JP2017225346A - Rotary electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotary electric machine which can secure cooling performance of a brush and inhibit vibration of a brush housing part.SOLUTION: A rotary electric machine 10 includes: an armature having a commutator 26; a brush 34 which slidably contacts with the commutator 26; a yoke 14 which houses the armature: a front housing 40 having a body part 42 which closes an opening at one axial side in the yoke 14 and having a brush housing part 44 which expands from the body part 42 to the opposite side of the yoke 14 and houses the brush 34; a ventilation port 58 which is formed at a side part of the brush housing part 44 in the body part 42 and penetrates through the front housing 40 in a thickness direction; and a connection part 60 which connects a side wall part 52 of the brush housing part 44 with the body part 42.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a rotating electrical machine.

  Conventionally, an armature having a commutator, a brush that is in sliding contact with the commutator, a yoke that accommodates the armature, and a main body that closes an opening on one axial side of the yoke, and the yoke from the main body There is a rotating electrical machine including a brush holder having a brush housing portion that bulges to the opposite side and houses a brush (see, for example, Patent Document 1).

JP 2011-234438 A

  In such a rotating electrical machine, the commutator and the brush are in sliding contact with each other, so that the brush generates heat. Further, since the brush vibrates the brush housing portion with the sliding contact between the commutator and the brush, the brush housing portion vibrates. Accordingly, it is required to secure the cooling property of the brush and to suppress the vibration of the brush housing portion.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a rotating electrical machine capable of ensuring brush cooling and suppressing vibration of the brush housing portion.

  In order to achieve the above object, a rotating electrical machine according to claim 1 is provided with a pair of armatures having commutators and a pair of sliding contacts with the commutators that are arranged at intervals of 90 degrees in the circumferential direction of the commutators. A brush, a yoke that houses the armature, a main body that closes an opening on one axial side of the yoke, and a brush housing that bulges from the main body to the opposite side of the yoke and houses the brush A brush holder, a vent hole formed in a side portion of the brush housing portion in the main body portion and penetrating in a thickness direction of the brush holder, and a side wall portion of the brush housing portion and the main body portion are coupled to each other. And a connecting portion.

  According to this rotating electrical machine, a vent hole penetrating in the thickness direction of the brush holder is formed in a side portion of the brush housing portion in the main body portion. Therefore, since the brush can be cooled by the cooling air flowing through the side of the brush through the vent hole, the cooling performance of the brush can be ensured.

  Moreover, the side wall part and main-body part of the brush accommodating part are connected by the connection part. Therefore, since the rigidity of the brush housing portion can be increased by this connecting portion, vibration of the brush housing portion can be suppressed.

  The rotating electrical machine according to claim 2 is the rotating electrical machine according to claim 1, wherein the brush accommodating portion accommodates the brush from a front end portion to a rear end portion, and the ventilation port is the main body portion. The brush housing portion is formed at the tip side portion.

  According to this rotating electrical machine, the ventilation opening is formed at the tip side portion of the brush housing portion in the main body portion. Therefore, even when the tip of the brush generates heat due to the sliding contact between the commutator and the brush, the cooling air flows through the ventilation port at a position close to the tip of the brush, so that the tip of the brush can be cooled.

  The rotating electrical machine according to claim 3 is the rotating electrical machine according to claim 1 or 2, wherein the connecting portion connects the rear end portion of the side wall portion of the brush housing portion and the main body portion. Has been.

  According to this rotating electrical machine, the connecting portion connects the rear end portion of the side wall portion of the brush housing portion and the main body portion. Therefore, even if the rear end of the brush largely swings with the contact point between the brush and the commutator as a fulcrum due to the sliding contact between the commutator and the brush, the vibration at the rear end of the side wall of the brush housing is connected. It can suppress effectively by a part.

  According to a fourth aspect of the present invention, in the rotating electric machine according to the third aspect, the connecting portion connects the rear end lower portion of the side wall portion of the brush housing portion and the main body portion.

