The geometric roughness when machining involute gear tooth with feed motion of variable speed

Résumé

The toothing process performed by enwrapping method presents high non-uniformities due to variation of removed chip area between successive cuts. A solution to this problem, based on varying the feed speed during the rolling motion has already been suggested and proved to be feasible. However, the feed motion practiced with variable speed impacts the geometric roughness of tooth flank generated surface. This paper investigates the degree to which feed speed variation after a given law affects the roughness of such a surface, by assessing the height of irregularities resulted between the successive trails left by tool teeth. An analytical solution and a graphical solution (the last one developed in CATIA graphical environment), addressing the case of using a mono-tooth rack-tool, are both presented and applied for an actual gear.