Shaft seal assembly and screw pump

Abstract

The application relates to a shaft seal assembly and a screw pump. The shaft seal assembly comprises a main body, a first limiting platform, a mechanical shaft seal member and a first lip seal member with elasticity. The main body surrounds a shaft seal cavity of the shaft seal assembly. The main body comprises a pressure receiving surface and a mounting surface, which are located at opposite sides of the main body along the extension direction of the shaft seal cavity. The shaft seal cavity is used for mounting a transmission shaft extending from the pressure receiving surface to the mounting surface. The first limiting platform is located in the shaft seal cavity. The mechanical shaft seal member is located in the shaft seal cavity and arranged on the side of the first limiting platform facing the mounting surface. The first lip seal member is located in the shaft seal cavity and attached to the side of the first limiting platform facing the pressure receiving surface. The mechanical shaft seal member and the first lip seal member are both sealingly arranged on the circumferential side of the transmission shaft. The design of the shaft seal assembly ensures that it can maintain stable sealing performance under complex working conditions, reduces the risk of leakage under high permeability, corrosion and other working conditions, and prolongs the service life of the shaft seal assembly.

Description

Technical Field

[0001] This application relates to the field of mechanical pumps, and more particularly to a shaft seal assembly and a screw pump. Background Technology

[0002] Single screw pumps require a shaft seal between the drive shaft and the suction chamber. Common shaft seal types include packing seals and mechanical seals. Packing seals are easy to install, widely applicable, low in operating costs, and easy to maintain. Mechanical seals, on the other hand, are more expensive and have a more complex structure, but offer better sealing performance and lower leakage. When screw pumps transport highly penetrating media, such as N-methylpyrrolidone (NMP) used in the lithium battery industry, even with conventional mechanical seal structures, media penetration into the sealing surface can occur after a period of operation, leading to seal failure. Furthermore, when screw pumps transport corrosive media, the mechanical seal structure can corrode, resulting in seal failure. Current solutions involve using mechanical seals made of materials with stronger corrosion resistance or higher strength to address the problems encountered when transporting highly penetrating and corrosive media. However, this approach significantly increases operating and maintenance costs. Utility Model Content

[0003] This application provides a shaft seal assembly and a screw pump to address some or all of the shortcomings in the related art.

[0004] This application provides a shaft seal assembly for use in a screw pump. The shaft seal assembly includes a body, a first limiting platform, a mechanical shaft seal, and a resilient first lip seal. The body surrounds a shaft seal cavity forming the shaft seal assembly. The body includes a pressure-receiving surface and a mounting surface, which are located on opposite sides of the body along the extending direction of the shaft seal cavity. The shaft seal cavity is used to mount a drive shaft extending from the pressure-receiving surface toward the mounting surface. The first limiting platform is located within the shaft seal cavity. The mechanical shaft seal is located within the shaft seal cavity and is disposed on the side of the first limiting platform facing the mounting surface. The first lip seal is located within the shaft seal cavity and is abutted against the side of the first limiting platform facing the pressure-receiving surface. Both the mechanical shaft seal and the first lip seal are used to seal the circumference of the drive shaft.

[0005] Optionally, the shaft seal assembly further includes a second lip seal, which is disposed at one end of the shaft seal cavity near the mounting surface and is used to seal the periphery of the drive shaft.

[0006] Optionally, the main body, the mechanical shaft seal, and the second lip seal surround a cooling cavity for circulating a cooling medium in the shaft seal assembly.

[0007] Optionally, the shaft seal assembly further includes a media storage device, which is connected to the cooling chamber via a pipeline for storing and providing cooling media.

[0008] Optionally, the first lip seal and / or the second lip seal are interference-fitted with the body.

[0009] Optionally, the first lip seal and / or the second lip seal includes a ring body and a sealing lip. The ring body is attached to the wall of the shaft seal cavity and forms a mounting hole. The mounting hole communicates with the shaft seal cavity, and the sealing lip is located within the mounting hole and connected to the inner wall of the ring body.

[0010] Optionally, the sealing lip includes a fixed end and a free end. The fixed end is connected to the ring body, and the free end extends from the inner wall of the ring body toward the mounting hole. The free end extends obliquely toward the pressure-bearing surface relative to the fixed end.

[0011] Optionally, the angle formed between the sealing lip and the ring body is an inclination angle, which is greater than or equal to 15° and less than or equal to 60°.

[0012] Optionally, there may be multiple sealing lips, which are spaced apart axially within the mounting hole.

[0013] Optionally, the angle formed between the sealing lip and the ring body is an inclination angle, and the inclination angles of the multiple sealing lips are the same; or the inclination angles of the multiple sealing lips are different.

[0014] Optionally, the first lip seal and / or the second lip seal are made of polytetrafluoroethylene (PTFE).

[0015] Optionally, the shaft seal assembly further includes a locking element. One end of the locking element is connected to the mechanical shaft seal, and the other end is connected to the body, along the radial direction of the body.

[0016] Optionally, the shaft sealing cavity includes a guide portion and a mounting portion, both located on the side of the first limiting platform facing the pressure-bearing surface. The first lip seal is interference-fitted with the mounting portion. The inner wall of the mounting portion is parallel to the extending direction of the shaft sealing cavity, and the first lip seal is affixed to the mounting portion. The guide portion is located on the side of the mounting portion opposite to the first limiting platform, and its inner diameter gradually increases in the direction from the mounting surface to the pressure-bearing surface.

