Simple mechanical seal for large pump

Abstract

The utility model provides a simple mechanical seal for a large pump, which is low in cost and high in operation stability. The sealing structure comprises a movable ring seat and a static ring seat, and the movable ring seat and the static ring seat are arranged on a water pump main shaft in a sleeving mode and are both annular pieces. The longitudinal section of the movable ring seat is T-shaped, an adjusting rod extending downwards is installed on the outer side of the top of the movable ring seat, the bottom of the adjusting rod is connected with the bottom of the movable ring friction pair, the longitudinal section of the adjusting rod is L-shaped, and the inner wall of the movable ring friction pair is tightly attached to the outer wall of the movable ring seat. The part, below the top of the movable ring seat, of the adjusting rod is provided with an adjusting nut in a threaded mode, and a compression spring is pressed between the bottom face of the adjusting nut and the top face of the bottom of the movable ring friction pair; the longitudinal section of the static ring seat is mountain-shaped, the bottom of the static ring seat is fixedly connected with the mounting seat, a gap is formed between the static ring seat and the water pump main shaft, the mounting seat is an annular piece, the longitudinal section of the mounting seat is L-shaped, and the mounting seat is mounted at the top end of the water pump shell; a static ring groove is formed in the middle of the static ring seat in a protruding mode, and a static ring friction pair is installed in the static ring groove.

Description

Technical Field

[0001] This utility model relates to the field of vertical pump technology, specifically a simple mechanical seal for large pumps. Background Technology

[0002] Pump shaft seal is an essential component of water pumps. Through the tight contact of the sealing end faces, it prevents the liquid inside the pump from leaking out axially, thus ensuring the pump's transport efficiency.

[0003] Existing water pumps use packing seals, such as Figure 1 As shown, a packing seal for a water pump includes a packing box 3 and a packing gland 4. The packing gland 4 covers the packing box 3. Both the packing box 3 and the packing gland 4 are annular components. The packing box 3 and the packing gland 4 are fitted onto a packing bushing 2. The packing bushing 2 is welded to the surface of the water pump main shaft 1. The bottom of the packing box 3 is fixedly installed on the water pump housing. The packing box 3 is filled with packing packing 5. The bottom end of the packing gland 4 is pressed into the packing box 3 to tighten the packing packing 5. The packing box 3 and the packing gland 4 are connected by an adjusting stud 8. A cooling water inlet 6 is provided on the side wall of the packing box 3, and the cooling water inlet 6 is connected to a water supply pipeline. A water seal ring 7 is provided inside the packing box 3. A leakage water groove is provided on the top of the packing box 3, and an overflow port 9 is provided on the groove wall.

[0004] During operation, the packing sleeve 2 rotates with the pump main shaft 1, generating friction with the packing packing 5. Cooling water is continuously supplied into the packing box 3 from the cooling water inlet 6, cooling the heat generated by friction and lubricating the packing packing 5. Excess water leaks from the top opening of the packing box 3 into the leakage water tank. By adjusting the adjusting stud 8, the pressure of the packing gland 4 pressing against the packing packing 5 can be changed, thereby altering the leakage rate of the cooling and lubricating water.

[0005] However, this type of packing seal, due to the friction between the packing gland and the pump shaft during operation, requires a packing bushing to protect the pump shaft during its construction. Since the shafts of medium and large pumps are typically forged as a single piece with flanged connections at both ends, quick-release packing bushings cannot be used; instead, the packing bushing is welded onto the surface of the pump shaft. To reduce friction, the material used in this type of packing seal must have the lowest possible surface roughness, often requiring grinding during manufacturing, which demands high precision and increases manufacturing costs. Furthermore, this type of pump packing seal necessitates frequent packing gland replacements and, after prolonged use, replacement of the packing bushing. Replacing the packing bushing involves peeling off the old bushing material and then welding a new layer of material, a time-consuming and labor-intensive process that further increases maintenance costs.

[0006] Furthermore, this type of water pump using a packing seal requires an external connection to cooling water and a cooling water supply pipeline. Cooling water is continuously supplied to the packing box throughout the entire operation for lubrication and cooling, increasing operating costs. At the same time, the additional external structure increases the overall complexity of the packing seal, leading to increased operational instability. Summary of the Invention

[0007] In view of the shortcomings of existing packing seals for water pumps, such as high manufacturing, operation and maintenance costs and low operational stability, this utility model provides a simple mechanical seal for large pumps, which has low cost and high operational stability.

