JP2009038936A - Commutator and electric motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a commutator for preventing short-circuit due to connection lines among segments at different potentials even when segments at the same potentials are located at positions where they do not face each other around a rotating shaft, and to provide an electric motor. <P>SOLUTION: The commutator 13 has a main body section 40 made of a synthetic resin fixed around the rotating shaft 5, a plurality of the segments 41 arranged on the outer peripheral surface of the main body section 40 and fitting risers 43 at one ends and the connection lines 42 being stretched among the risers 43 for the segments 41 at the same potential in a plurality of the segments 41 and short-circuiting the segments 41 at the same potential. In the commutator 13, projecting sections 46 guiding the lead-out directions of the connection lines 42 towards the central side in the radial direction are fitted at sites corresponding to the risers 43 as the end face 40a of the main body section 40. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a commutator for performing rectification to a winding wound around an armature core, and an electric motor using the commutator.

Generally, an electric motor with a brush has a configuration in which an armature is rotatably arranged inside a cylindrical yoke having a permanent magnet attached to an inner peripheral surface. The armature has an armature core that is externally fixed to a rotating shaft and wound with a coil. Further, a commutator is externally fixed to the rotating shaft so as to be adjacent to the armature core.
The commutator has a plurality of segments formed of a conductive material. The segment is made of a plate-shaped metal piece and is exposed on the rotating sliding surface of the commutator. A riser is integrally formed at the end of each segment, and a winding start end and a winding end end of the coil are wound around and connected by fusing or the like.

  Each segment is in sliding contact with the brush, and current is supplied to each coil by applying a voltage from the brush to the segment. At this time, a different magnetic field is formed in each coil by shifting the phase of the current flowing through each coil, and the rotating shaft is rotated by a magnetic attractive force or repulsive force generated between the magnets of the yoke. Also, by this rotation, the segments in sliding contact with the brush are sequentially changed, so that the direction of the current flowing in the coil is switched, so-called rectification is performed, and the armature rotates continuously.

  By the way, among the segments disposed in the commutator, the segments having the same potential may be short-circuited by a connecting line (equal pressure line). By configuring in this way, it is possible to supply a current to a segment where the brush is not in sliding contact, so that the number of brushes installed can be reduced. In addition, it is possible to suppress variations in excitation balance due to a shift in contact timing between each segment and the brush.

  Here, when the segments having the same potential are short-circuited by the connection line, the connection line is routed between the risers, and therefore, the connection line is routed so as to straddle the plurality of segments. At this time, there is a possibility that the connecting lines come into contact with risers of segments having different potentials, for example, adjacent risers, and adjacent segments are short-circuited due to peeling of the coating of the connecting lines. For this reason, a technique has been proposed in which a spacer having a slanted wall portion is provided on one end face of a commutator serving as a wiring path for connecting lines, and contact between the connecting line hung on the riser and the adjacent riser is prevented. .

That is, the inclined wall portion is formed so as to be gradually reduced in diameter as it moves away from the commutator in the axial direction, and the connecting line is guided in a direction away from the commutator by the inclined wall portion. For this reason, a clearance is secured in the axial direction between the connecting line hung around the riser and the adjacent riser, and contact between the two can be prevented (for example, see Patent Document 1).
JP 2003-32968 A

  However, in the above-described prior art, for example, when there are two segments having the same potential, such as an electric motor having four magnetic poles, and these are arranged opposite to each other around the rotation axis, Can be an effective means, but there are four segments with the same potential, such as an electric motor with eight magnetic poles, and these are arranged at intervals of 90 ° in the circumferential direction. It is difficult to become an effective means.

  In other words, when segments with the same potential are arranged at 90 ° intervals in the circumferential direction, the two segments with the same potential are applied to the riser compared to the case where two segments with the same potential are arranged opposite to each other around the rotation axis. The distance between the turned connection line and the adjacent riser is shortened. For this reason, it is difficult to secure a clearance between the connection line and the riser only by guiding the connection line in the direction away from the commutator using a spacer as in the prior art. There is a problem that there is a risk of short circuit.

  Therefore, the present invention has been made in view of the above-described circumstances, and even when segments having the same potential exist at positions other than the positions facing each other around the rotation axis, segments having different potentials are connected. The present invention provides a commutator and an electric motor that can prevent a short circuit due to a wire.

