Expanded tang airgap commutators

The tang connect style airgap commutator is one of the most commonly used commutator designs in motor production today. Its range of bar counts and brush track diameters run from miniature three bar by 6.6 millimeter diameter comms to oversize 48 bar by 58.67 millimeter diameter comms. In between these extremes are a multitude of bar counts, brush track diameters and molded features specially designed to meet the exacting needs of the motor industry. The single feature common to all tang airgap designs is the brush track diameter equal to the winding diameter. An expanded tang airgap commutator offers the cost saving features associated with typical tang style commutators plus a winding diameter larger than the brush track diameter. This enlarged winding diameter feature provides more clearance between tangs for use with larger diameter lead wires while still keeping the brush track diameter and brush holder dimensions at minimum levels for smaller sized motor designs. The authors discuss the development of tangs, their features and design considerations.