| 310 / | HD | ELECTRICAL GENERATOR OR MOTOR STRUCTURE |
| 10 | DF | DYNAMOELECTRIC {5} |
| 40 R | DF | .~ Rotary {28} |
| 261 | DF | .~.~ Rotor structure {5} |
| 264 | | .~.~.~ Armatures {5} |
| 265 | DF | .~.~.~.~> Drum |
| 266 | DF | .~.~.~.~> Hollow (e.g., double air gap) |
| 267 | DF | .~.~.~.~> Ring |
| 268 | DF | .~.~.~.~> Disc |
| 269 | DF | .~.~.~.~> Salient pole |