WO2019064899A1

WO2019064899A1 - Motor

Info

Publication number: WO2019064899A1
Application number: PCT/JP2018/028639
Authority: WO
Inventors: 小川　裕史; 佳明山下
Original assignee: 日本電産株式会社
Priority date: 2017-09-29
Filing date: 2018-07-31
Publication date: 2019-04-04
Also published as: JPWO2019064899A1; CN111033975B; CN111033975A

Abstract

Provided is a motor having: a motor body including a rotor which rotates about a center axis extending vertically and a stator which is located radially outside the rotor; a circuit board which is located at the upper side of the motor body and which extends in the direction orthogonal to the center axis; and a heat sink which is located at the lower side of the circuit board and which directly or indirectly contacts the circuit board. The circuit board includes a board body and a first heat-generating element mounted on the lower surface of the board body. The heat sink includes: a heat sink body part extending along the circuit board; a motor body housing part which houses the motor body; and an element housing part which houses the first heat-generating element. The motor body housing part and the element housing part separately extend downward from the heat sink body part, and the heat sink body part includes a rib located between the motor body housing part and the element housing part.

Description

motor

The present invention relates to a motor.

It is known to provide a heat sink for cooling a circuit board in a motor-integrated motor including a circuit board for controlling the motor body. Patent Document 1 discloses a structure in which a stepped storage portion for housing a capacitor which is a mounting component of a circuit board is provided inside a heat sink.

JP, 2013-062959, A

Conventional heat sinks have a problem in that they have a low function of releasing the heat absorbed from the circuit board and its mounting components to the outside.

SUMMARY OF THE INVENTION In view of the above-described problems, one aspect of the present invention aims to provide a motor with an improved heat dissipation effect of a heat sink.

One aspect of the motor according to the present invention is a motor main body having a rotor rotating about a central axis extending along the vertical direction and a stator located radially outward of the rotor, and located above the motor main body A circuit board extending in a direction orthogonal to a central axis, and a heat sink located on the lower side of the circuit board and in direct or indirect contact with the circuit board, the circuit board includes a substrate body, and the substrate And a first heat generating element mounted on the lower surface of the main body, wherein the heat sink is provided with a heat sink main body extending along the circuit board, a motor main body housing for housing the motor main body, and the first heat generating element. An element receiving portion for receiving a heat generating element, wherein the motor main body receiving portion and the element receiving portion separately extend downward from the heat sink main body; The sync body portion, the rib located between the element housing portion and the motor main body housing portion.

According to one aspect of the present invention, there is provided a motor having an enhanced heat dissipation effect of a heat sink.

FIG. 1 is a perspective view of a motor according to one embodiment. FIG. 2 is a cross-sectional view of the motor taken along line II-II of FIG. FIG. 3 is a cross-sectional view of the motor taken along line III-III of FIG. FIG. 4 is a bottom view of the motor as viewed from below.

Hereinafter, a motor 1 according to an embodiment of the present invention will be described with reference to the drawings. The scope of the present invention is not limited to the following embodiments, and can be arbitrarily changed within the scope of the technical idea of the present invention. Moreover, in the following drawings, in order to make each structure intelligible, a scale, the number, etc. in an actual structure and each structure may be varied.

In the drawings, an XYZ coordinate system is shown as a three-dimensional orthogonal coordinate system as appropriate. In the XYZ coordinate system, the direction is parallel to the axial direction of the central axis J described later. The X-axis direction is a direction orthogonal to the Z-axis direction. The Y-axis direction is orthogonal to both the X-axis direction and the Z-axis direction.

Further, in the following description, the positive side (+ Z side) in the Z-axis direction is referred to as "upper side", and the negative side (-Z side) in the Z-axis direction is referred to as "lower side". Note that the upper side and the lower side are names used merely for explanation, and do not limit the actual positional relationship or direction. Further, unless otherwise noted, a direction (Z-axis direction) parallel to the central axis J is simply referred to as “axial direction”, and a radial direction centered on the central axis J is simply referred to as “radial direction”. The circumferential direction centering around the center axis, that is, around the axis of the central axis J, is simply referred to as "circumferential direction". Furthermore, in the following description, “plan view” means a state viewed from the axial direction.

[motor]

FIG. 1 is a perspective view of a motor 1 of the present embodiment. FIG. 2 is a cross-sectional view of the motor 1 taken along the line II-II in FIG. FIG. 3 is a cross-sectional view of the motor 1 along the line III-III in FIG. FIG. 4 is a bottom view of the motor 1 as viewed from below.

As shown in FIG. 2, the motor 1 includes a motor body 2, an upper bearing (bearing) 7 A, a lower bearing 7 B, a bearing holder 30, a circuit board 60, and a housing (heat sink, first heat sink) 50. And an upper heat sink (second heat sink) 80 and a lid 40.

[Motor body]

The motor body 2 has a rotor 20 and a stator 25. The rotor 20 rotates about a central axis J extending along the vertical direction (axial direction). The rotor 20 has a shaft 21, a rotor core 22, and a rotor magnet 23. The shaft 21 extends along the central axis J. The shaft 21 is rotatably supported around the central axis J by the upper bearing 7A and the lower bearing 7B. The rotor core 22 is fixed to the shaft 21. The rotor core 22 circumferentially surrounds the shaft 21. The rotor magnet 23 is fixed to the rotor core 22. More specifically, the rotor magnet 23 is fixed to the outer surface of the rotor core 22 along the circumferential direction. The rotor core 22 and the rotor magnet 23 rotate with the shaft 21.

