US4413475A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thermodynamic working fluids for Stirling-cycle, reciprocating thermal machines
Assignee: SILENTPOWER TECHNOLOGIES Corp A DELAWARE CORPORATION
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Filing: 1982-05-14
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Granted: 1983-11-08
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Expires: 2002-05-14
Abstract
Abstract New thermodynamic working fluids with primary application to Stirling-cycle, reciprocating, thermal machines are disclosed which possess a greater dynamic heat transfer coefficient than either hydrogen or helium and which are both chemically inert and easily liquefied. A novel power level control subsystem based on the thermophysical properties of these fluids is disclosed for use in conjunction with Stirling-cycle machines; this new approach greatly simplifies procedures for changing the mean system working pressure, and thereby the instantaneous power level in such machines, during their operation.
Inventors
- 👤 William M. Moscrip
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 22:26
CPC Classifications
F; F02; F02G; F02G1/00; F02G1/04; F02G1/043; F02G1/044; F02G1/0435; F02G2244/00; F02G2244/02; F02G2244/06; F02G2244/12
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
117 words
A Stirling-cycle, reciprocating, thermal machine in which the internal working fluid is a gas that has a molecular weight substantially greater than that of air, is non-toxic, nonflammable, chemically and thermally stable, with a heat transfer coefficient substantially greater than that of hydrogen at machine operating temperatures and pressures and can be easily liquefied under pressure at room temperature, and comprising a control system including means for varying the main system mean operating pressure by rapid injection of working fluid from a reservoir into the working volume as a liquid to increase that pressure and by withdrawal of working fluid as a gas from that working volume and its condensation in the reservoir to reduce that pressure.
Claim 2
Dependent Claim
117 words
A Stirling-cycle, reciprocating, thermal machine in which the internal working fluid is a gas that has a molecular weight substantially greater than that of air, is non-toxic, nonflammable, chemically and thermally stable, with a heat transfer coefficient substantially greater than that of hydrogen at machine operating temperatures and pressures and can be easily liquefied under pressure at room temperature, and comprising a control system including means for varying the main system mean operating pressure by rapid injection of working fluid from a reservoir into the working volume as a liquid to increase that pressure and by withdrawal of working fluid as a gas from that working volume and its condensation in the reservoir to reduce that pressure.
Claim 3
Dependent Claim
31 words
A machine according to claim 1 in which the reservoir is maintained at a temperature below, and the working volume at a temperature above, the critical temperature of the working fluid.
Claim 4
Dependent Claim
37 words
A machine according to claim 2 in which the reservoir comprises a cylinder space and a free piston slidable in said space having condensed working fluid on one side and hydraulic control fluid on the other side.
Claim 5
Dependent Claim
31 words
A machine according to claim 3 which comprises means to augument or diminish the volume of hydraulic fluid in the cylinder in response to changes in the setting of an accelerator.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-11-07 | 1987-05-09 | 1987-11-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-11-07 | 1991-05-09 | 1991-11-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-11-07 | 1995-05-09 | 1995-11-08 | $7700.00 | Window Closed / Lapsed |