Inclining Work-Arbor Taper Hobbing of Conical Gear Using Cylindrical Hob

Abstract

The inclining work-arbor taper hobbing is considered one of the most practical methods to cut a conical gear. But an exact hobbing theory has not been made clear, and besides an ideal hobbing machine available inpractical use has not been developed so far. In this paper, an exact kinematic analysis of this taper hobbing is presented, and an imaginary generating rack is obtained. A gear generated by this rack is defined as an ideal gear. Practical hobbing of conical involute gears is discussed. A hobbing machine having an inclining rotary table is tested, and some test gears are cut and inspected. And it is confirmed that the ideal gear can be considered representative of the gear cut by this taper hobbing, and the hobbing machine with an inclining rotary table has a practical utility. Finally, grinding of the conical involute gear based on the principle of this taper hobbing is presented.