Three-stator disc and double-rotor disc type axial flux permanent magnet motor

Abstract

In order to solve the problems of small torque density, large vibration and noise and the like of an axial magnetic flux permanent magnet motor, the utility model provides a three-stator disc and double-rotor disc type axial magnetic flux permanent magnet motor, which comprises a first stator disc, an upper rotor disc, a second stator disc, a lower rotor disc and a third stator disc which are sequentially distributed along the axial direction, the upper rotor disc consists of an upper rotor iron core, and a first permanent magnet group and a second permanent magnet group which are fixedly connected to two axial sides of the upper rotor iron core; the lower rotor disc is composed of a lower rotor iron core, and a third permanent magnet group and a fourth permanent magnet group which are fixedly connected to two axial sides of the lower rotor iron core; the circumferential dislocation included angle between the first permanent magnet set and the second permanent magnet set is theta, the circumferential dislocation included angle between the third permanent magnet set and the fourth permanent magnet set is theta / 2, through the structural arrangement, the peak values and valley values of torque ripples and cogging torque ripples of the two rotors are superposed, the overall output torque ripple and cogging torque are effectively reduced, vibration and noise are reduced, and the service life of the motor is prolonged. And the safety, stability and reliability of operation are improved.

Description

Technical Field

[0001] The utility model relates to the technical field of axial flux permanent magnet motors, in particular to a three-stator disk and double-rotor disk type axial flux permanent magnet motor. Background Art

[0002] Since the single-stator single-rotor axial flux permanent magnet motor has only one rotor and stator combination, its energy conversion capacity may be limited and the power density is relatively low. At the same time, the single structure may cause internal heat accumulation, especially when operating at high power, heat dissipation becomes a challenge, which may affect the motor's continuous operation capability and life. In addition, the single-stator single-rotor axial flux permanent magnet motor has inevitable rotor unbalanced axial tension due to its own design problems, which will affect the positioning and stability of the rotor, especially when running at high speeds, this effect may be more obvious, and will also increase the load on the bearing, which may cause increased bearing wear and shorten the service life of the bearing. In addition, it will cause vibration and noise during the operation of the motor, affecting the smoothness and reliability of the motor. Finally, the single-stator single-rotor axial flux permanent magnet motor has relatively high torque pulsation and cogging torque, which will also cause vibration and noise, affecting the quality of the motor output and the safety and stability of operation.

[0003] Although the axial flux permanent magnet motor with a multi-disk composite structure can provide a larger torque density, its assembly and design are very complicated. The dynamic interaction of multiple rotors may cause system imbalance, vibration and noise. Utility Model Content

[0004] In order to solve the problems of low torque density, high vibration and noise of axial flux permanent magnet motor, the utility model provides a three-stator disk, double-rotor disk axial flux permanent magnet motor, and the technical solution adopted is as follows:

[0005] A three-stator-disc, double-rotor-disc axial flux permanent magnet motor, characterized in that it comprises:

[0006] A first stator disk, an upper rotor disk, a second stator disk, a lower rotor disk and a third stator disk are sequentially distributed along the axial direction;

[0007] Stator teeth are arranged on one side of the first stator disk close to the upper rotor disk, on both axial sides of the second stator disk, and on one side of the third stator disk close to the lower rotor disk, and windings are arranged in the stator teeth respectively;

[0008] The upper rotor disk is composed of an upper rotor core and a first permanent magnet group and a second permanent magnet group fixedly connected to both axial sides of the upper rotor core;

[0009] The lower rotor disk is composed of a lower rotor core and a third permanent magnet group and a fourth permanent magnet group fixedly connected to both axial sides of the lower rotor core;

[0010] The first permanent magnet group, the second permanent magnet group, the third permanent magnet group and the fourth permanent magnet group are each composed of multiple groups of permanent magnets, and the multiple groups of permanent magnets are evenly spaced and distributed along the circumferential direction of the respective rotor cores;

[0011] The misalignment angle between the first permanent magnet group and the second permanent magnet group in the circumferential direction of the upper rotor core is θ, and the misalignment angle between the third permanent magnet group and the fourth permanent magnet group in the circumferential direction of the lower rotor core is θ / 2.

