A low leakage, high reliability dynamic pressure sealing ring and mechanical sealing device

Abstract

The present application relates to a low leakage, high reliability dynamic pressure sealing ring and a mechanical sealing device, and relates to the technical field of mechanical sealing. The sealing ring comprises a ring body, and the sealing end face of the ring body is provided with at least one fluid dynamic pressure groove lower than the end plane. The sealing end face of the ring body is used for contacting with the mating ring as a sealing contact area. The end of the fluid dynamic pressure groove away from the center of the circle and exposed at the boundary of the sealing contact area is provided with a medium inlet and a medium outlet. The part of the fluid dynamic pressure groove located between the medium inlet and the medium outlet is located in the sealing contact area. When the ring body rotates around the axis, the fluid enters from the medium inlet and flows out toward the medium outlet through the fluid dynamic pressure groove. The mechanical sealing device comprises the above-mentioned sealing ring. The application has the advantage of being able to perform good sealing under high pressure to reduce leakage.

Description

Technical Field

[0001] The present application relates to the technical field of mechanical seals, and in particular to a low-leakage, high-reliability dynamic pressure seal ring and a mechanical seal device. Background Art

[0002] Mechanical seal is a device used to solve the sealing problem between the rotating shaft and the machine body. It is a device that prevents fluid leakage by keeping in contact and sliding relative to each other under the action of the fluid pressure of at least one pair of end faces perpendicular to the rotating axis and the elastic force (or magnetic force) of the compensation mechanism and the cooperation of the auxiliary seal. The most commonly used mechanical seal structure is the end face seal. The static ring and the dynamic ring of the end face seal form a pair of friction pairs, and the function of the friction pair is to prevent medium leakage.

[0003] In the current end face sealing mechanism, when the dynamic ring rotates at high speed, the fluid will form a pressure film at the sealing weir to push the sealing surface of the friction pair away. However, when the fluid pressure is high, the leakage of the fluid will increase, and it cannot be used in a high-pressure sealing environment. Summary of the invention

[0004] In order to improve the problem of increased leakage of the sealing ring of the current mechanical seal when the pressure increases, the present application provides a low-leakage, high-reliability dynamic pressure sealing ring and a mechanical sealing device.

[0005] In the first aspect, the present application provides a low leakage, high reliability dynamic pressure sealing ring adopting the following technical solution:

[0006] A low-leakage, high-reliability dynamic pressure sealing ring comprises a ring body, wherein the sealing end face of the ring body is provided with at least one fluid dynamic pressure groove which is lower than the end plane, the sealing end face of the ring body being used for the portion in contact with the mating ring as a sealing contact zone, the end of the fluid dynamic pressure groove away from the center of a circle and exposed at the boundary of the sealing contact zone being provided with a medium inlet and a medium outlet, the portion of the fluid dynamic pressure groove between the medium inlet and the medium outlet being located in the sealing contact zone; when the ring body rotates around an axis, the fluid enters from the medium inlet and flows out toward the medium outlet through the fluid dynamic pressure groove.

[0007] By adopting the above technical solution, when the sealing ring rotates at high speed, the fluid enters from the medium inlet and forms pressure in the fluid dynamic pressure groove, so that the sealing ring and the matching ring form a diaphragm at the contact area. When the pressure is high, the fluid leaks from the medium outlet to the cavity outside the sealing mechanism, reducing the possibility of medium leakage from the friction pair sealing surface and improving the sealing effect.

[0008] Optionally, the fluid dynamic pressure groove is an annular groove surrounding the center; or there are multiple fluid dynamic pressure grooves distributed in an array around the center of the ring body.

[0009] By adopting the above technical solution, the pressure of the fluid in the fluid dynamic pressure groove is kept balanced everywhere, so that the gap between the sealing surfaces of the friction pair remains the same, the possibility of fluid leakage is reduced, and the sealing effect is improved.

[0010] Optionally, the fluid dynamic pressure groove includes a plurality of connected flow channel units, each of the flow channel units includes a connected medium inlet and outlet groove and a medium flow groove, the medium inlet and the medium outlet are located on the medium inlet and outlet groove, and the medium flow groove is located in the sealing contact area.

[0011] By adopting the above technical solution, the fluid forms pressure in the medium flow groove at the sealing contact area, and a diaphragm can be formed at this position to perform sealing.

[0012] Optionally, the contour of the medium inlet and outlet slot is any one of an arc shape, a V shape, and a straight shape; and the medium flow slot is at least one of an arc shape, a V shape, and an S shape.

