Call it new wine in old bottles, or old wine in new bottles, but gear skiving has certainly aged well over time. Gear skiving's evolution, perhaps gaining momentum most dramatically since around 2004, has ultimately led to rather dramatic technological advancement and cost saving in the manufacture of certain gears.

The DVS gearing specialist Praewema Antriebstechnik continues to expand its technological expertise in order to keep pace with the growing significance of planetary geartrains for automatic and particularly electric vehicles, with the associated need for even higher-precision production of toothed gear components.

As the science of Scudding has rapidly evolved, the interest in the more advanced process Hard Scudding is increasing.

Toyoda's new GS300H5 Gear Skiving Center is the first in the world to equip a skiving function to a general purpose horizontal machining center (HMC), through which mass production of gear parts is achieved. CNC controls and a high speed rotary table were developed specifically to achieve high-speed, multifunctional machining, as a compact and lightweight product, simple in programming functions.

Skiving will be front and center when the gear industry comes together in Columbus this October. Attendees will find dedicated skiving equipment, multifunctional machines with skiving options and a slew of new cutting tools, machine designs and modifications to make the process more efficient and robust.

It has long been known that the skiving process for machining internal gears is multiple times faster than shaping, and more flexible than broaching, due to skiving's continuous chip removal capability. However, skiving has always presented a challenge to machines and tools. With 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 acceptance in shaping or hobbing, until recently.

Klingelnberg's new tool and machine concept allow for precise production.

In this paper, the potential for geometrical cutting simulations - via penetration calculation to analyze and predict tool wear as well as to prolong tool life - is shown by means of gear finish hobbing. Typical profile angle deviations that occur with increasing tool wear are discussed. Finally, an approach is presented here to attain improved profile accuracy over the whole tool life of the finishing hob.

Many people in the gear industry have heard of skiving, a process wherein solid carbide or inserted carbide blade hobs with 15 - 60 degrees of negative rake are used to recut gears to 62 Rc. The topic of this article is the use of neutral (zero) rake solid carbide hobs to remove heat treat distortion, achieving accuracies of AGMA 8 to AGMA 14, DIN 10-5 and improving surface finish on gears from 8 DP - 96 DP (.3 module - .26 m.).

Our company manufactures a range of hardened and ground gears. We are looking into using skiving as part of our finishing process on gears in the 4-12 module range made form 17 CrNiMO6 material and hardened to between 58 and 62 Rc. Can you tell us more about this process?