[0017] Optionally, the shaft seal cavity includes a guide portion and a mounting portion, both located at one end of the shaft seal cavity near the mounting surface. The shaft seal assembly further includes a second lip seal, which is disposed at the end of the shaft seal cavity near the mounting surface. The second lip seal is interference-fitted with the mounting portion. The inner wall of the mounting portion is parallel to the extending direction of the shaft seal cavity, and the second lip seal is abutted against the mounting portion. The guide portion is located on the side of the mounting portion opposite to the first limiting platform, and its inner diameter gradually increases in the direction from the pressure surface to the mounting surface.

[0018] Optionally, the shaft seal assembly further includes a second limiting platform disposed on the outer surface of the main body, the second limiting platform extending radially along the main body for engaging with the connection structure of the screw pump.

[0019] This application also provides a screw pump, including a drive shaft and a shaft seal assembly as described above, wherein the drive shaft passes through the shaft seal cavity, and the first lip seal and the mechanical shaft seal are both attached to the drive shaft.

[0020] Optionally, the screw pump further includes an intake chamber housing and a direct-drive bracket connected to each other. The intake chamber housing encloses an intake cavity, and the direct-drive bracket has a mating port on its side facing the intake chamber housing. The shaft seal assembly is located at the connection point between the intake chamber housing and the direct-drive bracket, and passes through the intake cavity and the mating port in sequence. One end of the drive shaft is located inside the intake cavity, and the other end passes through the shaft seal cavity of the shaft seal assembly and extends in a direction away from the intake chamber housing.

[0021] Optionally, the shaft seal assembly further includes a second limiting platform, which is disposed on the outer surface of the main body and extends radially along the main body. Specifically, in the extension direction along the drive shaft, one side of the second limiting platform is attached to the suction chamber housing, and the other side is attached to the direct-drive bracket.

[0022] Optionally, the screw pump further includes a buffer element disposed between the suction chamber housing and the second limiting platform.

[0023] Optionally, the inhalation chamber housing further includes a third limiting platform, which surrounds the periphery of the main body, and the side of the third limiting platform facing the direct connection bracket is connected to the direct connection bracket.

[0024] Optionally, at least a portion of the structure of the third limiting platform facing the direct-connection bracket forms a spacer groove for the screw pump between it and the direct-connection bracket.

[0025] The technical solutions provided by the embodiments of this application may include the following beneficial effects:

[0026] As can be seen from the above embodiments, the design of the shaft seal assembly in this application ensures stable sealing performance under complex working conditions, reduces the risk of leakage under conditions of high permeability and corrosiveness, and extends the service life of the shaft seal assembly. Furthermore, the first lip seal in this application has a simple structure, is easy to manufacture, assemble, and disassemble, effectively saving time and costs in the production, assembly, and maintenance processes, and greatly expanding the applicability of the shaft seal assembly.

[0027] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this application. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a partial structural schematic diagram of a screw pump in one embodiment of this application;

[0030] Figure 2 This is a cross-sectional view along the axial direction of a screw pump section structure in one embodiment of this application;

[0031] Figure 3 This is a radial cross-sectional view of the screw pump portion structure in one embodiment of this application;

[0032] Figure 4 This is a cross-sectional view of the shaft seal assembly along the axial direction in one embodiment of this application;

[0033] Figure 5 This is a schematic diagram of the structure of the first lip seal near the pressure-bearing surface in one embodiment of this application;

[0034] Figure 6 This is a schematic diagram of the structure of the first lip seal near the mounting surface in one embodiment of this application;

[0035] Figure 7 This is a cross-sectional view of the first lip seal in one embodiment of this application.

[0036] Explanation of reference numerals in the attached figures:

[0037] 100. Screw pump; 1. Shaft seal assembly; 11. Main body; 111. Pressure-bearing surface; 112. Mounting surface; 12. Shaft seal cavity; 121. Guide part; 122. Mounting part; 13a. First limiting platform; 13b. Second limiting platform; 14. First lip seal; 141. Ring body; 142. Sealing lip; 143. Mounting hole; 15. Mechanical shaft seal; 16. Second lip seal; 17. Cooling cavity; 171. Plug; 18. Medium storage component; 19. Locking component; 2. Drive shaft; 3. Suction chamber housing; 31. Suction cavity; 32. Third limiting platform; 4. Direct coupling bracket; 5. Buffer component; 6. Spacing groove; M. Axis; A. Inclination angle; X. Extension direction; Y. Radial. Detailed Implementation

[0038] The technical solutions in the embodiments (or "implementations") of this application will be clearly and completely described herein with reference to the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements.

[0039] If the embodiments of this application contain terms relating to directional indications or positional relationships (such as up, down, left, right, front, back, inside, outside, top, bottom, center, vertical, horizontal, longitudinal, transverse, length, width, counterclockwise, clockwise, axial, radial, circumferential, etc.), such terms are only used to explain the relative positional relationships and movements between components in a specific posture (as shown in the attached figures); if the specific posture changes, the directional indications or positional relationships will also change accordingly. Furthermore, the terms "first" and "second" used in the embodiments of this application are only for descriptive convenience and should not be construed as indicating or implying relative importance.

