Dual rotor motor, electric drive system and vehicle

Abstract

The application provides a double-rotor motor, an electric drive system and a vehicle, and relates to the technical field of automobile parts. The double-rotor motor comprises a stator unit, a permanent magnet rotor and an outer rotor. The stator unit has a ring structure, and comprises a first stator and a second stator. The permanent magnet rotor is coaxially arranged on the inner side of the stator unit, and the permanent magnet rotor and the first stator form an inner rotor permanent magnet synchronous motor. The outer rotor is coaxially arranged on the outer side of the stator unit, and the outer rotor and the second stator form an outer rotor motor. The double-rotor motor has a first working mode in which only the inner rotor permanent magnet synchronous motor works, and a second working mode in which the inner rotor permanent magnet synchronous motor and the outer rotor motor both work. The application can meet the requirements of the electric drive system on the high torque output and the wide and efficient power interval of the motor, and can also meet the needs of compactness and low-cost layout.

Description

Technical Field

[0001] This invention relates to the field of automotive parts technology, and more specifically, to a dual-rotor motor, an electric drive system, and a vehicle. Background Technology

[0002] With technological advancements, vehicles are placing increasingly stringent demands on the overall performance of their electric drive systems. Specifically, electric drive systems must simultaneously meet the dual requirements of high-efficiency operation under normal working conditions and high torque output under transient conditions such as low-speed climbing and rapid acceleration.

[0003] To meet this demand, some technologies employ high-power motors, which ensure instantaneous power reserves. However, this causes the motor's operating point to deviate significantly from its high-efficiency power range during low-to-medium load cruising conditions, which constitute a large portion of its lifecycle, resulting in lower average system efficiency. Other technologies utilize multi-motor solutions, covering different operating conditions through the coordination or switching of two independent motors. However, this setup typically involves parallel or coaxial side-by-side arrangement of the two motors, which is detrimental to vehicle layout and lightweight design, and also increases costs. Summary of the Invention

[0004] The present invention aims to address, to some extent, the problem in related technologies of how to balance the requirements of electric drive systems for high torque output limits and wide high-efficiency power ranges of motors, while also taking into account the need for compact and low-cost layout.

[0005] To at least partially address at least one aspect of the aforementioned problems, in a first aspect, the present invention provides a dual-rotor motor, the dual-rotor motor comprising a stator unit, a permanent magnet rotor, and an outer rotor; the stator unit has a ring-shaped structure, the stator unit comprising a first stator and a second stator, the permanent magnet rotor being coaxially disposed on the inner side of the stator unit, the permanent magnet rotor and the first stator constituting an inner rotor permanent magnet synchronous motor; the outer rotor being coaxially disposed on the outer side of the stator unit, the outer rotor and the second stator constituting an outer rotor motor; the dual-rotor motor has a first operating mode in which only the inner rotor permanent magnet synchronous motor operates and a second operating mode in which both the inner rotor permanent magnet synchronous motor and the outer rotor motor operate.

[0006] Optionally, the peak torque of the inner rotor permanent magnet synchronous motor is less than the peak torque of the outer rotor motor; And / or, the peak power of the inner rotor permanent magnet synchronous motor is less than the peak power of the outer rotor motor.

[0007] Optionally, the permanent magnet rotor includes an inner rotor core and multiple sets of permanent magnets embedded in the inner rotor core. The multiple sets of permanent magnets are evenly distributed along the circumference of the inner rotor core, and the magnetization directions of adjacent sets of permanent magnets are opposite, so that the outer periphery of the permanent magnet rotor forms alternating N poles and S poles.

[0008] Optionally, each group of permanent magnets includes multiple magnets, and the magnets of the same group of permanent magnets are arranged on the cross-section of the inner rotor core to form at least one of the two open structures: an open structure and a straight structure. The number of opening structures formed by the magnets of the same group of permanent magnets is one or more, and the opening direction of each opening structure is away from the center of the inner rotor core. The multiple opening structures are distributed at intervals along the radial direction of the inner rotor core. When the magnets of the same group of permanent magnets are arranged to form the opening structure and the straight structure, the straight structure is located on the opening side of the opening structure.

[0009] Optionally, the stator unit includes an annular stator core, the first stator and the second stator share the annular stator core, and each includes a first winding and a second winding; the annular stator core is provided with a first winding slot and a second winding slot at its radial inner end and radial outer end, respectively, the first winding is installed in the first winding slot, and the second winding is installed in the second winding slot; And / or, the outer rotor is an induction rotor, and the outer rotor motor is an asynchronous motor composed of the induction rotor and the first stator.

[0010] In a second aspect, the present invention provides an electric drive system comprising a dual-rotor motor as described in the first aspect above, wherein the inner rotor permanent magnet synchronous motor of the dual-rotor motor is used for drive connection with at least one of the front axle and the rear axle of a vehicle, and the outer rotor motor of the dual-rotor motor is used for drive connection with at least one of the front axle and the rear axle.

[0011] Optionally, the dual-rotor motor is arranged in either the front compartment or the rear compartment of the vehicle; When the dual-rotor motor is arranged in the front compartment, the outer rotor motor is driven to the front axle differential of the front axle, and the inner rotor permanent magnet synchronous motor is driven to the rear axle differential of the rear axle or the front axle differential. When the dual-rotor motor is arranged in the rear compartment, the inner rotor permanent magnet synchronous motor is driven and connected to the rear axle differential, and the outer rotor motor is driven and connected to the rear axle differential or the front axle differential.

[0012] Optionally, when the dual-rotor motor is arranged in the front compartment, the axial direction of the dual-rotor motor is arranged along the transverse direction of the vehicle. The electric drive system includes a first transmission assembly. The inner rotor permanent magnet synchronous motor is driven to the rear axle differential through the first transmission assembly. The first transmission assembly includes a first drive shaft arranged longitudinally and a first bevel gear and a second bevel gear disposed at both ends of the first drive shaft. The output end of the inner rotor permanent magnet synchronous motor is provided with a third bevel gear that meshes with the first bevel gear. The input end of the rear axle differential is provided with a fourth bevel gear that meshes with the second bevel gear. And / or, when the dual-rotor motor is arranged in the rear compartment, the axial direction of the dual-rotor motor is arranged laterally along the vehicle, the electric drive system includes a second transmission assembly, the outer rotor motor is driven connected to the front axle differential through the second transmission assembly, the second transmission assembly includes a second drive shaft arranged longitudinally and a fifth bevel gear and a sixth bevel gear disposed at both ends of the second drive shaft, the output end of the outer rotor motor is provided with a seventh bevel gear meshing with the fifth bevel gear, and the input end of the front axle differential is provided with an eighth bevel gear meshing with the sixth bevel gear.

