Harmonic high-efficiency field modulation type double-drive differential magnetic lead screw integrated actuator

Abstract

The invention provides a harmonic high-efficiency field modulation type dual-drive differential magnetic lead screw integrated actuator. The harmonic high-efficiency field modulation type dual-drive differential magnetic lead screw integrated actuator comprises a stator, a higher harmonic armature winding, a fundamental harmonic armature winding, an outer rotor, a middle rotor and an inner rotor, the higher harmonic armature winding and the fundamental harmonic armature winding are used as two electric ports; the higher harmonic armature winding, the outer rotor modulation part and the middle rotor excitation part form a higher harmonic magnetic flux modulation motor, the fundamental harmonic armature winding and the middle rotor excitation part form a vernier permanent magnet motor, and the outer rotor excitation part, the middle rotor modulation part and the inner rotor form a field modulation magnetic lead screw. According to the invention, three barriers of modulation depth, magnetic circuit decoupling and multi-port control can be broken through synchronously, so that unification of high thrust and high precision is realized in a highly integrated unit.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of precision electromagnetic driving and transmission technology, in particular to a harmonic high-efficiency field modulation type double-drive differential magnetic force screw integrated actuator. BACKGROUND

[0002] In the fields of high-end equipment manufacturing, precision measurement, semiconductor processing, and aerospace, the thrust density, motion accuracy, and dynamic response performance of linear driving systems are core key indicators. Existing linear driving technologies have evolved from mechanical transmission to magnetic transmission, but there are still a series of unresolved technical bottlenecks.

[0003] Firstly, as a classic rotary-linear motion conversion mechanism, the traditional ball screw has the advantages of simple structure, low cost, and strong carrying capacity. However, its working mode relying on mechanical contact leads to inherent problems such as friction, wear, mechanical backlash, and vibration noise, resulting in low transmission efficiency, limited service life, and difficulty in meeting the application requirements of ultra-precision environments.

[0004] To solve the control accuracy problem, a single motor driving single ball screw scheme has emerged. This scheme realizes digital closed-loop control through a servo motor, improving automation level and repeat positioning accuracy. However, it not only inherits all the mechanical defects of the ball screw, but also due to its single control degree of freedom, the output force and motion speed of the system are strongly coupled, making it impossible to independently adjust the output force while maintaining precise positioning, severely limiting dynamic response and control flexibility.

[0005] To further improve performance, a double-motor differential driving ball screw scheme has been developed. This scheme uses two motors to control the input and output of the ball screw (such as one motor driving the screw rotation, and the other motor driving the nut rotation through a reverse mechanism), and realizes differential adjustment by precisely controlling the relative motion of the two motors. This scheme can theoretically actively compensate for transmission errors and realize motion synthesis. However, this scheme is still based on mechanical contact transmission and cannot eliminate fundamental defects such as friction and wear, and has complex system structure, high control difficulty, and high cost, making it difficult to achieve ideal precision and stability in practical applications.

[0006] To completely get rid of mechanical friction, a non-contact traditional magnetic force screw was proposed. It uses permanent magnet field coupling to realize motion conversion, with the advantages of no friction, no wear, high efficiency, and maintenance-free. However, its thrust density is usually lower than that of high-performance ball screws, and there is thrust fluctuation, limiting its application in high-end scenarios.

[0007] To improve the thrust density and smoothness of the magnetic screw, the magnetic field modulation magnetic screw emerges as the times require. This technology modulates the permanent magnetic field by introducing a magnetic modulation ring, effectively enhancing the thrust density and reducing the thrust fluctuation. However, its performance improvement is strictly limited by the magnetic saturation effect of ferromagnetic materials, the thrust density has a theoretical upper limit, and the complex modulation structure also increases the system volume and weight, which is not conducive to dynamic response.

[0008] In terms of integration, single permanent magnet synchronous motor composite magnetic screw realizes the structural integration of motor and screw, with the advantage of compact structure. However, its essence is still single electromechanical port driving, which has the problem of force and position control coupling, and the magnetic fields of motor and screw interfere with each other, affecting the output smoothness.

[0009] There is also a scheme of double-motor composite field modulation magnetic screw in the prior art. The core of this scheme is to use two independent motors to directly drive two key rotor components of the field modulation magnetic screw (for example, one motor drives the outer rotor permanent magnet, and the other motor drives the intermediate magnetic modulation ring rotor). By controlling the rotational speed and relative phase of the two rotors, the effect of magnetic field modulation is actively and accurately controlled, so as to optimize the thrust output of the mover or achieve a special motion trajectory. However, the prior art still has the following problems: (1) The bottleneck of the underlying magnetic field modulation efficiency, i.e. the fundamental bottleneck of thrust density.

[0010] The existing magnetic field modulation technology, whether single-ring single-modulation or double-ring double-modulation, is severely limited by the magnetic saturation effect of ferromagnetic materials. When the magnetic field strength increases to the saturation point, further increasing the excitation will not effectively enhance the modulation magnetic field, resulting in a theoretical upper limit for the improvement of thrust density. This limits the ability of linear actuators to output greater thrust in a limited volume from the source of energy conversion.