The stator 25 is located radially outward of the rotor 20. The stator 25 faces the rotor 20 in the radial direction via a gap, and surrounds the radially outer side of the rotor 20. The stator 25 has a stator core 27, an insulator 28 and a coil 29. The insulator 28 is made of an insulating material. The insulator 28 covers at least a part of the stator core 27. When the motor 1 is driven, the coil 29 excites the stator core 27. The coil 29 is configured by winding a coil wire (not shown). The coil wire is wound around the teeth portion of the stator core 27 through the insulator 28. The end of the coil wire is drawn upward and passes through a through hole provided in the bearing holder 30 to be connected to the circuit board 60. When a bus bar is provided between the motor body 2 and the bearing holder 30, the end of the coil wire is connected to the bus bar and the bus bar is connected to the circuit board 60.

[Upper bearing and lower bearing]

The upper bearing 7A rotatably supports the upper end portion of the shaft 21. The upper bearing 7A is located above the stator 25. The upper bearing 7A is supported by the bearing holder 30. The lower bearing 7B rotatably supports the lower end portion of the shaft 21. The lower bearing 7B is located below the stator 25. The lower bearing 7B is supported by the lower bearing holding portion 54c of the housing 50.

In the present embodiment, the upper bearing 7A and the lower bearing 7B are ball bearings. However, the types of the upper bearing 7A and the lower bearing 7B are not particularly limited, and may be other types of bearings.

[Housing (heat sink, first heat sink)]

The housing 50 is located below the circuit board 60. The housing 50 of the present embodiment is in direct contact with the circuit board 60 and functions as a heat sink for cooling the circuit board 60. The housing 50 may be in direct contact with the circuit board 60 as long as the housing 50 is in thermal contact with the circuit board 60 to cool the circuit board 60. More specifically, the housing 50 may be in contact with the circuit board 60 via a heat dissipating material such as heat dissipating grease.

The housing 50 has a heat sink portion (heat sink main body portion) 53, a motor main body housing portion 54, and an element housing portion 55. The housing 50 absorbs heat generated mainly by the circuit board 60 in the heat sink portion 53. The housing 50 accommodates the motor body 2 in the motor body accommodating portion 54. Further, the housing 50 accommodates the capacitor (first heat generating element) 65 provided on the circuit board 60 in the element accommodating portion 55.

The housing 50 is configured as a single member. That is, the housing 50 has a function as a heat sink, a function of housing the motor body 2 and a function of housing the capacitor 65 in a single member. The housing 50 may be a separate part in which at least one of the heat sink portion 53, the motor main body housing portion 54, and the element housing portion 55 is fastened by fastening means such as a screw. Further, the heat sink portion 53 and the motor main body housing portion 54 may be separate parts, and the heat sink portion 53 may be a part of the bearing holder 30. However, since the housing 50 is a single member, the heat of the circuit board 60 absorbed in the heat sink portion 53 can be efficiently dissipated not only in the heat sink portion 53 but also in the motor main body housing portion 54 and the element housing portion 55. . That is, according to the present embodiment, since the housing 50 is configured as a single member, the heat dissipation effect in the housing 50 is enhanced. Further, according to the present embodiment, since the housing 50 is formed of a single member, the assembly process of the motor 1 can be simplified.

The housing 50 is made of a metal material having high heat dissipation characteristics and sufficient rigidity. As an example, the housing 50 is made of an aluminum alloy. In this case, the housing 50 is manufactured by cutting a surface requiring accuracy after forming a schematic shape by die casting or the like.

The heat sink portion 53 extends in a direction orthogonal to the central axis J. The heat sink portion 53 is located below the circuit board 60. The heat sink portion 53 extends along the circuit board 60 below the circuit board 60. The heat sink portion 53 is located between the motor body accommodating portion 54 and the element accommodating portion 55 in plan view, and connects the motor body accommodating portion 54 and the element accommodating portion 55. The heat sink portion 53 has an upper surface 53a facing upward and a lower surface 53b facing downward.

A heat dissipating surface 53c is provided on the upper surface 53a of the heat sink 53. The heat dissipating surface 53c is in direct contact with the lower surface 61c of the substrate body 61 of the circuit board 60 directly or indirectly via a member such as a heat dissipating material. That is, the heat sink portion 53 has a heat radiation surface 53 c in contact with the substrate body 61. The heat sink portion 53 absorbs heat from the circuit board 60 at the heat dissipation surface 53 c to cool the circuit board 60.

As described later, the circuit board 60 has a plurality of field effect transistors (second heat generating elements) 66 mounted on the upper surface 61 d of the substrate body 61. The field effect transistor 66 is also referred to as a FET (field effect transistor). The field effect transistor 66 is a heating element that easily generates heat in the circuit board 60. As viewed in the axial direction, at least a portion of the field effect transistor 66 overlaps the heat dissipation surface 53c. Thereby, the heat generated by the field effect transistor 66 can be effectively transferred to the heat sink portion 53 at the heat dissipation surface 53c. Thus, the temperature of the field effect transistor 66 can be prevented from rising excessively, and the operation reliability of the field effect transistor 66 can be enhanced.

In the present embodiment, the case is illustrated where the heat-generating element overlapping the heat dissipation surface 53 c in the axial direction is the field effect transistor 66. However, the heating element overlapping the heat dissipation surface 53c may be another mounted component (element). In the present specification, the heat generating element means an element of the mounted parts that generates heat and becomes high temperature during operation. As the heating element, in addition to the field effect transistor and the capacitor, a field effect transistor driving driver integrated circuit and a power supply integrated circuit are exemplified, but the type is not limited as long as it is an element which becomes high temperature.

