Method of manufacturing armature of rotary electric machine and armature manufactured by the method

• US 20050046298A1
• Filed: 07/12/2004
• Published: 03/03/2005
• Est. Priority Date: 08/29/2003
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Shiga, Tsutomu, Oomi, Masanori, Niimi, Masami
• Granted Patent: US 7,302,750 B2
• Time in Patent Office: Days
• US Class Current: 310/201
• CPC Class Codes: H02K 15/0056 Manufacturing winding connections
• CPC Class Codes: H02K 15/0081 for form-wound windings
• CPC Class Codes: H02K 3/12 arranged in slots
• CPC Class Codes: Y10T 29/49009 Dynamoelectric machine
• CPC Class Codes: Y10T 29/49012 Rotor
• CPC Class Codes: Y10T 29/49073 by assembling coil and core

Abstract

An armature of a rotary electric machine composed of an armature core, an armature winding and a shaft is manufactured in the following manner. A conductor bar including plural conductors connected in line is formed, and each conductor is cut out from the conductor bar. The conductor in a straight shape is inserted into each slot of the armature core, and then both side portions of the conductor are bent at substantially right angle so that the side portions are positioned along axial end surfaces of the armature core. The side portions are further skewed and electrically connected to form the armature winding. An outer surface of the side portions circularly arranged on the axial end surface of the armature core is used as a commutator surface.

Claims

1. A method of manufacturing an armature having a plurality of conductors inserted into slots formed around an outer periphery of an armature core, the method comprising steps of:

forming a conductor bar that includes a plurality of conductors connected in line, each conductor having an in-slot portion and a pair of side portions extending straight from both ends of the in-slot portion;

separating individual conductors form the conductor bar;

inserting the in-slot portions of conductors into the slots; and

then

bending the side portions of the conductors at substantially right angle so that the side portions are positioned substantially in parallel to axial end surfaces of the armature core.

2. The method of manufacturing an armature as in claim 1, the method further comprising a step of skewing the side portions of the conductors by a predetermined angle relative to a radial line connecting a center of the slot and a center of the armature, the step of skewing being performed after the step of bending the side portions.

3. The method of manufacturing an armature as in claim 1, wherein:

the side portions of the conductors are skewed, at the same time when the side portions are bent in the step of bending, by a predetermined angle relative to a radial line connecting a center of the slot and a center of the armature.

4. The method of manufacturing an armature as in claim 1, wherein:

the conductors inserted into each slot are composed of an inner conductor that is disposed at an inner portion of the slot and an outer conductor that is disposed at an outer portion of the slot; and

after the step of bending, the side portions of the inner conductors and the side portions of the outer conductors are electrically and mechanically connected, and then an armature shaft is forcibly inserted into a center hole of the armature core.

5. The method of manufacturing an armature as in claim 4, wherein:

the armature core includes claws for closing the slots, the claws being formed on the outer periphery of the armature core; and

after the outer conductors are inserted into the slots and before the side portions of the outer conductors are bent, the slots are closed by the claws.

6. An armature of a rotary electric machine manufactured by the method defined in claim 4.

7. The armature as in claim 6, wherein:

an outer surface of the side portions of the outer conductors positioned substantially in parallel to one of the axial end surfaces of the armature core is used as a commutator surface which brushes slidably contact.

8. The armature as in claim 7, wherein:

a thickness, in an axial direction of the armature, of the side portion of the outer conductor is the thickest at its radial inside and becomes gradually thinner toward its radial outside;

a width, in an circumferential direction of the armature, of the side portion of the outer conductor is the widest at its radial outside and becomes gradually narrower toward its radial inside; and

thereby electrical resistance of the side portion is substantially uniform throughout its entire length.

9. The armature as in claim 6, wherein:

bending portions are formed at portions connecting the in-slot portion and the side portions, in both of the inner conductor and the outer conductor, and a thickness of the bending portion is thinner than that of the in-slot portion.

10. The armature as in claim 6, wherein:

the side portion of the inner conductor includes a projection projected toward the side portion of the outer conductor and formed at its end;

the side portion of the outer conductor includes another projection projected toward the side portion of the inner conductor and formed at its end;

both projections abut with each other, forming a space between the side portion of the inner conductor and the side portion of the outer conductor; and

an insulating disc is disposed in the space so that the insulating disc engages with both projections.

11. The armature as in claim 10, wherein:

both of the projections abutting with each other are electrically and mechanically connected.

12. The armature as in claim 11, wherein:

the insulating disc has an center hole, and both of the projections connected to each other are located inside the center hole.