Axial type motor

Abstract

An axial type motor is provided. An axial type motor according to an embodiment of the present invention comprises: a stator which is arranged to be fixed to a motor housing in an inner space of a shaft rotatably provided in an inner space of the motor housing forming the inner space, and includes stator cores, a coil, and a stator bracket; and a rotor coupled to be fixed to the shaft and arranged to face the stator in the axial direction, and including a rotor base plate and a plurality of permanent magnets, wherein the rotor base plate includes a first surface facing the stator and a second surface opposite to the first surface, and the second surface has a vortex forming groove generating a vortex.

Description

Axial motor

[0001] The present invention relates to an axial motor.

[0002]

[0003] Recently, as the number of vehicles has increased and it has become difficult to drive personal vehicles, the number of people using public transportation or small mobility vehicles for transportation has been increasing.

[0004] Representative examples of small mobility devices include electric bicycles, electric kickboards, and electric mini bikes, and among these, demand for electric bicycles is increasing.

[0005] These small mobility vehicles are equipped with an axial type motor that can reduce the length in the axial direction, and have a structure in which the wheels are rotated by the rotational force of the motor.

[0006] When explaining the structure of a general axial motor, an axial motor is a motor in which the magnetic flux flow is formed in the axial direction, and since the output density is high and the motor diameter is large compared to the axial length, a relatively large number of poles can be designed, so it has a structure suitable for high-frequency or low-speed driving.

[0007] These axial motors include a stator that forms a magnetic field and a rotor that is rotatable relative to the stator.

[0008] The stator includes a plurality of cores arranged at regular intervals along the circumference and protruding axially to a certain height, and the cores are axially coupled to grooves formed in the stator bracket.

[0009] The rotor includes permanent magnets arranged at regular intervals along the circumference, and is configured to rotate while forming a fixed air gap with the stator.

[0010] However, after the motor is started and the rotor operates, high heat easily accumulates inside the motor housing, and since there is no cooling structure that can quickly dissipate the high heat generated by the operation of the motor, the magnetic force of the magnet is reduced due to the high heat accumulated inside the motor, and the operating efficiency of the motor gradually decreases.

[0011] Additionally, if the temperature rises to a certain level, the insulating material of the armature windings in the armature may be damaged, causing a short circuit in the armature windings, which may lead to a risk of fire in the entire motor.

[0012] To prevent these problems, a cooling blade fan is usually mounted on one end of the central rotational axis of the motor to suppress the temperature rise of the motor.

[0013] However, this technology only allows the forward airflow of the cooling blade fan to brush the outer surface of the motor housing, and in reality, it cannot allow the forward airflow to directly enter the inside of the housing, so it cannot cool the inside of the motor quickly and effectively.

[0014] Additionally, the axial motor generates rotational torque by generating a repulsive or attractive force between the core and the permanent magnet of the rotor by changing the direction of the current flowing in the coil wound on the core.

[0015] However, general permanent magnets are formed integrally and have a shape corresponding to the core, but the thickness of the area where the magnetic field is strongly generated and the area where the magnetic field is weak are formed to be the same, so there is a problem that the rotational efficiency of the rotor is lowered depending on the weight and shape of the permanent magnet.

[0016] Under the above-described background, the present invention proposes an axial motor capable of improving rotational efficiency by preventing heat accumulation by performing cooling inside the motor housing and making the shape of the permanent magnet correspond to the position where the magnetic field is formed.

[0017]

[0018] The present invention was created to solve the above-described problem, and its purpose is to provide an axial motor in which a rotor generates a vortex inside the motor housing to cool the inside of the motor housing.

[0019] In addition, the present invention aims to develop an axial motor in which a groove formed in a rotor can disperse force and prevent bending of the rotor.

[0020] In addition, the purpose is to provide an axial motor including a permanent magnet formed in multiple stages.

[0021] The problems to be solved by the present invention are not limited to the problems mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the description below.

[0022]

[0023] The above-described object is achieved by an axial motor comprising a motor housing forming an internal space, a shaft rotatably provided in the internal space, a stator disposed to be fixed to the motor housing in the internal space and including a stator core, a coil, and a stator bracket, and a rotor fixedly coupled to the shaft and disposed axially opposite to the stator, the rotor base plate and a plurality of permanent magnets, the rotor base plate including a first surface facing the stator and a second surface opposite the first surface, and having a vortex-forming groove for generating a vortex on the second surface.