[0011] (2) Interference bottleneck at the system integration level, i.e. unavoidable mutual interference of performance fusion.

[0012] The integration design of motor and magnetic screw for compact structure often leads to the close coupling of their magnetic field paths. This coupling will cause unavoidable magnetic-thermal-force multi-physical field two-way interference: high-frequency harmonics at the motor end will destroy the stability of the screw magnetic field, leading to increased thrust fluctuation; and sudden load changes at the screw end will also react on the motor, introducing torque pulsation. This inherent mutual interference fundamentally damages the output smoothness and control accuracy of the system under dynamic conditions, making it difficult to achieve high-precision positioning.

[0013] (3) Top-level architecture and control freedom bottleneck: the existing structure cannot realize macro-micro motion.

[0014] The existing architecture (such as single machine electrical port drive or complex mechanical double-motor composite) generally lacks sufficient, native integrated control freedom. Single control port makes the output force and the motion speed strongly coupled, and the system cannot simultaneously independently and decoupled finely adjust the two key parameters. This leads to the existing technical solutions naturally unable to balance the large thrust macro motion and high precision micro motion in the physical architecture and control logic. Usually only through the mechanical superposition of "macro stage + micro stage" to realize, resulting in a system that is bulky, complex, high cost and has control delay.

[0015] The above three bottlenecks together constitute a technical impasse: the modulation bottleneck limits the thrust base (macro motion ability), the coupling interference destroys the precision foundation (micro motion potential), and the lack of architecture and freedom cuts off the path of macro and micro motion integration in the same body. SUMMARY

[0016] In view of this, the present application provides a harmonic high-efficiency field modulation type double-drive differential magnetic force screw integrated actuator to synchronously break through the three major barriers of modulation depth, magnetic circuit decoupling and multi-port control, thereby realizing the unity of large thrust and high precision in a highly integrated unit.

[0017] A harmonic high-efficiency field modulation type double-drive differential magnetic force screw integrated actuator, comprising: The stator, the high-order harmonic armature winding, the fundamental harmonic armature winding, the outer rotor, the intermediate rotor, and the inner mover are included. The high-order harmonic armature winding is wound on the outer layer of the stator, and the fundamental harmonic armature winding is wound on the inner layer of the stator. The high-order harmonic armature winding and the fundamental harmonic armature winding serve as two electrical ports. The outer rotor is coaxially arranged on the inner side of the stator, the intermediate rotor is coaxially arranged on the inner side of the outer rotor, and the inner mover is coaxially arranged on the inner side of the intermediate rotor. The high-order harmonic armature winding and the outer rotor modulation part and the intermediate rotor excitation part form a high-order harmonic magnetic flux modulation motor. The fundamental harmonic armature winding and the intermediate rotor excitation part form a vernier permanent magnet motor. Through fundamental and high-order harmonic modulation, a high-order harmonic modulation and energy conversion path is established. The outer rotor excitation part and the intermediate rotor modulation part serve as two mechanical ports. The outer rotor excitation part, the intermediate rotor modulation part, and the inner mover form a field modulation magnetic force screw.

[0018] The harmonic high-efficiency field modulation type double-drive differential magnetic force screw integrated actuator provided by the present application has the following beneficial effects: (1) The fundamental bottleneck of the underlying magnetic field modulation efficiency, i.e., the thrust density, is faced with a fundamental bottleneck. To solve the fundamental problem that the thrust density is limited by the magnetic saturation of the core, two independent armature windings are provided in the stator to establish a double modulation path. The pole pair number of the high-order harmonic armature winding satisfies the relationship: , which together with the outer rotor modulation part and the intermediate rotor excitation part form a high-order harmonic flux modulation motor, opening up a dedicated high-order harmonic energy conversion channel. At the same time, the pole pair number of the fundamental harmonic armature winding satisfies the relationship: , which together with the intermediate rotor excitation part forms a vernier permanent magnet motor. Through this mechanism of coordinated modulation of fundamental and high-order harmonics, the system can make full use of magnetic field harmonics of different orders. Furthermore, the intermediate rotor excitation part adopts a hybrid excitation design (i.e., a combination of permanent magnet and electric excitation), which can actively enhance the high-order harmonic magnetic field component of the inner air gap, significantly improving the harmonic utilization rate and overall magnetic flux density without causing core saturation and affecting the fundamental magnetic field, thus fundamentally breaking through the upper limit of thrust density of a single modulation path.

