Submersible permanent magnet motor final assembly process

Abstract

The invention relates to a general assembly process of a submersible permanent magnet motor, and belongs to the technical field of motor assembly. The process comprises the following steps: cleaning each part of the motor; the stator is pressed into the shell in a thermal expansion mode; magnetic steel is installed on the iron core according to polarity marks to assemble a rotor, and a front end seat and a supporting assembly are installed; inserting the rotor into the shell to enable the rotor to be positioned in the stator; mounting a rear end seat and adjusting the concentricity of the front and rear end seats to ensure uniform air gaps; installing a rear sealing cap, detecting winding insulation, and injecting filling liquid for performance detection; and qualified motors are put in storage after being subjected to anti-corrosion treatment. In the process, a rotor is formed by arranging a plurality of groups of iron cores with magnetic steel along the axial direction, the magnetic steel is fixed in a bonding and press-fitting manner, and a shaft protecting tube is arranged to separate a rotating shaft from an armature lead. The assembly quality and the operation reliability of the submersible permanent magnet motor are improved, and the service life of the motor is prolonged.

Description

Technical Field

[0001] This invention relates to the field of motor manufacturing, specifically to the assembly process of a submersible oil motor, and more specifically, to an assembly process method for a submersible permanent magnet motor. Background Technology

[0002] With the continuous development of oil extraction technology, submersible motors, as an important component of oil extraction equipment, have a significant impact on oil extraction efficiency and cost due to their performance and reliability. Submersible permanent magnet motors (PMMs) are widely used in the oil extraction field due to their high efficiency, high power density, and good speed regulation performance. However, the assembly process of PMMs directly affects their operating performance and service life; therefore, researching an efficient and precise assembly process for PMMs has significant practical value.

[0003] Currently, there has been some research on the assembly process of permanent magnet motors.

[0004] For example, Chinese patent CN102005865B discloses a permanent magnet motor assembly process, which includes fixing the front end cover and stator as a single unit, vertically inserting a rotor without magnets into the vertically placed stator, then placing magnetic isolation blocks on one side of the rear end cover using the air gap between the stator and rotor, assembling the magnets one by one into the rotor magnet slots and fixing them with epoxy resin, and finally removing the magnetic isolation blocks through the process holes on the rear end cover. Although this method simplifies the tooling, the magnet installation process still suffers from complex operation and difficulty in precision control.

[0005] Chinese patent CN110266158B discloses an assembly process for a brushless motor, including steps such as assembling a rotor assembly, assembling a stator assembly, installing the rotor assembly into the stator assembly, and assembling induction magnets. In this process, the stator housing is first heated and expanded before being placed into the stator assembly. This process effectively ensures the stability and performance consistency of the brushless motor, but it does not propose corresponding protective measures for the special working environment of submersible motors.

[0006] Chinese patent CN115347696A discloses a novel rotor transfer structure and installation method for a permanent magnet motor. This method solves the installation difficulties and magnet surface scratches caused by the strong attraction between the permanent magnet motor rotor and the motor stator during installation by designing a special transfer structure. However, this method mainly focuses on the rotor's installation structure and lacks sufficient systematic consideration of the overall assembly process.

[0007] Chinese patent CN111313623A discloses an assembly method for a permanent magnet motor, including the assembly of a housing, stator, rotor, frequency converter module, and water-cooling plate. This method achieves the goal of reducing the weight of the permanent magnet motor and improving its reliability through a special structural design. However, this method does not consider the sealing and corrosion protection requirements of the motor in an oil-immersed environment.

[0008] Chinese patent CN113098220A discloses a permanent magnet motor and its manufacturing method. The rotor assembly includes a rotor core and tile-shaped magnets, with a spacer block abutting between adjacent tile-shaped magnets. The tile-shaped magnets are fixed to the rotor core by outer layers of wound metal wire. While this method has a reasonable structural design, there is a risk of metal wire corrosion in an oil-immersed environment.

[0009] In summary, the existing assembly process for permanent magnet motors has the following shortcomings:

[0010] 1. The permanent magnets on the rotor of a permanent magnet motor generate strong magnetic attraction, which can easily cause collisions between the rotor and stator during assembly, resulting in scratches or damage to the surface of the magnets and affecting the motor performance.

[0011] 2. The existing assembly process does not control the concentricity between the rotor and stator precisely enough, resulting in uneven air gap and affecting the motor's operating stability and efficiency;

[0012] 3. The lack of special protective measures for submerged oil environments, such as anti-corrosion treatment and sealing technology, affects the service life of the motor in harsh environments;

[0013] 4. The existing method of fixing magnets is not reliable enough. Under high temperature and high pressure submerged oil environment, the magnets may fall off, causing motor failure.

