Data Sheet

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247. Gears
Replace the switch (62) with the press switch (61) in project #242,
press the press switch (61) and you will hear a faint siren from the
motor (95). A gear is a part having teeth, or cogs, which can mesh with
another toothed part to transmit torque. By having different size parts,
gears can change the speed, torque, and direction of a power source.
248. Gear Ratio
Replace the switch (62) with the press switch (61) in project #242,
place a wire (4) across points C and D and when you press the press
switch (61) you will hear a faint gun shot and machine gun sounds.
Assuming circular gears, it can be shown that the speed ratio (or gear
ratio) is inversely related to the ratio of the radius (called the pitch
radius) of the two gears engaged. So going from a large radius gear to
a small radius gear increases speed, and vice versa.
249. Helical Gears
Replace the switch (62) with the press switch (61) in project #242,
place a wire (4) across points A and B and when you press the press
switch (61) you will hear the faint sound of an emergency re siren.
Your car uses helical gears. The leading edges of the teeth are set at
an angle relative to the axis of rotation. This makes the gear curved
to form the shape of a helix. The benets of helix gears are improved
strength and reduced noise in power transfer.
250. Gear Usages
Replace the switch (62) with the press switch (61) in project #242,
place a wire (4) across points E and F and when you press the press
switch (61) you will hear faint space battle sounds. The three main
usages of gears are to change/increase speed, increase force and
change direction.
251. Gear Applications
Replace the switch (62) with the press switch (61) in project #242, place
a wire (4) across points G and H and when you press the press switch (61)
you will hear music. Some common applications for gears are for factory
automation, food processors, printing machines and factory automation.
WARNING: Moving parts. Do not
touch the motor during operation. Do
not lean over the motor.
!
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