[0019] (2) For the inevitable mutual interference of the system integration level magnetic interference bottleneck, i.e., performance fusion, to achieve high-performance integration of the motor and the magnetic screw and avoid mutual magnetic interference, the present application performs physical isolation design on the key magnetic circuit. The outer rotor and the intermediate rotor bear dual functions: the outer rotor modulation part and the intermediate rotor excitation part participate in electric field modulation, and the outer rotor excitation part, the intermediate rotor modulation part, and the inner rotor constitute a field modulation magnetic screw. To realize magnetic circuit decoupling, a magnetic isolation bridge is provided between the intermediate rotor excitation part and the intermediate rotor modulation part. The magnetic isolation bridge forms a high-magnetic-resistance barrier, which can effectively block the interlinkage of the rich harmonic magnetic field (especially generated by the high-order harmonic armature winding) from the motor side to the magnetic screw side, enabling magnetic circuit isolation between the motor system and the magnetic screw system. This fundamentally eliminates the magnetic-force bidirectional interference between the two, ensuring the stability of the motor output torque and the stability of the magnetic screw transmitted thrust. At the same time, to realize winding decoupling of the dual-port motor, through the mechanism of coordinated modulation of fundamental and high-order harmonics, the system can make full use of magnetic field harmonics of different orders, realize active guidance and path separation of the dual-winding magnetic field distribution, and the high-order harmonic armature winding and the fundamental harmonic armature winding correspond to different magnetic field modulation targets and spatial harmonic orders, respectively. Through precise design of the pole pair number, spatial distribution, and their matching relationship with the rotor modulation teeth and permanent magnet poles of the two sets of windings, the magnetic fields excited by the two sets of windings form relatively independent modulation loops and harmonic channels in space, reducing the disorderly superposition and mutual interference of the two sets of magnetic fields in the stator and rotor cores from the excitation source.

[0020] (3) For the bottleneck of top-level architecture and control freedom, i.e., the existing structure cannot realize macro-micro motion, to realize decoupling control of thrust and speed in a compact unit, thus taking into account macro motion and large-thrust micro motion, the core innovation of the present application lies in the use of a differential field modulation magnetic screw, and the expansion of control freedom based on its unique kinematic relationship. The field modulation magnetic screw is composed of the outer rotor excitation part, the intermediate rotor modulation part, and the inner rotor. Its core kinematic relationship is defined as follows: ; Differential principle and degree of freedom creation: formula The differential nature of the system is revealed. The linear motion of the inner mover does not depend on the absolute position of either rotor, but only on the relative angular displacement between the two. This feature physically creates an independent control dimension.

[0021] Realization of macro-motion (large thrust output): When the system needs to output a large thrust or is in an energy storage state, control the outer rotor and the middle rotor to rotate in the same direction and at the same speed. At this time , substituting the formula gives , that is, the inner mover remains stationary. However, at this time, the magnetic fields of the two rotors are in a high-speed equivalent "tense" coupling state, and the system stores a large amount of magnetic energy (analogous to a wound spring). Once the speed balance is broken through control, the stored magnetic energy can be released instantly and converted into a large linear thrust, providing the power basis for macroscopic large-stroke motion.

[0022] Realization of micro-motion (high-precision positioning): When the system needs to perform high-precision positioning or micro-adjustment, control the outer rotor and the middle rotor to produce a small speed difference or reverse rotation. At this time, although the speed of each rotor itself may be high, its relative angular displacement can be a very small value. According to the kinematic formula above, the inner mover will produce a nanoscale precise linear displacement corresponding to it. This realizes extremely high positioning accuracy on the basis of macro thrust capability.

[0023] Flexibility of working mode: As a special case of differential mode, when the middle rotor modulation part is fixed, that is, , the system becomes a conventional magnetic force screw driven by the outer rotor alone, demonstrating the compatibility and flexibility of its architecture.

[0024] Therefore, through the differential field modulation magnetic force screw and its kinematic relationship, the invention physically binds the linear displacement of the inner mover with the relative motion of the two rotors, rather than absolute motion. This allows independent and coordinated control of the rotational speed and direction of the two rotors, enabling seamless switching and precise control from large thrust energy storage (macro-motion preparation) to nanoscale precise positioning (micro-motion execution) in a single actuator without mechanical switching or superposition, fundamentally solving the bottleneck of traditional architectures that cannot accommodate macro and micro motion.

[0025] (4) The application can independently control the current and frequency of the double electric port, accurately set the output force and movement speed in one actuator, and meet the complex working conditions of large force value output and precise speed regulation. Macroscopic large thrust and microscopic high precision movement are considered: based on the principle of differential magnetic force screw, the system can seamlessly switch between the macro motion preparation state of "double rotor rotating at the same speed to store energy" and the micro motion execution state of "double rotor with micro differential speed to realize nanoscale displacement", solving the contradiction that a single driver cannot consider thrust and precision. Provide high dynamic response and force control accuracy: magnetic field modulation and non-contact transmission give the system millisecond-level force establishment and removal speed, as well as extremely low force pulsation, which can quickly, smoothly and accurately feedback and adjust the instantaneous changes of the load. Realize high-density force / torque output in a compact space: through high harmonic modulation and hybrid excitation design, the effective harmonic component and overall magnetic flux density of the air gap magnetic field are significantly improved, thereby obtaining higher torque and thrust output capacity in a given volume. Ensure high reliability and long service life: the non-contact force transmission mode of the whole magnetic field synthesis fundamentally eliminates mechanical friction, wear and backlash, and has the characteristics of low noise, maintenance-free, long service life and high reliability. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 The structure schematic diagram of the harmonic high-efficiency field modulation type double-drive differential magnetic force screw integrated actuator provided by the embodiment of the application is shown in the figure. Figure 2 The structure schematic diagram of the stator, high harmonic armature winding, fundamental harmonic armature winding, outer rotor and intermediate rotor is shown in the figure. Figure 3 The left view schematic diagram of the stator, high harmonic armature winding, fundamental harmonic armature winding, outer rotor and intermediate rotor is shown in the figure. Figure 4 The structure schematic diagram of the outer rotor is shown in the figure. Figure 5 The structure schematic diagram of the intermediate rotor excitation part is shown in the figure. Figure 6 The structure schematic diagram of the intermediate rotor is shown in the figure. Figure 7 The structure schematic diagram of the inner rotor is shown in the figure. Figure 8 The comparison diagram of the magnetic field intensity in the air gap of the application and the traditional magnetic force screw is shown in the figure. Figure 9 The comparison diagram of the magnetic induction intensity spatial harmonic spectrum of the application and the traditional magnetic force screw is shown in the figure. DETAILED DESCRIPTION

