Axial flux motor stator assembly, axial flux motor and control method thereof

Abstract

The present invention relates to the field of electric motors and discloses an axial flux motor stator assembly, an axial flux motor, and a control method thereof. The axial flux motor stator assembly comprises an outer stator and an inner stator; the outer stator surrounds an outer axial hole, and the inner stator is disposed within the outer axial hole and surrounds an inner axial hole, wherein the central axis of the outer axial hole coincides with the central axis of the inner axial hole. Compared with the prior art, the axial flux motor stator assembly, axial flux motor, and control method thereof provided by embodiments of the present invention have the advantage of improving the output torque of the axial flux motor.

Description

Technical Field

[0001] The present invention relates to the field of motors, and in particular to an axial flux motor stator assembly, an axial flux motor and a control method thereof. Background Art

[0002] The axial flux motor has a compact structure and high torque power density, making it suitable for applications requiring high torque density, such as radar, electric vehicles, flywheel energy storage systems, and elevators.

[0003] However, the inventors of the present invention have discovered that the axial flux motors in the prior art are generally flat in structure, with a relatively large outer diameter and insufficient inner diameter space utilization. The windings have a relatively large number of turns, and in high-speed applications, a higher supply voltage is required to output the required torque. In practical applications, axial flux motors are used in conjunction with inverters and control systems. To provide high output torque at high speeds, a higher bus voltage is required. High bus voltage places higher demands on the system's power supply, battery voltage, or rectifier circuit. Therefore, how to improve the output torque of axial flux motors has become an urgent problem to be solved. Summary of the Invention

[0004] The purpose of the embodiments of the present invention is to provide an axial flux motor stator assembly, an axial flux motor and a control method thereof, which can improve the output torque of the axial flux motor.

[0005] In order to solve the above technical problems, an embodiment of the present invention provides an axial flux motor stator assembly, including: an outer stator and an inner stator; the outer stator is surrounded by an outer axial hole, the inner stator is arranged in the outer axial hole and surrounded by an inner axial hole, and the central axis of the outer axial hole coincides with the central axis of the inner axial hole.

[0006] An embodiment of the present invention also provides an axial flux motor, comprising: a first stator assembly, the first stator assembly being the axial flux motor stator assembly as described above; a rotor, the rotor being spaced apart from the first stator assembly, the rotor comprising a rotor axial hole, the central axis of the rotor axial hole coinciding with the central axis of the outer axial hole in the axial flux motor stator assembly, the rotor being arranged on one side of the first stator assembly in the axial direction.

[0007] An embodiment of the present invention also provides an axial flux motor control method, which is applied to the axial flux motor as described above, including: detecting the real-time speed of the axial flux motor; if the real-time speed is less than the base speed, inputting current into both the outer stator and the inner stator; if the real-time speed is greater than the base speed, inputting current into the outer stator or the inner stator.

[0008] Compared with the prior art, the embodiment of the present invention sets the stator assembly of the axial flux motor as a double-layer structure including an outer stator and an inner stator, and sets the inner stator in an outer axial hole formed around the outer stator. Since the outer axial hole and the center axis formed around the outer stator coincide with the center axis of the inner axial hole formed around the inner stator, when the control system detects that the motor speed is lower than the base speed, the inner and outer stators work simultaneously and output torque in the same direction, thereby effectively improving the overall output torque of the motor; in addition, when the control system detects that the motor speed is higher than the base speed, the outer stator winding or the inner stator winding can be disconnected, and the motor works in a single stator form. The inductance of the single stator is relatively reduced, which makes it easier to achieve high-speed operation requirements and improve the scope of use of the axial flux motor.

[0009] In addition, the outer stator and the inner stator have different numbers of coil turns. Setting the outer stator and the inner stator to have different numbers of coil turns can optimize the harmonics and noise vibrations generated during the operation of the axial flux motor, making the operation process of the axial flux motor more stable.

[0010] In addition, the coils of the outer stator and the coils of the inner stator are connected to each other. By connecting the coils of the outer stator and the coils of the inner stator, the outer stator and the inner stator can be controlled at the same time.

[0011] In addition, the coils of the outer stator and the coils of the inner stator are insulated from each other. By isolating the coils of the outer stator and the inner stator from each other, different power buses can be used to control the outer stator and the inner stator separately, or a three-phase power supply can be used to control the outer stator and the inner stator separately.

[0012] In addition, the cross-sectional area of ​​the rotor axial hole in the axial direction is equal to the cross-sectional area of ​​the inner axial hole in the stator assembly of the axial flux motor in the axial direction.

[0013] In addition, it also includes: a second stator assembly, the second stator assembly is the axial flux motor stator assembly as mentioned above, the first stator assembly and the second stator assembly are opposite to each other in the extension direction of the central axis and are coaxially arranged; the rotor is arranged between the first stator assembly and the second stator assembly.

