JP2924605B2 - Armature of commutator type rotating electric machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an armature of a commutator type rotating electric machine having a commutator.

[0002]

2. Description of the Related Art A conventional commutator of an armature of a commutator-type rotating electric machine has a plurality of commutator pieces which are electrically insulated from a rotating shaft and are arranged circumferentially around the rotating shaft. Japanese Patent Application Laid-Open No. 63-194541 discloses that a brush contact portion extending in the axial direction is partially embedded in a surface portion of a mold resin tube (insulating material) fitted on a rotating shaft, and the brush contact portion extends circumferentially inside the mold resin tube. An inner conductor extending in the axial direction while being inclined is embedded, and the outer riser portion is radially extended from one end of the brush contact portion, and the inner riser portion and the armature core are electrically insulated from both of the inner riser portion between the outer riser portion and the armature core. A commutator piece is disclosed in which an inner riser portion extends radially from one end of a conductor. By doing so, the coil end can be omitted.

A surface-type commutator in which commutator pieces are radially arranged in a radial direction is also known. In the surface type commutator, the commutator piece does not have to be carried on the outer peripheral portion of the molded resin cylinder, which is advantageous in high-speed rotation. Furthermore, there is a demand for a DC motor used in a starter for an automobile or the like to be reduced in size and weight . To meet this demand, Japanese Patent Application Laid-Open No. 61-240832 discloses an irregular shape in which the cross-sectional shape of an armature conductor is adjusted to a slot shape. It is proposed to improve the space factor by using a cross section.

[0004]

In the automotive starter, downsizing is particularly required because of its on-vehicle mounting. As means for reducing the size, reduction is performed by using a speed reducer to reduce the speed and increasing the rotation speed of the electric motor. In such a high-speed commutator-type rotating electric machine, an excessive centrifugal force acting on the coil end of the armature coil that is not held by the armature core poses a problem.

[0005] The coil end is bent in the circumferential direction while expanding in the axial direction by a predetermined pitch so that the armature coil goes out of the slot of the core and enters the next slot, so that it has a considerable weight and axial length. As a result, the armature is once supported by the armature core, and cannot withstand a large centrifugal force due to high-speed rotation. On the other hand, when the riser portion of the commutator piece disclosed in JP-A-63-194541 is extended in the radial direction and directly connected to the armature conductor coming out of the slot, the coil end can be omitted. The centrifugal force exerted on the commutator piece whose mass and radial length of the riser portion have been significantly increased will be greatly increased.

According to the above publication, the commutator pieces are supported by being buried in two steps in the surface of the molded resin cylinder and in the interior thereof. Decreases the support strength of the piece.
In addition, at the time of high-speed rotation, the mold resin cylinder cannot support the excessive centrifugal force of the commutator piece, and there is a problem that the commutator piece separates from the mold resin cylinder. Further, the inner conductor embedded in the mold resin cylinder and extending in the axial direction turns or bends instead of the coil end. Therefore, the inner conductor needs to have a complicated shape and arrangement, which is not easy to manufacture. Further, the molded resin cylinder must receive the resistance heat generated by the armature conductor embedded in a larger amount than the conventional commutator, in addition to the brush friction heat, and the heat resistance of the molded resin cylinder also becomes a problem. In addition, the coil end on the non-commutator side remains as it is, and after all, high-speed rotation higher than the number of rotations that this coil end can endure cannot be expected.

Further, in the above-mentioned surface commutator, the coil end itself is the same as the conventional one, and there is no solution to the problem that the high-speed rotation is restricted by the centrifugal force applied to the coil end. In the surface type commutator, the surface type commutator is arranged from the end face of the armature core through the coil end accommodating space of the armature coil in order to bend the armature coil at a required pitch. Must be placed sideways, which increases the axial length, size and weight of the motor.

