A valve timing adjusting apparatus, provided to a transmission system that transmits driving torque of a driving shaft of an internal combustion engine to a driven shaft that opens and closes at least one of an exhaust valve and an intake valve, for adjusting opening and closing timing of at least one of said exhaust valve and said intake valve, said apparatus comprising:
- a rotating member including a first internal gear and a second internal gear each using a driven axis, which is an axis of said driven shaft, as a rotational center line, and rotating around said driven axis with said driving torque of said driving shaft;
- a first eccentric shaft off-center with respect to said driven axis and rotating around said driven axis in association with a rotation of said rotating member;
- a first planetary gear supported on an outside wall of said first eccentric shaft to enable a relative rotation around a first eccentric axis, which is an axis of said first eccentric shaft, and rotating around said driven axis in association with a rotation of said rotating member through engagement with said first internal gear;
- a first output shaft coupled to said driven shaft that rotates around said driven axis together with said driven shaft in association with a rotation of said first planetary gear through engagement with said first planetary gear;
- a first brake portion for transmitting a first torque to said first eccentric shaft in a direction opposite to a rotational direction thereof;
- a second eccentric shaft off-center with respect to said driven axis, which rotates around said driven axis in association with a rotation of said rotating member;
- a second planetary gear supported on an outside wall of said second eccentric shaft to enable relative rotation around a second eccentric axis, which is an axis of said second eccentric shaft, which rotates around said driven axis in association with a rotation of said rotating member through engagement with said second internal gear;
- a second output shaft coupled to said first eccentric shaft that rotates around said driven axis together with said first eccentric shaft in association with a rotation of said second planetary gear through engagement with said second planetary gear;
- and
- a second brake portion for transmitting a second torque to said second eccentric shaft in a direction opposite to a rotational direction thereof, wherein:
- upon transmission of said first torque from said first brake portion to said first eccentric shaft while the first eccentric shaft rotates, said first eccentric shaft starts to rotate in a retarding direction relative to said rotating member, which causes said first planetary gear to rotate in an advancing direction together with said first output shaft and said driven shaft relative to said rotating member while maintaining rotation in the advancing direction relative to said first eccentric shaft;
- and
- upon transmission of said second torque from said second brake portion to said second eccentric shaft that is rotating, said second eccentric shaft starts to rotate in the retarding direction relative to said rotating member, which causes said second planetary gear to rotate in the advancing direction together with said second output shaft and said first eccentric shaft relative to said rotating member while maintaining rotation in the advancing direction relative to said second eccentric shaft, and causes said first planetary gear to rotate in the retarding direction together with said first output shaft and said driven shaft relative to said rotating member while maintaining rotation in the retarding direction relative to said first eccentric shaft.