US3678686A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Modified stirling cycle engine-compressor having a freely reciprocable displacer piston
Assignee: United States Atomic Energy Commission
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Filing: 1970-02-20
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Granted: 1972-07-25
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Expires: 1990-02-20
Abstract
Abstract A modified Stirling cycle engine operable as a compressor and having its displacer piston directly connected to a reversing piston to which high and low pressures are alternately applied at opposite ends for reciprocably driving the pistons. In one embodiment, the reversing piston is mounted in a double acting compression cylinder which acts as an oscillating spring to drive the pistons whereby energy to sustain oscillation of the reversing piston within the compression cylinder is supplied directly from the displacer piston. In another embodiment, the pistons are driven by high and low pressure gases alternately applied from respective reservoirs to opposite sides of the reversing piston through valves operated by the reversing piston. The modified Stirling cycle engine is capable of unattended operation over a period of years in an inaccessible location and therefore, is especially well suited for supplying motive power for an artificial heart pumping system.
Inventors
- 👤 Keith E Buck
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 19:53
CPC Classifications
F; F02; F02G; F02G1/00; F02G1/04; F02G1/043; F02G1/0435; F02G2244/00; F02G2244/50
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
501 words
A Stirling cycle engine for compressing a working gas from a low pressure to a high pressure, and having a hot zone and a cold zone, said Stirling cycle engine comprising: a displacer cylinder having opposite end portions respectively disposed in the hot and cold zones, a source of thermal energy operably associated with the end portion of said displacer cylinder disposed in the hot zone for heating the working gas in the hot zone, a regenerator having opposite ends respectively extending into the opposite end portions of said displacer cylinder within the hot and cold zones, a displacer piston mounted for reciprocation in said displacer cylinder to transfer the working gas between said zones through said regenerator, a reversing piston, a connecting rod extending between said displacer piston and said reversing piston and having its opposite ends respectively secured thereto, means for alternately applying forces at the opposite ends of said reversing piston to effect reciprocation of said reversing piston and said displacer piston, respective high and low pressure reservoirs of working gas maintained at said high and low pressures, means separately connecting each of said high and low pressure reservoirs to said displacer cylinder at the end portion thereof disposed in the cold zone, a first valve means in said means connecting said high pressure reservoir to said displacer cylinder, a second valve means in said means connecting said low pressure reservoir to said displacer cylinder, said displacer piston being positioned in the end portion of said displacer cylinder disposed in the hot zone at the beginning of its stroke and said first and second valve means being closed to prevent communication between the end portion of said displacer cylinder disposed in the cold zone and said high and low pressure reservoirs respectively, said first valve means opening in response to the movement of said displacer piston toward the end portion of said displacer cylinder disposed in the cold zone increasing the pressure of the working gas in said displacer cylinder to a magnitude at least equal to the pressure of the working gas in the high pressure reservoir for admitting working gas into the high pressure reservoir from said displacer cylinder until the end of the displacer piston stroke, said displacer piston in its return stroke moving toward the end portion of said displacer cylinder disposed in the hot zone so as to decrease the pressure of the working gas in said displacer cylinder closing said first valve means, and said second valve means opening in response to the continued movement of said displacer piston in its return stroke decreasing the pressure of the working gas in said displacer cylinder to a magnitude no greater than the pressure of the working gas in the low pressure reservoir for drawing working gas from said low pressure reservoir into said displacer cylinder, whereby the working gas is pumped from said low pressure reservoir to said high pressure reservoir which serves as a source of high pressure gas for doing work.
