Anti-corrosion mechanical seal

Abstract

The utility model relates to an anti-corrosion mechanical seal which comprises a rotating shaft, a shaft sleeve, a bearing, a sealing box body, a flange, a sealing structure and a gland, the shaft sleeve is rotatably installed in the sealing box body through the bearing, the sealing structure, the rotating shaft and the shaft sleeve are all located in the sealing box body, the flange is located below the sealing box body, fluororubber is installed at the bottom of the flange, and the gland is located above the sealing box body. The fixing bolt is inserted into the sealing box body and is in threaded fit with the flange, the flange is provided with a mounting groove corresponding to the fluororubber, the fluororubber comprises a first connecting section, a second connecting section and a third connecting section which are sequentially arranged from top to bottom, the diameter of the first connecting section is the same as that of the third connecting section, and the diameter of the second connecting section is smaller than that of the third connecting section; a plurality of positioning insertion blocks are arranged upwards in the circumferential direction of the third connecting section, and positioning insertion grooves are formed in the positions, corresponding to the positioning insertion blocks, of the flange. By the adoption of the scheme, the anti-corrosion mechanical seal enables the fluororubber to be stably located at the bottom of the flange through the positioning insertion block.

Description

Technical Field

[0001] This utility model relates to the field of mechanical seals, and in particular to a corrosion-resistant mechanical seal. Background Technology

[0002] Because the drive shaft runs through both the inside and outside of the equipment, there is a circumferential gap between the shaft and the equipment. The medium in the equipment leaks outward through this gap. If the pressure inside the equipment is lower than atmospheric pressure, air leaks into the equipment. Therefore, a shaft sealing device is necessary to prevent leakage. A mechanical seal is an oil seal device for rotating machinery. It relies on the close contact of two precision-ground surfaces of the rotating ring and the stationary ring to prevent medium leakage. The rotating ring rotates with the shaft, while the stationary ring is fixed to the pump casing or other fixed components. To ensure that the end faces between the rotating and stationary rings are always in close contact, elastic elements such as springs or bellows are usually used to apply a pressure towards the rotating ring to the stationary ring. When the flange is fixed to the equipment to complete the mechanical seal, if the shaft is connected to the reactor, acid or alkali solutions may fall into the connection between the flange and the reactor shell during the stirring process, causing corrosion of the flange.

[0003] Chinese Patent No. CN201920856034.9 discloses a mechanical seal with anti-corrosion function, which achieves anti-corrosion by sleeved fluororubber on the positioning block at the bottom of the flange. The direct sleeve method usually relies on the elasticity of the fluororubber itself and the shape of the flange to maintain the position of the seal. The tightening force provided by this method is relatively small, and it may loosen under conditions such as high-speed rotation of the shaft, vibration between the shaft and the equipment, and impact. Therefore, how to improve the connection strength between fluororubber and the flange has become an urgent problem to be solved by those skilled in the art. Summary of the Invention

[0004] In view of the shortcomings of the existing technology, the purpose of this utility model is to provide a corrosion-resistant mechanical seal that uses a positioning block to stably position fluororubber at the bottom of the flange.

[0005] To achieve the above objectives, this utility model provides the following technical solution: It includes a rotating shaft, a bushing, a bearing, a sealing housing, a flange, a sealing structure, and a pressure cap. The rotating shaft extends axially up and down. The bushing is rotatably mounted on the sealing housing via the bearing. The sealing structure, rotating shaft, and bushing are all located within the sealing housing. The flange is located below the sealing housing and has fluororubber installed at its bottom. The pressure cap is located above the sealing housing. It also includes fixing bolts, which are inserted into the sealing housing and threaded with the flange. The flange has an installation groove corresponding to the fluororubber. The fluororubber includes a first connecting section, a second connecting section, and a third connecting section from top to bottom. The first and third connecting sections have the same diameter, while the second connecting section has a smaller diameter than both the first and third connecting sections. A sealing section fitted with the second connecting section is provided inside the flange. The third connecting section has several positioning blocks arranged circumferentially upwards. A positioning slot is provided on the flange corresponding to each positioning block.

[0006] The present invention is further configured such that: each positioning block is provided with an inwardly recessed limiting slot, and the flange is provided with a limiting block in the corresponding positioning slot.

[0007] The present invention is further configured to include a first sealing ring and a second sealing ring, wherein the fluororubber also includes a mating groove located between the first connecting section and the third connecting section, the first sealing ring is located in the mating groove and its upper and lower end faces abut against the first connecting section and the third connecting section respectively, while its outer end face abuts against the flange, and the second sealing ring is located between the rotating shaft and the third connecting section.

