Free piston engine provided with a purging air dosing system

A free piston engine for the generation of energy through combustion of fuel mixed with air, comprising a combustion chamber formed at least in part by a first cylinder and a first piston movable in the first cylinder from a lower dead center to an upper dead center, exhaust ports for the exhaust of combustion gases from the combustion chamber, inlet openings for supply of combustion air into the combustion chamber, a purging air pump for bringing the combustion air in a purging air chamber connected with the inlet openings under overpressure, a fuel system for supply and mixing of fuel with the combustion air, moving means for accelerating or braking the first piston and for stopping it at the lower dead center, control means by which the duration of the first piston at the lower dead center may be adjusted so that stroke frequency can be varied, and a charge air dosing system comprising a charge air pump having a second piston independently movable in a second cylinder for supplying charge air via a connecting pipe to at least one of the purging air chamber and the combustion chamber, wherein the moving means comprise a hydraulic system, and the second piston is hydraulically driven.

A free piston engine for the generation of energy through combustion of fuel mixed with air, comprising a combustion chamber formed at least in part by a first cylinder and a first piston movable in the first cylinder from a lower dead center to an upper dead center, exhaust ports for the exhaust of combustion gases from the combustion chamber, inlet openings for supply of combustion air into the combustion chamber, a purging air pump for bringing the combustion air in a purging air chamber connected with the inlet openings under overpressure, a fuel system for supply and mixing of fuel with the combustion air, moving means for accelerating or braking the first piston and for stopping it at the lower dead center, control means by which the duration of the first piston at the lower dead center may be adjusted so that stroke frequency can be varied, and a charge air dosing system comprising a charge air pump having a second piston independently movable in a second cylinder for supplying charge air via a connecting pipe to at least one of the purging air chamber and the combustion chamber, wherein at least a portion of the energy is converted into an oil flow whose pressure is load-dependent, and the oil flow is utilized to move the second piston.