Chamfer Cutting of Interfering Contours & Internal Gears

Interfering contours, such as shoulders, pose a risk of collision that’s limited the chamfering of components such as shafts or idle gears. Liebherr Gear Technology (Saline, MI) gets around this by tilting the tool.

Left and right tooth flanks are machined separately with different tools. “A cutting arbor can hold up to four tools, so this isn’t a problem,” says Technology Application Head Oliver Winkel. “For small gears and shafts, the range of applications is great. About half the gears and shafts in a gearbox have interfering contours, an extremely high number of parts for which ChamferCut CG (collision gear) technology can prove its worth.”

Because the use of traditional ChamferCut tools is limited by interfering contours, this type of chamfering is usually employed on disc-shaped or simple component geometries. Production facilities, the automotive industry and suppliers, truck manufacturers, and industrial applications with repetitive series production can profit from the technology.

Based on the principle of ChamferCut, it’s possible to cut chamfers in internal gears provided the faces lie on the edges of the component. For ChamferCut IG (internal gear) tools, the tool profile is changed to the concave shape of the internal gear and positioned accordingly within the workpiece.

Apart from the use of milling pins, there aren’t many chamfering solutions for internal gears. ChamferCut is fast and precise, though until now it wasn’t  considered for internal gears. “As yet, we’re unable to estimate the demand in this area,” says Winkel. “We look forward to customer reaction, which will no doubt provide further impetus for the development.”

Liebherr Gear Technology, 1465 Woodland Drive East, Saline, MI 48176, 734-429-7225, www.liebherr.com.