Electric motor

Abstract

The invention provides a motor capable of stably dissipating heat generated by a circuit board. A motor according to one embodiment of the present invention is provided with: a resin outer contour having an open end on one end side in the axial direction; a stator; a rotor; a metal heat sink covering the open end; and a circuit board that is disposed in an internal space surrounded by the resin outer contour and the heat sink and that has an electronic component. The heat sink has a disk portion and a protrusion portion protruding from the disk portion toward the electronic component, the disk portion has a plurality of through-holes through which a fastening member for fastening the heat sink and the resin outer contour is inserted, the plurality of through-holes are arranged along the circumferential direction of the disk portion, and the protrusion portion has a planar tip surface in thermal contact with the electronic component. The front end surface has a first region facing the electronic component and a second region not facing the electronic component, and the second region is adjacent to at least one side of the first region in the circumferential direction of the disk portion.

Description

Technical Field

[0001] The present invention relates to an electric motor, and more particularly to a heat dissipation structure for a circuit board built in the electric motor. Background Art

[0002] Conventionally, an electric motor having a circuit board for controlling the rotational drive of the electric motor inside has been known. And this circuit board includes electronic components that generate heat due to energization, and an electric motor having a radiator that dissipates heat generated by the electronic components to the outside of the electric motor has also been known.

[0003] For example, Patent Document 1 describes an electric motor including: a resin outer contour that molds a stator core; a rotor disposed on the inner diameter side of the stator core; a radiator that covers an open end portion of the resin outer contour; a plurality of screws that fasten the resin outer contour and the radiator; and a circuit board disposed in an internal space covered by the resin outer contour and the radiator, wherein the resin outer contour has a plurality of thread receiving portions that receive the plurality of screws, and the radiator has: a circular plate portion having a plurality of threaded holes through which the plurality of screws are inserted, and a protrusion portion that protrudes from the circular plate portion toward the circuit board side and is in thermal contact with the electronic components of the circuit board.

[0004] Prior Art Documents Patent Documents Patent Document 1: Japanese Patent Application Laid-Open No. 2022-152645 Summary of the Invention Technical Problem to be Solved by the Invention In Patent Document 1, the screws inserted into the threaded holes are held by the thread receiving portions, whereby the radiator is circumferentially positioned with respect to the resin outer contour. However, when the radiator is fastened to the resin outer contour using a plurality of screws, due to dimensional deviations, the central axes of the axial threaded holes and the central axes of the thread receiving portions are offset, and a part of the plurality of screws may not be fastened.

[0005] Therefore, it is also considered to form the threaded holes of the radiator large so that the screws can be reliably fastened even in the presence of dimensional deviations. However, in this case, a deviation in the circumferential relative position between the protrusion portion of the radiator and the electronic components is likely to occur, and when viewed axially, a region where the protrusion portion of the radiator and the electronic components are not opposed may occur, etc., and sufficient heat dissipation may not be possible.

[0006] In view of the above circumstances, an object of the present invention is to provide an electric motor capable of stably dissipating heat generated by a circuit board.

[0007] Technical Solution for Solving the Technical Problem To achieve the above object, a motor according to one aspect of the present invention includes: a cylindrical resin outer contour having an open end portion on one end side in the axial direction; a stator including a winding and a stator core integrally formed with the resin outer contour; a rotor having a rotating shaft extending in the axial direction and disposed on the inner diameter side of the stator; a metal radiator covering the open end portion of the resin outer contour; and a circuit board disposed in an internal space surrounded by the resin outer contour and the radiator and having electronic components.

[0008] The radiator has a circular plate portion and a protruding portion protruding from the circular plate portion toward the electronic components. The circular plate portion has a plurality of through holes through which fastening members are inserted to fasten the radiator to the resin outer contour, and the plurality of through holes are arranged along the circumferential direction of the circular plate portion. The protruding portion has a planar front end surface that is in thermal contact with the electronic components. When viewed from the axial direction, the front end surface has a first region facing the electronic components and a second region not facing the electronic components, and the second region is adjacent to at least one side in the circumferential direction of the circular plate portion of the first region.

[0009] According to the above motor, the resin outer contour and the radiator are fastened by fastening members along the circumferential direction of the circular plate portion. The radiator has a first region facing the electronic components and a second region not facing the electronic components, and the second region is adjacent to at least one side in the circumferential direction of the circular plate portion of the first region. Therefore, when assembling the radiator to the resin outer contour, even if the radiator is offset in the circumferential direction due to dimensional deviation, heat generated by the electronic components can be stably dissipated.

[0010] The outer peripheral surface of the resin outer contour may also have a groove portion along the axial direction, and at least a part of the metal member may be in a band shape and housed in the groove portion.

[0011] It may also be that when viewed from the axial direction, the front end surface is fan-shaped with a width L having a given length LR or more in the radial direction orthogonal to the axial direction.

[0012] The above-mentioned given length LR can also be the length obtained by subtracting the distance L2 from the distance L1 in a cross-section orthogonal to the above-mentioned axis. The distance L1 is the distance from the rotation center of the above-mentioned rotation axis to the outermost diameter portion located on the outermost diameter side in the outer peripheral edge portion of the above-mentioned electronic component facing the above-mentioned first region, and the distance L2 is the distance from the rotation center of the above-mentioned rotation axis to the innermost diameter portion located on the innermost diameter side in the outer peripheral edge portion of the above-mentioned electronic component facing the above-mentioned first region. That is, the radial width L of the front end face can also be L≥LR = L1 - L2.

[0013] The above-mentioned fastening member can also have a shaft portion inserted into the above-mentioned through hole and a head portion with a diameter larger than the diameter of the above-mentioned shaft portion, and at least one of the above-mentioned plurality of through holes has a region that does not overlap with the above-mentioned shaft portion of the above-mentioned fastening member when viewed from the above-mentioned axis. The above-mentioned fastening member can be, for example, an external thread, and an external thread portion is formed on the above-mentioned shaft portion.

[0014] In a cross-section orthogonal to the above-mentioned axis, at least one of the above-mentioned plurality of through holes can be in the shape of a long hole with the circumferential direction of the above-mentioned circular plate portion as the length direction.

[0015] A step is provided on the above-mentioned circular plate portion of the above-mentioned radiator. It can also be that the radiator is positioned relative to the above-mentioned resin outer contour by making the above-mentioned step abut against the inner diameter side surface of the above-mentioned opening end portion of the above-mentioned resin outer contour.

[0016] When the straight line connecting the end on one side in the circumferential direction of the above-mentioned one through hole to the rotation center of the above-mentioned rotation axis is set as the first straight line S1, the straight line connecting the end on one side in the circumferential direction of the above-mentioned shaft portion to the rotation center is set as the second straight line S2, and the angle formed by the above-mentioned first straight line S1 and the above-mentioned second straight line S2 is set as the first angle θ1, the straight line connecting the end on one side in the circumferential direction of the above-mentioned front end face of the above-mentioned protrusion to the rotation center is set as the third straight line S3, the straight line connecting the end on one side in the circumferential direction of the above-mentioned electronic component to the rotation center is set as the fourth straight line S4, and the angle formed by the above-mentioned third straight line S3 and the above-mentioned fourth straight line S4 is set as the second angle θ2. It can also satisfy θ1<θ2 (Equation 1) The thickness of the above-mentioned circular plate portion in the above-mentioned axial direction can be 3 mm or more.

[0017] The above-mentioned resin outer contour can also have a receiving portion that receives the fastening member inserted into the above-mentioned circular plate portion.

[0018] Advantages of the Invention According to the present invention, a motor capable of stably dissipating heat generated by a circuit board can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 FIG. is a perspective view of a motor according to an embodiment of the present invention.

[0020] Figure 2 FIG. is a cross-sectional view of the above-described motor.

[0021] Figure 3 FIG. is a view of the radiator of the above-described motor as viewed from the fin portion side.

[0022] Figure 4 FIG. is a perspective view of the radiator of the above-described motor as viewed from the protrusion portion side.

[0023] Figure 5 FIG. is a view of the circuit board of the above-described motor as viewed from the radiator side.

[0024] Figure 6 FIG. is a view of the positional relationship between the front end face of the above-described motor and the electronic component as viewed from the radiator side.

[0025] Figure 7 FIG. is a top view of the radiator of the above-described motor as viewed from the protrusion portion side.

[0026] Figure 8 FIG. is a view of the above-described motor as viewed from the bottom side.

[0027] Figure 9 FIG. is a perspective view of the vibration-proof member as viewed from the upper surface side.

[0028] Figure 10 FIG. is a perspective view of the vibration-proof member as viewed from the lower surface side.

[0029] Figure 11 FIG. is a perspective view of a metal member.

[0030] Figure 12 FIG. is a side view of the above-described metal member. DETAILED DESCRIPTION OF THE INVENTION

[0031] Next, embodiments of the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic and may be different from reality. Therefore, for specific component parts, judgment should be made with reference to the following description.

