A shaft seal structure for a high-pressure high-speed double-suction centrifugal pump
By improving the shaft seal structure, including components such as sealing rings, support rings, and floating rings, the sealing problem of double-suction centrifugal pumps under high pressure and high speed is solved, achieving efficient sealing and extended service life, and reducing maintenance costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHANGHAI KAIQUAN PUMP IND GROUP
- Filing Date
- 2025-08-26
- Publication Date
- 2026-08-04
AI Technical Summary
Existing double-suction centrifugal pumps suffer from poor sealing performance under high pressure and high speed conditions, with the mechanical seal surface prone to uneven wear, resulting in short service life and high maintenance costs.
The shaft seal structure, composed of components such as sealing rings, support rings, floating rings, springs, sealing sleeves, and bearing sleeves, achieves efficient sealing and reduces leakage through the self-aligning function of the floating rings and the design of the sealing flushing port.
Under high pressure and high speed conditions, it ensures sealing performance, extends service life, reduces maintenance costs, and ensures stable operation of the double-suction centrifugal pump.
Smart Images
Figure CN224592409U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to a shaft seal structure, specifically a shaft seal structure for a high-pressure, high-speed double-suction centrifugal pump that can ensure sealing effect, effectively improve service life, and save maintenance costs. Background Technology
[0002] Double-suction centrifugal pumps typically use either packing seals or mechanical seals for their shaft seals. Packing seals are simple in structure and easy to maintain, but their service life is short under high-speed conditions, requiring frequent replacement, and their sealing effect is poor at high pressures. When using mechanical seals, the uneven pressure field distribution at both ends of the impeller in a double-suction pump generates a certain variable load, making the mechanical seal end face prone to uneven wear; especially under high-pressure and high-speed conditions, the temperature of the sealing surface rises rapidly, easily leading to failure.
[0003] Therefore, in order to ensure the sealing effect of the shaft seal of the double-suction pump under high pressure and high speed conditions, improve its service life, and ensure the operational stability of the pump unit, it is necessary to optimize its shaft seal structure. Utility Model Content
[0004] To address the aforementioned problems, the main objective of this utility model is to provide a shaft seal structure for high-pressure, high-speed, double-suction centrifugal pumps that can guarantee sealing performance, effectively improve service life, and save maintenance costs.
[0005] This utility model solves the above-mentioned technical problems through the following technical solution: a shaft seal structure for a high-pressure, high-speed, double-suction centrifugal pump, the shaft seal structure for the high-pressure, high-speed, double-suction centrifugal pump comprising: a sealing ring, a first support ring, a second support ring, a floating ring, a spring, a sealing sleeve, a shaft sleeve, a bearing sleeve, a water baffle, and a protective cover; the sealing ring, the first support ring, and the second support ring are installed in the groove between the pump body and the pump cover; the sealing sleeve presses the sealing ring, the first support ring, and the second support ring sequentially onto the end faces of the pump body and the pump cover.
[0006] The first and second support rings are provided with annular chambers, and floating rings are provided in the annular chambers. Floating rings are provided in the floating ring grooves, and springs are provided in the floating ring grooves. A protective cover is provided on the outer end face of the sealing sleeve. A bearing sleeve mounted on the pump shaft is provided between the protective cover and the pump shaft, and a water baffle is provided on the bearing sleeve.
[0007] In a specific embodiment of this utility model, three annular chambers are provided inside the first support ring and the second support ring, and each of the three annular chambers is provided with a floating ring. The two floating rings closest to the impeller are arranged back to back, and the third floating ring and the middle floating ring are aligned in the same direction.
[0008] In a specific embodiment of this utility model, the outer diameter of the bearing retainer is set in a stepped shape, and a water baffle is installed on the smaller outer diameter near the bearing retainer side, with the water baffle and the bearing retainer being interference fit.
[0009] In a specific embodiment of this utility model, a sealing ring is provided on the sealing sleeve and is threadedly connected to the outer end face of the pump body and the pump cover.
[0010] In a specific embodiment of this utility model, the number of springs is 6 to 8, which are evenly distributed along the circumference.
[0011] In a specific embodiment of this utility model, a small gap is formed between the floating ring and the bushing, and the range of the gap δ between the floating ring and the bushing is 0.1mm to 0.15mm.
[0012] In a specific embodiment of this utility model, the length of the floating ring is 0.4 to 0.6 times the inner diameter of the floating ring.
[0013] In a specific embodiment of this utility model, a positioning pin is provided on the surface of the floating ring that contacts the first support ring and the second support ring, and the gap between the pin hole corresponding to the positioning pin and the positioning pin is 0.2 to 0.3 mm.
[0014] In a specific embodiment of this utility model, a sealed flushing port is provided on the pump body and pump cover.
[0015] In a specific embodiment of this utility model, the protective cover and the sealing sleeve are connected by threads; the protective cover has an arc-shaped structure and is spaced a distance from the upper end face of the pump body, which is in the range of 20 to 30 mm.
