Permanent magnet motor rotor, permanent magnet motor, power assembly and vehicle

Abstract

A permanent magnet motor rotor, a permanent magnet motor, a power assembly and a vehicle belong to the field of motors. The permanent magnet motor rotor comprises a rotor core; the plurality of permanent magnet groups and the plurality of third permanent magnets are alternately arranged on the rotor core along the circumferential direction, each permanent magnet group comprises at least one first permanent magnet structure and at least one second permanent magnet structure which are arranged at intervals along the radial direction, the first permanent magnet structure comprises three first permanent magnets, and the second permanent magnet structure comprises three second permanent magnets; the coercive force of the first permanent magnet is smaller than the coercive force of the second permanent magnet and smaller than the coercive force of the third permanent magnet. The second permanent magnet plays a role in magnetizing the first permanent magnet, the working point, the magnetization degree and the working point stability of the first permanent magnet can be effectively improved, and the magnetizing current is reduced, and the third permanent magnet further improves the magnetizing effect on the first permanent magnet, so that the magnetic field of the permanent magnet motor is easy to adjust and has a wider speed regulation range and a wider high-efficiency interval. And the cruising ability of the vehicle can be improved.

Description

Technical Field

[0001] The present application relates to the field of motors, and in particular to a permanent magnet motor rotor, a permanent magnet motor, a powertrain and a vehicle. Background Art

[0002] As the trend of automobile electrification becomes clearer, new energy electric vehicles have put forward higher requirements on the efficiency of motors in order to improve endurance and power. Among them, the most widely used is the permanent magnet motor, which is recognized for its advantages such as high power density and high efficiency.

[0003] However, despite the many advantages of permanent magnet motors, their inherent technical characteristics also bring certain limitations. Specifically, the air gap magnetic field of the permanent magnet motor is generated by permanent magnet steel. This feature ensures the stability and continuity of the magnetic field during the operation of the motor, but it also limits the dynamic adjustment ability of the magnetic field. In the actual operation scenarios of new energy vehicles, vehicles often need to work in different speed ranges and load conditions. At present, the magnetic force of permanent magnet motors remains basically constant, and it is difficult to flexibly adjust according to specific working conditions. This leads to its efficiency performance under certain specific working conditions (such as high-speed and low-torque areas) is not satisfactory, and to a certain extent affects the overall endurance performance of new energy vehicles.

[0004] Therefore, how to achieve effective regulation of the air gap magnetic field and expand the speed regulation range and high-efficiency working range without sacrificing the original advantages of permanent magnet motors has become an important topic in the current research field of permanent magnet motors. Summary of the invention

[0005] In view of this, the purpose of the present application is to provide a permanent magnet motor rotor, a permanent magnet motor, a powertrain and a vehicle to solve at least one of the above technical problems.

[0006] In a first aspect, the present application provides a permanent magnet motor rotor, comprising: a rotor core; a plurality of permanent magnet groups, arranged along the circumference of the rotor core, each permanent magnet group comprising at least one first permanent magnet structure and at least one second permanent magnet structure arranged radially at intervals, the first permanent magnet structure comprising three first permanent magnets, the three first permanent magnets comprising a first central permanent magnet and two first side permanent magnets respectively located on both sides of the first central permanent magnet, the second permanent magnet structure comprising three second permanent magnets, the three second permanent magnets comprising a second central permanent magnet and two second side permanent magnets respectively located on both sides of the second central permanent magnet; and a plurality of third permanent magnets, arranged along the circumference of the rotor core and arranged alternately with the plurality of permanent magnet groups; wherein the coercive force of the first permanent magnet is smaller than the coercive force of the second permanent magnet, and smaller than the coercive force of the third permanent magnet.

[0007] In combination with the first aspect, in some optional embodiments, the first permanent magnet structure and the second permanent magnet structure of each permanent magnet group together with two adjacent third permanent magnets arranged on both sides of the permanent magnet group form a series magnetic circuit; and / or, a parallel magnetic circuit is formed between the three first permanent magnets; and / or, a parallel magnetic circuit is formed between the three second permanent magnets.

