When you built the crank fan, the spur gear system was producing
ROTATIONAL MOTION. Now let’s discover how a spur gear system
can produce LINEAR MOTION.
Now that you have built the Car Window,
let’s explore your model!
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Car Window Activity
(EN)
English
1. Explore your model by
turning the crank and
record your observations
to the questions below in
a notebook or on a piece
of paper.
2. How does the mechanism
work?
3. Which parts move?
4. What type of movement is applied to the blue crank?
This is called the input movement.
5. Describe the movement of the window. This is the output
movement.
6. How is the output movement different from the input
movement?
7. Identify the driver gear and driven gear. Why is a small gear
wheel used as the driver to turn a large driven gear?
8. How can you control the speed of the output movement?
9. Why does the crank turn many times but the window only rises
slowly?
SIMPLE MACHINES – like gears – make work easier by multiplying
the force applied or increasing the distance (speed) the
resistance moves. Force and distance cannot both be increased
at the same time. You should have just observed that the driven
gear is moving more slowly than the driver gear, therefore speed
is lost and force is multiplied, making it easier to lift the window!
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