[0032] In addition, the following embodiments illustrate embodiments of devices and methods for embodying the technical idea of the present invention. The technical idea of the present invention does not limit the shape, structure, configuration, etc. of the constituent components to the following content. The technical idea of the present invention can be subjected to various changes within the technical scope defined by the claims recited in the claims.

[0033] Figure 1 is a perspective view of the motor 1 according to the embodiment. Figure 2 is a cross-sectional view of the motor 1 according to the embodiment. The motor 1 of the present embodiment is, for example, a brushless DC motor, which is installed on a wall or ceiling of a building and is used as a drive source for a blower that communicates an indoor and outdoor air duct.

[0034] [Overall Structure of Motor] The motor 1 includes a resin outer contour 10, a stator 2 (stator core 21), a rotor 3, a radiator 4, a circuit board 5, and a metal member 11.

[0035] Hereinafter, as an example, an inner-rotor type brushless DC motor in which a cylindrical rotor 3 having a permanent magnet portion 32 is rotatably disposed inside the radial direction of a cylindrical stator 2 that generates a rotating magnetic field will be described as the motor 1.

[0036] In addition, in the following description, the axis C of the rotation shaft 6 is also the central axis (rotation center) of the motor 1, that is, the rotation shaft of the rotor 3. The radial direction refers to a direction passing through the axis C and orthogonal to the axial direction (a direction parallel to the axis C). In addition, the inner diameter side refers to the inner side in the radial direction (the inner circumferential surface side of the cylindrical stator 2), and the outer diameter side refers to the outer side in the radial direction (the outer circumferential surface side of the cylindrical stator 2). Further, the circumferential direction refers to a rotation direction centered on the axis C.

[0037] (Rotor) As Figure 2 shown, the rotor 3 has an annular permanent magnet portion 31, a rotor body 30, and a rotation shaft 6. The rotor body 30 has an outer peripheral surface fixed to the permanent magnet portion 31 and an inner peripheral surface fixed to the rotation shaft 6.

[0038] The rotor 3 is a surface magnet type in which the permanent magnet portion 31 is annularly arranged on the outer peripheral surface. The permanent magnet portion 31 is formed into an annular shape by a plurality of (for example, 8 or 10) permanent magnets such that the N poles and S poles alternately appear at equal intervals in the circumferential direction. It should be noted that the permanent magnet portion 31 is typically composed of a metal sintered body such as an Nd-Fe-B based alloy, but in addition to this, a plastic magnet formed by fixing magnet powder with resin can also be used.

[0039] The rotor body 30 has an outer peripheral side iron core 32, an insulating member 33, and an inner peripheral side iron core 34.

[0040] The outer peripheral side iron core 32 is formed in a ring shape and forms the outer peripheral surface of the rotor main body 30. The outer peripheral side iron core 32 is a laminate of plates made of soft magnetic materials such as a plurality of electromagnetic steel sheets.

[0041] The inner peripheral side iron core 34 is formed in a ring shape and is a laminate of plates made of soft magnetic materials such as a plurality of electromagnetic steel sheets that form the inner peripheral surface of the rotor main body 30. At the center of the inner peripheral side iron core 34, a rotating shaft 6 is fixedly connected by press-fitting or riveting or the like.

[0042] The insulating member 33 electrically insulates between the outer peripheral side iron core 32 and the inner peripheral side iron core 34. Thereby, the difference between the static capacitance on the stator side and the static capacitance on the rotor side of the motor 1 can be reduced to suppress the electrolytic corrosion of the bearing. The insulating member 33 is formed of a dielectric resin such as PBT (polybutylene terephthalate) or PET (polyethylene terephthalate) and is fixed between the outer peripheral side iron core 32 and the inner peripheral side iron core 34. The insulating member 33 may be a ring-shaped molded body or a resin material filled between the outer peripheral side iron core 32 and the inner peripheral side iron core 34 by insert molding or the like. It should be noted that although the case where the rotor main body 30 is divided into the outer peripheral side iron core 32 and the inner peripheral side iron core 34 and the insulating member 33 is formed therebetween is illustrated, the rotor main body 30 may also be formed of a cylindrical iron core without the insulating member 33.

[0043] (Stator) The stator 2 has a stator iron core 21, a coil (winding) 22, and an insulator (not shown). The stator iron core 21 is, for example, a laminate of plates made of soft magnetic materials such as a plurality of electromagnetic steel sheets. The stator iron core 21 has an annular yoke portion and a plurality of tooth portions protruding inward from the yoke portion. A coil 22 is wound around each tooth portion of the stator iron core 21 via an insulating member. The plurality of coils 22 include coils 22 corresponding to the three phases of U-phase, V-phase, and W-phase respectively. These coils are connected to each other, for example, at the electrical neutral point (N point). The outer peripheral surface of the stator 2 (stator iron core 21) is covered by a resin outer contour 10 (refer to Figure 2 ). The stator iron core 21 of the stator 2 is arranged so as to face the permanent magnet portion 32 of the rotor 3 with a gap (magnetic gap) therebetween in the radial direction.

[0044] (Resin outer contour) The resin outer contour 10 is made of an insulating resin material. As Figure 1 , Figure 2As shown, the resin outer contour 10 has an open end 101 on one end side in the axial direction (the output opposite end 61 side of the rotating shaft 6 in this embodiment), and a bottom 102 on the other end side in the axial direction (the output end 62 side of the rotating shaft 6 in this embodiment), and is formed in a hollow cylindrical shape. Here, the output opposite end 61 refers to the end of the rotating shaft 6 on the side opposite to the output end 62. The output end 62 refers to the end of the motor 1 on the load side (the side connected to the load).

[0045] As described above, the resin outer contour 10 is integrally formed with the stator 2. The resin material constituting the resin outer contour 10 is not particularly limited. For example, it is formed of BMC (Bulk Molding Compound: a thermoplastic resin mainly composed of unsaturated polyester).

[0046] In addition, the resin outer contour 10 has a mounting surface 9. The mounting surface 9 is the inner peripheral surface of the resin outer contour 10, and is provided on the output opposite end 61 side of the rotating shaft 6 with a gap from the rotor 3. The mounting surface 9 is provided to be able to support the circuit board 5 described later. In this embodiment, the mounting surface 9 is the surface on the output opposite end 61 side of the stepped portion provided so as to protrude toward the inner diameter side from the inner peripheral surface of the resin outer contour 10. The mounting surface 9 can be continuously formed in the circumferential direction on the inner peripheral surface of the resin outer contour 10, or can be formed at multiple locations at intervals along its circumferential direction.

[0047] Figure 8 It is a view seen from the bottom 102 side of the motor 1. As Figure 2 , Figure 8 shown, the bottom 102 of the resin outer contour 10 also has a cylindrical portion 102a for housing the metal second bearing housing portion 82. The second bearing housing portion 82 is provided on the bottom 102 and houses the second bearing 81 described later.

[0048] The cylindrical portion 102a protrudes from the bottom 102 of the resin outer contour 10 toward the output end 62 side of the rotating shaft 6 and surrounds the outer periphery of the cylindrical housing portion 821 of the second bearing housing portion 82 described later. When viewed from the axial direction, on the outer peripheral surface of the cylindrical portion 102a, second concave portions 1021a recessed radially inward and second convex portions 1022a protruding radially outward are alternately provided. At the center when viewed from the axial direction, the cylindrical portion 102a is formed with a through hole through which the rotating shaft 6 is inserted. The cylindrical portion 102a holds the second bearing housing portion 82 by housing the cylindrical portion 821 of the second bearing housing portion 81 on the inner peripheral surface side of the cylindrical portion 102a. A second vibration-proof member 12b (described later) is mounted on the outer peripheral surface of the cylindrical portion 102a and engages with the second concave portions 1021a and the second convex portions 1022a. The second concave portions 1021a and the second convex portions 1022a provided in the cylindrical portion 102a function as anti-rotation members with respect to the second vibration-proof member 12b.

[0049] On the outer peripheral surface 10A of the resin outer contour 10, in order to improve the heat dissipation performance, an outer peripheral surface convex portion 10a protruding in the outer diameter direction is formed extending in the axial direction. A plurality of the outer peripheral surface convex portions 10a are formed in the circumferential direction of the resin outer contour 10. The length of the outer peripheral surface convex portion 10a extending in the axial direction and the protruding height of the outer peripheral surface convex portion 10a protruding in the outer diameter direction can be appropriately set.

[0050] By forming the outer peripheral surface convex portion 10a, the surface area at the outer peripheral surface 10A of the resin outer contour 10 can be increased, and thus the heat dissipation performance can be improved.

[0051] In addition, a groove portion 10b for arranging a metal member 11 described later is provided in the resin outer contour 10. The groove portion 10b has a first groove portion 101b, a second groove portion 102b, a third groove portion 103b, and a fourth groove portion 104b.

