Valve-timing control apparatus for internal combustion engine

A valve-timing control apparatus for an internal combustion engine, comprising:

• a drive rotating member configured to receive a rotational force from a crankshaft;
• a driven rotating member fixed to a cam shaft;
• an electric motor including
• a stator fixed to the driven rotating member,
• a rotor configured to rotate relative to the stator,
• a plurality of coils provided to rotate integrally with the rotor and configured to form different magnetic poles in a circumferential direction of the rotor by energization,
• a commutator configured to switch an energized state of the coils,
• a power switching brush provided to the drive rotating member and abutting on the commutator, and
• a motor output shaft fixed to the rotor, and configured to be rotated by energizing the coils through the power switching brush and the commutator;
• a speed-reduction mechanism configured to reduce a rotational speed of the motor output shaft and to transmit the reduced rotational speed of the motor output shaft to the driven rotating member;
• a detection-target section provided to one of the fixed member and a tip side of the motor output shaft, and located on an inner circumferential side beyond a contact portion between the commutator and the power switching brush;
• and
• a detecting section provided to another of the fixed member and the tip side of the motor output shaft, and configured to detect a rotational position of the motor output shaft by detecting a position of the detection-target section.

A valve-timing control apparatus for an internal combustion engine, comprising:

• a drive rotating member configured to receive a rotational force from a crankshaft;
• a driven rotating member fixed to a cam shaft;
• an electric motor including
• a stator fixed to the driven rotating member,
• a rotor configured to rotate relative to the stator,
• a plurality of coils provided to rotate integrally with the rotor and configured to form different magnetic poles in a circumferential direction of the rotor by energization,
• a commutator configured to switch an energized state of the coils,
• a power switching brush provided to the drive rotating member and abutting on the commutator, and
• a motor output shaft fixed to the rotor, and configured to be rotated by energizing the coils through the power switching brush and the commutator;
• a speed-reduction mechanism configured to reduce a rotational speed of the motor output shaft and to transmit the reduced rotational speed of the motor output shaft to the driven rotating member;
• a slip ring provided to one of the drive rotating member and a fixed member facing the drive rotating member, and configured to feed electric power to the power switching brush;
• and
• a power-feeding brush provided to another of the drive rotating member and the fixed member, and being in contact with the slip ring,
• wherein a rotational position of the motor output shaft is detected on an inner circumferential side beyond a contact portion between the slip ring and the power-feeding brush and beyond a contact portion between the commutator and the power switching brush.