[0014] Therefore, it is urgent to develop an assembly process suitable for submersible permanent magnet motors to solve the above-mentioned technical problems and improve the assembly accuracy, operational stability and service life of submersible permanent magnet motors. Summary of the Invention

[0015] To address the technical challenges in the assembly of permanent magnet motors, such as the strong magnetic attraction causing permanent magnets to fall, the ease with which manual assembly can result in bumps and scratches, rotor eccentricity affecting stability, insufficient assembly efficiency and precision, and the lack of a reasonable assembly process, this paper provides a submersible permanent magnet motor assembly process. This process achieves stable installation of motor components, overcomes the problem of permanent magnet attraction, solves the problem of rotor eccentricity, and improves the motor's sealing performance and service life.

[0016] The technical solution adopted by this invention to solve its technical problem is: providing a submersible permanent magnet motor assembly process, including the following steps: cleaning each component of the motor to ensure that the assembly surface is clean and free of foreign objects; vertically fixing the motor housing to the workbench, and pressing the stator into place from the top of the housing through thermal expansion, and fixing the stator and housing together after the housing cools down; fixing the iron core on the rotating shaft, installing the magnets onto the iron core according to the polarity markings to complete the rotor assembly, and installing a front end seat at one end of the rotating shaft, and then fixing a support assembly on the rotating shaft, with the front end seat located between the support assembly and the rotor iron core; maintaining the front end seat in an upward position. The rotor is positioned inside the stator when the bottom end of the shaft is inserted into the housing and the front end seat contacts the top end of the housing. The rear end seat is installed at the bottom of the housing, and the concentricity of the front and rear end seats is adjusted to ensure a uniform air gap between the rotor and stator. The front and rear end seats are then fixed to the housing. A rear cap is installed on the rear end seat, and the insulation of the motor windings is tested. Once the winding insulation meets the requirements, filling fluid is injected into the motor. The motor is then started, and its performance is tested. After the performance test is completed, the filling fluid is drained. The surface of the motor that meets the performance requirements is treated with anti-corrosion measures. After the anti-corrosion treatment meets the requirements, the motor is sealed and stored.

[0017] Preferably, the rotor is composed of multiple sets of iron cores with magnets installed arranged sequentially along the axial direction of the rotating shaft. Bearings are installed on the rotating shaft at both ends of each iron core. The bearings need to be heated evenly before installation. After heating, the bearings are fitted into the rotating shaft. After the bearings cool down, they achieve a tight fit with the rotating shaft.

[0018] The rotor employs multiple sets of magnetized iron cores arranged axially, with heated bearings mounted on the shafts at both ends of the iron cores. Its advantages are: the multiple iron cores optimize the internal magnetic field distribution of the motor, improving output power and efficiency; the bearings are heated before installation, utilizing thermal expansion to make them easier to fit onto the shaft, and after cooling, a tight fit is formed, effectively preventing loosening and relative slippage between the bearings and shaft during operation, reducing vibration and noise, and enhancing the rotor's operational stability and service life.

[0019] Preferably, the magnets are fixed to the iron core by bonding and pressing. Before installation, adhesive is applied to the magnet mounting groove of the iron core, and then the magnets are positioned according to the polarity marks. The magnets are pressed into the magnet mounting groove in the marked order using a press machine. The magnets are left to stand at room temperature until the adhesive cures to enhance the connection strength between the magnets and the iron core. After the iron core is installed, the rotor needs to be dynamically balanced. The subsequent assembly process can be carried out after the dynamic balance meets the requirements.

[0020] The adhesive fills the gap between the magnet and the iron core, and the press fitting further enhances the connection strength. The double fixing method greatly improves the stability of the magnet installation and prevents the magnet from loosening or falling off during motor operation. The high-temperature resistant adhesive adapts to the high-temperature environment during motor operation and ensures long-term bonding effect. Dynamic balancing can eliminate the problem of uneven rotor mass distribution, reduce centrifugal force and vibration during operation, reduce wear on bearings and other components, and improve the smoothness and reliability of motor operation.

[0021] Preferably, protective shaft tubes are also fitted on the rotating shafts on both sides of the rotor. The protective shaft tubes are connected to the front end seat and the rear end seat respectively, and are used to isolate the rotating shaft from the armature lead wires to prevent wear on the insulation of the armature lead wires when the rotating shaft rotates.

[0022] The shaft guard tube effectively isolates the shaft from the armature leads, preventing friction and wear on the lead insulation when the shaft rotates, protecting the lead insulation performance, preventing short circuits and other faults caused by insulation damage, thereby improving the electrical safety and operational reliability of the motor and extending the lead service life.

[0023] Preferably, the adhesive is a high-temperature resistant type, whose temperature resistance meets the temperature requirements of the motor during operation, and has sufficient bonding strength after curing to ensure the stable installation of the magnet.

[0024] The motor generates heat during operation. The high-temperature resistant adhesive can maintain stable chemical properties and bonding strength in high-temperature environments, ensuring that the magnets and the iron core are always firmly connected. This prevents the magnets from shifting or falling off due to adhesive failure, ensuring the stability of the rotor structure and maintaining the normal electromagnetic performance and operating status of the motor.

[0025] Preferably, when cleaning the various components of the motor, a combination of high-pressure airflow blowing and anhydrous ethanol wiping is used.

