US 6,724,114 B2 · Doubly salient machine with angled permanent magnets in stator teeth

Abstract

Permanent magnet machines including doubly salient machines having one or more permanent magnets located at least partly and preferably entirely within the stator teeth, thereby avoiding weakening of the stator structure while reducing acoustic noise. The magnets may be located in only a subset of the stator teeth, thereby lowering magnet material and manufacturing costs, and all such magnets may have north poles directed toward an interior of the machine, resulting in reduced cogging and negative torques with improved torque densities. The permanent magnets may also extend within the stator teeth on an angle or diagonal, thereby allowing use of magnets which are wider than the teeth themselves to produce greater flux. Further, a magnetizing device having a single coil may be used to simultaneously magnetize all the stator magnets with a common polarity.

Claims14

Dependent claims

A stator for use in a permanent magnet machine, the stator comprising:

a frame having an outer peripheral edge and an inner peripheral edge extending about a central axis;
a plurality of stator teeth each extending along a radial axis from the frame's inner peripheral edge toward the central axis;
and
at least one permanent magnet located at least partly within one of the stator teeth;
wherein said one permanent magnet has a pole surface oriented at an oblique angle relative to the radial axis along which said one of the stator teeth extends.

2 more elements

A stator for use in a permanent magnet machine, the stator comprising:

a frame having an outer peripheral edge and an inner peripheral edge extending about a central axis;
a plurality of permanent magnets each having inwardly facing north poles;
a first plurality of stator teeth each extending along a radial axis from the frame's inner peripheral edge toward the central axis, each of the first plurality of stator teeth having one of the permanent magnets located at least partly therein;
and
a second plurality of stator teeth extending from the frame's inner peripheral edge toward the central axis, the second plurality of stator teeth each having no permanent magnets located therein;
wherein the first plurality of stator teeth are each positioned directly between two of the second plurality of stator teeth;
wherein the north poles of the permanent magnets are each oriented at an oblique angle relative to the radial axis along which its corresponding one of the stator teeth extends;
wherein each permanent magnet and its corresponding one of the stator teeth have a width extending in a direction of rotation of a rotor when the rotor is mounted for rotation about the central axis;
and
wherein the width of each permanent magnet is greater than the width of its corresponding one of the stator teeth.

7 more elements

Dependencies are inferred from the claim text.

Doubly salient machine with angled permanent magnets in stator teeth

Life of this patent

Doubly salient machine with angled permanent magnets in stator teeth

Life of this patent

Abstract

Claims14