[0016] The positive and progressive effects of this utility model are as follows: The shaft seal structure for high-pressure, high-speed double-suction centrifugal pump provided by this utility model has the following advantages: Under high-pressure and high-speed operating conditions, this utility model can ensure sealing performance, extend service life, save maintenance costs, and ensure the continuous and stable operation of the high-pressure, high-speed double-suction centrifugal pump. Attached Figure Description
[0017] Figure 1 This is an assembly drawing (sectional view) of the present invention.
[0018] Figure 2 for Figure 1 A magnified view of a portion of the image.
[0019] Figure 3-1 This is one of the structural schematic diagrams of the protective cover in this utility model.
[0020] Figure 3-2 This is the second schematic diagram of the structure of the protective cover in this utility model.
[0021] Figure 4-1This is a schematic diagram of the floating ring in this utility model.
[0022] Figure 4-2 for Figure 4-1 EE sectional view.
[0023] The following are the names corresponding to the reference numerals in this utility model:
[0024] In the above diagram: First support ring 1, Second support ring 2, Sealing ring 3, Floating ring 4, Spring 5, Positioning pin 6, Sealing sleeve 7, Shaft sleeve 8, Bearing sleeve 9, Water baffle 10, Protective cover 11, Pump body 12, Pump cover 13, Groove 14, Sealing flushing port 15, Floating ring groove 16, Circular chamber 17. Detailed Implementation
[0025] The preferred embodiments of this utility model are given below with reference to the accompanying drawings to illustrate the technical solution of this utility model in detail.
[0026] Figure 1 This is an assembly drawing (sectional view) of the present invention. Figure 2 for Figure 1 A magnified view of a portion of the image. For example... Figure 1 and 2 As shown: This utility model provides a shaft seal structure for a high-pressure, high-speed double-suction centrifugal pump. The shaft seal structure includes: a sealing ring 3, a first support ring 1, a second support ring 2, a floating ring 4, a spring 5, a positioning pin 6, a sealing sleeve 7, a shaft sleeve 8, a bearing sleeve 9, a water baffle 10, and a protective cover 11. The sealing ring 3, the first support ring 1, and the second support ring 2 are installed in a groove 14 between the pump body 12 and the pump cover 13. The sealing sleeve 7 connects the sealing ring 3 and the first support ring... 1. The second support ring 2 is pressed against the end faces of the pump body 12 and the pump cover 13 in sequence; the first support ring 1 and the second support ring 2 are provided with annular chambers 17, and floating rings 4 are provided in the annular chambers 17. The floating ring 4 is provided with a floating ring groove 16 on the larger annular end face A, and a spring 5 is provided in the floating ring groove 16; a protective cover 11 is provided on the outer end face of the sealing sleeve 7; a bearing sleeve 9 installed on the pump shaft is provided between the protective cover 11 and the pump shaft, and a water baffle 10 is provided on the bearing sleeve 9.
[0027] The first support ring 1 and the second support ring 2 each contain three annular chambers 17, and each of the three annular chambers 17 is equipped with a floating ring 4. The two floating rings closest to the impeller are arranged back to back, and the third floating ring and the middle floating ring are aligned in the same direction. The outer diameter of the bearing retainer 9 is stepped, and a baffle plate 10 is installed on the smaller outer diameter near the shaft sleeve 8. The baffle plate 10 is interference-fitted with the bearing retainer 9. A sealing ring is provided on the sealing retainer 7 of this invention, and it is threadedly connected to the outer end face of the pump body 12 and the pump cover 13. In this invention, there are 6 to 8 springs 5, which are evenly distributed along the circumference.
[0028] like Figure 2 The pump body 12 and pump cover 13 of this utility model are provided with sealing flushing ports 15. The sealing flushing fluid flows through the flow channel on the support ring to both sides of the floating ring 4. The pressure of the sealing flushing fluid is usually slightly higher than the pressure of the liquid being sealed. Under the action of the pressure difference on both sides and the spring force, the C surface of the floating ring 4 is tightly attached to the end face of the adjacent parts to achieve radial sealing.
[0029] A tiny gap forms between the floating ring and the shaft sleeve, throttling and depressurizing the sealed liquid to achieve axial sealing. When the pump shaft rotates, the liquid within the gap generates a supporting force, causing the floating ring to float up and down, automatically aligning itself. This self-aligning function allows for a small radial gap between the floating ring and the shaft sleeve to reduce leakage, while preventing collisions between the floating ring and the shaft sleeve during normal operation, which could affect the reliability of the seal. The gap δ between the floating ring and the shaft sleeve is 0.1mm to 0.15mm; this gap can be appropriately reduced to minimize leakage. The floating ring length L is 0.4 to 0.6 times the inner diameter D of the floating ring; the specific length can be adjusted according to actual needs. The sealing effect can be adjusted by adjusting the sealing gap δ or the floating ring length L.