As shown in FIG. 4, the heat sink portion 53 is provided with a rib 56. The rib 56 protrudes downward from the lower surface 53 b of the heat sink portion 53. The rib 56 is located between the motor main body housing portion 54 and the element housing portion 55. By providing the rib 56 on the heat sink portion 53, the surface area of the heat sink portion 53 is increased. Thereby, the heat dissipation effect of the heat sink portion 53 can be enhanced. Further, by providing the rib 56 on the heat sink portion 53, the rigidity of the heat sink portion 53 can be enhanced in the extending direction of the rib 56. Thereby, deformation of the heat sink portion 53 can be suppressed with respect to external stress or thermal expansion and thermal contraction. In particular, according to the present embodiment, the rib 56 is located between the motor main body housing portion 54 and the element housing portion 55. Therefore, it is possible to suppress the deformation of the heat sink portion 53 such that the relative positional relationship between the motor main body housing portion 54 and the element housing portion 55 changes.

As shown in FIG. 2, the rib 56 is located immediately below the heat dissipation surface 53 c in contact with the substrate body 61. That is, when viewed in the axial direction, at least a portion of the rib 56 overlaps the heat dissipation surface 53c. Thus, the heat capacity of the heat sink portion 53 can be increased immediately below the heat release surface 53c, and heat can be efficiently transferred from the substrate main body 61 to the heat sink portion 53 at the heat release surface 53c. In addition, the heat absorbed from the circuit board 60 at the heat dissipation surface 53 c and transferred to the heat sink portion 53 can be efficiently dissipated at the rib 56.

As shown in FIG. 4, the rib 56 includes a first rib portion 56 a and a second rib portion 56 b. The first rib portion 56 a extends in the radial direction (in the present embodiment, in the X-axis direction) of the motor body housing portion 54. The first rib 56 a connects the motor main body housing 54 and the element housing 55. The second rib 56b is connected to the first rib 56a. The second rib 56b extends in a direction perpendicular to the first rib 56a. The second rib 56b extends intersecting with the first rib 56a. In the present embodiment, three second rib portions 56 b are provided in the heat sink portion 53.

According to the present embodiment, the first rib portion 56 a extends between the motor body housing portion 54 and the element housing portion 55 to connect them. Therefore, the rigidity of the heat sink portion 53 can be enhanced in the direction in which the motor main body housing portion 54 and the element housing portion 55 are arranged. As a result, it is possible to effectively suppress the deformation of the heat sink portion 53 in which the relative positional relationship between the motor main body housing portion 54 and the element housing portion 55 changes.

According to the present embodiment, the surface area of the heat sink 53 can be further increased by providing the second rib 56 b in addition to the first rib 56 a. Further, since the second rib portion 56b is orthogonal to and intersects the first rib portion 56a, the rigidity of the heat sink portion 53 can be enhanced also in the direction orthogonal to the first rib portion 56a. The rib 56 preferably includes three or more second rib portions 56 b. The rigidity of the heat sink portion 53 can be sufficiently enhanced by providing three or more second rib portions 56 b.

As shown in FIG. 4, the width of the second rib 56 b becomes narrower as it is separated from the first rib 56 a side. In other words, the second rib 56b is thicker on the side of the first rib 56a. For this reason, according to the second rib portion 56b of the present embodiment, it is possible to increase the rigidity of the heat sink portion 53 while suppressing an increase in weight, as compared with the case where the volume extends equally and uniformly.

As shown in FIG. 2, the motor main body housing portion 54 has a cylindrical shape that opens on the upper side (+ Z side). The motor body accommodating portion 54 extends downward from the heat sink portion 53. The motor body accommodating portion 54 accommodates the rotor 20 and the stator 25. The motor body accommodating portion 54 has a cylindrical portion 54a, a bottom portion 54b, and a lower bearing holding portion 54c. The motor main body housing portion 54 may be a cylindrical member not having the bottom portion 54b. In this case, a bearing holder for holding a bearing is separately attached to the lower opening of the motor body housing portion 54.

The cylindrical portion 54 a surrounds the stator 25 from the radially outer side. In the present embodiment, the cylindrical portion 54a is cylindrical. The stator core 27 and the bearing holder 30 are fixed to the inner peripheral surface of the cylindrical portion 54a. A heat sink portion 53 is connected to an outer peripheral surface of the cylindrical portion 54a, which is an upper end portion of the cylindrical portion 54a.

The bottom portion 54b is located at the lower end of the cylindrical portion 54a. The bottom 54 b is located below the stator 25. The lower bearing holding portion 54c is located at the center in plan view of the bottom portion 54b. The lower bearing holding portion 54c holds the lower bearing 7B. A hole 54d penetrating in the axial direction is provided at the center of the lower bearing holding portion 54c in a plan view. The lower end portion of the shaft 21 is inserted into the hole 54 d.

The element housing portion 55 opens on the upper side (+ Z side). The element housing portion 55 extends downward from the heat sink portion 53. As shown in FIG. 4, the element housing portion 55 of the present embodiment houses three capacitors 65. The three capacitors 65 are arranged along one direction (the Y-axis direction in this embodiment) orthogonal to the central axis J. In the present embodiment, the direction in which the three capacitors 65 are arranged coincides with the direction in which the second rib 56 b extends. The element housing portion 55 has a longitudinal direction in which the three capacitors 65 are arranged (that is, the direction in which the second rib portion 56b extends) in plan view. The dimension S1 in the longitudinal direction of the element housing portion 55 is smaller than the diameter D of the motor main body housing portion 54. That is, even when the plurality of capacitors 65 are arranged in one direction, the dimension S1 in the longitudinal direction of the element housing portion 55 does not exceed the motor main body housing portion 54. Therefore, the dimension of the motor 1 can be suppressed in the direction orthogonal to the central axis J.

As shown in FIG. 2, the capacitor 65 has a top surface 65 b facing downward and a side surface 65 a facing in a direction orthogonal to the axial direction. The element housing portion 55 has a side wall portion 55a surrounding the side surface 65a of the capacitor 65, and a housing bottom portion 55b located below the capacitor 65 and axially opposed to the top surface 65b of the capacitor 65.

