A type of corrosion-proof fan combination shaft seal structure

Abstract

A kind of A type anticorrosion fan combination shaft seal structure, including seal seat and sealing lip.The seal seat includes seat disc and seat plate;Seat disc is in cylindrical structure, and seat plate is in annular circular plate structure, seat plate is fixed on the outer wall of seat disc, and loading hole is formed in the shaft part of seat disc;Seat plate edge is provided with seat body fixing hole;The front and rear ends of loading hole are provided with seat front mouth and seat rear mouth respectively;The inner diameter of seat front mouth is smaller than that of seat rear mouth.Two sealing lips are sleeved in the inner wall of loading hole in the shaft part of seal seat.It has the advantages of carbon ring seal, mechanical seal and packing seal, good replaceability, excellent sealing performance.No need for shaft seal body and rotating shaft to be closely matched, easy to disassemble and assemble, reduce the potential danger of outer circle air leakage.The whole machine occupies small space, and installation and maintenance are simple.The service life and maintenance period are applied in motor direct connection A type fan, and the cost performance is high, and the shaft seal cost is reduced.It is especially suitable for sealing occasions of pressure chemical liquid or fluid containing powder and strong adhesion.

Description

Technical Field

[0001] This utility model belongs to the technical field of shaft seals for fluid variable displacement mechanical or non-variable displacement pumps under IPC classification F04D29 / 10, and particularly relates to a structural improvement technology for an A-type anti-corrosion combined shaft seal structure applied to fan shaft seals. Background Technology

[0002] Currently, with the continuous improvement of product technology and the requirements for energy conservation, shaft seal mechanical seals are widely used in fluid machinery products.

[0003] A mechanical seal is a device that prevents fluid leakage. It consists of at least one pair of end faces perpendicular to the axis of rotation. Under the action of fluid pressure, the elastic or magnetic force of a compensation mechanism, and the cooperation of an auxiliary seal, these end faces remain in contact and slide relative to each other. Its core working principle is that an extremely thin liquid film is formed by the precisely fitted rotating ring and stationary ring end faces, achieving fluid isolation during rotation.

[0004] Patent application 201220125254.2 relates to an axial sealing device for various types of fans, particularly an axial labyrinth sealing device for nuclear power fans. It belongs to the field of sealing technology for mechanical products and includes a front cover, a sealing cover, and a rear cover that are assembled and combined in sequence by means of concave and convex surfaces. A sealing ring is installed in the sealing groove of the sealing cover.

[0005] The technical challenges of traditional anti-corrosion fan shaft seals on the market include: high requirements for the fit between the seal and the shaft, complex installation and debugging; easy intrusion of corrosive media leading to seal failure; short maintenance cycle and high replacement cost; and the current technology and products are insufficient to solve and meet the ever-increasing needs of users.

[0006] For example, in the metallurgical and chemical industries, when fans are used to transport pressurized chemical liquids or fluids containing powder and strong adhesion, C-type belt drives and D-type coupling drives are commonly used. In these working conditions, carbon ring seals are widely used for shaft seals. However, due to their high cost and complex structure, and when the customer's on-site installation space is limited and only A-type motor direct-drive shaft seals (referred to as A-type fan seals) can be used, carbon ring seals cannot be installed. At this time, there is an urgent need for a shaft seal with sealing performance that can replace carbon ring seals to meet the special leakage requirements of the chemical industry. Utility Model Content

[0007] This utility model designs an A-type anti-corrosion fan combined shaft seal structure. Through structural improvements, the sealing effect of the A-type fan is no less than that of the carbon ring seal, solving the problems of poor sealing performance, short life, complex structure, long cycle and high cost of fans in the chemical industry.

[0008] Therefore, this utility model discloses an A-type anti-corrosion fan combined shaft seal structure, including a sealing seat and sealing lips. The sealing seat includes a seat plate and a seat disk; the seat disk has a cylindrical structure, and the seat plate has an annular circular plate structure. The seat plate is fixed on the outer wall of the seat disk, and a loading hole is opened in the central shaft part of the seat disk; a seat fixing hole is opened on the edge of the seat plate; a front opening and a rear opening are respectively provided at the front and rear ends of the loading hole; wherein, the inner diameter of the front opening is smaller than that of the rear opening. Double sealing lips are fitted on the inner wall of the loading hole in the central shaft part of the sealing seat.

