US3809936A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Brushless generator
Assignee: Individual
•
Filing: 1972-05-18
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Granted: 1974-05-07
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Expires: 1992-05-18
Abstract
Abstract Apparatus for indicating velocity of rotation by developing an alternating voltage signal which when rectified provides a unidirectional voltage having a low ripple content and a magnitude proportional to the angular velocity of the rotation. A magnetic rotor mounted on a shaft is driven within a stator including an annular magnetic return path and a number of coils mounted within a constant width non-magnetic gap. The rotor, magnetic return path and coils form a geometrical arrangements such that the electromotive forces induced in each coil upon rotation of the rotor have trapezoidally shaped wave forms. The currents produced by these electromotive forces are summed using a full-wave rectifier circuit to obtain a low ripple DC signal.
Inventors
- 👤 E Klein
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 22:40
CPC Classifications
H; H02; H02K; H02K39/00; G; G01; G01P; G01P3/00; G01P3/42; G01P3/44; G01P3/46; G01P3/465; H02K21/00; H02K21/12; H02K21/14; H02K3/00
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
240 words
A brushless tachometer generator, comprising: an annular magnetic member having a smooth cylindrical inner surface of a first diameter; a rotor disposed along the longitudinal axis of said annular member and including a pair of oppositely polarized magnetic poles terminating in pole faces shaped as cylindrical segments which are concentric with said inner surface and have a second diameter smaller than said first diameter, the sector angle of each of said segments being substantially equivalent to an angle of 360*/n, the space separating said inner surface and said pole faces forming an annular gap of uniform radial dimension; an odd-numbered plurality of electrically conductive coils, each comprising a pair of elongated wire bundles disposed within said gap and lying in parallel relationship with said axis, the respective bundles of each coil being disposed on opposite sides of said axis and lying in planes including said axis, adjacent ones of said bundles being angularly positioned about said axis at intervals of 180*/n, wherein n is the number of coils; a cup-shaped non-magnetic member having cylindrical walls with an outer diameter smaller than said first diameter and an inner diameter larger than said second diameter, said walls having slots provided in the outer surface thereof for receiving said wire bundles; and semiconductor rectifying means coupled to said coils for converting the electromotive force developed in said coils into a uni-directional electric potential of magnitude proportional to the rotational speed of said rotor.
Claim 2
Dependent Claim
240 words
A brushless tachometer generator, comprising: an annular magnetic member having a smooth cylindrical inner surface of a first diameter; a rotor disposed along the longitudinal axis of said annular member and including a pair of oppositely polarized magnetic poles terminating in pole faces shaped as cylindrical segments which are concentric with said inner surface and have a second diameter smaller than said first diameter, the sector angle of each of said segments being substantially equivalent to an angle of 360*/n, the space separating said inner surface and said pole faces forming an annular gap of uniform radial dimension; an odd-numbered plurality of electrically conductive coils, each comprising a pair of elongated wire bundles disposed within said gap and lying in parallel relationship with said axis, the respective bundles of each coil being disposed on opposite sides of said axis and lying in planes including said axis, adjacent ones of said bundles being angularly positioned about said axis at intervals of 180*/n, wherein n is the number of coils; a cup-shaped non-magnetic member having cylindrical walls with an outer diameter smaller than said first diameter and an inner diameter larger than said second diameter, said walls having slots provided in the outer surface thereof for receiving said wire bundles; and semiconductor rectifying means coupled to said coils for converting the electromotive force developed in said coils into a uni-directional electric potential of magnitude proportional to the rotational speed of said rotor.
Claim 3
Dependent Claim
43 words
A brushless tachometer generator as recited in claim 1 wherein said magnetic poles include a main body of permanent magnet material and pole pieces of magnetically soft material affixed to said main body to form at least a portion of said pole faces.
Claim 4
Dependent Claim
27 words
A brushless tachometer generator as recited in claim 2 wherein said pole pieces have a transverse cross section in the shape of a segment of a circle.
Claim 5
Dependent Claim
39 words
A brushless tachometer generator as recited in claim 1 wherein said cup-shaped member is open at one end and is closed at the opposite end by an end wall having an aperture for receiving a shaft supporting said rotor.
Claim 6
Dependent Claim
55 words
A brushless tachometer generator as recited in claim 1 and further comprising a coil holder including an annular non-magnetic member disposed within said gap and having an outer diameter smaller than said first diameter and an inner diameter larger than said second diameter, said member having longitudinal slots provided therein for receiving said wire bundles.