[0052] As Figure 1 、 Figure 2 shown, the first groove portion 101b is provided at a position on the outer peripheral surface 10A of the resin outer contour 10 that does not overlap with the outer peripheral surface convex portion 10a, and is formed on the outer peripheral surface 10A of the resin outer contour 10 along the axial direction. In the present embodiment, the first groove portion 101b is located between two outer peripheral surface convex portions 10a adjacent in the circumferential direction on the outer peripheral surface 10A of the resin outer contour 10.

[0053] In addition, the second groove portion 102b is connected to the first groove portion 101b on the side of the opening end portion 101, and is formed on the opening end portion 101 along the radial direction. In addition, when viewed from the axial direction, the second groove portion 102b is formed at a position overlapping with a fin portion 45 of a radiator 4 described later.

[0054] In addition, the third groove portion 103b is connected to the second groove portion 102b on the inner peripheral surface 10B side of the resin outer contour 10, and is formed on the inner peripheral surface 10B of the resin outer contour 10 along the axial direction. In addition, when viewed from the axial direction, the third groove portion 103b is formed at a position overlapping with a fin portion 45 of a radiator 4 described later.

[0055] In addition, the fourth groove portion 104b is connected to the first groove portion 101b on the side of the bottom portion 102, and is formed on the bottom portion 102 along the radial direction. In addition, when viewed from the axial direction, the fourth groove portion 104b is formed at a position overlapping with at least a part of a second bearing housing portion 82 described later.

[0056] The width of the groove portion 10b only needs to be a size for housing the metal member 11 described later.

[0057] The depth of the first groove portion 101b in the inner diameter direction is not particularly limited, and for example, it is the depth for housing a first metal portion 11A described later.

[0058] The axial depth of the second groove portion 102b is not particularly limited, and is, for example, the same as or substantially the same as the axial thickness of the second metal portion 11B described later.

[0059] The depth of the third groove portion 103b in the outer diameter direction (resin outer contour 10 side) is not particularly limited, and is, for example, the same as or substantially the same as the radial thickness of the third metal portion 11C described later.

[0060] The axial depth of the fourth groove portion 104b is not particularly limited, and is, for example, a depth that accommodates the axial thickness of the fourth metal portion 11D described later.

[0061] The fourth groove portion 104b has a through hole 1041b through which a first fastening member N (e.g., a screw) is inserted, and the first fastening member N fastens the flange portion 822 of the second bearing housing portion 82 described later to the metal member 11.

[0062] (Circuit board) As Figure 2 and Figure 5 shown, the circuit board 5 includes a wiring board 50 and a heat-generating electronic component 51 mounted on the surface of the wiring board 50 (the surface on the output opposite end 61 side of the rotary shaft 6). The circuit board 5 has a circular plate shape, and the peripheral portion of the circuit board 5 is supported by the mounting surface 9 and is fixed to the resin outer contour 10, for example, by adhesion, sticking, screw fastening, welding, etc. It should be noted that positioning protrusions may be provided on the peripheral portion of the circuit board 5, and positioning recesses that engage with the above protrusions may be provided on the inner peripheral surface of the resin outer contour 10, whereby the circuit board 5 can be fixed to the mounting surface 9 in a circumferentially positioned state.

[0063] The electronic component 51 has a component main body 510 and lead portions 511 extending from two opposite side surfaces of the component main body 510. It should be noted that the lead portions 511 are not limited to extending from two side surfaces of the component main body 510, and may extend from only one side surface or from four side surfaces. The component main body 510 is a synthetic resin package portion incorporating semiconductor elements. The lead portions 511 are composed of a plurality of metal external terminals electrically connected to the wiring board 50.

[0064] The electronic component 51 is mainly a semiconductor package component such as a power IC integrating a power MOSFET, IGBT, etc., an IC for controlling a motor drive current, etc., but may also be a passive component such as a capacitor.

[0065] In addition, on the wiring substrate 50, other components such as a connector component connected to a power cable are mounted in addition to the electronic component 51, but their illustrations are omitted. The above-mentioned power cable is led out to the outside of the resin outer contour 10 through a cable insertion portion (illustration omitted) formed in a given angular range covering the circumferential direction near the opening end portion 101 of the resin outer contour 10 and is connected to a power supply (not shown).

[0066] (Bearing) As Figure 2 shown, the first bearing 71 is a ball bearing having an outer ring 711, an inner ring 712, a plurality of balls 713, etc. The second bearing 81 is a ball bearing having an outer ring 811, an inner ring 812, a plurality of balls 813, etc.

[0067] The outer ring 711 of the first bearing 71 is fixed to the heat sink 4 (the first bearing housing portion 41), and the inner ring 712 of the first bearing 71 is fixed to the output opposite end portion 61 side of the rotating shaft 6. The outer ring 811 of the second bearing 81 is fixed to the bottom portion 102 of the resin outer contour 10 (the second bearing housing portion 82). The inner ring 812 of the second bearing 81 is fixed to the output end portion 62 of the rotating shaft 6. Thus, the rotating shaft 6 is supported by the first bearing 71 and the second bearing 81 so as to be rotatable about the axis C relative to the heat sink 4 and the resin outer contour 10.

[0068] The second bearing housing portion 82 is made of metal and is a substantially cylindrical shape centered on the axis C as described above. The second bearing housing portion 82 has a cylindrical portion 821 for housing the second bearing 81 and a flange portion 822 extending in the outer diameter direction from the cylindrical portion 821, and is housed in the above-mentioned cylindrical portion 102a.

[0069] The flange portion 822 is in the shape of an annular plate, and when viewed axially, the flange portion 822 is provided at a position overlapping the above-mentioned fourth groove portion 104b.

[0070] When viewed axially, the flange portion 822 has a flange hole 822a at a position overlapping the through hole 1041b of the fourth groove portion 104b formed in the resin outer contour 10. The flange hole 822a is fastened by a metal member 11 and a first fastening member N through the through hole 1041b.

[0071] (Heat sink) Figure 3 is a view of the heat sink 4 as viewed from the fin portion 45 side, Figure 4 is a view of the heat sink 4 as viewed from the protrusion portion 44 side. Figure 5 is a view of the circuit board 5 as viewed from the heat sink 4 side, Figure 6 is a view of the positional relationship between the front end face 441 and the electronic component 51 as viewed from the heat sink 4 side. In addition, Figure 7It is a top view of the radiator 4 as viewed from the side of the protrusion 44.

[0072] The radiator 4 has a first bearing housing portion 41, a circular plate portion 42, an annular protrusion portion 43, a protrusion portion 44, a fin portion 45, and a first restricting portion 46. The radiator 4 is mounted and fixed to the opening end portion 101 of the resin outer contour 10. The radiator 4 is formed of a metal material having excellent thermal conductivity such as aluminum, aluminum alloy, or magnesium alloy. In the radiator 4, the circular plate portion 42, the annular protrusion portion 43, the protrusion portion 44, and the fin portion 45 are integrally formed. The radiator 4 is formed by die casting (casting), for example.

[0073] The radiator 4 has the function of a cover member (bracket) that closes the opening of the resin outer contour 10 by covering the opening end portion 101 of the resin outer contour 10, the function of a bearing housing portion (bearing seat) that supports the first bearing 71, and the function of a heat dissipation member that dissipates the heat generated by the electronic components 51 inside the motor to the outside of the motor.

[0074] The circular plate portion 42 is in a ring shape having a central hole 40 centered on the axis C. The circular plate portion 42 includes an inner surface portion 424 that covers the opening end portion 101 of the resin outer contour 10, and an outer surface portion 423 on the side opposite to the inner surface portion 424 (the output opposite end portion 61 side). In the present embodiment, the outer diameter of the circular plate portion 42 is the same as or substantially the same as the outer diameter of the opening end portion 101 of the resin outer contour 10. In addition, as Figure 2 、 Figure 3 shown, the first bearing housing portion 41, the fin portion 45, and the first restricting portion 46 are formed on the outer surface portion 423 of the circular plate portion 42. An axial positioning portion 420, an annular protrusion portion 43, and a protrusion portion 44 are provided on the inner surface portion 424 of the circular plate portion 42. In the present embodiment, the thickness of the circular plate portion 42 in the axial direction is, for example, 3 mm or more, and is 4 mm in the present embodiment.

[0075] Hereinafter, the axial positioning portion 420, the annular protrusion portion 43, and the protrusion portion 44 provided on the inner surface portion 424 of the circular plate portion 42 will be described.

[0076] The annular protrusion portion (step) 43 is a hollow cylindrical shape centered on the axis C, protrudes from the inner surface portion 424 side of the circular plate portion 42 in the axial direction toward the circuit board 5 side, and contacts the inner peripheral surface (inner side surface) 10B of the resin outer contour 10. The annular protrusion portion 43 has a hole having the same or substantially the same size as the central hole 40, and the rotating shaft 6 passes through it. The annular protrusion portion 43 faces the circuit board 5 and has a placement surface 431 for placing the protrusion portion 44 described later.

[0077] The cross section of the annular protrusion portion 43 parallel to the axis C is substantially rectangular. In addition, as Figure 4As shown, the annular protrusion 43 is continuously formed circumferentially without a slit, but is not limited thereto, and a slit may be present in a part thereof.

