Rotor for an axial flux motor and axial flux motor

Abstract

This disclosure relates to a rotor (1) for an axial flux motor, the rotor (1) being rotatable about an axial direction (X) and comprising at least two first permanent magnet elements (11) and at least two second permanent magnet elements (12) arranged alternately along the circumferential direction (U) of the rotor (1), the first permanent magnet elements (11) being axially magnetized and the second permanent magnet elements (12) being circumferentially magnetized, the rotor (1) further comprising a housing (13) integrally injection molded and accommodating and securing the first permanent magnet elements (11) and the second permanent magnet elements (12). An axial flux motor is also disclosed.

Description

Technical Field

[0001] This disclosure relates to a rotor for an axial flux motor and an axial flux motor. Background Technology

[0002] Axial flux motors are gaining increasing attention in high-end fields such as new energy vehicles, aerospace, and industrial servo systems due to their advantages such as compact structure, high power density, and large torque-to-inertia ratio. Among them, the rotor, as the core component for realizing electromechanical energy conversion, directly determines the overall performance and reliability of the motor through its manufacturing precision, structural strength, and magnetic circuit efficiency.

[0003] In the prior art, the rotor of an axial flux motor is typically manufactured using the following process:

[0004] 1. Rotor core preparation

[0005] When using laminated iron cores, silicon steel sheets must first be stamped into ring or fan-shaped laminations and then insulated between the laminations. Subsequently, the laminations are stacked into a whole by hydraulic or adhesive methods, and then cured by heating and pressure. Finally, machining methods such as turning and milling are used to ensure the parallelism of the end faces, surface roughness and dimensional accuracy.

[0006] 2. Permanent magnet assembly

[0007] For surface-mounted rotors, permanent magnets need to be arranged with alternating polarities and then pasted or bolted to the surface of the rotor disc, followed by pressure curing; for embedded rotors, permanent magnets need to be inserted into the iron core slots.

[0008] 3. Bracket fabrication

[0009] Non-magnetic metal supports (such as aluminum alloys) are typically formed by casting or integral turning.

[0010] 4. Dynamic balancing correction

[0011] Due to the dimensional errors and mass eccentricities introduced by the aforementioned multiple processes, dynamic balancing correction is required by drilling to remove weight or attaching counterweights.

[0012] 5. Protection and Sealing

[0013] To prevent corrosion or meet high-temperature operating conditions, the rotor surface needs to be electroplated, sprayed, or coated with a high-temperature resistant coating; if it is an internal rotor structure, an additional labyrinth or oil seal structure is required to prevent dust and liquid intrusion.

[0014] Existing axial motor rotors suffer from problems such as complex structure, numerous parts, long process chain, and difficulty in ensuring assembly accuracy, which seriously restrict the mass production and cost reduction of high-speed, high-power-density axial flux motors.

[0015] In addition, attempts have been made to replace the traditional laminated iron core with a magnet splicing structure. In this structure, the magnetic pole assembly includes a first magnet and a second magnet, which are arranged circumferentially with magnet fixing bolts. The inner and outer rings are connected by these fixing bolts to secure the magnets. However, this structure still has the following shortcomings:

[0016] (1) Poor mechanical reliability

[0017] When rotating at high speed, the magnet fixing bolts are prone to loosening due to vibration and centrifugal force, posing a safety hazard of the magnets being thrown away. At the same time, during installation, the first and second magnets must be arranged in circumferential direction according to polarity before being inserted into the magnet fixing bolts in sequence and mated with the inner and outer rings. This process is cumbersome and not conducive to automated mass production.

[0018] (2) Low magnetic circuit efficiency

[0019] Due to axial dimension constraints, the rotor has a relatively thin axial thickness. To ensure structural strength, grooves for mounting the magnet fixing shaft must be machined, further reducing the effective cross-sectional area of ​​the magnetic flux, resulting in a significant increase in magnetic reluctance and a decrease in magnetic permeability.

[0020] Therefore, how to simplify the rotor structure and shorten the manufacturing process while taking into account mechanical strength, magnetic circuit efficiency and mass production feasibility remains a problem that needs to be solved for rotors used in axial flux motors. Utility Model Content

[0021] This disclosure aims to provide a rotor for an axial flux motor and an axial flux motor that at least partially solves the aforementioned problems.

