Power Transmission Via A Chain - FISCHER Profi Cartech Manual Del Usuario

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1. Cartech: Total Automotive Technology!
Jump up onto your bike, start pedaling and off you go. In the car, start the
engine, shift to first and the trip begins. It's just the ways things are, isn't
it? But what's behind all this? What happens between the foot pedals and
the wheels, and how does the technology function when you drive in low
gear slowly but relatively easily up a mountain or in a high gear racing
down like mad? How do different steering and drive systems function? The
Cartech assembly kit answers all these questions. And the best thing is, you
can try out directly how it all functions using the models you assembly with
the help of the instructions. Then you can read in the accompanying booklet
what's behind all this. Okay then, time to get going!

2. Power Transmission via a Chain

Transmission of power from one axle to another can be done excellently us-
ing a chain. On a bicycle, for example, the power from the pedals (drive
axle) can be transmitted to the back wheel (output axle). We can see during
bicycle riding that the combination of different-sized chain sprockets (chain
gears) results in the fact that you must pedal more quickly in 1st gear but
only move forward slowly, while you only need to pedal slowly in the 21st
gear to go quickly, but you need a lot more power.
Model: Chain Drive
(see the assembly instructions on page 6)
In our first model, the drive axle is not powered by pedals, but instead by
an engine. We are going to build in different toothed gears and observe
what happens:
Experiment 1:
Drive axle on engine (1) with toothed gear Z20 (= 20 teeth), output
axle (2) with toothed gear Z10 (= 10 teeth), exactly as shown in the
assembly instructions. Which of the wheels rotates more quickly?
10
Observation:
The wheel on the output axle rotates more quickly than the wheel
on the drive axle.
If you detach the gears from the engine and rotate the drive axle by
hand, you can observe that the output axle rotates exactly twice as
fast as the drive axle.
Experiment 2:
Exchange the toothed gears on the two axles: drive axle with
toothed gear Z10 and output axle with toothed gear Z20. Which
wheel rotates faster now?
Observation:
The wheel on the output axle rotates more slowly than the wheel on
the drive axle.
If you detach the gears from the engine and rotate the drive axle by
hand, you can observe that the output axle rotates exactly half as
fast as the drive axle.
Experiment 3:
Both axles with toothed gear Z20 (= 20 teeth)
Observation:
Both wheels rotate at the same speed.
Experiment 4:
Both axles with toothed gear Z10 (= 10 teeth)
Observation:
Both wheels rotate at the same speed again.
Consequently, it does not matter how large the toothed gears are. As long
as they have the same size (have the same number of teeth), they rotate
the axles at the same speed.
And what does this mean for us? Very simple. We see that the speed of the
wheels depends solely on the size ratio of the gears. To put it more precise-
ly, it is a question of the relation of the number of teeth of the two gears.
The two gears have the same number of teeth in experiments 3 and 4. The
relation between
Number of teeth on the driven gear
Number of teeth on the drive gear
The number of teeth of the driven gear is always in the numerator of the
fraction and that of the drive gear in the denominator. The transmission re-
lation is 1 to 1. The wheels rotate at the same speed.
In experiment 1, the transm. relation is:
In experiment 2, the transm. relation is:
If the transmission relation is greater than 1, it is a transmission into slower
rotation, also called speed reduction. If it is smaller than 1, transmission is
to faster rotation.
20 10 1
is (Exp. 1) or = (Exp. 2)
20 10 1
20 2
= (two to one).
10 1
10 1
= (one to two).
20 2