Double-end-face mechanical seal structure for centrifugal pump
Patent Information
- Application Number
- CN202522031387.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-22
- Publication Date
- 2026-09-25
- Estimated Expiration
- 2035-09-22
AI Technical Summary
[0003]鉴于以上所述现有技术的缺点，本实用新型的目的在于提供一种离心泵用双端面机械密封结构，用于解决现有技术中单端面机械密封易磨损、冷却效率低下的问题
[0006]实现上述技术方案，离心泵用双端面机械密封结构在工作时，轴套随泵轴同步旋转，带动动环组件一同转动，而静环组件通过机封压盖固定于泵盖上保持静止。动环组件与静环组件之间通过预紧组件施加轴向压力，使动环与静环的端面紧密贴合，形成一对密封副，阻止泵内介质向外部泄漏。冷却组件中的冷却通道通过进液口引入外部冷却液或冲洗液，在密封腔内形成循环流动，带走摩擦产生的热量，降低密封面温度，并起到润滑与清洁作用，确保密封长期稳定运行。泵盖内腔的卡台对动环组件提供轴向定位支撑，机封压盖与泵盖连接后形成容纳静环组件的密封空间，整体构成完整的双端面密封系统。
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Figure CN224800545U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of mechanical seal technology, and in particular to a double-end mechanical seal structure for centrifugal pumps. Background Technology
[0002] During the operation of a centrifugal pump, the sealing structure is a core component that prevents leakage of the pump medium and ensures the safe and stable operation of the equipment. Traditional single-end mechanical seal structures rely on only one pair of sealing surfaces to achieve a seal. When gaps appear on the sealing end face due to frictional wear and thermal deformation, medium leakage is prone to occur. This risk is even higher when conveying toxic, flammable, high-pressure, or corrosive media, resulting in not only resource waste but also potential safety accidents. Furthermore, traditional sealing structures have low cooling efficiency, making it difficult to effectively dissipate the heat generated by friction on the sealing end face. This leads to accelerated aging of the seal components and a shortened service life. Additionally, in some sealing structures, the pre-tightening components are in direct contact with the medium, making them susceptible to corrosion or impurity blockage, further reducing seal reliability, increasing equipment maintenance frequency and costs, and failing to meet the stringent sealing performance requirements of industrial production. Utility Model Content
[0003] In view of the shortcomings of the prior art described above, the purpose of this utility model is to provide a double-end mechanical seal structure for centrifugal pumps, which solves the problems of easy wear and low cooling efficiency of single-end mechanical seals in the prior art.
[0004] To achieve the above and other related objectives, this utility model provides the following technical solution:
[0005] A centrifugal pump uses a double-end mechanical seal structure, comprising: a shaft sleeve that fits tightly with the pump shaft and rotates synchronously with the pump shaft; a sealing structure including a rotating ring assembly, a stationary ring assembly, and a pre-tightening assembly disposed between the stationary ring assembly and the rotating ring assembly; a pump cover with a retaining plate in its inner cavity that abuts against the rotating ring assembly; a mechanical seal gland connected to the pump cover by bolts, the inner wall of which forms a receiving cavity between itself and the pump shaft for accommodating the stationary ring assembly; and a cooling assembly including a cooling channel, an inlet and an outlet communicating with the cooling channel.
[0006] To achieve the above technical solution, the centrifugal pump's double-end-face mechanical seal structure operates with the shaft sleeve rotating synchronously with the pump shaft, causing the rotating ring assembly to rotate as well. The stationary ring assembly, however, remains stationary, fixed to the pump cover by the mechanical seal gland. An axial pressure is applied between the rotating and stationary ring assemblies via a pre-tightening assembly, ensuring a tight fit between their end faces to form a sealing pair, preventing leakage of the pump medium to the outside. The cooling channel in the cooling assembly introduces external coolant or flushing fluid through the inlet, creating a circulating flow within the sealing cavity. This carries away heat generated by friction, lowers the sealing surface temperature, and provides lubrication and cleaning, ensuring long-term stable operation of the seal. The retaining plate within the pump cover provides axial positioning support for the rotating ring assembly. The mechanical seal gland, connected to the pump cover, forms a sealing space to accommodate the stationary ring assembly, thus constituting a complete double-end-face sealing system.
