Mechanical seal device for anti-rotation ring and narrow sealing cavity

Abstract

The present application relates to a kind of anti-rotation ring and narrow sealed cavity with mechanical seal device, it includes anti-rotation ring body and first protrusion, second protrusion and third protrusion on anti-rotation ring body;The first protrusion extends to the side away from the center of anti-rotation ring body along the radial direction of anti-rotation ring body;The second protrusion extends to the side close to the center of anti-rotation ring body along the radial direction of anti-rotation ring body;The third protrusion extends to the side of anti-rotation ring body along the axial direction of anti-rotation ring body, can link three shaft sleeve, dynamic ring seat and dynamic ring without using screw / pin, shaft sleeve can drive dynamic ring seat and dynamic ring to rotate when rotating, so that mechanical seal can be installed into the sealed cavity, solve the problem that the radial and axial space of small sealed cavity cannot use mechanical seal.

Description

Technical Field

[0001] This invention relates to the technical field of mechanical seals, and in particular to a mechanical seal device for narrow sealing cavities. Background Technology

[0002] Mechanical seals are shaft sealing devices that rely on one or more pairs of end faces that slide relative to each other perpendicular to the shaft to keep in contact under the action of fluid pressure and compensation mechanism, and are equipped with auxiliary seals to achieve leakage prevention. Common mechanical seal structures consist of stationary rings, rotating rings, and elastic elements.

[0003] In the earliest equipment, packing seals also existed. Packing seals are dynamic sealing devices that use pre-tightening or the self-tightening effect of medium pressure to create a clamping force between the packing and the rotating and stationary parts. However, packing seals have problems such as large leakage and short service life. Therefore, with the development of the industry, it is necessary to gradually replace packing seals with mechanical seals.

[0004] The radial and axial space of the sealing cavity of the packing seal is relatively small, but the radial and axial space required by the existing mechanical seal is relatively large. As a result, the existing mechanical seal cannot meet the requirements of such a small sealing cavity. Therefore, it is urgent to solve the problem that mechanical seals cannot be used in such narrow sealing cavities. Summary of the Invention

[0005] To address the problem that mechanical seals cannot be used in narrow sealed cavities, this application provides an anti-rotation ring and a mechanical seal device for narrow sealed cavities.

[0006] Firstly, this application provides an anti-rotation ring, which adopts the following technical solution: An anti-rotation ring includes an anti-rotation ring body and a first protrusion, a second protrusion, and a third protrusion located on the anti-rotation ring body; the first protrusion extends radially away from the center of the anti-rotation ring body; the second protrusion extends radially towards the center of the anti-rotation ring body; and the third protrusion extends axially towards one side of the anti-rotation ring body.

[0007] By adopting the above technical solution, in use, the first protrusion, the second protrusion and the third protrusion cooperate with different components respectively, and the three different components can be linked together by the anti-rotation ring, so that when the anti-rotation ring rotates in the circumferential direction, it drives the three different components to rotate together in the circumferential direction. The reason why existing mechanical seals require larger radial and axial spaces is that existing mechanical seals require screws / pins to fix the rotating ring seat and the shaft sleeve, and also require screws / pins to fix the rotating ring seat and the rotating ring. When fixing with screws / pins, corresponding screw / pin holes need to be made on the shaft sleeve. Therefore, the size of the rotating ring seat cannot be too small; if it is too small, it will be impossible to make multiple screw / pin holes on the rotating ring seat. However, with the anti-rotation ring in this application, the shaft sleeve, rotating ring seat, and rotating ring can be linked together without using screws / pins. This allows the rotating ring seat and rotating ring to rotate when the shaft sleeve rotates, meeting the usage requirements. Since screw / pin holes do not need to be made on the rotating ring seat, the size of the rotating ring seat can be reduced according to the size of the existing sealing cavity, allowing the mechanical seal to be installed into the sealing cavity. This enables better sealing of sealing cavities with small radial and axial spaces, solving the problem of not being able to use mechanical seals in narrow sealing cavities.

[0008] Preferably, the anti-rotation ring body is annular in shape, the third protrusion includes a contact surface, the plane of the contact surface is perpendicular to the tangent direction on the anti-rotation ring body at the contact surface, and there are two contact surfaces; when the anti-rotation ring body rotates circumferentially, one contact surface is located upstream of the third protrusion along the rotation direction, and the other contact surface is located downstream of the third protrusion along the rotation direction.

