Based on the fixed-end beam calculation. Includes the majority of effects.
Safety factor of contact fatigue
where:
|
s ac |
allowable contact stress number (material property) |
|
F t |
tangential force acting at teeth |
|
d w1 |
operating pitch diameter of pinion |
|
b w |
operating tooth width |
Safety factor of bending fatigue
where:
|
s at |
allowable bending stress |
|
P t |
tangential diametral pitch |
|
b wF1,2 = min (b 1,2 , b w + 2m) |
operating tooth width |
Factor Calculations
where:
|
μ |
Poisson's ratio (material property) |
|
E |
modulus of elasticity (material property) |
|
I |
geometry factor for pitting resistance |
|
Z N |
stress cycle factor for pitting resistance |
|
C H |
hardness ratio factor |
|
K o |
overload factor |
|
K v |
dynamic factor |
|
K s |
size factor |
|
K m |
load distribution factor |
|
K m = 1 + C mc (C pf C pm + C ma C e ) |
|
|
C mc - Lead Correction Factor |
|
|
C pf - Pinion proportion factor |
|
|
C ma - Mesh Alignment Factor |
|
|
C e - Mesh Alignment Correction Factor |
|
|
J |
geometry factor for bending strength |
|
Y N |
stress cycle factor for bending strength |
|
Y a |
reverse loadingfactor |
|
C f |
surface condition factor |
|
K R |
reliability factor |
|
K T |
temperature factor |
|
K B |
rim thickness factor |