SPROCKET DRIVE WHEEL DESIGN

[PUMPMANPLEE]

Greetings Gear & Pulley gurus,

i have 2 identical circular drive
wheels, each 800 mm diameter which has
16 tooth each. a shaft connects the
2 drive wheels.

the drive wheels turn or drives
12 mm diameter shafts which wraps
around them.

how do i go about designing the tooth
profile so that they mesh nicely with
each of the 12 mm diameter shafts
as each shaft comes into contact &
leaves the drive wheels.

pumpmanplee

 

[MikeHalloran]

Make a drawing.


Mike Halloran
Pembroke Pines, FL, USA

 

[PUMPMANPLEE]

Yup, a drawing might be
clearer, i'll send one.

pumpmanplee

 

[L17Aurora]

sounds like a chain sprocket type drive?

 

[williedawg]

as L17 alludes to...

check out Machinery's Handbook or read this...

http://www.robo-works.net/Mechanics/week 3/day 1/draw_sprocket.pdf

Just convert the metric dimensions....the principles are the same.

I've set up Excel tables for various roller chain sizes/number of teeth combinations for designing sprockets.

 

[williedawg]

hmmmm, after drawing up the basic 800mm "gear" and 12 mm shafts, it appears that a sprocket is not what's required; as the openings for the 12mm shafts would not be adjacent because of the 16 teeth.

However, I think the geometry for the entry/exit curves for a standard sprocket can still be used for your application....depending on whether the 12mm shaft profiles are completely inside the 800mm circumference; or just where they lie.

Are the 12mm shafts linked? If so, what is the pitch?

 

[PUMPMANPLEE]

williedawg,
i think you've got the picture...

the 12 mm shafts are linked
together by a hinged plate

the pitch or distance between the
centreline of the 12mm shafts
is about 156 mm.

the 12 mm shaft profiles are
sitting tangent on the circumference
of the 800 mm diameter drive wheel.

the openings on the drive wheel would
not be adjacent as they will be spaced
out. you will have 16 openings spaced
out around the drive wheel circumference.

pumpmanplee

 

[williedawg]

which tangent condition? (guessing you mean the 12mm shafts are inside the 800mm circle)

for 800mm circle with (16) 12mm shafts tangent to the INSIDE, the straight-line distance between any two shaft centers is 153.73

for same with the 12mm shafts tangent to the OUTSIDE, the straight-line dimension between centers is 158.41

If the pitch of the links is set, something will have to give in order to get the distance = to 156mm

 

[PUMPMANPLEE]

thanks...
i've got hold of some basic
chain sprocket design &
managed to work out a 16 teeth
drive sprocket to drive the
12 mm shafts...seems
to mesh ok.