US3753062A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Polyphase motor system with dc motor characteristics
Assignee: Lear Motors Corp
•
Filing: 1971-05-19
•
Granted: 1973-08-14
•
Expires: 1991-05-19
Abstract
Abstract An electric induction motor/control system that provides the desirable high starting torque and wide speed characteristics of direct current motors. The stator of the induction motor has two specially interrelated winding sets per phase. The motor windings are supplied with unidirectional current pulses from silicon controlled rectifiers that are programmed to provide advantageous modes of operation for the motor. The unique relation and interaction between the motor windings hereof and the associated electronic circuitry results in high power factor, good efficiency, and self-clearing SCR commutation action. The preferred motors use a squirrel cage rotor with no commutator, brushes, or slip rings. The complementary stator winding arrangements are not voltage limited, and thereby permit the construction of large power motor systems. Practical motor ratings are from fractional to over 500 horsepower, at speeds ranging from 600 to 40,000 rpm, and higher. The electronic control sections for even the high horsepower motors are operated at low voltage and with few watts. Control circuitry is provided that can operate the motor systems: (a) at constant output torque over a wide speed range; (b) at constant horsepower over a selected speed range; (c) with traction output characteristics similar to that of series motors; (d) at constant speed; (e) and with direct speed reversal in any of these modes. These motor systems require little maintenance, and may be hermetically sealed.
Inventors
- 👤 J Greenwell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 20:02
CPC Classifications
H; H02; H02K; H02K3/00; H02K3/04; H02K3/28; H02K29/00; H02K29/03; H02P; H02P23/00; H02P23/28
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
139 words
A polyphase motor system comprising a stator and an induction rotor, said stator containing a plurality of half-phase windings in paired consequent pole array with one pair for each effective phase for the motor when in polyphase operation, each of said windings being wound in full pitch across 180 magnetic degrees, the complementary windings of each said pair being alternated in position along the stator at 180* magnetic separation, a controlled rectifier with first and second main electrodes for each of said windings, said first main electrodes being interconnected, said second main electrodes being connected to their respective windings, and control means connected with the control electrodes of said controlled rectifiers to selectively establish alternate conduction periods to their associated halfphase windings and provide a rotating magnetic field in the stator for corresponding operation of the said induction rotor.
Claim 2
Dependent Claim
139 words
A polyphase motor system comprising a stator and an induction rotor, said stator containing a plurality of half-phase windings in paired consequent pole array with one pair for each effective phase for the motor when in polyphase operation, each of said windings being wound in full pitch across 180 magnetic degrees, the complementary windings of each said pair being alternated in position along the stator at 180* magnetic separation, a controlled rectifier with first and second main electrodes for each of said windings, said first main electrodes being interconnected, said second main electrodes being connected to their respective windings, and control means connected with the control electrodes of said controlled rectifiers to selectively establish alternate conduction periods to their associated halfphase windings and provide a rotating magnetic field in the stator for corresponding operation of the said induction rotor.
Claim 3
Dependent Claim
27 words
A polyphase motor system as claimed in claim 1, in which adjacent turns of the said paired consequent windings are locAted in common slots in the stator.
Claim 4
Dependent Claim
39 words
A polyphase motor system as claimed in claim 1, in which adjacent turns of the said paired consequent windings are located in common slots in the stator, said half-phase windings being wound in the stator in substantially concentric form.
Claim 5
Dependent Claim
39 words
A polyphase motor system as claimed in claim 1, in which each of said half-phase windings provides a plurality of magnetic pole sets, all pole sets of which being interrelated in the stator as pairs and in polyphase array.
Claim 6
Dependent Claim
30 words
A polyphase motor system as claimed in claim 1, in which said half-phase windings are arrayed about the stator with equal physical separation between adjacent windings of each phase pair.
Claim 7
Dependent Claim
52 words
A polyphase motor system as claimed in claim 1, in which said half-phase windings are arrayed about the stator with equal physical separation between adjacent windings of each phase pair, associated windings of each pair being respectively interconnected into two symmetrical polyphase winding groups that are 180* apart magnetically in the stator.
Claim 8
Dependent Claim
37 words
A polyphase motor system as claimed in claim 1, in which said control means establishes the said conduction periods at respective 180* electrical separation between related half-phase pairs to provide said rotating magnetic field in the stator.
Claim 9
Dependent Claim
43 words
A polyphase motor system as claimed in claim 6, in which said control means establishes the said controlled rectifier conduction periods at respective 180* electrical separation between related half-phase pairs in said winding groups to provide said rotating magnetic field in the stator.
Claim 10
Dependent Claim
54 words
A polyphase motor system as claimed in claim 1, in which said half-phase windings are arrayed in the stator with relatively low mutual magnetic induction between the windings of respective pairs, whereby magnetic interaction among said stator windings cyclically effects self-clearing of the controlled rectifier conductions should any extend beyond its predetermined conduction period.
Claim 11
Dependent Claim
80 words
A polyphase motor system as claimed in claim 6, in which said control means includes a timing circuit that effects said successive conduction periods in equally spaced time intervals among said half-phase windings once during each cycle of applied motor frequency, said timing circuit having an electronic clock, and circuit means coupled to said clock and arranged to control its frequency and thereby the duration of said conduction periods to effect a predetermined mode of operation of the induction rotor.
Claim 12
Dependent Claim
80 words
A polyphase motor system as claimed in claim 7, in which said control means includes a timing circuit that effects said successive conduction periods in equally spaced time intervals among said half-phase windings once during each cycle of applied motor frequency, said timing circuit having an electronic clock, and circuit means coupled to said clock and arranged to control its frequency and thereby the duration of said conduction periods to effect a predetermined mode of operation of the induction rotor.
Claim 13
Dependent Claim
47 words
A polyphase motor system as claimed in claim 11, further including terminal means for connecting said half-phase windings to a source of DC operating voltage, said circuit means being arranged to vary the frequency of said clock and effect substantially constant horsepower output operation of the rotor.
Claim 14
Dependent Claim
63 words
A polyphase motor system as claimed in claim 11, further including electrical means providing a variable source of operating DC voltage for said half-phase windings, said circuit means including a Zener diode, said variable DC voltage being coupled to said Zener diode and thereby to said clock, whereby variation of the applied dc voltage directly effects substantially constant torque output by the rotor.
References Cited (Backward Citations)
US3187245A
Cited
US3624472A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-08-13 | 1977-02-12 | 1977-08-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-13 | 1981-02-12 | 1981-08-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-13 | 1985-02-12 | 1985-08-14 | $7700.00 | Window Closed / Lapsed |