[0078] The annular protrusion 43 has a radial positioning portion 430 for positioning the radiator 4 relative to the resin outer contour 10 in the radial direction around the axis C. In the present embodiment, the radial positioning portion 430 is formed on the outer peripheral surface of the annular protrusion 43 and abuts against the inner peripheral surface 10B of the resin outer contour 10. That is, as Figure 2 , Figure 4 shown, the radial positioning portion 430 has a cylindrical surface shape that fits with the inner peripheral surface 10B of the resin outer contour 10.

[0079] The protrusion 44 is disposed on the disposed surface 431 of the annular protrusion 43, protrudes from the inner surface portion 424 side of the circular plate portion 42 toward the circuit board 5 side, and is in thermal contact with the circuit board 5 (the electronic component 51 in the present embodiment).

[0080] As Figure 2 , Figure 4 shown, in the present embodiment, the protrusion 44 is a fan-shaped block that protrudes toward the electronic component 51 mounted on the circuit board 5. Further, the protrusion 44 has a planar front end surface 441 facing the electronic component 51, a first end portion 442 provided on one end side in the circumferential direction in the front end surface 441, and a second end portion 443 provided on the other end side in the circumferential direction in the front end surface 441. It should be noted that the shape of the protrusion 44 observed from the axial direction is not limited to a fan shape, and may be, for example, a rectangular parallelepiped shape or a cylindrical shape. In addition, the fan shape here means a substantially "C" shape that is not formed in a ring shape when observed from the axial direction (or a shape in which a part of a donut shape is cut off, an arc shape having a given width).

[0081] The shape of the front end surface 441 observed from the side of the electronic component 51 is a fan shape having a width L (described later) with a given length LR or more in the radial direction when observed from the axial direction (refer to Figure 4 ). In addition, as Figure 6 shown, the front end surface 441 has a first region W1 facing the electronic component 51 and a second region W2 not facing the electronic component 51. The second region W2 is adjacent to at least one side in the circumferential direction of the first region W1.

[0082] The shape of the first region W1 observed from the axial direction is a rectangular shape, but of course is not limited thereto, and any shape that overlaps with the electronic component 51 when observed from the axial direction is acceptable. Here, overlapping (opposing) with the electronic component 51 when observed from the axial direction means overlapping (opposing) with the component main body 510 of the electronic component 51 when observed from the axial direction. That is, the first region W1 is a region surrounded by the outer peripheral edge portion L0 of the component main body 510 when observed from the axial direction.

[0083] Further, in the present embodiment, the second region W2 viewed axially is substantially fan-shaped, but of course is not limited thereto and may also be rectangular. Further, in the present embodiment, the second region W2 adjacent to the first region W1 is provided only on one circumferential side (the left-handed rotation direction side, the counterclockwise rotation direction side) of the disc portion 42 of the first region W1. However, of course, the second region W2 may also be provided only on the other circumferential side (the right-handed rotation direction side, the clockwise rotation direction side) of the disc portion 42 of the first region W1, or may be provided adjacent to both directions (the counterclockwise rotation direction side and the clockwise rotation direction side).

[0084] The front end face 441 may also be machined into a flat surface by a machine tool such as a surface grinder after the radiator 4 is formed by die casting or the like, for example.

[0085] As Figure 4 shown, the first end portion 442 has a rectangular flat surface parallel to the surface orthogonal to the circumferential direction on one end side of the front end face 441 and is arranged along the radial direction, while the second end portion 443 has a rectangular flat surface parallel to the surface orthogonal to the circumferential direction on the other end side of the front end face 441 and is arranged along the radial direction.

[0086] Here, as Figure 4 , Figure 5 shown, the width L of the front end face 441 in the above-described radial direction is equal to or greater than a given length LR. In the present embodiment, the given length LR is a length obtained by subtracting the distance L2 from the distance L1. The distance L1 refers to the distance from the rotation center C of the rotation shaft 6 (the rotation center of the motor 1) to the outermost diameter portion 511A located on the outermost diameter side in the outer peripheral edge portion L0 of the electronic component 51 (component main body 510) opposed to the first region W1 in a cross section orthogonal to the axial direction. Further, the distance L2 refers to the distance from the rotation center C of the rotation shaft 6 (the rotation center of the motor 1) to the innermost diameter portion 511B located on the innermost diameter side in the outer peripheral edge portion L0 of the electronic component 51 (component main body 510) opposed to the first region W1 in a cross section orthogonal to the axial direction. That is, the given length LR is LR = L1 - L2. Further, the width L is L ≥ LR = L1 - L2.

[0087] In the present embodiment, the outermost diameter portion 511A corresponds to the angular portion of the outer peripheral edge portion LO of the electronic component 51 when viewed axially. Further, in the present embodiment, the innermost diameter portion 511B corresponds to the innermost diameter side portion in the portion where the line extending radially from the rotation center C (corresponding to the distance L2) is orthogonal to the outer peripheral edge portion LO.

[0088] Further, as Figure 7As shown, in the present embodiment, the angle θ0 from the first end portion 442 to the second end portion 443 of the front end surface 441 in the circumferential direction is approximately 75°, but of course it is not limited thereto, and can be appropriately changed according to the shape of the electronic component 51 observed from the axial direction and the like.

[0089] Between the electronic component 51 and the protrusion 44, a heat transfer member 52 and an adhesive member 53 are sequentially arranged from the side of the electronic component 51, and the front end surface 441 of the protrusion 44 is in thermal contact with the electronic component 51 via the heat transfer member 52 and the adhesive member 53. The distance between the front end surface 441 and the electronic component 51 is set to be equal to or less than the total thickness obtained by adding the thickness of the heat transfer member 52 and the thickness of the adhesive member 53.

[0090] Thus, the front end surface 441 can be stably in contact with the upper surface of the electronic component 51 via the heat transfer member 52 and the adhesive member 53. It should be noted that it is not limited thereto, and either the heat transfer member 52 or the adhesive member 53 may be arranged only between the electronic component 51 and the protrusion 44. In addition, the radiator 4 may not have the protrusion 44 formed integrally with the circular plate portion 42. For example, a heat transfer member made of metal and separated from the radiator 4 may be arranged between the inner surface of the circular plate portion 42 of the radiator 4 and the electronic component 51.

[0091] As the heat transfer member 52, a member with good thermal conductivity and high insulation is preferably used, such as a heat sink made of silicone resin. Similarly, for the adhesive member, a member with good thermal conductivity and high insulation is preferably used, such as an adhesive made of silicone resin. The adhesive member 53 not only bonds the heat transfer member 52 to the protrusion 44, but also absorbs the axial position deviation between the protrusion 44 and the electronic component 51 through the deformation of the adhesive member 53. And when the radiator 4 is fitted into the resin outer contour 10, the adhesive member 53 releases the pressing force from the protrusion 44 to the electronic component 51 through the deformation of the adhesive member 53. Thus, it is possible to prevent excessive pressure from being applied to the electronic component 51 and ensure a stable thermal connection between the protrusion 44 and the electronic component 51.

[0092] The circular plate portion 42 has an axial positioning portion 420 for positioning the relative position of the radiator 4 with respect to the resin outer contour 10 in the axial direction (the axial position of the radiator 4 when based on the resin outer contour 10). As Figure 4 shown, the axial positioning portion 420 is formed on the inner surface portion 424 side of the first outer peripheral edge portion 422 of the circular plate portion 42. In the present embodiment, the first outer peripheral edge portion 422 refers to the region of the circular plate portion 42 on the outer diameter side of the annular protrusion 43.

[0093] The axial positioning portion 420 is formed on the inner surface portion 424 side of the first outer peripheral edge portion 422 and abuts against the opening end portion 101 of the resin outer contour 10. AsFigure 2 As shown, the axial positioning portion 420 abuts against the opening end portion 101 in the direction of the axis C. For example, the axial positioning portion 420 may also be machined into a flat surface by a lathe or the like after the radiator 4 is formed by die casting or the like. In the present embodiment, the axial positioning portion 420 is formed as a plane orthogonal to the axis C.

[0094] As Figure 4 shown, with respect to the axial positioning portion 420, the entire region on the inner surface portion 424 side of the first outer peripheral edge portion 422 is formed by a plane orthogonal to the axis C, but it is not limited thereto. For example, the axial positioning portion 420 of the radiator 4 may also have an annular protruding portion protruding toward the opening end portion 101, and may also have an annular groove portion corresponding to the protruding portion at the opening end portion 101 of the resin outer contour 10. The cross-section of the protruding portion observed in the radial direction may be trapezoidal or may be a curved surface shape.

