Anti-slip stator excited field modulation axial magnetic gear

Abstract

The application discloses an anti-out-of-step stator-excited field modulation axial magnetic gear and relates to the field of magnetic gears. The magnetic gear comprises a coaxially arranged stator, a driving rotor and a driven rotor, and the driving rotor and the driven rotor are arranged on the two sides of the stator. The application utilizes the interaction between the specific harmonic of the air gap magnetic flux in the asynchronous operation stage of the magnetic gear and the introduced winding to generate the net driving torque acting on the driven rotor, thereby significantly improving the anti-out-of-step capability of the magnetic gear in the transient operation stage. Meanwhile, the damping winding induced current is zero in the steady operation stage of the magnetic gear, and the introduced damping winding does not affect the transmission quality. The magnetic gear of the application adopts the stator excitation to replace the traditional rotor excitation, the expensive and high-brittleness permanent magnet is protected by the stator core block clamping, the permanent magnet can be prevented from falling off, the damping winding and the permanent magnet are independent in the installation space, the geometric parameter design is not interfered, and the mechanical reliability and the design freedom of the magnetic gear are improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of magnetic gear, and particularly relates to an anti-out-of-step stator excitation type field modulation axial magnetic gear. BACKGROUND

[0002] The statements in this section merely provide background information related to the application and do not necessarily constitute the prior art.

[0003] In the industrial driving field, the contradiction between the single working speed of a prime mover and the diversity of the working speed of a driven load is widespread, and the mechanical gear is an effective way to solve this contradiction. The mechanical gear has the advantages of strong torque transmission capacity and compact spatial structure, but the friction between the teeth of the adjacent two wheels in the running stage leads to a series of defects and shortcomings of the transmission equipment, such as: (1) large running noise and large heat loss; (2) the need for lubrication and regular maintenance, and high operation cost; (3) the risk of irreversible damage such as tooth breakage when overloaded; (4) poor reliability, and it is one of the components with a high failure rate in the transmission system. In addition, due to the constraints of its transmission form, the mechanical gear cannot be applied to special occasions where the input and output ends need to be physically isolated.

[0004] Considering the above-mentioned defects of the mechanical gear, in recent years, scholars at home and abroad have carried out extensive exploration on non-contact variable speed transmission devices, and the magnetic gear has thus emerged as the times require. The magnetic gear realizes non-contact transmission of adjacent rotors by the action force between permanent magnets, and thus can avoid many problems caused by contact transmission. Early magnetic gears are mostly directly imitated from mechanical gears, and more typical ones include the straight-tooth cylindrical magnetic gear, the parallel shaft cylindrical magnetic gear, the cylindrical worm magnetic gear, the tapered worm magnetic gear, the involute magnetic gear and the planetary magnetic gear. These mechanical type magnetic gears use the mutual coupling of the magnetic field of permanent magnets to replace the tooth groove engagement of mechanical gears, and although they can realize non-contact variable speed transmission, only a small part of permanent magnets participate in work in the running stage, and thus they do not have ideal torque transmission capacity and have little practical value.

[0005] In 2001, D. Howe et al. in the United Kingdom abandoned the traditional design idea of simply imitating mechanical gears, took a different path, and based on the magnetic field modulation theory, proposed a field modulation magnetic gear, the structure of which is as shown in Figure 1The magnetic gear is coaxially sleeved by a magnetic adjusting ring and driving and driven rotors located on both sides of the ring. The driving and driven rotors have different rotating speeds, but the permanent magnet of the driving rotor can generate a modulated magnetic field with the same rotating speed and the same number of poles as the permanent magnet of the driven rotor in the adjacent air gap of the driven rotor after the action of the magnetic adjusting ring. The magnetic field is coupled with the self-excitation magnetic field of the permanent magnet of the driven rotor, thereby generating a constant torque acting on the driven rotor, and finally realizing stable non-contact variable speed transmission. Compared with the mechanical type magnetic gear with low utilization rate of permanent magnet, the field modulation magnetic gear can ensure that all permanent magnets participate in magnetic field coupling and torque generation during operation, and its torque transmission capacity is comparable to that of ordinary mechanical gears.

[0006] Due to the ability to realize non-contact variable speed transmission and the torque transmission capacity meeting the engineering application requirements, the field modulation magnetic gear has been widely concerned since its appearance. So far, scholars at home and abroad have adopted various technical measures to improve the field modulation magnetic gear from different angles, which can be summarized as the following five aspects.