[0012] Preferably, θ=360° / [s*p / GCD(s,p)], wherein s and p are the number of slots and the number of pole pairs of the single-rotor disc axial flux permanent magnet motor, and GCD(s,p) is the greatest common divisor of s and p.

[0013] Preferably, the two permanent magnets axially opposite to each other on the upper rotor core and the lower rotor core are both offset.

[0014] Preferably, the longitudinal cross-sections of the permanent magnets on the first permanent magnet group, the second permanent magnet group, the third permanent magnet group and the fourth permanent magnet group are all fan-shaped structures composed of two arc lines and two straight line segments, the two arc segments overlap with the inner circle and the outer circle of the rotor disk respectively, the inner and outer ends of the straight line are respectively connected between the endpoints on the same side of the two arc segments, and the angle γ=θ / 4 is formed between the line connecting the inner end of the straight line segment to the center of the rotor disk and the line connecting the outer end of the straight line to the center of the rotor disk.

[0015] Preferably, the angle between the line between the straight segments of two permanent magnets axially oppositely arranged on the upper rotor core or the lower rotor core and the center of the rotor disk is the same as the angle between the line between the outer ends of the straight segments and the center of the rotor disk and the deflection directions are opposite.

[0016] Preferably, the power supply phase difference between two axially adjacent windings on the first stator disk, the second stator disk and the third stator disk is p*θ / 2, p*θ / 4 and p*θ / 2 respectively.

[0017] The beneficial effects of the utility model are:

[0018] 1. The three-stator disc and double-rotor disc structure can effectively improve the motor power density and reduce the motor volume at the same output power;

[0019] 2. The first permanent magnet group and the second permanent magnet group are axially offset by θ, and the third permanent magnet group and the fourth permanent magnet group are circumferentially offset by θ / 2, so that the upper and lower surfaces of the upper rotor disk and the lower rotor disk are respectively subjected to the superposition of the peaks and troughs of the cogging torque ripples, and the total cogging torque fluctuations on the axial upper and lower surfaces of the respective rotor disks are reduced, and the second permanent magnet group and the third permanent magnet group are circumferentially offset by θ / 2 in the same or opposite direction, so that the peak values ​​and trough values ​​of the cogging torque between the upper rotor disk and the lower rotor disk are further superimposed, and the total cogging torque is further reduced;

[0020] 3. By limiting the shape of the permanent magnets and arranging two axially opposite permanent magnets on the same rotor disk in an offset manner, the overall output torque fluctuation and cogging torque can be reduced, vibration and noise can be reduced, and the safety, stability and reliability of the motor operation can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a three-dimensional structural diagram of the utility model

[0022] Figure 2 This is the main view of the utility model

[0023] Figure 3 Schematic diagram of the rotor disk structure

[0024] Figure 4 Schematic diagram of the permanent magnet distribution structure of the upper rotor disk

[0025] Figure 5 Schematic diagram of cogging torque distribution

[0026] Figure 6 Schematic diagram of torque fluctuation

[0027] Among them, 1-first stator disc, 11-stator teeth of the first stator disc, 12-first stator disc winding;

[0028] 2-upper rotor disk, 21-first permanent magnet group, 22-upper rotor core, 23-second permanent magnet group;

[0029] 3-second stator disc, 31-stator tooth 1 of second stator disc, 32-stator tooth 2 of second stator disc, 33-winding group 1 of second stator disc, 34-winding group 2 of second stator disc;

[0030] 4-lower rotor disc, 41-third permanent magnet group, 42-lower rotor core, 43-fourth permanent magnet group;

[0031] 5-third stator disc, 51-stator teeth of the third stator disc, 52-third stator disc winding. DETAILED DESCRIPTION

[0032] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0033] In the description of the utility model, it is necessary to understand that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the viewing direction or position relationship, and are only for the convenience of describing the utility model, 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 cannot be understood as a limitation on the utility model.