[0095] In addition, as Figure 3 , Figure 4 , Figure 7 shown, a plurality of through holes 421 through which a second fastening member (fastening member) T for fastening the radiator 4 to the resin outer contour 10 is inserted are formed at a plurality of positions on the first outer peripheral edge portion 422 of the circular plate portion 42. The second fastening member T has a shaft portion T1 inserted through the through hole 421 and a head portion T2 having a diameter larger than that of the shaft portion T1. The second fastening member T in the embodiment is an external thread having a head portion T2 pressing against the outer surface side of the radiator 4 and an external thread portion (shaft portion T1) screwed to a thread receiving portion U described later. It should be noted that the second fastening member T is not limited to an external thread, and may be, for example, a riveting member. In this case, the head portion T2 may also be formed by riveting one end of the riveting member inserted through the through hole 421, and the shaft portion T1 may be formed at the portion of the riveting member inserted through the through hole 421.

[0096] A plurality of through holes 421 are arranged along the circumferential direction of the circular plate portion 42. In the present embodiment, three are provided at equal angular intervals on the first outer peripheral portion 422. It should be noted that the number and positions of the plurality of through holes 421 provided on the first outer peripheral portion 422 can be appropriately changed. In the present embodiment, a thread receiving portion (receiving portion) U is formed at a position of the opening end portion 101 of the resin outer contour 10 that faces the plurality of through holes 421. In the present embodiment, an internal thread portion that engages with the external thread portion (shaft portion T1) is formed in the thread receiving portion U. The internal thread portion of the thread receiving portion U is formed, for example, by embedding an unillustrated insert nut in the opening end portion 101 of the resin outer contour 10, but is not limited thereto, and a hole having an internal thread portion may be directly formed in the opening end portion 101 of the resin outer contour 10. The heat sink 4 is fixed to the opening end portion 101 of the resin outer contour 10 by a second fastening member T inserted through each of the plurality of through holes 421. At this time, the heat sink 4 is positioned in the circumferential direction with respect to the opening end portion 101 of the resin outer contour 10. Of course, the thread receiving portion U is not limited to being provided at the opening end portion 101. For example, the thread receiving portion U may be provided on the outer peripheral surface 10A side of the resin outer contour 10 separately.

[0097] As Figure 4 shown, when viewed axially, the shape of the plurality of through holes 421 is a long hole shape with the circumferential direction of the circular plate portion 42 as the length direction. In the present embodiment, the shapes of all the plurality of through holes 421 are long hole shapes, but of course are not limited thereto. For example, one of the plurality of through holes 421 may be circular.

[0098] In addition, the shape of the plurality of through holes 421 is not limited to a long hole shape with the circumferential direction as the length direction, and may also be a long hole shape with the radial direction as the length direction. Moreover, the shape of the plurality of through holes 421 is not limited to a long hole shape, and as long as at least one has a region V that does not overlap with the shaft portion T1 (external thread portion) of the second fastening member T when viewed axially, it may be circular, for example.

[0099] In addition, the first angle θ1 of the circumferential movement of the plurality of through holes 421 and the second angle θ2 at which the front end surface 441 can face the electronic component 51 when the front end surface 441 moves will be described.

[0100] The first angle θ1 means the angle formed by a first straight line S1 that connects the through hole end portion 421A (end) on one side in the circumferential direction of the plurality of through holes 421 to the rotation center C of the rotation shaft 6 and a second straight line S2 that connects the shaft end portion T11 (end) on one side in the circumferential direction of the shaft portion T1 (external thread portion) of the second fastening member T to the rotation center C.

[0101] In addition, the second angle θ2 refers to the angle formed by a third straight line S3, which connects the second end portion 443 (end) on one circumferential side of the front end face 441 of the protruding portion 44 to the rotation center C, and a fourth straight line S4, which connects the circumferential end portion 511C (end) on one circumferential side of the electronic component 51 to the rotation center C.

[0102] Herein, the through-hole end portion 421A refers to the end portion provided in the region V side that does not overlap with the shaft portion T1 (external thread portion) of the second fastening member T in the circumferential direction. In addition, as Figure 6 shown, the circumferential end portion 511C refers to the end portion located on the outermost peripheral edge portion L0 of the electronic component 51 (component main body 510) and closest to the second region side in the circumferential direction.

[0103] Moreover, the relationship between the first angle θ1 formed by the first straight line S1 and the second straight line S2 and the second angle θ2 formed by the third straight line S3 and the fourth straight line S4 satisfies the following formula 1.

[0104] It may also satisfy θ1 < θ2 (Formula 1) Hereinafter, the first bearing housing portion 41, the fin portion 45, and the first restricting portion 46 provided on the outer surface portion 423 of the circular plate portion 42 will be described.

[0105] The fin portion 45 is provided on the outer surface portion 423 of the circular plate portion 42, protrudes in the axial direction, and extends in the radial direction. The fin portion 45 includes a plurality of fins and is arranged radially around the central hole 40 of the circular plate portion 42.

[0106] The radiator 4 transfers the heat generated by the electronic component 51 to the fin portion 45 via the above-mentioned protruding portion 44, and further dissipates the heat to the outside of the motor 1 via the fin portion 45. In the present embodiment, on this basis, the cooling effect of the motor 1 can be further improved by the air flowing between the plurality of fins provided in the fin portion 45 outside the motor 1. It should be noted that the material of the fin portion 45 is not limited to aluminum, and materials suitable for heat dissipation fins such as aluminum alloy and magnesium alloy can be appropriately selected.

[0107] The first bearing housing portion 41 houses the first bearing 71, which rotatably supports the rotating shaft 6. The first bearing housing portion 41 has a cylindrical shape centered on the axis C and through which the rotating shaft 6 passes, and houses the first bearing 71. In the present embodiment, the first bearing 71 housed in the first bearing housing portion 41 is provided at a position higher than the protruding height of the fin portion 45 in the axial direction.

[0108] On the outer peripheral surface of the first bearing housing portion 41, first concave portions 411a and first convex portions 412a are alternately provided in the circumferential direction. A first vibration-proof member 12a (described later) that engages with the first concave portions 411a and the first convex portions 412a is mounted on the outer peripheral surface of the first bearing housing portion 41. In the present embodiment, the first concave portions 411a and the first convex portions 412a are formed along the axial direction to both axial ends of the outer peripheral surface of the first bearing housing portion 41, but are not limited thereto, and the first concave portions 411a and the first convex portions 412a may also be formed along the axial direction of the outer peripheral surface of the first bearing housing portion 41 on a part of the axial direction of the outer peripheral surface of the first bearing housing portion 41.

[0109] The first restricting portion 46 is provided on the outer surface portion 423 side of the radiator 4 and has a first restricting surface 46A that contacts the first vibration-proof member 12a (described later). The first restricting surface 46A restricts the first vibration-proof member 12a from moving toward the fin portion 45 side. In the present embodiment, the first restricting surface 46A is axially disposed between the first vibration-proof member 12a and the fin portion 45, and as described above, a given gap H1 is formed between the first vibration-proof member 12a and the fin portion 45.

[0110] The first restricting portion 46 is an annular shape that surrounds the first bearing housing portion 41 with the axis C as the center. The given gap H1 means that as long as the first vibration-proof member 12a does not contact the fin portion 45 when an external force acting on the first vibration-proof member 12a toward the fin portion 45 side in the axial direction is applied, for example, it is 2 mm.

[0111] (Vibration-proof member) Figure 9 is a perspective view of the vibration-proof member 12 viewed from the upper surface side, Figure 10 is a perspective view of the vibration-proof member 12 viewed from the lower surface side.

[0112] The vibration-proof member 12 has a first vibration-proof member 12a mounted on the radiator 4 side and a second vibration-proof member 12b mounted on the bottom 102 side of the resin outer contour 10. In the present embodiment, by making the first vibration-proof member 12a and the second vibration-proof member 12b into members having the same shape, the two vibration-proof members 12a and 12b can be installed without distinction. It should be noted that the shapes of the first vibration-proof member 12a and the second vibration-proof member 12b may also be different.

[0113] The vibration-proof member 12 is, for example, vibration-proof rubber and uses a material having excellent absorbability of vibration energy.

[0114] As Figure 9 , Figure 10As shown, the first vibration isolator 12a has a hollow cylindrical shape. On the inner circumferential side of the first vibration isolator 12a, a first engaging convex portion 121a that engages with the first concave portion 411a of the first bearing housing portion 41 and a first engaging concave portion 122a that engages with the first convex portion 412a of the first bearing housing portion 41 are formed. In addition, on the lower surface 123a of the first vibration isolator 12a, an annular first contact portion 124a that protrudes from the lower surface 123a toward the fin portion 45 is formed. Here, the lower surface 123a of the first vibration isolator 12a refers to the surface on the fin portion 45 side in a state where the first vibration isolator 12a is installed in the first bearing housing portion 41 of the radiator 4.

[0115] By the first contact portion 124a contacting the above-described first restricting surface 46A, the first vibration isolator 12a is axially positioned with respect to the radiator 4. Thus, not only by the first restricting portion 46 formed on the radiator 4 side but also by the first contact portion 124a formed on the first vibration isolator 12a side, a gap can be formed between the lower surface 123a of the first vibration isolator 12a and the fin portion 45. In addition, in the present embodiment, the first contact portion 124a that protrudes from the lower surface 123a toward the fin portion 45 is formed in an annular shape that is continuous in the circumferential direction, but it is not limited thereto, and it may be formed in such a manner that a plurality of protrusions are arranged in an annular shape in the circumferential direction.