[0007] (1) Change the magnetizing arrangement of permanent magnets

[0008] Permanent magnets are the core components of field modulation magnetic gears that enable non-contact power transmission, and are naturally the primary concern for improving the performance of such gears. In addition to using high-quality permanent magnet materials, improving the magnetizing arrangement of permanent magnets is also an effective means to enhance the working performance of field modulation magnetic gears. For example, compared with the general surface-mounted permanent magnet array with alternating positive and negative polarity, the use of Halbach-type permanent magnet array can effectively improve the air gap magnetic flux density waveform distribution, thereby reducing torque pulsation and iron loss; the use of built-in permanent magnet arrangement can improve the magnetic flux density by using the magnetic aggregation effect; the use of alternating pole permanent magnet arrangement can reduce the amount of permanent magnets used while maintaining the basic torque density of the magnetic gear, thereby reducing the cost of gear materials and improving its performance-price ratio; the combination of variable-pole Halbach-type permanent magnet array and unequal-thickness air gap or built-in permanent magnet array can increase the effective harmonic components of the air gap magnetic flux density, thereby further improving the torque transmission capacity of the field modulation magnetic gear.

[0009] (2) Change the structure and material of the magnetic adjusting ring

[0010] As the key medium of magnetic field coupling between the driving and driven rotors of field modulation magnetic gear, the modulation ring is also the focus of the research field of this type of gear. Y. J. Kim of the University of Ulsan, South Korea, compared and analyzed the performance of magnetic gear transmission when the shape of the magnetic conductive block of the modulation ring changed, and then proposed a new type of magnetic conductive block structure with wide inside and narrow outside. The calculation results show that the new type of magnetic conductive block can effectively improve the maximum torque of the inner and outer rotors of the magnetic gear and reduce the torque ripple. A. M. Knight of the University of Calgary, Canada, replaced the traditional magnetic conductive block independent combination structure of the modulation ring with an interconnected structure of the magnetic conductive block. This structure can modulate the air gap magnetic field in the corresponding axial range for each layer of silicon steel sheet, and the material and processing cost are also significantly reduced compared with the traditional modulation ring. Liu Xia of Hunan University, China, proposed a double-ring modulation coaxial magnetic gear structure. This structure adds an auxiliary modulation ring to effectively suppress the inter-pole leakage of the outer rotor and significantly increase the working harmonic amplitude of the air gap flux density, and the corresponding torque transmission capacity is significantly improved compared with the ordinary single-ring structure.

[0011] To enhance the mechanical strength, the non-magnetic part of the modulation ring is usually made of solid epoxy resin during the manufacturing process. Since epoxy resin cannot completely block the magnetic field, when the magnetic saturation of the magnetic conductive block is high, part of the magnetic force lines will pass through the epoxy resin and form local leakage. Affected by this, the modulation effect and magnetic field transmission efficiency of the modulation ring will decrease. To solve this problem, Jing Libing of Three Gorges University uses high-temperature superconducting material to replace epoxy resin to form the non-magnetic part of the modulation ring. By using the magnetic field shielding effect of this type of material at the critical temperature to suppress the local leakage between the magnetic conductive blocks, the effective harmonic amplitude of the air gap flux density of the field modulation magnetic gear is significantly increased, and the torque transmission performance is also improved.

[0012] (3) Change the direction of magnetic flux

[0013] Most of the common field modulation magnetic gears are designed and manufactured based on the radial excitation structure. Since the inner and outer rotors need to be led out of the shaft and can only be fixed by single-sided support, the radial excitation field modulation magnetic gear is difficult to process, and the rotor dynamic balance performance is also difficult to fully guarantee. Considering the above problems of the radial structure, Cao Haitong et al. from Shanghai University replaced the radial excitation with axial excitation and further obtained an axial flux field modulation magnetic gear. The high-speed rotor, low-speed rotor and modulation ring of the field modulation magnetic gear do not interfere with each other in the installation space, and the shafts of the rotors can be supported by bearings at both ends. Compared with the radial structure, the component assembly difficulty and rotor axial eccentricity probability are significantly reduced. Li Yong et al. from Harbin Institute of Technology moved the modulation ring between the high-speed and low-speed rotors of the axial excitation field modulation magnetic gear to the outside of the two rotors, thereby obtaining a transverse flux field modulation magnetic gear. The magnetic gear still has the advantages of easy processing and high mechanical stability, and can be used to realize variable speed transmission in high-power applications. Fu Mingwang et al. from Hong Kong Polytechnic University bent the flux guide blocks of the transverse flux field modulation magnetic gear, thereby solving the problem of single power transmission direction when using the coaxial structure. Fang Yotong et al. from Zhejiang University proposed an axial-transverse flux composite field modulation magnetic gear. The flux guide blocks of the magnetic gear can modulate both the axial magnetic field and the radial magnetic field at the end of the rotor permanent magnet, and have better torque transmission capacity than the same specification field modulation magnetic gear with single axial or single transverse structure.