[0030] In this invention, the floating ring 4 cannot rotate circumferentially while floating up and down; otherwise, it will accelerate the wear of the sealing gap or cause fatigue failure of the floating ring, affecting the sealing stability. To prevent the floating ring from rotating, a positioning pin 6 is provided on the C-surface of the floating ring. The gap between the pin hole and the positioning pin 6 is 0.2-0.3mm, which does not affect the self-aligning function of the floating ring. The number of positioning pins 6 is 4-6, evenly distributed along the circumference; the specific number can be designed according to actual needs.
[0031] Since the shaft seal structure of this utility model cannot achieve absolute sealing and leak-proofness, a water baffle is provided on the bearing retainer to prevent leaked liquid from entering the bearing chamber and interfering with the normal operation of the bearing. The outer diameter of the bearing retainer is set in a stepped shape, and a water baffle 10 is installed on the smaller outer diameter near the shaft retainer side. The water baffle 10 is interference-fitted with the bearing retainer 9.
[0032] like Figure 2 , Figure 3-1 and 3-2As shown: A protective cover is installed on the outer end face of the sealing sleeve to prevent leaked liquid from splashing, and also to cover the baffle plate to prevent injury to the operator when the baffle plate rotates at high speed. The protective cover and the sealing sleeve are connected by threads. The protective cover has an arc-shaped structure and leaves a distance h between it and the upper end face of the pump body, which can be within the range of 20-30mm, allowing direct observation of the seal leakage.
[0033] This invention ensures sealing performance, extends service life, and saves maintenance costs under high pressure and high speed conditions, guaranteeing the continuous and stable operation of the high pressure and high speed double-suction centrifugal pump.
[0034] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of protection of this utility model as defined by the appended claims and their equivalents.
Claims
1. A shaft seal structure for a high-pressure, high-speed double-suction centrifugal pump, characterized in that: The shaft seal structure for the high-pressure, high-speed double-suction centrifugal pump includes: a sealing ring, a first support ring, a second support ring, a floating ring, a spring, a sealing sleeve, a shaft sleeve, a bearing sleeve, a water baffle, and a protective cover; the sealing ring, the first support ring, and the second support ring are installed in the groove between the pump body and the pump cover; the sealing sleeve presses the sealing ring, the first support ring, and the second support ring sequentially onto the end faces of the pump body and the pump cover; The first and second support rings are provided with annular chambers, and floating rings are provided in the annular chambers. Floating rings are provided in the floating ring grooves, and springs are provided in the floating ring grooves. A protective cover is provided on the outer end face of the sealing sleeve. A bearing sleeve mounted on the pump shaft is provided between the protective cover and the pump shaft, and a water baffle is provided on the bearing sleeve.
2. The shaft seal structure for a high-pressure high-rotation double-suction centrifugal pump according to claim 1, characterized by: The first and second support rings each contain three annular chambers, and each of the three annular chambers contains a floating ring. The two floating rings closest to the impeller are arranged back to back, and the third floating ring and the middle floating ring are aligned in the same direction.
3. The shaft seal structure for a high-pressure high-rotation double-suction centrifugal pump according to claim 1, characterized by: The outer diameter of the bearing retainer is stepped, and a water baffle is installed on the smaller outer diameter near the bearing retainer. The water baffle is interference-fitted with the bearing retainer.
4. The shaft seal structure for a high-pressure high-rotation double-suction centrifugal pump according to claim 1, characterized by: A sealing ring is installed on the sealing sleeve and is threadedly connected to the outer end face of the pump body and pump cover.
5. The shaft seal structure for a high-pressure high-rotation double-suction centrifugal pump according to claim 1, characterized by: The number of springs is 6 to 8, evenly distributed along the circumference.
6. The shaft seal structure for a high-pressure high-rotation double-suction centrifugal pump according to claim 1, characterized by: A small gap is formed between the floating ring and the bushing, and the range of the gap δ between the floating ring and the bushing is 0.1mm to 0.15mm.
7. The shaft seal structure for a high-pressure high-rotation double-suction centrifugal pump according to claim 1, characterized by: The length of the floating ring is 0.4 to 0.6 times the inner diameter of the floating ring.
8. The shaft seal structure for a high-pressure, high-speed double-suction centrifugal pump according to claim 1, characterized in that: The floating ring is provided with a positioning pin on the surface that contacts the first support ring and the second support ring. The gap between the pin hole corresponding to the positioning pin and the positioning pin is 0.2 to 0.3 mm.
9. The shaft seal structure for a high-pressure high-rotation double-suction centrifugal pump according to claim 1, characterized by: The pump body and pump cover are equipped with sealed flushing ports.
10. The shaft seal structure for a high-pressure high-rotation double-suction centrifugal pump according to claim 1, characterized by: The protective cover and the sealing sleeve are connected by threads; the protective cover has an arc-shaped structure and is separated from the upper end face of the pump body by a distance of 20-30mm.