[0024] Additionally, the vortex forming grooves may be formed in multiple numbers and arranged spaced apart from each other in the circumferential direction.

[0025] Additionally, the vortex forming grooves can be formed radially with the axis of the rotor base plate as the center.

[0026] Additionally, the vortex forming grooves may be formed with different depths in the inner region adjacent to the center of the rotor and in the outer region adjacent to the outer periphery of the rotor.

[0027] Additionally, the vortex forming groove can be formed deeper in the outer region than in the inner region.

[0028] Additionally, the vortex forming grooves may be formed with a wider width in the outer region adjacent to the outer periphery of the rotor than in the inner region adjacent to the center of the rotor.

[0029] Additionally, the rotor base plate may have a protruding member formed on the vortex forming groove that generates turbulence.

[0030] Additionally, the protruding member may be formed closer to the outer region of the rotor than the inner region within the vortex forming groove.

[0031] Additionally, the rotor base plate may have a perforation formed in a vortex forming groove to circulate air between the rotor and the stator.

[0032] An axial motor according to one embodiment of the present invention includes a motor housing forming an internal space, a shaft rotatably provided in the internal space, a stator disposed to be fixed to the motor housing in the internal space and including a stator core, a coil, and a stator bracket, and a rotor fixedly coupled to the shaft and disposed to face the stator along the axial direction, the rotor including a rotor base plate and a plurality of permanent magnets, wherein the permanent magnets may be formed such that the thicknesses of an inner region adjacent to the center of the rotor and an outer region adjacent to the outer periphery of the rotor are different.

[0033] Additionally, the permanent magnet can be formed so that the thickness of the outer region is greater than that of the inner region.

[0034] Additionally, the permanent magnet can be formed with a thickness that gradually increases from the inner region to the outer region.

[0035] Additionally, the permanent magnet can be formed with a width that gradually increases from the inner region to the outer region.

[0036] Additionally, the permanent magnet may be provided by combining multiple sub-permanent magnets of different sizes, and may be arranged in a step shape.

[0037] In addition, the rotor further includes a fixed member that couples the permanent magnet to the rotor base plate, and the fixed member can be formed in a shape in which a surface that contacts the permanent magnet is inversely corresponding to the shape of the permanent magnet.

[0038] Additionally, the fixed member can be formed so that the sum of its thickness with that of the permanent magnet is constant.

[0039] Additionally, the fixed member may have a discharge groove formed on the contact surface with the permanent magnet to discharge excess adhesive when the permanent magnet is bonded.

[0040]

[0041] According to an axial motor according to one embodiment of the present invention, the cooling efficiency of the motor can be improved by generating a vortex by the rotor inside the housing of the motor.

[0042] In addition, according to an axial motor according to one embodiment of the present invention, the baffles formed on the rotor distribute the force acting on the plane of the rotor at different angles, thereby preventing the rotor from bending, thereby maintaining an air gap between the rotor and the stator, thereby improving the rotational efficiency.

[0043] Additionally, the permanent magnets can be arranged in different sizes depending on the strength of the magnetic field to improve the rotational efficiency of the rotor.

[0044] In addition, since the fixed member is provided with a shape that corresponds to the permanent magnet, the fixing force of the rotor and the permanent magnet can be improved and an air gap can be maintained between the permanent magnet and the stator, thereby improving rotational efficiency.

[0045]

[0046] FIG. 1 is a perspective view of an axial motor according to one embodiment of the present invention.

[0047] Figure 2 is an exploded perspective view of an axial motor according to one embodiment of the present invention.

[0048] Fig. 3 is an exploded perspective view of a stator included in the axial motor of Fig. 1.

[0049] Fig. 4 is an exploded perspective view of a rotor included in the axial motor of Fig. 1.

[0050] Fig. 5 is a perspective view of the second surface of the rotor included in the axial motor of Fig. 1.

[0051] Fig. 6 is a front view of the second surface of the rotor included in the axial motor of Fig. 1.

[0052] Figure 7 is an exploded perspective view of the rotor illustrated in Figure 2.

[0053] Fig. 8 is a front view of the first surface of the rotor illustrated in Fig. 2.

[0054] Figure 9 is a side view of the permanent magnet and fixed member illustrated in Figure 7.

[0055] Fig. 10 is a side view showing the permanent magnet and fixed member of Fig. 9 combined.

