A reciprocating piston mechanism, a method of assembling this, and an internal combustion engine

摘要

A reciprocating piston mechanism (2) is provided with a crankshaft (3) which is rotatably connected to a crankcase (5) and includes at least a crankpin (7), a connecting rod including a big end and a small end, a piston which is rotatably connected to the small end, and a crank member (13) which is rotatably mounted on the crankpin (7). The crank member (13) comprises at least a bearing portion (14) which is eccentrically disposed with respect to the crankpin (7) and has an outer circumferential wall (15) which bears the big end of the connecting rod such that the connecting rod is rotatably mounted on the crank member (13) via the big end. The reciprocating piston mechanism (2) is provided with a rotary mechanism for rotating the crank member (13) with respect to the crankpin (7). The crank member (13) is made of at least two parts which are fixed to each other around the crankpin (7). An internal combustion engine may be provided with the reciprocating piston mechanism (2).