DOE Patents title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Free-piston engine

Abstract

A combustion system which can utilize high compression ratios, short burn durations, and homogeneous fuel/air mixtures in conjunction with low equivalence ratios. In particular, a free-piston, two-stroke autoignition internal combustion engine including an electrical generator having a linear alternator with a double-ended free piston that oscillates inside a closed cylinder is provided. Fuel and air are introduced in a two-stroke cycle fashion on each end, where the cylinder charge is compressed to the point of autoignition without spark plugs. The piston is driven in an oscillating motion as combustion occurs successively on each end. This leads to rapid combustion at almost constant volume for any fuel/air equivalence ratio mixture at very high compression ratios. The engine is characterized by high thermal efficiency and low NO.sub.x emissions. The engine is particularly suited for generating electrical current in a hybrid automobile.

Inventors:
 [1]
  1. Truckee, CA
Issue Date:
Research Org.:
Sandia National Laboratories (SNL), Albuquerque, NM, and Livermore, CA (United States)
OSTI Identifier:
873595
Patent Number(s):
6199519
Assignee:
Sandia Corporation (Alburquerque, NM)
Patent Classifications (CPCs):
B - PERFORMING OPERATIONS B60 - VEHICLES IN GENERAL B60L - PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES
F - MECHANICAL ENGINEERING F02 - COMBUSTION ENGINES F02B - INTERNAL-COMBUSTION PISTON ENGINES
DOE Contract Number:  
AC04-94AL85000
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
free-piston; engine; combustion; utilize; compression; ratios; burn; durations; homogeneous; fuel; air; mixtures; conjunction; equivalence; particular; two-stroke; autoignition; internal; including; electrical; generator; linear; alternator; double-ended; free; piston; oscillates; inside; closed; cylinder; provided; introduced; cycle; fashion; charge; compressed; spark; plugs; driven; oscillating; motion; occurs; successively; leads; rapid; constant; volume; ratio; mixture; characterized; thermal; efficiency; emissions; particularly; suited; generating; current; hybrid; automobile; thermal efficiency; generating electric; spark plug; electrical generator; equivalence ratio; particularly suited; internal combustion; electrical current; combustion engine; air mixture; free piston; compression ratio; combustion occurs; generating electrical; compression ratios; engine including; linear alternator; air mixtures; /123/

Citation Formats

Van Blarigan, Peter. Free-piston engine. United States: N. p., 2001. Web.
Van Blarigan, Peter. Free-piston engine. United States.
Van Blarigan, Peter. Mon . "Free-piston engine". United States. https://www.osti.gov/servlets/purl/873595.
@article{osti_873595,
title = {Free-piston engine},
author = {Van Blarigan, Peter},
abstractNote = {A combustion system which can utilize high compression ratios, short burn durations, and homogeneous fuel/air mixtures in conjunction with low equivalence ratios. In particular, a free-piston, two-stroke autoignition internal combustion engine including an electrical generator having a linear alternator with a double-ended free piston that oscillates inside a closed cylinder is provided. Fuel and air are introduced in a two-stroke cycle fashion on each end, where the cylinder charge is compressed to the point of autoignition without spark plugs. The piston is driven in an oscillating motion as combustion occurs successively on each end. This leads to rapid combustion at almost constant volume for any fuel/air equivalence ratio mixture at very high compression ratios. The engine is characterized by high thermal efficiency and low NO.sub.x emissions. The engine is particularly suited for generating electrical current in a hybrid automobile.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Mon Jan 01 00:00:00 EST 2001},
month = {Mon Jan 01 00:00:00 EST 2001}
}