Hybrid vehicle

1. A hybrid vehicle comprising:

an engine comprising a cylinder and a crankshaft;

a drive motor comprising a motor housing and a motor drive shaft projecting laterally from the motor housing;

a transmission comprising an input shaft, an output shaft, and a gear train, the transmission being configured to change the speed of rotation produced by rotational power transmitted from the engine and the drive motor to the input shaft and output the resulting rotation to a drive wheel;

a main clutch connected to one end of the input shaft of the transmission and disposed in a power transmission route between the crankshaft of the engine and the input shaft of the transmission;

a crankcase accommodating the crankshaft, the input shaft, the output shaft, the gear train, and the main clutch; and

a power transmission mechanism that transmits power from the motor drive shaft to the input shaft, wherein

the crankcase comprises: a main body portion aligned with the drive motor in a direction perpendicular to the motor drive shaft; and an extended portion continuous with the main body portion and located lateral to the motor housing, the extended portion receiving insertion of one end of the motor drive shaft, and

the power transmission mechanism is located partly in a first region defined by the main body portion and partly in a second region defined by the extended portion and communicating with the first region.

2. The hybrid vehicle according to claim 1 , wherein

the drive motor is disposed rearwardly of the cylinder and above the main body portion of the crankcase, and

the extended portion projects upwardly from the main body portion so as to be located lateral to the motor housing.

3. The hybrid vehicle according to claim 1 , wherein

the motor housing comprises a projecting tubular portion into which the motor drive shaft is inserted,

the extended portion comprises an insertion hole into which the projecting tubular portion is inserted with a sealing member interposed between the extended portion and the projecting tubular portion, and

the motor drive shaft extends through the insertion hole and the projecting tubular portion and leads to a region inside the extended portion.

4. The hybrid vehicle according to claim 1 , wherein

the crankcase comprises a case body and a cover removably mounted on the case body,

a main chamber accommodating at least the crankshaft, the input shaft, the output shaft, and the gear train is formed in the case body,

a subsidiary chamber accommodating at least the main clutch is formed between the case body and the cover, and

the first region and the second region are located in the subsidiary chamber.

5. The hybrid vehicle according to claim 4 , wherein

the crankcase comprises an engine lubricating oil passage through which a lubricating oil for lubrication of the engine flows and a motor power system lubricating oil passage branching from the engine lubricating oil passage, and

the extended portion comprises a discharge outlet through which a lubricating oil flowing in the motor power system lubricating oil passage is discharged into the second region.

6. The hybrid vehicle according to claim 5 , wherein

the motor power system lubricating oil passage is formed partly in the case body and partly in the cover, and

the discharge outlet is formed in the cover.

7. The hybrid vehicle according to claim 4 , wherein the cover comprises a portion covering the first region from outside in a vehicle width direction of the hybrid vehicle and a portion covering the second region from outside in the vehicle width direction, the portion covering the second region being located inwardly of the portion covering the first region in the vehicle width direction.

8. The hybrid vehicle according to claim 4 , wherein the cover is divided into a first cover covering the first region from outside in a vehicle width direction of the hybrid vehicle and a second cover covering the second region from outside in the vehicle width direction, the second cover being separate from the first cover.

9. The hybrid vehicle according to claim 1 , wherein

the hybrid vehicle is a straddle vehicle on which a rider is seated in a straddling position, and

the crankshaft, the input shaft, and the output shaft extend in a vehicle width direction of the straddle vehicle.