motor

Abstract

Provided is a motor in which heat generated by a stator and a rotor is hardly transmitted to a circuit board, and easily dissipated from the circuit board to a bracket.　The present invention comprises: a shaft (1); a rotor (2) that is fixed to the shaft (1); a stator (3) that is positioned on the outer circumferential side of the rotor (2); a housing plate (5) that holds a bearing (4a) rotatably supporting the shaft (1) and covers one end of the shaft (1) in the axial direction; a circuit board (6) that is in contact with the housing plate (5); and a bracket (7) that is disposed, on the side of one end of the shaft (1) in the axial direction, on the outside of the circuit board (6) in the axial direction. The circuit board (6) comprises an IC chip (61) and is disposed between the housing plate (5) and the bracket (7), and the IC chip (61) is thermally connected to the bracket (7) via a heat transfer member (8).

Description

motor

[0001] The present disclosure relates to a motor.

[0002] Conventionally, motors incorporating a circuit board that controls the current flowing through a stator have been known. In conventional motors, for example, the circuit board is directly connected to the stator terminals and supported in a cantilevered state, with a heat transfer member sandwiched between a cover member of the motor and the circuit board, thereby dissipating heat generated by the circuit board to the outside of the motor (see, for example, Patent Document 1). Another known structure is one in which the circuit board is directly connected to the stator terminals, a heat transfer member is sandwiched between the cover member and the circuit board, and the outer periphery of the circuit board is intermittently supported by the outer edge of the stator (see, for example, Patent Document 2).

[0003] International Publication No. 2019 / 039204 Patent No. 7255621

[0004] In conventional motors, there is nothing separating the stator and rotor from the circuit board, which means that heat generated by the stator and rotor is easily transferred to the circuit board.

[0005] The present disclosure discloses technology for solving the above-mentioned problems, and aims to provide a motor in which heat generated by the stator and rotor is less likely to be transmitted to the circuit board, and in which heat is easily dissipated from the circuit board to the bracket.

[0006] The motor of the present disclosure comprises a shaft, a rotor fixed to the shaft, a stator located on the outer periphery of the rotor, a housing plate that holds a bearing that rotatably supports the shaft and covers one axial end of the shaft, a circuit board abutting the housing plate, and a bracket that is arranged axially outside the circuit board on the side of the one axial end of the shaft, the circuit board comprising an IC chip and being arranged between the housing plate and the bracket, and the IC chip is thermally connected to the bracket via a heat transfer member.

[0007] The motor of the present disclosure comprises a shaft, a rotor fixed to the shaft, a stator located on the outer periphery of the rotor, a housing plate that holds a bearing that rotatably supports the shaft and covers one axial end of the shaft, a circuit board abutting the housing plate, and a bracket that is arranged axially outside the circuit board on the side of one axial end of the shaft, the circuit board having an IC chip and being arranged between the housing plate and the bracket, and the IC chip is thermally connected to the bracket via a heat transfer member, so that heat generated by the stator and rotor is not easily transferred to the circuit board and is easily dissipated from the circuit board to the bracket.

[0008] 1 is a top view of a motor according to embodiment 1. FIG. 2 is a cross-sectional view of the motor according to embodiment 1. FIG. 3 is an exploded perspective view of the motor according to embodiment 1. FIG. 4 is a perspective view showing a stator core, an insulator, a coil, and a stator terminal of the motor according to embodiment 1. FIG. 5 is a bottom view of a stator in embodiment 1. FIG. 6 is a perspective view of a housing plate in embodiment 1. FIG. 7 is a perspective view of a housing plate in embodiment 1. FIG. 8 is a perspective view showing another example of a housing plate in embodiment 1. FIG. 9 is a bottom view of the motor according to embodiment 1. FIG. 10 is a flowchart for explaining an assembly procedure of the motor according to embodiment 1. FIG. 11 is a diagram for explaining material yield of a circuit board in embodiment 1. FIG. 12 is a diagram for explaining material yield of a circuit board in a comparative example. FIG. 13 is another cross-sectional view of the motor according to embodiment 1. FIG. 14 is an enlarged view of an IC chip mounting portion of a circuit board in embodiment 1. FIG. 15 is a top view of a motor according to embodiment 2. FIG. 16 is a cross-sectional view of a motor according to embodiment 2.

