CN117650653A - Motor and robot - Google Patents

Abstract

The invention provides a motor and a robot. An electric machine according to an embodiment of the present invention includes a stator assembly and a rotor assembly rotatably disposed relative to the stator assembly. The stator assembly comprises a stator core, a plurality of windings and a plurality of magnetic field modulation modules, wherein the stator core comprises a magnetic conduction ring and a plurality of stator teeth which are distributed along the circumferential direction of the magnetic conduction ring at intervals, open slots are formed between two adjacent stator teeth, the windings are wound on the stator teeth, and the magnetic field modulation modules are arranged in the open slots. The rotor assembly comprises a plurality of rotor core units and a plurality of permanent magnets, the rotor core units are distributed along the circumferential direction of the motor, one permanent magnet is embedded between every two adjacent rotor core units, the permanent magnets comprise a first magnet and a second magnet, the polarities of the first magnet and the second magnet are opposite, and the first magnet and the second magnet are alternately arranged along the circumferential direction of the motor.

Description

Motor and robot

Technical Field

The invention relates to the technical field of motors, in particular to a motor and a robot.

Background

In the related art, a permanent magnet vernier motor comprises a stator, a rotor, a permanent magnet and an armature winding, wherein the stator generally adopts a split tooth structure, a magnetic circuit is easy to saturate, the design thickness of a stator yoke part, a tooth part and a rotor yoke part is larger, the armature winding generally adopts a distributed winding, the end part of a coil is higher, the weight is larger, and the dead weight and the volume of the motor are larger due to the structure, so that the torque density of the motor is not favorable.

Disclosure of Invention

The invention provides a motor and a robot.

An electric machine according to an embodiment of the present invention includes a stator assembly and a rotor assembly rotatably disposed relative to the stator assembly.

The stator assembly comprises a stator core, a plurality of windings and a plurality of magnetic field modulation modules, wherein the stator core comprises a magnetic conduction ring and a plurality of stator teeth which are distributed along the circumferential direction of the magnetic conduction ring at intervals, open slots are formed between two adjacent stator teeth, the windings are wound on the stator teeth, and the magnetic field modulation modules are arranged in the open slots.

The rotor assembly comprises a plurality of rotor core units and a plurality of permanent magnets, the rotor core units are distributed along the circumferential direction of the motor, one permanent magnet is embedded between every two adjacent rotor core units, the permanent magnets comprise a first magnet and a second magnet, the polarities of the first magnet and the second magnet are opposite, and the first magnet and the second magnet are alternately arranged along the circumferential direction of the motor.

In the motor of this application embodiment, be provided with the open slot that distributes along motor circumference on the stator core for hold winding coil and magnetic field modulation module, effectively utilized the motor space and alleviateed stator core dead weight, the winding adopts concentrated winding, further reduces motor weight, thereby increases the torque density of motor. Meanwhile, the permanent magnet is embedded into the rotor core unit in the rotor assembly, and the modulation effect can be utilized to cooperate with the stator assembly to generate air gap modulation magnetic density, so that the effective magnetic density amplitude is improved, and the torque density of the motor is further improved.

In some embodiments, the magnetic field modulation module is disposed between and spaced apart from the stator core and the rotor assembly.

Therefore, the magnetic field modulation module can modulate the stator rotating magnetic field and the exciting magnetic field at the air gap, and strengthen the magnetic barrier effect, so that the saturation of a magnetic circuit is weakened, and the peak torque density is indirectly improved.

In some embodiments, one magnetic field modulation module is disposed in each open slot, and the number of stator teeth is the same as the number of magnetic field modulation modules.

Thus, each opening slot is internally provided with a magnetic field modulation module, the number of teeth of the magnetic field modulation module is the same as that of teeth of the stator, and the magnetic field modulation modules are uniformly distributed along the circumferential direction of the motor. And because the magnetic field modulation module and the stator teeth jointly modulate the air gap magnetic field, the number of the effective modulation modules is 2 times of the number of the stator teeth.

In some embodiments, the number of magnetic field modulation modules Z, the stator field pole pair number Ps of the stator assembly, and the rotor field pole pair number Pr of the rotor assembly satisfy the relationship: pr=2z±ps.

Therefore, after stator cores with known stator tooth numbers are selected and the winding numbers and distribution are determined, the pole pair numbers of the permanent magnets in the rotor assembly can be selected according to the calculation result of the relation Pr=2Z+ -Ps.

In some embodiments, the stator field pole pair number Ps of the stator assembly and the number Z of magnetic field modulation modules satisfy the relationship: ps= (Z-2)/2.

In this way, the polar ratio can be improved as much as possible by adopting the less polar multi-slot matching, thereby enhancing the modulation effect.