[0027] Embodiments of the present application are described below in the following order: detailed description; brief description of the drawings; detailed description of embodiments; and brief description of drawings. Embodiments of the present application are described below in detail, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by reference to the drawings are exemplary and are intended to explain embodiments of the present application and cannot be understood as limiting the present application.

[0028] Referring to Figure 1 The harmonic high-efficiency field modulation type double-drive differential magnetic force screw integrated actuator provided by the present application comprises a stator 1, a high-order harmonic armature winding 2, a fundamental harmonic armature winding 3, an outer rotor 4, an intermediate rotor 5, and an inner rotor 6.

[0029] The stator 1 is made of a magnetic material and is laminated. The stator 1 is the outermost stationary component, and the yoke 1-1 thereof constitutes a magnetic circuit shell, and the pole shoe 1-2 extends inwardly.

[0030] In the radial space of the stator 1, the high-order harmonic armature winding 2 is wound on the outer layer of the stator 1, and the fundamental harmonic armature winding 3 is wound on the inner layer of the stator 1, forming an inner-outer nested double-winding configuration. The high-order harmonic armature winding 2 and the fundamental harmonic armature winding 3 serve as two electrical ports, allowing independent control of the current and frequency of each port, precise speed and torque regulation, and improved response speed and control accuracy. There is no direct coupling between the high-order harmonic armature winding 2 and the fundamental harmonic armature winding 3.

[0031] Through the two independent electrical ports of the high-order harmonic armature winding 2 and the fundamental harmonic armature winding 3, two parallel energy input and control channels can be obtained. A complete set of double-drive electric control system allows independent current, frequency, and phase control of each port. By precisely coordinating the outputs of the two ports (such as making them in the same direction / same speed, opposite direction / same speed), fine adjustment of the synthesized magnetic field and output thrust can be achieved. This differential capability enables a single electromagnetic structure to have two native operating modes, providing a fundamental basis for the synthesis of macro-micro motion and effectively improving control dimensions and flexibility.

[0032] The outer rotor 4 is coaxially arranged on the inner side of the stator 1, the intermediate rotor 5 is coaxially arranged on the inner side of the outer rotor 4, and the inner rotor 6 is coaxially arranged on the inner side of the intermediate rotor 5.

[0033] The outer rotor 4 comprises an outer rotor modulation portion 4-1 and an outer rotor excitation portion 4-2, and the outer rotor modulation portion 4-1 is arranged opposite to the pole shoe 1-2.

[0034] The intermediate rotor 5 comprises an intermediate rotor excitation portion 5-1 and an intermediate rotor modulation portion 5-2, and the intermediate rotor excitation portion 5-1 is arranged opposite to the outer rotor modulation portion 4-1.

[0035] The outer rotor modulation part 4-1 and the intermediate rotor excitation part 5-1 are two mechanical ports.

[0036] The integrated actuator improves the magnetic flux density distribution of the motor through the principle of high harmonic modulation magnetic field, thereby enhancing the torque output of the motor. Through the synergistic action of the stator 1 and the high harmonic armature winding 2 and the fundamental harmonic armature winding 3, the magnetic field distribution of the motor is accurately controlled, and the harmonic utilization efficiency is improved. In combination with the vernier motor modulated by the fundamental harmonic, effective torque output can be generated at a specific frequency, and stable operation can be achieved under different working conditions through the cooperative design of the outer rotor modulation part 4-1 and the intermediate rotor excitation part 5-1.

[0037] The intermediate rotor excitation part 5-1 adopts a hybrid excitation design, i.e., a combination of permanent magnet and electric excitation, which effectively enhances the high harmonic component of the inner air gap of the motor while ensuring that the fundamental component of the outer air gap remains unchanged. This design not only improves the harmonic magnetic field utilization rate of the motor but also enhances the modulation effect, effectively improving the torque density of the motor and the system efficiency.

[0038] The inner mover 6 is coaxially arranged at the innermost side of the entire structure as a linear motion output component, thereby forming a compact integrated layout of the whole.