[0056]

[0057] The embodiments described in this specification and the configurations illustrated in the drawings are merely preferred examples of the disclosed invention, and there may be various modified examples that can replace the embodiments and drawings of this specification at the time of filing of this application.

[0058] The same reference numbers or symbols used in each drawing of this specification represent parts or components that perform substantially the same functions. The shapes and sizes of elements in the drawings may be exaggerated for clarity.

[0059] The terminology used herein is for the purpose of describing embodiments and is not intended to limit and / or restrict the disclosed invention. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this specification, the terms "comprises" or "has" and the like are intended to indicate the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, but do not preclude the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0060] While terms including ordinal numbers, such as "first," "second," etc., used herein may be used to describe various components, the components are not limited by these terms, and these terms are used solely to distinguish one component from another. For example, without departing from the scope of the present invention, a first component could be referred to as a second component, and similarly, a second component could also be referred to as a first component.

[0061] Hereinafter, an axial motor according to one embodiment of the present invention will be described in detail with reference to the drawings.

[0062] FIG. 1 is a perspective view of an axial motor according to one embodiment of the present invention. FIG. 2 is an exploded perspective view of an axial motor according to one embodiment of the present invention. FIG. 3 is an exploded perspective view of a stator included in the axial motor of FIG. 1. FIG. 4 is an exploded perspective view of a rotor included in the axial motor of FIG. 1.

[0063] Referring to FIGS. 1 to 4, the axial motor (10) includes a motor housing (100), a shaft (200), a stator (300), and a rotor (400).

[0064] The motor housing (100) has an internal space (S) formed therein and is provided with a shaft (200), a stator (300), and a rotor (400) described later. The motor housing (100) may include a housing (120), a front cover (140), and a rear cover (160).

[0065] The housing (120) has a cylindrical shape with a hollow space formed on the inside. The housing (120) is combined with the front cover (140) and the rear cover (160) to form an internal space (S).

[0066] The front cover (140) and the rear cover (160) can be implemented in a circular plate shape. The front cover (140) and the rear cover (160) are joined to both sides of the opening formed in the housing (120) to form an internal space (S). The front cover (140) and the rear cover (160) are formed with a through hole (142, 162) through which a shaft (200) passes in the axial direction.

[0067] The shaft (200) is rotatably provided in the internal space (S). The shaft (200) can be coupled to the motor housing (100) with a plurality of bearings (not shown).

[0068] The stator (300) is placed in the internal space (S) of the motor housing (100). The stator (300) can be fixed to the motor housing (100). The stator (300) can be formed in a shape in which the outer side corresponds to the inner side of the motor housing (100). As illustrated in FIG. 3, the stator (300) includes a stator core (320), a coil (322), and a stator bracket (340).

[0069] A plurality of stator cores (320) may be provided. Each of the stator cores (320) may have the same shape. The stator cores (320) may be arranged at a constant interval from the center along the circumferential direction.

[0070] The coil (322) is placed on the stator core (320). The coil (322) may be wound on the stator core (320). Specifically, the coil (322) may be wound on the outer surface of each stator core (320) so as to generate magnetic flux in the axial direction. Accordingly, when power is applied to the coil (322) and an AC current flows, the permanent magnet (440) of the rotor (400) rotates due to the magnetic field generated.

[0071] The stator bracket (340) secures the stator core (320). The stator bracket (340) may be formed of an insulator so that each stator core (320) and coil (322) are not electrically connected. For example, the stator bracket (340) may be formed of a ceramic or a thermosetting resin such as bakelite or coated stainless steel.

[0072] The stator bracket (340) may be formed with a guide hole (342) into which an end of the stator core (320) is inserted and fixed. The guide hole (342) may guide the stator core (320) to be inserted in the axial direction. The number of guide holes (342) may correspond to the number of stator cores (320). Specifically, the guide holes (342) may be arranged at a constant interval from the center along the circumferential direction so as to correspond to the number of stator cores (320).

[0073] The stator bracket (340) is provided in a pair to secure the stator core (320) on both sides. The stator bracket (340) may have a hollow space formed in the center through which a shaft (200) passes in the axial direction.

[0074] The rotor (400) is provided in the internal space (S) of the housing (120). The rotor (400) is fixedly connected to the shaft (200). The rotor (400) is disposed on one side of the stator (300). The rotor (400) is disposed oppositely along the axial direction of the stator (300). When power is supplied to the stator (300), the rotor (400) interacts with the stator (300) to rotate. The rotor (400) includes a rotor base plate (420) and a permanent magnet (440).

