Variable ratio mechanical seal

Abstract

The utility model relates to mechanical seal technical field, and disclose variable ratio pressure's mechanical seal, including pivot and main static ring, the pivot outside fixed mounting has the shaft sleeve, the main static ring one side is provided with the driving ring, the shaft sleeve side fixed mounting has spring seat, the spring seat inside is provided with screw, spring no.

Description

Technical Field

[0001] This utility model relates to the field of mechanical seal technology, specifically to a mechanical seal with variable specific pressure. Background Technology

[0002] Mechanical seals, also known as end face seals, are devices that prevent working fluid from leaking along a rotating shaft. They consist of at least one pair of end faces perpendicular to the axis of rotation, which remain in contact and slide relative to each other under the action of the elastic force of the compensation mechanism and the cooperation of the auxiliary seal. The basic components of a mechanical seal are: end face sealing pair, elastic element, auxiliary seal, and transmission mechanism. It is an indispensable part of the sealing field today.

[0003] Chinese Invention Patent Publication No. CN109185221A discloses a variable balance diameter, spring-protected double-end-face mechanical seal. This seal features a balance sleeve and a set of compensating springs to compensate for both the medium-side and atmospheric-side mechanical seals. As pressure conditions change, the balance sleeve can switch the balance diameter position of the medium-side mechanical seal, maintaining a reasonable balance coefficient on the end face. However, this variable balance diameter, spring-protected double-end-face mechanical seal does not fix the sliding diameter of the mechanical seal, making the atmospheric-side seal susceptible to significant stress and pressure variations. Furthermore, the seal lacks a balance conversion boss, hindering easy switching between different operating conditions and making it difficult for the sealing ring to adapt to various conditions and switch freely between them. Summary of the Invention

[0004] The technical problem to be solved by this utility model is to provide a mechanical seal with variable specific pressure. It can effectively solve the problems in the prior art where the sliding diameter of the mechanical seal is fixed, which makes the atmospheric side seal subject to greater stress and pressure. It also solves the problems of not setting a balance conversion boss, which makes it inconvenient to switch between different conditions, and it is not convenient for the sealing ring surface to adapt to various working conditions and switch freely between different working conditions.

[0005] The technical solution adopted in this utility model is: a variable specific pressure mechanical seal, including a rotating shaft, a main stationary ring, and a medium side. A bushing is fixedly installed on the outer side of the rotating shaft. A driving ring is provided on one side of the main stationary ring. A spring seat is provided on one side of the bushing. A screw is provided on the inner side of the spring seat. A spring is provided on the inner side of the spring seat. The spring passes through the spring seat and is fixedly installed with the auxiliary driving ring. The other end of the spring away from the auxiliary driving ring abuts against the driving ring. An O-ring is fixedly installed on the outer side of the bushing. An auxiliary driving ring is provided on the outer side of the bushing. An auxiliary stationary ring is fixedly installed on one side of the auxiliary driving ring. A flange is fixedly installed on one side of the bushing. A positioning clip is fixedly installed on one side of the flange. A plug is provided on the inner side of the flange. A sealing ring is provided on the outer side of the flange. A fixing bolt is fixedly installed on one side of the flange. An outlet is opened on the outer side of the bushing. An inlet is opened on the outer side of the bushing. A drain port is opened on the outer side of the bushing. A groove is opened on the end of the bushing near the screw. The spring seat abuts against the bushing through the screw.

[0006] Preferably, the bushing is fixedly mounted with a main stationary ring, and an O-ring two is fixedly mounted on one side of the main stationary ring, the O-ring two being located between the main stationary ring and the flange.

[0007] The above technical solution effectively fills the tiny gap between the main stationary ring and the flange by setting the O-ring 2, preventing fluid leakage at the connection between the two, thereby improving the sealing performance of the entire device. In addition, the O-ring 2 plays a role in buffering and supporting, reducing the relative displacement between the main stationary ring and the flange caused by vibration or pressure changes during operation.

[0008] Preferably, a retaining ring is snapped onto one side of the main stationary ring, and two identical O-rings are provided, with the two O-rings being equidistant from the main stationary ring.

