High-pressure-resistant externally-mounted mechanical seal
By introducing a pressure reducing ring and a backpressure groove into the external mechanical seal, combining the elastic element and friction pair, changing the pressure direction of the medium, the problem of leakage under high pressure is solved, and a wider use conditions are achieved.
Patent Information
- Application Number
- CN202421080746.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-17
- Publication Date
- 2025-01-14
- Estimated Expiration
- 2034-05-17
AI Technical Summary
External mechanical seals are prone to leakage in high-pressure environments, which limit their use under low-pressure conditions.
A high-pressure resistant external mechanical seal is designed. By setting a pressure reduction ring and a backpressure groove between the sealing seat and the sleeve, the elastic element and friction pair components are used to change the direction of the medium pressure, reduce the medium pressure, and pass the sealing ring. and limit slots enhance sealing performance.
It effectively reduces the medium pressure of mechanical seals, promotes the closure of the seal end surface, gets rid of leakage problems in high-pressure environments, and expands the scope of use of external mechanical seals.
Smart Images
Figure CN222351450U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of mechanical seals, in particular to a high-pressure resistant external mechanical seal. Background Art
[0002] For external mounted mechanical seals, the static ring is installed on the outside of the seal seat. The outer circle of the sealing ring is generally exposed to the atmosphere on the low-pressure side and is not corroded by the medium. The end face leakage, wear and other operating conditions can be monitored intuitively. However, the force on the sealing end face is not as reasonable as that of the internal mounted mechanical seal. The medium pressure acting on the end face is usually opposite to the force of the elastic compensation element, which tends to open the sealing end face. Therefore, the use of external mounted mechanical seals is limited to the medium pressure of 0.5 MPa. Too high medium pressure can easily cause leakage. Utility Model Content
[0003] Aiming at the problem that the externally mounted mechanical seal in the prior art can only be used under low pressure conditions, the utility model provides a high pressure resistant externally mounted mechanical seal.
[0004] The utility model provides the following technical solutions: A high-pressure resistant external mechanical seal, comprising a sealing seat bolted to the outside of a pump body, a stationary ring seat arranged on the side of the sealing seat away from the pump body, and a sleeve rotating relative to the sealing seat and the stationary ring seat, the stationary ring seat being provided with a stationary ring, the sleeve being slidably connected with a moving ring seat, the moving ring seat being provided with a moving ring, the moving ring and the stationary ring forming a friction pair, and an elastic element being provided between the moving ring seat and the sleeve; a back-pressure groove being further provided on the inner wall of the moving ring seat, the diameter of the back-pressure groove being larger than the inner diameter of the sealing end face; a pressure reducing ring being further provided on the end of the sleeve facing the pump body, the pressure reducing ring extending between the sealing seat and the sleeve, and a threaded groove being provided on the outer surface of the pressure reducing ring.
[0005] Preferably, the stationary ring seat is provided with a limiting groove on the side facing the sealing seat, and the sealing seat is provided with an anti-rotation pin extending into the limiting groove; the dynamic ring seat is provided with a key groove, and the sleeve is provided with a transmission pin extending into the key groove, and the length of the key groove in the axial direction of the sleeve is greater than that of the transmission pin.
[0006] Preferably, a pressure plate is further provided on the side of the stationary ring seat facing away from the sealing seat, the pressure plate is bolted to the sealing seat, and a sealing ring is provided between the pressure plate and the stationary ring seat.
[0007] Preferably, sealing rings are provided between the stationary ring seat and the sealing seat, and between the dynamic ring seat and the shaft sleeve.
[0008] Preferably, the thread groove is a multi-start thread groove.
[0009] Preferably, the elastic element is a compression spring.
[0010] The beneficial effects of the utility model are as follows: a pressure reducing ring is arranged at one end of the shaft sleeve facing the pump body, a threaded groove is arranged on the surface of the pressure reducing ring, which effectively reduces the medium pressure of the mechanical seal during operation, and a back-pressure groove is arranged on the inner wall of the dynamic ring seat to change the direction of the medium pressure and promote the closing of the sealing end face, thereby freeing the external mechanical seal from the use limitation of low medium pressure. BRIEF DESCRIPTION OF THE DRAWINGS
[0011] Figure 1 It is a cross-sectional view of an embodiment of the utility model.
[0012] Figure 2 for Figure 1 Enlarged view of part A.
[0013] Figure numerals: 10, sealing seat; 11, anti-rotation pin; 12, pressure plate; 20, stationary ring seat; 21, stationary ring; 30, bushing; 31, transmission pin; 40, dynamic ring seat; 41, dynamic ring; 42, back-pressure groove; 50, elastic element; 60, pressure relief ring; 61, threaded groove; 70, sealing ring; 80, pump body; 90, rotating shaft. DETAILED DESCRIPTION
[0014] The following is a more detailed description of the implementation of the utility model in conjunction with the drawings and the figure marks, so that those skilled in the art can implement it after reading this specification. It should be understood that the specific embodiments described here are only used to explain the utility model, and are not used to limit the utility model.
