Axial gap motor and water pump using the same

Abstract

The present invention relates to an axial gap type motor using a non-rare earth magnet and a water pump using the same. The water pump (EWP) axial gap type motor of the present invention includes a rotor rotatably supported in a fluid flow passage between a pump cover and a main body case; a stator disposed in a lower space formed by the main body case and a top cover to rotatably drive the rotor by generating a rotating magnetic field; and a partition plate disposed in an upper portion of the main body case to separate the rotor and the stator. The rotor can be made of a ferrite magnet as a non-rare earth magnet.

Description

TECHNICAL FIELD

[0001] The present application relates to an axial gap motor, and more particularly, to an axial gap motor using a non-rare earth magnet and an electric water pump using the same. BACKGROUND

[0002] Generally, a water pump for a vehicle is a device for circulating coolant by rotating a pump impeller with a forced drive to suck and discharge coolant, and representative water pumps include an engine-driven water pump having a seal unit for preventing coolant from flowing out, and an electric water pump driven by power supplied from a battery or the like to rotate an impeller by an electric motor, thereby circulating coolant by sucking and discharging coolant.

[0003] Among them, the electric water pump does not require engine power of a vehicle, unlike the engine-driven water pump, and thus has an advantage of increasing engine efficiency and improving fuel efficiency, unlike the engine-driven water pump, and an advantage of precisely controlling coolant temperature, and thus is widely used in various vehicles recently.

[0004] Since an electric vehicle, a hybrid vehicle, or a fuel cell vehicle hybrid vehicle travels in a state where engine driving is stopped (in the case of a hybrid vehicle) or is not provided with an engine for driving a water pump (in the case of an electric vehicle or a fuel cell vehicle), the importance of the electric water pump will gradually increase, unlike the engine-driven water pump.

[0005] On the other hand, in the electric water pump, a canned type electric water pump is a pump driven by a motor having a can (CAN) shaped sealing container provided inside a stator, a can structure is inserted between a rotor and the stator, and a force receiving portion is extended to a rotor portion to allow the rotor to be cooled by coolant, thereby allowing water to be appropriately cooled by friction heat generated by the rotor.

[0006] A pump disclosed in Korean Patent Publication No. 10-0900120 (Patent Document 1) includes a pump portion provided with an impeller for sucking and discharging liquid, a motor portion for driving the pump portion, a housing in which the pump portion is built, a partition plate for separating the motor portion from the pump portion, and a mold resin for protecting the motor portion and formed in one body with the motor portion.

[0007] The existing pump of Patent Document 1 is structured such that a magnet and a core are positioned in a radial direction so that water flows into the magnet, and since it is necessary to prevent water from flowing into a stator (core winding portion), a waterproof structure using a waterproof can or an injection molding is formed. As a result, as the air gap between the rotor and the stator core increases, a large amount of magnetic flux loss occurs, and it will be difficult to match the desired pump (motor) capacity with a general magnet, and therefore, an expensive rare earth magnet is generally used.

[0008] Generally, an inner rotor type motor is applied to a water pump (EWP), a compressor, an oil pump, etc., but the magnet cross-sectional area (i.e., effective area) of the inner rotor type motor is relatively small, and therefore, there is a problem of high cost when using a rare earth to achieve performance.

[0009] Also, the water pump motor is an inner rotor type motor, and the rare earth magnet (Nd-Fe-B) applied to the rotor contains an iron component, and when it comes into contact with water, there is a problem of rusting of the magnet, and therefore, a waterproof structure is also required for the rotor portion. Also, the water pump motor has a structure in which the use amount of neodymium (Nd) of the rotor magnet is inevitably increased due to an increase in the air gap between the rotor and the stator.

[0010] Also, in the inner rotor type motor, the inner side shoe portion of the stator core facing the magnet of the rotor is not generally processed with a "round arc R", and since it is not possible to change the back electromotive force (Back EMF) waveform to a sine curve, there is a problem of noise and vibration. That is, in general, the inner side of the core is formed as a concentric circle with the center as a reference. Therefore, at the structural level, the existing stator core additionally requires an auxiliary member for improving the noise and vibration problems.

[0011] In the prior art, in order to improve such vibration and noise generation, the magnet of the rotor is generally processed with a "round arc R". If the magnet is a segment structure, there is no problem, but when the magnet is an integrated structure of a divided magnetization, it will not be possible to form a "round arc R" shape.

[0012] On the other hand, the existing water pump motor has a problem in that since the stator core and a printed circuit board (PCB) that packages a motor driving circuit are grounded, in order to achieve electromagnetic compatibility (EMC) and electromagnetic interference (EMI) improvement effects, an additional member is required to be added.

[0013] Generally, a roof fan ventilation device is installed on the roof of a house, a factory, a plastic greenhouse, a barn, or the like, and performs ventilation by forcibly sucking or discharging indoor air to the outside through a fan to maintain a proper temperature and humidity in the indoor.

[0014] Since a small roof fan including a small impeller and a small motor is rotated at a high speed, as the rotation speed (RPM, revolution per minute) increases, a problem of causing vibration and noise occurs.

[0015] In consideration of such a problem, other prior art discloses a roof fan ventilation device greatly improving a ventilation function by manufacturing a larger roof fan (for example, a diameter of the roof fan is manufactured to be about 3 m) than the prior art to reduce the rotation speed (RPM, revolution per minute), greatly reducing vibration and noise. In such a circulating roof fan ventilation device, since a fan blade is disposed separately from a driving motor, power is transmitted between the driving motor and the fan blade through a belt type transmission device.

[0016] Also, most of the existing roof fans have a complicated structure to some extent, and thus, not only are difficult to manufacture, but also have a reduced durability due to a relatively weak structural strength.

[0017] Generally, a roof fan ventilation device includes an impeller for forming a fan, a motor for driving the impeller, and a housing for disposing the impeller and the motor on a roof. The impeller is directly driven by the motor, or the impeller can be driven through a belt type transmission device.

[0018] In the existing roof fan ventilation device, it is generally considered that vibration and noise problems are caused by the size of the roof fan and the high or low rotation speed, and it is not realized that they are caused by the structure of the motor itself. In consideration of a disposition space, as a motor for driving the roof fan, an outer rotor type motor that can be compacted with respect to a diameter direction and an axial direction is mostly used.

[0019] The existing outer rotor type fan motor is a radial gap type motor, and generally includes a motor portion, and a fan portion that is rotated outside the motor portion by rotation of a rotation shaft of the motor portion.

[0020] Back-EMF is a voltage induced to a stator coil by a magnetized magnet, and the faster the rotation speed is, the stronger the magnet used is, and the higher the induced voltage is. As shown in FIG. 1, a brushless DC motor using a permanent magnet type motor has a trapezoidal shape. Figure 7a

[0021] ​And, even if it is a low level of noise / vibration, the vehicle roof fan needs to minimize the noise and vibration in order to improve the quality of the vehicle and the comfort of the passengers inside the vehicle. SUMMARY

[0022] TECHNICAL PROBLEM

[0023] In consideration of the above-described prior problems, an object of the present application is to provide an axial gap type motor and a water pump using the same, which can reduce an air gap by separating a rotor and a stator using a thin partition, and can obtain the same magnetic energy as a motor using a rare earth magnet even if a ferrite magnet, which is a non-rare earth magnet, is used.

[0024] Still another object of the present application is to provide an axial gap type motor and a water pump using the same, which can achieve complete waterproofing by designing a simple structure for waterproofing.

[0025] Still another object of the present application is to provide an axial gap type motor and a water pump using the same, which can reduce core loss generated by a motor to a maximum by optimizing a core shape by applying soft magnetic powder (SMC, Soft Magnetic Composites) instead of a general electrical steel sheet (S-60) to a stator core (teeth) of a longitudinal axis type motor.

[0026] Still another object of the present application is to provide an axial gap type motor and a water pump using the same, which can improve the generation of noise and vibration by performing "round arc R" processing on a core (teeth) shape to make a back EMF waveform a sine curve, by manufacturing teeth of a stator core using a compression molding method of soft magnetic powder (SMC, Soft Magnetic Composites).

[0027] Still another object of the present application is to provide an axial gap type motor and a water pump using the same, which can maximize heat generation reduction of a back yoke using a heat sink of a printed circuit board (PCB) by joining the back yoke connected to teeth (i.e., a coil winding portion) to a main body housing to achieve heat dissipation.

[0028] Still another object of the present application is to provide an axial gap motor and a water pump using the same, which can achieve an electromagnetic compatibility (EMC) and electro magnetic interference (EMI) improvement effect by erecting a back yoke pin and simply connecting a back yoke and a printed circuit board (PCB).

[0029] Still another object of the present application is to provide a radial gap motor and a roof fan for a vehicle using the same, which can improve noise and vibration generation by performing "arc R" processing on a shoe portion of a core to make a back electromotive force (Back EMF) waveform a sine curve when a stator core is manufactured by a punching forming method of an electrical steel sheet (S-60).

[0030] Technical Solution

[0031] According to an embodiment of the present application, an axial gap motor for a water pump (EWP) includes a rotor supported in a rotatable manner in a fluid flow passage between a pump cover and a main body case, a stator disposed in a lower space formed by the main body case and a top cover to rotationally drive the rotor by generating a rotating magnetic field, and a partition plate disposed in an upper portion of the main body case to separate the rotor and the stator, wherein a non-rare earth magnet is provided in the rotor.

[0032] The rotor can include a plurality of magnets disposed in a ring shape, and a back yoke provided at a back surface of the magnets to form a magnetic circuit, and the rotor can be formed in one body at a lower side of an impeller to be rotatably supported by a support shaft, and an end portion of the support shaft is supported by the partition plate.

[0033] In this case, the partition plate can function as an air gap between the rotor and the stator.

[0034] Also, the axial gap motor for the water pump (EWP) according to an embodiment of the present application can further include a sleeve bearing combined with an outer circumference of the support shaft to rotatably support the rotor, and a bearing housing formed in one body at a bottom plate of the impeller to accommodate the sleeve bearing therein.

[0035] The stator includes: multiple teeth; a stator core with a back yoke connected to the multiple teeth to form a magnetic circuit; multiple winding frames integrally formed with the multiple teeth to surround the outer peripheral surface of each coil to be wound, made of insulating material; and coils wound on the outer peripheral surface of the winding frames. The multiple teeth are each "T" shaped and made of soft magnetic composites (SMC). The back yoke can be formed by stacking multiple electrical steel plates.

