Patent US5146124A successfully refreshed from Google Patents.
US5146124A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Linear drive motor with flexible coupling
Assignee: Azenta Inc
•
Filing: 1991-03-29
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Granted: 1992-09-08
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Expires: 2011-03-29
Abstract
Abstract A linear drive motor of a cryogenic refrigerator, where a reciprocating armature is coupled to a piston which alternately compresses and expands a gaseous fluid in a thermodynamic cycle. The piston has a clearance seal and is attached at one end to a flexible coupling to reduce cross-bearing loads exerted by the piston along the clearance seal. A displacer assembly of the cryogenic refrigerator employs a displacer piston that reciprocates along a clearance seal. The displacer piston is coupled to the displacer cylinder and/or the armature of a displacer drive motor by a flexible coupling that reduces radial forces exerted by the displacer piston on the clearance seal.
Inventors
- 👤 Graham Higham
- 👤 Niels Young
- 👤 Alan Weeks
- 👤 Steven A. Michaud
- 👤 William Sand
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 18:54
CPC Classifications
F; F25; F25B; F25B9/00; F25B9/14; F16; F16F; F16F7/00; F16F7/10; F16F7/104; F16F7/116; H; H02; H02K; H02K33/00; H02K33/02; H02K33/04; H02K33/06; H02K33/12; F25B2309/00; F25B2309/001; Y; Y10; Y10S; Y10S417/00; Y10S417/901
Claims Analysis
Total Claims: 43
Claim 1
Independent Claim
150 words
A cryogenic refrigerator comprising a gaseous working fluid which is alternately compressed and expanded to cool a portion of the working fluid to cryogenic temperatures, the refrigerator having a linear drive motor comprising: a housing that seals the working fluid within a volume; a piston positioned within the housing along a longitudinal axis thereof, the piston having a clearance seal with, and having a linear reciprocating motion relative to, a clearance seal element; a flexible piston coupling secured at one end to the piston such that the piston coupling can undergo universal radial displacement relative to the longitudinal axis to maintain alignment of the piston with the clearance seal; a magnetic armature secured to a second end of the piston coupling; the armature extending concentrically about the coupling, the piston, and the clearance seal element; and a coil assembly concentric about the armature to drive the armature and the piston.
Claim 2
Dependent Claim
150 words
A cryogenic refrigerator comprising a gaseous working fluid which is alternately compressed and expanded to cool a portion of the working fluid to cryogenic temperatures, the refrigerator having a linear drive motor comprising: a housing that seals the working fluid within a volume; a piston positioned within the housing along a longitudinal axis thereof, the piston having a clearance seal with, and having a linear reciprocating motion relative to, a clearance seal element; a flexible piston coupling secured at one end to the piston such that the piston coupling can undergo universal radial displacement relative to the longitudinal axis to maintain alignment of the piston with the clearance seal; a magnetic armature secured to a second end of the piston coupling; the armature extending concentrically about the coupling, the piston, and the clearance seal element; and a coil assembly concentric about the armature to drive the armature and the piston.
Claim 3
Dependent Claim
40 words
The cryogenic refrigerator of claim 1 wherein said clearance seal element comprises a stationary cylinder concentric about the piston, the clearance seal operating to seal a compression space in which the working fluid is compressed and expanded by the piston.
Claim 4
Dependent Claim
34 words
The cryogenic refrigerator of claim 1 wherein the piston comprises a reciprocating cylindrical head about which a sleeve extends, the flexible coupling connecting the head to a magnetic armature for a linear drive motor.
Claim 5
Dependent Claim
21 words
The cryogenic refrigerator of claim 3 wherein the cylindrical head has a larger diameter than the diameter of the flexible coupling.
Claim 6
Dependent Claim
22 words
The cryogenic refrigerator of claim 1 wherein the coupling support assembly comprises a reciprocating displacer within a cold finger of the refrigerator.
Claim 7
Dependent Claim
25 words
The cryogenic refrigerator of claim 1 wherein the coupling support assembly is secured to the housing such that the piston is stationary along the axis.
