http://ecomodder.com/forum/showthrea...ted-10330.html
dcb;
here is a similar design dating back 130 years that was reported to be almost vibration free at 600 RPM
Check out the Arthur Rigg Water Engine:
Water Engines: Page 3
Of course assuming your belief in the imbalance is correct then the whole mass of the engine serves to control that imbalance in much the same way a flywheel does on other IC engines. There is no reciprocation in this engine (much like a rotary vane pump used in high speed air tools), which is a major factor in balance issues. In the same way a car wheel is imbalanced, the closer the difference in mass is to the center axis of rotation the less effect the imbalance will have.
With the pistons centrifugal force concentrated on the locating pin at the perimeter of the housing, I believe that the balance issues would be minimal.
The WW1 rotary aircraft engines were supposed to be virtually vibration free in operation.
Animated Engines, Gnome Rotary
This technology is ancient as you can see, going back over 100 years. There was supposed to be an Australian who flew a compressed air airplane many years before the Wrights.
I decided to abandon the patent on the engine design and pursue the IVT hydraulic configuration, because the Patent Office refused to acknowledge "novelty" in the design.
The central journal would be about 4 inches in diameter, while the support hub of the rotating block would be 10-12 inches in diameter. Bearings available in those diameters are rated for weights of 40,000 pounds per axle, so I don't think structural integrity is an issue, and research by Virginia Tech with stress analysis actually found the stress issues to be very minor in the hydraulic pump configuration.
The whole idea is based on a low speed, super high torque operation. To accomplish a 60-0 and back to 60 acceleration in a car would only require a change of 1800 RPM in the flywheel mode without any fuel consumption other than that necessary to cover the small percentage of losses.
regards
Mech