JP2017195663A - Motor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To inhibit entry of foreign objects into a control circuit side.SOLUTION: A motor device 10 includes: a motor body 18 having a stator 26 and a rotor 24; and a motor driving device 20 having a circuit board 40 forming a control circuit 38 which controls electrification to the stator 26, and a circuit element 42 attached to the circuit board 40. Further, the motor device 10 includes: a heat sink 44 having a heat radiation part 46 which radiates heat of the motor driving device 20; and a lower cover 50 covering the motor driving device 20. The lower cover 50 has: a bottom wall 52 which is disposed facing the motor driving device 20 and has an opening 66; and a vertical wall 68 which is erected from the bottom wall 52 to the motor driving device 20 side, is disposed along the opening 66, and forms at least a cylindrical part 70 in which air that has passed through the opening 66 can pass to the motor driving device 20 side.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a motor device.

  Patent Document 1 below discloses a fan motor that is a motor device that rotates a fan for blowing air. This fan motor is an outer rotor type brushless motor, and includes a motor body having a stator and a rotor, a motor holder provided around the rotor, and a center piece that supports the stator. The motor holder is formed with a cooling air introduction path that guides cooling air from the outside of the motor holder to the motor body side. Then, when the cooling air passing through the cooling air introduction path hits the heat sink, the heat of the circuit elements constituting a part of the control circuit for controlling the energization to the stator is radiated through the heat sink. .

Japanese Patent Laying-Open No. 2015-57014

  By the way, from the viewpoint of the stability and durability of the operation of a motor device such as a fan motor, it is desirable that foreign substances can be prevented from entering the control circuit.

  An object of the present invention is to obtain a motor device that can suppress the intrusion of foreign matter to the control circuit side in consideration of the above facts.

  The motor device according to claim 1 is a motor main body having a stator and a rotor that rotates by receiving a magnetic field of the stator, a circuit board that constitutes a control circuit that controls energization of the stator, and the motor apparatus attached to the circuit board. A control device having a circuit element; a center piece on which the motor main body is supported and the control device is supported on a side opposite to the side on which the motor main body is supported; and the control device attached to the control device. A heat sink having a heat dissipating part for dissipating heat, a bottom wall disposed opposite to the control device and having an opening, and standing from the bottom wall toward the control device and A vertical wall disposed along the opening and forming at least a part of a cylindrical portion through which the air that has passed through the opening can pass toward the control device side. And a, and a cover for covering the.

  According to the fan motor of the first aspect, when energization to the stator is controlled by the control device, a magnetic field is generated around the stator. Then, the rotor rotates by receiving the magnetic field of the stator. Here, the control device includes a circuit board and a circuit element, and heat of the circuit board and the circuit element is transmitted to the heat sink. And the heat | fever of the circuit board and circuit element which were transmitted to the heat sink is radiated from the thermal radiation part of a heat sink.

  Here, in the first aspect of the present invention, an opening is formed in the bottom wall of the cover. In addition to this, a vertical wall constituting a part of the cylindrical portion is provided upright on the bottom wall of the cover. By setting it as the said structure, compared with the case where an opening part is only provided in the bottom wall of a cover, it can suppress that a foreign material permeates into the space between a centerpiece and a cover.

  A motor device according to a second aspect is the motor device according to the first aspect, wherein the opening is provided at a position not facing the circuit board and the rotation axis direction of the rotor.

  According to the motor device of the second aspect, since the opening is provided at the above position, it is possible to prevent foreign matters such as water droplets entering from the opening from adhering to the circuit board.

  According to a third aspect of the present invention, in the motor device according to the first or second aspect, at least a part of the vertical wall is disposed to face the heat sink and the rotation axis direction of the rotor.

  According to the motor device of the third aspect, since the vertical wall portion of the cover is provided at the above position, the air flow introduced from the opening portion of the cover can be easily applied to the heat sink. Thereby, heat dissipation from the heat sink can be promoted.

