JP3156532B2 - 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.

[0002]

2. Description of the Related Art A conventional 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. JP 63
Japanese Patent Application Laid-Open No. 194541 discloses that a brush contact portion extending outward in the axial direction is partially buried in the surface of a molded resin cylinder (insulating material) fitted on a rotating shaft, and is inclined in the circumferential direction inside the molded resin cylinder. Embedding the inner conductor extending in the axial direction, extending the outer riser portion radially from one end of the brush contact portion, and between the outer riser portion and the armature core while electrically insulating the inner riser from the both, A commutator piece having an inner riser portion extending radially from one end is disclosed. 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.

[0004]

However, commutator-type small DC motors used in automobile starters and the like are required to be particularly compact and lightweight, and a means for reducing the size and speed of the motor by employing a speed reduction mechanism inside. Has been adopted.
Therefore, in order to withstand higher-speed rotation, the armature, which is the rotor, must have high centrifugal strength.

[0005] In particular, a mold resin tube carrying a commutator piece on its outer periphery must hold the commutator piece against its centrifugal force, and furthermore, it generates resistance heat of the commutator piece and frictional heat generated by the brush. Because it is affected, a large thermal and mechanical load is applied. 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, and a brush is further laterally disposed outside the commutator. However, there is a problem that the axial length, size and weight of the motor increase. In addition, there is a problem that the high-speed rotation of the motor is limited by the centrifugal force applied to the coil end.

On the other hand, since the commutator piece disclosed in the above-mentioned publication has a large-diameter riser portion, the centrifugal force of the commutator piece proportional to the square of the radius is increased remarkably, and the mold resin cylinder supporting the commutator piece has a large diameter. This involves a problem that the load is large and the motor cannot be rotated at high speed. Further, both the commutator piece, that is, both the brush contact portion and the inner conductor, must be carried in the mold resin cylinder in two stages in the radial direction, so that the burden on the mold resin cylinder is more severe than in the conventional case. Further, since the frictional heat generated in the brush contact portion due to friction with the brush needs to be transmitted to both riser portions, the temperature of the molded resin cylinder supporting the brush contact portion and the inner axial conductor becomes considerably high. Furthermore, since the inner conductor must be inclined in the circumferential direction, there is a problem that the axial length of the molded resin cylinder cannot be reduced.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has a remarkably high speed rotation of a commutator type rotating electric machine.
It is an object of the present invention to provide an armature of a commutator type rotating electric machine that can be reduced in size and weight.

[0008]

An armature of a commutator-type rotary electric machine according to the present invention has an upper conductor portion accommodated in a slot of an armature core and an outer diameter end electrically connected to one end of the upper conductor portion. A first armature coil holding portion that is connected and extends radially inward along the brush-side end surface of the armature core and has an axial outer end surface forming a brush sliding surface, and an outer diameter end. A second armature coil holding portion electrically connected to the other end of the upper conductor portion and extending radially inward along an end surface on the side opposite to the brush of the armature core; and A first protruding portion that protrudes from the radial inner end of the armature coil holding portion toward the axially opposite armature core side; and an axially anti-armature core that extends from the radial inner end of the second armature coil holding portion. An outer conductor having a second protrusion protruding to the side; and the armature iron positioned inside the upper conductor. The lower conductor portion accommodated in the slot, the outer diameter end is electrically connected to one end of the lower conductor portion, the brush-side end surface of the armature core and the first armature coil holding portion, A third armature coil holding portion extending inward in the radial direction, and an end surface of the armature core opposite to the brush side, the outer diameter end of which is electrically connected to one end of the lower conductor portion. A fourth armature coil holding portion extending radially inward between the second armature coil holding portion and the first armature coil holding portion from the radially inner end of the third armature coil holding portion; A third protruding portion that protrudes in the axial direction opposite to the armature core side while being in contact with the inner diameter side end surface of the protruding portion, and the second protruding portion from the radially inner end of the fourth armature coil holding portion. An inner conductor having a fourth protruding portion protruding toward the axially opposite armature core side while being in contact with the inner diameter side end surface; and the third and fourth electric machines An insulating material for electrically insulating the coil holding portion from the first and second armature coil holding portions and the armature core, and a spherical joint portion formed by welding a tip of the first and third protrusions. , A spherical joint formed by welding the tip of the second and fourth protrusions.

