JP6081880B2 - Brush device and motor - Google Patents

Description

  The present invention relates to a brush device for a motor.

  2. Description of the Related Art Conventionally, as shown in, for example, Patent Document 1, a motor brush device is a resin holder member (brush holder) having a base portion fixed to a motor housing and a brush housing portion integrally formed with the base portion. ). The brush housing portion has a base portion side as a bottom portion, a pair of side wall portions extending from the bottom portion, and a ceiling portion connecting the side wall portions, and a power feeding brush is provided inside the bottom portion, each side wall portion, and the ceiling portion. It is accommodated and supported so as to be slidable in the radial direction. In addition, a spring that urges the power supply brush toward the commutator side (inward in the radial direction) is held in the brush housing portion, and the power supply brush is pressed against the commutator.

JP 2004-135387 A

  However, in the brush device as described above, a mold having a slide mold for forming the internal space of the brush accommodating portion is required at the time of injection molding of the holder member, which increases the cost of the mold. .

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a brush device and a motor that can eliminate the need for a slide mold when a holder member is injection-molded. .

A brush device that solves the above problems includes a brush that contacts an outer peripheral surface of a commutator of an armature, a coil spring that presses the brush from the outer peripheral side, and a brush housing that holds the brush and the coil spring. A brush unit, and a resin holder integrally including a base portion fixed to the motor housing and a pair of support walls extending from the base portion in the axial direction of the armature and facing in the circumferential direction The brush housing portion includes a pair of support walls and a top plate member fixed to the support walls so as to straddle the open ends of the support walls, and the support walls face each other. on the inner surface, and a brush supporting surface for supporting the brush, and a spring support surface for supporting the formed the coil spring located on the open end side than the brush support surface, before The brush support surface has a planar shape along the radial direction of the armature to hold the widthwise side surface of the brush, and the spring support surface has an arc shape to hold the coil spring in the coil radial direction. An arc surface and a plane extending from the arc surface to the open end along the axial direction of the armature .

  According to this configuration, since the brush housing portion is configured by the support wall extending in pairs from the base portion and the top plate member fixed to the support wall, each of the holder members without a slide mold can be formed at the time of injection molding. The support wall can be molded, and as a result, it can contribute to cost reduction. Moreover, the spring support surface of the inner surface of each support wall is formed in the support wall at the open end side rather than the brush support surface. For this reason, it is possible to pull out the mold forming the support wall in the axial direction while the coil diameter of the coil spring is larger than the brush width, and the selection range of the coil spring can be expanded.

According to this configuration, the brush and the coil spring can be stably held by the brush support surface and the spring support surface, respectively.
The said brush apparatus WHEREIN: It is preferable that the coil diameter of the said coil spring is set larger than the width direction length of the said brush.
According to this configuration, the spring constant is reduced by increasing the coil diameter of the coil spring, and thereby the width of fluctuation of the urging force of the coil spring caused by shortening the brush due to wear can be reduced. it can.

In the above SL brush device, the brush is adapted to protrude in the axial direction from between the respective supporting walls, it is preferably configured so as to cover the protruding portion is the top plate member.

According to this configuration, it is possible to easily cope with the configuration in which the brush height in the axial direction of the armature is increased by changing the shape of the top plate member.
In the brush device, a clearance is preferably formed between the brush and the top plate member so that they do not contact each other in the brush width direction.

According to this structure, generation | occurrence | production of the sliding loss and abnormal noise which may arise when a brush contacts the width direction with respect to a top-plate member can be suppressed.
In the brush device, it is preferable that a lead-out window portion for leading a power supply line connected to the brush out of the brush housing portion is formed on the top plate member.

According to this configuration, it is possible to easily form the lead-out window when the top plate member is press-molded.
The motor which solves the said subject is a motor provided with said brush apparatus.

  According to this configuration, it is possible to eliminate the need for a slide mold when the holder member is injection molded.

  According to the brush device and the motor of the present invention, it is possible to eliminate the need for a slide mold for injection molding the holder member.

It is sectional drawing of the motor of embodiment. It is a perspective view which shows a part (brush accommodating part) of the brush apparatus of the same form. It is sectional drawing of the brush accommodating part of the same form. It is sectional drawing of the brush accommodating part of another example. It is a perspective view of the brush accommodating part of another example. It is a perspective view of the brush accommodating part of another example.

