Axial dual-rotor compound excitation integrated motor and manufacturing method

Abstract

The application provides an axial double-rotor compound excitation integrated motor and a manufacturing method, and relates to the technical field of motors.The motor comprises a permanent magnet rotor assembly, a single stator assembly and a salient pole rotor assembly arranged coaxially.The single stator assembly is located between the two rotors to form a symmetric topology structure of 'double-rotor sandwiching single stator'.The single stator assembly integrates a left stator assembly, a right stator assembly and a magnetic shielding assembly.The magnetic shielding assembly blocks the magnetic field cross talk between the two sides to achieve complete decoupling.The left permanent magnet synchronous motor and the right electric excitation magnetic reluctance modulation mechanism are coordinated to ensure high power density on the left side, and the right side is flexibly controlled by the electric excitation to adapt to wide working conditions, thereby effectively avoiding the magnetic circuit saturation and demagnetization risk caused by the magnetic field cross talk, and significantly improving the full working condition performance, power density and operation reliability of the motor.

Description

Technical Field

[0001] This invention relates to the field of motor technology, and more specifically, to an axial dual-rotor composite excitation integrated motor and its manufacturing method. Background Technology

[0002] Composite excitation motors combine the advantages of permanent magnet excitation and electric excitation, making them valuable for applications in power systems operating under wide conditions. However, existing technologies suffer from the following shortcomings: First, the permanent magnet and electric excitation magnetic fields are prone to crosstalk, leading to increased magnetic circuit saturation and torque pulsation, which affects operational stability. Second, the axial layout often adopts a "single rotor + double stator" structure, resulting in low space utilization and limited power density improvement. Third, the electromagnetic coupling design between excitation control and armature winding is unreasonable, resulting in a narrow electric excitation adjustment range that makes it difficult to simultaneously meet the demands of low-speed high torque and high-speed field weakening. Fourth, the lack of an effective magnetic field isolation mechanism makes the permanent magnets susceptible to irreversible demagnetization due to the reverse magnetic field of the electric excitation, reducing motor lifespan and reliability.

[0003] In existing technologies, although there have been attempts to achieve composite excitation through split-axis arrangement, the problems of low axial space reuse rate and crosstalk between the two magnetic fields have not been systematically solved from the perspective of "axial integration + magnetic field decoupling". Some integrated designs have deteriorated electromagnetic performance due to improper pole slot matching, and failed to achieve efficient operation under a wide range of working conditions. Therefore, it is urgent to design an axial dual-rotor composite excitation integrated motor to solve the above problems. Summary of the Invention

[0004] The present invention aims to solve the technical problems of magnetic field crosstalk, low space utilization and poor adaptability to operating conditions in existing motors.

[0005] To address the aforementioned problems, this invention provides an axial dual-rotor composite excitation integrated motor, comprising a permanent magnet rotor assembly, a single stator assembly, and a salient pole rotor assembly. The single stator assembly is coaxially disposed between the permanent magnet rotor assembly and the salient pole rotor assembly, and forms axial air gaps with the left permanent magnet rotor assembly and the right salient pole rotor assembly, respectively, constituting a symmetrical topology of dual rotors sandwiching a single stator. The single stator assembly includes a stator core, a left stator assembly, a right stator assembly, and a magnetic isolation assembly. The left stator assembly includes left stator teeth and a left armature winding, with the left stator teeth located on the left side of the stator core. The right stator assembly includes right stator teeth, a right armature winding, and an excitation winding, with the right stator teeth located on the right side of the stator core. The magnetic isolation assembly is used to block magnetic field crosstalk between the left and right sides of the stator core.

[0006] The present invention provides an axial dual-rotor composite excitation integrated motor, which, compared with the prior art, has, but is not limited to, the following beneficial effects: To address the technical problems of magnetic field crosstalk, low space utilization, and poor adaptability to operating conditions in existing motors, this motor mainly consists of three core modules: a permanent magnet rotor assembly, a single stator assembly, and a salient pole rotor assembly. In terms of overall structural layout, the single stator assembly, as a fixed core component, is coaxially positioned between the rotating permanent magnet rotor assembly and the salient pole rotor assembly, ensuring uniform axial air gaps between the left and right sides of the stator and the rotors on both sides. This design constitutes a symmetrical topology of "dual rotors clamping a single stator," which not only makes the axial dimensions extremely compact but also maximizes the space utilization within the housing. Inside the single stator assembly, it is further subdivided into a stator core, a left stator assembly, a right stator assembly, and a magnetic shielding assembly. The left stator assembly carries the left armature winding through left stator teeth and is specifically responsible for connecting with the left permanent magnet rotor. Electromagnetic interaction is achieved; the right stator assembly carries the right armature winding and the electric excitation winding through the right stator teeth, responsible for generating a reluctance modulation effect with the right salient pole rotor; at the same time, the magnetic isolation component integrated inside the stator core completely cuts off the magnetic circuit connection between the left permanent magnet field and the right electric excitation field from both physical and magnetic perspectives; when the motor is running, the left side forms a constant and high-density magnetic field based on the permanent magnet, while the right side forms an actively adjustable magnetic field based on the injected DC current. The magnetic isolation component forces the magnetic flux on both sides to form a closed loop with the corresponding rotor through the air gap in their respective half-regions, without interfering with each other, effectively avoiding the problem of local magnetic circuit deep saturation caused by crosstalk between the two magnetic fields, and completely eliminating the threat of demagnetization of the permanent magnet when the electric excitation reverses, thereby ensuring the high reliability and stable output of the motor under complex dynamic conditions.