[0009] The above technical solution, through the design of two O-rings, can further improve the sealing effect. Furthermore, the two O-rings working together can more comprehensively block the leakage path of fluid and enhance the reliability of the seal.

[0010] Preferably, the outlet, inlet, and drain port are connected, and the outlet, inlet, and drain port are connected to the cooling water side.

[0011] The above technical solution, with its interconnected outlet, inlet, and drain port, allows for smoother circulation of cooling water within the system. This interconnected design reduces flow resistance, improves cooling water flow efficiency, enhances the cooling effect, and contributes to uniform cooling. The cooling water can be more evenly distributed across the areas requiring cooling, preventing localized overheating or undercooling.

[0012] Preferably, an O-ring three is provided on one side of the active ring, a main push ring is provided on the main stationary ring, a balance conversion boss is fixedly installed on one side of the main push ring, and the O-ring three is slidably connected to the bushing.

[0013] Through the above technical solution, the setting of O-ring three helps to form a good seal between the active ring and other components, preventing fluid leakage. In addition, the sliding diameter of O-ring three and the bushing is constant, and the atmospheric mechanical seal is balanced. The atmospheric seal is less affected by force and pressure and is always in a closed state.

[0014] Preferably, an O-ring is fixedly installed on one side of the bushing, and the O-ring is located between the bushing and the rotating shaft.

[0015] The above technical solution, through the design of O-ring 1, can effectively enhance the sealing between the bushing and the shaft, and prevent leakage between the bushing and the shaft, thus affecting normal use.

[0016] Preferably, a bolt one is provided on the outside of the positioning clip, and a bolt two is fixedly installed on the outside of the positioning clip. The bolt one and the bolt two penetrate the flange and extend into the interior of the positioning clip.

[0017] By using the above technical solution, bolts one and two penetrate the flange and extend into the interior of the positioning clip, a more secure fixation can be provided for the connection between the positioning clip and the flange, ensuring that the positioning clip will not easily loosen or fall off when the equipment is running or subjected to external forces, thereby maintaining the stability of the system.

[0018] Preferably, there are multiple identical bolts one and bolt two, and the multiple bolts one and bolt two are distributed in a ring about the center line of the rotating shaft.

[0019] The above technical solution, through the design of multiple bolts one and bolt two, can effectively improve the stability between the flange and the positioning clip, and prevent them from falling off.

[0020] Preferably, the fixing bolt 2 penetrates the flange and extends to its outer side, and an O-ring 5 is fixedly installed on the outer side of the auxiliary stationary ring.

[0021] Through the above technical solution, the O-ring five fixedly installed on the outside of the auxiliary stationary ring can play a good sealing role. The O-ring five is elastic and can fill the tiny gaps between the auxiliary stationary ring and other components to prevent fluid or gas leakage, thereby ensuring the sealing performance of the system and avoiding media leakage.

[0022] Preferably, the sealing ring surface area is: Refers to the narrower outer diameter of the sealing end face With inner diameter The area of ​​the annular region between the two sealing surfaces is the effective contact area with the other sealing end face.

[0023] =

[0024] Spring pressure ratio: The elastic force generated by the spring itself when it is at its working height. The force applied per unit area of ​​the sealing ring.

[0025] =

[0026] In the formula The elastic force of a spring when it is at its working height.

[0027] Effective area of ​​sealed fluid pressure The effective area of ​​the sealing fluid pressure acting on the compensation ring, causing it to tend to close around the non-compensation ring.

[0028] =

[0029] =

[0030] In the formula Sliding diameter refers to the diameter of the shaft (or bushing) at the auxiliary sealing ring of the compensating ring where the sealing fluid pressure is applied.

[0031] Sealing fluid pressure action specific pressure This refers to the force exerted by the sealing fluid pressure on a unit area of ​​the sealing ring.

[0032] = In the formula Sealing fluid pressure refers to the pressure difference between the fluid inside and outside the mechanical seal.

[0033] = - In the formula Fluid pressure on the high-pressure side of the mechanical seal Fluid pressure on the low-pressure side of the mechanical seal

[0034] Load factor The effective area of ​​the sealing fluid pressure acting on the compensating ring, causing it to tend to close relative to the non-compensating ring, is equal to the sealing ring area. The ratio.