Claim 8
Dependent Claim
121 words
A dual piston linear drive motor comprising: a first piston and a second piston reciprocating within a cylinder to define a compression space there between in which a fluid is compressed and expanded; a first magnetic armature coupled to the first piston by a first flexible piston coupling and a second magnetic armature coupled to the second piston by a second flexible piston coupling such that each piston coupling bends to reduce radial forces exerted by the first and second pistons on clearance seals located between the cylinder and the first and second pistons; a first coil assembly surrounding the first armature to drive the first armature; and a second coil assembly surrounding the second armature to drive the second armature.
Claim 9
Dependent Claim
121 words
A dual piston linear drive motor comprising: a first piston and a second piston reciprocating within a cylinder to define a compression space there between in which a fluid is compressed and expanded; a first magnetic armature coupled to the first piston by a first flexible piston coupling and a second magnetic armature coupled to the second piston by a second flexible piston coupling such that each piston coupling bends to reduce radial forces exerted by the first and second pistons on clearance seals located between the cylinder and the first and second pistons; a first coil assembly surrounding the first armature to drive the first armature; and a second coil assembly surrounding the second armature to drive the second armature.
Claim 10
Dependent Claim
20 words
The linear drive motor of claim 7 wherein the first and second pistons reciprocate along an axis with opposite phase.
Claim 11
Dependent Claim
18 words
The linear drive motor of claim 7 wherein the motor operates as a compressor for a cryogenic refrigerator.
Claim 12
Dependent Claim
23 words
The linear drive motor of claim 9 wherein the cryogenic refrigerator further comprises a displacer reciprocating within a cold finger of the refrigerator.
Claim 13
Dependent Claim
47 words
The linear drive motor of claim 10 further comprising a displacer piston forming a clearance seal with the clearance seal element, the piston being coupled to the displacer by a flexible displacer piston coupling that permits universal radial displacement of the displacer piston relative to the displacer.
Claim 14
Dependent Claim
45 words
The linear drive motor of claim 10 further comprising a displacer drive motor having a linearly reciprocating armature coupled to the displacer by a radially flexible coupling that permits universal radial displacement of the armature relative to a displacer axis along which the displacer reciprocates.
Claim 15
Dependent Claim
57 words
A cryogenic refrigerator having a gas displacer which reciprocates in a housing to displace gaseous fluid in a working volume through a regenerator, the displacer comprising a displacer piston that is coupled to a displacer cylinder along an axis by a flexible piston coupling that provides for universal radial displacement of the coupling relative to the axis.
Claim 16
Dependent Claim
57 words
A cryogenic refrigerator having a gas displacer which reciprocates in a housing to displace gaseous fluid in a working volume through a regenerator, the displacer comprising a displacer piston that is coupled to a displacer cylinder along an axis by a flexible piston coupling that provides for universal radial displacement of the coupling relative to the axis.
Claim 17
Dependent Claim
38 words
The cryogenic refrigerator of claim 13 further comprising a linear drive motor to drive the displacer, the motor having an armature reciprocating along the axis that is coupled to the displacer piston by a second flexible piston coupling.
Claim 18
Dependent Claim
84 words
The cryogenic refrigerator of claim 13 further comprising a compressor having a linear drive motor, the motor comprising: a compressor piston positioned along an axis of a compressor housing and forming a clearance seal with a clearance seal element; a flexible compressor piston coupling secured to the compressor piston that bends relative to the axis to reduce radial forces exerted by the piston on the clearance seal; and a coupling support that is secured to the compressor piston coupling opposite from the compressor piston.
Claim 19
Dependent Claim
15 words
The cryogenic refrigerator of claim 15 wherein the coupling support is secured to the housing.
Claim 20
Dependent Claim
15 words
The cryogenic refrigerator of claim 15 wherein the coupling support comprises a reciprocating magnetic armature.
