Cam follower for rocker arm and cam follower device

Abstract

A cam follower for a rocker arm includes a cylindrical outer ring ( 11 ) having an outer circumference surface abutting on a cam, a support shaft ( 6 ) to support the outer ring ( 11 ), a plurality of rollers ( 12 ) arranged in an annular region between the support shaft ( 6 ) and the outer ring ( 11 ), and a side plate ( 16 ) composed of a ring-shaped disk penetrated by the support shaft ( 6 ), opposed to an end face ( 15 ) of the roller ( 12 ), and having an outer diameter Ds smaller than an inner diameter Dr of the outer ring ( 11 ), in which the side plate ( 16 ) is arranged at each end of the roller ( 12 ), and a relationship Lr<Lk+2t is satisfied in which Lk represents a shaft length of the roller ( 12 ), Lr represents a shaft length of the outer ring ( 11 ), and t represents a thickness of the side plate ( 16 ).

1 . A cam follower for a rocker arm comprising:
 a cylindrical outer ring having an outer circumference surface abutting on a cam;   a support shaft to support said outer ring;   a plurality of rollers arranged in an annular region between said support shaft and said outer ring; and   a side plate composed of a ring-shaped disk penetrated by said support shaft, opposed to an end face of said roller, and having an outer diameter smaller than an inner diameter of said outer ring, wherein   said side plate is arranged at each end of said roller, and a relationship Lr<Lk+2t is satisfied in which Lk represents a shaft length of said roller, Lr represents a shaft length of said outer ring, and t represents a thickness of said side plate.   
     
     
         2 . The cam follower for the rocker arm according to  claim 1 , wherein a relationship PCD<Ds is satisfied in which PCD represents a pitch circle diameter of said roller, and Ds represents the outer diameter of said side plate. 
     
     
         3 . The cam follower for the rocker arm according to  claim 1 , wherein
 said shaft length Lk of the roller and said shaft length Lr of the outer ring further satisfy Lk<Lr.   
     
     
         4 . The cam follower for the rocker arm according to  claim 1 , wherein said side plate has surface hardness of Hv 550 or more. 
     
     
         5 . The cam follower for the rocker arm according to  claim 1 , wherein said side plate has surface roughness of 0.8 μm or less in terms of the arithmetic average roughness Ra. 
     
     
         6 . The cam follower for the rocker arm according to  claim 1 , wherein each of said outer ring, said support shaft, said roller has a nitrogen enrichment layer, and
 an austenite grain of said nitrogen enrichment layer of at least one member of said support shaft and the roller is miniaturized so as to have the grain size number 10 or more, a residual austenite amount of said nitrogen enrichment layer of said member ranges from 11% by volume to 25% by volume, and a nitrogen content of said nitrogen enrichment layer of said member ranges from 0.1% by mass to 0.7% by mass.   
     
     
         7 . The cam follower for the rocker arm according to  claim 1 , wherein
 a crowning part is provided in at least one of a rolling surface of said roller and an inner circumference surface of said outer ring serving as the rolling surface of said roller.   
     
     
         8 . A cam follower device comprising:
 a sway member having a pair of leg parts;   a support shaft extending across said pair of leg parts;   a cylindrical outer ring rotatably supported by said support shaft and having an outer circumference surface, an inner circumference surface, and an end face, said outer circumference surface abutting on a cam;   a plurality of rollers arranged in an annular region between said support shaft and said outer ring; and   a side plate composed of a ring-shaped disk penetrated by said support shaft, having an outer diameter smaller than an inner diameter of said outer ring, and arranged between an end face of said roller and said leg part, wherein   said side plate is arranged at each end of said roller, and a relationship Lr<Lk+2t is satisfied in which Lk represents a shaft length of said roller, Lr represents a shaft length of said outer ring, and t represents a thickness of said side plate.