[0036] Furthermore, each of the aforementioned teeth includes: a coil winding portion on which the coil is wound; and a bearing extending from the coil winding portion to form a flange, wherein the corners between the side surface and the front surface of the bearing and the front surface of the bearing can be rounded (R-shaped). As a result, the axial gap type motor of the present invention can transform the back electromotive force (Back EMF) waveform into a sine curve to improve noise and vibration generation.

[0037] Furthermore, the aforementioned coil winding portion can be a triangular prism, and the cross-section of the aforementioned tile can be trapezoidal.

[0038] The stator core may include: a plurality of teeth arranged in a ring parallel to the axial direction on the same circumference and facing the magnets of the rotor; and a back yoke connected at right angles to the plurality of teeth to form a magnetic circuit.

[0039] In this case, the aforementioned teeth can be pressed into the assembly holes or assembly grooves that engage with each back yoke.

[0040] The stator may include a stator core, such that a plurality of teeth are arranged facing the magnets of the rotor in a ring on the same circumference parallel to the axial direction, such that the plurality of teeth are connected at right angles to the back yoke to form a magnetic circuit.

[0041] A water pump according to an embodiment of the present invention includes: a pump cover having an inlet and an outlet formed on one side and the other side, wherein the inlet is for allowing fluid to flow in and the outlet is for discharging the inflowing fluid; a main body housing, which is combined with the pump cover and forms a fluid flow channel inside the pump cover, forming a lower space; a top cover, which is combined with the lower end of the main body housing, thereby sealing the lower space; a rotor, which is rotatably supported in the fluid flow channel; an impeller, which is integrally formed with the rotor on the upper side of the rotor; a stator, which is disposed in the lower space and drives the rotor to rotate by generating a rotating magnetic field; and a partition, which is disposed on the upper part of the main body housing, thereby separating the rotor from the stator, wherein the rotor and stator form an axially spaced type motor.

[0042] Also, the water pump of one embodiment of the present application includes: a pump housing having a lower space formed in a sealed state at one side, and a flow inlet and a discharge outlet connected by a fluid flow passage at the other side, the flow inlet for allowing fluid to flow in, and the discharge outlet for discharging the fluid that has flowed in; a rotor rotatably supported in the fluid flow passage; an impeller formed in one body with the rotor at an upper side of the rotor; a stator disposed in the lower space to rotatively drive the rotor by generating a rotating magnetic field; a partition plate disposed inside the pump housing to separate the rotor from the stator; and a support shaft having one end portion supported by the partition plate to rotatably support the rotor, the rotor and the stator forming an axial gap type motor, and the rotor being provided with a non-rare earth magnet.

[0043] The stator includes a plurality of teeth on which each coil is wound, and a stator core provided with a back yoke that is connected at right angles to the plurality of teeth to form a magnetic circuit, the plurality of teeth being made of soft magnetic composites (SMC), and the back yoke being composed of an electrical steel plate.

[0044] In this case, in the plurality of teeth, pads respectively facing the rotor can be formed with flanges extending from coil winding portions, and corners between side surfaces and front end surfaces of the pads can be rounded with a radius R.

[0045] Also, a ferrite magnet can be provided in the rotor.

[0046] Further, the stator can include a stator core such that the plurality of teeth are disposed facing the magnets of the rotor in a ring shape in parallel to an axial direction on the same circumference, such that the plurality of teeth are connected at right angles to the back yoke to form a magnetic circuit, and the teeth can be compression-molded or extrusion-molded from one of amorphous metal powder, spherical soft magnetic powder, or alloy powder in which amorphous metal powder and spherical soft magnetic powder are mixed.

[0047] The water pump of one embodiment of the present application can further include a bearing combined with an outer circumference of the support shaft to rotatably support the rotor, and a bearing housing formed in one body with a bottom plate of the impeller to accommodate the bearing inside.

[0048] The water pump of one embodiment of the present application can further include a driver for driving the stator, provided with a printed circuit board (PCB) formed with a motor driving circuit, the printed circuit board (PCB) and the back yoke each having a plurality of protrusions with through holes formed in outer circumferences, and the printed circuit board (PCB) and the back yoke being fixed by fastening screws or bolts through the through holes to a height difference portion of the main body housing.

[0049] And, the water pump of one embodiment of the present application further comprises a driver for driving the stator, and a printed circuit board (PCB) forming the driver is electrically connected to the back yoke through a pin.

[0050] And, the water pump of one embodiment of the present application further comprises a driver for driving the stator, and a printed circuit board (PCB) forming the driver is electrically connected to the back yoke through a pin.

[0051] The water pump of one embodiment of the present application comprises: a pump cover having an inlet and an outlet formed on one side and the other side, the inlet for flowing into fluid, and the outlet for discharging the flowed-in fluid; a main body housing combined with the pump cover to form a fluid flow channel inside the pump cover and a lower space; a top cover combined with the lower end of the main body housing to seal the lower space; an impeller rotatably supported in the fluid flow channel; a partition plate arranged at the upper portion of the main body housing to separate the fluid flow channel from the lower space; and an axial gap motor having a rotor and a stator, the rotor rotatably supported in the fluid flow channel and integrated with the lower side of the impeller, and the stator arranged in the lower space through the partition plate to rotatably drive the rotor; the stator core is arranged in the stator, and the stator coil is wound on the stator core, the stator core comprising: a plurality of teeth arranged in parallel to the axial direction on the same circumference to face the magnet of the rotor with each front end; and a back yoke made of a ring-shaped disc and connected to the plurality of teeth at right angles to form a magnetic circuit.

[0052] The top fan driving motor of one embodiment of the present application comprises: a rotating shaft; a rotor in the shape of an inverted cup having a back yoke and a magnet arranged in the center portion, the back yoke combined with the rotating shaft, and the magnet attached to the inner side of the back yoke; a stator having an outer peripheral portion facing the magnet of the rotor with an air gap to apply a rotating magnetic field to the rotor; a bearing bushing arranged through the center portion of the stator and having a height difference portion formed in the upper portion and the lower portion; and an upper bearing and a lower bearing arranged in the upper height difference portion and the lower height difference portion of the bearing bushing to rotatably support the rotating shaft, the stator comprising a stator core having a plurality of teeth extending radially on the outer periphery of the ring-shaped yoke, and each front end of the plurality of teeth being processed by a "circular arc R".

[0053] The back yoke includes a first cylindrical portion to which the magnets are attached, a second cylindrical portion bent from the first cylindrical portion by two segments, and a top plate portion bent from an upper portion of the second cylindrical portion by one segment and formed with a plurality of through holes. A cylindrical support portion of the impeller is coupled to the outer periphery of the first and second cylindrical portions, and an upper portion of the rotating shaft is coupled to the top plate of the impeller and the rotor formed in the inner and outer portions of the top plate portion.

[0054] The stator includes a stator core with a plurality of teeth extending radially from the outer periphery of the annular yoke, a bobbin surrounding the outer periphery of the stator core and having a bearing bush inserted in the inner periphery thereof, and coils wound around the outer periphery of the teeth of the stator core. A cylindrical insert is inserted between the bobbin and the bearing bush to improve the perpendicularity of the rotating shaft.

[0055] The winding member further includes upper and lower protrusions extending along the upper and lower sides of the front end portions of the teeth to define a coil winding area of the wound coil, and the lower protrusion is used to maintain a predetermined interval when the printed circuit board (PCB) is assembled.

[0056] The stator includes three-phase (U, V, W) coils wound around the plurality of teeth, and the start and end terminals of the three-phase (U, V, W) coils are electrically connected to the printed circuit board (PCB) of the packaged motor driving circuit through six terminal pins.

[0057] In this case, the three terminal pins form a neutral point by being commonly connected to a conductive pattern of the printed circuit board (PCB).

[0058] The top-mounted fan includes an impeller, a motor for rotatingly driving the impeller, a motor driving circuit for applying a driving signal to the motor, a housing provided with a peripheral frame, a motor support portion, and a plurality of connection ribs, the peripheral frame being annular, the motor support portion being located inside the peripheral frame and supporting a lower portion of the motor, both end portions of the connection ribs being connected to the peripheral frame and the motor support portion, such that the front end portions of the connection ribs are fixed to a top-mounted fan installation module provided on the top of a vehicle, and a cover portion combined with one of the connection ribs and the motor support portion and forming an air cooling flow path portion.

[0059] In this case, the motor support portion includes at least one through hole serving as a discharge port of the air cooling flow path portion, and air cooling wind discharged through the through hole can cool a heat generating electronic component mounted on a printed circuit board (PCB) of a packaged motor driving circuit.

[0060] And, the housing includes a peripheral frame formed in a ring shape with a ring-shaped groove for receiving a lower end of the impeller, a motor support portion formed in a circular shape for supporting the motor such that a lower portion of a bearing bush of the motor is combined with the middle through-hole, and a plurality of connecting ribs for connecting the peripheral frame and the motor support portion, front end portions of the connecting ribs being fixed to the top fan installation module, respectively.

[0061] In this case, the connecting ribs and the motor support portion of the housing are combined with the cover portion and form an air cooling flow path portion, a through-hole is formed at the front end portion of the connecting ribs to serve as an air inlet of the air cooling flow path portion, and the motor support portion can include at least one through-hole to serve as an air outlet of the air cooling flow path portion.

[0062] Also, the cover portion includes a circular center portion forming a space inside and surrounding the motor support portion, and a flow path forming portion extending from the center portion and combined with one of the connecting ribs of the housing, and when the impeller is rotated by the motor, the surrounding air of a printed circuit board (PCB) is supplied to the impeller and a negative pressure is generated, a negative pressure is also generated at the motor support portion and the air cooling flow path portion which are disposed opposite to the printed circuit board (PCB), and thus an air cooling flow passing through the air cooling flow path portion can be formed.

[0063] The impeller includes a circular top plate, a plurality of blades extending radially outward from a bottom surface of the circular top plate, a ring-shaped bottom plate connecting and supporting lower portions of the plurality of blades, a cylindrical support portion extending in a cylindrical shape inside the bottom surface of the circular top plate, a lower end portion of the cylindrical support portion surrounding a side surface of a back yoke of a rotor, and a shaft support portion surrounding an upper portion of a rotating shaft of the rotor and a top plate portion of the back yoke, and in a case where the shaft support portion is formed, the upper portion of the rotating shaft and the top plate portion of the back yoke can be formed in one body by insert injection molding.

