| 摘要 |
PROBLEM TO BE SOLVED: To certainly rotate a roller by securing a rolling fatigue life of respective outer peripheral surfaces of a cam and a roller even when a narrow roller is combined by specifying a ratio of width to outer diameter of the roller, and by securing traction of abutting portions by specifying an average value of contact surface pressures on the abutting portions of the respective outer peripheral surfaces. SOLUTION: A rocker arm 3 is provided for receiving motion of a cam 2 for the cam 2 fixed to a camshaft 1, a pair of support wall portions 4 are provided at these ends, and a shaft 5 is linked between these. A roller 6 is journalled around the shaft 5 via a roller 14, and an outer peripheral surface 6a of the roller 6 is abutted to an outer peripheral surface 2a of the cam 2. An maximum value of surface hardness on the outer peripheral surface 2a of the cam 2 is set at HRC 50 or more and the ratio B/D of width B to outer diameter D of the roller 6 is set at 0.25 or less. When mis-alignment, gradient of respective central axes of the cam 2 and the roller 6, is set to zero for example, an average value of contact surface pressures on the abutting portions of respective outer peripheral surfaces 2a, 6a of the cam 2 and the roller 6 is set at 150 kg/mm2 or less.
|
