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### Phenolic Laminated Gears Design Formulas and Calculator

Phenolic Laminated Gears Design Formulas and Calculator

The characteristics of gears made of phenolic laminated materials are so different from those of metal gears that they should be considered in a class by themselves. Because of the low modulus of elasticity, most of the effects of small errors in tooth form and spacing are absorbed at the tooth surfaces by the elastic deformation, and have but little effect on the strength of the gears.

The following formula can be used to determine the safe working stress for a given gear velocity.

S = Ss ( 150 / ( 200 + V ) + 0.25 ) Imperial Units

S = Ss ( 0.76 / 1.016 + V ) + 0.25 ) SI Units

Where:

S = safe working stress for a given velocity lb/in2 (MPa)
Ss = allowable static stress lb/in2 (MPa)
V = pitch-line velocity in feet per minute (m/s)

Generally Ss for phenolic laminated materials are in the range of 6,000 psi (41.36 MPa).

References:

Machinery's Handbook, 29th Edition