Axial-radial flux hybrid winding switched three rotor permanent magnet synchronous motor

Abstract

The application discloses a kind of shaft radial flux hybrid winding switching type three rotor permanent magnet synchronous motor, belong to permanent magnet synchronous motor technical field.The permanent magnet synchronous motor includes rotor core, axial flux motor permanent magnet, axial flux motor winding, stator core, radial flux motor winding and radial flux motor permanent magnet.Affirmative effect is in that:the composite permanent magnet synchronous motor of shaft radial flux hybrid provided by the application includes two parts of axial magnetic circuit and radial magnetic circuit, and axial magnetic circuit is main, axial flux motor with intermediate stator double rotor structure, and symmetric structure effectively weakens axial magnetic tension caused by asymmetry;Radial magnetic circuit provides complementary magnetic flux path for axial magnetic circuit, increases total magnetic flux on the basis of fully utilizing space, improves output torque;Whether by series connection of two sets of windings, improve motor flux weakening speed performance, expand motor speed range.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of permanent magnet synchronous motors, and particularly relates to a shaft-radial flux hybrid winding switching type three-rotor permanent magnet synchronous motor. BACKGROUND

[0002] With the continuous development of social economy and the continuous improvement of people's quality, the state policy pays more attention to environmental protection, and the environmental pollution problem caused by the rapid growth of China's automobile industry needs to be solved urgently. The development of new energy vehicles is imminent. Permanent magnet synchronous motors are widely used in hub motors due to their high torque density and high power. The hub motor is a kind of power driving device for new energy vehicles, which is placed inside the wheel to directly drive the wheel to rotate, and its performance directly affects the performance of new energy vehicles.

[0003] At present, the research and development of hub motor technology at home and abroad have achieved certain research results, and electric vehicles equipped with hub motors have been developed. The structure of the motor is limited by the space inside the vehicle wheel and restricted by the battery technology, and there are still a series of problems, such as the maximum speed of the automobile and the climbing performance. These problems will have a great impact on the automobile, and the motor needs to provide a large torque when the electric vehicle starts and runs at low speed, so as to improve the starting, climbing and acceleration performance of the automobile. The ordinary motor commonly used in the market needs a large current when bearing a large torque, which is easy to damage the battery and the permanent magnet inside the motor. In order to make the automobile have better dynamic performance, the electric motor also needs to have a very wide torque and speed adjustment range, so the hub motor is required to have a large speed range, a large torque at low speed, and a soft characteristic of light load at high speed.

[0004] Chinese patent CN112994389A discloses an axial-radial flux permanent magnet motor structure, wherein the first outer rotor and the second outer rotor are respectively arranged on the two sides of the stator disc and coaxially arranged with the stator disc, the inner rotor is coaxially arranged with the stator disc and passes through the inner hole of the stator disc to be connected with the first outer rotor and the second outer rotor, and a magnetic adjusting assembly is arranged between the stator and the rotor. The stator disc includes a stator core and a stator winding, the first outer rotor and the second outer rotor have the same structure and include an outer rotor core and a first permanent magnet, the inner rotor includes an inner rotor core and a second permanent magnet, and the magnetic adjusting assembly includes a plurality of U-shaped magnetic conductive blocks. The radial energy transmission path is provided by the second permanent magnet on the inner rotor, and the torque density of the motor is improved. The U-shaped magnetic conductive block is used as the magnetic adjusting structure in the magnetic adjusting assembly, different pole pairs of the stator and the rotor are realized, and the motor can be applied in occasions with high torque at low speed and high torque stability. However, the shaft and the radial direction of the present application only adopt one set of winding, which is equivalent to the working condition of only the shaft and the radial direction winding in series, only the torque output at low speed is improved, and the radial flux transmission path still exists at high speed, which affects the flux weakening effect of the motor and reduces the maximum speed of the motor. SUMMARY

[0005] The embodiment of the present application aims to provide a shaft-radial magnetic flux hybrid winding switching type three-rotor permanent magnet synchronous motor, which combines an intermediate stator axial flux permanent magnet synchronous motor with an inner rotor radial flux permanent magnet synchronous motor on the basis of a traditional single shaft radial flux motor structure, fully utilizes the hub space, and improves the torque density; two sets of different windings are respectively adopted, the two sets of windings are connected in series at low speed, the radial winding is powered off at high speed, the double winding series connection switching is realized through switching, the motor performance is improved, and the speed range of the motor is greatly expanded; the torque is improved under the condition that the bus current is unchanged through series switching, the motor and the power supply system are prevented from being damaged by large current, the low-speed climbing and starting acceleration capability of the electric vehicle is effectively improved, and at least one technical problem involved in the background art can be solved.

