Novel shield pump

Abstract

The invention 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] The present invention relates to the technical field of permanent magnet canned pumps, and more specifically, to a novel canned pump. Technical Background

[0002] A canned pump belongs to a centrifugal seal-less pump. Both the pump and the drive motor are enclosed in a pressure vessel filled with the pumped medium. The drive motor places the stator and the rotor in a sealed, non-magnetic, corrosion-resistant metal cylinder respectively. The stator provides a rotating magnetic field to drive the rotor to rotate. The rotor and the impeller are fixed on the same shaft. The canned pump can be lubricated and cooled by its transported medium, so no additional lubricating grease and cooling fan are required. Due to its unique design, the dynamic seal structure of the pump shaft is cancelled and a static seal structure is adopted, making the canned pump completely leak-free, effectively avoiding environmental pollution and material loss, and thus making the canned pump suitable for transporting precious liquids or contaminated liquids.

[0003] The existing canned pumps, such as the utility model patent with the publication number CN216554442U announced by the State Intellectual Property Office on May 17, 2022, the utility model patent with the publication number CN222717084U announced on April 4, 2025, and the invention patent with the publication number CN119687037A published on March 25, 2025, basically have the problems of relatively fast wear of the lubrication part structure, the service life not reaching the expected value, and relatively high noise. Summary of the Invention

[0004] To overcome the above defects, the technical problem to be solved by the present invention is: to provide a novel canned pump with a more reasonable structural layout, which can reduce noise and has a longer service life.

[0005] To solve the above technical problem, the technical solution of the present invention is: a novel canned pump, which includes a pump barrel. One end of the pump barrel is provided with a liquid inlet, and the other end of the pump barrel is provided with a liquid outlet. A rotor shaft is arranged in the pump barrel between the liquid inlet and the liquid outlet. The rotor shaft is sequentially provided with a bearing seat, a rotor, a connecting seat, and an impeller assembly from one end close to the liquid inlet to the other end close to the liquid outlet. A stator is sleeved on the outer peripheral surface of the rotor with a gap. Bearings are respectively arranged in the bearing seat and the connecting seat. The bearings are sleeved on the rotor shaft. Liquid through holes arranged axially are also respectively arranged in the bearing seat and the connecting seat.

[0006] To address the aforementioned technical issues, the inventors carefully studied the structure and layout of existing canned motor pumps and investigated possible causes of the aforementioned technical issues. The research revealed that, because the rotor and impeller of existing canned motor pumps are fixed on the same shaft, the drive shaft and the axis of the liquid outlet are typically arranged perpendicularly. This means that the drive motor is located outside the liquid flow path, forming a "T"-shaped arrangement. The inventors analyzed that this structural layout could cause the liquid entering the canned motor pump to inevitably introduce some gas. This gas would then be disturbed by the impeller or blades, causing the gas to break and form multiple bubbles that would scatter. Once these bubbles enter the motor or areas requiring lubrication, they would continue to adversely affect these areas. The invention relates to a novel pump that is designed to reduce the noise of the motor and the bearings that support the motor. The invention also relates to a novel pump that is designed to reduce the noise of the motor and the bearings that support the motor. The invention also relates to a novel pump that is designed to reduce the noise of the motor and the bearings that support the motor. The invention relates to a pump that is designed to reduce the noise of the motor and the bearings that support the motor. The invention relates to a pump that is designed to reduce the noise of the motor and the bearings that support the motor. The invention relates to a pump that is designed to reduce the noise of the motor and the bearings that support the motor. The invention relates to a pump that is designed to reduce the noise of the motor and the bearings that support the motor. The invention relates to a pump that is designed to reduce the noise of the motor and the bearings that support the motor. The invention relates to a pump that is designed to reduce the noise of the motor and the bearings that support the motor. The invention relates to a pump that is designed to reduce the noise of the motor and the bearings that support the motor. The invention relates to a pump that is designed to reduce the noise of the motor and the bearings that support the motor. The invention relates to a pump that is designed to reduce the noise of the motor and the bearings that support the motor. The invention relates to a pump that is designed to reduce the noise of the motor and the bearings that support the motor. The invention relates to a pump that is designed to reduce the noise of the motor and the bearings that support the motor. The invention relates to a pump that is designed to reduce the noise of the motor and the bearings that support the motor. In order to verify the correctness of the above-mentioned countermeasures and mechanisms, the inventor specially made a shielded pump verification machine with transparent materials. Through many experiments, it was found that the technical solution of arranging a bearing seat, a rotor, a connecting seat, and an impeller assembly in sequence on the rotor shaft from one end close to the liquid inlet to the other end close to the liquid outlet is better than the technical solution of the impeller assembly, the connecting seat, the rotor, and the bearing seat. The reason is that the driving motor and the lubrication parts of the former technical solution are both located in a low-pressure environment, and the liquid flow is not disturbed by the impeller and is relatively stable. The driving motor and the lubrication parts of the latter technical solution are both located in a high-pressure environment, and the liquid flow is disturbed by the impeller, resulting in spiral rotation, which is not conducive to the removal of bubbles. Therefore, the inventor determined the technical solution of arranging a bearing seat, a rotor, a connecting seat, and an impeller assembly in sequence on the rotor shaft from one end close to the liquid inlet to the other end close to the liquid outlet as the optimal solution to solve the technical problem. In addition, an axially arranged liquid hole is provided on the outside of the bearing in the bearing seat and the connecting seat, which is conducive to the timely removal of heat generated by the stator, rotor and bearing, and is also conducive to extending the service life of the shielded pump.

