A high efficiency seal structure for a heat pump
By using a silicon carbide rotating ring and a stationary ring to form a sealing friction pair in the heating circulating pump, and combining it with an O-ring and a positioning plate, a balanced cartridge mechanical seal assembly is designed. This solves the problem of insufficient sealing performance in the heating circulating pump, achieves high-efficiency sealing, reduces energy consumption and safety hazards, and extends equipment life.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHAANXI WEIHE POWER GENERATION CO LTD
- Filing Date
- 2025-07-09
- Publication Date
- 2026-06-05
AI Technical Summary
The existing heating circulation pumps have poor sealing performance, which leads to media leakage, resulting in energy waste and safety hazards.
The dynamic and static rings, made of silicon carbide, form a sealing friction pair. Combined with O-rings and positioning plates, they are designed as a balanced cartridge mechanical seal assembly, including sealing end caps, flushing channels, and O-rings, to achieve multiple seals and precise positioning.
It effectively prevents media leakage, improves sealing performance, reduces energy consumption, ensures equipment safety, and extends equipment life.
Smart Images
Figure CN224326456U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of heating circulation pump technology, and more specifically, to a high-efficiency sealing structure for heating circulation pumps. Background Technology
[0002] In heating systems, the heating circulation pump is a core component, and its performance directly affects the operating efficiency and stability of the entire system. With the acceleration of global industrialization and urbanization, heating demand continues to rise, placing more stringent requirements on the performance of heating circulation pumps.
[0003] In the energy sector, especially in industries such as power, heat, and petrochemicals, heating circulation pumps are widely used. For example, thermal power plants need to use heating circulation pumps to efficiently transport high-temperature hot water or steam to urban heating networks to meet the heating needs of large areas. In the construction sector, with increasingly stringent building energy efficiency standards, high-efficiency heating circulation pumps have become key equipment for achieving energy-saving heating. Simultaneously, in chemical production processes, heating circulation pumps are used to maintain the temperature stability of reaction systems, ensuring the smooth progress of chemical reactions.
[0004] However, current heating circulating pumps on the market exhibit numerous problems during operation. Among these, poor sealing performance is one of the most prominent issues. Traditional heating circulating pumps often experience media leakage at the connection between the pump body and the pipeline, as well as at the rotating parts between the pump shaft and the pump body, due to unreasonable sealing structure design or poor sealing material performance. This not only wastes energy and reduces the efficiency of the heating system but also may pose safety hazards, such as the potential harm to surrounding personnel and equipment caused by leaked high-temperature hot water or steam. Furthermore, if the leaked medium contains chemical substances, it can also pollute the environment. Therefore, we propose a high-efficiency sealing structure for heating circulating pumps. Utility Model Content
[0005] The purpose of this invention is to provide a high-efficiency sealing structure for a heating circulation pump, so as to solve the problems mentioned in the background art.
[0006] To achieve the above objectives, this utility model provides the following technical solution:
[0007] A high-efficiency sealing structure for a heating circulating pump includes a mechanical seal assembly. The mechanical seal assembly includes a sealing bushing sleeved on the pump shaft. A rotating ring and a stationary ring that are in contact with each other are sleeved on the sealing bushing. A spring and a spring seat are provided on one side of the rotating ring.
[0008] The sealing bushing is fixedly connected to the dynamic ring as a whole, and a sealing end cover is provided on one side of the stationary ring. The sealing end cover is sealed to the pump cover end face at one end of the pump body through an O-ring.
[0009] The sealing end cap is provided with an inner flushing interface and a flushing channel. The inner flushing interface serves as the inlet for sealing cooling flushing water, and the flushing channel extends to the outer wall of the stationary ring.
[0010] Preferably, a positioning plate is provided at one end of the outer side of the sealing end cover, and a groove is provided on the sealing bushing, with the positioning plate extending into the groove.
[0011] Preferably, a positioning ring is provided at one end of the sealing bushing located outside the sealing end cover.