[0022] The rotor for an axial flux motor and the axial flux motor proposed in this disclosure overcome the above-mentioned disadvantages by adopting the following technical features, simplifying the structure and manufacturing process of the rotor for the traditional axial flux motor, reducing production costs, and adapting to large-scale industrial production.

[0023] According to a first aspect of this disclosure, a rotor for an axial flux motor is proposed, the rotor being rotatable about an axial direction and comprising at least two first permanent magnet elements and at least two second permanent magnet elements, the at least two first permanent magnet elements and at least two second permanent magnet elements being arranged alternately along the circumferential direction of the rotor for the axial flux motor, the first permanent magnet elements being axially magnetized and the second permanent magnet elements being circumferentially magnetized, the rotor for the axial flux motor further having a housing, the housing being integrally injection molded and accommodating and securing the first permanent magnet elements and the second permanent magnet elements.

[0024] In some embodiments, the magnetization directions of two adjacent first permanent magnet elements and two adjacent second permanent magnet elements are opposite.

[0025] In some embodiments, the at least two first permanent magnet elements and the at least two second permanent magnet elements are in contact with each other to form a ring.

[0026] In some embodiments, the first permanent magnet element and the second permanent magnet element are in contact with each other through the first magnetic flux surface and the second magnetic flux surface, as well as the first protective surface and the second protective surface.

[0027] In some embodiments, the corresponding first flux surface and second flux surface, as well as the first protective surface and second protective surface, are inclined relative to the axial and / or radial direction of the rotor of the axial flux motor, respectively.

[0028] In some embodiments, the rotor for the axial flux motor further has a reinforcing ring disposed between the outer periphery of the first permanent magnet element and the second permanent magnet element and the housing.

[0029] In some embodiments, the housing surrounds the first permanent magnet element and the second permanent magnet element axially at the first end side and circumferentially at the radial outer and inner circumferential portions of the first permanent magnet element and the second permanent magnet element.

[0030] In some embodiments, the housing partially surrounds the first permanent magnet element and the second permanent magnet element at their second end sides along the axial direction, such that a portion of the first permanent magnet element and the second permanent magnet element is exposed.

[0031] In some embodiments, the first permanent magnet element is provided with a first oblique cut and a second oblique cut at the radial outer periphery and the inner periphery of the second end side along the axial direction, and the second permanent magnet element is provided with a third oblique cut and a fourth oblique cut at the radial outer periphery and the inner periphery of the second end side along the axial direction.

[0032] In some embodiments, the first permanent magnet element has a radially extending groove formed on its end face along the axial direction.

[0033] In some embodiments, the groove extends centrally on the end face.

[0034] In some embodiments, the first permanent magnet element and the second permanent magnet element are respectively made of permanent magnet material or plastic magnet material.

[0035] In some embodiments, the permanent magnet material includes ferrite, neodymium iron boron, samarium iron nitrogen, or samarium cobalt.

[0036] Manufacturing a rotor for an axial flux motor according to this disclosure comprises the following steps:

[0037] Prepare at least two first permanent magnet elements and at least two second permanent magnet elements;

[0038] The at least two first permanent magnet elements and the at least two second permanent magnet elements are arranged alternately along the circumferential direction;

[0039] A first injection molding process is performed on the at least two first permanent magnet elements and the at least two second permanent magnet elements to form a housing that accommodates and fixes the first permanent magnet elements and the second permanent magnet elements.

[0040] In some embodiments, the first injection molding process includes:

[0041] Place the reinforcing ring into the mold;

[0042] The at least two first permanent magnet elements and the at least two second permanent magnet elements are arranged alternately in the circumferential direction within the reinforcing ring and injection molded to form the shell, such that the shell encloses the reinforcing ring.

[0043] In some embodiments, preparing at least two first permanent magnet elements and at least two second permanent magnet elements includes preparing the first permanent magnet elements and the second permanent magnet elements respectively by injection molding from a plastic magnetic material and completing the orientation of the first permanent magnet elements and the second permanent magnet elements respectively.

[0044] In some embodiments, preparing at least two first permanent magnet elements and at least two second permanent magnet elements includes preparing the first permanent magnet elements and the second permanent magnet elements from permanent magnet materials through a sintering process, and performing orientation pressing before sintering.

