JP2019122059A - Brushed motor, and fan motor for radiator cooling - Google Patents

Abstract

To provide a brushed motor, and a fan motor for radiator cooling capable of increasing brush cooling efficiency and prolonging a brush life, without increasing the number of parts with a simple structure.SOLUTION: A brushed motor includes a yoke portion, an end bracket 4 that closes one end of the york portion, a rotary shaft arranged radially inward of the yoke portion and rotatably supported by the end bracket 4, an armature core fixed to the rotary shaft and wound by winding, and an armature having a cylindrical commutator 15 fixed to the rotary shaft and to which the winding is connected, and a plurality of brushes 27 that are arranged on one surface of the commutator 15 side of the end bracket 4 and are in sliding contact with the outer circumferential surface of the commutator 15, in which an end-side air-cooling opening 36 is formed in the end bracket 4 at a position facing a position where the commutator 15 and the brush 27 are in sliding contact with each other in the axial direction of the rotary shaft.SELECTED DRAWING: Figure 7

Description

  The present invention relates to a brushed motor and a fan motor for cooling a radiator.

  For example, a motor with a brush is used as a fan motor for cooling a radiator of a car. The motor with a brush includes a cylindrical yoke (motor case) in which a magnet is disposed on the inner peripheral surface, an end bracket closing the opening of the yoke, and an armature (rotor) rotatably supported in the yoke. And a brush provided on the end bracket for supplying power to the armature.

  The armature has a rotary shaft, an armature core fixed to the rotary shaft, a coil wound around the armature core, and a cylindrical shaft fixed to the rotary shaft and connected to the end of the coil. And a commutator. On the outer peripheral surface of the commutator, a plurality of metal plate-like segments are arranged in the state of being mutually insulated in the circumferential direction. The end of the coil is connected to this segment.

  The brushes are arranged in sliding contact with the segments of the commutator. Also, the brush is electrically connected to an external power supply. Thereby, current is supplied to the coil through the brush and the segment. When current is supplied to the coil, a magnetic field is formed in the armature core. A magnetic attractive force or repulsive force is generated between the magnetic field and a magnet provided to the yoke to rotate the armature. In addition, when the armature rotates, the segment to which the brush is in sliding contact is sequentially changed, and so-called rectification is performed in which the direction of the current flowing through the coil is switched. This causes the armature to rotate continuously.

As described above, since the armature continues to rotate while the brush is in sliding contact with the commutator, the brush is worn away. Also, the amount of wear of the brush increases in proportion to the temperature of the brush. For this reason, various techniques for cooling the brush have been proposed in order to lower the brush temperature as much as possible.
For example, Patent Document 1 discloses a technique in which a cooling pipe is provided and cooling air is taken into the yoke through the cooling pipe.

JP 2003-153487 A

  However, as in the above-mentioned prior art, when it is attempted to take in cooling air in the yoke by providing a cooling pipe, etc., the structure of the brushed motor becomes complicated by the provision of the cooling pipe, and the number of parts increases. There was a problem that cost increased.

  Therefore, the present invention provides a brush motor and radiator fan motor that can increase brush cooling efficiency and extend the brush life without increasing the number of parts with a simple structure.

  In order to solve the above-mentioned problems, a motor with a brush according to the present invention is provided with a cylindrical yoke, an end bracket closing one end of the yoke, and a radial inner side of the yoke. An armature having a rotating shaft freely supported, an armature core fixed to the rotating shaft and wound with a winding, an armature fixed to the rotating shaft and a cylindrical commutator connected to the winding, and the end And a plurality of brushes disposed on the side of the bracket on the side of the commutator and in sliding contact with the outer peripheral surface of the commutator, wherein the end bracket has a portion where the commutator and the brush are in sliding contact and the rotation shaft A first air cooling opening is formed at a position opposed in the axial direction.

  With this configuration, the cooling air for cooling the brush from the first air cooling opening formed in the end bracket can be easily taken into the yoke without increasing the number of parts. Moreover, the brush is disposed on one surface of the end bracket on the commutator side, and the first air cooling opening is disposed at a position axially opposed to the brush. For this reason, the cooling air taken in from the first air cooling opening can be immediately applied to the brush as it is. Therefore, the brush can be cooled efficiently, and the life of the brush can be extended.

  The motor with a brush according to the present invention is characterized in that the first air cooling opening has a width in the circumferential direction as viewed from the axial direction larger than a width in the circumferential direction of the brush.

  With this configuration, cooling air can be efficiently applied to the entire tip of the brush. Therefore, the brush can be cooled more efficiently.

  The motor with a brush according to the present invention is characterized in that the end bracket is provided with a cylindrical hood that protrudes from the peripheral edge of the first air-cooling opening toward the brush.

  By configuring in this manner, it is possible to suppress that the abrasive powder of the brush scatters around the brush. And, it becomes possible to reliably discharge the abrasion powder of the brush to the outside of the end bracket through the first air cooling opening.

  The motor with a brush according to the present invention is characterized in that a cover is provided at the end of the hood at the downstream end in the rotational direction of the armature so as to close a part of the opening of the hood. .