  The motor device according to claim 4 is the motor device according to any one of claims 1 to 3, wherein the cover includes a peripheral wall extending from an outer peripheral portion of the bottom wall toward the control device. The cylindrical part is formed by the vertical wall and the peripheral wall.

  According to the motor device of the fourth aspect, the cylindrical portion is formed by the vertical wall and the peripheral wall. Thereby, the cylindrical part which is a part which guides the airflow introduced from the opening part toward the control apparatus side can be formed in a cover, suppressing that the volume in a cover reduces.

It is a longitudinal cross-sectional view which shows a fan motor. It is the perspective view which looked at the cover from the control device side. It is the perspective view which looked at the cover from the opposite side to a control device. It is the rear view which looked at the cover from the opposite side to a control device.

  A motor apparatus according to an embodiment of the present invention will be described with reference to FIGS.

  As shown in FIG. 1, the motor device 10 of the present embodiment is used for rotating a fan 12 that constitutes a part of the vehicle air conditioner. The motor device 10 includes a motor main body 18 that rotates the rotary shaft 16 about its axis, a motor drive device 20 as a control device that controls the rotation of the rotary shaft 16 by controlling energization to the motor main body 18, And a center piece 22 that supports the motor main body 18 and the motor driving device 20. The motor device 10 also includes an upper cover 48 attached to the center piece 22 and a lower cover 50 as a cover. In addition, the arrow Z direction, the arrow R direction, and the arrow C direction that are appropriately shown in the drawing indicate the axial direction, the radial direction, and the circumferential direction of the rotating shaft 16 of the motor body 18, respectively. In the following description, when only the axial direction, radial direction, and circumferential direction are indicated, the axial direction, radial direction, and circumferential direction of the rotating shaft 16 of the motor body 18 are indicated unless otherwise specified.

(Motor body 18)
The motor main body 18 is composed of the rotary shaft 16, the rotor 24, and the stator 26 as main elements.

  The rotary shaft 16 is configured by subjecting a columnar steel material to surface treatment such as carburizing treatment. The rotary shaft 16 is rotatably supported by a pair of bearings 28 fixed to the center piece 22. Has been.

  The rotor 24 is configured by fixing a rotor magnet 32 to a rotor housing 30 formed in a bottomed cylindrical shape with one end opened. The rotor housing 30 includes a disc-shaped bottom wall 30A and a peripheral wall 30B that is bent and extends from the outer peripheral end of the bottom wall 30A to the other side in the axial direction. Further, an insertion portion 30C into which the rotation shaft 16 is inserted is provided at the center portion of the bottom wall 30A, and the rotor housing 30 and the rotation shaft 16 are brought together by press-fitting the rotation shaft 16 into the insertion portion 30C. It is connected so that it can rotate integrally. A rotor magnet 32 is fixed to the radially inner surface of the peripheral wall 30B with an adhesive or the like.

  The stator 26 is configured by winding a conductive winding 34 around a tooth portion 36 </ b> A of the stator core 36. Further, the stator 26 is disposed on the radially inner side of the peripheral wall 30 </ b> B of the rotor housing 30. The rotor 24 can rotate together with the rotating shaft 16 by receiving a magnetic field generated by the stator 26. More specifically, the stator 26 is an electromagnet in which a winding 34 is wound around a stator core 36, and constitutes three phases of a U phase, a V phase, and a W phase. Each of the U-phase, V-phase, and W-phase of the stator 26 generates a so-called rotating magnetic field by switching the polarity of the magnetic field generated by the electromagnet under the control of the motor driving device 20 described later. In addition, the stator 26 is fixed to the center piece 22 in a state where the stator 26 is disposed on the radially outer side of the portion of the center piece 22 where the bearing 28 is fixed.

(Motor drive device 20 and heat sink 44)
The motor drive device 20 includes a circuit board 40 and a plurality of circuit elements 42 that constitute a control circuit 38 that controls energization to the stator 26 (winding 34) that constitutes a part of the motor body 18 described above. Further, the motor drive device 20 includes a heat sink 44 for radiating heat generated by the circuit element 42 and the like.

