JP2010283958A - Brush device of electric motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a brush device for an electric motor, which ensures insulation without insert molding of a resin-made base. <P>SOLUTION: The brush device 1 of an electric motor supplies electricity to at least four brushes 50. In the brush device 1, lead wires 11-14 are defined as front lead wires 11, 14 connected to front brush boxes 51, 54 near a base end portion 69, and rear lead wires 12, 13 connected to rear brush boxes 52, 53 farther from the base end portion 69 than the front lead wires 11, 14. The front lead wires 11, 14 extend along a base front surface 61a from the base end portion 69. The rear lead wires 12, 13 extend along the base back surface from the base end portion 69 and extend along the base front surface 61a through base through holes 63, 64. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a brush device for an electric motor that supplies electricity to a brush that is in sliding contact with a commutator.

  For example, a brush device provided in a four-pole electric motor includes two pairs of brushes having two different polarities on the positive side and the negative side. Since the four brushes facing each other have the same polarity, it is necessary to reverse the energizing polarity of the brush every 90 degrees.

  Conventionally, as a brush device of this type of electric motor, in FIG. 5 of Patent Document 1, four lead wires (6) extending from the end of the base (2) are connected to four brushes (3a, 3b). A configuration in which the lead wires (6) are arranged so as to cross each other is disclosed.

  Further, in FIG. 11 of Patent Document 2, two lead plates (25) are insert-molded on a resin base (21), and the lead plate (25) and the brush (22) connect the pigtail wire (24). The structure connected via is disclosed.

Japanese Patent Laid-Open No. 11-41868 JP 2001-238410 A

  However, the configuration shown in FIG. 5 of Patent Document 1 is a configuration in which the lead wires (6) are arranged so as to cross each other, and thus it is difficult to ensure insulation of the lead wires (6). In addition, there is a problem that the assembling work for arranging the lead wire (6) is troublesome at the time of production, and the productivity is poor.

  Further, the configuration shown in FIG. 11 of Patent Document 2 is a configuration in which two lead plates (25) are insert-molded on a resin base (21), so that the mold structure for molding the base (21) is complicated. As a result, there was a problem that the cost of the product was increased.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a brush device for an electric motor that does not require insert molding of a resin base and can ensure insulation.

  The present invention relates to a brush device of an electric motor that supplies electricity to at least four or more even-numbered brushes that are in sliding contact with a commutator, and a plurality of brush boxes in which brushes are slidably interposed, and the brush boxes A base made of a non-conductive material to which the brush is attached, and a lead wire that conducts between the power source and the brush box, and the base is located on the front side of the base on which the brush box is located and on the opposite side of the base front side The front brush box has a base back surface, a base end portion from which a lead wire extending to the power source is drawn, and a base through hole penetrating from the base back surface to the base front surface, and the lead wire is close to the base end portion. The front lead wire to be connected to the front lead wire and the back lead wire to be connected to the back brush box farther from the base end than the front lead wire are divided into the front lead wires. The wire extends from the base end along the front of the base, while the rear lead wire extends from the base end along the back of the base and extends through the base through hole along the front of the base. .

  According to the present invention, the brush device eliminates the need for a lead plate that is insert-molded on the resin base as a power line for supplying electricity to the brush, simplifies the mold configuration of the base, and reduces manufacturing costs.

  The near-side lead wire and the far-side lead wire having different polarities on the plus side and the minus side have a resin base made of a non-conductive material between them, so that insulation between them is ensured.

The front view which shows the brush apparatus which shows embodiment of this invention. The rear view which similarly shows a brush apparatus. The rear view which shows a base similarly, a longitudinal cross-sectional view, and a cross-sectional view.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

  The electric motor includes the brush device 1 shown in FIGS. 1 and 2, a stator composed of a permanent magnet (not shown), and a rotor that rotates inside the stator.

  The electric motor includes a disc-shaped bracket and a bottomed cylindrical case as a casing (not shown), and a motor chamber for accommodating the rotor is defined between the bracket and the case.

  The rotor includes a commutator with which the brush 50 is in sliding contact, and a winding connected to the commutator. In the electric motor, electricity flows to the winding through the commutator, and the magnetic force generated in the winding works in the rotation direction with respect to the magnetic force of the permanent magnet, so that the rotor rotates.

  A brush device 1 provided in a four-pole electric motor includes two pairs of brushes 50 having two different polarities on the positive side and the negative side. The number of magnetic poles of the electric motor is not limited to this, and may be set to an even number of four or more according to the specification.

  The four brushes 50 are arranged radially around the rotation axis O of the rotor so as to surround the commutator.

