US4403478A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Expander stroke delay mechanism for split stirling cryogenic cooler
Assignee: United States Department of the Navy
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Filing: 1982-03-26
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Granted: 1983-09-13
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Expires: 2002-03-26
Abstract
Abstract This invention comprises a cryogenic cooling device operating in the mannerf a split Stirling cycle engine whereby a sinusoidal pressure-wave generator distal to a regenerator displacer piston and accompanying cylinder, individually compresses in a delayed manner and expands a contained volume of gas in an expander housing respective to regenerator displacer piston travel to bring about a cooling effect in an attached displacer housing.
Inventors
- 👤 Roland W. Robbins
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 18:01
CPC Classifications
F; F25; F25B; F25B9/00; F25B9/14; F25B2309/00; F25B2309/003
Claims Analysis
Total Claims: 39
Claim 1
Independent Claim
174 words
A split Stirling cycle engine refrigerating device, comprising: an expander housing having a first second, and third compartment, each retaining a contained volume of gas, a gas inlet to vary the pressure on said first compartment, and an elongated displacer housing extending from said first compartment for gas expansion and contraction as gas pressure varies therein; an elongated regenerator displacer piston slidably situated within said displacer housing, extending into said expander housing for reciprocating movement therein; a first seal between said expander housing and said displacer to seal gas within said housing while said regenerator displacer piston reciprocates therein; a second seal within said expander housing to separate said first compartment from said second compartment; a plunger attached to said elongated regenerator displacer piston, extending through said second seal to reciprocate therethrough as gas pressure varies in said first compartment; and a cylindrical extension of said second seal, surrounding said plunger to separate said third compartment from said second compartment, having an orifice through the wall thereof to connect said second and third compartments.
Claim 2
Dependent Claim
174 words
A split Stirling cycle engine refrigerating device, comprising: an expander housing having a first second, and third compartment, each retaining a contained volume of gas, a gas inlet to vary the pressure on said first compartment, and an elongated displacer housing extending from said first compartment for gas expansion and contraction as gas pressure varies therein; an elongated regenerator displacer piston slidably situated within said displacer housing, extending into said expander housing for reciprocating movement therein; a first seal between said expander housing and said displacer to seal gas within said housing while said regenerator displacer piston reciprocates therein; a second seal within said expander housing to separate said first compartment from said second compartment; a plunger attached to said elongated regenerator displacer piston, extending through said second seal to reciprocate therethrough as gas pressure varies in said first compartment; and a cylindrical extension of said second seal, surrounding said plunger to separate said third compartment from said second compartment, having an orifice through the wall thereof to connect said second and third compartments.
Claim 3
Dependent Claim
21 words
A split Stirling cycle engine according to claim 1, wherein said expanner housing and said displacer housing are cylindrical in form.
Claim 4
Dependent Claim
22 words
A split Stirling cycle engine according to claim 1, wherein said displacer housing is somewhat smaller in diameter than said expander housing.
Claim 5
Dependent Claim
49 words
A split Stirling cycle engine according to claim 1, wherein said expander housing is made of a material of substantial strength for long life and capable of holding a compressed gas at high pressure while concomitantly having a high coefficient of heat conduction for rapid conduction of heat therethrough.
Claim 6
Dependent Claim
18 words
A split Stirling cycle engine according to claim 4 wherein said expander housing material is machined stainless steel.
Claim 7
Dependent Claim
33 words
A split Stirling cycle engine according to claim 1, wherein said varying gas pressure varies sinusoidally in time and at approximately 90° phase difference with said reciprocating displacement of said regenerator displacer piston.
Claim 8
Dependent Claim
29 words
A split Stirling cycle engine according to claim 1, wherein the cylinder wall of said elongated displacer housing is thin relative to the cylinder wall of said expander housing.
Claim 9
Dependent Claim
28 words
A split Stirling cycle engine according to claim 7, wherein said displacer housing is made of a material of relatively low thermal conductivity for low heat conduction therethrough.
Claim 10
Dependent Claim
19 words
A split Stirling cycle engine according to claim 8, wherein said displacer housing is made of a nickel alloy.
Claim 11
Dependent Claim
29 words
A split Stirling cycle engine accoridng to claim 1, wherein said elongated displacer housing is sealed, at the end distal to said expander housing, with a probe extension therefrom.
Claim 12
Dependent Claim
39 words
A split Stirling cycle engine according to claim 10, wherein said probe is a hollow cylinder in form, having a diameter of somewhat smaller dimension than said displacer housing, and having an open end distal to said displacer housing.
Claim 13
Dependent Claim
27 words
A split Stirling cycle engine according to claim 11 wherein said probe is made of a material of relatively high thermal conductivity for rapid heat conduction therethrough.