[0009] By adopting the above technical solution, during use, since the third protrusion is used to cooperate with the rotating ring, the rotational force is transmitted to the rotating ring through the third protrusion when the bushing rotates, so that the rotating ring and the bushing rotate together. By setting a contact surface, the contact surface between the rotating ring and the third protrusion can be made into a plane during rotation, increasing the contact area between the third protrusion and the rotating ring, making the rotating ring less prone to damage during use. By setting two contact surfaces on the third protrusion, the contact surface between the rotating ring and the third protrusion can be made into a plane when driving the rotating ring to rotate forward and backward, protecting the rotating ring under various usage conditions. At the same time, since the contact surface between the rotating ring and the third protrusion is a plane, the third protrusion is not prone to deformation during contact, so that the rotating ring and the third protrusion can maintain a stable fit for a long time, avoiding the situation where a large gap appears between the rotating ring and the third protrusion when the third protrusion deforms. Therefore, it also avoids the situation where the third protrusion and the rotating ring collide when the bushing starts to rotate to a certain extent.

[0010] Preferably, the anti-rotation ring body includes an outer ring sidewall and an inner ring sidewall, the first protrusion is located on the outer ring sidewall, the second protrusion is located on the inner ring sidewall, the third protrusion is formed by the anti-rotation ring body bending and deforming along the axial direction, the first protrusion and the second protrusion are integrally formed on the anti-rotation ring body, and the third protrusion is formed by stamping.

[0011] By adopting the above technical solution, when processing the anti-rotation ring, the anti-rotation ring body, the first protrusion, and the second protrusion are directly stamped out by stamping equipment, and then the anti-rotation ring body is bent by stamping equipment to form the third protrusion. No welding or other operations are required in the whole process, making the processing convenient. The first protrusion, the second protrusion, and the third protrusion are all integrally formed on the anti-rotation ring body, so the overall strength of the anti-rotation ring is higher, and the first protrusion, the second protrusion, or the third protrusion is less likely to break during use.

[0012] Secondly, this application provides a mechanical seal device for narrow sealing cavities, employing the following technical solution: A mechanical seal device for a narrow sealing cavity includes a bushing fitted onto a rotating shaft and an atmospheric side seal and a media side seal disposed on the bushing. The atmospheric side seal includes a first rotating ring assembly and a first stationary ring assembly. The first rotating ring assembly includes a first rotating ring seat and a first rotating ring. It also includes an anti-rotation ring as described in the above technical solution. The anti-rotation ring enables circumferential transmission between the first rotating ring seat and the first rotating ring, and between the first rotating ring seat and the bushing. The first rotating ring seat is provided with a first groove that mates with a first protrusion. The bushing is provided with a second groove that mates with a second protrusion. The first rotating ring is provided with a third groove that mates with a third protrusion.

[0013] By adopting the above technical solution, the anti-rotation ring enables circumferential transmission between the first rotating ring seat and the first rotating ring, and between the first rotating ring seat and the bushing. When the bushing rotates, the bushing can transmit force to the anti-rotation ring body through the cooperation of the second groove and the second protrusion. When the anti-rotation ring body rotates, it can transmit force to the first rotating ring seat through the cooperation of the first protrusion and the first groove, and simultaneously transmit force to the first rotating ring through the cooperation of the third protrusion and the third groove. At this time, the bushing will drive the first rotating ring seat and the first rotating ring to rotate synchronously, so that the transmission between the first rotating ring seat and the first rotating ring, and between the first rotating ring seat and the bushing, can be achieved without screws / pins. This allows the first rotating ring seat to be designed to meet the size requirements of narrow sealing cavities, solving the problem that mechanical seals cannot be used in sealing cavities with small radial and axial spaces.

[0014] Preferably, the first moving ring seat is provided with a pump efficiency groove, and the first moving ring seat is provided with a pump efficiency protrusion on the side facing the first stationary ring assembly; the pump efficiency protrusion extends along the axial direction of the bushing towards the side of the first stationary ring assembly; the pump efficiency groove passes through the first moving ring seat and the pump efficiency protrusion along the axial direction of the bushing.

