SUMMERY OF THE UTILITY MODEL
In view of the above problems, embodiments of the present application are proposed to provide a dual-rotor in-wheel motor and a vehicle that solve the above problems, or at least partially solve the above problems.
The embodiment of the application provides a dual-rotor hub motor, which comprises an outer rotor, an inner rotor and a stator which are coaxially arranged, wherein the stator is arranged between the outer rotor and the inner rotor;
the outer rotor comprises a plurality of permanent magnets which are sequentially arranged along the circumferential direction; the periphery of the stator is provided with an outer stator slot, and the outer stator slot is provided with an outer stator winding; the inner circumference of the stator is provided with an inner stator slot, the inner stator slot is provided with an inner stator winding, and the outer stator winding and the inner stator winding are independently arranged.
In some embodiments of the present application, the plurality of permanent magnets are arranged in a halbach array.
In some embodiments of the present application, the outer rotor includes a plurality of main magnetic poles and a plurality of auxiliary magnetic poles, and the main magnetic poles and the auxiliary magnetic poles are alternately distributed along a circumferential direction of the outer rotor; one of the two adjacent main magnetic poles is an N pole, and the other one is an S pole; the magnetizing directions of two adjacent auxiliary magnetic poles point to the same main magnetic pole;
the main magnetic pole comprises two first permanent magnets and at least one second permanent magnet, the first permanent magnets are arranged adjacent to the auxiliary magnetic pole, and the second permanent magnet is positioned between the two first permanent magnets;
the magnetizing direction of the first permanent magnet and the radial direction of the outer rotor form an included angle, the magnetizing direction of the first permanent magnet and the magnetizing direction of the second permanent magnet are inwards or outwards at the same time, and the magnetizing direction of the second permanent magnet is along the radial direction of the outer rotor.
In some embodiments of the present application, a magnetizing direction of the secondary magnetic pole is along a circumferential tangent of the outer rotor.
In some embodiments of the present application, the outer rotor includes only a plurality of the permanent magnets.
In some embodiments of the present application, the outer rotor includes a plurality of main body segments, the plurality of main body segments are sequentially distributed along an axial direction of the outer rotor, and each main body segment is separately disposed.
In some embodiments of the present application, the outer periphery of the inner rotor is toothed to form a plurality of salient pole structures and a plurality of inner rotor slots, the salient pole structures and the inner rotor slots are alternately distributed along the circumferential direction; wherein,
the inner stator winding is a concentrated winding, and the concentrated winding and the salient pole structure interact to form an inner rotor reluctance motor; or,
the inner stator winding is a distributed winding, a metal conductor is arranged in the inner rotor groove, and the distributed winding and the metal conductor interact to form an inner rotor asynchronous motor.
In some embodiments of the present application, the outer stator winding is a concentrated winding.
In some embodiments of the present application, a first air gap is provided between an inner circumferential surface of the outer rotor and an outer circumferential surface of the stator, and a width of the first air gap is 0.8mm to 1.2mm.
In some embodiments of the present application, a second air gap is provided between the inner circumferential surface of the stator and the outer circumferential surface of the inner rotor, and the width of the second air gap is 0.3mm to 1mm.
In some embodiments of the present application, the stator is provided with a cooling oil passage extending in an axial direction of the stator.
The embodiment of the application further provides a vehicle, which comprises a dual-rotor hub motor, wherein the dual-rotor hub motor comprises an outer rotor, an inner rotor and a stator which are coaxially arranged, and the stator is arranged between the outer rotor and the inner rotor; the outer rotor comprises a plurality of permanent magnets which are sequentially arranged along the circumferential direction; the periphery of the stator is provided with an outer stator slot, and the outer stator slot is provided with an outer stator winding; the inner circumference of the stator is provided with an inner stator slot, the inner stator slot is provided with an inner stator winding, and the outer stator winding and the inner stator winding are independently arranged.