[0008] The present invention is further configured to include a bushing seat located below the pressure cap, the bushing seat being located above the bushing, and the pressure cap being located above the bushing seat and detachably connected to the bushing seat.

[0009] The present invention is further configured to include a connecting bolt located between the bushing seat and the pressure cap, wherein the connecting bolt is inserted into the pressure cap and threadedly connected to the bushing seat.

[0010] The present invention is further configured such that: the pressure cap includes an insertion section for inserting a bushing seat, the insertion section being a cone-shaped part extending radially inward from top to bottom, and the bushing seat having an insertion groove, the shape and size of which are the same as those of the insertion section.

[0011] The present invention is further provided with a lifting ring at the top of the sealed box.

[0012] By adopting the above technical solution, 1. the connection between the flange and the sealing housing can be achieved by installing the fixing bolts between the flange and the sealing housing; 2. when the fluororubber is installed into the mounting groove, since the diameter of the second connecting section is smaller than the diameter of the first and third connecting sections, and the flange is provided with a sealing section that fits the second connecting section, the first connecting section that first enters the mounting groove needs to be forcibly squeezed past the sealing section to achieve the cooperation between the sealing section and the second connecting section. After the fluororubber is placed in the mounting groove, the second connecting section cannot move down due to the action of the sealing section, which in turn prevents the first connecting section from moving down and keeps it stably in the mounting groove, thus facilitating the cooperation between the positioning insert and the positioning slot; 3. after the fluororubber is stably installed below the flange, as the motor starts and drives the shaft to rotate, the splashed acid and alkali will come into contact with the third connecting section of the fluororubber. Because the diameter of the third connecting section is larger than that of the second connecting section, the occurrence of it continuing to enter the mechanical seal from the top is reduced; 4. the cooperation between the positioning insert and the positioning slot further improves the connection stability between the fluororubber and the flange. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1 This is a cross-sectional view of a specific embodiment of the present utility model;

[0015] Figure 2 for Figure 1 Enlarged view of A in the middle;

[0016] Figure 3 for Figure 1 Enlarged view of B in the middle;

[0017] Figure 4 for Figure 1 Enlarged view of C;

[0018] Figure 5 for Figure 1 A magnified view of D.

[0019] In the diagram: 1-Shaft, 2-Sleeve, 3-Bearing, 4-Sealing housing, 5-Flange, 6-Sealing structure, 7-Gland, 8-Fluororubber, 9-Fixing bolt, 10-Mounting groove, 11-First connecting section, 12-Second connecting section, 13-Third connecting section, 14-Positioning block, 15-Positioning slot, 16-Limiting slot, 17-Limiting block, 18-First sealing ring, 19-Sealing section, 20-Insertion groove, 21-Sleeve seat, 22-Connecting bolt, 23-Insertion section, 24-Lifting ring, 25-Upper moving ring, 26-Lower moving ring, 27-Upper stationary ring, 28-Lower stationary ring, 29-Upper compensating spring, 30-Lower compensating spring, 31-Spring seat. Detailed Implementation