[0009] The edge of the sealing seat is secured to the rear panel of the housing by a gasket and studs. In particular, the surface of the rear panel of the housing is coated with an anti-corrosion rubber lining.

[0010] The central shaft hole of the sealing seat is coaxially inserted and installed from front to back to the shaft disc hub connected to the central part of the impeller of the fan. The rear end of the shaft disc hub has a hub shaft hole. A double sealing lip is fitted between the inner wall of the central shaft hole of the sealing seat and the shaft disc hub.

[0011] The drive shaft of the motor is inserted first from the rear to the rear of the sealing seat, that is, in the hub shaft hole at the rear end of the axle disc hub.

[0012] The inner diameter of the front opening of the seat is larger than the outer diameter of the shaft disc hub, and the difference between the inner diameter of the loading hole of the sealing seat and the outer diameter of the shaft disc hub is close to the difference between the inner and outer diameters of the sealing lip.

[0013] The loading hole of the sealing seat has two sealing lips, which are single-lip sealing lips; or, the loading hole of the sealing seat has one sealing lip, which is double-lip sealing lip.

[0014] Furthermore, to achieve the above objectives, this utility model is configured as follows:

[0015] Specifically, the sealing lip includes a lip shell, a front lip opening, a rear lip opening, a first lip opening, an inner support ring, and a bushing. The lip shell is annular, with a through hole in the middle. The front and rear ends of this through hole are the front lip opening and the rear lip opening, respectively. The inner diameter of the front lip opening is smaller than that of the rear lip opening, meaning the front lip opening extends along a concentric annular constricted arc-shaped curved surface. The annular first lip opening is attached to the inner side of the end face of the front lip opening. The inner diameter of the first lip opening extends towards the rear lip opening through a constricted arc. An inner support ring is attached to the outer edge of the inner side of the first lip opening. The cross-section of the inner support ring is L-shaped, meaning the front part of the inner support ring abuts against the inner wall of the rear side of the first lip opening, and the rear part of the inner support ring abuts against the inner wall of the rear section of the lip shell. A bushing is inserted between the outer edge of the contact surface between the front part of the inner support ring and the inner wall of the rear side of the first lip opening.

[0016] Specifically, the sealing lip includes a lip shell, a front lip opening, a rear lip opening, a first lip opening, an inner support ring, a bushing, a second lip opening, and an isolation support ring. The lip shell is annular, with a through hole in the middle. The front and rear ends of this through hole are the front lip opening and the rear lip opening, respectively. The inner diameter of the front lip opening is smaller than that of the rear lip opening, meaning the front lip opening extends outward along a concentric annular neck. The annular first lip opening is attached to the inner side of the end face of the front lip opening, and the inner diameter of the first lip opening extends outward along the necked arc-shaped surface of the rear lip opening. The second lip opening is attached to the inner side of the first lip opening with spaced support from the isolation support ring. The second lip opening has the same structure as the first lip opening. An inner support ring is attached to the outer edge of the inner side of the second lip opening. The cross-section of the inner support ring is L-shaped, meaning the front part of the inner support ring abuts against the inner wall of the rear side of the second lip opening, and the rear part of the inner support ring abuts against the inner wall of the rear section of the lip shell. A bushing is inserted between the outer edge of the contact surface between the front part of the inner support ring and the inner wall of the rear side of the second lip opening.

[0017] Specifically, the sealing lip includes a lip shell, a front lip opening, a rear lip opening, a first lip opening, an inner support ring, a second lip opening, and an isolation support ring. The lip shell is annular, with a through hole in the middle. The front and rear ends of the through hole are the front lip opening and the rear lip opening, respectively. The inner diameter of the front lip opening is smaller than that of the rear lip opening, meaning the front lip opening extends outward along a concentric annular neck. The annular first lip opening is attached to the inner side of the end face of the front lip opening, and the inner diameter of the first lip opening extends outward toward the constricted oblique conical surface of the rear lip opening. The second lip opening is attached to the inner side of the first lip opening with spaced support by the isolation support ring. The second lip opening has the same structure as the first lip opening. An inner support ring is attached to the outer edge of the inner side of the second lip opening. The cross-section of the inner support ring is L-shaped, meaning the front part of the inner support ring abuts against the inner wall of the rear side of the second lip opening, and the rear part of the inner support ring abuts against the inner wall of the rear section of the lip shell.

