DC motor

An apparatus having a direct current motor comprising:

• a stator;
• a rotor including,
• a rotation shaft, and rotor coils;
• a commutator integrally provided with the stator and connected to the rotor coils;
• a pair of electrode brushes in sliding contact with the commutator and configured to supply electric power from the commutator to the rotor coils to change a state of a direct current drive voltage to the rotor coils;
• and
• at least one rotation detecting brush in sliding contact with the commutator and arranged at a position in a direction along an axis of the rotation shaft different from contact positions of the pair of electrode brushes, said at least one rotation detecting brush configured to detect a signal on the commutator indicative of an operation of the direct current motor.

A direct current motor comprising:

• a stator;
• a rotor including,
• a rotation shaft, and rotor coils;
• a commutator integrally provided with the stator and connected to the rotor coils;
• means for supplying electric power from the commutator to the rotor coils;
• means for changing a state of a direct current drive voltage to the rotor coils;
• and
• means for detecting a signal on the commutator indicative of an operation of the direct current motor,
• wherein the means for detecting a signal detects the signal on the commutator from a different axial position on the commutator than the means for supplying electric supplies power to the commutator.

A method of assembling a direct current motor with a stator, a rotor including a rotation shaft and rotor coils, a commutator, a pair of electrode brushes and at least one rotation detecting brush in sliding contact with the commutator, comprising the steps of:

• forming the electrode brushes and the at least one rotation detection brush in predetermined shapes configured to provide resilient tension against the commutator;
• fixing the electrode brushes and the at least one rotation detection brush on a support base of the rotor;
• inserting a jig through holes in the support base;
• displacing with the jig the electrode brushes and the at least one rotation detection brush to a position on the support base which is outside an outer diameter of the commutator;
• assembling the commutator and rotation shaft onto the support base;
• and
• removing the jig and thereby contacting the electrode brushes and the at least one rotation detection brush on the commutator.