JP6254926B2 - Axial gap type brushless motor - Google Patents

Description

  The present invention relates to an axial gap type brushless motor.

  BACKGROUND ART Motors (electric motors) that convert electrical energy into mechanical energy are used for various applications. In general, a rotor (rotor) that has an axis and rotates about the axis is relatively relative to the rotor. A stator (stator) that is stationary and magnetically interacts with the rotor is provided, and the rotor is rotated by a rotating magnetic field (rotating magnetic field). From the viewpoint of structure, such a motor is abbreviated as a radial gap type brushless motor (hereinafter, abbreviated as “RG type motor” as appropriate) and an axial gap type brushless motor (hereinafter, abbreviated as “AG type motor” as appropriate). ). The RG type motor has a structure in which the stator and the rotor are arranged with a gap in the radial direction, and the AG type motor has a structure in which the stator and the rotor are arranged with a gap in the axial direction. The AG type motor has an advantage that a larger torque can be obtained with a smaller diameter than the RG type motor, and is expected, for example, for vehicle use.

  In general, a motor is required to be small and have high output, that is, high torque density. In order to increase the torque density, it is required to drive the motor with a high magnetomotive force by supplying a large current to the coil. In the motor driving with this high magnetomotive force, the heat generation of the copper loss in the coil and the heat generation of the iron loss in the magnetic material are increased by a large current. Therefore, efficient heat dissipation is required for the motor in order to increase the torque density.

  The heat dissipation technology in such a motor is disclosed in, for example, Patent Document 1 and Patent Document 2. The water-cooled motor disclosed in Patent Document 1 is one in which a motor is housed in a cooling housing and a flow path for flowing cooling water is provided on the outer peripheral surface of the motor housing. In the AG type motor disclosed in Patent Document 2, the stator includes a case that houses a coil and its core, and a pump that pumps the refrigerant into the case, and the refrigerant that circulates in the case. To cool the coil and the core.

JP 2014-75870 A US2011 / 01309694A1

  By the way, in the water-cooled motor disclosed in Patent Document 1, the heat generated in the coil is conducted from the coil to the refrigerant through the motor housing, and the cooling efficiency is reduced by the amount of the motor housing. End up. Furthermore, when the coil is molded with a resin having a low thermal conductivity, the cooling efficiency is further reduced because the mold further intervenes. In this regard, the AG type motor disclosed in Patent Document 2 improves the cooling efficiency because the refrigerant is brought into direct contact with the coil.

  However, even with the AG type motor disclosed in Patent Document 2, the refrigerant can contact only the outer peripheral surface of the coil. Since a coil is generally formed by winding a long conductor with insulation coating, the heat inside the coil passes through each layer of insulation coating with poor thermal conductivity that exists between turns. Therefore, the AG type motor disclosed in Patent Document 2 cannot be said to have good heat dissipation (cooling efficiency) with respect to the heat inside the coil.

  The present invention has been made in view of the above-described circumstances, and an object thereof is to provide an axial gap type brushless motor that can further improve heat dissipation.

  As a result of various studies, the present inventor has found that the above object is achieved by the present invention described below. That is, an axial gap type brushless motor according to an aspect of the present invention includes a stator including a plurality of teeth arranged in the circumferential direction and a plurality of coils arranged for each of the plurality of teeth, and a circumferential arrangement. A plurality of magnets, and a stator and a rotor arranged at a predetermined interval, and each of the plurality of teeth has a shaft of the coil on a side surface facing the inner peripheral surface of the coil. Protruding portions that extend along the direction and project outward from the teeth are provided.

  In such an axial gap type brushless motor (AG type motor), for example, a long conductor member is wound around each of the plurality of teeth (motor core), and a plurality of coils are arranged for each of the plurality of teeth. Then, each space is formed between each side surface of the plurality of teeth and each inner peripheral surface of the plurality of coils by the convex portions of the plurality of teeth. With these spaces, a heat radiation path can be secured for each inner peripheral surface of each coil, and the heat generated inside the coil can be more efficiently wasted. And since a conductor member is also a good heat conductor excellent in heat conductivity generally, the heat generated at each turn of the coil can also be conducted to the inner peripheral surface and can be dissipated on the inner peripheral surface. Of course, the heat generated at each turn of the coil is also conducted to the outer peripheral surface of the coil and is radiated from the outer peripheral surface. In addition, the said convex part may be 1 or 2 with respect to one coil.