[0075] The rotor base plate (420) is arranged to face the stator (300). Specifically, the rotor base plate (420) may be arranged to face the stator bracket (340).

[0076] The rotor base plate (420) is formed with a permanent magnet coupling groove (422) to which a permanent magnet (440) is coupled.

[0077] The permanent magnet coupling groove (422) may be formed in multiple numbers. The permanent magnet coupling groove (422) may be formed along the circumferential direction of the rotor base plate (420). The permanent magnet coupling groove (422) may be formed on the first surface (P1) among the first surface (P1) facing the stator core (320) and the second surface (P2) opposite the first surface (P1). At this time, the permanent magnet (440) may be coupled to the permanent magnet coupling groove (422) with a bolt. Alternatively, the permanent magnet (440) may be coupled to the permanent magnet coupling groove (422) with an adhesive.

[0078] The permanent magnet (440) causes the rotor (400) to rotate by a magnetic field when power is applied to the stator (330). A plurality of permanent magnets (440) are provided. The number of permanent magnets (440) may correspond to the number of permanent magnet coupling grooves (422). The permanent magnets (440) may be arranged so that the N pole and the S pole are alternately exposed. If the permanent magnets (440) are provided in an odd number, adjacent pairs of the plurality of permanent magnets may be arranged with the same pole, so to prevent this, the permanent magnets (440) may be provided in an even number. In the above-described example, one rotor (400) is described as being arranged on one side of the stator (300), but as shown in FIG. 2, the rotors (400) may be provided in a pair and arranged on both sides of the stator (300). Hereinafter, the rotor base plate (420) will be described in more detail with reference to FIGS. 5 and 6.

[0079] Fig. 5 is a perspective view of a second surface of a rotor included in the axial motor of Fig. 1. Fig. 6 is a front view of a second surface of a rotor included in the axial motor of Fig. 1.

[0080] Referring to FIGS. 5 and 6, the rotor base plate (420) is formed with a vortex forming groove (424) and a protruding member (426).

[0081] The vortex forming groove (424) generates a vortex when the rotor (400) rotates inside the motor (10) to cool the inside of the motor (10). The vortex forming groove (424) may be formed on the second surface (P2) among the first surface (P1) facing the stator (300) and the second surface (P2) opposite the first surface (P1), as illustrated in FIGS. 5 and 6. A plurality of vortex forming grooves (424) may be formed. The vortex forming grooves (424) may be arranged to be spaced apart from each other in the circumferential direction of the rotor base plate (420). The vortex forming grooves (424) may be arranged at equal intervals. The vortex forming grooves (424) may be formed in the same shape. The vortex forming grooves (424) may be formed radially with respect to the axis of the rotor base plate (420).

[0082] The vortex forming groove (424) may be formed to have different depths depending on the position where it is formed on the rotor base plate (420). The vortex forming groove (424) may be formed to have different depths in an inner region adjacent to the center of the rotor base plate (420) and an outer region adjacent to the outer surface of the rotor base plate (420). For example, the vortex forming groove (424) may be formed to have a deeper depth in the outer region than in the inner region. Specifically, the vortex forming groove (424) may be formed to have a shape in which the depth gradually deepens from the inner region to the outer region.

[0083] In addition, the vortex forming groove (424) may be formed with different widths in the inner region adjacent to the center of the rotor base plate (420) and the outer region adjacent to the outer surface of the rotor base plate (420). Specifically, it may be formed in a shape in which the width gradually increases from the inner region to the outer region.

[0084] A protruding member (426) is formed on the rotor base plate (420) to generate turbulence during rotation of the rotor (400). The protruding member (426) may be formed on the second surface (P2). The protruding member (426) may be arranged on the vortex-forming groove (424). The protruding member (426) may be formed adjacent to an outer region among an inner region adjacent to the center of the rotor base plate (420) and an outer region adjacent to the outer surface of the rotor base plate (420). The protruding member (426) may be formed in multiple numbers. For example, the protruding member (426) may be formed in a number corresponding to the number of vortex-forming grooves (424). The protruding member (426) may be formed with an adhesive discharge hole (4262) through which excess adhesive is discharged when a permanent magnet (440) is bonded to a permanent magnet coupling groove (422) with adhesive.

