Axial magnetic-flux motor comprising wireless power transmission unit

Abstract

The present invention relates to an axial magnetic-flux motor comprising a wireless power transmission unit and, more specifically, to an axial magnetic-flux motor which has a motor housing and a motor shaft rotatably supported by the motor housing, and which comprises: a fixed substrate which is coupled to the motor housing, and on which a stator coil is provided; and a rotating substrate which is coupled to the motor shaft, and on which a metal piece is provided for generating an electromagnetic force for rotation of the motor shaft by means of electromagnetic interaction with the stator coil, wherein the metal piece is magnetized with power transmitted from a wireless transmission unit of the fixed substrate to a wireless reception unit of the rotating substrate so that a permanent magnet is not used.

Description

Axial flux motor including wireless power transmission unit

[0001] The present invention relates to an axial flux motor including a wireless power transmission unit, and more particularly, to an axial flux motor characterized in that a metal piece is magnetized by power transmitted from a wireless transmission unit of a fixed substrate to a wireless reception unit of a rotating substrate.

[0002] Recently, technology development for axial flux motors is actively underway as a next-generation motor that powers e-mobility, including electric vehicles and UAM (Urban Air Mobility).

[0003] The operating principle of the widely used and widely used radial motor is to generate radial magnetic flux in the stator to drive the rotor. This radial magnetic flux is generated in a direction perpendicular to the rotor's central axis, the shaft, and rotates the rotor by reacting with the permanent magnets in the rotor.

[0004] However, unlike radial flux motors, axial flux motors generate magnetic flux (Axial Flux) in a direction parallel to the rotor shaft, not perpendicular to it, so that the rotor reacts.

[0005] Figure 1 is a drawing showing an axial flux motor, (a) is a conceptual diagram, and (b) is a cross-sectional view.

[0006] Referring to FIG. 1, in an axial flux motor, the magnetic flux formed by the stator coil (130) and the stator core (131) of the stator (100) is generated in a direction parallel to the shaft, which is the rotation axis, rather than perpendicular to the shaft, unlike a radial flux motor, thereby generating an electromagnetic force on a rotor (permanent magnet) arranged side by side, thereby causing the rotor (200) to rotate.

[0007] Axial-flux motors, like this one, feature a rotor (permanent magnet) positioned axially parallel to the stator. Because the rotor is far from the axis of rotation, they can generate high output torque. Furthermore, because the main components are axially aligned, they can be miniaturized, resulting in a high power density relative to their size.

[0008] However, axial-flux motors rely heavily on permanent magnets compared to conventional motors. In particular, rare earth elements, including neodymium and Nd, are used in permanent magnets. Because their supply chains are concentrated in a few countries, they are highly volatile, leading to unstable supply and demand, high material costs, and, particularly during mining and processing, negatively impacting the environment.

[0009] In addition, since multiple coils must be installed facing each other in the axial direction, the structure is complex and the manufacturing cost is high.

[0010] Therefore, there is a need to develop an axial motor that uses a structurally simplified coil without using permanent magnets.

[0011] The technical problem to be solved by the present invention is to provide a structurally simplified axial motor without using permanent magnets by employing electromagnets instead of permanent magnets and forming coils in a pattern on a substrate.

[0012] The technical problems of the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art from the description below.

[0013] The axial flux motor including a wireless power transmission unit of the present invention for solving the above technical problem is an axial flux motor having a motor housing and a motor shaft rotatably supported by the motor housing, and includes a fixed substrate coupled to the motor housing and having a stator coil installed thereon, and a rotating substrate coupled to the motor shaft and having a metal piece installed thereon that generates an electromagnetic force for rotation of the motor shaft by electromagnetic interaction with the stator coil, and may be characterized in that the metal piece is magnetized by power transmitted from a wireless transmission unit of the fixed substrate to a wireless reception unit of the rotating substrate.

[0014] In some embodiments of the present invention, the fixed substrate and the rotating substrate are arranged side by side with an air gap apart in the shape of a shared disk centered on the rotational axis of the motor, and the wireless transmitter may face the wireless receiver, and the stator coil may face the metal piece, respectively.