According to the present embodiment, the element housing portion 55 for housing the capacitor 65 is provided. The capacitor 65 is a heating element that easily generates heat in the circuit board 60. Therefore, the heat generated in the capacitor 65 can be effectively absorbed in the element housing portion 55. It is preferable that a heat dissipation material such as heat dissipation grease be accommodated between the side wall 55 a of the element accommodation portion 55 and the side surface 65 a of the capacitor 65. Thus, heat can be efficiently transferred from the side surface 65 a of the capacitor 65 toward the element housing portion 55, and the reliability of the operation of the capacitor 65 can be enhanced. A heat dissipation material may be disposed between the housing bottom 55 b of the element housing 55 and the top surface 65 b of the capacitor 65. However, in general, an explosion-proof valve may be provided on the top surface 65 b of the condenser 65. In this case, the heat dissipating material is arranged to at least avoid the explosion-proof valve.

The element housing portion 55 may be configured to be opened downward without having the housing bottom portion 55b. Further, a part of the side wall 55 a of the element housing 55 may be opened in the horizontal direction. That is, the housing bottom 55 b and the side wall 55 a do not necessarily surround the top surface 65 b and the side surface 65 a of the capacitor 65.

In the present embodiment, the motor main body housing portion 54 and the element housing portion 55 separately extend downward from the heat sink portion 53. That is, the motor body accommodating portion 54 and the element accommodating portion 55 are separated from each other as viewed in the axial direction. According to the present embodiment, since the motor main body housing portion 54 and the element housing portion 55 are separately extended from the heat sink portion 53, the surface area of the outer peripheral surface of the housing 50 is increased, and the heat dissipation effect of the housing 50 can be enhanced. . As described above, the motor body housing portion 54 and the element housing portion 55 may be separate parts fixed to each other via the heat sink portion 53.

The housing 50 has an upper surface 50a facing upward. The upper surface 50 a is provided across the motor main body housing portion 54 of the housing 50, the element housing portion 55 and the heat sink portion 53. The upper surface 50 a faces the lid 40. The upper surface 50a is provided with a second groove 52 extending along the outer edge of the upper surface 50a. The second recessed groove 52 is recessed downward with respect to the upper surface 50a. The second recessed groove 52 extends in a plane perpendicular to the central axis J with a uniform width and a uniform depth. The second concave portion 52 accommodates the second convex portion 42 of the lid 40 described later.

[Bearing holder]

The bearing holder 30 is located on the upper side (+ Z side) of the stator 25. The bearing holder 30 supports the upper bearing 7A. The plan view shape of the bearing holder 30 is, for example, a circular shape concentric with the central axis J. The bearing holder 30 is positioned at the upper opening 54 e of the motor body housing 54 and is fixed to the inner circumferential surface of the motor body housing 54.

The bearing holder 30 includes a doughnut-shaped disk-shaped holder main body portion 31, an upper bearing holding portion 32 positioned radially inward of the holder main body portion 31, and a holder fixing portion positioned radially outward of the holder main body portion 31. And 33.

The upper bearing holder 32 holds the upper bearing 7A. The upper bearing holder 32 is located at the center of the bearing holder 30 in plan view. A hole 32 a penetrating in the axial direction is provided at the center of the upper bearing holder 32 in a plan view. The upper end portion of the shaft 21 is inserted into the hole 32a. The holder fixing portion 33 has a cylindrical shape that protrudes in the vertical direction at the radial outer edge of the holder main body 31. The outer peripheral surface of the holder fixing portion 33 radially faces the inner peripheral surface of the motor main body housing portion 54. The holder fixing portion 33 is fitted and fixed to the inner circumferential surface of the motor main body housing portion 54.

At least a part of the bearing holder 30 axially overlaps the heat sink portion 53 of the housing 50. Therefore, the space above the bearing holder 30 can be made sufficiently wide. As a result, the degree of freedom of the arrangement of the circuit board 60 located above the bearing holder 30 and the arrangement of the mounted components of the circuit board 60 can be increased.

[Circuit board]

The circuit board 60 is located above the motor body 2 and the bearing holder 30. The circuit board 60 extends in a direction orthogonal to the central axis J (that is, a direction orthogonal to the vertical direction). A coil wire extending from the coil 29 of the stator 25 is connected to the circuit board 60. The circuit board 60 supplies a current to the coil 29 to control the rotation of the rotor 20.

The circuit board 60 includes a substrate main body 61, a plurality of (three in the present embodiment) capacitors (first heating elements) 65, and a plurality of field effect transistors (second heating elements) 66. The substrate main body 61 further includes electronic components (not shown) for controlling the rotation of the rotor 20.

The substrate body 61 is disposed to be orthogonal to the axial direction (ie, the vertical direction). The substrate main body 61 has an upper surface 61 d facing upward and a lower surface 61 c facing downward. Further, the substrate body 61 has an overlap portion 61A overlapping with the motor body 2 when viewed in the vertical direction, and an overhang portion 61B positioned outside the motor body 2 when viewed in the vertical direction.

The capacitor 65 is mounted on the lower surface 61 c of the substrate body 61. The capacitor 65 has a cylindrical shape extending along the axial direction. The capacitor 65 has a top surface 65b located on the opposite side of the substrate body 61 and facing downward, and a side surface 65a facing in a direction orthogonal to the axial direction (vertical direction). The capacitor 65 has the largest dimension in the axial direction (vertical direction) among the mounted components of the circuit board 60. The field effect transistor 66 is mounted on the upper surface 61 d of the substrate body 61. The field effect transistor 66 has a rectangular shape in plan view. In addition to the capacitor 65 and the field effect transistor 66, electronic components such as a rotation sensor and a choke coil are mounted on one or both of the upper surface 61 d and the lower surface 61 c of the substrate main body 61.