[0085] The rotor base plate (420) may have a hole (428) formed therein. The hole (428) may be used as a passage for circulating air between the rotor (400) and the stator (300) while the rotor (400) rotates. The hole (428) may be formed in the axial direction of the rotor base plate (420). The hole (428) may be formed on a vortex forming groove (424). The hole (428) may be formed in a plurality of numbers. For example, the hole (428) may be formed in a number corresponding to the number of vortex forming grooves (424). Since the hole (428) must be formed at a position on the rotor base plate (420) that does not overlap with the permanent magnet (440) in the axial direction, the hole (428) may be formed adjacent to an inner region among an inner region adjacent to the center of the rotor base plate (420) and an outer region adjacent to the outer surface of the rotor base plate (420).

[0086] According to the above-described example, the rotor base plate (420) according to one embodiment of the present invention has a plurality of eddy current forming grooves (424) formed on the other side of the surface to which the permanent magnet (440) is coupled, so that eddy currents are generated when the rotor (400) rotates, thereby having the effect of improving the cooling efficiency inside the motor (10).

[0087] In addition, since the rotor (400) in which the vortex forming groove (424) is formed has an irregular shape, the force can be distributed at various angles when the rotor (400) rotates, thereby preventing the rotor (400) from bending, thereby having the effect of maintaining the air gap between the permanent magnet (440) placed on the rotor (400) and the stator (300) constant.

[0088] In addition, a plurality of holes are formed in the rotor base plate (420) to allow heated air to circulate between the rotor (400) and the stator (300), thereby improving cooling efficiency inside the motor (10).

[0089] Hereinafter, the permanent magnet (440) will be described in more detail with reference to FIGS. 7 to 10.

[0090] Fig. 7 is an exploded perspective view of the rotor illustrated in Fig. 2. Fig. 8 is a front view of the first surface of the rotor illustrated in Fig. 2. Fig. 9 is a side view of the permanent magnet and the fixed member illustrated in Fig. 7. Fig. 10 is a side view showing the permanent magnet and the fixed member illustrated in Fig. 9 combined.

[0091] Referring to FIGS. 7 to 10, a permanent magnet (440) can be formed by combining a plurality of sub-permanent magnets (440a, 440b, 440c, …, 440h) of different sizes. In one embodiment of the present invention, eight sub-permanent magnets (440a, 440b, 440c, …, 440h) are combined to form one permanent magnet (440), but the number of sub-permanent magnets combined is not limited. Hereinafter, an example in which a permanent magnet (440) is formed by combining a plurality of sub-permanent magnets (440a, 440b, 440c, …, 440h) will be described.

[0092] A plurality of sub permanent magnets (440a, 440b, 440c, …, 440h) can be aligned so that the same polarity faces the same side. The plurality of sub permanent magnets (440a, 440b, 440c, …, 440h) can each be fixed with an adhesive. The plurality of sub permanent magnets (440a, 440b, 440c, …, 440h) can be formed in different sizes. For example, the magnet having the strongest magnetic force among the plurality of sub permanent magnets (440a, 440b, 440c, …, 440h) can be aligned so that it is placed at a position where the intensity of the strong magnetic field is the strongest.

[0093] First, the plurality of sub permanent magnets (440a, 440b, 440c, …, 440h) can be formed with different widths so that each magnet has different weights and magnetic forces, as illustrated in FIG. 5. The plurality of sub permanent magnets (440a, 440b, 440c, …, 440h) can be arranged so that the combined permanent magnets have a trapezoidal shape. Among the plurality of sub permanent magnets (440a, 440b, 440c, …, 440h), the width of the permanent magnet (400h) arranged in the outer region adjacent to the outer periphery of the rotor can be larger than that of the permanent magnet (440a) arranged in the inner region adjacent to the center of the rotor base plate (420). For example, multiple sub permanent magnets (440a, 440b, 440c, …, 440h) can be arranged with a width that gradually increases from the inner region to the outer region, so that the outermost permanent magnet (440h) can be formed with the largest width.