[0015] In some embodiments of the present invention, the wireless transmitter may be formed inside the stator coil.

[0016] In some embodiments of the present invention, two rotating substrates may be installed on both sides of the fixed substrate.

[0017] In some embodiments of the present invention, the wireless transmitter may include a transmitting coil formed in a spiral-shaped pattern within a circular region, and the wireless receiver may include a receiving coil formed in a spiral-shaped pattern within a region opposite to the transmitting coil.

[0018] In some embodiments of the present invention, the wireless transmitter may further include an AC generator between the transmitter coil and the stator coil.

[0019] In some embodiments of the present invention, the AC generator may further include a transmission shield cover.

[0020] In some embodiments of the present invention, the wireless receiver may further include a rectifier between the receiving coil and the magnetizing coil.

[0021] In some embodiments of the present invention, the rectifier may further include a receiving shield cover.

[0022] In some embodiments of the present invention, the wireless receiver may further include a receiving shielding member covering one side of the receiving coil.

[0023] In some embodiments of the present invention, the stator coil can generate an axial magnetic flux with a plurality of input phase control currents, thereby generating an electromagnetic force on the metal pieces installed opposite to each other.

[0024] In some embodiments of the present invention, the rotating substrate further includes a plurality of magnetizing coils driven by an output current of the wireless receiver, and the metal piece can be magnetized by the magnetizing coils.

[0025] In some embodiments of the present invention, the rotating substrate may include a hole into which the metal piece is inserted and a magnetizing coil is formed around the hole.

[0026] In some embodiments of the present invention, the magnetization polarities of the metal pieces may be formed alternately opposite to each other.

[0027] In some embodiments of the present invention, a motor bearing may be included between the motor housing and the motor shaft.

[0028] In some embodiments of the present invention, two or more of the fixed substrates may be included.

[0029] An axial flux motor including a wireless power transmission unit according to the present invention can replace the permanent magnet of the axial flux motor with an electromagnet.

[0030] In addition, the simple structure of the motor and increased productivity can reduce the manufacturing cost of the axial motor.

[0031] In addition, there may be various effects obtained from the matters described in each claim, even if not mentioned herein.

[0032] Figure 1 is a conceptual diagram showing an axial flux motor.

[0033] FIG. 2 is a perspective view showing an axial flux motor according to one embodiment of the present invention.

[0034] FIG. 3 is a cross-sectional view illustrating an axial flux motor according to one embodiment of the present invention.

[0035] FIG. 4 is a cutaway perspective view of an axial flux motor according to one embodiment of the present invention.

[0036] FIG. 5 is a cutaway perspective view of an assembly of a rotating substrate and a fixed substrate according to one embodiment of the present invention.

[0037] FIG. 6 is a drawing showing a fixed substrate according to one embodiment of the present invention.

[0038] FIG. 7 is a drawing showing an assembly of a fixed substrate according to one embodiment of the present invention.

[0039] FIG. 8 is a drawing showing a rotating substrate according to one embodiment of the present invention.

[0040] FIG. 9 is a drawing showing an assembly of a rotating substrate according to one embodiment of the present invention.

[0041] Figure 10 is a drawing showing an axial flux motor according to another embodiment of the present invention.

[0042] The advantages and features of the present invention, and the methods for achieving them, will become clearer with reference to the embodiments described in detail below together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms. These embodiments are provided only to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention, and the present invention is defined only by the scope of the claims. Like reference numerals designate like elements throughout the specification.

[0043] “And / or” includes each and every combination of one or more of the items mentioned.

[0044] The terminology used herein is for the purpose of describing embodiments only and is not intended to limit the present invention. In this specification, the singular also includes the plural unless specifically stated otherwise. As used herein, the terms "comprises" and / or "comprising" do not exclude the presence or addition of one or more other components, steps, operations, and / or elements mentioned.

[0045] Additionally, throughout the specification, when a part is said to be "connected" to another part, this includes not only cases where it is "directly connected," but also cases where it is "indirectly" or "electrically connected" with other members or components in between.