[0040] like Figure 1 and Figure 2 As shown, this application provides a screw pump 100, including a drive shaft 2 and a shaft seal assembly 1. The shaft seal assembly 1 includes a first lip seal 14 and a mechanical shaft seal 15. The drive shaft 2 passes through the shaft seal cavity 12. Both the first lip seal 14 and the mechanical shaft seal 15 are attached to the drive shaft 2.

[0041] The screw pump 100 of this application, through the setting of the shaft seal assembly 1, can effectively reduce fluid leakage at the connection position of the drive shaft 2, especially in the process of conveying highly permeable, corrosive, or high-temperature media, and can significantly improve the sealing performance of the pump. Simultaneously, the design of the first lip seal 14 attached to the drive shaft 2 ensures a tighter contact between its sealing surface and the drive shaft 2, thereby reducing leakage channels and gaps, further ensuring the sealing performance of the shaft seal assembly 1, and improving the stability and safety of the screw pump 100. Furthermore, when the sealing surface of the shaft seal assembly 1 is corroded or deformed, only the first lip seal 14 needs to be replaced, without replacing the mechanical shaft seal 15. This design significantly reduces the use and maintenance costs of the shaft seal assembly 1.

[0042] like Figure 2 As shown, the shaft seal assembly 1 of this application includes a main body 11, a first limiting platform 13a, a mechanical shaft seal 15, and a resilient first lip seal 14. The main body 11 surrounds a shaft seal cavity 12 forming the shaft seal assembly 1. The main body 11 includes a pressure-receiving surface 111 and a mounting surface 112. Along the extending direction X of the shaft seal cavity 12, the pressure-receiving surface 111 and the mounting surface 112 are located on opposite sides of the main body 11. The shaft seal cavity 12 is used to mount a drive shaft 2 extending from the pressure-receiving surface 111 toward the mounting surface 112 (i.e., arranged along the axis M). The first limiting platform 13a is located within the shaft seal cavity 12. The mechanical shaft seal 15 is located within the shaft seal cavity 12 and is disposed on the side of the first limiting platform 13a facing the mounting surface 112. The first lip seal 14 is located within the shaft seal cavity 12 and is attached to the side of the first limiting platform 13a facing the pressure-receiving surface 111. The mechanical shaft seal 15 and the first lip seal 14 are both sealed around the drive shaft 2.

[0043] The shaft seal assembly 1 of this application provides a first lip seal 14 within the shaft seal cavity 12, and attaches the first lip seal 14 to the side of the first limiting platform 13a facing the pressure surface 111. This ensures that the first lip seal 14 remains fixedly attached to the first limiting platform 13a during the operation of the screw pump 100, thus forming a double protection with the mechanical shaft seal 15 and providing a tight seal around the circumference of the drive shaft 2. Simultaneously, the first lip seal 14 has an elastic design, allowing it to automatically adapt to the radial Y-displacement and rotational friction of the drive shaft 2 during high-speed rotation, maintaining a stable sealing effect and effectively reducing leakage. In the transportation of highly permeable media, the design of this application provides the shaft seal assembly 1 with a double sealing structure of the first lip seal 14 and the mechanical shaft seal 15, significantly improving the sealing performance of the shaft seal assembly 1. In the process of conveying corrosive or high-temperature media, the design of this application also allows the shaft seal assembly 1 to directly contact the medium through the first lip seal 14, while the mechanical shaft seal 15 does not need to be changed in material. When the shaft seal assembly 1 experiences corrosion of the sealing surface, leakage of the medium, or structural deformation, only the first lip seal 14 needs to be replaced. This method significantly reduces the use cost and maintenance cost of the shaft seal assembly 1.

[0044] Therefore, the design of the shaft seal assembly 1 in this application ensures stable sealing performance under complex working conditions, reduces the risk of leakage under conditions of high permeability and corrosiveness, and extends the service life of the shaft seal assembly 1. Furthermore, the first lip seal 14 in this application has a simple structure, is easy to manufacture, assemble, and disassemble, effectively saving time and costs in the production, assembly, and maintenance processes, and greatly expanding the applicability of the shaft seal assembly 1.

[0045] In an optional embodiment, the shaft seal assembly 1 further includes a second lip seal 16, which is disposed at one end of the shaft seal cavity 12 near the mounting surface 112 and is used to seal the periphery of the drive shaft 2.

[0046] At the end of the shaft seal assembly 1 near the mounting surface 112, a structure similar to the first lip seal 14 is used to seal the circumference of the drive shaft 2, thus forming a triple sealing structure of the first lip seal 14, the mechanical shaft seal 15, and the second lip seal 16. This significantly improves the sealing performance of the shaft seal assembly 1 under complex working conditions, reduces the risk of leakage under conditions of high permeability and corrosiveness, and extends the service life of the shaft seal assembly 1. At the same time, the design of the second lip seal 16 also provides better protection for the mechanical shaft seal 15, reducing the risk of corrosion, oxidation, rust, and deformation of the surface of the mechanical shaft seal 15, ensuring the sealing performance and structural strength of the mechanical shaft seal 15, and reducing the use and maintenance costs of the shaft seal assembly 1.

[0047] In an optional embodiment, the main body 11, the mechanical shaft seal 15 and the second lip seal 16 surround a cooling cavity 17 forming the shaft seal assembly 1, the cooling cavity 17 being used for the flow of cooling medium.

