A machine for dry grinding gears

Italy-based Samputensili S.p.A. unveiled a machine that eliminates the need for cutting oils when manufacturing gears, thereby reducing grinding costs.

During grinding, oil-based lubricants cool the workpiece, as well as reduce friction and help evacuate chips. On the downside, however, oil use accounts for a significant amount of a grinding operation’s total cost. Expensive equipment is required to supply, chill, catch and wash away oil in grinding processes. In addition, Samputensili estimates that oil-treatment equipment accounts for 75 percent of the energy consumed by a grinding machine.

Samputensili’s SG 160 Sky Grind, available from Star SU LLC, features two spindles, one for skive-hobbing and the other for grinding. With the first pass, the SG 160 removes 90 percent of the required material using its skive-hobbing tool, which does not heat the workpiece too much, explained Enrico Landi, division director of Samputensili Machine Tools.

Skive-hobbing, the hobbing of hardened gears with carbide tools, can be done without oil even in mass-production applications. But, according to Samputensili, the process has never successfully produced transmission gears, so grinding must be used for finishing.