Shaft seal device of transmission shaft for GIS (Gas Insulated Switchgear) equipment

Abstract

The invention discloses a shaft seal device of a transmission shaft for GIS equipment. The shaft seal device aims at solving the problems that in a traditional shaft seal, the sealing effect is poor, and gas leakage is caused due to the fact that a sealing ring is prone to being damaged. According to the device, an end cover is fixedly connected with a shell, a transmission shaft is sleeved with the end cover, the transmission shaft is sequentially sleeved with a first bearing assembly, a sealing assembly and a second bearing assembly, and the end cover is rotationally connected with the transmission shaft through the first bearing assembly and the second bearing assembly; the sealing assembly, the first bearing assembly and the second bearing assembly jointly form a sealing area between the transmission shaft and the end cover, and the sealing area is filled with silicone grease. The sealing assembly is matched with the bearing assembly, the silicone grease fills the gap to further eliminate a leakage channel and improve air tightness, the bearing assembly allows the transmission shaft to rotate, the sealing assembly prevents medium leakage and gives consideration to mechanical movement and sealing performance, the silicone grease provides lubrication at the same time, friction between the sealing assembly and the transmission shaft is reduced, the service life of a sealing piece is prolonged, and the jamming risk is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of power equipment, and in particular to a transmission shaft sealing device for GIS equipment. Background Art

[0002] GIS (gas-insulated switchgear) equipment, a key component of high-voltage power systems, relies on SF6 gas for insulation and arc extinguishing. Shaft seals, a critical sealing structure for moving components within GIS (such as the circuit breaker operating shaft and the disconnector rotating mechanism), must ensure airtightness while withstanding mechanical motion and environmental challenges.

[0003] Outdoor GIS equipment is exposed to harsh conditions such as long-term exposure to sunlight, rain and humid environments, especially equipment used in offshore wind farms. It also needs to deal with high salt spray corrosion and continuous high humidity unique to the marine environment. Such environmental factors can easily lead to aging and failure of the shaft seal protection structure of key moving parts of the equipment (such as the disconnector knife switch and the earthing switch operating shaft), which in turn causes moisture and rust on the bearings. When the equipment is in a non-operating state for a long time, rust accumulation may cause bearing jamming, and eventually lead to action blockage, stroke deviation or even complete inability to open and close the knife switch or earthing switch during electric operation. As the core components of the rotating mechanism, the knife switch and earthing switch bearings must not only support the stable rotation of the mechanical transmission components, but also accurately transmit the operating torque and withstand dynamic loads. Their reliability directly affects the overall operational stability of the equipment.

[0004] Furthermore, over long-term operation, some GIS equipment can experience seal failure in the disconnector chamber, potentially leading to SF6 gas leakage, due to a combination of factors, including shaft seal degradation, microparticle intrusion from mechanical friction, and external moisture penetration. This gas leakage directly weakens the equipment's insulation strength, threatening power system safety. On-site repairs for these types of failures present unique challenges. Firstly, outdoor or offshore operating environments often lack the dust-free assembly conditions (such as million-level air cleanliness) required for shaft seal replacement. Secondly, the strict requirements of existing technical standards for seal installation environments differ significantly from actual on-site conditions, further complicating repair efforts.

[0005] The shaft seals in existing GIS equipment usually use O-rings or gaskets. Frequent mechanical movement causes accelerated wear and easily damages the sealing effect, especially in the case of SF6 gas, which can also cause leakage problems. Summary of the Invention

[0006] (1) Purpose of the invention

[0007] The purpose of the present invention is to provide a transmission shaft seal device for GIS equipment, aiming to solve the problems of poor sealing effect and easy damage of the sealing ring leading to gas leakage in traditional shaft seals.