[0048] In practical applications, the drive shaft 2 needs to rotate continuously during the pumping process, and the shaft seal assembly 1 needs to fit as closely as possible to the outer surface of the drive shaft 2 to achieve good sealing performance. Therefore, heat is generated at the contact surfaces of the drive shaft 2 and the shaft seal assembly 1 due to mutual friction. The shaft seal assembly 1 of this application is designed with a cooling chamber 17 between the mechanical shaft seal 15 and the main body 11, and uses a cooling medium to cool the mechanical shaft seal 15, ensuring the safety and stability of the screw pump 100 during operation. Simultaneously, the design of the second lip seal 16 cleverly blocks the opening of the cooling chamber 17 facing the mounting surface 112, thereby sealing the cooling medium within the cooling chamber 17 to prevent outflow and ensure effective cooling.

[0049] Combination Figure 1 , Figure 2 and Figure 3 As shown, in an optional embodiment, the shaft seal assembly 1 further includes a media storage unit 18, which is connected to the cooling chamber 17 via a pipeline and is used to store and provide cooling media.

[0050] The design of the media storage device 18 continuously provides cooling medium to the cooling chamber 17, thereby providing continuous cooling for the mechanical shaft seal 15 and further improving the stability and safety of the screw pump 100 during operation. In the embodiment provided in this application, the media storage device 18 uses a cooling oil cup to provide coolant to the cooling chamber 17 for continuous cooling. Additionally, as... Figure 3 As shown, the main body 11 is also designed with an opening that connects the cooling chamber 17 to the outside. In the embodiment provided in this application, a plug 171 is also designed at the opening, which allows for more flexible replenishment and replacement of the cooling medium in the cooling chamber 17, effectively improving the practicality of the shaft seal assembly 1. Of course, in other optional embodiments, the specific structure of the medium storage component 18 and the cooling chamber 17 can be designed according to the actual working scenario and requirements. For example, a cooling pump connected to a water tank can be used to provide a continuous flow of coolant to the cooling chamber 17. Therefore, this application does not impose any limitations on this.

[0051] In optional embodiments, both the first lip seal 14 and the second lip seal 16 are interference-fitted with the main body 11. This design ensures that the first lip seal 14 and the second lip seal 16 not only have sufficient sealing performance but also allow for easy installation and disassembly, significantly improving the convenience of installation and maintenance of the shaft seal assembly 1 and reducing maintenance costs. Of course, in other optional embodiments, depending on the actual usage scenario and requirements, the lip seals can also be fixed by bonding, groove clamping, or other methods, or one lip seal can be interference-fitted while the other uses a more robust fixing method, thereby further improving the stability of the lip seal connection. Therefore, this application does not impose any limitations in this regard.

[0052] In an optional embodiment, the shaft seal assembly 1 further includes a locking member 19. Along the radial direction Y of the body 11, one end of the locking member 19 is connected to the mechanical shaft seal 15, and the other end is connected to the body 11.

[0053] During the installation of the shaft seal assembly 1, after the mechanical shaft seal 15 is installed in the shaft seal cavity 12, the mechanical shaft seal 15 is fixed to the main body 11 by the locking member 19. This design not only prevents the mechanical shaft seal 15 from sliding along the extension direction X, but also prevents the mechanical shaft seal 15 from rotating relative to the shaft seal cavity 12, thereby affecting the normal operation of the transmission shaft 2. Furthermore, the locking member 19 has a simple structure and is highly convenient to install and disassemble. This design can further improve the practicality and economy of the shaft seal assembly 1.

[0054] like Figure 4 As shown, in an optional embodiment, the shaft sealing cavity 12 includes a guide portion 121 and a mounting portion 122, both located on the side of the first limiting platform 13a facing the pressure surface 111. The inner wall of the mounting portion 122 is arranged parallel to the extending direction X of the shaft sealing cavity 12, and the first lip seal 14 is attached to the mounting portion 122. The guide portion 121 is located on the side of the mounting portion 122 opposite to the first limiting platform 13a, and its inner diameter gradually increases in the direction from the mounting surface 112 to the pressure surface 111.

[0055] The design of the guide portion 121 and the mounting portion 122 in this application allows the first lip seal 14 to be attached to the mounting portion 122, ensuring stable installation of the first lip seal 14 in the shaft sealing cavity 12 and enabling it to fit tightly against the surface of the drive shaft 2 without interference from additional stress, thus achieving a stable sealing effect. Simultaneously, the design of the guide portion 121 provides guidance for the installation of the first lip seal 14, allowing it to slide smoothly into the mounting portion 122 through the trumpet-shaped guide portion 121, thereby simplifying the installation process and improving installation efficiency.

[0056] In an optional embodiment, the first lip seal 14 is interference-fitted with the mounting portion 122.

[0057] In this application, the first lip seal 14 is installed in the mounting part 122 by an interference fit, thereby enabling the first lip seal 14 to generate a greater clamping force on the drive shaft 2 in the radial Y direction. This provides a better sealing effect for the drive shaft 2, preventing seal failure and leakage during the operation of the drive shaft 2. Furthermore, the interference fit assembly method also makes it easier to disassemble and maintain the first lip seal 14. Therefore, this design effectively improves the working stability of the shaft seal assembly 1, and also makes the radial Y pressure distribution of the first lip seal 14 more uniform, the sealing effect better, and the disassembly and maintenance processes more convenient.