According to the technical scheme provided by the embodiment of the application, a magnetic field formed by electrifying the outer stator winding and an outer rotor magnetic field interact to form an outer motor; the outer motor is a permanent magnet synchronous motor which is used as a main driving motor. The magnetic field formed by electrifying the inner stator winding and the magnetic field of the inner rotor interact to form an inner motor which is used as an auxiliary driving motor. Because the outer stator winding and the inner stator winding are independently arranged, the two windings can be independently electrified, and the inner motor and the outer motor can independently run. When the electric automobile climbs a slope, accelerates suddenly and the like, and needs the large-torque output of the hub motor, the inner motor and the outer motor work simultaneously, and the dynamic requirement is met. When the electric automobile is in the small torque demand operating mode commonly used, outer motor works alone, and the torque load factor is high, and work efficiency promotes, and interior motor is out of work simultaneously, can practice thrift the energy, satisfies the economic nature demand.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, 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, and it is obvious that the described embodiments are some, but not all, embodiments of the present application. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments in the present application without any creative effort belong to the protection scope of the embodiments in the present application.
It should be noted that, in the description of the present application, if the terms "first", "second", etc. appear, the terms "first", "second", etc. are only used for convenience in describing different components or names, and cannot be understood as indicating or implying a sequential relationship, relative importance, or implicitly indicating the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In addition, if "and/or" is presented throughout, it is meant to include three juxtapositions, exemplified by "A and/or B," including either scheme A, or scheme B, or schemes in which both A and B are satisfied.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the present application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.
The distributed driving system of the hub motor is adopted, power, transmission and braking devices are integrated into the hub, the mechanical part of the vehicle is greatly simplified, the transmission efficiency is increased, the arrangement space of the whole vehicle is saved, and the arrangement of the front cabin and the rear cabin is more flexible. Therefore, the hub motor is widely applied to vehicles and other fields.
The hub motor is positioned in the rim of the electric automobile, directly drives wheels, does not have the speed reduction and torque increase of a speed reducer, requires low rotating speed and large torque of the motor, simultaneously has small in-wheel space, and has strict limitation on the volume of the motor, particularly the axial size, namely the hub motor needs high torque density.
In order to meet the requirements of vehicle climbing and hundred-kilometer acceleration performance, the peak torque of the hub motor is high, but the actual operation working conditions of the electric vehicle are mostly in a small torque area, the torque load rate is low, the efficiency is low, the driving range of the electric vehicle is influenced, and the contradiction exists between the dynamic property and the economy.
In addition, the torque density of the conventional single-rotor permanent magnet hub motor is not high enough, the dual-rotor hub motor still adopts a single-motor operation mode, the problem of conflict between the power performance and the economy of the hub motor electric vehicle cannot be solved, and meanwhile, the outer rotor has an iron core structure, so that the size of the hub motor electric vehicle still has a further improvement space. The problem of heat dissipation of the stator winding of the dual-rotor hub motor exists.
In order to solve the above problem, the embodiment of the application provides a dual-rotor hub motor and a vehicle, which make full use of the inner space of the external rotor hub motor, establish the dual-rotor motor, and improve the torque output capacity in a limited space. The double-rotor motor forms a double-motor working mode, the inner motor and the outer motor work together under the large torque requirement, the single motor works when the small torque requirement is met, the double motors meet the strong power requirement, the single motor works to improve the torque load, and the driving efficiency is improved.
Referring to fig. 1 and fig. 2 in combination, an embodiment of the present application provides a dual-rotor hub motor, including an outer rotor 10, an inner rotor 20, and a stator 30, which are coaxially disposed, where the stator 30 is disposed between the outer rotor 10 and the inner rotor 20; the outer rotor 10 includes a plurality of permanent magnets 11 arranged in sequence in the circumferential direction; the outer periphery of the stator 30 is provided with outer stator slots 31, the outer stator slots 31 being provided with outer stator 30 windings (not shown); the inner circumference of the stator 30 is provided with an inner stator groove 32, the inner stator groove 32 is provided with an inner stator 30 winding (not shown), and the outer stator 30 winding and the inner stator 30 winding are independently provided.
In the embodiment of the application, the magnetic field formed by electrifying the winding of the outer stator 30 and the magnetic field of the outer rotor 10 interact to form an outer motor; the outer motor is a permanent magnet synchronous motor which is used as a main driving motor. The magnetic field formed by electrifying the winding of the inner stator 30 and the magnetic field of the inner rotor 20 interact to form an inner motor which is used as an auxiliary driving motor. Because the outer stator 30 winding and the inner stator 30 winding are independently arranged, the two windings can be independently electrified, and the inner motor and the outer motor can independently run.