  According to this rotating electrical machine, the connecting portion connects the rear end lower portion of the side wall portion of the brush housing portion and the main body portion. Therefore, when the commutator and brush are in sliding contact with each other, even if the brush rear end lower part swings greatly with the contact point between the brush and commutator as a fulcrum, the vibration at the rear end lower part of the side wall of the brush housing part is connected. It can suppress effectively by a part.

It is a longitudinal cross-sectional view of the rotary electric machine which concerns on this embodiment. It is the figure which looked at the rotary electric machine shown by FIG. 1 from the axial direction one side. It is a principal part expansion perspective view of the rotary electric machine shown by FIG. It is a figure explaining the case where the rear-end part of a brush shakes largely by making the contact point of a brush and a commutator into a fulcrum. It is a figure explaining the case where the back end lower part of a brush shakes largely by making the contact point of a brush and a commutator into a fulcrum.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  As shown in FIG. 1, a rotating electrical machine 10 according to an embodiment of the present invention is a DC motor with a brush, and includes an armature 12, a yoke 14, a magnet 16, an end housing 18, and a brush device 20. It has.

  The armature 12 is a rotor and includes a shaft 22, a core 24, a commutator 26, and a winding 28. The core 24 and the commutator 26 are fixed to the shaft 22. The shaft 22 is rotatably supported by a pair of bearings 30 and 32 provided in an end housing 18 and a brush device 20 described later. The winding 28 is wound around the core 24 and connected to the commutator 26.

  The yoke 14 is formed in a cylindrical shape, and the armature 12 is rotatably accommodated inside the yoke 14. The magnet 16 is fixed to the inner peripheral surface of the yoke 14, and is disposed on the radially outer side of the core 24 so as to face the core 24. The end housing 18 is provided on the yoke 14 on the side opposite to the brush device 20, and closes the opening of the yoke 14 on the side opposite to the brush device 20.

  The brush device 20 includes a plurality of brushes 34, a spring 36, a holding member 38, and a front housing 40 as a brush holder. The front housing 40 is made of resin and has a main body portion 42 and a plurality of brush housing portions 44. The main body 42 is provided on one side in the axial direction of the yoke 14, and closes the opening on one side in the axial direction of the yoke 14.

  A concave bearing housing portion 46 for housing the above-described bearing 32 is formed in the shaft core portion of the main body portion 42 (see also FIGS. 2 and 3). Further, as shown in FIG. 3, the main body portion 42 is formed with an inclined portion 48 that extends around the bearing housing portion 46. The inclined portion 48 is inclined with respect to the radial direction of the main body portion 42 so as to go to the yoke 14 side toward the radially outer side of the main body portion 42 in a side sectional view of the front housing 40. Further, the main body portion 42 is formed with a flange portion 50 that extends around the inclined portion 48. The flange portion 50 extends along the radial direction of the main body portion 42 in a side sectional view of the front housing 40, and is joined to an opening edge portion on one axial side of the yoke 14.

  The brush housing portion 44 is formed at a part of the circumferential direction of the main body portion 42 and bulges from the main body portion 42 to the side opposite to the yoke 14. The brush housing portion 44 includes a pair of side wall portions 52 and an upper wall portion 54 that connects the upper end portions of the pair of side wall portions 52. The brush accommodating portion 44 extends along the radial direction of the main body portion 42 and is formed across the inclined portion 48 and the flange portion 50.

  The side of the brush housing portion 44 on the side of the bearing housing portion 46 where the tip of the brush 34 described later is located is the tip side of the brush housing portion 44, and the tip of the brush housing portion 44 is the tip of the bearing housing portion 46. Connected to the peripheral wall. Further, the brush housing portion 44 is entirely inclined with respect to the radial direction of the main body portion 42 so as to go to the yoke 14 side toward the radially outer side of the main body portion 42 in a side sectional view of the front housing 40. (See FIG. 1). The side of the brush housing portion 44 opposite to the bearing housing portion 46 where the rear end of the brush 34 described later is located is the rear end side of the brush housing portion 44, and the rear end of the brush housing portion 44 is It is located at the outer edge of the front housing 40.

