How to Explain the Rotor/Eccentric Relationship?
 

Here is a question for the educators out there.

Has anyone found a good static diagram that shows why an eccentric shaft rotates three times for every one time of rotor rotation? All I have are very technical drawings, with lots of theory that is difficult to understand (from the Kenichi Yamamoto book).

What I am looking for is something that will help technicians understand the relationship between rotor and eccentric shaft, and the rotor's orbit around the stationary gear, without having to resort to working models (heavy) or animations (expensive).

Thanks...

If you sell me your Yamamoto book, or a copy of it, I'll tell you...

Its not mine, I'm borrowing it off somebody. And the only way he will let me have it permanently is if I kill him. Know any cheap assasins?

This is a decent link- there's some fairly straightforward math at the bottom of the page:
http://me.a-spec.ca:6001/Rotary.html

There are some very good *free* animations at www.rotaryengineillustrated.com.

A spirograph is an excellent way to work with epitrochoids.

Another way would be to get a Hula hoop. Wrap some masking tape around one point. Use the Hula hoop and count the number of hip rotations vs. hoop rotations.

I like the hula hoop idea!!

That rotary illustrated page has not been updated for ages, and the animations are unfortunately not free for what I want to use them for (teaching).

The other HP is getting close, close...

Thanks

He should be dead by now, shouldn't he?

Use this link.
http://www.rotaryengineillustrated.com/RE101.html