[0064] The bearing bush of the motor is supported on the motor support portion of the housing by a printed circuit board (PCB) in which a motor driving circuit is packaged, and in the motor, a lower protrusion of a bobbin formed at a plurality of teeth of a stator is spaced apart from the printed circuit board (PCB) by a predetermined distance, and a fixing combination of the stator and the printed circuit board (PCB) can be physically achieved by six terminal pins that electrically connect starting terminals and termination terminals of three-phase (U, V, W) coils wound around the stator core to the motor driving circuit of the printed circuit board (PCB).

[0065] Effects of the Invention

[0066] The present application as described above has the effect that, when a longitudinal axis type motor having the same outer diameter as a general interior rotation type motor is applied, the axial gap type motor of the present application can separate the rotor and the stator by a thin partition, thereby reducing the air gap, and even when a ferrite magnet is used as a non-rare earth magnet, the same magnetic energy as that of a motor using a rare earth magnet containing neodymium (Nd) can be obtained.

[0067] In the present application, the partition separates the rotor and the stator for the main body case of the built-in stator, and thus, complete waterproofing can be achieved by designing a simple structure for waterproofing.

[0068] Also, since the present application separates the rotor and the stator by a thin partition, a ferrite magnet can be used as a low-cost non-rare earth magnet for the magnet of the rotor.

[0069] Also, the motor of the present application is an axial gap type in which the rotor and the stator face each other with a thin partition, and thus, an open structure can be used without additionally forming a magnet waterproofing structure for a rare earth magnet or the like. Therefore, compared to a conventional motor using a rare earth magnet, the air gap can be further reduced to increase the motor efficiency.

[0070] In the present application, since the stator core (teeth) of the longitudinal axis type motor is applied with soft magnetic powder (SMC, Soft Magnetic Composites) instead of a general electrical steel sheet (S-60), the iron loss generated by the motor can be maximally reduced by optimizing the core shape.

[0071] Also, in the present application, the stator core (teeth) is manufactured by a compression molding method using soft magnetic powder (SMC, Soft Magnetic Composites), and thus, the core (teeth) shape is processed with a "round arc R" to make the back electromotive force (Back EMF, Back Electromotive Force) waveform a sine curve, thereby enabling improvement in the generation of noise and vibration.

[0072] Also, in the present application, the back yoke (Back yoke) connected to the teeth (i.e., the coil winding portion) is joined to the main body case to achieve heat dissipation, and thus, the heat generation of the back yoke can be maximally reduced using the heat dissipation plate of the printed circuit board (PCB).

[0073] In the present invention, electromagnetic compatibility (EMC), electro magnetic interference (EMI) improvement effect can be achieved by grounding (GND) between the back yoke vertical pin and the simple connection of the back yoke and the printed circuit board (PCB).

[0074] In the present invention, when the stator core is manufactured by the punching forming method of the electrical steel sheet (S-60), the shoe portion of the core is subjected to "arc R" processing to make the back electromotive force (Back EMF) waveform into a sine curve, thereby being able to improve the generation of noise and vibration.

[0075] Also, in the present invention, the perpendicularity of the rotor rotating shaft can be improved and the generation of noise and vibration can be improved by providing an insert between the stator support body and the bearing bush (Bearing Bush).

[0076] The present invention can cool the heat generating electronic components of the motor driving circuit using the air cooling flow path formed by the connecting rib of the housing and the cover portion. BRIEF DESCRIPTION OF DRAWINGS

[0077] Figure 1 Front view of a water pump using an axial gap type motor according to an embodiment of the present invention.

[0078] Figure 2 A-A line cross-sectional view of Figure 1

[0079] Figure 3 Exploded perspective view of each component of a water pump using an axial gap type motor according to an embodiment of the present invention.

[0080] Figure 4 Exploded perspective view of a water pump using an axial gap type motor according to an embodiment of the present invention.

[0081] Figure 5 Perspective view of an axial gap type motor according to an embodiment of the present invention.

[0082] Figure 6 Axial cross-sectional view showing that a partition is provided to the upper end of the main body housing to achieve a complete waterproof structure between the stator and the rotor in a water pump using an axial gap type motor according to an embodiment of the present invention.

[0083] Figures 7a to 7d View showing the coupling relationship between the teeth of the stator core and the back yoke of the first embodiment of the axial gap type motor according to the present invention, respectively, a plan view of the stator core, a plan view of the back yoke,​Figure 7a BB line cross-section and 3D view.

[0084] Figures 8a to 8d The diagrams illustrating the engagement relationship between the teeth of the stator core and the back yoke in a second embodiment of the axial gap type motor of the present invention are, respectively, a top view of the stator core and a top view of the back yoke. Figure 8a Cross-sectional view and 3D view of the CC line.

[0085] Figures 9a to 9d The diagrams illustrating the engagement relationship between the teeth of the stator core and the back yoke in the third embodiment of the axial gap type motor of the present invention are, respectively, a top view of the stator core and a top view of the back yoke. Figure 9a DD line cross-section and 3D view.

[0086] Figures 10a to 10d The diagrams illustrating the engagement relationship between the teeth of the stator core and the back yoke in the fourth embodiment of the axial gap type motor of the present invention are, respectively, a top view of the stator core and a top view of the back yoke. Figure 10a EE line cross-section diagram and 3D diagram.

[0087] Figures 11a to 11d The diagrams illustrating the engagement relationship between the teeth of the stator core and the back yoke in the fifth embodiment of the axial gap type motor of the present invention are, respectively, a top view of the stator core and a top view of the back yoke. Figure 11a FF line cross-section and 3D view.

[0088] Figure 12a and Figure 12b The figures show the back electromotive force waveforms in the form of a spherical wave obtained when the inner tile portion of the stator core of an existing inward-rotating motor is not treated with "circular arc R" and the back electromotive force waveforms in the form of a sinusoidal wave obtained by the axial gap type motor of the present invention, respectively.

[0089] Figure 13 An axial cross-sectional view of an axial gap type motor is shown, in which the back yoke, which is connected to the teeth (i.e., the coil winding), engages with the main body housing to achieve heat dissipation and a heat sink of a printed circuit board (PCB) is used to minimize the heat generated by the back yoke.

[0090] Figure 14a and Figure 14b The figures show perspective views of a back yoke and printed circuit board (PCB) connection structure that can achieve electromagnetic compatibility and electromagnetic interference improvement by simply connecting the back yoke to the printed circuit board (PCB) with a pin erected on the back yoke or by soldering the back yoke to the bottom of the back of the PCB for grounding (GND).

[0091] Figures 15a to 15dFIG. 1 is a plan view showing a roof fan using a radial gap motor according to the present application;

[0092] Figure 16 FIG. 4 is a cross-sectional view taken along the axial direction of the roof fan shown in FIG. 1. Figure 15a

[0093] Figure 17 FIG. 5 is an exploded perspective view showing the roof fan using the radial gap motor according to the present application.

[0094] Figure 18a FIG. 6 is a plan view showing the radial gap motor applied to the roof fan according to the present application. Figure 18b

[0095] Figure 19a FIG. 7 is a cross-sectional view taken along the radial direction of the radial gap motor applied to the roof fan according to the present application. Figure 19b

[0096] FIG. 8 is an exploded perspective view of the radial gap motor according to the present application. Figure 20 DETAILED DESCRIPTION

[0097] Hereinafter, a preferred embodiment of the present application will be described with reference to the accompanying drawings.

[0098] In this process, the dimensional or shape of the structural elements shown in the drawings can be exaggerated for the sake of clarity and convenience in explanation. Also, the terms particularly defined in relation to the structure and function of the present application can be different according to the intention or custom of the user or operator. Such terms should be defined based on the entire contents of the present specification.

[0099] The axial gap motor using a non-rare earth magnet according to the present application can be a longitudinal axis motor, and is applied to an embedded water pump (EWP), a compressor, an oil pump, etc. In the following description, the axial gap motor will be described by way of example in which the axial gap motor is applied to a water pump (EWP).

[0100] Also, the axial gap motor according to the present application can employ a design probability of a new type of stator core in order to improve the generation of noise and vibration.

[0101] Referring to Figures 1 to 6 , the water pump 200 using the axial gap motor according to the present application generally includes a housing 10, an axial gap motor 100, an impeller 20, and a driver 50.

[0102] ​​​In the pump housing 10, a flow inlet 11a for flowing in a fluid such as a coolant is formed in the center of one side end, and a flow outlet 11b for discharging the fluid flowed in the one side is formed in the other side end. The pump housing 10 includes a pump cover 11 whose center portion of the other side end is opened, a main body case 12 which is a cup-shaped body in reverse, covers the opened portion of the pump cover 11, and forms a fluid flow passage P inside the pump cover 11 to form a lower space 14 outside the fluid flow passage P, and a top cover 13 which is combined with the lower end of the main body case 12, and in which a stator 40 of a motor 100 which seals the lower space 14 inside the main body case 12 and a driver 50 for driving the stator 40 are built in.

[0103] Preferably, the pump cover 11 and the main body case 12 are cylindrical, and can have a structure in which they are fixedly combined with each other.

[0104] For example, the fixedly combined structure between the pump cover 11 and the main body case 12 can be achieved by fastening a screw or a bolt to the combined hole through four protruding fixing extensions 11c.

[0105] Also, between the pump cover 11 and the main body case 12, a circular protrusion 11d and a circular groove 12a can be formed in each of the flanges, and an O-ring 63 for sealing can be inserted into the groove 12a.

[0106] Also, the O-ring 63 can be inserted into the combined portion between the main body case 12 and the top cover 13, so that the sealing state of the lower space 14 can be maintained. Also, the combined portion between the main body case 12 and the top cover 13 can be combined by a laser welding method, so that a more perfect sealing state can be achieved.

[0107] A connection case 13a extending from the lower surface of the top cover 13 is provided with a terminal end for applying a driving signal from the outside to the driver 50.

[0108] For example, the pump cover 11, the main body case 12, and the top cover 13 which constitute the pump housing 10 can be made of a resin such as polyphenylene sulfide (PPS).

[0109] The fluid flow passage P of the curved portion between the flow inlet 11a and the flow outlet 11b of the pump cover 11 is provided with an impeller 20, and a rotor 30 of the motor 100 is formed integrally at the lower side thereof.