  In the brush device 1, electricity supplied from a power source flows to the four brushes 50 through the lead wires (power lines) 11 to 14, the brush boxes 51 to 54, and the four pigtail wires 40. .

  The brush device 1 includes a resin base 60 as a member that supports the brush 50. The base 60 is formed in a disk shape, and four brush boxes 51 to 54 are attached thereto.

  The base 60 has an annular base disk part 61 and a base cylinder part 62 extending in a cylindrical shape with a part thereof cut out from the outer peripheral end of the base disk part 61, and these are integrally formed of resin. .

  The base 60 has two fixing posts 65 and 66 and two through holes 67 and 68, and brackets are formed by four screws (not shown) that pass through the fixing posts 65 and 66 and the through holes 67 and 68. To be concluded.

  The brushes 50 are slidably interposed in the brush boxes 51 to 54, and their tip surfaces are pressed against the commutator by the urging force of a spring (not shown).

  The rotor is provided through the central hole 61 c of the base disk part 61. A commutator is disposed inside the base disk part 61.

  In the base disk portion 61, one surface on which the brush boxes 51 to 54 are arranged is a base front surface 61a, and the other surface is a base back surface 61b.

  The base 60 has reinforcing ribs 75 and 76 protruding from the base front surface 61a. As will be described later, the thin portion of the base disk portion 61 is reinforced by the reinforcing ribs 75 and 76.

  Each of the brush boxes 51 to 54 has three legs 55. An opening 61d (see FIG. 3A) is formed in the base disk portion 61 so as to penetrate each leg portion.

  Each leg portion 55 passes through the base disk portion 61 and is caulked and fixed to the base disk portion 61 by bending the protruding portion. As a result, the brush boxes 51 to 54 are attached to the base disk part 61.

  One end of the pigtail line 40 is fixed to the brush boxes 51 to 54 by spot welding, and the other end is inserted into the hole of the brush 50 and fixed.

  The four brushes 50 that are opposite to each other have the same polarity. For this reason, the lead wires 11 and 13 connected to the brush boxes 51 and 53 have the same energization polarity, and the lead wires 12 and 14 connected to the brush boxes 52 and 54 have the same energization polarity.

  The base 60 has a base end portion 69 from which the lead wires 11 to 14 are drawn. The base end portion 69 is formed by cutting out the outer peripheral portion of the base 60 in a straight line. Four lead wires 11 to 14 are pulled out from the base end portion 69 and extend to a power source (not shown).

  As for the lead wires 11-14, the wire 16 which protrudes from each coating | cover 15 is fixed to the brush boxes 51-54 by spot welding.

  The lead wires 11 to 14 are two front lead wires 11 and 14 connected to the front brush boxes 51 and 54 near the base end portion 69, and are farther from the base end portion 69 than the front lead wires 11 and 14. It is divided into two back side lead wires 12 and 13 connected to the back side brush boxes 52 and 53.

  The two front lead wires 11 and 14 extend from the base end portion 69 along the base front surface 61a.

  On the other hand, the two rear lead wires 12 and 13 extend from the base end portion 69 along the base back surface 61b and penetrate the base disk portion 61 and extend along the base front surface 61a.

  Two base through holes 63 and 64 are formed in the base disk portion 61. The two rear lead wires 12 and 13 are inserted through the base through holes 63 and 64 to penetrate the base disk portion 61 and extend from the base back surface 61b to the base front surface 61a.

  1 and 2, B is a base center line passing through the rotation axis O of the rotor. The base 60 is formed symmetrically with respect to the base center line B. The lead wires 11 to 14 are arranged symmetrically with respect to the base center line B.

  The fixed post 65 is disposed at the center portion of the base end portion 69. The lead wires 11 and 12 and the lead wires 13 and 14 are arranged so as to sandwich the fixed post 65.

  The two front lead wires 11 and 14 extend along the base front surface 61a to the brush boxes 51 and 54 through the vicinity of the fixed post 65.

  The two back side lead wires 12 and 13 pass through the vicinity of the fixed post 65 and extend along the base back surface 61b to the base through holes 63 and 64 through the back of the brush boxes 51 and 54, respectively.

  The two back-side lead wires 12 and 13 are bent so as to pass between caulking portions protruding from the base back surface 61b of the respective leg portions 55, respectively. Thereby, the back side lead wires 12 and 13 do not interfere with the caulking portion of each leg portion 55.

  3, (a) is a rear view of the base 60, (b) is a longitudinal sectional view of the base 60 along the center line C of the base through-hole 63, and (c) is a transverse sectional view of the base 60. .