[0008] In combination with the first aspect, in some optional embodiments, a first magnetic isolation groove is provided between adjacent ends of the three first permanent magnets, and a second magnetic isolation groove is provided between adjacent ends of the three second permanent magnets.

[0009] In combination with the first aspect, in some optional embodiments, the first central permanent magnet is arranged along the tangent direction of the rotor core, the two first side permanent magnets are arranged in an eight-shape and the narrow mouth of the eight-shape faces the radial inner side of the rotor core; and / or, the second central permanent magnet is arranged along the tangent direction of the rotor core, the two second side permanent magnets are arranged in an eight-shape and the narrow mouth of the eight-shape faces the radial inner side of the rotor core.

[0010] In combination with the first aspect, in some optional embodiments, the cross-sections of the three first permanent magnets are all rectangular, the long side of the cross-section of the first middle permanent magnet is along the tangent direction of the rotor core, the two first side permanent magnets are symmetrically arranged on both sides of the first middle permanent magnet about the midline of the long side of the cross-section of the first middle permanent magnet, the long sides of the cross-sections of the two first side permanent magnets respectively form an angle of 100°-160° with the long side of the cross-section of the first middle permanent magnet, the three first permanent magnets are all magnetized in parallel, and the magnetization direction is along the short side of the cross-section of the first permanent magnet, and And the magnetization directions are the same; and / or, the cross-sections of the three second permanent magnets are all rectangular, the long side of the cross-section of the second middle permanent magnet is along the tangent direction of the rotor core, the two second side permanent magnets are symmetrically arranged on both sides of the second middle permanent magnet about the midline of the long side of the cross-section of the second middle permanent magnet, the long sides of the cross-sections of the two second side permanent magnets respectively form an angle of 100°-160° with the long side of the cross-section of the second middle permanent magnet, the three second permanent magnets are all magnetized in parallel, the magnetization directions are all along the short side direction of the cross-section of the second permanent magnet, and the magnetization directions are the same.

[0011] In combination with the first aspect, in some optional embodiments, the number of the first permanent magnetic structure is one, the number of the second permanent magnetic structures is two, and the two second permanent magnetic structures are respectively arranged radially outside and radially inside the first permanent magnetic structure.

[0012] In combination with the first aspect, in some optional embodiments, the cross-section of the third permanent magnet is rectangular and the long side of the rectangle is along the radial direction of the rotor core, the third permanent magnet is magnetized in parallel, the magnetization direction is along the short side of the cross-section of the third permanent magnet, and the magnetization directions of two adjacent third permanent magnets are opposite.

[0013] Based on the above technical solution, the permanent magnet motor rotor provided by the present application, by alternately arranging permanent magnet groups and third permanent magnets in the circumferential direction of the rotor core, the second permanent magnets with high coercive force in each permanent magnet group can play a magnetizing role on the first permanent magnets with low coercive force, which can effectively improve the working point, magnetization degree and working point stability of the first permanent magnet, and effectively reduce the magnetizing current. The third permanent magnets with high coercive force on both sides of the permanent magnet group can further improve the magnetizing effect on the first permanent magnets with low coercive force, thereby improving the torque output capacity of the permanent magnet motor.

[0014] In a second aspect, the present application provides a permanent magnet motor, comprising at least a stator, an output shaft, and a permanent magnet motor rotor in any one of the embodiments of the first aspect.

[0015] Based on the above technical solution, the permanent magnet motor provided by the present application uses the permanent magnet motor rotor in the first aspect. By applying an additional pulse current, the magnetization direction of the first permanent magnet can be adjusted, thereby realizing linear adjustment of the air gap magnetic field, and the output torque of the permanent magnet motor can be continuously, smoothly and controllably changed by linearly adjusting the air gap magnetic field. The permanent magnet motor has the characteristic of easy adjustment of the magnetic field; the structure of the permanent magnet motor rotor enables the permanent magnet motor to have a higher torque at low speed during magnetization adjustment, and to have a higher power at high speed during weak magnetic adjustment. Therefore, the efficiency of the permanent magnet motor at low and high speed operation is improved, and it has a wider speed regulation range and a wider high efficiency range.