[0058] Of course, the guide portion 121 and the mounting portion 122 can also be designed at the end of the shaft sealing cavity 12 near the mounting surface 112, with the second lip seal 16 attached to the mounting portion 122. The guide portion 121 is located on the side of the mounting portion 122 opposite to the first limiting platform 13a, and the inner diameter of the guide portion 121 gradually increases in the direction from the pressure surface 111 to the mounting surface 112.

[0059] Similarly, the design of the guide portion 121 and the mounting portion 122 in this application allows the second lip seal 16 to be attached to the mounting portion 122, ensuring stable installation of the second lip seal 16 in the shaft sealing cavity 12 and enabling it to fit tightly against the surface of the drive shaft 2 without additional stress interference, achieving a stable sealing effect. At the same time, the design of the guide portion 121 provides guidance for the installation of the second lip seal 16, allowing it to slide smoothly into the mounting portion 122 through the flared guide portion 121, thereby simplifying the installation process and improving installation efficiency.

[0060] In addition, the second lip seal 16 is interference-fitted with the mounting part 122.

[0061] Similarly, this application installs the second lip seal 16 within the mounting portion 122 via an interference fit. This allows the second lip seal 16 to exert a greater clamping force on the drive shaft 2 in the radial Y direction, thereby providing a better sealing effect for the drive shaft 2 and preventing seal failure or leakage during the operation of the drive shaft 2. Furthermore, the interference fit assembly method also makes it easier to disassemble and maintain the second lip seal 16.

[0062] In optional embodiments, continue to refer to Figure 2The screw pump 100 also includes an intake chamber housing 3 and a direct-drive bracket 4 connected to each other. The intake chamber housing 3 encloses an intake cavity 31. The direct-drive bracket 4 has a mating port (not shown in the figure) on the side facing the intake chamber housing 3. The shaft seal assembly 1 is located at the connection position between the intake chamber housing 3 and the direct-drive bracket 4, and passes through the intake cavity 31 and the mating port in sequence. One end of the drive shaft 2 is located in the intake cavity 31, and the other end passes through the shaft seal cavity 12 of the shaft seal assembly 1 and extends in a direction away from the intake chamber housing 3.

[0063] In actual assembly and use, the shaft seal assembly 1 is fixed at the position where the drive shaft 2 passes through the suction chamber housing 3 to ensure that the medium in the suction chamber does not leak from the position where the drive shaft 2 passes through. In the embodiment provided in this application, the shaft seal assembly 1, through the design of the first lip seal 14 and the mechanical shaft seal 15, seals the gap between the drive shaft 2 and the suction chamber 31 facing the direct-drive bracket 4, thereby preventing the medium in the suction chamber 31 from leaking from this position, and thus effectively improving the safety and stability of the screw pump 100 during operation.

[0064] In an optional embodiment, the shaft seal assembly 1 further includes a second limiting platform 13b disposed on the outer surface of the main body 11. The second limiting platform 13b extends radially Y along the main body 11 and is used to engage with the connection structure of the screw pump 100. Specifically, in the extension direction X along the drive shaft 2, one side of the second limiting platform 13b is attached to the suction chamber housing 3, and the other side is attached to the direct coupling bracket 4.

[0065] As described above, during the assembly of the screw pump 100, the shaft seal assembly 1 needs to be fixed at the position where the drive shaft 2 passes through the suction chamber to ensure that the medium in the suction chamber does not leak out from the position where the drive shaft 2 passes through. The drive shaft 2 of this application, through the design of the second limiting platform 13b, allows the shaft seal assembly 1 to abut against the suction chamber housing 3 and the direct-drive bracket 4 after assembly, making the installation of the shaft seal assembly 1 more stable and thus effectively improving the stability and safety of the screw pump 100.

[0066] In an optional embodiment, the screw pump 100 further includes a buffer 5 disposed between the suction chamber housing 3 and the second limiting platform 13b.

[0067] The design of the buffer element 5 in this application provides a certain buffering amount between the suction chamber housing 3 and the second limiting stage 13b. This allows the deformation of the buffer element 5 to ensure a tighter connection and better sealing between the suction chamber housing 3, the shaft seal assembly 1, and the direct-drive bracket 4. Simultaneously, the design of the buffer element 5 also helps to prevent wear between the suction chamber housing 3 and the shaft seal assembly 1, further ensuring the safety and stability of the screw pump 100 during operation.

[0068] In an optional embodiment, the inhalation chamber housing 3 further includes a third limiting platform 32, which surrounds the periphery of the main body 11, and the side of the third limiting platform 32 facing the direct connection bracket 4 is connected to the direct connection bracket 4.

[0069] This application, through the design of the third limiting platform 32, can more firmly clamp the shaft seal assembly 1 between the suction chamber housing 3 and the direct-connect bracket 4 while connecting them. This design not only makes the assembly of the shaft seal assembly 1 simpler, reduces installation time and complexity, and enables rapid positioning and fixing of the shaft seal assembly 1, thus improving installation efficiency, but also greatly enhances the stability of the shaft seal assembly 1 after installation. This allows the shaft seal assembly 1 to maintain a stable working state even under continuous vibration conditions, thereby reducing displacement and leakage caused by vibration, significantly improving the vibration resistance of the shaft seal assembly 1, and ensuring the long-term stable operation of the screw pump 100.

