Variable valve mechanism for engine

A variable valve mechanism mounted on an engine, the variable valve mechanism comprising:

• a camshaft;
• and
• a cam unit fitted around the camshaft, the cam unit including a plurality of cams, one cam of the plurality of cams configured to be selected by causing the cam unit to slide in an axial direction, wherein
• internal spline teeth provided at an inner periphery of a sleeve of the cam unit are in mesh with external spline teeth provided at an outer periphery of the camshaft,
• a dent ball is provided at one of the inner periphery of the sleeve and the outer periphery of the camshaft, the dent ball is configured to retractably project toward a remaining one of the inner periphery of the sleeve and the outer periphery of the camshaft,
• an annular groove provided at the remaining one of the inner periphery of the sleeve and the outer periphery of the camshaft, the annular groove is configured to latch the dent ball, and
• the sleeve has a through-hole provided at a same position in a circumferential direction as the dent ball, the through-hole is configured to supply the inner periphery of the sleeve with lubricating oil that is supplied to an outer periphery of the sleeve.