[0039] The present application realizes a deep electromagnetic topology integrated structure, specifically including two levels of integration: the first level is the winding integration of the brushless double-machine electrical port motor, the high harmonic modulation winding 2 and the fundamental harmonic modulation winding 3 are arranged in layers in the same stator 1, share the magnetic circuit and are independently controlled, and constitute double-energy input ports in a single stator unit; the second level is the structural integration of the motor rotor and the magnetic screw modulation component, the outer rotor modulation part 4-1 and the intermediate rotor excitation part 5-1 are two mechanical ports, which are physically simultaneously the outer rotor excitation part 4-2 and the intermediate rotor modulation part 5-2 of the field modulation magnetic screw, realizing the deep integration of the rotary driving unit and the linear transmission unit on the core rotating component. The integrated design eliminates the mechanical connecting components in the traditional split type transmission chain and the gaps, friction and elastic deformation caused thereby, greatly improves the structural stiffness, power density and reliability of the system, and provides a physical basis for realizing precise differential control.

[0040] The outer rotor excitation part 4-2, the intermediate rotor modulation part 5-2 and the inner mover 6 are arranged from outside to inside in sequence, and the outer rotor excitation part 4-2, the intermediate rotor modulation part 5-2 and the inner mover 6 constitute a field modulation magnetic screw. The magnetic field is adjusted through the intermediate rotor modulation part 5-2 of the field modulation magnetic screw to realize non-contact and high-efficiency linear motion transmission. This design enables the motor to have more precise adjustment capability when driving the active suspension system and provides higher transmission efficiency and reliability.

[0041] Wherein, the high harmonic armature winding 2 and the outer rotor modulation part 4-1 and the intermediate rotor excitation part 5-1 constitute a high harmonic flux modulation motor, opening up a dedicated high harmonic energy conversion channel. Specifically, the pole pair number of the high harmonic armature winding 2 , the pole pair number of the permanent magnet of the intermediate rotor excitation part 5-1 , and the tooth number of the outer rotor modulation part 4-1 satisfy the following relationship:

[0042] Wherein, n is an integer greater than 1.

[0043] The fundamental harmonic armature winding 3 and the intermediate rotor excitation part 5-1 constitute a vernier permanent magnet motor, specifically, the pole pair number of the fundamental harmonic armature winding 3 , the tooth number of the pole shoe 1-2 on the stator 1 , and the pole pair number of the permanent magnet of the intermediate rotor excitation part 5-1 satisfy the following relationship: .

[0044] By simultaneously satisfying the above modulation relationship and implementing collaborative design, the integrated actuator constructs an active harmonic management mechanism including harmonic source construction and harmonic energy efficiency conversion: a) In terms of harmonic source construction, through the mixed excitation design of the intermediate rotor excitation part 5-1 and the specific tooth slot structure of the outer rotor modulation part 4-1, the amplitude of the nth high harmonic is preset and enhanced in the excitation magnetic field, and at the same time, through the structure design of the pole shoe 1-2 of the stator 1, the periodicity of the air gap permeance is optimized to guide the fundamental harmonic modulation path; b) In terms of harmonic energy efficiency conversion, by precisely satisfying the high harmonic modulation relationship, the preset enhanced nth harmonic is locked as the core effective working harmonic coupled with the high harmonic armature winding 2, and by satisfying the fundamental harmonic modulation relationship, the fundamental harmonic energy is guided to the fundamental harmonic armature winding 3. The active harmonic management mechanism systematically converts the specific high harmonic components in the multi-source harmonics generated by the magnetomotive force source and the magnetic circuit structure modulation, which usually causes additional loss in traditional design, into effective working harmonics that bear the main energy transmission task, thereby fundamentally reconstructing the flow direction of harmonic energy and achieving essential improvement of harmonic utilization rate and optimization of system energy efficiency. By simultaneously satisfying the high harmonic modulation relationship and the fundamental harmonic modulation relationship, the actuator establishes a dedicated high harmonic modulation and energy conversion path for the nth harmonic magnetic field higher than the fundamental harmonic, so that the harmonic energy that is usually dissipated in the form of loss in the traditional motor is efficiently captured and converted into effective mechanical output, thereby achieving collaborative improvement of the overall harmonic energy utilization rate and energy conversion efficiency of the system.

[0045] In this embodiment, the armature magnetic field generated by the high-order harmonic armature winding 2 interacts with the outer rotor modulation part 4-1 and the intermediate rotor excitation part 5-1, improving the power density and generating stable electromagnetic torque, and the number of pairs of permanent magnet poles of the intermediate rotor excitation part 5-1 The speed of the intermediate rotor excitation part 5-1 The number of teeth of the outer rotor modulation part 4-1 The speed of the outer rotor modulation part 4-1 The current frequency of the high-order harmonic armature winding 2 The following relationship is satisfied: .

