JP2009017654A - Dc motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a DC motor which effectively suppresses a temperature rise with a simple structure. <P>SOLUTION: A plurality of spoke parts extending radially outward from a shaft fixing part which externally engages with a shaft are arranged. A circumferential direction coupling part coupling tip parts of the spoke parts in a circumferential direction is formed. A teeth part is formed radially outward from the circumferential direction coupling part. A plurality of fins causing flow of air in an almost axial direction of the shaft are fitted to the spoke parts. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a DC motor having fins for cooling.

Conventionally, as a direct current motor that prevents a rise in temperature by improving the heat dissipation performance, an air gap is formed in the armature core, and the heat dissipation performance is improved by increasing the surface area of the armature core (for example, Patent Document 1). And in such a DC motor having an armature core, there is a DC motor having a spoke structure, a hollow portion is provided in the armature core, and heat generated in the armature core is actively dissipated from the surface of the armature core (for example, , See Patent Document 2).
JP 2006-333640 A JP 2006-304427 A

  However, in the DC motor having the armature as described above, the temperature of the armature core is significantly increased by the heat generated by the current flowing in the coil and the heat generated by the eddy current generated in the armature core, and the temperature increase of the entire motor cannot be sufficiently prevented. There is a case. In particular, when the yoke or the like has no vent hole and the motor case is hermetically sealed, the temperature of the brush becomes high due to the temperature rise of the entire motor, the brush sliding performance is deteriorated, and the brush life is shortened. Therefore, it is desired to suppress the temperature rise of the motor more effectively.

  The present invention solves the above-mentioned problems, and its purpose is to effectively utilize the spoke portion of the armature core to generate an axial air flow passing through the gap of the armature core. An object of the present invention is to provide a direct current motor capable of improving the heat dissipation performance of the entire motor and preventing temperature increase of the entire motor.

  In order to solve the above-described problem, the DC motor includes a yoke formed into a bottomed cylindrical shape with a magnetic material, an end bracket that covers the opening of the yoke, and a plurality of coils disposed on the inner surface of the yoke. A magnet, a shaft rotatably supported by the yoke and the end bracket, an armature core fixed to the shaft and surrounded by a plurality of magnets, and a coil wound around the armature core ing. The armature core is formed in an annular shape, and includes a shaft fixing portion into which the shaft is inserted and fixed, a plurality of spoke portions formed radially outward from the shaft fixing portion, and tip portions of the plurality of spoke portions. A circumferentially connected portion that is connected in the circumferential direction; and a teeth portion that is provided radially outward from the circumferentially connected portion and on which the coil is wound, and the plurality of spoke portions include a substantially axial line of the shaft. A plurality of fins are attached that create an air flow in the direction. Thereby, an air flow is generated in the substantially axial direction of the shaft passing through the gap surrounded by the shaft fixing portion, the spoke portion, and the circumferential connecting portion, and the heat dissipation performance of the entire motor can be improved.

 The plurality of fins are formed of an elastic member, and are formed in parallel to each other, and a first holding portion and a second holding portion that hold the spoke portion of the armature core, and the first holding portion. And a stopper part that couples the second holding part, and at least one of the first holding part and the second holding part has a first wing part or a second wing part formed continuously therewith. ing. The first wing portion and the second wing portion are formed in a circular arc shape in cross section. Thereby, while being able to attach a fin to the spoke part of an armature core simply and reliably, the flow of the air of the substantially axial direction of a shaft can be produced effectively.

    In the present invention, by providing a structure in which fins are attached to the spoke portion of the armature, it is possible to provide a DC motor that can effectively utilize the spoke portion and prevent the temperature of the entire motor from rising. it can.

(Embodiment 1)
Hereinafter, embodiments of the present invention will be described with reference to FIGS.
FIG. 1 and FIG. 2 are a longitudinal sectional view and a transverse sectional view of a DC motor which is an embodiment of the present invention used for a fan motor, for example.
The DC motor 1 includes a yoke 2 formed into a bottomed cylindrical shape with a magnetic material, an end bracket 3 that covers the opening of the yoke 2, a plurality of magnets 4 disposed on the inner surface of the yoke 2, and the yoke 2. A shaft 5 rotatably supported by the end bracket 3, an armature core 6 fixed to the shaft 5 and surrounded by a plurality of magnets 4, and a coil 7 wound around the armature core 6. ing.