[0045] In some embodiments, the first permanent magnet element and the second permanent magnet element are magnetized separately, or the first permanent magnet element and the second permanent magnet element are magnetized as a whole.

[0046] In some embodiments, the at least two first permanent magnet elements are magnetized along the axial direction and in the opposite direction relative to the axial direction, respectively, and the at least two second permanent magnet elements are magnetized along the circumferential direction and in the opposite direction relative to the circumferential direction, respectively.

[0047] In some embodiments, fabricating at least two first permanent magnet elements and at least two second permanent magnet elements includes constructing a first oblique cut and a second oblique cut on the second end side of the first permanent magnet element along the axial direction at the radial outer periphery and the inner periphery, respectively, and constructing a third oblique cut and a fourth oblique cut on the second end side of the second permanent magnet element along the axial direction at the radial outer periphery and the inner periphery, respectively.

[0048] In some embodiments, the housing is formed during a first injection molding process such that the housing surrounds the first permanent magnet element and the second permanent magnet element axially at the first end side and circumferentially at the radial outer and inner circumferential portions of the first permanent magnet element and the second permanent magnet element, and the housing also surrounds the first permanent magnet element and the second permanent magnet element partially axially at the second end side, such that a portion of the first permanent magnet element and the second permanent magnet element is exposed.

[0049] In some embodiments, fabricating at least two first permanent magnet elements includes constructing radially extending grooves on the end faces of the first permanent magnet elements along the axial direction.

[0050] In some embodiments, a radially extending groove is centrally constructed on the end face of the first permanent magnet element along the axial direction.

[0051] According to a second aspect of this disclosure, an axial flux motor is proposed, the axial flux motor having a rotor for an axial flux motor as described in this disclosure.

[0052] The embodiments of this disclosure will be described in more detail below with reference to the accompanying drawings, so that the features and advantages of this disclosure can be readily understood. Attached Figure Description

[0053] To more clearly illustrate the technical solutions of the embodiments of this disclosure, the accompanying drawings of the embodiments of this disclosure will be briefly described below. The drawings are merely illustrative of some embodiments of this disclosure and are not intended to limit all embodiments of this disclosure to them.

[0054] Figure 1 A partial cross-sectional view of a rotor for an axial flux motor according to the present disclosure is shown;

[0055] Figure 2A It shows Figure 1 A three-dimensional view of the partial sectional view shown;

[0056] Figure 2B A perspective view of the rotor for an axial flux motor is shown from the second end side;

[0057] Figure 3 A perspective view of a ring formed by the mutual contact of a first permanent magnet element and a second permanent magnet element, according to this disclosure, is shown from the second end side.

[0058] Figure 4 A perspective view of a ring formed by the contact of a first permanent magnet element and a second permanent magnet element according to this disclosure, viewed from the first end side, is shown.

[0059] Figure 5The magnetization directions of the first and second permanent magnet elements are shown in a straight line.

[0060] Figure 6 Show Figure 5 The magnetic circuit direction of the structure shown;

[0061] Figure 7 A partial disassembled view of a ring-shaped structure formed by the contact between a first permanent magnet element and a second permanent magnet element, according to this disclosure, is shown.

[0062] Figure 8 Views of the first permanent magnet element according to this disclosure are shown from different perspectives;

[0063] Figure 9 Views of the second permanent magnet element according to this disclosure are shown from different perspectives;

[0064] Figure 10 This shows a comparison of the effect of having or not having grooves on the end face of a permanent magnet on the surface magnetism.

[0065] List of reference numerals

[0066] 1. Rotor for axial flux motor

[0067] 11 First permanent magnet element

[0068] 111 First Magnetic Flux Surface

[0069] 112 First Protective Surface

[0070] 113 groove

[0071] 115 First oblique cut

[0072] 116 Second oblique cut

[0073] 12 Second permanent magnet element

[0074] 121 Second Magnetic Flux Surface

[0075] 122 Second Protective Surface

[0076] 123 Third oblique cut

[0077] 124 Fourth oblique cut

[0078] 13 shell

[0079] 14 toroids

[0080] 15 Enhanced Circles

[0081] X-axis

[0082] R radial

[0083] U-shaped circumferential direction Detailed Implementation

[0084] To make the objectives, technical solutions, and advantages of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. The same reference numerals in the drawings represent the same components. It should be noted that the described embodiments are only some, not all, of the embodiments of this disclosure. All other embodiments obtained by those skilled in the art based on the described embodiments of this disclosure without creative effort are within the scope of protection of this disclosure.

