Axial type motor including cooling plate

Abstract

An objective of the present invention is to provide an axial type motor which comprises: a motor housing forming an inner space; a shaft rotatably provided in the inner space; a stator arranged to be fixed to the motor housing in the inner space and including a stator core, a coil, and a stator bracket; a rotor fixedly coupled to the shaft, arranged to face the stator in an axial direction, and including a rotor base plate and a plurality of permanent magnets; a cooling pipe arranged along the circumference of the stator to cool the stator; and a cooling plate provided between the coil and the cooling pipe to disperse heat of the coil to the cooling pipe.

Description

Axial motor with cooling plate

[0001] The present invention relates to an axial motor including a cooling plate, and more particularly, to an axial motor including a cooling plate capable of improving the cooling performance of a stator.

[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 also 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] At this time, the coil of the stator is made of a conductor such as copper or aluminum, and when current passes through the conductor, heat is generated due to the resistance of the conductor.

[0010] Accordingly, 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 quickly dissipates 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] To prevent these problems, a cooling blade fan is usually mounted on one end of the motor's central rotational shaft to suppress the motor's temperature rise.

[0012] This technology only allows the forward airflow of the cooling blade fan to brush the outer surface of the motor housing, and does not allow the forward airflow to directly enter the inside of the housing, so it cannot cool the inside of the motor quickly and effectively.

[0013] Against this backdrop, the inventors of the present invention seek to develop an axial motor that prevents heat accumulation by performing cooling inside the motor housing.

[0014]

[0015] The present invention was created to solve the above-described problem, and its purpose is to provide an axial motor including a cooling plate capable of cooling a stator by providing a cooling pipe inside a motor housing.

[0016] 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.

[0017]

[0018] An axial motor including a cooling plate according to one embodiment of the present invention may include a motor housing forming an internal space, a shaft rotatably provided in the 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, a rotor fixedly coupled to the shaft and arranged to face the stator along the axial direction, the rotor including a rotor base plate and a plurality of permanent magnets, a cooling pipe arranged along the circumference of the stator to cool the stator, and a cooling plate arranged between the coil and the cooling pipe to disperse heat of the coil to the cooling pipe.

[0019] Additionally, the cooling tube may be provided to be wound multiple times along the circumferential direction of the stator.

[0020] Additionally, the cooling tubes may be arranged so that each adjacent cooling tube is spaced apart from the other in the coiled state.

[0021] Additionally, the cooling plate can be formed to wrap around the circumference of the stator.

[0022] Additionally, the cooling tube may be formed in a cut circular shape with a cross-section having a live wire, and may be positioned so that the cross-section is in contact with the cooling plate.

[0023] In addition, the cooling tube may be formed in a semicircular shape with one side open, and an internal space through which a refrigerant flows may be formed by combining the open side with a cooling plate.

[0024] Additionally, the cooling plate may have a cooling tube insertion groove formed on the surface that contacts the cooling tube, the groove corresponding to the outer shape of the cooling tube.

[0025] According to another embodiment of the present invention, an axial motor including a cooling plate may include a motor housing forming an internal space, a shaft rotatably provided in the 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, a rotor fixedly coupled to the shaft and arranged to face the stator in the axial direction, the rotor including a rotor base plate and a plurality of permanent magnets, a cooling pipe wound along a circumferential direction of the stator to cool the stator, and a cooling plate formed in an internal space to accommodate the cooling pipe and provided such that one surface is in contact with the stator to disperse heat.

[0026]

[0027] According to an axial motor including a cooling plate according to one embodiment of the present invention, the cooling efficiency of the motor can be improved by having the cooling tube contact the stator to directly cool the stator.

[0028] The effects of the present invention are not limited to the effects described above, and effects not mentioned can be clearly understood by a person skilled in the art to which the present invention pertains from this specification and the attached drawings.

[0029]

[0030] FIG. 1 is a perspective view of an axial motor including a cooling plate according to one embodiment of the present invention.

[0031] FIG. 2 is an exploded perspective view of an axial motor including a cooling plate according to one embodiment of the present invention.

[0032] Figure 3 is an exploded perspective view of the stator and cooling module of Figure 1.

[0033] Figure 4 is an exploded perspective view of the rotor of Figure 1.

[0034] Fig. 5 is a front view of the stator and cooling module of Fig. 1.