The capacitor 65 and the field effect transistor 66 which are heating elements are mounted on the overhang portion 61 B of the substrate main body 61. An upper heat sink 80, which will be described later, is located on the upper side of the overhang portion 61B. The upper heat sink 80 directly or indirectly contacts the field effect transistor 66 mounted on the overhang portion 61B and the upper surface 61d of the overhang portion 61B to cool them. Further, the heat sink portion 53 of the housing 50 and the element housing portion 55 are located below the overhang portion 61B. The heat sink portion 53 and the element housing portion 55 are in direct or indirect contact with the capacitor 65 mounted on the overhang portion 61B and the lower surface 61c of the overhang portion 61B to cool them. That is, according to the present embodiment, the overhang portion 61B on which the heating element (the capacitor 65 and the field effect transistor 66) is mounted is sandwiched by the upper heat sink 80 and the housing 50 in the vertical direction. As a result, the

heating elements

65 and 66 mounted on the overhang portion 61B can be effectively cooled by the upper heat sink 80 and the housing 50. Further, according to the present embodiment, by arranging the

heat generating elements

65 and 66 that need to be cooled to the overhang portion 61B of the substrate main body 61, the structure necessary for cooling the

heat generating elements

65 and 66 can be It can be arranged offset with the main unit 2. Therefore, the dimension in the axial direction (vertical direction) of the motor 1 can be reduced.

[Upper heat sink (second heat sink)]

The upper heat sink 80 is located on the upper side of the circuit board 60. The upper heat sink 80 covers a part of the circuit board 60 from the upper side. The upper heat sink 80 of the present embodiment is in direct or indirect contact with the circuit board 60 to function as an upper heat sink for cooling the circuit board 60. The upper heat sink 80 may be in direct contact with the circuit board 60 or may be in indirect contact as long as the upper heat sink 80 thermally contacts the circuit board 60 and cools the circuit board 60. More specifically, the upper heat sink 80 may be in contact with the circuit board 60 via a heat dissipating material such as heat dissipating grease.

The upper heat sink 80 has a heat absorbing portion 85 and fins 89 a located on the upper surface 85 a of the heat absorbing portion 85. The upper heat sink 80 is made of a metal material (for example, an aluminum alloy or a copper alloy) having high heat dissipation characteristics.

As shown in FIG. 3, the heat absorbing portion 85 has an upper surface 85 a facing upward and a lower surface 85 b facing downward. Further, the heat absorbing portion 85 is provided with a pair of screw insertion holes 85c. The screw insertion hole 85c penetrates the heat absorbing portion 85 along the axial direction. Fixing screws 88 are respectively inserted into the pair of screw insertion holes 85c. The fixing screw 88 is screwed to the heat sink portion 53 of the housing 50. As a result, the lower surface 85 b of the heat absorbing portion 85 is pressed against the upper surface 53 a of the heat sink portion 53, and the upper heat sink 80 is fixed to the housing 50.

According to the present embodiment, the upper heat sink 80 and the housing 50 are in direct contact and fixed to each other. The upper heat sink 80 and the housing 50 absorb heat from the circuit board 60, respectively. Fixing the upper heat sink 80 and the housing 50 in contact with each other causes heat transfer between the upper heat sink 80 and the housing 50. Therefore, when any one of the upper heat sink 80 and the housing 50 has a high temperature, the heat can be moved to the other side and the heat can also be radiated from the other side. As a result, the heat radiation efficiency is enhanced, and as a result, the cooling effect of the circuit board 60 can be enhanced.

A recess 86 is provided on the lower surface 85 b of the heat absorbing portion 85. The field effect transistor 66 of the circuit board 60 is disposed in the recess 86. The recess 86 is filled with a heat dissipating material such as heat dissipating grease, for example, to efficiently transfer the heat generated by the field effect transistor 66 to the heat absorbing portion 85. That is, according to the present embodiment, the heat-radiating material is filled in the concave portion 86 accommodating the field effect transistor 66 which is a heating element, whereby the field effect transistor 66 can be effectively cooled. In addition, when the heat dissipating material is fluid heat dissipating grease, the heat dissipating grease can be prevented from leaking out of the recess 86.

As described later, a lid 40 is provided on the upper side of the upper heat sink 80. The lid 40 is provided with an opening 49 penetrating in the vertical direction. The upper heat sink 80 has an exposed portion 89 exposed from the opening 49 of the lid 40. The exposed portion 89 is located on the upper surface 85 a of the heat absorbing portion 85.

According to the present embodiment, since the upper heat sink 80 has the exposed portion 89, the upper heat sink 80 can efficiently dissipate the heat absorbed from the circuit board 60 from the exposed portion 89 to the outside of the motor 1. Thereby, the cooling efficiency of the circuit board 60 by the upper heat sink 80 can be enhanced.

The exposed portion 89 of the upper heat sink 80 is located immediately above the field effect transistor 66 which is a heating element. That is, the exposed portion 89 of the upper heat sink 80 overlaps at least a part of the field effect transistor 66 when viewed in the axial direction (vertical direction). Thus, the heat transferred from the circuit board 60 to the upper heat sink 80 can be effectively dissipated at the exposed portion 89. The heating element overlapping the exposed portion 89 when viewed in the axial direction may be a heating element other than the field effect transistor 66 (for example, a capacitor, a driver integrated circuit for driving a field effect transistor, an integrated circuit for power supply).

As shown in FIG. 1, the fin 89 a is located at the exposed portion 89 of the upper heat sink 80. The fins 89 a protrude upward from the upper surface 85 a of the heat absorbing portion 85. The fin 89 a penetrates the opening 49 at the exposed portion 89.