In the above-described AG type motor, each of the plurality of coils includes a plurality of sub-coils stacked in the axial direction, and the convex portion is provided at a different position in the circumferential direction of the coil for each of the plurality of sub-coils. And a plurality of sub-projections.

  In such an AG type motor, even when a plurality of sub-coils stacked in the axial direction are provided, each sub-projection corresponding to each sub-coil is provided at a different position in the circumferential direction of the coil. A part of each side surface (upper and lower surfaces facing each other in the axial direction) is exposed without overlapping. For this reason, the AG type motor can secure heat radiation from each side surface of each subcoil in each subcoil.

  Further, in another aspect, in the above-described AG type motor, the stator is formed between each side surface of the plurality of teeth and each inner peripheral surface of the plurality of coils by each convex portion of the plurality of teeth. Each space formed in the above is provided with a refrigerant passage portion for circulating the refrigerant.

  Since such an AG type motor is provided with a refrigerant passage part, forced cooling becomes possible by circulation of the refrigerant, and cooling can be performed efficiently. For this reason, the AG type motor can be energized with a large current and can realize a high torque density.

  Further, in another aspect, in the above-described AG type motor, the side surface including the convex portion is a surface that contacts a radially outer side of the stator.

  Such an AG type motor is provided with a convex portion on the side surface of the teeth that contacts the outer side in the radial direction of the stator. The decrease in the coil space factor can be suppressed.

  Further, in another aspect, in the above-described AG type motor, each of the plurality of coils includes a strip-shaped conductor member with respect to each of the plurality of teeth, and the width direction of the conductor member is in the axial direction of the coil. It is characterized by having a flat-wise structure formed by winding through an insulating material so as to be along.

  Such an AG-type motor has a coil with a flat-wise structure, so it can achieve a higher coil space factor than a coil wound with a conductor member with a round cross-section, and can output a large torque with a high magnetomotive force. It becomes.

  The axial gap type brushless motor according to the present invention can further improve heat dissipation.

It is a longitudinal cross-sectional view which shows the structure of the axial gap brushless motor (AG type motor) in embodiment. It is a transverse cross section showing the composition of the stator in the AG type motor of an embodiment. It is an enlarged view showing a tooth and a portion around a coil in the AG type motor of the embodiment. It is a figure for demonstrating the deformation | transformation form of the convex part in AG type motor of embodiment.

  Hereinafter, an embodiment according to the present invention will be described with reference to the drawings. In addition, the structure which attached | subjected the same code | symbol in each figure shows that it is the same structure, The description is abbreviate | omitted suitably. Further, in this specification, when referring generically, it is indicated by a reference symbol without a suffix, and when referring to an individual configuration, it is indicated by a reference symbol with a suffix.

  FIG. 1 is a longitudinal sectional view showing a configuration of an axial gap brushless motor (AG type motor) in the embodiment. FIG. 1 is a cross-sectional view taken along the line ACB shown in FIG. FIG. 2 is a cross-sectional view showing a configuration of a stator in the AG type motor of the embodiment. FIG. 3 is an enlarged view showing portions around the teeth and the coils in the AG type motor of the embodiment. FIG. 3A is a cross-sectional view of a tooth and a coil. 3B is a vertical cross-sectional view taken along the DE cross-sectional line shown in FIG. 3A, and FIG. 3C is a vertical cross-sectional view taken along the FG cross-sectional line shown in FIG. 3A. FIG. 3D shows a side surface of the teeth that faces the inner peripheral surface of the coil. In FIG. 3D, the subcoils 3a and 3b are indicated by broken lines.

