Involute Spline Names, Symbols, and Relations for GOST Standard

Name

Symbol

Relation

Module

m

-

Pressure angle

α

α = 30 o

Diameter of pitch circle

d

d = m N

Shaft tooth height

h

h min = h a + h fmin

Shaft tooth height when centering to tooth sides

Shaft tooth height when centering outside

h a

h a = 0.45mm

h a = 0.55m

Shaft tooth height

h

h min = h a + h fmin

Hub dedendum:

flat bottom of groove

round bottom of groove

H f

H fmin = 0.55m

H fmin = 0.65m

H f = 0.77m

Radius of tooth transition curve

ρ r

ρ rmin = 0.15m

Nominal groove width on pitch circle

e

e = π / 2m + 2xm tg α

Hub root diameter: flat bottom of groove

round bottom of groove

D f

D f = D

D fmin = D + 0.44m

Displacement of basic profile

x m

x m = 1/2 (D-m N - 1.1m)

Shaft root diameter: flat bottom of groove

round bottom of groove

d f

d fmax = D - 2.2m

d fmax = D - 2.76m

Shaft outside diameter: centering to the tooth side

centering to the outside

d a

d a = D - 0.2m

d a = D

Hub tooth chamfering or fillet diameter

K

K = 0.15m

Pitch

p

p = π m

Number of teeth

N

-

Basic diameter

d b

d b = m N cos α

Hub tooth height

H

H = H a + H f

Addendum

H a

H a = 0.45m

Shaft addendum

for flat bottom of groove

for round bottom of groove

h f

h fmin = 0.55m

h fmin = 0.65m

h f = 0.83m

Shaft pitch width of tooth

s

s = π / 2m + 2xm tg α

Nominal diameter of splining

D

D = m N + 2xm +1.1m

Hub outside diameter

D a

Da = D - 2m

Radial clearance

c

c min = 0.1m

Diameter of circle of limit points of hub tooth sides

D 1

D 1imin = d a + F T

Diameter of circle of limit points of shaft tooth sides

d 1

d 1imax = D a + F T

Splining diameter

D d

-