Finish Gear Rolling by Screw-Shaped Tool. Simultaneous Rolling of Tooth and Fillet Surface.

Abstract

Widely used plunge-feed rolling method has some problems, such that the tooth profile accuracy of the product is low without some modification of teeth of the tool or the work, and the tooth surface and the fillet at the root cannot be rolled at the same time. A new rolling method by screw-shaped tool was proposed in our previous report. This method resembles finish gear hobbing. With a small rolling load due to a small contact area, it is expected that any modification of the tooth profile of the tool or the work is unnecessary. In this report, to finish the tooth surface and the fillet at the root of gears in one pass, we prepare several kinds of screw-shaped tools. Gears with good tooth profile accuracy and good surface finish are produced by this method. Tooth surfaces and fillets at roots are remarkably work hardened. TiN coating is effective to avoid scoring.