In some embodiments, the permanent magnets and the rotor core units are the same size, and the rotor core units and the permanent magnets are the same number and are both 2Pr.

In this way, the permanent magnets and the rotor core units have the same size, so that the magnetic leakage of the rotor assembly can be reduced, and the utilization rate of the permanent magnets is maximized.

In some embodiments, the permanent magnet has a polar arc coefficient in the range of 0.45-0.65.

Therefore, the pole arc coefficient of the permanent magnet is selected in a reasonable range, and stator iron cores with different tooth slot numbers and rotor components with different pole pairs are matched, so that the optimal output performance of the motor can be realized.

In some embodiments, the magnetic field modulation module is a circular arc shaped magnetically permeable block, and the outer diameter of the magnetic field modulation module is the same as the outer diameter of the stator core.

Therefore, the magnetic field modulation module is arc-shaped, the outer diameter of the magnetic field modulation module is kept identical with the outer diameter of the stator core, interference between the stator assembly and the rotor assembly can be avoided, and the utilization rate of the open slot is increased.

In some embodiments, the angle of the arc of the magnetic field modulation module ranges from 6deg to 8deg, the thickness of the magnetic field modulation module ranges from 1mm to 3mm, and the included angle of the centerline of the magnetic field modulation module with the centerline of the adjacent stator tooth ranges from 2deg to 5deg.

Therefore, the optimal output performance of the motor can be realized by setting the radian of the magnetic field modulation module, the size of the inner diameter and the outer diameter and the position of the magnetic field modulation module in the open slot in a reasonable range and matching different tooth slot numbers and pole pairs.

The robot according to the present embodiment includes the motor according to any of the above embodiments.

Therefore, the motor of the embodiment of the application has the advantages of small size, light weight, large torque inertia ratio and high torque density, and can meet the driving requirement of a robot on small-size high-explosion.

Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

Drawings

The foregoing and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a schematic diagram of the topology of an electric machine according to an embodiment of the present application;

fig. 2 is a schematic perspective view of a motor according to an embodiment of the present application;

fig. 3 is an exploded structural schematic view of the motor of the embodiment of the present application;

FIG. 4 is a schematic view of a partially enlarged structure of a motor according to an embodiment of the present application;

fig. 5 is a graph of tooth magnetic density distribution data of the stator core according to the embodiment of the present application;

fig. 6 is a diagram of magnetic density distribution data of a yoke of the stator core according to the embodiment of the present application;

FIG. 7 is a torque data diagram of an electric machine according to an embodiment of the present application;

fig. 8 is a schematic structural view of a robot according to an embodiment of the present application.

Description of main reference numerals:

robot 1000, motor 100, stator assembly 10, stator core 11, magnetic ring 111, stator teeth 112, open slot 113, winding 12, magnetic field modulation module 13, rotor assembly 20, rotor core unit 21, permanent magnet 22, first magnet 221, second magnet 222, air gap 30.

Detailed Description

Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals refer to the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary only for explaining the present invention and are not to be construed as limiting the present invention.

In the description of the present application, it should be understood that the terms "center," "longitudinal," "transverse," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," etc. indicate or are based on the orientation or positional relationship shown in the drawings, merely to facilitate description of the invention and to simplify the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be configured and operated in a particular orientation, and thus should not be construed as limiting the invention. Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more of the described features. In the description of the present invention, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.

In the description of the present application, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be mechanically connected, electrically connected or can be communicated with each other; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.

In this application, unless expressly stated or limited otherwise, a first feature "above" or "below" a second feature may include both the first and second features being in direct contact, and may also include the first and second features not being in direct contact but being in contact with each other by way of additional features therebetween. Moreover, a first feature being "above," "over" and "on" a second feature includes the first feature being directly above and obliquely above the second feature, or simply indicating that the first feature is higher in level than the second feature. The first feature being "under", "below" and "beneath" the second feature includes the first feature being directly under and obliquely below the second feature, or simply means that the first feature is less level than the second feature.

The following disclosure provides many different embodiments, or examples, for implementing different features of the invention. In order to simplify the present disclosure, components and arrangements of specific examples are described below. They are, of course, merely examples and are not intended to limit the invention. Furthermore, the present invention may repeat reference numerals and/or letters in the various examples, which are for the purpose of brevity and clarity, and which do not themselves indicate the relationship between the various embodiments and/or arrangements discussed. In addition, the present invention provides examples of various specific processes and materials, but one of ordinary skill in the art will recognize the application of other processes and/or the use of other materials.

Referring to fig. 1-3, fig. 1 is a topological structure diagram of an electric machine 100 of an embodiment of the present application, the electric machine 100 of an embodiment of the present application comprising a stator assembly 10 and a rotor assembly 20 rotatably disposed relative to the stator assembly 10.

