Novel shield pump

Abstract

The utility model discloses a novel shield pump which comprises a pump cylinder, one end of the pump cylinder is provided with a liquid inlet, the other end of the pump cylinder is provided with a liquid outlet, a rotor shaft is arranged in the pump cylinder, the rotor shaft is sequentially provided with a bearing seat, a rotor, a connecting seat and an impeller assembly from one end of the liquid inlet to the other end of the liquid inlet, the rotor is sleeved with a stator, and bearings are arranged in the bearing seat and the connecting seat respectively. The bearing is sleeved on the rotor shaft, and liquid through holes are further arranged in the bearing seat and the connecting seat. The shield pump has the beneficial effects that the shield pump is coaxially provided with the liquid inlet, the bearing seat, the rotor, the connecting seat, the impeller assembly and the liquid outlet in sequence, so that the motor and a lubricating part are located in a low-pressure environment, pumped liquid flow can take away bubbles and heat, noise is reduced, and the service life is prolonged.

Description

Technical Field

[0001] This utility model relates to the field of permanent magnet shielded pump technology, and more specifically, to a novel shielded pump. Technical Background

[0002] Canned motor pumps are centrifugal, seal-free pumps. Both the pump and the drive motor are enclosed within a pressure vessel filled with the pumped medium. The drive motor places the stator and rotor separately within sealed, non-magnetic, corrosion-resistant metal cylinders. The stator provides the rotating magnetic field to drive the rotor. The rotor and impeller are fixed to the same shaft. The canned motor pump can be lubricated and cooled by the pumped medium, thus eliminating the need for additional lubricating grease or a cooling fan. Due to its unique design, the dynamic seal on the pump shaft is eliminated, employing a static seal structure, making the canned motor pump completely leak-free. This effectively avoids environmental pollution and material loss, making it suitable for conveying valuable or contaminated liquids.

[0003] Existing shielded pumps, such as the utility model patent CN216554442U announced by the State Intellectual Property Office on May 17, 2022, the utility model patent CN222717084U announced on April 4, 2025, and the invention patent CN119687037A published on March 25, 2025, generally suffer from problems such as rapid wear of the lubrication parts, shorter service life than expected, and high noise levels. Summary of the Invention

[0004] To overcome the above-mentioned defects, the technical problem to be solved by this utility model is to provide a new type of shielded pump with a more reasonable structural layout, which can reduce noise and have a longer service life.

[0005] To solve the aforementioned technical problem, the technical solution of this utility model is: a novel shielded pump, comprising a pump barrel, an inlet at one end of the pump barrel, an outlet at the other end of the pump barrel, a rotor shaft disposed inside the pump barrel between the inlet and the outlet, the rotor shaft being provided with a bearing housing, a rotor, a connecting seat, and an impeller assembly sequentially from one end near the inlet to the other end near the outlet, a stator being fitted onto the outer circumference of the rotor with a gap, bearings being disposed in the bearing housing and the connecting seat respectively, the bearings being fitted onto the rotor shaft, and axially arranged liquid passage holes being disposed in the bearing housing and the connecting seat respectively.