  A back-side base inclined groove 71 and a front-side base inclined groove 72 are formed before and after the base through-hole 63, and the back-side lead wire 12 that passes through the base through-hole 63 is arranged to be inclined with respect to the base disk portion 61. Is done.

  As shown in FIG. 3A, the back-side base inclined groove 71 extends from the base through-hole 63 through the back of the brush box 51 toward the base end portion 69, and each leg portion 55 of the brush box 51. It arrange | positions between the crimping parts which protruded in the base back surface 61b.

  As shown in FIG. 3B, the back side base inclined groove 71 is formed such that the depth with respect to the base back surface 61b gradually decreases from the base through hole 63 to the opening end on the base back surface 61b.

  As shown in FIG. 3C, the back-side base inclined groove 71 is formed in a round cross-sectional shape whose inner wall surface is curved in an arc shape. The inner wall surface of the back side base inclined groove 71 is formed along the outer surface of the coating 15 of the lead wire 11.

  Thereby, the cross-sectional area of the base disk part 61 reduced by the back side base inclined groove 71 behind the brush box 51 is minimized, and the rigidity of the base 60 is ensured.

  As shown in FIG. 3B, the front-side base inclined groove 72 is formed such that its depth with respect to the base back surface 61b gradually decreases from the base through hole 63 to the opening end on the base front surface 61a.

  As shown in FIG. 3C, the front-side base inclined groove 72 has an inner wall surface formed in an angular cross-sectional shape along a quadrangle.

  The back-side base inclined groove 71 is formed in a round cross-sectional shape, and the front-side base inclined groove 72 is formed in a square cross-sectional shape, so that a mold that is divided vertically is used when molding the resin base 60. Thus, the base through-hole 63, the back-side base inclined groove 71, and the front-side base inclined groove 72 are formed, thereby ensuring productivity.

  A back-side base inclined groove 73 and a front-side base inclined groove 74 are formed before and after the base through-hole 64, and the back-side lead wire 12 that passes through the base through-hole 6 is arranged to be inclined with respect to the base disk portion 61. Is done. The base through hole 64, the back side base inclined groove 73, and the front side base inclined groove 74 are symmetric about the base center line B with respect to the base through hole 63, the back side base inclined groove 71, and the front side base inclined groove 72. Formed.

  As shown in FIG. 1, reinforcing ribs 75 and 76 projecting along the open ends of the base through holes 63 and 64 with respect to the base front surface 61 a are formed. The rigidity of the base disk portion 61 is enhanced by the reinforcing ribs 75 and 76 and the strength of the open ends of the base through holes 63 and 64 thinned by the back side base inclined grooves 71 and 73 is secured.

  When the electric motor is operated, the brush device 1 is supplied with power from the power source through the lead wires 11 to 14, the brush box 51, and the pigtail wire 40 to the four brushes 50. The rotor rotates as electricity flows from the brush 50 through the commutator to the winding, and the magnetic force generated in the winding acts in the rotation direction with respect to the magnetic force of the permanent magnet.

  As described above, in the present embodiment, the brush device 1 is an electric motor for flowing electricity to at least four or more even number of brushes 50 that are in sliding contact with the commutator, and the brushes 50 are slidably interposed. A plurality of brush boxes 51 to 54, a resin base 60 made of a non-conductive material to which the brush boxes 51 to 54 are attached, and lead wires 11 to 14 that conduct electricity between the power source and the brush boxes 51 to 54. The base 60 includes a base front surface 61a where the brush boxes 51 to 54 are located, a base rear surface 61b located on the opposite side of the base front surface 61a, and a base end portion 69 from which lead wires 11 to 14 extending to the power source are drawn. And base through-holes 63 and 64 penetrating from the base back surface 61b to the base front surface 61a, and the lead wires 11 to 14 are close to the base end portion 69. Front side lead wires 11 and 14 connected to the front side brush boxes 51 and 54, and back side lead wires 12 and 14 connected to the back side brush boxes 52 and 53 farther from the base end 69 than the front side lead wires 11 and 14, The front side lead wires 11 and 14 extend from the base end portion 69 along the base front surface 61a, while the back side lead wires 12 and 13 extend from the base end portion 69 along the base back surface 61b and It was set as the structure extended along the base front surface 61a through the base through-holes 63 and 64. FIG.

  Based on the above configuration, the brush device 1 eliminates the need for a lead plate that is insert-molded into the resin base 60 as a power line for supplying electricity to the brush 50, simplifies the mold configuration of the base 60, and reduces manufacturing costs. Reduction is achieved.

  The front side lead wires 11 and 14 and the back side lead wires 12 and 13 having different polarities on the positive side and the negative side have a resin base 60 made of a non-conductive material between them, so that the insulation between them is Is secured.

