Patent ID: 6390045
Filing Date: 2002-05-21
Classification: F01L,F02B,Y10T

Abstract:
By A variable valve timing apparatus for an internal combustion engine, comprising:a rotary crank body adapted to be coaxially coupled with a camshaft, and to be operatively rotated by a crankshaft; a moving member operatively coupling said rotary crank body to the camshaft along a rotational torque transmission path that transmits torque from said rotary crank body to the camshaft; a drum operatively coupled to said moving member to move said moving member in an axial direction relative to said drum upon relative rotational movement between said drum and said moving member; a biasing member elastically coupling said drum to said rotary crank body to apply a biasing force on said drum in a direction of rotation of the camshaft relative to said rotary crank body; an electromagnetic brake disposed opposite an axial side surface of said drum to attract said axial side surface of said drum towards said electromagnetic brake with a magnetic force upon energizing said electromagnetic brake to delay rotation of said drum about the camshaft and to change a phase of the camshaft relative to a phase of said rotary crank body due to an axial movement of said moving member; a cover fixed to an engine main body side of said electromagnetic brake to cover said electromagnetic brake; and a rotation regulation mechanism operatively coupled between a wall portion of said electromagnetic brake and a wall portion of said cover to regulate relative rotation of said electromagnetic brake about the camshaft relative to said cover, said rotation regulation mechanism including first and second protrusions provided on one of said wall portions and first and second concavities provided on the other of said wall portions, said wall portions being opposing each other with said first and second protrusions being coupled to said first and second concavities, respectively, said first and second protrusions lying on a base line passing substantially through a center of said drum.