  AG type motors are roughly classified into an inner rotor type and an outer rotor type. The inner rotor type AG type motor is a motor having a structure in which a coil is arranged in a stator, a magnet is arranged in a rotor, and the rotor is arranged inside the stator. The outer rotor type AG type motor is a motor having a structure in which a coil is arranged in a stator, a magnet is arranged in a rotor, and the rotor is arranged outside the stator. The present invention can be applied to an inner rotor type AG type motor, but here, a case where it is applied to an outer rotor type AG type motor will be described. The same applies to the case where the present invention is applied to an inner rotor type AG motor.

  The axial gap type brushless motor (AG type motor) M in the embodiment includes a stator 1 and a pair of rotors 2 (2-1, 2-2) as shown in FIGS.

  The stator (stator) 1 is a non-rotating portion and includes a plurality of teeth 4 arranged in the circumferential direction and a plurality of coils 3 arranged for each of the plurality of teeth 4. The stator 1 is connected and fixed to a pair of annular plate-like support members 6-1 and 6-2 on the outside via the rotors 2-1 and 2-2 and supported. Details of the stator 1 will be described later.

  The rotor (rotor) 2 includes a pair of first and second rotors 2-1, 2-2. The pair of first and second rotors 2-1 and 2-2 are arranged on both sides of the stator 1 so that the rotation axes coincide with each other at a predetermined interval in the rotation axis direction. The first rotor 2-1 includes a plurality of magnets (for example, permanent magnets) 7-1 disposed on the inner side and in the circumferential direction so as to face the coil 3 of the stator 1. The plurality of magnets 7-1 are arranged such that the magnetic poles are staggered like SNSN... Between the magnets 7-1 adjacent to each other in the circumferential direction. That is, the plurality of magnets 7-1 are arranged so that the directions of the magnetic fields coincide with each other in the circumferential direction. The second rotor 2-2 includes a plurality of magnets (for example, permanent magnets) 7-2 disposed on the inner side and in the circumferential direction so as to face the coil 3 of the stator 1. Similarly to the plurality of magnets 7-1, the plurality of magnets 7-2 are also arranged so that the magnetic poles are staggered between the magnets 7-2 adjacent to each other in the circumferential direction. The first and second rotors 2-1 and 2-2 have the same shape, and are flat plate-like members that are generally flat along an orthogonal direction orthogonal to the rotation axis direction. The plurality of magnets 7-1 and 7-2 described above are disposed in flat portions along the orthogonal direction in the first and second rotors 2-1 and 2-2, respectively. Each of the annular plate-like members of the first and second rotors 2-1 and 2-2 has its inner peripheral side portion gradually bent toward the rotation axis direction, and its innermost peripheral portion in the rotation axis direction. It is flat along. The ends of the flat portions of the annular plate-like members of the first and second rotors 2-1 and 2-2 along the rotation axis direction are connected to each other, and these flat portions are It is brought into contact with the outer peripheral side surface of the cylindrical or columnar rotating shaft 8 via a bearing.

  The number of the coils 3 and the magnets 7-1 and 7-2 may be arbitrary. For example, the number of coils 3 may be eight and the number of magnets 7-1 and 7-2 may be twelve (12 slots and eight poles). -2 may be 10 pieces (12 slots and 10 poles), and for example, the coil 3 may be 12 pieces and the magnets 7-1 and 7-2 may be 16 pieces (12 slots and 16 poles). For example, nine coils 3 and eight magnets 7-1 and 7-2 may be provided (9 slots and 8 poles). Thus, various aspects are possible.

  The above-described stator 1 will be further described in detail. The stator 1 includes a stator outer peripheral portion 11, a stator lower portion 12, a stator upper portion 13, and a stator inner peripheral portion 14 in order to accommodate the plurality of teeth 4 and the plurality of coils 3.

