Distributed electric driving system, driving method and vehicle

Abstract

The invention relates to the technical field of automobile driving, in particular to a distributed electric driving system, a driving method and a vehicle. A driving unit is arranged in the shell, the driving unit comprises a stator assembly, a rotor assembly and a modulation ring, and the stator assembly comprises a stator iron core and a plurality of winding coils; a corresponding stator permanent magnet is arranged on one side, facing the axis, of each group of winding coils; the rotor assembly comprises a rotor shaft and a rotor iron core, and a plurality of rotor permanent magnets which are distributed at equal intervals in the circumferential direction are arranged on the outer side of the circumference of the rotor iron core; the modulation ring is located between the stator iron core and the rotor iron core, the modulation ring, the stator iron core and the rotor iron core are coaxially arranged, air gaps are formed between the modulation ring and the stator iron core and between the modulation ring and the rotor iron core, and a plurality of modulation blocks which are arranged at equal intervals in the circumferential direction and correspond to the stator permanent magnets and the rotor permanent magnets are arranged on the outer side of the circumference of the modulation ring. The electric driving system is simple and compact in structure and has the advantages of being high in efficiency, low in noise, high in torque density and high in reliability.

Description

Technical Field

[0001] The present invention relates to the field of automobile drive technology, and in particular to a distributed electric drive system, a drive method and a vehicle. Background Art

[0002] At present, in the electric drive system of new energy vehicles, power generally flows from the motor to the wheels, which needs to pass through transmission mechanisms such as reducers, differentials, and drive shafts. The transmission efficiency is relatively low. At the same time, the entire system has disadvantages such as large space occupation, heavy weight, complex structure, and high vibration and noise. The degree of integration, modularization, and lightweight is relatively low.

[0003] With the rapid development of electrical component technology, distributed drive systems with short transmission chains, compact structures, and high energy utilization have become a hot topic in the research of new energy electric drive systems. They are drive system technologies that use different motors to drive different wheels. The speed and torque output of each drive motor in the distributed drive system are relatively independent, and the speed and torque of each drive motor can be independently controlled according to the driving force requirements of each wheel. For example, by collecting the changes in wheel adhesion or obtaining relevant control instructions, the different speeds of the wheels can be controlled to achieve differential steering of the vehicle.

[0004] For example, the Chinese invention patent application entitled "Dual-motor distributed drive device and vehicle" with patent number "CN118418686A" discloses a distributed electric drive system with dual motors. The electric drive and electric control housing of the housing assembly of the dual-motor distributed drive device is integrally formed, so that the screw connection structure between the two motors is reduced, thereby reducing the volume of the dual-motor distributed drive device. Moreover, through the integral formation of the electric drive and electric control housing, the oil cooling channel and the water cooling channel of the cooling assembly are arranged inside the electric drive and electric control housing, and can be connected to the first motor installation cavity, the second motor installation cavity, the first reducer installation cavity and the second reducer installation cavity, so that there is no need to arrange the oil cooling channel and the water cooling channel pipeline outside the housing assembly, thereby making the dual-motor distributed drive device more compact and smaller in size. However, there are also some problems with the device. The power of the distributed drive system flows from the motor to the wheel, and one or two mechanical gears are required to perform torque and speed scaling transmission, which has the disadvantages of occupying a large space, heavy mass, complex structure, and large vibration and noise. Summary of the invention

[0005] The purpose of the present invention is to solve the deficiencies of the above-mentioned background technology and to provide a distributed electric drive system, a drive method and a vehicle.

[0006] The technical solution of the present invention is: a distributed electric drive system, comprising a housing, wherein a drive unit is arranged in the housing; the drive unit comprises:

[0007] A stator assembly, the stator assembly comprising a stator core fixed in a housing and a plurality of winding coils located on the inner side of the circumference of the stator core; the plurality of winding coils are equidistantly spaced along the circumferential direction, and a corresponding stator permanent magnet is arranged on the side of each group of winding coils facing the axis;

[0008] A rotor assembly, the rotor assembly comprising a rotor shaft connected to the housing and rotatable about an axis, and a rotor core fixed to the rotor shaft, the rotor core being located inside the stator core, and a plurality of rotor permanent magnets equidistantly spaced along the circumferential direction being arranged on the circumferential outer side of the rotor core;

[0009] A modulation ring is disposed between the stator core and the rotor core, and the three are coaxially arranged. One end of the modulation ring is rotatably connected to the housing around the axis, and the other end is fixedly connected to the wheel. An air gap is provided between the modulation ring and the stator core and the rotor core. A plurality of modulation blocks corresponding to the stator permanent magnet and the rotor permanent magnet are arranged at equal intervals along the circumferential direction on the circumferential outer side of the modulation ring.