[0110] Also, in order to be able to provide the impeller 20 in the fluid flow passage P and to ensure that the opened lower end of the pump cover 11 is expanded to a space wider than the flow inlet 11a, a flange of a groove structure is formed in the upper portion of the main body case 12 corresponding to the opened lower end of the pump cover 11.

[0111] In order to allow fluids such as coolant flowing in from the inlet 11a to be discharged through the outlet 11b located on the side, the impeller 20 has multiple blades 23 arranged radially between the circular plate-shaped top plate 21 and bottom plate 22. The top plate 21 has a through hole in the middle and has a shape that is narrower at the top and wider at the bottom, with the diameter gradually increasing from the top to the bottom. The bottom plate 22 is a circular plate surrounding the upper side and the periphery of the rotor 20. The bottom plate 22 and the rotor 20 can be integrated by an inlay injection molding method.

[0112] Furthermore, a bearing housing 62 is formed protruding from the center of the base plate 22, and a sleeve bearing 61 is provided in the bearing housing 62, so that the rotor 20 is supported on the support shaft 60 in a rotatable manner.

[0113] Considering that the aforementioned sleeve bearing 61 is in contact with the fluid, preferably, the aforementioned sleeve bearing 61 should be an oil-free bearing such as a carbon bearing or a plastic bearing.

[0114] On the other hand, such as Figures 2 to 6 As shown, the axial clearance type motor 100 used as a drive unit for rotating the impeller 20 includes: a stator 40, which is core-shaped and disposed in a sealed lower space 14 inside the main body housing 12; and a rotor 30, which is disposed opposite to the stator 40 in a fluid flow channel P outside the main body housing 12.

[0115] First, the rotor 30 has a ring-shaped back yoke 31 and a magnet 32 ​​sequentially arranged on the bottom surface of the base plate 22, thus forming a single unit with the impeller 20. The magnet 32 ​​of the rotor 30 can be composed of multiple split magnet pieces with N poles and S poles, or a magnet that splits and magnetizes the N poles and S poles of the ring-shaped magnet into multi-pole magnets can be used. The back yoke 31 is arranged on the back of the magnet 32 ​​and forms a magnetic circuit.

[0116] A thin partition 12b is provided on the upper part of the main housing 12 to separate the stator 40 and the rotor 30, thereby achieving a completely waterproof structure for the stator 40. That is, the stator 40, which is disposed in the sealed lower space 14 inside the main housing 12, can be perfectly prevented from contacting water.

[0117] Compared to the cylindrical portion of the main body shell 12, the aforementioned partition 12b has a relatively thin thickness. Therefore, as described below, the magnet of the rotor 30 can be a ferrite magnet, which is a non-rare earth magnet.

[0118] That is, the motor 100 of the present invention, with its rotor 30 and stator 40 facing each other via a thin partition 12b, can be an open structure, eliminating the need for additional waterproof structures for rare-earth magnets or similar materials. In other words, even with the magnet 32 ​​of the rotor 30 in contact with the coolant flowing through the fluid flow channel P inside the pump cover 11, the performance of the magnets will not degrade even after prolonged operation of the motor 100 of the present invention. Therefore, compared to motors using rare-earth magnets with waterproof structures, the motor 100 of the present invention can increase efficiency by further reducing the air gap.

[0119] Furthermore, when using a longitudinal shaft type motor with the same outer diameter as a conventional internal rotation motor, the present invention can reduce the air gap by separating the rotor 30 and the stator 40 through a thin partition 12b. Therefore, even when using ferrite magnets as non-rare earth magnets, an axial gap type motor with the same magnetic energy as a motor containing neodymium (Nd) rare earth magnets can be realized.

[0120] The aforementioned support shaft 60 is integrated through the following insert molding method: when the main body shell 12 is injection molded, a part of the support shaft 60 is inserted into the center of the partition 12b, or it can be inserted into the support shaft receiving part 12c that is integrally formed in the center of the partition 12b.

[0121] A portion of the support shaft receiving portion 12c extends from the partition 12b to the lower space 14, and a portion extends to the upper side of the partition 12b to form and protrude, having sufficient contact area and firmly supporting the lower end of the support shaft 60.

[0122] The stator of an axial clearance type motor according to an embodiment of the present invention will be described below.

[0123] like Figures 4 to 6 As shown, the stator 40 is disposed in the lower space 14 that maintains a sealed state, and is arranged axially opposite to the rotor 30 along the axis of the space between the stator 40 and the rotor 30, forming an axial gap type motor.

[0124] The stator 40 includes: a plurality of teeth 41; a stator core 45 having a back yoke 42 connected to the plurality of teeth 41 to form a magnetic circuit; a plurality of winding frames 43 made of insulating material, surrounding the outer peripheral surface of each coil wound by the plurality of teeth 41 and forming an integral unit; and a coil 44 wound on the outer peripheral surface of the winding frames 43.

[0125] The plurality of teeth 41 forming the stator core 45 described above are each in a "T" shape, can be compression-molded from soft magnetic powder (SMC), and are arranged in a circular array parallel to the axial direction on the same circumference so that each shoe portion is arranged facing the magnet of the rotor 30.

[0126] The teeth 41 described above are made of an isotropic magnetic material having high magnetic permeability, low magnetic coercivity, and high saturation magnetic induction, and for example, iron-nickel (Fe-Ni), iron-cobalt (Fe-Co), or iron-silicon (Fe-Si) alloy powder can be used. When the teeth 41 are manufactured using the soft magnetic powder (SMC) by a compression molding or extrusion molding method, not only a three-dimensional structure can be formed, but also the teeth 41 can have isotropy.

[0127] As described above, the manufacture of the teeth 41 using the soft magnetic powder (SMC) by a compression molding method is particularly important because the "round arc R" processing required to form a curved surface in the shoe portion can be easily performed at the front end portion of the teeth 41 facing the magnet 32 of the rotor 30.

[0128] In addition to the compression molding of the soft magnetic powder (SMC), the teeth 41 of the present application can be molded by mixing amorphous metal powder having high magnetic permeability and a binder, or by mixing amorphous metal powder, spherical soft magnetic powder (SMC), and a binder in a prescribed ratio. In this case, compared to the use of 100% amorphous metal powder, the mixing of spherical soft magnetic powder (SMC) in a prescribed ratio not only solves the problem of high-pressure sintering, but also improves the magnetic permeability.

[0129] A plurality of electrical steel sheets (silicon steel sheets) composed of thin plates are laminated at the rear end portions of the plurality of teeth 41 described above, and a back yoke 42 is provided, which is annular, is combined with the plurality of teeth 41, and has a prescribed width forming a magnetic circuit.

[0130] The plurality of bobbins 43 described above have flanges 43a and 43b formed at both end portions, which respectively define regions in which the coils 44 are wound.

[0131] In a stator core used in a conventional radial gap type motor, a plurality of teeth are arranged in a radial direction at the inner or outer periphery of a back yoke. When a plurality of electrical steel sheets (silicon steel sheets) are punched into a cylinder (connected form) and are laminated to the back yoke and the teeth, the "round arc R" processing required to form a curved surface in the front end portion of the teeth (i.e., the shoe portion) facing the magnet of the rotor cannot be easily performed with respect to the core shape.

[0132] As a result, as Figure 12aAs shown, since the existing radial gap type motor changes the back electromotive force waveform into a square wave, it will not be possible to prevent the noise and vibration generated when the motor rotates.

[0133] Unlike the stator core of the above-described radial gap type motor, the stator core 45 of the present application is applied to an axial gap type motor, and since the plurality of teeth 41 and the back yoke 42 form a right-angle connection structure, it will not be possible to form a thin plate laminate in which the plurality of teeth and the back yoke are integrated.

[0134] To solve the above-described problem, the stator core 45 of the present application is manufactured by compression molding soft magnetic powder (SMC) having a complex three-dimensional (3D) shape, and the back yoke 42 is manufactured in the existing manner, that is, punching molding and laminating a prepared electrical steel plate (silicon steel plate), and as shown, Figure 7d as shown, the plurality of soft magnetic powder (SMC) teeth 41 can be assembled to the back yoke 42 to obtain.

[0135] The plurality of teeth 41 having the above-described "T" shape are each formed by compression molding of soft magnetic powder (SMC), and thus, it is easy to perform "round arc R" processing on the core shape, as shown, Figure 12b as shown, a back electromotive force waveform (S1: solid line) close to an ideal sine curve (S2: dotted line) (distortion rate: 0.5%) can be obtained, and as a result, it is possible to improve the noise and vibration generated when the motor rotates.

[0136] Also, the stator core 45 of the present application is a structure in which the plurality of teeth 41 and the back yoke 42 are connected at right angles, and is specialized for a longitudinal axis type motor, and the teeth 41 of the stator core 45 apply soft magnetic powder (SMC), and thus, it is possible to perform "round arc R" processing on the tooth shape to improve the core (tooth) shape to minimize the core loss generated by the motor.

[0137] The stator 40 of the present application is manufactured by first manufacturing the plurality of teeth 41 using soft magnetic powder (SMC) and punching molding the plurality of electrical steel plates (silicon steel plates) to prepare a ring-shaped back yoke 42 having a predetermined width.

[0138] Next, the plurality of teeth 41 are each inlaid injection molded by a thermosetting resin of an insulating material to integrate the teeth 41 and the bobbin 43, thereby defining an area in which a coil is wound.

[0139] Subsequently, as shown, Figure 7dAs shown, after the coil 44 is wound around the bobbin 43 formed in one piece with the tooth 41, if one end portion of the tooth 41 is coupled to the assembly hole 42b of the back yoke 42, the assembly of the stator 40 is completed.

[0140] The winding of the coil 44 around the bobbin 43 can also be performed in a state in which the tooth 41 formed in one piece with the bobbin is coupled to the back yoke 42 in priority.

[0141] A driver 50 for generating a rotating magnetic field by applying a driving signal to the three-phase coil of the stator 40 is provided at the lower portion of the stator 40. The driver 50 includes a printed circuit board 51 in which various electronic components 54 forming a motor driving circuit are packaged.

[0142] For example, three protrusions 52 are formed at the outer periphery of the printed circuit board 51, and through holes are formed in the three protrusions 52 so that the fixing portion 12d is fixed by a fixing screw or a fixing bolt 53, the fixing portion 12d being used to set the printed circuit board 51 inside the main body case 12.

