Patent ID: 7051696

Claim:
A bearing structure of a crankshaft in an internal combustion engine comprising a cylinder block and a crankcase which is integrally connected to the cylinder block, wherein a crankshaft which is connected with a piston slidably fitted in a cylinder of the cylinder block by way of a connecting rod in an interlocking manner is rotatably supported in a bearing hole of the crankcase by way of a rolling bearing, the bearing structure comprising: play absorbing means for preventing a play in the radial direction between the rolling bearing and the bearing hole, wherein the play absorbing means includes a push plug which pushes an outer race of the rolling bearing in the direction perpendicular to an axis of the crankshaft, the push plug being arranged parallel to the crankshaft between the cylinder and the crankshaft, and the outer race of the rolling bearing being resiliently biased toward a side of the bearing hole of the crankcase which receives an explosion pressure, wherein the play absorbing means includes: a spring set plate which is fixed to the crankcase by a bolt; and a spring member which is interposed between the push plug and the spring set plate and resiliently biases the push plug toward the outer race, wherein the spring set plate includes a bent portion which is bent toward the crankcase and the bent portion is, when the spring member is in a free elongation state and the spring set plate is in a temporarily stopped state, engaged with a positioning portion which is formed on the crankcase thus enabling the positioning of the spring set plate.