This new power skiving option from NUM enables CNC machine tool manufacturers to take advantage of a major market opportunity in the emerging compact gear manufacturing industry. It is now possible to create a completely new generation of automation systems for gear production, offering combined hobbing and skiving functions in one machine.

Gear manufacturers currently use a variety of machining processes, including gear hobbing, gear shaping, broaching and grinding. Which processes are used depends largely on the type and size of the gears and splines to be produced. Hobbing is ideal for external gears, while gear shaping and broaching are best suited to the production of internal gears - although the latter is only really practical for small gears. Power skiving, on the other hand, is potentially a much faster and more efficient method of producing external and internal gears of any size.

Although the process was developed and patented more than 100 years ago, it has only recently become practicable for industrial use with the advent of multi-axis machine tools that enable precise high-speed synchronization.

Based on NUM's high-performance Flexium+ CNC platform, the new gear skiving solution is the latest addition to the company's NUMgear gear manufacturing suite. NUMgear was originally developed specifically for gear hobbing, but continues to evolve to meet the needs of the industry and now offers solutions for a wide range of gear manufacturing processes and is used by many leading gear cutting machine manufacturers.

The new power skiving software harnesses the speed and precision of NUM's advanced multi-level electronic gearbox (MLEGB). This very powerful unit is capable of unprecedented speed and accuracy - it can handle up to 25,000 rpm on the leading axis and uses look-ahead algorithms to predict both the speed and acceleration of the axes to minimize synchronization time.

The MLEGB is defined by the user in the part program. Each axis can be leading or following, linear or rotary, and the relationship between leading and following axes can be controlled by a user-defined fixed parameter or a dynamic machine cycle variable (curve table). Flexibility is further increased by the fact that multiple MLEGBs can be cascaded, a following axis in one dynamic gearbox can be used as the leading axis in another MLEGB and either the leading or following axis in an MLEGB can be real or virtual.

A single multi-purpose CNC machine tool that offers gear manufacturers the ability to mill large gears on one axis and skive smaller gears and splines whenever tool space is limited - such as in a compact gearbox - would certainly enjoy rapid acceptance in the industry. Thanks to NUM, CNC control technology, together with the necessary precision servo motors and drives, is now a reality.

NUM's new power skiving software option can be installed and used on any Flexium+ CNC system with Flexium software version 4.1.00.00 or higher.