JP2010283956A - 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 for an electric motor for supplying electricity to a brush 50 in slide contact with a commutator includes a resin-made base 60 having a brush box 51 attached thereon. The base 60 has a front face 61a in which the brush box 51 is disposed, and a back face 61b in which first and second lead plates 21 and 22 are disposed on the side opposite to the front face 61a. The brush box 51 has a leg portion 52 penetrating through the base 60, the first lead plate 21 or the second lead plate 22. The brush box 51 and the first and second lead plates 21, 22 are attached to the base 60 by the leg portion 52. <P>COPYRIGHT: (C)2011,JPO&amp;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 lead-out portion 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 for an electric motor that supplies electricity to a brush that is in sliding contact with a commutator. The first and second lead wires are connected to a power source, and the first and second lead wires are connected to the first and second lead wires. A second lead plate, a plurality of brushes connected to the first and second lead plates, a brush box in which the brush is slidably interposed, and a resin made of a non-conductive material to which the brush box is attached A base, and the base has a front surface on which the brush box is disposed and a back surface on which the first and second lead plates are disposed on the opposite side, and the brush box has the base and the first lead plate or It has a leg portion penetrating the second lead plate, and the brush box and the first and second lead plates are respectively attached to the base by the leg portion.

  According to the present invention, the brush device needs to be insert-molded with the first and second lead plates on the base due to the structure in which the first and second lead plates are attached to the back surface of the base via the legs of the brush box. In addition, the base mold configuration is simplified and the manufacturing cost can be reduced.

  Since a base made of a non-conductive material is interposed between the first and second lead plates and the brush box, insulation between the two is ensured.

  Since the brush box and the first and second lead plates are respectively attached to the base by the legs, man-hours required for these assembling operations can be reduced and productivity can be increased.

The front view which shows the brush apparatus which shows embodiment of this invention. The rear view which similarly shows a brush apparatus. Sectional drawing which similarly shows a base etc. Sectional drawing which similarly shows a 1st lead wire.

  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 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 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, the electricity supplied from the power source passes through the first and second lead wires 11 and 12, the first and second lead plates 21 and 22, and the four pigtail wires 40. Each of the brushes 50 flows.

  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 the first and second lead plates 21 and 22 and the four brush boxes 51 are attached to the base 60.

  FIG. 3 is a sectional view showing the base 60, the brush box 51 and the like.

  The base 60 has an annular base disc portion 61 and a base cylinder portion 62 that extends in a cylindrical shape from the outer peripheral end of the base disc portion 61, and these are integrally formed of resin.

  The brush 50 is slidably inserted in the brush box 51, and the front end surface 50 a is pressed against the commutator by the urging force of the spring 70.

  The spring 70 is interposed between the base tube portion 62 and the brush 50 by being compressed in the brush box 51. One end of the spring 70 is supported by the base cylinder portion 62 via the brush plate 30, and the other end abuts on the base end surface 50 b of the brush 50.

  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.

  The brush box 51 is disposed on the front surface 61 a of the base disk part 61. On the other hand, the first and second lead plates 21 and 22 are disposed on the base back surface 61 b of the base disk portion 61.

  The brush box 51 has a pair of legs 52. The base disk portion 61 and the first and second lead plates 21 and 22 are formed with openings through which the respective leg portions 52 pass.

  Each leg portion 52 passes through the base disk portion 61 and the first and second lead plates 21 and 22, and the protruding portion is bent to be caulked and fixed to the base disk portion 61.

  As a result, the brush box 51 is attached to the base disk portion 61 and the first and second lead plates 21 and 22 are attached.

  The base 60 is integrally formed with four positioning pins 71 protruding from the back surface 61b. Each positioning pin 71 is inserted into a hole formed in the first and second lead plates 21 and 22, whereby the first and second lead plates 21 and 22 are positioned.

  Each positioning pin 71 is arranged to be aligned with each leg portion 52 on the radius of the base 60. Thereby, the opening part formed in the base disk part 61 through each positioning pin 71 and penetrating each leg part 52, and the opening part formed in the first and second lead plates 21 and 22 and penetrating each leg part 52 are formed. Is accurately aligned.

  The leg portions 52 of the brush boxes 51 are arranged on the same circumference S of the base 60. In other words, the distances r1, r2, r3, r4 from the rotation axis O of the rotor (the center of the base 60) to the legs 52 of the brush boxes 51 are set to be equal to each other. Thereby, each brush box 51 becomes the same position where the leg part 52 protrudes, and can make the shape the same.

  The four brushes 50 that are opposite to each other have the same polarity. For this reason, the first and second lead plates 21 and 22 each extend in a semicircular arc shape, and the two brushes 50 facing each other are electrically connected.