[0034] The three-stator-disc, double-rotor-disc axial flux permanent magnet motor comprises a stator, a rotor, and a winding. Specifically, the motor comprises a first stator disk 1, an upper rotor disk 2, a second stator disk 3, a lower rotor disk 4, and a third stator disk 5 which are coaxially arranged in sequence along the axial direction. The first stator disk 1 is provided with a first stator disk stator tooth 11 and a first stator disk winding 12, and Figure 2 In the direction of the view shown, the first stator disc stator tooth 11 is located at the lower part of the first stator disc 1; the upper rotor disc 2 is composed of an upper rotor core 22 and a first permanent magnet group 21 and a second permanent magnet group 23 fixedly connected to the upper and lower side surfaces of the upper rotor core 22; the upper and lower parts of the second stator disc 3 are respectively provided with a second stator disc stator tooth 1 31 and a second stator tooth 2 32, and the second stator disc stator tooth 1 31 and the second stator tooth 2 32 are respectively provided with a second stator disc winding group 1 33 and a second stator disc winding group 2 34; the lower rotor disc 4 is composed of a lower rotor disc core 42 and a third permanent magnet group 41 and a fourth permanent magnet group 43 fixedly connected to the upper and lower sides of the lower rotor disc core 42; the third stator disc stator tooth 51 is provided at the upper part of the third stator disc 5, and the third stator disc stator tooth 51 is provided with a third stator disc winding group 52.

[0035] Specifically, the permanent magnet groups on the upper and lower sides of the upper rotor disk 2 and the lower rotor disk 4 are composed of multiple permanent magnets, and the multiple permanent magnets are evenly spaced and distributed along the circumferential direction of their respective rotor cores, such as Figure 2 As shown, the first permanent magnet group 21 and the second permanent magnet group 23 are staggered in the circumferential direction of the upper rotor core 22, and the first staggered angle is θ. The third permanent magnet group 41 and the fourth permanent magnet group 43 are staggered in the circumferential direction of the lower rotor core 42, and the second staggered angle is θ / 2. The second staggered angle can be in the same direction as or opposite to the first staggered angle. The third staggered angle of the second permanent magnet group 23 and the third permanent magnet group 41 along the circumferential direction is θ / 2. Therefore, the circumferential staggered angle between the third stator disk stator tooth 51 and the second stator disk stator tooth 2 32 is θ, the circumferential staggered angle between the second stator disk stator tooth 2 32 and the second stator disk stator tooth 1 31 is θ / 2, and the circumferential staggered angle between the second stator disk stator tooth 1 31 and the first stator disk stator tooth 11 is θ.

[0036] Wherein, θ=360° / [s*p / GCD(s,p)], s and p are the number of slots and pole pairs of the single rotor disc axial flux permanent magnet motor, and GCD(s,p) is the greatest common divisor of s and p.

[0037] like Figure 5 As shown, by designing the offset angle of the first permanent magnet group 21 and the second permanent magnet group 23, the upper rotor disk 2 receives the cogging torque ripple peaks and troughs superimposed, so that the total cogging torque fluctuation received by the upper rotor disk 2 axially on the upper and lower sides is reduced; by designing the offset angle of the third permanent magnet group 41 and the fourth permanent magnet group 43, the upper and lower sides of the lower rotor disk 4 receive the cogging torque ripple peaks and troughs superimposed, so that the total cogging torque fluctuation received by the lower rotor disk 4 axially on the upper and lower sides is reduced; the offset angle between the third permanent magnet group 41 and the second permanent magnet group 23 in the circumferential direction can further superimpose the cogging torque ripple peaks and troughs of the upper rotor disk 2 and the lower rotor disk 4, so as to further reduce the total cogging torque.

[0038] The power supply phases of the four sets of windings from top to bottom differ by p*θ / 2, p*θ / 4, and p*θ / 2 respectively, which can make the torque ripple peak and valley values ​​of the upper rotor disk 2 and the lower rotor disk 4 be superimposed twice like the tooth torque, thereby further reducing the total torque fluctuation, reducing vibration and noise, and improving the output quality and the safety, stability and reliability of operation.

[0039] In this embodiment, taking a 6-pole 9-slot motor as an example, the permanent magnet group is Figure 2 In the direction shown, the circumferential misalignment angles from bottom to top are 10°, 5°, and 10° respectively, and the phase differences of the stator windings from bottom to top are 30°, 15°, and 30° respectively.

