Double-Acting, Two-Stroke HCCI Compound Free-Piston Rotating-Shaft Engine

• US 20110239642A1
• Filed: 11/03/2010
• Published: 10/06/2011
• Est. Priority Date: 11/03/2010
• Status: Active Grant

• Current Assignee: Dino Tomassetti Jr, Paul A. Schwiesow, Ronald L. Schwiesow
• Original Assignee: Dino Tomassetti Jr, Paul A. Schwiesow, Ronald L. Schwiesow
• Inventors: Schwiesow, Ronald L., Tomassetti, Dino JR., Schwiesow, Paul A.
• Granted Patent: US 8,127,544 B2
• Time in Patent Office: Days
• US Class Current: 60/595
• CPC Class Codes: F02B 1/12 with compression ignition with fuel-air charge ignited by compression ignition of an additional fuel F02B7/00
• CPC Class Codes: F02B 2075/025 two
• CPC Class Codes: F02B 25/08 Engines with oppositely-moving reciprocating working pistons
• CPC Class Codes: F02B 33/38 of Roots type
• CPC Class Codes: F02B 37/00 Engines characterised by provision of pumps driven at least for part of the time by exhaust
• CPC Class Codes: F02B 71/00 Free-piston engines; Engines without rotary main shaft

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.

Claims

1. A compound, two-stroke internal-combustion engine that delivers superior fuel economy and reduces emissions vs. existing internal combustion engines, comprising:

a) a free-piston component to produce energetic exhaust gas;

b) a rotary device to convert the energy in said energetic exhaust gas to power at a rotating output shaft; and

c) means whereby homogeneous charge compression ignition (HCCI) is utilized as the combustion mode of said free-piston component, thereby achieving superior fuel economy and reduced emissions vs. existing internal combustion engines.

2. The device of claim 1 wherein said rotary device is selected from the group consisting of:

a) a positive displacement air motor;

b) an axial turbine;

c) a centrifugal turbine; and

d) an impulse turbine.

3. The device of claim 1 further comprising a rotary precompressor to deliver intake air to said free-piston component, said rotary precompressor driven either by said rotating output shaft or by a portion of said energetic exhaust gas.

4. The free-piston component of the device of claim 1 further comprising at least one free-piston gas generator assembly, comprising:

a) a single cylinder;

b) intake and exhaust ports located in said cylinder; and

c) two cylinder heads closing the ends of said cylinder.

5. The free-piston gas generator assembly of claim 4 further comprising a double-ended, oscillating piston assembly slidably displaceable in said cylinder, wherein said double-ended, oscillating piston assembly comprises two pistons fixedly attached to each other via a rigid connecting rod.

6. The free-piston gas generator assembly of claim 5 further comprising means by which closed-cylinder fuel injection is used to produce a homogeneous charge of fuel and air well before achieving peak compression.

7. The free-piston gas generator assembly of claim 5 further comprising an axially fixed internal divider element inserted into said cylinder, centrally located between said two cylinder heads and surrounding said rigid connecting rod between said two pistons, thereby separating the regions between said pistons into two independent volumes for intake and charge-transfer functions.

8. The free-piston gas generator assembly of claim 7 wherein said axially fixed internal divider element is configured so that it can float over a limited distance transverse to the axis of said rigid connecting rod to allow easier mechanical tolerance on the alignment of said pistons and said cylinder.

9. The free-piston gas generator assembly of claim 7 further comprising a multiplicity of upper and lower transfer ports in said cylinder to accomplish charge transfer and exhaust scavenging, wherein said transfer ports are arranged perpendicularly to a radius of said cylinder centered on said exhaust ports.

10. The free-piston gas generator assembly of claim 7 further comprising a radial channel in said axially fixed internal divider element, wherein said radial channel is used to introduce lubricating substance into a split bushing in the center of said axially fixed internal divider element and thence though a port in said rigid connecting rod, by means of which arrangement said lubricating substance is distributed internally to said pistons.

11. The free-piston gas generator assembly of claim 7 further comprising means whereby compressed air is used to impart an oscillating movement to said double-ended, oscillating piston assembly to facilitate starting.

12. The free-piston gas generator assembly of claim 7 further comprising means whereby an integral linear electric motor/generator is used to impart an oscillating movement to said double-ended, oscillating piston assembly to facilitate starting.

13. The free-piston gas generator assembly of claim 7 further comprising means whereby an integral linear electric motor/generator is used to regularize the motion of said double-ended, oscillating piston assembly and to synchronize the motion of a multiplicity of said double-ended, oscillating piston assemblies in the event that said compound, two-stroke internal-combustion engine comprises more than one of said free-piston gas generator assemblies.

14. The free-piston gas generator assembly of claim 7 further comprising means by which conventional spark-ignition is used to initiate combustion during engine startup until operation utilizing homogeneous charge compression ignition is established.

15. The free-piston gas generator assembly of claim 7 further comprising electronic means for sensing the position of said pistons.

16. The free-piston gas generator assembly of claim 15 wherein said electronic means for sensing the position of said pistons provides data to be used to determine the timing of closed-cylinder fuel injection.

17. The free-piston gas generator assembly of claim 15 wherein said electronic means for sensing the position of said pistons provides data to be used to determine the timing of an igniting spark used during engine startup.