Patent ID: 7836861

Claim:
A variable valve mechanism for an internal combustion engine, comprising: a camshaft rotatably provided in an internal combustion engine; a cam formed in the camshaft; a rocker arm provided in the internal combustion engine and drives a valve; a swing cam swingably provided in the internal combustion engine and drives the rocker arm by receiving displacement of the cam; and a transmission member interposed between the swing cam and the cam and transmits the displacement of the cam to the swing cam, wherein the rocker arm includes, a rolling roller member which includes a fixed inner ring, an outer ring provided coaxially with the inner ring and accommodating the inner ring in its inside, and a plurality of rolling elements accommodated between the inner ring and the outer ring and supporting the outer ring in a rotatable manner with respect to the inner ring, and receives the displacement of the swing cam in a state that the outer ring is in rolling contact with the swing cam, and in a transmission path through which the displacement of the cam is transmitted to the swing cam, each of a first transmission part, in which the displacement of the cam is transmitted from the cam to the transmission member, and a second transmission part, in which the displacement of the cam is transmitted from the transmission member to the swing cam, includes a sliding roller member which transmits the displacement of the cam on an outer peripheral surface and is rotatably supported by a support part, wherein an inner peripheral surface of the sliding roller member is in surface contact with the support part, and the inner peripheral surface and the support part make a sliding bearing mechanism, wherein the diameter of the outer peripheral surface of each sliding roller member is larger than the diameter of the outer ring of the rolling roller member, and wherein the diameter of the outer peripheral surface of the sliding roller member of the first transmission part is larger than the diameter of the outer peripheral surface of the sliding roller member of the second transmission part.