Claim 7
Dependent Claim
44 words
A brushless tachometer generator as recited in claim 5 wherein said coil holder further inCludes at least one lid member mating with one end of said annular member and having a central opening provided therein through which the shaft supporting said rotor is passed.
Claim 8
Dependent Claim
67 words
A brushless tachometer generator as recited in claim 1 wherein said rectifying means comprise peak detecting means including a plurality of parallel connected diode pairs and wherein all of said coils are wound in the same direction with corresponding entrance terminals of each coil being connected in common, the exit terminal of the various ones of said coils being coupled to various ones of said diode pairs.
Claim 9
Dependent Claim
219 words
A brushless tachometer generator, comprising: a magnetic member having a cylindrical inner surface of a first diameter; a permanent magnet rotor disposed concentrically with and rotatable about the axis of said magnetic member, said rotor having a pair of oppositely polarized magnetic poles terminating in pole faces shaped as cylindrical segments which have a second diameter smaller than said first diameter, said segments spanning an angle of substantially 180*/m as measured about said axis; an even-numbered plurality of electrically conducting coils, each comprising a pair of elongated wire bundles disposed within the gap defined by said inner surfaces and said pole faces, the respective bundles of each coil being spaced apart by a radial angle of 90*, adjacent ones of said wire bundles being positioned about said axis at intervals of 180*/m, wherein m is the number of coils and is equal to 2q where q is an odd number; a cup-shaped member of non-magnetic material having cylindrical walls with an outer diameter smaller than said first diameter and an inner diameter larger than said second diameter, said walls having slots provided in a surface thereof for receiving said wire bundles; and semiconductor rectifying means coupled to said coils for converting the electromotive forces developed therein into an output voltage linearly related to the rotational speed of said rotor.
Claim 10
Dependent Claim
219 words
A brushless tachometer generator, comprising: a magnetic member having a cylindrical inner surface of a first diameter; a permanent magnet rotor disposed concentrically with and rotatable about the axis of said magnetic member, said rotor having a pair of oppositely polarized magnetic poles terminating in pole faces shaped as cylindrical segments which have a second diameter smaller than said first diameter, said segments spanning an angle of substantially 180*/m as measured about said axis; an even-numbered plurality of electrically conducting coils, each comprising a pair of elongated wire bundles disposed within the gap defined by said inner surfaces and said pole faces, the respective bundles of each coil being spaced apart by a radial angle of 90*, adjacent ones of said wire bundles being positioned about said axis at intervals of 180*/m, wherein m is the number of coils and is equal to 2q where q is an odd number; a cup-shaped member of non-magnetic material having cylindrical walls with an outer diameter smaller than said first diameter and an inner diameter larger than said second diameter, said walls having slots provided in a surface thereof for receiving said wire bundles; and semiconductor rectifying means coupled to said coils for converting the electromotive forces developed therein into an output voltage linearly related to the rotational speed of said rotor.
Claim 11
Dependent Claim
39 words
A brushless tachometer generator as recited in claim 8 wherein said cup-shaped member is open at one end and is closed at the opposite end by an end wall having an aperture for receiving the shaft supporting said rotor.
Claim 12
Dependent Claim
38 words
A brushless tachometer generator as recited in claim 9 and further comprising a closure member for mating with said one end, said closure member having an aperture for receiving the opposite end of the shaft supporting said rotor.
Claim 13
Dependent Claim
83 words
A brushless tachometer generator as recited in claim 8 wherein the first m/2 coils are positioned in sequence around said gap with each of said first m/2 coils having a first coil bundle in the first quadrant and a second coil bundle in the second quadrant, and the second m/2 coils are positioned in sequence around said gap with each of said second m/2 coils having a first coil bundle in the third quadrant and a second coil bundle in the fourth quadrant.
Claim 14
Dependent Claim
46 words
A brushless tachometer generator as recited in claim 11 wherein the first m/2 coils are wound in alternating directions and the second m/2 coils are also wound in alternating directions, the first coil in said first and second m/2 coils being wound in the same direction.
Claim 15
Dependent Claim
43 words
A brushless tachometer generator as recited in claim 8 wherein said magnetic poles include a main body of permanent magnet material and pole pieces of magnetically soft material affixed to said main body to form at least a portion of said pole faces.
Claim 16
Dependent Claim
27 words
A brushless tachometer generator as recited in claim 13 wherein said pole pieces have a transverse cross section in the shape of a segment of a circle.
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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) | 1977-05-06 | 1977-11-05 | 1978-05-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-05-06 | 1981-11-05 | 1982-05-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-05-06 | 1985-11-05 | 1986-05-07 | $7700.00 | Window Closed / Lapsed |