To provide a rocker arm bearing which can improve lubrication performance between an outer ring and a cam.
A rocker arm bearing 2 arranged at a dynamic valve mechanism 1 of an engine and assembled to a rocker arm 11 for opening and closing a valve 10 by the rotation of the cam 12 comprises: a support shaft 20 fixed to the rocker arm 11; the outer ring 21 which is arranged at an external periphery of the support shaft 20 and in which an external peripheral face 21a slides with the cam 12; and a plurality of rolling bodies 22 interposed between the outer ring 21 and the support shaft 20. A plurality of dynamic pressure generation oil grooves 3 are formed at the external peripheral face 21a of the outer ring 21 along the slide direction of the cam 12 which opposes the outer ring 21. Each dynamic pressure generation oil groove 3 includes a V-shaped part 3a at which a first groove 31 and a second groove 32 formed inclined to a reverse direction to each other with respect to the slide direction intersecting at a downstream end of the slide direction, and generates the fluid dynamic pressure of lubricant L at the downstream end of the V-shaped part 3a.
Takashi Nomiyama
Hiroyuki Ito
Next Patent: TRANSMISSION DEVICE FOR WORK VEHICLE