Claim 21
Dependent Claim
210 words
A cryogenic refrigerator having a gaseous working fluid which is alternately compressed and expanded to cool a portion of the working fluid to cryogenic temperatures, the refrigerator comprising: a compressor housing that seals the working fluid within a volume; a first piston and a second piston reciprocating within a cylinder to define a compression space there between in which a fluid is compressed and expanded; a first magnetic armature coupled to the first piston by a first flexible piston coupling and a second magnetic armature coupled to the second piston by a second flexible piston coupling such that each piston coupling bends to reduce radial forces exerted by the first and second pistons on clearance seals located between the cylinder and the first and second pistons a first coil assembly surrounding the first armature to drive the first armature; a second coil assembly surrounding the second armature to drive the second armature; a gas displacer within a cold finger of the refrigerator and having a displacer volume in fluid communication with the compressor volume and comprising a displacer piston reciprocating along an axis, the displacer piston being coupled to a displacer by a third flexible piston coupling that provides for universal radial displacement of the coupling relative to the axis.
Claim 22
Dependent Claim
210 words
A cryogenic refrigerator having a gaseous working fluid which is alternately compressed and expanded to cool a portion of the working fluid to cryogenic temperatures, the refrigerator comprising: a compressor housing that seals the working fluid within a volume; a first piston and a second piston reciprocating within a cylinder to define a compression space there between in which a fluid is compressed and expanded; a first magnetic armature coupled to the first piston by a first flexible piston coupling and a second magnetic armature coupled to the second piston by a second flexible piston coupling such that each piston coupling bends to reduce radial forces exerted by the first and second pistons on clearance seals located between the cylinder and the first and second pistons a first coil assembly surrounding the first armature to drive the first armature; a second coil assembly surrounding the second armature to drive the second armature; a gas displacer within a cold finger of the refrigerator and having a displacer volume in fluid communication with the compressor volume and comprising a displacer piston reciprocating along an axis, the displacer piston being coupled to a displacer by a third flexible piston coupling that provides for universal radial displacement of the coupling relative to the axis.
Claim 23
Dependent Claim
20 words
The cryogenic refrigerator of claim 18 further comprising a pneumatic volume in which one end of the displacer piston reciprocates.
Claim 24
Dependent Claim
28 words
The cryogenic refrigerator of claim 18 further comprising a displacer drive motor having a linear reciprocating armature coupled to the displacer piston by a fourth flexible piston coupling.
Claim 25
Dependent Claim
114 words
A gas displacer for a refrigerator in which the gas displacer reciprocates in a housing to displace gas in a working volume of pressurized gas through a regenerator, the gas displacer comprising: a working volume within a housing of the gas displacer through which the pressurized gas flows; a displacer reciprocating within an expander cylinder, the displacer having a regenerative matrix to absorb heat from the gas; and a flexible coupling that is coupled to the displacer at one end, and to a reciprocating element at the opposite end, the flexible coupling reciprocating along a longitudinal axis of the gas displacer and providing for universal radial displacement of the coupling relative to the axis.
Claim 26
Dependent Claim
114 words
A gas displacer for a refrigerator in which the gas displacer reciprocates in a housing to displace gas in a working volume of pressurized gas through a regenerator, the gas displacer comprising: a working volume within a housing of the gas displacer through which the pressurized gas flows; a displacer reciprocating within an expander cylinder, the displacer having a regenerative matrix to absorb heat from the gas; and a flexible coupling that is coupled to the displacer at one end, and to a reciprocating element at the opposite end, the flexible coupling reciprocating along a longitudinal axis of the gas displacer and providing for universal radial displacement of the coupling relative to the axis.
Claim 27
Dependent Claim
14 words
The gas displacer of claim 21 further comprising a compressor for a cryogenic refrigerator.
Claim 28
Dependent Claim
16 words
The gas displacer of claim 21 wherein the refrigerator further comprises a stirling cycle cryogenic refrigerator.
Claim 29
Dependent Claim
32 words
The gas displacer of claim 21 wherein the reciprocating element comprises a displacer piston, the displacer piston having an outer cylindrical surface that forms a clearance seal with a clearance seal element.