[0009] In a preferred aspect, a collar is fitted to the rotating shaft to which the armature core is fitted, and the collar locks the spherical joint.

[0010]

According to the present invention, since the coil end 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, unlike the conventional case, it is not necessary to carry the first armature coil holding portion from the surface portion of the molded resin cylinder, and the molded resin cylinder itself is not required. Thereby, the high-speed rotation and the high output are not restricted, and the axial length, the physique, and the weight of the motor can be reduced by the omission of the molded resin tube. In addition, the frictional heat generated by the brush is generated in the first armature coil holder, which is well cooled by the airflow generated in the centrifugal direction along the surface. The commutator does not limit the heat-resistant temperature of the motor because it can be temporarily absorbed well by the armature core having a large heat capacity.

Further, according to the present invention, the distal ends of the first and third projections and the distal ends of the second and fourth projections are welded to form a spherical joint. Play. First, the bonding becomes strong and the electrical resistance decreases. Next, since the spherical joints are formed by welding, these protrusions melted by welding can have a wider shape before welding, for example, a shape in which circumferentially adjacent protrusions are in close contact with each other.

According to a preferred aspect, each spherical joint is locked to the rotating shaft by the collar, so that the armature coil can be locked simply and firmly.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to an embodiment shown in the drawings. FIG. 1 is an axial sectional view of a commutator type rotating electric machine showing one embodiment of the present invention, and FIG. 7 is an enlarged axial sectional view of a commutator portion thereof. An armature core 11 formed by laminating a plurality of disk-shaped steel plates 15 is fitted in a substantially central portion of the rotating shaft 10, and a plurality of slots 13 are formed on the outer peripheral surface of the armature core 11. Inside, an armature coil (upper conductor) 20e and an armature coil (lower conductor) 21e
Are wound up and down in two steps.

A commutator section 40 described later is formed on the right end face of the armature core 11, and an anti-commutator section 90 described later is formed on the left end face to constitute an armature (rotor) of the motor. ing. Both ends of the rotating shaft 10 are connected to the end frame 6 of the electric motor.
0, and a bearing 62 attached to a member (not shown).
The opening of the yoke 70 made of a cylindrical steel plate is shielded. On the inner peripheral surface of the yoke 70, four magnetic pole cores 51 around which the field coil 50 is wound are fixed close to the periphery of the armature core 11 and are fixed at a 90-degree circumferential distance from each other. , The field coil 50 and the magnetic pole core 51 constitute a stator. Reference numeral 12 denotes a gear provided on the rotating shaft 10, which meshes with a gear of a not-shown reduction mechanism (for example, a planetary gear reduction mechanism), and transmits the rotation of the rotating shaft 10 to the not-shown gear.

A brush holder 80 is provided on the end frame 60.
Is fixed, and a brush 81 is held inside thereof so as to be slidable in the axial direction. The brush 81 is pressed against a first armature coil holding portion 20b of the commutator portion 40 described later by a spring 82 provided in the brush holder 80. Next, the commutator section 40 and the anti-commutator section 9
0, the armature coil 20e and the armature coil 21e will be described in further detail.

An insulating material 21 is provided on the right end face of the armature core 11.
The first armature coil holding portion 20b is arranged on the surface of the third armature coil holding portion 21b with the insulating material 20a interposed therebetween. Also, on the left end face,
Fourth armature coil holding portion 21d with insulating material 21c interposed
Are arranged, and a second armature coil holding portion 20d is arranged on the surface thereof with an insulating material 20c interposed therebetween. Insulation material 21
a, the third armature coil holding portion 21b, the insulating material 20a, and the first armature coil holding portion 20d constitute a commutator portion (brush side) 40, and the insulating material 21c, the fourth armature coil The holding part 21d, the insulating material 20c, and the second armature coil holding part 20d constitute an anti-commutator part (opposite the brush side) 90.

The upper conductor portion (armature coil) 20e, the first armature coil holding portion 20b, the second armature coil holding portion 20d, and projecting portions 20g and 20h to be described later are integrally connected with a material such as copper. Thus, the outer conductor 20 is formed. Also, a lower conductor portion (armature coil) 21e, a third armature coil holding portion 20d, and a fourth armature coil holding portion 21d
The protrusions 21g and 21h described below constitute the inner conductor 21.