A plurality of fins 89 a are provided on the upper heat sink 80. The plurality of fins 89 a extend along one direction orthogonal to the vertical direction. In the present embodiment, the fins 89a extend along the X-axis direction. According to the present embodiment, by providing the fins 89 a in the exposed portion 89, it is possible to increase the surface area of the exposed portion 89 and to enhance the heat dissipation efficiency of the upper heat sink 80 in the exposed portion 89. Further, according to the present embodiment, since the plurality of fins 89a extend in one direction, when arranging the motor 1 in the gas flowing in one direction, the fins 89a are arranged to extend along the flow direction of the gas. Thus, the heat radiation efficiency of the fins 89a can be enhanced. In the present embodiment, the case where the upper heat sink 80 has the fins 89a is illustrated. However, if the upper heat sink 80 has the exposed portion 89, even if the upper heat sink 80 does not have the fins 89a, it is possible to obtain a certain effect of enhancing the heat dissipation efficiency.

A first concave groove 81 surrounding the exposed portion 89 is provided on the upper surface 85 a of the heat absorption portion 85 as viewed in the axial direction (vertical direction). The first recessed groove portion 81 extends in a plane perpendicular to the central axis J with a uniform width and a uniform depth. The first recessed groove portion 81 is recessed downward with respect to the upper surface 85 a. The first convex portion 41 of the lid 40 described later is accommodated in the first concave groove 81.

[Lid]

As shown in FIG. 2, the lid 40 is located above the housing 50, the circuit board 60, and the upper heat sink 80. The lid 40 covers the top surface 50 a of the housing 50. The lid 40 covers the circuit board 60 from the upper side and protects the circuit board 60. In addition, the lid 40 covers the opening of the motor main body housing 54 of the housing 50 and suppresses the entry of contamination into the rotating portion of the motor main body 2 or the like.

As shown in FIG. 1, the lid 40 is a flat portion 45 and an outer edge 46 located at the outer edge of the flat portion 45 and projecting downward with respect to the flat portion 45, and a connector extending upward from the flat portion 45 And a part 47.

The connector portion 47 has a cylindrical shape extending upward from the flat portion 45. Inside the connector portion 47, a connection terminal (not shown) extending upward from the circuit board 60 is provided. The connection terminal is connected to an external device (not shown) that supplies power to the circuit board 60.

As shown in FIG. 2, the flat portion 45 extends in a direction orthogonal to the axial direction (vertical direction). That is, the flat portion 45 extends along the circuit board 60. The flat portion 45 has an upper surface 45 a facing upward and a lower surface 45 b facing downward.

The flat portion 45 is provided with an opening 49. The opening 49 is rectangular when viewed in the axial direction. The fin 89 a of the upper heat sink 80 is inserted into the opening 49. The upper end of the fin 89 a is located above the upper surface 45 a of the flat portion 45.

The lower surface 45 b of the flat portion 45 is axially separated from the heat absorbing portion 85. Therefore, the flat portion 45 does not contact the upper heat sink 80. The lower surface 45 b of the flat portion 45 is provided with a first convex portion 41 projecting downward.

The first convex portion 41 surrounds the opening 49 as viewed in the axial direction. The first convex portion 41 extends in a plane perpendicular to the central axis J with a uniform width and a uniform height. The first convex portion 41 is accommodated in a first concave groove portion 81 provided in the upper heat sink 80. The upper heat sink 80 is provided with an exposed portion 89 exposed from the opening 49. Therefore, the first convex portion 41 and the first concave groove portion 81 surround the exposed portion 89 when viewed from the axial direction (vertical direction). A gap is provided between the inner wall surface of the first recessed groove portion 81 and the first convex portion 41. The adhesive B is filled in the first recessed groove 81.

According to the present embodiment, the first convex portion 41 is accommodated in the first concave groove portion 81 filled with the adhesive B. In addition, since the first convex portion 41 and the first concave groove portion 81 surround the exposed portion 89, intrusion of water and contamination into the interior of the motor 1 from the opening 49 of the lid 40 can be suppressed. Thereby, the dust resistance and waterproofness of the motor 1 can be enhanced.

In the present embodiment, the adhesive B is filled in the first recessed groove portion 81, and the adhesive B closes the gap between the inner wall surface of the first recessed groove portion 81 and the first convex portion 41. For this reason, it is possible to more effectively block the entry of contamination. However, even when the filler such as the adhesive B is not filled, the first convex portion 41 is inserted into the first recessed groove portion 81, thereby forming a labyrinth structure in the intrusion path of the contamination. It is possible to suppress the entry of contamination.

Further, in the present embodiment, the configuration in which the first heat sink 80 is provided with the first recessed groove 81 and the lid 40 is provided with the first convex 41 is illustrated. However, as long as the first convex portion 41 and the first concave groove portion 81 surround the exposed portion 89, the first convex portion 41 and the first concave groove portion 81 may be provided on opposite sides of the upper heat sink 80 and the lid portion 40, respectively. That is, one of the lid 40 and the upper heat sink 80 is provided with the first convex portion 41 projecting to the other side, and the other is provided with the first concave groove portion 81 accommodating the first convex portion 41. It should be done.

According to the present embodiment, the adhesive B is filled between the inner wall surface of the first recessed groove portion 81 and the first convex portion 41. Thereby, the lid 40 and the upper heat sink 80 can be fixed to each other around the exposed portion 89. In addition, since the adhesive B is filled in the first recessed groove portion 81, the adhesive B can be provided in a uniform amount along the circumferential direction, and the adhesive strength stable against the stress from each direction can be obtained. Easy to realize.