[0046] The armature magnetic field generated by the fundamental harmonic armature winding 3 interacts with the stator 1 and the intermediate rotor excitation part 5-1, generating stable electromagnetic torque and improving power density, and the number of pairs of permanent magnet poles of the intermediate rotor excitation part 5-1 The speed of the intermediate rotor excitation part 5-1 The current frequency of the fundamental harmonic armature winding 3 The following relationship is satisfied: .

[0047] Please refer to the arrows in Figure 5 , Figure 5 , which indicate the magnetizing direction. The intermediate rotor excitation part 5-1 uses Halbach array magnetizing technology, which can reduce the dependence on the internal ferromagnetic material of the permanent magnet. A magnetic isolation bridge is provided between the intermediate rotor excitation part 5-1 and the intermediate rotor modulation part 5-2, so that the motor end harmonic will not pass through the intermediate rotor modulation part 5-2 of the magnetic screw, and the magnetic circuit decoupling design is formed between the motor and the magnetic screw, optimizing the force transmission between the motor and the screw.

[0048] The high-order harmonic armature winding 2 and the fundamental harmonic armature winding 3 are q-phase windings, where q≥3. By integrating two independent ports, efficient transmission and distribution are achieved, improving power density, reducing volume and weight, and improving energy efficiency and reliability.

[0049] The outer rotor excitation part 4-2 uses radial excitation permanent magnets, the intermediate rotor modulation part 5-2 is made of silicon steel sheets, and the inner rotor 6 uses radial excitation permanent magnets.

[0050] The strength and distribution of the magnetic field are adjusted by the intermediate rotor modulation part 5-2 to accurately control the force transmission between the magnetic screw rotor and the rotor. The number of pairs of poles of the outer rotor excitation part 4-2 The number of pairs of poles of the inner rotor 6 The number of pairs of poles of the intermediate rotor modulation part 5-2 , satisfies the following formula: .

[0051] Specifically in the present embodiment, , , .

[0052] Linear displacement of inner rotor 6 Rotation angle of outer rotor 4 Rotation angle of intermediate rotor 5 Satisfies the following relationship: ; Wherein, The equivalent magnetic path length represents the linear distance traveled by the inner rotor 6 when the two rotors rotate one revolution (2π radians) relative to each other.

[0053] As Figure 8 shown, Figure 8 shows the magnetic field strength distribution in the key working air gap of the traditional radial field modulation magnetic gear and the integrated actuator of the present application. From Figure 8 it can be seen that the peak strength of the air gap magnetic field waveform of the structure of the present application is significantly improved compared with the traditional structure.

[0054] As Figure 9 shown, Figure 9 shows the comparison of the magnetic induction strength spatial harmonic spectrum of the field modulation low-speed large-thrust magnetic force screw, which reveals the internal mechanism of performance improvement from the frequency domain. Compared with the prior art, the amplitude (peak value) of the harmonic of the structure of the present application is enhanced, and other non-working harmonic components are effectively suppressed.

[0055] In summary, the harmonic efficient field modulation type double-drive differential magnetic force screw integrated actuator according to the above embodiment has the following beneficial effects: (1) The fundamental bottleneck of the bottom magnetic field modulation efficiency, i.e. the thrust density, is solved. In order to solve the fundamental problem that the thrust density is limited by the magnetic saturation of the core, two sets of independent armature windings are arranged in the stator, and a double modulation path is constructed. Among them, the pole pair number of the high-order harmonic armature winding 2 satisfies the relationship: , so that it and the outer rotor modulation part 4-1 and the intermediate rotor excitation part 5-1 together constitute a high-order harmonic magnetic flux modulation motor, opening up a dedicated high-order harmonic energy conversion channel. At the same time, the pole pair number of the fundamental harmonic armature winding 3 satisfies the relationship: The intermediate rotor excitation part 5-1 forms a Vernier permanent magnet motor with the intermediate rotor excitation part 5-1. Through the mechanism of the fundamental wave and the high-order harmonic wave cooperative modulation, the system can make full use of the magnetic field harmonics of different orders. Further, the intermediate rotor excitation part 5-1 adopts a hybrid excitation design (i.e., a combination of permanent magnet and electric excitation), which can actively enhance the high-order harmonic magnetic field component of the inner air gap. Without causing core saturation and without affecting the fundamental wave magnetic field, the harmonic utilization rate and the overall magnetic flux density are greatly improved, thereby breaking through the upper limit of the thrust density of a single modulation path in principle.