Further, as described in the above-mentioned publication, when the space factor is improved by making the cross-sectional shape of the armature conductor a modified cross-section conforming to the slot shape, the following problem occurs. Such techniques have not been widely used. First, if an irregular cross section is given to the armature conductor, work hardening occurs, and if the irregular cross section is formed, the bending becomes more difficult, the coil end expands, and the axial length of the motor increases by that much. . In addition, since it must be always inserted into the slot in a fixed posture as compared with the case of a circular cross section, it is necessary to apply a predetermined twist accurately at the coil end, and the processing is complicated and troublesome. When inserting the armature conductor into the slot while bending the armature conductor, the corners of the armature conductor may be rubbed at the entrance of the slot or the like, resulting in insulation failure.

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above problems, and has as its object to provide an armature of a commutator-type rotating electric machine capable of high-speed rotation, high output, and small and light. I have.

[0010]

An armature of a commutator-type rotary electric machine according to the present invention is provided so as to extend along both end surfaces of an armature core and to have an outer end in a radial direction connected to an armature coil. A conductor, interposed between the both end surfaces of the armature core and the outer conductor along the both end surfaces, a radial inner end connected to a radial inner end of the outer conductor, and a radial outer end Are provided with an inner conductor connected to the armature coil, and an insulator for electrically insulating the inner conductor from the armature core and the outer conductor.

In a preferred aspect, the outer end surface in the axial direction of the outer conductor forms a brush sliding surface. In a preferred embodiment,
The armature coil has a cross-sectional shape that approximates the cross-sectional shape of the slot of the armature core .

[0012]

The outer conductor extends along both end surfaces of the armature core, and the outer end in the radial direction is connected to the armature coil. The inner conductor is individually interposed along both end faces between both end faces of the armature core and the outer conductor along the both end faces, and the radial inner end is connected to the radial inner end of the outer conductor,
A radially outer end is connected to the armature coil.

The outer conductor and the inner conductor are insulated from each other and from the armature core by an insulator. According to the present invention, the following operation and effect can be obtained. First, since the coil ends on both sides can be omitted, the high-speed rotation is not restricted by the centrifugal resistance, and the axial length, size and weight of the motor can be reduced. Further, since each armature conductor constituting the armature coil can be a linear conductor, the coil end expands even when the cross-sectional shape of the armature conductor is a modified cross section (non-circular) according to the slot shape. There is no need to increase the axial length of the motor by that much, it is not necessary to apply a predetermined torsion at the coil end precisely, and it is necessary to insert the armature conductor into the slot while bending the armature conductor. Damage to the insulating film between the daughter conductor and the slot can also be avoided.

As a result, a high output can be achieved by improving the space factor while avoiding complicated and troublesome winding steps of the armature coil.
Reduction of resistance heat generation can be realized. In a preferred aspect, the outer end surface in the axial direction of the outer conductor forms a brush sliding surface. By doing so, it is not necessary to carry the commutator piece by the surface of the mold resin cylinder as in the conventional case, and
Since the molding resin cylinder itself is not required, the high-speed rotation and high output are not restricted by the thermal and mechanical loads of the conventional molding resin cylinder, and the axial direction of the motor is reduced by the omission of the molding resin cylinder. Length, physique and weight can be reduced. Furthermore, frictional heat generated by the brush is generated in the outer conductor,
This outer conductor can be well cooled by the airflow generated in the centrifugal direction along its surface, and is temporarily well absorbed by the armature core with large heat capacity,
The commutator does not limit the heat-resistant temperature of the motor.
No. In addition to the commutator that slides on a normal brush,
Brush the outer end face of the outer conductor on the opposite side of the armature core in the axial direction.
Because it can be in contact with the surface,
Auxiliary brushes can be installed and electrical signals can be
It is also possible to take out the issue.

[0015] In a preferred embodiment, each armature conductor of the armature coil has a cross-sectional shape approximating the cross-sectional shape of the slot. In this way, the best space factor can be achieved.