The protruding portions 20g and 20h protrude individually from the armature coil holding portions 20b and 20d in the axial direction opposite to the armature core. The protruding portions 21g and 21h individually protrude from the armature coil holding portions 21b and 21d in the axial direction opposite to the armature core. The inner end surface of the projection 20g is the projection 2
1 g is in contact with the outer diameter side end face. The inner diameter side end face of the protrusion 20h is in contact with the outer diameter side end face of the protrusion 21h.

An insulating coating is applied, baked, wound, adhered, etc. on the surface of the outer conductor 20 except for the commutator portion 40 (particularly, the brush sliding surface) and the inner end surfaces of the protruding portions 20g and 20h. Is formed by In the same manner as the outer conductor 20, the inner conductor 21 is also provided with an insulating coating on the protruding portions 21g and 21h except for the periphery of the outer end surface. The first armature coil holding portion 20b and the third armature coil holding portion 21b are connected by welding at respective protruding portions 20g, 21g. On the opposite side, the second armature coil holding portion 20d and the fourth armature coil holding portion 21d are connected by welding at the projecting portions 20h, 21h.
The armature coil connection is made by this connection.

FIG. 2 shows an embodiment of a connection diagram between the outer conductor 20 and the inner conductor 21. In FIG. The solid line portion represents the outer conductor 20, and the broken line portion represents the inner conductor 21. Although the embodiment shown in FIG. 2 employs a single-wave winding connection, it is needless to say that other winding types such as a double winding can be employed. Here, Yb in the figure is a back pitch consisting of a pitch between the armature coil of the upper conductor and the armature coil of the lower conductor connected on the anti-commutator section 90 side. Yf is a front pitch composed of a pitch between the armature coil of the upper conductor and the armature coil of the lower conductor connected on the commutator section 40 side.

As shown in FIG. 3, in the conventional motor, the connection wiring between the conductors in the slot of the armature coil performed at the coil end of the armature coil is the third wiring of the inner conductor 21 in the above-described embodiment. It is replaced by the substantially spiral curve of the armature coil holding portion 21b and the first armature coil holding portion 20b of the outer conductor 20. Of course, as shown in FIG. 3, the spiral directions of both are opposite. More specifically, the first armature coil holding portion 20b and the third armature coil holding portion 21b in which the protruding portions 20g and 21g are connected to each other.
Are shifted in the circumferential direction by the front pitch. Therefore, in this embodiment, the third armature coil holding portion 21b and the first armature coil holding portion 20b
Are respectively bent by approximately フ ロ ン ト front pitch, but the curved or bent shape is freely designable. The first armature coil holding portion 20b is radially arranged, and the third armature coil holding portion is bent. 21b may be greatly curved.

The protruding portion 20g of the first armature coil holding portion 20b is fitted to the inner diameter portion of the collar 30 fixed to the armature rotating shaft 10 via an insulating member 32, and
Simultaneously presses and holds the armature coil holding portions 20b and 21b toward the armature core. Similarly, the protrusion 20h of the second armature coil holding portion 20d is also welded to the protrusion 21h of the fourth armature coil holding portion 21d, and then the inner diameter of the collar 31 fixed to the armature rotating shaft 10. Insulation member 3
3, the collar 31 is at the same time the second,
The fourth armature coil holding portions 20d and 21d are pressed and held toward the armature core.

FIG. 4 shows the first armature coil holding portion 20b.
And the projecting portion 20g of the third armature coil holding portion 21b,
1g shows a state before connection. A circumferentially wide portion 20k is formed at an axial end of the protruding portion 20g. Projection 21
A circumferential wide portion 21k is also formed at the axial end of g. In this embodiment, the first armature coil holding portion 20b
In the outer diameter portion, the armature coil 2 integrated with the first armature coil holding portion 20b in the slot 13 of the armature core 11
0e is inserted and positioned in the circumferential direction, and in the inner diameter portion, each circumferential wide portion 20k at the axial end of the protruding portion 20g integrated with the first armature coil holding portion 20b as described above.
Are positioned in the circumferential direction by being adjacent to each other in the circumferential direction, and as a result, the first armature coil holding portions 20b are uniformly arranged in the circumferential direction.

