Motor with brush and commutator, and electric apparatus using the same motor

摘要

An arc length in contact with a commutator of two brushes in a rotational direction of a motor is defined as not more than 5% of an outer rim length or circumference of the commutator, i.e., not more than piA/2O, where A is an outside diameter of the commutator. A number of shorted segments of the commutator, which short is caused by the brush, can be minimized so that reduction in output of the motor can be prevented. As a result, the motor employed in a car product or an electric tool can be downsized and made lighter.