[0007] Furthermore, the permanent magnet rotor assembly includes a permanent magnet rotor yoke and permanent magnets. The permanent magnet rotor yoke is made of high-permeability silicon steel sheets stacked to form a disk-shaped structure. The permanent magnets are arranged alternately on the side of the permanent magnet rotor yoke facing the single stator assembly, and radial magnetization is used to form a permanent magnet magnetic field with alternating N and N poles.

[0008] Furthermore, the permanent magnet is made of a high coercivity permanent magnet material and is fixed to the surface of the permanent magnet rotor yoke by pasting or embedding.

[0009] Furthermore, the left armature winding adopts a distributed winding structure and is wound on the left stator teeth to form a three-phase AC winding. The left stator teeth are made of high-permeability silicon steel sheets and are evenly distributed along the circumference, which is used to form synchronous electromagnetic coupling with the permanent magnet rotor assembly.

[0010] Furthermore, the magnetic shielding component is made of titanium alloy or epoxy resin-based composite material with a magnetic permeability ≤1.5μ0, an axial thickness ≥5mm, and is embedded in the middle yoke of the stator core to block magnetic field crosstalk between the left stator component and the right stator component.

[0011] Furthermore, the right armature winding is a concentrated winding wound at the root of the right stator teeth. The right stator teeth are made of high-permeability silicon steel sheets stacked and evenly distributed circumferentially. The excitation winding is a ring-shaped excitation winding embedded between the right stator teeth, used to generate adjustable excitation flux after a DC current is applied.

[0012] Furthermore, the salient pole rotor assembly is a disc-shaped magnetic salient pole structure, including a salient pole rotor yoke made of stacked high magnetic permeability silicon steel sheets in a disc shape and magnetic salient poles evenly distributed along the circumferential edge, and has no permanent magnets or windings, used to form a reluctance modulated electromagnetic coupling with the right stator assembly.

[0013] Furthermore, the permanent magnet rotor assembly has a permanent magnet magnetic field pole pair number P1, an excitation magnetic field pole pair number P2 in the electrically excited winding, and a salient pole number N in the salient pole rotor assembly. r The following matching relationship is satisfied: P1 = P2 + 2, N r =2P²+2; This is used to ensure that the number of main harmonic pole pairs generated by the salient pole rotor assembly after modulation of the electrically excited magnetic field is consistent with the number of permanent magnet pole pairs, thereby achieving synchronous coupling of the magnetic fields on both sides.

[0014] Furthermore, the number of slots N of the left armature winding S1 The permanent magnet magnetic field pole pairs P1 of the permanent magnet rotor assembly satisfy a coprime fit, and the number of slots N of the right armature winding... S2 Satisfying N S2 =N r It is used to make the electric angular velocities of the magnetic fields on both sides equal, thereby achieving electromagnetic synchronization under all operating conditions.

[0015] This invention also provides a method for manufacturing an axial dual-rotor composite excitation integrated motor, comprising the following steps: S1: High-permeability silicon steel sheets are stacked to form a stator core with annular grooves, and magnetic isolation components are embedded and solidified in the annular grooves of the middle yoke to form independent magnetic circuits that are decoupled from the left and right sides. S2: A distributed left armature winding is wound on the left stator teeth, a ring-shaped electric excitation winding is embedded between the right stator teeth, and a concentrated right armature winding is wound at the root of the right stator teeth to complete the manufacturing of a single stator assembly. S3: Permanent magnet rotor yoke and salient pole rotor yoke are respectively made by stacking high permeability silicon steel sheets. High coercivity permanent magnets with radial magnetization are alternately attached to the surface of the permanent magnet rotor yoke to form a permanent magnet rotor assembly. Then, a non-winding magnetic salient pole is processed to form a salient pole rotor assembly, thus completing the manufacturing of dual rotors. S4: The permanent magnet rotor assembly and the salient pole rotor assembly are coaxially assembled on the left and right sides of the single stator assembly, respectively. The axial air gap distance on both sides is adjusted and fixed in the motor housing to achieve coaxial assembly and air gap adjustment. Attached Figure Description

[0016] Figure 1 This is an exploded structural diagram of an axial dual-rotor composite excitation integrated motor according to an embodiment of the present invention. Figure 2 This is a schematic diagram of the permanent magnet rotor assembly and the salient pole rotor assembly in an axial dual-rotor composite excitation integrated motor according to an embodiment of the present invention. Figure 3 This is a schematic diagram of the structure of a single stator assembly in an axial dual-rotor composite excitation integrated motor according to an embodiment of the present invention; Figure 4 This is a planar unfolded schematic diagram of an axial dual-rotor composite excitation integrated motor according to an embodiment of the present invention; Figure 5 This is a schematic diagram of the magnetic field lines in the magnetized state of an axial dual-rotor composite excitation integrated motor according to an embodiment of the present invention. Figure 6 This is a schematic diagram of the magnetic field lines in the demagnetized state of an axial dual-rotor composite excitation integrated motor according to an embodiment of the present invention. Figure 7 This is a schematic diagram of the flux linkage waveforms under magnetization and demagnetization states of an axial dual-rotor composite excitation integrated motor according to an embodiment of the present invention. Figure 8 This is a comparison diagram of the electromagnetic torque waveforms under magnetization and demagnetization states of an axial dual-rotor composite excitation integrated motor according to an embodiment of the present invention. Figure 9 This is a schematic flowchart illustrating a manufacturing method for an axial dual-rotor composite excitation integrated motor according to an embodiment of the present invention.