[0009] Hereinafter, motors according to embodiments will be described in detail with reference to the drawings. Note that the same reference numerals in the various drawings indicate the same or corresponding parts.

[0010] Embodiment 1. FIG. 1 is a top view of a motor 100 according to embodiment 1 as seen from the output side, and FIG. 2 is a cross-sectional view showing the A-A cross section in FIG. 1. FIG. 3 is an exploded perspective view of the motor 100 according to embodiment 1. FIG. 3 is an exploded perspective view of the motor 100 as seen from the right side in FIG. 2. FIG. 4 is a perspective view of the stator core 31, insulator 32, coils 33, and stator terminals 34 of the motor 100 according to embodiment 1 as seen from the right side in FIG. 2. The motor 100 according to embodiment 1 includes a shaft 1, a rotor 2 fixed to the shaft 1, a stator 3 located on the outer periphery of the rotor 2, bearings 4a and 4b that rotatably support the shaft 1, a housing plate 5 that holds the bearing 4a and covers one end of the shaft 1 in the axial direction, which is the direction in which the rotation axis 11 of the shaft 1 extends, a circuit board 6 abutting against the housing plate 5, and a bracket 7 that is arranged axially outside the circuit board 6 on the side of one axial end of the shaft 1. The shaft 1 is covered by a housing plate 5 at one axial end, which is the right end as shown in Fig. 2. The shaft 1 protrudes to the left in Fig. 2, which is the other axial end, and the left side in Fig. 2 is the output side, to which a load is connected depending on the application.

[0011] The stator 3 is located on the outer periphery of the rotor 2 and includes a stator core 31, an insulator 32, a coil 33, and a molded resin 30. The stator core 31 is disposed at a position corresponding to the outer periphery of the rotor 2, and the coil 33 is wound around the stator core 31 via the insulator 32, which is an insulating material. The terminal wire of the wound coil 33 is electrically connected to a stator terminal 34 fixed to the insulator 32. The stator terminal 34 is electrically connected to the circuit board 6. The electrical connection between the stator terminal 34 and the circuit board 6 may be made by soldering or brazing, by mechanical pressing or clamping, or by welding.

[0012] The circuit board 6 controls the current flowing through the coil 33 of the stator 3 and has mounted components. An IC chip 61 is shown as an example of a component that generates a lot of heat, and other components are not shown. In the following description, the IC chip 61 will be described as a mounted component, but the same effects as those of the motor 100 can be achieved even if the IC chip 61 is replaced with another mounted component such as a capacitor. Power and signals are supplied to the circuit board 6 from outside the motor 100 via lead wires 9.

[0013] The stator 3 has a coil 33 wound around a stator core 31 via an insulator 32, and the stator core 31, insulator 32, coil 33, and stator terminal 34 molded together with molded resin 30. That is, the stator 3 has the stator core 31, insulator 32, coil 33, and stator terminal 34 molded together with molded resin 30, and the stator core 31, insulator 32, coil 33, and stator terminal 34 covered with molded resin 30. One end of the stator terminal 34 is connected to the coil 33, and the other end is exposed from the molded resin 30 and connected to the circuit board 6. The molded resin 30 holds the bearing 4b on the output side of the motor 100, i.e., on the left side in FIG. 2, and includes, for example, a housing that fits and supports the bearing 4b. In the following description, the left side in FIG. 2 is the output side, and the right side in FIG. 2 is the non-output side. The molded resin 30 is made of an insulating material, such as BMC (Bulk Molding Compound). BMC has high dimensional stability after molding, and the molded resin 30 made of BMC eliminates the need for machining the housing of the bearing 4b. The molded resin 30 may contain glass fiber depending on the required strength.

