Page 90 - Gear Technology Solutions

Figure 7: Elimination of Undercut (top) and elimination
of interference (bottom)

The more common way to avoid undercut is applied at the beginning of a
gearset design. Pinions with a low number of teeth show undercut due to the
high angular rotation amount while being generated in a cutting machine.
Therefore, most pinions below 17 teeth require a positive profile shift. The
profile shift increases the center distance between the work gear and the
manufacturing tool. Subsequently, the center distance between pinion and
gear is also changed. If a center distance change is not desirable, then a so-
called V0 profile shift is recommended. The V0 shift uses the same amount of
positive profile shift applied to the pinion with a negative sign for the gear. If
the gear has a much higher number of teeth, then it will not be prone to

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