[0070] In an optional embodiment, at least a portion of the structure of the third limiting stage 32 facing the direct-connection bracket 4 forms a spacer groove 6 for the screw pump 100 between it and the direct-connection bracket 4.

[0071] The design of the partition groove 6 in this application reduces the direct contact between the third limiting stage 32 and the direct coupling bracket 4, reducing wear caused by long-term friction. Furthermore, the buffering effect of the partition groove 6 significantly improves the durability of the shaft seal assembly 1 and extends its service life. Moreover, the partition groove 6 design allows operators to insert tools into it to pry open the suction chamber housing 3 and the direct coupling bracket 4 when disassembly is required, making the disassembly and maintenance of the shaft seal assembly 1 more convenient and reducing maintenance time and costs. Additionally, due to the presence of the partition groove 6, the suction chamber housing 3 can be further compressed during assembly to deform the buffer member 5, thereby further improving the sealing performance between the shaft seal assembly 1 and the suction chamber housing 3.

[0072] In optional embodiments, such as Figure 5 and Figure 6 As shown, the first lip seal 14 includes a ring 141 and a sealing lip 142. The ring 141 is attached to the wall of the shaft sealing cavity 12 and surrounds a mounting hole 143 forming the first lip seal 14. The mounting hole 143 communicates with the shaft sealing cavity 12, and the sealing lip 142 is located inside the mounting hole 143 and connected to the inner wall of the ring 141.

[0073] In this embodiment, the sealing lip 142 is located within the mounting hole 143 and connected to the inner wall of the ring 141. This allows the first lip seal 14 to form a tight fit with the surface of the drive shaft 2, further reducing the possibility of leakage and significantly improving sealing performance. Simultaneously, the elastic design of the sealing lip 142 allows the first lip seal 14 to adapt to the radial Y-displacement of the drive shaft 2 (e.g., displacement caused by vibration or eccentricity), thereby maintaining sealing stability, reducing installation errors, and simplifying the installation of the sealing lip 142 and the drive shaft 2.

[0074] In the embodiments described in this application, to facilitate manufacturing and save costs, the second lip seal 16 is also designed with a similar structure to the first lip seal 14. This improves the sealing performance of the cooling cavity 17 while simplifying the manufacturing process of both. It should be noted that during production, the lip seal can be designed in various sizes according to the actual application scenario and usage requirements, thereby meeting the needs of cavities with different inner diameters, such as in… Figure 2 In the illustrated embodiment, since one end of the pressure-bearing surface 111 of the shaft seal assembly 1 needs to be inserted into the suction chamber 31 for installation, its inner diameter is smaller than that of the mounting surface 112. Therefore, a smaller lip seal (outer diameter of the ring 141) can be selected as the first lip seal 14, while a larger lip seal can be selected as the second lip seal 16. This document does not impose any limitations on this, and the structure of the second lip seal 16 will not be described in detail below.

[0075] Of course, in other alternative embodiments, the structures of the first lip seal 14 and the second lip seal 16 can also be designed according to the actual working scenario and user needs. For example, the structures of the first lip seal 14 and the second lip seal 16 can be adjusted accordingly for different media in the suction chamber 31 and the cooling chamber 17, without needing to design them to be identical. Therefore, this application does not impose any limitations on this.

[0076] In an optional embodiment, combined with Figure 7 As shown, the sealing lip 142 includes a fixed end and a free end. The fixed end is connected to the ring body 141, and the free end extends from the inner wall of the ring body 141 toward the mounting hole 143. The free end extends obliquely toward the pressure surface 111 relative to the fixed end.

[0077] The design of the sealing lip 142 allows the first lip seal 14 and the second lip seal 16 to form a tighter fit with the surface of the drive shaft 2. Especially when the drive shaft 2 rotates at high speed, the inclined design of the free end can generate radial pressure on the side facing the pressure surface 111, further enhancing the sealing effect of the shaft seal assembly 1. At the same time, when the drive shaft 2 undergoes radial displacement, the inclined design of the free end also allows the sealing lip 142 to undergo slight deformation following the drive shaft 2, thereby ensuring the sealing performance of the first lip seal 14 and the second lip seal 16.

[0078] In an optional embodiment, the included angle formed between the sealing lip 142 and the ring 141 is an inclination angle A, which is greater than or equal to 15° and less than or equal to 60°.

[0079] The tilt angle A in this application allows the sealing lip 142 to receive more uniform radial pressure when the drive shaft 2 rotates at high speed, ensuring a tight fit with the surface of the drive shaft 2 and reducing the possibility of leakage. Furthermore, the setting of the angle range of 15° to 60° ensures that the sealing lip 142 forms a better seal on the surface of the drive shaft 2, avoiding insufficient radial pressure due to an excessively large angle or excessive axial pressure due to an excessively small angle, which could lead to seal failure.