[0046] Additionally, throughout the specification, the description that each layer (film), region, pattern or structure is formed "on" or "under" the substrate, each layer (film), region, pad or pattern includes both being formed directly or through the interposition of another layer. The criteria for being on / over or under / under each layer are explained based on the drawings.

[0047] Additionally, expressions such as 'first, second', etc. are used only to distinguish between multiple components, and do not limit the order or other characteristics between the components.

[0048] In addition, the flowcharts illustrated in the drawings are merely exemplary sequences for obtaining the most desirable results in carrying out the present invention, and it is obvious that other steps may be added or some steps may be deleted.

[0049] Unless otherwise defined, all terms (including technical and scientific terms) used herein may be used in their common sense to those of ordinary skill in the art to which the present invention pertains. Furthermore, terms defined in commonly used dictionaries are not to be interpreted ideally or excessively unless explicitly and specifically defined otherwise.

[0050] Hereinafter, an axial flux motor including a wireless power transmission unit according to the present invention will be described with reference to the drawings.

[0051] FIG. 2 is a perspective view showing an axial flux motor according to one embodiment of the present invention.

[0052] Referring to FIG. 2, the axial flux motor according to the present invention includes a motor housing (101) and a motor shaft (201) rotatably supported by the motor housing (101).

[0053] The motor housing (101) may include a three-phase input terminal (160) for supplying current for driving the motor to the stator coil (130), and a direct current input terminal (150) for supplying current to a wireless power transmission unit to be described later.

[0054] FIG. 3 is a cross-sectional view illustrating an axial flux motor according to one embodiment of the present invention, FIG. 4 is a cut-away perspective view of an axial flux motor according to one embodiment of the present invention, and FIG. 5 is a cut-away perspective view of an assembly of a rotating substrate and a fixed substrate according to one embodiment of the present invention.

[0055] Referring to FIGS. 3 to 5, a motor according to the present invention includes a fixed substrate (103) coupled to the motor housing (101) and having a stator coil (130) installed thereon, and a rotating substrate (203, 204) coupled to the motor shaft (201) and having a metal piece (240) installed thereon that generates an electromagnetic force for rotation of the motor shaft (201) by electromagnetic interaction with the stator coil (130), and may be characterized in that the metal piece (240) is magnetized by power wirelessly transmitted from a wireless transmitter (110) of the fixed substrate (103) to a wireless receiver (210) of the rotating substrate (203, 204).

[0056] The wireless transmitter (110) may include an AC generator (120) and a transmitting coil (111), and the wireless receiver (210) may include a receiving coil (211) and a rectifier (220).

[0057] The fixed substrate (103) and the rotating substrate (203, 204) are spaced apart by an air gap in the shape of a circular plate sharing the center of the rotation axis of the motor, and the wireless transmitter (110) and the stator coil (130) can be arranged to face each other with respect to the metal piece (240).

[0058] The fixed substrate (103) and the rotating substrate (203, 204) can be formed as a multilayer substrate and can include a coil formed in a pattern of copper foil.

[0059] The fixed substrate (103) can have its outer circumference fixed to the motor housing (101).

[0060] The inner circumference of the rotating substrate (203, 204) is fixed to the rotating substrate support (207), and the rotating substrate support (207) is fixed to the motor shaft (201), so that the motor shaft (201) can be rotated.

[0061] At this time, the fixed substrate (103) is placed in the center, and the first rotating substrate (203) is placed on one side of the fixed substrate (103) and the second rotating substrate (204) is placed on the other side, so that the magnetic flux formed in the fixed substrate (103) can be transferred to the two rotating substrates (203, 204).

[0062] The electromagnetic wave transmitted from the transmitting coil (111) of the fixed substrate (103) can be received by the receiving coil (211) of the rotating substrate (203, 204), and power for magnetizing the metal piece (240) can be transmitted.