[0006] To solve the aforementioned technical problem, the inventors carefully studied the structure and layout of existing canned motor pumps and investigated the possible causes of the problem. The study revealed that because the rotor and impeller of existing canned motor pumps are fixed on the same shaft, the drive shaft and the outlet axis are typically arranged perpendicularly. This means the drive motor is located outside the liquid flow path, essentially in a "T" shape. The inventors analyzed that this structural layout could inevitably cause some gas to be introduced into the pump due to unavoidable reasons. The impeller or blades agitate this gas, causing it to break apart and form numerous bubbles that scatter erratically. Once these bubbles enter the motor or lubrication points, they will continuously cause adverse effects on these parts. If air bubbles enter the motor and are located in the gap between the stator and rotor, the rotor will experience an imbalance in circumferential liquid pressure, resulting in rotor dynamic imbalance and noise. This will also cause uneven wear on the bearings supporting the rotor's rotation. Similarly, if air bubbles enter lubrication points, the shaft will also experience dynamic imbalance and noise. Furthermore, uneven wear may occur along with dry wear, leading to premature damage to lubricated parts and shortening the pump's lifespan. The "T"-shaped arrangement of the pump also hinders heat dissipation from the stator and rotor, and excessively high temperatures will further shorten the pump's lifespan. To address these issues, the inventors have adopted the following solution: changing the shape of the impeller blades, changing the impeller's liquid delivery direction from radial to axial, and arranging the pump's inlet, outlet, drive shaft, and impeller axis in a linear fashion. This allows the pumped liquid flow to carry away unwanted air bubbles and heat, eliminating the persistent effects of these bubbles, thus reducing noise and extending the pump's lifespan. To verify the correctness of the above countermeasures and mechanisms, the inventors specially made a shielded pump verification machine using transparent material. Through multiple experiments, they found that the technical solution of sequentially arranging the bearing housing, rotor, connecting seat, and impeller assembly from one end of the rotor shaft near the liquid inlet to the other end near the liquid outlet is superior to the technical solution of impeller assembly, connecting seat, rotor, and bearing housing. The reason for this is that in the former technical solution, the drive motor and lubrication parts operate in a low-pressure environment, and the liquid flow there is not disturbed by the impeller, resulting in a more stable flow. In contrast, in the latter technical solution, the drive motor and lubrication parts operate in a high-pressure environment, and the liquid flow there is disturbed by the impeller, resulting in a spiral rotation, which is not conducive to the removal of air bubbles. Therefore, the inventors determined that the technical solution of sequentially arranging the bearing housing, rotor, connecting seat, and impeller assembly from one end of the rotor shaft near the liquid inlet to the other end near the liquid outlet is the optimal solution for solving the aforementioned technical problem. In addition, the bearing housing and connecting seat are provided with axially arranged fluid passage holes on the outside of the bearing. This is conducive to the timely removal of heat generated by the stator, rotor and bearing, and also helps to extend the service life of the canned pump.

[0007] As a further technical solution, the bearing is a bearing sleeve, and the outer peripheral surface and the end face away from the rotor of the bearing sleeve are respectively provided with recesses, and buffer elements are provided in the recesses. The bearing can be a rolling bearing, a sliding bearing, or a bearing bush; this patent application preferably uses a bearing sleeve that falls under the category of sliding bearings. Providing recesses and buffer elements on the outer surface of the bearing sleeve that needs to contact the bearing housing and connecting seat allows the bearing sleeve to buffer impact loads from the bearing housing and connecting seat. This allows for the selection of inexpensive and durable, brittle yet wear-resistant materials for the bearing sleeve, thereby extending the service life of the canned pump.

[0008] As a further technical solution, the rotor shaft is provided with positioning rings at both ends of the rotor, and the positioning rings have annular grooves at the connection between the rotor shaft and the rotor, with sealing rings installed within the annular grooves. In the prior art, the rotor shaft and rotor, and the rotor and rotor sleeve, are all connected by welding to achieve a static seal. However, welding connections also have drawbacks; for example, if either the rotor shaft or the rotor is damaged, the entire rotor needs to be replaced, resulting in high maintenance costs. This technical solution uses positioning rings and sealing rings for static sealing, which allows for maintenance where only the damaged parts need to be replaced, thereby reducing the maintenance cost of the canned motor pump.

[0009] As a further technical solution, the fluid passage holes are circumferentially distributed on the bearing housing and connecting seat near the bearing sleeve, and the fluid passage holes are connected to the gaps between the stator and rotor. This is beneficial for cooling the stator, rotor, and bearings.

[0010] As a further technical solution, the bearing housing is integrated with the liquid inlet via a connecting pipe. The connecting pipe has a through hole that passes through both the bearing housing and the liquid inlet. The connecting pipe securely fuses the bearing housing to the liquid inlet, while the gap between adjacent connecting pipes provides space for liquid flow in the shielded pump. Furthermore, the through hole in the connecting pipe provides a channel for the potting process and wiring.

