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Title: Drift stabilizer for reciprocating free-piston devices

Abstract

A free-piston device has a stabilized piston drift. A piston having a frequency of reciprocation over a stroke length and with first and second sides facing first and second variable volumes, respectively, for containing a working fluid defining an acoustic wavelength at the frequency of reciprocation. A bypass tube waveguide connects the first and second variable volumes at all times during reciprocation of the piston. The waveguide has a relatively low impedance for steady flow and a relatively high impedance for oscillating flow at the frequency of reciprocation of the piston, so that steady flow returns fluid leakage from about the piston between the first and second volumes while oscillating flow is not diverted through the waveguide. Thus, net leakage about the piston is returned during each stroke of the piston while oscillating leakage is not allowed and pressure buildup on either the first or second side of the piston is avoided to provide a stable piston location.

Inventors:
; ;
Issue Date:
Research Org.:
The Regents of University of California, Los Alamos, NM (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1174331
Patent Number(s):
6564552
Application Number:
09/844,177
Assignee:
The Regents of the University of California (Los Alamos, NM)
Patent Classifications (CPCs):
F - MECHANICAL ENGINEERING F01 - MACHINES OR ENGINES IN GENERAL F01B - MACHINES OR ENGINES, IN GENERAL OR OF POSITIVE-DISPLACEMENT TYPE, e.g. STEAM ENGINES
F - MECHANICAL ENGINEERING F02 - COMBUSTION ENGINES F02G - HOT GAS OR COMBUSTION-PRODUCT POSITIVE-DISPLACEMENT ENGINE PLANTS
DOE Contract Number:  
W-7405-ENG-36
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
42 ENGINEERING

Citation Formats

Ward, William C., Corey, John A., and Swift, Gregory W. Drift stabilizer for reciprocating free-piston devices. United States: N. p., 2003. Web.
Ward, William C., Corey, John A., & Swift, Gregory W. Drift stabilizer for reciprocating free-piston devices. United States.
Ward, William C., Corey, John A., and Swift, Gregory W. Tue . "Drift stabilizer for reciprocating free-piston devices". United States. https://www.osti.gov/servlets/purl/1174331.
@article{osti_1174331,
title = {Drift stabilizer for reciprocating free-piston devices},
author = {Ward, William C. and Corey, John A. and Swift, Gregory W.},
abstractNote = {A free-piston device has a stabilized piston drift. A piston having a frequency of reciprocation over a stroke length and with first and second sides facing first and second variable volumes, respectively, for containing a working fluid defining an acoustic wavelength at the frequency of reciprocation. A bypass tube waveguide connects the first and second variable volumes at all times during reciprocation of the piston. The waveguide has a relatively low impedance for steady flow and a relatively high impedance for oscillating flow at the frequency of reciprocation of the piston, so that steady flow returns fluid leakage from about the piston between the first and second volumes while oscillating flow is not diverted through the waveguide. Thus, net leakage about the piston is returned during each stroke of the piston while oscillating leakage is not allowed and pressure buildup on either the first or second side of the piston is avoided to provide a stable piston location.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Tue May 20 00:00:00 EDT 2003},
month = {Tue May 20 00:00:00 EDT 2003}
}