[0015] By adopting the above technical solution, the contact surface between the first rotating ring and the first stationary ring assembly will generate heat during use, thus requiring cooling and flushing with flushing fluid. When the temperature of the first rotating ring or the first stationary ring assembly is too high, sealing failure is likely to occur. Therefore, in order to quickly remove the heat from the first rotating ring and the first stationary ring assembly, it is necessary to accelerate the flow rate of the flushing fluid in the sealing cavity. By setting a pump efficiency groove, the flushing fluid can be driven to flow rapidly and absorb heat in the sealing cavity, keeping the temperature of the first rotating ring or the first stationary ring assembly within a low range. At the same time, due to the small space of the sealing cavity, the size of the first rotating ring seat is small, resulting in a shallow depth of the pump efficiency groove, which leads to a low pumping effect on the flushing fluid. However, by extending the pump efficiency protrusion along the shaft sleeve axially on the first rotating ring seat, the length of the pump efficiency groove can be increased, thereby improving the pumping effect of the pump efficiency groove on the flushing fluid and further enhancing the heat absorption effect of the flushing fluid. Since the pump efficiency protrusion extends along the shaft sleeve axially, it does not occupy the radial space of the sealing cavity and will not affect the normal installation of the seal.

[0016] Preferably, the pump efficiency groove is provided with pump efficiency guide surfaces on the sidewalls of both the upstream and downstream sides in the rotation direction of the first moving ring seat, and the distance between the two pump efficiency guide surfaces in the pump efficiency groove gradually increases from the side of the pump efficiency groove closer to the bushing to the side farther away from the bushing.

[0017] By adopting the above technical solution, the pumping effect of the pump efficiency tank on the flushing fluid can be increased through the pump efficiency guide surface, thereby improving the flow rate of the flushing fluid and accelerating the heat exchange efficiency between the first moving ring and the first stationary ring assembly and the flushing fluid.

[0018] Preferably, the thickness of the pump efficiency convex ring along the axial direction perpendicular to the bushing is less than the depth of the pump efficiency groove, and a cooling gap is provided between the pump efficiency convex ring and the first moving ring.

[0019] By adopting the above technical solution, the contact area between the flushing fluid and the first moving ring can be increased through the cooling gap, thereby accelerating the heat exchange efficiency. Since the thickness of the pump effect convex ring is less than the depth of the pump effect groove, the pump effect convex ring is penetrated by the pump effect groove along the axial direction of the vertical shaft sleeve, which allows the flushing fluid at the cooling gap to flow and exchange quickly, avoiding the situation where the flushing fluid between the pump effect convex ring and the first moving ring cannot flow quickly due to the addition of the pump effect convex ring.

[0020] Preferably, the first moving ring includes a stepped surface, the stepped surface is located on the side of the first moving ring facing the first moving ring seat, and the plane where the stepped surface is located is perpendicular to the axial direction of the bushing, and a disassembly groove is formed between the stepped surface and the side of the first moving ring seat facing the first stationary ring assembly.

[0021] By adopting the above technical solution, if the first moving ring is damaged during use, it is necessary to remove the first moving ring from the first moving ring seat for replacement or repair. The disassembly groove is designed to facilitate disassembly by workers. At the same time, the disassembly groove is formed by the stepped surface and the end face of the first moving ring seat facing the first stationary ring assembly. Therefore, the tools can be easily inserted into the disassembly groove to disassemble the first moving ring by passing through the pump efficiency groove of the pump efficiency protrusion ring, reducing the difficulty of maintenance.

[0022] Preferably, it further includes an outer pressure cap. The first stationary ring assembly is located between the bushing and the outer pressure cap. The first stationary ring assembly includes a first stationary ring, a push ring, and a spring. The first stationary ring and the push ring are slidably disposed along the axial direction of the bushing. The spring is used to push the push ring so that the first stationary ring always tends to move towards the first moving ring side. The push ring includes a fourth protrusion and a fifth protrusion. The first stationary ring is provided with a fourth groove that mates with the fourth protrusion. The outer pressure cap is provided with a fifth groove that mates with the fifth protrusion. The fifth groove extends along the axial direction of the bushing. The fifth protrusion can slide along the axial direction of the bushing within the fifth groove.

[0023] By adopting the above technical solution, common anti-rotation components are designed between the stationary ring and the outer pressure cover to prevent rotation. However, since the radial and axial space of the sealing cavity in this application is very small, there is no space to design additional anti-rotation components. The push ring in this application can achieve the effect of the push ring in common seals and also keep the first stationary ring and the outer pressure cover circumferentially synchronized, avoiding the situation where the first stationary ring rotates when the first moving ring rotates. Since the push ring and the first stationary ring will float along the shaft sleeve axially during the sealing operation, the fifth groove is designed to extend along the shaft sleeve axially, which can ensure that the push ring floats along the shaft sleeve axially with the first stationary ring while keeping the push ring and the first stationary ring circumferentially stationary.