[0094] In addition, the plurality of sub permanent magnets (440a, 440b, 440c, …, 440h) may be formed with different thicknesses on the sides so that each magnet has different weights and magnetic forces, as illustrated in FIG. 6. The plurality of sub permanent magnets (440a, 440b, 440c, …, 440h) may be arranged in a multi-stage configuration. Among the plurality of sub permanent magnets (440a, 440b, 440c, …, 440h), the thickness of the permanent magnet (400h) arranged in the outer region adjacent to the outer periphery of the rotor may be larger than that of the permanent magnet (440a) arranged in the inner region adjacent to the center of the rotor base plate (420). For example, the plurality of sub permanent magnets (440a, 440b, 440c, …, 440h) may be arranged in a step shape with a thickness that gradually increases from the inner region to the outer region. The plurality of sub permanent magnets (440a, 440b, 440c, …, 440h) may be arranged so that the surfaces facing the stator (300) are spaced apart from the stator (300) by the same interval, and may be arranged so as to have different thicknesses in the direction coupled to the rotor base plate (420).

[0095] At this time, the rotor (400) may further include a fixing member (460) that fixes the permanent magnet (440) to the permanent magnet coupling groove (422).

[0096] A fixing member (460) is provided between a plurality of sub permanent magnets (440a, 440b, 440c, …, 440h) and a rotor base plate (420). The fixing member (460) supports and fixes a plurality of sub permanent magnets (440a, 440b, 440c, …, 440h) to the rotor base plate (420). The fixing member (460) fixes a plurality of sub permanent magnets (440a, 440b, 440c, …, 440h) arranged with different thicknesses to a permanent magnet coupling groove (422) so that they have the same spacing as the stator (300).

[0097] A plurality of fixing members (460) may be provided. The number of fixing members (460) may correspond to the number of permanent magnet coupling grooves (422). The fixing members (460) may be bolted to the permanent magnet coupling grooves (422).

[0098] The fixing member (460) can fix a plurality of sub permanent magnets (440a, 440b, 440c, …, 440h). The fixing member (460) can be formed in a shape corresponding to the plurality of sub permanent magnets (440a, 440b, 440c, …, 440h). When the plurality of sub permanent magnets (440a, 440b, 440c, …, 440h) are arranged in a step shape with a gradually increasing thickness, the fixing member (460) can be formed in an inverse step shape with a gradually decreasing thickness. The fixing member (460) can be formed so that the sum of the thicknesses is constant when fixed to the plurality of sub permanent magnets (440a, 440b, 440c, …, 440h). For example, as illustrated in FIG. 10, the sum (T1) of the thicknesses of the inner region of the permanent magnet (440a) and the fixed member (460) may be equal to the sum (T2) of the thicknesses of the outer region of the permanent magnet (440h) and the fixed member (460).

[0099] A plurality of sub permanent magnets (440a, 440b, 440c, …, 440h) can be bonded to the fixed member (460) with an adhesive. When a plurality of sub permanent magnets (440a, 440b, 440c, …, 440h) are bonded to the fixed member (460) with an adhesive, it becomes impossible to maintain a certain gap with the stator (300) due to the adhesive applied excessively. Accordingly, an adhesive discharge groove (462) through which excess adhesive is discharged when the plurality of sub permanent magnets (440a, 440b, 440c, …, 440h) are bonded can be formed in the fixed member (460).

[0100] The adhesive discharge groove (462) may be formed on a surface where a plurality of sub permanent magnets (440a, 440b, 440c, …, 440h) are coupled. The adhesive discharge groove (462) may be formed in a number corresponding to the number of sub permanent magnets (440a, 440b, 440c, …, 440h).

[0101] In the above-described example, it is described that one permanent magnet (440) is a combination of multiple sub-permanent magnets (440a, 440b, 440c, …, 440h), but the multiple sub-permanent magnets (440a, 440b, 440c, …, 440h) may be formed integrally. That is, one permanent magnet (440) may be formed with different widths and thicknesses in each region depending on the strength of the magnetic field.

[0102] According to the above-described example, a plurality of sub permanent magnets (440a, 440b, 440c, …, 440h) are formed in different sizes, and by arranging magnets with different magnetic forces according to the strength of the magnetic field, there is an effect of improving the rotation efficiency.

[0103] In addition, the thickness of the fixed member (460) is formed in a shape corresponding to that of the permanent magnet (440), so that the fixing force of the rotor (400) and the permanent magnet (440) can be improved, and the permanent magnet (440) and the stator (300) can maintain a constant gap, so that there is an effect of improving the rotation efficiency.

