Abstract: A rolling gear apparatus for an involute tooth gear cutting machine that rests on an engine bed of the machine. A primary carriage is longitudinally movable in both directions on the engine bed and carries at its top a secondary carriage that is guided in longitudinal movement in both directions. A crank element is connected to the secondary carriage and is glidingly movable in a guideway that is angularly adjustable relative to the engine bed. A roll-circle member is carried by the primary carriage and is connected to the secondary carriage through a band drive. The movement path II of the secondary carriage is at an oblique angle to the movement path I of the primary carriage to provide improved selectivity in adjusting the base-circle diameter of a toothed-wheel gear blank connected to the roll-circle member.

Abstract: A gear cutting machine is provided with gearing providing additional inaccuracies to superimpose the additional inaccuracies over the normal or residual gear cutting inaccuracies of the machine. The resultant errors cut into the gears provide gears having desired noise characteristics. The additional inaccuracies are of a higher frequency than the residual errors so that noise above the audible frequency range is provided by the gears so cut. The gear cutting machine has gearing for driving the hobbing spindle and for indexing a rotary table through worm gearing. The spindle drive gear and the worm drive gear are provided with eccentric sockets for introducing the additional inaccuracies. The drive gears also are provided with deformable portions providing the drive gear teeth so that the drive gears may be deformed into polygons. The eccentric sockets and polygonal drive gears are retained in position on the shafts that they drive by a nut and intermediary element.