OD - Outside diameter
FA - Face angle
ANG ADD - Angular addendum
PCA - Pitch cone angle
FW - Face width
CA - Cutting angle
PCR - Pitch cone radius
ADD - Addendum angle
PR - Pitch radius
DED - Dedendum angle
ADD - Addendum
BCA - Back cone angle
DED - Dedendum
PD - Pitch diameter
Figure 14-15.--Parts of a bevel gear.
BEVEL GEAR NOMENCLATURE
2. Pitch cone angle (PCA or
The dimension nomenclature of the bevel gear is
a. This angle is formed by a line down one
the same as that of a spur gear, with the exception of the
addendum on the tooth and the axis of the
angular addendum. Refer to figure 14-15.
gear.
1. Face angle (FA)
b. This angle cannot be measured, but it is
a. This angle is formed by the top edge of the
very important in calculations.
teeth and the axis of the gear.
b. The gear blank is machined to this angle.
3. Cutting angle (
or CA)
c. The face angle is obtained by adding one
a. This angle is formed by the bottom of the
tooth and the axis of the gear.
to the pitch cone
addendum angle
b. The index head is set at this angle when the
gear is cut.
angle
14-16