To provide a rocker arm at low cost and its needle-like roller bearing.
The rocker arm 1 is provided with an arm body 3 pivotably supported on a shaft 2 of an engine block; an operation part 4 provided on one end of the arm body 3; and the needle-like roller bearing 5 rotatably supported on the other end of the arm body 3. An outer ring 51 of the needle-like roller bearing 5 is functioned as a cam follower abutting on a cam 7 rotated in synchronous to an internal combustion engine (engine). The operation part 4 opens/closes an air feed/exhaust valve 6 of the internal combustion engine accompanying with pivot motion of the arm body 3. The permission upper limit value of surface roughness of a rolling surface of the outer ring 51 is 0.3 μm at a central line average roughness (Ra) and 0.2 μm at a lower limit value.
KATAYAMA AKIHIKO
Morishita Hachiro
Hiroyuki Yoshida
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