  The circuit board 40 is formed in a rectangular plate shape whose axial direction is the thickness direction, and the circuit board 40 is formed by forming a conductive pattern portion on a board body formed using an insulating material. It is configured. A rotation shaft insertion hole 40 </ b> A through which the rotation shaft 16 is inserted is formed at the center in the longitudinal direction of the circuit board 40. Further, a winding terminal joint portion 40B to which a terminal portion of the winding 34 is connected is provided on the peripheral edge portion of the rotating shaft insertion hole 40A in the circuit board 40. Further, the surface on the other side in the axial direction on one side (one side in the longitudinal direction of the circuit board 40) across the portion where the rotation shaft insertion hole 40A is formed in the circuit board 40 is in operation (when energized). A plurality of FETs 42A, which are circuit elements 42 that generate significant heat, are joined. Further, a heat sink 44 is bonded to the surface of the circuit board 40 opposite to the side where the plurality of FETs 42A are bonded (one side in the axial direction).

  The heat sink 44 is formed using a metal such as aluminum or copper having good thermal conductivity, a resin material, or the like. The heat sink 44 is erected on a base portion 44A formed in a substantially rectangular plate shape when viewed from the thickness direction of the circuit board 40 (see FIG. 1), and on one side portion of the base portion 44A in the short direction. And a plurality of boss portions 44 </ b> B constituting a heat radiating portion 46 that radiates most of the heat transmitted to the heat sink 44.

  Most of the motor drive device 20 described above is disposed between a lower cover 50 and a center piece 22 described later. The plurality of boss portions 44 </ b> B of the heat sink 44 are exposed to a space formed between the upper cover 48 and the center piece 22 through an opening 22 </ b> A formed in the center piece 22. The upper cover 48 is formed with an introduction hole 48 </ b> A through which air that passes between the plurality of boss portions 44 </ b> B of the heat sink 44 and flows toward the motor body 18 is introduced. The introduction hole 48A is formed in a portion adjacent to the plurality of boss portions 44B.

(Configuration of lower cover 50)
Next, the structure of the lower cover 50 which is the principal part of this embodiment is demonstrated.

  As shown in FIGS. 2 and 3, the lower cover 50 is formed in a bottomed box shape in which the motor driving device 20 (see FIG. 1) side is opened. The lower cover 50 is formed in a rectangular shape when viewed in the axial direction, and includes a bottom wall 52 that faces the circuit board 40 (see FIG. 1) and extends substantially parallel to the circuit board 40. A central rib 56 is provided at the center of the bottom wall 52 in the longitudinal direction and the lateral direction so as to form a rotating shaft insertion portion 54 into which an end of the rotating shaft 16 (see FIG. 1) is inserted. The lower cover 50 includes a first peripheral wall 58, a second peripheral wall 60, a third peripheral wall 62, and a fourth peripheral wall 64 as peripheral walls that bend and extend from the outer peripheral end of the bottom wall 52 toward the motor drive device 20 side. ing. The first peripheral wall 58 and the second peripheral wall 60 that are respectively disposed on both sides of the bottom wall 52 in the lateral direction are formed in a rectangular plate shape and are disposed in parallel to each other. The first peripheral wall 58 is provided with a connector connecting portion 65 to which a connector (not shown) is connected. Further, the third peripheral wall 62 disposed on one side in the longitudinal direction of the bottom wall 52 is formed in a rectangular flat plate shape connecting the first peripheral wall 58 and the second peripheral wall 60, and on the other side in the longitudinal direction of the bottom wall 52. The arranged fourth peripheral wall 64 is formed in a plate shape that connects the first peripheral wall 58 and the second peripheral wall 60 and is curved convexly toward the opposite side of the third peripheral wall 62.

  As shown in FIGS. 3 and 4, a long opening 66 is formed at the end of the bottom wall 52 on the side of the fourth peripheral wall 64 so that the short direction of the bottom wall 52 is the longitudinal direction. . As shown in FIG. 1, the opening 66 is disposed at a position that does not oppose the circuit board 40 in the axial direction. The air outside the lower cover 50 can be introduced into the inner side of the lower cover 50 through the opening 66.

