T-43
Table 5-1 The Calculation of a Profile Shifted Internal Gear and External Gear (1)
db 2
da2
d2
df 2
O2
O1
aw
aw
ax
Fig. 5-1 The Meshing of Internal Gear and External Gear
(a = 20° , z1 = 16, z2 = 24, x1 = x2 = 0.5)
Example
External Internal
Gear Gear
3
20°
16 24
0 0.5
0.060401
31.0937°
0.389426
13.1683
48.000 72.000
45.105 67.658
52.673 79.010
3.000 1.500
6.75
54.000 69.000
40.500 82.500
x2 – x1
2 tana (–––––– ) + inva
z2 – z1
Find from Involute Function Table
z2 – z1 cosa
–––––– (––––– – 1)
2 cosaw
z2 – z1
(––––– + y)m
2
zm
d cosa
db
––––
cosaw
(1 + x1)m
(1 – x2)m
2.25m
d1 + 2ha1
d2 – 2ha2
da1 – 2h
da2 + 2h
m
a
z1, z2
x1, x2
inva
aw
y
ax
d
db
dw
ha1
ha2
h
da1
da2
df1
df2
Module
Pressure Angle
Number of Teeth
Coefficient of Profile Shift
Involute Function a
Working Pressure Angle
Center Distance Increment Factor
Center Distance
Pitch Diameter
Base Circle Diameter
Working Pitch Diameter
Addendum
Whole Depth
Outside Diameter
Root Diameter
Item
Symbol
Formula
No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