  The stator outer peripheral portion 11 is a cylindrical (hollow columnar) member that forms the outer peripheral side wall of the stator 1. The stator lower part 12 is an annular plate-like member that forms the lower wall (bottom wall) of the stator 1. The stator upper part 13 is an annular plate-like member that forms the upper wall (ceiling wall) of the stator 1. The stator inner peripheral portion 14 is a cylindrical (hollow columnar) member that forms the inner peripheral side wall of the stator 1, and the diameter thereof is smaller than the diameter of the stator outer peripheral portion 11.

  The stator lower portion 12 and the stator upper portion 13 are arranged at a predetermined interval so as to face each other in the rotation axis direction. The inner peripheral edge of the stator lower part 12 is connected to one end (lower end) of the stator inner peripheral part 14, and the outer peripheral edge of the stator lower part 12 is connected to one end (lower end) of the stator outer peripheral part 11. ). The inner peripheral edge of the stator upper portion 13 is connected to the other end (upper end) of the stator inner peripheral portion 14, and the outer peripheral edge of the stator upper portion 13 is connected to the other end (upper end) of the stator outer peripheral portion 11. Connected. And the internal space formed by the stator outer peripheral part 11, the stator lower part 12, the stator upper part 13, and the stator inner peripheral part 14 connected in this way is with respect to each of the plurality of teeth 4 and the plurality of teeth. An accommodation space for accommodating the plurality of arranged coils (core coils) 3 is formed.

  Each of the plurality of coils 3 is a winding formed by winding a long conductor member. Each of the plurality of coils 3 may have a structure formed by winding a long conductor member having a round cross-section or a square cross-section that is insulated and coated, but each of the plurality of coils 3 in the present embodiment has a cross-section. This is a flatwise structure configured by winding a rectangular strip-shaped conductor member 31 via an insulating member so that the width direction of the conductor member 31 is along the axial direction of the coil 3. That is, each of the plurality of coils 3 is wound in a coil shape so as to finish winding on the outer peripheral side for the first time from the inner peripheral side, and is a long strip-shaped conductor in which the width in the coil axial direction is longer than the thickness in the coil radial direction The member 31 and the insulating member arrange | positioned between each turn in the said strip | belt-shaped conductor member 31 wound by the said coil shape are provided. Each of the plurality of coils 3 may have a single-layer single pancake structure, but each of the plurality of coils 3 in the present embodiment has a double pancake structure including a plurality of sub-coils stacked in the axial direction. is there. In the example illustrated in FIG. 3, each of the plurality of coils 3 includes two pieces, that is, a first subcoil 3 a on the lower side in the axial direction and a second subcoil 3 b on the upper side in the axial direction.

  The strip-shaped conductor member 31 may be, for example, a superconductive material, and may be a metal material having a relatively high thermal conductivity with a relatively low resistivity, such as pure copper (Cu) and aluminum (Al). It's okay.

  Each of the plurality of teeth 4 is also called a motor core or a stator core, and serves as a core of the coil 3. Each of the plurality of teeth 4 is formed of a magnetic material in a column shape. In the present embodiment, as shown in FIGS. 2 and 3, each of the plurality of teeth 4 is formed in a substantially triangular prism shape having a substantially triangular cross section (for example, an isosceles triangle). Each ridge of the triangular prism shape may be chamfered. Each of the plurality of teeth 4 in the present embodiment extends along the axial direction of the coil 3 on the side surface (the peripheral surface, the side surface on the coil end side) facing the inner peripheral surface of the coil 3. The convex part (projection part) 5 which protrudes to the outward direction of 4 is provided. In the example shown in FIGS. 2 and 3, the convex portion 5 is formed on the side surface of the triangular prism shape corresponding to the base of the cross-sectional triangle.

