A heat conducting oil pump with high efficient axial double circulating air bearing box structure

Abstract

The application discloses a heat conducting oil pump with a high-efficiency axial double-circulation air-cooled bearing box structure, which comprises a pump body, a mechanical sealing assembly, a bearing box, a connecting section, a mechanical sealing gland, a pump shaft, a mixed-flow fan, an auxiliary fan, an axial flow channel, a radial flow channel, a rear connecting hole, a central hole, a front connecting hole, a mixed-flow chamber, a radial hole, a cooling flow channel, a gland flow channel, a heat insulation cavity and an exhaust window, and forms double-circulation air cooling. The application has the following characteristics: the double-circulation air-cooled flow channel design can be used to implement high-efficiency cooling on multiple regions, so that the bearing working temperature is stably controlled below 75 DEG C, the mechanical sealing environment temperature is reduced to a safe working interval of 120-180 DEG C, the cooling efficiency of the heat conducting oil pump is improved, and the safety and reliability of the operation are improved, and the dependence on a complex external cooling system is reduced.

Description

Technical Field

[0001] This invention relates to the technical field of high-temperature fluid transport equipment, specifically to a heat transfer oil pump with a high-efficiency axial dual-circulation air-cooled bearing housing structure, which is particularly suitable for high-lift, multi-stage heat transfer oil pumps. Background Technology

[0002] Thermal oils (including mineral oils and synthetic oils), as highly efficient high-temperature heat transfer media, have gradually replaced traditional steam heating systems. Their closed-loop circulation relies on dedicated thermal oil pumps. These pumps are widely used in industries such as petrochemicals (e.g., reactor heating), chemical fibers (e.g., melt insulation), and new energy (e.g., solar thermal power generation thermal storage). The technological development of thermal oil pumps has consistently focused on three core challenges: high temperature resistance, leak prevention, and long service life. Their research and development stems from the urgent industrial demand for the safe and efficient transport of high-temperature heat transfer media.

[0003] Traditional heat transfer oil pumps generally suffer from the following technical problems during operation: 1. Insufficient bearing heat dissipation: High-temperature heat transfer oil continuously transfers heat to the bearing housing through components such as the pump shaft, pump cover, and connecting sections, easily leading to excessively high bearing operating temperatures (often exceeding 90℃). This can not only cause lubricant performance failure and the bearing clearance to be "eaten up" by thermal expansion, but may even lead to serious failures such as bearing seizure.

[0004] 2. High ambient temperature of mechanical seal: If the ambient temperature of the mechanical seal is too high (often above 180℃), it will significantly accelerate the wear of its sealing surface and the aging of materials, shorten its service life, and increase the risk of leakage of high temperature media.

[0005] 3. Complex and inefficient cooling system: Traditional water-cooled or simple air-cooled structures have limited heat exchange efficiency and often require external cooling water systems, which increases the complexity of the equipment, initial investment and maintenance difficulty, and also poses the risk of scaling or leakage in the water circuit.

[0006] 4. Uneven heat dissipation: A single cooling channel cannot effectively and evenly cool the bearing housing, pump shaft and mechanical seal area at the same time, which can easily lead to local hot spots, affecting the overall reliability and service life of the pump.

[0007] Therefore, there is an urgent need for an efficient, reliable and compact active cooling solution to ensure the long-term stable operation of the heat transfer oil pump under high-temperature conditions. Summary of the Invention

[0008] The purpose of this invention is to overcome the above-mentioned shortcomings and provide a heat transfer oil pump with a high-efficiency axial dual-circulation air-cooled bearing housing structure.

