Page 291 - Gear Technology Solutions

permissible deviations of the bevel gear shafts:

▪ Spiral angle
▪ Lead function (straight, circular, epicyclical, involute)
▪ Shaft arrangement (90°, angular, offset)
▪ Cutter diameter
▪ Crowning (length, profile, twist, higher order)

The Gleason Works developed a guideline with tolerances for allowable shaft
positioning deviations of average bevel gearsets of the following categories:

▪ Straight bevel gears
▪ Spiral bevel gears
▪ Miter spiral bevel gears
▪ Hypoid gears
▪ Super reduction hypoids

The new Gleason guidelines base on the Gleason backlash table and on max-
imal shaft displacement recommendations [3]. An average bevel gearset is the
gearset which is generated by the bevel gear design software when using de-
fault input parameters. It has to be acknowledged that particular applications of
bevel and hypoid gears can be significantly more or less sensitive and would
require their own custom set of tolerances.

Figure 2: Bevel gear axis definitions and nomenclature

276