Four-inch water immersion type permanent magnet submersible motor

Abstract

The utility model relates to the technical field of submersible motors, in particular to a four-inch water-immersed permanent magnet submersible motor, which comprises a casing, an upper guide bearing assembly, a lower guide bearing assembly, a motor shaft, a rotor assembly and a stator assembly, and water-lubricated guide bearings are arranged in the upper guide bearing assembly and the lower guide bearing assembly. A spiral flow guide groove is formed in the inner surface of the water-lubricated guide bearing and used for enhancing cooling water circulation. The rotor assembly comprises a rotor iron core and permanent magnets embedded on the rotor iron core, the permanent magnets are non-uniformly arranged at intervals along the circumferential direction of the rotor iron core, heat dissipation gaps are formed between adjacent permanent magnets, and ventilation holes are axially formed in the rotor iron core to enhance heat dissipation. Thrust bearings are symmetrically arranged on the motor shaft and symmetrically arranged on the two sides of the rotor assembly. The stator assembly is of a 12-slot structure, and the rotor assembly is of 8-pole 8-slot fractional slot matching, so that the cogging torque of the motor can be effectively reduced. The motor uses a water-lubricated bearing, and an additional lubricating system is not needed.

Description

Technical Field

[0001] This utility model relates to the field of submersible motor technology, and in particular to a four-inch water-immersed permanent magnet submersible motor. Background Technology

[0002] The motor of a submersible pump is directly connected to the pump, and the entire pump operates submerged in water. As a key piece of equipment for deep well water lifting, it has a wide range of applications. It can be used to supply domestic water, respond to mine emergencies, meet industrial cooling needs, carry out farmland irrigation, lift seawater, and adjust ship loads. It is also suitable for fountain landscaping and various water lifting projects such as rivers, reservoirs, and canals.

[0003] Currently, the windings of domestically produced 4-inch submersible motors generally employ oil-immersed cooling, coupled with a steel bearing mechanical seal structure. However, this structure has significant drawbacks; the mechanical seal is highly susceptible to damage, leading to oil leaks. Once an oil leak occurs, it can potentially cause water pollution, negatively impacting people's daily lives. Utility Model Content

[0004] To address the shortcomings of existing technologies, this utility model provides a four-inch water-immersed permanent magnet submersible motor.

[0005] The technical solution adopted in this utility model is as follows: a four-inch water-immersed permanent magnet submersible motor, including a housing, an upper guide bearing assembly, a lower guide bearing assembly, a motor shaft, a rotor assembly, and a stator assembly. Water-lubricated guide bearings are provided within the upper and lower guide bearing assemblies, and the inner surface of the water-lubricated guide bearings has spiral guide grooves to enhance cooling water circulation. The rotor assembly includes a rotor core and permanent magnets embedded thereon. The permanent magnets are arranged non-uniformly along the circumference of the rotor core, forming heat dissipation gaps between adjacent permanent magnets, and the rotor core has axial ventilation holes to enhance heat dissipation. The stator assembly has a 12-slot structure, and the rotor assembly has an 8-pole, 8-slot fractional slot configuration. Thrust bearings are symmetrically arranged on the motor shaft, and the thrust bearings are symmetrically arranged on both sides of the rotor assembly.

[0006] A further improvement to the above scheme is that the stator assembly uses polyethylene insulated nylon sheathed water-resistant winding wire, and the motor is filled with water to form a water-immersed cooling cavity, with the cooling water directly contacting the stator and rotor for heat dissipation.

[0007] A further improvement to the above scheme is that the permanent magnet is made of high coercivity neodymium iron boron rare earth material, with a remanence ≥1.4T and coercivity ≥2000kA / m.

[0008] A further improvement to the above scheme is that the surface of the permanent magnet is coated with an epoxy resin protective layer, and the epoxy resin protective layer is doped with aluminum nitride particles to improve thermal conductivity.

[0009] A further improvement to the above solution is that a mechanical seal structure is provided at the connection between the motor shaft and the housing, and the inner wall of the housing is coated with a corrosion-resistant ceramic coating.

[0010] A further improvement to the above scheme is that the width of the heat dissipation gap is 10-15% of the thickness of the permanent magnet, and the gap is filled with a thermally conductive silicone grease layer.