[0026] High-pressure airflow can efficiently remove loose foreign matter such as dust and debris from the surface of components, while anhydrous ethanol has good degreasing properties and can remove stubborn stains such as oil and fingerprints from the assembly surface. The combination of the two methods can thoroughly clean the components, ensuring that the assembly surface is clean and free of impurities, and preventing foreign objects from getting stuck on the mating surface and affecting the assembly accuracy, or causing problems such as component wear and short circuits when the motor is running.

[0027] Preferably, the injected filling fluid is insulating cooling oil, and the injection volume is 90%-95% of the internal cavity volume of the motor.

[0028] Insulating cooling oil has both insulation and heat dissipation functions. It ensures the insulation performance of the internal windings of the motor and prevents leakage. It can also carry away the heat generated during operation through flow and maintain the stable operating temperature of the motor. The injection volume is controlled at 90%-95%, which allows space for the oil to expand when heated, avoids the oil overflowing when the temperature rises, and ensures that the oil fully fills the internal cavity to maximize the cooling and insulation effects.

[0029] Preferably, the anti-corrosion treatment of the motor surface includes: sandblasting the motor housing surface to remove rust; spraying an epoxy zinc-rich primer onto the rust-removed housing surface and drying it after spraying; spraying a polyurethane topcoat after the primer has dried and drying it after spraying; and conducting a salt spray test after the topcoat has dried. If no rust is produced on the surface after the test, the device is packaged and stored; otherwise, the sandblasting and rust removal steps are repeated.

[0030] Sandblasting can thoroughly remove rust, scale, and other impurities from the outer casing, providing a good substrate for coating adhesion; epoxy zinc-rich primer has excellent cathodic protection, effectively isolating corrosive media and enhancing rust prevention; polyurethane topcoat has strong weather resistance, resisting external environmental erosion while improving surface aesthetics; salt spray testing verifies the anti-corrosion effect by simulating harsh corrosive environments, ensuring that the motor is not easily corroded in humid and corrosive environments such as underground mines, significantly extending the motor's service life.

[0031] Preferably, the support assembly includes a limiting groove, a thrust bearing, a sliding plate ring, a positioning ring, a split ring, and a retaining groove. The limiting groove is circumferentially formed on the side wall of the rotating shaft. The sliding plate ring is fitted onto the rotating shaft on one side of the limiting groove and is fixedly connected to the rotating shaft. The positioning ring is fitted onto the rotating shaft on the other side of the limiting groove and is fixedly connected to the sliding plate ring. The retaining groove is formed on the inner wall of the positioning ring, which fits against the sliding plate ring, and is aligned with the limiting groove. The inner wall of the split ring fits against the limiting groove, and the outer wall fits against the retaining groove. The thrust bearing is fitted onto the rotating shaft between the sliding plate ring and the front end seat.

[0032] The limiting groove, in conjunction with the split ring and the retaining groove, achieves axial limiting of the rotating shaft; the thrust bearing can effectively withstand the axial force generated during rotor operation and reduce axial movement; the sliding plate ring is fixed to the rotating shaft by the sliding plate key, and the positioning ring is connected to the sliding plate ring to ensure that all components work together, thereby improving the overall constraint capability of the support assembly on the rotating shaft, ensuring the stability of rotor operation, reducing vibration and wear, and extending the service life of key motor components.

[0033] Preferably, a sliding key is provided on the rotating shaft located on one side of the limiting groove, and the sliding ring is fixedly connected to the rotating shaft through the sliding key.

[0034] The sliding key connection method is simple and reliable, ensuring that the sliding ring and the shaft rotate synchronously, avoiding wear caused by relative sliding between the two. It also facilitates positioning and fixing during assembly, ensuring the overall structural stability of the support components, thereby maintaining the smooth operation of the rotor and improving the reliability of the motor.

[0035] The beneficial effects of this invention are as follows: By pressing the stator into the housing through thermal expansion, stable installation of all motor components is achieved, avoiding bumps and scratches, and improving assembly reliability and efficiency; installing the magnets onto the iron core according to polarity markings effectively overcomes the problem of strong magnetic attraction generated by permanent magnet motors, preventing the permanent magnets from falling downwards; by fixing the support components and installing the rear end seat, precise alignment between the rotor and stator is achieved, solving the eccentricity problem and improving the stability and reliability of the motor; the installation of the rear cap provides sealing protection for the motor, preventing magnetic leakage and extending the motor's service life; insulation testing and filling fluid injection ensure that the electrical performance of the motor meets the standard requirements, improving the motor's service life and reliability. Furthermore, by using a combination of bonding and press-fitting to fix the magnets, and by using high-temperature resistant adhesives, the connection strength between the magnets and the iron core is further enhanced, ensuring the stable operation of the motor in high-temperature environments. The installation of the shaft guard tube effectively prevents wear on the armature lead insulation when the shaft rotates, improving the safety of the motor. The improved anti-corrosion treatment process significantly enhances the motor's corrosion resistance in harsh environments and extends the motor's service life. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 This is a schematic diagram of the internal structure of the present invention;

[0038] Figure 2 This is a schematic diagram of the positioning ring structure of the present invention;

[0039] Figure 3 This is a schematic diagram of the adjusting block structure of the present invention;

[0040] Figure 4 yes Figure 1 Enlarged view of the structure at point A in the image;

[0041] Figure 5 yes Figure 1 Enlarged view of the structure at point B in the image;

[0042] Figure 6 This is a flowchart of the motor assembly process of the present invention;

[0043] Figure 7 This is a schematic diagram of the three-phase winding connection of the present invention;

[0044] Figure 8This is a schematic diagram of the U-phase winding unfolded structure of the present invention;

[0045] Figure 9 This is a schematic diagram of the unfolded structure of the V-phase winding of the present invention;

[0046] Figure 10 This is a schematic diagram of the unfolded structure of the W-phase winding of the present invention.

