ROTOR FOR DYNAMOELECTRIC MACHINES

A large salient pole rotor is provided, especially for hydro generators, utilizing a spider member having generally radial arms with a laminated cylindrical rim supported on the ends of the spider arms and carrying a plurality of salient poles. The rim is connected to the spider arms by means of spring keys but, in accordance with the invention, the springs are so designed that their deflection is limited. That is, the keys have a definite gap when undeflected and when the rim is assembled on the spider and the springs are deflected, the gap closes and further deflection of the springs is prevented. The rim is shrunk in place and its total deflection is greater than that of the spring keys so that the spider arms are subjected to a substantial radial stress.