[0013] Optionally, the axial direction of the dual-rotor motor is arranged along the transverse direction of the vehicle, and the electric drive system further includes a parallel shaft transmission assembly, which includes a third transmission shaft, a fourth transmission shaft, and a first reduction gear pair disposed between the third transmission shaft and the fourth transmission shaft, wherein the third transmission shaft is coaxially arranged with the dual-rotor motor; When the dual-rotor motor is arranged in the front compartment, at least one of the inner rotor permanent magnet synchronous motor and the outer rotor motor, the output end of the outer rotor motor is connected to the third drive shaft, and a second reduction gear pair is provided between the fourth drive shaft and the input end of the front axle differential; When the dual-rotor motor is arranged in the rear compartment, at least one of the inner rotor permanent magnet synchronous motor and the outer rotor motor, the output end of the inner rotor permanent magnet synchronous motor is connected to the third drive shaft, and a third reduction gear pair is provided between the fourth drive shaft and the input end of the front axle differential.

[0014] Thirdly, the present invention provides a vehicle including the electric drive system described in the second aspect above.

[0015] Compared to existing technologies, in the dual-rotor motor, electric drive system, and vehicle of this invention, the annular stator unit includes a first stator and a second stator. A permanent magnet rotor is coaxially disposed inside the stator unit and forms an inner rotor permanent magnet synchronous motor with the first stator. An outer rotor is coaxially disposed outside the stator unit and forms an outer rotor motor with the second stator, thus achieving a compact layout for the dual motors. Simultaneously, under normal low-load conditions, such as low-to-medium load cruising and low-acceleration acceleration in vehicles, the dual-rotor motor can adopt a first operating mode where only the inner rotor permanent magnet synchronous motor operates. This utilizes the inner rotor permanent magnet synchronous motor to meet the corresponding power demands, which helps increase the proportion of the inner rotor permanent magnet synchronous motor operating within its high-efficiency power range. Under high-load conditions, such as rapid acceleration in vehicles, the dual-rotor motor can adopt a second operating mode where both the inner rotor permanent magnet synchronous motor and the outer rotor motor operate. The two motors can collaboratively output high torque to meet higher power output demands, thus allowing the dual-rotor motor to balance the requirements of high torque output limits and a wide high-efficiency power range. In addition, the external rotor motor can be a non-permanent magnet motor, such as an induction motor or an electrically excited synchronous motor. The external rotor of the external rotor motor is on the outside, and the lever arm is longer, which can output a larger torque. This is beneficial to ensure the output capability of the external rotor motor's ultimate torque, thereby meeting the working performance of the dual rotor motor under extreme conditions. It is also beneficial to reduce the design power and torque requirements of the internal rotor permanent magnet synchronous motor, and ensure the working efficiency of the internal rotor permanent magnet synchronous motor under medium and low load conditions.

[0016] Overall, this invention can take into account both the requirements of electric drive systems for high torque output limits and a wide range of high-efficiency power, as well as the need for compact and low-cost layout. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of the dual rotor motor after removing the outer casing and other structures in an embodiment of the present invention; Figure 2 for Figure 1 Schematic diagram of the structure at section AA; Figure 3 This is a schematic diagram of the stator unit in an embodiment of the present invention; Figure 4 This is a schematic diagram of the permanent magnet rotor structure when the I-shaped structure in the same permanent magnet is located on one side of the opening of the opening structure in an embodiment of the present invention; Figure 5 This is a schematic diagram of the permanent magnet rotor structure when the opening structure is V-shaped and the number of opening structures in the same permanent magnet is two, according to an embodiment of the present invention. Figure 6 This is a schematic diagram of the permanent magnet rotor structure when the opening structure is V-shaped and the number of opening structures in the same permanent magnet is three, according to an embodiment of the present invention. Figure 7 This is a schematic diagram of the permanent magnet rotor structure when the opening structure is C-shaped and the number of opening structures in the same permanent magnet is three, according to an embodiment of the present invention. Figure 8 This is a schematic diagram of the permanent magnet rotor when the opening structure is U-shaped in an embodiment of the present invention; Figure 9 This is a schematic diagram of the permanent magnet rotor structure when the opening structure is U-shaped and the number of opening structures in the same permanent magnet is two, according to an embodiment of the present invention. Figure 10 This is a schematic diagram of the electric drive system in an embodiment of the present invention, where the dual rotor motor is located in the front compartment, the outer rotor motor is driven and connected to the front axle differential, and the inner rotor permanent magnet synchronous motor is driven and connected to the rear axle differential. Figure 11 This is a schematic diagram of the electric drive system in an embodiment of the present invention, where the dual rotor motor is located in the front compartment, the outer rotor motor is driven and connected to the front axle differential, and the inner rotor permanent magnet synchronous motor is driven and connected to the front axle differential. Figure 12 This is a schematic diagram of the electric drive system in an embodiment of the present invention, in which the dual rotor motor is located in the rear compartment, the outer rotor motor is driven and connected to the rear axle differential, and the inner rotor permanent magnet synchronous motor is driven and connected to the front axle differential. Figure 13 This is a schematic diagram of the electric drive system in an embodiment of the present invention, where the dual rotor motor is located in the rear compartment, the outer rotor motor is driven and connected to the rear axle differential, and the inner rotor permanent magnet synchronous motor is driven and connected to the rear axle differential.