[0014] In addition, the rotor includes a first rotating part and a second rotating part; the first rotating part is arranged opposite to the outer stator in the axial flux motor stator assembly in the extension direction of the central axis; the second rotating part is arranged opposite to the inner stator in the axial flux motor stator assembly in the extension direction of the central axis.

[0015] In addition, it also includes: a connecting part, which is connected to both the first rotating part and the second rotating part, and is used to fix the first rotating part and the second rotating part to each other or separate them from each other. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 1 is a schematic structural diagram of a stator assembly of an axial flux motor provided by a first embodiment of the present invention;

[0017] Figure 2 is an axial view of the stator assembly of the axial flux motor provided by the first embodiment of the present invention;

[0018] Figure 3 is a schematic structural diagram of an axial flux motor provided by a second embodiment of the present invention;

[0019] Figure 4 is a schematic structural diagram of an axial flux motor provided by a third embodiment of the present invention;

[0020] Figure 5 4 is a flow chart of an axial flux motor control method provided by the fourth embodiment of the present invention. DETAILED DESCRIPTION

[0021] To make the objectives, technical solutions, and advantages of the present invention more apparent, various embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, those skilled in the art will appreciate that many technical details are provided in various embodiments of the present invention to help readers better understand the present application. However, even without these technical details and various variations and modifications based on the following embodiments, the technical solutions claimed in this application can still be implemented.

[0022] The first embodiment of the present invention relates to an axial flux motor stator assembly, the specific structure of which is as follows: Figure 1 、 Figure 2 As shown, it includes: an outer stator 10 and an inner stator 20, wherein the outer stator 10 surrounds to form an outer axial hole 11, the inner stator 20 is arranged in the outer axial hole 11 formed by the outer stator 10, and the inner stator 20 surrounds to form an inner axial hole 21. The central axis of the outer axial hole 11 coincides with the central axis of the inner axial hole 21, and both are Figure 1 Axis OO' in.

[0023] Compared to the prior art, the axial flux motor stator assembly provided in the first embodiment of the present invention includes an outer stator 10 and an inner stator 20. Because the inner stator 20 is disposed within an outer axial bore 11 formed around the outer stator 10, and the central axis of the outer axial bore 11 coincides with the central axis of the inner axial bore 21, during use, power can be supplied to both the outer stator 10 and the inner stator 20 simultaneously, causing them to output torque in the same direction, thereby increasing the output torque of the axial flux motor. Furthermore, during use, power can be supplied to only one of the outer stator 10 and the inner stator 20, depending on demand. This reduces the inductance of a single stator, making it easier to achieve high-speed operation requirements and expanding the range of applications for the axial flux motor.

[0024] Specifically, in this embodiment, if Figure 1 、 2 As shown, the outer stator 10 includes a plurality of outer stator coils 12, and the inner stator 20 includes a plurality of inner stator coils 22. The outer stator coils 12 and the inner stator coils 22 have different numbers of turns. Setting the outer stator 10 and the inner stator 20 to have different numbers of turns can optimize the harmonics and noise vibrations generated during the operation of the axial flux motor, making the operation of the axial flux motor more stable.

[0025] Furthermore, in this embodiment, the outer stator coil 12 and the inner stator coil 22 are interconnected. By interconnecting the outer stator coil 12 and the inner stator coil 22, a single power bus can simultaneously input current to the outer stator 10 and the inner stator 20, thereby simultaneously controlling the outer stator 10 and the inner stator 20.

[0026] It will be appreciated that the aforementioned interconnection of the outer stator coil 12 and the inner stator coil 22 is merely an example of a specific embodiment of the present invention and does not constitute a limitation. In other embodiments of the present invention, the outer stator coil 12 and the inner stator coil 22 may be insulated from each other. By isolating the coils of the outer stator 10 and the inner stator 20 from each other, the outer stator 10 and the inner stator 20 can be controlled separately using different power busbars, or by using a three-phase power supply to control the outer stator 10 and the inner stator 20, thereby expanding the applicability of the axial flux motor.

[0027] The second embodiment of the present invention relates to an axial flux motor. Figure 3 As shown, it includes: a first stator assembly 100, the first stator assembly 100 is the axial flux motor stator assembly provided in the above embodiment, which can include the outer stator 10, the outer axial hole 11, the inner stator 20 and the inner axial hole 21 in the axial flux motor stator assembly provided in the above embodiment. A rotor 200, the rotor 200 and the first stator assembly 100 are spaced apart from each other, and the rotor 200 is arranged on the first stator assembly 100 along the axial direction ( Figure 3 On one side (in the middle A direction), the rotor 100 includes a rotor axial hole 101, and the central axis of the rotor axial hole 101 coincides with the central axis of the outer axial hole 11 in the first stator assembly 100, that is, they are both axis OO'.