  As shown in FIG. 2, the peripheral portion of the opening 66 in the bottom wall 52 is formed in a convex shape toward the motor drive device 20 side, and both ends in the longitudinal direction are connected to the fourth peripheral wall 64, respectively. A vertical wall 68 is erected. A cylindrical portion 70 that guides the air flow (cooling air) introduced from the opening 66 toward the motor drive device 20 side is formed by the longitudinal central portion 64A of the vertical wall 68 and the fourth peripheral wall 64. . As shown in FIG. 1, the portion of the vertical wall 68 on the third peripheral wall 62 side is disposed so as to face the end portion of the heat sink 44 in the rotation axis direction.

  Further, the fourth peripheral wall 64 is locked to the lower cover locking portion 22 </ b> B provided on the center piece 22. Thus, a labyrinth 72 that is bent in a crank shape in a cross-sectional view is formed on the motor drive device 20 side with respect to the cylindrical portion 70.

  As shown in FIG. 2, a heat sink support protrusion 68 </ b> A that protrudes toward the heat sink 44 (see FIG. 1) is formed at the longitudinal center of the vertical wall 68. By positioning the end of the heat sink 44 between the heat sink support protrusion 68A and the center piece 22, the heat sink 44 is positioned. In FIG. 1, the motor device cut along a line corresponding to the line 1-1 shown in FIG. 2 in order to make the flow path of the air flow flowing into the lower cover 50 from the opening 66 easier to understand. 10 shows a cross section.

(Operation and effect of this embodiment)
Next, the operation and effect of this embodiment will be described.

  As shown in FIG. 1, when the motor device 10 of the present embodiment is operated, that is, energization of the stator 26 is controlled by the motor driving device 20, and the rotor 24 is rotated by a magnetic field generated around the stator 26. Then, the fan 12 is rotated, and air blowing by the fan 12 is started.

  Here, in the present embodiment, when the circuit element 42 constituting a part of the motor drive device 20 is energized, the circuit element 42 generates heat. In particular, the heat generation of the FET 42A is significant. The heat of the FET 42A is transmitted to the heat sink 44 through the circuit board 40.

  Here, in this embodiment, the air introduced into the upper cover 48 through the introduction hole 48 </ b> A formed in the upper cover 48 passes between the plurality of boss portions 44 </ b> B of the heat sink 44. Thereby, the heat of the FET 42A and the like transmitted to the heat sink 44 can be radiated from the plurality of boss portions 44B to the air flow passing between the plurality of boss portions 44B.

  Here, in the present embodiment, the motor drive device 20 (the circuit board 40, the circuit element 42, and a part of the heat sink 44) disposed in the lower cover 50 through the opening 66 formed in the bottom wall 52 of the lower cover 50. ) Air passes to the side. The air introduced into the lower cover 50 flows to the end side of the heat sink 44 through the cylindrical portion 70 formed by the vertical wall 68 standing on the bottom wall 52 and the central portion 64A of the fourth peripheral wall 64. Thereby, the motor drive device 20 can be cooled by the air flow introduced from the opening 66. Thus, in this embodiment, the motor drive device 20 can be cooled not only by the heat sink 44 but also by the air flow introduced from the lower cover 50 side, and the heat dissipation performance of the motor drive device 20, that is, the control circuit 38. The heat dissipation performance can be improved. Further, in this configuration, compared to the case where the simple opening portion 66 is formed in the bottom wall 52 of the lower cover 50, the entry of foreign matter into the lower cover 50 is suppressed (the foreign matter that has passed through the opening portion 66 is removed from the vertical wall 68. Can be rebounded by

  Further, in the present embodiment, the opening 66 formed in the bottom wall 52 of the lower cover 50 is provided at a position that does not face the circuit board 40 in the axial direction, so that water droplets that have entered from the opening 66 are connected to the circuit. Adhesion to the substrate 40 can be suppressed. In addition, in the present embodiment, a labyrinth 72 that bends in a crank shape in a cross-sectional view is provided on the motor drive device 20 side with respect to the cylindrical portion 70 formed in the lower cover 50, so that the opening 66 and It is possible to prevent water droplets that have entered from the cylindrical portion 70 from entering the lower cover 50.