[0006] In order to solve the above technical problems, the present application is implemented as follows:

[0007] The embodiment of the present application provides a shaft-radial magnetic flux hybrid winding switching type three-rotor permanent magnet synchronous motor, which comprises a rotor core, an axial flux motor permanent magnet, an axial flux motor winding, a stator core, a radial flux motor winding and a radial flux motor permanent magnet.

[0008] The rotor core comprises a cylindrical inner rotor disc and two annular outer rotor discs which are respectively arranged at both ends of the inner rotor disc and are arranged in parallel and at intervals.

[0009] The stator core is annular and is sleeved on the inner rotor disc and located between the two outer rotor discs, and comprises a plurality of radial stator slots arranged in the circumferential direction and a plurality of axial stator slots arranged on the hole wall of the inner hole in the circumferential direction.

[0010] The number of the axial flux motor permanent magnets is multiple, and the multiple axial flux motor permanent magnets are respectively arranged on the surfaces of the two outer rotor discs opposite to the stator core and are arranged at intervals with the stator core.

[0011] The number of the radial flux motor permanent magnets is multiple, and the multiple radial flux motor permanent magnets are arranged on the surfaces of the inner rotor disc opposite to the stator core and are arranged at intervals with the stator core.

[0012] The number of the axial flux motor windings is multiple, and the multiple axial flux motor windings are arranged in the radial stator slots.

[0013] The number of the radial flux motor windings is multiple, and the multiple radial flux motor windings are arranged in the axial stator slots.

[0014] Optionally, the outer rotor disc is integrally formed with the inner rotor disc.

[0015] Optionally, the polarities of any two adjacent axial flux motor permanent magnet poles are opposite in the circumferential direction of the outer rotor disc.

[0016] Optionally, the radial flux motor permanent magnet has the same polarity as the axial flux motor permanent magnet closest to it.

[0017] Optionally, the axial flux motor windings are equidistantly arranged in the circumferential direction of the stator core.

[0018] Optionally, the radial flux motor windings are located in the gaps between the axial flux motor windings.

[0019] Optionally, the axial flux motor permanent magnet and the radial flux motor permanent magnet are surface-mounted on the surface of the rotor core.

[0020] The beneficial effects of the embodiment of the application are as follows:

[0021] 1. The axial-radial flux hybrid composite permanent magnet synchronous motor provided by the application comprises an axial magnetic circuit and a radial magnetic circuit, and the axial magnetic circuit is the main part, the axial flux motor adopts a middle stator double rotor structure, and the symmetrical structure effectively weakens the axial magnetic pull caused by asymmetry; the radial magnetic circuit provides a supplementary magnetic flux path for the axial magnetic circuit, increases the total magnetic flux on the basis of fully utilizing the space, and improves the output torque.

[0022] 2. The application adopts two sets of windings, the two sets of windings are connected in series at low speed to improve the output torque; and the radial windings are powered off at high speed to expand the motor speed range.

[0023] 3. The application can improve the torque under the condition that the bus current remains unchanged through series connection, avoids damage to the motor and the power supply system caused by large current, and effectively improves the low-speed climbing and starting acceleration ability of the electric vehicle.

[0024] 4. The application fully utilizes the wheel hub space, meets the demand of large motor speed range, and improves the output torque density. BRIEF DESCRIPTION OF DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the application, the following will briefly introduce the drawings needed to be used in the embodiment description. Obviously, the drawings in the following description are only some embodiments of the application, and for those skilled in the art, other drawings can also be obtained from these drawings without creative labor.

[0026] Figure 1The axial-radial magnetic flux mixed winding switching type three-rotor permanent magnet synchronous motor provided by the present application is shown in the exploded structure diagram.

[0027] Figure 2 The axial-radial magnetic flux mixed winding switching type three-rotor permanent magnet synchronous motor provided by the present application is shown in the cross-sectional structure diagram.

[0028] Figure 3 The structure diagram of the rotor core provided by the present application is shown in the structure diagram.

[0029] Figure 4 The structure diagram of the stator core provided by the present application is shown in the structure diagram.