[0024] Preferably, the medium-side seal includes a second moving ring assembly and a second stationary ring assembly. The second moving ring assembly includes a second moving ring seat and a second moving ring integrally formed with the bushing. A stepped pin is connected to the second moving ring seat, and a sixth groove that mates with the stepped pin is provided on the second moving ring.

[0025] By adopting the above technical solution, since the medium-side seal is located at the end of the bushing, the second moving ring seat and the bushing can be designed as an integral unit, avoiding the need for other components to connect when the two are assembled separately. Therefore, the second moving ring seat can be designed to be smaller to meet the installation requirements of the sealing cavity with small radial and axial space. The stepped pin can enable circumferential transmission between the second moving ring and the second moving ring seat.

[0026] In summary, the present invention has at least one of the following beneficial technical effects: 1. The anti-rotation ring in this application enables the mechanical seal to be installed in a sealing cavity with small radial and axial spaces, thus solving the problem that mechanical seals cannot be used in narrow sealing cavities; 2. The anti-rotation ring can link the bushing, the first rotating ring seat, and the first rotating ring together without the use of screws / pins, so that when the bushing rotates, it drives the first rotating ring seat and the first rotating ring to rotate, thus meeting the usage requirements. Attached Figure Description

[0027] Figure 1 This is a structural schematic diagram of Embodiment 1.

[0028] Figure 2 This is a top view of Embodiment 1.

[0029] Figure 3 This is an isometric view of Embodiment 1.

[0030] Figure 4 This is a schematic diagram of the structure of Embodiment 2.

[0031] Figure 5 yes Figure 4 A magnified view of part A in the diagram.

[0032] Figure 6 yes Figure 4 A magnified view of part B in the diagram.

[0033] Figure 7 This is a schematic diagram of the structure of the first moving ring seat in Embodiment 2.

[0034] Figure 8 This is a schematic diagram of the push ring structure in Example 2.

[0035] In the picture, 100. Anti-rotation ring body; 110. First protrusion; 120. Second protrusion; 130. Third protrusion; 131. Contact surface; 140. Outer ring sidewall; 150. Inner ring sidewall; 200, bushing; 210, second groove; 300. Atmospheric side seal; 310. First moving ring assembly; 311. First moving ring seat; 311a. First groove; 311b. Pump efficiency groove; 311c. Pump efficiency convex ring; 311d. Pump efficiency guide surface; 312. First moving ring; 312a. Third groove; 312b. Stepped surface; 320. First stationary ring assembly; 321. First stationary ring; 321a. Fourth groove; 322. Push ring; 322a. Fourth protrusion; 322b. Fifth protrusion; 323. Spring; 400, Medium-side seal; 410, Second rotating ring assembly; 411, Second rotating ring seat; 411a, Stepped pin; 412, Second rotating ring; 412a, Sixth groove; 420, Second stationary ring assembly; 500, cooling gap; 600. Disassembly slot; 700, outer pressure cap; 710, fifth groove; 720, inlet; 730, outlet. Detailed Implementation

[0036] The present invention will be further described in detail below with reference to the accompanying drawings.

[0037] Example 1: Reference Figure 1 , 2 This invention discloses an anti-rotation ring, comprising an anti-rotation ring body 100, which is annular in shape and includes an outer ring sidewall 140 and an inner ring sidewall 150. A first protrusion 110 is provided on the outer ring sidewall 140, a second protrusion 120 is provided on the inner ring sidewall 150, and a third protrusion 130 is located between the inner ring sidewall 150 and the outer ring sidewall 140. The first protrusion 110 extends radially away from the center of the anti-rotation ring body 100; the second protrusion 120 extends radially towards the center of the anti-rotation ring body 100; and the third protrusion 130 extends axially towards one side of the anti-rotation ring body 100.

[0038] In this embodiment, four first protrusions 110 are provided, and the four first protrusions 110 are evenly distributed along the circumference of the anti-rotation ring body 100. The end face of the first protrusion 110 facing away from the anti-rotation ring body 100 is an arc surface. There is one second protrusion 120. As an optimal method, the second protrusion 120 is provided on the inner side of the anti-rotation ring body 100 directly opposite one of the first protrusions 110. This arrangement makes it convenient to install the anti-rotation ring during assembly.