In some specific application scenarios, taking an electric automobile as an example, when the electric automobile needs large torque output of the hub motor during climbing, sudden acceleration and the like, the inner motor and the outer motor work simultaneously, and the dynamic requirement is met. When the electric automobile is in the small torque demand operating mode commonly used, outer motor works alone, and the torque load factor is high, and work efficiency promotes, and interior motor is out of work simultaneously, can practice thrift the energy, satisfies the economic nature demand.
When the inner motor is a reluctance motor or an asynchronous motor, the inner motor is dragged by wheels without large dragging loss of the permanent magnet motor, and only a small amount of mechanical loss exists, so that the endurance mileage can be effectively improved, and the economic requirement is met. The inner motor and the outer motor directly drive the wheels without a clutch or a planetary gear structure, so that the axial space is saved, the weight is reduced, and the torque density is improved.
In the embodiment of the present application, the outer periphery of the inner rotor 20 is in a toothed structure to form a plurality of salient pole structures 21 and a plurality of inner rotor slots 22, and the salient pole structures 21 and the inner rotor slots 22 are alternately distributed in the circumferential direction. The cross section of the salient pole structure 21 can be rectangular, square, T-shaped, V-shaped and the like; the cross-section of the inner rotor slots 22 may be rectangular, square, V-shaped, U-shaped, etc.
Depending on the structure of the inner rotor 20 and the winding of the inner stator 30, the type of the inner motor formed by energizing the winding of the inner stator 30 and the magnetic field of the inner rotor 20 is also different. In some embodiments, the inner stator 30 windings are concentrated windings that interact with the salient pole structures 21 to form an inner rotor 20 reluctance machine. Specifically, the inner circumference of the stator 30 is provided with a plurality of inner stator slots 32, inner stator teeth 33 are formed between adjacent two inner stator slots 32, and the inner stator slots 32 and the inner stator teeth 33 are alternately distributed in the circumferential direction. Each turn of the winding in the inner stator slot 32 spans only one inner stator tooth 33, i.e. a concentrated winding.
Alternatively, in some embodiments, the inner stator winding is a distributed winding, and a metal conductor (not shown) is disposed in the inner rotor slot 22, and the distributed winding interacts with the metal conductor to form the inner rotor 20 asynchronous motor. In particular, each turn of the coil in the inner stator slot 32 spans a plurality of inner stator teeth 33, i.e. forms a distributed winding.
In the above, the inner motor is a reluctance motor or an asynchronous motor, and the permanent magnet 11 is not provided, so that the motor reliability is improved, and the motor cost is reduced.
Alternatively, the outer stator 30 windings are concentrated windings. Specifically, the outer periphery of the stator 30 is provided with a plurality of outer stator slots 31, outer stator teeth 34 are formed between two adjacent outer stator slots 31, and the outer stator slots 31 and the outer stator teeth 34 are alternately distributed in the circumferential direction. Each turn of the winding in the outer stator slot 31 spans only one outer stator tooth 34, i.e. the concentrated winding.
The outer motor is a permanent magnet synchronous motor and is used as a main drive motor, and the inner motor is a reluctance motor or an asynchronous motor and is used as an auxiliary drive motor. When the main drive motor works, the auxiliary drive motor is dragged to operate, and because the reluctance motor and the asynchronous motor do not have a magnetic field formed by the permanent magnet 11, dragging loss does not exist, and the driving range can be effectively increased.
For a traditional high-torque permanent magnet hub, in a vehicle sliding or braking state, a permanent magnet motor is dragged due to the existence of a large number of permanent magnets 11, so that the problem of high dragging loss is caused. However, in the embodiment of the present application, when the dual motors do not work and are dragged at the same time, even though a part of the dragging loss still exists in the permanent magnet motor of the outer rotor 10, the motor of the inner rotor 20 is not provided with the permanent magnet 11 no matter it is a reluctance motor or an asynchronous motor, so that compared with a large-torque permanent magnet hub motor with a single rotor and a large-torque hub motor with both inside and outside permanent magnet motors, the dragging loss is greatly reduced, and the driving range is further improved.
