The above image is an original idea of my own.  Simply publishing it to the web protects many of my rights to this idea.  I'm not sure how unique it is, but I would like to give it to the public like Wally Minto did. 

This thermal engine is comprised of a ring, loosely held in the center of a plate by four bearings.  The drive shaft is located "off-center" from the ring.  The vanes shown are actually bimetallic and have a slight curve in their natural state.  Heat is applied to the curved vanes, causing them to try to straighten.  Likewise lack of heat, or cooling is applied to the straighter vanes causing them to try to curve.  This shape change causes the ring to rotate, thus turning the center shaft.

Here I have made the top plate transparent so you can see the bimetallic vanes.  Eight vanes are currently being shown.  In production, that number would be increased till they almost touched each other when curved.  This would generate the maximum surface area for heat transfer, thus providing the most torque or power.  Like Wally Minto's wheel, this is not a high speed device.  Any heat source could be used to power this device, including solar.

If you have any comments what so ever on this idea, please e-mail me.