[0008] (2) Technical solution

[0009] To solve the above problems, the present invention provides a transmission shaft sealing device for GIS equipment, comprising a housing, an end cover, a transmission shaft, a sealing assembly, a first bearing assembly, and a second bearing assembly;

[0010] The end cover is fixedly connected to the housing, the end cover is sleeved on the transmission shaft, the first bearing assembly, the sealing assembly and the second bearing assembly are sleeved on the transmission shaft in sequence, and the end cover is rotatably connected to the transmission shaft through the first bearing assembly and the second bearing assembly;

[0011] The sealing assembly, the first bearing assembly, and the second bearing assembly together form a sealing area between the transmission shaft and the end cover, and the sealing area is filled with silicone grease.

[0012] Preferably, the end cover includes an integrally formed boss and a connecting section, the boss is fixedly connected to the side of the shell, the outer side of the connecting section abuts the shell, and the inner side of the connecting section is rotatably connected to the transmission shaft through the first bearing assembly and the second bearing assembly, and the first bearing assembly and the second bearing assembly are located on both sides of the sealing assembly.

[0013] Preferably, the sealing assembly includes a first lip-type sealing ring and a second lip-type sealing ring, the sealing lip of the first lip-type sealing ring faces the first bearing assembly, and the sealing lip of the second lip-type sealing ring faces the second bearing assembly.

[0014] Preferably, the first bearing assembly includes a first deep groove ball bearing and a first pressure plate, the first deep groove ball bearing abuts against the first pressure plate, and the first pressure plate abuts against the first lip seal ring;

[0015] The second bearing assembly includes a second deep groove ball bearing and a second pressure plate. The second deep groove ball bearing abuts against the second pressure plate, and the second pressure plate abuts against the second lip seal ring.

[0016] Preferably, the first bearing assembly further includes a first dust cover, which abuts against the first deep groove ball bearing, and the second bearing assembly further includes a second dust cover, which abuts against the second deep groove ball bearing.

[0017] Preferably, a first protrusion is provided on the end cover, and a second protrusion is provided on the transmission shaft. The first protrusion and the second protrusion are arranged on both sides of the first deep groove ball bearing and abut against the first deep groove ball bearing.

[0018] Preferably, the device further includes a limit plate, the connecting section is formed with a first groove, one end of the limit plate is inserted into the first groove, the limit plate is sleeved on the transmission shaft, and the limit plate abuts against the second deep groove ball bearing.

[0019] Preferably, a second groove is formed on the boss, an O-ring is provided in the groove, and the O-ring abuts against the housing.

[0020] Preferably, the boss is connected to the housing via bolts, and the bolts are located outside the O-ring.

[0021] Preferably, the device further comprises a shaft sleeve, which is fixedly connected to the outer end portion of the transmission shaft for transmitting operating torque.

[0022] The present invention provides an end cover, a transmission shaft and a sealing assembly. The end cover is connected to the housing through a fixed connection and is sleeved on the outside of the transmission shaft; the first bearing assembly, the sealing assembly, and the second bearing assembly are sleeved in sequence along the axial direction of the transmission shaft, and the end cover and the transmission shaft are rotationally connected through the first bearing assembly and the second bearing assembly; a sealing area is formed between the sealing assembly, the first bearing assembly, and the second bearing assembly, and is filled with silicone grease to enhance sealing and lubrication. The transmission shaft rotates in the end cover through the bearing assembly, and the sealing assembly fits the surface of the transmission shaft and combines with silicone grease to fill the gap to prevent gas or liquid from leaking from the gap between the end cover and the transmission shaft; the bearing assembly supports the rotation of the transmission shaft to reduce friction.

[0023] (3) Beneficial effects

[0024] The above technical solution of the present invention has the following beneficial technical effects:

[0025] 1. The sealing assembly and the bearing assembly work together to form a composite protection of "bearing support + sealing barrier". The silicone grease fills the gap to further eliminate leakage channels and improve air tightness. The bearing assembly allows the drive shaft to rotate, and the sealing assembly prevents medium leakage, taking into account both mechanical movement and sealing performance. The silicone grease also provides lubrication, reducing friction between the sealing assembly and the drive shaft, extending the life of the seal and reducing the risk of jamming.