[0039] Among them, such as Figure 2 , 3 As shown, the third protrusion 130 is formed by stamping along the axial direction of the anti-rotation ring body 100 using a stamping device. The third protrusion 130 has two contact surfaces 131, as shown in the figure. Figure 2 Two contact surfaces 131 are arranged on the left and right sides of the third protrusion 130, and the plane of the contact surface 131 is perpendicular to the plane of the anti-rotation ring body 100. In order to make the contact surface 131 fit with other components during the force transmission process, the plane of the contact surface 131 is perpendicular to the tangent direction of the anti-rotation ring body 100 at the contact surface 131. This can better transmit force and increase the contact area between the third protrusion 130 and other components.

[0040] In this embodiment, the anti-rotation ring body 100 has a thickness of 0.5-1.5mm, the third protrusion 130 has a stamping depth of 2-3mm, and the third protrusion 130 has various corner γ (e.g., after stamping) at each corner. Figure 2 The maximum radius (as shown) is 0.3 mm.

[0041] In use, the first protrusion 110 engages with the rotating ring seat, the second protrusion 120 engages with the bushing, and the third protrusion 130 engages with the rotating ring. This allows the rotating ring, rotating ring seat, and bushing to rotate synchronously without the use of fixing screws / pins, thus achieving the purpose of using a mechanical seal in a sealing cavity with a small radial and axial space.

[0042] Example 2: Reference Figure 4 , 5 As shown, this invention discloses a mechanical seal device for a narrow sealing cavity, including a bushing 200 and an outer pressure cover 700 for mounting on a rotating shaft. An atmospheric side seal 300 and a medium side seal 400 are sequentially mounted on the bushing 200 from the atmospheric side to the medium side. The atmospheric side seal 300 is located between the outer pressure cover 700 and the bushing 200. The atmospheric side seal 300 includes a first moving ring assembly 310 and a first stationary ring assembly 320. An inlet 720 and an outlet 730 are provided on the outer pressure cover 700. The inlet 720 is located inside the sealing cavity and faces the first stationary ring assembly 320, and the outlet 730 is located inside the sealing cavity and faces the first moving ring assembly 310. During use, flushing fluid enters the sealing cavity through the inlet 720 and carries away the heat from the first stationary ring assembly 320 and the first moving ring assembly 310. After absorbing the heat, the flushing fluid flows out of the sealing cavity through the outlet 730.

[0043] The medium-side seal 400 includes a second moving ring assembly 410 and a second stationary ring assembly 420. In this embodiment, the second stationary ring assembly 420 has the same structure as the first stationary ring assembly 320. The second moving ring assembly 410 includes a second moving ring seat 411 and a second moving ring 412. The second moving ring seat 411 is integrally formed with the bushing 200. A stepped pin 411a is provided on the second moving ring seat 411 along the axial direction of the bushing 200. The stepped pin 411a is interference-fitted onto the second moving ring seat 411. A sixth groove 412a is provided on the second moving ring 412 to engage with the stepped pin 411a. In use, the second moving ring 412 is fitted onto the bushing 200 and pushed to slide along the axial direction of the bushing 200 until the stepped pin 411a is inserted into the sixth groove 412a to complete the installation of the second moving ring 412.

[0044] In use, since the second moving ring assembly 410 is located at the end of the bushing 200, the second moving ring seat 411 can be integrally set with the bushing 200. This eliminates the need for fixing components between the second moving ring seat 411 and the bushing 200, allowing the second moving ring seat 411 to be designed to be smaller, so that the second moving ring seat 411 can enter the sealing cavity with a small radial and axial space.

[0045] Reference Figure 5 , 6 The first rotating ring assembly 310 includes a first rotating ring seat 311, a first rotating ring 312, and an anti-rotation ring as described in Embodiment 1. The anti-rotation ring body 100 is located between the first rotating ring seat 311 and the first rotating ring 312. The first rotating ring seat 311 and the bushing 200 form a space for installing the first rotating ring 312. The anti-rotation ring body 100 is located within this space. A first groove 311a is formed on the side wall of the first rotating ring seat 311 located within this space and facing the bushing 200. A second groove 210 is formed on the bushing 200 opposite to the first groove 311a. A third groove 312a is provided on the first rotating ring 312. During use, the first protrusion 110... The first protrusion 120 is inserted into the first groove 311a and engages with it. The second protrusion 130 is inserted into the second groove 210 and engages with it. The third protrusion 130 is inserted into the third groove 312a and engages with it. When the bushing 200 rotates, the bushing 200 transmits the rotational force to the second protrusion 120 through the second groove 210, thereby causing the anti-rotation ring body 100 to rotate together. At the same time, the anti-rotation ring body 100 drives the first moving ring 312 and the first moving ring seat 311 to rotate together through the third protrusion 130 and the first protrusion 110, thereby achieving circumferential synchronization among the bushing 200, the first moving ring seat 311 and the first moving ring 312.