[0017] Explanation of reference numerals in the attached figures: 1. Permanent magnet rotor assembly; 11. Permanent magnet rotor yoke; 12. Permanent magnet; 2. Left stator assembly; 21. Left stator tooth; 22. Left armature winding; 3. Right stator assembly; 31. Right stator tooth; 32. Right armature winding; 33. Electrically excited winding; 4. Salient pole rotor assembly; 41. Salient pole rotor yoke; 42. Magnetic conductive salient pole; 5. Magnetic isolation assembly. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this application clearer, specific embodiments of this application are described clearly and completely below with reference to the accompanying drawings. It should be understood that the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments described in this application without creative effort will fall within the scope of protection of this application.

[0019] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the specification of this application is for the purpose of describing specific embodiments only and is not intended to limit this application; the terms "comprising," "including," "having," "containing," "comprise," etc., in the specification, claims, and accompanying drawings of this application are open-ended terms, indicating that a method comprises one or more steps, or an apparatus comprises one or more elements, but do not exclude the inclusion of other steps or elements. The terms "first," "second," etc., in the specification, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or primary / secondary relationship. Furthermore, the terms "first" and "second" 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" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0020] In the description of this application, it should be understood that the terms "upper", "lower", "left", "right", "front", "rear", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application 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. Therefore, they should not be construed as limitations on this application.

[0021] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" 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 direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0022] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0023] See Figures 1-8 An axial dual-rotor composite excitation integrated motor according to an embodiment of the present invention includes a permanent magnet rotor assembly 1, a single stator assembly, and a salient pole rotor assembly 4. The single stator assembly is coaxially disposed between the permanent magnet rotor assembly 1 and the salient pole rotor assembly 4, and forms axial air gaps with the left permanent magnet rotor assembly 1 and the right salient pole rotor assembly 4 respectively, constituting a symmetrical topology structure of dual rotors sandwiching a single stator. The single stator assembly includes a stator core, a left stator assembly 2, a right stator assembly 3, and a magnetic isolation assembly 5. The left stator assembly 2 includes a left stator tooth 21 and a left armature winding 22, and the left stator tooth 21 is located on the left side of the stator core. The right stator assembly 3 includes a right stator tooth 31, a right armature winding 32, and an excitation winding 33, and the right stator tooth 31 is located on the right side of the stator core. The magnetic isolation assembly 5 is used to block magnetic field crosstalk between the left and right sides of the stator core.

[0024] In this embodiment, addressing the technical problems of magnetic field crosstalk, low space utilization, and poor adaptability to operating conditions in existing motors, the motor mainly consists of three core modules: a permanent magnet rotor assembly 1, a single stator assembly, and a salient pole rotor assembly 4. In terms of overall structural layout, the single stator assembly, as a fixed core component, is coaxially positioned between the rotating permanent magnet rotor assembly 1 and the salient pole rotor assembly 4, ensuring that the left and right sides of the stator form uniform axial air gaps with the rotors on both sides. This design constitutes a symmetrical topology of "double rotors clamping a single stator," which not only makes the axial dimensions extremely compact but also maximizes the space utilization within the housing. Inside the single stator assembly, it is further subdivided into a stator core, a left stator assembly 2, a right stator assembly 3, and a magnetic shielding assembly 5. The left stator assembly 2 carries the left armature winding 22 through the left stator teeth 21, specifically responsible for connecting with the left permanent magnet rotor. The rotor and the right stator assembly 3 carry the right armature winding 32 and the electric excitation winding 33 through the right stator teeth 31, which are responsible for generating a magnetic reluctance modulation effect with the right salient pole rotor. At the same time, the magnetic isolation assembly 5 integrated inside the stator core completely cuts off the magnetic circuit connection between the left permanent magnet magnetic field and the right electric excitation magnetic field from both physical and magnetic perspectives. When the motor is running, the left side forms a constant and high-density magnetic field based on the permanent magnet 12, while the right side forms an actively adjustable magnetic field based on the injected DC current. The magnetic isolation assembly 5 forces the magnetic flux on both sides to form a closed loop with the corresponding rotor through the air gap in their respective half-regions, without interfering with each other. This effectively avoids the problem of local magnetic circuit deep saturation caused by crosstalk between the two magnetic fields, and completely eliminates the threat of demagnetization of the permanent magnet 12 when the electric excitation reverses, thereby ensuring the high reliability and stable output of the motor under complex dynamic conditions.