[0056] (2) For the inevitable mutual interference of the system integration level magnetic interference bottleneck, i.e., performance fusion, in order to realize the high-performance integration of the motor and the magnetic screw and avoid mutual magnetic interference, the application carries out physical isolation design on the key magnetic circuit. The outer rotor 4 and the intermediate rotor 5 bear double functions: the outer rotor modulation part 4-1 and the intermediate rotor excitation part 5-1 participate in the electric field modulation, the outer rotor excitation part 4-2, the intermediate rotor modulation part 5-2 and the inner mover 6 form a field modulation magnetic screw. In order to realize the decoupling of the magnetic circuit, a magnetic isolation bridge is arranged between the intermediate rotor excitation part 5-1 and the intermediate rotor modulation part 5-2. The magnetic isolation bridge forms a high magnetic resistance barrier, which can effectively block the rich harmonic magnetic field generated by the motor side (especially the high-order harmonic armature winding) from interlinking to the magnetic screw side, so that the motor system and the magnetic screw system are magnetically isolated. This fundamentally eliminates the magnetic-force bidirectional interference between them, ensuring the stability of the motor output torque and the stability of the magnetic screw transmitted thrust. At the same time, in order to realize the winding decoupling of the double-port motor, through the mechanism of the fundamental wave and the high-order harmonic wave cooperative modulation, the system can make full use of the magnetic field harmonics of different orders, realize the active guidance and path separation of the double-winding magnetic field distribution, and the high-order harmonic armature winding and the fundamental wave armature winding correspond to different magnetic field modulation targets and spatial harmonic orders. Through accurate design of the pole pair number, spatial distribution and matching relationship with the rotor modulation tooth and permanent magnet of the two sets of windings, the magnetic fields excited by the two sets of windings form relatively independent modulation loops and harmonic channels in space, reducing the disorderly superposition and mutual interference of the two sets of magnetic fields in the stator and rotor cores from the source.

[0057] (3) For the bottleneck of top-level architecture and control freedom, i.e., the existing structure cannot realize macro-micro motion, in order to realize the decoupling control of thrust and speed in a compact unit, so as to consider macro motion and large thrust micro motion, the core innovation of the application is to adopt a differential field modulation magnetic screw, and based on its unique kinematic relationship, the control freedom is expanded. The field modulation magnetic screw is composed of the outer rotor excitation part 4-2, the intermediate rotor modulation part 5-2 and the inner mover 6. Its core kinematic relationship is defined as follows: ; Differential principle and freedom creation: formula The differential nature of the system is revealed. The linear motion of the inner mover 6 is not dependent on the absolute position of either rotor, but only on the relative angular displacement between the two. This property physically creates an independent control dimension.

[0058] Macro-motion (large thrust output) implementation: When the system needs to output a large thrust or is in an energy storage state, the control rotates the outer rotor 4 and the intermediate rotor 5 in the same direction and at the same speed. At this time , substituting the formula gives , that is, the inner mover 6 remains stationary. However, at this time, the two rotor magnetic fields are in a high-speed equivalent "tense" coupling state, and the system stores a large amount of magnetic energy (analogous to a wound spring). Once the speed balance is broken by control, the stored magnetic energy can be released instantaneously and converted into a large linear thrust, providing the power basis for macroscopic large-stroke motion.

[0059] Micro-motion (high-precision positioning) implementation: When the system needs to perform high-precision positioning or micro-adjustment, the control causes a small speed difference or a small reverse rotation between the outer rotor 4 and the intermediate rotor 5. At this time, although the speed of each rotor itself can be high, its relative angular displacement can be a very small value. According to the kinematic formula above, the inner mover 6 will produce a nanoscale precise linear displacement corresponding to it. This realizes extremely high positioning accuracy on the basis of macroscopic thrust capacity.

[0060] Working mode flexibility: As a special case of differential mode, when the intermediate rotor modulation part 5-2 is fixed, that is, , the system becomes a conventional magnetic force screw driven by the outer rotor 4 alone, demonstrating the compatibility and flexibility of its architecture.

[0061] Therefore, through the differential field modulation magnetic force screw and its kinematic relationship, the invention physically binds the linear displacement of the inner mover with the relative motion of the two rotors, rather than the absolute motion. This makes it possible to directly realize seamless switching and precise control from large thrust energy storage (macro-motion preparation) to nanoscale precise positioning (micro-motion execution) in a single actuator without mechanical switching or superposition by independently and cooperatively controlling the rotational speed and direction of the two rotors.

[0062] (4) The application can set output force and movement speed respectively and accurately in one actuator by independently regulating the current and frequency of the double electric port, so as to meet the complex working conditions of both large force output and precise speed regulation. Macroscopic large thrust and microscopic high precision movement are considered: based on the principle of differential magnetic force screw, the system can seamlessly switch between the macro motion preparation state of "double rotor rotating at the same speed to store energy" and the micro motion execution state of "double rotor with micro differential speed to realize nanoscale displacement", solving the contradiction that a single driver cannot consider thrust and precision. Provide very high dynamic response and force control accuracy: magnetic field modulation and non-contact transmission give the system millisecond-level force establishment and withdrawal speed, as well as very low force pulsation, which can quickly, smoothly and accurately feedback and adjust the instantaneous change of the load. Realize high-density force / torque output in a compact space: through high harmonic modulation and hybrid excitation design, the effective harmonic component and overall magnetic flux density of the air gap magnetic field are significantly improved, so that higher torque and thrust output capacity is obtained in a given volume. Ensure high reliability and long life operation: the non-contact force transmission mode of the whole magnetic field synthesis fundamentally eliminates mechanical friction, wear and backlash, and has the characteristics of low noise, maintenance-free, long life and high reliability.