[0026] 2. By setting the specific arrangement of the first lip seal ring and the second lip seal ring in the sealing assembly, the inner seal ring blocks gas leakage, and the outer seal ring resists environmental pollutants, forming a double protection, while enhancing the fit of the sealing interface and reducing the probability of leakage;

[0027] 3. By limiting and fixing the first bearing assembly and the second bearing assembly, the bearings are ensured to be stably positioned under dynamic loads, and wear of the seals due to movement is avoided. By providing a combination of a protrusion, a groove and a limit plate, reliable axial fixation is achieved in a compact structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a cross-sectional schematic diagram of a transmission shaft sealing device for GIS equipment provided by the present invention;

[0029] Figure 2 yes Figure 1 Schematic enlarged view of the middle part A;

[0030] Figure 3 yes Figure 1 A schematic enlarged view of the middle portion B;

[0031] Figure 4 The figure is a side view of a transmission shaft sealing device for GIS equipment provided by the present invention.

[0032] Reference numerals:

[0033] 1. Shell;

[0034] 2. End cap; 21. Boss; 21a. Second groove; 22. Connecting section; 22a. First groove; 23. First protrusion;

[0035] 3. Transmission shaft; 31. Second raised portion;

[0036] 4. Sealing assembly; 41. First lip seal ring; 42. Second lip seal ring;

[0037] 5. First bearing assembly; 51. First deep groove ball bearing; 52. First pressure plate; 53. First dust cover;

[0038] 6. Second bearing assembly; 61. Second deep groove ball bearing; 62. Second pressure plate; 63. Second dust cover;

[0039] 7. Limit plate;

[0040] 8. O-ring;

[0041] 9. Bushing. DETAILED DESCRIPTION

[0042] To make the objectives, technical solutions, and advantages of the present invention more clearly understood, the present invention will be further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings. It should be understood that these descriptions are merely exemplary and are not intended to limit the scope of the present invention. In addition, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessary confusion of the concepts of the present invention.

[0043] The accompanying drawings illustrate schematic diagrams of layer structures according to embodiments of the present invention. These figures are not drawn to scale; for clarity, some details are exaggerated and some details may be omitted. The shapes, relative sizes, and positional relationships of the various regions and layers shown in the figures are merely exemplary and may deviate in practice due to manufacturing tolerances or technical limitations. Those skilled in the art may design regions / layers with different shapes, sizes, and relative positions based on actual needs.

[0044] Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0045] In the description of the present invention, it should be noted that the terms “first” and “second” are only used for descriptive purposes and should not be understood as indicating or implying relative importance.

[0046] Combine Figures 1 to 4 The present invention provides a transmission shaft sealing device for GIS equipment, hereinafter referred to as the device, which includes a housing 1, an end cover 2, a transmission shaft 3, a sealing assembly 4, a first bearing assembly 5, and a second bearing assembly 6; the end cover 2 is fixedly connected to the housing 1 and sleeved on the transmission shaft 3, the first bearing assembly 5, the sealing assembly 4, and the second bearing assembly 6 are sequentially sleeved on the transmission shaft 3, and the end cover 2 and the transmission shaft 3 are rotationally connected via the first bearing assembly 5 and the second bearing assembly 6; the sealing assembly 4, the first bearing assembly 5, and the second bearing assembly 6 together form a sealing area between the transmission shaft 3 and the end cover 2, and the sealing area is filled with silicone grease. Specifically, the end cover 2 is connected to the housing 1 by a fixed connection and sleeved on the outside of the transmission shaft 3; the first bearing assembly 5, the sealing assembly 4, and the second bearing assembly 6 are sequentially sleeved along the axial direction of the transmission shaft 3, and the end cover 2 and the transmission shaft 3 are rotationally connected via the bearing assembly; a sealing area is formed between the first bearing assembly 5, the sealing assembly 4, and the second bearing assembly 6, and is filled with silicone grease to enhance sealing and lubrication. The transmission shaft 3 rotates in the end cover 2 through the first bearing assembly 5 and the second bearing assembly 6. The sealing assembly 4 fits the surface of the transmission shaft 3 and fills the gap with silicone grease to prevent gas or liquid from leaking from the gap between the end cover 2 and the transmission shaft 3; the bearing assembly supports the rotation of the transmission shaft 3 to reduce friction.