In order to solve the above-mentioned problem, the invention described in claim 1 includes a plurality of main body portions made of synthetic resin fixed around a rotating shaft, and a plurality of risers provided on one end of the main body portion and disposed on the outer peripheral surface of the main body portion. And a connecting line for short-circuiting the segments having the same potential between the risers of the segments having the same potential among the plurality of segments. And the convex part which guides the pulling-out direction of the said connecting wire toward the radial direction center side was provided in the site | part corresponding to the said riser.
In this case, as in the invention described in claim 2, there may be at least four segments having the same potential, and the segments having the same potential may be arranged at equal intervals in the circumferential direction.
By configuring in this way, the convex portion can be reliably interposed between the connecting line hung around the riser and the adjacent riser, and the connecting line is not moved in the axial direction as in the past. In addition, the movement of the connection line drawn from the riser in the circumferential direction can be restricted.

  According to a third aspect of the present invention, the commutator according to the first or second aspect, a brush provided so as to be slidable on the segment of the commutator, and the rotary shaft adjacent to the commutator are provided. An electric motor including an armature core around which a winding is wound and a yoke having eight or more magnetic poles is provided.

  According to the present invention, it is possible to reliably interpose the convex portion between the connecting line hung around the riser and the adjacent riser, and instead of moving the connecting line in the axial direction as in the prior art, The movement of the connection line drawn from the riser in the circumferential direction can be restricted. For this reason, for example, even when segments having the same potential exist in positions other than the positions facing each other around the rotation axis as in an electric motor having eight magnetic poles, the segments between different potentials are connected by connecting lines. It is possible to reliably prevent short circuit.

Next, embodiments of the present invention will be described with reference to the drawings.
As shown in FIGS. 1 and 2, the electric motor 1 with a brush serves as a drive source for an electrical component (for example, a radiator fan) mounted on a vehicle, and rotates in a yoke 2 having a bottomed cylindrical shape. A freely provided armature 3 is provided, and the opening 2 c of the yoke 2 is closed with an end bracket 17.

  A plurality of permanent magnets 4 (eight in this embodiment) are arranged in parallel on the inner surface of the circumferential wall 2a of the yoke 2 along the circumferential direction. Further, a boss portion 10 is formed in the end portion (bottom portion) 2b of the yoke 2 at a substantially radial center. The boss portion 10 is formed with an insertion hole 11 for inserting the rotation shaft 5 of the armature 3 and a bearing 12 for rotatably supporting one end side of the rotation shaft 5.

  The armature 3 includes an armature core 6 that is externally fitted and fixed to the rotating shaft 5, an armature coil 7 that is wound around the armature core 6, and a commutator 13 that is disposed on the other end side of the rotating shaft 5. . The armature core 6 is formed by laminating a plurality of metal plates in the axial direction or press-molding soft magnetic powder. The armature core 6 has a core body 8 formed in a substantially annular shape. In the center of the core body 8 in the radial direction, concave portions 30 are formed on both side surfaces. A plurality of through holes 31 penetrating in the axial direction are formed in the recess 30 at equal intervals along the circumferential direction (five in this embodiment).

  The through-hole 31 is formed in a substantially fan shape in the axial direction plan view. An insertion hole 32 is formed in the center of the recess 30 in the radial direction. By means of these through holes 31 and insertion holes 32, the core body 8 has two annular portions 33 and 34 formed concentrically in a plan view in the axial direction, and a spoke portion 35 that connects these annular portions 33 and 34 to each other. It is in a state composed of and. Here, the rotary shaft 5 is press-fitted into the insertion hole 32.

  A plurality of teeth (10 in this embodiment) are radially formed on the outer peripheral portion of the core body 8 at regular intervals along the circumferential direction in a substantially T-shape in a plan view in the axial direction. Between adjacent teeth 36, a dovetail slot 37 is formed. The slots 37 extend along the axial direction, and a plurality (10 in the present embodiment) are formed at equal intervals along the circumferential direction. An enamel-coated winding 38 is wound around the tooth 36 through the slot 37. As a result, a plurality of armature coils 7 are formed on the outer periphery of the armature core 6.

As shown in FIGS. 1 and 3, the commutator 13 disposed on the other end side of the rotary shaft 5 has a substantially columnar main body 40 that is externally fixed to the rotary shaft 5 and made of synthetic resin. A plurality (20 in this embodiment) of segments 41 are exposed on the outer peripheral surface of the main body 40.
The segments 41 are made of plate-like metal pieces that are long in the axial direction, and are arranged in parallel at equal intervals along the circumferential direction. Moreover, the slit 45 is formed between the adjacent segments 41, and the adjacent segments 41 are mutually insulated.