[0018] Explanation of reference numerals in the attached figures: 1-Dual rotor motor; 1A-Inner rotor permanent magnet synchronous motor; 1B-Outer rotor motor; 11-Stator unit; 11A-First stator; 11B-Second stator; 111-Annular stator core; 112-First winding; 113-Second winding; 1111-First winding slot; 1112-Second winding slot; 12-Permanent magnet rotor; 121-Inner rotor core; 122-Permanent magnet; 1221-Magnet; 122A-Open structure; 122B-Line structure; 13-Outer rotor; 131-Outer rotor core; 132-Guide bar; 2-Front axle; 21-Front axle differential; 211-Eighth cone Gear; 22-Left front half-shaft; 23-Right front half-shaft; 3-Rear axle; 31-Rear axle differential; 311-Fourth bevel gear; 32-Left rear half-shaft; 33-Right rear half-shaft; 4-First transmission assembly; 41-First drive shaft; 42-First bevel gear; 43-Second bevel gear; 5-Second transmission assembly; 51-Second drive shaft; 52-Fifth bevel gear; 53-Sixth bevel gear; 6-Parallel shaft transmission assembly; 61-Third drive shaft; 62-Fourth drive shaft; 63-First reduction gear pair; 7-Third bevel gear; 8-Seventh bevel gear; 91-Second reduction gear pair; 92-Third reduction gear pair. Detailed Implementation

[0019] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0020] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0021] In the description of this specification, the references to terms such as "embodiment," "one embodiment," "some implementations," "exemplary," and "one implementation," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or implementation is included in at least one embodiment or implementation of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or implementation. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or implementations.

[0022] The terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature.

[0023] With technological advancements, vehicles are placing increasingly stringent demands on the overall performance of their electric drive systems. Specifically, electric drive systems must simultaneously meet the dual requirements of high-efficiency operation under normal working conditions and high torque output under transient conditions such as low-speed climbing and rapid acceleration.

[0024] To meet this demand, some technologies employ high-power motors, which ensure instantaneous power reserves. However, this causes the motor's operating point to deviate significantly from its high-efficiency power range during low-to-medium load cruising conditions, which constitute a large portion of its lifecycle, resulting in lower average system efficiency. Other technologies utilize multi-motor solutions, covering different operating conditions through the coordination or switching of two independent motors. However, this setup typically involves parallel or coaxial side-by-side arrangement of the two motors, which is detrimental to vehicle layout and lightweight design, and also increases costs.

[0025] In particular, some technologies, although equipped with dual motors, still design the main drive motor with higher power to ensure dynamism. This results in low power utilization of the main drive motor under most medium and low load conditions. The auxiliary motor only intervenes briefly under a few extreme conditions, with a very low overall utilization rate. This configuration does not effectively leverage the advantages of the dual-motor solution. Instead, it increases the cost and space burden due to the added complexity of the dual system.

[0026] like Figure 1 , 2 As shown, an embodiment of the present invention provides a dual-rotor motor 1, which includes a stator unit 11, a permanent magnet rotor 12, and an outer rotor 13. The stator unit 11 has a ring-shaped structure and includes a first stator 11A and a second stator 11B. The permanent magnet rotor 12 is coaxially disposed on the inner side of the stator unit 11, and the permanent magnet rotor 12 and the first stator 11A constitute an inner rotor permanent magnet synchronous motor 1A. The outer rotor 13 is coaxially disposed on the outer side of the stator unit 11, and the outer rotor 13 and the second stator 11B constitute an outer rotor motor 1B.

[0027] The dual-rotor motor 1 has a first operating mode in which only the inner rotor permanent magnet synchronous motor 1A operates, and a second operating mode in which both the inner rotor permanent magnet synchronous motor 1A and the outer rotor motor 1B operate.

[0028] The dual-rotor motor 1 is used in the electric drive system of a vehicle to drive one or more axles, thereby enabling the vehicle to move. However, it should be understood that it can also be used in other similar applications without departing from the design concept of this invention.

[0029] Specifically, the permanent magnet rotor 12, stator unit 11, and outer rotor 13 are arranged radially from the inside to the outside in the dual-rotor motor 1. The permanent magnet rotor 12 is located on the inner side (i.e., the inner side of the ring) of the stator unit 11 and interacts electromagnetically with the first stator 11A to form an inner rotor permanent magnet synchronous motor 1A. The outer rotor 13 is located on the outer side (i.e., the outer side of the ring) of the stator unit 11 and interacts electromagnetically with the second stator 11B to form an outer rotor motor 1B.

[0030] In the first operating mode, only the inner rotor permanent magnet synchronous motor 1A is powered on in the inner rotor permanent magnet synchronous motor 1A and the outer rotor motor 1B. For example, only the first winding 112 of the first winding 112 and the second winding 113 described later is powered on, thereby allowing the inner rotor permanent magnet synchronous motor 1A in the dual rotor motor 1 to operate independently. Under relatively low vehicle load conditions, such as low-to-medium load cruising conditions (e.g., cruising speed less than 120 km / h) and low acceleration conditions, the inner rotor permanent magnet synchronous motor 1A can meet the corresponding power requirements, operating within its high-efficiency power range.

[0031] In the second working mode, the inner rotor permanent magnet synchronous motor 1A and the outer rotor motor 1B are powered separately, for example, the first winding 112 and the second winding 113 are powered separately, so that the inner rotor permanent magnet synchronous motor 1A and the outer rotor motor 1B in the dual rotor motor 1 work simultaneously. The two motors output torque at the same time, which can provide greater driving force and can be used for high load conditions of vehicles, such as rapid acceleration, climbing, and getting out of trouble.

[0032] Of course, although the above only describes that the dual rotor motor 1 has a first operating mode and a second operating mode, it should be understood that it can also have a third operating mode. In the third operating mode, only the outer rotor motor 1B of the dual rotor motor 1 works, that is, only the outer rotor motor 1B of the inner rotor permanent magnet synchronous motor 1A and the outer rotor motor 1B is powered, for example, only the second winding 113 of the first winding 112 and the second winding 113 described later is powered, so that the outer rotor motor 1B of the dual rotor motor 1 works alone.