[0010] According to a distributed electric drive system provided in the present application, the circumferential outer side surface of the modulation ring is provided with a plurality of trapezoidal grooves arranged at equal intervals along the circumferential direction; the modulation block is a block structure in which multiple layers of silicon steel sheets are stacked and clamped in the trapezoidal grooves.

[0011] According to a distributed electric drive system provided by the present application, the number of pole pairs of the stator permanent magnet poles, the rotor permanent magnet poles and the modulation ring are P1, P3 and P2 respectively, satisfying the following formula:

[0012] P2=P1+P3.

[0013] According to a distributed electric drive system provided by the present application, the number of pole pairs of the rotor permanent magnet poles, the modulation ring, and the corresponding angular velocity satisfy the following formula:

[0014]

[0015] Where: ω2——angular velocity of the modulation ring;

[0016] ω3——angular velocity of the rotor permanent magnet poles;

[0017] P2——the number of pole pairs of the modulation ring;

[0018] P3——Rotor permanent magnet pole.

[0019] According to a distributed electric drive system provided by the present application, a plurality of stator slots evenly spaced along the circumferential direction are provided on the circumferential inner side of the stator core; a group of winding coils and stator permanent magnets are arranged in the stator slots; the winding coils and stator permanent magnets are clamped in the stator slots in order from the outside to the inside.

[0020] According to a distributed electric drive system provided by the present application, two groups of stator permanent magnets are arranged in each stator slot, and the two groups of stator permanent magnets are distributed on both sides of the stator slot at intervals in the circumferential direction.

[0021] According to a distributed electric drive system provided in the present application, the stator core is formed by stacking multiple silicon steel sheets.

[0022] According to a distributed electric drive system provided by the present application, two groups of drive units are integrated in the shell, and the two groups of drive units are coaxially supported and arranged in the shell.

[0023] The present application also provides a driving method for a distributed electric drive system, the driving method is used to drive the above-mentioned distributed electric drive system, and includes:

[0024] The motor controller inputs three-phase current to the winding coil, and the electromagnetic torque generated drives the rotor assembly to rotate. The rotor permanent magnet poles of the rotor assembly form a magnetic field modulation effect with the modulation ring and the stator permanent magnet poles, and transmit the rotation deceleration on the rotor assembly to the modulation ring, and the modulation ring drives the wheel to rotate.

[0025] According to a driving method of a distributed electric drive system provided by the present application, the method of transmitting the rotational speed reduction on the rotor assembly to the modulation ring includes: controlling the torque of the rotor assembly and the torque of the modulation ring to satisfy the following formula:

[0026]

[0027] Where: T2 – torque of the modulation ring;

[0028] T3 – torque of the rotor assembly;

[0029] P2——the number of pole pairs of the modulation ring;

[0030] P3——Rotor permanent magnet pole.

[0031] According to a driving method of a distributed electric drive system provided in the present application, when used as a braking energy recovery system, the wheels drive the modulation ring to rotate, and the speed is increased by the magnetic field modulation effect and transmitted to the rotor assembly, and finally a three-phase current is induced in the winding coil of the stator assembly to recover electric energy.

[0032] The present application also provides a vehicle, which is equipped with the above-mentioned distributed electric drive system.

[0033] The advantages of the present application are as follows: 1. The electric drive system of the present application is a distributed structure. Compared with the traditional distributed electric drive system, the wheels of the present application are directly connected to the modulation ring, and the wheels are driven to rotate through the modulation ring, which eliminates the mechanical gear contact transmission of torque. The entire electric drive system has a simple structure and has the advantages of high efficiency and low noise. It does not need to be configured with a differential or other structures. The torque transmission efficiency is extremely high and the energy loss is extremely small, which has great promotion value.

