How to calculate centre distance of spur gears?

[JCA490]

Hi everybody,

I have the following gear application:

1)Pinion data
Module = 3.5
Z1=14
Pressure angle = 20°
x1(Addendum correction factor)= 0.228
Diametral pitch = 49 mm

2)Gearwheel data
Module = 3.5
Z2=286
Pressure angle = 20°
x2(Addendum correction factor)= 0
Diametral pitch = 1001 mm

I need to calculate the distance between axis to complete my project. Can Somebody give me the formulas to do it (or bibliography to search)?

Thank you in advance,

Carlos

 

[asong]

The formulas will be like these (if your geat set are outer mesh)

use the following formula to find out operating pressure angle first,
inv(PA')=inv(PA)+2*tan(PA)*(x2+x1)/(z2+z1)
inv(PA)=tan(PA)-PA
PA in radians. you must find out PA' by iterative caculation.
then use the next formula to find out the center distance
a'=(m*(z2+z1)/2)*cos(PA)/cos(PA')

 

[diamondjim]

A rough estimate for your system
would be 1/2 the pitch diameters
plus .228 x 3.5
i.e. (pd1 + pd2)/2 plus xm x module.