[0016]

【Example】

(Embodiment 1) Figs. 1 to 3 show an example in which the present invention is applied to a DC motor of an automobile starter. FIG. 1 shows an axial sectional view of this motor. An armature core 11 formed by laminating a plurality of disk-shaped steel plates is fitted to a substantially central portion of the rotating shaft 10.
A plurality of slots 12 are formed on the outer peripheral surface of the armature core 11, and inside the slots 12, the armature conductors 20 of the armature coil 2,
21 are wound up and down in two stages. Hereinafter, 20 is also called an upper conductor and 21 is also called a lower conductor. A commutator portion 4 to be described later is formed on the right end face of the armature core 11 to constitute an armature (rotator) of the electric motor. 13 is on the rotating shaft 10
Gears (not shown) (for example,
Meshes with the gears of the planetary gear reduction mechanism, and rotates the rotation shaft 10.
To the gear (not shown). Both ends of the rotating shaft 10 are provided with bearings 61 attached to an end frame 60 of the electric motor.
The end frame 60 shields an opening of the yoke 50 made of a cylindrical steel plate. A magnetic pole core 52 on which a field coil 51 is wound is provided on the inner peripheral surface of the yoke 50.
The four yokes 50, the field coils 51, and the magnetic pole cores 52 are fixed to each other in proximity to the periphery of the rotor 1. The yokes 50, the field coils 51, and the magnetic pole cores 52 form a stator.

A brush holder 70 is provided on the end frame 60.
Is fixed, and a brush 71 is slidably held in the inside thereof. The brush 71 is pressed against a commutator piece (outer conductor) 42 of the commutator 4 described later by a spring 72 provided in the brush holder 70.
In this embodiment, a winding field type DC motor is described. However, the present invention is not limited to this, and a magnet field type DC motor that generates a field magnetic field by a permanent magnet is used. Obviously, it can also be applied to a commutator motor.

Next, the commutator 4 and the armature coil 2 will be described in more detail. Inner conductors 41 are fixed to both end surfaces of the armature core 11 with a resin-based insulating material 41a interposed therebetween,
Further, outer conductors 42 are fixed to the surfaces of the inner conductors 41 on both sides with a resin-based insulating material 42a interposed therebetween. The resin-based insulating material 41a on the right side of the armature core 11, the inner conductor 41,
The resin-based insulating material 42a and the outer conductor 42 constitute a commutator 4 also serving as a coil end, and include a resin-based insulating material 41a, an inner conductor 41, and a resin-based insulating material 4 on the left side of the armature core 11.
2a and the outer conductor 42 merely constitute a coil end, and the resin-based insulating material 41a and the resin-based insulating material 42a constitute an insulator referred to in the present invention.

The inner conductor 41 and the outer conductor 42 on both sides are spirally arranged as viewed in the axial direction. FIG.
3 shows an arrangement state of the outer conductor 42. 42b is a groove between adjacent outer conductors 42. The inner conductor 41 and the outer conductor 42 are formed by punching a copper plate, but can be manufactured by another manufacturing method. Therefore, the outer conductor 42 extending along the right end face of the armature core 11 forms a commutator piece, and the outer end face in the axial direction forms a brush sliding surface.
The inner conductor 41 is provided radially outward between the armature core 11 and the outer conductor 42. The radial inner ends of the outer conductors 42 and the radial inner ends of the inner conductors 41 are individually electrically connected (in this embodiment, the radial inner ends of the outer conductor 42 and the inner conductor 41 are respectively connected). The end is
The resin-based insulating material 42 is stamped in a direction approaching each other.
Contact protrusions are formed by the thickness of a, and the two conductors 41 and 42 are pressed against the armature core 11 while the contact protrusions are in contact with each other during assembly to ensure contact.

The contact portions may be joined by welding, brazing, soldering or the like. An upper conductor 20 and a lower conductor 21 are inserted into a pair of upper and lower conductors in each slot 12 of the armature core 11, and a radially outer end of each outer conductor 42 is welded to an end of the upper conductor 20. The radial outer end of the inner conductor 41 is welded to the end of the lower conductor 21. The upper side
The conductor 20 and the lower conductor 21 are also collectively referred to as an armature coil.
You. Of course, instead of welding, brazing, soldering, pressing contact, etc. can also be adopted.

