Valve-timing control device for internal combustion engine

A valve timing control device for an internal combustion engine comprising:

• a driving rotation member to which a rotational force is transmitted from a crank shaft;
• a driven rotation member fixed to a cam shaft;
• an electric motor provided to the driving rotation member;
• an eccentric rotation member which is provided to a motor output shaft, and which is eccentrically rotated with respect to a rotation center;
• an internal teeth constituting section provided to the driving rotation member, and which includes a plurality of internal teeth that are formed on an inner circumference;
• a plurality of rolling members which are provided on an outer circumference side of the eccentric rotation member at a substantially regular interval in a circumferential direction, and engaging portions between the rolling members and the internal teeth being moved in the circumferential direction by the eccentric rotation of the eccentric rotation member, and
• a holding member which is provided to the driven rotation member, and which has holding holes that are configured to restrict a circumferential movement of each of the rolling members, and to allow a radial movement of the each of the rolling members,
• a movable range of the each of the rolling member being set within an angle range of 0.01° to 0.4° in a circumferential direction from a center line extending from a rotation axis of the driving rotation member in a radial direction, in a space which is constituted by the eccentric rotation member, the internal teeth constituting section, and the one of the holding holes, and which receives the one of the rollers.

A assembling method of a valve timing control device for an internal combustion engine which includes a driving rotation member to which a rotational force is transmitted from a crank shaft, and a driven rotation member fixed to a cam shaft to which the rotational force is transmitted from the driving rotation member, the valve timing control device being vary a relative rotation position of the driven a rotation member with respect to the driving rotation member, and thereby to vary operation characteristics of an engine valve, the assembling method comprising:

• providing an electric motor, a speed reduction mechanism configured to reduce a speed of a rotation of an output shaft of the electric motor, and to vary a relative rotation phase between the driving rotation member and the driven rotation member, the speed reduction mechanism including an eccentric rotation member provided to the motor output shaft of the electric motor, an internal teeth constituting section which is provided to the driving rotation member, and which has a plurality of internal teeth provided on an inner circumference, a plurality of rolling members which are provided on an outer circumference side of the eccentric rotation member in a circumferential direction, and engaging portions between the rolling members and the internal teeth being moved in the circumferential direction by the eccentric rotation of the eccentric rotation member, and a holding member which is provided to the driven rotation member, and which has holding holes that are configured to restrict a circumferential movement of each of the rolling members, and to allow a radial movement of the each of the rolling members,
• selectively assembling one or both of the eccentric rotation member and the internal teeth constituting section in accordance with an outside diameter of the rolling member so that a clearance in which the each of the rolling member is movable in the circumferential direction is within an angle range of 0.01° to 0.4° in a circumferential direction from a reference line extending from a rotation axis of the driving rotation member in a radial direction.