[0046] Reference Figure 5 , 6 Since the anti-rotation ring body 100 needs to be fitted onto the bushing 200 during use, in order to facilitate the installation of the anti-rotation ring body 100 onto the bushing 200, the second groove 210 is set as a groove extending along the axial direction of the bushing 200. Thus, when installing the anti-rotation ring body 100, the second protrusion 120 needs to be aligned with the second groove 210, and then the anti-rotation ring body 100 is slidably installed along the axial direction of the bushing 200. At this time, the second protrusion 120 will slide in the second groove 210 until the anti-rotation ring body 100 slides to the specified position, and the installation of the anti-rotation ring body 100 is completed.

[0047] Reference Figure 5 , 6Since the sealing cavity is an annular cavity, the flushing fluid entering the sealing cavity through the inlet 720 needs a certain amount of time to fill the sealing cavity. At the same time, when the flushing fluid exits the sealing cavity through the outlet 730, it can only exit from the outlet 730. Therefore, the flushing fluid distribution in the sealing cavity will be uneven during use. In order to reduce the uneven distribution of flushing fluid, a pump-efficiency convex ring 311c and a pump-efficiency groove 311b are provided on the first moving ring seat 311. The pump-efficiency convex ring 311c is located on the side of the first moving ring seat 311 facing the first stationary ring assembly 320, and the pump-efficiency convex ring 311c extends along the axial direction of the bushing 200 towards the first stationary ring assembly 320. The pump-efficiency groove 311b passes through the first moving ring seat 311 and the pump-efficiency convex ring 311c along the axial direction of the bushing 200.

[0048] A cooling gap 500 is provided between the pump-efficiency convex ring 311c and the first moving ring 312. This cooling gap 500 increases the contact area between the flushing fluid and the first moving ring 312, improving the heat dissipation efficiency of the first moving ring 312. The vertical thickness of the pump-efficiency convex ring 311c is less than the depth of the pump-efficiency groove 311b. Therefore, the pump-efficiency groove 311b vertically penetrates the pump-efficiency convex ring 311c, allowing the flushing fluid in the cooling gap 500 to flow through the pump-efficiency groove 311b at the pump-efficiency convex ring 311c, increasing the fluidity of the flushing fluid at the cooling gap 500 and further improving the heat dissipation efficiency of the first moving ring 312.

[0049] Reference Figure 7 To improve the pumping effect of the pumping efficiency groove 311b, two pumping efficiency guide surfaces 311d are provided inside the pumping efficiency groove 311b. The pumping efficiency guide surfaces 311d are located on both side walls of the pumping efficiency groove 311b and are inclined so that the opening of the pumping efficiency groove 311b gradually increases from the side near the first moving ring seat 311 to the side away from the first moving ring seat 311. This allows the pumping efficiency groove 311b to have a better pumping effect when the first moving ring seat 311 rotates, thereby increasing the fluidity of the flushing fluid in the sealed cavity.

[0050] like Figure 5 , 6 As shown, a stepped surface 312b is provided on the side of the first moving ring 312 facing the first moving ring seat 311. In this embodiment, the plane where the stepped surface 312b is located is perpendicular to the axial direction of the bushing 200. At this time, a disassembly groove 600 is formed between the end face of the first moving ring seat 311 facing the first stationary ring assembly 320 and the stepped surface 312b. The disassembly groove 600 can facilitate the disassembly of the first moving ring 312 when it needs to be replaced later. At the same time, since the pump effect groove 311b passes through the pump effect protrusion 311c in the vertical direction, the tool can also be directly passed through the pump effect groove 311b between the pump effect protrusion 311c when disassembling the first moving ring 312, which further facilitates the disassembly of the first moving ring 312.