[0014] A housing plate 5 is fixed to the molded resin 30 on the non-output side, which is the right side in FIG. 2 . The housing plate 5 can be fixed to the molded resin 30 using a common mechanical fixing method such as press-fitting, adhesive bonding, or screw fastening. The housing plate 5 holds the bearing 4a on the non-output side of the motor 100, i.e., the right side in FIG. 2 , and includes, for example, a housing that fits and supports the bearing 4a. A bracket 7 is fixed to the molded resin 30 at the outermost part on the non-output side, which is the right side in FIG. 2 . The bracket 7 desirably has high heat dissipation performance and is desirably made of a highly thermally conductive material such as an aluminum alloy.

[0015] The circuit board 6 is disposed between the housing plate 5 and the bracket 7. A heat transfer member 8 is sandwiched between the bracket 7 and an IC chip 61 mounted on the circuit board 6, and the heat transfer member 8 is in contact with both the IC chip 61 and the bracket 7. The heat transfer member 8 is made of a soft material with high thermal conductivity, such as a heat dissipation sheet, and is used to absorb unevenness in contacting components, improving adhesion and heat transfer efficiency. The housing plate 5 has board support protrusions 51, which are protrusions that support the circuit board 6, on the surface facing the circuit board 6. The housing plate 5 abuts against the circuit board 6 at the board support protrusions 51. The board support protrusions 51 contact the circuit board 6 on the surface of the circuit board 6 opposite the surface that contacts the heat transfer member 8, thereby suppressing deformation of the circuit board 6. The board support protrusions 51 may be protrusions with a wider contact surface with the circuit board 6. However, if the circuit board 6 is a double-sided mounted board, it is desirable to reduce the area of ​​the contact surface of the board support protrusions 51 with the circuit board 6 and to distribute the board support protrusions 51 in necessary locations in order to avoid contact between the components mounted on the surface facing the housing plate 5 and the board support protrusions 51 and to suppress the transfer of heat from the bearing 4a or stator 3 to the circuit board 6.

[0016] The housing plate 5 is made of, for example, an electrically insulating material, such as resin. If the housing plate 5 is made of metal, the board support projections 51 may be coated with an insulating material, or the board support projections 51 and the housing plate 5 may be in contact with each other via an insulating material, or the surface of the housing plate 5 may be coated with an insulating material. If the housing plate 5 is made of metal, the number of parts or processes will increase, so it is desirable for the housing plate 5 to be made of resin, and like the molded resin 30 of the stator 3, it is desirable for the housing plate 5 to be made of BMC in terms of dimensional stability after molding.

[0017] FIG. 5 is a bottom view of the stator 3 according to the first embodiment, as viewed from the right side in FIG. 2 . Three stator terminals 34 are exposed in the stator 3 in the area where the circuit board 6 is disposed. In the first embodiment, the motor 100 is described as being driven by three phases, so three stator terminals 34 are exposed. However, the number of stator terminals 34 may be two, six, or other numbers depending on the motor configuration. The molded resin 30 of the stator 3 includes a seat 35 for supporting the circuit board 6 in the area where the circuit board 6 is disposed. If the board support protrusions 51 of the housing plate 5 alone can adequately support the circuit board 6, the seat 35 of the molded resin 30 may be omitted. The molded resin 30 of the stator 3 includes a housing plate support protrusion 36 at the portion where the housing plate 5 is attached, which abuts against the circumferential surface of the housing plate 5 to prevent circumferential movement of the housing plate 5. In the motor 100 according to the first embodiment, the housing plate 5 is Y-shaped, as shown in FIG. 3 , for example. The two housing plate support protrusions 36 are arranged to match the circumferential length of the tip portion of the Y-shape of the housing plate 5, and the two housing plate support protrusions 36 clamp the circumferential side surfaces of the tip portion of the Y-shape of the housing plate 5 from both sides, thereby preventing circumferential movement of the housing plate 5. While Fig. 5 shows a structure for supporting the tip portion of the Y-shape of the housing plate 5, the housing plate support protrusions 36 may be provided in a different position as long as it prevents circumferential movement of the housing plate 5. Alternatively, a recess may be provided on the surface of the housing plate 5 facing the molded resin 30, and the housing plate support protrusions 36 may be provided at a corresponding position on the molded resin 30, and the housing plate support protrusions 36 may be fitted into the recess in the housing plate 5 to prevent circumferential movement.