The stator assembly 10 includes a stator core 11, a plurality of windings 12 and a plurality of magnetic field modulation modules 13, wherein the stator core 11 includes a magnetic ring 111 and a plurality of stator teeth 112 distributed at intervals along the circumferential direction of the magnetic ring 111, an open slot 113 is formed between two adjacent stator teeth 112, the windings 12 are wound on the stator teeth 112, and the magnetic field modulation modules 13 are disposed in the open slot 113.

The rotor assembly 20 includes a plurality of rotor core units 21 and a plurality of permanent magnets 22, the rotor core units 21 are distributed along the circumferential direction of the motor 100, one permanent magnet 22 is embedded between every two adjacent rotor core units 21, the permanent magnets 22 include a first magnet 221 and a second magnet 222, the polarities of the first magnet 221 and the second magnet 222 are opposite, and the first magnet 221 and the second magnet 222 are alternately arranged along the circumferential direction of the motor 100.

In the motor 100 of the embodiment of the present application, the stator core 11 is provided with the open slots 113 distributed along the circumferential direction of the motor 100, for accommodating the coils of the winding 12 and the magnetic field modulation module 13, so that the space of the motor 100 is effectively utilized, the dead weight of the stator core 11 is reduced, the winding 12 adopts the concentrated winding 12, and the weight of the motor 100 is further reduced, thereby increasing the torque density of the motor 100. Meanwhile, the permanent magnet 22 is embedded into the rotor core unit 21 in the rotor assembly 20, and the modulation effect can be utilized to cooperate with the stator assembly 10 to generate an air gap 30 for modulating magnetic density, so that the effective magnetic density amplitude is improved, and the torque density of the motor 100 is further improved.

The motor 100 of the embodiment of the application adopts the stator core 11 with the open slot 113, the separated magnetic field modulation module 13 and the spoke type rotor, improves the magnetic density of the air gap 30 fundamental wave, weakens the saturation of the magnetic circuit, obviously improves the torque density, can achieve high torque output in a limited volume, and has good application scenes in various direct-drive systems. The motor 100 of the embodiment of the application can be widely applied to the fields of robots 1000, new energy vehicles, unmanned aerial vehicles, ship propulsion, rail transit and the like, and provides driving and control of rotation speed output.

Specifically, an air gap 30 exists between the stator assembly 10 and the rotor assembly 20. The rotor core unit 21 constitutes a rotor core in which the permanent magnets 22 are embedded and generate an excitation magnetic field. The windings 12 are embedded in the stator core 11, and a stator rotating magnetic field can be generated when the windings 12 are energized. The magnetic field modulation module 13 is placed in the open slot 113 of the stator core 11, the excitation magnetic field and the stator rotating magnetic field generate main working magnetic fields in the air gap 30 through the modulation action of the magnetic field modulation module 13 and the stator teeth 112, and the working magnetic fields generate torque to drive the rotor assembly 20 to move. Under modulation, one of the air gap 30 densities is converted to an effective operating density, thereby increasing the effective operating density and increasing the output torque of the motor 100.

In the stator assembly 10, each set of coils is wound around a single stator tooth 112, forming a concentrated winding 12, reducing the coil end size and reducing the weight of the motor 100 as compared to a distributed winding 12. The stator teeth 112 may be uniformly distributed along the circumference of the magnetic ring 111, and the same number of turns of winding 12 coils are wound on each stator tooth 112. An open slot 113 is formed between every two adjacent stator teeth 112, and the open slots 113 are uniformly distributed in the circumferential direction of the magnetic ring 111. The winding 12 is accommodated in the open slot 113, so that the effective accommodating space is larger, and compared with the split tooth stator structure in the related art, the stator core 11 in the embodiment of the application can be provided with more coils when the slot filling rate is the same.

The permanent magnets 22 and the rotor core unit 21 are fitted to each other and disposed at the same position in the radial direction of the motor 100. The first and second magnets 221, 222 are tangentially magnetized such that the first and second magnets 221, 222 each form one of the N, S poles. The first magnets 221, the rotor core unit 21, and the second magnets 222 are alternately distributed along the circumferential direction of the motor 100, and the magnetic lines of force of the N, S poles converge to generate a magnetic focusing effect. Under the action of magnetism concentration, the rotor assembly 20 can cross the limit of residual magnetism of the permanent magnet 22, so that the magnetic density value of the air gap 30 is improved, and the output torque performance of the motor 100 is improved.