  In the present embodiment, as described above, each of the plurality of coils 3 includes the first and second subcoils 3a and 3b. The number of the convex portions 5 in each of the plurality of teeth 4 may be one for each of the first and second subcoils 3a and 3b. However, in the present embodiment, as shown in FIG. Each convex part 5 is provided with two, the 1st sub convex part 5a with respect to the 1st subcoil 3a, and the 2nd sub convex part 5b with respect to the 2nd subcoil 3b. In each of the plurality of teeth 4, the first and second sub-projections 5 a and 5 b are provided at different positions in the circumferential direction of the coil 3. In the example shown in FIG. 3, the first sub-projections 5 a are provided at one end in the circumferential direction of the coil 3 on the side surface of the triangular prism shape corresponding to the bottom of the cross-sectional triangle so as to be farthest in each tooth 4. The sub convex portion 5b is provided at the other end in the circumferential direction of the coil 3 on the side surface of the triangular prism shape corresponding to the base of the triangular cross section. Thus, each convex part 5 in each of the plurality of teeth 4 includes a plurality of sub-convex parts 5a and 5b provided at different positions in the circumferential direction of the coil 3 for each of the plurality of sub-coils 3a and 3b.

  Each of the plurality of coils 3 (3a, 3b) is arranged with respect to each of the plurality of teeth 4 so that each of the plurality of teeth 4 is located at each core portion of each of the plurality of coils 3 (3a, 3b). For example, each of the plurality of coils 3 (3a, 3b) is arranged on each of the plurality of teeth 4 by winding the respective strip-shaped conductor members 31 around the plurality of teeth 4 via insulating members. May be. Further, for example, by inserting each of the plurality of teeth 4 into each core portion of the plurality of coils 3 (3a, 3b) formed by winding the respective strip-shaped conductor members 31 via the insulating members, Each of the coils 3 (3a, 3b) may be disposed on each of the plurality of teeth 4.

  When the plurality of coils 3 (3a, 3b) are arranged for each of the plurality of teeth 4 as described above, the plurality of teeth 4 are formed by the convex portions 5 (5a, 5b) of the plurality of teeth 4, as shown in FIG. Each space is formed between each side surface and each inner peripheral surface of the plurality of coils 3 (3a, 3b). With this space, a heat radiation path can be secured for each inner peripheral surface of each coil 3 (3a, 3b), and heat generated inside the coil can be more efficiently wasted. In addition, the convex part 5 may be one or two with respect to one coil 3. For example, the number of the first sub-projections 5a may be one or two for one first sub-coil 3a, and the number of the second sub-projections 5b may be one or two for one second sub-coil 3b. It may be an individual.

  The plurality of teeth 4 and the plurality of coils 3 (3a, 3b) are formed by the stator outer peripheral portion 11, the stator lower portion 12, the stator upper portion 13, and the stator inner peripheral portion 14 as described above. It is arranged in an internal space (accommodating space). More specifically, the plurality of teeth 4 and the plurality of coils 3 (3a, 3b) are spaced apart from each other in the circumferential direction at equal intervals in the circumferential direction of the stator 1 (coils 3 ( 3a, 3b) so that the stator outer peripheral portion 11 and the stator inner peripheral portion 14 are spaced apart from each other (each coil 3 (3a, 3b) is an inner peripheral surface of the stator outer peripheral portion 11). And the upper and lower surfaces of each tooth 4 so that the side surface provided with each convex portion 5 is a surface that contacts the radially outer side of the stator 1. Are arranged in contact with the inner surface of the stator lower portion 12 and the inner surface of the stator upper portion 13. Thereby, between the inner peripheral surface of the stator outer peripheral portion 11 and the outer peripheral surface of each coil 3, between the outer peripheral surfaces of the coils 3 (3 a, 3 b) adjacent in the circumferential direction, and between the inner peripheral portion 14 of the stator A space is formed between the inner surface and the outer peripheral surface of each coil 3 (3 a, 3 b), and this space becomes the refrigerant passage portion 15. The refrigerant passage portion 15 not only serves as a refrigerant passage for bringing the refrigerant into contact with the outer peripheral surfaces of the plurality of coils 3 (3a, 3b), but also includes a plurality of teeth 4 formed by the convex portions 5 of the plurality of teeth 4. This also serves as a refrigerant passage for allowing the refrigerant to flow through the spaces formed between the respective side surfaces and the inner peripheral surfaces of the plurality of coils 3 (3a, 3b). Necessary for the accommodation space formed by the stator outer peripheral portion 11, the stator lower portion 12, the stator upper portion 13 and the stator inner peripheral portion 14 to accommodate the plurality of teeth 4 and the plurality of coils 3 (3a, 3b). By forming the stator outer peripheral portion 11, the stator lower portion 12, the stator upper portion 13 and the stator inner peripheral portion 14 so as to be larger than the space, the refrigerant passage portion 15 can be formed.