Hereinafter, an embodiment of the motor will be described.
A motor 1 according to this embodiment shown in FIG. 1 includes a yoke housing 2 (hereinafter simply referred to as a yoke 2) having a substantially bottomed cylindrical shape, an armature 3 housed in the yoke 2, and an opening of the yoke 2. And a brush device 4 disposed on the surface.

  The yoke 2 includes a cylindrical portion 2a having a cylindrical shape, and a substantially disc-shaped bottom portion 2b that closes one end of the cylindrical portion 2a in the axial direction. A plurality of magnets 6 arranged in the circumferential direction are fixed to the inner circumferential surface of the cylindrical portion 2a so that the N pole and the S pole are alternately arranged in the circumferential direction. The cylindrical portion 2a and the magnet 6 constitute a stator.

  The armature 3 is arranged inside the magnet 6 inside the yoke 2. The armature 3 can rotate integrally with the rotary shaft 11, the armature core 12 fixed to the rotary shaft 11 so as to be integrally rotatable, the winding 13 wound around the armature core 12, and the rotary shaft 11. And a commutator 14 fixed to the head.

  The rotating shaft 11 has a columnar shape and is disposed in the central portion in the radial direction of the yoke 2 inside the yoke 2. A base end portion (right end portion in FIG. 1) of the rotating shaft 11 is pivotally supported by a bearing 15 provided at the center portion of the bottom portion 2 b of the yoke 2. The armature 3 can rotate in the circumferential direction around the rotation shaft 11.

  The armature core 12 is externally fitted to a portion closer to the base end than the central portion in the axial direction of the rotary shaft 11 so as to be integrally rotatable. The armature core 12 has a plurality of teeth 12a extending radially outward from the rotation shaft 11 in the radial direction. The front end surface (outer peripheral surface) of the tooth 12a faces the magnet 6 in the radial direction.

  A commutator 14 is externally fitted to a portion slightly closer to the tip than the central portion of the rotating shaft 11 in the axial direction so as to be integrally rotatable. The commutator 14 is adjacent to the armature core 12 in the axial direction. A plurality of commutator pieces 14 a are provided on the outer peripheral surface of the commutator 14. A riser 14b for connecting the winding 13 is integrally formed at one axial end portion (end portion on the armature core 12 side) of each commutator piece 14a.

[Brush device configuration]
The brush device 4 includes a resin holder member 21 that is assembled to the opening of the yoke 2. The holder member 21 has a base portion 22 fitted in the opening of the yoke 2. The base portion 22 has an annular shape, and its outer diameter is formed substantially equal to the inner diameter of the cylindrical portion 2 a of the yoke 2. The base portion 22 has a plate shape that is perpendicular to the axis of the rotary shaft 11. An insertion hole 22b through which the rotation shaft 11 is inserted is formed through the center of the diameter of the base portion 22. In the base portion 22, an axial end surface facing the inner side of the yoke 2 is defined as an inner end surface 22 a.

  A plurality of brush accommodating portions 25 that respectively hold the power supply brush 23 and the coil spring 24 are configured on the inner end surface 22 a of the base portion 22. In addition, each brush accommodating part 25 (each brush 23 for electric power feeding) is arrange | positioned at the circumferential direction equal intervals.

  As shown in FIGS. 2 and 3, each brush housing portion 25 includes a pair of support walls 26 that are formed to extend from the base portion 22 in the axial direction of the rotary shaft 11, and a top plate member that is fixed to the support walls 26. 27. The pair of support walls 26 are opposed to each other in the circumferential direction, and a brush support surface 31 that supports the power supply brush 23 and a spring support surface 32 that supports the coil spring 24 are disposed on the inner surfaces facing each other. Are formed respectively.

  As shown in FIG. 3, the brush support surface 31 is formed in a planar shape that is parallel to the axial direction of the rotating shaft 11 and substantially perpendicular to the circumferential direction of the rotating shaft 11. Further, the brush support surfaces 31 of the pair of support walls 26 are parallel to each other. The bottom surface 33 connecting the brush support surfaces 31 is formed to be orthogonal to the brush support surface 31 and the axis of the rotation shaft 11.