[0018] FIG. 6 is a perspective view of the housing plate 5 according to the first embodiment, as seen from the left side in FIG. 2 . FIG. 7 is a perspective view of the housing plate 5 according to the first embodiment, as seen from the right side in FIG. 2 . The housing plate 5 includes a bearing housing 52 that fits and supports the bearing 4 a in its center. The housing plate 5 includes a fitting portion 53 on the radial outside of the bearing housing 52. The fitting portion 53 is used to align the central axis of the housing plate 5 with the rotation shaft 11 when the housing plate 5 is fixed to the stator 3. The housing plate 5 includes an outermost diameter portion 54, radially outward of the fitting portion 53, for fixing the housing plate 5 to the stator 3. The housing plate 5 shown in the first embodiment is Y-shaped to reduce material usage, and the radial surfaces of the three fitting portions 53 form part of a cylinder. The housing plate 5 has a three-fold rotationally symmetric shape with respect to the central axis that coincides with the rotation axis 11 when the housing plate 5 is fixed to the stator 3, and is shaped so that it overlaps with itself when rotated 120 degrees around the central axis. To facilitate management during assembly of the motor 100, by arranging any one of the three outermost diameter portions 54 in a predetermined position, the board support protrusions 51 are arranged in the same position relative to the stator 3.

[0019] The housing plate 5 is positioned in the axial direction by abutting an abutment surface 56 between the fitting portion 53 and the outermost diameter portion 54 of the housing plate 5 against the stator 3. When the housing plate 5 is press-fitted to the stator 3, the fitting portion 53 and the inner wall of the stator 3 that abuts against the fitting portion 53 may be adjusted to have an interference fit. When the housing plate 5 is fixed to the stator 3 with a screw, a screw hole may be formed in the position of the abutment surface 56 between the fitting portion 53 and the outermost diameter portion 54 of the housing plate 5. When the housing plate 5 is fixed to the stator 3 with an adhesive, the adhesive may be applied to the position of the abutment surface 56 between the fitting portion 53 and the outermost diameter portion 54 of the housing plate 5. The circumferential width of the outermost diameter portion 54 of the housing plate 5 is the same as the distance between two housing plate support protrusions 36 provided on the molded resin 30. By disposing one of the outermost diameter portions 54 between the two housing plate support protrusions 36, circumferential movement of the housing plate 5 is prevented. A plurality of board support protrusions 51 are disposed on the surface of the housing plate 5 facing the circuit board 6. The positions, sizes, and numbers of the board support protrusions 51 are determined based on the layout of the components mounted on the circuit board 6 and the allowable deflection of the circuit board 6 due to the compressive load of the heat transfer member 8. In the first embodiment, the housing plate 5 includes four board support protrusions 51. However, depending on the required specifications, the housing plate 5 may be supported by a seat surface 35 provided on the molded resin 30 and one board support protrusion 51. In the first embodiment, the housing plate 5 has a Y-shape and a rotationally symmetrical, three-fold symmetric shape. However, the housing plate 5 may be X-shaped or disk-shaped depending on the required strength or the arrangement of the board support protrusions 51. In this case, to facilitate management during assembly, it is desirable to use a rotationally symmetrical shape such as four-fold symmetry or two-fold symmetry. Furthermore, if an asymmetrical shape is necessary for reasons of component arrangement or strength, the asymmetry does not impair the thermal insulation effect between the housing plate and the circuit board, which is the main effect of the motor according to the embodiment.

[0020] In the above description, the housing plate 5 has a structure in which the board support protrusions 51 are provided in the portion having the fitting portion 53 and the outermost diameter portion 54. However, a structure in which pedestals having the board support protrusions 51 are added may also be used. FIG. 8 is a perspective view showing another example of a housing plate 5a according to the first embodiment, as seen from the right side of FIG. 2. Compared to the housing plate 5 shown in FIG. 7, the housing plate 5a shown in FIG. 8 has three pedestals 57 added, and a board support protrusion 51 is provided on each pedestal 57. Furthermore, the outer peripheral surface of the outermost diameter portion 54 is provided with positioning recesses 55 having a radially recessed shape. When the housing plate 5a has the positioning recesses 55, instead of providing the housing plate support protrusions 36 in the molded resin 30 of the corresponding stator 3, positioning protrusions having a radially inward convex shape are provided in the molded resin 30 at positions corresponding to the positioning recesses 55. By aligning the positioning recesses 55 with the positioning protrusions during assembly, circumferential movement of the housing plate 5a is prevented.