[0011] Compared with the prior art, the beneficial effects of this utility model are:

[0012] Firstly, the motor adopts a water-immersed structure, with its interior filled with water for direct cooling. This cooling method is effective, efficient, and easy to maintain. The motor uses water-lubricated bearings, eliminating the need for an additional lubrication system, which simplifies maintenance and offers the advantages of being environmentally friendly and pollution-free.

[0013] Secondly, the permanent magnet motor's windings adopt an 8-pole fractional-slot design with 8 slots on the rotor and 12 slots on the stator. This design effectively reduces the motor's cogging torque, improves operational smoothness, and reduces noise and vibration.

[0014] Thirdly, the permanent magnets are distributed non-uniformly along the circumference of the rotor core, forming heat dissipation gaps between adjacent permanent magnets. Simultaneously, ventilation holes are provided along the axial direction of the rotor core to enhance heat dissipation. The heat dissipation gaps are filled with a layer of thermally conductive silicone grease, significantly improving the motor's heat dissipation performance and thus extending its service life. Attached Figure Description

[0015] The accompanying drawings are provided to further illustrate the present invention and form part of the specification. They are used together with the embodiments of the present invention to explain the present invention, but do not constitute a limitation thereof. In the drawings:

[0016] Figure 1 This is a schematic diagram of the internal structure of this utility model;

[0017] Figure 2 for Figure 1 Enlarged schematic diagram of section A in the middle;

[0018] Figure 3 This is a schematic diagram of the stator assembly and rotor assembly structure.

[0019] In the diagram: 1. Housing; 2. Upper guide bearing assembly; 3. Lower guide bearing assembly; 4. Motor shaft; 5. Rotor assembly; 51. Rotor core; 52. Permanent magnet; 6. Stator assembly; 7. Water-lubricated guide bearing; 71. Spiral guide groove; 8. Thrust bearing; 9. Sealing structure; 10. Thermal grease layer; 11. Ventilation hole. Detailed Implementation

[0020] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0021] A four-inch water-immersed permanent magnet submersible motor includes a housing 1, an upper guide bearing assembly 2, a lower guide bearing assembly 3, a motor shaft 4, a rotor assembly 5, and a stator assembly 6. Water-lubricated guide bearings 7 are installed within the upper and lower guide bearing assemblies 2 and 3, respectively. The inner surface of each water-lubricated guide bearing 7 has a spiral guide groove 71 to enhance cooling water circulation. The rotor assembly 5 includes a rotor core 51 and permanent magnets 52 embedded thereon. The permanent magnets 52 are non-uniformly spaced circumferentially along the rotor core 51, with heat dissipation gaps between adjacent permanent magnets. The rotor core 51 also has axial ventilation holes 11 to enhance heat dissipation. The stator assembly 6 has a 12-slot structure, and the rotor assembly 5 has an 8-pole, 8-slot fractional slot configuration, which reduces cogging torque, improves operational stability, and reduces noise and vibration. Thrust bearings 8 are symmetrically arranged on the motor shaft 4. The thrust bearings 8 are symmetrically arranged on both sides of the rotor assembly 5, which can better withstand axial force, reduce the impact of axial force on other parts of the motor, reduce wear, and ensure the stability and reliability of the motor during operation. At the same time, the thrust bearings 8 can restrict the axial movement of the rotor, ensure that the air gap between the rotor and the stator is constant, avoid friction or collision, improve the smoothness of motor operation, and extend the service life of the motor.

[0022] The stator assembly 6 uses polyethylene insulated nylon sheathed water-resistant winding wire. The motor is filled with water to form a water-immersed cooling chamber. The cooling water directly contacts the stator and rotor for heat dissipation. The direct water cooling is effective, efficient, and easy to maintain.

[0023] The permanent magnet 52 is made of high coercivity neodymium iron boron rare earth material, with a remanence of ≥1.4T and coercivity of ≥2000kA / m, which can provide a stronger magnetic field and improve the efficiency of the motor.

[0024] The permanent magnet 52 is coated with an epoxy resin protective layer, and the epoxy resin protective layer is doped with aluminum nitride particles to improve thermal conductivity.

[0025] The motor shaft 4 is provided with a mechanical seal structure 9 at the connection between it and the housing 1, and the inner wall of the housing 1 is coated with a corrosion-resistant ceramic coating.

