Hobbing of Bevel and Hypoid Gears

The paper presents a hyperboloidal hob cutter similar to a cylindrical hob cutter used to fabricate spur and helical gear elements today. This hyperboloidal cutter can be used to manufacture bevel and hypoid gear elements using an existing CNC hobbing machine. These bevel and hypoid gear elements can be either spur or spiral. This hyperboloidal hob cutter is entirely different from the circular face cutters today as part of face hobbing. A brief overview of the existing circular face cutting technology is presented along with some of its geometric limitations. Subsequently, concepts of the hyperboloidal hob cutter are presented. These concepts include crossed hyperboloidal gears, cutter spiral angle, invariant speed relations, and cutter coordinates. Two illustrative examples are presented to demonstrate the concept of the hyperboloidal hob cutter. The first example is a spur bevel gear pair and the second example is a spiral hypoid gear pair. Virtual models of the cutter in mesh with the gear elements are presented.