[0021] FIG. 9 is a bottom view showing the motor 100 according to embodiment 1 before the bracket 7 is attached, with the position of the board support protrusion 51 on the housing plate 5 indicated by a hidden dashed line. In other words, FIG. 9 is a bottom view of the motor 100 according to embodiment 1 as seen from the right side of FIG. 2 , with the bracket 7 omitted. The board support protrusion 51 on the housing plate 5 and the seating surface 35 of the molded resin 30 support the circuit board 6. The board support protrusion 51 and seating surface 35 that support the circuit board 6 are located near the outer edge of the circuit board 6 where no mounted components are located, but may be located within a range that allows for the placement of mounted components or suppression of deflection of the circuit board 6. Furthermore, a connector 62 for connecting lead wires 9 is mounted on the circuit board 6. The board support protrusion 51 can suppress deflection due to the load when inserting the lead wires 9 into the connector 62. In particular, when inserting the lead wires 9 manually, the load applied when inserting varies depending on the worker and is difficult to control, so providing the board support protrusions 51 makes it easier to guarantee the quality of the product.

[0022] The IC chip 61 on the circuit board 6 is thermally connected to the bracket 7 via the heat transfer member 8. The heat transfer member 8 is configured to protrude from the housing plate 5 when viewed in the axial direction. The circuit board 6 is also configured to protrude from the housing plate 5 when viewed in the axial direction. In order to ensure cooling capacity, the heat transfer member 8 must thermally connect the bracket 7 and the IC chip 61 on the circuit board 6, and a pressing force from the bracket 7 is applied to the IC chip 61 and the circuit board 6. In this case, by configuring an imaginary polygon having vertices at the contact points between the circuit board 6 and the board support protrusions 51 so that only a portion of the heat transfer member 8 overlaps with the heat transfer member 8 when viewed in the axial direction, it is possible to apply a pressing force to the heat transfer member 8 while suppressing distortion of the circuit board 6.

[0023] 10 is a flowchart illustrating the assembly procedure for the motor according to embodiment 1. Step S01 is an insulator mounting step, step S02 is a stator terminal mounting step, step S03 is a coil winding step, step S04 is a mold resin sealing step, step S05 is a rotor insertion step, step S06 is a housing plate fixing step, step S07 is a circuit board arrangement step, step S08 is a heat transfer member arrangement step, step S09 is a lead wire connection step, and step S10 is a bracket fixing step. Note that the structure of the rotor 2 is not particularly limited as long as it is a general one, and therefore the steps for assembling the rotor 2 and the steps for fixing the rotor 2 to the shaft 1 are omitted in FIG. 10.

[0024] In step S01, the insulator 32 is attached to the stator core 31, and the process proceeds to step S02. In step S02, the stator terminal 34 is attached to the insulator 32, and the process proceeds to step S03. In step S03, the coil 33 is wound around the stator core 31 via the insulator 32, and the process proceeds to step S04. In step S04, the stator core 31 with the wound coil 33 is placed in a mold for resin molding, and the stator core 31, insulator 32, and coil 33 are sealed with molding resin 30 to create the stator 3, and the process proceeds to step S05. In step S05, the rotor 2 fixed to the shaft 1 is inserted into the stator 3, and the process proceeds to step S06. In step S06, the housing plate 5 is fitted and fixed to the stator 3, and the process proceeds to step S07. In step S07, the circuit board 6 is placed in a predetermined position on the stator 3, and the stator terminal 34 and the circuit board 6 are electrically connected, and the process proceeds to step S08. In step S08, the heat transfer member 8 is placed in a predetermined position on the circuit board 6, and the process proceeds to step S09. In step S09, the lead wires 9 are connected to the connectors 62 of the circuit board 6, and the process proceeds to step S10. In step S10, the bracket 7 is fitted and fixed to the stator 3, and the assembly is completed.

