Multiple chain sprocket reduction ratio?

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1

Hello, I would like to know how to calculate the reduction ratio for a multiple sprocket-to-chain transmission system.

2

Hello

To calculate a ratio, you have to divide the diameter of the driving wheel with that of the driven wheel (or the number of teeth)

  • Example: Roue_1 = 80 teeth; Roue_2 = 20 teeth;
  • 80/20 = 4 so the ratio is 4. If you have a speed of 20 rpm then the speed at the output will be 20*4 = 80 rpm.
  • Example 2: If you have a 120-tooth cogwheel after our example above then the 20-tooth wheel becomes the leading wheel and the ratio is 20/120 = 1/6th or 0.167. The rotation speed therefore goes from 80rpm to 80*0.167 = 13.33 rpm.

Instead of calculating the speed at each pinion/wheel, we calculate the overall ratio and multiply the input speed by it.

The relationships between them multiplied.

  • The overall ratio is therefore 4*(1/6) = 2/3.
  • Checking: 20rpm * 2/3 = 13.33rpm. We get the same result as Example 2.

There you go, hoping to have helped you.

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