[0009] The technical solution adopted by the present invention to achieve the above objectives is as follows: A heat transfer oil pump with a high-efficiency axial dual-circulation air-cooled bearing housing structure includes a pump body and a bearing housing sleeved on a pump shaft. A mechanical seal assembly is provided at the connection between the two. The mechanical seal assembly is sleeved on the pump shaft. The bearing housing is connected to the pump body through a connecting section. The front and rear ends of the bearing housing are respectively mounted on the pump shaft via a front bearing and a rear bearing. A rear bearing cover is press-fitted onto the rear end of the rear bearing. The rear bearing cover is mounted on the pump shaft and fixed to the bearing housing. A front bearing cover is press-fitted onto the front end of the front bearing. The front bearing cover is mounted on the pump shaft and fixed to the bearing housing. The pump shaft is fitted with a mixed flow fan at the rear end of the bearing housing. The mixed flow fan is fitted with a fan cover, and the fan cover has an air inlet. The open end of the fan cover is fitted onto the bearing housing, and an axial flow channel is formed between the two. The axial flow channel is connected to the outside of the bearing housing. The pump shaft is located between the rear end of the bearing housing and the mixing fan, and a rear connection hole is radially opened therein. A radial flow channel communicating with the rear connection hole is formed between the mixing fan and the bearing housing. The pump shaft is located between the front end of the bearing housing and the auxiliary fan and has a front connecting hole in the radial direction. The front connecting hole and the rear connecting hole are connected through an axial center hole opened inside the pump shaft. The mechanical seal assembly is fitted with a mechanical seal cover, which is fixed to the pump body. An auxiliary fan is provided between the mechanical seal cover and the front end of the bearing housing. The auxiliary fan is fitted on the pump shaft. The auxiliary fan and the mechanical seal cover are located inside the connecting section and form a cooling channel with the connecting section and the pump shaft. The auxiliary fan has a mixing chamber at its hub. One end of the mixing chamber is connected to the front connection hole, and the other end is connected to the cooling channel through a radial hole on the impeller of the auxiliary fan. A heat insulation cavity is formed between the middle section and the connecting section of the mechanical seal gland. An exhaust window is provided on the connecting section. The heat insulation cavity is connected to the outside of the connecting section through the exhaust window. The middle section of the mechanical seal gland has a double-layer structure with a gland flow channel formed between the two layers. The rear end of the gland flow channel is connected to the cooling flow channel, and the front end is connected to the heat insulation cavity.

[0010] The outer wall of the bearing housing is evenly distributed with heat sinks, and the open end of the fan shroud is fitted onto the heat sinks, forming an axial flow channel between the fan shroud, the heat sinks, and the bearing housing.

[0011] The rear bearing is an angular contact ball bearing, and the front bearing is a cylindrical roller bearing.

[0012] A bearing isolator is installed between the rear bearing cover and the pump shaft, and a magnetic seal is installed between the front bearing cover and the pump shaft.

[0013] The pump shaft is located inside the bearing housing and is fitted with an oil splash ring.

[0014] The pump body is connected to the connecting section via a flange, and the mechanical seal gland is fixed to the flange.

[0015] The invention features a dual-circulation air-cooled channel design, which enables targeted and efficient cooling of multiple areas, thereby stabilizing the bearing operating temperature below 75°C and reducing the mechanical seal ambient temperature to a safe operating range of 120-180°C. This improves the cooling efficiency of the heat transfer oil pump, as well as its operational safety and reliability, and reduces reliance on complex external cooling systems. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a schematic diagram of the dual-cycle air-cooling structure of the present invention; Figure 3 This is a schematic diagram of the first cycle of the present invention; Figure 4 This is a schematic diagram of the second cycle of the present invention; Figure 5 This is a schematic diagram of the bearing housing structure of the present invention; Figure 6 yes Figure 5 Side sectional view; Figure 7 This is a schematic diagram of the connecting segment structure of the present invention; Figure 8 The structure of the connecting segment of the present invention Figure 1 ; Figure 9 The structure of the connecting segment of the present invention Figure 2 ; Figure 10 This is a schematic diagram of the mixed-flow fan structure of the present invention; Figure 11 yes Figure 10 Side view; Figure 12 This is a schematic diagram of the fan cover structure of the present invention; Figure 13 yes Figure 12 Side view; Figure 14 This is a schematic diagram of the auxiliary fan structure of the present invention; Figure 15 yes Figure 14 Side view; Figure 16 This is a schematic diagram of the mechanical seal gland structure of the present invention; Figure 17 This is a cross-sectional view of the mechanical seal gland of the present invention. Figure 1 ; Figure 18 This is a cross-sectional view of the mechanical seal gland of the present invention. Figure 2 .

