Halbach array motor

Abstract

The invention discloses a halbach array motor, and the motor comprises a stator which is fixedly disposed on a motor housing; the rotor is coaxially arranged on the inner side of the stator and is rotatably mounted on the motor shaft; the air gap is located between the stator and the rotor, the rotor comprises rotor segmented halbach array magnets, the rotor segmented halbach array magnets are annular halbach magnets and are divided into 10 poles, each pole comprises 6 segments of magnets, the 6 segments of magnets of each pole are adjacently arranged and are in axial symmetry, and the symmetry axis is the geometric center between two segments of magnets of the arrangement center of the 6 segments of magnets. According to the invention, the six-segment halbach array magnets are arranged, so that the magnetic field intensity in the unit direction can be enhanced, the counter potential capability of the motor is improved, the counter potential harmonic is reduced, and the performance of the motor is improved. In addition, on the premise of the same performance, the usage amount of the permanent magnets can be greatly reduced, so that the cost of the motor is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of motors, and in particular to a Halbach array motor. Background Art

[0002] The traditional braking system uses the engine to provide a vacuum source and relies on a vacuum booster to achieve braking assistance. However, the new generation of one-box brake-by-wire system gets rid of the dependence on vacuum assistance and optimizes the vacuum booster in the braking system into a brake motor booster to achieve braking for intelligent assisted driving. This makes the brake motor particularly important in the new generation of brake-by-wire systems. However, currently, the cost of the mainstream one-box motor in the market accounts for about 20% of the cost of the entire braking system, with a relatively high proportion, and the NVH performance cannot reach the optimal level of the whole vehicle.

[0003] In order to further improve the performance and cost advantage of the brake motor, a new type of Halbach array rotor is adopted. In the prior art, a scheme of a four-segment Halbach array surface-mounted permanent magnet motor is proposed, but it does not involve the optimization and performance improvement of the Halbach rotor, as well as optimizations such as increasing the back electromotive force of the motor, reducing the torque ripple of the motor, and increasing the power density of the whole motor. Summary of the Invention

[0004] In view of this, the present invention proposes a Halbach array motor, which can at least solve the aforementioned technical problems.

[0005] The Halbach array motor of the present invention includes: a stator, which is fixedly installed in the motor housing; a rotor, which is coaxially arranged inside the stator and is rotatably installed on the motor shaft; an air gap, which is between the stator and the rotor, and the rotor includes a rotor segmented Halbach array magnet. The rotor segmented Halbach array magnet is a circular Halbach magnet, divided into 10 poles, each pole contains 6 segments of magnets, and the 6 segments of magnets in each pole are arranged adjacent to each other and axially symmetric, and the axis of symmetry is the geometric center between 2 segments of magnets at the center of the arrangement of the 6 segments of magnets.

[0006] In some exemplary embodiments, the 6 segments of magnets in each pole are symmetrically arranged in pairs with respect to the axis of symmetry in terms of the magnetizing angle.

[0007] In some exemplary embodiments, the magnetizing angles of the 6 segments of magnets in each pole are 78°, 54°, 30°, 6°, -18°, and 318° respectively.

[0008] In some exemplary embodiments, the radial magnet thickness of the rotor segmented Halbach array magnet is 1.8 mm.

[0009] In some exemplary embodiments, the rotor has a surface-mounted magnetic pole structure.

[0010] In some exemplary embodiments, the rotor further includes a rotor yoke, which is a hollow shaft made of stainless steel, and the segmented Halbach array magnets of the rotor are arranged around the rotor yoke.

[0011] In some exemplary embodiments, the stator is a split stator, including a stator core and a plurality of stator windings distributed in the stator core.

[0012] In some exemplary embodiments, the plurality of stator windings are 12 slot-shaped stator windings, and the 12 slot-shaped stator windings are evenly distributed in the stator core.

[0013] In some exemplary embodiments, each of the slot-shaped stator windings has a winding structure in which 2 branches are connected in series and then 2 paths are connected in parallel, and each of the slot-shaped stator windings contains 12 turns of copper wire.

[0014] In some exemplary embodiments, the width of the air gap is 0.7 mm.

