INDEX TABLE FOR SPACING IN BLOCKS ON THE BROWN AND SHARPE GEAR CUTTER

THE DIMENSIONS OF GEARS BY METRIC PITCH Module is the pitch diameter in mm. divided by the number of teeth in the gear.

Pitch diameter in mm. is the Module multiplied by the number of teeth in the gear.

M

D'

N

=

=

=

=

Module.

The pitch diameter of gear.

D The whole diameter of gear.
The number of teeth in gear.
The working depth of teeth.
Thickness of teeth on pitch line.
Amount added to depth for clearance.

D"

t

f

M

D'

=

=

=

=

=

=

D

N

=

N N+ 2
N M.

(N + 2) M.

D' D
or

M M

D" = 2 M.

2.

t

f

M 1.5708

=

IO

The Module is equal to the part marked "S" in cut, measured n mm. and parts of mm.

Example: Module 3.50 mm. 100 teeth.

Sprocket Wheels the Bottom Diameter is the most important.

DIAMETER OF SPROCKET WHEELS - FOR BLOCK CHAINS I" PITCH

Diameter of Sprocket Wheels for Roller Chains 1" pitch where D= .45.

DIAMETER OF SPROCKET WHEELS FOR ROLLER CHAINS OF I" PITCH WHEN D = .45′′

BEVEL Gears are used to transmit power when shafts are not parallel. They can be made for any angle, but are more often at right angles than any other. Right angle bevel gears are often called miter gears. The teeth are or should be radial so that they are lower at the outer end. The names of the various parts are shown in Fig. II.

LAYING OUT BEVEL GEAR BLANKS

IN laying out bevel gears, first decide upon the pitch, and draw the center lines B B and C C, intersecting at right angles at A as shown in Fig. 12. Then draw the lines D D to E E the same distance each