[0063] The magnetized metal piece (240) reacts to the magnetic flux formed by the stator coil (130) of the fixed substrate (103), and when the rotating substrate (203, 204) rotates due to the force of the electromagnetic force induced in the magnetized metal piece (240), the motor shaft (201) fixed to the rotating substrate rotates, so that the motor can be driven.

[0064] In this way, the motor according to the present invention can exclude the use of rare earth metals by replacing the permanent magnet used as the rotor with an electromagnet.

[0065] That is, a metal piece (240) formed of a ferromagnetic material such as iron is installed on a rotating substrate (203, 204), and the metal piece (240) is changed into an electromagnet to replace a permanent magnet.

[0066] Before current is applied to the magnetizing coil (230) arranged to surround the metal piece (240), the magnetic domains of the metal piece (240) are arranged randomly without a specific direction, resulting in a state of non-magnetism. However, when current flows through the magnetizing coil (230) and magnetic force lines are formed, the magnetic domains of the metal piece (240) are arranged along the magnetic force lines and exhibit magnetic force lines like a permanent magnet.

[0067] At this time, the wireless transmitter (110) is formed inside the stator coil (130), and the wireless receiver (210) is formed inside the metal piece (240), so that the output torque of the motor can be increased. The force that rotates an object is expressed as the product of the force (F) and the distance (L) between the point where the force (F) is applied and the rotation axis, that is, torque = FXL. Since the rotation of the motor is driven by the electromagnetic force generated from the magnetized metal piece (240), the driving torque of the motor increases as the distance from the motor shaft (201) to the magnetized metal piece (240) increases.

[0068] FIG. 6 is a drawing showing a fixed substrate according to one embodiment of the present invention, and FIG. 7 is a drawing showing an assembly of a fixed substrate according to one embodiment of the present invention, where (a) shows an upper surface and (b) shows a lower surface, respectively.

[0069] Referring to FIGS. 5 to 7, the fixed substrate (103) according to the present invention may be formed in multiple layers to increase the length of the coil formed in a pattern on the substrate and secure strength, and may be, for example, a 10-layer multilayer substrate having 10 wiring layers.

[0070] The wireless transmitter (110) of the fixed substrate (103) may include a transmitting coil (111) formed in a spiral-shaped pattern within a circular area. The transmitting coil (111) may be formed in a pattern on the fixed substrate (103) in the shape of a coil that winds around a rotation axis.

[0071] When a high-frequency alternating current is applied to the transmission coil (111) formed in this manner, a magnetic flux is generated perpendicular to the surface on which the coil is formed, so that electromagnetic waves can be transmitted to the adjacent rotating substrate (203, 204).

[0072] The wireless transmitter (110) may include an AC generator (120) between the transmitting coil (111) and the stator coil (130). As described above, the current supplied through the DC input terminal (150) for wireless power transmission to the fixed substrate (103) may be a DC current. In order to transmit high-frequency inductive power, a high-frequency AC current must be applied to the transmitting coil (111), and therefore, the DC current may be converted into a high-frequency AC current by the AC generator (120) and supplied to the transmitting coil (111).

[0073] The alternating current generator (120) is placed between the transmitting coil (111) and the stator coil (130), so that the transmitting coil (111) and the stator coil (130) can be separated from each other. This is to prevent the magnetic fields generated from the transmitting coil (111) and the stator coil (130) from interfering with each other.

[0074] The above-mentioned AC generator (120) may further include a transmission shield cover (121).

[0075] The transmission shield cover (121) can block electromagnetic wave radiation components generated from the electronic circuit of the alternating current generator (120), thereby preventing interference with the transmission coil (111) or the stator coil (130). In addition, the transmission shield cover (121) can also prevent electromagnetic fields generated from the coil (111) and the stator coil (130) from interfering with each other.

[0076] The material of the transmission shield cover (121) is not particularly limited as long as it is a material commonly used in the industry, and may be, for example, a magnetic material with a high permeability, specifically a magnetic material with a high permeability that can shield and reflect the magnetic force lines of a magnet. Specifically, the material may be a carbon steel sheet (e.g., S45C, etc.) or a stainless steel sheet (e.g., SUS430, SUS304, etc.).

