Lift-variable valve-operating system for internal combustion engine

A lift-variable valve-operating system for an internal combustion engine, comprising:

• a subsidiary cam swingably carried on a movable support shaft that is displaceable in a plane perpendicular to a rotational axis of a valve-operating cam and which swing follows the valve-operating cam;
• a cam follower operatively connected to an engine valve and which is operated to follow the subsidiary cam,
• wherein a lift amount of the engine valve is varied by displacing the movable support shaft,
• a control arm connected to the movable support shaft and which is turnable about an axis parallel to the rotational axis of the valve-operating cam;
• and
• drive means for turnably driving the control arm,
• wherein the subsidiary cam, which has an oil sump provided in an upper surface and is opened upwards to store oil, is provided with an abutment face and a lubricating oil bore,
• wherein the abutment face of the subsidiary cam abuts against the cam follower, and includes a lift portion for turnably driving the cam follower;
• and a base circle portion connected to the lift portion and equally spaced apart from the axis of the movable support shaft to retain the cam follower in a rest state, and
• wherein the lubricating oil bore guides the oil in the oil sump to the base circle portion.