[0016] In a third aspect, the present application provides a power assembly, comprising at least the permanent magnet motor in the second aspect.

[0017] Based on the above technical solution, the powertrain provided in the present application uses the permanent magnet motor in the second aspect and has excellent power output and power regulation capabilities.

[0018] In a fourth aspect, the present application provides a vehicle comprising at least the powertrain of the third aspect.

[0019] Based on the above technical solution, the vehicle provided in the present application uses the powertrain in the third aspect. Since the permanent magnet motor in the powertrain has the characteristics of easy adjustment of the magnetic field, and has a wider speed regulation range and a wider high efficiency range, the vehicle has excellent endurance. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 A schematic structural diagram of a permanent magnet motor rotor provided in the first embodiment of the present application.

[0022] Figure 2 A schematic structural diagram of a permanent magnet motor provided in the second embodiment of the present application.

[0023] Figure 3 A schematic diagram of the magnetization state of a permanent magnet motor provided in the second embodiment of the present application.

[0024] Figure 4 A schematic diagram of a weak magnetic state of a permanent magnet motor provided in the second embodiment of the present application.

[0025] Figure 5 A schematic structural diagram of a powertrain provided in the third embodiment of the present application.

[0026] Figure numerals: 100, permanent magnet motor; 10, permanent magnet motor rotor; 11, rotor core; 12, permanent magnet group; 121, first permanent magnet structure; 1211, first permanent magnet; 1211a, first central permanent magnet; 1211b, first side permanent magnet; 1212, first magnetic isolation groove; 122, second permanent magnet structure; 1221, second permanent magnet; 1221a, second central permanent magnet; 1221b, second side permanent magnet; 1222, second magnetic isolation groove; 13, third permanent magnet; 20, stator; 21, stator core; 211, stator yoke; 212, stator teeth; 22, armature winding; 30, output shaft; 200, reducer; 300, controller; 1000, powertrain. DETAILED DESCRIPTION

[0027] The specific embodiments of the present application will be described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the description of the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present application.

[0028] In the description of this application, unless otherwise clearly specified and limited, the terms "connection", "setting", "installation", etc. should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be that two elements are internally connected. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0029] The terms "upper", "lower", "left", "right", "front", "back", "center", "top", "bottom", "inside", "outside", "vertical", "horizontal", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the accompanying drawings, or are the orientation or position relationship commonly placed when the product of the application is used. They are only for the convenience of description and simplified description, and do not indicate or imply that the device or element referred to 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 application.

[0030] The terms “first”, “second”, “third”, etc. are merely used to distinguish elements of similar nature, and do not indicate or imply relative importance or a particular order, unless expressly specified and limited otherwise.

[0031] The terms "comprises," "includes," "has," or any other variation thereof, are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprises a ..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes the element.

[0032] The term "plurality" means two or more (including two).

[0033] The term "and / or" is merely a description of the association relationship between associated objects, indicating that three relationships may exist. For example, A and / or B may represent three situations: A exists alone, A and B exist at the same time, and B exists alone.

[0034] The terms "one embodiment", "as an example", "in one implementation", etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example may be included in at least one embodiment or example of the present application. Schematic representations of such terms do not necessarily refer to the same embodiment, nor are they independent or alternative embodiments that are mutually exclusive with other embodiments. In the absence of conflict, the embodiments in the present application and the features in the embodiments may be combined in a suitable manner.

[0035] First embodiment

[0036] Figure 1 This is a schematic diagram of the structure of a permanent magnet motor rotor 10 provided in the first embodiment of the present application. Figure 1 As shown, the first embodiment of the present application provides a permanent magnet motor rotor 10 , including a rotor core 11 , and a plurality of permanent magnet groups 12 and a plurality of third permanent magnets 13 arranged on the rotor core 11 .