[0077] The above stator coil (130) can generate an axial magnetic flux with a plurality of input phase control currents, thereby generating an electromagnetic force in the metal piece (240) installed opposite to it.

[0078] As described above, a phase control current can be input to the fixed substrate (103) and supplied to the stator coil (130) through a three-phase input terminal (160) that supplies current for driving the motor installed in the motor housing (101).

[0079] The stator coil (130) of the fixed substrate (103) can be formed in a pattern having a shape that surrounds a certain area. A certain area of ​​the fixed substrate (103) can act as a stator core of the stator coil (130), thereby generating magnetic flux in the vertical direction of the fixed substrate (103).

[0080] The magnetic flux generated in the stator coil (130) can induce an electromagnetic force in the magnetized metal piece (240) installed opposite the stator coil (130).

[0081] FIG. 8 is a drawing showing a rotating substrate according to one embodiment of the present invention, and FIG. 9 is a drawing showing an assembly of a rotating substrate according to one embodiment of the present invention, where (a) shows an upper surface and (b) shows a lower surface, respectively.

[0082] Referring to FIGS. 5, 8 and 9, the rotating substrate (203, 204) according to the present invention may be formed in multiple layers to increase the length of the coil forming the pattern and to secure strength, and may be, for example, a 10-layer multilayer substrate having 10 wiring layers.

[0083] The wireless receiver (210) of the rotating substrate (203, 204) may include a receiving coil (211) formed in a spiral-shaped pattern in an area facing the transmitting coil (111). The receiving coil (211) may be formed in a pattern on the rotating substrate (203, 204) in the shape of a coil that winds around a rotation axis.

[0084] Power transmission can be achieved by receiving electromagnetic waves emitted from a transmitting coil (111) at a receiving coil (211).

[0085] The wireless receiver (210) may include a rectifier (220) between the receiving coil (211) and the magnetizing coil (230). The rectifier (220) may convert a high-frequency alternating current received by the receiving coil (211) into a direct current for magnetizing a metal piece (240).

[0086] The rectifier (220) can be placed between the receiving coil (211) and the magnetizing coil (230) to separate the receiving coil (211) and the magnetizing coil (230) from each other. This is to prevent the electromagnetic fields received by the receiving coil (211) and the magnetizing coil (230) from interfering with each other.

[0087] The above rectifier (220) may further include a receiving shield cover (221).

[0088] The receiving shield cover (221) can block electromagnetic wave radiation components generated from the electronic circuit of the rectifier (220), thereby preventing interference with the receiving coil (211) or the magnetizing coil (230). In addition, the receiving shield cover (221) can also prevent electromagnetic fields generated from the receiving coil (211) and the magnetizing coil (230) from interfering with each other.

[0089] The material of the receiving shield cover (221) is not particularly limited as long as it is a material commonly used in the industry, and may be, for example, a magnetic material with a high permeability, specifically a magnetic material with a high permeability that can shield and reflect the magnetic force lines of a magnet. Specifically, the material may be a carbon steel sheet (e.g., S45C, etc.) or a stainless steel sheet (e.g., SUS430, SUS304, etc.).

[0090] When a direct current is applied to the magnetizing coil (230), the metal pieces (240) formed on the inside of the magnetizing coil (230) can be magnetized to become an electromagnet. At this time, the polarity of the direct current applied to the magnetizing coil (230) can be alternately applied in reverse to each magnetizing coil (230), so that the magnetization direction (N pole or S pole) of the metal pieces (240) can be alternately formed in reverse to each metal piece (240). Therefore, the magnetized metal pieces (240) can continuously generate electromagnetic force in synchronization with the stator coil (130) whose phases are controlled differently and input, so that the rotating substrate (203, 204) can continuously maintain rotation.

[0091] The above rotating substrate (203, 204) includes a hole, a metal piece (240) can be inserted into the hole, and a magnetizing coil (230) can be formed around the hole.

[0092] That is, a metal piece (240) can be formed on the inside of the magnetizing coil (230).

