Patent ID: 8232697

Claim:
A power unit comprising: a connection shaft section that connects an output shaft of an engine and an input shaft to which a drive force of the output shaft is transmitted; a generator motor provided in an outer circumferential section of the connection shaft section, the generator motor including a rotor that rotates integrally with the connection shaft section; an external spline that is formed in parallel with a center axis direction of the connection shaft section to form a spline joint with one of the output shaft and the input shaft at an outer circumferential surface on one end section side of the connection shaft section; and an internal spline that is formed in parallel with the center axis direction of the connection shaft section to form a spline joint with one of the input shaft and the output shaft at an inner circumferential surface on the other end section side of the connection shaft section, wherein the connection shaft section includes a hole that communicates with a hollow recess that forms the internal spline and opens to an end face on the one end section side of the connection shaft section, and an oil passage communicating the internal spline with the external spline includes the hole and a gap formed between the end face on the one end section side of the connection shaft section and one of the output shaft and the input shaft.