Outer rotor and outer rotor electric motor
AssigneeAichi Steel Corporation
InventorTadashi Fujimaki
Life of this patent
Estimating the term…
Abstract
Provided is an outer rotor, in which an anchor part is provided with a first bulge portion bulging in one direction of rotation directions beyond a first generating line and a second bulge portion bulging in the other direction of the rotation directions beyond a second generating line. This makes it possible to inhibit shrinkage of a binder toward a rotation center. Strain resulting from shrinkage of a magnet part can be distributed over its outer peripheral side and inner peripheral side with the first bulge portion and the second bulge portion therebetween, and thus, occurrence of cracks in the magnet part can be inhibited in the vicinity of the anchor part.
Claims8
An outer rotor of an electric motor, the outer rotor comprising:
- a rotor core that is formed of metal and that has an annular shape;
- an anchor part that is provided on an inner peripheral surface of the rotor core and that protrudes toward a rotation center axis of the rotor core;
- a magnet part provided on the inner peripheral surface of the rotor core and formed of a bond magnet, the magnet part being formed in an annular shape to cover an entirety of the anchor part from a side of the inner peripheral surface;
- a first bulge portion that is provided to the anchor part and that bulges in one direction of rotation directions;
- and
- a second bulge portion that is provided to the anchor part and that bulges in another direction of the rotation directions,
- wherein, when definitions are given of:
- a centroid of the anchor part projected onto a virtual plane orthogonal to a rotation center axis of the rotor core, as an anchor center,
- a virtual line passing through the anchor center and the rotation center axis projected onto the virtual plane, as an anchor center line,
- a virtual line that passes through the rotation center axis projected onto the virtual plane and that is shifted relative to the anchor center line in the one direction of the rotation directions by a central angle set in advance to intersect the first bulge portion, as a first generating line, and
- a virtual line that passes through the rotation center axis projected onto the virtual plane and that is shifted relative to the anchor center line in another direction of the rotation directions by a central angle set in advance to intersect the second bulge portion, as a second generating line,
- the magnet part is present on one side and another side of the first bulge portion across the first bulge portion in a direction of the first generating line, and
- the magnet part is present on one side and another side of the second bulge portion across the second bulge portion in a direction of the second generating line.
Dependencies are inferred from the claim text.