Camshaft bearing structure for over-head camshaft type internal combustion engine

The structure has a camshaft (21) provided with a cam chain sprocket (27). A bearing portion (41) is formed adjacent to the sprocket on the covered surface of a cylinder head. A journal portion (25) is provided between the bearing portion and a bracket (51) and is axially supported and to be sandwiched. A covered surface of the cylinder head, intake camshaft and an exhaust camshaft are arranged parallel to each other.