[0047] This arrangement addresses the seal failure and gas leakage caused by single-layer sealing and insufficient lubrication, as well as wear and seizure caused by lack of bearing protection in traditional shaft seals. The seal assembly 4 and the bearing assembly together form a composite sealing area, providing a composite protection of "bearing support + seal barrier." Filling with silicone grease achieves integrated dynamic sealing and lubrication. The first and second bearing assemblies 5 and 6 allow the drive shaft 3 to rotate, while the seal assembly 4 prevents media leakage, balancing mechanical movement and sealing performance, addressing the problem of traditional static seals being unable to adapt to dynamic operating conditions. The silicone grease also provides lubrication, reducing friction between the seal assembly 4 and the drive shaft 3, extending seal life and reducing the risk of seizure. The dual bearing assembly supports the drive shaft 3, reducing wear on the sealing interface caused by rotational offset.

[0048] It should be noted that the specific material of the end cover 2 is not limited here. In a preferred case, the end cover 2 is made of aluminum. When the equipment is running, the thermal expansion of the equipment in certain operating stages may cause uneven gaps between the end cover 2 and the drive shaft 3, which may cause friction between the shaft seal and the drive shaft 3. However, because the shaft seal is made of aluminum, that is, the end cover 2 is made of aluminum, it is soft in texture and can reduce wear on the drive shaft 3.

[0049] In a preferred embodiment, the end cap 2 includes an integrally formed boss 21 and a connecting section 22. The boss 21 is fixedly connected to the side of the housing 1, the outer side of the connecting section 22 abuts the housing 1, and the inner side of the connecting section 22 is rotatably connected to the transmission shaft 3 via a first bearing assembly 5 and a second bearing assembly 6. The first bearing assembly 5 and the second bearing assembly 6 are located on either side of the sealing assembly 4. Specifically, the end cap 2 is divided into a boss 21 fixed to the housing 1 and a connecting section 22 with a bearing assembly disposed therein. The boss 21 is fixed to the side of the housing 1 by bolts. The outer side of the connecting section 22 abuts the housing 1, and the inner side is rotatably connected to the transmission shaft 3 via the bearing assembly. The bearing assembly is located on either side of the sealing assembly 4. Through such a setting, the integrally formed boss 21 and connecting section 22 ensure the rigidity of the end cover 2, reduce deformation caused by vibration or thermal expansion, avoid eccentricity of the transmission shaft 3, and ensure overall stability; the bearing assembly is located on both sides of the sealing assembly 4, and the sealing assembly 4 isolates external impurities (such as salt spray and dust), prevents the bearing grease from being contaminated, and extends the life of the bearing; the boss 21 is directly fixed to the housing 1, and the bearing assembly is pre-positioned on the inner side of the connecting section 22, which simplifies the assembly process and ensures that the components are installed coaxially.

[0050] It should be noted that the specific structure of the sealing assembly 4 is not limited here, as long as it can achieve a shaft sealing effect between the first bearing assembly 5 and the second bearing assembly 6. The specific distribution of the first bearing assembly 5 and the second bearing assembly 6 in the sealing assembly 4 is also not limited. In a preferred case, the sealing assembly 4 includes a first lip-shaped sealing ring 41 and a second lip-shaped sealing ring 42. The sealing lip of the first lip-shaped sealing ring 41 faces the first bearing assembly 5, and the sealing lip of the second lip-shaped sealing ring 42 faces the second bearing assembly 6. Specifically, as Figures 1 to 3 As shown, the first bearing assembly 5 is located near the outside of the housing 1. The sealing lip of the first lip seal 41 faces the first bearing assembly 5, that is, the outside of the housing 1. The sealing lip of the second lip seal 42 faces the second bearing assembly 6, that is, the inside of the housing 1, forming an "inside + outside" bidirectional seal. The inside lip seal prevents the leakage of SF6 gas inside the housing 1, while the outside lip seal prevents the intrusion of external moisture, salt spray, and dust. Silicone grease fills the gap between the seal and the drive shaft 3 to enhance the sealing effect.