[0020] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0021] like Figures 1-5As shown, this utility model discloses a corrosion-resistant mechanical seal, including a rotating shaft 1 whose top is fixed to a power output component such as a motor (not shown in the figure), a mechanism such as an impeller and fan blades (which is prior art and will not be described in detail here) typically mounted at the end of the rotating shaft 1, a bushing 2, a bearing 3, a sealing housing 4, a flange 5, a sealing structure 6, and a pressure cap 7. The sealing structure 6 includes a spring seat 31 fixedly connected to the bushing 2. The spring seat 31 is connected to an upper moving ring 25 via an upper compensating spring 29 and to a lower moving ring 26 via a lower compensating spring 30. The upper moving ring 25 and the lower moving ring 26 cannot rotate relative to the spring seat 3. The upper stationary ring 27 is fixedly connected to the sealing housing 4, and the lower stationary ring 28 is fixedly connected to the flange 5. Therefore, with With the high-speed rotation of the rotating shaft 1, the bushing 2, which is interference-fitted with the rotating shaft 1, can drive the spring seat 31 to rotate. Since one end of the upper compensating spring 29 is connected to the upper moving ring 25, and the lower compensating spring 30 is connected to the lower moving ring 26, the rotation of the upper moving ring 25 and the lower moving ring 26 is synchronized with that of the rotating shaft 1, meaning they can rotate relative to the upper stationary ring 27 and the lower stationary ring 28. Simultaneously, one end of the upper moving ring 25 is in contact with the upper stationary ring 27, and one end of the lower moving ring 26 is in contact with the lower stationary ring 28, achieving dynamic sealing (this is existing technology and will not be described in detail here). The rotating shaft 1 extends axially up and down, and the bushing 2 is rotatably mounted on the sealing housing 4 via the bearing 3. The sealing structure 6, the rotating shaft 1, and the bushing 2 are all located within the sealing housing 4. Flange 5 is located below the sealing housing 4 and has fluororubber 8 installed at its bottom. The gland 7 is located above the sealing housing 4 (this is prior art and will not be described in detail here). Since the mechanical seal is installed above the equipment, the bottom of flange 5 will abut against the top of the equipment. If the equipment is a reactor or similar vessel containing acid or alkaline solutions, and the motor is started to engage with the rotating shaft 1, the acid or alkaline solution may rise and enter the contact surface between flange 5 and the equipment as the shaft 1 rotates. Because fluororubber 8 is located at the bottom of flange 5 and has excellent corrosion resistance, the upward-splashing liquid will contact fluororubber 8, thus reducing the possibility of corrosion to the mechanical seal. The system also includes fixing bolts 9. Bolt 9 is inserted into the sealing housing 4 and threaded into the flange 5. The flange 5 has an installation groove 10 corresponding to the fluororubber 8. The fluororubber 8 includes a first connecting section 11, a second connecting section 12, and a third connecting section 13 from top to bottom. The first connecting section 11 and the third connecting section 13 have the same diameter, while the diameter of the second connecting section 12 is smaller than that of the third connecting section 13. The third connecting section 13 has several positioning blocks 14 arranged circumferentially upward. The flange 5 has a positioning slot 15 corresponding to each positioning block 14 and a sealing section 19 that fits onto the second connecting section 12. 1. The connection between the flange 5 and the sealing housing 4 can be achieved by inserting the fixing bolt 9 between the flange 5 and the sealing housing 4; 2.When the fluororubber 8 is inserted into the mounting groove 10, since the diameter of the second connecting section 12 is smaller than the diameters of the first connecting section 11 and the third connecting section 13, and the flange 5 has a sealing section 19 fitted over the second connecting section 12, the first connecting section 11, which enters the mounting groove 10 first, needs to be forcibly squeezed past the sealing section 19 to achieve the fit between the sealing section 19 and the second connecting section 12. After the fluororubber 8 is placed in the mounting groove 10, the second connecting section 12 cannot move down due to the action of the sealing section 19, thus preventing the first connecting section 11 from moving down as well. The downward movement allows the fluororubber 8 to be stably positioned within the mounting groove 10, facilitating the engagement of the positioning insert 14 and the positioning slot 15; 3. After the fluororubber 8 is stably installed below the flange 5, as the motor starts and drives the rotating shaft 1 to rotate, the splashed acid and alkali will contact the third connecting section 13 of the fluororubber 8 upwards. Because the diameter of the third connecting section 13 is larger than that of the second connecting section 12, the likelihood of it continuing to enter the mechanical seal upwards is reduced; 4. The engagement of the positioning insert 14 and the positioning slot 15 further improves the connection stability between the fluororubber 8 and the flange 5.

[0022] Preferably, each positioning block 14 is provided with an inwardly recessed limiting slot 16, and each flange 5 is provided with a limiting block 17 within its corresponding positioning slot 15. Due to the presence of the limiting slot 16 on each positioning block 14, when the fluororubber 8 enters the mounting groove 10 and the positioning block 14 on the third connecting section 13 enters the corresponding positioning slot 15, the presence of the limiting blocks 17 means that the top of each positioning block 14 must forcibly pass over the corresponding limiting block 17 during its entry into the corresponding positioning slot 15, thus allowing the positioning block 14 to connect with the positioning slot 15. Under the action of external force, each positioning block 14 can be stably positioned in the corresponding positioning slot 15, thereby further improving the connection strength between the fluororubber 8 and the flange 5. When it is necessary to remove the fluororubber 8 from the flange 5, a downward force is applied to the third connecting section 13, thereby causing the portion of each positioning block 14 above the corresponding limiting block 17 to move downward and pass over the corresponding limiting block 17, thus achieving the cooperation between each positioning block 14 and the positioning slot 15. At this time, as the third connecting section 13 moves downward, it can cause the second connecting section 12 and the first connecting section 11 to separate from the mounting groove 10. When the first connecting section 11 passes over the sealing section 19, the fluororubber 8 can be completely removed from the flange 5.

[0023] It also includes a first sealing ring 18, which is located between the rotating shaft 1 and the third connecting section 13. The first sealing ring 18 is set so that when the rotating shaft 1 rotates at high speed and causes the acidic and alkaline liquids in the reactor to splash and move upward, they can be restricted by the first sealing ring 18 and cannot enter the mechanical seal through the connection position between the flange 5 and the rotating shaft 1, thereby improving the sealing performance of the mechanical seal.

