ANSI : American
National Standards Institute.
Addendum : It can be defined as the radial or
perpendicular distance between the pitch circle and the top of the
teeth.
Alignment : Accurate alignment of shafts on which
gears are mounted is an important factor in gear life and performance.
Shafts are set parallel in spur and helical gearboxes, and perpendicular
in most bevel and worm gearboxes. Dis-alignment of shafts could lead to
premature gear failure or other performance issues including noise.
Brinell Hardness Number (BHN) : It is a measure of the
hardness of a material such as steel.
Backlash : It is the extent by which the width of a
tooth space exceeds the thickness of the engaging tooth on the pitch
circles.
Backlash Variation : It can be defined as the
difference between maximum and minimum backlash occurring in a complete
revolution of the larger of a pair of mating gears.
Bevel Gears : These are conical shaped gears designed
to operate on intersecting axes. In most gearboxes the shafts will
intersect at a 90
o angle. Straight bevel gears and spiral
bevel gears are the two common types.
Bore : It is the diameter of the hole in a sprocket,
gear, bushing, etc.
Bottom Diameter : Also known as a root diameter, it is
the diameter of a circle measured across the bottoms of opposite tooth
spaces.
Bull Gear : A bullgear is the larger gear in two or
more gear set, the smaller one, known as a pinion.
Burning : Cutting a steel plate with the help of a
torch.
Bushing : A mechanical device/tool used for mounting a
sprocket or gear on a shaft.
CD : Center Distance.
CP : Circular Pitch.
Center Distance (CD) : It is the shortest distance
between non-intersecting axes of engaged gears.
Circular Pitch (CP) : It is the distance along the
pitch line between corresponding profiles of adjacent teeth.
Circular Thickness : It is the thickness of the tooth
on the pitch circle.
Coupling Sprockets, Chains, and Covers : A product
line used for connecting two non-continuous shaft ends.
DP : Diametral Pitch.
Dedendum (DED) : It is the radial or perpendicular
distance between the pitch circle and the bottom of the gullet.
Diametral Pitch (DP) : It is the ratio of the number
of teeth to the number of inches in the pitch diameter.
Gearbox Glossary