[0037] The plurality of permanent magnet groups 12 and the plurality of third permanent magnets 13 are alternately and evenly distributed along the circumferential direction of the rotor core 11 .

[0038] The number of permanent magnet groups 12 and third permanent magnets 13 corresponds to the number of rotor poles, both of which are even numbers. A third permanent magnet 13 is arranged between every two adjacent permanent magnet groups 12. Exemplarily, the number of permanent magnet groups 12 and third permanent magnets 13 are both 8.

[0039] In the plurality of permanent magnet groups 12, each permanent magnet group 12 includes at least one first permanent magnet structure 121 and at least one second permanent magnet structure 122. The first permanent magnet structure 121 and the second permanent magnet structure 122 are arranged at intervals along the radial direction of the rotor core 11. The first permanent magnet structure 121 and the second permanent magnet structure 122 are both U-shaped, and the U-shaped openings both point to the radial outside of the rotor core 11.

[0040] Exemplarily, there is one first permanent magnetic structure 121 and two second permanent magnetic structures 122 . The two second permanent magnetic structures 122 are respectively arranged radially outside and radially inside the first permanent magnetic structure 121 , and both maintain a certain distance from the first permanent magnetic structure 121 .

[0041] The single first permanent magnet structure 121 includes three first permanent magnets 1211. A parallel magnetic circuit is formed between the three first permanent magnets 1211. The three first permanent magnets 1211 are arranged in a U shape as a whole. Specifically, the three first permanent magnets 1211 include a first central permanent magnet 1211a and two first side permanent magnets 1211b respectively located on both sides of the first central permanent magnet 1211a. The first central permanent magnet 1211a is arranged along the tangent direction of the rotor core 11, and the two first side permanent magnets 1211b are arranged in an eight-shaped shape, and the narrow mouth of the eight-shaped shape faces the radial inner side of the rotor core 11. A first magnetic isolation groove 1212 is provided between the adjacent ends of the three first permanent magnets 1211. The first magnetic isolation groove 1212 plays a role in limiting the leakage of the three first permanent magnets 1211 and improving the utilization rate of the three first permanent magnets 1211, and can also improve the power density of the permanent magnet motor.

[0042] Among them, the cross-sections of the three first permanent magnets 1211 (referring to the cross-sections of the first permanent magnets 1211 obtained by a plane perpendicular to the axis of the rotor core 11) are all rectangular, the long side of the cross-section of the first central permanent magnet 1211a is along the tangent direction of the rotor core 11, and the two first side permanent magnets 1211b are symmetrically arranged on both sides of the first central permanent magnet 1211a about the midline of the long side of the cross-section of the first central permanent magnet 1211a, and the long sides of the cross-sections of the two first side permanent magnets 1211b form an angle of 100°-160° with the long sides of the cross-section of the first central permanent magnet 1211a.

[0043] The three first permanent magnets 1211 are magnetized in parallel, and the magnetization directions are all in the short side direction of the cross section of the first permanent magnet 1211, and the magnetization directions of the three first permanent magnets 1211 are the same. The three first permanent magnets 1211 are all low coercive force permanent magnets made of aluminum nickel cobalt. During the magnetic adjustment process of the permanent magnet motor, the magnetization directions of the three first permanent magnets 1211 can be changed by applying a pulse current externally. It should be noted that the low coercive force permanent magnet refers to a permanent magnet with a coercive force less than 250kA / m.

[0044] The single second permanent magnet structure 122 includes three second permanent magnets 1221. A parallel magnetic circuit is formed between the three second permanent magnets 1221. The three second permanent magnets 1221 are arranged in a U shape as a whole. Specifically, the three second permanent magnets 1221 include a second central permanent magnet 1221a and two second side permanent magnets 1221b respectively located on both sides of the second central permanent magnet 1221a. The second central permanent magnet 1221a is arranged along the tangential direction of the rotor core 11, and the two second side permanent magnets 1221b are arranged in an eight-shaped shape, and the narrow mouth of the eight-shaped shape faces the radial inner side of the rotor core 11. The three second permanent magnets 1221 are respectively arranged in parallel with the three first permanent magnets 1211 of the first permanent magnet structure 121. Second magnetic isolation grooves 1222 are provided between adjacent ends of the three second permanent magnets 1221. The second magnetic isolation grooves 1222 limit the magnetic leakage of the three second permanent magnets 1221 and improve the utilization rate of the three second permanent magnets 1221, while also improving the power density of the permanent magnet motor.