[0143] The back yoke 42 at the upper side of the printed circuit board 51 or the portions corresponding to the three protrusions 52 of the printed circuit board 51 are extended to form three protrusions 42c, and through holes are formed in the respective protrusions 42c so that the fixing screw or the fixing bolt 53 is passed therethrough when it is fastened to the fixing portion 12d.

[0144] As described above with reference to Figures 7a to 11d The stator core 45 of the present application can be deformed in various ways based on the assembly structure of the soft magnetic powder tooth 41 and the back yoke 42.

[0145] As described above with reference to Figures 7a to 7d The stator core 45 of the first embodiment of the present application includes nine soft magnetic powder teeth 41 and a back yoke 42.

[0146] The tooth 41 is formed in a "T" shape by compression molding of soft magnetic powder, and the front end portion facing the magnet of the rotor, i.e., the tile 41a has a structure in which a flange is extended from the coil winding portion 41b in which the coil 44 is wound.

[0147] The coil winding portion 41b is substantially a triangular column, and the tile 41a is substantially a rectangular column. The cross section of the tile 41a and the coil winding portion 41b is substantially a trapezoid, and the edges at the boundary between the respective faces of the tile 41a and the coil winding portion 41b are processed in a "rounding R" to be curved surfaces.

[0148] Therefore, as Figure 12bAs shown, the motor using the stator core 45 of the first embodiment can obtain a Back Electromotive Force waveform S1 (distortion rate: 0.5%) close to an ideal sine curve S2, as a result, not only the noise and vibration generated when the motor rotates can be improved, but also the core loss generated by the motor can be minimized.

[0149] In the stator core 45 of the first embodiment of the present application, nine teeth 41 are assembled in the back yoke 42 having nine assembly holes 42b.

[0150] The back yoke 42 is formed by laminating a plurality of electrical steel sheets (silicon steel sheets) punched and formed, and a through hole 42a is formed in the center portion in a ring shape having a predetermined width for the magnetic path between the adjacent teeth 41, and nine assembly holes 42b are formed on the same circumference.

[0151] Three protrusions 42c are formed extending from the outer circumference of the back yoke 42, and a through hole is formed in each protrusion 42c, and when the printed circuit board 51 is fixed, it can be fixed together with the fixing bolt 53 in the fixing portion 12d.

[0152] When the nine teeth 41 are assembled in the nine assembly holes 42b of the back yoke 42, the stator core 45 of the first embodiment of the present application can apply a structure of press-fit bonding or positioning and fixing on the same line, in which case, the stopper function can be achieved by the bobbin 43 on which the coil 44 is wound.

[0153] Reference Figures 8a to 8d The stator core 45a of the second embodiment of the present application includes nine soft magnetic powder teeth 41 and a back yoke 421.

[0154] In the stator core 45a of the second embodiment, the nine soft magnetic powder teeth 41 are the same as those of the first embodiment, and the back yoke 421 is different.

[0155] The back yoke 421 is formed by laminating a plurality of electrical steel sheets (silicon steel sheets) punched and formed, and a through hole 42a is formed in the center portion in a ring shape having a predetermined width for the magnetic path between the adjacent teeth 41, and nine assembly grooves 421b are formed on the same circumference.

[0156] The back yoke 421 of the second embodiment is formed with a through hole in the portion forming the assembly groove 421b, and an electrical steel sheet (silicon steel sheet) can be additionally laminated on the lower side of the assembly groove 421b.

[0157] When the nine teeth 41 are assembled in the nine assembly holes 421b of the back yoke 421, the stator core 45a of the second embodiment of the present application can apply a structure of press-fit bonding, in which case, the stopper function can be achieved by the bobbin 43 on which the coil 44 is wound.

[0158] As a result, if one end of the tooth 41 is assembled in the assembly groove 421b of the back yoke 421, the contact area between the tooth 41 and the back yoke 421 will be greater than that in the first embodiment.

[0159] Therefore, as the contact area between the nine soft magnetic powder teeth 41 and the back yoke 421 increases, when heat is generated from the coil 44 wound on the teeth 41, the heat generated from the teeth 41 can be quickly dispersed through the large area of ​​the back yoke 421. Thus, the stator core 45 of the second embodiment of the present invention has a better heat dissipation function than that of the first embodiment.

[0160] In the stator core 45a of the second embodiment of the present invention, except for the back yoke 421, the structure of the soft magnetic powder teeth 41 is the same as that of the first embodiment. The corners of the boundary portions of each surface of the tile 41a and the coil winding portion 41b are formed into curved surfaces by "rounded arc R".

[0161] Therefore, as Figure 12b As shown, in the second embodiment, the stator core 45a is treated with "rounded arc R" at the corners of the boundary portions between the surfaces to obtain a back electromotive force waveform S1 (distortion rate: 0.5%) that is close to an ideal sine curve S2. As a result, not only can the noise and vibration generated when the motor rotates be improved, but the core loss generated by the motor can also be minimized.

[0162] Reference Figures 9a to 9d The stator core 45b of the third embodiment of the present invention includes nine soft magnetic powder teeth 411 and a back yoke 421.

[0163] In the stator core 45b of the third embodiment, the back yoke 421 is the same as in the second embodiment, but the nine soft magnetic powder teeth 411 are different.

[0164] The aforementioned tooth 411 is formed into a "T" shape by compression molding of soft magnetic powder. At the front end facing the magnet of the rotor, i.e., the tile 411a has a structure that extends from the coil winding portion 41b of the coil 44 to form a flange.

[0165] The coil winding portion 41b forming the aforementioned teeth 411 is approximately a triangular prism, the tile 411a is approximately a rectangular prism, the cross-section of the tile 411a is approximately trapezoidal, and the corners of the boundary portions between the surfaces of the tile 411a and the coil winding portion 41b are rounded to form curved surfaces. Furthermore, as... Figure 9c As shown, in the tile 411a facing the magnet of the rotor, the front end is formed with a curved shape.

[0166] Therefore, as Figure 12bAs shown, the stator core 45b of the third embodiment is processed with a "round arc R" at the corners that are the boundary portions between the respective faces and faces, to obtain a back electromotive force waveform S1 (distortion rate: 0.5%) close to an ideal sine curve S2, as a result, the noise and vibration generated when the motor rotates can be improved.

[0167] Also, the stator core 45b of the third embodiment can minimize the core loss generated by the motor, and thus has an excellent heat dissipation function.

[0168] The stator core 45b of the third embodiment of the present application is the same as the second embodiment, and when the teeth 41 are assembled in the assembly grooves 421b of the back yoke 421, a press-fit structure can be applied, and in this case, the stopper function can be implemented by the bobbin 43 on which the coil 44 is wound.

[0169] Referring to Figures 10a to 10d , the stator core 45c of the fourth embodiment of the present application includes nine soft magnetic powder teeth 41 and a back yoke 422.

[0170] In the stator core 45c of the fourth embodiment, the nine soft magnetic powder teeth 41 are the same as the first embodiment, and the back yoke 422 is different.

[0171] As shown, Figure 10b the back yoke 422 of the fourth embodiment is structured such that a through-hole 42a is formed in the center portion with a ring shape having a predetermined width in order to function as a magnetic path between the adjacent teeth 41, and an assembly hole for assembling the one end portion of the teeth 41 is not formed.

[0172] As shown, Figure 10c , in the stator core 45c of the fourth embodiment of the present application, face-to-face engagement is implemented between the nine soft magnetic powder teeth 41 and the back yoke 422.

[0173] Therefore, in order to implement the assembly between the nine soft magnetic powder teeth 41 and the back yoke 422, the stator core 45c of the fourth embodiment can be fixed to the fixing portion provided inside the main body case 12 by fastening a fixing screw or a fixing bolt 53 in the plurality of assembly insertion grooves 42d formed in the outer periphery of the back yoke 422.

[0174] Referring to Figures 11a to 11d , the stator core 45d of the fifth embodiment of the present application includes nine soft magnetic powder teeth 41 and a back yoke 42.

[0175] In the stator core 45d of the fifth embodiment, the nine soft magnetic powder teeth 41 and the back yoke 42 are the same as the first embodiment. The difference from the first embodiment is that, as Figure 11cAs shown, in order to achieve electromagnetic compatibility, electromagnetic interference improvement effect, a pin 55 for joining between the back yoke 42 and the printed circuit board 51 is provided at the back yoke 42.

[0176] In the prior art, a ring-shaped bearing housing or a core end grounding method for grounding is used, and thus, not only an additional connection structure such as a jumper wire is required, but also there are problems in terms of cost and assembly.

[0177] In the present application, a hole is formed in the back yoke 42 to press the pin 55, and if the pin 55 protrudes from the front surface of the printed circuit board 51 due to assembly of the printed circuit board 51, electromagnetic compatibility, electromagnetic interference improvement effect can be achieved by soldering the ground (GND) of the back yoke 42 and the printed circuit board 51 to the pin 55.

[0178] When heat is generated from the coil 44 wound around the tooth 41, the stator core 45 of the present application can quickly disperse the heat generated from the tooth 41 through the large area of the back yoke 42, as shown in Figure 2 and Figure 6 As shown, the back yoke 42 can be fixed to the main body housing 12 by a fixing screw or a fixing bolt 53, or heat dissipation can be achieved by joining a portion of the back yoke 42 to the main body housing 12.

[0179] In the first to fifth embodiments described above, only the tooth 41 is made of soft magnetic powder, and the back yoke 42 is made of a punched and formed thin electrical steel sheet (silicon steel sheet) and is laminated. However, the present application is not limited thereto, and the tooth and the back yoke can be both made of soft magnetic powder and assembled.

[0180] Referring to Figure 13 In the axial gap type motor 100 of the present application, the stator core 45 is composed of the soft magnetic powder tooth 41 and the back yoke 42.

[0181] In this case, the back yoke 42 is made of an electrical steel sheet (silicon steel sheet) or soft magnetic powder, is formed in a ring shape having a predetermined width, and is connected at right angles to the teeth 41 arranged in parallel to the axial direction, respectively, and thus, the back yoke 42 is disposed perpendicular to the axial direction.

[0182] In the inner circumferential surface of the main body housing 12 described above, a height difference portion 12e is formed at a portion facing the back yoke 42, and a portion of the outer side surface of the back yoke 42 is in contact with the height difference portion 12e, for example, as shown in Figure 6 and can be fixed by a fixing screw or a fixing bolt 53.