  The armature core 6 is formed in an annular shape, a shaft fixing portion 6a into which the shaft 5 is inserted and fixed, a plurality of spoke portions 6b formed radially outward from the shaft fixing portion 6a, and a plurality of spoke portions A plurality of spokes having a circumferential connection portion 6c for connecting the distal end portion of 6b in the circumferential direction, and a tooth portion 6d provided radially outward from the circumferential connection portion 6c and around which the coil 7 is wound. A plurality of fins 8 that cause an air flow in the substantially axial direction of the shaft 5 are attached to the portion 6b. In the DC motor 1, the yoke 2 and the end bracket 3 are not provided with vent holes.

  One end 5a of the shaft 5 of the DC motor 1 is supported on the yoke bottom 2a of the yoke 2 via a bearing 9, and a fan (not shown) is provided at a projecting tip 5b projecting outward from the yoke bottom 2a. Is set to Here, the bearing 9 is adjusted in the center of the inner periphery of the bearing ring 10 disposed inside the second projecting cylindrical portion 2d of the yoke bottom 2a, while the first projecting cylindrical portion 2c of the yoke bottom 2a is adjusted. While being press-fitted inside, it is fixed to the yoke 2 by a bearing holder 11 disposed inside the second projecting cylindrical portion 2d.

  The other end 5 c of the shaft 5 is supported by the end bracket bottom 3 a of the end bracket 3 that covers the yoke 2 via the sintered metal 12. Here, the sintered metal 12 is disposed on the inner peripheral portion of the third projecting cylindrical portion 3 b of the end bracket 3, and the end bracket is provided by a metal holder 13 provided inside the fourth projecting cylindrical portion 3 c of the end bracket 3. 3 is fixed. An oil-impregnated felt 14 is disposed on the outer peripheral portion of the sintered metal 12 to supply oil to the sintered metal 12.

  A commutator 15 is integrally fitted on the shaft 5 in the vicinity of the end bracket bottom 3a, and an armature core 6 formed by laminating a plurality of core materials made of a magnetic material is fitted inside the yoke side surface 2b. ing. Further, the armature 60 is configured by winding the coil 7 around each of the plurality of tooth portions 6d provided radially outward of the armature core 6 by concentrated winding.

  Here, the commutator 15 includes a commutator main body 15a made of resin and a plurality of segments 15b made of a conductive material integrally formed with the commutator main body 15a. Each segment 15b is integrated with the commutator main body 15a. An anchor 15c is provided on the outer peripheral surface of the commutator main body 15a, and a riser 15d that is electrically connected to the lead wire 7a of each coil 7 is an end of the commutator 15 that is close to the armature core 6. Are provided radially outward.

  Then, current is supplied from the external power source to each segment 15b of the commutator 15 through the brush 16, current is supplied to each coil 7 through the lead wire 7a, and a magnetic field is generated in each tooth portion 6d, and the inner peripheral surface of the yoke 2 The armature 60 rotates by an attractive force (repulsive force) between the magnet 4 and the magnetic field formed by the magnet 4 fixed to the armature.

  On the other hand, a brush holder stay 17 is fixed to the end bracket bottom 3a, and a through hole 17a through which the shaft 5 passes is formed at the center of the brush holder stay 17, and the inside of the cylinder of the yoke 2 is provided. On one of the disk surfaces 17b facing the surface, brush holders 18 are provided at four locations in the circumferential direction in a radial positional relationship with respect to the hole center of the through hole 17a. The brushes 16 are respectively accommodated in the brush holders 18, and pigtails (not shown) drawn from the brushes 16 are electrically connected to four terminal plates (not shown) incorporated in the brush holder stays 17. External pull-out couplers (not shown) are connected to these terminal plates. Further, an external power source is supplied to the brush 16 by connecting an external coupler (not shown) to the external drawing coupler. Note that the end bracket 3 and the yoke 2 of the DC motor 1 have no air holes for positively introducing or discharging air, and the case formed by the end bracket 3 and the yoke 2 has a substantially sealed shape. .

  A brush stopper 19 is provided at an outer diameter side portion of the brush holder 18 arranged radially, and the brush holder 18 is fixed to the brush holder stay 17 by the brush stopper 19. A coil spring 20 is compressed and accommodated inside the brush holder 18 between the brush stopper 19 and the outer diameter side tip of the brush 16, and the brush 16 is pressed against the inner diameter side by the pressing force of the coil spring 20. The tip portion of the commutator 15 is slidably contacted with the outer peripheral surface of the segment 15b of the commutator 15, and the current supplied to the brush 16 from the external drawing coupler (not shown) via the terminal plate is the commutator. 15 is supplied to each coil 7 via 15.

