Free piston variable-stroke linear-alternator generator

• US 5,850,111 A
• Filed: 06/16/1997
• Issued: 12/15/1998
• Est. Priority Date: 05/05/1994
• Status: Expired due to Fees

• Current Assignee: Lockheed Martin Energy Research Corporation (Martin Marietta Corporation)
• Original Assignee: Lockheed Martin Energy Research Corporation (Martin Marietta Corporation)
• Inventors: Haaland, Carsten M.
• Primary Examiner(s): Ramirez, Nestor
• Assistant Examiner(s): JONES, JUDSON
• Application Number:
  US08/876,435
• Time in Patent Office: 547 Days
• Field of Search: 310/36, 310/15, 310/17, 310/30, 310/168
• US Class Current: 310/15
• CPC Class Codes: F02G 2243/54 thermo-acoustic
• CPC Class Codes: H02K 44/24 by reversing the direction of fluid

Abstract

A free-piston variable stroke linear-alternator AC power generator for a combustion engine. An alternator mechanism and oscillator system generates AC current. The oscillation system includes two oscillation devices each having a combustion cylinder and a flying turnbuckle. The flying turnbuckle moves in accordance with the oscillation device. The alternator system is a linear alternator coupled between the two oscillation devices by a slotted connecting rod.

Claims

1. A free piston variable stroke generator comprising:

oscillating means for obtaining a variable stroke;

alternator means for generating electric current in accordance with the variable stroke from said oscillating means; and

turnbuckle means connected to said oscillating means for obtaining a variable stroke.

2. A free piston variable stroke generator according to claim 1, wherein said oscillating means includes:

an internal combustion cylinder;

a piston;

a sliding exhaust-port sleeve coupled through which said piston moves; and

a connecting rod.

3. A free piston variable stroke generator according to claim 2, wherein said turnbuckle means comprises:

a threaded turnbuckle screw;

a slotted turnbuckle sleeve having internal threads, said threaded turnbuckle screw located inside said slotted turnbuckle sleeve;

a sleeve turning gear surrounding said slotted turnbuckle sleeve and including a lug to engage a slot in said slotted turnbuckle sleeve; and

a selsyn-driven gear engaging said sleeve turning gear to engage said threaded turnbuckle screw.

4. A free piston variable stroke generator according to claim 3, further comprising a selsyn motor for driving said selsyn-driven gear.

5. A free piston variable stroke generator according to claim 4, wherein said connecting rod is a slotted connecting rod having a push-pull bearing at one end engaging said piston.

6. A free piston variable stroke generator according to claim 5, including two oscillating means and one alternator means.

7. A free piston variable stroke generator according to claim 5, including four oscillating means and two alternator means.

8. A free piston variable stroke generator according to claim 5, including 2n oscillating means and n alternator means, n being an integer greater than or equal to 1.

9. A free-piston variable-stroke generator comprising:

two systems moving in opposing directions, each said system including;

two internal combustion cylinders;

two sliding exhaust-port sleeves respectively coupled to said internal combustion cylinders;

two pistons respectively connected to said two sliding exhaust-port sleeves; and

two connecting rods having a first end respectively connected to said two pistons;

two turnbuckles, respectively connected to a second end of said two connecting rods, said two turnbuckles oscillating with said two pistons, respectively;

a linear alternator coupled between said two turnbuckles and including a plunger, said two pistons being rigidly attached to each side of said plunger through said respective two turnbuckles; and

means connected to said linear alternator for providing AC output power.

10. A free-piston variable-stroke generator, according to claim 9, further comprising two push-pull bearings respectively connecting said two connecting rods to said two pistons.

11. A free-piston variable-stroke generator, according to claim 10, wherein said connecting rods are slotted connecting rods.

12. A free piston variable stroke generator, comprising:

an alternator operatively connectable to provide a demanded electric power output;

an oscillator having a variable stroke and being connected to drive said alternator so that the variable stroke varies in response to the demanded electric power output.

13. The free piston variable stroke generator of claim 12, wherein said alternator includes a plurality of spatially separated magnetic poles.

14. The free piston variable stroke generator according to claim 13, wherein said alternator is a linear alternator coupled to said oscillator to provide alternating current output power.

15. The free piston variable stroke generator according to claim 14, further including:

a plunger magnetically coupling said oscillator to said spatially separated magnetic poles.

16. The free piston variable stroke generator according to claim 15, wherein said plunger includes a laminated iron core passing between said spatially separated magnetic poles.

17. The free piston variable stroke generator according to claim 16, wherein said magnetic coupling between said plunger and said plurality of spatially related magnetic poles increases when a length of said varying stroke is lengthened, and decreases when the length of said varying stroke is shortened.

18. The free piston variable stroke generator according to claim 17, wherein said varying stroke length increases in response to an increase in said demanded electric power output.

19. The free piston variable stroke generator according to claim 18, wherein said oscillator drives said alternator at a variable frequency.

20. A free piston variable stroke generator according to claim 12, further including a plunger magnetically coupling said oscillator to said alternator, said plunger including a plurality of spatially separated magnets.