| TO GET |
HAVING |
RULE |
FORMULA |
| Module |
Diametral
pitch |
Divide 25.4
by the diametral pitch |
m=25.4/Pd |
| Diametral
pitch |
Module |
Divide 25.4
by the module |
Pd=25.4/m |
| Circular
pitch |
Divide
π by the circular pitch |
Pd=π/P |
| Pitch
diameter and number of teeth |
Divided the
number of teeth by pitch diameter |
Pd=N/D |
| Outside of
gear and number of teeth |
Divide
number of teeth plus 2 by the outside diameter |
Pd=N+2/Do |
| Base pitch
and pressure angle |
Divide the
base pitch by the cosine of the pressure angle then divide by π |
Pd=(Pb/cos.Φ)/π |
| Operating
diametral pitch |
Center
distance between 2 gears and no. of teeth in both |
Add the no.
of teeth in both gears and divide by 2, then divide by center distance |
dp=
(n1+n2/2)/C |
| Pressure
angle |
Base
diam..
and pitch diam. |
Divide the
base diameter by the pitch diam. |
cos.Φ=Db/D |
| Base pitch
and diametral pitch |
Divide
π by the diametral pitch, then divide by the base pitch |
cos.Φ=Pb/(π/Pd) |
| Base pitch
and circular pitch |
Divide the
base pitch by the circular pitch= cosine pressure angle |
cos.Φ=Pb/P |
| Pitch
Diameter |
Number of
teeth and diametral pitch |
Divide the
no. of teeth by the diametral pitch |
D=N/Pd |
| Number of
teeth and outer diameter |
Divide the
product of the outer diam.. and number of teeth by number of teeth +2 |
D=N•Do/n+2 |
| Outside
diameter and diametral pitch |
Subtract
from the outside diameter, the quotient of 2 divided by the diametral
pitch |
D=Do-2/pd |
| Addendum and
no. of teeth |
Multiply
addendum by the no. of teeth |
D=a•n |
| Base
diameter and pressure angle |
Divide the
base diameter by the cosine of the pressure angle |
dp=Db/cos.f |
| Outside
Diameter |
Number of
teeth and diametral pitch |
Divide no.
of teeth plus two by the diametral pitch |
Do=N+2/Pd |
| Pitch
diameter and diametral pitch |
Add the
pitch diameter to the quotient of 2 divided by the diametral pitch |
Do=D+2/Pd |
| Pitch
diameter and number of teeth |
Divide the
no. of teeth plus 2 by the quotient of no. of teeth divided by the pitch
diameter |
Do=N+2/N/D |
| Number of
teeth and addendum |
Multiply the
no. of teeth plus 2 by addendum |
Do=(N+2)a |
| Number
of teeth |
Pitch
diameter and diametral pitch |
Multiply
pitch diameter by the diametral pitch |
N=D•Pd |
| Outside
diameter and diametral pitch |
Multiply
outside diameter by the diametral pitch and subtract 2 |
N=Do•Pd-2 |
| Std.
thickness of tooth |
Diametral
pitch |
Divide
1.5708 by the diametral pitch |
t=1.5708/Pd |
| Std.
addendum |
Diametral
pitch |
Divide 1 by
the diametral pitch |
a=1/Pd |
| Std.
Dedendum |
Diametral
pitch |
Divide 1.157
(or 1.25) by the diametral pitch |
b=1.157/Pd |
| Std. whole
depth |
Diametral
pitch |
Divide 2.157
(or 2.25) by the diametral pitch |
ht=2.157/Pd |
| Clearance |
Diametral
pitch |
Divide .157
or (.250) by the diametral pitch |
c= .157/Pd |
| Thickness of
tooth |
Divde
thickness of tooth at pitch line by 10 |
c=t/10 |
| Center
distance |
Normal
diametral pitch and no. of teeth in both gears |
Add no. of
teeth in both gears and divide by 2, then divide result by the normal
diametral pitch |
dp=((n1+n)2/2)/Pnd |
| Operating
center distance |
Operating
diametral pitch and no. of teeth in both gears |
Add the no.
of teeth in both gears together and divide results by 2, then divide
results by operating diametral pitch |
dp=(n1+n2/2)/Pod |
| Base
diameter |
Pitch
diameter and pressure angle |
Multiply the
pitch diameter by cosine of the pressure angle |
Db=D•cosΦ |
| Base pitch |
Diametral
pitch and pressure angle |
Divide the
diametral pitch by π, then multiply by cosine of pressure angle |
Pb=cos.Φ•π/Pd |