[0007] As a further technical solution, the bearing is a bearing sleeve. Concave pits are respectively provided on the outer peripheral surface of the bearing sleeve and one end face away from the rotor, and buffer members are provided in the concave pits. The bearing can be a rolling bearing, a sliding bearing, or a bearing bush. In this patent application, the bearing sleeve belonging to the category of sliding bearings is preferably selected. Concave pits are provided on the outer side surface of the bearing sleeve that needs to contact the bearing housing and the connecting seat, and buffer members are placed therein, so that the bearing sleeve can buffer the impact load from the bearing housing and the connecting seat, which is beneficial for the bearing sleeve to select a brittle and wear-resistant material with low price, thereby extending the service life of the canned motor pump.

[0008] As a further technical solution, positioning rings are provided at both end faces of the rotor shaft at the positions of the rotor. An annular groove is provided at the connection between the rotor shaft and the rotor in the positioning ring, and a sealing ring is provided in the annular groove. Between the rotor shaft and the rotor, and between the rotor and the rotor sleeve in the prior art, welding connections are all used to achieve the effect of static sealing, but welding connections also have deficiencies. For example, as long as one of the rotor shaft and the rotor is damaged, all need to be updated, so the maintenance cost is relatively high. In this technical solution, static sealing is carried out through the positioning ring and the sealing ring, which is beneficial for only updating the damaged parts during maintenance, thereby reducing the maintenance cost of the canned motor pump.

[0009] As a further technical solution, the liquid through holes are circumferentially and uniformly distributed at the positions of the bearing housing and the connecting seat close to the bearing sleeve, and the liquid through holes are communicated with the gap between the stator and the rotor. This is beneficial for cooling the stator, rotor, and bearing.

[0010] As a further technical solution, the bearing housing is integrally connected to the liquid inlet through a connecting pipe. A through hole is provided in the connecting pipe, and the through hole penetrates through the bearing housing and the liquid inlet. The bearing housing is firmly integrated on the liquid inlet by using the connecting pipe. At the same time, the gap between adjacent connecting pipes is used to provide space for the liquid flow of the canned motor pump, and the through hole provided in the connecting pipe is used to provide a channel for the potting process and wiring.