[0015] For the Halbach array motor according to the present invention, a 6-segment surface-mounted rotor is adopted, and through the arrangement of the 6-segment Halbach array magnets, the magnetic field strength in the unit direction can be enhanced, the back electromotive force ability of the motor can be improved, the back electromotive force harmonics can be reduced, thereby improving the motor performance. In addition, on the premise of the same performance, the usage amount of the permanent magnets can be greatly reduced, thereby reducing the cost of the motor. In addition, since the permanent magnet motor with the Halbach array structure has an air gap magnetic field closer to the sine distribution than the traditional permanent magnet motor, it is beneficial to the smooth output of the motor torque and the reduction of losses. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following is the description of the drawings used in the embodiments or the prior art description. Obviously, the drawings in the following description are some embodiments of the present invention, and for those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0017] Figure 1 It is a schematic structural diagram of the Halbach array motor according to the embodiment of the present invention;

[0018] Figure 2 It is a partial enlarged schematic diagram of the stator of the Halbach array motor according to the embodiment of the present invention;

[0019] Figure 3A partially enlarged schematic view of the rotor of the Halbach array motor according to an embodiment of the present invention. Detailed implementation manners

[0020] Here, exemplary embodiments will be described in detail, and examples thereof are shown in the drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The implementation manners described in the following exemplary embodiments do not represent all implementation manners consistent with the present disclosure. On the contrary, they are merely examples of devices and methods consistent with some aspects of the present disclosure as detailed in the appended claims.

[0021] The essence of the technical solution of the present invention will be elaborated in detail below in conjunction with the drawings.

[0022] Figure 1 A structural schematic view of the Halbach array motor according to an embodiment of the present invention.

[0023] As Figure 1 shown, the Halbach array motor 10 according to an embodiment of the present invention includes a stator 1, a rotor 2, and an air gap 3. The stator 1 is fixedly installed on a motor housing (not shown), and the rotor 2 is coaxially arranged inside the stator 1 and rotatably installed on a motor shaft. That is, in this embodiment, the Halbach array motor 10 is an inner rotor motor, and the rotor 2 is rotatably installed on the motor shaft inside the stator 1. There is an air gap 3 between the stator 1 and the rotor 2. Preferably, the air gap has a width of 0.7 mm.

[0024] Figure 2 A partially enlarged schematic view of the stator of the Halbach array motor according to an embodiment of the present invention.

[0025] As Figure 1 , 2 shown, in this embodiment, the stator 1 includes a stator core 1a and a plurality of stator windings 1b distributed in the stator core 1a. In this embodiment, a split stator with a slot-shaped stator winding is adopted, and a plurality of slot-shaped stator windings 1b are evenly distributed in the stator core 1a. More specifically, the stator 1 can be a split stator with a diameter of 86 mm, a length of 25 mm, and 12 slot-shaped stator windings. Furthermore, each slot-shaped stator winding 1b has a winding structure in which 2 branches are connected in series and then 2 paths are connected in parallel. Preferably, each slot-shaped stator winding contains 12 turns of copper wire, and the diameter of the copper wire can be 1.63 mm.

[0026] Figure 3 A partially enlarged schematic view of the rotor of the Halbach array motor according to an embodiment of the present invention.

[0027] As Figure 1 , 3As shown, in this embodiment, the rotor 2 adopts a surface-mounted magnetic pole structure, including a segmented rotor Halbach array magnet 2a and a rotor yoke 2b.

[0028] The segmented rotor Halbach array magnet 2a uses a circular Halbach permanent magnet, and is divided into 10 poles. Each pole contains 6 segments of magnets, and there are 60 segments of magnets in total for 10 poles. The 6 segments of magnets in each pole are arranged adjacent to each other and are axisymmetric. The axis of symmetry is the geometric center between the 2 segments of magnets at the center of the arrangement of the 6 segments of magnets.

[0029] Preferably, in this embodiment, the radial magnet thickness of the segmented rotor Halbach array magnet 2a is 1.8 mm, and as Figure 3 shown, the 6 segments of magnets in each pole are symmetrically magnetized in pairs with the axis of symmetry as the center. The specific magnetization angles are shown in Table 1 below.

[0030] Table 1 Magnetization Angles of the Segmented Rotor Halbach Array Magnet

[0031]

[0032] The magnetization angles in the above table are obtained through electromagnetic simulation. Used Br-X(T) and Used Br-Y(T) are the magnetic field intensities in the X direction and Y direction respectively.

[0033] The rotor yoke 2b is a hollow shaft machined from stainless steel.

[0034] Thus, the structure of the rotor 2 is that 60 magnets of the same size are wound around the rotor yoke 2b and assembled into a 10-pole rotor magnetic pole with a 6-segment Halbach array. The rotor 2 cooperates with the corresponding stator 1 to form a 6-segment Halbach array surface-mounted motor.

[0035] In the case of the same amount of magnets used, the performance of the Halbach array motor 10 in this embodiment is compared with the traditional scheme. The torque is increased by 26.7% under the traditional scheme, the back electromotive force is also increased by 19.6%, the back electromotive force harmonics are decreased by 30%, and the torque ripple is decreased by 8%. The specific comparison data are shown in Table 2 below.