[0047] The annotations in the attached figures are explained as follows:

[0048] 1. Stator; 2. Rotor; 3. Shaft; 4. Coil winding; 5. Quick connector; 6. Lead wire cover; 7. Temperature sensor; 8. Rear end seat; 9. Rear cap; 10. Support bearing; 11. Housing; 12. Front end seat; 13. Shaft guard tube; 14. Thrust bearing; 15. Slide key; 16. Slide ring; 17. Split ring; 18. Positioning ring; 19. Insulating tube; 20. Retaining ring; 21. Elastic retaining ring; 22. Spline sleeve; 23. Front cap; 24. Slot; 25. Reinforcing sleeve; 26. Fixing hole; 27. Adjusting block; 28. Baffle; 29. ​​Mounting hole; 30. Oil passage hole; 31. Spring; 32. Sealing block; 33. Plug; 34. Limiting groove; 35. Connecting hole; 36. Socket hole; 37. Through hole; 38. Filler fluid. Detailed Implementation

[0049] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention 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 the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0050] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0051] The present invention will be further described below with reference to the accompanying drawings:

[0052] Example 1: As Figures 1-5 As shown, a permanent magnet submersible motor includes a housing 11. A front end seat 12 is provided at one end of the housing 11, and a lead wire cover 6 is provided on the front end seat 12. A rear end seat 8 is provided at the other end of the housing 11. Both the front end seat 12 and the rear end seat 8 are provided with injection and discharge assemblies. A stator 1 is fixedly installed inside the housing 11. A rotating shaft 3 and several rotors 2 are provided inside the stator 1. The several rotors 2 are fixedly mounted on the rotating shaft 3. One end of the rotating shaft 3 passes through the front end seat 12, and a support assembly is mounted on the rotating shaft 3 located outside the front end seat 12. The support assembly is connected to the front end seat 12.

[0053] The outer casing 11 serves as the basic load-bearing structure of the motor, with its two ends connected to the front end seat 12 and the rear end seat 8, respectively, facilitating connection with other structures. The internal space accommodates core components such as the stator 1 and rotor 2. The injection and drainage assemblies on the front end seat 12 and the rear end seat 8 enable the injection and drainage of oil into the motor and can also be connected to pipes to form a circulation system. The stator 1 is fixed inside the outer casing 11, providing a magnetic field environment for the rotor 2. The rotor 2 is mounted on the shaft 3, and when the rotor 2 is subjected to magnetic force, it drives the shaft 3 to rotate synchronously. After the shaft 3 passes through the front end seat 12, its outer support assembly connects to the front end seat 12, providing stable support for the shaft 3 with the fixing effect of the front end seat 12, ensuring the shaft 3 maintains axial stability during high-speed rotation.

[0054] The support assembly includes a limiting groove 34, a thrust bearing 14, a sliding plate ring 16, a positioning ring 18, a split ring 17, and a retaining groove 24. The limiting groove 34 is circumferentially formed on the side wall of the rotating shaft 3. The sliding plate ring 16 is fitted onto the rotating shaft 3 on one side of the limiting groove 34 and is fixedly connected to the rotating shaft 3. The positioning ring 18 is fitted onto the rotating shaft 3 on the other side of the limiting groove 34 and is fixedly connected to the sliding plate ring 16. The retaining groove 24 is formed on the inner wall of the positioning ring 18, which fits against the sliding plate ring 16, and is aligned with the limiting groove 34. The inner wall of the split ring 17 fits against the limiting groove 34, and the outer wall fits against the retaining groove 24. The thrust bearing 14 is fitted onto the rotating shaft 3 between the sliding plate ring 16 and the front end seat 12.

[0055] The limiting groove 34 facilitates the installation of the split ring 17. After the slide ring 16 is fixed to the rotating shaft 3, the position of the positioning ring 18 is limited by the fixed connection with the positioning ring 18, so that the slot 24 on the inner wall of the positioning ring 18 is precisely aligned with the limiting groove 34. After the split ring 17 is embedded between the two, the radial force of the rotating shaft 3 can be transmitted to the positioning ring 18 and the slide ring 16. The thrust bearing 14 is located between the slide ring 16 and the front end seat 12. On the one hand, it bears the fixed support force of the front end seat 12. On the other hand, it limits the axial displacement of the rotating shaft 3 through its cooperation with the rotating shaft 3. Together with the radial constraint formed by the split ring 17, it achieves all-round stable support for the rotating shaft 3.