  Here, the abrasive powder of the brush is ejected to the first air cooling opening while being blown to the downstream side in the rotational direction of the armature by the rotation of the armature. For this reason, by providing a cover on the downstream side of the rotational direction of the armature at the tip of the hood, the cover prevents the wear powder that has once risen to the first air cooling opening from scattering back to the inside (brush side) of the end bracket. it can. Therefore, it is possible to more reliably discharge the abrasion powder of the brush to the outside of the end bracket.

  In the motor with a brush according to the present invention, the brush is supported by a plate-like brush holder stay provided on the one surface of the end bracket, and the brush holder stay contacts the radially outer surface of the hood. A contact portion in contact is provided.

  With this configuration, radial positioning of the brush holder stay with respect to the end bracket can be easily performed. For this reason, the assembly operation of the motor with a brush can be facilitated.

  The motor with a brush according to the present invention is characterized in that the contact portion is a peripheral edge of a stay opening portion formed in the brush holder stay.

  With this configuration, the stay opening is fitted to the radially outer side surface of the hood. Therefore, radial positioning of the brush holder stay with respect to the end bracket can be performed more accurately and easily.

  The motor with a brush according to the present invention is characterized in that a plurality of through holes penetrating in the axial direction are formed in the armature core.

  With this configuration, the passage of the cooling air in the axial direction can be improved in the yoke. Therefore, the flow of the cooling air can be improved, and the cooling efficiency of the brush can be further enhanced.

  In the motor with a brush according to the present invention, the first air cooling opening portion of the end bracket has a first opening surface seen from the brush side and a second opening surface seen from the opposite side to the brush, the axial direction It is characterized in that they are offset from each other in terms of perspective.

  With such a configuration, for example, even if water or dust intrudes from the second opening surface on the outside of the end bracket, the water or dust smoothly reaches the first opening surface on the inside of the end bracket. It becomes difficult. Therefore, the dustproof and waterproof function of the motor with a brush can be enhanced.

  The motor with a brush according to the present invention includes a front bracket that closes the other end of the yoke, and the front bracket is formed with at least one second air cooling opening communicating the inside and the outside of the front bracket. It is characterized by

  As described above, by forming the second air-cooling opening in the front bracket opposite to the end bracket with the yoke interposed therebetween, the passage of the cooling air in the yoke can be further improved. Therefore, the flow of the cooling air can be further improved, and the cooling efficiency of the brush can be further enhanced.

  In the motor with a brush according to the present invention, the second air cooling opening of the front bracket has a third opening as viewed from the armature and a fourth opening as viewed from the opposite side to the armature. It is characterized in that they are offset from each other in terms of perspective.

  With this configuration, for example, even if water or dust intrudes from the fourth opening surface on the outer side of the front bracket, the water or dust smoothly reaches the third opening surface on the inner side of the front bracket. It becomes difficult. Therefore, the dustproof and waterproof function of the motor with a brush can be further enhanced.

The motor with a brush according to the present invention is characterized in that the end bracket is made of resin.

  This configuration can reduce the weight of the end bracket. As a result, the motor with a brush can be reduced in weight.

  A radiator cooling fan motor according to the present invention is characterized in that the brushed motor described above is used for cooling a radiator of an automobile, and a fan blade is provided on the rotating shaft of the brushed motor.

  By this configuration, it is possible to provide a fan motor for radiator cooling that is low in cost and has a long product life as the brush life is extended.

  According to the present invention, the cooling air for cooling the brush can be easily taken into the yoke from the first air cooling opening formed in the end bracket without increasing the number of parts. Moreover, the brush is disposed on one surface of the end bracket on the commutator side, and the first air cooling opening is disposed at a position axially opposed to the brush. For this reason, the cooling air taken in from the first air cooling opening can be immediately applied to the brush as it is. Therefore, the brush can be cooled efficiently, and the life of the brush can be extended.

The perspective view which decomposed | disassembled the fan blade of the fan motor for radiator cooling in 1st Embodiment of this invention. The disassembled perspective view of the motor with a brush in 1st Embodiment of this invention. Sectional drawing which follows the AA of FIG. The perspective view of the armature core in a 1st embodiment of the present invention. The perspective view which saw the brush holder stay in 1st Embodiment of this invention from the back surface. The perspective view of the end bracket in a 1st embodiment of the present invention. The top view which looked at the motor with a brush in 1st Embodiment of this invention from the outer surface side of an end bracket. The B section enlarged view of FIG. The perspective view which shows the assembly state of the end bracket and the brush holder stay of a brush holder unit in 1st Embodiment of this invention. The C section enlarged view of FIG. Operation | movement explanatory drawing of the food | hood in 1st Embodiment of this invention, and a cover. Graph comparing the temperature of the brush holder between the case with the armature core through hole in the first embodiment of the present invention and the case with the end side air cooling opening 36 in addition to the case with the armature core through hole and the case with the prior art. . The perspective view of the end bracket in 2nd Embodiment of this invention. FIG. 14 is a cross-sectional view taken along the line C-C of FIG. 13;

  Next, an embodiment of the present invention will be described based on the drawings.

First Embodiment
(Fan motor for radiator cooling)
FIG. 1 is an exploded perspective view of a fan blade 101 of a radiator cooling fan motor 100. FIG. 2 is an exploded perspective view of the brushed motor 1.
A radiator cooling fan motor (hereinafter simply referred to as a fan motor) 100 is used, for example, for cooling a radiator (not shown) of a car.

