| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a DC motor with a brush that has a simple structure and can change relative positions of the brush and a commutator without any increase in size.SOLUTION: A DC motor 1 with a brush includes: a permanent magnet 3 provided on an inner surface of a housing 2; a motor shaft 5 pivoted rotatably on the housing 2 and a cap 4; a coil 7 wound around a core 6 rotating integrally with the motor shaft 5; a brush 9 coming into slide contact with a commutator 8 provided on the motor shaft 5, and has a displacement member 10 arranged on one axial end side of the motor shaft 5. The displacement member 10 is made of a shape memory alloy, and restores itself into a conic shape from a flat plate shape when the ambient environmental temperature rises above the transformation temperature of the shape memory alloy owing to heat generation accompanying motor rotation so as to move the motor shaft 5 in its axial direction, so that the commutator 8 and brush 9 shift in slide contact position along the axis of the motor shaft 5.</p> |
