip with the cooperation of steel cover, the advantage is: simple structure, low in production cost, good sealing performance, convenient for popularization and application.

Description

Technical Field

[0001] This utility model belongs to the field of Roots pump technology, and particularly relates to a sealing structure for a Roots pump. Background Technology

[0002] A Roots pump is a positive displacement vacuum pump that moves gas by the pushing action of a pair of figure-eight rotors rotating synchronously and in opposite directions within the pump chamber. It typically has a very low compression ratio, thus requiring a backing pump. With the demands of industrial development, more and more Roots vacuum pumps are now widely used in conjunction with backing pumps in industries such as semiconductors, photovoltaics, vacuum coating, and pharmaceuticals. Depending on the specific production processes in different industries, the sealing requirements for Roots vacuum pumps are becoming increasingly stringent.

[0003] While the existing Roots pump sealing structure can meet the needs of simple working conditions, it will have problems such as short service life, poor sealing performance, and easy oil leakage in harsh working conditions or high-requirement occasions, resulting in high oil consumption or even damage due to lack of oil. Summary of the Invention

[0004] The purpose of this invention is to provide a sealing structure for a Roots pump with good sealing performance.

[0005] The purpose of this utility model is to solve the following problem:

[0006] A sealing structure for a Roots pump includes a motor, a pump body, a rotating shaft within the pump body driven by the motor, rotor blades fixed on the rotating shaft, and end caps fixed at both ends of the pump body. Bushings are fixed to the rotating shaft at both ends of the rotor blades. The bushings rotatably engage with the center holes of the end caps. A first annular groove and a second annular groove are spaced apart on the outer wall of the bushings. A piston ring is disposed in the first annular groove, and the bushings and end caps form a piston-type seal through the engagement of the piston ring. A steel sleeve is disposed in the second annular groove. A third annular groove is disposed on the outer side of the end caps, and a sealing ring with a sealing lip on its inner wall is fixed in the third annular groove. The end caps form a lip-type seal through the engagement of the sealing lip and the steel sleeve.

[0007] As a further optimization of the above technical solution, the sealing lip is inclined toward the rotor blade direction.

[0008] As a further optimization of the above technical solution, the sealing ring with the sealing lip is located on the outside of the piston ring.

[0009] As a further optimization of the above technical solution, the bushing is a steel-clad ceramic bushing.

[0010] As a further optimization of the above technical solution, the specific structure of the sealing ring with sealing lips is as follows: two or more arc-shaped sealing lips are spaced apart on the inner wall of the annular body, a first groove is provided between two adjacent arc-shaped sealing lips, and the lower ends of all sealing lips are inclined to the same side.

[0011] As a further optimization of the above technical solution, an outer cover is fixed to the outside of the end cover, and a cavity is provided on the side of the end cover and the outer cover respectively. The two cavities match to form a cooling chamber. An inlet connector or an outlet connector communicating with the cooling chamber is provided on the end cover, and an outlet connector or an inlet connector communicating with the cooling chamber is provided on the outer cover.

[0012] As a further optimization of the above technical solution, the cooling chamber is equipped with circulating cooling water.

[0013] As a further optimization of the above technical solution, there are two first annular grooves, and piston rings are provided in both first annular grooves.

[0014] As a further optimization of the above technical solution, mounting brackets are fixed to the lower side of the outer arm of the end cover, the outer ring of the bearing is fixed on the mounting bracket, the inner ring of the bearing is fixed on the rotating shaft, and a bushing is fitted on the rotating shaft between the inner ring of the bearing and the bushing.

[0015] As a further optimization of the above technical solution, the outer surface of the steel sleeve is provided with a chrome plating layer.

[0016] The advantages of this invention compared to the prior art are:

[0017] 1. The pump body and end cover of this utility model adopt a three-combination sealing of piston seal + lip seal + steel-clad ceramic bushing, which significantly improves the sealing performance of the product, reduces or eliminates oil leakage, prevents chemical media in the pump body from entering the oil chambers of the bearings at both ends and contaminating the oil, saves oil and improves the safety of the product.

