A motor includes a rotor, a commutator, a brush, and a bias member. The
commutator has a rectifying surface. The commutator rectifies an electric
current supplied to the rotor through the rectifying surface. The rotor
is rotated by being supplied with the electric current. The brush makes
contact with the commutator via the rectifying surface. The rotor is
supplied with the electric current through the brush. The brush starts
making contact with the commutator on an entry side of the brush as the
rotor and the commutator rotate with respect to the brush along a
rotative direction and the commutator intermittently makes contact with
the brush. The bias member biases the brush toward the entry side.