Abstract: A control mechanism for shifting the rotational phase transmitted from an engine, and for controlling the timing of the intake and exhaust valves. A first gear mechanism integrally rotates with respect to a timing pulley, and has a set of inner peripheral gear teeth. A second gear mechanism integrally rotates with respect to a camshaft, and has a set of outer peripheral gear teeth. The number of gear teeth of the first gear mechanism is greater than that of the second gear mechanism. This gear ratio generates a rotational phase shift of the timing pulley with respect to the camshaft, in order to vary the opening and closing timing of the intake and exhaust valves. A drive means drives the first gear mechanism in order to vary the phase shift and to control the opening and closing timing of the intake and exhaust valves in accordance with the operating state of the engine.

Abstract: Disclosed is an apparatus for shifting a phase between shafts in an internal combustion engine. A phase shifting device for shifting a rotational phase of the driven shaft to the drive shaft and an amplifying gear mechanism having a plurality of gears are disposed between the drive shaft and driven shaft. The amplifying gear mechanism amplifies the amount of phase shifting when the phase shifting is made by the phase shifting device and rotates all the gears integrally when no phase shifting is made.