Three-phase permanent magnet stepping motor
US5289064A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 16, 1992 |
| Grant date | Feb 22, 1994 |
| Priority date | — |
| Expiry date | Oct 16, 2012 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02K37/14
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An inner- or outer-rotor type three-phase permanent magnet stepping motor constituted by a stator having circumferentially equidistantly arranged three magnetic poles each having small teeth equal in number and in pitch, and a rotor rotatably arranged along the circumference of the stator and constituted by a cylindrical permanent magnet magnetized to provide circumferentially alternately arranged pairs of north and south poles, the number of the pairs being selected to Zm under the condition that Zm satisfies Zm=3n-1 or Zm =3n+1 (n being a natural number not smaller than 1). Alternatively, the rotor is constituted by a ring-like permanent magnet magnetized so as to form two magnetic poles in the axial direction thereof and a pair of gear-like magnetic bodies each having Zr teeth on its circumference are arranged respectively on the axially opposite ends of the ring-like permanent magnet. The respective teeth arrangements of the gear-like magnetic bodies are circumferentially shifted by 1/2 teeth pitch, under the condition that the number Zr of the teeth satisfies Zr=3n-1 or Zr-3n+1. Further, the small teeth of the stator are circumferentially arranged substantially in the same pit…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.