| 摘要 |
PROBLEM TO BE SOLVED: To provide a valve timing control device in which a phase in an opening/closing timing of an engine valve even in a cold start can be stabilized in a phase suitable for starting.SOLUTION: A valve timing control device includes an electric motor 12 which relatively rotates a motor output shaft 13 with respect to a timing sprocket 1, and a speed reducer 8 which decelerates the rotation of the motor output shaft to transmit it to a driven member 9. Grease 45 which has a property of becoming semi-solid at normal temperature or lower and decreases in viscosity when a predetermined time passes after engine start is charged in and applied to rotating parts of ball bearings 37, 43, 47, a needle bearing 38, and the like, and friction parts of a retainer 41 and the like, provided inside the speed reducer, and the effect of the alternate torque in cold start is controlled by this viscous resistance so that stabilization of starting can be achieved. |