[0056] A sliding key 15 is provided on the rotating shaft 3 located on one side of the limiting groove 34, and the sliding ring 16 is fixedly connected to the rotating shaft 3 through the sliding key 15.

[0057] The slide key 15 is embedded in the keyway of the rotating shaft 3 and the keyway of the slide ring 16, eliminating the relative rotational freedom between the slide ring 16 and the rotating shaft 3 through a mechanical interlocking structure. This connection method allows the slide ring 16 to rotate synchronously with the rotating shaft 3 while providing a fixed base point for the positioning ring 18, ensuring that the positioning ring 18, the split ring 17, and other components maintain a stable relative position with the rotating shaft 3, and ensuring a continuous mechanical transmission path for the entire support assembly.

[0058] The injection assembly includes fixing holes 26 on the front end seat 12 and the rear end seat 8. An adjusting block 27 is provided on the fixing hole 26. One end of the adjusting block 27 has a connecting hole 35, and a plug 33 is installed inside the connecting hole 35. The other end of the adjusting block 27 has a mounting hole 29, which is connected to the connecting hole 35 via a through hole 37. Several oil passage holes 30 are provided on the side wall of the mounting hole 29. A baffle 28 is detachably installed on the free end of the mounting hole 29. A sealing block 32 and a spring 31 are also provided inside the mounting hole 29. The sealing block 32 is fitted and sealed against the through hole 37. One end of the spring 31 is fitted against the sealing block 32, and the other end is connected to the baffle 28. Lead gaskets are provided for sealing at the shoulder of the adjusting block 27 and the limiting hole 34, and at the shoulder of the plug 33 and the connecting hole 35.

[0059] The injection and discharge assembly is connected to the front seat 12 and the rear seat 8 through the fixing hole 26. The fixing hole 26 not only provides an installation position for the core components of the injection and discharge assembly, but also communicates with the inside of the motor to facilitate the injection and discharge of the filling fluid 38. The adjusting block 27, as a core functional component, has a connection hole 35 that connects to external injection and discharge equipment. The plug 33 closes the connection hole 35 to maintain a seal when not in operation. The sealing block 32 in the mounting hole 29 is tightly fitted with the through hole 37 under the elastic force of the spring 31, blocking the passage between the connection hole 35 and the oil passage hole 30 and preventing oil leakage. When performing oil injection and discharge operations, external pressure pushes the sealing block 32 to compress the spring 31 through the connection hole 35, making the through hole 37 connect with the mounting hole 29. The oil flows into or out of the motor through the through hole 37 and the mounting hole 29 from the oil passage hole 30. After the operation is completed, the spring 31 resets and pushes the sealing block 32 to reseal the through hole 37. The detachable design of the baffle 28 provides operating space for the maintenance of the sealing block 32 and the spring 31. Lead has a lower hardness and deforms when subjected to external pressure, allowing it to fit more tightly against the contact surface and achieve a seal.

[0060] The sealing block 32 has a spherical structure and its diameter is larger than that of the through hole 37.

[0061] The through-hole 37 has a trumpet-shaped structure, and the curved surface structure of the spherical sealing block 32 can form a line contact seal with the port of the through-hole 37. Compared with the planar seal, it can adapt to the slight deformation of the port of the through-hole 37, thus improving the sealing reliability. Its design, with a diameter larger than that of the through-hole 37, not only prevents the sealing block 32 from being sucked into the through-hole 37 and causing sealing failure, but also ensures that the sealing block 32 always fits the through-hole 37 with a complete spherical surface, forming an effective sealing barrier.

[0062] A reinforcing sleeve 25 is fitted at the joint between the front end seat 12 and the outer shell 11, and the reinforcing sleeve 25 is welded and fixed to the front end seat 12 and the outer shell 11 respectively.

[0063] By installing a reinforcing sleeve 25 at the joint between the front end seat 12 and the outer casing 11, and welding the reinforcing sleeve 25 to both, the stress at the joint is distributed to the entire reinforcing sleeve 25, reducing joint deformation caused by motor vibration or external water pressure. Welding ensures that the reinforcing sleeve 25 forms a rigid whole with the front end seat 12 and the outer casing 11, further improving the sealing performance at the joint and preventing liquid from seeping into the motor.

[0064] The front end seat 12 is provided with a socket hole 36, and a quick connector 5 is provided in the socket hole 36. A temperature sensor 7 and a coil winding 4 are respectively connected to the quick connector 5. The temperature sensor 7 is located in the rear end seat 8, and the coil winding 4 is fixed on the stator 1.

[0065] The socket hole 36 provides installation positioning for the quick-connect plug 5, which acts as an intermediate connector. One end of the quick-connect plug 5 connects to the coil winding 4 on the stator 1 to transmit electrical energy, and the other end connects to the temperature sensor 7 inside the rear seat 8 to transmit temperature signals. This integrated connection method reduces the number of wiring connectors, enables quick installation and removal of the coil winding 4 and the temperature sensor 7 through the quick-connect structure, and protects the connector from external liquid corrosion thanks to the sealing design of the socket hole 36.

