Patent ID: 7484485

Claim:
A variable-valve-actuation (VVA) apparatus for an internal combustion engine with a valve, comprising: a control shaft arranged to be rotatable in accordance with operating conditions of the engine; an alteration mechanism which changes at least an operating angle of the valve in accordance with rotation of the control shaft; and a drive mechanism which rotates the control shaft, the drive mechanism comprising an electric motor and a reduction mechanism, the reduction mechanism comprising: an output shaft linked to the motor and having an external thread formed on an outer peripheral surface; a moving member having an internal thread formed on an inner peripheral surface, wherein the external thread is meshed with the internal thread, the moving member moving in an axial direction of the output shaft in accordance with rotation of the output shaft; a link member having a first end swingably linked to the moving member; and a linkage swingably linked to a second end of the link member, the linkage rotating the control shaft by torque transmitted from the link member in accordance with axial movement of the moving member, wherein when the valve is under control of small operating angle, an angle formed between the link member and the output shaft is relatively large.