US3795848A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Collectorless d. c. motor
Assignee: Buehler GmbH
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Filing: 1972-03-21
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Granted: 1974-03-05
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Expires: 1992-03-21
Abstract
Abstract A collectorless D.C. motor includes a rotor, a stator, and a plurality of stator windings arranged on the stator in angularly spaced relationship. Each winding when energized produces a stationary magnetic field having a respective orientation. A control circuit including an oscillator energizes successive ones of the windings for respective time intervals determined by the oscillatory frequency of the oscillator. The resulting magnetic field revolves with an angular velocity determined by the oscillator.
Inventors
- 👤 G Schaub
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 16:25
CPC Classifications
H; H02; H02P; H02P6/00; H02P6/14
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
221 words
A collectorless D.C. motor, comprising, in combination, a rotor; a stator; a plurality of stator windings arranged on said stator in angularly spaced relationship and each producing when energized a stationary magnetic field having a respective angular orientation; triggering means comprising free-running adjustablefrequency oscillator means having an output and operative for furnishing at said output a train of triggering signals having a signal repetition frequency, and rotor-speed-responsive frequency-varying means connected to said free-running adjustable-frequency oscillator means and operative for continuously varying the frequency of said free-running adjustable-frequency oscillator means in dependence upon the speed of said rotor; and a ring counter ciruit having an input connected to said output for receipt of triggering signals, and comprising a plurality of circuit stages each capable of undergoing transistions between a first and a second state, and each stage being so connected to a respective one of said stator winding means as to effect energization of the respective one of said stator winding means when in said second state, and wherein said stages are connected together in a circle in such a manner that upon receipt of successive triggering pulses at said input successive ones of said stages undergo a transition to said second state, so that successive ones of said stator winding means are energized in sequence to create a rotating magnetic field.
Claim 2
Dependent Claim
221 words
A collectorless D.C. motor, comprising, in combination, a rotor; a stator; a plurality of stator windings arranged on said stator in angularly spaced relationship and each producing when energized a stationary magnetic field having a respective angular orientation; triggering means comprising free-running adjustablefrequency oscillator means having an output and operative for furnishing at said output a train of triggering signals having a signal repetition frequency, and rotor-speed-responsive frequency-varying means connected to said free-running adjustable-frequency oscillator means and operative for continuously varying the frequency of said free-running adjustable-frequency oscillator means in dependence upon the speed of said rotor; and a ring counter ciruit having an input connected to said output for receipt of triggering signals, and comprising a plurality of circuit stages each capable of undergoing transistions between a first and a second state, and each stage being so connected to a respective one of said stator winding means as to effect energization of the respective one of said stator winding means when in said second state, and wherein said stages are connected together in a circle in such a manner that upon receipt of successive triggering pulses at said input successive ones of said stages undergo a transition to said second state, so that successive ones of said stator winding means are energized in sequence to create a rotating magnetic field.
Claim 3
Dependent Claim
78 words
A motor as defined in claim 1, wherein said free-running adjustable-frequency oscillator means consists of a free-running adjustable-frequency oscillator having an input for receipt of a D.C. signal and is operative for furnishing a train of triggering signals having a signal repetition frequency dependent upon the amplitude of such D.C. signal, and wherein said frequency-varying means fuRther comprises speed signal means for applying to said input of said free-running adjustable-frequency oscillator a D.C. signal indicative of rotor speed.
Claim 4
Dependent Claim
37 words
A motor as defined in claim 2, wherein said speed signal means consists of means for applying to said input of said free-running adjustable-frequency oscillator a substantially flat D.C. signal having a level indicative of rotor speed.
Claim 5
Dependent Claim
30 words
A motor as defined in claim 1, said frequency-varying means comprising means for producing an increase in said signal repetition frequency in response to to an increase of rotor speed.
Claim 6
Dependent Claim
29 words
A motor as defined in claim 1, said frequency-varying means comprising means for establishing a signal repetition frequency having a predetermined start-up value when said rotor is being started-up.
Claim 7
Dependent Claim
29 words
A motor as defined in claim 1, said triggering means comprising additional frequency-varying means for varying the signal repetition frequency of said train at the will of an operator.
Claim 8
Dependent Claim
15 words
A motor as defined in claim 6, said additional frequency-varying means comprising an adjustable RC-network.
Claim 9
Dependent Claim
33 words
A motor as defined in claim 1, said signal repetition frequency having a start-up value when said rotor is being started-up, and said triggering means comprising means for adjustably determining said start-up value.
Claim 10
Dependent Claim
20 words
A motor as defined in claim 1, and further including speed regulating means for regulating the speed of said rotor.
Claim 11
Dependent Claim
29 words
A motor as defined in claim 1, and further including shut-off means for terminating energization of successive ones of said winding means when the rotor exceeds a predetermined value.
Claim 12
Dependent Claim
41 words
A motor as defined in claim 10, said shut-off means including voltage-threshold means connected with at least one of said stator for producing a shut-off signal when the induced voltage in said at least one stator winding reaches a threshold value.
Claim 13
Dependent Claim
14 words
A motor as defined in claim 11, said voltage-threshold means comprising Zener diode means.
Claim 14
Dependent Claim
13 words
A motor as defined in claim 1, said triggering means comprising a multivibrator.
Claim 15
Dependent Claim
13 words
A motor as defined in claim 1, said rotor comprising permanent magnet means.
Claim 16
Dependent Claim
28 words
A motor as defined in claim 1, said circuit stages comprising a plurality of current-furnishing power transistors, each connected with a respective one of said stator winding means.
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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) | 1977-03-04 | 1977-09-03 | 1978-03-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-03-04 | 1981-09-03 | 1982-03-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-03-04 | 1985-09-03 | 1986-03-05 | $7700.00 | Window Closed / Lapsed |