[0014] (4) Change the motion form

[0015] The traditional field modulation magnetic gear makes rotational motion when the driving and driven parts change speed. K. Atallah et al. from the University of Sheffield in the UK proposed a cylindrical linear field modulation magnetic gear structure based on the principle of magnetic field modulation, which expands the motion form of the magnetic gear from rotation to linear motion. Fu Xinghe et al. from Southeast University proposed a linear-rotary two-degree-of-freedom field modulation magnetic gear to realize the relative speed transformation of linear and rotary motion forms.

[0016] (5) Improve transient transmission performance

[0017] Adding damping bars to the rotor core is a common method for traditional permanent magnet motors to suppress transient oscillation. Based on the same idea, Texas A&M University in the United States proposed a field modulation magnetic gear with cage winding. The magnetic gear can effectively reduce the speed oscillation amplitude and shorten the adjustment time during the transient operation stage by using the damping torque generated by the interaction between the permanent magnet modulation magnetic field and the cage conductor. Ge Yanjun et al. from Dalian Jiaotong University in China proposed a cage rotor field modulation magnetic gear structure, which can also use the damping torque provided by the cage conductor to improve the transient transmission performance of the magnetic gear.

[0018] It is not difficult to find that the use of these technical measures can enhance the steady-state and transient operating performance of the field modulation magnetic gear, but it still cannot solve the three problems faced by the variable speed transmission device in the actual use process, namely:

[0019] 1. The asynchronous net driving torque of the field modulation magnetic gear is zero, and the synchronous maintaining ability in the transient transmission stage cannot meet the actual demand.

[0020] The field modulation magnetic gear generates electromagnetic torque by the mutual coupling of the permanent magnet excitation magnetic field. This torque, which is a pulsating torque with a direct current component equal to zero, has no slip characteristic during the asynchronous operation of the magnetic gear. When the input speed or load torque changes suddenly, the working state of the field modulation magnetic gear quickly changes from synchronous operation to asynchronous operation, and the driven rotor is easily out of step under the alternating action of positive and negative torques. From the practical application point of view, the working quality of the field modulation magnetic gear depends not only on the torque transmission ability in stable operation, but also on the synchronous maintaining ability after the working condition changes, and this ability is the "weak link" and "short board" of the field modulation magnetic gear.

[0021] 2. The air gap magnetic flux of the field modulation magnetic gear has a high proportion of invalid harmonics, and the simple introduction of cage winding will cause many adverse effects.

[0022] Unlike permanent magnet motors where the fundamental component of air gap magnetic flux dominates, the field modulation magnetic gear has a large amplitude and high content of invalid harmonics. If a cage winding is added to the driven rotor of the device to improve the anti-slip ability, the electromagnetic torque generated by the interaction of the invalid harmonics of the air gap magnetic flux and the cage conductors will not only greatly offset the asynchronous driving torque generated by the effective harmonics, but also interfere with the stable transmission of the magnetic gear. In addition, the cage eddy current loss caused by invalid harmonics will also reduce the transmission efficiency of the magnetic gear.

[0023] 3. The permanent magnets of the field modulation magnetic gear rotor are at risk of falling off due to radial centrifugal force, and the mechanical reliability is poor.

