I am trying to solve gear ratios for a differential gearset when one of the output shaft's rotation is limited...(adsbygoogle = window.adsbygoogle || []).push({});

Let's say:

I have a power split device with an input (A), output1 (B) and output2 (C).

C has a speed limiting mechanism attached to it.

Without limiting the speed of C, ratio A:B is 2:1 and ratio A:C is 2:1.

Let's apply a 300 RPM input to A without the speed limiting device engaged.

B will be spinning at 150 RPM.

C will be spinning at 150 RPM.

Engage the speed limiter and slow C down to 75 RPM.

How do I find the speed of B?

My guess is C(before limiter) - C(after limiter) + B(before limiter)

150-75+150 = 225

So, the functional output gear ratio A:B after limiting C to 150 RPM would be 300/225 or 1.3333:1

I think this is right so far.

Please correct me if I am wrong.

If that is right, what happens if A:B does NOT equal A:C?

If A:B = 3:1 and A:C = 2:1...

If we apply the same 300 RPM input(without the limiter) we will have:

B = 100 RPM

C = 150 RPM

If we slow C down to 75 RPM again how do we solve for B?

If we apply C(before limiter) - C(after limiter) + B(before limiter) we get:

150 - 75 + 100 = 175 RPM @ B

Therefore A:B after the limiter is engaged is 1.714:1

Is this right?

It feels like there is missing something.

Thanks for any help you can give.

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Differential gearset math

**Physics Forums | Science Articles, Homework Help, Discussion**