[0033] Thus, the dual-rotor motor 1 of the present invention has a stator unit 11 with a ring structure, which is provided with a first stator 11A and a second stator 11B. The permanent magnet rotor 12 is coaxially arranged inside the stator unit 11 and forms an inner rotor permanent magnet synchronous motor 1A with the first stator 11A. The outer rotor 13 is coaxially arranged outside the stator unit 11 and forms an outer rotor motor 1B with the second stator 11B, thereby achieving the compact layout requirement of the dual motors. Meanwhile, under normal low-load conditions, such as low-to-medium load cruising and low-acceleration acceleration conditions in vehicles, the dual-rotor motor 1 can adopt a first operating mode in which only the inner rotor permanent magnet synchronous motor 1A operates. The inner rotor permanent magnet synchronous motor 1A is used to meet the corresponding power requirements, which helps to increase the proportion of the inner rotor permanent magnet synchronous motor 1A in the high-efficiency power range. Under high-load conditions, such as rapid acceleration conditions in vehicles, the dual-rotor motor 1 can adopt a second operating mode in which both the inner rotor permanent magnet synchronous motor 1A and the outer rotor motor 1B operate. The two motors can work together to output high torque to meet higher power output requirements. Thus, the dual-rotor motor 1 can meet the requirements of both high torque output upper limit and wide high-efficiency power range. Furthermore, with this configuration, the outer rotor motor 1B can be a non-permanent magnet motor, such as an induction motor or an electrically excited synchronous motor. The outer rotor 13 of the outer rotor motor 1B is on the outside, with a longer lever arm, which can output a larger torque. This helps to ensure the ultimate torque output capability of the outer rotor motor 1B, thereby meeting the working performance of the dual rotor motor under extreme conditions. It also helps to reduce the design power and torque requirements of the inner rotor permanent magnet synchronous motor 1A, ensuring the working efficiency of the inner rotor permanent magnet synchronous motor 1A under medium and low load conditions.

[0034] Overall, this invention can take into account both the requirements of electric drive systems for high torque output limits and a wide range of high-efficiency power, as well as the need for compact and low-cost layout.

[0035] Optionally, the peak torque of the inner rotor permanent magnet synchronous motor 1A is less than the peak torque of the outer rotor motor 1B.

[0036] In this way, the outer rotor motor 1B has a larger peak torque reserve. Under the premise that the design value of the maximum combined output torque in the second working mode is the same for the ultimate total torque of the dual rotor motors, the inner rotor permanent magnet synchronous motor 1A is designed to have a smaller peak torque. This helps to lower the upper limit of the application of the first working mode, so that the critical torque for switching between the first and second working modes is lowered. This improves the efficiency of energy utilization and system economy in this mode. When the inner rotor permanent magnet synchronous motor 1A is running in the first working mode under medium and low load conditions, the operating point of the inner rotor permanent magnet synchronous motor 1A can stably fall within the optimal operating range of high efficiency and low loss.

[0037] Optionally, the peak power of the inner rotor permanent magnet synchronous motor 1A is less than the peak power of the outer rotor motor 1B.

[0038] Correspondingly, the outer rotor motor 1B is endowed with a stronger peak power output capability. Given a fixed total power demand for both rotor motors, the peak power of the inner rotor permanent magnet synchronous motor 1A is set to be the smaller of the two, directly limiting its maximum power output in the first operating mode. The threshold for switching operating modes based on power demand is also lowered accordingly. Therefore, when the vehicle is under low to medium load conditions, such as medium-to-high speed cruising, the ratio of the required power to the peak power of the inner rotor permanent magnet synchronous motor 1A can be increased. This allows the operating point of the inner rotor permanent magnet synchronous motor 1A to stably fall within the optimal operating range of high efficiency and low loss, significantly improving energy utilization efficiency and system economy in this mode.

[0039] Taking a pure electric vehicle with a curb weight of 1.6t as an example, the inner rotor permanent magnet synchronous motor 1A has a power of 160kW and a peak torque of 320N, while the outer rotor motor 1B has a peak power of 250kW and a peak torque of 360N. The inner rotor permanent magnet synchronous motor 1A alone can achieve an acceleration time of over 6.5s from 0-100km / h, while the combined use of the inner rotor permanent magnet synchronous motor 1A and the outer rotor motor 1B can achieve an acceleration time of under 4s from 0-100km / h.

[0040] like Figure 2 , 4 As shown, the permanent magnet rotor 12 includes an inner rotor core 121 and multiple sets of permanent magnets 122 embedded in the inner rotor core 121. The multiple sets of permanent magnets 122 are evenly distributed along the circumference of the inner rotor core 121, and the magnetization directions of adjacent sets of permanent magnets 122 are opposite, so that alternating N poles and S poles are formed on the outer periphery of the permanent magnet rotor 12. Each set of permanent magnets 122 includes one or more magnets 1221, which are respectively embedded in slots provided in the permanent magnet rotor 12.

[0041] like Figure 2 and Figures 4 to 9 As shown, optionally, each group of permanent magnets 122 includes multiple magnets 1221, and the magnets 1221 of the same group of permanent magnets 122 are arranged on the cross section of the inner rotor core 121 to form at least one of the two structures: an open structure 122A and a straight structure 122B.

[0042] The number of opening structures 122A formed by the magnets 1221 of the same group of permanent magnets 122 is one or more, and the opening direction of each opening structure 122A is away from the center of the inner rotor core 121. The multiple opening structures 122A are distributed at intervals along the radial direction of the inner rotor core 121.

[0043] like Figure 4 As shown, when the magnets 1221 of the same group of permanent magnets 122 are arranged to form an open structure 122A and a straight structure 122B, the straight structure 122B is located on the open side of the open structure 122A.

[0044] Specifically, the magnetic focusing effect of the open structure 122A can guide the magnetic flux generated by the permanent magnet 122 to the working air gap more concentratedly, thereby obtaining a higher air gap magnetic flux density with the same amount of permanent magnet 122, and improving the torque and power density of the inner rotor permanent magnet synchronous motor 1A.

[0045] like Figure 2 and Figures 4 to 9 As shown, the opening structure 122A can optionally be any one of V-shape, U-shape and C-shape.

