ELECTRICAL COMMUTATOR AND METHOD FOR MAKING SAME

摘要

A commutator (10) for a motor is disclosed which includes a plurality of commutator segments (12) arranged in a cylindric array (14) such that the array has a cylindrical outer periphery (20) and two axial ends. An annular recess (26, 28) is formed adjacent each end (22, 24) of the array so that a portion of each commutator segment (12) forms a part of the radially inner wall of each recess. Two or more rings (34, 36) constructed of an insulating material are provided and one or more rings are press fit into each recess so that the rings (34, 36) exert a radially inward force on the commutator segment (12). The anchoring portions of the commutator segments (12) are then encapsulated with a settable and electrically insulating material (40), such as phenolic. Upon hardening and curing, the phenolic secures the commutator segments (12) together. At the same time, the radially inward force exerted by the rings (34, 36) on the commutator segments (12) serves to stabilize the commutator segments (12) against movement relative to each other during high speed rotation of the commutator (10). A method for manufacturing the commutator is also disclosed.