[0183] When a portion of the outer side surface of the back yoke 42 is in contact with the height difference portion 12e, the back yoke 42 can also be fixed to the inner circumferential surface of the main body housing 12 by a press-fit joining method.

[0184] As described above, as the back yoke 42 is in contact with the inner circumferential surface of the main body case 12, if heat is generated from the coil 44 wound around the tooth 41, the heat generated from the tooth 41 is quickly dispersed through the large area of the back yoke 42, and then the heat is released to the outside of the water pump through the main body case 12.

[0185] Also, in the axial gap type motor 100 of the present application, the stator core 45 is composed of the soft magnetic powder tooth 41 and the back yoke 42, and the printed circuit board 51 forming the driver 50 is attached to the bottom surface of the back yoke 42.

[0186] For example, three protrusions 52 are formed on the outer periphery of the above-described printed circuit board 51, and when a screw or a bolt 53 is fastened to the fixing portion 12d provided inside the main body case 12, the back yoke 42 is also fixed to the through holes formed in the three protrusions 52.

[0187] The above-described printed circuit board 51 is packaged with various electronic components 54 forming a motor driving circuit, and the above-described electronic components 54 can include heat generating devices.

[0188] Therefore, if heat is generated from the electronic components 54, heat dissipation can be achieved through the back yoke 42 and the main body case 121 in close contact with the printed circuit board 51.

[0189] Also, as another method of cooling the printed circuit board 51, a cooling heat sink (not shown) is provided between the back yoke 42 and the printed circuit board 51, so that heat of the printed circuit board 51 is transferred to the back yoke 42 through the heat sink, and then heat dissipation to the outside can be achieved through the main body case 12.

[0190] Figure 14a and Figure 14b The back yoke and the printed circuit board (PCB) combined structure for achieving electromagnetic compatibility and electromagnetic interference improvement effect by grounding (GND) through the back yoke erected on the pin and connected between the back yoke and the printed circuit board (PCB) or welded to the bottom of the back surface of the printed circuit board (PCB) are shown.

[0191] In the prior art, a ring-shaped bearing housing or a core end grounding method for grounding is used, and thus not only an additional connection structure such as a jumper wire is required, but also there are problems in terms of cost and assembly.

[0192] As shown in Figure 14a and Figure 14b In the present application, a hole is formed in the back yoke 42 to press the pin 55, and if the pin 55 protrudes from the front surface of the printed circuit board 51 due to assembly of the printed circuit board 51, the pin 55 can be soldered. As a result, electromagnetic compatibility and electromagnetic interference improvement effect can be achieved by electrically connecting the back yoke 42 and the printed circuit board 51 using the pin 55.

[0193] Figure 11c An example in which a hole is formed in the back yoke 42 to press the pin 55 is shown.

[0194] A direct grounding method in which the back yoke 42 is connected to the ground of the printed circuit board 51 can be used.

[0195] The direct grounding method is shown in FIGS. 1 and 2, in which a Land formed on the back surface of the printed circuit board 51 is surface-mounted (SMD), and tin is used to connect the back yoke 42 to achieve electrical connection to achieve direct grounding. Figure 2 Figure 6 In the case of surface mounting (SMD) of the Land formed on the back surface of the printed circuit board 51, direct grounding can be achieved by using tin to bond the back yoke 42 to achieve electrical connection.

[0196] The back yoke 42 connected to the printed circuit board 51 described above is connected to the main housing 12.

[0197] The axial gap motor 100 of the present application can be connected to the printed circuit board 51 to achieve electromagnetic compatibility and electromagnetic interference improvement effects.

[0198] For example, in the water pump 200 of the present application, the axial gap motor 100 can be a brushless direct current (BLDC) motor having a 10-pole 9-slot structure. Also, when the coils 44 of the stator 40 are wound around the plurality of teeth 41, the above-described motor 100 winds the coils 44 in a U, V, W three-phase structure, and the other ends of the U, V, W three-phase coils 44 are connected by star connection. Also, for example, the above-described motor 100 can be driven by a six-step method using an inverter.

[0199] The axial gap motor 100 of the present application of the water pump 200 is disposed in a waterproof space in which the fluid flow passage P inside the pump cover 11 is completely separated from the stator 40, i.e., the lower space 14 inside the main housing 12, and the rotor 30 and the impeller 20 are integrally disposed in the fluid flow passage P, and the stator 40 and the rotor 30 have a structure separated by the partition 12b.

[0200] In the axial gap motor 100 of the present application, as a water pump control signal is applied to the driver 50 from a water pump 200 control device inside a vehicle, if the driver 50 receives a rotor position signal from a Hall sensor (not shown), a driving signal for the stator coil 44 of the axial gap motor 100 is applied from the driver 50, and the stator 40 generates a rotating magnetic field in the plurality of teeth 41.

[0201] ​If a rotating magnetic field is generated from the plurality of teeth 41 of the stator 40, the rotor 30 and the impeller 20 are rotated together with the support shaft 60 by the partition 12b disposed in the fluid flow passage P, as a result, as the impeller 43 rotates, the coolant flows into the flow inlet 11a of the pump cover 11, and the flowed-in coolant is discharged toward the discharge port 11b along the fluid flow passage P.

[0202] The present application can achieve complete waterproofing of the stator 40 of the motor 100 by driving the impeller 20 and the rotor 30 disposed inside the fluid flow passage P in a magnetic coupling manner by the stator 40 of the motor 100 disposed outside the fluid flow passage P.

[0203] Further, in the present application, since the stator 40 of the motor 100 is completely separated from the fluid flow passage P, an additional waterproofing process can be omitted, and thus, the motor 100 can be made efficient by setting the air gap between the rotor 30 and the stator 40 of the motor 100 to an optimal state.

[0204] Further, in the present application, since the stator 40 of the motor is completely separated from the fluid flow passage P, the support shaft 60 of the motor can be supported by a general bearing without using a waterproof structure, and thus, durability can be improved while reducing costs.

[0205] The present application applies a longitudinal shaft type motor having the same outer diameter as an internal rotor type motor, and thus, even if a ferrite magnet, which is a non-rare earth magnet, is used, the same magnetic energy as that of a motor using a rare earth magnet can be obtained.

[0206] In the present application, a stator core 45 of a longitudinal shaft type motor can apply soft magnetic powder (SMC, Soft Magnetic Composites) instead of a general electrical steel sheet to optimize the core shape to minimize iron loss generated by the motor.

[0207] Further, the present application can perform "round arc R" processing on the core (tooth) shape by manufacturing the teeth of the stator core 45 using a compression molding method of soft magnetic powder, and thus, the counter electromotive force can be changed to a sine curve to improve the generation of noise and vibration.

[0208] On the other hand, in the description of the above-described embodiment, although an axial gap type motor in which a rotor and a stator are disposed to face each other in an axial direction is exemplified as a new type of stator core for improving the generation of noise and vibration, the design of the new type of stator core of the present application can also be applied to a radial gap type motor in which a rotor and a stator are disposed to face each other in a circumferential direction.

[0209] For example, the present application can be applied to a radial gap type motor of an outer rotor type structure in which a stator is disposed on the inside and a rotor is disposed on the outside.

[0210] Even if it is a radial gap type motor, in the case where the stator core of the outer rotor type structure including teeth and back yokes is entirely composed of a general electrical steel sheet, the present application can perform "arc R" processing on the shoe portion of the core facing the magnet of the rotor to change the back electromotive force (EMF) waveform into a sine curve.

[0211] Hereinafter, an embodiment in which the radial gap type motor of the present application is applied to a roof fan for a vehicle will be described.

[0212] Figures 15a to 15d FIGS. 1 to 4 are views showing a roof fan using the radial gap type motor of the present application, respectively showing a plan view, a rear view, a rear view of a cover portion, and a side view, Figure 16 is a cross-sectional view of the roof fan shown in FIG. 1, which is axially cut, Figure 15a is a cross-sectional view of the roof fan shown in FIG. 1, which is axially cut, Figure 17 is an exploded perspective view of the roof fan using the radial gap type motor of the present application.

[0213] Referring to Figures 15a to 17 , the roof fan 300 for a vehicle of the present application generally includes a housing 110, a cover portion 112, a radial gap type motor 100a, and an impeller 120.

[0214] A vehicle fan directly discharges air generated without any difference and directly supplies the air to nearby users (or passengers), however, some users (or passengers) do not like or desire to avoid such direct strong wind.

[0215] The roof fan 300 for a vehicle described above is disposed at a roof of a vehicle on which an air conditioner is not disposed, instead of directly discharging, discharges air generated by the impeller or fan from the side to circulate air inside the vehicle, whereby it can play a role of cooling passengers in summer.

[0216] The roof fan 300 for a vehicle of the present application is installed in a roof fan installation module (not shown) attached to a ceiling of a vehicle.

[0217] The housing 110 includes a peripheral frame 110a in the shape of a ring for receiving a lower end of the impeller 120, a motor support portion 110b in the shape of a circle combined with a lower portion of the motor 100a for supporting the motor 100a, and three connecting ribs 110c, 110d, and 110e connecting the peripheral frame 110a and the motor support portion 110b.

[0218] A pad 113 for absorbing vibration is provided on the flange of the outer peripheral frame 110a in the above-described ring shape, and is disposed between the housing 110 and a ceiling fan setting module (not shown) to prevent vibration of the impeller 300 or the motor 100a from being transmitted to the ceiling fan setting module.

[0219] In this case, a circular protrusion 110f is formed on each of the three connecting ribs 110c, 110d, 110e, which extend in the above-described manner, for setting the ceiling fan 300 in the ceiling fan setting module, and a through hole for fastening a fixing screw or bolt is formed at the center of the circular protrusion 110f. In the case where a fixing screw or bolt is fastened to the above-described through hole, when fastening is performed using a rubber gasket 111, not only is loosening of the fixing screw or bolt prevented, but also vibration generated when the impeller 300 rotates is prevented from being transmitted to the ceiling fan setting module via the fixing screw or bolt.

[0220] Among the above-described three connecting ribs 110c, 110d, 110e, the width of one connecting rib 110e is greater than that of the remaining two connecting ribs 110c, 110d, and the cover portion 112 incorporated therein forms an air-cooling flow path portion 110h in conjunction with the connecting rib 110e.