[0051] Through this setting, the double sealing rings are arranged in opposite directions, respectively aiming at "internal leakage prevention and external intrusion prevention", forming a three-dimensional sealing system, which is particularly suitable for offshore environments with high humidity and high salt fog; the inner sealing ring prioritizes to prevent SF6 gas from leaking, and the outer sealing ring blocks the entry of external corrosive media, and the layers respond to different failure risks to improve sealing reliability; at the same time, even if one side of the sealing ring is partially worn, the other side can still temporarily maintain the sealing function, extending the maintenance cycle and ensuring operational stability.

[0052] The number of the first lip seal ring 41 and the second lip seal ring 42 is not limited here, and can be single or multiple, and can be arranged in sequence in the sealing space to achieve the sealing effect. Figure 1 A first lip-shaped sealing ring 41 and two second lip-shaped sealing rings 42 are provided in the middle to achieve sealing.

[0053] In a preferred embodiment, the first bearing assembly 5 includes a first deep groove ball bearing 51 and a first pressure plate 52. The first deep groove ball bearing 51 abuts the first pressure plate 52, and the first pressure plate 52 abuts the first lip seal 41. The second bearing assembly 6 includes a second deep groove ball bearing 61 and a second pressure plate 62. The second deep groove ball bearing 61 abuts the second pressure plate 62, and the second pressure plate 62 abuts the second lip seal 42. Specifically, the first deep groove ball bearing 51 supports the transmission shaft 3, and the first pressure plate 52 abuts the first deep groove ball bearing 51 and the first lip seal 41, limiting the axial movement of the first deep groove ball bearing 51 and the first lip seal 41. The second deep groove ball bearing 61 supports the transmission shaft 3, and the second pressure plate 62 abuts the second deep groove ball bearing 61 and the second lip seal 42, similarly limiting the axial displacement of the second deep groove ball bearing 61 and the second lip seal 42.

[0054] Through such a setting, the pressure plate forcibly fixes the outer ring of the bearing, ensures the neutrality of the transmission shaft 3, avoids bearing displacement caused by vibration and impact, and thus protects the seal from abnormal wear; the pressure plate disperses the axial force to the overall structure of the end cover 2, reduces local stress on the bearing, extends the bearing life, and avoids lip deformation or tearing of the seal due to uneven force; the pressure plate connects the bearing and the seal at the same time, simplifies the assembly steps, ensures the accurate axial position of each component, and improves the overall stability.

[0055] In a preferred embodiment, the first bearing assembly 5 further includes a first dust cover 53, which abuts the first deep groove ball bearing 51. The second bearing assembly 6 further includes a second dust cover 63, which abuts the second deep groove ball bearing 61. The dust cover acts as a rigid barrier, fixed to the outer ring of the bearing to form a fully enclosed structure, and cooperates with the sealing assembly 4 to prevent solid particles (such as dust and gravel) from entering the bearing raceway. Through this arrangement, the double-sided dust cover cooperates with the sealing assembly 4 to form a dual protection of "dust cover physical blocking + sealing ring dynamic sealing", which is particularly suitable for dusty and high salt fog environments (such as offshore wind power); the dust cover prevents external moisture and particles from contaminating the grease, maintaining the stable lubrication performance of the bearing, reducing frictional heating and wear caused by insufficient lubrication, and extending the service life of the bearing.

