Patent US1286037A successfully refreshed from Google Patents.
Patent US5158828A successfully refreshed from Google Patents.
US4418533A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Free-piston stirling engine inertial cancellation system
Assignee: Soluna Holdings Inc
•
Filing: 1980-07-14
•
Granted: 1983-12-06
•
Expires: 2000-07-14
Abstract
Abstract A free piston Stirling engine inertial cancellation system includes a displacer reciprocating in a hermetic vessel enclosing a working space to circulate working gas through a heater, regenerator, and cooler to create a pressure wave in the working space. A power piston, mechanically unconnected to the displacer, is reciprocally driven by the pressure wave to produce a power output stroke in one direction and a working gas compression stroke in the other direction. The displacer and the power piston form substantially a first mass in the working space. A second mass, outside the working space and preferably including an alternator plunger, is mounted in the vessel and is coupled to the first mass momentum exchange relationship. Spring means and tuning means cause the second mass to reciprocate out-of-phase with the displacer and the power piston so that the phase of the moving masses produces inertia phasors which substantially cancel and so that little or no inertia of the reciprocating masses is transmitted through the vessel to the mounting structure of the engine.
Inventors
- 👤 Lawrence R. Folsom
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 01:32
CPC Classifications
F; F02; F02G; F02G1/00; F02G1/04; F02G1/043; F02G1/0435; F02G2244/00; F02G2244/50; F02G2258/00; F02G2258/10
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
198 words
A free-piston Stirling engine including a hermetically sealable vessel enclosing a working space containing a working gas and having a first end of said working space heated by a heater for heating the working gas and having a second end of said working space cooled by a cooler for cooling the working gas; said vessel also containing a displacer having a mass for shuttling the working gas between said ends through said heater, a regenerator, and said cooler to produce a periodic pressure wave in said working gas; a power piston having a mass driven in axial oscillation in said vessel to produce output power; said displacer mass and said power piston mass forming substantially a first mass in said working space; wherein the improvement comprises: a second mass in said vessel and outside said working space; means for coupling said second mass in momentum exchange relationship with respect to said first mass; and means for causing oscillation of said second mass in phase opposition to said first mass, whereby the shaking forces exerted by said first mass are cancelled by movement of said second mass, and the shaking forces exerted through said vessel to ground are minimized.
Claim 2
Dependent Claim
198 words
A free-piston Stirling engine including a hermetically sealable vessel enclosing a working space containing a working gas and having a first end of said working space heated by a heater for heating the working gas and having a second end of said working space cooled by a cooler for cooling the working gas; said vessel also containing a displacer having a mass for shuttling the working gas between said ends through said heater, a regenerator, and said cooler to produce a periodic pressure wave in said working gas; a power piston having a mass driven in axial oscillation in said vessel to produce output power; said displacer mass and said power piston mass forming substantially a first mass in said working space; wherein the improvement comprises: a second mass in said vessel and outside said working space; means for coupling said second mass in momentum exchange relationship with respect to said first mass; and means for causing oscillation of said second mass in phase opposition to said first mass, whereby the shaking forces exerted by said first mass are cancelled by movement of said second mass, and the shaking forces exerted through said vessel to ground are minimized.
Claim 3
Dependent Claim
48 words
The engine defined in claim 1, wherein said means for coupling said second mass in momentum exchange relationship with respect to said first mass further comprises: a first spring coupling said first means and said second mass; and a second spring coupling said second mass to said vessel.
Claim 4
Dependent Claim
51 words
The engine defined in claim 2, further comprising: tuning means operatively associated with at least one of said first and second springs wherein said first spring, said second spring and said tuning means substantially form said means for causing oscillation of said second mass in phase opposition to said first mass.
Claim 5
Dependent Claim
57 words
The engine defined in claim 3, wherein said tuning means further comprises means for adjusting the spring constant of at least one of said first and said second springs in response to changing power demands on said first mass and said second mass to maintain said phase opposition of said first mass and said second mass oscillation.
Claim 6
Dependent Claim
57 words
The engine defined in claim 4, further comprising a first variable load associated with said first mass and a second variable load associated with said second mass, wherein the changing power demand on said first means results from said first variable load and the changing power demand on said second mass results from said second variable load.
Claim 7
Dependent Claim
112 words
The engine defined in claim 2, wherein said springs include gas springs, and further comprising: a gas compressor connected to said power piston, and a linear alternator armature comprising a portion of said second mass; a linear alternator stator fastened to said vessel and having an axial bore receiving said armature, said stator and said armature defining therebetween a radial gap; a dielectric coating on at least one of said stator bore and said armature completely filling the radial extent of said gap over a portion of the axial length of said gap to support said aramture radially in said bore and to seal said gap against axial passage of gas therethrough.