[0012] Preferably, a first O-ring is provided between the sealing end cover and the outer wall of the stationary ring, and a second O-ring is provided between the inner wall of the sealing bushing and the outer wall of the pump shaft.
[0013] Preferably, the spring seat and the sealing bushing are connected by a set screw.
[0014] Preferably, polytetrafluoroethylene (PTFE) gaskets are provided on both ends of the sealing bushing.
[0015] Preferably, the rotating ring and the stationary ring are made of silicon carbide materials to form a sealing friction pair.
[0016] Compared with the prior art, the beneficial effects of this utility model are as follows:
[0017] (1) This utility model has three innovations: reducing the load on the sealing surface through a balanced structure, achieving self-circulation cooling of the dynamic ring pump wheel, and simplifying installation and maintenance through a modular design. Under high temperature, high vibration, and variable load conditions, this mechanical seal assembly has constructed a three-dimensional sealing system with wear-resistant friction pairs, multiple seals, and precise positioning. It not only solves the problem of shaft end leakage and bearing damage in traditional heat pumps, but also becomes the core technical support for efficient heating systems through its energy-saving, environmentally friendly, and long-life characteristics.
[0018] (2) In this utility model, the dynamic ring and stationary ring are made of silicon carbide (CSI) to form a sealing friction pair to prevent leakage of liquid end face seal; the sealing end cover is sealed to the pump cover end face of one end of the pump body through O-ring seal to block the leakage of pump cavity medium to the atmosphere. The positioning plate prevents the sealing end cover from rotating circumferentially relative to the sealing shaft sleeve, ensuring that the sealing surfaces of the dynamic ring and stationary ring are always correctly aligned, avoiding seal failure due to circumferential misalignment. The first O-ring fills the gap to prevent the pump cavity medium from leaking to the outside or bearing chamber along the outer wall of the stationary ring; the second O-ring needs to prevent the pump cavity medium from leaking to the bearing chamber along the pump shaft surface under dynamic conditions. Attached Figure Description
[0019] Figure 1 This is a schematic diagram of the overall structure of this utility model.
[0020] The following are the labels in the diagram: 1. Pump shaft; 2. Sealing bushing; 3. Rotary ring; 4. Stationary ring; 5. Sealing end cover; 6. Positioning plate; 7. Positioning ring; 8. First O-ring; 9. Spring; 10. Spring seat; 11. Second O-ring; 12. Set screw. Detailed Implementation
[0021] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.
[0022] Example:
[0023] Please see Figure 1 A high-efficiency sealing structure for a heating circulating pump includes a mechanical seal assembly. A pump shaft 1 axially penetrates the pump body, extending to bearing chambers outside the pump body at both ends. A motor is connected to the drive end of the pump shaft 1, and a support bearing is installed at the free end of the pump shaft 1. The middle section of the pump shaft 1 is located inside the pump body and is used to install core components such as the impeller, shaft sleeve, and mechanical seal assembly. The mechanical seal assembly adopts a balanced cartridge mechanical seal, including a sealing shaft sleeve 2 fitted onto the pump shaft 1. A moving ring 3 and a stationary ring 4 are fitted onto the sealing shaft sleeve 2, which are in contact with each other. The moving ring 3 and the stationary ring 4 are made of silicon carbide (CSI) paired with silicon carbide (CSI) to form a sealing friction pair to prevent leakage of liquid. The friction pair is made of silicon carbide, which improves the wear resistance, self-lubrication, and heat dissipation performance of the moving sealing ring. Silicon carbide has basic properties such as high strength, high hardness, high wear resistance, high temperature resistance, corrosion resistance, good thermal conductivity, and resistance to rapid heating and cooling at high speeds. The high-speed rotating friction pair moving seal ring sealing seat has a blade-shaped pump wheel structure. In this way, the high-temperature medium leaking between the friction pair sealing ring assembly is drained back into the pump by the moving ring pump wheel for recovery. As the equipment continues to operate, the leaked high-temperature medium is sent back into the pump, carrying away the heat generated by friction, forming a seal between the moving and stationary parts, so that the leakage at the shaft end returns to the pump and prevents leakage to the outside.