In some embodiments, the winding 12 may be a copper wire coil, the stator core 11 and the magnetic field modulation module 13 may be made of materials with high magnetic permeability and difficult magnetization, such as silicon steel materials, iron-cobalt alloy materials, and the like, and the permanent magnet 22 may be made of materials with better magnetic properties, such as ferrite, neodymium-iron-boron, and the like.

Referring to fig. 1 and 2, in some embodiments, the stator assembly 10 is disposed inside the rotor assembly 20 in a radial direction of the motor 100. In some embodiments, the stator assembly 10 is disposed outside of the rotor assembly 20 in a radial direction of the motor 100.

In this way, the stator assembly 10 may be disposed on the inner side or the outer side of the rotor assembly 20, and the motor 100 of the embodiment of the present application may be applied to an inner rotor motor and an outer rotor motor, with a wide application range.

Specifically, the stator assembly 10 and the rotor assembly 20 are coaxial, forming a circumferential air gap 30 between the stator assembly 10 and the rotor assembly 20. The magnetic field modulation module 13 is placed in the open slot 113 at the air gap 30.

In some embodiments, the motor 100 is an external rotor motor, the stator assembly 10 is disposed in the rotor assembly 20, and the magnetic conductive ring 111, the stator teeth 112, the windings 12, the magnetic field modulation module 13, and the rotor assembly 20 are sequentially disposed from inside to outside along the radial direction of the motor 100. The first magnet 221, the second magnet 222, and the rotor core unit 21 are disposed at the same position in the radial direction of the motor 100. Stator teeth 112 extend radially outward from magnetic ring 111 of motor 100, with the tips of stator teeth 112 pointing toward rotor assembly 20. An open slot 113 is formed between adjacent two of the stator teeth 112 and opens toward the rotor assembly 20, the slot bottom of the open slot 113 being adjacent to the axial center of the motor 100 and the slot opening being adjacent to the outer diameter of the motor 100. The magnetic field modulation module 13 is placed within the open slot 113 near the slot opening, with an air gap 30 formed between the magnetic field modulation module 13 and the tips of the stator teeth 112 and the rotor assembly 20. In this embodiment, the rotor assembly 20 is located near the outer diameter of the motor 100, facilitating maintenance of the rotor assembly 20.

In some embodiments, the motor 100 is an inner rotor motor, and the rotor assembly 20, the magnetic field modulation module 13, the windings 12, the stator teeth 112, and the magnetically permeable ring 111 are disposed in order from inside to outside in a radial direction of the motor 100. Stator teeth 112 extend inward from magnetic conductive ring 111 in the radial direction of motor 100, with the tips of stator teeth 112 pointing toward rotor assembly 20. An open slot 113 is formed between adjacent two of the stator teeth 112 and opens toward the rotor assembly 20, the slot bottom of the open slot 113 being adjacent to the outer diameter of the motor 100, and the slot opening being adjacent to the axial center of the motor 100. In this embodiment, the rotational inertia of the rotor assembly 20 is small relative to the rotational inertia of the rotor set 20 in an external rotor motor, which facilitates higher rotational speeds.

Referring to fig. 1 and 4, in some embodiments, the magnetic field modulation module 13 is disposed between the stator core 11 and the rotor assembly 20 and is spaced apart from the stator core 11 and the rotor assembly 20.

In this way, the magnetic field modulation module 13 can modulate the stator rotating magnetic field and the exciting magnetic field at the air gap 30, and enhance the magnetic barrier effect, so that the saturation of the magnetic circuit can be weakened, and the peak torque density of the motor 100 can be indirectly improved.

Specifically, the magnetic field modulation module 13 is disposed at a distance from the stator core 11 and the rotor assembly 20. In the motor 100 according to the embodiment of the present application, the stator field pole pair number Ps, the rotor field pole pair number Pr, and the effective modulation module number Y need to satisfy the relationship pr=y±ps, and the stator field pole pair number Ps is far smaller than the rotor field pole pair number Pr. Thus, the low pole pair number of primary flux lines passing through the rotor assembly 20 are forced to bypass the opposing poles into the adjacent air gap 30 region, which increases the primary magnetic circuit reluctance, which is beneficial for weakening the armature reaction of the motor 100 and reducing magnetic saturation. The magnetic field modulation module 13 is disposed separately from the stator core 11 and the rotor assembly 20 to enhance the magnetic barrier effect, thereby facilitating suppression of magnetic circuit saturation and improvement of effective working flux density in the air gap 30.