According to the present embodiment, a gap is provided between the inner wall surface of the first recessed groove portion 81 and the first convex portion 41. For this reason, the inner wall surface of the first recessed groove portion 81 and the first convex portion 41 do not directly contact in the vertical direction and the horizontal direction. Therefore, vertical and horizontal positioning of the lid 40 with respect to the upper heat sink 80 can be performed in other portions. Specifically, lid 40 and upper heat sink 80 can be brought into contact with housing 50, and lid 40 and upper heat sink 80 can be positioned relative to housing 50, respectively. Therefore, the dimensions of each part can be managed in another member (housing 50 in the present embodiment) in which management of dimensional accuracy and surface accuracy is easy.

According to the present embodiment, the lower surface 45b of the flat portion 45 is axially separated from the heat absorbing portion 85, so the adhesive B filled in the first recessed groove portion 81 is exposed to the outside air. Thereby, the curing of the adhesive B filled in the first recessed groove portion 81 can be promoted. Further, in the step of accommodating the first convex portion 41 in the first concave groove portion 81, excess adhesive B overflowing from the first concave groove portion 81 may be released to the outside of the first concave groove portion 81. it can.

The outer edge portion 46 protrudes downward from the outer edge of the flat portion 45. The outer edge portion 46 surrounds the flat portion 45 over the entire circumference when viewed in the axial direction. At the lower end portion of the outer edge portion 46, a second convex portion 42, an inner lower end surface 46a and an outer lower end surface 46b are provided.

The second convex portion 42 protrudes downward. The second convex portion 42 extends in a plane perpendicular to the central axis J with a uniform width and a uniform height. The second protrusion 42 extends over the entire outer edge 46. Therefore, the second convex portion 42 surrounds the flat portion 45 over the entire circumference when viewed from the axial direction.

The second convex portion 42 is accommodated in a second concave groove portion 52 provided in the housing 50. The second convex portion 42 and the second concave groove portion 52 surround the first convex portion 41 and the first concave groove portion 81 from the outside as viewed from the axial direction. A gap is provided between the inner wall surface of the second recessed groove portion 52 and the second convex portion 42. The adhesive B is filled in the second recessed groove 52.

According to the present embodiment, the second convex portion 42 is accommodated in the second concave groove portion 52 filled with the adhesive B. Further, since the second convex portion 42 and the second concave groove portion 52 surround the first convex portion 41 and the first concave groove portion 81 from the outer side when viewed from the axial direction, the first convex portion 41 and the first concave portion Also on the outer side than the concave groove portion 81, the entry of water and contamination into the interior of the motor 1 from between the lid portion 40 and the housing 50 can be suppressed. Thereby, the dust resistance and waterproofness of the motor 1 can be enhanced.

In the present embodiment, the adhesive B is filled in the second recessed groove 52, and the adhesive B closes the gap between the inner wall surface of the second recessed groove 52 and the second protrusion 42. For this reason, it is possible to more effectively block the entry of contamination. However, even if the filler such as the adhesive B is not filled, the second convex portion 42 is inserted into the second recessed groove portion 52, thereby forming a labyrinth structure in the intrusion path of the contamination. It is possible to suppress the entry of contamination.

In the present embodiment, the configuration in which the second concave portion 52 is provided in the housing 50 and the second convex portion 42 is provided in the lid 40 has been illustrated. However, the second convex portion 42 and the second concave groove portion 52 may be provided on opposite sides of the housing 50 and the lid portion 40, respectively. That is, one of the lid 40 and the housing 50 is provided with a second convex portion 42 projecting to the other side, and the other is provided with a second concave portion 52 accommodating the second convex portion 42. It should just be.

According to the present embodiment, the adhesive B is filled between the inner wall surface of the second recessed groove 52 and the second protrusion 42. Thus, the lid 40 can be fixed to the housing 50 at the outer edge 46 of the lid 40. In addition, since the adhesive B is filled in the second groove 52, the adhesive B can be provided in a uniform amount along the circumferential direction, and the adhesive strength stable against the stress from each direction can be obtained. Easy to realize.

The inner lower end surface 46 a is a surface facing downward. The inner lower end surface 46 a is located inside the area surrounded by the second convex portion 42 in a plan view. The inner lower end surface 46 a contacts the upper surface 50 a of the housing 50. When the inner lower end surface 46 a is in contact with the upper surface 50 a of the housing 50, the lid 40 can be positioned in the axial direction (vertical direction) with respect to the housing 50.

The outer lower end surface 46b is a surface facing downward. The outer lower end surface 46 b is located inside the area surrounded by the second convex portion 42 in a plan view. The outer lower end surface 46 b is axially separated from the upper surface 50 a of the housing 50. Thereby, the adhesive B filled in the second recessed groove 52 can be exposed to the outside air, and the curing of the adhesive B can be promoted. Further, in the step of accommodating the second convex portion 42 in the second concave groove portion 52, the adhesive B overflowing from the second concave groove portion 52 is placed between the outer lower end surface 46b and the upper surface 50a of the housing 50. It can be stored in the gap. Therefore, when the filling amount of the adhesive B varies, the excess adhesive B can be released to the gap between the outer lower end surface 46 b and the upper surface 50 a of the housing 50. In addition, by providing a gap between the outer lower end surface 46 b and the upper surface 50 a of the housing 50, the filling state and the curing state of the adhesive B can be confirmed from the appearance. As a result, it is easy to ensure product quality in the manufacturing line.

In the present embodiment, it is preferable to use a moisture-curable adhesive as the adhesive B filled in the first recessed groove portion 81 and the second recessed groove portion 52. Moisture-curable adhesives cure with moisture in the air. By using a moisture-curable adhesive as the adhesive B, the deterioration of the adhesive due to moisture can be suppressed, and the waterproof reliability of the motor 1 can be enhanced.