[0046] like Figure 4 This illustration shows a case where each group of permanent magnets 122 includes an open structure 122A and a straight structure 122B. Figure 5 This illustration shows a case where each permanent magnet 122 includes two opening structures 122A, and the opening structures 122A are V-shaped. Figure 6 This illustration shows a case where each permanent magnet 122 includes three opening structures 122A, and the opening structures 122A are V-shaped. Figure 7 This illustration shows a case where each permanent magnet 122 includes three opening structures 122A, and the opening structures 122A are C-shaped. Figure 8 This illustration shows a case where each permanent magnet 122 includes an opening structure 122A, and the opening structure 122A is U-shaped. Figure 9 The diagram shows that each permanent magnet 122 includes two opening structures 122A, and the opening structures 122A are U-shaped. It can be seen that each opening structure 122A in the figure includes multiple magnets 1221. The inner rotor core 121 is provided with slots corresponding to each magnet 1221. The slots may or may not be connected.

[0047] When the magnets 1221 of the same group of permanent magnets 122 are arranged to form multiple open structures 122A and straight structures 122B, a straight structure 122B is provided on the opening side of the outermost radially open structure 122A. This can further improve the torque and power density of the inner rotor permanent magnet synchronous motor 1A.

[0048] like Figure 2 , 3As shown, optionally, the stator unit 11 includes an annular stator core 111, the first stator 11A and the second stator 11B share the annular stator core 111, and each includes a first winding 112 and a second winding 113; the annular stator core 111 has a first winding slot 1111 and a second winding slot 1112 at its radially inner end and radially outer end, respectively, the first winding 112 is installed in the first winding slot 1111, and the second winding 113 is installed in the second winding slot 1112.

[0049] The first winding slot 1111 includes multiple slots arranged circumferentially along the annular stator core 111 according to the arrangement requirements of the first winding 112. The second winding slot 1112 includes multiple slots arranged circumferentially along the annular stator core 111 according to the arrangement requirements of the second winding 113. Related technologies can be adopted, which will not be elaborated here.

[0050] The toroidal stator core 111 is typically made of multiple toroidal laminations stacked axially and fixed together by welding, riveting, or bonding to ensure high magnetic permeability and structural strength. Each toroidal lamination is stamped from electrical steel sheet (such as silicon steel sheet), and its structural features are formed on the lamination itself.

[0051] The inner ring of the annular stator core 111, after the first winding slot 1111 is provided, the remaining part forms the internal tooth portion. The outer ring of the annular stator core 111, after the second winding slot 1112 is provided, the remaining part forms the external tooth portion. The annular portion of the annular stator core 111 located in the radial direction between the internal tooth portion and the external tooth portion constitutes the stator yoke portion of the annular stator core 111. The stator yoke portion provides a structural connection between the internal tooth portion and the external tooth portion and serves as a common magnetic conductive channel for the inner rotor permanent magnet synchronous motor 1A and the outer rotor motor 1B.

[0052] Thus, the first stator 11A and the second stator 11B share the annular stator core 111, that is, the first stator 11A and the second stator 11B share the intermediate yoke of the annular stator core 111, avoiding the use of a separate stator design. This achieves structural integration of the first stator 11A and the second stator 11B, allowing them to share cooling structures, which helps reduce the space occupied by the dual-rotor motor 1 and promotes a more compact design. Furthermore, this intermediate yoke facilitates the effective use of magnetic materials such as annular laminations. In both the first and second operating modes, the entire cross-section of the intermediate yoke participates in effective magnetic conduction, resulting in high material utilization and avoiding the idleness of some stator yokes when the first stator 11A and the second stator 11B are physically separated. Simultaneously, the shared intermediate yoke can serve as a magnetic flux buffer. In the second operating mode, when the loads of the inner rotor permanent magnet synchronous motor 1A and the outer rotor motor 1B are uneven, the magnetic flux buffer can be used to balance the magnetic flux distribution, reduce the risk of local saturation, and improve the overload capacity and overall magnetic circuit efficiency of the dual-rotor motor 1.

[0053] Optionally, the annular stator core 111 has one or more magnetic isolation structures in the middle yoke, the magnetic isolation structures including magnetic isolation grooves or magnetic isolation holes (not shown in this schematic diagram).

[0054] Thus, arranging a magnetic shielding structure in the middle yoke helps to suppress harmful coupling such as harmonic coupling between the two magnetic fields in the stator unit 11, ensuring the working performance of the dual rotor motor 1.

[0055] Optionally, the dual-rotor motor 1 also has a cooling flow path, a portion of which is arranged within a magnetic shielding structure. For example, the cooling flow path includes a flow channel tube that passes through a magnetic shielding hole. The flow channel tube is made of a non-magnetic material (not shown in the figure).

[0056] In this way, the magnetic shielding structure can not only achieve the magnetic shielding effect, but also be used to arrange the cooling flow path, which can enhance the heat dissipation performance of the dual rotor motor 1.

[0057] Optionally, the outer rotor 13 is an induction rotor, and the outer rotor motor 1B is an asynchronous motor composed of an induction rotor and a second winding 113.

[0058] The outer rotor 13 includes an outer rotor core 131 and a rotor guide bar 132 embedded inside the outer rotor core 131. The two ends of the rotor guide bar 132 are short-circuited by end rings.

[0059] Thus, the outer rotor 13 is an induction rotor, which eliminates the need for permanent magnet 122, resulting in lower costs. The induction rotor and the second winding 113 together form an asynchronous motor, which can meet larger power requirements.

[0060] like Figure 10 As shown, an embodiment of the present invention also provides an electric drive system, which includes a dual rotor motor 1 as described in the above embodiment. The inner rotor permanent magnet synchronous motor 1A of the dual rotor motor 1 is used for drive connection with at least one of the front axle 2 and the rear axle 3 of the vehicle, and the outer rotor motor 1B of the dual rotor motor 1 is used for drive connection with at least one of the front axle 2 and the rear axle 3.

[0061] Specifically, the internal rotor permanent magnet synchronous motor 1A and the dual rotor motor 1 can be driven and connected to the same axle, such as the rear axle 3, or they can be driven and connected to different axles, as will be illustrated later. The electric drive system typically also includes a controller to adjust and control the operating mode of the dual rotor motor 1. This will not be described in detail here.

[0062] Thus, the electric drive system equipped with the dual rotor motor 1 has multiple power output modes, which correspond to the multiple working modes of the dual rotor motor 1. This can take into account the electric drive system's requirements for the high torque output limit and wide high-efficiency power range of the motor, as well as the need for compact and low-cost layout.