[0025] Optional, please refer to Figure 1 , Figure 2 and Figure 4 The permanent magnet rotor assembly 1 includes a permanent magnet rotor yoke 11 and a permanent magnet 12. The permanent magnet rotor yoke 11 is made of high-permeability silicon steel sheets stacked to form a disk-shaped structure. The permanent magnet 12 is arranged alternately on the side of the permanent magnet rotor yoke 11 facing the single stator assembly, and is radially magnetized to form a permanent magnet magnetic field with alternating N and N poles.

[0026] In this embodiment, the permanent magnet rotor assembly 1 mainly includes a permanent magnet rotor yoke 11 and permanent magnets 12 uniformly distributed thereon. The permanent magnet rotor yoke 11, as a key component for magnetic circuit closure, has an overall disk-shaped structure and is made of high-permeability silicon steel sheets laminated layer by layer. The use of laminated silicon steel sheets effectively suppresses high-frequency eddy current losses generated during rotation and provides a magnetically conductive path with extremely low magnetic resistance for the magnetic field. The permanent magnets 12 are arranged alternately along the circumferential direction on the side of the permanent magnet rotor yoke facing the single stator assembly. In terms of magnetization, all permanent magnets 12 employ a radial magnetization process, thereby forming a magnetic field at the axial air gap between the stator and rotor. The permanent magnet main magnetic field exhibits a strict alternation of N and S poles. The alternating permanent magnets 12 emit strong magnetic flux, which passes through the left axial air gap and enters the left stator tooth 21 of the stator. Then, it reaches the adjacent stator tooth along the low-impedance path formed by silicon steel sheets, and then returns through the air gap to the permanent magnet 12 of the adjacent polarity, forming a complete and efficient left closed magnetic circuit system. Through the cooperation of the low-impedance silicon steel sheet rotor yoke and the specifically arranged radially magnetized permanent magnets 12, the leakage coefficient is greatly reduced, so that the effective main magnetic flux entering the working air gap is maximized, laying a solid electromagnetic hardware foundation for the efficient steady-state operation and high power density output of the motor.

[0027] Optionally, the permanent magnet 12 is made of a high coercivity permanent magnet material and is fixed to the surface of the permanent magnet rotor yoke 11 by pasting or embedding.

[0028] In this embodiment, to ensure the performance stability of the motor under high temperature and strong electromagnetic shock environments, the permanent magnet 12 is made of rare earth permanent magnet materials with high coercivity, such as neodymium iron boron. These materials not only have extremely high remanence density, but also have a strong ability to resist demagnetization by external reverse magnetic fields. The high coercivity material itself can resist the instantaneous strong armature reaction caused by sudden load changes on the stator side, which greatly enhances the mechanical strength and anti-magnetic decay ability of the rotor assembly, ensuring that the magnetic field strength of the motor does not decline during its long life cycle, and further improving the safety of the whole machine operation.

[0029] Optional, please refer to Figure 1 , Figure 3 and Figure 4 The left armature winding 22 is wound on the left stator tooth 21 using a distributed winding structure to form a three-phase AC winding. The left stator tooth 21 is made of high-permeability silicon steel sheets stacked and evenly distributed along the circumference, and is used to form synchronous electromagnetic coupling with the permanent magnet rotor assembly 1.

[0030] In this embodiment, the left armature winding 22 adopts a distributed winding structure. This winding is orderly wound on the left stator teeth 21, forming a standard three-phase AC winding system in space. At the same time, the left stator teeth 21 that carry these windings are also made of high-permeability silicon steel sheets and are distributed at an absolutely uniform distance along the circumference. When three-phase symmetrical AC current is passed into the distributed left armature winding 22, an armature magnetomotive force with a sinusoidal distribution and smooth rotation can be generated in the left air gap space. This rotating magnetomotive force and the constant permanent magnet magnetic field emitted by the permanent magnet rotor assembly 1 generate a strong mutual drag effect, that is, a synchronous electromagnetic coupling mechanism is formed. The distributed winding design can greatly reduce the high-order harmonic components in the air gap magnetic field, thereby making the synchronous electromagnetic torque waveform generated by the motor during operation smoother, effectively suppressing torque pulsation and electromagnetic noise, and ensuring that the motor can output high-quality steady-state driving force.

[0031] Optionally, the magnetic shielding component 5 is made of titanium alloy or epoxy resin-based composite material with a magnetic permeability ≤1.5μ0, an axial thickness ≥5mm, and is embedded in the middle yoke of the stator core to block magnetic field crosstalk between the left stator component 2 and the right stator component 3.