[0080] Specifically, the tilt angle A can be adjusted according to different working scenarios or usage requirements of the shaft seal assembly 1. For example, the tilt angle AA can be designed to be 15°, 20°, 25°, 30°, 35°, 40°, 45°, 50°, 55°, or 60°, etc., and this application does not impose any limitations on this. Furthermore, since the first lip seal 14 and the second lip seal 16 have different installation positions, different dimensions, and different pressures, in the embodiments described in this application, the tilt angle A of the second lip seal 16 can be designed to be smaller than the tilt angle A of the first lip seal 14. This design enables the shaft seal assembly 1 to maintain a stable sealing effect under different working conditions, thereby effectively reducing media leakage and friction loss, and further extending the service life of the equipment.

[0081] It should be noted that, depending on different working scenarios or usage requirements, the number of sealing lips 142 is not limited to one, but can be multiple, with multiple sealing lips 142 spaced apart along the axial direction (i.e., in the direction parallel to axis M) within the mounting hole 143. For example, in the exemplary embodiment provided in this application, both the first lip seal 14 and the second lip seal 16 are designed with two sealing lips 142, which are sequentially spaced apart within the mounting hole 143. Of course, in other optional embodiments, three, four, or more can also be designed, and this application does not limit this.

[0082] The design of multiple sealing lips 142 provides sealing protection at multiple locations on the drive shaft 2, forming multiple sealing barriers and significantly improving the sealing effect. Furthermore, the multiple sealing lips 142 complement each other during the operation of the drive shaft 2. Even if some sealing lips 142 experience slight leakage, the other sealing lips 142 can still maintain their sealing effect, ensuring the stability of the overall sealing performance. For example, when the drive shaft 2 undergoes radial movement, a slight leakage may occur in the sealing lip 142 near the pressure surface 111. However, for the sealing lip 142 closer to the mounting surface 112, the medium pressure is lower, and the impact of radial displacement is less, thus maintaining its sealing performance. Therefore, in high-pressure, high-temperature, or high-speed operating scenarios, the design of multiple sealing lips 142 can better adapt to complex working conditions, ensuring good sealing performance even under extreme conditions.

[0083] In an optional embodiment, the tilt angle A of the multiple sealing lips 142 is the same, which simplifies the manufacturing and processing of the first lip seal 14 and the second lip seal 16 while ensuring the sealing effect of the first lip seal 14 and the second lip seal 16 on the drive shaft 2, reduces production costs, and makes the installation and debugging of the first lip seal 14 and the second lip seal 16 more convenient, reducing assembly errors and assembly time.

[0084] In some alternative embodiments, the tilt angles A of the multiple sealing lips 142 can also be designed to be different. This design allows the first lip seal 14 to provide different radial pressure distributions at different positions on the drive shaft 2, achieving a tighter fit and more precise sealing control at different locations on the drive shaft 2, thereby adapting to different sealing requirements and further enhancing the sealing effect. Furthermore, the different tilt angles A also allow the first lip seal 14 and the second lip seal 16 to better adapt to drive shafts 2 of different diameters, expanding the applicability of the sealing assembly.

[0085] In an optional embodiment, both the first lip seal 14 and the second lip seal 16 are made of polytetrafluoroethylene (PTFE).

[0086] First, polytetrafluoroethylene (PTFE) material possesses extremely strong chemical corrosion resistance, enabling it to meet the sealing requirements of various corrosive media. When conveying corrosive media such as strong acids, strong alkalis, or organic solvents, the first lip seal 14 and the second lip seal 16, made of PTFE, can effectively prevent media leakage and extend the service life of the equipment. Simultaneously, PTFE material can operate stably within a temperature range of -200℃ to +260℃. Therefore, even in extreme temperature environments, PTFE material can maintain stable mechanical properties, preventing shaft seal failure caused by high-temperature media. Thus, this application, by employing the first lip seal 14 and the second lip seal 16 made of PTFE material, can significantly improve the physical and chemical properties and reliability of the sealing components, ensuring stable operation of the equipment in various complex working environments such as high pressure, high temperature, high speed, or corrosive media.

[0087] Of course, it should be noted that the materials of the first lip seal 14 and the second lip seal 16 can be selected according to different usage scenarios and requirements. For example, in scenarios involving pumping highly permeable media, a stronger material can be selected, while in scenarios involving pumping highly corrosive media, a softer material with stronger corrosion resistance can be selected. Furthermore, since the first lip seal 14 and the second lip seal 16 have different application scenarios, they can be made from different materials, and this application does not impose any restrictions on this.

[0088] It should be noted that the technical solutions or features described in the above embodiments can be combined or supplemented with each other without conflict. The scope of protection of this application is not limited to the precise structures described in the above embodiments and shown in the accompanying drawings; all modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A shaft seal assembly, characterized in that, The shaft seal assembly, used in screw pumps, includes: The main body encloses a shaft sealing cavity forming the shaft sealing assembly; the main body includes a pressure-receiving surface and a mounting surface, which are located on opposite sides of the main body along the extending direction of the shaft sealing cavity; the shaft sealing cavity is used to mount a drive shaft extending from the pressure-receiving surface toward the mounting surface; The first limiting stage is located inside the shaft sealing cavity; A mechanical shaft seal, located within the shaft seal cavity and disposed on the side of the first limiting platform facing the mounting surface; and A first lip seal with elasticity is located inside the shaft sealing cavity and is attached to the side of the first limiting platform facing the pressure surface; wherein, both the mechanical shaft seal and the first lip seal are used to seal the circumference of the drive shaft.