[0017] The components are as follows: 1. Bearing housing; 2. Connecting section; 3. Mechanical seal assembly; 4. Mechanical seal gland; 5. Pump shaft; 6. Mixing fan; 7. Auxiliary fan; 8. Front bearing; 9. Front bearing gland; 10. Magnetic seal; 11. Rear bearing; 12. Rear bearing gland; 13. Bearing isolator; 14. Oil splash ring; 15. Eye bolt; 16. Oil-gas separator; 17. Oil window; 18. Oil cup; 19. Heat sink; 20. Axial flow channel; 21. Radial flow channel; 22. Rear connection hole; 23. Center hole; 24. Front connection hole; 25. Mixing chamber; 26. Radial hole; 27. Cooling flow channel; 28. Gland flow channel; 29. ​​Heat insulation cavity; 30. Exhaust window; 31. Air inlet; 32. Fan cover; 33. Flange; 34. Pump body. Detailed Implementation

[0018] like Figure 1-18As shown, this invention relates to a heat transfer oil pump with a high-efficiency axial dual-circulation air-cooled bearing housing structure, comprising a pump body 34 sleeved on a pump shaft 5 and a bearing housing 1. A mechanical seal assembly 3 is provided at the connection between the two. The mechanical seal assembly 3 is sleeved on the pump shaft 5 and prevents liquid inside the pump body 34 from leaking outward along the pump shaft 5 to the bearing housing 1 or the external environment. The bearing housing 1 is connected to the flange 33 installed at the end of the pump body 34 through a connecting section 2. Isolation, i.e., isolation from the high-temperature side of the pump, is achieved by using a material with relatively high thermal resistance and designing a hollow heat insulation cavity structure to effectively block high-temperature heat conduction from the pump body 34 end. The bearing housing 1 is equipped with a lifting eye bolt 15, an oil-gas separator 16, an oil window 17, and an oil cup 18. The bearing housing 1 is made of high-strength cast iron or cast steel, with a low coefficient of thermal expansion and minimal thermal deformation. The front and rear ends of the bearing housing 1 are respectively mounted on the pump shaft 5 via a front bearing 8 and a rear bearing 11. All bearings 11 are rolling bearings, wherein the rear bearing 11 is an angular contact ball bearing, and the front bearing 8 is a cylindrical roller bearing. The bearing housing 1 uses thin oil lubrication to ensure sufficient lubrication of the internal front bearing 8 and rear bearing 11. A rear bearing cover 12 is press-fitted to the rear end of the rear bearing 11. The rear bearing cover 12 is fitted onto the pump shaft 5 and fixed to the bearing housing 1. A bearing isolator 13 is installed between the rear bearing cover 12 and the pump shaft 5. A front bearing cover 9 is press-fitted to the front end of the front bearing 8. The front bearing cap 9 is fitted onto the pump shaft 5 and fixed to the bearing housing 1. A magnetic seal 10 is installed between the front bearing cap 9 and the pump shaft 5. The front and rear ends of the bearing housing 1 are sealed by the magnetic seal 10 and the bearing isolator 13, respectively, to prevent the high-temperature lubricating oil from atomizing and escaping, causing environmental pollution. The outer wall of the bearing housing 1 is evenly distributed with heat sinks 19. The heat generated by the operation of the bearings (front bearing 8 and rear bearing 11) is absorbed by the lubricating oil, and the lubricating oil is then dissipated in the form of heat radiation through the heat sinks 19 of the bearing housing 1.

[0019] The pump shaft 5 is fitted with an oil splash ring 14 inside the bearing housing 1. When the pump shaft 5 rotates, the oil splash ring 14 can be driven to rotate synchronously by static friction. The oil splash ring 14 is an eccentric ring that can splash the lubricating oil at the bottom of the bearing housing 1, forming a fine oil mist or oil droplets. The oil droplets adhere to the inner wall of the bearing housing 1 and can transfer the internal heat to the outer wall of the bearing housing 1 through heat conduction. Moreover, the splashed lubricating oil flows to the bearings at both ends under the action of centrifugal force, forming a local forced oil circulation that flows through the bearing rolling elements and cage, which significantly enhances the cooling and lubrication effect of the bearing itself.

