Patent ID: 7640819

Claim:
An internal combustion engine comprising: a transmission for transmitting power from a crankshaft to an output shaft through speed change, with the speed change in said transmission being performed by the driving of a speed change electric motor through a speed change drive mechanism, wherein power transmission control means for controlling the transmission of power from said crankshaft to said transmission is provided at one end of said crankshaft, and at least a part of said speed change electric motor and said speed change drive mechanism is disposed on an outside of said power transmission control means, wherein said speed change drive mechanism includes an idle gear shaft integrally and coaxially provided with a large diameter gear and a small diameter gear which are operative to transmit rotational power of a motor drive shaft of said speed change drive mechanism to a shift spindle through speed reduction; said transmission includes a main shaft to which power is inputted by said power transmission control means, and a counter shaft for transmitting the rotational power of said main shaft to said output shaft; and an arrangement of said motor drive shaft, said idle gear shaft and said shift spindle and an arrangement of said main shaft and said counter shaft are so set as to avoid an area between said crankshaft and said output shaft.