[0066] A protective shaft tube 13 is fixedly connected to the front end seat 12. The rotating shaft 3 passes through the protective shaft tube 13. An insulating tube 19 is sleeved on the protective shaft tube 13. An elastic retaining ring 21 is provided at the end of the insulating tube 19. A retaining ring ring 20 is provided on the protective shaft tube 13 to cooperate with the elastic retaining ring 21 to block the insulating tube 19.

[0067] Several rotors 2 are provided with support bearings 10 at both ends, and the rotors 2 and stator 1 are connected through the support bearings 10.

[0068] The inner rings of the support bearings 10 at both ends of the rotor 2 are fixed to the rotor 2, while the outer rings contact the stator 1. This converts the rotation of the rotor 2 inside the stator 1 into rolling friction of the support bearings 10, significantly reducing mechanical losses between the rotor 2 and the stator 1. The support bearings 10 also provide radial positioning for the rotor 2, ensuring a uniform air gap between the rotor 2 and the stator 1, preventing direct contact and frictional wear, and guaranteeing efficient and stable motor operation.

[0069] A spline sleeve 22 is fixedly installed on the free end of the rotating shaft 3 located outside the front seat 12. A front cap 23 is fitted on the outside of the spline sleeve 22 and is connected to the front seat 12. A rear cap 9 is detachably installed on the rear seat 8.

[0070] The spline sleeve 22 at the free end of the shaft 3 is connected to the external load transmission mechanism via a spline connection to achieve torque transmission. The spline structure can withstand large axial and radial forces, ensuring stable power transmission. The front cap 23 and the rear cap 9 can be installed on the front end seat 12 and the rear end seat 8 during transportation to protect the inside of the motor. The front cap 23 is fitted on the outside of the spline sleeve 22 and connected to the front end seat 12, forming a closed space to protect the spline sleeve 22 from external impurities and to prevent the oil inside the motor from leaking from the gap between the shaft 3 and the front end seat 12.

[0071] Before assembly, all components of the submersible permanent magnet motor must be thoroughly cleaned. The cleaning targets include key components such as the motor housing 11, stator 1, rotor 2 core, shaft 3, front end seat 12, rear end seat 8, support components, and rear cap 9. During cleaning, appropriate cleaning methods should be selected based on the material and surface condition of the components: for oil stains on metal parts, industrial alcohol or a special cleaning agent can be used for wiping; for attached dust, iron filings, and other foreign matter, compressed air should be used to blow them away first, followed by careful wiping with a clean, lint-free cotton cloth. Special attention should be paid to cleaning the assembly surfaces, including the inner walls of the stator 1 mounting holes 29 on the housing 11, the contact surface between the front end seat 12 and the housing 11, and the connection surface between the rear end seat 8 and the housing 11, ensuring these areas are free of oil, rust, burrs, and particulate matter to avoid problems such as poor contact, accelerated wear, or impaired electrical performance after assembly. After cleaning, the components should be placed on a workbench covered with a clean protective mat to prevent secondary contamination.

[0072] First, fix the motor housing 11 vertically onto the special tooling fixture to ensure that the housing 11 will not shake or shift during assembly. During fixing, check the verticality of the housing 11; the deviation should be controlled within the specified range. Next, install the stator 1 using the thermal expansion method: first, heat the motor housing 11 using an oven or induction heating equipment. The heating temperature needs to be determined based on the material of the housing 11 and the fit tolerance between the stator 1 and the housing 11, typically controlled between 100-200℃. Monitor the temperature in real time during heating to avoid localized overheating that could deform the housing 11. After the housing 11 reaches the set temperature and is held at that temperature for a period of time, quickly press the stator 1 vertically into the housing 11 from the top. During pressing, ensure that the axis of the stator 1 coincides with the axis of the housing 11. A guide fixture can be used for positioning assistance. The pressing speed should be uniform until the stator 1 reaches the preset installation position. After pressing, allow the outer shell 11 to cool naturally or use air cooling to accelerate cooling. During the cooling process, the outer shell 11 will shrink and tightly fit with the stator 1, forming a firm interference fit. After cooling to room temperature, check the fit between the stator 1 and the outer shell 11 to ensure that there is no looseness or misalignment.

[0073] The rotor 2 assembly must be carried out in sequence: First, fix the iron core onto the rotating shaft 3. Select a suitable connection method according to the design requirements. If it is an interference fit, the inner hole of the iron core can be heated before fitting it onto the rotating shaft 3, or a press can be used to press it in place. Ensure that there is no relative rotation between the iron core and the rotating shaft 3, and that the perpendicularity of the iron core end face to the rotating shaft 3 meets the requirements. Second, install the magnets onto the iron core according to the polarity markings. Before installation, the surface of the iron core and the mounting surface of the magnets must be cleaned. The magnets can be fixed to the iron core with adhesive or mechanical clamps. During installation, strictly follow the polarity markings to ensure that the polarity of adjacent magnets is correct and to avoid polarity errors. To prevent damage to the motor performance, it is essential to ensure that the magnets are securely installed, accurately positioned, and free from scratches. The third step involves installing the front-end seat 12 at one end of the rotating shaft 3. The fit between the front-end seat 12 and the rotating shaft 3 is typically a transition fit or clearance fit. During installation, it is crucial to ensure that the axis of the front-end seat 12 coincides with the axis of the rotating shaft 3. This can be achieved using locating pins or stopes, and then secured with screws or nuts. The fourth step involves fixing the support assembly onto the rotating shaft 3. The support assembly must be accurately positioned, ensuring that the front-end seat 12 is located between the support assembly and the rotor core 2. The support assembly must be firmly fixed to the rotating shaft 3 to prevent displacement during motor operation.