[0011] As a further technical solution, the impeller assembly includes an impeller and guide vanes, with the impeller fixedly connected to the rotor shaft. Integrating the impeller and guide vanes into a single impeller assembly creates a complementary and organic whole, allowing the impeller to focus on energy conversion and liquid transport, while the guide vanes reduce energy loss during liquid flow, thereby improving the overall efficiency of the pump.

[0012] As a further technical solution, the connecting hole of the impeller is an oblong hole. The cross-section of the rotor shaft at the location matching the connecting hole of the impeller is also oblong. This power transmission structure is the simplest and has the lowest manufacturing cost.

[0013] As a further technical solution, the bearing sleeve is made of carbon graphite material. Carbon graphite material has excellent self-lubricating properties, wear resistance, light weight, corrosion resistance, and a low coefficient of thermal expansion, making it the most cost-effective choice for canned pump bearing sleeves. However, due to the manufacturing process of carbon graphite material, it is hard and brittle, making it unsuitable for applications with impact loads. Furthermore, since the technical solution of this utility model includes a buffer protection structure on the outer side of the bearing sleeve, choosing carbon graphite material for manufacturing the canned pump bearing sleeve becomes a logical choice.

[0014] The beneficial effects of this utility model are as follows: 1. Because the inlet, outlet, rotor shaft, and impeller of the canned motor pump are arranged coaxially, the pumped liquid flow can promptly remove unwanted air bubbles and heat, eliminating the continuous influence of unwanted air bubbles, which helps reduce the noise of the canned motor pump and extend its service life; 2. Because the impeller assembly is configured between the rotor and the outlet, it ensures that the drive motor and lubrication parts operate in a low-pressure environment, and the liquid flow there is not disturbed by the impeller, making it more stable, which helps to further reduce the noise of the canned motor pump and extend its service life; 3. Because the bearing housing and connecting seat are provided with axially arranged liquid passage holes on the outside of the bearing sleeve, it helps to promptly remove the heat generated by the stator, rotor, and bearing sleeve, which also helps to extend the service life of the canned motor pump. Attached Figure Description

[0015] Figure 1 This is a structural cross-sectional view of the present invention;

[0016] Figure 2 This is a three-dimensional visual diagram of the liquid inlet of this utility model;

[0017] Figure 3 This is a three-dimensional schematic diagram of the liquid inlet of this utility model from another perspective;

[0018] Figure 4 This is a three-dimensional schematic diagram of the connector of this utility model;

[0019] Figure 5 This is a three-dimensional schematic diagram of the impeller of this utility model.

[0020] In the diagram: 1. Pump barrel; 2. Inlet; 3. Bearing sleeve; 4. Positioning ring; 5. Rotor; 6. Motor barrel; 7. Impeller; 8. Guide vane; 9. Outlet; 10. Connecting seat; 11. Sealing ring; 12. Rotor shaft; 13. Stator; 14. Rotor sleeve; 15. Rotor end ring; 16. Stator shielding sleeve; 17. Buffer; 18. Bearing seat; 19. Through hole; 20. Liquid passage hole; 21. Waist-shaped hole. Detailed Implementation

[0021] The present invention will be further described below with reference to specific embodiments and accompanying drawings.