[0008] A simple mechanical seal for large pumps is characterized by comprising a rotating ring seat and a stationary ring seat, both of which are fitted onto the pump's main shaft and are annular components. The rotating ring seat has a T-shaped longitudinal section, and an mounting ring is provided on the inner side of its top end. The mounting ring is fixedly connected to the main shaft by a locking anti-loosening component. A downwardly extending adjusting rod is installed on the outer side of the top end of the rotating ring seat, and the bottom of the adjusting rod is connected to the bottom of a rotating ring friction pair. The rotating ring friction pair is annular with an L-shaped longitudinal section, and its inner wall is in close contact with the outer wall of the rotating ring seat. An adjusting nut is threaded onto the portion of the adjusting rod below the top end of the rotating ring seat, and a compression spring is fitted onto the adjusting rod, pressing between the bottom surface of the adjusting nut and the top surface of the bottom of the rotating ring friction pair. The stationary ring seat has a mountain-shaped longitudinal section, and its bottom is fixedly connected to a mounting component. The mounting base has a gap between the stationary ring seat and the main shaft of the water pump. The mounting base is an annular component with an L-shaped longitudinal section and is installed on the top of the water pump housing. The central protrusion of the stationary ring seat divides it into an inner water inlet groove and an outer water inlet groove. The central protrusion of the stationary ring seat has a stationary ring groove, in which a stationary ring friction pair is installed. The stationary ring friction pair is an annular component, and the shapes of the stationary ring groove and the stationary ring friction pair are matched. The bottom surface of the moving ring friction pair contacts the top surface of the stationary ring friction pair. The inner side surface of the moving ring seat, the inner water inlet groove of the stationary ring seat, the side surface of the main shaft of the water pump, the inner side surface and bottom surface of the moving ring friction pair, the top surface of the stationary ring friction pair, and the top surface of the central protrusion of the stationary ring seat constitute a sealed water cavity. The bottom surface of the stationary ring seat, the inner side surface of the mounting base, and the side surface of the main shaft of the water pump constitute a pump water cavity. The pump water cavity is connected to the sealed water cavity.

[0009] Its further features are:

[0010] The bottom surface of the moving ring friction pair is an arc surface;

[0011] The bottom center of the stationary ring seat is threaded with a disassembly bolt that is screwed in from below, and the top surface of the disassembly bolt abuts against the bottom surface of the stationary ring friction pair;

[0012] A sealing ring is provided between the inner side of the moving ring friction pair and the outer side of the moving ring seat;

[0013] An overflow hole is provided on the outer wall of the outer water injection tank.

[0014] In the above-described structure of this utility model, the bottom surface of the rotating ring friction pair contacts the top surface of the stationary ring friction pair. The adjusting rod and the clamping spring mounted on it press the rotating ring friction pair and the stationary ring friction pair together, thus achieving a sealing effect. During operation, friction only occurs between the stationary ring friction pair and the rotating ring friction pair, avoiding friction between the packing and the pump shaft. This reduces operating and maintenance costs and improves operational stability by extending the service life of the pump shaft. When the mechanical seal experiences wear, if the wear is minor, the adjusting rod can be adjusted to make the rotating ring friction pair and the stationary ring friction pair fit more tightly, maintaining the sealing effect. If the wear is significant, replacing either the rotating ring friction pair or the stationary ring friction pair is quick and easy, reducing the number of parts replacements and eliminating the need to replace the entire mechanical seal, thereby reducing maintenance costs. During pump operation, some water from the pump enters the pump water chamber and then the sealing water chamber. A water film forms between the dynamic and static ring friction pairs, providing lubrication. Water in the sealing water chamber then leaks through the gap between the dynamic and static ring friction pairs into the outer water injection tank, carrying away the heat generated by friction and achieving a cooling effect. No additional water supply is required, eliminating the need for external cooling and lubrication water supply pipes. This simplifies the overall structure of the mechanical seal, saving manufacturing and operating costs while increasing operational stability. Because friction between the mechanical seal and the pump shaft is avoided, materials with higher surface roughness can be selected for both the sealing device and the pump shaft, eliminating the need for grinding and reducing manufacturing costs. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the existing technology;

[0016] Figure 2 This is a schematic diagram of the structure of this utility model. Detailed Implementation

