Abstract: A shaft mounted eddy current variable speed drive or clutch has a hub which is adapted to be mounted on the shaft of a prime mover, such as an electric motor, and drives an armature. The hub includes an annular armature. A driven magnetic body is mounted for rotation on the hub and includes an array of poles magnetically associated with the armature through a working air grap and are energized from an electric coil mounted on the magnetic body. A slip ring assembly is also mounted on the magnetic body as well as an output pulley through which power is taken from the body. A non-rotating brush holder assembly, as well as a magnetic speed pick-up are mounted on a support bracket which bracket is, in turn, piloted to and mounted on the hub through a bearing. A torque arm prevents the rotation of the brush assembly and magnetic pick-up.