[0022] Example: A novel shielded pump, as shown in the figure, includes a pump barrel 1. One end of the pump barrel 1 has an inlet 2, and the other end has an outlet 9. A rotor shaft 12 is disposed inside the pump barrel 1 between the inlet 2 and the outlet 9. From the end near the inlet 2 to the end near the outlet 9, the rotor shaft 12 sequentially includes a bearing seat 18, a rotor 5, a connecting seat 10, and an impeller assembly. Rotor end rings 15 are fixedly connected to both ends of the rotor 5. Rotor sleeves 14 are fixedly fitted onto the outer circumferential surfaces of the rotor 5 and the rotor end rings 15. A stator 13 is fitted onto the outer circumferential surface of the rotor sleeves 14. A stator shielding sleeve 16 is provided on the inner surface of the stator 13. The stator shielding sleeve 16 and the rotor sleeve 14 are clearance-fitted. The outer circumferential surface of the stator 13 is fixedly fitted with... A motor cylinder 6 is connected to the bearing housing 18 and the connecting seat 10 at both ends. The bearing housing 18 and the connecting seat 10 are respectively provided with bearing sleeves 3 made of carbon graphite material. The bearing sleeves 3 are sleeved on the rotor shaft 12. The rotor shaft 12 is rotatable relative to the bearing sleeves 3. The outer circumferential surface of the bearing sleeve 3 and the end face away from the rotor 5 are respectively provided with a pit. A buffer member 17 is provided in the pit. Part of the outer surface of the buffer member 17 protrudes from the pit and abuts against the bearing housing 18 and the connecting seat 10. The bearing housing 18 and the connecting seat 10 are circumferentially distributed with axially extending liquid passage holes 20 near the bearing sleeve 3. The liquid passage holes 20 are connected to the gap between the stator shield sleeve 16 and the rotor sleeve 14. The rotor shaft 12 is provided with a positioning ring 4 on the outer side of the rotor end ring 15. The positioning ring 4 has an annular groove at the connection between the rotor shaft 12 and the rotor end ring 15. A sealing ring 11 is provided in the annular groove. The positioning ring 4 is interference-fitted with the rotor shaft 12, and the sealing ring 11 effectively seals the connection between the rotor shaft 12 and the rotor end ring 15. The impeller assembly includes an impeller 7 and a guide vane 8. The impeller 7 is fixedly connected to the rotor shaft 12. The connection hole between the impeller 7 and the rotor shaft 12 is a waist-shaped hole 21. The cross-section of the rotor shaft 12 at the position matching the connection hole of the impeller 7 is also waist-shaped. The bearing housing 18 is connected to the liquid inlet 2 by a connecting pipe. The connecting pipe has a through hole 19 that passes through the bearing housing 18 and the liquid inlet 2.

[0023] The embodiments described above are merely preferred embodiments of this utility model and are not intended to limit this utility model in any way. Other variations and modifications are possible without departing from the technical solutions described in the claims.

[0024] Any content not described in detail in this specification is prior art known to those skilled in the art.

Claims

1. A novel shielded pump, comprising a pump barrel, an inlet at one end of the pump barrel, an outlet at the other end of the pump barrel, and a rotor shaft disposed inside the pump barrel between the inlet and the outlet, characterized in that: The rotor shaft is provided with a bearing housing, a rotor, a connecting seat, and an impeller assembly in sequence from one end near the liquid inlet to the other end near the liquid outlet. A stator is fitted onto the outer circumference of the rotor with a gap. Bearings are provided in the bearing housing and the connecting seat, and the bearings are fitted onto the rotor shaft. The bearing housing and the connecting seat are also provided with axially arranged liquid passage holes.

2. The novel shielded pump according to claim 1, characterized in that: The bearing is a bearing sleeve, and the outer peripheral surface of the bearing sleeve and the end face away from the rotor are respectively provided with a recess, and a buffer is provided in the recess.

3. The novel shielded pump according to claim 1, characterized in that: The rotor shaft is provided with positioning rings at both ends of the rotor. The positioning rings are provided with annular grooves at the connection between the rotor shaft and the rotor. A sealing ring is provided in the annular grooves.

4. The novel shielded pump according to claim 2 or 3, characterized in that: The fluid passage holes are circumferentially distributed on the bearing housing and connecting seat near the bearing sleeve, and the fluid passage holes are connected to the gap between the stator and the rotor.

5. The novel shielded pump according to claim 1, 2, or 3, characterized in that: The bearing housing is connected to the liquid inlet by a connecting pipe. The connecting pipe has a through hole that passes through the bearing housing and the liquid inlet.

6. The novel shielded pump according to claim 1, 2, or 3, characterized in that: The impeller assembly includes an impeller and guide vanes, and the impeller is fixedly connected to the rotor shaft.

7. The novel shielded pump according to claim 6, characterized in that: The impeller has a waist-shaped connection hole.

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