[0034] 2. The present application drives the wheels through a modulation ring, which has a simple structure and transmits torque electromagnetically through a laminated modulation block, and has the advantages of high torque density and high reliability;

[0035] 3. The present application optimizes the design of the number of pole pairs of the stator permanent magnet poles, the rotor permanent magnet poles and the modulation ring. According to such a design structure, the torque can be transmitted to the maximum extent and with high efficiency. The magnetic field generated by the stator assembly can drive the rotor assembly to rotate to the maximum extent, thereby mobilizing the modulation ring to drive the wheel to rotate. The torque transmission efficiency is extremely high and the transmission loss is extremely small.

[0036] 4. The present application optimizes the relationship between the rotor permanent magnet poles, the number of pole pairs of the modulation ring and the corresponding angular velocity. Through such a design, a reduction ratio can be created between the output end of the electric drive system and the input end of the wheel. The deceleration effect is achieved through the structure of the electric drive system itself, replacing the traditional mechanical reduction ratio. The structure is simple, easy to use and highly integrated.

[0037] 5. The present application opens stator slots on the stator core, and clamps the winding coils and stator permanent magnets into the stator slots, which can form a good magnetic field effect, and the installation structure is very simple, which is convenient for production;

[0038] 6. The present application arranges two groups of stator permanent magnets in the stator slots. The two groups of stator permanent magnets are spaced apart to form a stable magnetic field, which has an excellent driving effect on the rotor assembly and is convenient for installation and assembly.

[0039] 7. The stator core of the present application is simple to prepare, and is formed by laminating multiple silicon steel sheets, and is extremely easy to produce and prepare;

[0040] 8. The present application integrates two sets of drive units in the housing. The entire electric drive system has the advantages of high integration, light weight, and high power density, which improves the feasibility of mounting;

[0041] 9. The present application also provides a driving method. The driving method of the present application is simple, does not require the configuration of a reducer or other structures, has extremely high torque transmission efficiency, works based on the principle of magnetic field modulation, adopts electromagnetic transmission of torque, and has the advantages of high torque density and high reliability.

[0042] 10. The rotor assembly and the modulation ring of the present application operate according to the set requirements, and can transmit the torque to the modulation ring to the greatest extent, thereby determining the rotation of the wheel, and the torque transmission efficiency of the entire driving process is extremely high;

[0043] 11. The present application also relates to a vehicle. The vehicle of the present application is equipped with the above-mentioned electric drive system, which does not require mechanical gears to transmit torque in a contact manner. The entire electric drive system has a simple and compact structure and has the advantages of high torque density and high reliability.

[0044] The electric drive system of the present application has a simple and compact structure, and has the advantages of high efficiency and low noise; it works on the principle of magnetic field modulation, adopts electromagnetic torque transmission, and has the advantages of high torque density and high reliability; the two drive units are coaxially symmetrically arranged in the same integrated shell, which has the advantages of high degree of integration, light weight, and high power density, and improves the feasibility of mounting; the distributed electric drive system based on the magnetic field modulation effect solves the current unavoidable problem of mechanical vibration noise, and has great promotion value. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 : Schematic diagram of the electric drive system structure of the present application;

[0046] Figure 2 : A cross-sectional schematic diagram of the drive unit of the present application;

[0047] Among them: 1—stator core; 2—winding coil; 3—stator permanent magnet; 4—rotor shaft; 5—rotor core; 6—rotor permanent magnet; 7—modulation ring; 8—modulation block; 9—housing; 10—wheel. DETAILED DESCRIPTION

[0048] The embodiments of the present invention are described in detail below, wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0049] In the description of the present invention, it should be understood that the terms "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0050] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0051] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0052] The present application relates to a distributed electric drive system. The electric drive system of the present application is mainly used in new energy vehicles. The electric drive system generates torque when it is energized. The torque acts on the wheels to drive the wheels. Each wheel corresponds to a group of drive units. Each group of drive units drives the corresponding wheels independently, so there is no need to configure differentials and other structures. The electric drive system of the present application is a distributed electric drive system based on the magnetic field modulation effect. It eliminates the mechanical gear contact method for torque transmission. It has a simple and compact structure and has the advantages of high efficiency and low noise. It works based on the principle of magnetic field modulation and adopts electromagnetic torque transmission. It has the advantages of high torque density and high reliability. At the same time, because the entire electric drive system has a simple and compact structure and occupies a small space, it has the advantages of high integration, light weight, and high power density, which improves the feasibility of installation.

