Bearing device for containment heat export pump

Abstract

The utility model relates to a bearing device for a containment heat export pump. The bearing device comprises a pump shaft, a stop lever, a bearing box body, a deflation rotary plug, a bearing, a bearing gland, an oil slinger, a screwed plug and a finned tube, the pump shaft is connected with the bearings; oil slingers are respectively arranged on the inner sides of the bearings at two ends; the top of the bearing box body is provided with a vent hole and a stop lever hole, and the bottom is provided with an oil discharge hole; a finned tube is arranged in the bearing box body; a plurality of radial labyrinth type sealing grooves are formed in an inner cavity of the bearing gland, and gaps are formed between the inner surfaces of the labyrinth type sealing grooves and the outer surface of the pump shaft. The bearing is suitable for a higher rotating speed, and safe and reliable long-term operation of the bearing in an external high-temperature environment is ensured. Labyrinth sealing belongs to non-contact sealing, no solid-phase friction heat is generated, lubrication is not needed, and deformation is not prone to occurring. The oil slinger is lubricated in a splashing manner, so that the bearing does not need to be immersed in high-temperature lubricating oil and the lubricating agent does not need to be replaced during operation; the finned tube cooling system adopted by the bearing box body is simple in structure and has good cooling performance.

Description

Technical Field

[0001] This utility model relates to a bearing device, specifically a bearing device for a containment heat removal pump that is simple in structure, easy to disassemble and maintain, easy to replace parts, widely applicable, and increases the safety and reliability of unit operation. Background Technology

[0002] The containment heat removal pump is a crucial component of the containment heat removal system (EHR). Its primary function, under extended design conditions, is to draw water from the internal containment refueling tank (IRWST) to perform functions such as filter backwashing, spraying, active sump filling, and primary loop filling. As a major component of the centrifugal pump, the bearing assembly requires careful consideration during pump design regarding its lubrication and bearing cavity cooling methods.

[0003] In containment heat removal pumps, the reliability and stability of the bearing assembly are crucial to the safety and lifespan of the entire system. Traditional containment heat removal pump bearing assemblies use grease lubrication combined with a water-cooled jacket to ensure operational stability. However, in the event of an over-design-base accident, under high-temperature operating conditions, the grease easily evaporates and oxidizes, leading to insufficient bearing lubrication. This prevents the pump unit from meeting the requirement of continuous, trouble-free operation for 8800 hours without re-lubrication. Water-cooled jacket cooling requires a water-cooling cavity designed into the bearing housing, complicating the bearing structure, increasing casting difficulty, and imposing stricter sealing requirements. Furthermore, an improperly designed water-cooling cavity not only affects the overall strength of the device but also results in poor cooling performance. Utility Model Content

[0004] To address the aforementioned problems, the main objective of this utility model is to provide a bearing device for a containment heat removal pump that is simple in structure, easy to disassemble and maintain, easy to replace parts, widely applicable, and increases the safety and reliability of unit operation.

[0005] This utility model solves the above-mentioned technical problems through the following solution: a bearing device for a containment heat removal pump, the bearing device for the containment heat removal pump comprising: a pump shaft, a stop rod, a bearing housing, a venting plug, a bearing, a bearing cap, an oil slinger ring, a plug, and a finned tube.

[0006] The pump shaft is connected to the bearing, and an oil slinger ring is installed on the inner side of each bearing. The oil slinger ring is loosely hung on one side of the bearing, and the bottom end of the oil slinger ring is immersed in the oil sump in the lower half of the bearing housing.

[0007] The top of the bearing housing has a vent hole with a venting plug and two stop holes with long rods. The bottom of the bearing housing has an oil drain hole with a plug.

[0008] The bearing housing has finned tubes inside; the bearing cover is set at one end of the bearing in the bearing housing, and the inner cavity of the bearing cover has several radial labyrinth seal grooves, with a gap between the inner surface of the labyrinth seal groove and the outer surface of the pump shaft.

[0009] The bottom of the inner surface of the bearing cap that mates with the pump shaft is provided with a wedge-shaped groove near the bearing side.

[0010] In a specific embodiment of this utility model, the two ends of the finned tube are fixed to the bearing housing by welding through end caps; the end caps are matched with the flange through a stop, and the external cooling water pipe is butt-welded to the flange.

[0011] In a specific embodiment of this utility model, an O-ring is provided between the end cap and the bearing housing.

[0012] In a specific embodiment of this utility model, the depth of the gap between the inner surface of the labyrinth seal groove and the outer surface of the pump shaft is in the range of 0.20-0.30 mm.

[0013] In a specific embodiment of this utility model, the bottom of the inner surface of the bearing cap that mates with the pump shaft is near the bearing side, and a wedge-shaped groove with an axial length of 11 mm, a maximum width of 5 mm, a depth of 6.5 mm, and an inclination angle of 5° is arranged.

[0014] In a specific embodiment of this utility model, an O-ring is provided between the bearing housing and the bearing cap.