  The power supply brush 23 has a rectangular parallelepiped shape, and its axial end portion is inserted inside a U-shaped section whose one end portion in the axial direction (lower end portion in FIG. 3) is composed of the brush support surface 31 and the bottom surface 33. ing. Note that the power supply brush 23 is set such that the axial height (the length along the axial direction of the rotating shaft 11) is longer than the widthwise length W.

  The interval between the brush support surfaces 31 is set to be slightly longer than the length W in the width direction of the power supply brush 23 (the length in the left-right direction in FIG. 3). The brush accommodating portion 25 holds a part of both side surfaces in the width direction of the power supply brush 23 at each brush support surface 31, and an axial end surface (the lower surface in FIG. 3) of the power supply brush 23 at the bottom surface 33. Hold. The brush support surface 31 is formed from one end to the other end in the radial direction of the support wall 26, and the radial length of the brush support surface 31 is longer than the radial length of the power supply brush 23. ing.

  The spring support surface 32 of each support wall 26 is formed on the axially open end (upper end) side of the brush support surface 31 and is formed from one end to the other end of the support wall 26 in the radial direction. The spring support surface 32 includes an arc surface 32a extending outward in the width direction from the brush support surface 31, and a plane 32b extending from the arc surface 32a along the axial direction of the rotary shaft 11 to the open end 26a in the axial direction of the support wall 26. Have.

  The coil spring 24 is held by the arc surface 32a and the flat surface 32b of each spring support surface 32. The coil spring 24 is arranged such that its coil axis L (center axis) is along the radial direction of the rotary shaft 11, and the coil axis L is arranged so as to coincide with the center axis of the power supply brush 23. The arc surface 32 a of each spring support surface 32 has an arc shape centered on the coil axis L of the coil spring 24 and partially holds the outer periphery of the coil spring 24.

  The flat surface 32b of each spring support surface 32 holds the coil spring 24 from both sides in the brush width direction. The planes 32b are parallel to each other and are also parallel to the brush support surfaces 31. Further, the interval between the flat surfaces 32b in the width direction is set wider than the interval between the brush support surfaces 31 in the width direction.

  The coil diameter D (diameter) of the coil spring 24 is set to be larger than the width direction length W of the power supply brush 23 and smaller than the height in the axial direction of the power supply brush 23. Since the coil spring 24 is arranged so that the coil axis L coincides with the central axis of the power supply brush 23, the coil spring 24 is larger than the power supply brush 23 in the width direction and in the axial direction. Is configured to be small.

  The top plate member 27 is formed by pressing from a metal plate. The top plate member 27 is provided so as to cover the space between the support walls 26 from the axial direction. Yes.

  The top plate member 27 includes a ceiling portion 34 that is parallel to the bottom surface 33 between the brush support surfaces 31, a side wall portion 35 that extends in the axial direction from both edges in the brush width direction of the ceiling portion 34, and each side wall portion 35. And a plurality of fixing pieces 36 (two in the present embodiment). The fixing piece 36 of each side wall 35 is press-fitted and fixed to the open end 26 a in the axial direction of the support wall 26. That is, the top plate member 27 is provided so as to straddle the open end 26 a of each support wall 26. The open end 26 a in the axial direction of each support wall 26 is formed in a planar shape perpendicular to the axis of the rotary shaft 11 (that is, parallel to the ceiling portion 34 of the top plate member 27).

  Further, the interval in the width direction between the side wall portions 35 is set larger than the interval in the width direction between the brush support surfaces 31. That is, since the interval in the width direction between the side wall portions 35 is larger than the width direction length W of the power supply brush 23, there is a clearance C between the width directions of the side wall portions 35 and the side surfaces of the power supply brush 23. Is formed. In addition, the power supply brush 23 is configured to protrude in the axial direction from between the support walls 26, and the top plate member 27 covers the protruding portion.

  Further, the interval in the width direction between the side wall portions 35 is set to be smaller than the interval in the width direction between the flat surfaces 32 b of the spring support surfaces 32. That is, the interval in the width direction between the side wall portions 35 is formed smaller than the coil diameter D of the coil spring 24.

  The power supply brush 23 has one end side in the axial direction (lower end in FIG. 3) held by each brush support surface 31 and the bottom surface 33 and the other end side in the axial direction (upper surface in FIG. 3) is the ceiling of the top plate member 27. Held by the section 34. Thereby, the power supply brush 23 is held in the brush housing portion 25 so as to be slidable in the radial direction of the rotary shaft 11.