[0053] Specifically, Figures 1-2 As shown, a distributed electric drive system of the present application includes a shell 9. The shell 9 of the present application is an integrated shell. The drive unit is installed in the shell 9. The drive unit includes a stator assembly, a rotor assembly and a modulation ring 7. The stator assembly includes a stator core 1 fixed in the shell 9 and a plurality of winding coils 2 located on the inner side of the circumference of the stator core 1; the plurality of winding coils 2 are equidistantly spaced along the circumferential direction, and each group of winding coils 2 is provided with a corresponding stator permanent magnet 3 on the side facing the axis; the stator assembly is fixed in the shell 9, that is, all structures of the stator assembly are stationary relative to the shell 9, and a magnetic field can be generated on the inner side of the stator core 1 by passing current into the winding coil 2, and the magnetic field can generate torque, thereby achieving the effect of driving the wheels. During the driving process, the torque can be controlled by adjusting the size, direction and frequency of the winding coil current.

[0054] The rotor assembly includes a rotor shaft 4 connected to a housing 9 and rotatable around an axis, and a rotor core 5 fixed on the rotor shaft 4. The rotor core 5 is located inside the stator core 1, and a plurality of rotor permanent magnets 6 are arranged on the outer circumference of the rotor core 5 and are equidistantly spaced along the circumferential direction. The rotor assembly is arranged on the inner side of the stator assembly, and the rotor shaft 4 of the rotor assembly is rotatably connected to the housing 9, that is, the rotor assembly can rotate around the axis relative to the housing 9 and the stator assembly. When the winding coil 2 of the stator assembly is passed through a current, a magnetic field is generated, and the magnetic field acts on the rotor assembly. The rotor core 5 of the rotor assembly generates torque under the action of the magnetic field, and the rotor core 5 rotates around the axis. At present, the rotor assembly of the electric drive system is used as a power output unit, that is, the rotor assembly outputs torque to the wheel or the load structure, but the rotor assembly of the present application is not used as a power output unit. The rotor assembly of the present application is idling during use. The rotor assembly of the present application applies a rotational force to the modulation ring 7 during rotation, driving the modulation ring 7 to rotate around the axis.

[0055] The structure of the modulation ring 7 of the present application is as follows Figure 1 and 2 As shown, the modulation ring 7 is located between the stator core 1 and the rotor core 5, and the three are coaxially arranged. One end of the modulation ring 7 is connected to the housing 9 and can rotate around the axis, and the other end is fixedly connected to the wheel 10. There is an air gap between the modulation ring 7 and the stator core 1 and the rotor core 5. A plurality of modulation blocks 8 corresponding to the stator permanent magnet 3 and the rotor permanent magnet 6 are arranged at equal intervals along the circumference of the modulation ring 7. That is, the modulation ring 7 of the present application is a power output unit, the modulation ring 7 is connected to the wheel 10, and the torque applied to the modulation ring 7 by the stator assembly and the rotor assembly is finally transmitted to the wheel 10 through the modulation ring 7, driving the wheel 10 to rotate.

[0056] The present application is provided with a stator permanent magnet 3 and a rotor permanent magnet 6, which correspond to the modulation ring 7. The harmonic-dominated magnetic field generated by the rotating rotor permanent magnet 6 is modulated by the stator permanent magnet 3, and a harmonic-dominated magnetic field is generated in the air gap between the modulation ring 7 and the stator permanent magnet 3. The harmonic component of the magnetic field matches the harmonic component generated by the magnetic field of the stator permanent magnet 3, thereby interacting to transmit torque.

[0057] During use, the motor controller inputs three-phase current to the winding coil 2, and the electromagnetic torque generated by it drives the rotor assembly to rotate, that is, the magnetic field generated by the winding coil 2 drives the rotor core 5 to rotate around the rotor shaft 4, and the harmonic-dominated magnetic field generated by the rotating rotor permanent magnet 6 is modulated by the stator permanent magnet 3, and a harmonic-dominated magnetic field is generated in the air gap between the modulation ring 7 and the stator permanent magnet 3. The harmonic component of the magnetic field matches the harmonic component generated by the magnetic field of the stator permanent magnet 3, thereby driving the modulation ring 7 to rotate around the axis. The magnetic poles of the rotor permanent magnet 6 of the rotor assembly form a magnetic field modulation effect with the magnetic poles of the modulation ring 7 and the stator permanent magnet 3, and the rotation deceleration on the rotor assembly is transmitted to the modulation ring 7, and the modulation ring 7 drives the wheel 10 to rotate.