[0020] The pump shaft 5 is fitted and fixed at the rear end of the bearing housing 1 with a mixed-flow fan 6. The mixed-flow fan 6 rotates synchronously with the pump shaft 5. The mixed-flow fan 6 adopts a mixed-flow impeller design, which can take into account both air volume and air pressure, and has the advantages of high efficiency and low operating noise. A fan cover 32 is fitted on the mixed-flow fan 6. The open end of the fan cover 32 is fitted on the heat sink 19. An axial flow channel 20 is formed between the fan cover 32, the heat sink 19, and the bearing housing 1. The axial flow channel 20 is connected to the outside of the bearing housing 1. The fan cover 32 is manufactured by stamping process. Its end face has an air inlet 31. The air inlet 31 can be optimized by aerodynamic design (such as using a specific shape and arrangement of holes). The fan cover 32 is provided with stress buffer groove to release the internal stress generated by stamping and prevent the cover from deforming. An interface can be reserved on the fan cover 32 to facilitate the installation of monitoring elements such as temperature sensors and vibration sensors.

[0021] The pump shaft 5 is located between the rear end of the bearing housing 1 and the mixed flow fan 6, and a rear connection hole 22 is radially opened therein. A radial flow channel 21 is formed between the mixed flow fan 6 and the bearing housing 1, which communicates with the rear connection hole 22. The pump shaft 5 is located between the front end of the bearing housing 1 and the auxiliary fan 7, and a front connection hole 24 is radially opened therein. The front connection hole 24 and the rear connection hole 22 are connected through an axial center hole 23 opened inside the pump shaft 5.

[0022] The mechanical seal assembly 3 is fitted with a mechanical seal cover 4, which is fixed to the flange 33. An auxiliary fan 7 is provided between the mechanical seal cover 4 and the front end of the bearing housing 1. The auxiliary fan 7 is fitted and fixed on the pump shaft 5. The auxiliary fan 7 rotates synchronously with the pump shaft 5. The auxiliary fan 7 and the mechanical seal cover 4 are located in the connecting section 2 and form a cooling channel 27 with the connecting section 2 and the pump shaft 5.

[0023] The auxiliary fan 7 has a mixing chamber 25 at its hub. One end of the mixing chamber 25 is connected to the front connection hole 24, and the other end is connected to the cooling channel 27 through the radial hole 26 on the impeller of the auxiliary fan 7. The mixing chamber 25 can mix the uneven airflow from the pump shaft 5 evenly, and after being radially pressurized by its blades, it is evenly distributed to the subsequent cooling channel 27, thereby improving the cooling uniformity and reducing vibration and noise caused by airflow pulsation.

[0024] A heat insulation cavity 29 is formed between the middle section of the mechanical seal gland 4 and the connecting section 2. An exhaust window 30 is provided on the connecting section 2. The heat insulation cavity 29 is connected to the outside of the connecting section 2 through the exhaust window 30. The middle section of the mechanical seal gland 4 has a double-layer structure, and a gland flow channel 28 is formed between the two layers. The rear end of the gland flow channel 28 is connected to the cooling flow channel 27, and the front end is connected to the heat insulation cavity 29.

[0025] This invention adopts an axial dual-circulation air-cooling design, consisting of a first circulation (cooling circulation for the main bearing housing 1) and a second circulation (cooling circulation for the shaft system and sealing depth). The mixed-flow fan 6 is fixedly installed at the rear end of the pump shaft 5, and rotates synchronously with the pump shaft 5. The mixed-flow fan 6 is responsible for air intake, cooling of the bearing housing 1, and air delivery to the central hole 23. That is, the mixed-flow fan 6 provides the main airflow for the first circulation and provides the source airflow for the second circulation. The auxiliary fan 7 is fixedly installed at the front end of the pump shaft 5, and rotates at the same speed and starts and stops at the same time as the pump shaft 5 and the mixed-flow fan 6. The auxiliary fan 7 is responsible for secondary stabilization and pressurization of the airflow from the central hole 23 and sending it into the cooling channel 27. The mixed-flow fan and the auxiliary fan always operate simultaneously and work together.