[0035] =

[0036] when When ≥1, that is ≥ A mechanical seal is called an unbalanced mechanical seal when the area of ​​the sealing fluid pressure is greater than or equal to the area of ​​the sealing ring (bearing area).

[0037] when When <1, that is < When the area of ​​the sealing fluid pressure is smaller than the area of ​​the sealing ring (bearing area), it is called a balanced mechanical seal.

[0038] Mean fluid membrane pressure The average pressure of the fluid membrane between the sealed end faces.

[0039] =

[0040] In the formula : Fluid film pressure at the sealed end face at radius r

[0041] back pressure coefficient The average pressure of the fluid film between the sealed end faces With sealing fluid pressure The ratio;

[0042] =

[0043] Regarding water, =0.5 ,Right now =0.5;

[0044] Closing force Refers to the pressure of the sealed fluid and spring elasticity Forces such as these act on the compensating ring, causing it to tend to close relative to the uncompensated ring.

[0045] = +

[0046] Opening force This refers to the force acting on the compensation ring that tends to open it relative to the non-compensation ring.

[0047] =

[0048] Cross-sectional pressure This refers to the net closing force per unit area acting on the sealing ring.

[0049] = = +

[0050] Compared with the prior art, this utility model provides a mechanical seal with variable specific pressure, which has the following advantages:

[0051] 1. By calculating the parameters of the sealing ring surface and setting a balance conversion boss on the mechanical seal bushing, the main end seal can switch between state 1 and state 2, allowing the sealing ring surface to adapt to various working conditions and switch freely in various working conditions, so that the sealing ring surface is always in a closed state.

[0052] 2. In this variable pressure mechanical seal, the atmospheric side mechanical seal only bears the cooling water pressure, and the direction of the pressure difference does not change. Therefore, the sliding diameter remains unchanged. The atmospheric side mechanical seal is a balanced type, and the atmospheric side seal is less affected by force and pressure, and is always in a closed state.

[0053] 3. This variable pressure mechanical seal solves the problem that the medium-side mechanical seal end face is easily opened due to unstable cooling water system pressure in double-end mechanical seals. It realizes the purpose of changing the sliding diameter of the series double-end mechanical seal, ensuring that the series double-end mechanical seal has a wider range of applications and can operate stably for a long period of time under complex working conditions. Attached Figure Description

[0054] Figure 1 This is a three-dimensional structural diagram of the present invention;

[0055] Figure 2 This is a schematic diagram of the disassembled structure of this utility model;

[0056] Figure 3 This is a schematic diagram of the first state cross-sectional structure of the present invention. Figure 1 ;

[0057] Figure 4 This is a schematic diagram of the first state structure of the present invention. Figure 2 ;

[0058] Figure 5 This is a schematic diagram of the cross-sectional structure of the second state of this utility model. Figure 1 ;

[0059] Figure 6 This is a schematic diagram of the second state structure of the present invention. Figure 2 .

[0060] The components are as follows: 1. Shaft; 2. Bushing; 3. O-ring 1; 4. Main stationary ring; 5. O-ring 2; 6. Snap ring; 7. Driving ring; 8. O-ring 3; 9. Main thrust ring; 10. Balance conversion boss; 11. Spring seat; 12. Screw; 13. Spring 1; 14. O-ring 4; 15. Auxiliary driving ring; 16. Auxiliary stationary ring; 17. O-ring 5; 18. Flange; 19. Positioning clip; 20. Bolt 1; 21. Bolt 2; 22. Plug; 23. Sealing ring 1; 24. Fixing bolt 2; 25. Slot; 26. Cooling water side; 27. Outlet; 28. Inlet; 29. ​​Drain port; 30. Medium side. Detailed Implementation

[0061] 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.