[0018] Compared with the prior art, the beneficial effects of this utility model are:

[0019] 1) This technology is used in direct-drive A-type fans, offering high cost-effectiveness and reducing shaft seal costs. The unit occupies little space and is easy to install and maintain. The maintenance cycle is extended from 3 months to 1 year.

[0020] 2) The outer circle of the sealing lip and the mating surface of the sealing seat are bonded with adhesive, which makes disassembly and assembly convenient and reduces the potential danger of air leakage from the outer circle.

[0021] 3) After machining the sealing seat, two sealing lips are installed, which provides good maintenance and replaceability, and excellent sealing performance.

[0022] 4) It combines the advantages of carbon ring seals, mechanical seals and packing seals, with a simple structure and low cost.

[0023] 5) Adaptable to harsh corrosive environments; meets the environmental protection requirements of zero leakage of corrosive and toxic gases in the transportation of many industries.

[0024] 6) No tight fit between the shaft seal body and the rotating shaft is required, making shaft seal disassembly and maintenance simple.

[0025] 7) Sealing performance improved by more than 30%; service life extended by 2-3 times;

[0026] 8) Widely used in axial seals of various types of fans. Particularly suitable for sealing pressurized chemical liquids or fluids containing powders and strong adhesives. Attached Figure Description

[0027] The following figures are illustrative and should not be construed as limiting the scope of this invention. Referring to the figures helps the reader understand the embodiments of this invention and further appreciate its advantages and technical features.

[0028] Figure 1 This is a schematic diagram of the structure of Example 1.

[0029] Figure 2 This is a schematic diagram of the installation structure for Example 1.

[0030] Figure 3 This is a side view of the sealing seat structure in Example 1.

[0031] Figure 4 This is a schematic diagram of the main structure of the sealing seat in Example 1.

[0032] Figure 5 This is a schematic diagram of the single sealing lip structure in Example 1.

[0033] Figure 6 This is a schematic diagram of the double sealing lip structure in Example 1.

[0034] Figure 7 This is a schematic diagram of the double sealing lip structure in Example 2.

[0035] The reference numerals in the figures include:

[0036] 1-Anti-corrosion lining coating, 2-Rear side plate of casing, 3-Sealing gasket, 4-Sealing seat, 5-Stud, 6-Nut, 7-Sealing lip, 8-Shaft disc hub, 9-Impeller, 10-Motor.

[0037] 41-Seat plate, 42-Seat plate, 43-Loading hole, 44-Rear opening of seat, 45-Front opening of seat, 46-Seat body fixing hole;

[0038] 71-lip shell, 72-anterior lip opening, 73-posterior lip opening, 74-first lip opening, 75-inner support ring, 76-liner ring, 77-second lip opening, 78-isolation support ring. Detailed Implementation

[0039] It should be noted that:

[0040] In the description of this utility model, unless otherwise expressly specified and limited, the terms "comprising" and "having," and any variations thereof, are intended to cover other possible options under the same logic not listed. For example, a process, method, system, product, or device comprising a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such process, method, product, or device. The terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," "outer," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings, or the orientation or positional relationships commonly used when the utility model product is in use. They are only for the convenience of describing the utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the utility model. Furthermore, the terms "first," "second," "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance. Furthermore, terms such as "horizontal," "vertical," and "suspended" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," not that the structure must be completely horizontal, but can be slightly tilted. The terms "set up," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal connection between two components.

[0041] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. In case of any conflict, the definitions in this specification shall prevail.

[0042] Type A shaft seals are friction seals or stuffing box devices primarily used to prevent liquid leakage between the shaft and bearings in fluid transport equipment such as compressors and pumps; they fall under the category of dynamic seals. Their core function is to prevent media leakage at the pump shaft and housing.

[0043] A typical corrosion-resistant centrifugal fan booster shaft seal structure includes the following components:

[0044] Connecting disc: A ring-shaped component with mounting holes;

[0045] Shaft seal: cylindrical structure with an internal annular partition forming different functional chambers;

[0046] Shaft seal cavity: The sealing space that accommodates the shaft seal body;

[0047] Lubricating oil chamber: An intermediate chamber that provides lubrication.