[0017] See Figure 2A simple mechanical seal for a large pump includes a rotating ring seat 10 and a stationary ring seat 11, which are fitted onto the pump main shaft 1. Both the rotating ring seat 10 and the stationary ring seat 11 are annular components. The rotating ring seat 10 has a T-shaped longitudinal section. An installation ring 26 is provided on the inner side of the top of the rotating ring seat 10. The installation ring 26 is fixedly connected to the main shaft by a locking anti-loosening component 13. An adjusting rod 12 extending downward is installed on the outer side of the top of the rotating ring seat 10. The bottom of the adjusting rod 12 is connected to the bottom of the rotating ring friction pair 15. The rotating ring friction pair 15 is an annular component with an L-shaped longitudinal section. The inner wall of the rotating ring friction pair 15 is in close contact with the outer wall of the rotating ring seat 10. An adjusting nut 20 is threadedly installed on the part of the adjusting rod 12 below the top of the rotating ring seat 10. A compression spring 14 is fitted on the adjusting rod 12. The compression spring 14 is pressed between the bottom surface of the adjusting nut 20 and the bottom and top surfaces of the rotating ring friction pair 15. The longitudinal section of the stationary ring seat 11 is mountain-shaped, and the mounting seat 17 is fixedly connected to its bottom. There is a gap between the stationary ring seat 11 and the water pump main shaft 1. The mounting seat 17 is a ring-shaped part with an L-shaped longitudinal section. The mounting seat 17 is installed on the top of the water pump housing 18. The central protrusion of the stationary ring seat 11 divides the stationary ring seat 11 into an inner water injection groove 24 and an outer water injection groove 23. An overflow hole 19 is opened on the outer side wall of the outer water injection groove 23.

[0018] The stationary ring seat 11 has a stationary ring groove protruding in the middle, and a stationary ring friction pair 16 is installed in the stationary ring groove. The stationary ring friction pair 16 is an annular part, and the stationary ring groove and the stationary ring friction pair 16 are matched in shape. The bottom surface of the moving ring friction pair 15 is in contact with the top surface of the stationary ring friction pair 16. The inner side of the moving ring seat 10, the inner water injection groove 24 of the stationary ring seat 11, the side of the water pump main shaft 1, the inner side and bottom surface of the moving ring friction pair 15, the top surface of the stationary ring friction pair 16, and the top surface of the central protrusion of the stationary ring seat 11 constitute a sealed water cavity 21. The bottom surface of the stationary ring seat 11, the inner side of the mounting seat 17, and the side of the water pump main shaft 1 constitute a pump water cavity 22. The pump water cavity 22 is connected to the sealed water cavity 21.

[0019] The bottom surface of the moving ring friction pair 15 is an arc surface, which can reduce the contact area between the moving ring friction pair 15 and the stationary ring friction pair 16, thereby reducing friction.

[0020] The bottom center of the stationary ring seat 11 is threaded with a disassembly bolt 27 that is screwed in from below. The top surface of the disassembly bolt 27 abuts against the bottom surface of the stationary ring friction pair 16 for quick disassembly of the stationary ring friction pair 16.

[0021] A sealing ring 25 is provided between the inner side of the rotating ring friction pair 15 and the outer side of the rotating ring seat 10 to provide the sealing performance of the mechanical seal.

[0022] Before operation, check whether the water in the outer water tank 23 and the inner water tank 24 has reached the specified water level. If the water level is not reached, add water to the outer water tank 23 and the inner water tank 24 until the specified water level is reached to prevent the mechanical seal from running dry before sufficient lubricating water is pumped in. During operation, part of the water pumped up will enter the sealing water chamber 21, and a water film will form between the dynamic ring friction pair 15 and the stationary ring friction pair 16 to achieve a sealing and lubrication effect. No additional water needs to be added during the entire operation.

[0023] There is a pressure difference between the inner and outer sides of the moving ring friction pair 15 and the stationary ring friction pair 16, which will cause a small amount of water leakage. This small amount of water leakage can carry away the heat generated by the friction between the moving ring friction pair 15 and the stationary ring friction pair 16, preventing the equipment from overheating. By rotating the adjusting nut 20, the pressure of the clamping spring 14 can be adjusted, thereby changing the size of the small gap between the moving ring friction pair 15 and the stationary ring friction pair 16, thus regulating the leakage rate of the lubricating cooling water. After the leaked water reaches a certain amount, it will be discharged from the overflow hole 19.