  The first lead plate 21 has a wide portion 21c, a small portion 21b, and a wide portion 21d. Brush boxes 51 are connected to the wide portion 21c and the wide portion 21d, respectively.

  The second lead plate 22 has a wide portion 22c, a small portion 22b, and a wide portion 22d. Brush boxes 51 are connected to the wide portion 22c and the wide portion 22d, respectively.

  The first and second lead plates 21 and 22 have a wide portion 21d, a second lead plate 22 and a narrow portion 22b of the first lead plate 21, and a wide portion 22d of the second lead plate 22 and the first lead plate 22. The lead plate 21 is provided side by side with the narrow portion 21 b and is stored in a limited space on the base disk portion 61.

  Four through holes 63 are formed in the base disk portion 61, and the pigtail wire 40 is connected to the first and second lead plates 21 and 22 facing the through holes 63.

  One end of the pigtail wire 40 is fixed by spot welding, and the other end is inserted into the hole 50c of the brush 50 and fixed.

  Accordingly, the first and second lead plates 21 and 22 disposed on the back surface 61 b side of the base 60 and the brush 50 disposed on the front surface 61 a side of the base 60 are electrically connected via the pigtail line 40.

  Two through holes 68 are formed in the base disk portion 61, and the wire rods 11b and 12b of the first and second lead wires 11 and 12 facing the through hole 68 are connected.

  As shown in FIG. 4, the first lead wire 11 has a wire 11 b protruding from the coating 11 a fixed to the first lead plate 21 by spot welding.

  Similarly, the wire 12b of the second lead wire 12 is fixed to the second lead plate 22 by spot welding.

  As a result, the first and second lead plates 21 and 22 disposed on the back surface 61b side of the base 60 and the first and second lead wires 11 and 12 disposed on the front surface 61a side of the base 60 are electrically connected. The

  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.

  Grommets 80 through which the first and second lead wires 11 and 12 are inserted are provided. The grommet 80 is made of a flexible resin material such as rubber, and supports the first and second lead wires 11 and 12 with respect to the bracket and the case, and seals between them.

  The electric motor includes a pair of bearings that rotatably support the shaft of the rotor, and each bearing is attached to the bracket and the case.

  The base 60 has three fixing posts 65, 66, and 67, and is fastened to the bracket by three screws (not shown) that pass through the fixing posts 65, 66, and 67.

  The fixed post 65 is disposed between the first and second lead plates 21 and 22 and positions both of them.

  The fixed post 65 is disposed between connection portions (through holes 68) where the first and second lead wires 11 and 12 are connected to the first and second lead plates 21 and 22. Engaging portions 21 a and 22 a that engage with the outer peripheral surface of the cylindrical fixed post 65 are formed at the ends of the first and second lead plates 21 and 22.

  The base 60 is formed with a central rib 73 that is connected to the fixed post 65 and extends in the central direction of the rotation axis O of the rotor (center of the base 60) base 60.

  Even when the first and second lead wires 11 and 12 are pulled by the resin-made central rib 73 and the fixing post 65 being interposed between the first and second lead plates 21 and 22, the first, The distance between the second lead plates 21 and 22 is held so as not to be narrower than that, and the insulation between the first and second lead plates 21 and 22 is maintained.

  The fixed post 66 is disposed inside the first lead plate 21. The cylindrical fixed post 66 is formed with an engaging portion 66 a that engages with the narrow portion 21 b of the first lead plate 21.

  The first lead plate 21 is positioned by the narrow portion 21b interposed between the engaging portion 66a of the fixed post 66 and the base tube portion 62.

  The fixed post 67 is disposed outside the second lead plate 22. The cylindrical fixing post 67 is formed with an engaging portion 67 a that engages with the narrow portion 22 b of the second lead plate 22.

  The second lead plate 22 is positioned by the narrow portion 22b interposed between the engaging portion 66a of the fixed post 66 and the base tube portion 62.

  As shown in FIG. 3, an insulating rib 72 and a central rib 73 protruding from the back surface 61b of the base 60 are integrally formed. The insulating rib 72 and the central rib 73 extend in an arc shape along the first and second lead plates 21 and 22. The first lead plate 21 is interposed between the insulating rib 72 and the base cylindrical portion 62, and the second lead plate 22 is interposed between the insulating rib 72 and the central rib 73, so that each positioning is possible. As it is done, insulation between the two is removed.