[0028] Compared with the prior art, the axial flux motor provided in the second embodiment of the present invention is provided with the axial flux motor stator assembly provided in the aforementioned embodiment. Therefore, the axial flux motor provided in this embodiment also has the technical effects provided by the aforementioned embodiment, which will not be repeated here. For details, please refer to the specific description of the aforementioned embodiment.

[0029] Preferably, in this embodiment, the rotor axial hole 101 is axially ( Figure 3 The cross-sectional area in the direction A) of the rotor axial hole 101 is equal to the cross-sectional area in the axial direction of the inner axial hole 21 in the first stator assembly 100. It can be understood that the cross-sectional area in the direction A) of the rotor axial hole 101 is equal to the cross-sectional area in the axial direction of the inner axial hole 21 in the first stator assembly 100. Figure 3 The cross-sectional area in the axial direction (A) of the rotor axial hole 101 is equal to the cross-sectional area in the axial direction of the inner axial hole 21 in the first stator assembly 100. This is only a specific example in this embodiment and does not constitute a limitation. In other embodiments of the present invention, the cross-sectional area of ​​the rotor axial hole 101 in the axial direction (A) may be equal to the cross-sectional area in the axial direction of the inner axial hole 21 in the first stator assembly 100. Figure 3 The cross-sectional area in the direction A) is smaller or larger than the cross-sectional area of ​​the inner axial hole 21 in the first stator assembly 100 in the axial direction. For example, the cross-sectional area of ​​the rotor axial hole 101 in the axial direction ( Figure 3 The difference between the cross-sectional area in the direction A in the middle and the cross-sectional area of ​​the inner axial hole 21 in the first stator assembly 100 in the axial direction is less than 5%, 10%, etc. of the cross-sectional area of ​​the rotor axial hole 101 in the axial direction, and can be flexibly set according to actual needs.

[0030] Preferably, in this embodiment, the rotor 200 includes a first rotating portion 202 and a second rotating portion 203, wherein the first rotating portion 202 is disposed opposite the outer stator 10 of the first stator assembly along the direction of extension of the central axis OO'; and the second rotating portion 203 is disposed opposite the inner stator 20 of the first stator assembly 100 along the direction of extension of the central axis OO'. With the first rotating portion 202 disposed opposite the stator 10 and the second rotating portion 203 disposed opposite the inner stator 20, when power is supplied solely to the outer stator, the magnetic field at the position opposite the outer stator 10 is more stable and has a higher magnetic field intensity. This allows the first rotating portion 202 to be driven more stably by the outer stator 10, thereby preventing interference with rotor rotation in an unstable magnetic field when power is supplied solely to the outer stator, thereby improving the operational stability of the axial flux motor. Similarly, when power is supplied solely to the inner stator 20, interference with the stability of the axial flux motor by the portion of the rotor opposite the outer stator 10 is prevented.

[0031] The rotor 200 also includes a connecting portion 204 connecting the first rotating portion 202 and the second rotating portion 203. The connecting portion 204 is connected to both the first rotating portion 202 and the second rotating portion 203 and is used to secure or separate the first rotating portion 202 and the second rotating portion 203 from each other. Specifically, the connecting portion 204 separates the first rotating portion 202 and the second rotating portion 203 when power is supplied to only the outer stator 10 or the inner stator 20, and secures the first rotating portion 202 and the second rotating portion 203 when power is supplied to both the outer stator 10 and the inner stator 20. It should be understood that the foregoing is merely an example of the operating principle of the connecting portion 204 in this embodiment of the present invention. In actual use, the connecting portion 204 can also secure the first rotating portion 202 and the second rotating portion 203 when current is supplied in the same direction to the outer stator 10 and the inner stator 20, respectively, and secure the first rotating portion 202 and the second rotating portion 203 when current is supplied in different phases to the outer stator 10 and the inner stator 20, respectively. The specific settings can be flexibly made according to actual needs.

[0032] The third embodiment of the present invention relates to an axial flux motor, the specific structure of which is as follows: Figure 4 As shown, in addition to the first stator assembly 100 and the rotor 200, the motor may also include a second stator assembly 300. The second stator assembly 300 is the stator assembly of the axial flux motor provided in the aforementioned embodiment. The first stator assembly 100 and the second stator assembly 300 are opposite to each other in the extension direction of the central axis OO' and are coaxially arranged. The rotor 200 is arranged between the first stator assembly 100 and the second stator assembly 300.