[0032] In this embodiment, to achieve absolute physical isolation of the magnetic fields on both sides, the magnetic isolation component 5 abandons traditional magnetic conductive materials and instead uses titanium alloy or epoxy resin-based composite materials for processing and manufacturing. A common physical characteristic of these materials is their extremely low magnetic permeability, with specific parameters strictly controlled within the range of less than or equal to 1.5 μ0 (μ0 being the vacuum permeability). This forms a clear physical boundary with the stator tooth silicon steel sheet material, whose magnetic permeability is typically as high as several thousand μ0. In terms of structural dimensions, the axial thickness of the magnetic isolation component 5 is limited to no less than 5 mm and is precisely embedded. It is solidified in the annular groove of the middle layer yoke of the stator core; when the high-voltage permanent magnet flux on the left or the strong electric excitation flux on the right attempts to penetrate the middle layer of the stator and intersect laterally, the extremely low magnetic permeability material layer of more than 5 mm forms a high magnetic reluctance isolation wall, forcing the magnetic lines of force to bend and close towards the corresponding rotor side; fundamentally blocking any form of magnetic field crosstalk between the left stator assembly 2 and the right stator assembly 3, so that the originally complex composite excitation magnetic circuit is separated into two completely independent systems, so that the two rotors can exert their optimal electromagnetic performance without interference.

[0033] Optional, please refer to Figure 1 , Figure 3 and Figure 4The right armature winding 32 is a concentrated winding wound at the root of the right stator tooth 31. The right stator tooth 31 is made of high permeability silicon steel sheets stacked and evenly distributed along the circumference. The electric excitation winding 33 is a ring excitation winding, embedded between the right stator teeth 31, and is used to generate adjustable excitation flux after a DC current is applied.

[0034] In this embodiment, unlike the synchronous structure on the left, the armature winding 32 on the right is designed as a concentrated winding, tightly wound at the root of the stator tooth 31 on the right. The stator tooth 31 on the right is also composed of stacked high-permeability silicon steel sheets evenly distributed around its circumference. In addition, the right structure introduces a core electric excitation mechanism, namely, a complete annular excitation winding is embedded in the reserved space between each stator tooth on the right. The system continuously supplies DC current to the annular electric excitation winding 33 through an external controller. By changing the amplitude and direction of the DC current, the intensity of the generated excitation fundamental magnetic flux can be adjusted in real time, continuously and over a wide range. The adjustable magnetic flux then enters the air gap on the right through the stator tooth and participates in the subsequent electromagnetic energy conversion process. The system effectively adjusts the strength of the internal magnetic field through simple electrical control. In the low-speed stage where a large torque is required for starting, the system can increase the excitation current to achieve "magnetization" and generate a powerful driving force. In the high-speed cruising stage, the system reduces or even reverses the excitation current to achieve "magnetization," effectively overcoming the limitation of back electromotive force and thus greatly expanding the speed range of the motor.

[0035] The flux linkage and torque waveforms were obtained through simulation experiments, as shown below. Figure 7 , Figure 8 As shown, Figure 7 The variation of magnetic flux with electrical angle in the magnetization and demagnetization states of the motor is shown; the peak magnetic flux of magnetization is about 0.25 Wb and the peak magnetic flux of demagnetization is about 0.15 Wb, both of which show a sinusoidal distribution. Figure 8 The figure shows the electromagnetic torque waveforms under magnetization and demagnetization states. The peak magnetization torque is about 140 Nm, which is suitable for low-speed, high-torque conditions. The peak demagnetization torque is about 75 Nm, which meets the requirements for high-speed field weakening acceleration. The waveform is smooth, which verifies the design advantages of the invention and demonstrates the stable operation characteristics of the motor under all operating conditions.

[0036] Optional, please refer to Figure 1 , Figure 2 and Figure 4 The salient pole rotor assembly 4 is a disc-shaped magnetic salient pole 42 structure, including a salient pole rotor yoke 41 made of stacked high magnetic permeability silicon steel sheets in a disc shape and magnetic salient poles 42 evenly distributed along the circumferential edge, and has no permanent magnet 12 and windings, and is used to form a magnetoresistive modulated electromagnetic coupling with the right stator assembly 3.

[0037] In this embodiment, the salient pole rotor assembly 4 adopts a disc-shaped pure magnetic salient pole 42 structure. The entire assembly consists only of a salient pole rotor yoke 41 made of stacked high magnetic permeability silicon steel sheets and several magnetic salient poles 42 uniformly distributed along the circumferential edge of the yoke. The most significant feature of this rotor assembly is that it completely eliminates the expensive permanent magnet 12 and the complex rotor winding structure. Utilizing the magnetoresistance effect, when the salient pole rotor without any active excitation source rotates in the right space, the magnetic permeability distribution in the right air gap exhibits a drastic periodic change due to the alternating appearance of grooves between its magnetic salient poles 42 and adjacent salient poles. At this time, the constant fundamental magnetic flux from the right stator annular excitation winding is forced to undergo spatial modulation when passing through this constantly changing periodic air gap reluctance, thereby exciting a large number of harmonic magnetic flux containing a specific number of pole pairs. These harmonic magnetic fluxes then cut with the concentrated right armature winding 32 on the stator, generating induced electromotive force and reluctance torque. The complex reluctance modulation electromagnetic coupling process is effectively realized through a simple brushless iron core structure, which not only greatly reduces the manufacturing cost and dependence on rare earth materials, but also eliminates the risk of demagnetization caused by rotor heating, making the right drive unit more robust and durable.