  During operation of the electric motor, the brush device 1 is supplied with electricity from the first and second lead wires 11 and 12, the first and second lead plates 21 and 22, and the four pigtail wires 40. And supplied 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 of an electric motor that supplies electricity to the brush 50 that is in sliding contact with the commutator, the first and second lead wires 11 and 12 connected to the power source, and the first The first and second lead plates 21 and 22 connected to the second lead wires 11 and 12, the plurality of brushes 50 connected to the first and second lead plates 21 and 22, and the brush 50 are slidable. A brush box 51 to be interposed; and a resin base 60 made of a non-conductive material to which the brush box 51 is attached. The base 60 is disposed on a front surface 61a on which the brush box 51 is disposed, and on the opposite side. The brush box 51 is a leg that penetrates the base 60 and the first lead plate 21 or the second lead plate 22. Has 52, brush box 51 and the first relative to the base 60 by the leg portion 52, a second lead plate 21 is configured to be mounted respectively.

  Based on the above configuration, the brush device 1 has a structure in which the first and second lead plates 21 and 22 are attached to the back surface 61 b of the base 60 via the leg portions 52 of the brush box 51, thereby providing the first and second lead plates 21. , 22 need not be insert-molded into the base 60, the mold configuration of the base 60 is simplified, and the manufacturing cost can be reduced.

  Since the base 60 made of a non-conductive material is interposed between the brush box 51 and the first and second lead plates 21 and 22, insulation between the two is ensured.

  Since the brush box 51 and the first and second lead plates 21 and 22 are respectively attached to the base 60 by the legs 52, the number of man-hours required for these assembly operations can be reduced and the productivity can be increased.

  In the present embodiment, the leg portions 52 of the brush boxes 51 are arranged on the same circumference S of the base 60.

  Based on the above-described configuration, the shape of each brush box 51 is made the same, the energization conditions for each brush 60 are made uniform, and the press dies and the like forming the brush box 51 are reduced, thereby reducing the manufacturing cost.

  In the present embodiment, the base 60 is fastened to the casing of the electric motor via a screw, and the base 60 has a fixing post 65 through which the screw is inserted. The fixing post 65 is the first and second lead plates 21 and 22. Between the first and second lead plates 21 and 22, and the connection portion to which the first and second lead wires 11 and 12 are connected is arranged so as to sandwich the fixed post 65.

  Based on the above configuration, when the first and second lead wires 11 and 12 are pulled by the fixed post 65 being interposed between the first and second lead plates 21 and 22, the first and second leads The distance between the plates 21 and 22 is maintained so as not to be narrowed further, and the insulation between the first and second lead plates 21 and 22 is maintained.

  In the present embodiment, a plurality of positioning pins 71 projecting from the back surface 61b of the base 60 are provided, and the positioning pins 71 are inserted into holes formed in the first and second lead plates 21 and 22, and the positioning pins 71 are The base 60 is arranged to be aligned with the legs 52 on the radius.

  Based on the above configuration, the positioning of the base 60 and the first and second lead plates 21 and 22 is accurately performed in the circumferential direction of the base 60 via the positioning pins 71, and the legs 52 of the brush boxes 51 are used as the bases. 60 and the first and second lead plates 21 and 22 are smoothly inserted.

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

  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 apparatus 11 1st lead wire 12 2nd lead wire 21 1st lead plate 22 2nd lead plate 30 Brush plate 40 Pigtail wire 50 Brush 51 Brush box 52 Leg part 60 Base 65 Fixed post 66 Fixed post 67 Fixed post 71 Positioning Pin 72 Insulating rib 73 Central rib

Claims (4)

A brush device for an electric motor that supplies electricity to a brush that is in sliding contact with a commutator,
First and second leads connected to the power supply;
First and second lead plates connected to the first and second lead wires; and
A plurality of brushes connected to the first and second lead plates;
A brush box in which the brush is slidably interposed;
A resin base made of a non-conductive material to which the brush box is attached;
This base is
A front surface on which the brush box is disposed;
A back surface on which the first and second lead plates are disposed on the opposite side;
The brush box has legs that penetrate the base and the first lead plate or the second lead plate;
The brush device of the electric motor, wherein the brush box and the first and second lead plates are respectively attached to the base by the leg portions.   The brush device for an electric motor according to claim 1, wherein the leg portions of the brush boxes are arranged on the same circumference of the base. The base is fastened to the casing of the electric motor via a screw,
The base has a fixing post through which the screw is inserted,
This fixed post is disposed between the first and second lead plates,
The brush for an electric motor according to claim 1 or 2, wherein a connecting portion for connecting the first and second lead wires to the first and second lead plates is disposed so as to sandwich the fixed post. apparatus. A plurality of positioning pins protruding from the back surface of the base;
This positioning pin is inserted into the hole formed in the first and second lead plates,
The brush device for an electric motor according to any one of claims 1 to 3, wherein the positioning pin is arranged so as to be aligned with the leg portion on a radius of the base.

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