[0051] Reference Figure 5 , 6 The first stationary ring assembly 320 includes a first stationary ring 321, a push ring 322, and a spring 323. The first stationary ring 321 and the push ring 322 are both annular components and are sleeved on the bushing 200. In order to cooperate with the first moving ring 312, the first stationary ring 321 and the push ring 322 are slidably arranged along the axial direction of the bushing 200. One end of the spring 323 abuts against the side of the push ring 322 away from the first stationary ring 321, and the other end of the spring 323 abuts against the outer pressure cover 700. In use, the spring 323 is always in a compressed state, so that the spring 323 can push the first stationary ring 321 and make the first stationary ring 321 always have a tendency to move towards the first moving ring 312.

[0052] Reference Figure 8 The push ring 322 includes a fourth protrusion 322a extending axially along the bushing 200 and a fifth protrusion 322b extending away from the center of the push ring 322. A fourth groove 321a that mates with the fourth protrusion 322a is provided on the first stationary ring 321. A fifth groove 710 that mates with the fifth protrusion 322b is provided on the outer pressure cover 700. Since the push ring 322 needs to slide axially along the bushing 200, the fifth groove 710 is extended axially along the bushing 200. In use, the fifth protrusion 322b can slide axially along the bushing 200 within the fifth groove 710.

[0053] The implementation principle of this embodiment is as follows: During use, the rotating shaft rotates and drives the bushing 200 to rotate. The bushing 200 transmits the rotational force to the second rotating ring 412 and the anti-rotation ring body 100 through the second groove 210 and the second rotating ring seat 411. The anti-rotation ring body 100 rotates with the bushing 200, and the rotational force on the anti-rotation ring body 100 is transmitted to the first rotating ring seat 311 through the first protrusion 110 and to the first rotating ring 312 through the third protrusion 130, so that the rotating ring of the first rotating ring seat 311 and the bushing 200 can achieve circumferential synchronization without other fixing components.

[0054] The embodiments described herein are preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, all equivalent changes made in accordance with the structure, shape, and principle of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A mechanical seal device for a narrow sealing cavity, characterized in that: It includes a bushing (200) for sleeved on a rotating shaft and an atmospheric side seal (300) and a medium side seal (400) disposed on the bushing (200). The atmospheric side seal (300) includes a first moving ring assembly (310) and a first stationary ring assembly (320). The first moving ring assembly (310) includes a first moving ring seat (311) and a first moving ring (312). It also includes an anti-rotation ring, which includes an anti-rotation ring body (100) and a first protrusion (110), a second protrusion (120), and a third protrusion (130) located on the anti-rotation ring body (100); the first protrusion (110) extends radially away from the center of the anti-rotation ring body (100); the second protrusion (120) extends radially towards the center of the anti-rotation ring body (100); the third protrusion (130) extends axially towards one side of the anti-rotation ring body (100); the anti-rotation ring is used to be disposed between the bushing (200), the first moving ring seat (311), and the first moving ring (312), so that circumferential transmission is maintained between the first moving ring seat (311) and the first moving ring (312), and between the first moving ring seat (311) and the bushing (200); the first protrusion (110) extends radially away from the center of the anti-rotation ring body (100); the second protrusion (120) extends radially towards the center of the anti-rotation ring body (100); the third protrusion (130) extends radially towards one side of the anti-rotation ring body (100); the anti-rotation ring is used to be disposed between the bushing (200), the first moving ring seat (311), and the first moving ring (312), such that circumferential transmission is maintained between the first moving ring seat (311) and the first moving ring (312), and between the first moving ring seat (311) and the bushing (200); the first protrusion (110) extends radially away from the center of the anti-rotation ring body (100) and the third protrusion (130) extends radially away from the center of the anti-rotation ring body (100); the first protrusion (110) extends radially away from the center of the 110) cooperates with the first groove (311a) provided on the first moving ring seat (311), the second protrusion (120) cooperates with the second groove (210) provided on the bushing (200), and the third protrusion (130) cooperates with the third groove (312a) provided on the first moving ring (312). In use, the bushing (200) transmits rotational force to the anti-rotation ring body (100) through the cooperation of the second groove (210) and the second protrusion (120). When the anti-rotation ring body (100) rotates, it transmits force to the first moving ring seat (311) through the cooperation of the first protrusion (110) and the first groove (311a), and transmits force to the first moving ring (312) through the cooperation of the third protrusion (130) and the third groove (312a), thereby realizing circumferential synchronization among the bushing (200), the first moving ring seat (311), and the first moving ring (312).