[0085] Compared to the embodiments shown in the accompanying drawings, feasible embodiments within the scope of this disclosure may have fewer components, other components not shown in the drawings, different components, components arranged differently, or components with different connections, etc. Furthermore, two or more components in the drawings may be implemented in a single component, or a single component shown in the drawings may be implemented as multiple separate components.

[0086] Unless otherwise defined, the technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this disclosure pertains. The terms “first,” “second,” and similar terms used in this patent application specification do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms “an” or “a” and similar terms do not necessarily indicate a quantity limitation. The terms “comprising” or “including” and similar terms mean that the element or object preceding the word encompasses the element or object listed following the word and its equivalents, without excluding other elements or objects. The terms “connected” or “linked” and similar terms are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. The terms “upper,” “lower,” “left,” and “right” are used only to indicate relative positional relationships, which may change accordingly when the absolute position of the described object changes.

[0087] Figure 1 A partial cross-sectional view of a rotor for an axial flux motor according to the present disclosure is shown. Figure 2A It shows Figure 1 The figure shows a perspective view of a partial cross-sectional view. The rotor 1 for an axial flux motor is visible in the figure. The rotor 1 is rotatable about an axis X, and in this disclosure, the radial direction R and the circumferential direction U are defined based on the axis X.

[0088] The flux motor rotor 1 includes at least two first permanent magnet elements 11 and at least two second permanent magnet elements 12 arranged alternately along the circumferential direction U of the rotor 1 for the axial flux motor. The shaft of the axial flux motor is also visible in the figure. The first permanent magnet elements 11 are axially magnetized, and the second permanent magnet elements 12 are circumferentially magnetized, as described below. The rotor 1 for the axial flux motor also has a housing 13, which is integrally injection molded and houses and secures the first permanent magnet elements 11 and the second permanent magnet elements 12. The rotor 1 for the axial flux motor according to this disclosure improves the magnetic circuit structure, increases magnetic permeability, and reduces magnetic reluctance.

[0089] The magnetization directions of two adjacent first permanent magnet elements 11 and two adjacent second permanent magnet elements 12 are opposite. This is achieved through... Figure 5 To elaborate further. For ease of explanation, Figure 5 The magnetization directions of the first and second permanent magnet elements are shown in a straight line. The rotor is composed of first permanent magnet elements 11 and second permanent magnet elements 12 arranged circumferentially in a spaced-apart order. The first permanent magnet element 11 is magnetized axially (X), and there are two cases: one where the magnetization direction of the first permanent magnet element 11 is along the axial direction, and the other where the magnetization direction of the first permanent magnet element 11 is in the opposite direction to the axial direction. Figure 5 The first permanent magnet element 11 is indicated by two types of arrows, one up and one down; the second permanent magnet element 12 is magnetized in the circumferential direction, which also has two cases: one is that the second permanent magnet element 12 is magnetized in the circumferential direction, or clockwise, and the other is that the second permanent magnet element 12 is magnetized in the opposite direction to the circumferential direction, or counterclockwise. Figure 5 The second permanent magnet element 12 is indicated by two arrows, one on the left and one on the right.

[0090] The first permanent magnet element 11 is flanked by second permanent magnet elements 12 on both sides, and the magnetization directions of the second permanent magnet elements 12 on both sides are opposite; the second permanent magnet element 12 is flanked by first permanent magnet elements 11 on both sides, and the magnetization directions of the first permanent magnet elements 11 on both sides are opposite.

[0091] Figure 6 Show Figure 5 The magnetic circuit direction of the structure shown is as follows. When the motor is working normally, the magnetic lines of force enter the rotor from the first permanent magnet element 11, split into two parts and enter the second permanent magnet elements 12 on the left and right sides of the first permanent magnet element 11 respectively. Then the magnetic lines of force enter the other first permanent magnet element 11 with the opposite magnetization direction and leave the rotor. The magnetic lines of force form a complete loop.