[0018] 2. The bushing of this utility model adopts a steel-clad ceramic bushing, which gives the bushing good wear resistance and impact resistance, long service life, excellent high temperature resistance and corrosion resistance, adaptability to harsh working conditions, low coefficient of friction and self-lubrication, reduced operating energy consumption, lightweight and structural adaptability, and improved installation and maintenance convenience, thus further improving the performance of the product.

[0019] 3. This utility model forms a cooling chamber between the end cover and the outer cover. The cooling chamber is equipped with circulating coolant to carry away the heat generated by the high-speed operation friction and pump inlet and outlet compression at the sealing point, which ensures the reliable operation of the Roots pump and extends the service life of the seal.

[0020] 4. This utility model has a chrome-plated layer on the outer surface of the steel sleeve, which can reduce wear on the sealing lip and improve the sealing performance of the product; the sealing ring is made of PTFE material and uses three sealing lips for better sealing effect.

[0021] 5. This utility model has a simple structure, low production cost, good sealing performance, and is easy to promote and apply. Attached Figure Description

[0022] Figure 1 This is a cross-sectional view of the present invention.

[0023] Figure 2 yes Figure 1 Enlarged view of part A.

[0024] Figure 3 This is a partial cross-sectional view of the sealing lip of this utility model. Detailed Implementation

[0025] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. See also: Figures 1-3 :

[0026] A sealing structure for a Roots pump includes a motor 10, a pump body 14, a rotating shaft 15 inside the pump body 14 driven by the motor 10, rotor blades 16 fixed on the rotating shaft 15, and end caps 13 fixed at both ends of the pump body 14. A bushing 19 is fixed to the rotating shaft 15 at both ends of the rotor blades 16. The bushing 19 rotatably engages with the center hole of the end cap 13. A first annular groove and a second annular groove are spaced apart on the outer wall of the bushing 19. A piston ring 20 is disposed in the first annular groove. The bushing 19 and the end cap 13 form a piston seal through the engagement of the piston ring 20. A steel sleeve 27 is disposed in the second annular groove. A third annular groove 21 is disposed on the outer side of the end cap 13. A sealing ring 22 with a sealing lip 33 on its inner wall is fixed in the third annular groove 21. The end cap 13 forms a lip seal through the engagement of the sealing lip 33 and the steel sleeve 27.

[0027] As a further optimization of the above technical solution, the sealing lip 33 is inclined toward the rotor blade 16.

[0028] As a further optimization of the above technical solution, the sealing ring 22 with sealing lip 33 is located on the outside of piston ring 20.

[0029] As a further optimization of the above technical solution, the bushing 19 is a steel-clad ceramic bushing 19.

[0030] As a further optimization of the above technical solution, the specific structure of the sealing ring 22 with sealing lips 33 is as follows: two or more arc-shaped sealing lips 33 are spaced apart on the inner wall 32 of the annular body 30 (for example, two, three or four annular sealing lips 33 are used). A first groove 35 is provided between the sealing lips 33 of two adjacent arc-shaped 33, so that the root of the sealing lip 33 becomes thicker and the elastic deformation performance of the sealing lip 33 is increased. The lower ends 34 of all sealing lips 33 are inclined towards the same side (rotor blade side). A second groove 29 is provided at the lower part of the inner arm of the annular body 30 on the rotor blade side to form a mounting seat 31 for the sealing lip 33, so as to increase the elastic deformation space of the sealing lip 33.

[0031] As a further optimization of the above technical solution, an outer cover 12 is fixed to the outside of the end cover 13. The side surfaces of the end cover 13 and the outer cover 12 opposite to each other are respectively provided with concave cavities. The two concave cavities match to form a cooling chamber 18. The end cover 13 is provided with a water inlet connector 11 or a water outlet connector communicating with the cooling chamber 18. The outer cover 12 is provided with a water outlet connector 17 or a water inlet connector communicating with the cooling chamber 18.