[0026] First cycle (cooling cycle of main bearing housing 1): Cooling air is drawn in through the air inlet 31 on the end face of the fan shroud 32 installed at the rear end of the bearing housing 1, and after being pressurized by the mixed-flow fan 6, it is forced to flow along the axial flow channel 20 on the outer periphery of the bearing housing 1 (see...). Figure 3 At point A), cooling air directly washes over the outer surface of the bearing housing 1, efficiently carrying away the heat conducted from the inner wall of the bearing housing 1 to the outer wall.

[0027] Second cycle (shaft and seal depth cooling cycle): from the radial flow channel 21 of the first cycle (see...) Figure 3 A portion of the cooling air diverted from point B enters the center hole 23 of the pump shaft 5 through the rear connection hole 22 (see...). Figure 4 (At point C), the pump shaft 5 has a hollow structure. The cooling airflow flows through the shaft center, directly cooling the pump shaft 5 body, effectively suppressing the axial thermal expansion of the pump shaft 5 caused by heat transfer from the high-temperature heat transfer oil. Afterward, the airflow passes through the front connecting hole 24 and then along the annular flow channel formed between the outer surface of the pump shaft 5 and the mixing chamber 25 of the auxiliary fan 7 (see...). Figure 4 At point D), the pump shaft 5 undergoes secondary external surface cooling. Then, the airflow, pressurized by the radial holes 26 on the blades of the auxiliary fan 7, enters the cooling channel 27 on the inner wall of the connecting section 2 (see...). Figure 4 At point E), the connecting section 2 is cooled to further block the heat flow from the pump body 34 end to the bearing housing 1. Finally, the airflow is directed to the gland flow channel 28 of the mechanical seal gland 4 (see...). Figure 4 At point F, the mechanical seal is directly cooled, and finally discharged from the system through the exhaust window 30 on the connecting section 2 via the heat insulation cavity 29.

[0028] The workflow of this invention is as follows: When the pump starts running, the mixed-flow fan 6 starts synchronously, driving the first and second cycles at the same time. The cooling air flows according to the above-mentioned design path, forming two cooling circuits that are both relatively independent and interconnected. At the same time, the oil splashing ring 14 starts to work, enhancing the heat exchange inside the bearing housing 1. The entire system thus constitutes a synergistic and efficient cooling system from external forced air cooling to internal active oil splashing circulation.

[0029] The present invention achieves at least the following beneficial effects: 1. High-efficiency and precise cooling: The axial dual-circulation air-cooling design enables zoned and directional high-efficiency cooling of key components such as bearing housing, pump shaft (including inner hole and outer surface), and mechanical seal, effectively solving the problems of uneven heat dissipation and the existence of cooling dead zones in traditional cooling methods; 2. Significant temperature reduction effect: It can reliably control the bearing operating temperature below 75℃ and reduce the mechanical seal ambient temperature to a safe and reliable operating range of 120-180℃, thereby greatly extending the service life of the bearing and mechanical seal; 3. Safe and reliable operation: By effectively suppressing the overheating expansion of the pump shaft, the loss of bearing clearance due to thermal expansion is prevented, reducing the risk of bearing seizure. At the same time, the probability of leakage caused by mechanical seal failure due to high temperature is reduced, significantly improving the operational stability and safety of the entire pump under high temperature conditions. 4. Compact structure and self-sufficiency: The high-efficiency cooling system is highly integrated into the pump unit itself, eliminating the need for a complex external cooling water system. This simplifies equipment installation and piping layout, reduces operation and maintenance costs and dependence on water resources, making it particularly suitable for areas with water shortages or poor water quality. 5. Energy saving and noise reduction: The optimized mixed-flow fan and flow channel design improves airflow organization efficiency, reduces fan power consumption while ensuring cooling effect, and effectively suppresses airflow noise and vibration through the flow stabilization structure such as the mixed-flow chamber.