[0092] Figure 3A perspective view of a ring formed by the mutual contact of a first permanent magnet element and a second permanent magnet element, according to this disclosure, is shown from the second end side. Figure 4 A perspective view of a ring-shaped structure, comprising a first permanent magnet element and a second permanent magnet element in contact with each other, is shown from the first end side, according to this disclosure. Figure 1 In the diagram, the first end side corresponds to the upper side of the axial flux rotor; the second end side corresponds to the lower side, which is opposite to the stator in the final axial flux motor.

[0093] The at least two first permanent magnet elements 11 and the at least two second permanent magnet elements 12 are in contact with each other to form a ring 14, such as Figure 3 , Figure 4 and Figure 7 As shown.

[0094] Figure 8 , Figure 9 Views of the first permanent magnet element and the second permanent magnet element according to this disclosure are shown from different perspectives, wherein, starting from the top left view and proceeding clockwise, they are: side view, front view, first perspective view, second perspective view which is upside down from the first perspective view, and top view.

[0095] The first permanent magnet element 11 and the second permanent magnet element 12 are in contact with each other through the first magnetic flux surface 111 and the second magnetic flux surface 121, as well as the first protective surface 112 and the second protective surface 122.

[0096] The corresponding first flux surface 111 and second flux surface 121, as well as the first protective surface 112 and second protective surface 122, are inclined relative to the axial X and / or radial R of the rotor 1 of the axial flux motor, respectively.

[0097] When forming a ring, the first magnetic flux surface 111 of the first permanent magnet element 11 is in contact with the second magnetic flux surface 121 of the second permanent magnet element 12, and the first protective surface 112 of the first permanent magnet element 11 is in contact with the second protective surface 122 of the second permanent magnet element 12.

[0098] Since the magnetic field lines enter the second magnetic field surface 121 from the first magnetic flux surface 111, the first magnetic flux surface 111 and the second magnetic flux surface 121 are the channels for the magnetic field lines between the first permanent magnet element 11 and the second permanent magnet element 12. The inclined surface is constructed to increase the contact area between the first permanent magnet element 11 and the second permanent magnet element 12, increase the magnetic field line channel, improve the magnetic permeability, and reduce the magnetic resistance.

[0099] The first protective surface 112 and the second protective surface 122 are designed to increase the buffer between the first permanent magnet element 11 and the second permanent magnet element 12, reducing the risk of damage to the first permanent magnet element 11 and the second permanent magnet element 12. If the area of ​​the first magnetic flux surface 111 and the second magnetic flux surface 121 is increased, the area of ​​the first protective surface 112 and the second protective surface 122 will gradually decrease and eventually become an edge. When the motor is working, the rotor rotates at high speed and generates vibration. If the two edges are in direct contact, they are very easy to collide and break due to vibration. However, by making the first protective surface 112 and the second protective surface 122 in contact, the contact area of ​​the first permanent magnet element 11 and the second permanent magnet element 12 is increased, the buffering performance is improved, and the rotor's resistance to damage is increased.

[0100] The rotor 1 for the axial flux motor also has a reinforcing ring 15, which is arranged between the outer periphery of the first permanent magnet element 11 and the second permanent magnet element 12 and the housing 13. The inner diameter of the reinforcing ring is in contact with the outer diameter of the permanent magnet structure. The function of the reinforcing ring is to increase the radial strength of the permanent magnet structure and prevent the permanent magnet from being flung off during high-speed rotation.

[0101] The housing 13 surrounds the first permanent magnet element 11 and the second permanent magnet element 12 along the axial direction X at the first end side of the first permanent magnet element 11 and the second permanent magnet element 12 and along the circumferential direction U at the radial outer and inner circumferences of the first permanent magnet element 11 and the second permanent magnet element 12.

[0102] The housing 13 surrounds the first permanent magnet element 11 and the second permanent magnet element 12 along the axial direction X at the second end sides, such that a portion of the first permanent magnet element 11 and the second permanent magnet element 12 is exposed. Figure 2B As shown, it presents a perspective view of the rotor for an axial flux motor, viewed from the second end. The housing encloses the permanent magnet from one end of the rotor axially and circumferentially, exposing the other end. This serves two purposes: firstly, to improve the overall mechanical strength of the rotor, and secondly, to expose the side of the rotor facing the stator without increasing the air gap between the stator and rotor.