[0038] Optionally, the permanent magnet rotor assembly 1 has a permanent magnet field pole pair number P1, the electric excitation winding 33 has an excitation field pole pair number P2, and the salient pole number N of the salient pole rotor assembly 4 is... r The following matching relationship is satisfied: P1 = P2 + 2, N r =2P²+2; This is used to ensure that the number of main harmonic pole pairs generated by the salient pole rotor assembly 4 after modulation of the electrically excited magnetic field is consistent with the number of permanent magnet pole pairs, thereby achieving synchronous coupling of the magnetic fields on both sides.

[0039] In this embodiment, to achieve synchronization between the left permanent magnet magnetic field and the right electrically excited magnetic field, the following numerical relationships exist: First, the mechanical speeds of the permanent magnet rotor and the salient pole rotor are exactly the same, i.e., n1=n2=n (n1 is the mechanical speed of the permanent magnet rotor, n2 is the mechanical speed of the salient pole rotor, and n is the common mechanical speed); second, after the number of pole pairs P2 of the excitation magnetic field is modulated by the reluctance of the salient pole rotor, the number of harmonic flux pole pairs P2' satisfies P2'=N. r -P2, to synchronize the modulated magnetic field with the permanent magnet magnetic field, P2'=P1, that is, P1=P2+2; from the electric angular velocity ω=PΩ (Ω is the mechanical angular velocity), it can be seen that since P2'=P1, the electric angular velocities of the magnetic fields on both sides are naturally equal, thus achieving electromagnetic synchronization under all working conditions; ensuring that although the left and right sides adopt completely different electromagnetic force generation mechanisms (one side is permanent magnet synchronization, and the other side is magnetoresistive modulation), they can achieve tight synchronous coupling of the magnetic fields on both sides in space and time under the premise of sharing a single output shaft, completely eliminating the phenomenon of electromagnetic interlocking or severe oscillation inside the system caused by pole number mismatch.

[0040] Optionally, the number of slots N of the left armature winding 22 S1 The permanent magnet magnetic field pole pairs P1 of the permanent magnet rotor assembly 1 satisfy a coprime fit, and the number of slots N of the right armature winding 32 is... S2 Satisfying N S2 =N r It is used to make the electric angular velocities of the magnetic fields on both sides equal, thereby achieving electromagnetic synchronization under all operating conditions.

[0041] In this embodiment, the number of slots N of the left armature winding 22 is... S1 The number of permanent magnet pole pairs P1 of the permanent magnet rotor assembly 1 (i.e., gcd(N)) S1 P1)=1, P1=6 in the diagram) satisfies coprime fit to suppress cogging torque and magnetomotive force harmonics; the number of slots N of the armature winding 32 on the right side. S2 The number of pole pairs P2 of the excitation flux of the electric excitation winding 33 satisfies N S2 =2P²+2 (N in the diagram) S2 =10), while the number of salient poles N of the salient pole rotor assembly 4. r =N S2 To ensure that the number of pole pairs of the fundamental electromagnetic flux and the reluctance modulation harmonic flux are consistent, so as to optimize the waveform of the reluctance modulation electromotive force.

[0042] The left side employs a coprime slot-pole pairing to break the periodic symmetry between the stator teeth and rotor magnetic poles, allowing the harmonic components of the cogging torque to cancel each other out. The right side, on the other hand, uses a slot number equal to the salient pole number to maximize the capture and utilization of the main harmonic flux generated by salient pole modulation, thereby producing the optimal back electromotive force waveform. This further reduces the inherent torque pulsation during operation at the hardware level, optimizing the smoothness of the overall output torque and ensuring that the electric angular velocities of both electric drive units are highly consistent across all operating conditions, from low-speed climbing to high-speed cruising. This achieves unimpeded electromagnetic synchronization and power superposition, resulting in better performance.

[0043] This invention achieves efficient electromagnetic control under wide operating conditions through a dual-mechanism synergy of left-side permanent magnet synchronization and right-side electric excitation reluctance modulation, combined with the magnetic field decoupling design of the magnetic isolation component. The left-side permanent magnet 12 provides a stable main magnetic field to ensure power density, while the right-side electric excitation flexibly adjusts the magnetic flux to adapt to changes in operating conditions. Both mechanisms work together to output torque through independent magnetic circuits. The radial magnetomotive force generated by the permanent magnet 12 of the left-side permanent magnet rotor is defined as follows: F p ( θ ), which are distributed in alternating N, N poles along the circumference, satisfying F p ( θ )= F p0 sin(p 1· θ )(in p 1 represents the left pole pair. θ From a spatial perspective, F p0 (The fundamental amplitude of the permanent magnet magnetomotive force); the axially adjustable magnetomotive force generated by the right-side electrically excited winding 33 is... F e ( θ ), which are periodically distributed along the circumference, satisfying F e ( θ )= F e0 sin( p 2· θ )(in p 2 is the right-hand pole logarithm. F e0 (This is the amplitude of the fundamental wave of the electrically excited magnetomotive force, the magnitude of which is linearly adjusted with the excitation current).