Claim 14
Dependent Claim
14 words
A split Stirling cycle engine according to claim 12 wherein said material is copper.
Claim 15
Dependent Claim
24 words
A split Stirling cycle engine according to claim 10 wherein said sealant is a bronze ring between said probe extension and said displacer housing.
Claim 16
Dependent Claim
34 words
A split Stirling cycle engine according to claim 1, wherein said elongated regenerator displacer piston is a hollow cylinder made of a strong material of relatively low thermal conductivity for limited heat conduction therethrough.
Claim 17
Dependent Claim
17 words
A split Stirling cycle engine according to claim 15, wherein said material is fiber glass reinforced epoxy.
Claim 18
Dependent Claim
20 words
A split Stirling cycle engine according to claim 15, wherein said hollow cylinder is filled with a gas permeable substance.
Claim 19
Dependent Claim
20 words
A split Stirling cycle engine according to claim 17, wherein said gas permeable substance comprises a plurality of nickel balls.
Claim 20
Dependent Claim
27 words
A split Stirling cycle engine according to claim 1, wherein said elongated regenerator displacer piston is sealed at said probe end by a first gas porous plug.
Claim 21
Dependent Claim
28 words
A split Stirling cycle engine according to claim 1, wherein said elongated regenerator displacer piston is sealed at said expander housing end by a second gas porous plug.
Claim 22
Dependent Claim
28 words
A split Stirling cycle engine according to claims 19 and 20, wherein said plugs are made of a material of relatively high thermal conductivity for rapid heat conduction.
Claim 23
Dependent Claim
15 words
A split Stirling cycle engine according to claim 21, wherein said material comprises sintered bronze.
Claim 24
Dependent Claim
26 words
A split Stirling cycle engine according to claim 1, wherein said elongated regenerator displacer piston is capped at said expander housing end by a hard material.
Claim 25
Dependent Claim
14 words
A split Stirling cycle engine according to claim 23, wherein said material is ceramic.
Claim 26
Dependent Claim
29 words
A split Stirling cycle engine according to claim 1, wherein said first seal is cylindrical in form slidably surrounding said displacer cap and forming a sliding gas tight seal.
Claim 27
Dependent Claim
39 words
A split Stirling cycle engine according to claim 25 wherein said first seal is made of a strong, durable material having a relatively high thermal conductivity creating a sliding metal-to-metal seal between said expander housing and said displacer cap.
Claim 28
Dependent Claim
16 words
A split Stirling cycle engine according to claim 26, wherein said material is hardened stainless steel.
Claim 29
Dependent Claim
19 words
A split Stirling cycle engine according to claim 1, wherein said first seal is sealed to said expander housing.
Claim 30
Dependent Claim
25 words
A split Stirling cycle engine according to claim 28, wherein said seal comprises a ring of Indium between said first seal and said expander housing.
Claim 31
Dependent Claim
37 words
A split Stirling cycle engine according to claim 1, wherein said second seal is cylindrical in form having a circular flange extending from said cylinder outer surface to intersect the inner cylinder wall of said expander housing.
Claim 32
Dependent Claim
31 words
A split Stirling cycle engine according to claim 30, wherein said second seal cylinder is made of a strong, durable material having a relatively high thermal conductivity for rapid heat conduction.
Claim 33
Dependent Claim
16 words
A split Stirling cycle enging according to claim 31, wherein said material is hardened stainless steel.
Claim 34
Dependent Claim
18 words
A split Stirling cycle engine according to claim 30, wherein said flange is sealed to said expander housing.
Claim 35
Dependent Claim
24 words
A split Stirling cycle engine according to claim 33, wherein said bond comprises a circular copper ring between said flange and said expander housing.
Claim 36
Dependent Claim
34 words
A split Stirling cycle engine according to claim 30, wherein said cylindrical seal has an orifice of small dimension through the wall thereof for regulated flow of gas from compartment three to compartment two.
Claim 37
Dependent Claim
18 words
A split Stirling cycle engine according to claim 1, wherein said plunger is a solid cylinder in form.
Claim 38
Dependent Claim
28 words
A split Stirling cycle engine according to claim 36, wherein said plunger is made of a hard material having the ability to be highly polished and abrasion resistant.
Claim 39
Dependent Claim
31 words
A split Stirling cycle engine according to claim 37, wherein said material comprises hardened stainless steel, to create a sliding, gas tight, metal-to-metal seal between said plunger and said second seal.
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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) | 1986-09-12 | 1987-03-14 | 1987-09-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-09-12 | 1991-03-14 | 1991-09-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-09-12 | 1995-03-14 | 1995-09-13 | $7700.00 | Window Closed / Lapsed |