[0030] Figure 5 The position relationship diagram of the axial magnetic flux motor winding and the radial magnetic flux motor winding provided by the present application is shown in the position relationship diagram.

[0031] Figure 6 The axial magnetic flux magnetic circuit diagram provided by the present application is shown in the axial magnetic flux magnetic circuit diagram.

[0032] Figure 7 The axial-radial magnetic flux mixed magnetic circuit diagram provided by the present application is shown in the axial-radial magnetic flux mixed magnetic circuit diagram. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0034] The terms "first", "second", and the like in the specification and claims of the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described herein, and the objects distinguished by "first", "second", etc. are generally of a kind and do not limit the number of objects, for example, the first object can be one or more. In addition, "and / or" in the specification and claims indicates at least one of the connected objects, and the character " / ", generally indicates that the front and rear associated objects are in an "or" relationship.

[0035] Please refer to Figure 1 and Figure 2 The axial-radial magnetic flux mixed winding switching type three-rotor permanent magnet synchronous motor provided by the present application is shown in the exploded structure diagram.

[0036] Recombine Figure 3 As shown, the rotor core 1 includes a cylindrical inner rotor disc 11 and two annular outer rotor discs 12 respectively arranged at both ends of the inner rotor disc 11 and parallelly spaced.

[0037] Specifically, the outer rotor disc 12 is integrally formed with the inner rotor disc 11.

[0038] The stator core 4 is annular and is sleeved on the inner rotor disc 11 and located between the two outer rotor discs 12.

[0039] Recombine Figure 4 As shown, the stator core 4 includes a plurality of radial stator slots 41 arranged along the circumferential direction thereof and a plurality of axial stator slots 42 arranged on the inner hole wall along the circumferential direction thereof.

[0040] The number of the axial flux motor permanent magnets 2 is multiple, and the multiple axial flux motor permanent magnets 2 are respectively arranged on the surfaces of the two outer rotor discs 12 opposite to the stator core 4 and are spaced apart from the stator core 4. The axial flux motor permanent magnets 2 arranged on the two outer rotor discs 12 are arranged in opposite poles.

[0041] Further, the polarities of any two adjacent axial flux motor permanent magnets 2 along the circumferential direction of the outer rotor disc 12 are opposite.

[0042] The number of the radial flux motor permanent magnets 6 is multiple, and the multiple radial flux motor permanent magnets 6 are arranged on the surfaces of the inner rotor disc 11 opposite to the stator core 4 and are spaced apart from the stator core 4.

[0043] Further, the radial flux motor permanent magnet 6 and the axial flux motor permanent magnet 2 closest to it have the same polarity.

[0044] In a specific embodiment, the axial flux motor permanent magnets 2 and the radial flux motor permanent magnets 6 are both surface-mounted on the surface of the rotor core 1.

[0045] The number of the axial flux motor windings 3 is multiple, and the multiple axial flux motor windings 3 are arranged in the radial stator slots 41.

[0046] Specifically, the axial flux motor windings 3 are arranged at equal intervals along the circumferential direction of the stator core 4, and the axial flux motor windings 3 are annular.

[0047] The number of the radial flux motor windings 5 is multiple, and the multiple radial flux motor windings 5 are arranged in the axial stator slots 42.

[0048] The radial flux motor winding 5 is in the shape of a rectangular ring.

[0049] Specifically, and then combined Figure 5 As shown, the radial flux motor winding 5 is located in the gap of the axial flux motor winding 3.

[0050] See also Figure 6 As shown, the axial flux motor permanent magnet 2, the rotor core 1, and the stator core 4 constitute the axial flux magnetic circuit (a), see Figure 6 As indicated by the dashed arrow, adjacent permanent magnets in the circumferential direction have opposite polarities. The axial flux motor permanent magnets 2 on the two outer rotor disks 12 are arranged with their same poles facing each other, and form parallel magnetic circuits with the air gap, windings, and part of the stator core on that side, respectively. The two parallel magnetic circuits pass through the stator core 4 in the circumferential direction. When the stator core 4 is sufficiently thick, the two magnetic circuits do not interfere with each other.

[0051] See also Figure 7 As shown, the radial flux motor permanent magnet 6, the rotor core 1, and the stator core 4 constitute a radial flux magnetic circuit and combine with the axial flux magnetic circuit (a) to form a hybrid axial-radial flux magnetic circuit (b). Figure 7 As indicated by the dashed arrow, the radial flux motor permanent magnet 6 has the same polarity as the nearest axial flux motor permanent magnet 2. Compared to a single axial flux, this composite motor provides a radial energy transfer path, resulting in a larger total flux of the motor. This allows the motor to have a larger output torque under the same conditions, thus improving the motor's torque density.