[0035] Figure 6 is a cross-sectional view of a stator and cooling module according to one embodiment of the present invention.

[0036] Figure 7 is a cross-sectional view of a stator and cooling module according to another embodiment of the present invention.

[0037] Figure 8 is a cross-sectional view of a stator and cooling module according to another embodiment of the present invention.

[0038] FIG. 9 is a cross-sectional view of a stator and cooling module according to another embodiment of the present invention.

[0039] Fig. 10 is a cross-sectional view of a stator and cooling module according to another embodiment of the present invention.

[0040] FIG. 11 is a cross-sectional view of a stator and cooling module according to another embodiment of the present invention.

[0041] FIG. 12 is a cross-sectional view of a stator and cooling module according to another embodiment of the present invention.

[0042]

[0043] 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.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] Hereinafter, an axial motor including a cooling plate according to one embodiment of the present invention will be described in detail with reference to the drawings.

[0048] FIG. 1 is a perspective view of an axial motor including a cooling plate according to one embodiment of the present invention. FIG. 2 is an exploded perspective view of an axial motor including a cooling plate according to one embodiment of the present invention. FIG. 3 is an exploded perspective view of the stator and cooling module of FIG. 1. FIG. 4 is a front view of the stator and cooling module of FIG. 1. FIG. 5 is a front view of the stator and cooling module of FIG. 1. FIG. 6 is a cross-sectional view of the stator and cooling module according to one embodiment of the present invention.

[0049] Referring to FIGS. 1 to 6, an axial motor (10) including a cooling plate includes a motor housing (100), a shaft (200), a stator (300), a rotor (400), and a cooling module (500).

[0050] The motor housing (100) has an internal space (S) formed therein and is provided with a shaft (200), a stator (300), a rotor (400), and a cooling module (500). The motor housing (100) accommodates the stator (300), the rotor (400), and the cooling module (500) therein. The motor housing (100) may include a housing (120), a front cover (140), and a rear cover (160).

[0051] 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).

[0052] 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.

[0053] 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).

[0054] 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). The stator (300) includes a stator core (320), a coil (322), and a stator bracket (340).

[0055] 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.

[0056] 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.

[0057] 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.

[0058] 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).

[0059] 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 (344) formed in the center through which a shaft (200) passes in the axial direction.

[0060] 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).

[0061] 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).

[0062] The rotor base plate (420) is formed with a permanent magnet coupling groove (422) to which a permanent magnet (440) is coupled.

[0063] 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). The permanent magnet coupling groove (422) may be coupled to the permanent magnet (440) with a bolt. Alternatively, the permanent magnet coupling groove (422) may be coupled to the permanent magnet (440) with an adhesive.

[0064] The permanent magnet (440) causes the rotor (400) to rotate by a magnetic field when power is applied to the stator (300). 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, an adjacent pair among 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.

[0065] The cooling module (500) cools the stator (300). Specifically, the cooling module (500) can cool the stator (300) by having one surface in contact with the stator (300) along its circumference. The cooling module (500) can be provided between the stator (300) and the motor housing (100). The cooling module (500) includes a cooling pipe (520) and a cooling plate (540).

[0066] A cooling tube (520) is arranged along the circumference of the stator (300) to cool the stator (300). The cooling tube (520) is formed as a tube through which a refrigerant flows, and cools the stator (300) by allowing the low-temperature refrigerant to flow. A refrigerant inlet (522) and a refrigerant outlet (524) are formed at both ends of the cooling tube (520). The cooling tube may be formed of a material with high thermal conductivity. For example, the cooling tube (520) may be formed of a copper material or an aluminum material.

[0067] The cooling tube (520) may be wound multiple times along the circumferential direction of the stator (300) to improve cooling efficiency. Among the multiple-wound cooling tubes (520a, 520b, 520c, 쪋), adjacent multiple-wound cooling tubes (520a, 520b, 520c, 쪋) may be arranged to be spaced apart from each other. The multiple-wound cooling tubes (520a, 520b, 520c, 쪋) may be spaced apart at equal intervals, but the present invention is not limited thereto, and the distance between the multiple-wound cooling tubes (520a, 520b, 520c, 쪋) and the distance between the coil (322) will be understood as a position that can improve cooling efficiency.