[0011] As a further technical solution, the impeller assembly includes an impeller and a diffuser. The impeller is fixedly connected to the rotor shaft. The impeller and the diffuser are integrated into an impeller assembly, which becomes an organic whole that complements each other, enabling the impeller to focus on energy conversion and liquid transportation, and the diffuser to reduce the energy loss during the liquid flow process and improve the overall efficiency of the pump.

[0012] As a further technical solution, the connection hole of the impeller is an oval hole. The cross-section at the position of the rotor shaft that matches the connection hole of the impeller is also oval-shaped. Such a 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 the characteristics of good self-lubrication, wear resistance, light weight, corrosion resistance, low coefficient of thermal expansion, etc., making it the most cost-effective choice for the bearing sleeve of canned motor pumps. However, due to the manufacturing process of carbon graphite material, it is hard and brittle and not suitable for applications with impact loads. Also, since the technical solution of the present invention is provided with a buffer protection structure on the outer side of the bearing sleeve, it becomes a logical thing to choose carbon graphite material to make the bearing sleeve of canned motor pumps.

[0014] The beneficial effects of the present invention are as follows: 1. Since the liquid inlet, liquid outlet, rotor shaft, and impeller of the canned motor pump are coaxially arranged, the pumped liquid flow can take away the bad air bubbles and heat in time, eliminate the continuous influence of bad air bubbles, and is beneficial to reducing the noise of the canned motor pump and extending its service life; 2. Since the impeller assembly is arranged between the rotor and the liquid outlet, it can ensure that the drive motor and the lubrication part are both working in a low-pressure environment. The liquid flow there is not disturbed by the impeller and is relatively stable, which is beneficial to further reducing the noise of the canned motor pump and extending its service life; 3. Since the bearing seat and the connecting seat are provided with axially arranged liquid through holes on the outer side of the bearing sleeve, it is beneficial to take away the heat generated by the stator, rotor, and bearing sleeve in time, and is also beneficial to extending the service life of the canned motor pump. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a schematic cross-sectional view of a structure of the present invention; Figure 2 is a three-dimensional schematic view of a visual angle of the liquid inlet of the present invention; Figure 3 is a three-dimensional schematic view of another visual angle of the liquid inlet of the present invention; Figure 4 is a three-dimensional schematic view of the connecting seat of the present invention; Figure 5 is a three-dimensional schematic view of the impeller of the present invention.

[0016] In the figure: pump barrel 1, liquid inlet 2, bearing sleeve 3, positioning ring 4, rotor 5, motor barrel 6, impeller 7, guide vane 8, liquid outlet 9, connecting seat 10, sealing ring 11, rotor shaft 12, stator 13, rotor sleeve 14, rotor end ring 15, stator shielding sleeve 16, buffer member 17, bearing seat 18, through hole 19, liquid through hole 20, kidney-shaped hole 21. DETAILED DESCRIPTION OF THE INVENTION

[0017] The present invention will be further described below through specific embodiments in conjunction with the drawings.