[0007] In one embodiment of the present invention, the moving ring assembly includes a moving ring seat that abuts against the card plate and a moving ring whose one end abuts against the moving ring seat and whose other end abuts against the pre-tightening assembly; the stationary ring assembly includes a stationary ring seat pinned to the mechanical seal cover and a stationary ring whose one end abuts against the stationary ring seat and whose other end abuts against the pre-tightening assembly.
[0008] To achieve the above technical solution, in the centrifugal pump double-end mechanical seal structure of this utility model, the rotating ring assembly consists of a rotating ring seat and a rotating ring. The rotating ring seat is installed on the shaft sleeve and is axially positioned and supported by a retaining plate inside the pump cover. When the pump shaft rotates, the shaft sleeve drives the rotating ring seat and the rotating ring to rotate synchronously. The rotating ring is axially floating on the rotating ring seat, with one end in contact with the rotating ring seat and the other end forming contact pressure with the stationary ring through a pre-tightening assembly. The stationary ring assembly includes a stationary ring seat and a stationary ring. The stationary ring seat is fixed to the mechanical seal cover by a pin to achieve circumferential limiting and prevent it from rotating with the shaft; the stationary ring is installed inside the stationary ring seat, with one end in contact with it and the other end also subjected to the pre-tightening assembly, tightly fitting the end face of the rotating ring to form a stable double-end sealing pair. During operation, this structure relies on the pre-tightening force to maintain the sealing surface contact, while allowing slight axial movement to compensate for assembly errors and thermal deformation.
[0009] In one embodiment of the present invention, the pre-tightening assembly includes a first spring seat embedded in the moving ring, a second spring seat embedded in the stationary ring, a spring sleeved on the pump shaft and located between the first spring seat and the second spring seat, and a transmission ring with one end clamped between the moving ring and the first spring seat and the other end clamped between the stationary ring and the second spring seat.
[0010] To achieve the above technical solution, the first spring seat embedded in the rotating ring and the second spring seat embedded in the stationary ring provide stable support for the spring sleeved on the pump shaft. The spring is in a compressed state between the two spring seats, continuously applying axial preload to the rotating and stationary rings to ensure that the sealing end faces of the rotating and stationary rings are always tightly fitted, maintaining a reliable sealing pressure. Simultaneously, a transmission ring, with one end clamped between the rotating ring and the first spring seat and the other end clamped between the stationary ring and the second spring seat, can transmit the rotational power of the rotating ring to the second spring seat, preventing torsional damage to the spring due to the relative rotation of the rotating and stationary rings. It also helps to limit the displacement of each component, ensuring the overall operational stability of the preload assembly.
[0011] In one embodiment of the present invention, the cooling channel includes a cooling cavity formed by the pump cover, the moving ring, the transmission ring and the stationary ring, and a cooling gap formed by the mechanical seal cover, the stationary ring and the stationary seal seat; the pump cover has an inlet port communicating with the cooling cavity, and the mechanical seal cover has an outlet port communicating with the cooling gap.
[0012] To achieve the above technical solution, when the centrifugal pump's double-end mechanical seal structure is running, the cooling channel relies on the space formed by the collaborative efforts of multiple components to complete the cooling operation. The cooling chamber, enclosed by the pump cover, rotating ring, transmission ring, and stationary ring, and the cooling gap formed by the mechanical seal cover, stationary ring, and stationary seal seat are interconnected, constructing a complete path for the circulation of the cooling medium. External cooling medium is injected through the inlet on the pump cover that connects to the cooling chamber. After entering the cooling chamber, it comes into full contact with the high-speed rotating rotating ring and transmission ring, quickly absorbing the heat generated by friction between the sealing end faces of the rotating and stationary rings. Subsequently, the cooling medium carrying heat flows naturally to the cooling gap, further exchanging heat with the stationary ring and mechanical seal cover, continuously reducing the overall temperature of the sealing assembly, and finally being discharged through the outlet on the mechanical seal cover that connects to the cooling gap, forming a stable cooling cycle.
[0013] In one embodiment of this utility model, sealing rings are provided between the moving ring and the first spring seat, and between the stationary ring and the second spring seat.
