Form
Capability
Most tooth shapes can be formed if the space
between the teeth is such that forming die may be withdrawn
radially without being obstructed by the flanks of the formed
teeth. The flanks of the formed tooth may have straight,
involute, or other complex, convex forms provided that there are
not sharp corners between the root of the form and the flanks
and all the surfaces of the flanks have an angle of at
least 3 degrees with respect to the
local radius. |
Form
Characteristics
Spacing and form tolerances are a function of
the form being produced. However, the overall part
configuration is highly repeatable provided there is good blank
control. In general, spacing errors of less than .002
(.05mm) are practical for many typical involute and similar
forms. The crest of the teeth will generally fall away at
each end of the form because the process does not axially
constrain the growth of the part during forming. |
Material
Requirements
Generally, materials having a hardness
of Rc 25 or
less and elongation of at least 15% can be used to produce forms
with adequate die life. As the hardness increases and
elongation decreases the depth of form that is practical to
produce declines accordingly. Also, as the flank angle with
respect to the local pitch radius decreases, the die loads
increase to further affect die life and tooth spacing accuracy. |
Automatic
Feeding
The machines are designed for simple mounting
of feeders, and pick and place units.
With such equipment,
production rates of up to 12 parts per minute can be achieved. |
Manual
Production Rates
Forming times are generally from 3 to 6
seconds, depending upon the size of the machine and the depth of
the form. |
Set-up
The dies and holder system are designed for
quick change and easy regrind. Therefore, changeover of a
manual machine from one part to another requires only about 15
to 30 minutes, depending upon the size of the machine and the
number of dies. Three die holders handle the full range of
teeth from 2 to 10. |
