Patent ID: 7694597
Filing Date: 2010-04-13
Classification: F01M,F02B,F16H,Y10T

Abstract:
1. A power unit for a vehicle, the power unit comprising an internal combustion engine and a transmission, the internal combustion engine comprising a crankshaft rotatably supported in a crankcase, the crankcase adapted to receive part of the transmission, the crankcase formed with an oil storage portion located in an inner lower side thereof, the oil storage portion adapted to collect lubricating oil, the transmission transmitting the rotation of the crankshaft to vehicle wheels, the transmission comprising: a gear chamber supported by the crankcase; an input shaft, an intermediate shaft and an output shaft which are housed in the gear chamber; and gear trains executing power transmission among the input shaft, the intermediate shaft and the output shaft, wherein a communicating port extends between the crankcase and the gear chamber, the communicating port being formed in one side face of the crankcase and allowing the gear chamber to communicate with a crank chamber, the lubricating oil fed to the gear chamber is discharged through the communicating port to the inside of the crankcase and returned to the oil storage portion, the input shaft and the output shaft are arranged so that a line connecting a shaft center of the input shaft and a shaft center of the output shaft extends substantially horizontally, the intermediate shaft is disposed above and between the input shaft and the output shaft, and the communicating port is disposed below the intermediate shaft.