Machine Drawings, Continued
WHOLE DEPTH (WD): The distance from the top of the tooth to the
bottom, including the clearance.
FACE: The working surface of the tooth over the pitch line.
THICKNESS: The width of the tooth, taken as the chord of the pitch circle.
PITCH CIRCLE: The circle having the pitch diameter.
WORKING DEPTH: The greatest depth to which a tooth of one gear
extends into the tooth space of another gear.
RACK TEETH: Compare a rack to a spur gear that is straightened out, then
the linear pitch of the rack teeth equals the circular pitch of the mating gear.
Figure 4-38 illustrates gear nomenclature.
Figure 4-38.Gear nomenclature.
Continued on next page