[0025] Regarding the placement of the circuit board 6 in step S07 and the connection of the lead wires 9 in step S09, it is possible to connect the lead wires 9 to the circuit board 6 in advance and then place the circuit board 6 with the lead wires 9 connected in a predetermined position on the stator 3. However, if the circuit board 6 and the lead wires 9 are connected, the lead wires 9 are likely to become tangled around the circuit board 6, which is an assembly of precision components, making storage space and transportation management difficult. Therefore, as shown in FIG. 10 , it is preferable to connect the lead wires 9 after placing the circuit board 6. Even in this case, providing the board support protrusions 51 can suppress deflection due to the load when inserting the lead wires 9 into the connector 62. Furthermore, because the circuit board 6 can be attached after the rotor 2 is inserted, assembly can be performed without worrying about interference between the circuit board 6 and the rotor 2, making assembly easier. Furthermore, because the circuit board 6 can be placed so that it overlaps the rotor 2 and the shaft 1 when viewed axially, the circuit board 6 can be placed with greater flexibility.

[0026] FIG. 11 is a diagram for explaining the material yield of the circuit board 6 in the first embodiment, showing the process of cutting four circuit boards from one rectangular circuit board material. In FIG. 11, the hatched area indicates a circuit board use area 63 used as the circuit board 6, and the blank area indicates a discarded area 64 to be discarded. FIG. 12 is a diagram for explaining the material yield of the circuit board in a comparative example, showing the process of cutting four circuit boards from one rectangular circuit board material, similar to FIG. 11. In FIG. 12, the hatched area indicates a circuit board use area 63a used as the circuit board in the comparative example, and the blank area indicates a discarded area 64a to be discarded. In the comparative example shown in FIG. 12, the ends of the shaft protrude on both sides of the motor in the axial direction, and a hole for passing the shaft through is provided in the center of the circuit board. In the comparative example shown in FIG. 12, because a hole must be provided in the center of the circuit board, the proportion of the discarded area 64a in the circuit board material is large, resulting in a low material yield of the circuit board. In the first embodiment, when viewed in the axial direction, the circuit board 6 can be arranged so that it overlaps the rotor 2 and the shaft 1, which allows for a high degree of freedom in the shape of the circuit board 6, and as shown in FIG. 11 , the proportion of waste area 64 in the circuit board material can be reduced, thereby enabling a high material yield for the circuit board.

[0027] Although the structure shown is such that IC chip 61 is mounted on the right side in FIG. 2 , which is the side opposite to the output side of circuit board 6, and IC chip 61 is in direct contact with heat transfer member 8, IC chip 61 may be mounted on the left side in FIG. 2 , which is the output side of circuit board 6, with heat transfer member 8 in contact with the area on the opposite side of circuit board 6 at the position where IC chip 61 is mounted, and IC chip 61 may be in contact with bracket 7 via circuit board 6 and heat transfer member 8.

[0028] Specifically, as shown in FIG. 13 , which is another cross-sectional view of motor 100 according to embodiment 1, IC chip 61 may be mounted on the output side of circuit board 6, opposite heat transfer member 8, on the left side in FIG. 13 . FIG. 14 is an enlarged view of the mounting portion of circuit board 6 according to embodiment 1, where IC chip 61 is mounted. As shown in FIG. 14 , by providing through holes 65 or via holes 66 in circuit board 6 toward the right side in FIG. 14 , which is the side of circuit board 6 that contacts heat transfer member 8, it is possible to reduce the thermal resistance between IC chip 61 and the right side of circuit board 6, which is the side opposite the output side in FIG. 14 . Furthermore, since the variation in the thickness direction absorbed by heat transfer member 8 can be minimized, the thickness of heat transfer member 8 can be reduced. Furthermore, compared to the motor shown in FIG. 2 , the motor shown in FIG. 13 has a larger contact area between circuit board 6 and heat transfer member 8, which reduces the overall thermal resistance and suppresses temperature rise in circuit board 6. 14, which is the side of the circuit board 6 that contacts the heat transfer member 8, there may be solder 67 or a land 68 around the through hole 65.

