AGMA 22FTM05 PDF

There is a strong and growing demand for skiving cutters, used for the mass production of gears. Compared to the shaping process, the skiving process avoids a brutally interrupted cut, providing new opportunities for carbide tooling. This presents new challenges for cutter manufacturing: pinion cutters may deviate from the involute profile significantly, and the use of diamond wheels makes dressing relatively expensive and time-consuming. We have developed two complementary methods to address these problems for the index generation grinding process. Firstly: we have developed a grinding path compensation, allowing for errors in the cutter’s pressure angle and crowning, to be addressed, without having to alter the wheel profile. This has proved effective to the point where we can add a crowning of more than 10 micro-meters to a design, purely using path compensation. Secondly: we have developed an in-process flank profile measurement procedure, using an analogue ruby probe. This procedure makes use of modern machine axis control, allowing for a nonlinear path to be followed with better than micro-meter accuracy. The procedure calculates the reference geometry for the flank profile, using the nominal wheel profile and grinding path. The deviations of the flank geometry relative to this reference geometry are measured and graphed. For the case where the reference geometry is an involute curve, the measurement result will be directly comparable to a traditional gear measuring machine report. When setting up to grind a skiving cutter, we can assess whether the ground flanks match the intended design directly, without having to understand complex geometric design details. One can then instantly see what compensation should be applied for the desired outcome, without removing the cutter from the machine. There is a strong synergy between the two approaches, simplifying the otherwise difficult setup for grinding these cutters.