[0048] The working principle of a typical Type A shaft seal includes:

[0049] Pressure balance mechanism: Seal is achieved by balancing the pressure of the sealing medium with the external pressure;

[0050] Multi-stage sealing design: typically employs a multi-ring sealing structure to improve sealing reliability;

[0051] Automatic adjustment function: Some advanced designs can automatically adjust the sealing pressure according to changes in working conditions;

[0052] The latest technological breakthroughs in Type A shaft seals or sealing lips include:

[0053] Self-sealing technology: It can achieve self-sealing function under specific load conditions, reducing the consumption of external sealing vapor;

[0054] Labyrinth seal: Through a multi-stage steam seal tooth design, steam pressure energy is gradually converted into heat energy for consumption;

[0055] Future improvements to mechanical shaft seal technology have been studied and addressed:

[0056] Intelligent control: Integrates pressure sensors and an automatic adjustment system to achieve real-time monitoring of the sealing status;

[0057] Materials innovation: High-performance composite materials are used to improve corrosion resistance and wear resistance;

[0058] Modular design: facilitates quick replacement and maintenance, reducing downtime;

[0059] This utility model includes a sealing seat 4 and a sealing lip 7.

[0060] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0061] Example 1: As shown in the attached document Figure 1 and 2 As shown, the edge of the sealing seat 4 is fixed to the rear side plate 2 of the housing by a gasket 3, studs 5, and nuts 6. The central shaft hole of the sealing seat 4 is coaxially inserted from front to back to connect the impeller 9 of the fan to the central shaft hub 8. The rear end of the shaft hub 8 has a hub shaft hole. A double sealing lip 7 is fitted between the inner wall of the central shaft hole of the sealing seat 4 and the shaft hub 8. Correspondingly, the drive shaft of the motor 10 is inserted from back to front into the rear shaft hole of the rear end of the sealing seat 4, i.e., the rear end of the shaft hub 8.

[0062] As mentioned above, the surface of the rear side panel 2 of the housing is fixed with an anti-corrosion rubber coating 1.

[0063] As mentioned above, as attached Figure 3 and 4 As shown, the sealing seat 4 includes a seat plate 41 and a seat plate 42. The seat plate 41 has a cylindrical structure, and the seat plate 42 has an annular circular plate structure. The seat plate 42 is fixed on the outer wall of the seat plate 41. A loading hole 43 is opened in the central shaft of the seat plate 41. A seat fixing hole 46 is opened on the edge of the seat plate 42. A front opening 45 and a rear opening 44 are respectively provided at the front and rear ends of the loading hole 43. The inner diameter of the front opening 45 is smaller than that of the rear opening 44. In particular, the inner diameter of the front opening 45 is larger than the outer diameter of the shaft disc hub 8, and the difference between the inner diameter of the loading hole 43 of the sealing seat 4 and the outer diameter of the shaft disc hub 8 is close to the difference between the inner and outer diameters of the sealing lip 7.

[0064] As mentioned above, the loading hole 43 of the sealing seat 4 is fitted with two sealing lips 7, which are single-lip sealing lips; or, the loading hole 43 of the sealing seat 4 is fitted with one sealing lip 7, which is a double-lip sealing lip.

[0065] In this embodiment of the invention, the sealing seat 4 is made of brass. The stud 5 is an M8x25 stud, the nut 6 is an M8 hexagonal nut, and the sealing lip 7 is made of polytetrafluoroethylene.

[0066] In this embodiment of the invention, during installation, the sealing lip 7 is pressed into the loading hole 43 in the shaft portion of the hub 8. An adhesive or sealing compound is used to bond the sealing ring to the loading hole. This avoids the potential hazard of air leakage at the outer diameter. Sealing compounds such as Loctite 601 or 641 are used.

[0067] This utility model embodiment is applied to a fan shaft seal. The installation structure includes a shaft disc hub 8 fitted on an impeller 9, a sealing seat 4, and a PTFE sealing lip 7 coaxially fixed with the sealing seat 4. Two specially designed PTFE sealing lips 7 are installed in the inner cavity of the sealing seat 4 in contact with the outer circle of the fan shaft disc hub 8. The outer circle of the sealing lip 7 is bonded to the brass sealing seat 4 with adhesive.