[0104] Although all components constituting the embodiments of the present invention have been described above as being combined or operating in combination, the present invention is not necessarily limited to these embodiments. That is, within the scope of the purpose of the present invention, all components may be selectively combined and operated one or more times. In addition, terms such as "include," "comprise," or "have" described above, unless specifically stated to the contrary, mean that the corresponding component may be inherent, and therefore should be interpreted as including other components rather than excluding other components. All terms, including technical or scientific terms, have the same meaning as generally understood by a person of ordinary skill in the art to which the present invention pertains, unless otherwise defined. Commonly used terms, such as terms defined in a dictionary, should be interpreted as being consistent with the contextual meaning of the related technology, and shall not be interpreted in an ideal or overly formal sense, unless explicitly defined in the present invention.

[0105] The above description is merely an illustrative description of the technical idea of ​​the present invention, and those skilled in the art will appreciate that various modifications and variations may be made without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical idea of ​​the present invention, but rather to explain it, and the scope of the technical idea of ​​the present invention is not limited by these embodiments. The scope of protection of the present invention should be interpreted by the following claims, and all technical ideas within a scope equivalent thereto should be interpreted as being included in the scope of the rights of the present invention.

Claims

1. Motor housing forming the internal space; A shaft rotatably provided in the above internal space; A stator arranged to be fixed to the motor housing in the internal space, and including a stator core, a coil, and a stator bracket; and A rotor is fixedly connected to the shaft and is axially opposed to the stator, and includes a rotor base plate and a plurality of permanent magnets. The above rotor base plate, An axial motor comprising a first surface facing the stator and a second surface opposite the first surface, and having a vortex-forming groove that generates a vortex on the second surface.

2. In paragraph 1, The above vortex forming groove is, Axial motors formed in multiple pieces and arranged spaced apart from each other in the circumferential direction.

3. In paragraph 2, The above vortex forming groove is, An axial motor formed radially with the axis of the above rotor base plate as the center.

4. In paragraph 1, The above vortex forming groove is, An axial motor in which the depths of an inner region adjacent to the center of the rotor and an outer region adjacent to the outer periphery of the rotor are formed differently.

5. In paragraph 4, The above vortex forming groove is, An axial motor in which the depth of the outer region is formed deeper than that of the inner region.

6. In paragraph 1, The above vortex forming groove is, An axial motor in which the width of the outer region adjacent to the outer periphery of the rotor is formed wider than the width of the inner region adjacent to the center of the rotor.

7. In paragraph 1, The above rotor base plate, An axial motor in which a protruding member that generates turbulence is formed on the above vortex forming groove.

8. In paragraph 7, The above protruding member is, An axial motor formed closer to the outer region than the inner region of the rotor within the above vortex forming groove.

9. In paragraph 1, The above rotor base plate, An axial motor having a through hole formed in the above vortex forming groove to circulate air between the rotor and the stator.

10. Motor housing forming the internal space; A shaft rotatably provided in the above internal space; A stator arranged to be fixed to the motor housing in the internal space, and including a stator core, a coil, and a stator bracket; and A rotor is fixedly connected to the shaft and is axially opposed to the stator, and includes a rotor base plate and a plurality of permanent magnets. The above permanent magnet, An axial motor in which the inner region adjacent to the center of the rotor and the outer region adjacent to the outer periphery of the rotor have different thicknesses.

11. In paragraph 10, The above permanent magnet, An axial motor in which the thickness of the outer region is formed to be greater than that of the inner region.

12. In paragraph 11, The above permanent magnet, An axial motor formed with a thickness that gradually increases from the inner region to the outer region.

13. In paragraph 10, The above permanent magnet, An axial motor formed with a width that gradually widens from the inner region to the outer region.

14. In paragraph 10, The above permanent magnet, An axial motor comprising a combination of multiple sub permanent magnets of different sizes, arranged in a step shape.

15. In paragraph 10, The above rotor, Further comprising a fixing member that couples the permanent magnet to the rotor base plate, The above fixed member is, An axial motor in which a surface in contact with the permanent magnet is formed in a shape that is inversely corresponding to the permanent magnet.

16. In paragraph 15, The above fixed member is, An axial motor formed so that the sum of the thicknesses of the permanent magnets is constant.

17. In paragraph 15, The above fixed member is, An axial motor in which a discharge groove is formed on the contact surface with the permanent magnet to discharge excess adhesive when the permanent magnet is bonded.

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