Thus, a single-wave winding is completed. Of course, various other winding types such as lap winding can be naturally used. Figure 3 shows the electrical wiring diagram of the armature of the present invention, the solid portion is the upper conductor 20, and the broken line portion represents a lower conductor 21, x is anti commutator 4
Upper conductor (armature coil) 20 and lower side connected on opposite sides
A battery having a pitch between the conductor (armature coil) 21 and
The pitch. Y is the upper conductor connected on the side of the commutator 4
Body (armature coil) 20 and lower conductor (armature coil) 2
This is a front pitch consisting of one pitch. Therefore, in the conventional motor, at the coil end of the armature coil
The connection between the conductors in the slot of the armature coil 2 is made by the coil itself.
Is curved, but in this embodiment, it is shown in FIG.
So that the inner conductor 41 and the outer conductor 42 have a substantially spiral bay.
It is replaced by a song. And the inner conductor 41 and the outer
The spiral direction of the conductor 42 is opposite. In FIG.
The inner end in the direction is shown connected to the inner end in the radial direction of the inner conductor 41.
The outer conductor 42 is a conductor forming the commutator.
is there. Outside of these inner conductor 41 and outer conductor 42 in the radial direction
Pitch between armature coils 20, 21 connected to the ends
Is the front pitch Y shown in FIG. This commutator side
With respect to the inner conductor 41 and the outer conductor 42,
The inner conductor 41 and the outer conductor 42 to be arranged are not shown.
However, separate outer conductors and inner conductors
Mukouchi end comrades are connected. These inner conductors 41 and
An armature coil connected to the radially outer end of the outer conductor 42
The pitch between the channels 20 and 21 is the back pitch shown in FIG.
You. In this embodiment, the inner conductor 41 and the outer conductor
42 are respectively curved by approximately 1/2 front pitch
However, the curved or bent shape is free to be designed,
Side conductors 42 are arranged radially, and inner conductor 41 is
You may make it tune.

The resin-based insulating material 41a and the resin-based insulating material 42a are made of an epoxy resin. In this case, the outer conductor 42 and the inner conductor 41 are integrally formed by insert molding, and then are armatured with an adhesive. Although bonded to the right end face of the iron core 11, each may be insulated and fixed by a separate heat-resistant resin sheet material. In the insert molding, the armature iron core 11 can also be integrally molded by inserting.

As is apparent from the above description, according to the present embodiment, it is considered that the coil ends on both sides of the armature coil 2 are converted into the inner conductors 41, so that the axial length of the armature is significantly reduced. In addition, the size and weight of the motor can be reduced in size and weight. Also, resin-based insulating materials 41a, 41b
The centrifugal force acts in a parallel direction on the contact interface between the commutator 4 and the two conductors 41 and 42, so that the centrifugal resistance performance of the commutator 4 can be improved. Further, the sliding contact area with the brush 71 can be realized without increasing the physique. Further, the resistance heat and friction heat generated in the outer conductor 42 are well cooled by the inevitably generated centrifugal airflow, and are well absorbed by the armature core 11 having a large heat capacity through solid-state heat transfer. Suitable for electric motors. In particular, a motor using a speed reduction mechanism
The effect is enormous when the size and speed are increased.

Further, since each of the armature conductors 20 and 21 constituting the armature coil 2 can be a linear conductor, the armature conductor can have a modified cross section (non-circular shape) in accordance with the slot shape. Unlike the conventional case, the coil end does not swell, there is no need to apply a predetermined twist at the coil end of the armature conductor accurately, and the armature conductor is not bent, so that the insulating film does not peel off. . That is, it is possible to realize a high output and a reduction in resistance heat generation by improving the space factor while avoiding complicated and troublesome winding steps of the armature coil 2. In a preferred embodiment,
Each outer conductor 42 and each inner conductor 41 are
The armature coils 20 and 21 separated from each other are electrically connected to each other.
ing. In a preferred embodiment, each outer conductor and each inner conductor
The body is electrically connected between the armature coils separated by one back pitch.
Connected to In this way, the conventional armature coil
1 front pitch and 1
Electrical connection of armature coils separated by back pitch is axial
Direction can be extremely short.

