| 摘要 |
PROBLEM TO BE SOLVED: To inhibit increase in surface pressure to prevent abrasion and separation and to improve performance of an internal combustion engine by applying crowning to a contact surface with a cam in a tappet roller, and forming the generating line of the crowning to satisfy a specified condition. SOLUTION: In this tappet roller rotatably journalled to abut on a cam of a cam shaft, crowning is applied to its contact surface with the cam. When the half of an effective contact length in the direction of a generating line of the contact surface is taken to be Le, the shape of the generating line of the crowning is set so that when the crowning fall amount δ in the axial position x taking the center of the contact surface as an origin satisfies the expression: 1/E'=(1-ν12)/E1+(1-ν22)/E2 (wherein, E1 and E2 are the respective longitudinal elastic coefficients of contact surfaces of the tappet roller and the cam; ν1 and ν2 are the respective Poisson's ratios of the contact surface materials of the tappet roller and the cam; and 1n is natural logarithm function). |
