Patent ID: 7621167
Filing Date: 2009-11-24
Classification: F01C,F04C,F05C

Abstract:
1. A method of constructing a rotary device having an outer hub and an inner hub disposed within the outer hub where one of the inner and outer hub is rotatable with respect to the other one of the inner and outer hub about an axis, said method comprising the steps of: roll forming a first ribbon of material which extends between opposite ends to achieve a desired profile of an outer peripheral wall; securing the roll formed first ribbon of material to maintain the desired profile and achieve the outer peripheral wall; roll forming a second ribbon of material which extends between opposite ends to achieve a desired profile of an inner peripheral wall; securing the roll formed second ribbon of material to maintain the desired profile and achieve the inner peripheral wall; and inserting the inner peripheral wall inside the outer peripheral wall such that the outer peripheral wall surrounds the inner peripheral wall; further comprising the step of abutting ends of one of the first and second ribbons of material and said steps of securing are further defined as securing at least one of the ribbons of material where the ends of the one of the first and second ribbons of material abut.