[0068] The cooling plate (540) disperses the heat of the coil (322) to the cooling tube (520). The cooling plate (540) is disposed between the coil (322) and the cooling tube (520). The cooling plate (540) may be formed to surround the stator (300) along its circumference. For example, the cooling plate (540) may be provided in a cylindrical shape and may have a hollow space formed therein into which the stator (300) is inserted in the axial direction. The cooling plate (540) may have an inner side in contact with a plurality of coils (322) and an outer side in contact with the cooling tube (520) so as to exchange heat between the coils (322) and the cooling tube (520). The cooling plate (540) may be formed of an insulating material. For example, the cooling plate (540) may be formed of a material having insulating properties and high thermal conductivity, such as alumina, silica, or epoxy.

[0069] However, although the cooling plate (540) has been described as being in contact with a plurality of coils (322), it is not limited thereto and may exchange heat by being spaced apart from a plurality of coils (322) by a predetermined distance.

[0070] According to another embodiment of the present invention, a cooling tube (520) may be formed in a cut circular shape with a cross-section having a live wire, as illustrated in FIG. 7. In this case, the cooling tube (520) may be wound around a cooling plate (540) such that the cross-section comes into contact with the outer surface of the cooling plate (540). Accordingly, the contact surface between the cooling tube (520) and the cooling plate (540) increases, thereby having the effect of improving the cooling efficiency of the coil (322).

[0071] In addition, the cooling tube (520) according to another embodiment of the present invention may be formed in a semicircular shape with one side open, as illustrated in FIG. 8. In this case, the open surface of the cooling tube (520) may be coupled along the outer surface of the cooling plate (540) to form a space through which the refrigerant flows. Accordingly, the cooling tube (520) is formed integrally with the cooling plate (540), thereby not only improving cooling efficiency but also reducing material costs.

[0072] In addition, the cooling tube (520) according to another embodiment of the present invention is formed in a cylindrical shape as illustrated in FIG. 9, and the cooling plate (540) may have a cooling tube insertion groove (542) formed along the outer surface corresponding to the shape of the cooling tube (520). The cooling tube (520) may be wound along the cooling tube insertion groove (542). Accordingly, the cooling tube (520) is formed in a cylindrical shape, thereby increasing the contact surface with the cooling plate (540) while maintaining the supply amount of refrigerant flowing therein, thereby having the effect of improving cooling efficiency.

[0073] In the above-described example, the cooling tube (520) is described as having a cylindrical or semicircular shape, but the shape of the cooling tube (520) is not limited thereto, and it will be understood that it is a shape that is easy to manufacture and can increase the contact area with the cooling plate (540).

[0074] The cooling module (500) according to one embodiment of the present invention has been described as having a cooling plate (540) provided between the coil (322) and the cooling tube (520) to disperse the heat of the coil (322) to the cooling tube (520), but the cooling module (500) according to another embodiment of the present invention may be provided in a form in which an internal space is formed in the cooling plate (550) to accommodate the cooling tube (520).

[0075] Fig. 10 is a cross-sectional view of a stator and cooling module according to another embodiment of the present invention.

[0076] Referring to FIG. 10, the cooling module (500) includes a cooling tube (520) and a cooling plate (550).

[0077] The structure and function of the cooling tube (520) are the same as the cooling tube (520) described above, so description thereof is omitted below.

[0078] The cooling plate (550) disperses the heat of the coil (322) to the cooling tube (520). The cooling plate (550) is arranged so that one surface is in contact with the coil (322). The cooling plate (550) may be formed to wrap around the circumference of the stator (300). For example, the cooling plate (550) may be provided in a cylindrical shape and may have a hollow formed therein into which the stator (300) is inserted in the axial direction. The cooling plate (550) has an internal space formed therein in which the cooling tube (520) is accommodated. At this time, the cooling tube (520) may be provided to be wound multiple times inside the cooling plate (550). A method for accommodating the cooling tube (520) in the cooling plate (550) will be described. After the wound cooling tube (520) is inserted into a mold of a desired shape, it is filled with liquid epoxy and cured, thereby forming a cooling plate (550) that accommodates the cooling tube (520).

[0079] According to this, there is an effect of improving heat exchange efficiency by having the entire area of ​​the cooling tube (520) accommodated inside the cooling plate (550) come into contact with the cooling plate (550).

