Methods of assembling field subassemblies

摘要

A field subassembly is assembled by positioning two coil supports adjacent respective core end faces of a ferromagnetic core. The core-engaging surfaces of the coil supports and the core end faces have respective surfaces which are uninterrupted by projections. During the assembly of the field, fasteners are pushed into the respective coil supports and the core such that the fasteners engage mounting holes in the coil support with a press-fit. After the field is wound, a brush holder subassembly is also pressed onto the fasteners and the resultant core subassembly is connected to a field housing by driving the fasteners in a conventional fashion. In the preferred embodiment, the fasteners provide a three-point contact with mounting holes formed in the coil supports and the brush holder subassembly. This enables the fasteners to maintain the coil supports and the brush holder subassembly in alignment with the core while shearing a minimum of material from the coil supports and brush holder subassembly when the fasteners are pushed into their respective mounting holes. Then, the same fasteners remain with the subassembly to connect the field subassembly to the field housing.