[0044] Left permanent magnet magnetomotive force F p The dominant magnetic flux originates from the permanent magnet 12, passes through the left air gap to the left stator tooth 21, extends along the left stator tooth 21 to the left stator yoke of the stator core, is transmitted through the adjacent left stator tooth 21, passes through the left air gap, and finally returns to the adjacent permanent magnet 12, transmitting along a closed axial path. It is orthogonally coupled with the three-phase rotating magnetic field of the left armature winding 22, generating steady-state torque through synchronous electromagnetic action to ensure efficient operation; the right-side electrically excited magnetomotive force... F e A constant fundamental magnetic flux is generated. As the salient-pole rotor rotates, the air gap permeability changes periodically, modulating a harmonic magnetic flux that matches the number of pole pairs in the right armature winding 32. This harmonic flux interacts with the alternating magnetic field of the right armature winding 32, generating a reluctance-modulated torque. F e0 The magnetic flux can be flexibly controlled by adjusting the excitation current (magnetizing to increase low-speed torque and weakening to extend the high-speed range).

[0045] The magnetic shielding component 5 blocks the crosstalk between the left and right magnetomotive forces, making... F p and F eThey function independently in space: the left side relies on the stability of the permanent magnet magnetomotive force to achieve high power density output, while the right side utilizes the adjustability of the electrically excited magnetomotive force to adapt to fluctuations in operating conditions. The torque coordination between the two adopts a dynamic allocation strategy of "left-side V / f control + right-side field-oriented control (FOC)," which maintains the high efficiency characteristics of the permanent magnet motor while possessing the wide speed regulation capability of the electrically excited motor. This solves the problem that traditional single-excitation motors cannot simultaneously achieve "high power density" and "wide operating condition adaptability," adapting to complex drive scenarios that require dynamic response and efficient operation.

[0046] This invention also provides a method for manufacturing an axial dual-rotor composite excitation integrated motor, comprising the following steps: S1: High-permeability silicon steel sheets are stacked to form a stator core with annular grooves, and magnetic isolation component 5 is embedded and solidified in the annular groove of the middle yoke to form independent magnetic circuits that are decoupled from left and right. S2: A distributed left armature winding 22 is wound on the left stator tooth 21, an annular electric excitation winding 33 is embedded between the right stator teeth 31, and a concentrated right armature winding 32 is wound at the root of the right stator tooth 31 to complete the manufacturing of a single stator assembly. S3: Permanent magnet rotor yoke 11 and salient pole rotor yoke 41 are respectively made by stacking high permeability silicon steel sheets. High coercivity permanent magnets 12 with radial magnetization are alternately attached to the surface of permanent magnet rotor yoke 11 to form permanent magnet rotor assembly 1. And unwinding magnetic salient poles 42 are processed to form salient pole rotor assembly 4, thus completing the manufacturing of dual rotors. S4: The permanent magnet rotor assembly 1 and the salient pole rotor assembly 4 are coaxially assembled on the left and right sides of the single stator assembly, respectively. The axial air gap distance on both sides is adjusted and fixed in the motor housing to achieve coaxial assembly and air gap adjustment.

[0047] In this embodiment, see Figure 9The specific manufacturing method of the integrated motor is described. The manufacturing process follows a logic of inside-out and step-by-step decoupling. First, a stator core with specific annular grooves is prepared by high-pressure stacking of silicon steel sheets. The low-permeability magnetic isolation component 5 is precisely embedded into the middle yoke and subjected to high-temperature curing treatment, creating two sets of physically isolated independent magnetic circuit bases from the source. Subsequently, distributed coils are wound on the left teeth of the base to form the left armature winding 22, and an annular electric excitation coil is placed in the slot between the right teeth. Then, a concentrated right armature winding 32 is wound at the root of the right teeth, thus completing the overall manufacturing of the most complex core single stator component. Then, the focus shifts to the processing of dynamic components. Two disc rotor yokes are stamped and stacked using silicon steel sheets. High-performance neodymium iron boron permanent magnets 12 are radially magnetized and attached to the surface of the left rotor yoke according to the alternating N and N polarities. The permanent magnet rotor assembly 1 is completed, while only a specific number of magnetically conductive salient poles 42 are machined on the right side to complete the minimalist salient pole rotor assembly 4. Finally, the manufactured permanent magnet rotor assembly 1 and salient pole rotor assembly 4 are coaxially aligned and assembled on both sides of the single stator assembly, one on the left and one on the right. The axial air gap between the two sides is adjusted by a precision micrometer until the design tolerance is met. Finally, it is locked and sealed and fixed in the external motor housing. Based on the above manufacturing steps, the prototype machine can achieve a peak magnetization flux of about 0.25 Wb and a peak demagnetization flux of about 0.15 Wb in simulation experiments. In terms of torque characteristics, the peak torque in the magnetization state reaches about 140 Nm to adapt to low speed and high torque, while the torque in the demagnetization state is about 75 Nm to meet the requirements of high speed and field weakening. This ensures that the motor can perfectly exhibit excellent dynamic performance with smoothness, high efficiency and wide speed range under all working conditions.

[0048] While the present invention has been disclosed above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the scope of protection of the present invention.

