Camshaft apparatus

Abstract

Among a plurality of bearings that rotatably support a camshaft ( 1 ), the bearing closest to a pulley (P) is a rolling bearing ( 4 ), and the other bearings are plain bearings ( 3 ). The rolling bearing ( 4 ) is formed of a roller bearing portion ( 5 ) that has a first outer ring raceway surface ( 51 ) and a plurality of cylindrical rollers ( 53 ) that roll on the first outer ring raceway surface ( 51 ) and a ball bearing portion ( 6 ) that is arranged next to the roller bearing portion ( 5 ) in an axial direction and that has a second outer ring raceway surface ( 61 ) and a plurality of balls ( 63 ) that roll on the second outer ring raceway surface ( 61 ). The first outer ring raceway surface ( 51 ) and the second outer ring raceway surface ( 61 ) are formed on the inner peripheral surface ( 7 a) of a single outer ring ( 7 ).

1 . A camshaft apparatus that includes: a camshaft having a plurality of cams at predetermined intervals along an axial direction and one end to which a pulley is connected; and a plurality of bearings that rotatably support the camshaft on a housing, characterized in that:
 the bearing closest to, the pulley among the plurality of bearings is formed of a rolling bearing, and the other bearing is formed of a plain bearing,   the rolling bearing includes: a roller bearing portion that has a first outer ring raceway surface and a plurality of rollers that roll on the first outer ring raceway surface; and a ball bearing portion that is arranged next to the roller bearing portion in the axial direction and that has a second outer ring raceway surface and a plurality of balls that roll on the second outer ring raceway surface, and   the first outer ring raceway surface and the second outer ring raceway surface are formed on an inner periphery of a single outer ring.   
     
     
         2 . The camshaft apparatus according to  claim 1 , wherein a first inner ring raceway surface on which the rollers of the roller bearing portion roll and a second inner ring raceway surface on which the balls of the ball bearing portion roll are formed on an outer peripheral surface of the camshaft. 
     
     
         3 . The camshaft apparatus according to  claim 2 , wherein
 the camshaft includes a shaft body and a shaft member that is concentrically connected to one end of the shaft body and to which the pulley is connected, and   the first inner ring raceway surface and the second inner ring raceway surface are formed on an outer peripheral surface of the shaft member.