[0024] The system also includes a bushing seat 21 located below the gland 7. The bushing seat 21 is located above the bushing 2, and the gland 7 is located on top of the bushing seat 21 and is detachably connected to the bushing seat 21 by bolts, clips, or other means. 1. Since the gland 7 can be detachably connected to the bushing seat 21, when maintenance or replacement of the seal is required, only the gland 7 needs to be removed to access the internal components without disassembling the entire device. 2. The gland 7 can fix the various components of the mechanical seal together and provide physical protection to prevent external impurities from entering the mechanical seal from above, while also reducing the possibility of media leakage when the inside is facing upwards.

[0025] It also includes a connecting bolt 22 located between the bushing seat 21 and the cover 7. The connecting bolt 22 is inserted into the cover 7 and threadedly connected to the bushing seat 21. The connection between the cover 7 and the bushing seat 21 is achieved by the connecting bolt 22, which provides a simple and effective assembly method, making the assembly and disassembly process more convenient, which is conducive to improving work efficiency and reducing maintenance costs.

[0026] The pressure cap 7 includes an insertion section 23 for inserting the bushing seat 21. The insertion section 23 is tapered from top to bottom and radially inward. The bushing seat 21 is provided with an insertion groove 20. The shape and size of the insertion groove 20 are the same as those of the insertion section 23. The tapered design of the insertion section 23 of the pressure cap 7 ensures that when the pressure cap 7 is inserted into the bushing seat 21, the bottom of the insertion section 23, which is the smallest in diameter, will first enter the bottom of the insertion groove 20, which is the largest in diameter. This facilitates the alignment of the bushing seat 21 and the insertion section 23. After the insertion section 23 is completely placed in the insertion groove 20, it facilitates the subsequent insertion of the connecting bolt 22.

[0027] In addition, a lifting ring 24 is provided on the top of the sealing housing 4. The lifting ring 24 provides a convenient and safe way to move the mechanical seal as a whole. Especially when dealing with larger and heavier sealing devices, the use of the lifting ring 24 can ensure that the equipment can be lifted and transported smoothly by cranes, electric hoists or other lifting equipment, reducing the risks that may be caused by manual handling.

[0028] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A corrosion-resistant mechanical seal, comprising a rotating shaft, a bushing, a bearing, a sealing housing, a flange, a sealing structure, and a gland, wherein the rotating shaft extends axially vertically, the bushing is rotatably mounted on the sealing housing via the bearing, the sealing structure, the rotating shaft, and the bushing are all located within the sealing housing, the flange is located below the sealing housing and has fluororubber installed at its bottom, and the gland is located above the sealing housing, characterized in that: It also includes fixing bolts, which are inserted into the sealing housing and threaded with the flange. The flange has an installation groove corresponding to the fluororubber. The fluororubber includes a first connecting section, a second connecting section, and a third connecting section from top to bottom. The first connecting section and the third connecting section have the same diameter. The diameter of the second connecting section is smaller than the diameters of the first connecting section and the third connecting section. A sealing section fitted with the second connecting section is provided inside the flange. The third connecting section has several positioning blocks arranged circumferentially upward. The flange has positioning slots corresponding to each positioning block.

2. The corrosion-resistant mechanical seal according to claim 1, characterized in that: Each positioning block is provided with an inwardly recessed limiting slot, and each flange is provided with a limiting block in its corresponding positioning slot.

3. A corrosion-resistant mechanical seal according to claim 1 or 2, characterized in that: It also includes a first sealing ring, which is located between the rotating shaft and the third connecting section.

4. The corrosion-resistant mechanical seal according to claim 1, characterized in that: It also includes a bushing seat located below the pressure cap, the bushing seat being located above the bushing, and the pressure cap being located on the bushing seat and detachably connected to the bushing seat.

5. The corrosion-resistant mechanical seal according to claim 4, characterized in that: It also includes a connecting bolt located between the bushing seat and the gland, the connecting bolt being inserted into the gland and threadedly connected to the bushing seat.

6. The corrosion-resistant mechanical seal according to claim 4, characterized in that: The pressure cap includes an insertion section for inserting a bushing seat. The insertion section is a cone-shaped structure that extends from top to bottom and radially inward. The bushing seat is provided with an insertion groove, the shape and size of which are the same as those of the insertion section.

7. The corrosion-resistant mechanical seal according to claim 1, characterized in that: A lifting ring is provided at the top of the sealed box.

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