[0063] like Figure 10-11 As shown, optionally, when the dual rotor motor 1 is arranged in the front compartment of the vehicle, the outer rotor motor 1B is driven connected to the front axle differential 21 of the front axle 2, and the inner rotor permanent magnet synchronous motor 1A is driven connected to the rear axle differential 31 or the front axle differential 21 of the rear axle 3.

[0064] like Figure 10 As shown (hereinafter referred to as Scheme 1), when the dual rotor motor 1 is arranged in the front compartment of the vehicle, the outer rotor motor 1B is driven and connected to the front axle differential 21 of the front axle 2, and the inner rotor permanent magnet synchronous motor 1A is driven and connected to the rear axle differential 31 of the rear axle 3.

[0065] Under this scheme, the electric drive system has multiple power output modes. In the mode where only the inner rotor permanent magnet synchronous motor 1A drives, the electric drive system is in rear drive mode. In the mode where the inner rotor permanent magnet synchronous motor 1A and the outer rotor motor 1B drive together, the electric drive system is in four drive mode.

[0066] like Figure 11 As shown (hereinafter referred to as Scheme 2), when the dual rotor motor 1 is arranged in the front compartment of the vehicle, both the outer rotor motor 1B and the inner rotor permanent magnet synchronous motor 1A are driven connected to the front axle differential 21 of the front axle 2.

[0067] Under this second scheme, the electric drive system has multiple power output modes. In the mode driven only by the inner rotor permanent magnet synchronous motor 1A, the electric drive system is in front-drive mode. In the mode driven by both the inner rotor permanent magnet synchronous motor 1A and the outer rotor motor 1B, the electric drive system is also in front-drive mode, but can obtain greater output power.

[0068] like Figure 12-13 As shown, optionally, when the dual rotor motor 1 is arranged in the rear compartment, the inner rotor permanent magnet synchronous motor 1A is driven and connected to the rear axle differential 31, and the outer rotor motor 1B is driven and connected to the rear axle differential 31 or the front axle differential 21.

[0069] like Figure 12 As shown (hereinafter referred to as Scheme 3), when the dual rotor motor 1 is arranged in the rear compartment, the inner rotor permanent magnet synchronous motor 1A is driven and connected to the rear axle differential 31, and the outer rotor motor 1B is driven and connected to the front axle differential 21.

[0070] Under this scheme three, the electric drive system has multiple power output modes. In the mode where only the inner rotor permanent magnet synchronous motor 1A drives, the electric drive system is in rear drive mode. In the mode where the inner rotor permanent magnet synchronous motor 1A and the outer rotor motor 1B drive together, the electric drive system is in four drive mode.

[0071] like Figure 13 As shown (hereinafter referred to as Scheme 4), when the dual rotor motor 1 is arranged in the rear compartment, the inner rotor permanent magnet synchronous motor 1A is driven and connected to the rear axle differential 31, and the outer rotor motor 1B is driven and connected to the rear axle differential 31.

[0072] Under this scheme, the electric drive system has multiple power output modes. In the mode driven only by the inner rotor permanent magnet synchronous motor 1A, the electric drive system is in rear-drive mode. In the mode driven by both the inner rotor permanent magnet synchronous motor 1A and the outer rotor motor 1B, the electric drive system is in rear-drive mode, but can obtain a larger output power.

[0073] Thus, it can be seen that the electric drive systems of Scheme 1 and Scheme 3 can be used to switch between rear-wheel drive and four-wheel drive, and select different drive modes according to different working conditions; the electric drive systems of Scheme 2 and Scheme 4 respectively realize front-wheel drive and rear-wheel drive with multiple power output modes. At this time, although four-wheel drive cannot be realized, it is beneficial to the position layout of the electric drive system and reduces the space occupation of the electric drive system.

[0074] like Figure 10 As shown, in the optional scheme of driving between the inner rotor permanent magnet synchronous motor 1A and the rear axle differential 31 in Scheme 1, that is, when the dual rotor motor 1 is arranged in the front compartment, the axial direction of the dual rotor motor 1 is arranged along the transverse direction of the vehicle. The electric drive system includes a first transmission assembly 4. The inner rotor permanent magnet synchronous motor 1A is driven and connected to the rear axle differential 31 through the first transmission assembly 4. The first transmission assembly 4 includes a first transmission shaft 41 arranged along the longitudinal direction of the vehicle and a first bevel gear 42 and a second bevel gear 43 disposed at both ends of the first transmission shaft 41. The output end of the inner rotor permanent magnet synchronous motor 1A is provided with a third bevel gear 7 that meshes with the first bevel gear 42. The input end of the rear axle differential 31 is provided with a fourth bevel gear 311 that meshes with the second bevel gear 43.

[0075] Specifically, one end of the output shaft of the internal rotor permanent magnet synchronous motor 1A is provided with a third bevel gear 7 that meshes with the first bevel gear 42, and the third bevel gear 7 and the first bevel gear 42 form a reduction gear pair; the input gear of the rear axle differential 31 is a fourth bevel gear 311 that meshes with the second bevel gear 43, and the second bevel gear 43 and the fourth bevel gear 311 form another reduction gear pair.

[0076] Thus, the dual-rotor motor 1 is arranged in the front compartment, and the first drive shaft 41 can be used to adapt to the axial distance between the dual-rotor motor 1 and the rear axle differential 31. The third bevel gear 7, the first bevel gear 42, the second bevel gear 43 and the fourth bevel gear 311 form a multi-stage reduction to meet the corresponding reduction ratio requirements.

[0077] Similarly, such as Figure 12 As shown, in the optional scheme of driving between the inner rotor permanent magnet synchronous motor 1A and the rear axle differential 31 in Scheme 3, that is, when the dual rotor motor 1 is arranged in the rear compartment, the axial direction of the dual rotor motor 1 is arranged along the transverse direction of the vehicle. The electric drive system includes a second transmission assembly 5. The outer rotor motor 1B is driven and connected to the front axle differential 21 through the second transmission assembly 5. The second transmission assembly 5 includes a second transmission shaft 51 arranged along the longitudinal direction of the vehicle and a fifth bevel gear 52 and a sixth bevel gear 53 set at both ends of the second transmission shaft 51. The output end of the outer rotor motor 1B is provided with a seventh bevel gear 8 that meshes with the fifth bevel gear 52. The input end of the front axle differential 21 is provided with an eighth bevel gear 211 that meshes with the sixth bevel gear 53.