[0062] Example 1: As Figure 1-6 As shown, the variable specific pressure mechanical seal provided by this utility model includes a rotating shaft 1, a main stationary ring 4, and a medium side 30. A bushing 2 is fixedly installed on the outer side of the rotating shaft 1. A driving ring 7 is provided on one side of the main stationary ring 4. A spring seat 11 is provided on one side of the bushing 2. A screw 12 is provided on the inner side of the spring seat 11. A spring 13 is provided on the inner side of the spring seat 11. The spring 13 passes through the spring seat 11 and is fixedly installed with the auxiliary driving ring 15. The other end of the spring 13 away from the auxiliary driving ring 15 abuts against the driving ring 7. An O-ring 4 14 is fixedly installed on the outer side of the bushing 2. There is a secondary moving ring 15, a secondary stationary ring 16 is fixedly installed on one side of the secondary moving ring 15, a flange 18 is fixedly installed on one side of the bushing 2, a positioning clip 19 is fixedly installed on one side of the flange 18, a threaded plug 22 is provided on the inner side of the flange 18, a sealing ring 23 is provided on the outer side of the flange 18, a fixing bolt 24 is fixedly installed on one side of the flange 18, an outlet 27 is opened on the outer side of the bushing 2, an inlet 28 is opened on the outer side of the bushing 2, a drain port 29 is opened on the outer side of the bushing 2, a groove 25 is opened on the end of the bushing 2 near the screw 12, and the spring seat 11 abuts against the bushing 2 through the screw 12.

[0063] Specifically, when the pressure on the medium side 30 is higher than the cooling water pressure, the pressure on the medium side 30 is considered high pressure. The pressure on the cooling water side 26 is low pressure. The O-ring at the position of the main stationary ring (4) (medium-side compensation ring) slides down to the position shown in the figure under the action of pressure, with a sliding diameter of As shown in the figure, at this time

[0064] = = + = +

[0065] In this state expression ≈0.7 < 1, at this time the sealing surface is of the balanced type.

[0066] Take the slurry as water =0.5

[0067] achievable = + +0.2 ≫0

[0068] At this time, the sealing ring surface is in a closed state.

[0069] Specifically, the bushing 2 is fixedly mounted with the main stationary ring 4, and an O-ring 2 5 is fixedly mounted on one side of the main stationary ring 4. The O-ring 2 5 is located between the main stationary ring 4 and the flange 18. The advantage is that the O-ring 2 5 can effectively fill the small gap between the main stationary ring 4 and the flange 18, preventing fluid leakage at the connection between the two, thereby improving the sealing performance of the entire device. In addition, the O-ring 2 5 plays a role in buffering and supporting, reducing the relative displacement between the main stationary ring 4 and the flange 18 caused by vibration or pressure changes during operation.

[0070] Specifically, a retaining ring 6 is snapped onto one side of the main stationary ring 4, and two identical O-rings 3 are provided. The two O-rings 3 are equidistant from the main stationary ring 4. The advantage is that the design of two O-rings 3 can further improve the sealing effect, and the two O-rings 3 work together to more comprehensively block the leakage path of fluid and enhance the reliability of the seal.

[0071] Specifically, outlet 27, inlet 28, and drain port 29 are interconnected, and these outlets are also connected to the cooling water side 26. The advantage of this interconnection is that it allows the cooling water to circulate more smoothly within the system. This interconnected design reduces water flow resistance, improves cooling water flow efficiency, thereby enhancing the cooling effect and contributing to uniform cooling. The cooling water can be more evenly distributed in the areas requiring cooling, avoiding localized overheating or overcooling.

[0072] Specifically, an O-ring 3 8 is provided on one side of the active ring 7, and a main thrust ring 9 is provided on the main stationary ring 4. A balance conversion boss 10 is fixedly installed on one side of the main thrust ring 9. The O-ring 3 8 and the bushing 2 are slidably connected. The advantage is that the O-ring 3 8 helps to form a good seal between the active ring 7 and other components, preventing fluid leakage. In addition, the sliding diameter of the O-ring 3 8 and the bushing 2 is constant. The atmospheric mechanical seal is a balanced type, and the atmospheric seal is less affected by force and pressure, and is always in a closed state.

[0073] Example 2: Figure 2-6 As shown, this is an improvement on the previous embodiment.

[0074] Specifically, when the pressure on the medium side is lower than the pressure on the cooling water side, the pressure on the medium side is low pressure. The pressure on the cooling water side (26) is high. The O-ring at the position of the main stationary ring (4) (medium-side compensation ring) slides down to the position shown in the figure under the action of pressure, with a sliding diameter of As shown in the figure, at this time

[0075] = = + = +

[0076] In this state expression ≈1.01>1, the value is 1, at this time the sealing surface is unbalanced.