  The armature core 6 constituting the armature 60 is formed by laminating thin cores of magnetic material, and a substantially annular shaft fixing portion 6a having a through hole for fitting the shaft 5 is formed at the center thereof. The five spoke portions 6b are provided radially outward from the shaft fixing portion 6a so as to be integrated with the shaft fixing portion 6a at an interval of approximately 72 °. Further, a circumferential connecting portion 6c that connects the tip portion of the outer diameter of the spoke portion 6b in the circumferential direction is provided integrally with the spoke portion 6b, and is approximately 36 radially outward from the circumferential connecting portion 6c. 10 teeth 6d for winding the coil 7 at equal intervals are provided radially outward integrally with the circumferential connecting portion 6c. A plurality of fins 8 are attached to the plurality of spoke portions 6b.

  FIG. 3 is a side view of the fin. For example, the fin 8 is formed by molding a resin material that is an elastic member, and includes a first holding portion 8a, a second holding portion 8b, a stopper portion 8c, a first blade 8d, a second blade 8e, and the like. It consists of a clip claw portion 8f. In the fin 8, the substantially flat plate-like first holding portion 8 a and the second holding portion 8 b are coupled to be formed in the same direction and substantially in parallel at both ends of the substantially flat plate-like stopper portion 8 c. Is formed in a substantially U-shape by the stopper portion 8c, the first holding portion 8a and the second holding portion 8b. Further, a clip claw portion 8f is formed at the distal end portion of the first holding portion 8a on the opening side toward the second holding portion 8b. The distance L between the opposing surfaces of the first holding portion 8a and the second holding portion 8b is slightly smaller than the width of the spoke side surface portion 6e at the opening. Further, a first wing portion 8d having an arcuate cross section is integrally formed from the vicinity of the intersection 8g of the stopper portion 8c and the first holding portion 8a, and from the tip of the second holding portion 8b. A second wing portion 8e having a circular arc cross section is integrally formed.

  4 and 5 are perspective views showing a state in which the fin is attached to the armature. The armature 60 with the fins 8 is formed by attaching the fins 7 to the spoke portions 6b of the armature 6 electrically connected to the riser 15d of the coil 7. As described above, the distance L between the opposing surfaces of the first holding portion 8a and the second holding portion 8b is formed to be smaller than the width of the spoke side surface portion 6e in the opening. Therefore, when the opening portion of the fin 8 is positioned on the spoke portion 6b of the armature 6 and the fin 8 is biased, the first holding portion 8a and the second holding portion 8b of the fin 8 are elastically deformed. And the fin 8 is fixed to the spoke part 6b by moving the fin 8 until the stopper part 8c of the fin 8 abuts against the spoke part 6b. At this time, the first sandwiching portion 8a and the second sandwiching portion 8b of the fin 8 made of an elastic member sandwich the spoke side surface portion 6e, and the clip claw portion 8f is on the end surface facing the commutator 15 of the spoke portion 6b. I get caught. As a result, the fin 8 is simply and reliably fixed to the spoke portion 6b. In addition, it can also be set as stronger fixation by adhere | attaching and fixing the spoke side surface part 6e and the said substantially U-shaped inner side.

  When the DC motor 1 is driven, the plurality of fins 8 fixed to the plurality of spoke portions 6b are rotated together with the rotation of the armature 60. By this rotation, an air flow in the axial direction is generated by the first wing portion 8d and the second wing portion 8e having an arc cross section. The yoke 2 and the end bracket 3 of the DC motor 1 are not provided with vent holes, but the turbulent flow is generated inside the DC motor 1 by the axial air flow generated by the fins 8, and the yoke 2 and the end bracket. The transfer of heat from 3 etc. to the outside is promoted, and a reduction in motor temperature can be expected even though the yoke 2 and the end bracket 3 are not provided with vent holes.

  FIG. 6 is a graph showing the coil temperature and brush temperature of the DC motor in the present embodiment. FIG. 6 compares the temperatures of the coil 7 and the brush 16 when the DC motor 1 of the same specification is driven to a steady state where there is no temperature change, with and without the fins 8 attached. As shown in FIG. 6, the coil temperature and the brush temperature are both reduced by attaching the fins 8, and it has been confirmed that the coil temperature is reduced by about 3 ° C. and the brush temperature is further reduced by about 6 ° C.

  As described above, the present invention can effectively and effectively use the spoke portion 6b of the armature 6 to attach the motor cooling fin 8 to the spoke portion 6b easily and surely, and the yoke 2 and the end bracket 3 can be vented. Even if the motor is not provided, it is possible to provide the DC motor 1 that can prevent the temperature of the motor from rising.