[0074] With the front end 12 facing upwards, slowly insert the bottom end of the shaft 3 of the assembled rotor 2 assembly into the motor housing 11. During insertion, handle with care to avoid collisions between the rotor 2 core, magnets, and stator 1. The insertion depth can be controlled by observing the relative position of the front end 12 and the top of the housing 11. When the front end 12 contacts the top of the housing 11, the rotor 2 should be precisely inside the stator 1, maintaining a certain initial air gap between the rotor 2 and the stator 1. At this point, check whether the rotor 2 can rotate freely within the housing 11 without any jamming. If jamming occurs, adjust accordingly and troubleshoot before proceeding to the next step.

[0075] The rear end seat 8 is installed at the bottom of the outer casing 11. The connection between the rear end seat 8 and the outer casing 11 is typically secured with bolts. Before installation, sealant should be applied to the connecting surfaces to enhance sealing. During installation, the concentricity of the front end seat 12 and the rear end seat 8 should be adjusted simultaneously. A dial indicator or other measuring tools can be used to monitor the radial runout of the front end seat 12 and the rear end seat 8. Correction can be made by adjusting the tightness of the bolts or by adding or removing shims to the connecting surfaces until the concentricity error of the front end seat 12 and the rear end seat 8 is controlled within the allowable range. After the concentricity adjustment is satisfactory, the air gap between the rotor 2 and the stator 1 needs to be checked. A feeler gauge can be used to measure the air gap value at different positions on the inner circle of the stator 1 to ensure that the air gap is uniform and that the air gap deviation at each point does not exceed the specified value. After confirming that the air gap meets the requirements, the connecting bolts of the front end seat 12 and the rear end seat 8 to the outer casing 11 are tightened respectively. Tightening should be done diagonally and evenly to avoid deformation of components due to uneven force. Finally, the concentricity and air gap are checked again to ensure there are no changes.

[0076] First, install the rear cap 9 on the rear end bracket 8. The connection between the rear cap 9 and the rear end bracket 8 must be reliably sealed to prevent dust, moisture, and other impurities from entering the motor. Next, test the insulation performance of the motor windings. Use an insulation resistance meter to measure the insulation resistance between the windings and the outer casing 11. Before measurement, ensure the winding surface is dry. Apply the specified DC voltage, typically 500V or 1000V, and maintain it for a period before reading the insulation resistance value. The insulation resistance should not be lower than the specified standard, such as 1MΩ. If the insulation resistance does not meet the requirements, find the cause and address it until it is acceptable. After the insulation test is passed, inject a special filling liquid 38 into the motor. The amount of filling liquid 38 injected must be determined according to the motor model, ensuring that the filling liquid 38 fully wets the windings and gaps between components. Avoid generating air bubbles during injection. Then, start the motor and perform performance testing. Test items include rated speed, rated current, rated power, efficiency, temperature rise, vibration, and noise. During the test, monitor all parameters in real time and record the test data. After the motor performance test is completed, the internal filling fluid 38 should be completely drained. After draining, compressed air can be used to blow the inside of the motor to remove any remaining filling fluid 38.

[0077] For motors that pass performance testing, surface anti-corrosion treatment is required. First, clean the motor surface of oil, dust, and other debris. Then, select an appropriate anti-corrosion process according to design requirements, such as painting, galvanizing, or applying anti-corrosion coatings. If painting is used, a primer must be applied first, and the topcoat applied after the primer dries. The paint layer thickness should be uniform, meeting specified requirements, and the surface should be smooth, without runs, bubbles, or missed areas. After anti-corrosion treatment, it needs to be tested. This can be verified by visual inspection, adhesion testing, and salt spray testing to ensure the anti-corrosion performance meets requirements. Motors that pass anti-corrosion treatment need to be packaged, usually wrapped in plastic film or placed in a special packaging box. During packaging, avoid collisions and compression to ensure the motor is not damaged during transportation and storage. Finally, store the packaged motors in a warehouse according to model and specifications. The warehouse should be dry, well-ventilated, free of corrosive gases, and the temperature and humidity should meet storage requirements.

[0078] The foregoing has provided a detailed description of one embodiment of the present invention, but this description is merely a preferred embodiment and should not be construed as limiting the scope of the invention. All equivalent variations and modifications made within the scope of the claims of this invention should still fall within the patent coverage of this invention.