[0077] Take the slurry as water =0.5

[0078] achievable = + +0.5 ≫0

[0079] At this point, the sealing ring is still in a closed state.

[0080] By calculating the parameters of the sealing ring surface and setting the balance conversion boss 10 on the mechanical seal bushing, the main end seal can switch between state 1 and state 2, allowing the sealing ring surface to adapt to various working conditions and switch freely in various working conditions, so that the sealing ring surface is always in a closed state.

[0081] The atmospheric-side mechanical seal only withstands cooling water pressure, and the direction of the pressure difference remains unchanged. Therefore, the sliding diameter is constant, and the atmospheric-side mechanical seal is a balanced type. ≈0.7,

[0082] = + +0.2 ≫0

[0083] Atmospheric side seal stress and pressure The impact is relatively small, and it remains in a closed state.

[0084] Specifically, an O-ring 3 is fixedly installed on one side of the bushing 2, and the O-ring 3 is located between the bushing 2 and the rotating shaft 1.

[0085] The advantage is that the design of O-ring 3 can effectively enhance the sealing between bushing 2 and shaft 1, and prevent leakage between bushing 2 and shaft 1, which would affect normal use.

[0086] Specifically, a bolt 20 is provided on the outside of the positioning clip 19, and a bolt 21 is fixedly installed on the outside of the positioning clip 19. Bolt 20 and bolt 21 pass through the flange 18 and extend into the interior of the positioning clip 19. The advantage is that by having bolts 20 and 21 pass through the flange 18 and extend into the interior of the positioning clip 19, a more secure connection between the positioning clip 19 and the flange 18 can be provided, ensuring that the positioning clip 19 will not easily loosen or fall off when the equipment is running or subjected to external forces, thereby maintaining the stability of the system.

[0087] Specifically, there are multiple bolts 20 and 21, which are arranged in a ring around the center line of the rotating shaft 1. The advantage is that the design of multiple bolts 20 and 21 can effectively improve the stability between the flange 18 and the positioning clip 19, and prevent them from falling off.

[0088] Specifically, the fixing bolt 24 penetrates the flange 18 and extends to its outer side. An O-ring 5 17 is fixedly installed on the outer side of the auxiliary stationary ring 16. The advantage is that the O-ring 5 17 fixedly installed on the outer side of the auxiliary stationary ring 16 can play a good sealing role. The O-ring 5 17 is elastic and can fill the small gaps between the auxiliary stationary ring 16 and other components to prevent fluid or gas leakage, thereby ensuring the sealing performance of the system and avoiding media leakage.

[0089] Working Principle: During use, the O-ring 25 effectively fills the tiny gap between the main stationary ring 4 and the flange 18, preventing fluid leakage at the connection point and thus improving the overall sealing performance of the device. O-ring 25 also acts as a buffer and support, reducing the relative displacement between the main stationary ring 4 and the flange 18 caused by vibration or pressure changes during operation. The design of two O-rings 13 further enhances the sealing effect, and the combined action of the two O-rings 13 more comprehensively blocks the leakage path, enhancing the reliability of the seal. The interconnected outlet 27, inlet 28, and drain port 29 allow for smoother circulation of cooling water within the system. This interconnected design reduces water flow resistance, improves cooling water flow efficiency, enhances the cooling effect, and helps achieve uniform cooling. Cooling water can be more evenly distributed in the areas requiring cooling, avoiding localized overheating or overcooling. The O-ring 38 helps form a good seal between the active ring 7 and other components, preventing fluid leakage, and works in conjunction with the O-rings... The sliding diameter of the three-sleeve 8 and the shaft sleeve 2 remains constant. The atmospheric side mechanical seal is a balanced type, and the atmospheric side seal is less affected by force and pressure, always remaining in a closed state. The design of O-ring 3 effectively enhances the sealing performance between the shaft sleeve 2 and the rotating shaft 1, preventing leakage between the shaft sleeve 2 and the rotating shaft 1, which would affect normal use. Bolts 20 and 21 penetrate the flange 18 and extend into the interior of the positioning clip 19, providing a more secure fixation for the connection between the positioning clip 19 and the flange 18. This ensures that the positioning clip 19 will not easily loosen or fall off when the equipment is running or subjected to external forces, thus maintaining the stability of the system. The design of multiple bolts 20 and 21 effectively improves the stability between the flange 18 and the positioning clip 19, and prevents it from falling off easily. The O-ring 17 fixedly installed on the outside of the auxiliary stationary ring 16 provides a good sealing effect. The O-ring 17 is elastic and can fill the small gaps between the auxiliary stationary ring 16 and other components, preventing fluid or gas leakage, thus ensuring the sealing performance of the system and preventing media leakage.

