Permanent Magnet Machine with Different Pole Arc Angles
AssigneeFord Global Technologies, LLC
InventorsFeng Liang, Wei Wu, Michael W. Degner, Franco Leonardi
Life of this patent
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Abstract
An internal permanent magnet machine has multiple rotor sections, each section having multiple rotor laminations. Permanent magnets are placed asymmetrically in lamination openings to attenuate oscillations in torque caused by harmonic components of magnetic flux. Asymmetry is achieved by placing adjacent permanent magnets or magnet sets on the rotor periphery with different rotor magnetic pole arc angles.
Claims14
A permanent magnet machine comprising a stator with electromagnetic windings for stator poles and a rotor located on a rotor axis that is common to an axis for the stator with an air gap between the stator and the rotor;
- the rotor having a plurality of pairs of permanent magnets on its periphery, the magnets of each pair being located in a “V” shape configuration defining an angle therebetween;
- the rotor comprising laminations arranged in multiple sections in stacked axial relationship;
- magnetic poles for the magnet pairs being characterized by flux flow patterns that interact with flux flow patterns for the electromagnetic stator windings to create rotor torque;
- the magnets of one pair for one section defining an arc angle therebetween that differs from an arc angle defined by the magnets of an adjacent rotor section whereby harmonic components of rotor torque are manipulated to obtain smooth torque production.
A permanent magnet machine comprising a stator with electromagnetic windings for stator poles and a rotor located on a rotor axis that is common to an axis for the stator with an air gap between the stator and the rotor;
- the rotor having a plurality of pairs of permanent magnets on its periphery, the magnets of each pair being located in a “V” shape configuration defining an angle therebetween;
- the rotor comprising laminations arranged in multiple sections in stacked axial relationship;
- magnetic poles for the magnet pairs being characterized by flux flow patterns that interact with flux flow paths for the electromagnetic stator windings to create rotor torque;
- the magnets of one pair for one section defining an arc angle therebetween that differs from an angle defined by another pair of magnets of the same rotor section whereby harmonic components of rotor torque are manipulated to obtain smooth torque production.
A permanent magnet machine comprising a stator with electromagnetic windings for stator poles and a rotor located on a rotor axis that is common to an axis for the stator with an air gap between the stator and the rotor;
- the rotor having a plurality of permanent magnets on its periphery;
- the rotor having laminations arranged in axially-stacked relationship, the magnets being placed in the laminations;
- magnetic poles for the magnets being characterized by flux flow patterns that interact with flux flow patterns for the electromagnetic stator windings to create rotor torque;
- and
- at least one magnet having an arc angle that differs from an arc angle defined by another magnet whereby harmonic components of rotor torque are manipulated to obtain smooth torque production.
A permanent magnet machine comprising a stator with electromagnetic windings for stator poles and a rotor located on a rotor axis that is common to an axis for the stator with an air gap between the stator and the rotor;
- the rotor having a plurality of sets of permanent magnets on its periphery, each set having at least two magnets;
- the rotor having laminations arranged in axially-stacked relationship, the magnets being placed in the laminations;
- magnetic poles for the magnet sets being characterized by flux flow patterns that interact with flux flow patterns for the electromagnetic stator windings to create rotor torque;
- and
- at least one magnet set having an arc angle that differs from an arc angle defined by another magnet set whereby harmonic components of rotor torque are manipulated to obtain smooth torque production.
Dependencies are inferred from the claim text.