Half-stepping motor with bifilar winding ratio for smooth motion
US6969930B2 · kind B2 · utility
Inventors
Key dates
| Filing date | Jul 28, 2004 |
| Grant date | Nov 29, 2005 |
| Priority date | — |
| Expiry date | Jul 28, 2024 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02K37/18
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A half-stepping motor with bifilar coil windings about its stator poles has two layers of stator coils with different numbers of turns per pole for each layer. The ratio between the number turns is selected to provide a desired angular phase shift in the torque profile. A first layer wound about a first group of poles is connected in series in a forward sense with a second layer wound about a second distinct group of poles and driven by a first phase, while a second layer wound about the first group of poles is connected in series in a reverse sense with a first layer wound about the second group of poles and driven by a second phase in quadrature relation to the first phase. For a motor with 8 stator poles, the desired phase shift is 22.5 degrees, resulting from a turn ratio between the layers of about 0.4142.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.