[0045] Among them, the cross-sections of the three second permanent magnets 1221 (referring to the cross-sections of the second permanent magnets 1221 obtained by a plane perpendicular to the axis of the rotor core 11) are all rectangular, the long side of the cross-section of the second central permanent magnet 1221a is along the tangent direction of the rotor core 11, and the two second side permanent magnets 1221b are symmetrically arranged on both sides of the second central permanent magnet 1221a about the midline of the long side of the cross-section of the second central permanent magnet 1221a, and the long sides of the cross-sections of the two second side permanent magnets 1221b are respectively aligned with the cross-sections of the second central permanent magnet 1221a. The long sides of the faces form an angle of 100°-160°; the three second permanent magnets 1221 are magnetized in parallel, and the magnetization directions are all in the direction of the short sides of the cross section of the second permanent magnets 1221, and the magnetization directions of the three second permanent magnets 1221 are the same; the three second permanent magnets 1221 are all high coercive force permanent magnets made of neodymium iron boron, that is, the coercive force of the second permanent magnet 1221 is greater than the coercive force of the first permanent magnet 1211, so that the high coercive force second permanent magnet 1221 can play a magnetizing role on the low coercive force first permanent magnet 1211. During the magnetic adjustment process of the permanent magnet motor, the magnetization directions of the three second permanent magnets 1221 remain unchanged. It should be noted that the high coercive force permanent magnet refers to a high magnetic energy product permanent magnet with a coercive force greater than 800kA / m.

[0046] The first permanent magnet structure 121 and the second permanent magnet structure 122 of each permanent magnet group 12 form a series magnetic circuit together with two adjacent third permanent magnets 13 arranged on both sides thereof.

[0047] In order to better optimize the magnetic flux path, illustratively, in the two second permanent magnet structures 122 of each permanent magnet group 12, the cross-sectional length of the three second permanent magnets 1221 of the second permanent magnet structure 122 located radially outside the first permanent magnet structure 121 is slightly smaller than the cross-sectional length of the three first permanent magnets 1211 of the first permanent magnet structure 121, and the cross-sectional length of the three second permanent magnets 1221 of the second permanent magnet structure 122 located radially inside the first permanent magnet structure 121 is slightly larger than the cross-sectional length of the three first permanent magnets 1211 of the first permanent magnet structure 121. This design can optimize the magnetic flux path, so that the magnetic flux can pass through the first permanent magnet structure 121 and the two second permanent magnet structures 122 of each permanent magnet group 12 more concentratedly, reduce magnetic leakage, thereby improving the air gap magnetic flux density of the permanent magnet motor, and further improving the power density of the permanent magnet motor.

[0048] Among the multiple third permanent magnets 13, the cross section of each third permanent magnet 13 (referring to the cross section of the third permanent magnet 13 in the figure obtained by the plane perpendicular to the axis of the rotor core 11) is rectangular, and the long side of the rectangle is arranged along the radial direction of the rotor core 11. Each third permanent magnet 13 is magnetized in parallel, and the magnetization direction is the short side direction of the cross section of the third permanent magnet 13. The magnetization directions of two adjacent third permanent magnets 13 are opposite, that is, the adjacent surface magnetic poles of two adjacent third permanent magnets 13 are the same. The third permanent magnet 13 is a high coercive force permanent magnet made of neodymium iron boron, that is, the coercive force of the third permanent magnet 13 is greater than the coercive force of the first permanent magnet 1211, so that the high coercive force third permanent magnet 13 can play a magnetizing role on the low coercive force first permanent magnet 1211. During the magnetic modulation process of the permanent magnet motor, the magnetization direction of the third permanent magnet 13 remains unchanged.