  As shown in FIG. 1, the brush 34 is accommodated in the brush accommodating portion 44 from the front end portion to the rear end portion. The brush 34 is disposed radially outside the commutator 26, and the tip of the brush 34 is in contact with the outer peripheral surface of the commutator 26. The brush 34 is in sliding contact with the commutator 26 as the armature 12 rotates. The holding member 38 is assembled to the brush housing portion 44 and has a lid portion 56 that closes the rear end opening of the brush housing portion 44. The spring 36 is interposed between the rear end of the brush 34 and the lid portion 56, and biases the brush 34 toward the commutator 26 with respect to the lid portion 56.

  As shown in FIG. 2 and FIG. 3, ventilation openings 58 penetrating in the thickness direction of the front housing 40 are formed in the side portions on both sides of the brush housing portion 44 in the main body portion 42. The ventilation port 58 is formed by a rectangular slit along the longitudinal direction of the brush housing portion 44 as viewed in the axial direction of the front housing 40, and communicates the inside of the yoke 14 with the outside of the front housing 40. . More specifically, the ventilation port 58 is formed at a tip side portion of the main body portion 42 of the brush housing portion 44 (a portion of the main body portion 42 positioned on the side of the tip portion of the brush housing portion 44). Yes. That is, the ventilation port 58 overlaps the tip end portion (the tip side portion) of the brush 34 in the longitudinal direction of the brush 34.

  In addition, connecting portions 60 that connect the side wall portion 52 of the brush housing portion 44 and the main body portion 42 are respectively formed on the side portions on both sides of the brush housing portion 44 in the main body portion 42. The connecting portion 60 includes a first arm portion 62 that extends laterally from the side wall portion 52 of the brush housing portion 44, and an inclined portion 48 along the longitudinal direction of the brush housing portion 44 from the tip of the first arm portion 62. It is formed in a substantially L shape having a second arm portion 64 extending to the side.

  As shown in FIG. 3, the lower ends of the first arm portion 62 and the second arm portion 64 are connected to the flange portion 50, and the tip of the second arm portion 64 is connected to the inclined portion 48. More specifically, the connecting portion 60 is formed on the outer side in the radial direction of the front housing 40 with respect to the above-described vent hole 58, and the rear end portion 52A (more specifically, the side wall portion 52 of the brush accommodating portion 44). Is connecting the rear end lower part 52A1) of the side wall part 52 and the main body part 42.

  Next, the operation and effect of one embodiment of the present invention will be described.

  According to the rotating electrical machine 10, the vent hole 58 penetrating in the thickness direction of the brush holder is formed in the side portion of the brush housing portion 44 in the main body portion 42. Therefore, the cooling air flows through the ventilation port 58 to the side of the brush 34, whereby the brush 34 can be cooled. Therefore, the cooling performance of the brush 34 can be ensured.

  In particular, the ventilation port 58 is formed at a tip side portion of the main body portion 42 of the brush housing portion 44 (a portion of the main body portion 42 positioned on the side of the tip portion of the brush housing portion 44). Therefore, even when the tip of the brush 34 generates heat due to the sliding contact between the commutator 26 and the brush 34, the cooling air flows through the ventilation port 58 in a position close to the tip of the brush 34, so that the tip of the brush 34 is cooled. can do.

  Further, the side wall portion 52 and the main body portion 42 of the brush accommodating portion 44 are connected by a connecting portion 60. Therefore, since the rigidity of the brush housing portion 44 can be increased by the connecting portion 60, the vibration of the brush housing portion 44 can be suppressed.

  Incidentally, as shown in FIG. 4, the brush 34 vibrates so that the rear end portion 34 </ b> A swings greatly with the contact point with the commutator 26 as a fulcrum. More specifically, as shown in FIG. 5, the brush 34 vibrates so that the rear end lower portion 34 </ b> A <b> 1 swings greatly with the contact point with the commutator 26 as a fulcrum.

  In this regard, according to the rotating electrical machine 10, the connecting portion 60 connects the rear end portion 52A of the side wall portion 52 of the brush accommodating portion 44 and the main body portion 42 as shown in FIGS. . Therefore, even when the rear end portion of the brush 34 swings greatly with the contact point between the brush 34 and the commutator 26 as a fulcrum as the commutator 26 and the brush 34 slide, The vibration at the rear end portion 52A can be effectively suppressed by the connecting portion 60.

