Low detent torque hybrid step motor
US10958146B2 · kind B2 · utility
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12References
8Claims
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Key dates
| Filing date | Jun 12, 2019 |
| Grant date | Mar 23, 2021 |
| Priority date | — |
| Expiry date | Nov 21, 2039 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02K2201/03
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A step motor that provides reduced detent torque while maintaining adequate holding torque is characterized by a rotor that includes an annular ring of soft magnetic material (such as medium carbon steel) that surrounds the outer diameter of the rotor permanent magnet and is sandwiched by magnetic insulators of specified axial thickness. This provides a path within the rotor for flux from the permanent magnet in those areas where the radially adjacent stator poles are unenergized, but the magnetic flux can be pulled out by the ampere-turns of energized stator poles.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.