[0049] For the description of the magnetic field adjustment principle of the permanent magnet motor rotor 10 , please refer to the second embodiment.

[0050] In summary, the first embodiment of the present application provides a permanent magnet motor rotor 10, by alternately arranging permanent magnet groups 12 and third permanent magnets 13 in the circumferential direction of the rotor core 11, each permanent magnet group 12 includes at least one first permanent magnet structure 121 and at least one second permanent magnet structure 122, the first permanent magnet structure 121 is U-shaped and consists of three first permanent magnets 1211 with low coercivity, the second permanent magnet structure 122 is U-shaped and consists of three second permanent magnets 1221 with high coercivity, the first permanent magnet structure 121 and the second permanent magnet structure 122 are connected in series on the magnetic circuit. The third permanent magnet 13 is a high coercive force permanent magnet, and the permanent magnet motor rotor 10 has at least the following advantages: the high coercive force second permanent magnet 1221 of the permanent magnet group 12 can play a magnetizing effect on the low coercive force first permanent magnet 1211, which can effectively improve the working point, magnetization degree and working point stability of the first permanent magnet 1211, and effectively reduce the magnetizing current; the high coercive force third permanent magnet 13 on both sides of the permanent magnet group 12 can further improve the magnetizing effect on the low coercive force first permanent magnet 1211, thereby improving the torque output capacity of the permanent magnet motor.

[0051] Second embodiment

[0052] Figure 2 A structural diagram of a permanent magnet motor 100 provided in the second embodiment of the present application is shown in FIG. Figure 2 As shown, the second embodiment of the present application provides a permanent magnet motor 100 , including the permanent magnet motor rotor 10 in the first embodiment, as well as a stator 20 and an output shaft 30 .

[0053] The stator 20 includes a stator core 21 and an armature winding 22 disposed on the stator core 21. The stator core 21 includes a stator yoke 211 and a plurality of stator teeth 212, wherein the plurality of stator teeth 212 are evenly distributed on the inner periphery of the stator yoke 211 along the circumferential direction, a stator slot is formed between two adjacent stator teeth 212, and the armature winding 22 is installed in the stator slot.

[0054] The permanent magnet motor rotor 10 is mounted on the output shaft 30 and is disposed together at the inner side of the stator 20. An air gap is provided between the permanent magnet motor rotor 10 and the stator 20.

[0055] Working principle of permanent magnet motor 100: A three-phase alternating current having the same rotation speed as permanent magnet motor rotor 10 can be passed through armature winding 22 of stator 20, so that stator 20 and permanent magnet motor rotor 10 respectively form rotating magnetic fields and interact with each other, thereby realizing electromechanical energy conversion and driving output shaft 30.

[0056] Magnetic field adjustment principle of permanent magnet motor 100: Before explaining the magnetic field adjustment principle of permanent magnet motor 100, it should be made clear that the first permanent magnet 1211 is a low coercive force permanent magnet, and the second permanent magnet 1221 and the third permanent magnet 13 are both high coercive force permanent magnets; the permanent magnetic flux starts from the N pole of the second permanent magnet 1221 of each permanent magnet group and the N pole of each third permanent magnet 13, and returns to the S pole of the second permanent magnet 1221 of the adjacent permanent magnet group to form a magnetic circuit; the permanent magnet motor rotor 10 is externally connected to a device for applying a DC pulse current to it. During the magnetic field adjustment process of permanent magnet motor 100, the magnetization direction of the first permanent magnet 1211 can be changed by externally applying a DC pulse current due to the characteristics of low coercive force permanent magnets, and the magnetization directions of the second permanent magnet 1221 and the third permanent magnet 13 remain unchanged due to the characteristics of high coercive force permanent magnets.

