US3947155A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Linear compressor
Assignee: Tecumseh Products Co
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Filing: 1974-09-19
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Granted: 1976-03-30
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Expires: 1994-09-19
Abstract
Abstract A moving-iron, linear-motor compressor suitable for use in a refrigerant system, wherein a conical armature reciprocates in a complementary air-gap under the influence of an electromagnetic circuit and a pair of linear (constant rate) complementary return springs connected to the armature between the compressor piston and an outboard bearing. The armature rod is made of magnetically permeable material. The electromagnetic circuit includes a pair of abutting convoluted loops of spirally wound magnetic strip material with a conical air-gap fabricated in the area of abutment. The motor has a layered construction which cooperates with the conical armature and air-gap such that the motor is self-aligning at the assembly stage.
Inventors
- 👤 Michael K. Bidol
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 20:35
CPC Classifications
F; F04; F04B; F04B35/00; F04B35/04; F04B35/045; H; H02; H02K; H02K33/00; H02K33/02; H02K33/04
Claims Analysis
Total Claims: 31
Claim 1
Independent Claim
168 words
In an electromagnetic circuit of the type in which a magnetically permeable armature is disposed to axially reciprocate within an air-gap defined by a pair of spaced-apart coaxial poles on a fixed magnetic core, the improvement wherein said poles are square in cross section perpendicular to the pole axis, wherein said circuit includes electrical windings coiled around each said poles coaxially therewith to energize said circuit, and wherein said air gap comprises means providing a first space between said poles, said space having a circular cross section pependicular to the axis of reciprocation of said armature, and means providing on each said pole a pair of exposed coplanar gap surfaces, the surface plane of each pole being parallel to that of the opposing pole, said planes being displaced on opposite sides of said axis of reciprocation such that the maximum displacement between said pairs of surfaces is less than the maximum diameter of said first space, the space between respective coplanar surface pairs being devoid of core material.
Claim 2
Dependent Claim
168 words
In an electromagnetic circuit of the type in which a magnetically permeable armature is disposed to axially reciprocate within an air-gap defined by a pair of spaced-apart coaxial poles on a fixed magnetic core, the improvement wherein said poles are square in cross section perpendicular to the pole axis, wherein said circuit includes electrical windings coiled around each said poles coaxially therewith to energize said circuit, and wherein said air gap comprises means providing a first space between said poles, said space having a circular cross section pependicular to the axis of reciprocation of said armature, and means providing on each said pole a pair of exposed coplanar gap surfaces, the surface plane of each pole being parallel to that of the opposing pole, said planes being displaced on opposite sides of said axis of reciprocation such that the maximum displacement between said pairs of surfaces is less than the maximum diameter of said first space, the space between respective coplanar surface pairs being devoid of core material.
Claim 3
Dependent Claim
29 words
The improvement set forth in claim 1 wherein said first space is a substantially conical space, the axis of said conical space being coaxial with said axis of reciprocation.
Claim 4
Dependent Claim
37 words
The improvement set forth in claim 2 wherein the minimum diameter of said conical space is less than the width of said poles measured along a line perpendicular to said pole and to said axis of reciprocation.
Claim 5
Dependent Claim
152 words
A moving-iron linear-motor compressor comprising, in combination, a gas pump having a pump chamber, a magnetic circuit stationarily connected to said pump and having spaced-apart poles defining a substantially conical air-gap, the taper of said gap converging in the direction of said chamber and the center of said gap being coaxial with said chamber, a rod extending between said spaced-apart poles and having a pumping member carried on one end thereof and a substantially conical armature carried by the central portion thereof for movement between said poles, bearing means disposed on the side of said air-gap remote from said pumping member and supporting the other end of said rod for axial movement and restraining lateral movement thereof, means for magnetically activating said circuit thereby driving said armature in one direction toward said chamber, and return means operatively connected to said armature drive said armature in a direction opposite to said one direction.