[0024] The rotating ring 3 is provided with a spring 9 and a spring seat 10 on one side, and the rotating ring is integrated with the pump wheel structure; the sealing bushing 2 is fixedly connected to the rotating ring 3 as one piece, and a sealing end cover 5 is provided on one side of the stationary ring 4. The sealing end cover 5 is sealed to the pump cover end face at one end of the pump body through an O-ring seal to prevent the pump cavity medium from leaking to the atmosphere.
[0025] The sealing end cover 5 is provided with an internal flushing interface 501 and a flushing channel. The internal flushing interface 501 serves as the inlet for sealing cooling flushing water, and the flushing channel extends to the outer wall of the stationary ring 4. Specifically, sealing water is drawn from the top of the pump chamber impeller, exited through the reserved hole on the outlet side, and enters the mechanical seal chamber through the 1-G1 / 4 internal flushing interface 501. It is cooled, lubricated, and flushed with residue by the action of the pump impeller of the moving ring 3. A needle valve is provided at the sealing water inlet, which can manually adjust the water flow rate. The sealing water pressure is slightly higher than the internal pressure of the mechanical seal, and the mechanical seal is located in the low-pressure area on the inlet side of the pump body.
[0026] In this application, a positioning plate 6 is provided at one outer end of the sealing end cover 5, and a groove is provided on the sealing sleeve 2. The positioning plate 6 extends into the groove. The positioning plate 6 prevents the sealing end cover 5 (stationary ring 4 side) from rotating circumferentially relative to the sealing sleeve 2 (dynamic ring 3 side), ensuring that the sealing surfaces of the dynamic ring 3 and stationary ring 4 are always correctly aligned, avoiding sealing failure due to circumferential misalignment. During assembly, the circumferential installation position of the sealing end cover 5 can be quickly determined by the cooperation between the positioning plate 6 and the groove, such as aligning with the positioning pin or marking line of the pump body, avoiding a decrease in sealing performance due to installation angle deviation.
[0027] In this application, a positioning ring 7 is provided at one end of the sealing sleeve 2 located outside the sealing end cover 5. The positioning ring 7 is located at one end of the outer side of the sealing sleeve 2 (near the bearing chamber side), and its axial position forms a limiting fit with the inner end face of the sealing end cover 5, ensuring the accurate axial distance between the dynamic ring assembly (including the sealing sleeve 2) and the stationary ring assembly (including the sealing end cover 5) of the mechanical seal. When the heating circulating pump is running, the pump shaft 1 may experience axial movement due to temperature changes, fluid reaction forces, etc. The positioning ring 7 can cooperate with the axial limiting structure of the bearing chamber (such as the bearing end cover, retaining ring) to prevent the sealing sleeve 2 from moving outward (towards the bearing chamber), thus avoiding leakage due to excessive axial clearance between the dynamic and stationary ring sealing surfaces.
[0028] In this application, a first O-ring 8 is provided between the sealing end cover 5 and the outer wall of the stationary ring 4. The stationary ring 4 needs to remain stationary (fixed to the pump body) during operation, but there is a radial gap between it and the sealing end cover 5. The first O-ring 8 fills this gap to prevent the pump cavity medium from leaking along the outer wall of the stationary ring 4 to the outside or the bearing chamber. A second O-ring 11 is provided between the inner wall of the sealing sleeve 2 and the outer wall of the pump shaft 1. The sealing sleeve 2 rotates at high speed with the pump shaft 1, and the second O-ring 11 needs to prevent the pump cavity medium from leaking along the surface of the pump shaft 1 to the bearing chamber under dynamic conditions.