Next, in the manufacturing process of the motor 1, a procedure for assembling the lid 40 will be described. In the present embodiment, the assembly of the lid 40 is performed at the end of the assembly process of the motor 1. First, the inside of the first recessed groove 81 of the upper heat sink 80 and the second recessed groove 52 of the housing 50 is filled with the uncured adhesive B. Then, the lid 40 is brought close to the upper heat sink 80 and the housing 50 fixed to the upper heat sink 80 from the upper side, the first convex portion 41 is inserted into the first concave groove portion 81, and the second convex portion 42 is The second groove 52 is inserted. Then, the adhesive B is cured. The lid 40 is assembled to the motor 1 through the above steps.

According to this embodiment, the first convex portion 41 and the second convex portion 42 project in the same direction, and the first concave groove portion 81 and the second concave groove portion 52 open in the same direction. Further, the uncured adhesive B is filled in the first recessed groove portion 81 and the second recessed groove portion 52. Since the first recessed groove 81 and the second recessed groove 52 are opened in the same direction, the uncured adhesive B can be simultaneously filled in the first recessed groove 81 and the second recessed groove 52. In addition, after filling the first recessed groove 81 and the second recessed groove 52 with the uncured adhesive B, the lid 40 is lowered to set the first recessed groove 81 and the second recessed groove 52 respectively. A step of housing the first protrusion 41 and the second protrusion 42 can be employed. Thereby, the assembly | attachment process of the cover part 40 can be simplified.

As shown in FIG. 1, the housing 50 and the lid 40 are fixed to each other by the snap fit portion 6. A plurality of snap fit portions 6 are provided in the motor 1 along the circumferential direction.

The snap fit portion 6 includes a hook 43 provided on the lid 40 and a claw 58 provided on the housing 50. The hooked portion 43 of the lid portion 40 extends downward in a U-shape from the outer edge portion 46. The claws 58 protrude outward in the horizontal direction from the outer side surface of the housing 50. In the assembling procedure of the lid 40, when the operator brings the lid 40 close to the housing 50 in the axial direction, the claws 58 fit into the engagement portions 43, and the lid 40 is fixed to the housing 50. In the present embodiment, the snap fit portion 6 is provided to hold the lid portion 40 from when the lid portion 40 is assembled to the housing 50 until the adhesive B is cured. When the adhesive B is not used to fix the lid 40, the lid 40 is permanently fixed to the housing 50 by the fixing function of the snap fit portion 6.

Although the embodiment and the modified example of the present invention have been described above, each configuration and the combination thereof in the embodiment and the modified example are an example, and addition and omission of the configuration are possible without departing from the spirit of the present invention , Substitution and other modifications are possible. Further, the present invention is not limited by the embodiments.

DESCRIPTION OF SYMBOLS 1 ... motor, 2 ... motor main body, 6 ... snap fitting part, 7A ... upper side bearing (bearing), 20 ... rotor, 21 ... shaft, 25 ... stator, 30 ... bearing holder, 40 ... lid part, 41 ... first Convex part 42: Second convex part 49: Opening part 50: Housing (heat sink, first heat sink) 52: Second concave groove part 53: Heat sink part (heat sink main body part) 53c: Heat dissipation surface , 54: motor body housing portion, 54e opening, 55: element housing portion, 56: rib, 56a: first rib portion, 56b: second rib portion, 60: circuit board, 61: board body, 61A: Overlap part, 61 B: overhang part, 65: capacitor (first heating element, heating element) 66: field effect transistor (second heating element, heating element), 80: upper heat sink (second Heat sink), 81 ... first groove section, 89 ... exposed portion, 89a ... fin, B ... adhesives, D ... diameter, J ... central axis, S1 ... dimensions

Claims

A motor body having a rotor rotating about a central axis extending along the vertical direction, and a stator located radially outward of the rotor;

A circuit board located above the motor body and extending in a direction perpendicular to the central axis;

A heat sink located below the circuit board and in direct or indirect contact with the circuit board;

The circuit board is

Substrate body,

And a first heating element mounted on the lower surface of the substrate body,

The heat sink is

A heat sink body extending along the circuit board;

A motor body accommodating portion for accommodating the motor body;

And an element accommodating portion for accommodating the first heat generating element;

The motor body housing portion and the element housing portion separately extend downward from the heat sink body portion,

The motor, wherein the heat sink main body is provided with a rib positioned between the motor main body housing and the element housing.
The heat sink is configured as a single member;

The rotor has a shaft extending along the central axis,

A bearing rotatably supporting the shaft; and a bearing holder supporting the bearing,

The bearing holder is located at an upper opening of the motor main body housing.

The bearing holder at least partially axially overlaps the heat sink main body portion.

The motor according to claim 1.
The rib includes a first rib extending along a radial direction and connecting the motor main body housing and the element housing.

A motor according to claim 1 or 2.
The rib includes a second rib connected to the first rib and extending in a direction perpendicular to the first rib.

The motor according to claim 3.
The second rib extends transverse to the first rib,

The motor according to claim 4.
The width of the second rib portion is narrowed as it is separated from the first rib portion side.

A motor according to claim 4 or 5.
The rib includes three or more of the second rib portions,

A motor according to any one of claims 4 to 6.
The element accommodating portion has a longitudinal direction in which a direction in which the second rib extends is seen from the axial direction.

The longitudinal dimension of the element housing portion is smaller than the diameter of the motor main body housing portion.

A motor according to any one of claims 4 to 7.
The circuit board has a second heating element mounted on the upper surface of the substrate body,

The heat sink main body has a heat dissipation surface in contact with the lower surface of the substrate main body,

When viewed in the axial direction, at least a portion of the second heating element overlaps the heat dissipation surface.

A motor according to any one of the preceding claims.
The motor according to claim 9, wherein when viewed in the axial direction, at least a portion of the rib overlaps the heat dissipation surface.