Hybrid vehicle driving system

A hybrid vehicle driving system to be used in a hybrid vehicle which utilizes an internal combustion engine and an electric motor as drive sources, the hybrid vehicle driving system including:

• a transmission having:
• a first transmission mechanism in which mechanical driving force from an output shaft of the internal combustion engine and the electric motor is received by a first input shaft which is in engagement with the electric motor so as to put any of plural gears in an engaged state to thereby bring the first input shaft and driving wheels into engagement with each other;
• a second transmission mechanism in which the mechanical driving force from the output shaft of the internal combustion engine is received by a second input shaft so as to put any of plural gears in an engaged state to thereby bring the second input shaft and the driving wheels into engagement with each other;
• a first engaging and disengaging unit which can bring the output shaft of the internal combustion engine and the first input shaft into engagement with each other;
• and
• a second engaging and disengaging unit which can bring the output shaft of the internal combustion engine and the second input shaft into engagement with each other,
• a lubrication pump which is connected to the first input shaft to thereby implement the lubrication of the transmission;
• and
• a lubricated state determination unit which determines a lubricated state of the transmission,
• wherein, when the lubricated state determination unit determines that lubrication is necessary, the lubrication pump is driven by rotating the first input shaft by the electric motor, or the lubrication pump is driven by rotating the first input shaft by the internal combustion engine by engaging the first engaging and disengaging unit.