  More specifically, as shown in FIG. 3, the connecting portion 60 connects the rear end lower portion 52 </ b> A <b> 1 of the side wall portion 52 of the brush housing portion 44 and the main body portion 42. Therefore, even when the rear end lower portion 34 </ b> A <b> 1 of the brush 34 largely swings with the contact point between the brush 34 and the commutator 26 as a fulcrum as the commutator 26 and the brush 34 slide, The vibration at the rear end lower portion 52A1 can be effectively suppressed by the connecting portion 60.

  In addition, as described above, in order to suppress the vibration of the brush housing portion 44, the thickness of the brush housing portion 44 is not increased uniformly, but the connecting portion 60 is locally provided in a part of the brush housing portion 44. Since it is a structure, an increase in weight and an increase in cost can be suppressed.

  Next, a modification of one embodiment of the present invention will be described.

  In the above embodiment, the brush device 20 has the front housing 40 that holds the brush 34 and forms the exterior of the rotating electrical machine 10 as an example of the brush holder (the front housing 40 also serves as the brush holder). . However, the brush device 20 may have a brush holder that holds the brush 34 separately from the front housing 40 that forms the exterior of the rotating electrical machine 10. And the above-mentioned ventilation opening 58, the brush accommodating part 44, the connection part 60, etc. may be formed in this brush holder.

  Further, the front housing 40 is formed with a ventilation port 58 and a connecting portion 60 on the sides on both sides of the brush accommodating portion 44, respectively. However, the ventilation opening 58 and the connecting portion 60 may be formed only on one side of the brush accommodating portion 44.

  The connecting portion 60 connects the rear end portion 52 </ b> A (more specifically, the rear end lower portion 52 </ b> A <b> 1) and the main body portion 42 of the side wall portion 52 of the brush accommodating portion 44. However, the connecting portion 60 may connect the portion including the rear end portion 52 </ b> A (rear end lower portion 52 </ b> A <b> 1) of the side wall portion 52 of the brush housing portion 44 and the main body portion 42.

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

DESCRIPTION OF SYMBOLS 10 ... Rotary electric machine, 12 ... Armature, 14 ... Yoke, 16 ... Magnet, 18 ... End housing, 20 ... Brush apparatus, 22 ... Shaft, 24 ... Core, 26 ... Commutator, 28 ... Winding, 30, 32 ... Bearing, 34 ... Brush, 36 ... Spring, 38 ... Holding member, 40 ... Front housing (an example of brush holder), 42 ... Main body part, 44 ... Brush housing part, 46 ... Bearing housing part, 48 ... Inclined part, 50 ... Flange portion, 52 ... side wall portion, 52A ... rear end portion, 52A1 ... lower rear end portion, 54 ... upper wall portion, 56 ... lid portion, 58 ... vent hole, 60 ... connecting portion, 62 ... first arm portion, 64 ... Second arm

Claims (4)

An armature having a commutator;
A pair of brushes arranged in the circumferential direction of the commutator at intervals of 90 degrees and in sliding contact with the commutator;
A yoke that houses the armature;
A brush holder having a main body portion that closes an opening on one axial side of the yoke, and a brush accommodating portion that bulges from the main body portion to the opposite side of the yoke and accommodates the brush;
A vent hole formed in a side part of the brush housing part in the main body part and penetrating in a thickness direction of the brush holder;
A connecting portion for connecting the side wall portion of the brush housing portion and the main body portion;
Rotating electric machine with The brush accommodating portion accommodates the brush from the front end portion to the rear end portion,
The vent hole is formed at a tip side part of the brush housing part in the main body part,
The rotating electrical machine according to claim 1. The connecting part connects the rear end part of the side wall part of the brush housing part and the main body part,
The rotating electrical machine according to claim 1 or 2. The connecting portion connects the lower end of the side wall portion of the brush housing portion and the main body portion,
The rotating electrical machine according to claim 3.