Abstract: A transmission system for a hybrid electric vehicle includes a planetary gear mechanism, a gear, a parking lock mechanism, and a resistance imposing device. A parking meshing member of the parking lock mechanism acts so as to switch between a first state where a claw is in mesh with a parking gear and a second state where the claw is out of mesh with the parking gear. The resistance imposing device includes a resistance imposing member configured to impose a rotational resistance on the parking gear or a third rotating element of the planetary gear by coming in contact with the parking gear or the third rotating element. The resistance imposing device is configured to operate the resistance imposing member such that a larger rotational resistance is imposed on the third rotating element in the first state than in the second state.

Abstract: A gear change from a parking position is predicted, in response to an ON operation of a gearshift cancellation button concurrently with the driver's depression of a brake pedal. The control procedure of the invention sets an auxiliary driving force F* in a direction of canceling a force, which acts in a longitudinal direction of a motor vehicle based on a road surface gradient ?. When the auxiliary driving force F* is less than a preset driving force F1, a motor MG2 is controlled to output the auxiliary driving force F*. When the auxiliary driving force F* is not less than the preset driving force F1, on the other hand, motors MG2 and MG3 are controlled to cooperatively output the auxiliary driving force F*. This arrangement effectively reduces the force in the longitudinal direction of the motor vehicle applied to a parking mechanism and ensures a smooth gearshift operation of a gearshift lever from the P position to another gear position.

Abstract: In response to a brake OFF operation (step S110) after a gearshift operation of a gearshift lever to a parking position, a motor is controlled to output a torque corresponding to an adjusted driving force F*, which is applied in a direction of canceling a force component of a vehicle weight M acting in a longitudinal direction of a motor vehicle based on a measured road surface gradient ? (steps S120 to S180). Such control reduces the force applied in the longitudinal direction of the vehicle and decreases the moving speed of the vehicle. The decreased moving speed of the vehicle enables moderate engagement of gears in a parking lock mechanism to decrease the potential shock of gear engagement and reduces the driver's feeling of idle running.

Abstract: A hybrid vehicle may run with only the power from a motor MG2, while an engine is at a stop. In this state, the control procedure drives a motor MG1 to rotate a crankshaft at an idling engine speed for a predetermined time period, when at least one of an observed oil temperature in a sump, an observed temperature of the motor MG1, an observed temperature of the motor MG2, an observed revolving speed of the motor MG1, and an observed revolving speed of the motor MG2 is not less than a corresponding preset value. Rotation of the crankshaft at the idling engine speed results in driving an oil pump to feed a supply of lubricating oil to mechanical part of the power output apparatus including a power distribution integration mechanism.

Abstract: A hybrid vehicle 20 may run with only the power from a motor MG2, while an engine 22 is at a stop. In this state, the control procedure drives a motor MG1 to rotate a crankshaft 26 at an idling engine speed for a predetermined time period, when at least one of an observed oil temperature in a sump 62, an observed temperature of a motor MG1, an observed temperature of another motor MG2, an observed revolving speed of the motor MG1, and an observed revolving speed of the motor MG2 is not less than a corresponding preset value. Rotation of the crankshaft 26 at the idling engine speed results in driving an oil pump 60 to feed a supply of lubricating oil to mechanical part of the power output apparatus including a power distribution integration mechanism 30.

Abstract: An oil pressure generator 20 includes a drive gear 30, a driven gear 32, and a crescent 34, which constitute a gear pump unit, as well as one-way clutches 36 and 38 that respectively interlock with two rotating shafts 42 and 46 when the rotating shafts 42 and 46 rotate in an identical direction relative to the drive gear 30. In case that both the rotating shafts 42 and 46 rotate in the interlocking direction, the corresponding one-way clutch interlocks with the rotating shaft having a greater revolving speed, thereby driving the drive gear 30. This structure enables the oil pressure generator 20 to produce an oil pressure through rotation of the rotating shaft having a greater revolving speed out of the two rotating shafts 42 and 46.