Power Skiving of Cylindrical Gears on Different Machine Platforms

摘要

Skiving is a cutting process which was first patented in 1910 [1] as an efficient process to manufacture internal ring gears. Like honing, Power Skiving uses the relative sliding motion between two "cylindrical gears" whose axes are inclined. The skiving cutter looks like a shaping cutter with a helix angle for example, 20° different than the helix angle of the cylindrical gear to be machined. The skiving process is multiple times faster than shaping and more flexible than broaching, due to the continuous chip removal in skiving, but it presents a challenge to machines and tools. While the roll motion between the cutting edge and the gear slots occurs with the spindle RPM, the relative axial cutting motion is only about one third of the circumferential speed of the cutter. The cutting components of rolling and cutting which result in a "spiral peeling" are represented with the process designation skiving. Because of the relatively low dynamic stiffness in the gear trains of mechanical machines as well as the fast wear of uncoated cutters, skiving of cylindrical gears never achieved a breakthrough against shaping or hobbing until recently. The latest machine tools with direct drive train and stiff electronic gear boxes present an optimal basis for the skiving process. Complex tool geometry and the latest coating technology were required to give the soft skiving of cylindrical gears a breakthrough. Gleason has developed a line of dedicated power skiving machines, which apply solid HSS cutters for small to medium modules.