As shown in FIG. 1 and FIG. 2, the radiator cooling fan motor 100 includes a brushed motor 1 and a fan blade 101 attached to a rotating shaft 13 described later of the brushed motor 1.
In the following description, the axial direction of the rotary shaft 13 is simply referred to as the axial direction, the rotational direction of the rotary shaft 13 as the circumferential direction, and the radial direction of the rotary shaft 13 orthogonal to the axial direction and the circumferential direction as the radial direction. explain.

(Motor with brush)
The motor with brush 1 has a substantially bottomed cylindrical motor case 2, an armature 3 rotatably accommodated in the motor case 2, an end bracket 4 for closing the opening 2 a of the motor case 2, and an end bracket 4. And the brush holder unit 5 provided on the inner surface 4a (surface on the side of the armature 3).

(Motor case)
The motor case 2 is formed, for example, by subjecting a metal plate to deep drawing. That is, the motor case 2 is formed by integrally molding the substantially cylindrical yoke portion 6 and the front bracket 7 constituting the bottom portion.
On the inner peripheral surface of the yoke portion 6, a plurality of magnets (not shown) are arranged such that the magnetic poles become in order in the circumferential direction. The yoke portion 6 forms a magnetic path of a plurality of magnets.

  In addition, an external mounting member 50 is attached to the outer peripheral surface of the yoke portion 6. The external attachment member 50 is for attaching the brushed motor 1 to a vehicle body (not shown), for example. The external mounting member 50 has a substantially cylindrical ring portion 51 fitted to the outer peripheral surface of the yoke portion 6, and a plurality (three in the first embodiment) protruding radially outward from the outer peripheral surface of the ring portion 51. Mounting stays 52).

The ring portion 51 is integrated with the yoke portion 6 by press-fitting or welding to the outer peripheral surface of the yoke portion 6.
The mounting stays 52 are arranged at equal intervals in the circumferential direction. The mounting stay 52 is formed in a substantially triangular shape as viewed in the axial direction so as to be tapered toward the radially outer side. The mounting stay 52 is formed with a bolt insertion hole 52a through which a bolt (not shown) can be inserted.

(Front bracket)
A recess 7 b is formed at the radial center of the front bracket 7 so that the outer surface 7 a (surface opposite to the armature 3) is recessed. A substantially cylindrical bearing boss 9 is integrally formed at the radial center of the recess 7 b so as to project axially outward. The bearing boss 9 holds a ball bearing 8 for rotatably supporting one end 13 a side of a rotating shaft 13 described later.

FIG. 3 is a cross-sectional view taken along the line A-A of FIG.
As shown in FIGS. 1 to 3, a plurality of (four in the first embodiment) front air-cooling openings 10 are formed in the front bracket 7 near the outer peripheral portion.
The front air-cooling opening 10 has an outer hood 11 which is formed by cutting and raising the front bracket 7 and projecting to the outer surface 7a side, and an inner surface 7c which is opposite to the outer surface 7a by cutting and raising the front bracket 7 (armature 3 side And the inner hood 12 made to project. More specifically, the front air-cooling opening 10 is formed by the two hoods 11 and 12 having the openings 11a and 12a facing each other in the surface direction of the front bracket 7, and the openings 11a and 12a communicating with each other.

  Here, the outer opening surface 11b seen from the outer surface 7a (outer hood 11) side of the front bracket 7 along the axial direction and the inner opening surface seen from the inner surface 7c (inner hood 12) side of the front bracket 7 along the axial direction 12 b are offset from each other in the axial direction. As a result, the front air cooling opening 10 is not visible when viewed from the axial direction.

(Armature)
Returning to FIG. 2, the armature 3 has a rotary shaft 13 whose one end 13 a side is rotatably supported by the front bracket 7, an armature core 14 externally fitted and fixed to the rotary shaft 13, and an armature core 14 of the rotary shaft 13. And a commutator 15 which is externally fitted and fixed to the end bracket 4 side.

FIG. 4 is a perspective view of the armature core 14.
As shown in FIGS. 2 and 4, the armature core 14 is formed by laminating a plurality of metal plates in the axial direction, or pressing and forming a soft magnetic powder. The armature core 14 is disposed at a position radially opposed to a magnet (not shown) provided on the yoke portion 6 in the radial direction. The armature core 14 has a substantially annular rotary shaft fixing portion 16 which is externally fitted and fixed to the rotary shaft 13. The rotary shaft 13 is press-fitted and fixed to a through hole 16 a formed in the rotary shaft fixing portion 16 and penetrating in the axial direction.

  An outer annular portion 17 formed concentrically with the rotary shaft fixing portion 16 is provided on the radially outer side of the rotary shaft fixing portion 16. Between the rotary shaft fixing portion 16 and the outer annular portion 17, a plurality of spoke portions 18 are provided extending in the circumferential direction at equal intervals in the circumferential direction and extending across the two 16 and 17 (10 in the first embodiment) It is done. That is, the armature core 14 is axially penetrated by the rotary shaft fixing portion 16, the outer annular portion 17 and the spoke portion 18, and a plurality of substantially fan-shaped through holes 19 viewed from the axial direction (the first embodiment) 10) are to be formed.

