Kinematic Approach on Chip Formation Analysis in Gear Skiving

Abstract

Although the arrangement with a shaft angle enables a pinion cutter to cut a gear by skiving in mechanism theory, it may or may not work in practical skiving depending on the tooth geometries. The present study describes chip flow in a skiving process to evaluate the machinability. The oblique cutting model allows itself to define cutting parameters, i.e., depth of cut, cutting velocity, rake angle, and relief angle. The parameters change with the progress of cutting. Therefore, they enable themselves to define the states of a chip at any instance. Merchant's theory can give chip thickness and chip flow rate after giving shear angle or friction coefficient between chip and tool face. In the present paper, assuming a linear relationship between rake angle and friction coefficient enables kinematics to apply to the analysis of chip flow, which leads to calculating the chip shapes. The comparison of them with ones obtained from practical skiving showed that their figures were quite similar except for the curling portion seen in practical ones, but indicated that their dimensions are different. That means further discussions are necessary, e.g., considering the effect of friction on the tool face.