Rotor core design

Abstract

An axial flux motor for an automobile includes a stator assembly and a rotor assembly. The rotor assembly includes a plurality of laminated blocks arranged in a ring, and a plurality of electrically conductive wedges, one between each pair of adjacent laminated blocks, the plurality of laminated blocks and the plurality of electrically conductive wedges defining a rotor core disk having an inner diameter and an outer diameter and opposite axial faces, and a plurality of permanent magnets attached to one of the opposite axial faces of the rotor core disk.

Description

Technical Field

[0001] This disclosure relates to an axial flux motor for use in automobiles, and more specifically, to a rotor core for an axial flux motor, the rotor core comprising a soft magnetic composite material (SMC) and a laminated stack. Background Technology

[0002] An electric motor is a machine that converts electrical energy into mechanical energy through the magnetic field generated in coils. Electric motors rotate or move in a circular motion. The central part of an electric motor is a cylinder called the armature or rotor. The rotor is the rotating part of the motor. An axial flux motor (also called an axial clearance motor or disc motor) is a motor structure with the following geometry: the gap between the rotor and stator is parallel to the axis of rotation, so the direction of the magnetic flux between them is also parallel to the axis of rotation, unlike the most common radial clearance motor, whose geometry aligns the magnetic flux direction radially with a concentric cylinder. In an axial flux motor, the stator is adjacent to the rotor and houses insulated coils, typically copper coils. When current is applied to the motor, the stator generates a magnetic field that drives the rotor.

[0003] The rotor core is entirely constructed from laminated stacks comprising multiple layers of laminated steel. This rotor core exhibits good magnetic flux permeability, reducing core losses. However, fabricating a rotor core using laminated stacks is highly complex, presenting manufacturing and cost challenges. Soft magnetic composite materials can be used as an alternative to laminated stacks. SMC (Silicon Molding Compound) is easier to manufacture; however, compared to laminated stacks, SMC has lower magnetic flux permeability and higher core losses. The rotor core comprises permanent magnets spaced apart circumferentially. Magnetic flux current flows between the permanent magnets through the core disk, creating regions of high and low magnetic flux current concentration.

[0004] Therefore, although the current axial flux motor rotor has achieved its intended purpose, there is still a need for a completely new and improved rotor and axial flux motor, whose core is composed of SMC material and laminated stacks, wherein the laminated stacks are located at the locations with the highest flux density and the SMC material is used at the locations with lower flux current density. Summary of the Invention

[0005] According to several aspects of this disclosure, an axial flux motor for an automobile includes a stator assembly and a rotor assembly. The rotor assembly includes a plurality of laminated blocks arranged in annular arrangement and a plurality of conductive wedges, with one conductive wedge between each pair of adjacent laminated blocks. The plurality of laminated blocks and the plurality of conductive wedges define a rotor core disk having an inner diameter and an outer diameter as well as opposing axial surfaces. The rotor core disk also includes a plurality of permanent magnets attached to one of the opposing axial surfaces of the rotor core disk.

[0006] According to several aspects of this disclosure, a rotor core for an axial flux motor for an automobile includes a plurality of annularly arranged laminated blocks and a plurality of conductive wedges, with a conductive wedge provided between each pair of adjacent laminated blocks. The plurality of laminated blocks and the plurality of conductive wedges define a rotor core disk having an inner diameter and an outer diameter and opposing axial surfaces, and a plurality of permanent magnets attached to one of the opposing axial surfaces of the rotor core disk.

[0007] According to another aspect, the laminated block is composed of multiple layers of laminated steel.

[0008] On the other hand, the laminated block is generally rectangular.

[0009] According to another aspect, the laminated block is stepped.

[0010] According to another aspect, the laminated steel is a grain-oriented laminated steel.

[0011] According to another aspect, the laminated steel is amorphous grain-oriented laminated steel.

[0012] According to another aspect, the conductive wedge is made of a soft magnetic composite material.

[0013] According to another aspect, the rotor core also includes a back plate made of a soft magnetic composite material, the back plate being integrally formed with the plurality of conductive wedges, the back plate and the plurality of conductive wedges defining a frame, the plurality of laminates being supported by the frame.