[0068] The implementation principle of this embodiment is as follows: First, the sealing seat 4 is installed on the rear side plate 2 of the casing. Then, two polytetrafluoroethylene (PTFE) sealing lips 7 are installed in the loading hole 43 of the sealing seat 4. When the fan is running, the pressurized airflow entering the fan from the front side of the impeller 9 forms a pressure barrier, preventing external media from entering the loading hole 43. The inner lip of the sealing lip 7 installed in the loading hole 43 of the sealing seat 4 forms an excellent sealing effect, which, combined with the lubrication oil cavity, provides continuous lubrication and reduces shaft seal wear. The sealing lip 7 can be a general-purpose part, which is easy for customers to maintain and replace, and has excellent sealing performance. In the A-type fan directly connected to the motor 10, the use of this seal is cost-effective, has good sealing performance, occupies little space, and is simple to install and maintain.

[0069] In this embodiment of the invention, based on manufacturer test data, the actual operating conditions were verified under the following conditions: working temperature -20℃ to 120℃, speed range 500-3000rpm, and accelerated aging test service life ≥20,000 hours. The sealing performance is excellent, with a leakage rate <0.5% according to GB / T 1236-2017; corrosion resistance was tested according to GB / T 10125-2012, passing a 96-hour salt spray test.

[0070] Example 2: A single-lip sealing lip 7, as shown in the attached diagram. Figure 5 As shown, the sealing lip 7 includes a lip shell 71, a front lip opening 72, a rear lip opening 73, a first lip opening 74, an inner support ring 75, and a bushing 76. The lip shell 71 is annular, with a through hole in the middle. The front and rear ends of the through hole are a front lip opening 72 and a rear lip opening 73, respectively. The inner diameter of the front lip opening 72 is smaller than that of the rear lip opening 73. That is, the front lip opening 72 extends along the concentric annular constricted arc-shaped curved surface. An annular first lip opening 74 is attached to the inner side of the end face of the front lip opening 72. The inner diameter of the first lip opening 74 extends towards the rear lip opening 73. An inner support ring 75 is attached to the outer edge of the inner side of the first lip opening 74. The cross-section of the inner support ring 75 is L-shaped. That is, the front part of the inner support ring 75 abuts against the inner rear wall of the first lip opening 74, and the rear part of the inner support ring 75 abuts against the inner wall of the rear section of the lip shell 71. In particular, a bushing ring 76 is inserted between the outer edge of the contact surface between the front part of the inner support ring 75 and the inner rear wall of the first lip opening 74.

[0071] Example 3: A double-lip structure sealing lip 7, as shown in the attached figure. Figure 6 As shown, the sealing lip 7 includes a lip shell 71, a front lip opening 72, a rear lip opening 73, a first lip opening 74, an inner support ring 75, a bushing 76, a second lip opening 77, and an isolation support ring 78. The lip shell 71 is annular, with a through hole in the middle. The front and rear ends of this through hole are the front lip opening 72 and the rear lip opening 73, respectively. The inner diameter of the front lip opening 72 is smaller than that of the rear lip opening 73, meaning that the front lip opening 72 extends outward in a concentric annular necking pattern. The annular first lip opening 74 is attached to the inner side of the end face of the front lip opening 72. The inner diameter of the first lip opening 74 extends outward in a constricted arc-shaped surface towards the rear lip opening 73. The first lip opening 74 is supported at intervals by the isolation support ring 78 inside the first lip opening 74. A second lip 77 is installed; the second lip 77 has the same structure as the first lip 74; an inner support ring 75 is attached to the outer edge of the inner side of the second lip 77, and the cross-section of the inner support ring 75 is L-shaped, that is, the front part of the inner support ring 75 is attached to the inner wall of the rear side of the second lip 77, and the rear part of the inner support ring 75 is attached to the inner wall of the rear section of the lip shell 71 of the rear side of the first lip 74; in particular, a bushing ring 76 is inserted between the outer edge of the contact surface between the front part of the inner support ring 75 and the inner wall of the rear side of the second lip 77.