[0078] Thus, the dual-rotor motor 1 is arranged in the rear compartment, and the second drive shaft 51 can be used to adapt to the axial distance between the dual-rotor motor 1 and the front axle differential 21. The seventh bevel gear 8, the fifth bevel gear 52, the sixth bevel gear 53 and the eighth bevel gear 211 form a multi-stage reduction to meet the corresponding reduction ratio requirements.

[0079] like Figures 10 to 13 As shown, optionally, the axial direction of the dual-rotor motor 1 is arranged along the transverse direction of the vehicle. The electric drive system also includes a parallel shaft transmission assembly 6, which includes a third transmission shaft 61, a fourth transmission shaft 62, and a first reduction gear pair 63 disposed between the third transmission shaft 61 and the fourth transmission shaft 62. The third transmission shaft 61 is coaxially arranged with the dual-rotor motor 1.

[0080] like Figure 10 and Figure 11 As shown, when the dual rotor motor 1 is arranged in the front compartment, at least the output end of the outer rotor motor 1B is connected to the third drive shaft 61, and a second reduction gear pair 91 is provided between the fourth drive shaft 62 and the input end of the front axle differential 21.

[0081] Figure 10 In the first scheme shown, only the output end of the outer rotor motor 1B is connected to the third transmission shaft 61. In this case, the first transmission component 4 and the parallel shaft transmission component 6 are located on different sides of the axial direction of the dual rotor motor 1.

[0082] Figure 11In the second embodiment shown, both the inner rotor permanent magnet synchronous motor 1A and the outer rotor motor 1B have their output ends connected to the third drive shaft 61. In this case, the output ends (output shafts) of the inner rotor permanent magnet synchronous motor 1A, the output ends (which can be rotating frames, which may have output shafts) of the outer rotor motor 1B, and the third drive shaft 61 can be fixedly connected together. In this configuration, the dual rotor motor 1 is only used to drive the left front half-shaft 22 and the right front half-shaft 23, thereby rotating the left and right front wheels.

[0083] In the first operating mode, the outer rotor motor 1B is not powered, and the outer rotor 13 is in follow-up mode. Of course, in some scenarios, a clutch structure can be set, for example, a clutch structure can be set between the output end of the outer rotor motor 1B and the third transmission shaft 61 to prevent the outer rotor 13 from following.

[0084] It should be understood that in some solutions, the inner rotor permanent magnet synchronous motor 1A may be connected to both the rear axle differential 31 and the front axle differential 21. In this case, it can be considered a combination of solutions one and two. In this scenario, four-wheel drive can be achieved using the inner rotor permanent magnet synchronous motor 1A, and the driving force can be enhanced using the second operating mode. A clutch structure can be installed between the inner rotor permanent magnet synchronous motor 1A and the third drive shaft 61. This clutch structure allows switching between two-wheel drive and four-wheel drive when the inner rotor permanent magnet synchronous motor 1A is driven independently. In this case, four-wheel drive can be used for low-speed, slippery road conditions. Under these conditions, the vehicle speed requirement is low, but the requirement for driving stability is high, so there is no need to use the second operating mode with excessive power to achieve four-wheel drive.

[0085] Accordingly, such as Figure 12 and Figure 13 As shown, when the dual rotor motor 1 is arranged in the rear compartment, at least the output end of the inner rotor permanent magnet synchronous motor 1A and the outer rotor motor 1B is connected to the third drive shaft 61, and a third reduction gear pair 92 is provided between the fourth drive shaft 62 and the input end of the front axle differential 21.

[0086] like Figure 12 In the third scheme shown, only the output end of the inner rotor permanent magnet synchronous motor 1A is connected to the third transmission shaft 61 between the inner rotor permanent magnet synchronous motor 1A and the outer rotor motor 1B. In this case, the second transmission assembly 5 and the parallel shaft transmission assembly 6 are located on different sides of the axial direction of the dual rotor motor 1.

[0087] like Figure 13In Scheme 4, it is shown that the output terminals of both the inner rotor permanent magnet synchronous motor 1A and the outer rotor motor 1B are connected to the third drive shaft 61. In this case, the dual rotor motor 1 is only used to drive the left rear half-shaft 32 and the right rear half-shaft 33, thereby driving the left and right rear wheels to rotate.

[0088] It should be understood that in some schemes, the inner rotor permanent magnet synchronous motor 1A may be driven and connected to both the rear axle differential 31 and the front axle differential 21. In this case, the end of the output shaft of the inner rotor permanent magnet synchronous motor 1A away from the parallel shaft transmission assembly 6 is coaxial and connected to the shaft where the seventh bevel gear 8 is located. For example, a clutch structure can be set between the output shaft of the inner rotor permanent magnet synchronous motor 1A and the shaft where the seventh bevel gear 8 is located. Similarly, a clutch engagement can be set between the output shaft of the outer rotor motor 1B and the shaft where the seventh bevel gear 8 is located. Thus, the drive mode can be flexibly switched through various clutch structures.

[0089] Embodiments of the present invention also provide a vehicle, which includes the electric drive system described above. The vehicle has all the technical effects of the electric drive system, which will not be repeated here.

[0090] While the present invention has been disclosed above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the scope of protection of the present invention.

Claims

1. A dual-rotor motor, characterized in that, The dual-rotor motor includes a stator unit (11), a permanent magnet rotor (12), and an outer rotor (13). The stator unit (11) has a ring structure and includes a first stator (11A) and a second stator (11B). The permanent magnet rotor (12) is coaxially disposed inside the stator unit (11), and the permanent magnet rotor (12) and the first stator (11A) constitute an inner rotor permanent magnet synchronous motor (1A). The outer rotor (13) is coaxially disposed outside the stator unit (11), and the outer rotor (13) and the second stator (11B) constitute an outer rotor motor (1B). The dual-rotor motor has a first working mode in which only the inner rotor permanent magnet synchronous motor (1A) works and a second working mode in which both the inner rotor permanent magnet synchronous motor (1A) and the outer rotor motor (1B) work.