[0080] In addition, a cooling tube (520) according to another embodiment of the present invention may be formed in a cut circular shape with a cross-section having a live wire, as illustrated in FIG. 11. At this time, the cooling tube (520) may be accommodated inside the cooling plate (550) such that the cross-section is adjacent to the coil (322). Accordingly, the cross-sectional area of ​​the cooling tube (520) is formed to be largest at a location where the heat generation of the coil (322) is greatest, thereby improving heat exchange efficiency.

[0081] In addition, the cooling tube (520) according to another embodiment of the present invention may be formed in a semicircular shape with one side open, as illustrated in FIG. 12. The cooling tube (520) may be accommodated inside the cooling plate (550) so that the open surface is coupled with the cooling plate (550) to form a space through which the refrigerant flows. At this time, the cooling tube (520) may be arranged so that the open surface is adjacent to the coil (322). Accordingly, the cooling tube (520) is formed integrally with the cooling plate (550), which not only improves cooling efficiency but also has the effect of reducing material costs.

[0082] According to the above-described example, the cooling module (500) is in contact with the stator (300) to cool the stator (300), thereby improving the cooling efficiency, thereby having the effect of efficiently controlling the heat generation inside the motor.

[0083] In addition, the cooling module (500) may further include a cooling pump (not shown). The cooling pump circulates refrigerant through the cooling tube (520) to remove heat from the coil (322). The cooling pump contains refrigerant therein. For example, the refrigerant may be provided as cooling water or cooling gas. One end of the cooling pump is connected to the refrigerant inlet (522) and the other end is connected to the refrigerant outlet (524). The cooling pump cools the refrigerant discharged through the refrigerant outlet (524) and supplies it to the refrigerant inlet (522). Therefore, the cooling pump can supply the refrigerant to the cooling tube (520) by maintaining the temperature of the refrigerant at a constant temperature lower than that of the heated coil (322).

[0084] 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.

[0085] 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, the stator including a stator core, a coil, and a stator bracket; A rotor fixedly connected to the shaft and axially opposed to the stator, the rotor including a rotor base plate and a plurality of permanent magnets; A cooling tube arranged along the circumference of the stator to cool the stator; and An axial motor including a cooling plate provided between the coil and the cooling tube to disperse heat of the coil to the cooling tube.

2. In paragraph 1, The above cooling tube, An axial motor including a cooling plate that is arranged to be wound multiple times along the circumferential direction of the stator.

3. In paragraph 2, The above cooling tube, An axial motor comprising a cooling plate arranged so that each of the adjacent cooling tubes is spaced apart from each other in a coiled state.

4. In paragraph 1, The above cooling plate, An axial motor comprising a cooling plate formed to wrap around the circumference of the stator.

5. In paragraph 4, The above cooling tube, An axial motor comprising a cooling plate formed in a cut circular shape with a cross section having a live wire, the cross section being arranged so as to be in contact with the cooling plate.

6. In paragraph 4, The above cooling tube, An axial motor including a cooling plate formed in a semicircular shape with one side open, wherein the open side is joined to the cooling plate to form an internal space through which a coolant flows.

7. In paragraph 1, The above cooling plate, An axial motor including a cooling plate having a cooling tube insertion groove formed on a surface in contact with the cooling tube, the cooling tube having a shape corresponding to the outer shape of the cooling tube.

8. 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, the stator including a stator core, a coil, and a stator bracket; A rotor fixedly connected to the shaft and axially opposed to the stator, the rotor including a rotor base plate and a plurality of permanent magnets; A cooling tube wound along the circumference of the stator to cool the stator; and An axial motor comprising an internal space formed to accommodate the cooling tube and a cooling plate provided so that one surface thereof is in contact with the stator to disperse heat.

9. In paragraph 8, The above cooling tube, An axial motor including a cooling plate that is arranged to be wound multiple times along the circumferential direction of the stator.

10. In paragraph 8, The above cooling tube, An axial motor comprising a cooling plate arranged so that each of the adjacent cooling tubes is spaced apart from each other in a coiled state.

11. In paragraph 8, The above cooling tube, An axial motor comprising a cooling plate formed in a cut circular shape with a cross section having a live wire, the cross section being arranged so as to be in contact with the cooling plate.

12. In paragraph 8, The above cooling tube, An axial motor including a cooling plate formed in a semicircular shape with one side open, wherein the open side is joined to the cooling plate to form an internal space through which a coolant flows.

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