A new record high efficiency of ninety-four percent (94%) for a piston engine was achieved by this Class 4 Free Piston Engine during dynamometer testing at Kennedy Engine Company; being the latest model of the series of engines created by Inventor, Robert D. Hunt. His Free Piston Engines do not have a crankshaft; and, back and forth reciprocating motion of its pistons is converted into rotation in a single direction by his patented Sprague Gear Transmission innovation, which always maintains a perfect ninety degree force vector angle for maximum transfer of power, which is responsible for its high record high efficiency. And, the engine is uniquely exhaust actuated whereby the exhaust discharge pressure times the engine without the need of electricity or any other timing means which is the second patent held by Mr. Hunt on the technology.
The 94% efficiency attained during the recent dynamometer tests rivals that of the most precision turbines ever built; and, therefore holds the promise of providing an inexpensive piston technology capable of replacing expensive turbines by providing a very low cost robust piston technology that works equally well under a broad range of conditions and with multiphase working fluids; with the free piston engine capable of being substituted in place of turbines that are extremely expensive and fragile and only work well when using perfectly dry gases under stringently set conditions.
Mr. Hunt's Exhaust Actuated Free Piston Engine with the Sprague Gear Transmission holds the potential dramatically lower the cost of power generation and to provide long range hybrid natural gas-fired / compressed air powered vehicles in the foreseeable future.
Also see the Kennedy Engine Dynamometer Test Results Video on YouTube