[0013] By adopting the above technical solution, the structure of the medium flow groove makes it possible for the fluid to be blocked in the medium flow groove and generate pressure when the sealing ring rotates, thereby forming a diaphragm. When the diaphragm pressure is large, the fluid can flow through the medium flow groove to the medium outlet for discharge, thereby maintaining the operating balance of the friction pair and improving the sealing performance of the sealing surface.

[0014] Optionally, the medium inlet and outlet slot and the medium circulation slot are both arc-shaped, the arc of the medium inlet and outlet slot is convex away from the center of the ring body, and the arc of the medium circulation slot is concave toward the center of the ring body;

[0015] Preferably, the medium inlet and outlet groove is arranged tangent to the medium circulation groove; preferably, the arc radius of the medium circulation groove is larger than the arc radius of the medium inlet and outlet groove.

[0016] By adopting the above technical solution, the fluid is pressurized and flows smoothly in the fluid dynamic pressure groove, and the sealing effect is better.

[0017] Optionally, the medium inlet and outlet slots and the medium flow slots are both V-shaped;

[0018] Preferably, the fluid dynamic pressure groove is in the shape of a regular N-gon, N≥5, and the medium inlet and the medium outlet are located at the vertex positions of the regular N-gon;

[0019] Preferably, the fluid dynamic pressure groove is in a regular M-angled star shape, M≥5;

[0020] Preferably, a communication groove is provided between at least one group of two adjacent flow channel units, and the communication groove is located in the sealing contact area.

[0021] By adopting the above technical solution, the sealing effect of the friction pair is better.

[0022] Optionally, the number of the flow channel units is any integer from 5 to 15.

[0023] By adopting the above technical solution, the friction pair can maintain mechanical strength under high-speed rotation while having good sealing effect and being easy to process.

[0024] Optionally, the width of the fluid dynamic pressure groove at the medium inlet and the medium outlet along the radial direction of the ring body is h, and the width of the medium inlet and the medium outlet along the radial direction of the ring body is w, then w / h=1 / 4~3 / 4.

[0025] By adopting the above technical solution, the sealing effect of the sealing ring is better.

[0026] Optionally, the depth of the fluid dynamic pressure groove perpendicular to the end face of the ring body is 0.2~2mm, and the width of the fluid dynamic pressure groove along the radial direction of the ring body is 1~3mm; preferably, the depth of the fluid dynamic pressure groove perpendicular to the end face of the ring body is 1mm, w=1mm, h=3mm.

[0027] By adopting the above technical solution, the sealing ring has excellent sealing performance and there is almost no leakage of the fluid.

[0028] In a second aspect, the present application provides a mechanical sealing device that adopts the following technical solution:

[0029] A mechanical sealing device comprises the low leakage and high reliability dynamic pressure sealing ring mentioned above.

[0030] By adopting the above technical solution, the sealing device has good sealing effect and extremely low leakage.

[0031] In summary, the present application includes at least one of the following beneficial technical effects: the sealing surface of the friction pair formed by the sealing ring under high pressure can maintain good sealing performance and low leakage. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a schematic diagram of the structure of the sealing ring in Example 1 of the present application;

[0033] Figure 2 for Figure 1 Schematic cross-sectional view along the AA direction;

[0034] Figure 3 Schematic diagram of the flow of medium in the fluid dynamic pressure tank;

[0035] Figure 4 This is a schematic diagram of the structure of the sealing ring in the second embodiment of the present application;

[0036] Figure 5 This is a schematic diagram of the structure of the sealing ring in the third embodiment of the present application;

[0037] Figure 6 This is a schematic diagram of the flow of the medium in the fluid dynamic pressure tank in the third embodiment of the present application;

[0038] Figure 7 This is a schematic diagram of the structure of the sealing ring in the fourth embodiment of the present application;

[0039] Figure 8 This is a schematic diagram of the structure of the sealing ring in Example 5 of the present application.

[0040] Description of reference numerals:

[0041] 1. Ring body;

[0042] 2. Fluid dynamic pressure groove; 21. Medium inlet and outlet groove; 211. Medium inlet; 212. Medium outlet; 22. Medium flow groove; 23. Communication groove;

[0043] 3. Match the ring profile. DETAILED DESCRIPTION

[0044] The following is combined with Figures 1 to 8 This application is described in further detail.

[0045] The embodiments of the present application disclose a low-leakage, high-reliability dynamic pressure sealing ring and a mechanical sealing device.

[0046] Embodiment 1:

[0047] refer to Figure 1 and Figure 2 The low leakage and high reliability dynamic pressure sealing ring comprises a circular ring body 1, a fluid dynamic pressure groove 2 is opened in the sealing end surface of the ring body 1 along the circumferential direction, and the fluid dynamic pressure groove 2 is arranged below the end plane of the ring body 1.