In the forward pole region, the permanent magnet 22 further enhances the magnetic barrier effect, and the combined action of the magnetic field modulation module 13 and the permanent magnet 22 can greatly weaken the armature reaction of the motor 100 and reduce the magnetic saturation of the motor 100. Referring to fig. 5 and 6, fig. 5 and 6 are diagrams showing the magnetic density distribution of the teeth and fig. 5 and 6 showing the magnetic density distribution of the teeth, respectively, of the stator core 11 of the motor 100 according to the embodiment of the present application, the stator motor with split tooth structure and the stator core 11 of the surface-mounted rotor motor with the same size, and the magnetic density distribution of the teeth and the stator core 11 with the same size, respectively, under the same electrical load obtained by finite element simulation analysis. As shown in fig. 5 and 6, the motor 100 according to the embodiment of the present application significantly weakens the magnetic saturation of the yoke of the stator teeth 112, so that the working field magnetic flux can be enhanced, and the torque output performance of the motor 100 can be improved.

Referring to fig. 1, in some embodiments, one magnetic field modulation module 13 is disposed in each open slot 113, and the number of stator teeth 112 is the same as the number of magnetic field modulation modules 13.

In this way, each open slot 113 is provided with one magnetic field modulation module 13, the number of the magnetic field modulation modules 13 is the same as that of the stator teeth 112, and the magnetic field modulation modules 13 are uniformly distributed along the circumferential direction of the motor 100. And because the magnetic field modulation module 13 and the stator teeth 112 jointly modulate the magnetic field of the air gap 30, the number of effective modulation modules is 2 times that of the stator teeth 112.

Specifically, since the stator teeth 112 are uniformly distributed on the outer side or the inner side of the magnetic ring 111 along the circumference of the motor 100, an open slot 113 is formed between every two adjacent stator teeth 112, and each open slot 113 is provided with one magnetic field modulation module 13, and the number of stator teeth 112, the number of magnetic field modulation modules 13 and the number of open slots 113 are all the same, which is Z. The magnetic field modulation module 13 is placed in the open slot 113, and the exciting magnetic field generated by the permanent magnet 22 generates two main working magnetic fields in the air gap 30 under the modulation action of the magnetic field modulation module 13 and the stator teeth 112, and the pole pair numbers of the two working magnetic fields are respectively consistent with the pole pair number Ps of the stator magnetic field and the pole pair number Pr of the rotor magnetic field, so that the working magnetic density of the motor 100 in the embodiment of the application is one more than that of a common permanent magnet motor, the effective working magnetic density amplitude is improved, and the torque density of the motor 100 is further improved.

Referring to fig. 1 and 3, in some embodiments, two sides of the stator teeth 112 are planar, and opposite sides of the stator teeth 112 define open slots 113.

In this manner, the open slots 113 defined by the opposite sides of the two stator teeth 112 increases the in-slot area of the open slots 113, facilitates the winding 12 to be taken off line and reduces the weight of the stator core 11.

Specifically, both side surfaces of the stator teeth 112 are flat surfaces, and no bifurcation occurs in the extending path in the radial direction of the motor 100, unlike the conventional split tooth structure. The two sides of the stator teeth 112 may be flat surfaces or cambered surfaces with a certain curvature. The present application does not limit the occurrence of curvature and camber to the sides of the stator teeth 112, but the magnitude of curvature is limited so as not to cause the occurrence of steps to the sides of the stator teeth 112.

Two opposite sides of the adjacent two stator teeth 112 and a side surface of the magnetic ring 111 facing the rotor assembly 20 define an open slot 113, and a side surface of the magnetic ring 111 facing the rotor assembly 20 forms a slot bottom of the open slot 113. The winding 12 is wound on each stator tooth 112, and each set of coils is accommodated in two adjacent open slots 113, the winding 12 being close to the bottom of the open slots 113 in the radial direction of the motor 100. The open slot 113 is open toward the rotor assembly 20, and the magnetic field modulation module 13 is accommodated in the open slot 113 at the opening of the open slot 113. Compared with a motor adopting a split tooth structure stator, the design of the open slot 113 reduces the magnetic conducting ring 111 and the stator teeth 112, enlarges the effective space in the slot, reduces the weight of the stator core 11, and simplifies and lightens the structure of the motor 100.

In some embodiments, the number Z of magnetic field modulation modules 13, the stator field pole pair number Ps of the stator assembly 10, and the rotor field pole pair number Pr of the rotor assembly 20 satisfy the relationship: pr=2z±ps.

Thus, after the stator core 11 with a known number of stator teeth 112 is selected and the number and distribution of windings 12 are determined, the pole pair number of the permanent magnets 22 in the rotor assembly 20 can be selected according to the calculation result of the relation pr=2z±ps.

