| 摘要 |
PURPOSE:To check a jumping phenomenon in a belt as well as to surely prevent the occurrence of irregular driving force transmission, by installing a belt guide, which faces on the peripheral surface of a timing belt with a small clearance in between. CONSTITUTION:A crankshaft 5 is supported by a bearing part 31 and a bearing cap 41 of a crankcase 2 at a journal part 61 and transmits the driving force of a valve from a toothed drive pulley 11 via a timing belt 4. On one side of the bearing cap 41, a belt guide 17 facing on the peripheral surface of the timing belt 14 with a small celearance in between is projectingly installed whereby jumping in the timing belt is checked and the irregular transmission of driving force attributable to the jumping of the timing belt is prevented. |
