Armature Rewinding Shops

A generator, or dynamo, converts mechanical energy into electrical energy by rotating an armature through a magnetic field. Most electricity used in cars, homes, and industry is created by generators. The armature, which is usually made of copper wire wound around a laminated core of soft iron, is the rotating or stationary assembly in the generator, and is the main current-carrying conductor. A steel shaft is fitted through the center of the core to which the two ends of the copper wire connect.

Companies in the armature rewinding business rewind damaged coils or stators, fix hermetic seals on electric motors, and generally restore electric motors and components. They fix everything from small automotive generators to giant industrial and utility devices. Typically, firms in the industry operate a core facility with specialized equipment for coil manufacturing and rewinding, and usually have a machine shop, pre-assembly facilities, and assembly-testing facilities as well. They typically offer field service for analysis and testing and operate a sales unit for selling and distributing stock of manufactured and refurbished motors, from starters, alternators, and generators for industrial, automotive, farm, and marine use, to lawnmowers and other products using electric motors and drives.

Some of the larger and established companies in the industry in 2008 included Warwood Armature Repair Company, of Wheeling, West Virginia, and American Generator & Armature, of Lincolnwood, Illinois. Around 2,000 firms operated in the industry in the late 2000s in this $1.25 billion industry. Other leading firms included American Armature Products, of Davenport, Iowa; Armature Rewind & Rebuild, of Bay City, Michigan; Central Armature Works, located in Washington, D.C.; San Antonio Armature Works, of San Antonio, Texas; and Tri-State Armature & Electrical Works, of Memphis, Tennessee.

Many other firms provide armature rewinding services as a smaller part of operations. Tampa Armature Works (TAW), Inc., of Tampa, Florida, identified itself primarily as an energy conversion and control business. A privately held company, TAW had four functional business units: equipment services, custom equipment, new equipment, power systems, and mechanical service.

Englishman Michael Faraday and American Joseph Henry developed the generator during the 1830s after discovering they could make a magnet produce electric current. Generators became widely used during the late 1800s, which, in turn, created a demand for repair shops to service them. After World War II, the industry benefited from U.S. economic expansion, which increased electricity consumption and need for generators. Since its inception, the basic design of the generator and armature have hardly changed.