[0048] refer to Figure 2 and Figure 3 The fluid dynamic pressure groove 2 includes a multi-stage medium inlet and outlet groove 21 and a multi-stage medium flow groove 22. The sealing ring contacts the mating ring to form a friction pair, and the mating ring profile 3 forms a sealing contact area on the sealing end face of the sealing ring. The mating ring medium inlet and outlet groove 21 is exposed to the sealing contact area at a portion away from the center of the ring body 1. The fluid dynamic pressure groove 2 is provided with a medium inlet 211 and a medium outlet 212 at the position where the medium inlet and outlet groove 21 exposes the sealing contact area; the medium flow groove 22 is located between the outer diameter and the inner diameter of the contour of the sealing contact area.

[0049] refer to Figure 2 and Figure 3Here, the contours of the medium inlet and outlet grooves 21 and the medium flow grooves 22 are both in arc shape, the arc of the medium inlet and outlet grooves 21 bulges outward away from the center of the ring body 1, and the arc of the medium flow grooves 22 is concave toward the center of the ring body 1. The medium inlet and outlet grooves 21 and the medium flow grooves 22 can be alternately arranged and distributed in a circular array around the center of the ring body, and the medium inlet and outlet grooves 21 and the medium flow grooves 22 are tangent at the connection. The arc radius of the medium inlet and outlet grooves 21 can be smaller than the arc radius of the medium flow grooves 22.

[0050] The outer radius of the ring body 1 is R2, the inner radius of the ring body 1 is R1, the outer diameter of the matching ring profile 3 is smaller than R2, and the inner diameter of the matching ring profile 3 is larger than R1. The inner contour radius of the medium inlet and outlet groove 21 is r2, the inner contour radius of the medium flow groove 22 is r1, the radial width of the fluid dynamic pressure groove 2 along the ring body 1 is h, the radial width of the medium inlet 211 and the medium outlet 212 along the ring body 1 is w, w / h=1 / 4~3 / 4, the depth of the medium inlet 211 and the medium outlet 212 perpendicular to the sealing end face of the ring body 1 is d, and the radial dimension of the inner side of the medium inlet 211 and the medium outlet 212 from the edge of the ring body 1 is L.

[0051] Here, there are 9 medium inlet and outlet slots 21 and 9 medium circulation slots 22, and the central angle α between the centers of the medium inlet and outlet slots 21 and the medium circulation slots 22 in the ring body 1 is 20°, R2 is 154mm, R1 is 138.5mm, r1 is 200mm, r2 is 60mm, d is 1mm, h is 3mm, w is 1.5mm, and L is 5mm.

[0052] In other implementations of the embodiments of the present application, since the number of the medium inlet and outlet slots 21 and the medium flow slots 22 can be other numbers, the above dimensions can be adjusted as needed, wherein d is controlled between 0.2 and 2 mm, and h is controlled between 1 and 3 mm. The number of the medium inlet and outlet slots 21 and the medium flow slots 22 is preferably selected within the range of 5 to 15 to obtain a better sealing effect.

[0053] In other implementations of the embodiments of the present application, the fluid dynamic pressure grooves 2 may also be distributed on the two sealing end faces of the ring body 1, and in this case the sealing ring can be used for double-sided sealing.

[0054] Embodiment 2:

[0055] refer to Figure 4, a sealing ring, which is different from Example 1 in that the sealing ring further includes a connecting groove 23, the two ends of which can be connected to the medium inlet and outlet grooves 21 or the medium flow grooves 22, and the connecting groove 23 is located in the sealing contact area of ​​the ring body 1. There can be more than one connecting groove 23, and here there are two connecting grooves 23 and they are centrally symmetrically arranged with respect to the center of the ring body 1. In other embodiments of the embodiments of the present application, the number of the connecting grooves 23 can also be 3, 4 or 5 or more, and the number of the connecting grooves 23 is not more than the number of the medium flow grooves 22.

[0056] The connecting groove 23 can be any one of an arc shape, a V shape, and an S shape. Here, the connecting groove 23 is an arc shape. The width of the connecting groove 23 along the radial direction of the ring body 1 is the same as the width of the medium flow groove 22. The central angle of the connecting groove 23 in the ring body 1 is β, and β can be 5°~270°, preferably 10°~90°. Here, when α is 20°, β can take a value between 0.5α~2α. For the convenience of processing, any value of 10°, 20°, 30°, and 40° can be taken.