[0015] In a specific embodiment of this utility model, the two ends of the end cap are connected to the outer sides of the two side walls of the bearing housing by flanges, and external cooling water pipes are connected to the flanges.

[0016] The positive and progressive effects of this utility model are as follows: Compared with common similar technologies, the bearing device for containment heat removal pumps provided by this utility model has a lubrication method and cooling system that can be applied to higher speeds, ensuring safe and reliable long-term operation of the bearing in external high-temperature environments. The labyrinth seal is a non-contact seal, with no solid-phase frictional heat generation, requiring no lubrication and being less prone to deformation; the splash lubrication of the oil slinger ring allows the bearing to avoid immersing in high-temperature lubricating oil, eliminating the need to replace the lubricant during operation; the finned tube cooling system used in the bearing housing has a simple structure and good cooling performance; this bearing device has a simple structure, is easy to disassemble and maintain, facilitates parts replacement, has wide applications, and increases the safety and reliability of the unit operation. Attached Figure Description

[0017] Figure 1 This is an overall structural diagram of the present invention.

[0018] Figure 2This is a schematic diagram of the structure of the labyrinth-type sealing groove and the wedge-shaped groove of this utility model.

[0019] Figure 3 This is a schematic diagram of the structure of the finned tube and end cap of this utility model.

[0020] The following are the names corresponding to the reference numerals in this utility model:

[0021] 1. Pump shaft, 2. Stop rod, 3. Bearing housing, 4. Vent plug, 5. O-ring seal, 6. Bearing gland, 7. Oil slinger ring, 8. Plug, 9. Finned tube, 10. End cap, 11. Flange, 12. Labyrinth seal groove, 13. Inner surface, 14. Gap, 15. Wedge groove, 16. Detailed Implementation

[0022] 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.

[0023] Figure 1 This is an overall structural diagram of the present invention. Figure 2 This is a schematic diagram of the structure of the labyrinth-type sealing groove and the wedge-shaped groove of this utility model. Figure 3 The above figure shows a schematic diagram of the structure of the finned tube and end cap of this utility model: This utility model proposes a bearing device for a containment heat removal pump. The bearing device for the containment heat removal pump includes: a pump shaft 1, a stop rod 2, a bearing housing 3, a vent plug 4, a bearing 5, an O-ring seal 6, a bearing cap 7, an oil slinger ring 8, a plug 9, a finned tube 10, an end cap 11, and a flange 12. The pump shaft 1 is connected to the bearing 5. An oil slinger ring 8 is provided on the inner side of each bearing at both ends. The oil slinger rings are loosely hung on one side of the bearing 5, and the bottom end of the oil slinger ring is immersed in the oil sump in the lower half of the bearing housing 3.

[0024] The bearing housing 3 has a vent hole with a vent plug 4 on the top and two stop holes with a long rod stop 2 on the bottom. The bearing housing 3 has an oil drain hole with a plug 9 on the bottom.

[0025] The inner cavity of the bearing cover 7 is provided with several radial labyrinth seal grooves, and the inner surface of the labyrinth seal groove is provided with a gap from the outer surface of the pump shaft 1; the gap between the inner surface and the outer surface of the pump shaft 1 is set to 0.20-0.30mm.

[0026] In this invention, the bottom of the inner surface of the bearing cap 7 that mates with the pump shaft 1, near the bearing side, is provided with a wedge-shaped groove. Specifically, the bottom of the inner surface of the bearing cap 7 that mates with the pump shaft 1, near the bearing side, is provided with a wedge-shaped groove 16 (i.e., an oil return hole) with an axial length of 11 mm, a maximum width of 5 mm, a depth of 6.5 mm, and an inclination angle of 5°. In this invention, the above parameters can be replaced with other values ​​or ranges depending on the specific circumstances.

[0027] The bearing housing 3 of this utility model has a finned tube 10 inside. The two ends of the finned tube 10 are fixed to the bearing housing 3 by welding through end caps 11. The end caps 11 are matched with the flange 12 through a stop, and the external cooling water pipe is butt welded to the flange 12. An O-ring is provided between the end caps 11 and the bearing housing 3.

[0028] A stop bar 2 is installed on the inner side of each of the two oil slinger rings 8 to limit the oil slinger ring and ensure that the oil slinger ring does not move axially when it is running at high speed.

[0029] Both ends of the bearing housing 3 are connected to the bearing cap 7. The inner cavity of the bearing cap is provided with 6 to 7 axial labyrinth seal grooves. The axial movement of the lubricating oil must pass through the labyrinthine tortuous gap formed by the bearing cap 7 and the pump shaft 1. This gap effectively prevents the tendency of lubricating oil to leak axially and also effectively prevents external dust from moving into the bearing housing 3. The non-contact labyrinth seal of the bearing cap 7 has no solid-phase friction with the pump shaft 1, and has the advantages of no lubrication required, lower power consumption, simple maintenance, and easy replacement.

