SPUR GEAR force components:
(I) Tangential force Ft =T/r, where T = gear torque r = pitch radius
of the gear.
(2) Separating or radial force Fr = Ft tanφ , where φ is the pressure
angle. Note that the radial force is always directed towards the
center of the gear.
Gear ratio/ velocity ratio
Gear A – pinion / driving (input)
Gear B – driven (output)
power flow is constant
P = TAωA= TBωB
velocity v of the point of contact on the pitch circles is the same on
both gears, assuming no slip at contact point
v = rAωA= rBωB
input gear A has radius rA and meshes with output gear B of radius
rB
ωA/ωB = rB /rA = NB/NA
ωA – angular velocity of gear A (input)
TA – torque of gear A
NA - number of teeth on input gear
NB - number of teeth on output gear.
Gears
Gear A – pinion / driving (input)
Gear B – driven (output)