US Patent 7621167 Method of forming a rotary device

The present invention is a method of constructing a rotary device which as an outer hub and an inner hub disposed within the outer hub. One of the inner and outer hubs is rotatable with respect to the other one of the inner and outer hubs about an axis. A ribbon of material extends between opposite ends and is roll formed to achieve a desired profile of an inner and outer peripheral wall of the inner and outer hub, respectively. The roll formed ribbons of material are each secured to maintain the desired profile and achieve the respective peripheral wall. The inner peripheral wall is inserted inside the outer peripheral wall such that the outer peripheral wall surrounds the inner peripheral wall.