[0024] Traditional field modulation magnetic gears generally use rotor excitation structure. Under long-term operation or high-speed operation, the permanent magnets that rotate synchronously with the rotor are easily displaced or even fall off due to the action of radial centrifugal force, and the overall transmission stability and mechanical reliability of the magnetic gear cannot be fully guaranteed. In addition, even if the negative effects caused by the introduction of cage winding are not considered, embedding cage conductors on the surface of the driven rotor of the traditional field modulation magnetic gear will inevitably occupy the original installation space of the permanent magnets, and the size design of the two will also interfere with each other. SUMMARY

[0025] The application aims to provide an anti-out-of-step stator excitation type field modulation axial magnetic gear, which can generate driving property induction torque acting on the driven rotor in an asynchronous state where the driving and driven rotor rotation speeds do not meet the stable transmission ratio, so as to ensure that the driven rotor rotation speed can timely follow the driving rotor rotation speed change in sudden mutation working conditions such as instantaneous operation, sudden increase or decrease of input rotation speed or connected load, and thus avoid out-of-step phenomenon; in a synchronous state where the driving and driven rotor rotation speeds meet the stable transmission ratio, the magnetic gear does not generate induction torque acting on the driven rotor, so as to ensure that the stable operation is not affected; the magnetic gear uses stator excitation to replace the traditional rotor excitation, and the expensive and high-brittleness permanent magnet is clamped and protected by the stator core, which fundamentally eliminates the permanent magnet falling phenomenon caused by centrifugal force in the high-speed operation state of the ordinary rotor excitation type field modulation magnetic gear, and ensures that the damping winding and the permanent magnet are independent of each other in the installation space and do not interfere with each other in the geometric parameter design, so as to improve the mechanical reliability and design freedom of the magnetic gear, and thus effectively solve the existing technical problems given in the foregoing.

[0026] To achieve the above-mentioned purpose, the application adopts the following technical solutions:

[0027] The application is an anti-out-of-step stator excitation type field modulation axial magnetic gear, which comprises a stator, a driving rotor and a driven rotor arranged coaxially, and the driving rotor and the driven rotor are arranged on the two sides of the stator respectively.

[0028] Preferably, the stator comprises stator core blocks and stator permanent magnets arranged between the stator core blocks, and the number of pole pairs of the stator permanent magnets is P, and P is a positive integer.

[0029] Preferably, the stator core blocks provide clamping protection for the stator permanent magnets and also constitute a magnetic conducting medium.

[0030] Preferably, the driving rotor comprises driving rotor magnetic conducting blocks and driving rotor non-magnetic conducting blocks, the circumferential width of each driving rotor magnetic conducting block is the same and presents non-uniform symmetrical distribution along the circumference, and the driving rotor non-magnetic conducting blocks are filled between the driving rotor magnetic conducting blocks.

[0031] Preferably, the number of the driving rotor magnetic conducting blocks and the driving rotor non-magnetic conducting blocks is both 2Z, Z is a positive integer, and Z

[0032] Preferably, the driven rotor comprises driven rotor magnetic conducting blocks and driven rotor non-magnetic conducting blocks, the circumferential width of each driven rotor magnetic conducting block is the same and presents uniform symmetrical distribution along the circumference, and the driven rotor non-magnetic conducting blocks are filled between the driving rotor magnetic conducting blocks.

[0033] Preferably, the number of the driven rotor magnetic conducting blocks and the driven rotor non-magnetic conducting blocks is both 2(P-Z).

[0034] Preferably, the inner surface of the driven rotor magnetic block in contact with the air gap is uniformly slotted, and the number of slots is 4(P-Z).

[0035] Preferably, the first set of damping windings and the second set of damping windings are both double-layer full-pitch windings.

[0036] Preferably, the first set of damping windings and the second set of damping windings have pole pair numbers P-Z and are 90 degrees apart in electrical angle, forming two-phase symmetrical damping windings.

[0037] The present application has the following beneficial effects:

[0038] 1. The driven rotor surface of the present application is embedded with two-phase symmetrical damping windings, which can utilize the interaction between the specific harmonic of the air gap magnetic flux density in the asynchronous running stage of the magnetic gear and the introduced windings to generate a net driving torque acting on the driven rotor, thereby significantly improving the anti-slip ability of the magnetic gear in the transient running stage. At the same time, the damping winding current of the magnetic gear in the steady running stage is zero, and the introduced damping winding will not affect the transmission quality.

[0039] 2. By reasonably selecting the pole pair number of the damping winding, the damping winding can completely shield the invalid harmonic of the air gap magnetic flux density in the asynchronous running stage of the magnetic gear and all harmonics of the air gap magnetic flux density in the synchronous running stage, thereby avoiding the negative effects of various harmonics on the anti-slip ability improvement, stable operation and transmission efficiency of the magnetic gear.