Claim 2
Dependent Claim
501 words
A Stirling cycle engine for compressing a working gas from a low pressure to a high pressure, and having a hot zone and a cold zone, said Stirling cycle engine comprising: a displacer cylinder having opposite end portions respectively disposed in the hot and cold zones, a source of thermal energy operably associated with the end portion of said displacer cylinder disposed in the hot zone for heating the working gas in the hot zone, a regenerator having opposite ends respectively extending into the opposite end portions of said displacer cylinder within the hot and cold zones, a displacer piston mounted for reciprocation in said displacer cylinder to transfer the working gas between said zones through said regenerator, a reversing piston, a connecting rod extending between said displacer piston and said reversing piston and having its opposite ends respectively secured thereto, means for alternately applying forces at the opposite ends of said reversing piston to effect reciprocation of said reversing piston and said displacer piston, respective high and low pressure reservoirs of working gas maintained at said high and low pressures, means separately connecting each of said high and low pressure reservoirs to said displacer cylinder at the end portion thereof disposed in the cold zone, a first valve means in said means connecting said high pressure reservoir to said displacer cylinder, a second valve means in said means connecting said low pressure reservoir to said displacer cylinder, said displacer piston being positioned in the end portion of said displacer cylinder disposed in the hot zone at the beginning of its stroke and said first and second valve means being closed to prevent communication between the end portion of said displacer cylinder disposed in the cold zone and said high and low pressure reservoirs respectively, said first valve means opening in response to the movement of said displacer piston toward the end portion of said displacer cylinder disposed in the cold zone increasing the pressure of the working gas in said displacer cylinder to a magnitude at least equal to the pressure of the working gas in the high pressure reservoir for admitting working gas into the high pressure reservoir from said displacer cylinder until the end of the displacer piston stroke, said displacer piston in its return stroke moving toward the end portion of said displacer cylinder disposed in the hot zone so as to decrease the pressure of the working gas in said displacer cylinder closing said first valve means, and said second valve means opening in response to the continued movement of said displacer piston in its return stroke decreasing the pressure of the working gas in said displacer cylinder to a magnitude no greater than the pressure of the working gas in the low pressure reservoir for drawing working gas from said low pressure reservoir into said displacer cylinder, whereby the working gas is pumped from said low pressure reservoir to said high pressure reservoir which serves as a source of high pressure gas for doing work.
Claim 3
Dependent Claim
265 words
In a Stirling cycle engine, for compressing a working gas from a low pressure to a high pressure, and having a hot zone and a cold zone, the combination of: a regenerator having ends that extend into said hot and cold zones; a displacer cylinder having first and second ends extending respectively into said hot and said cold zones; a displacer piston mounted for reciprocation in said cylinder to transfer said working gas between said zones through said regenerator; energy transfer means including a reversing piston, a connecting rod having first and second ends, said first End being integral with said displacer piston and said second end being integral with said reversing piston; reversing means including means for applying high and low pressure gas masses alternately at opposite ends of said reversing piston, for reciprocation of said reversing piston and said displacer piston, high and low pressure reservoirs of said working gas maintained respectively at said high and low pressures, and wherein said reversing means includes a reversing cylinder in which said reversing piston is mounted for reciprocation, said cylinder having first and second closed ends, said reversing piston having first and second inlet passage means for alternately connecting said high pressure reservoir to said first and second closed ends of said cylinder, said reversing piston having first and second outlet passage means for alternately connecting said first and second closed ends of said cylinder to said low pressure reservoir, the connections of said high pressure reservoir to said closed ends being opposite to the connections of said low pressure reservoir to said closed ends.
Claim 4
Dependent Claim
265 words
In a Stirling cycle engine, for compressing a working gas from a low pressure to a high pressure, and having a hot zone and a cold zone, the combination of: a regenerator having ends that extend into said hot and cold zones; a displacer cylinder having first and second ends extending respectively into said hot and said cold zones; a displacer piston mounted for reciprocation in said cylinder to transfer said working gas between said zones through said regenerator; energy transfer means including a reversing piston, a connecting rod having first and second ends, said first End being integral with said displacer piston and said second end being integral with said reversing piston; reversing means including means for applying high and low pressure gas masses alternately at opposite ends of said reversing piston, for reciprocation of said reversing piston and said displacer piston, high and low pressure reservoirs of said working gas maintained respectively at said high and low pressures, and wherein said reversing means includes a reversing cylinder in which said reversing piston is mounted for reciprocation, said cylinder having first and second closed ends, said reversing piston having first and second inlet passage means for alternately connecting said high pressure reservoir to said first and second closed ends of said cylinder, said reversing piston having first and second outlet passage means for alternately connecting said first and second closed ends of said cylinder to said low pressure reservoir, the connections of said high pressure reservoir to said closed ends being opposite to the connections of said low pressure reservoir to said closed ends.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-07-25 | 1976-01-24 | 1976-07-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-25 | 1980-01-24 | 1980-07-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-25 | 1984-01-24 | 1984-07-25 | $7700.00 | Window Closed / Lapsed |