Tuesday 28 September 2010

Salmson Radial "Canton Unne" System?

This isn't a very well prepared section, but if I don't write it now I might not get around to it. Again lots of this is from memory, so bear with me.

The Salmson 7 cylinder radial featured previously has a brass label stating patent for a "Canton Unne" system.
I remember spending ages going through books and old engineers hand written notes to try and see or understand this application. I also remember that it was really difficult to picture the following without accurately drawing it out.
The small amount of information always stated a reason but never how it was achieved.

On the radial engine, there is one Master conrod attached to the single crankpin. The remainig six rods are attached to the outer housing of the master rod big end. The attachment is similar to a small end and gudgeon pin arrangement.
As the crank rotates the master rod centre point is the centre of the journal, however the centre pivots of the remaining rods are through the housing (circumference) of the master rod. If you plot the path of these and compare  with the crankpin centre path you will see a different form during one rotation.
I believe that the "Canton Unne" system was to allow a form of gear indexing to compensate for this. I can see the principle but the operation of a suitable arrangement is very difficult to visualise. For me it is just too far for my minds eye to grasp, I could try and labouriously draw each sequence and design in order to visualise it, but it is more likely that it is beyond me.
The forces of this  increased rotating mass (ie compensating sun and planet gears or similar)would also become an issue I would expect.

It seems the design was not used although the recognition plate still proudly states that it has been in existence.

I have never seen a drawing for this system, perhaps someone has, it would be good to say "Ah thats how they did it!"

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