Abstract
In order to efficiently obtain mirrorlike ground gears, the authors designed and made a computer numerically controlled (CNC) gear grinder. For obtaining the desired surface finish, a cubic boron nitride (CBN) grinding wheel with a medium grain size was used under creep-feed gririding conditions with grinding fluid. The profiles of the gear being ground were generated by a rolling motion produced by a master worm gear and a high-accuracy ball screw. The trial gear grinder could produce spur gears with mirror-like tooth surfaces having a roughness of about 0.2μm Rmax. By controlling the two servomotors, gears with any type of tooth profile modification could be ground easily. Using the same principle, an intermittent grinding process was introduced for preventing grinding burn under severe grinding, and ground gears with modules of 2 and 3 were made without a cutting process.