[0014] To achieve the above technical solution, during the operation of the centrifugal pump's double-end mechanical seal structure, the sealing rings between the rotating ring and the first spring seat, and between the stationary ring and the second spring seat, achieve their sealing function through elastic deformation. Regarding the mating surface between the rotating ring and the first spring seat, since the rotating ring rotates synchronously with the pump shaft and the first spring seat is embedded within the rotating ring, there is a relative movement tendency between the two. The sealing ring relies on its own elasticity to tightly fit the mating surface, filling the tiny gaps and blocking the channel for the pump medium to seep into the pre-tightening component from these gaps. While the mating surface between the stationary ring and the second spring seat does not exhibit significant relative rotation, it may experience slight displacement due to changes in medium pressure and temperature. The sealing ring also uses elastic sealing to prevent the medium from leaking from these gaps into the cooling channel or external environment, while simultaneously adapting to dimensional changes caused by component thermal deformation, continuously maintaining sealing effectiveness.
[0015] As described above, the double-end mechanical seal structure for centrifugal pumps of this utility model has the following beneficial effects: Through multi-component collaborative design, this double-end mechanical seal structure for centrifugal pumps significantly improves sealing performance and operational stability. Firstly, the design of the double-end sealing pair with pre-tightening components allows the springs to apply a stable axial pre-tightening force to the dynamic and static rings via the first and second spring seats. This can compensate for wear and thermal deformation gaps on the sealing end faces in real time. Combined with the sealing rings between the dynamic ring and the first spring seat, and between the static ring and the second spring seat, multiple sealing defenses are constructed, significantly reducing the risk of media leakage. This makes it suitable for various harsh working conditions and ensures production safety. The cooling channel is formed by multiple components cooperating to create a continuous cooling chamber and cooling gap. A circulating cooling path is constructed through the inlet and outlet, allowing the cooling medium to fully contact the sealing surface and transmission components, effectively removing frictional heat and preventing media vaporization or coking. Sealing rings are set at key mating surfaces to further block media leakage channels and enhance the multi-layered protection capabilities of the sealing system. Attached Figure Description
[0016] Figure 1 The diagram shown is a structural schematic of this utility model.
[0017] Figure 2 Displayed as Figure 1 A magnified view of a portion of point A in the middle.
[0018] Component designation explanation
[0019] 1. Shaft sleeve; 2. Pump cover; 21. Clamping platform; 3. Mechanical seal cover; 4. Liquid inlet; 5. Liquid outlet; 6. Moving ring seat; 7. Moving ring; 8. Stationary ring seat; 9. Stationary ring; 10. First spring; 11. Second spring seat; 12. Spring; 13. Transmission ring; 14. Cooling chamber; 15. Cooling gap; 16. Sealing ring. Detailed Implementation
[0020] The following specific embodiments illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. It should be noted that, unless otherwise specified, the following embodiments and features can be combined with each other.
[0021] Please see Figures 1 to 2 This utility model provides a double-end mechanical seal structure for a centrifugal pump, comprising: a bushing 1, which is tightly fitted with the pump shaft and rotates synchronously with the pump shaft; a sealing structure, including a rotating ring 7 assembly, a stationary ring 9 assembly, and a pre-tightening assembly disposed between the stationary ring 9 assembly and the rotating ring 7 assembly; a pump cover 2, the inner cavity of which is provided with a retaining platform 21 that abuts against the rotating ring 7 assembly; a mechanical seal cover 3, which is connected to the pump cover 2 by bolts, and its inner wall forms a receiving cavity between the pump shaft for accommodating the stationary ring 9 assembly; and a cooling assembly, including a cooling channel, an inlet 4 communicating with the cooling channel, and an outlet 5.
[0022] In the centrifugal pump using a double-end-face mechanical seal structure, the bushing 1 rotates synchronously with the pump shaft, causing the rotating ring 7 assembly to rotate as well, while the stationary ring 9 assembly remains stationary, fixed to the pump cover 2 by the mechanical seal gland 3. An axial pressure is applied between the rotating ring 7 assembly and the stationary ring 9 assembly via a pre-tightening assembly, ensuring a tight fit between their end faces to form a sealing pair, preventing leakage of the pump medium to the outside. The cooling channel in the cooling assembly introduces external coolant or flushing fluid through the inlet 4, creating a circulating flow within the sealing cavity. This carries away heat generated by friction, lowers the sealing surface temperature, and provides lubrication and cleaning, ensuring long-term stable operation of the seal. The retaining plate 21 within the pump cover 2 provides axial positioning support for the rotating ring 7 assembly. The mechanical seal gland 3, connected to the pump cover 2, forms a sealing space to accommodate the stationary ring 9 assembly, thus constituting a complete double-end-face sealing system.