[0103] The first permanent magnet element 11 has a first oblique cut 115 and a second oblique cut 116 at its radial outer and inner circumferences on its second end side along the axial direction X. The second permanent magnet element 12 has a third oblique cut 123 and a fourth oblique cut 124 at its radial outer and inner circumferences on its second end side along the axial direction X. After the shell encloses the permanent magnet, the presence of the oblique cuts improves the enclosure effect. With the reinforcement ring, the overall mechanical strength of the rotor is further increased, making it less likely for the permanent magnet to fall off when the rotor rotates at high speed.

[0104] The first permanent magnet element 11 has a radially extending groove 113 formed on its end face along the axial direction X. The first permanent magnet element 11 has a radially extending groove 113, which makes the motor more suitable for high-speed operating scenarios.

[0105] The groove 113 extends centrally on the end face. (The following is a simplified explanation of the groove 113.) Figure 10 To explain this in more detail: Figure 10 The image shows a comparison of the surface magnetism of the first permanent magnet element 11 with and without a groove on its end face. The following points can be observed:

[0106] 1. Regardless of whether the first permanent magnet element 11 has a groove or not, the measured surface magnetic curve shows a saddle shape, and the highest point of the surface magnetic field appears near the two sides of the first permanent magnet element 11 along the circumferential direction, that is, near the boundary line between the first permanent magnet element 11 and the second permanent magnet element 12 along the circumferential direction. At the middle position of the first permanent magnet element 11 along the circumferential direction, the surface magnetic field is reduced.

[0107] 2. If the first permanent magnet element 11 has no groove, the surface magnetic field first decreases and then increases along the circumferential direction from one side of the first permanent magnet element 11 to the other, and the surface magnetic field curve is an arc shape, which is relatively smooth. If the first permanent magnet element 11 has a groove, the surface magnetic field curve along the circumferential direction from one side of the first permanent magnet element 11 to the other is no longer smooth. First, the arc-shaped area becomes smaller, and the decreasing and increasing curves become steeper; second, the amplitude of the arc decrease becomes larger and exceeds that of the case without a groove; finally, two small secondary arcs appear on the left and right sides of the main arc, which can be understood as the appearance of the area between the side of the first permanent magnet element 11 and the groove along the circumferential direction on the surface magnetic field curve.

[0108] 3. Regardless of whether the first permanent magnet element 11 has a groove or not, its maximum surface magnetic value is almost the same. However, due to the presence of the groove, the high surface magnetic region of the first permanent magnet element 11 extends from the vicinity of the side to the middle region along the circumference, expanding the high surface magnetic region and improving the magnetic field utilization rate; while in the groove region, the surface magnetic value decreases sharply, which reduces the magnetic resistance and helps the rotor to maintain its original speed.

[0109] In summary, the presence of a groove in the middle of the first permanent magnet element 11 is more advantageous for applications involving high-speed motors.

[0110] The first permanent magnet element 11 and the second permanent magnet element 12 may be made of permanent magnet material or plastic magnet material, respectively.

[0111] The permanent magnet material may include ferrite, neodymium iron boron, samarium iron nitrogen, or samarium cobalt.

[0112] Manufacturing a rotor for an axial flux motor involves the following steps:

[0113] Prepare at least two first permanent magnet elements 11 and at least two second permanent magnet elements 12;

[0114] The at least two first permanent magnet elements 11 and the at least two second permanent magnet elements 12 are arranged alternately along the circumferential direction U.

[0115] A first injection molding process is performed on the at least two first permanent magnet elements 11 and the at least two second permanent magnet elements 12 to form a housing 13 that accommodates and fixes the first permanent magnet elements 11 and the second permanent magnet elements 12.

[0116] The manufacturing process of the axial flux rotor disclosed herein only requires arranging the first permanent magnet element 11 and the second permanent magnet element 12 in sequence in the mold, and then performing injection molding. It has few production steps, simple process, is suitable for large-scale industrial production, and has high production efficiency.

[0117] After the first permanent magnet element 11 and the second permanent magnet element 12 are assembled, the rotor shaft can be inserted in the middle; or the shaft can be pressed into the shaft hole after injection molding.

