| 摘要 |
<p>A cam lobe (62, 72) of a camshaft (6, 7) has a base circle portion (72a) and a lifting lobe portion (72b). A camshaft journal (61, 71) of the camshaft (6, 7) has first and second bearing portions (71a and 71b) that bear reaction forces from the base circle portion (72a) and the lifting lobe portion (72b), respectively. The first bearing portion (71a) has an axial width (w1) smaller than that of the second bearing portion (71 b) with at least a portion of an axial end surface of the first bearing portion (71a) facing the cam lobe (62, 72) being disposed away from the cam lobe (62, 72) relative to an axial end surface of the second bearing portion (71b). The base circle portion (72a) has an axial width (w3) smaller than that of the lifting lobe portion (72b) with at least a portion of an axial end surface of the base circle portion (72a) facing the camshaft journal (61, 71) being disposed away from the camshaft journal (61, 71) relative to an axial end surface of the lifting lobe portion (72b).</p> |
