Page 94 - Gear Technology Solutions

7 The Hunting Tooth and its Effect on Break-In

7.1 Is the Hunting Tooth only an Academic Phenomenon?

When referring to the literature, it will be noticed that there is no comprehen-
sive explanation with visualizing graphics about the hunting tooth and its rela-
tionship to the performance of a gearset. This is the reason why this article
turned out larger than expected for the answer to the question “if the hunting
tooth is a more academic phenomena or if there is a practical implication”. The
expression “hunting tooth” is a descriptive term created in the practical world. It
describes that each tooth of one member chases and then touches each tooth
(or slot) of the mating member after a certain number of revolutions.

Figure 1 shows a spur gearset with an integer ratio of 2. The twelve pinion
teeth will mesh with the first 12 gear teeth and then with the next twelve gear
teeth, continued by repeating the meshing with the first twelve gear teeth and
so on. The case where each pinion tooth meshes with each gear tooth after a
certain number of rotations is impossible.

Figure 1: Integer ratio 12x24

In the following sections the impact of integer ratios, non-integer ratios with a
common denominator in the tooth count and ratios with a prime tooth count are
analyzed. Regarding the hunting tooth, there is no difference between single
prime and co-prime tooth counts between pinion and gear.

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