Claim 6
Dependent Claim
152 words
A moving-iron linear-motor compressor comprising, in combination, a gas pump having a pump chamber, a magnetic circuit stationarily connected to said pump and having spaced-apart poles defining a substantially conical air-gap, the taper of said gap converging in the direction of said chamber and the center of said gap being coaxial with said chamber, a rod extending between said spaced-apart poles and having a pumping member carried on one end thereof and a substantially conical armature carried by the central portion thereof for movement between said poles, bearing means disposed on the side of said air-gap remote from said pumping member and supporting the other end of said rod for axial movement and restraining lateral movement thereof, means for magnetically activating said circuit thereby driving said armature in one direction toward said chamber, and return means operatively connected to said armature drive said armature in a direction opposite to said one direction.
Claim 7
Dependent Claim
41 words
A moving-iron linear compressor as set forth in claim 4 wherein said pumping member abuts said armature on a plane perpendicular to said central axis of said armature and pump chamber, whereby relative movement of said armature and piston is prevented.
Claim 8
Dependent Claim
37 words
A moving-iron linear compressor as set forth in claim 4 wherein said conical armature moves in said one direction such that the large-diameter face of said armature moves into said conical air-gap beyond the large-diameter end thereof.
Claim 9
Dependent Claim
141 words
A moving-iron linear-motor compressor as set forth in claim 4 wherein the bore of said pump chamber is substantially equal to 1.156√S inches, the combined mass of said compression member, armature and rod plus the effective mass of said return means is substantially equal to 1.3S pounds-mass, the spring rate of said return means is substantially equal to 200S pounds per inch, the cross-sectional area of each of said spaced-apart poles taken on a plane parallel to the axis of movement of said armature and perpendicular to the direction of magnetic flux through said poles is substantially equal to 2.25√S square inches, the electrical resistance of said magnetically activating means is substantially equal to 2.1/S ohms, and the number of coil turns in said magnetically activating means is substantially equal to 400/√S turns, where S is a positive, non-zero, real number.
Claim 10
Dependent Claim
36 words
A moving-iron linear compressor as set forth in claim 4 wherein the included angle of taper of said conical air-gap and conical armature are substantially identical and wherein said angle of taper is at least 10°.
Claim 11
Dependent Claim
26 words
A moving-iron linear compressor as set forth in claim 8 wherein the included angle of taper of said armature and air-gap is between 10° and 14°.
Claim 12
Dependent Claim
19 words
A moving-iron linear compressor as set forth in claim 4 wherein said rod is formed of magnetically permeable material.
Claim 13
Dependent Claim
68 words
A moving-iron linear compressor as set forth in claim 10 wherein the gross cross-sectional area of said armature taken through the center of said armature on a plane parallel to the axis of movement thereof is greater than the cross-sectional area of said spaced-apart poles taken on a plane parallel to the axis of movement of said armature and perpendicular to the direction of flux through said poles.
Claim 14
Dependent Claim
33 words
A moving-iron linear compressor as set forth in claim 11 wherein said gross cross-sectional area excluding the area of said rod is substantially 80 percent of said cross-sectional area of said spaced-apart poles.
Claim 15
Dependent Claim
38 words
A moving-iron linear compressor as set forth in claim 4 wherein during travel of said conical armature in said one direction the small-diameter face of said armature moves out of said conical air-gap at the small-diameter end thereof.
Claim 16
Dependent Claim
41 words
A moving-iron linear-motor compressor as set forth in claim 13 wherein said small diameter face of said armature is coplanar with the minimum diameter of said air-gap substantially at the time of maximum flux through said magnetic circuit, armature and air-gap.
Claim 17
Dependent Claim
32 words
A moving-iron linear compressor as set forth in claim 4 wherein the natural frequency of said return means, rod, pumping member and armature is less than the frequency of said activating means.
Claim 18
Dependent Claim
39 words
A moving-iron linear compressor as set forth in claim 15 wherein the frequency of said activating means is 60 Hz and the mechanical frequency of said return means and said rod, pumping member and armature is substantially 38 Hz.