Claims

1. An axial dual-rotor composite excitation integrated motor, characterized in that, The system includes a permanent magnet rotor assembly (1), a single stator assembly, and a salient pole rotor assembly (4). The single stator assembly is coaxially disposed between the permanent magnet rotor assembly (1) and the salient pole rotor assembly (4), and forms axial air gaps with the left permanent magnet rotor assembly (1) and the right salient pole rotor assembly (4) respectively, forming a symmetrical topology structure of a double rotor sandwiching a single stator. The single stator assembly includes a stator core, a left stator assembly (2), a right stator assembly (3), and a magnetic isolation assembly (5). The left stator assembly (2) includes a left stator tooth (21) and a left armature winding (22). The left stator tooth (21) is located on the left side of the stator core; the right stator assembly (3) includes a right stator tooth (31), a right armature winding (32), and an excitation winding (33). The right stator tooth (31) is located on the right side of the stator core. The magnetic isolation assembly (5) is used to block magnetic field crosstalk between the left and right sides of the stator core. The left armature winding (22) is wound on the left stator tooth (21) using a distributed winding structure to form a three-phase AC winding. The left stator tooth (21) is made of high-permeability silicon steel sheets and is evenly distributed circumferentially. The armature winding (32) is a concentrated winding wound at the root of the right stator tooth (31). The right stator tooth (31) is made of high-permeability silicon steel sheets and is evenly distributed circumferentially. The excitation winding (33) is a ring-shaped excitation winding embedded between the right stator teeth (31) and is used to generate adjustable excitation flux after DC current is applied. The salient pole rotor assembly (4) is a disc-shaped salient pole structure, including a salient pole rotor yoke (41) made of high-permeability silicon steel sheets in a disc shape. The salient poles (42) are evenly distributed along the circumferential edge and have no permanent magnets or windings. They are used to form a reluctance-modulated electromagnetic coupling with the right stator assembly (3). The permanent magnet rotor assembly (1) has a permanent magnet magnetic field pole pair number P1, an excitation magnetic field pole pair number P2 of the electric excitation winding (33), and a salient pole number Nr of the salient pole rotor assembly (4) that satisfy the following matching relationship: P1=P2+2, Nr=2P2+2. This is used to make the number of main harmonic pole pairs generated by the salient pole rotor assembly (4) after modulating the electric excitation magnetic field consistent with the number of permanent magnet magnetic field pole pairs, so as to realize the synchronous coupling of the magnetic fields on both sides.

2. The axial dual-rotor composite excitation integrated motor according to claim 1, characterized in that, The permanent magnet rotor assembly (1) includes a permanent magnet rotor yoke (11) and a permanent magnet (12). The permanent magnet rotor yoke (11) is made of high-permeability silicon steel sheets stacked to form a disk-shaped structure. The permanent magnet (12) is arranged circumferentially alternately on the side of the permanent magnet rotor yoke (11) facing the single stator assembly, and radial magnetization is used to form a permanent magnet magnetic field with alternating N and N poles.

3. The axial dual-rotor composite excitation integrated motor according to claim 2, characterized in that, The permanent magnet (12) is made of a high coercivity permanent magnet material and is fixed to the surface of the permanent magnet rotor yoke (11) by pasting or embedding.

4. The axial dual-rotor composite excitation integrated motor according to claim 1, characterized in that, The magnetic shielding component (5) is made of titanium alloy or epoxy resin-based composite material with a magnetic permeability ≤1.5μ0. The axial thickness of the magnetic shielding component (5) is ≥5mm. The magnetic shielding component (5) is embedded in the middle layer yoke of the stator core to block magnetic field crosstalk between the left stator component (2) and the right stator component (3).

5. An axial dual-rotor composite excitation integrated motor according to claim 1, characterized in that, The number of slots NS1 of the left armature winding (22) and the number of permanent magnet pole pairs P1 of the permanent magnet rotor assembly (1) satisfy mutual prime matching, and the number of slots NS2 of the right armature winding (32) satisfies NS2=Nr, which is used to make the electric angular velocities of the magnetic fields on both sides equal, thereby achieving electromagnetic synchronization under all working conditions.

6. A method for manufacturing an axial dual-rotor composite excitation integrated motor as described in any one of claims 1-5, characterized in that, Includes the following steps: S1: High permeability silicon steel sheets are stacked to form a stator core with an annular groove, and a magnetic isolation component (5) is embedded and solidified in the annular groove of the middle yoke to form an independent magnetic circuit with left and right decoupled. S2: A distributed left armature winding (22) is wound on the left stator teeth (21), a ring-shaped electric excitation winding (33) is embedded between the right stator teeth (31), and a concentrated right armature winding (32) is wound at the root of the right stator teeth (31) to complete the manufacturing of a single stator assembly. S3: Permanent magnet rotor yoke (11) and salient pole rotor yoke (41) are respectively made by stacking high permeability silicon steel sheets. High coercivity permanent magnets (12) with radial magnetization are alternately attached to the surface of permanent magnet rotor yoke (11) to form permanent magnet rotor assembly (1). A non-winding magnetic salient pole (42) is processed to form salient pole rotor assembly (4), thus completing the manufacturing of dual rotors. S4: The permanent magnet rotor assembly (1) and the salient pole rotor assembly (4) are coaxially assembled on the left and right sides of the single stator assembly, respectively. The axial air gap distance on both sides is adjusted and fixed in the motor housing to achieve coaxial assembly and air gap adjustment.

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