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Figure 4: Phoenix bevel gear cutting machine with chamfering unit attached

8.3 Nominal Data Based Chamfering Part Program Generation

The topping method is based on the utilization of nominal flank surface data as
used on coordinate measuring machines. The mathematical approach calculates
the path 20 in Figure 5 as the average of the topland corner points PFL11 and
PFL21 to PFL1n and PFL2n. The cross product of the normal vector of the convex
topland/flank point N1i and the concave topland flank point N2i delivers the aver-
age tangent vector VTANi, which is directed tangentially to the tool path 20 at each
of the discrete points along the face width. The direction of the tangent vector VTAN
is utilized to rotate the work piece around its Z-axis until the tangent vector of each
instant point of tool contact is oriented vertically.

In order to avoid any gaging of the chamfer unit, the stock division, which is re-
quired during the machine setup, is additionally used to synchronize the actual
stock division point with the calculated chamfer path 20. The stock division is per-
formed in the middle of the face width with a vertical tool path tangent vector VTAN.

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