Abstract: The solution of the invention is an internal combustion engine with oxygen concentrating equipment (80) wherein the air taken in the cylinder space (15) during the intake stroke and pushed out by the piston (5) during the charging stroke charges one or more cells (41A-41Z, 51A-51Z) of the oxygen concentrating equipment (80) and after separating most of the nitrogen in the cells (41A-41Z, 51A-51Z), the oxygen rich air is injected into the cylinder space (15) through a compressor (33) at the beginning of the expansion stroke by an injector (11). The fuel is also introduced into the cylinder space (15) at the beginning of the expansion stroke by a fuel injector (19). The ignition may be spark ignition, self-ignition or their combination.

Abstract: The solution of the invention is an internal combustion engine with oxygen concentrating equipment (80) wherein the air compressed in the compression stroke is not yet used for combustion but taken out of the cylinder space (15) and used for operating the oxygen concentrating equipment (80). The essence of the invention is that the cylinder space (15) and one or more cells of the oxygen concentrating equipment (80) are temporarily connected during each compression stroke of the engine. The air taken in the cylinder space (15) during the intake stroke and pushed out by the piston (5) during the compression stroke charges one or more cells (41 A-41Z, 51 A-51Z) of the oxygen concentrating equipment (80) and after separating most of the nitrogen in the cells (41 A-41Z, 51A-51Z), the oxygen rich air is injected into the cylinder space (15) through a compressor (33) at the beginning of the expansion stroke by an injector (11).