[0040] 3. The present application uses stator excitation instead of traditional rotor excitation, and the expensive and high-brittleness stator permanent magnet is protected by stator core block clamping, which can avoid the phenomenon of permanent magnet falling off, and ensure that the damping winding and the permanent magnet are independent in installation space and do not interfere with each other in geometric parameter design, thereby improving the mechanical reliability and design freedom of the magnetic gear. BRIEF DESCRIPTION OF DRAWINGS

[0041] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiment description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0042] Figure 1 It is a structure schematic diagram of the ordinary field modulation magnetic gear.

[0043] Figure 2 It is a structure schematic diagram of the anti-slip stator excitation type field modulation axial magnetic gear of the present application.

[0044] Figure 3The damping winding connection diagram of the driven rotor of the anti-out-of-step stator-excited field-modulation axial magnetic gear.

[0045] Figure 4 The adjacent air gap magnetic flux main harmonic component diagram of the driven rotor of the anti-out-of-step stator-excited field-modulation axial magnetic gear.

[0046] Figure 5 The driven rotor speed time-varying simulation curve of the anti-out-of-step stator-excited field-modulation axial magnetic gear and Figure 1 the ordinary field-modulation magnetic gear shown in the figure when the driving rotor speed increases at the same rate.

[0047] Figure 6 The driven rotor damping winding current time-varying simulation curve of the anti-out-of-step stator-excited field-modulation axial magnetic gear under Figure 5 the corresponding working condition.

[0048] In the drawings, the components represented by each reference numeral are listed as follows:

[0049] 1-1 magnetic adjusting ring magnetic block, 1-2 magnetic adjusting ring non-magnetic block, 1-3 outer rotor permanent magnet, 1-4 inner rotor permanent magnet, 1-5 inner air gap, 1-6 outer air gap, 1-7 outer rotor core, 1-8 inner rotor core;

[0050] 2-1-0 stator, 2-3-0 driving rotor, 2-5-0 driven rotor, 2-1 stator permanent magnet, 2-2 stator core block, 2-3 driving rotor magnetic block, 2-4 driving rotor non-magnetic block, 2-5 driven rotor magnetic block, 2-6 driven rotor non-magnetic block, 2-7 first set of damping winding, 2-8 second set of damping winding. DETAILED DESCRIPTION

[0051] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0052] In the description of the present application, it should be understood that the terms "upper", "middle", "outer", "inner", "lower", "periphery" and the like indicate the orientation or positional relationship, which are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the indicated components or elements must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present application.

[0053] Embodiment one:

[0054] The anti-out-of-step stator-excited field-modulation axial magnetic gear of the present application, as shown in Figure 2 , comprises three basic components: a stator 2-1-0, a driving rotor 2-3-0, and a driven rotor 2-5-0. Among them:

[0055] The stator 2-1-0 is composed of stator permanent magnets 2-1 with a pole pair number equal to P (P is a positive integer) and stator core blocks 2-2, which not only provide clamping protection for the former but also constitute a magnetic conduction medium.

[0056] The driving rotor 2-3-0 comprises driving rotor magnetic blocks 2-3 and driving rotor non-magnetic blocks 2-4. The number of components of the driving rotor magnetic blocks 2-3 and the driving rotor non-magnetic blocks 2-4 is both 2Z (Z is a positive integer and Z < P). The circumferential width of each component of the driving rotor magnetic blocks 2-3 is the same and presents a non-uniform symmetrical distribution along the circumference. The components of the driving rotor non-magnetic blocks 2-4 are filled between the components of the driving rotor magnetic blocks 2-3.

[0057] The driven rotor 2-5-0 comprises driven rotor magnetic blocks 2-5 and driven rotor non-magnetic blocks 2-6. The number of components of the driven rotor magnetic blocks 2-5 and the driven rotor non-magnetic blocks 2-6 is both 2(P-Z). The circumferential width of each component of the driven rotor magnetic blocks 2-5 is the same and presents a uniform symmetrical distribution along the circumference. The components of the driven rotor non-magnetic blocks 2-6 are filled between the components of the driven rotor magnetic blocks 2-5.

[0058] As shown in Figure 3 , the inner surface of the contact between each component of the driven rotor magnetic blocks 2-5 and the air gap is uniformly slotted along the circumference. The number of slots is 4×(P-Z), and the slot pitch angle is 360 / 4 / (P-Z) = 90 / (P-Z) degrees (mechanical angle). The first set of damping windings 2-7 and the second set of damping windings 2-8 are embedded in the slots. Both sets of damping windings are double-layer windings with a coil pitch equal to two slots. The upper and lower layer coil edges on each slot belong to the same set of damping windings, and the coil edges in adjacent slots belong to different sets of damping windings. Thus, the two sets of damping windings together form two symmetrical damping windings with a pole pair number of (P-Z) and an axial difference of 90 / (P-Z)×(P-Z) = 90 degrees (electrical angle).