The armature coil 21 integrated with the third armature coil holding portion 21b is provided in the slot 13 of the armature core 11 at the outer diameter of the third armature coil holding portion 21b.
e is inserted and positioned in the circumferential direction, and in the inner diameter portion, each circumferential wide portion 21 at the axial end of the protruding portion 21g integrated with the third armature coil holding portion 21b as described above.
When k contacts each other in the circumferential direction, they are positioned in the circumferential direction. As a result, each third armature coil holding portion 21b is evenly arranged in the circumferential direction.

The circumferential wide portion 20k at the axial end of the protrusion 20g and the circumferential wide portion 2 at the axial end of the protrusion 21g
The width of 1k is arranged such that the centers of the circumferential widths thereof are substantially coincident with each other. The arrangement state before connecting the protruding parts 20h, 21h in the second armature coil holding part 20d and the fourth armature coil holding part 21d is the same as above.

FIG. 5 shows the first armature coil holding portion 20b.
And the projecting portion 20g of the third armature coil holding portion 21b,
The state where 1 g is welded will be described. Projection 20g, 21g
The circumferentially wide portions 20k and 21k which are the axial end portions of
When melted by IG welding or the like, the melted tip has a shape close to a spherical shape due to its own surface tension, the radial dimension increases, and conversely, the circumferential width decreases. That is, the original circumferential wide portion 20k wider in the circumferential direction than in the radial direction,
From the shape of 21k, it changes to a sphere and solidifies as it is to form a spherical joint L.

Therefore, the fact that the wide circumferential portions 20k and 21k of the protruding portions 20g and 21g are spherical joints L means that the circumferential width of the wide circumferential portions 20k and 21k is reduced. This ensures that the circumferential gap x is provided between the protrusions 20g and 21g that are adjacent in the circumferential direction. That is, simultaneously with the connection between the first armature coil holding portion 20b and the third armature coil holding portion 21b,
In addition, a gap is reliably formed in the circumferential direction between the adjacent third armature coil holding portions 21b.

At the end face of the armature core 11 opposite to the above, the protruding portions 20h, 2h are formed similarly to the third armature coil holding portion.
At 1 h, a spherical joint is formed by welding with melting of the wide part in the circumferential direction, and the same function and effect can be obtained. By the above connection, the streak-shaped gap 20f formed between the first armature coil holding portions 20b, 20b adjacent in the circumferential direction becomes an undercut of the commutator.

In this embodiment, the protrusions 20g, 21g
As shown in FIG. 4 (c), g has a gradually increasing circumferential width toward the side opposite to the armature core in the axial direction, and only the respective ends on the side opposite to the armature core in the axial direction are in contact with each other. That is, the wide portions 20k and 21k in the circumferential direction are the protruding portions 20g and 21k.
g has almost only the tip. Therefore, when this portion is heated and melted, each circumferentially wide portion 20
The projections 20g and 21g including the projections 20g and 21k are spherical joints independent of each other, and are adjacent to each other in the circumferential direction.
1 g is not welded together. Alternatively, every other protrusion 20g, 21g in the circumferential direction can be welded at once, and then the remaining protrusions 20g, 21g can be welded at once.

Next, the collars 30 and 31 will be described with reference to FIG. The collar 30 fixed to the rotating shaft 10 is in contact with the spherical joint L of the protruding portion 20g via an insulating member 32. Similarly, a collar 31 fixed to the rotating shaft 10 is in contact with an outer peripheral portion of the protruding portion 20h via an insulating member 33. The collar 30 is a commutator fixing member made of a soft metal such as aluminum. As shown in FIG. 7, the collar 30 has an inner cylindrical portion 30a fitted to the rotating shaft 10 and an outer cylindrical portion 30a. Wheel plate portion 30b extending in the radial direction and wheel plate portion 3
0b extending from the outer diameter end toward the armature core 11, and the inner diameter end of the wheel plate portion 30b is
It has a bulging portion 30d that fits into the 0 annular groove 10a. The collar 31 has the same structure as the collar 30.

The insulating member 32 is also provided on the inner cylindrical portion 30 of the collar 30.
a, the inner cylindrical portion in contact with the outer peripheral surface of the
b has an annular plate portion in contact with the surface on the armature core 11 side and an outer cylinder portion of the outer cylinder portion 30c in contact with the inner peripheral surface on the armature core 11 side, and the insulating member 32 has protrusions 20g and 21g. Color 3
It is electrically insulated from zero. The insulating member 33 has the same structure as the insulating member 32.