Claim 30
Dependent Claim
35 words
The gas displacer of claim 21 wherein the reciprocating element comprises a reciprocating armature of a linear drive motor that surrounds the armature, the drive motor operating to drive the displacer through the flexible coupling.
Claim 31
Dependent Claim
35 words
The gas displacer of claim 25 wherein the flexible coupling is coupled to the displacer through a displacer piston that reciprocates relative to a clearance seal element that forms a clearance seal with the piston.
Claim 32
Dependent Claim
66 words
The gas displacer of claim 21 wherein the reciprocating element comprises a displacer piston, an armature driven by a linear drive motor, and a second flexible coupling secured at one end to the displacer piston and secured at the opposite end to the armature such that the second flexible coupling provides a universal radial displacement of the armature and the piston relative to the longitudinal axis.
Claim 33
Dependent Claim
131 words
A linear drive motor for a cryogenic refrigerator in which a gaseous working fluid is alternately compressed and expanded to cool a portion of the working fluid to cryogenic temperatures, the refrigerator comprising: a housing that seals the working fluid within a volume; a piston positioned within the housing along a longitudinal axis thereof, the piston forming a clearance seal with, and having a linear reciprocating motion relative to, a clearance seal element; a magnetic armature secured to the piston, the armature reciprocating concentrically within a coil assembly that surrounds the housing; and a sleeve support bearing positioned between an outer cylindrical surface of the armature and an inner cylindrical surface of the housing such that the sleeve support bearing supports the armature during its reciprocating movement relative to the housing.
Claim 34
Dependent Claim
131 words
A linear drive motor for a cryogenic refrigerator in which a gaseous working fluid is alternately compressed and expanded to cool a portion of the working fluid to cryogenic temperatures, the refrigerator comprising: a housing that seals the working fluid within a volume; a piston positioned within the housing along a longitudinal axis thereof, the piston forming a clearance seal with, and having a linear reciprocating motion relative to, a clearance seal element; a magnetic armature secured to the piston, the armature reciprocating concentrically within a coil assembly that surrounds the housing; and a sleeve support bearing positioned between an outer cylindrical surface of the armature and an inner cylindrical surface of the housing such that the sleeve support bearing supports the armature during its reciprocating movement relative to the housing.
Claim 35
Dependent Claim
37 words
The linear drive motor of claim 28 further comprising a second piston that defines a compression space with the piston, the second piston being coupled to a second armature that reciprocates within a second sleeve support bearing.
Claim 36
Dependent Claim
20 words
The linear drive motor of claim 28 further comprising a flexible piston coupling that secures the piston to the armature.
Claim 37
Dependent Claim
22 words
The linear drive motor of claim 28 wherein the sleeve support bearing comprises a soft sleeve that is secured to the armature.
Claim 38
Dependent Claim
27 words
The linear drive motor of claim 28 wherein the sleeve support bearing comprises a soft sleeve that is secured to the inner cylindrical surface of the housing.
Claim 39
Dependent Claim
19 words
The linear drive motor of claim 28 wherein the sleeve support bearing comprises a soft sleeve of plastic material.
Claim 40
Dependent Claim
34 words
The linear drive motor of claim 28 wherein the clearance seal comprises a second sleeve support bearing positioned between an outer surface of the piston and an inner surface of the clearance seal element.
Claim 41
Dependent Claim
27 words
The linear drive motor of claim 34 wherein the second sleeve support bearing comprises a soft sleeve secured to the piston or to the clearance seal element.
Claim 42
Dependent Claim
33 words
The linear drive motor of claim 28 wherein the sleeve support bearing comprises a cylindrical sleeve extending along a longitudinal length of the armature to cover the outer cylindrical surface of the armature.
Claim 43
Dependent Claim
22 words
The linear drive motor of claim 28 wherein the sleeve support bearing comprises at least one ring extending concentrically about the armature.
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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) | 1995-09-08 | 1996-03-09 | 1996-09-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-09-08 | 2000-03-09 | 2000-09-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-09-08 | 2004-03-09 | 2004-09-08 | $7700.00 | Window Closed / Lapsed |