[0058] The power transmission of the drive unit of the present application is from the stator assembly to the rotor assembly to the modulation ring to the wheel 10. There is no need for mechanical gears to transmit torque. The torque transmission efficiency is extremely high and the transmission loss is extremely small. Moreover, since the mechanical gears are eliminated for torque transmission, no noise is generated, the torque density is greatly improved, and it has good reliability. The entire electric drive system is greatly reduced in weight, making it convenient to be installed on new energy vehicles.

[0059] Embodiment 1: This embodiment optimizes the structure of the stator core 1. Specifically, Figure 2 As shown, the stator core 1 of this embodiment is an annular structure fixed in the housing 9. The stator core 1 is the outermost part of the entire drive unit. The stator core 1 is a structure formed by stacking silicon steel sheets. Each silicon steel sheet is an annular sheet structure. A plurality of U-shaped grooves are evenly arranged on the inner side of the circumference of the silicon steel sheet. The silicon steel sheets are aligned with each other and then stacked. The U-shaped grooves are aligned with each other to form the stator slots of the stator core 1. Then, the winding coils 2 and the stator permanent magnets 3 are installed in the stator slots to form the required stator core 1.

[0060] The inner side of the circumference of the stator core 1 is provided with a plurality of stator slots evenly spaced in the circumferential direction, and a group of winding coils 2 and stator permanent magnets 3 are arranged in the stator slots. The winding coils 2 and stator permanent magnets 3 are clamped in the stator slots in the order from outside to inside. Figure 2 As shown, two groups of stator permanent magnets 3 are arranged in each stator slot, and the two groups of stator permanent magnets 3 are distributed at intervals on both sides of the stator slot in the circumferential direction.

[0061] The stator core 1 is made of stacked silicon steel sheets, which can reduce the production difficulty of the entire stator core 1 and greatly improve the manufacturing efficiency of the stator core 1. It is only necessary to prepare multiple silicon steel sheets according to the set requirements, and finally assemble them together and stack them to form the required stator core 1. The overall manufacturing is very simple and the production cost is greatly reduced.

[0062] The winding coils 2 and stator permanent magnets 3 on the stator core 1 of this embodiment are arranged in pairs, and the stator permanent magnets 3 in the same stator slot are located on the inner side of the winding coils 2, which is convenient for assembling the winding coils 2 and the stator permanent magnets 3 on the one hand, and convenient for modulating the magnetic field by the stator permanent magnets 3 on the other hand.

[0063] Embodiment 2: This embodiment optimizes the structure of the rotor core 5. Figure 2 As shown, the rotor core 5 of this embodiment is fixed on the rotor shaft 4, and both ends of the rotor shaft 4 are connected to the housing 9 through bearing structures respectively. The rotation of the rotor core 5 is idling, that is, it is not used as a power output unit.

[0064] The rotor core 5 is an annular structure coaxially arranged with the stator core 1. The rotor permanent magnet 6 is fixedly mounted on the outer circumference of the rotor core 5 by surface mounting. Figure 2 shown.

[0065] Embodiment 3: This embodiment optimizes the structure of the modulation ring 7. Specifically, Figure 2 As shown, the modulation ring 7 of this embodiment is an annular structure arranged coaxially with the rotor core 5 and the stator core 1, and the circumferential outer side surface of the modulation ring 7 is provided with a plurality of trapezoidal grooves arranged at equal intervals along the circumferential direction, and the modulation block 8 is a block structure in which multiple layers of silicon steel sheets are stacked and clamped in the trapezoidal grooves.

[0066] The modulation ring 7 includes a cup-shaped connecting bridge and a modulation block 8. The outer circumferential surface of the cup-shaped connecting bridge is evenly provided with a plurality of trapezoidal grooves. The cup bottom of the cup-shaped connecting bridge is assembled on the rotor shaft through a bearing (the cup bottom of the cup-shaped connecting bridge can rotate on the rotor shaft), and the cup mouth end face of the cup-shaped connecting bridge is rigidly connected to the wheel 10.

[0067] The modulation block 8 is arranged in a paired relationship with the above-mentioned stator permanent magnet 3 and rotor permanent magnet 6 , that is, it is ensured that the modulated magnetic field can drive the modulation block 8 to rotate, thereby transmitting torque to the wheel 10 .