[0221] The above-described cover portion 112 includes a center portion 112a in the shape of a circle that forms a space inside and surrounds the motor support portion 110b, and a flow path forming portion 112b that extends from the above-described center portion 112 and surrounds the connecting rib 110e of the housing 110, forming an air-cooling flow path portion 110h in conjunction with the connecting rib 110e, and a plurality of snap-fit coupling protrusions 112c are formed protruding from the outer periphery of the circular center portion 112a, such that the center portion 112a is coupled and fixed to the motor support portion 110b in a snap-fit coupling manner.

[0222] Also, a through hole 110g is formed at the front end portion of the connecting rib 110e, serving as an inlet of the air-cooling flow path portion 110h, and the above-described motor support portion 110b includes at least one through hole 110i, 110j, serving as an outlet of the air-cooling flow path portion 110h.

[0223] The above-described motor support portion 110b is formed with a through hole 110k in the middle, which is coupled to the lower portion of the motor 100a, i.e., to the bearing bush 161, and a printed circuit board 150 is disposed on the facing portions of the motor support portion 110b, in which a motor driving power circuit for driving and controlling the motor 100a is encapsulated.

[0224] The above-described printed circuit board 150 encapsulates a heat-generating electronic component such as an integrated circuit (IC), a transistor, etc., which constitutes a motor driving circuit.

[0225] As described below, when the impeller 120 is operated by the motor 100a, a negative pressure is generated as air around the printed circuit board 150 is supplied to the impeller 120. Thus, a negative pressure is generated in the motor support portion 110b and the air cooling flow path portion 110h disposed opposite the printed circuit board 150, so that air drawn in through the through hole 110g formed in the front end portion of the connecting rib 110e passes through the air cooling flow path portion 110h and is then discharged through the through holes 110i, 110j formed in the motor support portion 110b to the heat generating electronic components packaged in the printed circuit board 150 to achieve cooling.

[0226] The impeller 120 includes a circular top plate 121, a plurality of blades 125 extending radially outward from the bottom surface of the circular top plate 121, an annular bottom 122 connecting and supporting lower portions of the plurality of blades 125, a cylindrical support portion 123 extending in a cylindrical shape inside the bottom surface of the circular top plate 121, the lower end portion of which surrounds the side surface of the back yoke 131 of the rotor 130, and a shaft support portion 121a surrounding the upper portion of the rotating shaft 160 of the rotor 130 and the top plate portion 131c of the back yoke 131.

[0227] In this case, preferably, when the shaft support portion 121a is formed, the rotating shaft 160 of the rotor 130 and the shaft support portion 121a are formed in one body by an insert injection molding method in which the rotating shaft 160 is inserted. Preferably, a plurality of grooves 160a are formed in the outer circumferential portion of the rotating shaft 160 to improve the coupling force with the shaft support portion 121a.

[0228] As shown in FIG. 1, Figure 20 The back yoke 131 of the rotor 30 includes a first cylindrical portion 131b to which a magnet 132 is attached inside, a second cylindrical portion 131a bent in two stages from the first cylindrical portion 131b to extend in a diameter smaller than that of the first cylindrical portion 131b, and a top plate portion 131c vertically bent from the upper portion of the second cylindrical portion 131a and formed with a plurality of through holes 131d.

[0229] To form the impeller 120 and the rotor 130 in one body, when the circular top plate 121, the cylindrical support portion 123, and the shaft support portion 121a are formed, the impeller 120 is inserted into the back yoke 131 and the rotating shaft 160 such that a portion of the top plate 121 is formed in both side surfaces of the top plate portion 131c through the plurality of through holes 131d provided in the top plate portion 131c of the back yoke 131, thereby improving the coupling force of the impeller 120 and the rotor 130.

[0230] As shown in FIG. 1, Figures 16 to 20As shown, the lower end of the motor 100a for rotating the impeller 120 is supported by the motor support portion 110b of the housing 110, and the motor 100a includes a rotor 130 to which the impeller 120 is coupled to the outer circumferential portion, and a stator 140 disposed inside the rotor 130 to generate a rotating magnetic field by rotating the rotor 130. As a result, the motor 100a forms a radial gap type outer rotor type motor.

[0231] The rotor 130 includes a back yoke 131 in the shape of an inverted cup, and a magnet 132 attached to the inside of the back yoke 131.

[0232] The magnet 132 of the rotor 130 can be composed of a plurality of divided magnet pieces of N and S poles, or a magnet in which a ring-shaped magnet N and S poles are divided and magnetized into a plurality of poles can be used. For example, the back yoke 131 can be composed of an electrical steel sheet (S-60) disposed on the back of the magnet 132 and forming a magnetic circuit.

[0233] As described above, the back yoke 131 is in the shape of an inverted cup, and includes a first cylindrical portion 131b, a second cylindrical portion 131a, and a top plate portion 131c, and the magnet 132 is attached to the inside of the first cylindrical portion 131b through a curved portion between the first cylindrical portion 131b and the second cylindrical portion 131a.

[0234] The stator 140 has U, V, and W three-phase coils 143 wound around a stator core 141 and packaged in a printed circuit board 150, and a motor driving circuit linked to the stator 140 for driving control alternately applies a switching driving signal to the U, V, and W three-phase coils 143 to generate a rotating magnetic field for rotating the rotor 130, based on a rotor position signal received from a Hall sensor (not shown) packaged in the printed circuit board 150.

[0235] The stator 140 includes an integrated stator core 141 from which a plurality of teeth 141b (i.e., coil winding portions) extend in a radial direction from a ring-shaped yoke 141a (body), an insulation bobbin 142 formed on the outer circumference of the stator core 141 by assembly or insert molding, and three-phase (U, V, W) coils 143 wound around the outer circumference of the insulation bobbin 142.

[0236] In this case, the stator core 141 is composed of a plurality of thin electrical steel sheets (T-60) (typically, silicon steel) punched and formed. As shown, the front end portions 141c of the plurality of teeth 141b of the plurality of stator cores 141 laminated, i.e., the profiles of the shoe portions, facing the magnet 132 of the rotor are each formed in a "circular arc R" shape. Figure 20

[0237] ​As a result, the radial gap type motor 100a of the present invention can improve the generation of noise and vibration by changing the back EMF (Electromotive Force) waveform into a sine curve.

[0238] The winding frame 142, which is integrally formed on the outer periphery of the stator core 141, can be made of thermosetting resin, for example, by inserting injection molding using bulk molding compound (BMC) materials such as polyester or thermoplastic resin.

[0239] The multiple teeth 141b are T-shaped, and the aforementioned insulating winding frame 142 surrounds the entire surface except for the front end facing the rotor magnet 132. The portion surrounding the multiple teeth 141b forms the coil winding area for winding the three-phase (U, V, W) coil 143.

[0240] The aforementioned insulating winding frame 142 has an upper protrusion 142a and a lower protrusion 142b, which are integrally formed on the upper and lower sides of the "T"-shaped front end, and are used to define the winding area of ​​the three-phase (U, V, W) coil 143. When the stator 140 and the printed circuit board 150 are assembled, the lower protrusion 142b serves to maintain a preset interval, thereby enabling air cooling of the stator 140 and the printed circuit board 150.

[0241] And, as Figure 19b As shown, the aforementioned insulated winding frame 142 allows the six end pins 151 connected to the start and end terminals of the three-phase (U, V, W) coil 143 to be integrally formed by injection molding.

[0242] Moreover, such as Figure 19b As shown, the insulating winding frame 142 located inside the magnetic yoke 141a (body) has a groove 142c formed on its inner circumference for inserting a cylindrical insert 165 to improve the perpendicularity of the rotating shaft 160.

[0243] A cylindrical bearing bushing 161 is inserted inside the cylindrical insert 165. Inside the cylindrical bearing bushing 161, an upper bearing 162a and a lower bearing 162b that support the rotating shaft 160 in a rotatable manner are pressed together at the upper and lower parts.

[0244] In this case, sleeve bearings or ball bearings can be used as the upper bearing 162a and the lower bearing 162b. When using sleeve bearings, oilless bearings or oil-impregnated bearings such as carbon bearings or plastic bearings can be used.

[0245] In the upper and lower portions of the bearing bush 161, height difference portions 161a, 161b are formed on the inner side, respectively, and the upper bearing 162a is provided on the upper height difference portion 161a. The lower bearing 162b is provided together with a spring 164 on the lower height difference portion 161b, and a C-ring 163 for preventing the lower bearing 162b from being separated is coupled to the rotating shaft 160 on the lower side of the lower bearing 162b. The spring 164 serves to prevent noise and sliding.

[0246] The lower portion of the bearing bush 161 extends along the lower side of the printed circuit board 150 through a central through-hole 150a formed in the center of the printed circuit board 150, and is coupled to the through-hole 110k formed in the center of the motor support portion 110b to support the motor 100a and the impeller 120. That is, after the lower portion of the bearing bush 161 is inserted into the central through-hole 150a of the printed circuit board 150, the lower end portions of the motor 100a and the impeller 120 are coupled to the through-hole 110k of the motor support portion 110b, so that stable support is achieved.

[0247] The stator 140 is configured such that three-phase (U, V, W) driving signals required for motor driving are connected to the starting terminals of the three-phase (U, V, W) coils 143 through three terminal pins 151 from a motor driving circuit (inverter circuit) provided on the lower side, and the ending terminals of the three-phase (U, V, W) coils 143 reach the printed circuit board 150 through the three terminal pins 151, and a neutral point (NP) required for Y-connection is connected by using a conductive pattern.

[0248] That is, in the three-phase (U, V, W) coils 143, one side (starting terminal) of each phase is connected to U, V, W output terminals of an inverter circuit constituting a motor driving circuit, and the other side (ending terminal) of each phase is connected to the printed circuit board 150 by Y-connection, and electrical connection is achieved between the three-phase (U, V, W) coils 143 and the motor driving circuit (inverter circuit) of the printed circuit board 150 through six terminal pins 151. Also, the lower end portions of the six terminal pins 151 are fixed to the printed circuit board 150 by welding after passing through the through-holes 150b of the printed circuit board 150, thereby serving to stably support the motor 100a on the printed circuit board 150.

[0249] The printed circuit board 150 is encapsulated on the lower side with various electronic components forming a motor driving circuit (inverter circuit), and the ending terminals of the three-phase (U, V, W) coils 143 reach the printed circuit board 150 through the three terminal pins 151, and a neutral point NP required for Y-connection is connected by using a conductive pattern. A connector 152 connected by a wiring harness is formed on one side of the printed circuit board 150.

