1.1 Rating formulas
This standard provides a method by which different
gear designs can be compared.
The formulas in this standard are intended to
establish a uniformly acceptable method for calculating
the pitting resistance and bending strength
capacity of generated straight bevel, zerol bevel and
spiral bevel gear teeth; curved and skewed tooth.
They apply equally to tapered depth and uniform
depth teeth.
The knowledge and judgment required to evaluate
the various rating factors come from years of
accumulated experience in designing, manufacturing
and operating gear units. Empirical factors given
in this standard are general in nature. AGMA
application standards may use other empirical
factors that are more closely suited to the particular
field of application. This standard is intended for use
by the experienced gear designer, capable of
selecting reasonable values for the factors. It is not
intended for use by the engineering public at large.
1.2 Exceptions
The rating formulas in this standard are not applicable
to other types of gear tooth deterioration such as
scuffing, wear, plastic yielding, scoring, case crushing crushing
and welding and are not applicable when
vibratory conditions exceed the limits specified for
the normal operation of the gears (see ANWAGMA
6000-896, Specification for Measurement of Lateral
vibration on Gear Units).
The formulas of this standard are not applicable
when any of the following conditions exist:
- bevel gears with offset, such as hypoids;
- straight and zerol bevel gears with transverse
contact ratios, m, (&a) less than 1 .O;
- bevel gears with modified contact ratios, m,
( E ~ )le ss than 1.O ;
- bevel gears which have a poor contact pattern;
- interference exists between tips of teeth and
root fillets;
- teeth are pointed;
- backlash is zero;
-
sintering.
bevel teeth finished by forging, casting or
Design considerations to prevent fractures emanating
from stress risers on the tooth profile, tip chipping
and failures of the gear blank through the web or hub
should be analyzed by general machine design
methods.
1.2.1 Scuffing
Formulas for scuffing resistance on bevel gear teeth
are not included in this standard. At the present time,
there is insufficient agreement concerning the
method for designing bevel gears to resist scuffing
failure.
1.2.2 Wear
Very little attention and concern have been devoted
to the study of gear tooth wear. This subject primarily
concerns gear teeth with low surface hardness or
gears with improper lubrication. No attempt has
been made to cover gear tooth wear in this standard.
1.2.3 Plastic yielding
This standard does not extend to stress levels above
those permissible for 1 6 cycles, since stresses in
this range may exceed the elastic limit of the gear tooth in bending or in surface compressive stress.
Depending on the material and the load imposed, a
single load cycle exceeding the stress level for 1 6
life cycles (see clause 16) can result in plastic
yielding of the gear tooth.
AGMA 2003-B97-1997 history
2010AGMA 2003-C10-2010 Rating the Pitting Resistance and Bending Strength of Generated Straight Bevel, Zerol Bevel and Spiral Bevel Gear Teeth
1997AGMA 2003-B97-1997 Rating the Pitting Resistance and Bending Strength of Generated Straight Bevel, Zerol Bevel, and Spiral Bevel Gear Teeth
AGMA 2003-B97-1997 Rating the Pitting Resistance and Bending Strength of Generated Straight Bevel, Zerol Bevel, and Spiral Bevel Gear Teeth was changed to AGMA 2003-C10-2010 Rating the Pitting Resistance and Bending Strength of Generated Straight Bevel, Zerol Bevel and Spiral Bevel Gear Teeth.