[0068] Embodiment 4: This embodiment optimizes the arrangement of the drive unit in the housing 9. Specifically, Figure 1 As shown, two groups of drive units are integrated in the housing 9 , and the two groups of drive units are coaxially supported and arranged in the housing 9 .

[0069] The two groups of drive units are independent of each other and have no connection relationship with each other. The rotor shafts 4 of the two groups of drive units are arranged symmetrically with respect to the coaxial axis and are not connected with each other.

[0070] The operation of the two sets of drive units will not affect or interfere with each other. The two drive units are arranged coaxially and symmetrically in the same integrated shell, which has the advantages of high integration, light weight, and high power density, and improves the feasibility of mounting.

[0071] Embodiment 5: This embodiment optimizes the arrangement structure of the above-mentioned stator permanent magnet 3, rotor permanent magnet 6 and modulation ring 7. Specifically, the number of pole pairs of the stator permanent magnet 3, the rotor permanent magnet 6 and the modulation ring 7 are P1, P3 and P2, respectively, satisfying the following formula:

[0072] P2=P1+P3.

[0073] The rotor assembly and the stator assembly form a driving motor. When the winding coil 2 is supplied with a current of frequency f, the electromagnetic torque generated drives the rotor assembly (rotor core 5) to rotate. The angular velocity of the rotation of the rotor core 5 is:

[0074]

[0075] Where: ω3——angular velocity of the rotor permanent magnet 6 poles;

[0076] P3——Rotor permanent magnet 6 poles;

[0077] f——frequency of current flowing through winding coil 2.

[0078] The magnetic field dominated by the P3 subharmonic generated by the rotating rotor permanent magnet 6 is modulated by the modulation ring 7 of the modulation block 8 by P2, and a magnetic field dominated by |P2-P3| subharmonic is generated in the circumferential air gap between the modulation ring 7 and the stator permanent magnet 3. The harmonic component of this magnetic field matches the harmonic component generated by P1 on the stator permanent magnet 3, thereby interacting to transmit torque.

[0079] To ensure the maximum torque transmission, the number of pole pairs of the stator permanent magnet 3, the rotor permanent magnet 6, the modulation ring 7 and the corresponding angular velocity satisfy the following formula:

[0080]

[0081] Where: ω1——angular velocity of stator core 1;

[0082] ω2——angular velocity of modulation ring 7;

[0083] ω3——angular velocity of the rotor permanent magnet 6 poles;

[0084] P1——the number of pole pairs of stator permanent magnet 3;

[0085] P2——the number of pole pairs of modulation ring 7;

[0086] P3——Rotor permanent magnet 6 poles.

[0087] Since the stator permanent magnet 3 is fixed on the stator core 1 in this embodiment, and the stator core 1 is fixed on the housing 9, that is, the stator permanent magnet 3 is actually stationary, the angular velocity of the stator permanent magnet 3 is 0, and therefore the number of pole pairs of the rotor permanent magnet 6 and the modulation ring 7 and the corresponding angular velocity satisfy the following formula:

[0088]

[0089] Where: ω2——angular velocity of modulation ring 7;

[0090] ω3——angular velocity of the rotor permanent magnet 6 poles;

[0091] P2——the number of pole pairs of modulation ring 7;

[0092] P3——Rotor permanent magnet 6 poles.

[0093] The rotor assembly is the key structure of this embodiment. The rotor core 5 of the rotor assembly is subjected to the load applied by the stator assembly and the magnetic field modulation load from the modulation ring 7. The two loads are equal in magnitude and opposite in direction, thereby achieving stable idling of the rotor core 5, that is, the torque T3 of the rotor core 5 and the torque T2 of the modulation ring 7 satisfy the following relationship:

[0094]

[0095] Where: T2 – torque of modulation ring 7;

[0096] T3 – torque of the rotor assembly;

[0097] P2——the number of pole pairs of modulation ring 7;

[0098] P3——Rotor permanent magnet 6 poles.

[0099] Based on the above formula, there is a reduction ratio P2 / P3 between the wheel 10 as the output end of the driving unit and the input end, which can replace the traditional mechanical reduction ratio.

[0100] In addition, the present application also provides a vehicle, which is equipped with the above-mentioned distributed electric drive system.

