Patent ID: 7219411

Claim:
A method for manufacturing a commutator, the method comprising: rotating an unfinished commutator product about a central axis of the unfinished commutator product, wherein the unfinished commutator product includes a plurality of commutator segments, each of which axially extends along an outer peripheral surface of the unfinished commutator product between a first axial end and a second axial end of the unfinished commutator product and includes a coil connection at a location adjacent the second axial end of the unfinished commutator product; and axially moving at least one of a cutting tool and the unfinished commutator product to create relative movement of the cutting tool along a cutting region of the outer peripheral surface of the unfinished commutator product from the first axial end of the unfinished commutator product toward the second axial end of the unfinished commutator product while the unfinished commutator product is rotated, so that an outer surface of each commutator segment is cut from a cutting operation start point to a cutting operation end point of the commutator segment, wherein: the cutting operation start point of each commutator segment is located in the first end of the unfinished commutator product; the cutting operation end point of each commutator segment is located adjacent the coil connection of the commutator segment between the cutting operation start point and the coil connection; and a feed rate of the cutting tool, which is an axial relative moving distance of the cutting tool along the outer peripheral surface of the unfinished commutator product per revolution of the unfinished commutator product, is reduced in an end part of the cutting region, which includes the cutting operation end point and a section of the cutting region adjacent the cutting operation end point, in comparison to that of the rest of the cutting region; and the feed rate of the cutting tool in the end part of the cutting region is in a range of 0.001–0.012 mm/revolution.