[0023] The moving ring 7 assembly includes a moving ring 7 seat 6 that abuts against the card plate 21, and a moving ring 7 whose one end abuts against the moving ring 7 seat 6 and whose other end abuts against the pre-tightening assembly; the stationary ring 9 assembly includes a stationary ring 9 seat 8 that is pinned to the mechanical seal cover 3, and a stationary ring 9 whose one end abuts against the stationary ring 9 seat 8 and whose other end abuts against the pre-tightening assembly.
[0024] In the double-end mechanical seal structure for centrifugal pumps of this utility model, the rotating ring 7 assembly consists of a rotating ring 7 seat 6 and a rotating ring 7. The rotating ring 7 seat 6 is mounted on the bushing 1 and is axially positioned and supported by the retaining plate 21 inside the pump cover 2. When the pump shaft rotates, the bushing 1 drives the rotating ring 7 seat 6 and the rotating ring 7 to rotate synchronously. The rotating ring 7 is axially floatingly mounted on the rotating ring 7 seat 6, with one end in contact with the rotating ring 7 seat 6 and the other end forming contact pressure with the stationary ring 9 through the pre-tightening assembly. The stationary ring 9 assembly includes a stationary ring 9 seat 8 and a stationary ring 9. The stationary ring 9 seat 8 is fixed to the mechanical seal cover 3 by a pin to achieve circumferential limiting and prevent it from rotating with the shaft; the stationary ring 9 is mounted inside the stationary ring 9 seat 8, with one end in contact with it and the other end also subjected to the pre-tightening assembly, tightly fitting the end face of the rotating ring 7 to form a stable double-end sealing pair. During operation, this structure relies on the pre-tightening force to maintain the sealing surface contact, while allowing slight axial movement to compensate for assembly errors and thermal deformation.
[0025] The pre-tightening assembly includes a first spring seat 10 embedded in the moving ring 7, a second spring seat 11 embedded in the stationary ring 9, a spring 12 sleeved on the pump shaft and located between the first spring seat 10 and the second spring seat 11, and a transmission ring 13 with one end locked between the moving ring 7 and the first spring seat 10 and the other end locked between the stationary ring 9 and the second spring seat 11.
[0026] The first spring seat 10 embedded in the rotating ring 7 and the second spring seat 11 embedded in the stationary ring 9 provide stable support for the spring 12 sleeved on the pump shaft. The spring 12 is in a compressed state between the two spring seats 12, continuously applying axial preload to the rotating ring 7 and the stationary ring 9, ensuring that the sealing end faces of the rotating ring 7 and the stationary ring 9 are always tightly fitted, maintaining a reliable sealing pressure. At the same time, the transmission ring 13, with one end clamped between the rotating ring 7 and the first spring seat 10 and the other end clamped between the stationary ring 9 and the second spring seat 11, can transmit the rotational power of the rotating ring 7 to the second spring seat 11, preventing the spring 12 from being torsional damaged due to the relative rotation of the rotating ring 7 and the stationary ring 9, and also helping to limit the displacement of each component, ensuring the overall operational stability of the preload assembly.
[0027] The cooling channel includes a cooling cavity 14 formed by the pump cover 2, the moving ring 7, the transmission ring 13 and the stationary ring 9, and a cooling gap 15 formed by the mechanical seal cover 3, the stationary ring 9 and the stationary sealing seat; the pump cover 2 has an inlet 4 that communicates with the cooling cavity 14, and the mechanical seal cover 3 has an outlet 5 that communicates with the cooling gap 15.
