Patent ID: 6945202
Filing Date: 2005-09-20
Classification: F02B,H02K

Abstract:
1. A free piston engine comprising: a housing that includes a cylinder; a first piston that is contained within the cylinder and capable of being axially reciprocated; a second piston that is contained within the cylinder, capable of being axially reciprocated, and opposed to the first piston, wherein a combustion chamber is formed as a space surrounded by the first piston, the second piston, and the housing; a first shaft that is connected with the first piston at a first end of the first piston and capable of being axially reciprocated along with the first piston, wherein the first end of the first piston is opposite to a second end of the first piston, wherein the second end of the first piston faces the combustion chamber; a second shaft that is connected with the second piston at a third end of the second piston and capable of being axially reciprocated along with the second piston, wherein the third end of the second piston is opposite to a fourth end of the second piston, wherein the fourth end of the second piston faces the combustion chamber; a first spring unit that is connected with the first shaft, supports the first piston and the first shaft, applies to the first shaft a force that corresponds to a first displacement of the first piston and has a direction opposite to a direction of the first displacement; and a second spring unit that is connected with the second shaft, supports the second piston and the second shaft, applies to the second shaft a force that corresponds to a second displacement of the second piston and has a direction opposite to a direction of the second displacement.