Power skiving can offer huge benefits for gear manufacturing, but it comes with challenges that must be considered.
- Shaping 15% 15%
- Hobbing 40% 40%
- Power Skiving 100% 100%
Power skiving is a machining process that uses a tool in a crossed-axis mesh and synchronicity with the workpiece to cut internal or external gears. Although the process was invented in the early 20th century, it is truly a 21st century solution because it requires a very rigid machine design (eg direct drive torque motors, work and tool holding) and high-speed synchronized work and tool spindles. It is mostly compared to shaping because it too can produce internal and external parts, but power skiving is far more productive by a factor of 6 to 12. Compared to hobbing, power skiving can be 2 to 3 times more productive.
Unfortunately, challenges and limitations face the power skiving process. The cutting tool, which can be described as a pinion in mesh with the workpiece gear, creates a generative cutting motion by inclining while remaining in mesh. This inclination is typically at least 20 degrees off-axis, so clearance may not be available for long-face internal gears or sweepout may interfere with adjacent part features designed for the shaping process. Low inclination angles may also require spindle speeds more than the machine’s ability.
Unlike hobbing and shaping, power skiving cutting tools are dedicated to specific workpieces by module and number of teeth. This increases the engineering resource cost of each application; more time is needed to engineer the cutting tool within the machine tool’s specifications. Consequently, power skiving is most appropriate for medium- to large-volume gear manufacturing.