[0093] The above wireless receiver (210) may further include a receiving shielding member (213) covering one side of the receiving coil (211).

[0094] The receiving shielding member (213) is preferably a ferrite core that can prevent a magnetic field from being unnecessarily radiated and has excellent electromagnetic wave blocking properties.

[0095] As described above, since the wireless receiving units (210) of the rotating substrates (203, 204) are arranged on both sides of the wireless transmitting unit (110) of the fixed substrate (103) arranged in the center, the receiving shielding member (213) can be formed on the side opposite to the direction in which the receiving coil (211) faces the transmitting coil (111). The receiving shielding member (213) installed in this manner can prevent leakage of power by allowing the receiving coil (211) to receive the power radiated from the transmitting coil (111) without loss.

[0096] Referring to FIGS. 3 and 4, a motor bearing (300) can be installed between the motor housing (101) and the motor shaft (201) to ensure smooth rotation of the motor shaft (201).

[0097] Figure 10 is a drawing showing an axial flux motor according to another embodiment of the present invention.

[0098] Referring to Fig. 10, two or more fixed substrates (103) may be formed. Accordingly, the rotating substrates (203, 204) formed on both sides of the fixed substrate (103) may also be formed in a corresponding manner, i.e., four 2-multiplications of two.

[0099] In this way, the motor drive unit is formed in multiple parts to double the output torque of the motor.

[0100] As described above, the metal piece installed on the motor shaft is magnetized by wirelessly transmitted power, thereby replacing the permanent magnet of an axial flux motor with an electromagnet. Furthermore, since the transmitting and receiving coils for wireless transmission, and the stator and magnetizing coils for motor drive are patterned on a multilayer substrate, the motor structure is simplified, thereby increasing productivity and dramatically increasing the spread of axial motors.

[0101] Although the present invention has been described as above, those skilled in the art will recognize that the present invention can be implemented in other forms while maintaining the technical spirit and essential features of the present invention.

[0102] The scope of the present invention will be fundamentally determined by the patent claims, but it should be interpreted that not only the configuration directly derived from the description of the patent claims, but also all changes or modified forms derived from equivalent configurations are included in the scope of the present invention.

Claims

1. An axial flux motor having a motor housing and a motor shaft rotatably supported by the motor housing, A fixed substrate coupled to the above motor housing and having a stator coil installed thereon; and It includes a rotating substrate coupled to the above motor shaft and having a metal piece installed thereon that generates electromagnetic force for rotation of the motor shaft, The fixed substrate includes a wireless transmitter, and the rotating substrate includes a wireless receiver. A motor characterized in that the metal piece is magnetized by power transmitted from the wireless transmitting section of the fixed substrate to the wireless receiving section of the rotating substrate.

2. In paragraph 1, The above fixed substrate and the rotating substrate are shaped like a disk having a hollow space that accommodates the rotational axis of the motor, and are arranged side by side with an air gap between them, and the wireless transmitter is a motor in which the wireless receiver and the stator coil face each other with the metal piece.

3. In paragraph 1, A motor in which two rotating substrates are installed on both sides of the fixed substrate.

4. In paragraph 1, A motor in which the wireless transmitter includes a transmitting coil formed in a spiral-shaped pattern within a circular area, and the wireless receiver includes a receiving coil formed in a spiral-shaped pattern within an area opposite to the transmitting coil.

5. In paragraph 4, The wireless transmitter further includes an AC generator between the transmitter coil and the stator coil, A motor wherein the wireless receiver further includes a rectifier between the receiving coil and the magnetizing coil.

6. In paragraph 1, The above rotating substrate further includes a plurality of magnetizing coils driven by an output current of a wireless receiver, and the metal piece is a motor magnetized by the magnetizing coils.

7. In paragraph 6, A motor in which the above rotating substrate includes a hole into which the metal piece is inserted and a magnetizing coil is formed around the hole.

8. In paragraph 6, A motor in which the magnetization polarities of the above metal pieces are formed alternately in opposite directions.

Images