[0057] Embodiment 3:

[0058] refer to Figure 5 and Figure 6 , a sealing ring, which is different from Example 1 in that there are two or more fluid dynamic grooves 2 that are independent and not connected, the medium inlet 211 on the fluid dynamic groove 2 is located at one end, and the medium outlet 212 on the fluid dynamic groove 2 is located at the other end. Here, there are 9 fluid dynamic grooves 2 and they are evenly distributed around the center of the ring body 1. The fluid dynamic grooves 2 are arc-shaped grooves, and the arc is concave toward the center of the ring body 1. The central angle 2α of the fluid dynamic grooves 2 in the ring body 1 is 40°.

[0059] In other implementations of the embodiments of the present application, the number of the fluid dynamic grooves 2 can also be 3, 4, 5 or more, preferably 5 to 15 to obtain a better sealing effect.

[0060] Embodiment 4:

[0061] refer to Figure 7 , a sealing ring, which is different from the embodiment 1 in that the medium inlet and outlet groove 21 and the medium flow groove 22 are V-shaped, the angle between the medium inlet and outlet groove 21 is γ, the angle between the medium flow groove 22 is δ, and the central angle between the cusps of the medium inlet and outlet groove 21 and the medium flow groove 22 at the ring body 1 is α. Here, γ can be 135°, δ can be 173°, and α can be 20°.

[0062] In other implementations of the embodiments of the present application, the respective angles of the medium inlet and outlet slot 21 and the medium flow slot 22 can be adjusted.

[0063] Embodiment 5:

[0064] refer to Figure 8 , a sealing ring, which is different from the embodiment 4 in that the angle of the medium flow groove 22 is 180°, so that the fluid power groove 2 is a regular polygon or a regular polygon star as a whole. The medium inlet 211 and the medium outlet 212 are located at the vertices of the regular polygon or the regular polygon star.

[0065] Here, the fluid dynamic groove 2 is a regular pentagon. In other implementations of the embodiments of the present application, the number of sides of the regular polygon N≥5. The number of angles of the regular polygon star M≥5. In order to obtain a better sealing effect, the values ​​of M and N are not more than 15.

[0066] Embodiment 6:

[0067] A mechanical sealing device comprises any one of the sealing rings in embodiments 1 to 5.

[0068] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A low leakage, high reliability dynamic pressure sealing ring, comprising a ring body (1), wherein the sealing end surface of the ring body (1) is provided with at least one fluid dynamic pressure groove (2) lower than the end plane, characterized in that: The sealing end surface of the ring body (1) is used for the contact portion with the mating ring as the sealing contact zone, and the end of the fluid dynamic pressure groove (2) away from the center of the circle and exposed at the boundary of the sealing contact zone is provided with a medium inlet (211) and a medium outlet (212), and the portion of the fluid dynamic pressure groove (2) between the medium inlet (211) and the medium outlet (212) is located in the sealing contact zone; when the ring body (1) rotates around the axis, the fluid enters from the medium inlet (211) and flows out toward the medium outlet (212) through the fluid dynamic pressure groove (2), and the medium inlet (211) and the medium outlet (212) are located between the outer diameter of the contour of the sealing contact zone and the outer diameter of the ring body (1); The fluid dynamic pressure groove (2) is an annular groove that surrounds the center and is connected; The fluid dynamic pressure groove (2) comprises a plurality of connected flow channel units, each of the flow channel units comprises a connected medium inlet and outlet groove (21) and a medium flow groove (22), the medium inlet (211) and the medium outlet (212) are located on the medium inlet and outlet groove (21), and the medium flow groove (22) is located in the sealing contact area; The medium inlet and outlet groove (21) and the medium circulation groove (22) are both arc-shaped, the arc of the medium inlet and outlet groove (21) is convex away from the center of the ring body (1), and the arc of the medium circulation groove (22) is concave toward the center of the ring body (1); The medium inlet and outlet groove (21) is arranged tangentially to the medium circulation groove (22); the circular arc radius of the medium circulation groove (22) is greater than the circular arc radius of the medium inlet and outlet groove (21); The width of the fluid dynamic pressure groove (2) located at the medium inlet (211) and the medium outlet (212) along the radial direction of the ring body (1) is h, and the width of the medium inlet (211) and the medium outlet (212) along the radial direction of the ring body (1) is w, then w / h=1 / 4~3 / 4.

2. The low leakage, high reliability dynamic pressure sealing ring according to claim 1, characterized in that: The number of the flow channel units is any integer from 5 to 15.

3. The low leakage, high reliability dynamic pressure sealing ring according to claim 1, characterized in that: The depth of the fluid dynamic pressure groove (2) perpendicular to the end face of the ring body (1) is 1 mm, and the width of the fluid dynamic pressure groove (2) along the radial direction of the ring body (1) is 3 mm, w=1 mm.

4. A mechanical sealing device, characterized in that: It comprises the low leakage and high reliability dynamic pressure sealing ring as described in any one of claims 1 to 3.

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