[0014] Further applicability will become apparent from the description provided herein. It should be understood that the specification and specific examples are for illustrative purposes only and are not intended to limit the scope of this disclosure. Attached Figure Description

[0015] The accompanying drawings described herein are for illustrative purposes only and do not limit the scope of this disclosure in any way.

[0016] Figure 1 This is an exploded view of an axial flux motor according to an exemplary embodiment of the present disclosure;

[0017] Figure 2 This is a perspective view of a rotor core disk according to an exemplary embodiment of the present disclosure;

[0018] Figure 3 This is a perspective view of a rotor core according to an exemplary embodiment, including laminates that are generally rectangular;

[0019] Figure 4 yes Figure 3 Top view of the rotor core shown;

[0020] Figure 5This is a top view of a rotor core according to an exemplary embodiment, including stepped laminated blocks; and

[0021] Figure 6 This is a perspective view of a stator core according to an exemplary embodiment, including a back plate. Detailed Implementation

[0022] The following description is merely illustrative and is not intended to limit this disclosure, its application, or its uses.

[0023] Reference Figure 1 An axial flux motor 10 for automobiles includes a rotor assembly 12 and a stator core assembly 14. The rotor assembly 12 may include a single rotor 12 disposed adjacent to the stator core assembly 14, or the rotor assembly 12 may include two rotors 12, each located on either side of the stator core assembly 14, such as... Figure 1 As shown.

[0024] Reference Figure 2 The rotor core 12 includes a plurality of laminated blocks 16 arranged in a ring and a plurality of conductive wedges 18. A conductive wedge 18 is provided between each pair of adjacent laminated blocks 16. The plurality of laminated blocks 16 and the plurality of conductive wedges 18 define a rotor core disk 20 having an inner diameter 22, an outer diameter 24, and opposing axial surfaces 26. A plurality of permanent magnets 28 are attached to one of the opposing axial surfaces 26 of the rotor core disk 20. The permanent magnets 28 are located on the axial surface 26 of the rotor core 12 facing the stator 14.

[0025] The laminated block 16 is composed of multiple layers of laminated steel. The laminated steel can be grain-oriented or non-grain-oriented. The material properties of grain-oriented laminated steel ensure efficient conduction of the magnetic field 30 through the laminated steel in a specific direction. The laminated block 16 is composed of multiple layers of laminated steel oriented in a specific manner, and the laminated block 16 is oriented in a specific manner within the rotor core 12 to promote efficient conduction of the magnetic field 30 during operation of the motor 10. Considering the specific design requirements of the motor 10, the laminated block 16 may include multiple layers of laminated steel with appropriate thickness, or a combination of multiple layers of laminated steel with different thicknesses. Furthermore, the laminated block 16 may be formed from different combinations of grain-oriented and non-grain-oriented laminated steel.

[0026] The conductive wedge 18 is made of a soft magnetic composite material. (See again...) Figure 2A magnetic field 30 flows between adjacent permanent magnets 28 spaced apart around the axial surface 26 of the rotor core 12. The laminate 16 is located between a pair of adjacent permanent magnets 28 to accommodate the high-density magnetic field 30 flowing through this location (as shown in 32). A soft magnetic composite material is used to form the conductive wedge 18, which is placed adjacent to the permanent magnets 28 where the density of the magnetic field 30 is lower (as shown in 34). At location 32, where the high-density magnetic field 30 flows, the laminate 16 needs to have a higher permeability. The lower permeability of the soft magnetic composite material of the conductive wedge 18 is suitable for location 34, where the lower-density magnetic field 30 flows.

[0027] Reference Figure 3 and Figure 4 In one exemplary embodiment, the laminate 16 is generally rectangular. The laminate 16 provides a high-density magnetic field 30. A higher ratio of laminate 16 to soft magnetic composite material in the rotor core 12 results in a greater torque generated by the motor 10. (Refer to...) Figure 5 In one exemplary embodiment, the laminate 16' is stepped. By using the stepped laminate 16', the ratio of laminate 16' to soft magnetic composite material is increased, thereby enhancing the torque generation capability of the motor 10. The use of the laminates 16 and 16', which have higher magnetic permeability, allows the rotor core disk 20 to be designed thinner than the rotor core 12 by reducing the proportion of laminate 16 or by not using laminate 16 at all.