[0030] The bearing housing 3 is also equipped with an oil return path. When the pump shaft 1 rotates, the oil slinger ring 8 rotates along with it. Under the action of centrifugal force, the oil is transported from the bottom of the bearing housing 3 to the bearing 5. The lubricating oil flows through the bearing 5, and then returns to the oil sump at the bottom of the bearing housing 3 through the bearing cover 7 and the oil return hole of the bearing housing 3, forming a circulating lubrication process. This ensures the stability of bearing lubrication, thereby allowing the pump unit to operate continuously without failure without the need for re-lubrication.

[0031] The bearing housing 3 is equipped with a venting plug 4 at the top to facilitate venting and reduce internal pressure. The bearing housing 3 is equipped with a threaded plug 9 at the bottom for draining oil and removing contaminants.

[0032] according to Figure 2 As shown, the internal temperature of the pump can reach approximately 180℃ and the external temperature can reach approximately 60℃ during operation under accident conditions. To ensure the stable operation of the bearing assembly and meet the conditions for high-temperature operation, a cooling system is designed inside the bearing housing to cool the bearing.

[0033] A finned tube 10 is installed inside the bearing housing 3. The finned tube 10 is connected to the end cap 11 by socket welding. An O-ring seal is provided between the end cap 11 and the bearing housing 3 to prevent lubricating oil leakage at the mating surface of the end cap and the bearing housing. A flange connection is used on the outer wall of the bearing housing 3. The end cap 11 mates with the flange 12 through a stop, and the external cooling water pipe is butt-welded to the flange 12. Compared with threaded connections, flange connections can withstand greater pressure and have better sealing performance. Multiple fins are wound around the outside of the finned tube 10, increasing the effective contact area between the fins and the lubricating oil, which is beneficial for heat dissipation. Furthermore, the length and diameter of the finned tube 10 can be adjusted according to the space inside the bearing housing 3. Maintenance and replacement are also very convenient; the flange 12 is removed, and the finned tube 10 and end cap 11 can be directly replaced as a whole by core extraction. The finned tube cooling system has a simple structure and is easy to cast. Under high-speed and high-temperature conditions on site, it can provide sufficient cooling effect, enabling the bearing to operate safely and stably for a long time.

[0034] This utility model adopts a labyrinth seal combined with an oil slinger ring for splash lubrication, which can cope with high temperature and high speed operating conditions. The parts are also easy to disassemble and replace.

[0035] The finned tube and end cap, together with the external flange, form a finned tube cooling system that improves heat exchange efficiency. It is also simple in structure, easy to use, safe and reliable, and easy to maintain and replace.

[0036] 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 bearing assembly for a containment heat removal pump, characterized in that: The bearing assembly for the containment heat removal pump includes: a pump shaft, a stop rod, a bearing housing, a venting plug, a bearing, a bearing cap, an oil slinger ring, a plug, and a finned tube. The pump shaft is connected to the bearing, and an oil slinger ring is installed on the inner side of each bearing. The oil slinger ring is loosely hung on one side of the bearing, and the bottom end of the oil slinger ring is immersed in the oil sump in the lower half of the bearing housing. The top of the bearing housing has a vent hole with a venting plug and two stop holes with long rods. The bottom of the bearing housing has an oil drain hole with a plug. The bearing housing has finned tubes inside; the bearing cover is set at one end of the bearing in the bearing housing, and the inner cavity of the bearing cover has several radial labyrinth seal grooves, and the inner surface of the labyrinth seal grooves is provided with a gap between the outer surface of the pump shaft. The bottom of the inner surface of the bearing cap that mates with the pump shaft is provided with a wedge-shaped groove near the bearing side.

2. The bearing assembly for a containment heat removal pump according to claim 1, characterized in that: The two ends of the finned tube are fixed to the bearing housing by welding through end caps; the end caps are matched with the flange through a stop, and the external cooling water pipe is butt welded to the flange.

3. The bearing assembly for a containment heat removal pump according to claim 2, characterized in that: An O-ring is provided between the end cap and the bearing housing.

4. The bearing assembly for a containment heat removal pump according to claim 1, characterized in that: The depth of the gap between the inner surface of the labyrinth seal groove and the outer surface of the pump shaft ranges from 0.20 to 0.30 mm.

5. The bearing assembly for a containment heat removal pump according to claim 1, characterized in that: The bottom of the inner surface of the bearing cap that mates with the pump shaft is near the bearing side, and a wedge-shaped groove with an axial length of 11 mm, a maximum width of 5 mm, a depth of 6.5 mm, and an inclination angle of 5° is arranged.

6. The bearing assembly for a containment heat removal pump according to claim 1, characterized in that: An O-ring is provided between the bearing housing and the bearing cover.

7. The bearing assembly for a containment heat removal pump according to claim 2, characterized in that: The two ends of the end cap are connected to the outer sides of the two side walls of the bearing housing by flanges, and external cooling water pipes are connected to the flanges.

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