Patent ID: 7414345

Claim:
A commutator comprising: a commutator main body including a cylindrical main body insulator and a plurality of commutator pieces held on an outer circumferential surface of the main body insulator so that the commutator pieces are arranged in a circumferential direction of the main body insulator; and a short-circuit member attached to the commutator main body and including a short-circuit conductor that short-circuits the commutator pieces; wherein the short-circuit conductor includes first and second short-circuit member formation groups arranged with one of said first and second short-circuit member formation groups superimposed over the other with respect to a direction of an axis of the commutator, with each of the short-circuit member formation groups having a plurality of outer terminals arranged about the axis of the commutator, a plurality of inner terminals arranged about the axis of the commutator radially inward from the outer terminals, and a plurality of linking portions linking each of the outer terminals to one of the inner terminals, wherein the linking portions in at least one of the first and second short-circuit member formation groups links the outer terminals and the inner terminals that are separated from each other by a predetermined angle in the circumferential direction; wherein each of the outer terminals in the first short-circuit member formation group contacts one of the outer terminals in the second short-circuit member formation group, each of the inner terminals in the first short-circuit member formation group contacts one of the inner terminals in the second short-circuit member formation group, and the linking portions in the first short-circuit member formation group are maintained in non-contact with the linking portions in the second short-circuit member formation group; and wherein the first short-circuit member formation group is thinner than the second short-circuit member formation group with respect to the direction of the axis of the commutator, the second short-circuit member formation group has a plurality of projections formed through punching, the first short-circuit member formation group has a plurality of holes respectively corresponding to the projections, and the first short-circuit member formation group and the second short-circuit member formation group are fixed to each other by crimping the projections in a state inserted through the corresponding holes.