Abstract: A system for transmitting torque to a driven member from a drive shaft extending axially throughout the driven member which is itself of a tubular shape. The drive shaft is of a circular cylindrical configuration and at least one resilient spherical drive element is used to transmit torque between the drive shaft and the driven tubular member. The diameter of the resilient member is somewhat greater than the distance between the opposed surfaces of the drive shaft and the driven tubular member. A means is included on either or both the drive shaft and tubular member to retain the resilient member in a substantially fixed orbiting path and to retain it against longitudinal movement along the surfaces of the drive shaft and the driven tubular member.