Abstract: Rotating rectifying device for excitation of a synchronous machine. The device includes an armature mounted on the machine shaft in a magnetic field with rotating coils connected to rectifier assemblies mounted on the inside flange surface of a support wheel, also mounted on the machine shaft. Each rectifier assembly has a first cooling body mounted on the inside flange surface, and a second cooling body that is resiliently spring biased with an outwardly facing surface against a disc-shaped semiconductor rectifier that rests with its other surface against the first cooling body. The second cooling body has parallel ribs that project into the circular space formed by the support wheel flange. In one version of the invention the second cooling body and the spring element is of circular construction.