[0029] In this application, the spring seat 10 and the sealing sleeve 2 are connected by a set screw 12. The spring seat 10 is fitted onto the outside of the sealing sleeve 2 and needs to rotate synchronously with the pump shaft 1 to drive the rotating ring assembly. The set screw 12 rigidly locks the spring seat 10 and the sealing sleeve 2 through radial tightening, ensuring that there is no relative sliding between them and avoiding the twisting of the spring 9 or the misalignment of the rotating and stationary rings 4 due to slippage. When the heating circulating pump starts, stops, or is adjusted by frequency conversion, the torque of the pump shaft 1 fluctuates greatly. If the starting torque is 1.5 times the rated value, the tightening force of the set screw 12 can resist instantaneous overload and prevent the spring seat 10 from loosening circumferentially.
[0030] In this application, polytetrafluoroethylene (PTFE) gaskets are provided on both ends of the sealing sleeve 2. Annular sealing grooves are machined on both ends of the sealing sleeve 2, and the PTFE gaskets are interference-fitted into these grooves. The clearance between the outer diameter of the PTFE gasket and the end face of the pump body / bearing chamber is ≤0.05mm, forming a planar static seal. The PTFE gaskets are resistant to high temperatures, acids and alkalis, and water erosion, adapting to the chemical environment of the heating circulating water. Furthermore, the PTFE gaskets have a low surface friction coefficient, which can compensate for minor deformations on the end face of the sealing sleeve 2. During operation of the heating circulating pump, the sealing sleeve 2 undergoes axial thermal expansion due to temperature changes. The elastic compressibility of the PTFE gaskets absorbs this displacement, preventing wear on the sealing surface caused by rigid contact.
[0031] 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 preferred examples and are not intended to limit the 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 the claims. The scope of protection of this utility model is defined by the appended claims and their equivalents.
Claims
1. A high-efficiency sealing structure for a heating circulating pump, characterized in that, The mechanical seal assembly includes a sealing bushing (2) fitted on the pump shaft (1), on which a moving ring (3) and a stationary ring (4) in contact with each other are fitted, and a spring (9) and a spring seat (10) are provided on one side of the moving ring (3). The sealing bushing (2) is fixedly connected to the moving ring (3) as a whole. A sealing end cover (5) is provided on one side of the stationary ring (4). The sealing end cover (5) is sealed to the pump cover end face at one end of the pump body through an O-ring seal. The sealing end cap (5) is provided with an inner flushing interface (501) and a flushing channel. The inner flushing interface (501) serves as a sealing cooling flushing water inlet, and the flushing channel extends to the outer wall of the static ring (4).
2. The high-efficiency sealing structure for a heating circulating pump according to claim 1, characterized in that: A positioning plate (6) is provided on one side of the sealing end cap (5), and a groove is provided on the sealing bushing (2), with the positioning plate (6) extending into the groove.
3. The high-efficiency sealing structure for a heating circulating pump according to claim 1, characterized in that: The sealing bushing (2) is provided with a positioning ring (7) at one end outside the sealing end cover (5).
4. The high-efficiency sealing structure for a heating circulating pump according to claim 1, characterized in that: A first O-ring (8) is provided between the sealing end cover (5) and the outer wall of the stationary ring (4), and a second O-ring (11) is provided between the inner wall of the sealing bushing (2) and the outer wall of the pump shaft (1).
5. The high-efficiency sealing structure for a heating circulating pump according to claim 1, characterized in that: The spring seat (10) and the sealing bushing (2) are connected by a set screw (12).
6. The high-efficiency sealing structure for a heating circulating pump according to claim 1, characterized in that: The sealing bushing (2) is provided with polytetrafluoroethylene gaskets on both ends.
7. The high-efficiency sealing structure for a heating circulating pump according to claim 1, characterized in that: The moving ring (3) and the stationary ring (4) are made of silicon carbide material to form a sealing friction pair.