[0101] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. The present invention may be subject to various changes and improvements without departing from the spirit and scope of the present invention. These changes and improvements fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A distributed electric drive system, comprising a housing (9), Features: A driving unit is arranged in the housing (9); the driving unit comprises: A stator assembly, the stator assembly comprising a stator core (1) fixed in a housing (9) and a plurality of winding coils (2) located on the inner side of the circumference of the stator core (1); the plurality of winding coils (2) are distributed at equal intervals along the circumference, and each group of winding coils (2) is provided with a corresponding stator permanent magnet (3) on the side facing the axis; A rotor assembly, the rotor assembly comprising a rotor shaft (4) connected to a housing (9) and rotatable about an axis, and a rotor core (5) fixed to the rotor shaft (4), the rotor core (5) being located inside a stator core (1), and a plurality of rotor permanent magnets (6) being arranged on the circumferential outer side of the rotor core (5) and distributed at equal intervals in a circumferential direction; A modulation ring (7) is disposed between a stator core (1) and a rotor core (5) so that the three are coaxially arranged. One end of the modulation ring (7) is connected to a housing (9) so as to be rotatable about an axis, and the other end is fixedly connected to a wheel. An air gap is provided between the modulation ring (7) and the stator core (1) and the rotor core (5). A plurality of modulation blocks (8) corresponding to the stator permanent magnets (3) and the rotor permanent magnets (6) are arranged at equal intervals along the circumferential direction on the outer circumference of the modulation ring (7).

2. A distributed electric drive system as claimed in claim 1, Features: The circumferential outer side surface of the modulation ring (7) is provided with a plurality of trapezoidal grooves arranged at equal intervals in the circumferential direction; the modulation block (8) is a block structure in which multiple layers of silicon steel sheets are stacked and clamped in the trapezoidal grooves.

3. A distributed electric drive system as claimed in claim 1, Features: The number of pole pairs of the stator permanent magnet (3), the rotor permanent magnet (6) and the modulation ring (7) are P and 1 , P 3 and P 2 , satisfying the following formula: P 2 =P 1 +P 3 。 4. A distributed electric drive system as claimed in claim 3, Features: The number of magnetic poles of the rotor permanent magnet (6), the number of pole pairs of the modulation ring (7) and the corresponding angular velocity satisfy the following formula: Where: 2 - angular velocity of the modulation ring (7); ω 3 - the angular velocity of the magnetic poles of the rotor permanent magnets (6); P 2 - the number of pole pairs of the modulation ring (7); P 3 ——Magnetic poles of the rotor permanent magnet (6).

5. A distributed electric drive system as claimed in claim 1, Features: A plurality of stator slots are arranged evenly spaced along the circumferential direction on the inner side of the circumference of the stator core (1); a group of winding coils (2) and stator permanent magnets (3) are arranged in the stator slots; the winding coils (2) and stator permanent magnets (3) are clamped in the stator slots in a sequence from outside to inside.

6. A distributed electric drive system as claimed in claim 5, Features: Two groups of stator permanent magnets (3) are arranged in each stator slot, and the two groups of stator permanent magnets (3) are distributed at intervals along the circumferential direction on both sides of the stator slot.

7. A distributed electric drive system as claimed in claim 1, Features: Two groups of drive units are integrated in the housing (9), and the two groups of drive units are coaxially arranged in opposition to each other in the housing (9).

8. A driving method for a distributed electric drive system, Features: The driving method is used to drive a distributed electric drive system as claimed in any one of claims 1 to 7, comprising: When used as an electric drive system, the motor controller inputs three-phase current to the winding coil (2), and the electromagnetic torque generated thereby drives the rotor assembly to rotate. The magnetic poles of the rotor permanent magnet (6) of the rotor assembly form a magnetic field modulation effect with the modulation ring (7) and the magnetic poles of the stator permanent magnet (3), and the rotation speed of the rotor assembly is transmitted to the modulation ring (7), and the modulation ring (7) drives the wheel to rotate.

9. A driving method for a distributed electric drive system as claimed in claim 8, Features: The method for transmitting the rotation speed reduction of the rotor assembly to the modulation ring (7) comprises: controlling the torque of the rotor assembly and the torque of the modulation ring (7) so that they satisfy the following formula: Where: T 2 - the torque of the modulation ring (7); T 3 - torque of the rotor assembly; P 2 - the number of pole pairs of the modulation ring (7); P 3 ——Magnetic poles of the rotor permanent magnet (6).

10. A vehicle, Features: The vehicle is equipped with a distributed electric drive system as described in any one of claims 1 to 6.

Images