[0026] The width of the heat dissipation gap is 10-15% of the thickness of the permanent magnet 52, and the gap is filled with a thermally conductive silicone grease layer 10, which improves the heat dissipation performance of the motor and thus improves the service life of the motor.

[0027] The motor adopts a water-immersed structure, with its interior filled with water for direct cooling. This cooling method is effective, highly efficient, and easy to maintain. The motor uses water-lubricated bearings, eliminating the need for an additional lubrication system, which simplifies maintenance and offers the advantages of being environmentally friendly and pollution-free.

[0028] The permanent magnet motor's windings employ an 8-pole fractional-slot design with 8 slots on the rotor and 12 slots on the stator. This design effectively reduces the motor's cogging torque, improves operational smoothness, and simultaneously reduces noise and vibration.

[0029] The addition of a thrust bearing 8 to the motor enables it to more effectively withstand axial forces, reduce the impact of axial forces on other motor components, decrease wear, and thus ensure the stability and reliability of motor operation. The thrust bearing 8 also restricts the axial movement of the rotor, ensuring a constant air gap between the rotor and stator, preventing friction or collisions, further improving the smoothness of motor operation, and extending the motor's service life.

[0030] The permanent magnets 52 are non-uniformly distributed circumferentially on the rotor core 51, with heat dissipation gaps formed between adjacent permanent magnets 52. Simultaneously, ventilation holes 11 are provided axially on the rotor core 51 to enhance heat dissipation. The heat dissipation gaps are filled with a layer of thermally conductive silicone grease 10, greatly improving the motor's heat dissipation performance and thus extending its service life.

[0031] In the description of this utility model, it should be noted that, unless otherwise stated, "a plurality of" means two or more; the terms "upper", "lower", "left", "right", "inner", "outer", "top", "bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0032] Although the present invention has been described in detail through the above preferred embodiments, it should be understood that the above description should not be considered as a limitation of the present invention. Various modifications and substitutions to the present invention will be apparent to those skilled in the art after reading the above content. Therefore, the scope of protection of the present invention should be defined by the appended claims.

Claims

1. A four-inch water-immersed permanent magnet submersible motor, comprising a casing (1), an upper guide bearing assembly (2), a lower guide bearing assembly (3), a motor shaft (4), a rotor assembly (5) and a stator assembly (6), characterized in that: the upper guide bearing assembly (2) and the lower guide bearing assembly (3) are provided with water-lubricated guide bearings (7), and the inner surface of the water-lubricated guide bearings (7) is provided with spiral flow guide grooves (71); the rotor assembly (5) comprises a rotor core (51) and embedded permanent magnets (52), the permanent magnets (52) are arranged in a non-uniform interval along the circumference of the rotor core (51), and the adjacent permanent magnets (52) form a heat dissipation gap, and the rotor core (51) is provided with a ventilation hole (11) in the axial direction; the stator assembly (6) is a 12-slot structure, and the rotor assembly (5) is an 8-pole 8-slot fractional slot matching; the motor shaft (4) is symmetrically provided with a thrust bearing (8), and the thrust bearing (8) is symmetrically arranged on both sides of the rotor assembly (5).

2. A four-inch water-jet permanent magnet submersible motor according to claim 1, characterized in that: The winding of the stator assembly (6) adopts water-resistant winding wire with polyethylene insulation and nylon sheath, and the inside of the motor is filled with water to form a water-immersed cooling cavity.

3. A four-inch water-jet permanent magnet submersible motor according to claim 1, characterized in that: The permanent magnet (52) adopts high-coercivity neodymium-iron-boron rare earth material, with residual magnetism ≥1.4T and coercivity ≥2000kA / m.

4. A four-inch water-jet permanent magnet submersible motor according to claim 1, characterized in that: The surface of the permanent magnet (52) is coated with an epoxy resin protective layer.

5. A four-inch water-jet permanent magnet submersible motor according to claim 1, characterized in that: The motor shaft (4) and the casing (1) are provided with a mechanical seal structure (9) at the connection, and the inner wall of the casing (1) is coated with a corrosion-resistant ceramic coating.

6. A four-inch water-jet permanent magnet submersible motor according to claim 1, characterized in that: The width of the heat dissipation gap is 10-15% of the thickness of the permanent magnet (52), and the gap is filled with a layer of heat-conducting silicone grease (10).

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