Three-phase induction motor
US4868438A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 27, 1987 |
| Grant date | Sep 19, 1989 |
| Priority date | — |
| Expiry date | Mar 27, 2007 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02K2201/06
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A three-phase induction motor is subjected to countermeasure for the rotor and the stator in order to remove two harmonic components of the orders causing a torque ripple, among a plurality of harmonic components included in a magnetic flux generated in an air gap between a stator core and a rotor core. In the three-phase induction motor, conductor grooves of the rotor core are skewed by an electrical angle of 2.pi./n where n is the order of one of the harmonic components to be removed. In the stator, the number of slots (N) is selected so that an equation N=l.times.m.times.q is satisfied, where l=the number of poles, m=the number of phase, and q is a non integer number representing the number of slots per pole per phase, and the stator winding pitch is determined according to the order of another harmonic component to be removed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.