[0036] Table 2 Performance Comparison between this Embodiment and the Traditional Scheme

[0037]

[0038]

[0039] It can be seen that the Halbach array motor 10 of this embodiment adopts a six-segment surface-mounted rotor. Through the arrangement of the six-segment Halbach array magnets, the magnetic field intensity in the unit direction can be enhanced, the back electromotive force ability of the motor can be improved, and the back electromotive force harmonics can be reduced, thereby improving the motor performance. In addition, it can be understood that on the premise of the same performance, the usage amount of permanent magnets can be greatly reduced, thereby reducing the motor cost.

[0040] In addition, the radial air-gap magnetic flux density of the six-segment Halbach array motor 10 of this embodiment is more sinusoidal, which can reduce the high-order harmonic loss, improve the power density of the entire motor, and is beneficial to the smooth output of the motor torque and the reduction of losses.

[0041] In addition, the Halbach array motor 10 of this embodiment is a slotted motor and can be applied to the chassis brake motor of new energy electric vehicles, thereby improving the NVH performance of the entire braking system.

[0042] Specifically, the present invention has the following advantages compared with the prior art.

[0043] 1. By arranging the six-segment Halbach array magnets, the present invention improves the sinusoidality of the magnetic flux density waveform, can reduce the torque ripple of the motor, reduce the high-order harmonic loss, and has a very obvious effect on reducing the current and speed fluctuations of the motor and the entire braking system including the motor, and can achieve the purpose of optimizing NVH.

[0044] 2. The six-segment Halbach array magnetic pole structure of the rotor of the present invention has magnetic self-shielding properties, can adopt a thinner rotor yoke, or even a rotor yoke-free structure. The moment of inertia of the rotor is small, and the material cost of the rotor yoke is reduced.

[0045] Although the Halbach array motor 10 of the embodiment of the present invention has been described in detail above, various deformations can also be made to the above embodiment.

[0046] For example, although it is described in the above embodiment that the rotor 2 includes a rotor segmented Halbach array magnet 2a and a rotor yoke 2b, as described above, it can also be a structure without the rotor yoke 2b. Thus, the moment of inertia of the rotor is small, and the material cost of the motor is reduced.

[0047] In addition, in the present invention, unless otherwise clearly specified or limited, terms such as "connection" and "fixation" shall be understood in a broad sense. For example, "fixation" may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection, an electrical connection, a physical connection, or a wireless communication connection; it may be directly connected, or indirectly connected through an intermediate medium, or it may be the communication inside two components or the interaction relationship between two components, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0048] It should be noted that in this text, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not explicitly listed, or further includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising one..." does not exclude the existence of additional identical elements in the process, method, article or device comprising such element.

[0049] As described above, it is only the implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of changes or substitutions, which should all be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A Halbach array motor, characterized in that: include: The stator is mounted and fixed on the motor housing; A rotor, which is coaxially arranged on the inner side of the stator and rotatably mounted on the motor shaft; an air gap between the stator and the rotor, The rotor includes a rotor segmented Halbach array magnet, which is a circular Halbach magnet with 10 poles, each pole including 6 segments of magnets, and the 6 segments of magnets in each pole are arranged adjacently and axially symmetrically, and the symmetry axis is the geometric center between the two segments of magnets at the arrangement centers of the 6 segments of magnets.

2. The Halbach array motor according to claim 1, characterized in that: The magnetization angles of the six segments of magnets in each pole are symmetrical in pairs with the symmetry axis as the center.

3. The Halbach array motor according to claim 1 or 2, characterized in that: The magnetizing angles of the six segments of magnets in each pole are 78°, 54°, 30°, 6°, -18°, and 318° respectively.

4. The Halbach array motor according to claim 1, characterized in that: The radial magnet thickness of the rotor segmented Halbach array magnet is 1.8 mm.

5. The Halbach array motor according to claim 1, characterized in that: The rotor has a surface-mounted magnetic pole structure.

6. The Halbach array motor according to claim 1, characterized in that: The rotor further comprises a rotor yoke, which is a hollow shaft made of stainless steel. The rotor segmented Halbach array magnet is arranged around the rotor iron yoke.

7. The Halbach array motor according to claim 1, characterized in that: The stator is a block-type stator, comprising a stator core and a plurality of stator windings distributed in the stator core.

8. The Halbach array motor according to claim 7, characterized in that: The multiple stator windings are 12 slot-shaped stator windings, and the 12 slot-shaped stator windings are evenly distributed in the stator core.

9. The Halbach array motor according to claim 8, characterized in that: Each of the slot-shaped stator windings is a winding structure in which two branches are connected in series and then two branches are connected in parallel. Each of the slot-shaped stator windings contains 12 turns of copper wire.

10. The Halbach array motor according to claim 1, characterized in that: The width of the air gap is 0.7 mm.

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