  In the present embodiment, back side base inclined grooves 71 and 73 are formed in the base back surface 61b, and the back side base inclined grooves 71 and 73 pass from the base through holes 63 and 64 to the back of the brush box 51. The structure is such that it extends in the direction of the base end portion 69, and the depth of the back side base inclined grooves 71, 73 with respect to the base back surface 61b gradually decreases from the base through holes 63, 64 to the opening end on the base back surface 61b.

  Based on the above configuration, the back-side lead wires 12 and 13 are inserted into the back-side base inclined grooves 71 and 73 from the base through holes 63 and 64 so that the back-side lead wires 12 and 13 are connected to the base disk portion 61. It is arranged to be inclined. Thereby, even if it arrange | positions along with the brush box 51 and the rotating shaft direction of a rotor, it is suppressed that the dimension of the brush apparatus 1 becomes large in the rotating shaft direction of a rotor, and the compactization of an electric motor is achieved.

  In the present embodiment, front-side base inclined grooves 72 and 74 that open to the base front surface 61a are formed, and the depth of the front-side base inclined grooves 72 and 74 with respect to the base front surface 61a is determined from the base through holes 63 and 64 to the base front surface 61a. The configuration is such that it gradually becomes smaller toward the upper opening end.

  Based on the above configuration, the back-side lead wires 12 and 13 are inserted into the front-side base inclined grooves 72 and 74 from the base through holes 63 and 64 so that the back-side lead wires 12 and 13 are connected to the base disk portion 61. It is arranged to be inclined. Thereby, the dimension of the brush device 1 is suppressed from increasing in the direction of the rotation axis of the rotor, and the electric motor is made compact.

  In the present embodiment, the back side base inclined grooves 71 and 73 are formed so that the inner wall surfaces thereof are curved in an arc shape, and the front side base inclined grooves 72 and 74 are formed so that the inner wall surfaces thereof have an angular sectional shape along a quadrangle. The configuration is as follows.

  Based on the above configuration, the rear side base inclined grooves 71, 73 can minimize the cross-sectional area that reduces the base 60 behind the brush box 51, and the rigidity of the base 60 is ensured.

  During the process of molding the resin base 60, the base through-holes 63, 64, the back side base inclined grooves 71, 73, and the front side base inclined grooves 72, 74 are formed by using a mold divided vertically. Is secured.

  The brush device of the present invention is not limited to a four-pole electric motor, and may be applied to an electric motor having six or more poles.

  The present invention is not limited to the above-described embodiment, and it is obvious that various modifications can be made within the scope of the technical idea.

DESCRIPTION OF SYMBOLS 1 Brush device 11, 14 Front side lead wire 12, 13 Back side lead wire 40 Pigtail wire 50 Brush 51-54 Brush box 55 Leg part 60 Base 61 Base disk part 61a Base front surface 61b Base back surface 62 Base cylinder part 63, 64 Base Through hole 69 Base end 71, 73 Rear side base inclined groove 72, 74 Front side base inclined groove

Claims (4)

A brush device for an electric motor that causes electricity to flow through at least four or more even brushes in sliding contact with a commutator,
A plurality of brush boxes in which the brush is slidably interposed; and
A resin base made of a non-conductive material to which the brush box is attached;
A lead wire for conducting the power source and the brush box;
The base is
A base front where the brush box is located;
The back of the base located on the opposite side of the front of the base;
A base end from which the lead wire extending to the power source is drawn;
A base through-hole penetrating from the back of the base to the front of the base,
The lead wire is
A front lead wire connected to the brush box near the base end,
It is divided into a back side lead wire connected to the brush box far from the base end portion than the front side lead wire,
The front lead wire extends along the front surface of the base from the base end portion,
The back lead wire extends along the back surface of the base from the end of the base, and extends along the front surface of the base through the base through hole. Forming a back-side base inclined groove opening in the back of the base;
This back side base inclined groove
Extending from the base through hole through the back of the brush box toward the base end,
2. The brush device for an electric motor according to claim 1, wherein a depth of the back side base inclined groove with respect to the back surface of the base gradually decreases from the base through hole to an opening end on the back surface of the base. Forming a front-side base inclined groove opening in the front of the base;
3. The brush device for an electric motor according to claim 1, wherein a depth of the front side base inclined groove with respect to the front surface of the base gradually decreases from the base through hole to an opening end on the front surface of the base.   4. The brush device for an electric motor according to claim 1, wherein the back side base inclined groove is formed such that an inner wall surface thereof is curved in an arc shape. 5.

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