[0033] Compared with the prior art, the second stator assembly 300 additionally arranged opposite to the first stator assembly 100 in the axial flux motor provided in the third embodiment of the present invention can effectively enhance the magnetic field strength and magnetic field stability between the first stator assembly 100 and the second stator assembly 300. The rotor 200 arranged between the first stator assembly 100 and the second stator assembly 300 can rotate more stably in a magnetic field with higher strength and higher stability, thereby effectively improving the stability of the axial flux motor.

[0034] The fourth embodiment of the present invention provides an axial flux motor control method, which is applied to the axial flux motor provided in the above embodiment. The specific steps are as follows: Figure 5 Shown, including:

[0035] Step S101: detecting the real-time rotation speed of the axial flux motor.

[0036] Step S102: Determine whether the implementation speed is less than the base speed. If so, execute step S103; if not, execute step S104.

[0037] Step S103: inputting current into both the outer stator and the inner stator;

[0038] Step S104: inputting current into the outer stator or the inner stator.

[0039] It is understandable that the step division of the various methods above is only for the purpose of clear description. During implementation, they can be combined into one step or some steps can be split and decomposed into steps. As long as they contain the same logical relationship, they are all within the scope of protection of this patent; adding insignificant modifications to the algorithm or process or introducing insignificant designs without changing the core design of the algorithm and process are all within the scope of protection of this patent.

[0040] It is not difficult to see that this embodiment is an embodiment of the axial flux motor control method corresponding to the aforementioned embodiment, and this embodiment can be implemented in conjunction with the aforementioned embodiment. The relevant technical details and technical effects mentioned in the aforementioned embodiment are still valid in this embodiment, and to reduce repetition, they are not repeated here. Accordingly, the relevant technical details mentioned in this embodiment can also be applied to the external embodiment.

[0041] Those skilled in the art will appreciate that the above-mentioned embodiments are specific examples for implementing the present invention, and that in actual applications, various changes may be made thereto in form and detail without departing from the spirit and scope of the present invention.

Claims

1. An axial flux motor, characterized in that: include: A first stator assembly, comprising: an outer stator and an inner stator; The outer stator is surrounded to form an outer axial hole, the inner stator is arranged in the outer axial hole and is surrounded to form an inner axial hole, and the central axis of the outer axial hole coincides with the central axis of the inner axial hole; a rotor, the rotor being spaced apart from the first stator assembly, the rotor comprising a rotor axial hole, the central axis of the rotor axial hole coinciding with the central axis of the outer axial hole in the stator assembly of the axial flux motor, the rotor being disposed on one side of the first stator assembly in the axial direction; The rotor includes a first rotating part and a second rotating part; The first rotating portion is arranged opposite to the outer stator in the axial flux motor stator assembly in the extending direction of the central axis; The second rotating portion is arranged opposite to the inner stator in the stator assembly of the axial flux motor in the extending direction of the central axis; a connecting portion connected to both the first rotating portion and the second rotating portion, wherein the connecting portion separates the first rotating portion and the second rotating portion from each other when the outer stator or the inner stator receives input current, and fixes the first rotating portion and the second rotating portion to each other when both the outer stator and the inner stator receive input current; Among them, if the real-time speed of the axial flux motor is less than the base speed, both the outer stator and the inner stator receive input current; if the real-time speed of the axial flux motor is greater than the base speed, the outer stator or the inner stator receives input current.

2. The axial flux motor according to claim 1, characterized in that The outer stator and the inner stator have different numbers of coil turns.

3. The axial flux motor according to claim 1, characterized in that The coils of the outer stator and the coils of the inner stator are connected to each other.

4. The axial flux motor according to claim 1, characterized in that The coils of the outer stator and the coils of the inner stator are insulated from each other.

5. The axial flux motor according to claim 1, characterized in that The cross-sectional area of ​​the rotor axial hole in the axial direction is equal to the cross-sectional area of ​​the inner axial hole in the first stator assembly in the axial direction.

6. The axial flux motor according to claim 1, characterized in that Also includes: A second stator assembly, comprising: an outer stator and an inner stator; The outer stator is surrounded to form an outer axial hole, the inner stator is arranged in the outer axial hole and is surrounded to form an inner axial hole, and the central axis of the outer axial hole coincides with the central axis of the inner axial hole; The first stator assembly and the second stator assembly are opposite to each other in the extension direction of the central axis and are coaxially arranged; The rotor is disposed between the first stator assembly and the second stator assembly.

7. A method for controlling an axial flux motor, characterized in that: The axial flux motor according to any one of claims 1 to 6 comprises: detecting a real-time rotational speed of the axial flux motor; If the real-time speed is less than the base speed, current is input into both the outer stator and the inner stator; If the real-time rotation speed is greater than the base speed, current is input into the outer stator or the inner stator.

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