Specifically, the winding 12 in the stator assembly 10 is capable of generating a stator rotating magnetic field, the pole pair number of the stator rotating magnetic field is the pole pair number Ps of the stator magnetic field, and the pole pair number of the magnetic field generated by the permanent magnet 22 in the rotor assembly 20 is the pole pair number Pr of the rotor magnetic field. As described above, the magnetic field modulation module 13 and the stator teeth 112 together modulate the magnetic field of the air gap 30, and the number Y of effective modulation modules is 2 times the number Z of the stator teeth 112. Since the number of stator field pole pairs Ps, the number of rotor field pole pairs Pr, and the number of effective modulation modules Y in the motor 100 according to the embodiment of the present application need to satisfy the relationship pr=y±ps, the number Z of magnetic field modulation modules 13, the number of stator field pole pairs Ps, and the number of rotor field pole pairs Pr satisfy the relationship: pr=2z±ps. After selecting the stator core 11 of the known stator teeth 112 and determining the number and distribution of windings 12, the pole pair numbers of the permanent magnets 22 in the rotor assembly 20 can be selected by calculation of the relationship pr=2z±ps.

In the case of meeting pr=2z—ps, the number of pole pairs of the rotor magnetic field is small, the number of permanent magnets 22 and the number of rotor core units 21 are small, production and assembly are facilitated, and the process is relatively easy to implement.

Under the condition that Pr=2Z+Ps is met, the pole pair number of the rotor magnetic field is more, so that the effective working flux density of the air gap 30 is improved, and the output torque performance of the motor 100 is improved.

In some embodiments, the stator field pole pair number Ps of the stator assembly 10 and the number Z of magnetic field modulation modules 13 satisfy the relationship: ps= (Z-2)/2.

In this way, the polar ratio can be improved as much as possible by adopting the less polar multi-slot matching, thereby enhancing the modulation effect.

Specifically, in the related art, a motor using a centralized winding generally uses a multi-slot matching with a few poles, and the motor 100 according to the embodiment of the present application uses a multi-slot matching with a few poles, so as to increase the pole ratio, that is, the ratio of the pole pair number Pr of the rotor magnetic field to the pole pair number Ps of the stator magnetic field, so as to increase the modulation effect in the motor 100. As described above, the number of stator teeth 112, the number of magnetic field modulation modules 13, and the number of open slots 113 are all Z. Considering the maximization of the winding 12 factor, in the motor 100 of the embodiment of the present application, the stator field pole pair number and the number Z of the magnetic field modulation modules 13 (or the stator teeth 112, the open slots 113) satisfy the relation ps= (Z-2)/2.

Referring to fig. 1-3, in some embodiments, the permanent magnets 22 and the rotor core units 21 are the same size, and the number of the rotor core units 21 and the permanent magnets 22 is the same and is 2Pr.

In this way, the permanent magnet 22 and the rotor core unit 21 are the same size, and the leakage flux of the rotor assembly 20 can be reduced, so that the utilization rate of the permanent magnet 22 is maximized.

Specifically, the permanent magnet 22 and the rotor core unit 21 are each sector-shaped in shape. As described above, the permanent magnet 22 and the rotor core unit 21 are located at the same position in the radial direction of the motor 100, and the side surface of the permanent magnet 22 is closely fitted to the side surface of the rotor core unit 21 in the circumferential direction of the motor 100. The first magnet 221 and the second magnet 222 are identical in shape, size and number.

The first magnets 221 and the second magnets 222 are alternately fitted with the rotor core unit 21, the inner diameter, the outer diameter and the width of the rotor core unit 21 are the same as those of the permanent magnets 22, and the inner and outer diameters of the rotor core unit 21 and the permanent magnets are the inner and outer diameters of the rotor assembly 20.

The number of the rotor core units 21 and the number of the permanent magnets 22 are the same, and the number of the first magnets 221 and the second magnets 222 are the same and half of the number of the permanent magnets 22, so that the number of pole pairs Pr of the rotor magnetic field is half of the number of the rotor core units 21. As described above, the number of permanent magnets 22 and rotor core units 21 may be selected by the relation pr=2z±ps.

In some embodiments, the permanent magnet 22 has a polar arc coefficient in the range of 0.45-0.65 (inclusive).

In this way, the pole arc coefficient of the permanent magnet 22 is selected in a reasonable range, and the stator iron cores 11 with different tooth slot numbers and the rotor components 20 with different pole pairs are matched, so that the optimal output performance of the motor can be realized.

Specifically, the magnitude of the pole arc coefficient of the permanent magnet 22 may affect the output performance of the motor 100, the permanent magnet 22 having a pole arc coefficient that is too large may cause the rotor core unit 21 to be supersaturated, and the permanent magnet 22 having a pole arc coefficient that is too small may impair the magnetic focusing capability of the spoke rotor assembly 20. In the same motor 100, the pole arc coefficients of the first magnet 221 and the second magnet 222 are the same.