[0028] Figure 3 , Figure 4 and Figure 5 The rotor core 12 shown includes ten laminated blocks 16, 16' and ten conductive wedges 18. Those skilled in the art will understand that any suitable number of alternating laminated blocks 16, 16' and conductive wedges 18 can be used without departing from the scope of this disclosure.

[0029] like Figure 5 As shown, each laminate 16' includes a first portion 36 having a first width 38 and a second portion 40 having a second width 42, wherein the second width 42 is smaller than the first width 38. It should be understood that each laminate 16' may include any suitable number of portions whose widths gradually decrease along a direction approaching the inner diameter 22 of the rotor core 12.

[0030] Reference Figure 6 In another exemplary embodiment, the rotor core 12 includes a backplate 44 made of a soft magnetic composite material. The backplate 44 and the plurality of conductive wedges 18 are integrally formed and define a frame 46. This provides additional structure to support the laminate 16 and to secure the laminate 16 and the conductive wedges 18 together. (Refer again) Figure 2 Without the back plate 44, the laminate 16 and the conductive wedge 18 are bonded together. When the laminate 16 is bonded to the back plate 44, the back plate 44 provides greater rigidity. Furthermore, the rotor core 12 including the back plate 44 reduces the complexity of assembling the rotor core 12 and improves the mechanical tolerances of the rotor core 12.

[0031] According to this disclosure, the rotor core 12 and the axial flux motor 10 having the rotor core 12 have several advantages. By using the higher permeability of the laminate 16 at position 32 through which the high-density magnetic field 30 flows, a higher torque capacity of the motor 10 with lower core losses can be achieved. By using the lower permeability of the soft magnetic composite material of the conductive wedge 18 at position 34 through which the low-density magnetic field 30 flows, the manufacturability of the rotor core 12 can be simplified without sacrificing the performance of the motor 10.

[0032] The descriptions in this disclosure are merely illustrative in nature, and any modifications made without departing from the spirit and scope of this disclosure will also fall within its scope. Such modifications should not be considered as a departure from the spirit and scope of this disclosure.

Claims

1. A rotor core for an axial flux motor, comprising: Multiple laminated blocks arranged in a ring; Multiple conductive wedges, with one conductive wedge between each pair of adjacent laminated blocks, the multiple laminated blocks and the multiple conductive wedges defining a rotor core disk, the rotor core disk having an inner diameter and an outer diameter as well as opposing axial surfaces; as well as Multiple permanent magnets are attached to one of the opposing axial surfaces of the rotor core disk; The laminated block is composed of multiple layers of laminated steel, and the conductive wedge is made of soft magnetic composite material; and Each of the laminated blocks is disposed between a corresponding pair of adjacent permanent magnets in the rotor core disk to accommodate a high-density magnetic field, and each of the conductive wedges is disposed adjacent to the corresponding permanent magnet to accommodate a low-density magnetic field.

2. The rotor core according to claim 1, wherein, The laminated block is rectangular.

3. The rotor core according to claim 1, wherein, The laminated blocks are stepped.

4. The rotor core according to claim 1, wherein, The laminated steel is a grain-oriented laminated steel.

5. The rotor core according to claim 1, wherein, The laminated steel is amorphous grain-oriented laminated steel.

6. The rotor core according to claim 1 further includes a back plate made of soft magnetic composite material and integrally formed with the plurality of conductive wedges, the back plate and the plurality of conductive wedges defining a frame, the plurality of laminated blocks being supported by the frame.

7. An axial flux motor, comprising: Stator assembly; and Rotor assembly, the rotor assembly comprising: Multiple laminated blocks arranged in a ring; A plurality of conductive wedges, one conductive wedge between each pair of adjacent laminated blocks, the plurality of laminated blocks and the plurality of conductive wedges defining a rotor core disk having an inner diameter and an outer diameter and opposing axial faces; and Multiple permanent magnets are attached to one of the opposing axial surfaces of the rotor core disk; The laminated block is composed of multiple layers of laminated steel, and the conductive wedge is made of soft magnetic composite material; and Each of the laminated blocks is disposed between a corresponding pair of adjacent permanent magnets in the rotor core disk to accommodate a high-density magnetic field, and each of the conductive wedges is disposed adjacent to the corresponding permanent magnet to accommodate a low-density magnetic field.

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