[0052] The aforementioned axial flux motor winding 3 and radial flux motor winding 5 are independently wound on the stator core 4. During the uphill phase of the vehicle, the motor is in a low-speed, high-torque output state. At this time, the axial flux motor winding 3 and radial flux motor winding 5 are connected in series. When the vehicle is running at high speed and smoothly, the motor is in a high-speed state. At this time, the radial flux motor winding 5 is set to 0 current excitation, that is, in a de-energized state, to reduce the magnetic flux density and increase the speed.

[0053] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0054] Furthermore, it is to be understood that the scope of the methods and systems of the present embodiments are not limited to what can be presently described and / or demonstrated. As such, the present embodiments are not to be limited to the specific illustrative situations and / or examples, but rather can be practiced with other like applications and / or in other like circumstances. Additionally, the features of certain examples can be combined with features of other examples.

[0055] The embodiments of the present application are described above with reference to the accompanying drawings, but the present application is not limited to the above-described specific embodiments, and the above-described specific embodiments are merely illustrative, but are not restrictive, and a person of ordinary skill in the art can make many forms under the inspiration of the present application without departing from the purpose of the present application and the scope protected by the claims, and all belong to the protection of the present application.

Claims

1. A wound-field switched three rotor permanent magnet synchronous machine with radial flux, characterized in that, The motor comprises a rotor core, axial flux motor permanent magnets, axial flux motor windings, a stator core, radial flux motor windings and radial flux motor permanent magnets, wherein: The rotor core comprises a cylindrical inner rotor disc and two annular outer rotor discs arranged in parallel at both ends of the inner rotor disc; The stator core is annular and is sleeved on the inner rotor disc and located between the two outer rotor discs, and comprises a plurality of radial stator slots arranged along the circumferential direction thereof and a plurality of axial stator slots arranged on the inner hole wall along the circumferential direction thereof; The number of the axial flux motor permanent magnets is multiple, and the multiple axial flux motor permanent magnets are arranged on the surfaces of the two outer rotor discs opposite to the stator core and are arranged in parallel with the stator core, and the axial flux motor permanent magnets arranged on the two outer rotor discs are arranged in opposite poles; The number of the radial flux motor permanent magnets is multiple, and the multiple radial flux motor permanent magnets are arranged on the surface of the inner rotor disc opposite to the stator core and are arranged in parallel with the stator core; The number of the axial flux motor windings is multiple, and the multiple axial flux motor windings are arranged in the radial stator slots; The number of the radial flux motor windings is multiple, and the multiple radial flux motor windings are arranged in the axial stator slots; The axial flux motor windings and the radial flux motor windings can be connected in series by an external switch circuit or the radial flux motor windings can be powered off alone, so that the two sets of windings are connected in series to improve the output torque in low-speed working conditions, and the radial flux motor windings are powered off to perform flux-weakening speed expansion in high-speed working conditions.

2. The axial-radial flux hybrid wound-field switched three-rotor permanent magnet synchronous machine of claim 1, wherein, The outer rotor disc and the inner rotor disc are integrally formed.

3. The axial-radial flux hybrid wound-switched three-rotor permanent magnet synchronous machine of claim 1 or 2, wherein, In the circumferential direction of the outer rotor disc, the polarities of any two adjacent axial flux motor permanent magnets are opposite.

4. The axial-radial flux hybrid wound-switched three-rotor permanent magnet synchronous machine of claim 3, wherein, The radial flux motor permanent magnet and the closest axial flux motor permanent magnet have the same polarity.

5. The axial-radial flux hybrid wound-switched three-rotor permanent magnet synchronous machine of claim 1, wherein, The axial flux motor windings are arranged at equal intervals in the circumferential direction of the stator core.

6. The axial-radial flux hybrid wound-switched three-rotor permanent magnet synchronous machine of claim 5, wherein, The radial flux motor windings are located in the gaps of the axial flux motor windings.

7. The axial-radial flux hybrid wound-switched three-rotor permanent magnet synchronous machine of claim 1, wherein, Both the axial flux motor permanent magnets and the radial flux motor permanent magnets are surface-mounted on the surface of the rotor core.

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