Crankless Internal Rotating Cylinder Engine - CIRCE

[Ken I]

Crankless Internal Rotating Cylinder Engine (CIRCE)

I have seen a few engines based on the following design :-

Uncredited / Unknown Source Photo

And decided to design my own version by eliminating the crank by placing the cylinder within the flywheel – hence CIRCE – Greek goddess of magic.

I have posted the plans and build notes in the downloads section for anyone who's interested.


This the resulting design – the primary flywheel (or “Crankwheel”) has to run in a cradle of ball bearings and be held into that cradle by a further pair of bearings running against the inclined inner surface at 45°

The G.A. Drawing.

A video of it running on YouTube:-



Cross Section:

Airflow Diagram:

This is how the inlet / exhaust is commutated by the collector ring and distributor axle :-

The annulus grooves in the distributor axle

The “blind” zones (there is another on the opposite side) between grooves transits past the inlet/exhaust ports when the cylinder is vertical – commutating the inlet to exhaust and vice versa at the transition.

Note: In the main cross section drawing the axles is shown out of position by 90° to illustrate the porting rather than physical orientation – FYI to avoid confusion.
https://www.homemodelenginemachinist.com/threads/crankless-rotating-cylinder-engine-circe.31900/
Go to the downloads section to get the AutoCad *.dwg files and a *.pdf of the build notes.
The *.zip file contains the *.dxf & *.docx versions

Regards, Ken

 

[johnmcc69]

Outstanding work Ken! Both in the engine & the documentation. The ACAD drawing is great, a great example in drawing set-up & proper use of "layers". For the more adventurous, check out the "blocks" Ken used..

I'm still a little confused by the compensation of the "angled" bearing contact on the flywheel, I can understand the difference in speed by the diameter, but ...I'm lost.

John

 

[franscubitt]

Ken this is a really inspiring engine.
I planned to build something from this site after I retired but have never been so busy so it had to be delayed till I can finish our barn workshop,
Thanks for sharing
Frans

 

[Ken I]

John, thanks - you are the first person ever to comment on my use of blocks - I normally delete them - other than those specifically used in the drawing - as they are mostly my personal aide to drawing creation.
I design machines for a living and part per layer works well for me - otherwise it just gets too confusing. I sometimes move everything into a single layer to confound my customers - to whom I have issued the drawings - to stop them plagiarizing - or at least make it difficult. Nowadays I mostly give them pdf's.
The problem with the wheel is it will want to run off tangentially - it can't so there is lateral "scuffing" but it doesn't seem to cause any problems. However if you want to be precise about it then the ratio of the inner and outer running radii of both the raceway and the roller must be the same so that the running surface velocity matches at any radius across the entire running face. I only included it because I was sure someone would point out the "error" - i.e. D1/D2 = d1/d2
Regards, Ken

 

[Ken I]

Second Thoughts:

The crankwheel and cylinder has a suitable “old fashioned” feel to it. The side plate assemblies don’t and to my mind don’t jibe visually with the cylinder and crankwheel.

These would look better if fashioned to look more like Victorian engineering – like riveted “I” beam and cast iron latticework – I’m going to think about it.

Special thanks to johnmcc69 for the 3D rendering of my musings on better aesthetics.
I'll post a picture when this is translated into metal.
Regards Ken

 

[Ken I]

O.K. with lockdown I got around to finishing it. Much more aesthetically pleasing now (I think) looks more Victorian.

Regards,
Ken

 

[Brian Hutchings]

That looks superb Ken. It could even get me making one.
Brian

 

[Uhu]

Great looking unusual engine Ken, and a great job you did of it.
Now in Vancouver, I moved here from Paarl 20 years ago, so I know that if you live in Cape Town, you must actually be within 10 miles of two entirely different oceans. I`m collecting projects for my imminent retirement and this one is definitely going in the file. Thank you for sharing your design.

 

[Ken I]

Once again a special thank you to Johnmcc69 for his 3D rendering and the following animation.

It's very short - just a single revolution - right click & select "loop" to run continuously.
Regards, Ken