(Embodiment 2)
7 to 9 are diagrams of the DC motor according to the second embodiment, FIG. 7 is a front view of the DC motor in the present embodiment, FIG. 8 is a side view thereof, and FIG. 9 is a vent hole. It is an enlarged view which shows the part (P) of. In the first embodiment shown in FIGS. 1 and 2, the yoke 2 and the end bracket 3 are substantially hermetically sealed without a vent hole, but in the second embodiment shown in FIGS. A vent hole 2e is formed. Note that detailed description of portions having the same configuration as in the first embodiment is omitted.

  Eight air holes 2e are formed on the yoke bottom 2a of the yoke 2 on substantially the same circumference around the shaft 5 by punching with a press. The vent holes 2e are all formed in the same direction, and the DC motor 1 of the present embodiment can prevent intrusion of rainwater or the like by being attached to a vehicle or the like so that the opening is located below. .

  Even when the DC motor 1 in the embodiment is driven, the plurality of fins 8 fixed to the plurality of spoke portions 6b are also rotated by the rotation of the armature 6. This rotation causes the air flow in the axial direction to be generated by the arc-shaped first wing portion 8d and the second wing portion 8e. However, outside air can be sucked from the plurality of vent holes 2e, and the outside air lower than the motor temperature is positively applied. The motor temperature can be reduced more effectively by inhaling or discharging.

  As described above, the present invention makes it possible to easily and reliably attach the motor cooling fin 8 to the spoke portion 6b by effectively utilizing the spoke portion 6b of the armature 6, and to provide a vent hole provided on the bottom surface of the yoke 2. The direct-current motor 1 that can more effectively suppress the temperature rise of the motor can be provided by sucking or discharging the outside air from 2e.

It is a longitudinal cross-sectional view of the DC motor in Embodiment 1 of this invention. It is a cross-sectional view of the DC motor in Embodiment 1 of the present invention. It is a side view of the fin in Embodiment 1 of this invention. It is a perspective view which shows the attachment of the fin in Embodiment 1 of this invention. It is a perspective view which shows the armature after attaching the fin in Embodiment 1 of this invention. It is a figure which shows coil temperature and brush temperature in Embodiment 1 of this invention. It is a front view of the DC motor in Embodiment 2 of this invention. It is a side view of the DC motor in Embodiment 2 of this invention. It is an enlarged view which shows the part (P) of the air vent in FIG.

Explanation of symbols

1 DC motor 2 Yoke 3 End bracket 4 Magnet 5 Shaft 6 Armature core (armature)
6a Shaft fixing portion 6b Spoke portion 6c Circumferential connection portion 6d Teeth portion 6e Spoke side surface portion 7 Coil 8 Fin 8a First holding portion 8b Second holding portion 8c Stopper portion 8d First blade 8e Second blade 8f Clip claw portion

Claims (7)

A yoke formed into a bottomed cylindrical shape with a magnetic material;
An end bracket covering the opening of the yoke;
A plurality of magnets disposed on the inner surface of the yoke;
A shaft rotatably supported by the yoke and the end bracket;
An armature core fixed to the shaft and disposed between the plurality of magnets;
A coil wound around the armature core,
The armature core is
A shaft fixing portion that is formed in an annular shape and into which the shaft is inserted and fixed;
A plurality of spoke portions formed radially outward from the shaft fixing portion;
A circumferential connecting portion that connects tip ends of the plurality of spoke portions in the circumferential direction;
In a direct current motor having a teeth portion provided radially outward from the circumferential connection portion and wound with the coil,
A direct current motor characterized in that a plurality of fins for generating an air flow in a substantially axial direction of the shaft are attached to the plurality of spoke portions. The fin is formed of an elastic member, formed in parallel with each other, and a first sandwiching portion and a second sandwiching portion that sandwich the spoke portion of the armature core,
A stopper part for coupling the first holding part and the second holding part;
The DC motor according to claim 1, further comprising a first wing portion formed continuously with the first holding portion.   The DC motor according to claim 2, wherein the first wing portion of the fin is formed in an arc shape in cross section. The fin is formed of an elastic member, formed in parallel with each other, and a first sandwiching portion and a second sandwiching portion that sandwich the spoke portion of the armature core,
A stopper part for coupling the first holding part and the second holding part;
A first wing formed continuously with the first holding portion;
The DC motor according to claim 1, further comprising a second wing portion formed continuously with the second holding portion.   5. The DC motor according to claim 4, wherein at least one of the first wing portion and the second wing portion of the fin is formed in an arc shape in cross section.   6. A clip claw portion that is engaged with the spoke portion of the armature core is formed at a tip portion of the first holding portion of the fin. The direct current motor described in 1.   The DC motor according to any one of claims 1 to 6, wherein the fin is formed of a resin.

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