US3745435A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Driving circuit for brushless motor
Assignee: Suwa Seikosha KK
•
Filing: 1971-10-04
•
Granted: 1973-07-10
•
Expires: 1991-10-04
Abstract
Abstract A driving circuit for a brushless motor wherein each driving coil is energized in response to the receipt of a signal by a receiving coil from a transmitting coil. A continuously rotating slotted shield disk rotates synchronously with the rotor shaft of the motor for intermittently preventing the transmission of the signal from the transmitting coil to the receiving coil. A transmitting and receiving coil pair is provided for each driving coil.
Inventors
- 👤 Y Futagawa
- 👤 C Komatsu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 01:07
CPC Classifications
H; H02; H02K; H02K29/00; H02K29/06; H02K29/12
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
342 words
A multi-phase brushless motor comprising a rotor shaft; magnetic circuit means mounted on said shaft and formed with an air gap; at least three driving coils in said air gap for driving said motor; at least three pairs of further coils, one of each of said pair being a transmitting coil and the other of each of said pairs of further coils being a receiving coil; a single oscillatory circuit connected to all of said transmitting coils for applying oscillating energy to each of said transmitting coils; a rotative shield disc coaxially mounted on said rotor shaft and formed with cut out regions, said pairs of further coils being positioned so that said shield disc passes therebetween, each of said transmitting coils transmitting electrical oscillating energy to the associated receiving coil when a cut out region is in registration therewith, such transmission being otherwise barred by said shield disc; a demodulator circuit connected to each of said receiving coils for changing the signal received thereby to a direct current signal; a driver circuit connecting each of said demodulator circuits to a driving coil for actuating said driving coil in response to said direct current signal, the number of said pairs of further coils being equal to the number of said driving Coils, said oscillatory, demodulator and driver circuits including a plurality of components; a first base plate formed with a notch therein dimensioned to receive said shaft to permit displacement of said first base plate into and out of an operative position, said first base plate carrying a portion of said circuit components and having said driving coils embedded therein in circumferentially spaced relation relative to said shaft; second and third base plates; and means mounting said second and third base plates in spaced relation with each other and with said first base plate, said transmitting coils being embedded in said second base plate, said receiving coils being embedded in said third base plate, at least one of said second and third base plates carrying a further portion of said circuit components.
Claim 2
Dependent Claim
342 words
A multi-phase brushless motor comprising a rotor shaft; magnetic circuit means mounted on said shaft and formed with an air gap; at least three driving coils in said air gap for driving said motor; at least three pairs of further coils, one of each of said pair being a transmitting coil and the other of each of said pairs of further coils being a receiving coil; a single oscillatory circuit connected to all of said transmitting coils for applying oscillating energy to each of said transmitting coils; a rotative shield disc coaxially mounted on said rotor shaft and formed with cut out regions, said pairs of further coils being positioned so that said shield disc passes therebetween, each of said transmitting coils transmitting electrical oscillating energy to the associated receiving coil when a cut out region is in registration therewith, such transmission being otherwise barred by said shield disc; a demodulator circuit connected to each of said receiving coils for changing the signal received thereby to a direct current signal; a driver circuit connecting each of said demodulator circuits to a driving coil for actuating said driving coil in response to said direct current signal, the number of said pairs of further coils being equal to the number of said driving Coils, said oscillatory, demodulator and driver circuits including a plurality of components; a first base plate formed with a notch therein dimensioned to receive said shaft to permit displacement of said first base plate into and out of an operative position, said first base plate carrying a portion of said circuit components and having said driving coils embedded therein in circumferentially spaced relation relative to said shaft; second and third base plates; and means mounting said second and third base plates in spaced relation with each other and with said first base plate, said transmitting coils being embedded in said second base plate, said receiving coils being embedded in said third base plate, at least one of said second and third base plates carrying a further portion of said circuit components.
Claim 3
Dependent Claim
36 words
A brushless motor as recited in claim 1, wherein said driver circuit includes a driver transistor having a collector and base, said demodulator circuit including a demodulating condenser connected between said driver transistor collector and base.
Claim 4
Dependent Claim
51 words
A brushless motor as recited in claim 1, including a control means for regulating the rotational speed of said rotor, said control means being connected to all of said demodulator circuits for varying the magnitude of the signal applied to said demodulator circuitsin response to the rotational speed of said rotor.
Claim 5
Dependent Claim
55 words
A brushless motor as recited in claim 1, including control means for regulating the rotational speed of said rotor shaft, said control means being connected to all of said driver circuits for varying the magnitude of the direct current signal applied to said driver circuits in response to the rotational speed of said rotor shaft.
Claim 6
Dependent Claim
95 words
A brushless motor as recited in claim 1, wherein each of said demodulator circuits includes a preamplifying transistor having an emitter, collector and base for changing the signal received by the receiving coil to said direct current signal, said receiving coil being connected between said preamplifying transistor emitter and base, each of said driver circuit including a driver transistor having an emitter, collector and base, said preamplifying transistor collector and emitter being connected between said driver transistor collector and base, a driving coil being connected in series with said driver transistor emitter to collector path.
Claim 7
Dependent Claim
51 words
A brushless motor as recited in claim 1, including control means for regulating the rotational speed of said rotor shaft, said control means being connected to said oscillatory circuit for varying the magnitude of the oscillating energy applied to said transmitting coils in response to the rotational speed of said rotor.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-07-09 | 1977-01-08 | 1977-07-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-09 | 1981-01-08 | 1981-07-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-09 | 1985-01-08 | 1985-07-10 | $7700.00 | Window Closed / Lapsed |