The plurality of permanent magnets 11 are arranged in a Halbach array (Halbach). The Halbach magnet structure is an approximation of an engineering ideal structure, with the goal of producing the strongest magnetic field with the least amount of magnets, and with the special arrangement of magnet elements, enhancing field strength in the unit direction.
Specifically, the outer rotor 10 includes a plurality of main magnetic poles 12 and a plurality of auxiliary magnetic poles 13, and the main magnetic poles 12 and the auxiliary magnetic poles 13 are alternately distributed along the circumferential direction of the outer rotor 10; one of the two adjacent main magnetic poles 12 is an N pole, and the other one is an S pole; the magnetizing direction of the auxiliary magnetic pole 13 points to the same main magnetic pole 12. I.e. the main pole 12 is located between two sub-poles 13. The main magnetic pole 12 is magnetized in a direction substantially along the radial direction of the outer rotor 10, and the auxiliary magnetic pole 13 is magnetized in a direction toward the main magnetic pole 12.
In some embodiments of the present application, one of the secondary magnetic poles 13 is a permanent magnet 11, and one of the primary magnetic poles 12 includes a plurality of permanent magnets 11. Specifically, the main magnetic pole 12 includes two first permanent magnets 121 and at least one second permanent magnet 122, the first permanent magnet 121 is disposed adjacent to the auxiliary magnetic pole 13, and the second permanent magnet 122 is disposed between the two first permanent magnets 121. The magnetizing direction of the first permanent magnet 121 forms an included angle with the radial direction of the outer rotor 10, and is inward or outward simultaneously with the magnetizing direction of the second permanent magnet 122. The second permanent magnets 122 are magnetized in the radial direction of the outer rotor 10.
Specifically, for the first permanent magnet 11 of the S-pole magnetic pole, the magnetizing direction thereof and the magnetizing direction of the second permanent magnet 122 are disposed close to each other; for the first permanent magnet 11 with the N-pole magnetic pole, the magnetizing direction thereof and the magnetizing direction of the second permanent magnet 122 are away from each other. That is, in the main magnetic pole 12, the S pole is close to the middle, and the N pole diverges to both sides. The direction of magnetization of the auxiliary pole 13 is directed toward the first permanent magnet 121.
In two adjacent groups of magnetic groups, the magnetizing directions of the second permanent magnets 122 are opposite, that is, the magnetizing direction of the second permanent magnets 122 in one group of magnetic groups is radially outward and inward magnetized, the first permanent magnets 121 are also radially inward magnetized, the magnetizing direction of the second permanent magnets 122 in the other group of magnetic groups is radially outward magnetized, and the first permanent magnets 121 are also substantially radially outward magnetized.
Therefore, in the outer rotor 10, the main magnetic pole 12 is composed of N poles and S poles alternately, and forms Halbach arrangement together with the auxiliary magnetic pole 13, and the permanent magnet 11 is magnetized in the direction of the closed magnetic circuit. Alternatively, the outer rotor 10 only includes a plurality of permanent magnets 11, and two adjacent permanent magnets 11 are connected with each other, for example, fixed by bonding. Compared with the permanent magnet 11 of the conventional NS array, the permanent magnet does not need a rotor core yoke part of a magnetic field path, so that a commonly used rotor core in the motor is cancelled, the diameter of an air gap between the outer rotor 10 and the middle stator 30 is increased, the output capacity of the motor is improved, and the torque density is increased.
If the S-pole magnetic field direction is defined as the direction from outside to inside to the center of the circle, the magnetizing direction of the auxiliary magnetic pole 13 is the circumferential direction to point to the S-pole magnetic pole, i.e. the magnetic flux is concentrated in the air gap direction between the outer rotor 10 and the middle stator 30, so that the air gap flux of the outer motor is effectively improved, the torque density of the motor is improved, the sine degree of the rotor flux is improved, the harmonic wave is reduced, the torque ripple is improved, and the NVH performance is improved.
In the above, the magnetizing direction of the first permanent magnet 121 and the radial direction of the outer rotor 10 form an included angle, which may be any one of angles such as 45 °, 60 °, and 70 °, as long as the relationship that the magnetizing direction of the first permanent magnet 121 and the magnetizing direction of the second permanent magnet 122 are close to each other (S pole) or far from each other (N pole) is satisfied. Optionally, the included angle is 45 °.
