Abstract: The horizontally opposed center fired engine improves on the traditional design of the horizontally opposed engines and center fired engines with a better engine geometry. The present invention utilizes four pairs of opposing pistons to compress a larger volume of air-fuel mixture within four different cylinders. The four different cylinders are radially positioned around a center axle in order to achieve a perfectly symmetric engine geometry. The center axle consists of two different shafts spinning in two different directions, which could drastically reduce engine vibrations in the present invention. Engine vibrations are caused by a change in engine speed and result in a loss of energy. Due to the design, the present invention will only experience energy loss in the form of entropy and friction. Thus, the present invention can convert a higher percentage of chemical energy into mechanical energy than any other internal combustion engine.

Abstract: This invention provides a compact, fuel-efficient internal combustion engine that can be used to provide rotating shaft output power to a wide variety of mobile and stationary applications. It is based on a two-stroke free-piston gas generator that implements the homogeneous charge compression ignition (HCCI) combustion principle for essentially constant-volume combustion, and it employs a variable piston stroke to maintain a high level of efficiency across a wide range of loads and speeds. A rotary device, which may be of either an aerodynamic or positive displacement type, converts the energetic gas stream to power at a rotating shaft.

Abstract: Disclosed herein are a uniform pressure unequal surface engine and an engine for power generators using the same. The uniform pressure unequal surface engine includes a kernel cylinder having a fuel supply unit. A kernel piston is airtightly provided in the kernel cylinder and reciprocated by explosive force when fuel is burnt, thus providing rotating force to a rotating shaft. A pressure reducing cylinder is connected to the kernel cylinder via an openable exhaust gas pipe, has a relatively larger inner diameter than the kernel cylinder, and has no fuel supply unit.