[0116] A first mounting metal member G1 is mounted on the outer circumferential surface of the first vibration isolator 12a. For the first mounting metal member G1, for example, a fixing member (not shown) for fixing to an air duct or the like is mounted.

[0117] As Figure 9 、 Figure 10 shown, the second vibration isolator 12b has a hollow cylindrical shape. On the inner circumferential side of the second vibration isolator 12b, a second engaging convex portion 121b that engages with the second concave portion 1021a of the cylindrical portion 102a formed in the resin outer contour 10 and a second engaging concave portion 122b that engages with the second convex portion 1022a of the cylindrical portion 102a are formed.

[0118] In addition, on the lower surface 123b of the second vibration isolator 12b, an annular second contact portion 124b that protrudes from the lower surface 123b toward the bottom portion 102 of the resin outer contour 10 is formed. Here, the lower surface 123b of the second vibration isolator 12b refers to the surface on the bottom portion 102 side in a state where the second vibration isolator 12b is installed in the cylindrical portion 102a of the resin outer contour 10.

[0119] The second contact portion 124b contacts the bottom portion 102 of the resin outer contour 10, and the second vibration isolator 12b is axially positioned with respect to the resin outer contour 10.

[0120] On the outer peripheral surface of the second vibration-proof member 12b, a second mounting metal fitting G2 is similarly mounted as in the case of the first vibration-proof member 12a. For the second mounting metal fitting G2, for example, a fixing member (not shown) for fixing to an air duct or the like is mounted. By mounting the fixing member to the above-described first mounting metal fitting G1 and second mounting metal fitting G2, the motor 1 is fixed to an air duct or the like.

[0121] Figure 11 is a perspective view of the metal member 11, Figure 12 is a side view of the metal member 11.

[0122] (Metal member) As Figure 1 、 Figure 2 、 Figure 11 、 Figure 12 shown, the metal member 11 is formed in a bent shape along from the inner peripheral surface 10B of the resin outer contour 10 to the outer shape of the bottom portion 102. The metal member 11 is housed in the above-described groove portion 10b.

[0123] The metal member 11 is formed, for example, by processing a conductive metal material (such as SUS304 of stainless steel) into a strip shape. It should be noted that the metal member 11 may also be formed of an alloy.

[0124] In addition, as Figure 11 、 Figure 12 shown, the metal member 11 has a first metal portion 11A, a second metal portion 11B, a third metal portion 11C, and a fourth metal portion 11D.

[0125] The first metal portion 11A is arranged along the axial direction on the outer peripheral surface 10A of the resin outer contour 10 and is housed in the first groove portion 101b. In the present embodiment, the first groove portion 101b is located between two outer peripheral surface convex portions 10a adjacent in the circumferential direction on the outer peripheral surface 10A of the resin outer contour 10.

[0126] The second metal portion 11B is continuous with the first metal portion 11A on the opening end portion 101 side and is arranged along the radial direction of the resin outer contour 10 on the opening end portion 101 and is housed in the second groove portion 102b.

[0127] The third metal portion 11C is continuous with the second metal portion 11B and is arranged along the axial direction on the inner peripheral surface 10B of the resin outer contour 10 and is housed in the third groove portion 103b.

[0128] The fourth metal portion 11D is continuous with the first metal portion 11A and contacts the second bearing housing portion 82. The fourth metal portion 11D is arranged along the radial direction on the bottom portion 102 and is housed in the fourth groove portion 104b.

[0129] In the present embodiment, by housing the metal member 11 (the first metal part 11A to the fourth metal part 11D) in the corresponding groove parts 10b (the first groove part 101b to the fourth groove part 104b) formed in the resin outer contour 10, it is possible to prevent the metal member 11 from shifting in the circumferential direction and being fixed. In addition, even when the metal member 11 is formed of a plate-like member with a large thickness, it is possible to suppress the metal member 11 from protruding from the outer peripheral surface of the resin outer contour 10.

[0130] In addition, in the resin outer contour 10 of the present embodiment, since a plurality of outer peripheral surface convex parts 10a protruding in the outer diameter direction are formed on the outer peripheral surface 10A of the resin outer contour 10 in the circumferential direction, the air flowing outside the motor 1 hardly passes through the portion between the outer peripheral surface convex parts 10a in the outer peripheral surface 10A of the resin outer contour 10. Therefore, in the present embodiment, the first groove part 101b formed on the outer peripheral surface 10A of the resin outer contour 10 is located between two adjacent outer peripheral surface convex parts 10a in the circumferential direction. Thereby, the first metal part 11A of the metal member 11 can be located between two adjacent outer peripheral surface convex parts 10a in the circumferential direction on the outer peripheral surface 10A of the resin outer contour 10, and the heat of the portion where air hardly passes through in the outer peripheral surface 10A of the resin outer contour 10 can be transferred to the radiator 4 via the metal member 11, improving the heat dissipation performance.

[0131] It should be noted that although the case where the first metal part 11A is formed of a strip-shaped plate is illustrated, it is not limited thereto. It may also be a fin shape protruding in the radial direction like the outer peripheral surface convex part 10a of the resin outer contour 10, or a nameplate may be used. In the case of a nameplate, a strip-shaped metal plate connected to the nameplate and extending from both axial ends of the nameplate may also be arranged. Thereby, the surface area at the outer peripheral surface 10A of the resin outer contour 10 can be increased, and thus the heat dissipation performance can be improved.

[0132] In addition, when the first metal part 11A has the same fin shape as the outer peripheral surface convex part 10a of the resin outer contour 10, the surface area at the outer peripheral surface 10A of the resin outer contour 10 can be increased, and thus the heat dissipation performance can be improved.

[0133] In the present embodiment, the second metal part 11B faces the axial positioning part 420 of the radiator 4 at a given interval. In addition, as Figure 1 , Figure 2 shown, when viewed axially, the second metal part 11B is arranged at a position overlapping the fin part 45. The given interval is not particularly limited, for example, it is 0.3 mm.

[0134] The third metal part 11C has an elastic contact part 111C that is in thermal contact and elastic contact with the annular protrusion 43 (radial positioning part 430). Here, thermal contact (connection) means that heat transfer occurs by thermal conduction between two members in contact (connected) with each other. In addition, when viewed axially, the third metal part 11C is disposed at a position overlapping the fin part 45.

[0135] When the radiator 4 is embedded in the resin outer contour 10, the elastic contact part 111C is pressed into the third groove part 103b on the inner peripheral surface 10B of the resin outer contour 10 through the annular protrusion 43. At this time, the elastic contact part 111C of the metal member 11 is in elastic contact with the radiator 4, and thus a conduction state between the metal member 11 and the radiator 4 can be stably obtained. The length of the third metal part 11C in the axial direction is the same as or substantially the same as the length of the annular protrusion 43 in the axial direction. Although the case where the third metal part 11C is received in the third groove part 103b when being pressed from the annular protrusion 43 toward the inner peripheral surface 10B side of the resin outer contour 10 is illustrated, it is not limited thereto, and a part of the elastic contact part 111C may protrude in the inner diameter direction from the third groove part 103b.

[0136] The fourth metal part 11D is provided on the first metal part 11A on the bottom 102 side of the resin outer contour 10, and has a bent part 111D continuous with the first metal part 11A and a straight part 112D continuous with the bent part 111D and extending in the inner diameter direction.

[0137] The bent part 111D is formed in a shape that bends along the bottom 102. The bent part 111D has elasticity considering the installation on the resin outer contour 10. In addition, the straight part 112D has a fastening hole 113D and a discrimination hole 114D. When viewed axially, the fastening hole 113D is disposed at a position overlapping the through hole 1041b of the fourth groove part 104b and the flange hole 822a of the second bearing housing part 82. The discrimination hole 114D is located at a position closer to the bent part 111D side than the fastening hole 113D. Moreover, through the first fastening member N, the fastening hole 113D and the flange hole 822a are fastened via the through hole 1041b. In addition, the discrimination hole 114D is a hole for identifying the metal member 11 installed in the motor 1 of the present embodiment and the metal members for other motors.

[0138] Thus, the first bearing housing part 41 disposed on the radiator 4 and the second bearing housing part 82 disposed on the resin outer contour 10 are electrically connected.

[0139] (Function of the metal member) When the electric motor 1 is driven by an inverter in a PWM method that performs high-frequency switching, since the first bearing housing portion 41 and the second bearing housing portion 82 are not electrically conductive, a potential difference (shaft voltage) is generated between the inner ring 712 and the outer ring 711 of the first bearing 71 and between the inner ring 812 and the outer ring 811 of the second bearing 81, respectively.