Claims

1. An assembly process for a submersible permanent magnet motor, characterized in that, Includes the following steps: S1. Clean all parts of the motor to ensure that the assembly surfaces are clean and free of foreign objects; S2. Fix the motor housing vertically to the workbench. Use thermal expansion to press the stator into the housing from the top and install it in place. After the housing cools down, the stator and housing will be fixed together. S3. Fix the iron core on the rotating shaft, install the magnets onto the iron core according to the polarity marking to complete the rotor assembly, install the front end seat at one end of the rotating shaft, and then fix the support assembly on the rotating shaft. The front end seat is located between the support assembly and the rotor iron core. S4. With the front end seat facing up, insert the bottom end of the shaft into the housing. When the front end seat contacts the top end of the housing, the rotor is located inside the stator. S5. Install the rear end seat at the bottom of the housing, and at the same time adjust the concentricity of the front end seat and the rear end seat to ensure that the air gap between the rotor and the stator is uniform. Then fix the front end seat and the rear end seat to the housing. S6. Install the rear cap on the rear end seat, test the insulation of the motor windings, and inject filling liquid into the motor after the winding insulation meets the requirements. Then start the motor and test the motor performance. After the motor performance test is completed, drain the filling liquid. S7. Apply anti-corrosion treatment to the surface of motors that meet the performance requirements, and then package and store them after the anti-corrosion treatment meets the requirements.

2. The assembly process of a submersible permanent magnet motor according to claim 1, characterized in that: The rotor consists of multiple sets of iron cores with magnets installed, arranged sequentially along the axial direction of the shaft. Bearings are installed on the shaft at both ends of each iron core. The bearings need to be heated evenly before installation. After heating, the bearings are fitted into the shaft. After the bearings cool down, they achieve a tight fit with the shaft.

3. The assembly process of a submersible permanent magnet motor according to claim 1, characterized in that: The magnets are fixed to the iron core by bonding and pressing. Before installation, adhesive is applied to the magnet mounting slots in the iron core. Then, the magnets are positioned according to the polarity marks. The magnets are pressed into the magnet mounting slots in the marked order using a press. The magnets are left to stand at room temperature until the adhesive cures to enhance the connection strength between the magnets and the iron core. After the iron core is installed, the rotor needs to be dynamically balanced. After the dynamic balance meets the requirements, the subsequent assembly process can be carried out.

4. The assembly process of a submersible permanent magnet motor according to claim 1, characterized in that: Protective shaft tubes are also fitted on the rotating shafts on both sides of the rotor. The protective shaft tubes are connected to the front end seat and the rear end seat respectively, and are used to isolate the rotating shaft from the armature lead wires to prevent the rotating shaft from causing wear on the insulation of the armature lead wires when it rotates.

5. The assembly process of a submersible permanent magnet motor according to claim 3, characterized in that: The adhesive is a high-temperature resistant type, and its temperature resistance meets the temperature requirements of the motor during operation. After curing, it has sufficient bonding strength to ensure the stable installation of the magnet.

6. The assembly process of a submersible permanent magnet motor according to claim 1, characterized in that: When cleaning the various components of the motor in S1, a combination of high-pressure airflow blowing and anhydrous ethanol wiping is used.

7. The assembly process of a submersible permanent magnet motor according to claim 1, characterized in that: The filling fluid injected into S6 is insulating cooling oil, and the injection volume is 90%-95% of the internal cavity volume of the motor.

8. The assembly process of a submersible permanent magnet motor according to claim 1, characterized in that: The anti-corrosion treatment of the motor surface in S7 includes: S7-1. Sandblast the surface of the motor housing to remove rust; S7-2. Spray epoxy zinc-rich primer onto the rust-removed outer shell surface, and dry it after spraying. S7-3. After the primer dries, spray the polyurethane topcoat and then dry it. S7-4. After the topcoat dries, perform a salt spray test. If no rust appears on the surface after the test, package and store the product; otherwise, proceed with S7-1.

9. The assembly process of a submersible permanent magnet motor according to claim 1, characterized in that: The support assembly includes a limiting groove, a thrust bearing, a sliding plate ring, a positioning ring, a split ring, and a retaining groove. The limiting groove is circumferentially formed on the side wall of the rotating shaft. The sliding plate ring is fitted onto the rotating shaft on one side of the limiting groove and is fixedly connected to the rotating shaft. The positioning ring is fitted onto the rotating shaft on the other side of the limiting groove and is fixedly connected to the sliding plate ring. The retaining groove is formed on the inner wall of the positioning ring, which is in contact with the sliding plate ring, and is aligned with the limiting groove. The inner wall of the split ring is in contact with the inner wall of the limiting groove, and the outer wall is in contact with the inner wall of the retaining groove. The thrust bearing is fitted onto the rotating shaft between the sliding plate ring and the front end seat.

10. The assembly process of a submersible permanent magnet motor according to claim 9, characterized in that: A sliding key is provided on the rotating shaft located on one side of the limiting groove, and the sliding ring is fixedly connected to the rotating shaft through the sliding key.

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