Patent ID: 6932036
Filing Date: 2005-08-23
Classification: F01L,F01P

Abstract:
1. An electromagnetic-brake cooling structure of a phase varying apparatus for use with an automobile engine, said phase varying apparatus including: an annular sprocket to which the driving power of the crank shaft of said engine is transmitted; a camshaft coaxial with, and slidable relative to, said annular sprocket, said camshaft constituting a valve mechanism; a rotational drum rotatably supported by said camshaft; and an electromagnetic brake means mounted at an axial position facing said rotational drum for applying a retarding force onto said rotational drum such that said retarding force causes a delay in rotational motion of said rotational drum to vary the phase of said camshaft relative to said sprocket, said electromagnetic brake means including: an annular clutch case pinned not to rotate about its axis and having a U-shaped cross section with its open end facing a disc-shaped surface of said rotational drum; an electromagnetic coil housed in said clutch case; a plate for holding a friction member (friction member holding plate) fixed inside the opening of said clutch case; and a generally flat friction member bonded to said friction member holding plate and having a surface slightly projecting from the leading edges of the inner and outer circular walls of said clutch case; an oil sump formed in a radially small section of said clutch case, said oil sump communicating with an oil passage of said camshaft and with the radially inner potions of the sliding sections of said clutch case and rotational drum; oil lead-in notches formed in the leading edge of the inner circular wall of said clutch case to lead engine oil from said oil sump to the sliding surfaces of said friction member and rotational drum via said oil lead-in notches, wherein oil lead-out notches are formed in the leading edge of the outer wall of said clutch case to outwardly lead said engine oil from said sliding surfaces of said friction member and rotational drum to the outside of said of the clutch case.