  An external supply port 16 is formed in a proper position on the outer periphery 11 of the stator in order to supply the refrigerant to the refrigerant passage 15 from the outside, and an external discharge port 17 for discharging the refrigerant from the refrigerant passage 15 to the outside. A through hole is formed at a suitable position on the outer periphery 11 of the stator. Further, between the formation position of the external supply port 16 and the formation position of the external discharge port 17, it extends from the inner peripheral surface of the stator outer peripheral portion 11 to the inner peripheral surface of the stator inner peripheral portion 14 along the radial direction. A plate-like stator partition wall 18 is disposed extending from the inner surface of the stator lower portion 12 along the axial direction to the inner surface of the stator upper portion 13. In addition, when the coil 3 (3a, 3b) is located in the arrangement | positioning position of the stator partition part 18, the recessed part which the coil 3 (3a, 3b) fits in the stator partition part 18 is formed. .

  The stator outer peripheral part 11, the stator lower part 12, the stator upper part 13, the stator inner peripheral part 14, and the stator partition part 18 which comprise these stators 1 are magnetic, such as soft magnetic materials, such as iron and steel, for example. A laminated body in which plate materials made of materials are laminated, a powder molded body using a powder of the magnetic material and a coating powder in which an insulating coating is formed on the surface of the magnetic material, and a combination of the laminated body and the powder molded body Formed with. In addition, the stator outer peripheral part 11, the stator lower part 12, the stator upper part 13, the stator inner peripheral part 14 and the stator partition part 18 may be formed individually, for example, and for example, the stator outer peripheral part 11, A part of the stator lower part 12, the stator upper part 13, the stator inner peripheral part 14, and the stator partition part 18 may be formed integrally. Or the stator 1 may be divided | segmented up and down and comprised by two members. The teeth 4 may also be formed individually, for example, and may be formed integrally with either the stator lower part 12 or the stator upper part 13, for example.

  In the AG type motor M having such a configuration, a predetermined refrigerant is supplied from an unillustrated heat exchanger through the external supply port 16 during operation. Examples of the predetermined refrigerant include, in the liquid phase, antifreeze-added pure water, nonpolar insulating oil, chlorofluorocarbon-based or non-fluorocarbon organic solvent, liquid nitrogen, and liquefied natural gas. In this case, an inert gas, hydrogen, helium, nitrogen, argon, chlorofluorocarbon or non-fluorocarbon gas is used.

