WO2000051210A3 - Methods and results of manufacturing commutators - Google Patents

Abstract

Addressed herein are commutators and methods of manufacturing them. The methods permit the carbonaceous material and core of a commutator to be molded simultaneously, rather than in a two-step process, and can eliminate one of two curing procedures used in connection with other manufacturing techniques. The necessity of machining the inner surface of the commutator shell to remove undesired excess phenolic or other material additionally is avoided by use of the techniques detailed herein. Commutators formed according to these methods may have increased useful lives and provide better performance than others presently available. An alternative commutator design addressed herein incorporates a system for anchoring its conductive segments. One or more undercuts in either or both of the metal shell and insulating core of the commutator receive protruding portions of the conductive material to prevent its axial displacement. The metal shell, which for protective purposes may extend above the face of the conductive material during some or all of the manufacturing process, minimizes radial displacement of the segments formed of the conductive material. Differing or non-concentric curvature of the inner surface of the shell and the outer surface of a portion of the insulating core restrict undesired circumferential movement of the segments.