[0250] As Figure 20 shown in the above-described stator core 141 is an integrated stator core, a plurality of (12) teeth 141b of T-shape extend radially from the annular back yoke 141a, or the above-described stator core 141 can also be composed of a plurality of divided cores, the front end portions of the above-described divided cores are of T-shape and the rear end portions are connected to form an annular back yoke.

[0251] In this case, instead of the integrated stator core 141, the motor 100a of the present application can be composed of divided cores, after winding the three-phase (U, V, W) coils 143 using a plurality of divided cores, annular integration is achieved using a molding resin to form a stator support body at the same time.

[0252] Also, the stator 140 of the present application can form an insulating bobbin and a stator support body in the plurality of teeth 141b by an assembly method, whereby the three-phase (U, V, W) coils 143 can be wound.

[0253] In the present application, in addition to 12 slots and 10 poles, the number of magnets (poles) and the number of teeth (slots) of the rotor 130 included in the brushless DC motor of the single rotor type can have various combinations.

[0254] For example, the motor 100a of the present application can be a brushless DC motor composed of a 10-pole single rotor 130 and a single stator 140 of a 12-slot structure. In the stator 140, the three-phase (U, V, W) coils 143 are wound around the teeth 141b of the stator core 141, and a driving signal is applied to the three-phase (U, V, W) coils 143 in a six-step manner from the motor driving circuit provided on the printed circuit board 150 through the six terminal pins 151.

[0255] The existing outer rotor type motor uses a stator core in which a plurality of teeth are arranged radially on the outer periphery of a back yoke. When a thin electrical steel sheet (silicon steel sheet) is formed by punching in layers on the back yoke and the teeth, for the core shape, in particular, the front end portion of the teeth (i.e., the shoe portion) facing the magnet of the rotor is designed such that the outer shoe portion of the core forms a concentric circle with the center as a reference.

[0256] Therefore, the existing outer rotor type motor does not perform "arc R" processing on the outer shoe portion of the stator core. As a result, as Figure 12a shown in the above-described stator core 141 is an integrated stator core, a plurality of (12) teeth 141b of T-shape extend radially from the annular back yoke 141a, or the above-described stator core 141 can also be composed of a plurality of divided cores, the front end portions of the above-described divided cores are of T-shape and the rear end portions are connected to form an annular back yoke.

[0257] As Figure 20As shown, when the radial gap type motor 100a of the present application is an external rotor type motor, in the case where the stator core 141 is formed by laminating thin electrical steel sheets (silicon steel sheets) punched and formed, the profile of each of the front end portions 141c of the plurality of teeth 141b, i.e., the pad portion, can be designed as a "circular arc R".

[0258] In the present application, as shown, with respect to the front end portions 141c of the teeth 141b of the stator core 141, i.e., with respect to the pad portion, the shape is processed as a "circular arc R", and thus Figure 12b a back electromotive force waveform S1 (distortion rate: 0.5%) close to an ideal sine curve S2 can be obtained, and as a result, noise and vibration generated when the motor rotates can be improved, and the core loss generated by the motor can be minimized.

[0259] In the top-mounted fan 300 of the present application, if a driving signal is applied to the three-phase (U, V, W) coils 143 from the motor driving circuit provided in the printed circuit board 150 through the six terminal pins 151, the rotor 130 is rotated by the rotating magnetic field generated from the stator 140 in which the three-phase (U, V, W) coils 143 are wound.

[0260] As the rotor 130 rotates, the impeller 120 combined as one with the back yoke 131 of the rotor 130 also rotates.

[0261] As described above, when the impeller 120 rotates, indoor air is sucked through the space between the three connecting ribs 110c, 110d, 110e of the housing 110, is discharged to the side surface of the impeller 120, and is discharged to the upper space inside the vehicle through the duct provided in the top-mounted fan installation module (not shown).

[0262] That is, instead of being directly discharged downward, the air generated by the impeller 120 is supplied from the side surface to circulate the air inside the vehicle, and thus, the function of cooling the passengers can be indirectly performed.

[0263] Also, in the present application, when the impeller 120 operates, since negative pressure is generated in the air cooling flow path 110h formed by one connecting rib 110e and the cover portion 112, and the air flow flowing into the air cooling flow path 110h is discharged through the through holes 110i, 110j formed in the motor support portion 110b, the discharged air cooling wind cools the heat generating electronic components packaged in the printed circuit board 150. Thus, not only can the malfunction of the motor 100a be prevented, but also the efficiency of the motor 100a can be improved.

[0264] Industrial applicability

[0265] The present invention relates to an axial gap type motor using a non-rare earth magnet, and more particularly, to a longitudinal axis type permanent magnet motor, and can be applied to a water pump (EWP) for a cooling device for cooling water circulation of an electric component, a battery, a fuel cell stack, a compressor, an oil pump, etc.

Claims

1. An axial gap motor for a water pump including an impeller, characterized by comprising: a rotor rotatably supported in a fluid flow passage between a pump cover and a main body case; and a stator disposed in a lower space formed by the main body case and a top cover combined to a lower end of the main body case, rotationally driving the rotor by generating a rotating magnetic field, the main body case is formed in a reverse cup shape to have the lower space, an upper portion of the main body case is composed of a partition plate formed of a thin plate for separating the stator and the rotor, a thickness of the partition plate is thinner than a cylindrical portion of the main body case formed integrally with the partition plate, the rotor is formed integrally at a lower side of the impeller to be rotatably supported by a support shaft, an end portion of the support shaft is supported by the partition plate, the rotor includes a back yoke of a ring shape and a magnet, the magnet is maintained in a state of being in contact with a coolant flowing through the fluid flow passage, the back yoke is provided at a back surface of the magnet and forms a magnetic circuit, the partition plate serves as an air gap between the rotor and the stator, the magnet of the rotor is a ferrite magnet, and an additional magnet waterproof structure is not required.

2. The axial gap motor according to claim 1, characterized in that, the stator includes: a plurality of teeth each having a "T" shape, on which a coil is wound; and a stator core provided with a back yoke, the back yoke of the stator core is connected at right angles to the plurality of teeth to form a magnetic circuit, the plurality of teeth are made of soft magnetic powder, and the back yoke of the stator core is composed of an electrical steel plate. the stator is provided with a stator core, and a stator coil is wound on the stator core, the stator core includes: a plurality of teeth arranged in a ring shape in parallel to an axial direction on the same circumference so that each front end portion faces the magnet of the rotor; and a back yoke made of a ring-shaped disc and connected at right angles to the plurality of teeth to form a magnetic circuit. the plurality of teeth are each made of soft magnetic powder, and the back yoke of the stator core is made by laminating a plurality of electrical steel plates.

5. The axial gap motor according to claim 3, characterized in that, the plurality of teeth each include: a coil winding portion on which the coil is wound; and a shoe extending from the coil winding portion to form a flange, corners between a side surface and a front end surface of the shoe and the front end surface of the shoe are rounded. the coil winding portion is a triangular column, and a cross section of the shoe is a trapezoid.

3. The axial gap motor of claim 1, wherein assembly holes or assembly grooves are formed in the back yoke of the stator core, and one end portions of the plurality of teeth are respectively press-fitted into the assembly holes or the assembly grooves of the back yoke.

8. The axial gap motor according to claim 2, characterized by further comprising a driver for driving the stator, provided with a printed circuit board on which a motor driving circuit is formed, a bottom portion of the printed circuit board is electrically connected to a bottom surface of the back yoke of the stator core. the axial gap motor further comprises: a sleeve bearing combined to an outer periphery of the support shaft to rotatably support the rotor; and a bearing housing formed integrally with a bottom plate of the impeller to accommodate the sleeve bearing therein.

4. The axial gap motor of claim 3, wherein 10. A water pump, characterized by comprising: ​ ​ ​ ​ ​ 6. The axial gap electric machine of claim 5, wherein, ​ 7. The axial gap motor of claim 3, wherein, ​ ​ ​ ​ 9. The axial gap electric machine of claim 1, wherein, ​ ​ ​ ​ ​ ​ A pump housing forms a lower space in a sealed state at one side and forms an inlet and an outlet connected by a fluid flow passage at the other side, the inlet for flowing in fluid, and the outlet for discharging the flowed-in fluid; A rotor is rotatably supported in the fluid flow passage, the rotor including a back yoke of a ring shape and a magnet maintained in contact with cooling liquid flowing through the fluid flow passage, the back yoke being provided at a back surface of the magnet and forming a magnetic circuit; An impeller is formed in one body with the rotor at an upper side of the rotor, discharges fluid from the inlet to the outlet after the fluid flows in from the inlet; A stator is disposed in the lower space, rotates the rotor by generating a rotating magnetic field; A partition is disposed inside the pump housing, separates the rotor from the stator; and A support shaft rotatably supports the rotor at one end supported by the partition, The rotor and the stator form an axial gap type motor, a ferrite magnet is provided at the rotor, and an additional magnet waterproof structure is not required.

11. The water pump according to claim 10, wherein A stator core is provided at the stator, and a stator coil is wound on the stator core, The stator core includes: a plurality of teeth arranged in a ring shape in parallel to an axial direction on the same circumference such that each front end portion faces the magnet of the rotor; and a back yoke made of a ring-shaped disc and connected at right angles to the plurality of teeth to form a magnetic circuit.

12. The water pump of claim 11, wherein, The plurality of teeth are respectively made of soft magnetic powder, and the back yoke of the stator core is composed of an electrical steel plate.

13. The water pump of claim 11, wherein, The teeth are compression-molded or extrusion-molded from one of amorphous metal powder, spherical soft magnetic powder, or alloy powder in which amorphous metal powder and spherical soft magnetic powder are mixed.

14. The water pump according to claim 11, further comprising a driver for driving the stator, the driver being provided with a printed circuit board on which a motor driving circuit is formed, The printed circuit board and the back yoke of the stator core respectively form a plurality of protrusions with through holes at outer circumferences, The printed circuit board and the back yoke of the stator core are fixed by fastening a screw or a bolt through the through holes to a height difference portion of a main body housing of the pump housing.

15. The water pump according to claim 11, further comprising a driver for driving the stator, A printed circuit board forming the driver is electrically connected to the back yoke of the stator core by a pin.

16. The water pump according to claim 11, further comprising a driver for driving the stator, the driver being provided with a printed circuit board on which a motor driving circuit is formed, A bottom of the printed circuit board is electrically connected to a bottom surface of the back yoke of the stator core. ​ ​ ​

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