  A plurality of teeth 21 (10 in the first embodiment) are formed radially outward of the outer annular portion 17 radially outward of the T-shaped in plan view in the axial direction. Dovetail shaped slots 22 are formed between adjacent teeth 21. A plurality (10 in the first embodiment) of the slots 22 are also formed at equal intervals along the circumferential direction. Each tooth 21 is fitted with an insulator 44 that covers the circumference of the tooth 21. Then, a coil 23 of enamel coating is passed through the slot 22, and the coil 23 is wound around the teeth 21 from above the insulator 44. The end of the coil 23 wound around each tooth 21 is drawn toward the commutator 15.

  The commutator 15 has a plurality of segments 24 arranged on the outer peripheral surface of a cylindrical resin mold body (not shown) externally fitted and fixed to the rotary shaft 13. Each segment 24 is formed in a rectangular shape elongated in the axial direction by a metal plate. The segments 24 are arranged side by side in the circumferential direction in a state of being insulated from each other. The end of the desired coil 23 is connected to each segment 24. Thereby, each segment 24 and the coil 23 are electrically connected. The brush 27 of the brush holder unit 5 is in sliding contact with each segment 24.

(Brush holder unit)
As shown in FIG. 2, the brush holder unit 5 includes a substantially disk-shaped brush holder stay 25, a brush holder 26 provided on a surface 25 a of the brush holder stay 25 on the armature core 14 side, and a brush holder 26. The brush 27 housed inside is mainly configured.

FIG. 5 is a perspective view of the brush holder stay 25 as viewed from the back surface 25b opposite to the front surface 25a.
As shown in FIGS. 2 and 5, the brush holder stay 25 is formed of resin. A cylindrical rib 29 for reinforcement of the brush holder stay 25 is integrally formed on the outer peripheral portion of the brush holder stay 25. The ribs 29 are formed to project from both surfaces 25 a and 25 b of the front surface 25 a and the back surface 25 b of the brush holder stay 25.

  In addition, a connector 30 is integrally formed on the outer peripheral portion of the brush holder stay 25. The connector 30 can be fitted with an external connector (not shown) extending from an external power supply. The connector 30 has a terminal (not shown), and this terminal is electrically connected to an external power supply.

  An opening 25 c through which the commutator 15 can be inserted is formed at the radial center of the brush holder stay 25. The brush holder stay 25 is disposed in a state where the commutator 15 is inserted through the opening 25 c. Further, a cylindrical fitting cylindrical portion 28 slightly projecting toward the back surface 25 b side of the brush holder stay 25 is integrally molded on the peripheral edge of the opening 25 c.

  The brush holders 26 provided on the surface 25 a of the brush holder stay 25 are formed of, for example, a rectangular parallelepiped box made of brass or the like, and four are arranged. In addition, the brush holders 26 are disposed around the opening 25 c of the brush holder stay 25 so that the longitudinal direction is along the radial direction and at equal intervals in the circumferential direction.

  The brush 27 is accommodated in such a brush holder 26 so as to be slidable along the radial direction. That is, a total of four brushes 27 are provided by two anode brushes and two cathode brushes. The brush 27 is biased toward the radial center side, that is, toward the commutator 15 by a spring (not shown) housed in the brush holder 26. Thereby, the tip of the brush 27 is always in sliding contact with the segment 24 of the commutator 15.

  That is, the tip end of the brush 27 is in a state of being faced from the periphery of the opening 25 c of the brush holder stay 25 toward the center in the radial direction. This tip is in sliding contact with the segment 24 of the commutator 15 at the position of the tip of the brush 27 exposed in the opening 25 c. That is, the sliding contact position between the segment 24 and the brush 27 is exposed through the opening 25 c as viewed from the back surface 25 b of the brush holder stay 25.

  Further, one end of the pigtail 31 is connected to the brush 27. The other end of the pigtail 31 is connected to a terminal (not shown) of the connector 30 provided on the brush holder stay 25. Thereby, the power of the external power supply is supplied to the brush 27 via the connector 30 and the pigtail 31. Further, the power of the external power supply is supplied to the coil 23 through the segment 24 in sliding contact with the brush 27.

The brush holder 26 is formed with a slit 32 which allows the pigtail 31 to move in accordance with the sliding movement of the brush 27.
In addition to this, on the surface 25 a of the brush holder stay 25, a choke coil 33 and a capacitor 34 as a noise prevention element are provided. The choke coil 33 and the capacitor 34 are provided to connect between a pigtail 31 extending from a predetermined brush 27 and a terminal (not shown) of the connector 30.
The brush holder unit 5 configured in this manner is arranged such that the rib 29 of the brush holder stay 25 abuts on the end bracket 4 and is fixed to the end bracket 4.

(End bracket)
FIG. 6 is a perspective view of the end bracket 4. FIG. 7 is a plan view of the brush motor 1 as viewed from the outer surface 4 b side opposite to the inner surface 4 a of the end bracket 4.
As shown in FIGS. 2, 6, and 7, the end bracket 4 closing the opening 2 a of the motor case 2 is formed in a substantially disc shape of resin. The rib 29 of the brush holder stay 25 is disposed in contact with the inner surface 4 a of the end bracket 4.

