Free Piston Engine

• US 20120280513A1
• Filed: 12/17/2010
• Published: 11/08/2012
• Est. Priority Date: 12/24/2009
• Status: Active Grant

• Current Assignee: Libertine FPE Ltd.
• Original Assignee: Libertine FPE Ltd.
• Inventors: Cockerill, Sam
• Granted Patent: US 8,794,198 B2
• Time in Patent Office: Days
• US Class Current: 290/1.A
• CPC Class Codes: F01B 11/001 in which the movement in the two directions is obtained by one double acting piston motor
• CPC Class Codes: F01L 9/20 by electric means
• CPC Class Codes: F02B 63/04 for electric generators
• CPC Class Codes: F02B 71/04 Adaptations of such engines for special use; Combinations of such engines with apparatus driven thereby
• CPC Class Codes: F02B 75/002 Double acting engines

Abstract

A free-piston engine comprising an engine cylinder and a single piston member comprising a double-ended piston configured to move within the cylinder, wherein the piston member partitions the cylinder into two separate chambers, each of which are supplied with a compressible working fluid from one or more intake means, the piston being arranged to move over and past the intake means during each stroke such that the fluid is replenished within one chamber while the piston compresses the fluid held in the other chamber.

Claims

1. A free-piston engine comprising an engine cylinder and a single piston member comprising a double-ended piston configured to move within the cylinder, wherein the piston member partitions the cylinder into two separate chambers, each of which are supplied with a compressible working fluid from one or more intake means, the piston being arranged to move over and past the intake means during each stroke such that the fluid is replenished within one chamber while the piston compresses the fluid held in the other chamber.

2. The engine of claim 1, wherein the intake means is (are) located at a central position along the cylinder.

3. The engine of claim 1, wherein the intake means comprises an air intake means and a fuel injection means.

4. The engine of claim 1, wherein the air intake means comprises a sliding port valve and a solenoid poppet valve.

5. The engine of claim 3, wherein the fuel injection means comprises two fuel injectors arranged one on each side of the air intake means.

6. The engine of claim 4, wherein the fuel injection means is configured to inject fuel immediately prior to the closing of the sliding port valve

7. The engine of claim 1, further comprising spark ignition means configured to produce a spark in each of the combustion chambers.

8. The engine of claim 1, further comprising exhaust means provided in each combustion chamber.

9. The engine of claim 8, wherein the exhaust means is a solenoid poppet valve provided in each combustion chamber, the valves being coaxial with the cylinder.

10. The engine of claim 1, wherein

the piston is configured to be elongate;

and

the engine cylinder has a bore dimensioned such that a compression ratio of about 15;

1 and an expansion ratio greater than twice the compression ratio is obtained.

11. The engine of claim 1, wherein the cylinder has a length at least ten times greater than its diameter.

12. A vehicle having an engine according to claim 1.

13. An electrical power generator, comprising the engine of claim 1 and further comprising a plurality of coils positioned along the cylinder of the engine, wherein movement of the piston within the cylinder induces magnetic flux within the coils.

14. A vehicle having an electrical power generator according to claim 13.