[0056] It should be noted that the specific fixing method of the first bearing assembly 5 and the second bearing assembly 6 in the device is not limited here. It can be achieved by providing a mounting groove or interference fit on the transmission shaft 3. The axial position of the bearing can also be achieved by providing a protruding structure on both sides of the bearing. In a preferred embodiment, a first protruding portion 23 is provided on the end cover 2, and a second protruding portion 31 is provided on the transmission shaft 3. The first protruding portion 23 and the second protruding portion 31 are provided on both sides of the first deep groove ball bearing 51 and abut against the first deep groove ball bearing 51. Specifically, the protruding portions fix the position of the bearings through mechanical stops, replacing the traditional complex structure that relies on pressure plates or retaining rings, ensuring the axial positioning accuracy of the bearings on the transmission shaft 3. Furthermore, the device also includes a limiting plate 7. The connecting section 22 is formed with a first groove 22a. One end of the limiting plate 7 is inserted into the first groove 22a. The limiting plate 7 is sleeved on the transmission shaft 3 and abuts against the second deep groove ball bearing 61. The limit plate 7 is used as an axial positioning element, fixed to the end cover 2 through the groove, and at the same time presses the outer ring of the bearing, and cooperates with the protrusion or pressure plate on the other side to form a two-way limit. Figure 1 As shown, the second protrusion 31 on the transmission shaft 3 passes through the sealing assembly 4 , and two sides of the second protrusion 31 respectively abut against the first deep groove ball bearing 51 and the second deep groove ball bearing 61 .

[0057] Through such a setting, the raised parts of the end cover 2 and the transmission shaft 3 are in direct contact with the inner and outer rings of the bearing, forming a rigid connection of "end cover 2-bearing-transmission shaft 3", eliminating the assembly gap and ensuring the coaxiality of the bearing; the raised part provides stable axial support, effectively bearing the impact load when the operating shaft is opened and closed, preventing the bearing from shifting due to instantaneous overload, and improving the reliability of the transmission system; the cooperation between the limit plate 7 and the groove provides stronger vibration resistance than a single retaining ring, ensuring the stable positioning of the bearing under dynamic load and avoiding wear of the seal due to movement; the plug-in design of the limit plate 7 is easy to disassemble, and there is no need to completely disassemble the end cover 2 when replacing the bearing or seal, which shortens the maintenance time and improves the maintainability of the equipment.

[0058] In a preferred embodiment, a second groove 21a is formed on the boss 21, and an O-ring 8 is arranged in the groove, and the O-ring 8 abuts against the shell 1. Furthermore, the boss 21 is connected to the shell 1 by bolts, and the bolts are located on the outside of the O-ring 8. The O-ring 8 acts as a static seal, and cooperates with the pre-tightening force of the bolts to prevent gas from leaking from the connection surface between the end cover 2 and the shell 1, forming a first sealing barrier, thereby achieving dual protection of external static sealing and internal dynamic sealing. Through such a setting, the O-ring achieves static sealing between the end cover 2 and the shell 1, and cooperates with the dynamic sealing of the internal lip-shaped seal ring to form a double protection, completely blocking the path of gas leakage and impurity entry; the O-ring is arranged on the inside of the bolt, completely isolating the bolt hole outside the sealing area, preventing gas from leaking through the bolt hole. At the same time, the bolt load is distributed on the outside of the O-ring, ensuring that the O-ring is evenly pressurized, reducing rubber aging caused by local excessive compression, and extending the life of the static seal.

[0059] It should be noted that the present invention does not limit the specific setting and driving form of the device in the GIS equipment, and it is sufficient that the shaft sealing effect can be achieved through the above-mentioned structure and setting. In a preferred case, the device also includes a sleeve 9, which is fixedly connected to the outer end of the transmission shaft 3 for transmitting the operating torque. The sleeve 9 serves as a torque transmission medium, converting the external driving force into the rotational motion of the transmission shaft 3, driving the internal components of the housing 1 (such as the isolating switch) to operate. The sleeve 9 adopts a universal connection form (such as a hexagonal sleeve), which is compatible with existing operating mechanisms, reduces the difficulty of equipment modification, and improves interchangeability and maintenance convenience.

