Patent ID: 8469844

Claim:
An engine comprising: a case member; a drive shaft journaled on the case member; a drive rotation member secured to the drive shaft; a driven shaft journaled on the case member; a driven rotation member secured to the driven shaft; an endless transmission belt connected to the drive rotation member and the driven rotation member; a guide member disposed so as to make contact with the endless transmission belt, one end section of the guide member being swingably supported on the case member and the other end section of the guide member a free end; and a chain tensioner for pressing the free end of the guide member to apply tension to the endless transmission belt, wherein the chain tensioner includes: (i) an accommodating concave section disposed in the case member, wherein an outer side of the accommodating concave section in a direction parallel to an axis of rotation of the drive shaft has an opening section; (ii) an elastic member being accommodated in the accommodating concave section to press the guide member toward the endless transmission belt; and (iii) a lid member covering the opening section of the accommodating concave section in the direction of the axis of rotation of the drive shaft.