[0140] If this shaft voltage reaches the breakdown voltage of the oil film inside the bearing, current will flow inside the bearing and cause electrical erosion to the bearing. Electrical erosion is a phenomenon in which the bearing is damaged due to discharge (spark) generated when the shaft voltage between the inner ring 712 and the outer ring 711 of the first bearing 71 and between the inner ring 812 and the outer ring 811 of the second bearing 81 is high. If electrical erosion occurs in the bearing, due to the damage generated on the rolling surface of the bearing, noise will be generated during the rotation of the bearing, or the rotational efficiency of the electric motor will be reduced.

[0141] By making the first bearing housing portion 41 that houses the first bearing 71 and the second bearing housing portion 82 that houses the second bearing 81 conductive, the metal member 11 can make the potentials of the outer rings 711 and 811 of the first bearing 71 and the second bearing 81 the same potential. By relatively reducing the potential difference between the inner and outer rings of each bearing, the generation of electrical erosion can be suppressed. In the present embodiment, by bringing the third metal portion 11C, which is one end side of the metal member 11, into contact with the first bearing housing portion 41 (radiator 4), and bringing the fourth metal portion 104b, which is the other end side of the metal member 11, into contact with the second bearing housing portion 82, the first bearing housing portion 41 and the second bearing housing portion 82 are made conductive.

[0142] In addition, the heat generated by the stator 2 is transferred from the first metal portion 11A disposed on the outer peripheral surface 10A of the resin outer contour 10 to the third metal portion 11C, and is dissipated via the fin portion 45 from the annular protrusion 43 in thermal contact with the third metal portion 11C. Thus, the heat generated by the coil 22 heated by energization and the heat generated by the stator core 21 can be transferred to the radiator 4 having the fin portion 45 with high heat dissipation performance, and therefore the heat dissipation characteristics of the motor 1 can be improved. As an example, in the present embodiment, the thermal conductivity of the BMC as the material of the resin outer contour 10 is about 0.9 (W / m·K), while the thermal conductivity of the stainless steel (SUS304) as the material of the metal member 11 is about 16.7 (W / m·K). The thermal conductivity of the metal member 11 is more than 10 times higher than that of the resin outer contour 10. Further, the thermal conductivity of the aluminum alloy (e.g., ADC12) as the material of the radiator 4 is about 96 (W / m·K). Therefore, the thermal conductivity of the radiator 4 is more than 100 times higher than that of the resin outer contour 10. Thus, in the present invention, the heat generated by the stator 3 can be transferred to the radiator 4 with higher thermal conductivity via the metal member 11 having a higher thermal conductivity than that of the resin outer contour 10, and the heat dissipation characteristics of the motor 1 can be improved.

[0143] The second metal portion 11B faces the axial positioning portion 420 of the radiator 4 at a given interval, but is not limited thereto, and it may also be in contact with the axial positioning portion 420. In this case, the heat generated by the stator 2 is transferred to the fin portion 45 via the axial positioning portion 420, the heat of the fin portion 45 is transferred in the inner diameter direction, and the transferred heat is radially diffused to the plurality of fin portions 45 for heat dissipation. Thus, not only the annular protrusion 43 can be used, but also the entire radiator 4 can be used to release the heat generated by the stator 2, and therefore the heat dissipation characteristics of the motor 1 can be improved.

[0144] In addition, since the first groove portion 101b is provided on the outer peripheral surface 10 of the resin outer contour 10, as Figure 2 shown, the distance between the stator 2 and the first metal portion 11A becomes shorter, and thus it is easier to release the heat generated by the stator 2.

[0145] Furthermore, since the bent portion 111D of the fourth metal portion 11D has elastic characteristics, when the metal member 11 and the resin outer contour 10 are installed, they can be installed in such a way as to increase the contact area (contact density) between the first metal portion 11A and the first groove portion 101b. Therefore, it is easy to release the heat generated by the stator 2 via the first metal portion 11A.

[0146] [Function of radiator] As described above, the radiator 4 of the present embodiment has: an axial positioning portion 420 that abuts against the opening end portion 101 of the resin outer contour 10; and a radial positioning portion 430 that abuts against the inner peripheral surface of the opening end portion 101 of the resin outer contour 10. Therefore, when assembling the radiator 4 to the resin outer contour 10, the radiator 4 is positioned in the axial and radial directions with respect to the resin outer contour 10.

[0147] More specifically, an axial positioning portion 420 for positioning the relative position of the radiator 4 in the axial direction (the position of the radiator 4 in the axial direction with respect to the resin outer contour 10) is provided on the radiator 4, and a front end surface 441 of a protrusion 44 for positioning the relative position of the radiator 4 in the axial direction with respect to the electronic component 51 of the circuit board 5 (the position of the radiator 4 in the axial direction with respect to the electronic component 51) is provided on the radiator 4. Therefore, the accuracy of the relative position of the radiator 4 in the axial direction with respect to the resin outer contour 10 is ensured. Thereby, it is possible to prevent excessive pressure from being applied to the electronic component 51, and it is possible to stably transfer heat from the electronic component 51 to the radiator 4 and sufficiently dissipate heat to the outside of the motor 1.

[0148] In addition, by forming the radial positioning portion 430 on the radiator 4, it is possible to reduce the deviation of the relative positions of the components (the position of another component with respect to the position of one component) generated during the radial assembly of the radiator 4 and the resin outer contour 10. Therefore, the front end surface 441 of the protrusion 44 of the radiator 4 can be opposed to the electronic component 51 fixed on the circuit board 5 of the resin outer contour 10 with good accuracy in the axial direction. Thereby, even if there is a deviation in the relative position, it is possible to ensure the area where the electronic component 51 and the front end surface 441 are opposed in the axial direction required for dissipating the heat generated by the electronic component 51. Therefore, the heat generated by the electronic component 51 can be sufficiently dissipated to the outside of the motor 1.

[0149] In the present embodiment, a ring-shaped protrusion 43 (step) is provided on the circular plate portion 42 of the radiator 4, and the radiator 4 is positioned in the radial direction with respect to the resin outer contour 10 by the outer peripheral surface of the ring-shaped protrusion 43 (step), that is, the radial positioning portion 430, abutting against the inner peripheral surface 10B of the resin outer contour 10. That is, the step provided on the circular plate portion 42 functions as the radial positioning portion 430.

[0150] In addition, when viewed axially, the front end face 441 of the protrusion 44 has a first region W1 facing the electronic component 51 and a second region W2 not facing the electronic component 51, and the second region W2 is adjacent to at least one side in the circumferential direction of the first region W1. Thus, when assembling the heat sink 4 to the resin outer contour 10 by the second fastening member T, even if the heat sink 4 is offset in the circumferential direction due to dimensional deviation (moving the heat sink 4 in the circumferential direction such that the thread receiving portion U and the plurality of through holes 421 are axially opposed), the electronic component 51 still faces the front end face 441. Therefore, even in the presence of dimensional deviation, the area where the electronic component 51 and the front end face 441 are axially opposed can be ensured. Thus, the heat generated by the electronic component 51 can be stably dissipated.

[0151] In addition, the front end face 441 of the protrusion 44 is fan-shaped with a width L having a given length LR or more in the radial direction. Thus, even if the heat sink 4 moves in the circumferential direction, when viewed axially, the front end face 441 still faces the electronic component 51, and therefore the heat generated by the electronic component 51 can be stably dissipated.

[0152] In the embodiment, the given length LR is the length obtained by subtracting the distance L2 from the distance L1. That is, the radial width L of the front end face 441 in the embodiment is L ≥ LR = L1 - L2. Thus, even if the heat sink 4 moves in the circumferential direction, when viewed axially, the entire upper surface of the component body 510 of the electronic component 51 still faces the front end face 441, and therefore the heat generated by the electronic component 51 can be stably dissipated.

[0153] In addition, the second angle θ2 formed by the third straight line S3 and the fourth straight line S4 is an angle greater than the first angle θ1 formed by the first straight line S1 and the second straight line S2. Therefore, even if the heat sink 4 is moved in the circumferential direction such that the thread receiving portion U and the plurality of through holes 421 are axially opposed, the front end face 441 of the protrusion 44 converges within the range facing the component body 510 of the electronic component 51, and therefore the heat generated by the electronic component 51 can be stably dissipated.

[0154] In addition, at least one of the plurality of through holes 421 has a region V that does not overlap with the shaft portion T1 (external thread portion) of the second fastening member T when viewed axially. Therefore, even when dimensional deviation occurs in the plurality of through holes 421 or the thread receiving portion U, the shaft portion T1 (external thread portion) of the second fastening member T can pass through the through hole 421 in a state where the central axis of the second fastening member T is offset and coincides with the central axis of the thread receiving portion U of the resin outer contour 10, and the heat sink 4 and the resin outer contour 10 can be easily fastened by the second fastening member T.