The magnetizing direction of the auxiliary magnetic pole 13 may be perpendicular to the first permanent magnet 121 or at another angle, and optionally, the magnetizing direction of the auxiliary magnetic pole 13 is tangential to the circumference of the outer rotor 10, and is focused toward the air gap between the outer rotor 10 and the stator 30, that is, the magnetizing direction of the auxiliary magnetic pole 13 is perpendicular to the first permanent magnet 121.
Optionally, each set of main poles 12 includes two second permanent magnets 122.
Optionally, the ratio of the number of main poles 12 to the number of outer stator slots 31 is an even multiple of 8/9 or an even multiple of 2/3. Illustratively, the ratio of the number of main poles 12 to the number of outer stator slots 31 is 8 times of 8/9, i.e. the number of main poles 12 of outer rotor 10 is 64 poles, and the number of outer stator slots 31 is 72 slots. In other embodiments, the even number multiple may be 6 times, 10 times, or other multiples, and may be determined according to factors such as the power required by the vehicle.
In some embodiments, the outer rotor 10 includes a plurality of main body segments, which are distributed in sequence along the axial direction of the outer rotor 10, and each main body segment is separately disposed. In this embodiment, the outer rotor 10 is axially divided into multiple sections, which can reduce eddy current loss of the permanent magnet 11 and improve motor efficiency.
There is a first air gap B between the inner circumferential surface of the outer rotor 10 and the outer circumferential surface of the middle stator 30, and optionally, the width of the first air gap ranges from 0.8mm to 1.2mm, and specifically, the first air gap may be 0.8mm, 0.9mm, 0.95mm, 1.2mm, or the like. If the width of the first air gap is too wide, the magnetic field transmission efficiency is low; if the width of the first air gap is too narrow, the outer rotor 10 and the intermediate stator 30 are easily scratched. Therefore, in the embodiment, the width of the first air gap ranges from 0.8mm to 1.2mm, which can avoid the above problems.
There is a second air gap between the inner peripheral surface of the middle stator 30 and the outer peripheral surface of the inner rotor 20, optionally, the second air gap has a width ranging from 0.3mm to 1mm. Specifically, the second air gap may be 0.3mm, 0.5mm, 0.95mm, 1.0mm, etc. If the width of the second air gap is too wide, the magnetic field transmission efficiency is low; if the width of the second air gap is too narrow, the inner rotor 20 and the intermediate stator 30 are easily scratched. Therefore, in the embodiment, the width of the second air gap ranges from 0.3mm to 1mm, which can avoid the above problems.
Further, the stator 30 is provided with a cooling oil passage 35, and the cooling oil passage 35 extends in the axial direction of the stator 30. Alternatively, the stator 30 is provided with a plurality of cooling oil passages 35, the plurality of cooling oil passages 35 are sequentially distributed along the circumferential direction of the stator 30, two adjacent cooling oil passages 35 are arranged at intervals, and the cooling oil passages 35 penetrate through two end faces of the stator 30, that is, through holes extending in the axial direction are formed in the stator 30. One end of the cooling oil duct 35 serves as a liquid inlet and is communicated with an oil supply device, the other end of the cooling oil duct serves as a liquid outlet, the liquid outlet is communicated with a spraying structure, cooling oil enters the cooling oil duct 35 from the liquid inlet to cool the interior of the stator 30 and then flows to the spraying structure from the liquid outlet, the spraying structure faces the inner stator winding and the outer stator winding 30 to spray the cooling oil to the inner stator winding and the outer stator winding 30 to cool, and the heat dissipation capacity of the motor is improved.
In other embodiments, other cooling configurations may be used to cool the stator 30, the inner stator windings, and the outer stator 30 windings.
The embodiment of the present application further provides a vehicle, where the vehicle includes a dual-rotor hub motor, and the specific structure of the dual-rotor hub motor is please refer to the above-mentioned embodiment, which is not described herein again. The vehicle can be an electric vehicle, a hybrid electric vehicle or a pure fuel vehicle.
Finally, it should be noted that: the above embodiments are only used for illustrating the technical solutions of the embodiments of the present application, and are not limited thereto; although the embodiments of the present application have been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the spirit and scope of the technical solutions of the embodiments of the present application.