Patent ID: 8210137

Claim:
A link type variable stroke engine in which a piston slidably fitted to a cylinder block; a crankshaft rotatably supported at a crankcase; and a rotary shaft having an axis parallel with the crankshaft, being rotatably supported at the crankcase, and being provided with an eccentric shaft at an eccentric position, are linked by a linking mechanism, the linking mechanism including: a sub connecting rod having a connection tubular part into which a crank pin of the crankshaft is relatively rotatably fitted, and being rotatably connected with the crank pin; a main connecting rod connecting the sub connecting rod and the piston; and a swing rod connecting the sub connecting rod and the eccentric shaft, and oil scattered in the crankcase is guided to a position between the connection tubular part of the sub connecting rod and the crank pin, wherein an oil supply hole for supplying lubricating oil to the position between the connection tubular part of the sub connecting rod and the crank pin is provided in an upper portion of the connection tubular part at a position which is deviated from a direction of application of maximum load applied from the crank pin to an inner surface of the connection tubular part by maximum in-tube pressure, and which is immediately behind a point of application of the maximum load along a direction in which the crank pin rotates relative to the sub connecting rod.