[0072] Example 4: A double-lip structure sealing lip 7, as shown in the attached figure. Figure 7As shown, the sealing lip 7 includes a lip shell 71, a front lip opening 72, a rear lip opening 73, a first lip opening 74, an inner support ring 75, a second lip opening 77, and an isolation support ring 78. The lip shell 71 is annular, with a through hole in the middle. The front and rear ends of the through hole are a front lip opening 72 and a rear lip opening 73, respectively. The inner diameter of the front lip opening 72 is smaller than that of the rear lip opening 73. That is, the front lip opening 72 extends outward along the concentric annular neck. An annular first lip opening 74 is attached to the inner side of the end face of the front lip opening 72. The inner diameter of the first lip opening 74 extends outward toward the constricted oblique conical surface of the rear lip opening 73. A second lip opening 77 is attached to the inner side of the first lip opening 74 through a spacer ring 78. The second lip opening 77 has the same structure as the first lip opening 74. An inner support ring 75 is attached to the outer edge of the inner side of the second lip opening 77. The cross-section of the inner support ring 75 is L-shaped. That is, the front part of the inner support ring 75 abuts against the inner rear wall of the second lip opening 77, and the rear part of the inner support ring 75 abuts against the inner rear wall of the first lip opening 74.

[0073] In the aforementioned embodiments 2, 3, and 4, the lip shell 71 is made of metal or rigid polyester material, the first lip 74 and the second lip 77 are made of polytetrafluoroethylene, the inner support ring 75 and the bushing 76 are made of rigid polyurethane, and the isolation support ring 78 is made of corrosion-resistant foamed polyurethane or other elastic filling support material.

[0074] Example 5: Application of anti-corrosion fan in a chemical plant to Example 3: Medium: Corrosive gas containing chloride ions; Operating temperature: 80-100℃; Operating speed: 1450rpm; Results: No leakage after 18 months of continuous operation, and maintenance costs reduced by 65%.

[0075] The main application areas of this utility model embodiment include:

[0076] Chemical industry: Transportation of corrosive gases such as chlor-alkali and pesticides.

[0077] Environmental engineering: waste gas treatment, desulfurization and denitrification systems.

[0078] Marine engineering: Ventilation systems for offshore platforms.

[0079] Food and pharmaceutical: Corrosive cleaning gas circulation.

[0080] Based on the embodiments of this utility model described above, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this utility model.

Claims

1. A type A corrosion-resistant fan combined shaft seal structure, comprising a sealing seat (4) and a sealing lip (7); characterized in that, The sealing seat (4) includes a seat plate (41) and a seat plate (42); the seat plate (41) is cylindrical and the seat plate (42) is an annular circular plate. The seat plate (42) is fixed on the outer wall of the seat plate (41). The central shaft of the seat plate (41) has a loading hole (43). The edge of the seat plate (42) has a seat fixing hole (46). The front and rear ends of the loading hole (43) are respectively provided with a front opening (45) and a rear opening (44). The inner diameter of the front opening (45) is smaller than that of the rear opening (44). A double sealing lip (7) is fitted on the inner wall of the loading hole (43) in the central shaft of the sealing seat (4).

2. The type A anti-corrosion fan combined shaft seal structure according to claim 1, characterized in that, The edge of the sealing seat (4) is fixed to the rear side plate (2) of the housing by means of a gasket (3) with a stud (5) and a nut (6).

3. The type A anti-corrosion fan combined shaft seal structure according to claim 1, characterized in that, The central shaft hole of the sealing seat (4) is coaxially inserted from front to back to connect the impeller (9) of the fan to the central shaft hub (8), and the rear end of the shaft hub (8) has a hub shaft hole; a double sealing lip (7) is fitted between the inner wall of the central shaft hole of the sealing seat (4) and the shaft hub (8).

4. The type A anti-corrosion fan combined shaft seal structure according to claim 1, characterized in that, The drive shaft of the motor (10) is first inserted into the rear hub shaft hole of the sealing seat (4), i.e. the rear end hub shaft hole of the shaft disc hub (8).

5. The type A anti-corrosion fan combined shaft seal structure according to claim 1, characterized in that, The inner diameter of the front opening (45) of the seat is larger than the outer diameter of the shaft disc hub (8), and the difference between the inner diameter of the loading hole (43) of the sealing seat (4) and the outer diameter of the shaft disc hub (8) is close to the difference between the inner and outer diameters of the sealing lip (7).

6. The type A anti-corrosion fan combined shaft seal structure according to claim 1, characterized in that, The loading hole (43) of the sealing seat (4) is fitted with two sealing lips (7), which are single-lip sealing lips; or, the loading hole (43) of the sealing seat (4) is fitted with one sealing lip (7), which is double-lip sealing lip.