[0028] When the centrifugal pump's double-end mechanical seal structure is in operation, the cooling channel relies on the space formed by the collaboration of multiple components to complete the cooling operation. The cooling chamber 14, which is jointly enclosed by the pump cover 2, the rotating ring 7, the transmission ring 13, and the stationary ring 9, and the cooling gap 15 formed by the mechanical seal cover 3, the stationary ring 9, and the stationary seal seat, are interconnected, constructing a complete path for the circulation of the cooling medium. The external cooling medium is injected from the inlet 4 on the pump cover 2, which connects to the cooling chamber 14. After entering the cooling chamber 14, it comes into full contact with the high-speed rotating rotating ring 7 and the transmission ring 13, quickly absorbing the heat generated by the friction between the sealing end faces of the rotating ring 7 and the stationary ring 9. Subsequently, the cooling medium carrying heat flows naturally to the cooling gap 15, where it further exchanges heat with the stationary ring 9 and the mechanical seal cover 3, continuously reducing the overall temperature of the sealing assembly. Finally, it is discharged through the outlet 5 on the mechanical seal cover 3, which connects to the cooling gap 15, forming a stable cooling cycle.
[0029] A sealing ring 16 is provided between the moving ring 7 and the first spring seat 10, and between the stationary ring 9 and the second spring seat 11.
[0030] During the operation of the centrifugal pump's double-end mechanical seal structure, the sealing rings 16 between the rotating ring 7 and the first spring seat 10, and between the stationary ring 9 and the second spring seat 11, achieve their sealing function through elastic deformation. Regarding the mating surfaces of the rotating ring 7 and the first spring seat 10, since the rotating ring 7 rotates synchronously with the pump shaft and the first spring seat 10 is embedded within the rotating ring 7, there is a relative movement tendency between the two. The sealing ring 16 relies on its own elasticity to tightly fit the mating surfaces, filling the tiny gaps and blocking the channel for the pump medium to seep into the pre-tightening assembly from these gaps. While the mating surfaces of the stationary ring 9 and the second spring seat 11 do not exhibit significant relative rotation, they may experience slight displacement due to changes in medium pressure and temperature. The sealing ring 16 also uses elastic sealing to prevent the medium from leaking from these gaps into the cooling channel or external environment, while simultaneously adapting to dimensional changes caused by component thermal deformation, thus continuously maintaining sealing effectiveness.
[0031] The above embodiments are merely illustrative of the principles and effects of this utility model and are not intended to limit this utility model. All equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model should still be covered by the claims of this utility model.
Claims
1. A double-end mechanical seal structure for centrifugal pumps, characterized in that, include: The bushing fits tightly with the pump shaft and rotates synchronously with the pump shaft. A sealing structure includes a dynamic ring assembly, a stationary ring assembly, and a preload assembly disposed between the stationary ring assembly and the dynamic ring assembly; The pump cover has a retaining plate in its inner cavity that abuts against the moving ring assembly; The mechanical seal cover is connected to the pump cover by bolts, and its inner wall forms a receiving cavity between the pump shaft to accommodate the stationary ring assembly; A cooling assembly includes a cooling channel, an inlet and an outlet communicating with the cooling channel; The moving ring assembly includes a moving ring seat that abuts against the card table, and a moving ring whose one end abuts against the moving ring seat and whose other end abuts against the pre-tightening assembly; The stationary ring assembly includes a stationary ring seat pinned to the mechanical seal cover, and a stationary ring with one end abutting against the stationary ring seat and the other end abutting against the pre-tightening assembly; The preload assembly includes a first spring seat embedded in the moving ring, a second spring seat embedded in the stationary ring, a spring sleeved on the pump shaft and located between the first spring seat and the second spring seat, and a transmission ring with one end clamped between the moving ring and the first spring seat and the other end clamped between the stationary ring and the second spring seat.
2. The double-end mechanical seal structure for centrifugal pumps according to claim 1, characterized in that: The cooling channel includes a cooling cavity formed by the pump cover, dynamic ring, transmission ring and stationary ring, and a cooling gap formed by the mechanical seal cover, stationary ring and stationary seal seat. The pump cover has an inlet port that connects to the cooling chamber, and the mechanical seal cover has an outlet port that connects to the cooling gap.
3. The double-end mechanical seal structure for centrifugal pumps according to claim 1, characterized in that: A sealing ring is provided between the moving ring and the first spring seat, and between the stationary ring and the second spring seat.