[0118] The first injection molding process may include:

[0119] Place the reinforcing ring 15 into the mold;

[0120] The at least two first permanent magnet elements 11 and the at least two second permanent magnet elements 12 are arranged alternately in a circumferential direction U within the reinforcing ring 15 and injection molded to form the shell, such that the shell encloses the reinforcing ring 15. The reinforcing ring is placed in the injection mold, and the first permanent magnet elements 11 and the second permanent magnet elements 12 are arranged circumferentially within the reinforcing ring in an alternating order. The second permanent magnet elements 12 are positioned to the left and right of the first permanent magnet elements 11, and vice versa, thus forming a ring structure for the motor rotor. The inner diameter of the reinforcing ring is slightly larger than the outer diameter of the assembled permanent magnet ring structure, and the reinforcing ring is fitted onto the permanent magnet ring structure.

[0121] The first permanent magnet element 11 and the second permanent magnet element 12 can be permanent magnet materials such as ferrite, neodymium iron boron, samarium iron nitrogen, and samarium cobalt, or they can be plastic magnet materials. Depending on the material, the processing technology of the first permanent magnet element 11 and the second permanent magnet element 12 is also different.

[0122] Fabricating at least two first permanent magnet elements 11 and at least two second permanent magnet elements 12 may include fabricating the first permanent magnet elements 11 and the second permanent magnet elements 12 respectively from a plastic magnetic material through an injection molding process, and oriented the first permanent magnet elements 11 and the second permanent magnet elements 12 respectively.

[0123] Magnetization can be performed after injection molding. The first permanent magnet element 11 and the second permanent magnet element 12 can be magnetized separately, or they can be assembled into a permanent magnet ring structure and then magnetized as a whole. The preferred method is to magnetize the first permanent magnet element 11 and the second permanent magnet element 12 separately. The advantage of this method is that the first permanent magnet element 11 and the second permanent magnet element 12 can be fully magnetized.

[0124] Furthermore, fabricating at least two first permanent magnet elements 11 and at least two second permanent magnet elements 12 may include fabricating the first permanent magnet elements 11 and the second permanent magnet elements 12 from permanent magnet materials through a sintering process, wherein orientation pressing is performed before sintering, followed by sintering, and then processing into the required shape. Magnetization can also be performed separately for the first permanent magnet elements 11 and the second permanent magnet elements 12 after processing and shaping, or it can be assembled into a permanent magnet ring structure and then magnetized as a whole.

[0125] This disclosure may further include magnetizing the at least two first permanent magnet elements 11 along the axial direction X and in the opposite direction relative to the axial direction X, respectively, and magnetizing the at least two second permanent magnet elements 12 along the circumferential direction U and in the opposite direction relative to the circumferential direction U, respectively.

[0126] Furthermore, fabricating at least two first permanent magnet elements 11 and at least two second permanent magnet elements 12 may include constructing a first oblique cut portion 115 and a second oblique cut portion 116 on the second end side along the axial direction X at the radial outer and inner circumferences, respectively, for the first permanent magnet element 11, and constructing a third oblique cut portion 123 and a fourth oblique cut portion 124 on the second end side along the axial direction X at the radial outer and inner circumferences, respectively.

[0127] Furthermore, the housing is formed during the first injection molding process such that the housing 13 can surround the first permanent magnet element 11 and the second permanent magnet element 12 at the first end side along the axial direction X and at the radial outer and inner circumferences of the first permanent magnet element 11 and the second permanent magnet element 12 along the circumferential direction U. The housing 13 can also partially surround the first permanent magnet element 11 and the second permanent magnet element 12 at the second end side along the axial direction X, such that a portion of the first permanent magnet element 11 and the second permanent magnet element 12 is exposed.

[0128] When injection molding the permanent magnet ring structure, the injection molding material wraps around the ring structure from one axial side and the circumferential direction, leaving the other axial side exposed. During injection molding, when the injection molding material is flush with the other axial side, the chamfer is already enclosed, thus increasing the encapsulation. Without a chamfer, the encapsulation is worse when the injection molding material is flush with the other axial side compared to when it is chamfered. These beveled cuts allow the injection molding material to better encapsulate the permanent magnet ring structure, preventing cracking or permanent magnet detachment during operation and improving the mechanical strength of the new rotor.

[0129] In addition, fabricating at least two first permanent magnet elements 11 may include constructing a radially extending groove 113 on the end face of the first permanent magnet element 11 along the axial direction X.

