Dynamoelectric machine commutator structure and method of making same

摘要

A dynamoelectric machine commutator structure having a plurality of conductive commutator segments secured in operating position by a commutator banding is characterized by including a flexible, thermally stable dielectric coating material between the outer edges of the commutator banding and the conductor segments in order to effectively seal the junction between those members, thereby preventing the deposit or buildup of electrically conductive contaminants at that junction so that the likelihood of electrically short circuiting the conductive segments of the commutator is effectively eliminated. According to the preferred method of the invention, a banded commutator is formed by applying such a coating to predetermined portions of the banding grooves so that the coating effectively seals the junctions between the banding and the conductive segments of the commutator, thereby preventing the accumulation of conductive contaminants at those junctions. In one embodiment a release layer is provided on the side of the coating facing the commutator banding in order to establish the junction between the banding and the release layer as the most preferred site of any contaminant-collecting fissures that may be created by relative movement between the banding and the commutator segments.