[0060] It should be understood that the above-described specific embodiments of the present invention are merely illustrative or illustrative of the principles of the present invention and do not constitute limitations of the present invention. Therefore, any modifications, equivalent substitutions, improvements, etc. made without departing from the spirit and scope of the present invention should be included within the scope of protection of the present invention. In addition, the appended claims are intended to cover all variations and modifications that fall within the scope and metes and bounds of the appended claims, or equivalents thereof.

Claims

1. A transmission shaft sealing device for GIS equipment, characterized in that: The device comprises a housing (1), an end cover (2), a transmission shaft (3), a sealing assembly (4), a first bearing assembly (5) and a second bearing assembly (6); The end cover (2) is fixedly connected to the housing (1), the end cover (2) is sleeved on the transmission shaft (3), the first bearing assembly (5), the sealing assembly (4) and the second bearing assembly (6) are sleeved on the transmission shaft (3) in sequence, and the end cover (2) and the transmission shaft (3) are rotatably connected via the first bearing assembly (5) and the second bearing assembly (6); The sealing assembly (4), the first bearing assembly (5) and the second bearing assembly (6) together form a sealing area between the transmission shaft (3) and the end cover (2), and the sealing area is filled with silicone grease.

2. The device according to claim 1, characterized in that The end cover (2) includes an integrally formed boss (21) and a connecting section (22), wherein the boss (21) is fixedly connected to the side of the housing (1), the outer side of the connecting section (22) abuts against the housing (1), and the inner side of the connecting section (22) is rotationally connected to the transmission shaft (3) via the first bearing assembly (5) and the second bearing assembly (6), and the first bearing assembly (5) and the second bearing assembly (6) are located on both sides of the sealing assembly (4).

3. The device according to claim 2, characterized in that The sealing assembly (4) comprises a first lip-shaped sealing ring (41) and a second lip-shaped sealing ring (42), wherein the sealing lip of the first lip-shaped sealing ring (41) faces the first bearing assembly (5), and the sealing lip of the second lip-shaped sealing ring (42) faces the second bearing assembly (6).

4. The device according to claim 3, characterized in that The first bearing assembly (5) comprises a first deep groove ball bearing (51) and a first pressure plate (52), the first deep groove ball bearing (51) abuts against the first pressure plate (52), and the first pressure plate (52) abuts against the first lip seal ring (41); The second bearing assembly (6) comprises a second deep groove ball bearing (61) and a second pressure plate (62), the second deep groove ball bearing (61) abuts against the second pressure plate (62), and the second pressure plate (62) abuts against the second lip seal ring (42).

5. The device according to claim 4, characterized in that The first bearing assembly (5) further includes a first dust cover (53), the first dust cover (53) abutting against the first deep groove ball bearing (51), and the second bearing assembly (6) further includes a second dust cover (63), the second dust cover (63) abutting against the second deep groove ball bearing (61).

6. The device according to claim 4, characterized in that The end cover (2) is provided with a first protrusion (23), and the transmission shaft (3) is provided with a second protrusion (31). The first protrusion (23) and the second protrusion (31) are arranged on both sides of the first deep groove ball bearing (51) and abut against the first deep groove ball bearing (51).

7. The device according to claim 4, characterized in that The device further comprises a limit plate (7), the connecting section (22) is formed with a first groove (22a), one end of the limit plate (7) is inserted into the first groove (22a), the limit plate (7) is sleeved on the transmission shaft (3), and the limit plate (7) abuts against the second deep groove ball bearing (61).

8. The device according to claim 2, characterized in that A second groove (21a) is formed on the boss (21), an O-type sealing ring (8) is arranged in the groove, and the O-type sealing ring (8) abuts against the housing (1).

9. The device according to claim 8, characterized in that The boss (21) is connected to the housing (1) via bolts, and the bolts are located outside the O-ring (8).

10. The device according to claim 1, characterized in that The device further comprises a shaft sleeve (9), which is fixedly connected to the outer end of the transmission shaft (3) and is used for transmitting operating torque.

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