[0130] A radially extending groove 113 can be constructed centered on the end face of the first permanent magnet element 11 along the axial direction X.

[0131] The rotor for an axial flux motor as described in this disclosure can be installed in an axial flux motor (not shown).

[0132] The exemplary implementation of the solution proposed in this disclosure has been described in detail above with reference to the embodiments. However, those skilled in the art will understand that various modifications and alterations can be made to the above specific embodiments without departing from the spirit of this disclosure, and various combinations can be made to the various technical features and structures proposed in this disclosure without exceeding the protection scope of this disclosure.

Claims

1. A rotor (1) for an axial flux motor, characterized in that, The rotor (1) for the axial flux motor is rotatable about an axis (X) and includes at least two first permanent magnet elements (11) and at least two second permanent magnet elements (12), which are arranged alternately along the circumferential direction (U) of the rotor (1) for the axial flux motor. The first permanent magnet elements (11) are axially magnetized and the second permanent magnet elements (12) are circumferentially magnetized. The rotor (1) for the axial flux motor also has a housing (13), which is integrally injection molded and houses and fixes the first permanent magnet elements (11) and the second permanent magnet elements (12).

2. The rotor (1) for an axial flux motor according to claim 1, characterized in that, The two adjacent first permanent magnet elements (11) and the two adjacent second permanent magnet elements (12) are magnetized in opposite magnetization directions.

3. The rotor (1) for an axial flux motor according to claim 1, characterized in that, The at least two first permanent magnet elements (11) and the at least two second permanent magnet elements (12) are in contact with each other to form a ring (14).

4. The rotor (1) for an axial flux motor according to claim 3, characterized in that, The first permanent magnet element (11) and the second permanent magnet element (12) are in contact with each other through the first magnetic flux surface (111) and the second magnetic flux surface (121), as well as the first protective surface (112) and the second protective surface (122).

5. The rotor (1) for an axial flux motor according to claim 4, characterized in that, The corresponding first flux surface (111) and second flux surface (121), as well as the first protective surface (112) and second protective surface (122), are inclined relative to the axial (X) and / or radial (R) of the rotor (1) for the axial flux motor, respectively.

6. The rotor (1) for an axial flux motor according to claim 1, characterized in that, The rotor (1) for the axial flux motor also has a reinforcing ring (15) arranged between the outer periphery of the first permanent magnet element (11) and the second permanent magnet element (12) and the housing (13).

7. The rotor (1) for an axial flux motor according to claim 1, characterized in that, The housing (13) surrounds the first permanent magnet element (11) and the second permanent magnet element (12) along the axial direction (X) at the first end side of the first permanent magnet element (11) and the second permanent magnet element (12) along the circumferential direction (U) at the radial outer and inner circumferences of the first permanent magnet element (11) and the second permanent magnet element (12).

8. The rotor (1) for an axial flux motor according to claim 7, characterized in that, The housing (13) surrounds the first permanent magnet element (11) and the second permanent magnet element (12) at the second end side along the axial direction (X), such that a portion of the first permanent magnet element (11) and the second permanent magnet element (12) is exposed.

9. The rotor (1) for an axial flux motor according to claim 1, characterized in that, The first permanent magnet element (11) has a first oblique cut (115) and a second oblique cut (116) on the radial outer periphery and inner periphery of the second end side along the axial direction (X), and the second permanent magnet element (12) has a third oblique cut (123) and a fourth oblique cut (124) on the radial outer periphery and inner periphery of the second end side along the axial direction (X).

10. The rotor (1) for an axial flux motor according to claim 1, characterized in that, The first permanent magnet element (11) has a radially extending groove (113) on its end face along the axial direction (X).

11. The rotor (1) for an axial flux motor according to claim 10, characterized in that, The groove (113) extends centrally on the end face.

12. The rotor (1) for an axial flux motor according to claim 1, characterized in that, The first permanent magnet element (11) and the second permanent magnet element (12) are respectively made of permanent magnet material or plastic magnet material.

13. The rotor (1) for an axial flux motor according to claim 12, characterized in that, The permanent magnet material includes ferrite, neodymium iron boron, samarium iron nitrogen, or samarium cobalt.

14. An axial flux motor, characterized in that, The axial flux motor has a rotor (1) for an axial flux motor as described in any one of claims 1 to 13.

Images