[0059] The driving rotor 2-3-0 and the driven rotor 2-5-0 both produce a modulation effect on the excitation magnetic field of the stator permanent magnets 2-1.

[0060] The operating principle of the present application is as follows:

[0061] For the anti-out-of-step stator-excited field-modulation axial magnetic gear of the present application (as shown in Figure 2 ), the driving rotor speed and the driven rotor speed are denoted as -Ω i and Ω o , respectively (Ω i > 0, Ωo 0); the air gap magnetic flux produced in the adjacent air gap of the driven rotor after the stator permanent magnet 2-1 is modulated by the driving rotor and the driven rotor is recorded as B i , o B i , B o The pole pair number and the rotating speed (ignoring high order harmonics) of the harmonic components contained are given by Figure 4 It can be known from the analysis of the figure that:

[0062] (1) The pole pair number of B i , B o harmonic component 1 is P-2Z. Let ZΩ i =(P-Z)Ω o , the rotating speeds of the two components are equal, the mutual coupling can produce constant electromagnetic torque, and then realize stable variable speed transmission, and the corresponding stable transmission ratio is: G=-Ω i / Ω o =-(P-Z) / Z;

[0063] (2) In the transient operation stage, the driven rotor rotating speed Ω o ≠-Ω i / G. The slip ratio of the driven rotor relative to B i harmonic component 2 is not zero, the harmonic component and the I set of damping windings 2-7 and the II set of damping windings 2-8 with the pole pair number equal to P-Z exist relative motion, and then produce asynchronous driving torque acting on the driven rotor, thereby the anti-loss step ability of the magnetic gear can be significantly improved;

[0064] (3) If P, P+Z, P+2Z, P-2Z, 3P-2Z are not equal to P-Z or odd multiples of P-Z, B i harmonic component 1, 3, 4 and 5 and B o all harmonic components will not produce induced current in the I set of damping windings 2-7 and the II set of damping windings 2-8 with the pole pair number equal to P-Z, and thus will not cause disorder influence on the asynchronous torque generation in the transient transmission stage and the synchronous torque generation in the stable transmission stage; B i harmonic component 2 has the pole pair number equal to the pole pair number of the I set of damping windings 2-7 and the II set of damping windings 2-8, but the component rotating speed is equal to the stable rotating speed of the driven rotor of the magnetic gear, and thus will not produce induced current by interacting with the damping windings in the stable transmission stage of the magnetic gear;

[0065] (4) For the anti-loss step stator excitation type field modulation axial magnetic gear of the embodiment of the application (such as Figure 2As shown, the stator permanent magnet 2-1 is sandwiched between the stator core blocks 2-2 and remains stationary during the operation of the magnetic gears. The centrifugal force it experiences is zero, eliminating the risk of it falling off due to mechanical force. The stator permanent magnet 2-1 does not share space with the first set of damping windings 2-7 and the second set of damping windings 2-8, and their dimensional parameters are designed independently.

[0066] This embodiment applies to ordinary field-modulated magnetic gears (such as...) Figure 1 (as shown) and the anti-out-of-step stator excitation type field modulation axial magnetic gear (such as) in the embodiments of the present invention. Figure 2 Simulation comparison was performed (as shown). The stable transmission ratio of both magnetic gears was -5:2, the load torque was 15 N·m, and the speed of the driving rotor decreased linearly from 0 r / min to -500 r / min within 0-0.5s, and then remained constant.

[0067] Figure 5 The present invention provides an embodiment of an anti-out-of-step stator excitation type field-modulated axial magnetic gear (e.g.) Figure 2 (as shown) and ordinary field-modulated magnetic gears (such as) Figure 1 (As shown) The time-varying simulation curve of the driven rotor speed under the given operating conditions above; Figure 6 The present invention provides an embodiment of an anti-out-of-step stator excitation type field-modulated axial magnetic gear (e.g., ...) under the given operating conditions described above. Figure 2 (As shown) The time-varying simulation curve of the current of the I-th set of damping windings 2-7.