[0155] Further, since the plurality of through holes 421 are in the shape of long holes with the circumferential direction as the length direction, even when dimensional deviations occur in the plurality of through holes 421 or the thread receiving portion U, the shaft portion T1 (external thread portion) of the second fastening member T can pass through the through holes 421 in a state where the central axis of the second fastening member T is offset in the circumferential direction to coincide with the central axis of the thread receiving portion U of the resin outer contour 10, and the radiator 4 can be fastened to the resin outer contour 10 by the second fastening member T. At this time, the front end surface 441 of the radiator 4 is offset in the circumferential direction, but since the front end surface 441 is formed along the circumferential direction, this offset can be absorbed. Absorbing the offset means that even if the front end surface 441 moves in the circumferential direction, the front end surface 441 still faces the electronic component 51. Thus, the heat generated by the electronic component 51 can be stably dissipated.

[0156] In addition, since the overall shape of the radiator 4 is substantially circular plate-shaped, the plurality of through holes 421 formed in the radiator 4 are formed with relatively high positional accuracy in the radial direction. Therefore, as described above, a ring-shaped protrusion 43 (step) is provided on the circular plate portion 42 of the radiator 4, and the outer peripheral surface (radial positioning portion 430) of the ring-shaped protrusion 43 (step) abuts against the inner peripheral surface 10B of the resin outer contour 10, so that the radiator 4 can be positioned in the radial direction relative to the resin outer contour 10. Even if the plurality of through holes 421 of the radiator 4 are not enlarged in the radial direction, the through holes 421 can be axially opposed to the thread receiving portion U of the resin outer contour 10.

[0157] In addition, since the front end surface 441 of the protrusion 44 has a second region W2 adjacent to at least one side in the circumferential direction of the first region W1, even if the arrangement of the electronic component 51 changes due to design or the like, it is not necessary to redesign the front end surface 441 of the radiator 4 based on this arrangement again. That is, the change in the arrangement of the electronic component 51 can be accommodated by the second region W2. Thus, it is not necessary to manufacture the radiator 4 separately according to the arrangement of the electronic component 51 (the number of molds can be reduced), so the manufacturing cost can be suppressed.

[0158] In addition, the movement of the first vibration-proof member 12a in the axial direction toward the fin portion 45 side is restricted by the first restricting surface 46A of the first restricting portion 46, so that a given gap H1 is formed between the lower surface 123a of the first vibration-proof member 12a and the fin portion 45 in the axial direction. Thereby, the situation where the fin portion 45 is covered by the first vibration-proof member 12a and the heat dissipation from the fin portion 45 is blocked by the first vibration-proof member 12a can be suppressed, and the heat dissipation performance can be improved. Further, by forming the above-mentioned given gap H1, it is possible to prevent the first mounting metal member G1 mounted on the outer peripheral surface of the first vibration-proof member 12a from contacting the fin portion 45 of the radiator 4. Thus, it is possible to prevent breakage caused by the direct contact between the first mounting metal member G1 and the radiator 4, both of which are made of metal.

[0159] In addition, in the present embodiment, the thickness of the circular plate portion 42 of the radiator 4 is 3 mm or more. Therefore, when the accuracy of the position where the through hole 421 is formed in the cross section perpendicular to the axial direction is low, it may be difficult to insert the shaft portion T1 of the fastening member T. However, as described above, since the front end surface 441 of the protrusion 44 has the second region W2 adjacent to at least one side in the circumferential direction of the first region W1, by moving the radiator 4 in the circumferential direction such that the thread receiving portion U and the plurality of through holes 421 are axially opposed to each other, the shaft portion T1 can be inserted through the through hole 421.

[0160] In addition, in the present embodiment, since the radiator 4 is formed of aluminum, aluminum alloy, or magnesium alloy, the dimensional accuracy of the shape may be reduced due to the formation of the radiator 4 by die casting or the like, and it may be difficult to insert the shaft portion T1 of the fastening member T. However, as described above, since the front end surface 441 of the protrusion 44 has the second region W2 adjacent to at least one side in the circumferential direction of the first region W1, by moving the radiator 4 in the circumferential direction such that the thread receiving portion U and the plurality of through holes 421 are axially opposed to each other, the shaft portion T1 can be inserted through the through hole 421.

[0161] <Variation Example> In each of the above embodiments, the metal member 11 is formed so as to extend from the outer peripheral surface 10A of the resin outer contour 10 along the opening end portion 101 and along the inner peripheral surface 10B of the resin outer contour 10. However, of course, it is not limited thereto, and it may be directly mounted on the radiator 4. That is, it may be a structure in which the metal member 11 disposed on the outer peripheral surface 10A of the resin outer contour 10 extends in the axial direction and contacts the outer surface portion 423 of the radiator 4. In addition, in the present embodiment, the metal member 11 is single, but the metal member 11 may also be plural, whereby the heat dissipation performance can be improved.

[0162] Moreover, in the present embodiment, the metal member 11 is in direct contact with the resin outer contour 10. However, it is not limited thereto, and it may be thermally connected to the resin outer contour 10 via an adhesive or the like having excellent thermal conductivity.

[0163] Explanation of Reference Numerals 1 Electric motor 2 Stator 21 Stator core 3 Rotor 31 Permanent magnet portion 32 Outer peripheral side core 33 Insulating member 34 Inner peripheral side core 4 Radiator 41 First bearing housing portion 42 Circular plate portion 420 Axial positioning portion 43 Annular protrusion (step) 430 Radial positioning portion 44 Protrusion 441 Front end face 5 Circuit board 51 Electronic component 52 Heat transfer member 6 Rotating shaft 10 Resin outer contour 101 Open end C Axis center.

[0164] T Second fastening member (external thread) T1 Shaft portion (external thread portion) T2 Head U Receiving portion (internal thread portion) W1 First region W2 Second region.

Claims

1. An electric motor comprising: A cylindrical resin outer profile having an open end at one end side in the axial direction; a stator having a winding and a stator core formed integrally with the outer contour of the resin; a rotor having a rotation axis extending in the axial direction and arranged on the inner diameter side of the stator; a metal heat sink covering the open end of the resin outer profile; and A circuit board is arranged in an internal space surrounded by the resin outer frame and the heat sink and has electronic components. In the electric motor, The heat sink includes a disk portion and a protrusion protruding from the disk portion toward the electronic component. The circular plate portion has a plurality of through holes through which a fastening member is inserted, the fastening member fastens the heat sink to the resin outer shell, and the plurality of through holes are arranged along the circumferential direction of the circular plate portion. The protrusion has a planar front end surface that is in thermal contact with the electronic component. When viewed in the axial direction, the front end surface includes a first region facing the electronic component and a second region not facing the electronic component, and the second region is adjacent to at least one side of the first region in the circumferential direction of the disk portion.

2. The electric motor according to claim 1, wherein: When viewed from the axial direction, the front end surface has a fan shape having a width greater than a given length in a radial direction orthogonal to the axial direction.

3. The electric motor according to claim 2, wherein: The given length is the length obtained by subtracting the distance L2 from the distance L1 in a cross section orthogonal to the axial direction, wherein the distance L1 is the distance from the rotation center of the rotation axis to the outermost diameter portion of the outer peripheral edge portion of the electronic component opposite to the first region, which is located on the outermost diameter side, and the distance L2 is the distance from the rotation center of the rotation axis to the innermost diameter portion of the outer peripheral edge portion of the electronic component opposite to the first region, which is located on the innermost diameter side.

4. The electric motor according to claim 1, wherein: The fastening member includes a shaft portion inserted into the through hole and a head portion having a diameter larger than a diameter of the shaft portion. At least one through-hole among the plurality of through-holes has a region that does not overlap with the shaft portion of the fastening member when viewed from the axial direction.

5. The electric motor according to claim 4, wherein: In a cross section perpendicular to the axial direction, at least one through-hole among the plurality of through-holes is in the shape of an elongated hole whose longitudinal direction is the circumferential direction of the circular plate portion.

6. The electric motor according to claim 5, wherein: A step is provided on the circular plate portion of the radiator, The step is brought into contact with the inner diameter side surface of the opening end portion of the resin outer shell, so that the heat sink is positioned in the radial direction relative to the resin outer shell.

7. The electric motor according to any one of claims 4 to 6, wherein: When a straight line connecting one end of the through hole on one side in the circumferential direction and the rotation center of the rotating shaft is set as a first straight line (S1), a straight line connecting one end of the shaft portion on one side in the circumferential direction and the rotation center is set as a second straight line (S2), an angle formed by the first straight line (S1) and the second straight line (S2) is set as a first angle θ1, a straight line connecting one end of the front end surface of the protrusion on one side in the circumferential direction and the rotation center is set as a third straight line (S3), a straight line connecting one end of the electronic component on one side in the circumferential direction and the rotation center is set as a fourth straight line (S4), and an angle formed by the third straight line (S3) and the fourth straight line (S4) is set as a second angle θ2, satisfy θ1<θ2 (Formula 1).

8. The electric motor according to claim 1, wherein: The disc portion has a thickness of 3 mm or more in the axial direction.

9. The electric motor according to claim 8, wherein: The heat sink is formed of aluminum or an aluminum alloy or a magnesium alloy.

10. The electric motor according to claim 1, wherein The resin outer shell has a receiving portion that receives a fastening member inserted through the circular plate portion.

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