7. The type A anti-corrosion fan combined shaft seal structure according to claim 2, characterized in that, The rear side panel (2) of the housing is fixed with an anti-corrosion rubber coating (1).

8. The type A anti-corrosion fan combined shaft seal structure according to claim 6, characterized in that, The sealing lip (7) includes a lip shell (71), a front lip opening (72), a rear lip opening (73), a first lip opening (74), an inner support ring (75), and a bushing (76); The lip shell (71) is circular. A through hole is opened in the middle of the lip shell (71). The front and rear ends of the through hole are the front lip opening (72) and the back lip opening (73), respectively. The inner diameter of the front lip opening (72) is smaller than that of the back lip opening (73). That is, the front lip opening (72) extends out along the concentric annular constricted arc surface. The annular first lip opening (74) is attached to the inner side of the end face of the front lip opening (72). The inner diameter of the first lip opening (74) extends out along the constricted neck of the back lip opening (73). The inner support ring (75) is attached to the outer edge of the inner side of the first lip opening (74). The cross section of the inner support ring (75) is L-shaped. That is, the front part of the inner support ring (75) is attached to the inner wall of the back side of the first lip opening (74), and the rear part of the inner support ring (75) is attached to the inner wall of the back side of the first lip opening (74) and the inner wall of the rear section of the lip shell (71). A bushing (76) is inserted between the front part of the inner support ring (75) and the outer edge of the inner wall of the rear side of the first lip (74).

9. The type A anti-corrosion fan combined shaft seal structure according to claim 6, characterized in that, The sealing lip (7) includes a lip shell (71), a front lip opening (72), a rear lip opening (73), a first lip opening (74), an inner support ring (75), a liner ring (76), a second lip opening (77), and an isolation support ring (78); The lip shell (71) is circular, and a through hole is opened in the middle of the lip shell (71). The front and rear ends of the through hole are the front lip opening (72) and the back lip opening (73), respectively. The inner diameter of the front lip opening (72) is smaller than that of the back lip opening (73). That is, the front lip opening (72) extends outward from the concentric annular neck. The annular first lip opening (74) is attached to the inner side of the end face of the front lip opening (72). The inner diameter of the first lip opening (74) extends outward from the necked arc surface of the back lip opening (73). A second lip (77) is attached to the inner side of the first lip (74) by means of an isolation support ring (78) at intervals; the second lip (77) has the same structure as the first lip (74); an inner support ring (75) is attached to the outer edge of the inner side of the second lip (77), and the cross section of the inner support ring (75) is L-shaped, that is, the front part of the inner support ring (75) is attached to the inner wall of the rear side of the second lip (77), and the rear part of the inner support ring (75) is attached to the inner wall of the rear section of the lip shell (71) of the rear side of the first lip (74); a bushing ring (76) is placed between the outer edge of the contact surface between the front part of the inner support ring (75) and the inner wall of the rear side of the second lip (77).

10. The type A anti-corrosion fan combined shaft seal structure according to claim 6, characterized in that, The sealing lip (7) includes a lip shell (71), a front lip opening (72), a rear lip opening (73), a first lip opening (74), an inner support ring (75), a second lip opening (77), and an isolation support ring (78); The lip shell (71) is circular, and a through hole is opened in the middle of the lip shell (71). The front and rear ends of the through hole are the front lip opening (72) and the back lip opening (73), respectively. The inner diameter of the front lip opening (72) is smaller than that of the back lip opening (73). That is, the front lip opening (72) extends outward from the concentric annular neck. The annular first lip opening (74) is attached to the inner side of the end face of the front lip opening (72). The inner diameter of the first lip opening (74) extends outward from the concentric oblique conical surface of the back lip opening (73). The second lip (77) is attached to the inner side of the first lip (74) by means of an isolation support ring (78) at intervals; the second lip (77) has the same structure as the first lip (74); an inner support ring (75) is attached to the outer edge of the inner side of the second lip (77), and the cross section of the inner support ring (75) is L-shaped, that is, the front part of the inner support ring (75) is attached to the inner wall of the rear side of the second lip (77), and the rear part of the inner support ring (75) is attached to the inner wall of the rear section of the lip shell (71) of the first lip (74).

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