[0030] 6. Enhanced Lubrication and Heat Dissipation Synergy: The oil splash ring design not only realizes the internal circulation and splash lubrication of lubricating oil, but also actively participates in the transfer and dissipation of heat inside the bearing housing, effectively complementing the external dual-circulation air-cooling system, resulting in high overall thermal management efficiency.

[0031] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A heat transfer oil pump with a high-efficiency axial dual-circulation air-cooled bearing housing structure, comprising a pump body and a bearing housing sleeved on a pump shaft, wherein a mechanical seal assembly is provided at the connection between the two, the mechanical seal assembly being sleeved on the pump shaft, characterized in that: The bearing housing is connected to the pump body via a connecting section; the front and rear ends of the bearing housing are respectively fitted onto the pump shaft via a front bearing and a rear bearing. A rear bearing cap is press-fitted onto the rear end of the rear bearing, which is fitted onto the pump shaft and fixed to the bearing housing. A front bearing cap is press-fitted onto the front end of the front bearing, which is fitted onto the pump shaft and fixed to the bearing housing. A mixed-flow fan is fitted onto the pump shaft at the rear end of the bearing housing. The mixed-flow fan is fitted with a fan shroud, which has an air inlet. The open end of the fan shroud is fitted onto the bearing housing, forming an axial flow channel between them, which communicates with the outside of the bearing housing. A rear connection hole is radially formed between the pump shaft at the rear end of the bearing housing and the mixed-flow fan, and a radial flow channel communicating with the rear connection hole is formed between the mixed-flow fan and the bearing housing. A front connection hole is radially formed between the pump shaft at the front end of the bearing housing and the auxiliary fan. The front and rear connecting holes are connected through an axial center hole inside the pump shaft. A mechanical seal cover is fitted onto the mechanical seal assembly and fixed to the pump body. An auxiliary fan is provided between the mechanical seal cover and the front end of the bearing housing. The auxiliary fan is fitted onto the pump shaft. The auxiliary fan and the mechanical seal cover are located within the connecting section and form a cooling channel with the connecting section and the pump shaft. A mixing chamber is provided at the hub of the auxiliary fan. One end of the mixing chamber is connected to the front connecting hole, and the other end is connected to the cooling channel through a radial hole on the impeller of the auxiliary fan. A heat insulation cavity is formed between the middle section of the mechanical seal cover and the connecting section. An exhaust window is provided on the connecting section, and the heat insulation cavity is connected to the outside of the connecting section through the exhaust window. The middle section of the mechanical seal cover has a double-layer structure, with a cover flow channel formed between the two layers. The rear end of the cover flow channel is connected to the cooling channel, and the front end is connected to the heat insulation cavity.

2. The heat transfer oil pump with a high-efficiency axial dual-circulation air-cooled bearing housing structure as described in claim 1, characterized in that: The outer wall of the bearing housing is evenly distributed with heat sinks, and the open end of the fan shroud is fitted onto the heat sinks, forming an axial flow channel between the fan shroud, the heat sinks, and the bearing housing.

3. The heat transfer oil pump with a high-efficiency axial dual-circulation air-cooled bearing housing structure as described in claim 1, characterized in that: The rear bearing is an angular contact ball bearing, and the front bearing is a cylindrical roller bearing.

4. The heat transfer oil pump with a high-efficiency axial dual-circulation air-cooled bearing housing structure as described in claim 1, characterized in that: A bearing isolator is installed between the rear bearing cover and the pump shaft, and a magnetic seal is installed between the front bearing cover and the pump shaft.

5. A heat transfer oil pump with a high-efficiency axial dual-circulation air-cooled bearing housing structure as described in claim 1, characterized in that: The pump shaft is located inside the bearing housing and is fitted with an oil splash ring.

6. A heat transfer oil pump with a high-efficiency axial dual-circulation air-cooled bearing housing structure as described in claim 1, characterized in that: The pump body is connected to the connecting section via a flange, and the mechanical seal gland is fixed to the flange.

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