  As shown in FIG. 1, the coil spring 24 is arranged in a compressed state between the stopper 37 assembled to the support wall 26 or the top plate member 27 and the power supply brush 23 in the brush housing portion 25. The power supply brush 23 is urged radially inward by the elastic force of the coil spring 24. The front end surface of the power supply brush 23 is pressed against the outer peripheral surface of the commutator 14 (commutator piece 14a).

  As shown in FIGS. 2 and 3, the ceiling 34 of the top plate member 27 is formed with a notch 34 a (leading window) extending in the radial direction from the radially inner end to the center. The notch 34 a is formed at the center in the width direction of the ceiling 34.

  The pigtail 38 (power supply line) connected to the upper surface in the axial direction of the power supply brush 23 is led out to the outside of the brush housing part 25 through the notch 34a. The pigtail 38 is electrically connected to a power supply terminal 39 extending in the axial direction from the holder member 21 to the outside, and power can be supplied from the power supply terminal 39 to the power supply brush 23 via the pigtail 38. The armature 3 is rotated by supplying current from the power supply brush 23 to the winding 13 via the commutator 14.

Next, the operation of this embodiment will be described.
The spring support surface 32 on the inner surface of each support wall 26 is formed on the support wall 26 closer to the open end 26a than the brush support surface 31. The width interval between the spring support surfaces 32 is the width interval between the brush support surfaces 31. Is set larger than. Therefore, in the injection molding of the holder member 21, the support wall 26 does not have an undercut shape, and the mold on the inner end face 22a side of the holder member 21 can be pulled out in the axial direction. As a result, the radial slide mold It is possible to use a mold having no.

  Then, the top plate member 27 is provided so as to cover between the support walls 26 and the power supply brush 23 is held in the axial direction, so that the power supply brush 23 is stably held. In the present embodiment, the brush support surfaces 31 and the bottom surface 33 that hold the axial bottom surface side of the power supply brush 23 hold the power supply brush 23 over the entire radial direction. 23 is held more stably.

  Further, since the coil diameter D of the coil spring 24 is set to be larger than the length W in the width direction of the power supply brush 23, the spring constant of the coil spring 24 can be reduced. The width of the fluctuation of the urging force of the coil spring 24 caused by shortening due to wear is reduced.

  As described above, in the present embodiment, the shape of the spring support surface 32 is maintained while the power supply brush 23 is held over the entire radial direction by the top plate member 27 and the brush support surfaces 31 and the bottom surface 33 of the holder member 21. The change can cope with a design change such as the coil diameter D of the coil spring 24.

Next, characteristic effects of the present embodiment will be described.
(1) The resin holder member 21 includes a base portion 22 fixed to the yoke 2 and a pair of support members extending from the base portion 22 in the axial direction of the rotary shaft 11 (armature 3) and facing in the circumferential direction. The wall 26 is integrally formed. The brush accommodating portion 25 that accommodates and holds the power supply brush 23 includes a pair of support walls 26 and a top plate member 27 fixed to the support walls 26 so as to straddle the axially open ends 26 a of the respective support walls 26. It consists of. As a result, when the holder member 21 is injection molded, each support wall 26 can be molded without a slide mold, and as a result, it is possible to contribute to cost reduction.

  Further, the spring support surface 32 on the inner surface of each support wall 26 is formed on the support wall 26 closer to the open end 26 a than the brush support surface 31. For this reason, it is possible to pull out the mold forming the support wall 26 in the axial direction while configuring the coil diameter D of the coil spring 24 to be larger than the width direction length W of the power supply brush 23, and the coil spring 24. The selection range can be expanded.

  (2) The coil diameter D of the coil spring 24 is set larger than the length W in the width direction of the power supply brush 23. According to this configuration, the spring constant is reduced by increasing the coil diameter D of the coil spring 24, and thereby the fluctuation of the urging force of the coil spring 24 caused by the shortening of the power supply brush 23 due to wear. The width can be reduced. As a result, the motor performance can be improved.

  (3) The brush support surface 31 has a planar shape along the radial direction of the rotary shaft 11 so as to hold the side surface in the width direction of the power supply brush 23, and the spring support surface 32 holds the coil spring 24 in the coil radial direction. Since it has an arc shape as much as possible, the power supply brush 23 and the coil spring 24 can be stably held.