2. The shaft seal assembly according to claim 1, characterized in that, The shaft seal assembly further includes a second lip seal, which is disposed at one end of the shaft seal cavity near the mounting surface and is used to seal the periphery of the drive shaft.

3. The shaft seal assembly according to claim 2, characterized in that, The main body, the mechanical shaft seal, and the second lip seal form a cooling cavity for the shaft seal assembly, the cooling cavity being used for the flow of cooling medium.

4. The shaft seal assembly according to claim 3, characterized in that, The shaft seal assembly also includes a media storage device, which is connected to the cooling chamber via a pipeline and is used to store and provide cooling media.

5. The shaft seal assembly according to claim 2, characterized in that, The first lip seal and / or the second lip seal are interference-fitted with the body.

6. The shaft seal assembly according to claim 2, characterized in that, The first lip seal and / or the second lip seal includes a ring body and a sealing lip; the ring body is attached to the wall of the shaft seal cavity and forms a mounting hole; wherein the mounting hole communicates with the shaft seal cavity, and the sealing lip is located inside the mounting hole and connected to the inner wall of the ring body.

7. The shaft seal assembly according to claim 6, characterized in that, The sealing lip includes a fixed end and a free end; the fixed end is connected to the ring body, and the free end extends from the inner wall of the ring body toward the mounting hole; wherein the free end extends obliquely toward the pressure surface relative to the fixed end.

8. The shaft seal assembly according to claim 7, characterized in that, The angle formed between the sealing lip and the ring body is an inclination angle, which is greater than or equal to 15° and less than or equal to 60°.

9. The shaft seal assembly according to claim 6, characterized in that, The number of sealing lips is multiple, and the multiple sealing lips are spaced apart along the axial direction within the mounting hole.

10. The shaft seal assembly according to claim 9, characterized in that, The angle formed between the sealing lip and the ring body is an inclination angle; The tilt angles of the multiple sealing lips are the same; or the tilt angles of the multiple sealing lips are different.

11. The shaft seal assembly according to claim 2, characterized in that, The first lip seal and / or the second lip seal are made of polytetrafluoroethylene material.

12. The shaft seal assembly according to claim 1, characterized in that, The shaft seal assembly further includes a locking element; one end of the locking element is connected to the mechanical shaft seal and the other end is connected to the body along the radial direction of the body.

13. The shaft seal assembly according to claim 1, characterized in that, The shaft sealing cavity includes a guide portion and a mounting portion, both of which are located on the side of the first limiting platform facing the pressure surface; the first lip seal is interference-fitted with the mounting portion; The inner wall of the mounting portion is arranged parallel to the extension direction of the shaft sealing cavity, and the first lip seal is attached to the mounting portion; the guide portion is located on the side of the mounting portion away from the first limiting platform, and the inner diameter of the guide portion gradually increases in the direction from the mounting surface to the pressure surface.

14. The shaft seal assembly according to claim 1, characterized in that, The shaft seal cavity includes a guide portion and a mounting portion, both of which are located at one end of the shaft seal cavity near the mounting surface; the shaft seal assembly further includes a second lip seal, which is disposed at one end of the shaft seal cavity near the mounting surface; the second lip seal is interference-fitted with the mounting portion; The inner wall of the mounting portion is arranged parallel to the extension direction of the shaft sealing cavity, and the second lip seal is attached to the mounting portion; the guide portion is located on the side of the mounting portion away from the first limiting platform, and the inner diameter of the guide portion gradually increases in the direction from the pressure surface to the mounting surface.

15. The shaft seal assembly according to claim 1, characterized in that, The shaft seal assembly further includes a second limiting platform disposed on the outer surface of the main body. The second limiting platform extends radially along the main body and is used to engage with the connection structure of the screw pump.

16. A screw pump, characterized in that, The assembly includes a drive shaft and a shaft seal assembly as described in any one of claims 1-15, wherein the drive shaft passes through the shaft seal cavity, and the first lip seal and the mechanical shaft seal are both attached to the drive shaft.

17. The screw pump according to claim 16, characterized in that, The screw pump also includes an intake chamber housing and a direct-drive bracket connected to each other; the intake chamber housing forms an intake cavity, and the direct-drive bracket has a mating port on the side facing the intake chamber housing; the shaft seal assembly is located at the connection position between the intake chamber housing and the direct-drive bracket, and passes through the intake cavity and the mating port in sequence; one end of the drive shaft is located in the intake cavity, and the other end passes through the shaft seal cavity of the shaft seal assembly and extends in a direction away from the intake chamber housing.

18. The screw pump according to claim 17, characterized in that, The shaft seal assembly further includes a second limiting platform, which is disposed on the outer surface of the main body and extends radially along the main body; In the direction of extension of the drive shaft, one side of the second limiting platform is attached to the inhalation chamber housing, and the other side is attached to the direct connection bracket.

19. The screw pump according to claim 18, characterized in that, The screw pump also includes a buffer component, which is disposed between the suction chamber housing and the second limiting platform.

20. The screw pump according to claim 17, characterized in that, The inhalation chamber housing also includes a third limiting platform, which surrounds the periphery of the main body, and the side of the third limiting platform facing the direct connection bracket is connected to the direct connection bracket.

21. The screw pump according to claim 20, characterized in that, At least a portion of the structure of the third limiting platform facing the direct-connection bracket has a spacer groove for the screw pump between it and the direct-connection bracket.

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