A substantially cylindrical fitting portion 37 which is bent toward the inner surface 4 a is extendedly formed on the outer peripheral portion of the end bracket 4. By fitting the fitting portion 37 into the opening 2 a of the motor case 2, the end bracket 4 closes the opening 2 a.
Further, the fitting portion 37 is formed with a notch 40 for receiving the connector 30 of the brush holder stay 25.

A substantially cylindrical bearing boss 35 protruding from the inner surface 4 a is integrally formed at the radial center of the end bracket 4. The bearing boss 35 holds a ball bearing (not shown) for rotatably supporting the other end of the rotary shaft 13.
In the end bracket 4, end-side air-cooling openings 36 are formed around the bearing boss 35 and at positions axially opposed to the sliding contact between the commutator 15 and the brush 27. The end-side air-cooling opening 36 is an oval-shaped opening extending in a circular arc along the circumferential direction. The outer peripheral portion (segment 24) of the commutator 15 and the tip of the brush 27 are exposed through the end side air cooling opening.

FIG. 8 is an enlarged view of a portion B of FIG.
As shown in FIG. 8, the width W1 of the end side air cooling opening 36 in the circumferential direction as viewed in the axial direction is set larger than the width W2 of the brush 27 in the circumferential direction.

  As shown in FIG. 6, a cylindrical hood 38 protruding from the inner surface 4 a of the end bracket 4 is integrally molded on the peripheral edge of the end-side air-cooling opening 36. The protruding height H1 of the hood 38 is set so as not to contact the brush 27 in a state where the brush holder unit 5 is attached to the end bracket 4.

In addition, covers 39 are provided at both ends in the circumferential direction of the end of the hood 38 so as to close both sides in the circumferential direction of the end-side air-cooling opening 36. The cover 39 is slightly curved so that the radial center protrudes most toward the armature 3 side.
Here, the end side air cooling opening 36 extends in a circular arc along the circumferential direction, and the armature 3 is rotated relative to the end bracket 4. That is, the two circumferential sides of the hood 38 are the two sides of the hood 38 in the rotational direction of the armature 3.

(Assembly state of end bracket and brush holder unit)
Next, an assembled state of the end bracket 4 and the brush holder unit 5 will be described.
FIG. 9 is a perspective view showing an assembled state of the end bracket 4 and the brush holder stay 25 of the brush holder unit 5. FIG. 10 is an enlarged view of a portion C of FIG.
As shown in FIGS. 9 and 10, the brush holder stay 25 has the back surface 25b (see FIG. 5) side facing the inner surface 4a of the end bracket 4, and the fitting portion 37 of the end bracket 4 is the inner surface 4a. Is disposed radially inward of the

Ribs 29 are integrally formed on the outer periphery of the brush holder stay 25. Therefore, when the axial end of the rib 29 abuts on the inner surface 4 a of the end bracket 4, the back surface 25 b of the brush holder stay 25 does not directly contact the inner surface 4 a of the end bracket 4. That is, a slight gap is formed between the back surface 25 b of the brush holder stay 25 and the inner surface 4 a of the end bracket 4.
Further, in a state where the brush holder stay 25 is set on the inner surface 4 a of the end bracket 4, the inner peripheral surface of the opening 25 c of the brush holder stay 25 is fitted to the radial outer surface of the hood 38 of the end bracket 4. . Thereby, radial positioning of the brush holder stay 25 with respect to the end bracket 4 is performed.

  Further, the circumferential direction of the brush holder stay 25 is aligned with the end bracket 4 so that the connector 30 of the brush holder stay 25 is positioned at the notch 40 formed in the fitting portion 37 of the end bracket 4. Be Therefore, interference between the end bracket 4 and the connector 30 of the brush holder stay 25 is prevented.

(Operation of fan motor for radiator cooling)
Next, the operation of the radiator cooling fan motor 100 will be described.
When power from an external power supply (not shown) is supplied to the coil 23 through the connector 30, the pigtail 31, the brush 27, and the commutator 15, a predetermined magnetic field is formed in the armature core 14. A magnetic attractive force or repulsive force is generated between this magnetic field and a magnet (not shown) provided on the yoke portion 6, and the armature 3 is rotated. Also, when the armature 3 rotates, the segments 24 of the commutator 15 with which the brush 27 is in sliding contact are sequentially changed, and so-called rectification is performed in which the direction of the current flowing through the coil 23 is switched. Thereby, the armature 3 rotates continuously.

Here, a plurality of (four in the first embodiment) front air-cooling openings 10 are formed in the front bracket 7 near the outer peripheral portion. Further, in the end bracket 4, a plurality of (four in the first embodiment) end-side air-cooling openings 36 are formed around the bearing boss 35. The front air cooling opening 10 and the end air cooling opening 36 are arranged to face each other in the axial direction when viewed from the entire brushed motor 1. For this reason, the air flow along the axial direction is generated in the motor case 2 through the air cooling openings 10 and 36.
At this time, since a plurality of (approximately 10 in the first embodiment) substantially fan-shaped through holes 19 are formed in the armature core 14, the flow of air in the axial direction is improved in the motor case 2.