FIGS. 5 and 6 show examples in which the armature conductors 20 and 21 are deformed according to the cross-sectional shape of the slot 12. FIG.
Reference numeral 22 denotes an in-slot insulating layer. Although the right outer conductor 42 is a commutator piece in the above embodiment, a commutator having a commutator piece extending in the axial direction as usual may be employed instead. Embodiment 2 Another embodiment is shown in FIG.

In this embodiment, a protrusion 42c projecting in the axial direction is formed on the outer peripheral portion of the groove 42b between the adjacent outer conductors 42.
Is provided. The protrusion 42c is made of a resin-based insulating material 42.
a, and protrudes axially outward from the outer conductor 42. In this way, the projections 42c serve as centrifugal wings to generate a centrifugal airflow along the outer surface of the outer conductor 42, thereby enabling good cooling.

In FIG. 7, a concentric area surrounded by a dashed line is a brush sliding surface, and the projection 42c does not interfere with the brush. (Embodiment 3) Another embodiment is shown in FIG. In this embodiment, the conical projections 20a and 21a are provided at both ends of the armature conductors 20 and 21, while the inner and outer conductors 41 and 42 are provided with conical holes 41d and 42d into which the conical projections 20a and 21a fit. Provided.

Then, the resin insulating materials 41a, 42a
The commutator 4 joined to form a semi-assembly is aligned with the end face of the armature iron core 11, and the conical projections 20a, 21a
Into the conical holes 41d and 42d. Conical protrusions 20a, 2
1a is larger than the conical holes 41d and 42d. In this way, when the semi-assembly is pressed against the right end face of the armature core 11 by the pressing force in the axial direction, the conical projections 20a and 21a of the armature conductors 20 and 21 made of copper become inner conductors made of hard copper. 41 and a conical hole 41d of the outer conductor 42,
It deforms plastically within 42d and tightly bonds.

It is needless to say that the connecting portion is formed into a conical shape, and various connecting portion shapes such as a rod shape, a tapered shape, and a tubular shape are possible. The plastic deformation of the relatively soft armature conductors 20 and 21 made of copper and aluminum does not require high-temperature heating, is simple, and can avoid deterioration of the resin insulating materials 41a and 42a.

[Brief description of the drawings]

FIG. 1 is an axial sectional view of a commutator-type rotary electric machine to which Embodiment 1 is applied.

FIG. 2 is a layout view of an outer conductor of FIG. 1;

FIG. 3 is a partial wiring diagram of the armature coil of FIG. 1;

FIG. 4 is a schematic perspective view showing an arrangement state of an armature coil and a commutator of FIG. 1;

FIG. 5 is an enlarged sectional view in the radial direction showing an example of the armature conductor of FIG. 1;

FIG. 6 is an enlarged radial sectional view showing another example of the armature conductor of FIG. 1;

FIG. 7 is a layout diagram of an outer conductor to which the second embodiment is applied.

FIG. 8 is an enlarged axial sectional view of a main part of a commutator-type rotary electric machine to which a third embodiment is applied.

[Explanation of symbols]

4 is a commutator, 10 is a rotating shaft, 11 is an armature core, 12 is a slot, 20 and 21 are armature coils, 41 is an inner conductor, 42 is an outer conductor, and 41a and 42a are resin-based insulating materials (insulators). , 71 are brushes.

Claims (3)

(57) [Claims] An outer conductor extending along both end faces of the armature core and having a radially outer end connected to an armature coil; and an outer conductor connected to the both end faces of the armature core and the outer conductor. An inner conductor, which is interposed along the both end faces, a radial inner end is connected to a radial inner end of the outer conductor, and a radial outer end is connected to the armature coil; An insulator for a commutator-type rotary electric machine, comprising: an insulator that electrically insulates the armature core and the outer conductor. 2. An armature for a commutator-type rotary electric machine according to claim 1, wherein an axially outer end surface of said outer conductor forms a brush sliding contact surface. 3. The armature coil according to claim 1, wherein said armature coil has a cross-sectional shape similar to a cross-sectional shape of a slot of said armature core.
An armature of the commutator-type rotary electric machine according to the description.