[0032] As a further optimization of the above technical solution, the cooling chamber 18 is provided with circulating cooling water.

[0033] As a further optimization of the above technical solution, there are two first annular grooves, and piston rings 20 are provided in both first annular grooves.

[0034] As a further optimization of the above technical solution, a mounting bracket 23 is fixed to the lower side of the outer arm of the end cover 13, the outer ring 24 of the bearing 25 is fixed on the mounting bracket 23, the inner ring 26 of the bearing 25 is fixed on the rotating shaft 15, and a bushing 28 is fitted on the rotating shaft 15 between the inner ring 26 of the bearing 25 and the bushing 19.

[0035] As a further optimization of the above technical solution, the outer surface of the steel sleeve 27 is provided with a chrome-plated layer to reduce wear on the sealing lip 33.

[0036] The above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that simple substitutions or modifications can still be made to the technical solutions or technical features described in the foregoing embodiments, and these simple substitutions or modifications do not cause the essence of the corresponding technical solutions to deviate from the spirit and substance of the technical solutions of the embodiments of this utility model, and are still within the protection scope of this utility model.

Claims

1. A sealing structure of a Roots pump, comprising a motor, a pump body, a rotating shaft in the pump body driven by the motor, a rotor blade fixed on the rotating shaft, an end cover fixed on both ends of the pump body, characterized in that: A bushing is fixed on the shaft at both ends of the rotor blade. The bushing is rotatably engaged with the center hole of the end cover. A first annular groove and a second annular groove are provided at intervals on the outer wall of the bushing. A piston seal is formed by the bushing and the end cover through the engagement of the first annular groove. A steel sleeve is provided in the second annular groove. A third annular groove is provided on the outer side of the end cover. A sealing ring with a sealing lip on its inner wall is fixed in the third annular groove. The end cover forms a lip seal by engaging with the steel sleeve through the sealing lip.

2. The sealing structure of a Roots pump according to claim 1, characterized in that: The sealing lip is inclined toward the rotor blades.

3. The sealing structure of a Roots pump according to claim 1, characterized in that: The sealing ring with the sealing lip is located on the outer side.

4. The sealing structure of a Roots pump according to claim 1, characterized in that: The bushing is a steel-clad ceramic bushing.

5. The sealing structure of a Roots pump according to claim 1, characterized in that: The specific structure of the sealing ring with sealing lips is as follows: two or more arc-shaped sealing lips are spaced apart on the inner wall of the annular body, and a first groove is provided between two adjacent arc-shaped sealing lips. The lower ends of all sealing lips are inclined to the same side.

6. The sealing structure of a Roots pump according to claim 1, characterized in that: An outer cover is fixed to the outside of the end cover. The side of the end cover and the outer cover opposite each other are respectively provided with a cavity. The two cavities match to form a cooling chamber. The end cover is provided with a water inlet connector or a water outlet connector that communicates with the cooling chamber. The outer cover is provided with a water outlet connector or a water inlet connector that communicates with the cooling chamber.

7. The sealing structure of a Roots pump according to claim 6, characterized in that: The cooling chamber is equipped with circulating cooling water.

8. The sealing structure of a Roots pump according to claim 1, characterized in that: There are two first annular grooves, and each of the two first annular grooves is provided with one.

9. The sealing structure of a Roots pump according to claim 1, characterized in that: Mounting brackets are fixed to the lower side of the outer arm of the end cap, the outer ring of the bearing is fixed to the mounting bracket, the inner ring of the bearing is fixed to the rotating shaft, and a bushing is fitted on the rotating shaft between the inner ring of the bearing and the bushing.

10. The sealing structure of a Roots pump according to claim 1, characterized in that: The outer surface of the steel sleeve is provided with a chrome plating layer.

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