According to different situations of the motor 100 in the specific embodiment, for example, the pole pair number of the rotor assembly 20, the number of tooth slots of the stator core 11, the diameter of the stator and the rotor, materials selected by different components, the application scenario of the motor 100, and the like, optimal parameter matching can be selected, so that optimal output torque performance is realized. By way of example, the polar arc coefficient of the permanent magnet 22 may be 0.45, 0.48, 0.5, 0.52, 0.6, 0.65.

Referring to fig. 1, in some embodiments, the magnetic field modulation module 13 is a circular arc-shaped magnetic conductive block, and the outer diameter of the magnetic field modulation module 13 is the same as the outer diameter of the stator core 11.

In this way, the magnetic field modulation module 13 has an arc shape, and the outer diameter thereof is kept equal to the outer diameter of the stator core 11, so that interference between the stator assembly 10 and the rotor assembly 20 can be avoided, and the utilization rate of the open slot 113 can be increased.

Specifically, the magnetic field modulation module 13 is an arc-shaped magnetic conductive block, the magnetic field modulation module 13 is placed at the notch of the open slot 113, and the arc-shaped outer diameter of the magnetic field modulation module 13 is kept consistent with the outer diameter of the stator core 11, so that the accommodating space of the winding 12 in the open slot 113 is increased as much as possible. The magnetic field modulation modules 13 can be uniformly distributed at the circumferential air gap 30, so that interference between the stator assembly 10 and the rotor assembly 20 is avoided, and smooth rotation of the rotor assembly 20 is ensured.

Referring to fig. 4, in some embodiments, the angle w of the arc of the magnetic field modulation module 13 ranges from 6deg to 8deg (inclusive), the thickness t of the magnetic field modulation module 13 ranges from 1mm to 3mm (inclusive), and the angle α of the center line of the magnetic field modulation module 13 with the center line of the adjacent stator teeth 112 ranges from 2deg to 5deg (inclusive).

In this way, by setting the radian of the magnetic field modulation module 13, the size of the inner and outer diameters, and the position of the magnetic field modulation module 13 in the open slot 113 within a reasonable range, different tooth slot numbers and pole pairs are matched, so that the optimal output performance of the motor 100 can be realized.

Specifically, the radian of the magnetic field modulation module 13, the size of the inner diameter and the outer diameter, and the position of the magnetic field modulation module 13 placed in the open slot 113 all affect the amplitude of the working magnetic density of the air gap 30, thereby affecting the output torque performance of the motor 100. The size of the magnetic field modulation module 13 can be determined by the angle w and the thickness t of the circular arc, and the thickness t of the magnetic field modulation module 13 is the difference between the outer diameter and the inner diameter of the magnetic field modulation module 13. The outer diameter of the magnetic field modulation module 13 coincides with the outer diameter of the stator teeth 112, so that the position of the magnetic field modulation module 13 in the radial direction in the open slot 113 can be determined by the thickness t of the magnetic field modulation module 13. The position in the circumferential direction of the motor 100 where the magnetic field modulation module 13 is placed in the open slot 113 may be determined by the size of the angle α between the center line of the stator teeth 112 forming the open slot 113 in which the magnetic field modulation module 13 is located and the center line of the magnetic field modulation module 13.

The optimal parameter fit is selected according to the different conditions of the motor 100 in the specific embodiment, thereby achieving optimal output torque performance. For example, the arc w of the magnetic field modulation module 13 may be 6deg, 6.1deg, 6.8deg, 7.3deg, 7.7deg, 8deg, the thickness t of the magnetic field modulation module 13 may be 1mm, 1.2mm, 1.45mm, 2.1mm, 2.6mm, 3mm, and the angle α of the centerline of the magnetic field modulation module 13 to the centerline of the adjacent stator tooth 112 may be 2deg, 2.4deg, 3deg, 3.5deg, 4deg, 4.8deg, 5deg.

In a specific embodiment, the number Z of the stator teeth 112 and the magnetic field modulation modules 13 is 18, the number Ps of the stator field pole pairs is 8, the pitch of the winding 12 is 1, the number Pr of the rotor field pole pairs is 28, the radian w of the magnetic field modulation modules 13 is 7deg, the thickness t of the magnetic field modulation modules 13 is 2mm, the included angle α between the center of the stator teeth 112 and the center of the magnetic field modulation modules 13 is 3deg, and the pole arc coefficient of the permanent magnet 22 is 0.55. The materials of the stator core 11 and the magnetic field modulation module 13 are made of high-saturation ferrocobalt alloy, and the materials of the permanent magnet 22 and the rotor core unit 21 are made of neodymium iron boron. Under the condition that the external dimensions and the electric load are the same, the finite element simulation result shows that the peak torque density of the motor 100 of the embodiment is 38 N.m/kg, and the peak torque density can reach 1.4 times of the motor adopting the surface-mounted rotor and 1.6 times of the motor adopting the stator with the conventional split tooth structure.