Claim 19
Dependent Claim
76 words
A moving-iron linear compressor as set forth in claim 4 wherein said pumping member and chamber comprise a piston and cylinder reciprocable relative to one another and having a close-clearance sliding relationship with one another whereby insertion of said rod and armature into said magnetic circuit is guided by assembly of said cylinder and piston until said armature abuts said spaced-apart poles, thereby aligning said magnetic circuit with said pump and with said rod and armature.
Claim 20
Dependent Claim
58 words
A moving-iron linear compressor as set forth in claim 17 wherein said piston is fixedly connected to said rod and the maximum diameter of said piston is less than the minimum diameter of said air-gap whereby said piston, rod and armature are insertable as one unit into said magnetic circuit until said piston extends into said pump chamber.
Claim 21
Dependent Claim
41 words
A moving-iron linear-motor compressor as set forth in claim 4 wherein the magnetic reluctance through said magnetic circuit, armature and air-gap is a substantially linear function of armature movement during the time of travel of said armature in said one direction.
Claim 22
Dependent Claim
19 words
A moving-iron linear-motor compressor as set forth in claim 19 wherein said substantially linear function is of low slope.
Claim 23
Dependent Claim
20 words
A moving-iron linear-motor compressor as set forth in claim 20 wherein said low slope is substantially 0.022 amp-turns per maxwell-inch.
Claim 24
Dependent Claim
92 words
The combination set forth in claim 4 wherein said poles defining said air-gap are coaxial and include means providing a conical hole coaxially with said chamber, and means providing opposing pairs of exposed coplanar gap surfaces, the planes of said surfaces being perpendicular to the common axis of said poles but displaced on opposite sides of said axis of reciprocation such that the maximum displacement between said pairs of surfaces is less than the maximum diameter of said conical hole, the space between said pairs of surfaces being devoid of core material.
Claim 25
Dependent Claim
22 words
The improved magnetic core set forth in claim 22 wherein said opposing pairs of exposed coplanar surfaces are parallel to each other.
Claim 26
Dependent Claim
62 words
A moving-iron linear compressor as set forth in claim 4 wherein said return means comprises paired, complementary coil springs with substantially straight end-tangs, means clamping one end of each of said springs in fixed relation to said magnetic circuit, and means operatively clamping the other end of each of said springs to said armature between said pumping member and said bearing means.
Claim 27
Dependent Claim
22 words
A moving-iron linear compressor as set forth in claim 24 wherein said coil springs comprise a pair of single turn, internested springs.
Claim 28
Dependent Claim
76 words
A moving-iron linear-motor compressor as set forth in claim 24 wherein said fixed clamping means comprises a post extending from said bearing means in a direction remote from said air-gap and chamber coaxially therewith, means slidable on said post fixedly clamping said one end of each of said springs, and means mounted on said slidable means to clamp said slidable means to said post when said armature and pumping member are in the desired rest position.
Claim 29
Dependent Claim
41 words
A moving-iron linear-motor compressor as set forth in claim 24 wherein said operatively clamping means comprises a spring clamp mounted on said rod against the large-diameter face of said armature tightly clamping the said other end of each of said springs.
Claim 30
Dependent Claim
49 words
A moving-iron linear-motor compressor as set forth in claim 24 wherein said coil springs are coiled in the same direction and wherein each of said springs enters said fixed clamping means and operatively clamping means respectively from a direction substantially 180° from the direction of entry of the other.
Claim 31
Dependent Claim
36 words
A moving-iron linear-motor compressor as set forth in claim 24 wherein said springs are so disposed that the coils thereof are diametrically contained within the peripheral boundary defined substantially by the diameter of said magnetic circuit.
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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) | 1979-03-30 | 1979-09-29 | 1980-03-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-03-30 | 1983-09-29 | 1984-03-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-03-30 | 1987-09-29 | 1988-03-30 | $7700.00 | Window Closed / Lapsed |