[0029] As described above, motor 100 according to embodiment 1 comprises shaft 1, rotor 2 fixed to shaft 1, stator 3 located on the outer periphery of rotor 2, housing plate 5 that holds bearing 4a that rotatably supports shaft 1 and covers one axial end of shaft 1, circuit board 6 abutting housing plate 5, and bracket 7 that is arranged axially outside circuit board 6 on the side of one axial end of shaft 1, circuit board 6 comprising IC chip 61 and arranged between housing plate 5 and bracket 7, and IC chip 61 is thermally connected to bracket 7 via heat transfer member 8. Therefore, heat generated by stator 3 and rotor 2 is not easily transferred to circuit board 6 and is easily dissipated from circuit board 6 to bracket 7.

[0030] Embodiment 2. FIG. 15 is a top view of a motor 100a according to embodiment 2 as seen from the output side, and FIG. 16 is a cross-sectional view showing the B-B cross section in FIG. 15. Comparing the motor 100a according to embodiment 2 with the motor 100 according to embodiment 1, the stator 3 is replaced with a stator 3a. The rest of the configuration of the motor 100a according to embodiment 2 is the same as that of the motor 100 according to embodiment 1. The stator 3a is configured such that a coil 33 is wound around a stator core 31 via an insulator 32, and the outer peripheral surface of the stator core 31 is fixed to a steel plate frame 37. The steel plate frame 37 is fixed to the outer peripheral surface of the stator core 31 by press fitting or shrink fitting. The steel plate frame 37 has a housing that fits and supports the bearing 4b on the left side of FIG. 16 (the output side), and has a contact surface on the inner peripheral side on the right side of FIG. 16 (the non-output side) that positions the housing plate 5 and bracket 7 in the axial direction. The steel frame 37 is formed by deep drawing a sheet metal material such as rolled steel. Instead of the steel frame 37, a frame formed by aluminum die-casting or casting, with machining performed on portions requiring precision fitting or abutment surface accuracy, may be used. A housing plate 5 is disposed on the opposite output side of the stator 3a, and is positioned and fixed by the abutment surface of the steel frame 37. In the motor 100a according to the second embodiment, the shape of the housing plate 5 is the same as that shown in FIGS. 6 and 7 , but the outermost diameter portion 54 of the housing plate 5 is positioned so that the central axis is aligned with the abutment surface on the inner periphery of the steel frame 37. By supporting the stator 3a by the steel frame 37 rather than by covering it with the molded resin 30, the motor 100a is easily disassembled and highly recyclable.

[0031] In the illustrated structure, IC chip 61 is mounted on the right side in FIG. 16 , which is the side opposite to the output side of circuit board 6, and IC chip 61 is in direct contact with heat transfer member 8. However, similar to embodiment 1, IC chip 61 may be mounted on the left side in FIG. 16 , which is the output side of circuit board 6, with heat transfer member 8 in contact with the area on the opposite side of circuit board 6 at the position where IC chip 61 is mounted, and IC chip 61 may be in contact with bracket 7 via circuit board 6 and heat transfer member 8.

[0032] Although various exemplary embodiments are described in this disclosure, the various features, aspects, and functions described in one or more embodiments are not limited to the application of a particular embodiment, but may be applied to the embodiments alone or in various combinations. Therefore, countless variations not illustrated are contemplated within the scope of the technology disclosed in this specification. For example, this includes cases where at least one component is modified, added, or omitted, or where at least one component is extracted and combined with components of another embodiment.

[0033] The above describes in detail preferred embodiments, but the present invention is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments without departing from the scope of the claims.

[0034] Various aspects of the present disclosure are summarized below as appendices.

