Patent ID: 7055480

Claim:
A valve gear of an internal combustion engine, comprising: a cam mechanism for converting rotational motion of an electric motor into linear motion to drive a valve for opening and closing a cylinder against a valve spring; and a torque reduction mechanism for adding an opposite torque, which serves so as to reduce a torque applied to the cam mechanism from the valve spring at the time of driving the valve, to the cam mechanism, wherein the torque reduction mechanism comprises an opposite phase cam which rotates in an interlocking manner at a rotational speed of 1/N (where N is an integral number) times of the rotational speed of a cam in the cam mechanism and has a cam surface formed on a surface thereof, a cam holding member which is in contact with the cam surface, and an urging member which urges the cam holding member toward the cam surface of the opposite phase cam, and an outline of the cam surface in the opposite phase cam is set such that an opposite torque canceling a valve spring torque applied to the cam mechanism based on the reaction force of the valve spring is applied to the opposite phase cam from the urging member.