2. The dual-rotor motor as described in claim 1, characterized in that, The peak torque of the inner rotor permanent magnet synchronous motor (1A) is less than the peak torque of the outer rotor motor (1B); And / or, the peak power of the inner rotor permanent magnet synchronous motor (1A) is less than the peak power of the outer rotor motor (1B).

3. The dual-rotor motor as described in claim 1, characterized in that, The permanent magnet rotor (12) includes an inner rotor core (121) and multiple sets of permanent magnets (122) embedded in the inner rotor core (121). The multiple sets of permanent magnets (122) are evenly distributed along the circumference of the inner rotor core (121), and the magnetization directions of two adjacent sets of permanent magnets (122) are opposite, so that the outer periphery of the permanent magnet rotor (12) forms alternating N poles and S poles.

4. The dual-rotor motor as described in claim 3, characterized in that, Each group of permanent magnets (122) includes a plurality of magnets (1221), and the magnets (1221) of the same group of permanent magnets (122) are arranged on the cross section of the inner rotor core (121) to form at least one of the two open structures (122A) and the straight structure (122B). The number of opening structures (122A) formed by the magnets (1221) of the same group of permanent magnets (122) is one or more, and the opening direction of each opening structure (122A) is away from the center of the inner rotor core (121). The multiple opening structures (122A) are distributed radially at intervals along the inner rotor core (121). When the magnets (1221) of the same group of permanent magnets (122) are arranged to form the opening structure (122A) and the straight structure (122B), the straight structure (122B) is located on the opening side of the opening structure (122A).

5. The dual-rotor motor as described in claim 1, characterized in that, The stator unit (11) includes an annular stator core (111), the first stator (11A) and the second stator (11B) share the annular stator core (111), and each includes a first winding (112) and a second winding (113); the annular stator core (111) has a first winding slot (1111) and a second winding slot (1112) at its radial inner end and radial outer end, respectively, the first winding (112) is installed in the first winding slot (1111), and the second winding (113) is installed in the second winding slot (1112); And / or, the outer rotor (13) is an induction rotor, and the outer rotor motor (1B) is an asynchronous motor composed of the induction rotor and the first stator (11A).

6. An electric drive system, characterized in that, The electric drive system includes a dual-rotor motor as described in any one of claims 1 to 5, wherein the inner rotor permanent magnet synchronous motor (1A) of the dual-rotor motor is used for drive connection with at least one of the front axle (2) and the rear axle (3) of the vehicle, and the outer rotor motor (1B) of the dual-rotor motor is used for drive connection with at least one of the front axle (2) and the rear axle (3).

7. The electric drive system as described in claim 6, characterized in that, The dual-rotor motor is arranged in either the front compartment or the rear compartment of the vehicle; When the dual rotor motor is arranged in the front compartment, the outer rotor motor (1B) is driven to the front axle differential (21) of the front axle (2), and the inner rotor permanent magnet synchronous motor (1A) is driven to the rear axle differential (31) of the rear axle (3) or the front axle differential (21). When the dual rotor motor is arranged in the rear compartment, the inner rotor permanent magnet synchronous motor (1A) is driven to the rear axle differential (31), and the outer rotor motor (1B) is driven to the rear axle differential (31) or the front axle differential (21).

8. The electric drive system as described in claim 7, characterized in that, When the dual-rotor motor is arranged in the front compartment, the axial direction of the dual-rotor motor is arranged along the transverse direction of the vehicle. The electric drive system includes a first transmission assembly (4). The inner rotor permanent magnet synchronous motor (1A) is driven to the rear axle differential (31) through the first transmission assembly (4). The first transmission assembly (4) includes a first drive shaft (41) arranged along the longitudinal direction of the vehicle and a first bevel gear (42) and a second bevel gear (43) disposed at both ends of the first drive shaft (41). The output end of the inner rotor permanent magnet synchronous motor (1A) is provided with a third bevel gear (7) that meshes with the first bevel gear (42). The input end of the rear axle differential (31) is provided with a fourth bevel gear (311) that meshes with the second bevel gear (43). When the dual rotor motor is arranged in the rear compartment, the axial direction of the dual rotor motor is arranged along the transverse direction of the vehicle. The electric drive system includes a second transmission assembly (5). The outer rotor motor (1B) is driven to the front axle differential (21) through the second transmission assembly (5). The second transmission assembly (5) includes a second transmission shaft (51) arranged along the longitudinal direction of the vehicle and a fifth bevel gear (52) and a sixth bevel gear (53) disposed at both ends of the second transmission shaft (51). The output end of the outer rotor motor (1B) is provided with a seventh bevel gear (8) that meshes with the fifth bevel gear (52). The input end of the front axle differential (21) is provided with an eighth bevel gear (211) that meshes with the sixth bevel gear (53).

9. The electric drive system as described in claim 7, characterized in that, The axial direction of the dual rotor motor is arranged along the transverse direction of the vehicle. The electric drive system also includes a parallel shaft transmission assembly (6). The parallel shaft transmission assembly (6) includes a third transmission shaft (61), a fourth transmission shaft (62), and a first reduction gear pair (63) disposed between the third transmission shaft (61) and the fourth transmission shaft (62). The third transmission shaft (61) is coaxially disposed with the dual rotor motor. When the dual rotor motor is arranged in the front compartment, at least one of the inner rotor permanent magnet synchronous motor (1A) and the outer rotor motor (1B) is connected to the third drive shaft (61) at the output end of the outer rotor motor (1B), and a second reduction gear pair (91) is provided between the fourth drive shaft (62) and the input end of the front axle differential (21). When the dual-rotor motor is arranged in the rear compartment, at least one of the inner rotor permanent magnet synchronous motor (1A) and the outer rotor motor (1B) is connected to the third drive shaft (61) at the output end of the inner rotor permanent magnet synchronous motor (1A), and a third reduction gear pair (92) is provided between the fourth drive shaft (62) and the input end of the front axle differential (21).

10. A vehicle, characterized in that, Includes the electric drive system as described in any one of claims 6 to 9.

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