Learning About Sprockets - Thames & Kosmos AIR Plus Water Power Experiment Manual

Learning about Sprockets

1. The power transmission in chain gear systems depends on
chains instead of the direct meshing of gears. Chains must fit
on the teeth of chain gears. Gears used with chains are called
sprockets. The "working" diameters of the sprockets in this
kit are about 10 mm (10-tooth), 20 mm (20-tooth) and 30 mm
(30-tooth). Try to ensure that when connecting drive chains
they are neither too tight nor too loose so that the motion of
one is transmitted efficiently to the other. If the chain lengths
do not exactly fit, opt for adding an extra chain segment: a
chain that is a little loose will work better than one that is too
tight. However, the chain has to be tight enough so that it does
not fall off the sprockets. Chain gear systems can be found in
normal bikes or escalators.
2.
Connect a 10-tooth sprocket to a 30-tooth sprocket as
shown.
3. Use a pencil point, or something similar, to turn sprocket B.
Which direction does sprocket A turn?
Would this be the same if A and B were two gears meshing?
How many times do you have to turn A for B to rotate once?
The gear ratio of these two sprockets would be __ to __ ?
4. Repeat the experiment for the two assemblies below and
make a table of your results for all three.
A
5. Try chaining a 10-tooth sprocket and two 30-tooth sprockets
together as shown. Turn A clockwise.
What happens to B and C?
Do they turn in the same direction?
Do they turn at the same speed?
6. Now try to chain the 10-tooth sprocket C as shown.
Turn A clockwise. What happens to B and C?
Do they turn in the same direction?
Do they turn at the same speed?
7.
By connecting two sets of chain gears together three speeds
can be obtained.
This system is widely used in the transmission on bicycles by
adding a gear shift in between.
A
B
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| AIR+WATER power
A
B
C
A
A
B
B
C
B