  (4) The power supply brush 23 protrudes in the axial direction from between the support walls 26 and is configured so that the top plate member 27 covers the protruding portion. This can be easily handled by changing the shape of the plate member 27.

  (5) A clearance C is formed between the power supply brush 23 and the top plate member 27 so that they do not contact each other in the brush width direction. Thereby, it is possible to suppress the occurrence of sliding loss and abnormal noise that may occur when the power supply brush 23 contacts the top plate member 27 in the width direction.

  (6) The top plate member 27 is formed with a notch 34 a for leading the pigtail 38 connected to the power supply brush 23 out of the brush housing portion 25. Thereby, the notch 34a can be easily formed when the top plate member 27 is press-formed.

In addition, you may change the said embodiment as follows.
In the above embodiment, the clearance C is provided between the side walls 35 and the side surface of the power supply brush 23. However, as shown in FIG. The power supply brush 23 may be configured to be able to be held in the width direction by each side wall portion 35 so as to be narrower than the form. According to such a configuration, the power supply brush 23 can be held more stably.

In the above embodiment, the notch 34a as the lead-out window for leading the pigtail 38 is formed in the ceiling 34 of the top plate member 27, but is not particularly limited thereto.
For example, as shown in FIG. 5, a cutout portion 35 a as a lead-out window portion may be formed on one of the pair of side wall portions 35. The cutout portion 35a is formed from the radially inner end of the side wall portion 35 to the central portion, and the pigtail 38 is led out of the brush housing portion 25 through the cutout portion 35a. Even with this configuration, it is possible to obtain substantially the same effect as in the above embodiment.

  For example, as shown in FIG. 6, a cutout portion 26 b as a lead-out window portion may be formed on one of the pair of support walls 26. The notch 26b has a shape in which a part of the open end 26a of the support wall 26 is recessed in the axial direction between the radial directions of the fixed piece 36, and the pigtail 38 accommodates the brush through the notch 26b. It is led out of the part 25.

  The shape of the spring support surface 32 of the support wall 26 is not limited to the above embodiment. For example, the arc surface 32a of the above embodiment is a plane perpendicular to the axial direction (that is, a plane orthogonal to the plane 32b). You may change to

  DESCRIPTION OF SYMBOLS 1 ... Motor, 2 ... Yoke housing (motor housing), 3 ... Armature, 4 ... Brush apparatus, 14 ... Commutator, 21 ... Holder member, 22 ... Base part, 23 ... Brush for electric power feeding, 24 ... Coil spring, 25 ... Brush housing part, 26 ... support wall, 26a ... open end, 27 ... top plate member, 31 ... brush support surface, 32 ... spring support surface, 26b, 34a, 35a ... notch (leading window part), 38 ... Pigtail (feed line), C ... clearance.

Claims (6)

A brush that contacts the outer peripheral surface of the commutator of the armature;
A coil spring that presses the brush from the outer peripheral side;
A brush device including the brush and a brush accommodating portion for holding the coil spring,
A resin holder member integrally including a base portion fixed to the motor housing, and a pair of support walls extending from the base portion in the axial direction of the armature and facing in the circumferential direction;
The brush housing portion includes the pair of support walls and a top plate member fixed to the support walls so as to straddle the open ends of the support walls.
A brush support surface that supports the brush and a spring support surface that is positioned closer to the open end than the brush support surface and supports the coil spring are formed on inner surfaces of the support walls facing each other. And
The brush support surface has a planar shape along the radial direction of the armature to hold the width direction side surface of the brush,
The spring support surface includes an arc surface that forms an arc shape to hold the coil spring in the coil radial direction, and a plane that extends from the arc surface to the open end along the axial direction of the armature. A brush device characterized by that. The brush device according to claim 1, wherein
The brush device according to claim 1, wherein a coil diameter of the coil spring is set larger than a length in a width direction of the brush. The brush device according to claim 1 or 2 ,
The brush device is configured so that the brush protrudes in the axial direction from between the support walls, and the top plate member covers the protruding portion. In the brush apparatus of any one of Claims 1-3 ,
A brush device, wherein a clearance is formed between the brush and the top plate member so that they do not contact each other in the brush width direction. In the brush device according to any one of claims 1 to 4 ,
The top plate member is formed with a lead-out window portion for leading a power supply line connected to the brush out of the brush housing portion. A motor comprising the brush device according to any one of claims 1 to 5 .