[0063] The above-described embodiments only express several embodiments of the present application, which are described in detail and specifically, but should not be understood as a limitation on the scope of the patent. It should be noted that for ordinary skilled in the art, without departing from the concept of the present application, several modifications and improvements can be made, which belong to the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the appended claims.

Claims

1. A harmonic high-efficiency field-modulated dual-drive differential magnetic screw integrated actuator, characterized in that, It includes a stator (1), a higher harmonic armature winding (2), a fundamental harmonic armature winding (3), an outer rotor (4), an intermediate rotor (5), and an inner mover (6); the higher harmonic armature winding (2) is wound on the outer layer of the stator (1), the fundamental harmonic armature winding (3) is wound on the inner layer of the stator (1), and the higher harmonic armature winding (2) and the fundamental harmonic armature winding (3) serve as two electrical ports; the outer rotor (4) is coaxially arranged on the inner side of the stator (1), the intermediate rotor (5) is coaxially arranged on the inner side of the outer rotor (4), and the inner mover (6) is coaxially arranged on the inner side of the intermediate rotor (5); The high-order harmonic armature winding (2), the outer rotor modulation section (4-1), and the intermediate rotor excitation section (5-1) constitute a high-order harmonic flux modulation motor. The fundamental harmonic armature winding (3) and the intermediate rotor excitation section (5-1) constitute a vernier permanent magnet motor. Through fundamental and high-order harmonic modulation, a high-order harmonic modulation and energy conversion path is established. The outer rotor modulation section (4-1) and the intermediate rotor excitation section (5-1) serve as two mechanical ports. The outer rotor excitation section (4-2), the intermediate rotor modulation section (5-2), and the inner mover (6) constitute a field-modulated magnetic screw.

2. The harmonic high-efficiency field modulation type dual-drive differential magnetic screw integrated actuator according to claim 1, characterized in that, Number of pole pairs of the higher harmonic armature winding (2) The number of permanent magnet pole pairs in the intermediate rotor excitation section (5-1) The number of teeth of the external rotor modulation section (4-1) The following relationship exists between them: Where n is an integer greater than 1.

3. The harmonic high-efficiency field modulation type dual-drive differential magnetic screw integrated actuator according to claim 2, characterized in that, Number of pole pairs of the fundamental harmonic armature winding (3) Number of teeth on the pole shoes (1-2) of the stator (1) The number of permanent magnet pole pairs in the intermediate rotor excitation section (5-1) The following relationship exists between them: 。 4. The harmonic high-efficiency field modulation type dual-drive differential magnetic screw integrated actuator according to claim 3, characterized in that, The armature magnetic field generated by the high-order harmonic armature winding (2) interacts with the outer rotor modulation section (4-1) and the intermediate rotor excitation section (5-1), and the number of permanent magnet pole pairs of the intermediate rotor excitation section (5-1) is... Intermediate rotor excitation section (5-1) speed Number of teeth in the external rotor modulation section (4-1) External rotor modulation section (4-1) speed The current frequency of the higher harmonic armature winding (2) The following relationship exists between them: 。 5. The harmonic high-efficiency field modulation type dual-drive differential magnetic screw integrated actuator according to claim 4, characterized in that, The armature magnetic field generated by the fundamental harmonic armature winding (3) interacts with the upper pole shoe (1-2) of the stator (1) and the intermediate rotor excitation section (5-1), and the number of permanent magnet pole pairs of the intermediate rotor excitation section (5-1) is... Intermediate rotor excitation section (5-1) speed , and the frequency of the fundamental harmonic armature winding (3) current The following relationship exists between them: 。 6. The harmonic high-efficiency field modulation type dual-drive differential magnetic screw integrated actuator according to claim 1, characterized in that, The intermediate rotor excitation section (5-1) adopts Halbach array magnetization technology, and a magnetic isolation bridge is set between the intermediate rotor excitation section (5-1) and the intermediate rotor modulation section (5-2).

7. The harmonic high-efficiency field modulation type dual-drive differential magnetic screw integrated actuator according to claim 1, characterized in that, The higher harmonic armature winding (2) and the fundamental harmonic armature winding (3) are Phase winding, of which, .

8. The harmonic high-efficiency field-modulated dual-drive differential magnetic screw integrated actuator according to claim 1, characterized in that, The outer rotor excitation section (4-2) uses a radially excitation permanent magnet, the intermediate rotor modulation section (5-2) is made of stacked silicon steel sheets, and the inner rotor (6) uses a radially excitation permanent magnet.

9. The harmonic high-efficiency field-modulated dual-drive differential magnetic screw integrated actuator according to claim 8, characterized in that, Number of pole pairs in the external rotor excitation section (4-2) The number of pole pairs of the intermolecular (6) The number of pole pairs of the intermediate rotor modulation section (5-2) The following equation is satisfied: 。 10. The harmonic high-efficiency field-modulated dual-drive differential magnetic screw integrated actuator according to claim 1, characterized in that, Linear displacement of the internal mover (6) Rotation angle with outer rotor (4) The rotation angle of the intermediate rotor (5) The following relationship must be satisfied: ； in, It is the equivalent magnetic permeability.

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