Abstract (Inputs.Engineering)OptionalmoduleThe normal module: the tooth size measured square to the teeth, in model units, as the cutter's module. Only gears of one module mesh.
OptionalteethHow many teeth the gear has, at least 3.
OptionalhelixThe teeth's lean from the axis in degrees: positive for a right hand, negative for a left. Two external helical gears mesh at one angle in opposite hands.
OptionalpressureThe angle at which meshing teeth push on each other, in degrees, measured square to the teeth; 20 is the common standard, and meshing gears share it.
OptionalprofileHow far the teeth are moved out from the pitch circle, as a share of the module. Positive values give thicker teeth that small gears need, negative values thinner ones.
OptionalbacklashHow much thinner each tooth is round the pitch circle than a tight fit, in model units; two meshing gears leave the sum of their backlash between their teeth.
OptionaladdendumHow far the teeth reach above the pitch circle, as a share of the module.
OptionaldedendumHow deep the gaps reach below the pitch circle, as a share of the module; more than
addendum leaves room for the tips of the mating gear.
OptionalrootThe radius that rounds the bottom of each gap, as a share of the module. It shrinks to fit a narrow gap, and 0 leaves a sharp corner.
The teeth of an involute helical gear, shared by
engineering.mechanical.gears.helicalGearSizesandengineering.mechanical.gears.helicalGearOutline: their size and lean, their shape and how loosely they fit, measured square to the teeth.