[0068] Depend on Figure 5 It can be seen that, under the same given working conditions, ordinary field-modulated magnetic gears (such as...) Figure 1 The driven rotor of the (shown) loses synchronization, while the anti-synchronization stator excitation type field-modulated axial magnetic gear (such as) of the embodiment of the present invention (e.g.) Figure 2 As shown, the driven rotor can maintain synchronization, which indicates that the anti-out-of-step stator excitation type field modulation axial magnetic gear provided by the present invention has a stronger anti-out-of-step capability compared with the traditional field modulation magnetic gear.

[0069] Depend on Figure 6 It can be seen that, under given operating conditions, the anti-out-of-step stator excitation type field-modulated axial magnetic gear (such as...) of the embodiments of the present invention... Figure 2 As shown, during the steady-state transmission phase, the current in the driven rotor damping winding is zero, thus it will not have any additional impact on steady-state operation.

[0070] Therefore, compared with the prior art, the field-modulated magnetic gear proposed in this invention can generate induced driving torque by utilizing the interaction between specific harmonics of the air gap magnetic field and the damping winding during the transient transmission stage, thereby significantly improving the anti-stepping capability. At the same time, the induced current in the damping winding of this magnetic gear is zero during the steady-state operation stage, and the introduced damping winding will not affect its transmission quality.

[0071] In addition, the field modulation magnetic gear adopts stator excitation instead of traditional rotor excitation, effectively avoids permanent magnet falling off failure, solves the problem of mutual restriction of winding and magnetic steel in installation space and mutual interference in parameter design, and has the advantages of high mechanical reliability and large design freedom.

[0072] In the description of the present specification, the description referring to the terms "one embodiment", "an example", "a specific example" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0073] The preferred embodiments of the application disclosed above are only used to help explain the application. The preferred embodiments do not describe all the details and limit the application to the specific embodiments. Obviously, many modifications and variations can be made according to the content of the present specification. The present specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the application, so that those skilled in the art can well understand and utilize the application. The application is limited only by the claims and their full scope and equivalents.

Claims

1. A stall-resistant stator-excited field-modulated axial magnetic gear, characterized in that, The stator, the driving rotor and the driven rotor are arranged coaxially, and the driving rotor and the driven rotor are arranged on two sides of the stator respectively; The driven rotor comprises driven rotor magnetic conductive blocks and driven rotor non-magnetic conductive blocks, each driven rotor magnetic conductive block has the same circumferential width and is uniformly and symmetrically distributed along the circumference, and the driven rotor non-magnetic conductive blocks are filled between the driving rotor magnetic conductive blocks. The inner surface of the driven rotor magnetic block in contact with the air gap is uniformly slotted, the slot number is 4 P - Z ); the first set of damping windings and the second set of damping windings are embedded in the slot; The first set of damping windings and the second set of damping windings are both double-layer pitch windings.

2. The anti-slip stator excited field modulation axial magnetic gear, according to claim 1, characterized in that, The stator comprises stator core blocks and stator permanent magnets arranged between the stator core blocks, the number of pole pairs of the stator permanent magnets is P , P is a positive integer.

3. The anti-slip stator excited field modulation axial magnetic gear, according to claim 2, characterized in that, The stator core blocks provide clamping protection for the stator permanent magnets and form a magnetic conductive medium.

4. The anti-slip stator excited field modulation axial magnetic gear, according to claim 1, characterized in that, The driving rotor comprises driving rotor magnetic conductive blocks and driving rotor non-magnetic conductive blocks, each driving rotor magnetic conductive block has the same circumferential width and is non-uniformly and symmetrically distributed along the circumference, and the driving rotor non-magnetic conductive blocks are filled between the driving rotor magnetic conductive blocks.

5. The anti-slip stator- excited field-modulated axial magnetic gear according to claim 4, wherein, The number of the active rotor magnetic conductive blocks and the number of the active rotor non-magnetic conductive blocks are both 2 Z , Z is a positive integer, and Z P .​ 6. The anti-slip stator excited field modulation axial magnetic gear, according to claim 1, characterized in that, The number of the driven rotor magnet conducting blocks and the driven rotor non-magnet conducting blocks is 2 P - Z ).

7. The anti-slip stator excited field modulation axial magnetic gear according to claim 1, wherein, The pole pairs of the first damping winding and the second damping winding are both P - Z and the axes are mutually different by 90 degrees of electric angle, constituting two symmetrical damping windings.

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