  Each end-side air-cooling opening 36 is formed at a position axially opposed to the sliding contact portion between the commutator 15 and the brush 27. Therefore, the cooling air that has flowed into the motor case 2 through the end-side air-cooling openings 36 immediately hits the tip of the brush 27 in sliding contact with the commutator 15.

  In addition, a cylindrical hood 38 protruding from the inner surface 4 a of the end bracket 4 is integrally formed on the peripheral edge of the end side air cooling opening 36. Covers 39 are provided at both ends in the circumferential direction (the downstream end in the rotational direction of the armature 3) of the hood 38 so as to close both sides in the circumferential direction of the end-side air-cooling opening 36. For this reason, scattering of the wear powder of the brush 27 due to the brush 27 coming into sliding contact with the commutator 15 is suppressed, and the wear powder of the brush 27 is discharged from the end side air-cooling opening 36. This matter will be specifically described below.

FIG. 11 is an operation explanatory view of the hood 38 and the cover 39 provided in the end side air cooling opening 36.
As indicated by arrows Y1 and Y2 in FIG. 11, the armature 3 rotatably supported by the end bracket 4 rotates with respect to the end bracket 4. Since the brush 27 is attached to the end bracket 4, the commutator 15 rotates with respect to the brush 27. Since a wind is generated by the rotation of the commutator 15, the abrasion powder P of the brush 27 due to sliding contact with the commutator 15 is scattered toward the downstream side in the rotational direction of the commutator 15 (armature 3).
In addition, in FIG. 11, the scattering state of the abrasion powder P when, for example, the armature 3 is rotating in the arrow Y1 direction is shown.

  At this time, since the hood 38 is formed on the periphery of the end side air cooling opening 36, the wear powder P is concentrated to the end side air cooling opening 36 by the hood 38. Further, covers 39 are provided at both ends of the hood 38 at the circumferential direction on the downstream side in the rotational direction of the armature 3. For this reason, it is possible to prevent the wear powder P, which has once risen to the end side air cooling opening 36, from coming back to the brush 27 side.

  As described above, in the above-described first embodiment, the brush 27 is disposed on the inner surface 4 a of the end bracket 4, and at a position where the commutator 15 and the brush 27 in the end bracket 4 axially oppose each other. The end side air cooling opening 36 was formed. Therefore, the cooling air for cooling the brush from the end-side air-cooling opening 36 can be easily taken into the motor case 2 without increasing the number of parts. Moreover, the cooling air taken in from the end side air cooling opening 36 can be immediately applied to the brush 27 as it is. Therefore, the brush 27 can be cooled efficiently and the life of the brush can be extended.

  Further, the end side air cooling opening portion 36 is set such that the width W1 in the circumferential direction as viewed in the axial direction is larger than the width W2 in the circumferential direction of the brush 27. Therefore, the cooling air can be efficiently applied to the entire tip of the brush 27. Therefore, the brush 27 can be cooled more efficiently.

  Further, a plurality of (approximately 10 in the first embodiment) substantially fan-shaped through holes 19 are formed in the armature core 14. Therefore, the flow of air in the axial direction can be improved in the motor case 2. That is, the flow of the cooling air is improved, and the cooling efficiency of the brush 27 can be further enhanced.

  In addition, a plurality of (four in the first embodiment) front-side air-cooling openings 10 are also formed on the front bracket 7. The front air cooling opening 10 faces the end air cooling opening 36 in the axial direction. That is, the front air cooling opening 10 is located on the opposite side to the end air cooling opening 36 across the yoke portion 6 of the motor case 2. Therefore, the passage of the cooling air in the motor case 2 can be further improved. As a result, the cooling efficiency of the brush 27 can be further enhanced.

  In FIG. 12, the vertical axis represents the temperature of the brush holder 26, and the temperature of the brush holder 26 in the conventional case, in the case of the armature core through hole, and in the armature core through hole, the end side air cooling opening 36 It is the graph which compared by the case of, and. The presence of the armature core through hole means that the through hole 19 is formed in the armature core 14. Moreover, the term “conventional” means that the through hole 19 is not formed in the armature core 14 and the end side air cooling opening 36 is not formed. Moreover, in any case of FIG. 12, it is assumed that the front side air-cooling opening 10 is not formed.

  As shown in FIG. 12, it can be confirmed that the temperature of the brush holder 26 is lower in the presence of the armature core through hole as compared with the conventional case. Further, it can be confirmed that the temperature of the brush holder 26 is lower in the presence of the armature core through hole and in the presence of the end side air-cooling opening 36 than in the presence of the armature core through hole. For this reason, the armature core through hole and the end side air cooling opening 36 can effectively cool the brush 27.

  Further, in the first embodiment described above, the cylindrical hood 38 protruding from the inner surface 4 a of the end bracket 4 is integrally formed on the peripheral edge of the end-side air-cooling opening 36. Covers 39 are provided at both ends in the circumferential direction (the downstream end in the rotational direction of the armature 3) of the hood 38 so as to close both sides in the circumferential direction of the end-side air-cooling opening 36. For this reason, scattering of the wear powder of the brush 27 due to the brush 27 coming into sliding contact with the commutator 15 is suppressed, and the wear powder of the brush 27 is discharged from the end side air-cooling opening 36. Therefore, the abrasion powder of the brush 27 can be reliably discharged through the end side air cooling opening 36, and the contamination into the motor case 2 can be suppressed.