  The refrigerant supplied from the external supply port 16 flows through the above-described refrigerant passage portion 15 as indicated by arrows in FIG. That is, first, the refrigerant supplied from the external supply port 16 circulates in the space formed between the stator outer peripheral portion 11 and the plurality of coils 3 (3a, 3b), and the plurality of coils 3 (3a 3b) The heat generated in each of the plurality of coils 3 (3a, 3b) is deprived from the outer peripheral surface of each, and the plurality of coils 3 (3a, 3b) are cooled. Secondly, the refrigerant supplied from the external supply port 16 circulates in the spaces formed between the coils 3 (3a, 3b) adjacent to each other in the circumferential direction in each of the plurality of coils 3 (3a, 3b). The heat generated in each of the plurality of coils 3 (3a, 3b) is taken from the outer peripheral surface of each of the plurality of coils 3 (3a, 3b), and each of the plurality of coils 3 (3a, 3b) is cooled. Thirdly, the refrigerant supplied from the external supply port 16 circulates in the space formed between the stator inner peripheral portion 14 and the plurality of coils 3 (3a, 3b), and the plurality of coils 3 (3a, 3b) The heat generated in each of the plurality of coils 3 (3a, 3b) is deprived from the outer peripheral surface of each, and each of the plurality of coils 3 (3a, 3b) is cooled. In the AG type motor according to the present embodiment, the refrigerant supplied from the external supply port 16 is, fourthly, in each of the plurality of coils 3 (3a, 3b), a plurality of protrusions 5 in the plurality of teeth 4 and a plurality of Through each space formed between each side surface of the teeth 4 and each inner peripheral surface of the plurality of coils 3 (3a, 3b), from the inner peripheral surface in each of the plurality of coils 3 (3a, 3b), The heat generated in each of the plurality of coils 3 (3a, 3b) is removed, and each of the plurality of coils 3 (3a, 3b) is cooled. Furthermore, in the AG type motor in the present embodiment, in each of the plurality of teeth 4, the first and second sub-projections 5a and 5b are provided at different positions in the circumferential direction of the coil 3 (3a and 3b). Therefore, the refrigerant supplied from the external supply port 16 contacts the side surfaces (upper and lower surfaces facing each other in the axial direction) of the first and second subcoils 3a between the first and second subcoils 3a and 3b, The heat generated in each of the coils 3 (3a, 3b) is taken away, and each of the plurality of coils 3 (3a, 3b) is cooled. Thus, the refrigerant | coolant which distribute | circulated the refrigerant | coolant channel | path part 15 while taking heat from each of the some coil 3 (3a, 3b) is discharged | emitted from the external discharge port 17, and returns to the heat exchanger of the said illustration omission.

  As described above, the AG-type motor M according to the present embodiment is configured such that each of the side surfaces of the plurality of teeth 4 and each of the plurality of coils 3 (3a, 3b) are formed by the convex portions 5 (5a, 5b) of the plurality of teeth 4. Each space is formed between the inner peripheral surface. With these spaces, a heat radiation path can be secured for each inner peripheral surface of each coil 3 (3a, 3b), and the heat generated inside the coil 3 (3a, 3b) can be more efficiently wasted. And since the conductor member 31 is also a good heat conductor excellent in thermal conductivity, heat generated in each turn of the coil 3 (3a, 3b) can also be conducted to the inner peripheral surface, Heat can be dissipated on the peripheral surface. Of course, the heat generated in each turn of the coil 3 (3a, 3b) is also conducted to the outer peripheral surface of the coil 3 (3a, 3b), and is radiated on the outer peripheral surface as described above.

  Further, the AG type motor M according to the present embodiment includes a plurality of sub-coils stacked in the axial direction, and in the above-described example, includes the first and second sub-coils 3a and 3b, but corresponds to the first and second sub-coils 3a and 3b. Since the first and second sub-projections 5a and 5b are provided at different positions in the circumferential direction of the coil 3, the side surfaces (upper side) of the first and second sub-coils 3a and 3b are placed between the first and second sub-coils 3a and 3b. Part of the lower surface is exposed without overlapping. For this reason, the AG type motor M in the present embodiment can ensure heat radiation from the side surfaces of the first and second subcoils 3a and 3b in the first and second subcoils 3a and 3b, respectively.

  In addition, since the AG type motor M in the present embodiment includes the refrigerant passage portion 15, forced cooling can be performed by circulating the refrigerant, and cooling can be performed efficiently. For this reason, the AG type motor M in the present embodiment can be energized with a large current and can realize a high torque density.

  Moreover, since the AG type motor M in this embodiment is provided with the convex part 5 in the side surface which hits the radial direction outer side of the stator 1 in the teeth 4, the coil 3 space | interval is shortened in the circumferential direction of the stator 1, and each coil 3 is arranged. It becomes possible to arrange | position, and the fall of the coil space factor in the circumferential direction can be suppressed.

  Further, since the AG type motor M in the present embodiment forms the coil 3 with a flat-wise structure, it can realize a higher coil space factor than a coil in which a conductor member having a round cross section is wound, and with a high magnetomotive force. Large torque output is possible.

