US3740628A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Linear electric motor
Assignee: Toshiba Corp
•
Filing: 1971-06-08
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Granted: 1973-06-19
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Expires: 1991-06-08
Abstract
Abstract A linear electric motor, which includes an elongated reaction rail having north and south magnetic poles alternately disposed therealong and an armature having polyphase windings which is moved along the reaction rail, is provided with a position detector for detecting the relative position between the magnetic poles of the reaction rail and the armature. The armature windings are energized from an electric power supply through a static commutator formed of semiconductor elements. The position detector responds to the speed electromotive force induced in the armature windings and causes the semiconductor elements in the static commutator to turn on and off in a perdetermined sequence.
Inventors
- 👤 J Inagaki
- 👤 S Tadakuma
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 10:07
CPC Classifications
B; B60; B60L; B60L15/00; B60L15/002; B60L15/005; B60L2200/00; B60L2200/26; B60L2220/00; B60L2220/10; B60L2220/14; Y; Y02; Y02T; Y02T10/00; Y02T10/60; Y02T10/64
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
174 words
A linear electric motor comprising: an elongated reaction rail having north and south poles alternately disposed therealong; an elongated armature having polyphase windings and being magnetically coupled with said reaction rail, said armature being combined with the reaction rail so as to allow rectilinear movement therebetween; a static commutator connected to said armature windings of said armature and for applying excitation current selectively and periodically to the respective phase windings of the armature; and means for electrically detecting the relative position between said armature windings and the magnetic poles of said reaction rail and to generate control signals for said static commutator, said detecting means being connected directly to said armature windings so as to respond to speed electromotive forces induced in the armature windings by a magnetomotive force of said rail; wherein said position detecting means includes a plurality of transformers each having a primary, a secondary and a tertiary winding wound on a core, and a high frequency oscillator for applying its output signals to the primary winding of each said transformer.
Claim 2
Dependent Claim
174 words
A linear electric motor comprising: an elongated reaction rail having north and south poles alternately disposed therealong; an elongated armature having polyphase windings and being magnetically coupled with said reaction rail, said armature being combined with the reaction rail so as to allow rectilinear movement therebetween; a static commutator connected to said armature windings of said armature and for applying excitation current selectively and periodically to the respective phase windings of the armature; and means for electrically detecting the relative position between said armature windings and the magnetic poles of said reaction rail and to generate control signals for said static commutator, said detecting means being connected directly to said armature windings so as to respond to speed electromotive forces induced in the armature windings by a magnetomotive force of said rail; wherein said position detecting means includes a plurality of transformers each having a primary, a secondary and a tertiary winding wound on a core, and a high frequency oscillator for applying its output signals to the primary winding of each said transformer.
Claim 3
Dependent Claim
45 words
A linear electric motor according to claim 1, wherein: said position detecting means includes photoluminescence-diodes connected directly to said armature windings and a photoelectric transducer for generating the control signals for said commutator in accordance with the illumination of light beams emitted from the photoluminescence-diodes.
Claim 4
Dependent Claim
71 words
A linear electric motor according to claim 1, further comprising: means in said position detecting means for providing a short circuit across said secondary coil only when thE polarity of said speed electromotive force induced in said armature winding is of a predetermined polarity, whereby output signals from said tertiary winding are introduced to said static commutator to control the same only when the terminals of the secondary winding are opened.
Claim 5
Dependent Claim
23 words
A linear electric motor according to claim 3, wherein: said means for providing a short circuit across said secondary coil includes a diode.
Claim 6
Dependent Claim
23 words
A linear electic motor according to claim 3, wherein: said means for providing a short circuit across said secondary coil includes a transistor.
Claim 7
Dependent Claim
23 words
A linear electric motor according to claim 3, wherein: said means for providing a short circuit across said secondary coil includes a thyristor.
References Cited (Backward Citations)
US3225228A
Cited
US3435312A
Cited
US3407749A
Cited
US3577929A
Cited
US3594622A
Cited
US3575650A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-06-18 | 1976-12-18 | 1977-06-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-06-18 | 1980-12-18 | 1981-06-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-06-18 | 1984-12-18 | 1985-06-19 | $7700.00 | Window Closed / Lapsed |