[0090] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A variable specific pressure mechanical seal, comprising a rotating shaft (1), a main stationary ring (4), and a medium side (30), characterized in that: A bushing (2) is fixedly installed on the outside of the rotating shaft (1). A driving ring (7) is provided on one side of the main stationary ring (4). A spring seat (11) is provided on one side of the bushing (2). A screw (12) is provided on the inside of the spring seat (11). A spring (13) is provided on the inside of the spring seat (11). The spring (13) passes through the spring seat (11) and is fixedly installed with the auxiliary driving ring (15). The other end of the spring (13) away from the auxiliary driving ring (15) abuts against the driving ring (7). An O-ring (14) is fixedly installed on the outside of the bushing (2). An auxiliary driving ring (15) is provided on the outside of the bushing (2). An auxiliary stationary ring (7) is fixedly installed on one side of the auxiliary driving ring (15). The bushing (2) is fixedly mounted with a flange (18) on one side, and a positioning clip (19) is fixedly mounted on one side of the flange (18). A plug (22) is provided inside the flange (18), and a sealing ring (23) is provided outside the flange (18). A fixing bolt (24) is fixedly mounted on one side of the flange (18). An outlet (27) is provided outside the bushing (2), an inlet (28) is provided outside the bushing (2), and a drain port (29) is provided outside the bushing (2). A groove (25) is provided at one end of the bushing (2) near the screw (12). The spring seat (11) is abutted against the bushing (2) by the screw (12).

2. The variable specific pressure mechanical seal according to claim 1, characterized in that: The bushing (2) is fixedly installed with a main stationary ring (4), and an O-ring two (5) is fixedly installed on one side of the main stationary ring (4). The O-ring two (5) is located between the main stationary ring (4) and the flange (18).

3. The variable specific pressure mechanical seal according to claim 1, characterized in that: A retaining ring (6) is snapped onto one side of the main stationary ring (4), and two identical O-rings (3) are provided, with the two O-rings (3) being equidistant from the main stationary ring (4).

4. The variable specific pressure mechanical seal according to claim 3, characterized in that: The outlet (27), inlet (28) and drain outlet (29) are connected, and the outlet (27), inlet (28) and drain outlet (29) are connected to the cooling water side (26).

5. The variable specific pressure mechanical seal according to claim 4, characterized in that: The active ring (7) is provided with an O-ring three (8) on one side, the main stationary ring (4) is provided with a main push ring (9), and a balance conversion boss (10) is fixedly installed on one side of the main push ring (9). The O-ring three (8) and the bushing (2) are slidably connected.

6. The variable specific pressure mechanical seal according to claim 5, characterized in that: O-ring 1 (3) is fixedly installed on one side of the bushing (2), and the O-ring 1 (3) is located between the bushing (2) and the rotating shaft (1).

7. The variable specific pressure mechanical seal according to claim 1, characterized in that: The positioning clip (19) is provided with a bolt one (20) on the outside and a bolt two (21) is fixedly installed on the outside of the positioning clip (19). The bolt one (20) and the bolt two (21) pass through the flange (18) and extend into the interior of the positioning clip (19).

8. The variable specific pressure mechanical seal according to claim 7, characterized in that: The bolts one (20) and bolt two (21) are provided in multiples, and the multiple bolts one (20) and bolt two (21) are distributed in a ring about the center line of the rotating shaft (1).

9. The variable specific pressure mechanical seal according to claim 8, characterized in that: The second fixing bolt (24) passes through the flange (18) and extends to its outer side, and the outer side of the auxiliary stationary ring (16) is fixedly installed with an O-ring five (17).

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