  FIG. 4 is a view for explaining a modified form of the convex portion in the AG type motor of the embodiment. In the above description, the coil 3 has a double pancake structure in which two subcoils 3a and 3b are stacked in two layers in the axial direction. However, subcoils may be further stacked. In this case, when the convex portion 5 is composed of a plurality of sub-convex portions, the plurality of sub-convex portions may be disposed at alternate positions for each layer adjacent in the axial direction, for example, They may be arranged at different positions sequentially in the circumferential direction. For example, when the coil 3 is configured by stacking three subcoils 3a, 3b, and 3c in three layers, the convex portion 5 is configured by three sub convex portions 5a, 5b, and 5c. For example, as shown in FIG. 4A, the sub-projections 5b disposed in the intermediate layer (second layer) of these three sub-projections 5a, 5b, 5c The remaining sub-projections 5a, 5c, which are disposed at one end in the circumferential direction of the side surface opposite to the inner peripheral surface of 3 and disposed on both sides (the first layer and the third layer) of the intermediate layer, The tooth 4 is disposed at the position of the other end in the circumferential direction of the side surface facing the inner peripheral surface of the coil 3. Also, for example, as shown in FIG. 4B, the sub-projection 5a disposed in the first layer among these three sub-projections 5a, 5b, 5c is the inner circumference of the coil 3 in the tooth 4. The sub-projection 5c disposed in the third layer of the three sub-projections 5a, 5b, and 5c is disposed at the position of the other circumferential end of the side surface facing the surface. The sub-projections 5b disposed in the second layer of the three sub-projections 5a, 5b, and 5c are disposed at the position of one end in the circumferential direction of the side surface facing the inner circumferential surface of 3. The tooth 4 is disposed at the center in the circumferential direction of the side surface facing the inner peripheral surface of the coil 3. As described above, the three sub-projections 5a, 5b, and 5c are disposed at respective positions sequentially from the other circumferential end to the one end of the side surface of the tooth 4 that faces the inner peripheral surface of the coil 3.

  In order to express the present invention, the present invention has been properly and fully described through the embodiments with reference to the drawings. However, those skilled in the art can easily change and / or improve the above-described embodiments. It should be recognized that this is possible. Therefore, unless the modifications or improvements implemented by those skilled in the art are at a level that departs from the scope of the claims recited in the claims, the modifications or improvements are not covered by the claims. To be construed as inclusive.

M Axial gap type brushless motor 1 Stator 2 Rotor 3 Coils 3a and 3b Subcoil 4 Teeth 5 Convex part 5a and 5b Sub convex part 15 Refrigerant passage

Claims (4)

A stator comprising a plurality of teeth arranged in the circumferential direction and a plurality of coils arranged for each of the plurality of teeth;
A plurality of magnets arranged in a circumferential direction, the stator and a rotor arranged at a predetermined interval;
Each of the plurality of teeth includes, on a side surface facing the inner peripheral surface of the coil, a protrusion that extends along the axial direction of the coil and protrudes outward of the tooth.
Each of the plurality of coils includes a plurality of sub-coils stacked in the axial direction ,
The convex portion, the axial gap type brushless motor according to claim Rukoto comprises a plurality of sub projection provided on different positions in the circumferential direction of the coil for each of the plurality of sub-coils. The stator is a refrigerant passage for circulating a refrigerant in each space formed between each side surface of the plurality of teeth and each inner peripheral surface of the plurality of coils by the convex portions of the plurality of teeth. The axial gap type brushless motor according to claim 1, further comprising: a portion. 3. The axial gap type brushless motor according to claim 1, wherein the side surface including the convex portion is a surface that contacts a radially outer side of the stator. 4. Each of the plurality of coils is configured by winding a strip-shaped conductor member with respect to each of the plurality of teeth via an insulating material so that the width direction of the conductor member is along the axial direction of the coil. The axial gap type brushless motor according to any one of claims 1 to 3 , wherein the axial gap type brushless motor has a flat-wise structure.

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