  Further, in the present embodiment, the portion on the third peripheral wall 62 side in the vertical wall 68 that forms a part of the cylindrical portion 70 is disposed so as to face the end portion of the heat sink 44 in the rotation axis direction. The cooling air introduced into the lower cover 50 through the opening 66 and the cylindrical portion 70 can be easily applied to the heat sink 44. Thereby, heat dissipation from the heat sink 44 can be promoted.

  Further, in the present embodiment, the cylindrical portion 70 is formed by the central portion 64 </ b> A of the fourth peripheral wall 64 that forms the outer peripheral portion of the lower cover 50 and the vertical wall 68 that stands upright at the end of the bottom wall 52. Thereby, the cylindrical part 70 which is a part which guides the airflow introduced from the opening part 66 toward the motor drive device 20 side is formed in the lower cover 50 while suppressing the volume in the lower cover 50 from decreasing. can do.

  In the present embodiment, the example in which the cylindrical portion 70 is formed by the central wall 64A of the fourth peripheral wall 64 and the vertical wall 68 standing at the end of the bottom wall 52 has been described, but the present invention is limited to this. Not. Depending on the position of the opening provided in the bottom wall 52, the position and configuration of the vertical wall may be changed, and the cylindrical portion may be formed including at least a part of the vertical wall.

  In the present embodiment, an example in which a part of the vertical wall 68 is disposed so as to face the end of the heat sink 44 in the rotation axis direction has been described, but the present invention is not limited to this. For example, a part or all of the vertical wall 68 may be arranged to face the FET 42A in the rotation axis direction so that the air flow introduced from the opening 66 can be easily applied to the FET 42A.

  Furthermore, in this embodiment, although the example which has arrange | positioned the opening part 66 formed in the bottom wall 52 of the lower cover 50 in the position which does not oppose the circuit board 40 in an axial direction was demonstrated, this invention is not limited to this. The position of the opening 66 may be appropriately set in consideration of the environment where the motor device 10 is used.

  Although one embodiment of the present invention has been described above, the present invention is not limited to the above, and various modifications other than the above can be implemented without departing from the spirit of the present invention. Of course.

DESCRIPTION OF SYMBOLS 10 Motor apparatus 18 Motor main body 24 Rotor 26 Stator 38 Control circuit 40 Circuit board 42 Circuit element 44 Heat sink 46 Heat radiating part 50 Lower cover (cover)
52 bottom wall 58 first peripheral wall (peripheral wall)
60 Second perimeter wall (perimeter wall)
62 3rd wall (surrounding wall)
64 Fourth wall (surrounding wall)
66 Opening 68 Vertical wall 70 Cylindrical part

Claims (4)

A motor body having a stator and a rotor that rotates in response to the magnetic field of the stator;
A control board having a circuit board constituting a control circuit for controlling energization to the stator and a circuit element attached to the circuit board;
A center piece on which the motor body is supported and on which the control device is supported on the side opposite to the side on which the motor body is supported;
A heat sink attached to the control device and having a heat radiating portion for radiating heat of the control device;
A bottom wall disposed opposite to the control device and having an opening, and is erected from the bottom wall toward the control device and is disposed along the opening and passes through the opening. A vertical wall that forms at least a part of a cylindrical portion through which air can pass toward the control device, and a cover that covers the control device;
A motor device comprising:   The motor device according to claim 1, wherein the opening is provided at a position not facing the circuit board and the rotation axis direction of the rotor.   The motor device according to claim 1, wherein at least a part of the vertical wall is disposed so as to face the heat sink and the rotation axis direction of the rotor. The cover is formed including a peripheral wall extending from an outer peripheral portion of the bottom wall toward the control device side,
The motor device according to claim 1, wherein the cylindrical portion is formed by the vertical wall and the peripheral wall.