The collars 30, 31 are pressed together with the insulating members 32, 33, and the collars 30, 31 made of a soft alloy such as an aluminum alloy are plastically deformed by the force at this time. It protrudes to 10a and regulates the displacement of the collars 30, 31. (Effect) As is apparent from the above description, according to the present embodiment, it is considered that the coil ends of the armature coils 20e and 21e are replaced with the third armature coil holding portion 21b of the inner conductor 21, and so on. The axial length of the armature can be significantly reduced, and the motor size and weight can be reduced in size and weight. Further, a resin-based insulating material (insulating material in the present invention) 21
Since the centrifugal force acts in the direction parallel to the contact interface between the a and 20a and the third armature coil holding portion 21b and the first armature coil holding portion 20b, the centrifugal resistance performance of the commutator portion 40 is improved. I can do it. Further, the sliding contact area with the brush 81 can be realized without increasing the physique. Furthermore, the resistance heat and frictional heat generated in the first armature coil holding portion 20b are absorbed by the inevitably generated centrifugal airflow, and are particularly suitable for a fully closed starter motor. In particular, when a speed reduction mechanism is employed to reduce the size and speed, the effect is remarkable.

According to the test results of the present inventors, 1.4K
W, a motor rated for 30 seconds and having a temperature difference of 50 ° C. from the commutator portion of the brush, had a temperature difference of 15 ° C. in the product of the present invention. Furthermore, since the outer conductor 20 is formed integrally and the inner conductor 21 is also formed integrally, the connection resistance is reduced, and the rotating electric machine can be rotated at high speed.

Further, since the outer conductor 20 and the inner conductor 21 are locked by the collar fitted to the spherical joint L, the centrifugal resistance performance between the outer conductor 20 and the inner conductor 21 is improved. In addition, in this embodiment, in the conventional armature, a complicated and accurate motor was required in which the copper wire was connected to a predetermined position of the commutator while twisting and bending the winding and coil ends according to the required shape. The crawling of the child coil is replaced with a very simple operation of integrally forming the outer conductor 20 and the inner conductor 21 and inserting them from the slot outer diameter side of the armature core 11 (see FIG. 6). ing.
In this insertion step, the armature coils 20e and 21e are automatically positioned in the circumferential direction at the outer diameter portions of the conductors 20 and 21 by the slots 13, and at the inner diameter portions of the conductors 20 and 21, the protrusions 20g, 20h, 21g, 21h is automatically positioned in the circumferential direction by contacting adjacent ones of the 21h at the time of assembly. Also, the projections 20g, 20h,
When the circumferential wide portions 20k and 21k of the 21g and 21h are in contact with each other, their circumferential widths can be reduced by welding to automatically form circumferential gaps.

Further, since the conductors 20, 21 are fixed in both the diameter and the axial direction by the collars 30, 31, it is not necessary to fix the armature coil to the armature core unlike the conventional armature, and therefore, the armature core is not fixed. An armature coil fixing process for impregnating the slot 13 with a resin is not necessary. However, there is no problem even if this fixing process is performed. (Other Embodiments) In addition to TIG welding, other arc welding or laser beam welding may be used.

Each armature coil holding portion 20b, 21
It is also possible to deform the spherical joint L and the protruding portions 20g, 21g, 20h, 21h, etc. by external force before or after welding of b, 20d, 21d. If the strength and insulating properties of the insulating film of the armature coil are sufficient, the insulating materials 20a, 21a, 2
Some or all of 0c and 21c may be omitted.

Although the collars 30 and 31 are made of metal in the embodiment, they may be made of an insulating material such as a resin or a metal subjected to an insulating surface treatment. At this time, the insulating materials 32 and 33 become unnecessary. The fixing of the collars 30 and 31 to the rotating shaft 10 is shown in an enlarged view in FIG. 7, but the shapes of the collars 30 and 31 may be simple such as taper fitting. FIG. 8 shows a modification of the collars 30 and 31.