[0040] In order to further reduce torque ripple and cogging torque, the shape of the permanent magnet is further improved in this embodiment, such as Figure 4 As shown, the longitudinal section of the permanent magnet is fan-shaped, consisting of two arc segments and two straight segments. The two arc segments include an inner arc segment and an outer arc segment, which are respectively concentric with the inner circle and the outer circle of the rotor core and have the same tangent radius. The two straight segments are respectively connected between the end points of the inner arc segment and the outer arc segment, and the angle γ between the line connecting the inner end of one straight segment to the center of the rotor core and the line connecting the outer end of the straight segment to the rotor core is θ / 4, and the angle γ between the line connecting the inner end of the other straight segment to the center of the rotor core and the line connecting the outer end of the straight segment to the rotor core is also θ / 4.

[0041] In addition, the deflection directions of the angles between the inner ends of the two axially opposite permanent magnet straight segments and the lines between the outer ends and the center of the rotor core are opposite to each other on the same rotor disk, forming a permanent magnet offset structure. Through the design of this structure, Figure 6As shown, the overall output torque fluctuation and cogging torque can be further reduced, vibration and noise can be reduced, and the quality of motor output and the safety, stability and reliability of operation can be improved.

[0042] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements can be made without departing from the principle of the present invention, and these improvements should also be regarded as the protection scope of the present invention.

Claims

1. A three-stator-disc, double-rotor-disc axial flux permanent magnet motor, characterized in that: include: A first stator disk, an upper rotor disk, a second stator disk, a lower rotor disk and a third stator disk are sequentially distributed along the axial direction; Stator teeth are arranged on one side of the first stator disk close to the upper rotor disk, on both axial sides of the second stator disk, and on one side of the third stator disk close to the lower rotor disk, and windings are arranged in the stator teeth respectively; The upper rotor disk is composed of an upper rotor core and a first permanent magnet group and a second permanent magnet group fixedly connected to both axial sides of the upper rotor core; The lower rotor disk is composed of a lower rotor core and a third permanent magnet group and a fourth permanent magnet group fixedly connected to both axial sides of the lower rotor core; The first permanent magnet group, the second permanent magnet group, the third permanent magnet group and the fourth permanent magnet group are each composed of multiple groups of permanent magnets, and the multiple groups of permanent magnets are evenly spaced and distributed along the circumferential direction of the respective rotor cores; The misalignment angle between the first permanent magnet group and the second permanent magnet group in the circumferential direction of the upper rotor core is θ, and the misalignment angle between the third permanent magnet group and the fourth permanent magnet group in the circumferential direction of the lower rotor core is θ / 2.

2. The three-stator-disc, double-rotor-disc axial flux permanent magnet motor according to claim 1 is characterized in that: The θ=360° / [s*p / GCD(s,p)], wherein s and p are the number of slots and the number of pole pairs of the single rotor disc axial flux permanent magnet motor, and GCD(s,p) is the greatest common divisor of s and p.

3. The three-stator-disc, double-rotor-disc axial flux permanent magnet motor according to claim 1, characterized in that: The two permanent magnets axially opposite to each other on the upper rotor core and the lower rotor core are both offset.

4. The three-stator-disc, double-rotor-disc axial flux permanent magnet motor according to claim 1 or 3, characterized in that: The longitudinal cross-sections of the permanent magnets on the first permanent magnet group, the second permanent magnet group, the third permanent magnet group and the fourth permanent magnet group are all fan-shaped structures composed of two arc lines and two straight line segments, the two arc segments overlap with the inner circle and the outer circle of the rotor disk respectively, the inner and outer ends of the straight line are respectively connected between the end points on the same side of the two arc segments, and the angle γ=θ / 4 between the line connecting the inner end of the straight line segment to the center of the rotor disk and the line connecting the outer end of the straight line to the center of the rotor disk.

5. The three-stator-disc, double-rotor-disc axial flux permanent magnet motor according to claim 4, characterized in that: The included angle between the line between the straight segments of the two permanent magnets axially oppositely arranged on the upper rotor core or the lower rotor core and the center of the rotor disk is the same as the line between the outer ends of the straight lines and the center of the rotor disk, and the deflection directions are opposite.

6. The three-stator-disc, double-rotor-disc axial flux permanent magnet motor according to claim 1, characterized in that: The power supply phase differences between two axially adjacent windings on the first stator disk, the second stator disk and the third stator disk are p*θ / 2, p*θ / 4 and p*θ / 2 respectively.

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