[0024] During operation, the rotating ring friction pair 15 rotates together with the water pump main shaft 1. After long-term operation, wear may occur on either the rotating ring friction pair 15 or the stationary ring friction pair 16. When the wear is minor, the adjusting nut 20 can be moved down to increase the pressure of the compression spring 14, thereby making the rotating ring friction pair 15 and the stationary ring friction pair 16 fit more tightly and maintain the sealing effect. When the wear is significant, the rotating ring friction pair 15 and the stationary ring friction pair 16 need to be replaced. To replace the rotating ring friction pair 15, simply unscrew the bottom of the adjusting rod 12 from inside the rotating ring friction pair 15, remove the worn rotating ring friction pair 15, place the bottom surface of the new rotating ring friction pair 15 against the top surface of the stationary ring friction pair 16, and place the inner side against the outer side of the rotating ring seat 10. Then screw the adjusting rod 12 into the new rotating ring friction pair 15. Finally, adjust the compression spring 14 to the appropriate tightness using the adjusting nut 20 to complete the replacement. To replace the stationary ring friction pair 16, remove the rotating ring friction pair 15. Then, tighten the disassembly bolt 27 upwards to push the stationary ring friction pair 16 out of the stationary ring groove, thus removing the worn stationary ring friction pair 16. Next, place the new stationary ring friction pair 16 into the stationary ring groove, tighten the disassembly bolt 27 back to its original position, and reinstall the rotating ring friction pair 15. This completes the replacement of the stationary ring friction pair 16. The replacement method for the rotating ring friction pair 15 and the stationary ring friction pair 16 is simple and quick.

Claims

1. A simple mechanical seal for large pumps, characterized by: It includes dynamic ring seat and static ring seat, the dynamic ring seat and the static ring seat are sleeved on water pump main shaft, and the dynamic ring seat and the static ring seat are annular pieces;The longitudinal section of the dynamic ring seat is T-shaped, the inner side of the top end of the dynamic ring seat is provided with a mounting ring, the mounting ring is fixedly connected with the main shaft through a locking anti-loose piece, the top outer side of the dynamic ring seat is provided with a downward extending adjusting rod, the bottom of the adjusting rod is connected with the bottom of the dynamic ring friction pair, the dynamic ring friction pair is an annular piece, and the longitudinal section thereof is L-shaped, and the inner wall of the dynamic ring friction pair is tightly attached to the outer wall of the dynamic ring seat;The part of the adjusting rod below the top of the dynamic ring seat is screw-mounted with an adjusting nut, the adjusting rod is sleeved with a compression spring, and the compression spring is pressed between the bottom surface of the adjusting nut and the top surface of the bottom of the dynamic ring friction pair;The longitudinal section of the static ring seat is mountain-shaped, and the bottom of the static ring seat is fixedly connected with a mounting seat, there is a gap between the static ring seat and the water pump main shaft, the mounting seat is an annular piece, and the longitudinal section thereof is L-shaped, and the mounting seat is mounted on the top end of the water pump housing;The middle part of the static ring seat is protruded to divide the static ring seat into an inner water injection groove and an outer water injection groove, the middle part of the static ring seat is provided with a static ring groove, the static ring groove is provided with a static ring friction pair, the static ring friction pair is an annular piece, and the shape of the static ring groove and the static ring friction pair is matched;The bottom surface of the dynamic ring friction pair is in contact with the top surface of the static ring friction pair;The inner side surface of the dynamic ring seat, the inner water injection groove of the static ring seat, the side surface of the water pump main shaft, the inner side surface and the bottom surface of the dynamic ring friction pair, the top surface of the static ring friction pair and the top surface of the middle part of the static ring seat form a sealing water cavity;The bottom surface of the static ring seat, the inner side surface of the mounting seat and the side surface of the water pump main shaft form a pump water cavity;The pump water cavity is communicated with the sealing water cavity.

2. A simple mechanical seal for large pumps according to claim 1, characterized in that: The bottom surface of the dynamic ring friction pair is an arc surface.

3. A simple mechanical seal for large pumps according to claim 1 or 2, characterized in that: The bottom of the static ring seat is screw-mounted with a dismounting bolt from below, and the top surface of the dismounting bolt is in abutment with the bottom surface of the static ring friction pair.

4. A simple mechanical seal for large pumps according to claim 1 or 2, characterized in that: A sealing ring is arranged between the inner side surface of the dynamic ring friction pair and the outer side surface of the dynamic ring seat.

5. A simple mechanical seal for large pumps according to claim 1 or 2, characterized in that: An overflow hole is formed in the outer side wall of the outer water injection groove.

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