[0015] The utility model provides Figure 1-2The high-pressure resistant external mechanical seal shown in the figure comprises a sealing seat 10 connected to the outside of a pump body 80 by bolts, a stationary ring seat 20 arranged on the side of the sealing seat 10 away from the pump body 80, and a sleeve 30. The sleeve 30 is bolted to the rotating shaft 90 of the pump, and the sleeve 30 rotates relative to the sealing seat 10 and the stationary ring seat 20 under the drive of the rotating shaft 90. A limiting groove is provided on the side of the stationary ring seat 20 facing the sealing seat 10, and the sealing seat 10 is provided with an anti-rotation pin 11 extending into the limiting groove, so that the stationary ring seat 20, the stationary ring 21 and the sealing seat 10 are relatively stationary. A pressure plate 12 is also provided on the side of the stationary ring seat 20 away from the sealing seat 10, and the pressure plate 12 is bolted to the sealing seat 10, which plays a limiting role on the stationary ring seat 20 to prevent the medium pressure from pushing the stationary ring seat 20 out. A sealing ring 70 is provided between the pressure plate 12 and the stationary ring seat 20, and between the stationary ring seat 20 and the sealing seat 10 to enhance the sealing performance. The shaft sleeve 30 is slidably connected with a dynamic ring seat 40, and the dynamic ring seat 40 is provided with a keyway, and the shaft sleeve 30 is provided with a transmission pin 31 extending into the keyway to transmit torque so that the dynamic ring seat 40 rotates with the shaft sleeve 30. The length of the keyway in the axial direction of the shaft sleeve 30 is greater than the transmission pin 31, so as to avoid affecting the sliding of the dynamic ring seat 40 relative to the shaft sleeve 30 along the axial direction of the shaft sleeve 30. A sealing ring 70 is also provided between the dynamic ring seat 40 and the shaft sleeve 30.
[0016] The stationary ring seat 20 is provided with a stationary ring 21, and the dynamic ring seat 40 is provided with a dynamic ring 41. The dynamic ring 41 and the stationary ring 21 form a friction pair to form a seal, and the overlapped end surface of the two is the sealing end surface. An elastic element 50 is provided between the dynamic ring seat 40 and the sleeve 30. The elastic element 50 can be a compression spring, which squeezes the dynamic ring 41 toward the stationary ring 21 to provide compensation when the friction pair is worn. Figure 1 The left side of the middle mechanical seal is the medium side, and the right side is the atmosphere side, forming an external structure.
[0017] In the utility model, a pressure relief ring 60 is provided at one end of the sleeve 30 facing the pump body, and the pressure relief ring 60 extends between the sealing seat 10 and the sleeve 30, and a thread groove 61 extending in the axial direction is provided on the outer surface of the pressure relief ring 60, and the thread groove 61 is a multi-start thread groove. The pressure relief ring 60 is bolted to the sleeve 30, and when it rotates with the sleeve 30, it generates an axial thrust on the medium, preventing part of the medium from entering the gap of the mechanical seal, and can effectively reduce the medium pressure of the mechanical seal.
[0018] Furthermore, the inner wall of the dynamic ring seat 40 is also provided with a back pressure groove 42, which is connected to the inside of the pump body through the gaps between the shaft sleeve 30 and the dynamic ring seat, the dynamic ring, the static ring, the static ring seat, and the sealing seat, and forms a back pressure cavity with the shaft sleeve 30. The diameter d0 of the back pressure groove 42 is larger than the inner diameter d1 of the sealing end face, please refer to Figure 2, the medium enters the back pressure groove 42 from the gap and acts on the left bottom surface of the back pressure groove 42, which helps the sealing end face to close, which is opposite to the medium pressure direction of the external mechanical seal acting on the sealing end face in the prior art; the medium pressure direction is as follows Figure 2 Indicated by the arrow.
[0019] The above are one or more embodiments of the utility model, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the utility model patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the utility model, which all belong to the protection scope of the utility model. Therefore, the protection scope of the utility model patent shall be based on the attached claims.
Claims
1. A high pressure resistant external mechanical seal, characterized in that: It includes a sealing seat bolted to the outside of the pump body, a stationary ring seat arranged on the side of the sealing seat away from the pump body, and a sleeve rotating relative to the sealing seat and the stationary ring seat, the stationary ring seat is provided with a stationary ring, the sleeve is slidably connected with a dynamic ring seat, the dynamic ring seat is provided with a dynamic ring, the dynamic ring and the stationary ring form a friction pair, and an elastic element is arranged between the dynamic ring seat and the sleeve; the inner wall of the dynamic ring seat is also provided with a back-pressure groove, the diameter of the back-pressure groove is larger than the inner diameter of the sealing end face; a pressure reducing ring is also arranged on the end of the sleeve facing the pump body, the pressure reducing ring extends between the sealing seat and the sleeve, and the outer surface of the pressure reducing ring is provided with a threaded groove.
2. A high pressure resistant external mechanical seal according to claim 1, characterized in that: The stationary ring seat is provided with a limiting groove on one side facing the sealing seat, and the sealing seat is provided with an anti-rotation pin extending into the limiting groove; the dynamic ring seat is provided with a key groove, and the sleeve is provided with a transmission pin extending into the key groove, and the length of the key groove in the axial direction of the sleeve is greater than that of the transmission pin.
3. The high pressure resistant external mechanical seal according to claim 1, characterized in that: A pressure plate is also arranged on the side of the stationary ring seat away from the sealing seat. The pressure plate is bolted to the sealing seat, and a sealing ring is arranged between the pressure plate and the stationary ring seat.
4. The high pressure resistant external mechanical seal according to claim 1, characterized in that: Sealing rings are arranged between the stationary ring seat and the sealing seat, and between the dynamic ring seat and the shaft sleeve.
5. The high pressure resistant external mechanical seal according to claim 1, characterized in that: The thread groove is a multi-start thread groove.
6. The high pressure resistant external mechanical seal according to claim 1, characterized in that: The elastic element is a compression spring.