The armature coil holding portions 20b and 21b, which are in contact with the commutator portion 40, are also preliminarily coated with an insulating film, and this portion is cut during or after assembling the armature to cut the commutator portion 40.
The insulating coating may be removed by cutting. In this case, the workability of attaching the armature coil insulating film is improved. Further, in the above embodiment, a winding field type DC motor is described, but the present invention is not limited to this, and a magnet field type DC motor that generates a field by a permanent magnet, and further another AC type Obviously, it can also be applied to a commutator motor.

Further, in the above embodiment, the protrusions 20 on both sides are used.
Each of g, 21g, 20h, and 21h is a spherical joint L, but may be only one of them.

[Brief description of the drawings]

FIG. 1 is an axial cross-sectional view showing one embodiment of a commutator-type rotary electric machine to which the present invention is applied.

FIG. 2 is a connection diagram of an armature coil.

FIG. 3 is a perspective view showing an arrangement of an outer conductor 20;

4A is an axial sectional view showing a state before welding of armature coil holding portions 20b and 21b, FIG. 4B is a front view in an axial direction of the armature coil holding portions 20b and 21b, and FIG. It is a principal part enlarged plan view which expands and shows the part 20g.

5A is an axial sectional view showing a state after welding of armature coil holding portions 20b and 21b, FIG. 5B is a front view in the axial direction, and FIG. It is a principal part enlarged plan view which expands and shows the part 20g.

FIG. 6 is a diagram showing a state where conductors 20 and 21 are inserted into a slot 13 in an inner diameter direction.

7 is a partially enlarged axial sectional view showing a fixed state of the collar 30. FIG.

FIG. 8 is a partially enlarged axial sectional view showing a modification of the collar 30.

[Explanation of symbols]

11 is an armature core, 13 is a slot, 20 is an outer conductor,
20e is an armature coil (upper conductor portion), 20b is a first armature coil holding portion, 20d is a second armature coil holding portion, 20g is a first projecting portion, 20h is a second projecting portion,
1 is an inner conductor, 21e is an armature coil (lower conductor),
21b is a third armature coil holding portion, 21d is a fourth armature coil holding portion, 21g is a third protrusion, 21h is a fourth protrusion, 20a, 21a, 20c, 21c is an insulating material, L Is a spherical joint, and 30 and 31 are collars.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-63-194541 (JP, A) JP-A 50-109801 (JP, U) JP-A 3-48371 (JP, U) (58) Investigation Field (Int.Cl. ⁷ , DB name) H02K 13/04

Claims (2)

(57) [Claims] An upper conductor portion accommodated in a slot of an armature core, an outer diameter end of which is electrically connected to one end of the upper conductor portion, and has an inner diameter extending along a brush-side end surface of the armature core. A first armature coil holding portion extending in the axial direction and having an axial outer end surface forming a brush sliding surface; and an armature having an outer diameter end electrically connected to the other end of the upper conductor portion. A second armature coil holding portion extending radially inward along an end surface of the iron core on a side opposite to the brush, and an axially anti-armature core extending from a radially inner end of the first armature coil holding portion; An outer conductor having a first protrusion protruding to the side, and a second protrusion protruding from the radially inner end of the second armature coil holding portion toward the axially opposite armature core side; A lower conductor portion located inside the upper conductor portion and accommodated in the slot of the armature core; A third armature coil retainer electrically connected to one end of the side conductor portion and extending radially inward between the brush-side end surface of the armature core and the first armature coil retainer; Portion, an outer diameter end of which is electrically connected to one end of the lower conductor portion, and extends in a radially inward direction between the end surface of the armature core on the side opposite to the brush and the second armature coil holding portion. A fourth armature coil holding portion provided, and from the radially inner end of the third armature coil holding portion to the inner side of the inner side of the first protruding portion while moving in the axial direction opposite to the armature core. A third protruding portion that protrudes, and a fourth protruding from the radially inner end of the fourth armature coil holding portion to the axially opposite armature core side while being in contact with the inner diameter side end surface of the second protruding portion. An inner conductor having a protrusion, and the third and fourth armature coil holding portions are connected to the first and second armature coil holding portions. An insulating material that electrically insulates the armature core from the armature; a spherical joint formed by welding the tip of the first and third protrusions; and a weld of the tip of the second and fourth protrusions. An armature for a commutator-type rotary electric machine, comprising: 2. An armature for a commutator-type rotary electric machine according to claim 1, further comprising a collar fitted to a rotating shaft to which said armature core is fitted to lock said spherical joint.