[0018] Embodiment: A new type of canned motor pump, as shown in the figure, includes a pump barrel 1. One end of the pump barrel 1 is provided with a liquid inlet 2, and the other end of the pump barrel 1 is provided with a liquid outlet 9. A rotor shaft 12 is arranged in the pump barrel 1 between the liquid inlet 2 and the liquid outlet 9. The rotor shaft 12 is successively provided with a bearing seat 18, a rotor 5, a connecting seat 10, and an impeller assembly from the end close to the liquid inlet 2 to the end close to the liquid outlet 9. Both ends of the rotor 5 are fixedly connected with rotor end rings 15. A rotor sleeve 14 is fixedly sleeved on the outer peripheral surfaces of the rotor 5 and the rotor end rings 15 at both ends. A stator 13 is sleeved on the outer peripheral surface of the rotor sleeve 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 in clearance fit. A motor barrel 6 is fixedly sleeved on the outer peripheral surface of the stator 13. Both ends of the motor barrel 6 are respectively fixedly connected to the bearing seat 18 and the connecting seat 10. Bearing sleeves 3 made of carbon graphite material are respectively arranged in the bearing seat 18 and the connecting seat 10. The bearing sleeves 3 are sleeved on the rotor shaft 12. The rotor shaft 12 is rotatable relative to the bearing sleeves 3. Concave pits are respectively arranged on the outer peripheral surface and the end surface far from the rotor 5 of the bearing sleeves 3. A buffer member 17 is arranged in the concave pits. Part of the outer surface of the buffer member 17 protrudes from the concave pits and abuts against the bearing seat 18 and the connecting seat 10. Liquid through holes 20 extending axially are circumferentially and uniformly distributed at positions of the bearing seat 18 and the connecting seat 10 close to the bearing sleeves 3. The liquid through holes 20 are communicated with the gap between the stator shielding sleeve 16 and the rotor sleeve 14. A positioning ring 4 is arranged on the outer side surface of the rotor end ring 15 of the rotor shaft 12. An annular groove is arranged at the connection position of the rotor shaft 12 and the rotor end ring 15 of the positioning ring 4. A sealing ring 11 is arranged in the annular groove. The positioning ring 4 and the rotor shaft 12 are in interference fit and the sealing ring 11 effectively seals the connection position of the rotor shaft 12 and the rotor end ring 15. The impeller assembly includes an impeller 7 and a diffuser 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 an oval hole 21, and the cross section at the position of the rotor shaft 12 matching the connection hole of the impeller 7 is also in a matching oval shape. The bearing seat 18 is integrally connected with the liquid inlet 2 through a connecting pipe. A through hole 19 is arranged in the connecting pipe. The through hole 19 penetrates through the bearing seat 18 and the liquid inlet 2.

[0019] The above-described embodiment is only a preferred solution of the present invention, and does not impose any form of limitation on the present invention. There are other variants and modifications without exceeding the technical solutions recorded in the claims.

[0020] The content not described in detail in this specification belongs to the prior art well-known to those skilled in the art.

Claims

1. A new type of canned motor pump, which comprises a pump barrel, one end of the pump barrel is provided with a liquid inlet, the other end of the pump barrel is provided with a liquid outlet, and a rotor shaft is arranged in the pump barrel between the liquid inlet and the liquid outlet, and is characterized in that: The rotor shaft is sequentially provided with a bearing seat, a rotor, a connecting seat, and an impeller assembly from one end close to the liquid inlet to the other end close to the liquid outlet. A stator is sleeved on the outer peripheral surface of the rotor with a gap. Bearings are respectively arranged in the bearing seat and the connecting seat, and the bearings are sleeved on the rotor shaft. Liquid through holes arranged axially are also respectively provided in the bearing seat and the connecting seat.

2. The novel canned motor pump according to claim 1, wherein: The bearing is a bearing sleeve. Concave pits are respectively provided on the outer peripheral surface and the end face far from the rotor of the bearing sleeve, and buffer members are arranged in the concave pits.

3. The novel canned motor pump according to claim 1, wherein: Positioning rings are arranged at the two end face positions of the rotor on the rotor shaft. An annular groove is provided at the connection position between the rotor shaft and the rotor of the positioning ring, and a sealing ring is arranged in the annular groove.

4. The novel canned motor pump according to claim 2 or 3, characterized in that: The liquid through holes are circumferentially and uniformly distributed at positions of the bearing seat and the connecting seat close to the bearing sleeve, and the liquid through holes are communicated with the gap between the stator and the rotor.

5. The novel canned motor pump according to claim 1 or 2 or 3, characterized in that: The bearing seat is integrally connected with the liquid inlet through a connecting pipe, and a through hole is provided in the connecting pipe, and the through hole penetrates through the bearing seat and the liquid inlet.

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

7. The novel canned motor pump according to claim 6, characterized in that: The connection hole of the impeller is an oval hole.

8. The novel canned motor pump according to claim 2, characterized in that: The bearing sleeve is made of carbon graphite material.

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