Direct-current motor
Abstract
Abstract The invention generally concerns a DC motor with an armature, several poles and with field coils surrounding said poles. According to the instant invention, each pole includes two pole halves which are displaced from each other in the peripheral sense by a given distance. Pole halves belonging to a given pair are connected to each other by a common pole shoe so that each pole is approximately U-shaped in its radial cross-section with the legs of the U (the pole halves) pointing outwardly. Each pole half is individually surrounded by its own field coil. In general, the principle of the invention is that the pole of a classic DC motor is split in two and that the thus obtained pole halves are displaced symmetrically relative ends of the pole shoe. In this manner, a shorter yoke length Lj 8 , together with lower magnetomotive force in ampere-windings than in a classic DC motor are made possible. Furthermore, a lower coil resistance is obtained, i.e. for identical current consumption there is a lower production of loss heat. The lower number of ampere-windings results in further reduction of the number of windings for an identical current. Hence, the range of applications for a DC motor according to the invention of a given size is broader than for a classic DC motor.
Inventors
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Bibliographic Details
Claims Analysis
Total Claims: 6References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-01-11 | 1991-07-13 | 1992-01-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-01-11 | 1995-07-13 | 1996-01-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-01-11 | 1999-07-13 | 2000-01-12 | $7700.00 | Window Closed / Lapsed |