[0035] (Supplementary Note 1) A motor comprising: a shaft; a rotor fixed to the shaft; a stator located on the outer periphery of the rotor; a housing plate holding a bearing that rotatably supports the shaft and covering one axial end of the shaft; a circuit board abutting the housing plate; and a bracket arranged axially outside the circuit board on the side of the one axial end of the shaft, the circuit board having an IC chip arranged between the housing plate and the bracket, the IC chip abutting the bracket via a heat transfer member. (Supplementary Note 2) The motor according to Supplementary Note 1, wherein the housing plate has board support protrusions and abuts the circuit board at the board support protrusions. (Supplementary Note 3) The motor according to Supplementary Note 1 or 2, wherein the stator has housing plate support protrusions abutting a circumferential surface of the housing plate. (Supplementary Note 4) The motor according to any one of Supplements 1 to 3, wherein the housing plate is made of an insulating material. (Supplementary Note 5) The motor according to Supplementary Note 4, wherein the housing plate is made of BMC. (Supplementary Note 6) The motor according to any one of Supplementary Notes 1 to 5, characterized in that the stator is configured such that a coil is wound around a stator core via an insulator, and the stator core, the insulator, and the coil are covered with a molded resin. (Supplementary Note 7) The motor according to any one of Supplementary Notes 1 to 5, characterized in that the stator is configured such that a coil is wound around a stator core via an insulator, and the outer peripheral surface of the stator core is fixed to a steel plate frame.

[0036] REFERENCE SIGNS LIST 1 shaft, 2 rotor, 3, 3a stator, 4a, 4b bearing, 5, 5a housing plate, 6 circuit board, 7 bracket, 8 heat transfer member, 9 lead wire, 11 rotating shaft, 30 molded resin, 31 stator core, 32 insulator, 33 coil, 34 stator terminal, 35 seat surface, 36 housing plate support protrusion, 37 steel plate frame, 51 board support protrusion, 52 bearing housing, 53 fitting portion, 54 outermost diameter portion, 55 positioning recess, 56 contact surface, 57 base, 61 IC chip, 62 connector, 63, 63a circuit board used area, 64, 64a waste area, 65 through hole, 66 via hole, 67 solder, 68 land, 100, 100a motor.

Claims

1. A motor comprising: a shaft; a rotor fixed to said shaft; a stator located on the outer periphery of said rotor; a housing plate that holds a bearing that rotatably supports said shaft and covers one axial end of said shaft; a circuit board abutting said housing plate; and a bracket that is located on the axial outside of said circuit board on the side of said one axial end of said shaft, wherein said circuit board comprises an IC chip and is located between said housing plate and said bracket, and wherein said IC chip is thermally connected to said bracket via a heat transfer member.

2. The motor according to claim 1, wherein the heat transfer member protrudes from the housing plate when viewed in the axial direction.

3. The motor according to claim 1, wherein the circuit board protrudes from the housing plate when viewed in the axial direction.

4. The motor according to any one of claims 1 to 3, wherein the housing plate is provided with a board support protrusion, and the circuit board abuts against the board support protrusion.

5. The motor according to claim 4, wherein an imaginary polygon having vertices at the contact points between the circuit board and the board support projections overlaps only a portion of the heat transfer member when viewed from the axial direction.

6. A motor according to any one of claims 1 to 5, wherein the housing plate is made of an insulating material.

7. The motor according to claim 6, wherein the housing plate is made of BMC.

8. A motor comprising: a shaft; a rotor fixed to the shaft; a stator located on the outer periphery of the rotor; a housing plate that holds a bearing that rotatably supports the shaft and covers one axial end of the shaft; a circuit board abutting against the housing plate; and a bracket that is arranged axially outside the circuit board on the side of the one axial end of the shaft, wherein the circuit board has an IC chip and is arranged between the housing plate and the bracket, the IC chip abutting against the bracket via a heat transfer member, and the stator has a housing plate support protrusion that abuts against a circumferential surface of the housing plate.

9. The motor according to any one of claims 1 to 8, wherein the IC chip is mounted on the surface of the circuit board opposite to the surface that contacts the heat transfer member.

10. The motor according to claim 9, wherein a through hole or a via hole is arranged in the area of ​​the circuit board where the IC chip is arranged.

11. A motor according to any one of claims 1 to 10, characterized in that the stator comprises a stator core with a coil wound therearound via an insulator, and the stator core, the insulator and the coil are covered with a molded resin.

12. A motor according to any one of claims 1 to 10, characterized in that the stator comprises a stator core with a coil wound therearound via an insulator, and the outer circumferential surface of the stator core is fixed to a steel plate frame.

Images