An anchor 44 bent inward in the radial direction is integrally formed at an end (upper end in FIG. 1) opposite to the armature core 6 of each segment 41. The anchor 44 is for preventing the segment 41 from peeling off from the main body 40 and is embedded in the main body 40 by being bent radially inward.
On the other hand, a riser 43 is integrally formed at the end of each segment 41 on the armature core 6 side (lower end in FIG. 1). The riser 43 is for connecting the armature coil 7 to the segment 41. The winding start end and the winding end end of the winding 38 drawn from the armature coil 7 are respectively wound around and fixed by fusing. It has become so. Thereby, the segment 41 and the armature coil 7 corresponding to this are electrically connected.

  The riser 43 also has a role of connecting an enamel-coated connecting line (equal pressure equalizing line) 42 that short-circuits the segments 41 having the same potential. In other words, in this embodiment, the electric motor 1 is composed of 8 poles, 10 slots, 20 segments each having 8 permanent magnets 4, 10 slots 37, and 20 segments 41. There will be four 41 each. Therefore, the connection line 42 is routed between the risers 43 of the four segments 41 having the same potential (see FIG. 4).

  Since the connecting wires 42 are respectively wound around the risers 43, they are routed on the side of the main body 40 where the risers 43 are disposed, that is, on the end face 40a of the main body 40 on the armature core 6 side. . The connection line 42 wound around each riser 43 is fixed by fusing. In addition, among the plurality of segments 41, the four segments 41 having the same potential exist at every fourth interval, so that the segments 41 are arranged at equal intervals while being spaced apart by 90 ° in the circumferential direction.

  Here, on the end surface 40 a of the main body 40, 20 resin-made convex portions 46 formed in a bowl shape at a portion corresponding to the riser 43 are integrally formed. The convex portion 46 is for restricting the drawing direction of the connecting line 42 from the riser 43 so as to guide the radial direction toward the central side in the radial direction, and the flat surface 46a faces the riser 43 side and the arc surface 46b. Is formed so as to face radially inward.

More specifically, the operation of the convex portion 46 formed on the main body 40 will be described with reference to FIGS. 4 and 5.
As shown in FIG. 4, in order to short-circuit the segments 41 having the same potential, the connection line 42 is wound around every four risers 43 spaced by 90 ° in the circumferential direction. At this time, the connecting line 42 laid around the riser 43 is in a state where the routing route is restricted by the convex portion 46 of the adjacent riser 43 and drawn toward the center in the radial direction.

  That is, normally, when the connection line 42 is laid around between the risers 43 spaced by 90 ° in the circumferential direction, the connection line 42 comes into contact with the adjacent risers 43 as shown by a two-dot chain line in FIG. There is a fear. However, since the hook-shaped convex part 46 is formed in the part corresponding to each riser 43 of the main-body part 40, the drawer | drawing-out part from the riser 43 of the connecting wire 42 is guided to radial inner side. For this reason, a clearance C is formed in the circumferential direction between the connecting line 42 hung around the riser 43 and the adjacent riser 43, thereby preventing contact between the two.

Moreover, since the convex part 46 is formed so that the circular arc surface 46b faces inward in the radial direction, the connecting line 42 can be routed between the risers 43 while being gently curved. For this reason, it is possible to prevent damage to the connection line 42 and peeling of the enamel coating without forcibly bending the connection line 42. The connection lines 42 are sequentially wound between the risers 43 of the four segments 41 at intervals of 90 °, so that the connection lines 42 that short-circuit the segments 41 having the same potential overlap each other so that the end faces 40a of the main body 40 overlap each other. (See FIG. 5). In addition, the protrusion height of the convex part 46 is set to the dimension which all the connection lines 42 which overlap in an axial direction are hooked.
In addition, a cylindrical external fitting fixing auxiliary portion 47 for improving the fixing strength with respect to the rotating shaft 5 is integrally formed in the main body portion 40 of the commutator 13 in the radial center.

As shown in FIG. 1, the end bracket 17 is made of metal and is formed in a substantially disk shape, and a boss portion 18 is formed so as to protrude substantially at the center in the radial direction. A bearing 19 for rotatably supporting the other end side of the rotating shaft 5 is press-fitted and fixed to the boss portion 18.
A stay 9 is provided on the outer peripheral side of the end bracket 17 and extends outward. This stay 9 is used when fixing the electric motor 1, and is provided with a bolt hole 9 a that is formed by burring and projects toward the side opposite to the yoke 2.

  A holder stay 20 is attached to the inner side of the end bracket 17 (lower side in FIG. 1). The holder stay 20 is made of resin and is formed in a substantially disk shape, and a brush holder 21 is fixed thereto. Each brush holder 21 is provided with a brush 22 that can be moved in and out in a state where the brush 22 is urged through a spring 23. The tips of the brushes 22 are urged by the springs 23 and are in sliding contact with the segments 41 of the commutator 13. The brush 22 is connected to an external power source (not shown). Thereby, an electric current can be supplied to the armature coil 7 through the segment 41 with which the brush 22 is slidably contacted.