  Further, an opening 25 c through which the commutator 15 can be inserted is formed at the radial center of the brush holder stay 25. Furthermore, the opening 25 c is formed to be fitted to the radially outer side surface of the hood 38 of the end bracket 4. Therefore, when setting the brush holder stay 25 on the inner surface 4 a of the end bracket 4, the radial positioning of the brush holder stay 25 with respect to the end bracket 4 can be easily performed.

  Further, the front air-cooling opening 10 has an outer opening surface 11b viewed from the outer surface 7a (outside hood 11) side of the front bracket 7 in the axial direction, and an inner surface 7c of the front bracket 7 in the axial direction (the inner hood 12 And the inner opening surface 12b viewed from the side are offset from each other when viewed from the axial direction. That is, when viewed from the axial direction, the front air cooling opening 10 can not be viewed. Therefore, for example, even if water or dust intrudes from the outer opening surface 11b of the front bracket 7, it is difficult for the water or dust to reach the inner opening surface 12b smoothly. For this reason, the dust and waterproof function of the brushed motor 1 can be enhanced.

  Further, the end bracket 4 is formed of resin. Therefore, the end bracket 4 can be reduced in weight, and further, the brushed motor 1 can be reduced in weight.

  In the first embodiment described above, the front air-cooling opening 10 includes the outer hood 11 which is formed by cutting and raising the front bracket 7 and projecting to the outer surface 7 a side, and the outer bracket 7 by cutting and raising the front bracket 7. The case where it is formed by the inner hood 12 made to project on the opposite inner surface 7c side (armature 3 side) has been described. However, the present invention is not limited to this, and the front air cooling opening 10 may be a simple through hole penetrating the front bracket 7.

  Further, in the above-described first embodiment, the case where the width W1 in the circumferential direction as viewed from the axial direction is set larger than the width W2 in the circumferential direction of the brush 27 when viewed from the axial direction has been described. However, the present invention is not limited to this, and the end side air cooling opening 36 may be formed at a position axially opposed to the sliding contact between the commutator 15 and the brush 27 in the end bracket 4, and the size thereof May be set arbitrarily.

Second Embodiment
Next, a second embodiment of the present invention will be described based on FIGS. 13 and 14.
FIG. 13 is a perspective view of the end bracket 204 of the motor with brush 201 in the second embodiment. FIG. 14 is a cross-sectional view taken along the line B-B of FIG. In the second embodiment, the same reference numerals are given to the same aspects as the first embodiment described above, and the description will be omitted.
As shown in FIG. 13 and FIG. 14, the outer surface 204 b of the end bracket 204 is integrally formed with a shed 60 that covers the end air cooling opening 36 from the outer surface 204 b at a position corresponding to the end air cooling opening 36. It is done. This point is a point different from the first embodiment described above.

  Among the peripheries of the end-side air cooling opening 36, the weir 60 is integrally formed at the side wall 61 rising from the periphery of approximately half in the longitudinal direction and at the tip of the side wall 61 and axially faces the end-side air cooling opening 36 The ceiling wall portion 62 is configured. The top wall portion 62 is formed to correspond to the shape of the end-side air cooling opening 36. That is, the top wall portion 62 is formed in an oval shape extending in an arc shape along the circumferential direction as viewed from the axial direction.

  By forming the shed portion 60, the end-side air-cooling opening portion 36 is configured as an opening surface 36a on the inner surface 204a side of the end bracket 204 (hereinafter referred to as an inner opening surface 36a). Further, in the end-side air-cooling opening portion 36, the opening between the weir 60 and the outer surface 204b of the end bracket 204 is configured as an opening surface 36b on the outer surface 204b side (hereinafter referred to as an outer opening surface 36b). Thus, the inner opening surface 36a and the outer opening surface 36b are offset from each other as viewed in the axial direction. Thus, the end side air cooling opening 36 can not be viewed when viewed from the axial direction.

  Therefore, according to the above-described second embodiment, the same effect as that of the above-described first embodiment can be obtained. Further, in addition to this, the end side air cooling opening 36 is not visible when viewed from the axial direction. Therefore, for example, even if water or dust intrudes from the outer opening surface 36b of the end bracket 204, it is difficult for the water or dust to reach the inner opening surface 36a smoothly. Therefore, the dust and waterproof function of the brushed motor 201 can be further enhanced.

The present invention is not limited to the above-described embodiment, and includes the above-described embodiment with various modifications, without departing from the spirit of the present invention.
For example, in the above embodiment, the case where the brushed motor 1, 201 is used for the radiator cooling fan motor 100 has been described. However, the present invention is not limited to this, and the brushed motor 1, 201 can be used for various electric motors.