In the motor 100 of the embodiment of the application, the rotor assembly 20 adopts a spoke type structure, compared with a surface-mounted type structure, the fundamental magnetic density of the air gap 30 is greatly improved, the magnetic barrier effect is improved by combining the separated magnetic field modulation module 13, the saturation of a magnetic circuit is further weakened, and meanwhile, the modulation effect is utilized to generate the air gap 30 to modulate the magnetic density, so that the magnetic density amplitude of the effective air gap 30 is improved. On the other hand, providing the open slot 113 on the stator core 11 simplifies the structure compared to the conventional split tooth stator core, reduces the weight of the motor 100, and increases the effective accommodation space.

Fig. 7 is a torque comparison of an electric machine 100 of an embodiment with an electric machine of the same size using a conventional split tooth stator and an electric machine using a surface mounted rotor for the same electrical load as determined by finite element analysis. As shown in fig. 7, the torque of the motor 100 according to the embodiment of the present application is significantly increased when the external dimensions and the electric load are the same.

Referring to fig. 8, a robot 1000 according to an embodiment of the present application includes the motor 100 according to any of the embodiments described above.

As such, the motor 100 according to the embodiment of the present application has advantages of small volume, light weight, large torque inertia ratio, and high torque density, and can meet the driving requirement of the robot 1000 for small volume and high explosion.

Specifically, the robot 1000 may be a robot 1000, a four-legged robot 1000, a multi-legged robot 1000, or the like, and the motor 100 may be disposed at a trunk, leg, or joint of the robot 1000 to provide driving force to the robot 1000. The motor 100 has higher torque density, and can realize larger torque operation in a limited installation space of the robot 1000, so that the motor 100 in the embodiment of the application is particularly suitable for joints of the robot 1000 and flexibly drives the robot 1000 to move.

In the description of the present specification, reference to the terms "one embodiment," "certain embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present application. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

While embodiments of the present application have been shown and described, it will be understood by those of ordinary skill in the art that: many changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the application, the scope of which is defined by the claims and their equivalents.

Claims (10)

1. An electric machine, comprising:

the stator assembly comprises a stator core, a plurality of windings and a plurality of magnetic field modulation modules, wherein the stator core comprises a magnetic conduction ring and a plurality of stator teeth which are distributed at intervals along the circumferential direction of the magnetic conduction ring, open slots are formed between two adjacent stator teeth, the windings are wound on the stator teeth, and the magnetic field modulation modules are arranged in the open slots;

the rotor assembly is rotationally arranged relative to the stator assembly, the rotor assembly comprises a plurality of rotor core units and a plurality of permanent magnets, the rotor core units are distributed along the circumferential direction of the motor, one permanent magnet is embedded between every two adjacent rotor core units, the permanent magnets comprise a first magnet and a second magnet, the polarities of the first magnet and the second magnet are opposite, and the first magnet and the second magnet are alternately arranged along the circumferential direction of the motor.

2. The electric machine of claim 1, wherein the magnetic field modulation module is disposed between and spaced apart from the stator core and the rotor assembly.

3. The electric machine of claim 2, wherein one of the magnetic field modulation modules is disposed in each of the open slots, the number of stator teeth being the same as the number of magnetic field modulation modules.

4. A machine according to claim 3, wherein the number Z of field modulation modules, the stator field pole pair number Ps of the stator assembly and the rotor field pole pair number Pr of the rotor assembly satisfy the relation: pr=2z±ps.

5. The electric machine of claim 4, wherein the stator field pole pair number Ps of the stator assembly and the number Z of field modulation modules satisfy the relationship: ps= (Z-2)/2.

6. The electric machine according to claim 1, wherein the permanent magnets and the rotor core units are the same in size, and the rotor core units and the permanent magnets are the same in number and are each 2Pr.

7. The electric machine of claim 6, wherein the permanent magnet has a pole arc coefficient in the range of 0.45-0.65.

8. The electric machine of claim 1, wherein the magnetic field modulation module is an arcuate magnetically permeable block and an outer diameter of the magnetic field modulation module is the same as an outer diameter of the stator core.

9. The machine of claim 8 wherein the arc of the field modulation module has an angle in the range of 6deg-8deg, the field modulation module has a thickness in the range of 1mm-3mm, and the centerline of the field modulation module is at an angle in the range of 2deg-5deg from the centerline of the adjacent stator teeth.

10. A robot comprising a motor according to any one of claims 1-9.