Claim 8
Dependent Claim
31 words
The engine defined in claim 3, wherein said second mass includes a linear alternator armature and said vessel also contains a linear alternator stator disposed in concentric relationship to said armature.
Claim 9
Dependent Claim
56 words
The engine defined in claim 7, wherein said tuning means further comprises means for adjusting the spring constant of at least one of said first and said second springs in response to changing power demands on said power piston and said alternator to maintain said phase opposition of said power piston and said alternator armature oscillation.
Claim 10
Dependent Claim
197 words
A Stirling engine having two variable volume chambers defined by a vessel and a displacer movable in said vessel to shuttle a working gas between said chambers; a heater, a cooler and a regenerator for creating cyclic changes in the gas temperature and pressure to produce a pressure wave in the working gas; a power piston, and a linear alternator having an armature driven in reciprocating linear oscillation opposite a stator by said pressure wave; wherein the improvement comprises vibrations cancellation means including: a first gas spring coupled between said alternator armature and said power piston; a second gas spring coupled between said alternator armature and said vessel, said armature being driven in the drive direction exclusively by said power piston through said first gas spring, and being returned in the opposite direction by said second gas spring; means for adjusting the dynamics of the spring-mass system formed by said piston, said alternator and said gas springs to cause said alternator armature to lag said power piston and said displacer motion by an angle sufficient to substantially cancel the inertial forces exerted by said displacer, said power piston, and said alternator armature through said vessel to ground.
Claim 11
Dependent Claim
197 words
A Stirling engine having two variable volume chambers defined by a vessel and a displacer movable in said vessel to shuttle a working gas between said chambers; a heater, a cooler and a regenerator for creating cyclic changes in the gas temperature and pressure to produce a pressure wave in the working gas; a power piston, and a linear alternator having an armature driven in reciprocating linear oscillation opposite a stator by said pressure wave; wherein the improvement comprises vibrations cancellation means including: a first gas spring coupled between said alternator armature and said power piston; a second gas spring coupled between said alternator armature and said vessel, said armature being driven in the drive direction exclusively by said power piston through said first gas spring, and being returned in the opposite direction by said second gas spring; means for adjusting the dynamics of the spring-mass system formed by said piston, said alternator and said gas springs to cause said alternator armature to lag said power piston and said displacer motion by an angle sufficient to substantially cancel the inertial forces exerted by said displacer, said power piston, and said alternator armature through said vessel to ground.
Claim 12
Dependent Claim
55 words
The engine defined in claim 9, further comprising a sliding gas seal between said gas springs, said seal including an insulating, low-friction coating on at least one of said armature and said stator facing surfaces which substantially fills the gap between said surfaces, said coating also centering and radially supporting said armature in said stator.
References Cited (Backward Citations)
US2157229A
Cited
US2127286A
Cited
US2545861A
Cited
US2611236A
Cited
US2992536A
Cited
US3339077A
Cited
FR1407682A
Cited
US3400281A
Cited
US3296808A
Cited
US3487635A
Cited
US3434162A
Cited
USRE30176E
Cited
US3559398A
Cited
US3525215A
Cited
US3548589A
Cited
US3478695A
Cited
US3597766A
Cited
US3563028A
Cited
US3530681A
Cited
US3604821A
Cited
US3583155A
Cited
US3678686A
Cited
US3645649A
Cited
US3608311A
Cited
US3733837A
Cited
US3807904A
Cited
USRE27567E
Cited
USRE29518E
Cited
US3782859A
Cited
US3805527A
Cited
US3899888A
Cited
US3827675A
Cited
US3767325A
Cited
US3949554A
Cited
US3894911A
Cited
US3822388A
Cited
US3828558A
Cited
US3902328A
Cited
US3937018A
Cited
US3928974A
Cited
US4044558A
Cited
US3906739A
Cited
GB1539034A
Cited
US4012910A
Cited
US4072010A
Cited
US4077216A
Cited
US3991586A
Cited
US4058382A
Cited
US4036018A
Cited
US4132505A
Cited
US4183214A
Cited
US4148195A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-12-05 | 1987-06-06 | 1987-12-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-12-05 | 1991-06-06 | 1991-12-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-12-05 | 1995-06-06 | 1995-12-06 | $7700.00 | Window Closed / Lapsed |