Therefore, according to the above-mentioned embodiment, the convex part 46 is integrally molded by the main body part 40 of the commutator 13 in the site | part corresponding to the riser 43 on the end surface 40a by the side of the armature core 6. For this reason, the convex part 46 is reliably interposed between the riser 43 and the connection line 42, and the lead-out part of the connection line 42 from the riser 43 is guided radially inward. That is, the clearance C can be reliably ensured between the riser 43 and the connection line 42 in the circumferential direction.
Therefore, even in the electric motor 1 having 8-pole magnetic poles in which the segments having the same potential exist at positions other than the positions facing each other around the rotation axis, the segments 41 having different potentials are short-circuited by the connection line 42. In addition, it is not necessary to connect the riser 43 and the connection line 42 to a connection method such as an α hook in order to prevent a short circuit caused by the connection line 42.

  In this case, the α hook is used to hang the connection line 42 around the riser 43 from the rear side of the riser 43 toward the front side, and then to hang the connection line 42 around the next riser 43. This refers to a connection method in which the connection line 42 is drawn from the back side to the riser 43 (see FIG. 6). That is, as a means for securing the clearance C between the riser 43 and the connection line 42, it is conceivable to hang the connection line 42 around the riser 43 by a method such as an α hook, but the connection line 42 becomes long. , The weight and manufacturing cost will increase. However, according to this embodiment, it is possible to ensure the clearance C in the circumferential direction between the riser 43 and the connection line 42 without connecting the connection line 42 to the riser 43 with an α hook.

  Further, the convex portion 46 is formed in a bowl shape, and the flat surface 46a faces the riser 43 side, while the arc surface 46b faces the radially inner side. For this reason, the connection line 42 pulled out from the riser 43 is routed between the risers 43 while being gently bent without being bent excessively. Therefore, damage to the connecting wire 42 and peeling of the enamel coating can be prevented.

The present invention is not limited to the above-described embodiment, and includes various modifications made to the above-described embodiment without departing from the spirit of the present invention.
In the above-described embodiment, the case has been described in which the flange-shaped convex portion 46 is integrally formed on the end surface 40a of the main body portion 40. However, the present invention is not limited to this, and the pull-out direction of the connecting wire 42 is regulated. Any shape that can secure the clearance C in the circumferential direction between the riser 43 and the connection line 42 may be used.

Furthermore, although the case where the convex part 46 was formed with resin was demonstrated in the above-mentioned embodiment, it is not restricted to this, What is necessary is just to have insulation. In this case, the main body portion 40 and the convex portion 46 may be molded separately and then integrated, or two-color molding may be performed.
In the above-described embodiment, the case where the electric motor 1 is the electric motor 1 having the eight magnetic poles including the eight permanent magnets 4 has been described. If it is. In particular, it is suitable for an electric motor having more than four poles where the connecting line 42 may come into contact with the adjacent riser 43.

It is a longitudinal section showing the composition of the electric motor in the embodiment of the present invention. It is sectional drawing which follows the AA line of FIG. It is a top view before connecting line wiring of the commutator in embodiment of this invention. It is wiring route explanatory drawing in the embodiment of the present invention. It is a top view of a commutator in an embodiment of the present invention. It is explanatory drawing which shows the connection method of the riser and connection line by (alpha) hook.

Explanation of symbols

1 Electric motor 2 Yoke 3 Armature 4 Permanent magnet (magnetic pole)
5 Rotating shaft 6 Armature core 7 Armature coil (coil)
13 Commutator 22 Brush 40 Body 40a End surface 41 Segment 42 Connection line 43 Riser 46 Convex 46a Flat surface 46b Arc surface

Claims (3)

A main body made of synthetic resin fixed around the rotation axis;
A plurality of segments disposed on the outer peripheral surface of the main body portion and provided with a riser at one end;
In a commutator provided with a connecting line that is hung between risers of segments having the same potential among the plurality of segments and short-circuiting the segments having the same potential,
A commutator, characterized in that a convex portion for guiding the pulling-out direction of the connection line toward the radially central side is provided at a portion corresponding to the riser on the end surface of the main body portion.   The commutator according to claim 1, wherein there are at least four segments having the same potential, and the segments having the same potential are arranged at equal intervals in the circumferential direction. The commutator according to claim 1 or 2,
A brush provided to be slidable on the segment of the commutator;
An armature core provided on the rotating shaft adjacent to the commutator and wound with a winding;
An electric motor including a yoke having eight or more magnetic poles.

Images