Moreover, in the above-mentioned embodiment, the case where the four front side air-cooling opening parts 10 were formed in the front bracket 7 by the outer peripheral part side was demonstrated. However, the present invention is not limited to this, and the number of the front air-cooling openings 10 can be arbitrarily set.
Further, in the above-described embodiment, the end bracket 4 is formed with the end side air cooling openings 36 around the bearing boss 35 and at positions axially opposed to the sliding contact between the commutator 15 and the brush 27. The case has been described. However, the present invention is not limited to this, and in addition to the position around the bearing boss 35 and in the axial direction facing the sliding contact point between the commutator 15 and the brush 27, the end side air cooling opening 36 is formed in other places. You may

Moreover, in the above-mentioned embodiment, the case where the cylindrical hood 38 which protrudes from the inner surface 4a of the end bracket 4 was integrally molded by the periphery of the end side air-cooling opening part 36 was demonstrated. However, the present invention is not limited to this, and the hood 38 may not be formed. Even when the hood 38 is not formed, the brush 27 can be cooled efficiently and the life of the brush can be extended.
Moreover, even when the hood 38 is formed, the shape is not limited to the tubular shape, and various shapes can be adopted.

Moreover, in the above-mentioned embodiment, the case where the cover 39 was provided in the front-end | tip of the food | hood 38 so that the circumferential direction both sides of the end side air-cooling opening part 36 may be obstruct | occluded at circumferential direction both sides was demonstrated. However, the present invention is not limited to this, and the cover 39 may not be provided.
Moreover, in the above-mentioned embodiment, the case where the cover 39 is slightly curved and formed so that the radial center protrudes most toward the armature 3 side was described. However, the present invention is not limited to this, and the cover 39 may not be curved. For example, the cover 39 may be formed in a flat plate shape.

  Moreover, in the above-mentioned embodiment, the case where motor case 2 was formed by giving deep-drawing process to a metal plate was demonstrated, for example. The motor case 2 is described as being integrally molded with the substantially cylindrical yoke portion 6 and the front bracket 7 constituting the bottom portion. However, the present invention is not limited to this, and the yoke portion 6 and the front bracket 7 are configured separately, and the front bracket 7 blocks the opening of the yoke portion 6 opposite to the end brackets 4 and 204. You may configure it.

  Moreover, in the above-mentioned embodiment, the case where the four brush holders 26 were provided on the surface 25a of the brush holder stay 25 and the four brushes 27 were accommodated in each brush holder 26 was described. However, the present invention is not limited to this, and the number of brush holders 26 and brushes 27 can be set arbitrarily.

1, 201: motor with brush, 2: motor case, 3: armature, 4, 204: end bracket, 6: yoke portion, 7: front bracket, 10: front side air-cooled opening (second air-cooled opening) 11b: outer opening surface (fourth opening surface) 12b: inner opening surface (third opening surface) 13: rotation axis 14: armature core 15: commutator 19: through hole 25: brush holder stay , 25c: opening, 27: brush, 36: end side air cooling opening (first air cooling opening), 36a: inner opening surface (first opening), 36b: outer opening surface (second opening), 38 ... Hood, 39 ... Cover, 100 ... Fan motor for radiator cooling, 101 ... Fan blade

Claims (12)

With a cylindrical yoke,
An end bracket closing one end of the yoke;
A rotating shaft disposed radially inward of the yoke and rotatably supported by the end bracket, an armature core fixed to the rotating shaft and wound with a winding, fixed to the rotating shaft, and the winding An armature having a cylindrical commutator to which
A plurality of brushes disposed on one surface of the end bracket on the commutator side and in sliding contact with the outer peripheral surface of the commutator;
Equipped with
A motor with a brush, wherein a first air-cooling opening is formed in the end bracket at a position where the commutator and the brush are in sliding contact with each other and in the axial direction of the rotation shaft. 2. The brush motor according to claim 1, wherein a width of the first air cooling opening in a circumferential direction when viewed from the axial direction is set larger than a width of the brush in a circumferential direction. The motor with a brush according to claim 1 or 2, wherein the end bracket is provided with a cylindrical hood that protrudes from the periphery of the first air-cooling opening toward the brush. . The brush motor according to claim 3, wherein a cover is provided at a tip end of the hood at a downstream end in the rotational direction of the armature so as to close a part of the opening of the hood. . The brush is supported by a plate-like brush holder stay provided on the one surface of the end bracket;
The motor with a brush according to claim 3 or 4, wherein the brush holder stay is provided with an abutting portion that abuts on a radially outer surface of the hood. The motor with a brush according to claim 5, wherein the contact portion is a peripheral edge of a stay opening formed in the brush holder stay. The brush motor according to any one of claims 1 to 6, wherein a plurality of through holes penetrating in the axial direction are formed in the armature core. The first air cooling opening of the end bracket is characterized in that the first opening surface seen from the brush side and the second opening surface seen from the opposite side to the brush are mutually shifted as viewed from the axial direction The motor with a brush according to any one of claims 1 to 7, wherein the motor is a motor. A front bracket that closes the other end of the yoke;
The brush according to any one of claims 1 to 8, wherein at least one second air-cooling opening communicating the inside and the outside of the front bracket is formed in the front bracket. motor. The second air-cooling opening of the front bracket is characterized in that the third opening viewed from the armature and the fourth opening viewed from the opposite side to the armature are offset from each other when viewed from the axial direction. The motor with a brush according to claim 9. The motor with a brush according to any one of claims 1 to 10, wherein the end bracket is formed of a resin. The brushed motor according to any one of claims 1 to 11 is used for cooling a radiator of an automobile,
A fan motor for cooling a radiator, characterized in that a fan blade is provided on the rotation shaft of the motor with a brush.

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