[0057] Figure 3 This is a schematic diagram of a magnetization state of a permanent magnet motor 100 provided in the second embodiment of the present application, wherein the direction of the arrow indicates the magnetization direction. Figure 3 As shown, when the permanent magnet motor 100 is subjected to magnetization adjustment, the magnetization direction of the first permanent magnet 1211 is changed by applying a pulse current externally, so that the magnetization direction of the first permanent magnet 1211 is the same as the magnetization direction of the second permanent magnet 1221 and the third permanent magnet 13. At this time, the first permanent magnet 1211 is in a magnetization state, and the permanent magnetic flux of the first permanent magnet 1211 will flow in the same direction after being superimposed with the permanent magnetic flux of the second permanent magnet 1221 and the third permanent magnet 13. In this way, the permanent magnet motor 100 can have a higher torque at a low speed.

[0058] Figure 4 The schematic diagram of the weak magnetic state of a permanent magnet motor 100 provided in the second embodiment of the present application, wherein the direction of the arrow indicates the magnetization direction. Figure 4 As shown, when the permanent magnet motor 100 performs weak magnetic adjustment, the magnetization direction of the first permanent magnet 1211 is changed by applying a pulse current externally, so that the magnetization direction of the first permanent magnet 1211 is opposite to the magnetization directions of the second permanent magnet 1221 and the third permanent magnet 13. At this time, the first permanent magnet 1211 is in a weak magnetic state, a part of the permanent magnetic flux is short-circuited, and the other part of the permanent magnetic flux passes through the stator 20 and then reaches the S pole of the second permanent magnet 1221 and the S pole of the third permanent magnet 13. In this way, the permanent magnet motor 100 can prevent the passive demagnetization of the first permanent magnet 1211 with low coercive force at high speed, and enable the permanent magnet motor 100 to have higher power at high speed.

[0059] In summary, the permanent magnet motor 100 provided in the second embodiment of the present application uses the permanent magnet motor rotor 10 in the first embodiment. By applying an additional pulse current, the magnetization direction of the first permanent magnet 1211 can be adjusted, thereby realizing linear adjustment of the air gap magnetic field. By linearly adjusting the air gap magnetic field, the output torque of the permanent magnet motor 100 can be continuously, smoothly and controllably changed. The permanent magnet motor 100 has the characteristic of easy adjustment of the magnetic field. The structure of the permanent magnet motor rotor 10 enables the permanent magnet motor 100 to have a higher torque at a low speed during magnetization adjustment, and to have a higher power at a high speed during weak magnetic adjustment. Therefore, the efficiency of the permanent magnet motor 100 at both low and high speeds is improved, and it has a wider speed regulation range and a wider high efficiency range.

[0060] Third embodiment

[0061] Figure 5 A schematic diagram of the structure of a powertrain 1000 provided in the third embodiment of the present application is shown in FIG. Figure 5 As shown, the third embodiment of the present application provides a power assembly 1000, including the permanent magnet motor 100 in the second embodiment, as well as a reducer 200 and a controller 300. The reducer 200, the controller 300, and the permanent magnet motor 100 can be integrated and installed in a housing, wherein the reducer 200 is connected to the output shaft 30 of the permanent magnet motor 100, and the controller 300 is connected to and controls the operation of the permanent magnet motor 100.

[0062] The power assembly 1000 provided in the third embodiment of the present application utilizes the advantages of the permanent magnet motor 100 in the second embodiment and has excellent power output and power regulation capabilities.

[0063] Fourth embodiment

[0064] The fourth embodiment of the present application provides a vehicle, including the powertrain 1000 of the third embodiment. To be precise, the vehicle is a new energy vehicle.

[0065] Since the permanent magnet motor 100 in the powertrain 1000 has the characteristics of easy adjustment of the magnetic field and a wider speed regulation range and a wider high efficiency range, the vehicle has excellent endurance by using the powertrain 1000 of the third embodiment.

[0066] The above description is only a specific implementation mode of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the field can easily think of various changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application.