2. The mechanical seal device for narrow sealing cavities according to claim 1, characterized in that: The anti-rotation ring body (100) is annular in shape. The third protrusion (130) includes a contact surface (131). The plane containing the contact surface (131) is perpendicular to the tangent direction on the anti-rotation ring body (100) at the contact surface (131). There are two contact surfaces (131). When the anti-rotation ring body (100) rotates circumferentially, one of the contact surfaces (131) is located upstream of the third protrusion (130) along the rotation direction, and the other contact surface (131) is located downstream of the third protrusion (130) along the rotation direction.

3. The mechanical seal device for narrow sealing cavities according to claim 2, characterized in that: The anti-rotation ring body (100) includes an outer ring sidewall (140) and an inner ring sidewall (150). The first protrusion (110) is located on the outer ring sidewall (140), the second protrusion (120) is located on the inner ring sidewall (150), and the third protrusion (130) is formed by bending and deforming the anti-rotation ring body (100) along the axial direction. The first protrusion (110) and the second protrusion (120) are integrally formed on the anti-rotation ring body (100), and the third protrusion (130) is formed by stamping.

4. The mechanical seal device for narrow sealing cavities according to claim 1, characterized in that: The first moving ring seat (311) is provided with a pump efficiency groove (311b), and the first moving ring seat (311) is provided with a pump efficiency convex ring (311c) facing the first stationary ring assembly (320); the pump efficiency convex ring (311c) extends along the axial direction of the bushing (200) toward the first stationary ring assembly (320); the pump efficiency groove (311b) passes through the first moving ring seat (311) and the pump efficiency convex ring (311c) along the axial direction of the bushing (200).

5. The mechanical seal device for narrow sealing cavities according to claim 4, characterized in that: The pump efficiency groove (311b) is provided with pump efficiency guide surfaces (311d) on both the upstream and downstream sidewalls of the first moving ring seat (311) in the rotation direction. The distance between the two pump efficiency guide surfaces (311d) in the pump efficiency groove (311b) gradually increases from the side of the pump efficiency groove (311b) closer to the bushing (200) to the side farther away from the bushing (200).

6. The mechanical seal device for narrow sealing cavities according to claim 4, characterized in that: The thickness of the pump effect convex ring (311c) along the axial direction of the vertical bushing (200) is less than the depth of the pump effect groove (311b), and a cooling gap (500) is provided between the pump effect convex ring (311c) and the first moving ring (312).

7. The mechanical seal device for narrow sealing cavities according to claim 6, characterized in that: The first moving ring (312) includes a stepped surface (312b), which is located on the side of the first moving ring (312) facing the first moving ring seat (311), and the plane on which the stepped surface (312b) is located is perpendicular to the axial direction of the bushing (200). A disassembly groove (600) is formed between the stepped surface (312b) and the side of the first moving ring seat (311) facing the first stationary ring assembly (320).

8. The mechanical seal device for narrow sealing cavities according to claim 1, characterized in that: It also includes an outer pressure cap (700). The first stationary ring assembly (320) is located between the bushing (200) and the outer pressure cap (700). The first stationary ring assembly (320) includes a first stationary ring (321), a push ring (322), and a spring (323). The first stationary ring (321) and the push ring (322) are slidably disposed along the axial direction of the bushing (200). The spring (323) is used to push the push ring (322) so that the first stationary ring (321) always has a tendency to move toward the first moving ring (312). The push ring (322) includes a fourth protrusion (322a) and a fifth protrusion (322b). The first stationary ring (321) is provided with a fourth groove (321a) that cooperates with the fourth protrusion (322a). The outer pressure cover (700) is provided with a fifth groove (710) that cooperates with the fifth protrusion (322b). The fifth groove (710) extends along the axial direction of the bushing (200). The fifth protrusion (322b) can slide along the axial direction of the bushing (200) in the fifth groove (710).

9. The mechanical seal device for narrow sealing cavities according to claim 1, characterized in that: The medium-side seal (400) includes a second moving ring assembly (410) and a second stationary ring assembly (420). The second moving ring assembly (410) includes a second moving ring seat (411) and a second moving ring (412) integrally formed with the bushing (200). A stepped pin (411a) is connected to the second moving ring seat (411), and a sixth groove (412a) is provided on the second moving ring (412) to cooperate with the stepped pin (411a).

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