Symbol

Description

Units

T₁

Applied torque to drive gear

Nm

n₁

Speed of drive gear

rpm

r₁

Effective radius of drive gear

m

F_a

Axial force

N

F_r

Radial force

N

F_t

Tangential force (effective force that does useful work)

N

F_n

Total force (force normal to the tooth surface)

N

a

Pressure angle

^o

b

Helix angle