Claims

1. A permanent magnet motor rotor, characterized in that: include: Rotor core; A plurality of permanent magnet groups are arranged along the circumference of the rotor core, each of the permanent magnet groups includes at least one first permanent magnet structure and at least one second permanent magnet structure arranged in a radially spaced manner, the first permanent magnet structure includes three first permanent magnets, the three first permanent magnets include a first central permanent magnet and two first side permanent magnets respectively located on both sides of the first central permanent magnet, the second permanent magnet structure includes three second permanent magnets, the three second permanent magnets include a second central permanent magnet and two second side permanent magnets respectively located on both sides of the second central permanent magnet; as well as A plurality of third permanent magnets are arranged along the circumference of the rotor core and are arranged alternately with the plurality of permanent magnet groups; The coercive force of the first permanent magnet is smaller than the coercive force of the second permanent magnet, and smaller than the coercive force of the third permanent magnet.

2. The permanent magnet motor rotor according to claim 1, characterized in that: The first permanent magnet structure and the second permanent magnet structure of each permanent magnet group together with the two adjacent third permanent magnets arranged on both sides of the permanent magnet group form a series magnetic circuit; and / or, A parallel magnetic circuit is formed between the three first permanent magnets; and / or, A parallel magnetic circuit is formed between the three second permanent magnets.

3. The permanent magnet motor rotor according to claim 1, characterized in that: A first magnetic isolation groove is provided between adjacent ends of the three first permanent magnets, and a second magnetic isolation groove is provided between adjacent ends of the three second permanent magnets.

4. The permanent magnet motor rotor according to claim 1, characterized in that: The first central permanent magnet is arranged along the tangent direction of the rotor core, and the two first side permanent magnets are arranged in an eight-shaped shape with the narrow opening of the eight-shaped shape facing the radial inner side of the rotor core; and / or, The second middle permanent magnet is arranged along the tangent direction of the rotor core, and the two second side permanent magnets are arranged in an eight-shaped shape with the narrow opening of the eight-shaped shape facing the radial inner side of the rotor core.

5. The permanent magnet motor rotor according to claim 4, characterized in that: The cross sections of the three first permanent magnets are all rectangular, the long side of the cross section of the first middle permanent magnet is along the tangent direction of the rotor core, the two first side permanent magnets are symmetrically arranged on both sides of the first middle permanent magnet about the midline of the long side of the cross section of the first middle permanent magnet, the long sides of the cross sections of the two first side permanent magnets respectively form an angle of 100°-160° with the long side of the cross section of the first middle permanent magnet, the three first permanent magnets are magnetized in parallel, the magnetization direction is along the short side of the cross section of the first permanent magnet, and the magnetization direction is the same; and / or, The cross-sections of the three second permanent magnets are all rectangular, the long side of the cross-section of the second middle permanent magnet is along the tangent direction of the rotor core, the two second side permanent magnets are symmetrically arranged on both sides of the second middle permanent magnet about the midline of the long side of the cross-section of the second middle permanent magnet, the long sides of the cross-section of the two second side permanent magnets respectively form an angle of 100°-160° with the long side of the cross-section of the second middle permanent magnet, the three second permanent magnets are all magnetized in parallel, the magnetization direction is along the short side of the cross-section of the second permanent magnet, and the magnetization direction is the same.

6. The permanent magnet motor rotor according to claim 1, characterized in that: The number of the first permanent magnetic structure is one, the number of the second permanent magnetic structure is two, and the two second permanent magnetic structures are arranged on the radial outer side and the radial inner side of the first permanent magnetic structure respectively.

7. The permanent magnet motor rotor according to claim 1, characterized in that: The cross section of the third permanent magnet is rectangular and the long side of the rectangle is along the radial direction of the rotor core. The third permanent magnet is magnetized in parallel, and the magnetization direction is along the short side of the cross section of the third permanent magnet. The magnetization directions of two adjacent third permanent magnets are opposite.

8. A permanent magnet motor, characterized in that: The invention comprises a stator, an output shaft, and a permanent magnet motor rotor as claimed in any one of claims 1 to 7.

9. A powertrain, characterized in that: Comprising the permanent magnet motor as claimed in claim 8.

10. A vehicle, characterized in that: Comprising the powertrain as claimed in claim 9.

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