HYBRID TRANSMISSION SYSTEM DETAILS


  1. CONSTRUCTION


    1. Hybrid Vehicle Transaxle Assembly


      1. This transaxle consists primarily of MG1, MG2, a compound gear unit, a transmission input damper assembly, a counter gear, a final gear, a differential gear unit and an oil pump.

      2. This transaxle has a 3-shaft configuration. The compound gear unit, a transmission input damper assembly, an oil pump, MG1 and MG2 are provided on the input shaft. The counter driven gear and the final drive gear are provided on the second shaft. The final driven gear and the differential gear unit are provided on the third shaft.

      3. The engine, MG1 and MG2 are mechanically joined via the compound gear unit.

        A01LPMTE09
        Text in Illustration
        *1 MG1 *2 MG2
        *3 Compound Gear Unit *4 Transmission Input Damper Assembly
        *5 Counter Driven Gear *6 Final Drive Gear
        *7 Final Driven Gear *8 Differential Gear Unit
        *9 Oil Pump - -

    2. Compound Gear Unit


      1. The compound gear unit consists of the power split planetary gear unit and the motor speed reduction planetary gear unit. Each planetary ring gear is integrated with the compound gear. Furthermore, this compound gear is integrated with a counter drive gear and parking gear.

      2. The power split planetary gear unit splits the motive force of the engine 2 ways: one to drive the wheels, and the other to drive MG1, so that MG1 can function as a generator.

      3. The motor speed reduction planetary gear unit, whose purpose is to reduce MG2 speed, is used to enable the high-speed, high-output MG2 to adapt optimally to the compound gear.

        A01LPDAE01
        Text in Illustration
        *1 Compound Gear Unit *2 Power Split Planetary Gear Unit
        *3 Counter Drive Gear (Compound Gear) *4 Motor Speed Reduction Planetary Gear Unit

      4. The connection of the sun gear, ring gear and carrier of each planetary gear unit is as shown below.

        Item Connection
        Power Split Planetary Gear Unit Sun Gear MG1
        Ring Gear Compound Gear (to Wheels)
        Carrier Input Shaft (from Engine)
        Motor Speed Reduction Planetary Gear Unit Sun Gear MG2
        Ring Gear Compound Gear (to Wheels)
        Carrier Fixed
        A01LPJ3E09
        Text in Illustration
        *1 MG1 *2 MG2
        *3 Power Split Planetary Gear Unit *4 Motor Speed Reduction Planetary Gear Unit
        *5 Counter Drive Gear *6 Sun Gear
        *7 Ring Gear *8 Carrier
        *9 Counter Driven Gear - -

    3. Transmission Input Damper Assembly


      1. A transmission input damper assembly that consists of a coil spring with low-twist characteristics is used in order to absorb the torque fluctuation in the motive force of the engine. The torque limiter uses a dry-type, single-plate friction material. Through the use of these parts, a damper construction that excels in absorbing the vibrations of the engine motive force has been achieved.

        A01LPNME01
        Text in Illustration
        *1 Torque Limiter *2 Coil Spring
        *a A-A Cross Section - -
        A01LPNB from Engine - -

    4. Oil Pump Mechanism


      1. The oil pump consists of the oil pump drive shaft, oil pump drive rotor, oil pump driven rotor and oil pump cover. The pump is driven by the engine via the input shaft and lubricates the gears.

        A01LP9SE08
        Text in Illustration
        *1 Oil Pump Drive Shaft *2 Oil Pump Drive Rotor
        *3 Oil Pump Driven Rotor *4 Oil Pump Cover

    5. Oil Sling Type Lubrication Mechanism


      1. This lubrication mechanism uses the final gear, which employs an oil sling type lubrication method via oil catch tanks. This construction minimizes the drive torque of the oil pump, which reduces the drive loss.

      2. Oil catch tanks are used in this transaxle in order to supply oil in a stable manner. The oil catch tanks temporarily store the oil that is slung up, and supply oil to the gears from there. Furthermore, oil holes are provided in the oil catch tanks in order to efficiently supply oil to MG1 and MG2.

        A01LP7RE08
        Text in Illustration
        *1 Input Shaft *2 Oil Hole
        *3 Oil Catch Tank *4 Second Shaft
        *5 Final Gear Rotational Direction *6 Third Shaft
        *7 Final Gear - -
        A01LPNB Oil Flow - -

  2. OPERATION


    1. Motive Force Transmission Path


      1. The motive force created by the engine and MG2 is transmitted by the counter drive gear of the compound gear unit, the counter driven gear, the final drive gear, and then the differential gear unit, in order to drive the front wheels.

        A01LPHPE01
        Text in Illustration
        *1 Engine *2 Transmission Input Damper Assembly
        *3 MG1 *4 Compound Gear Unit
        *5 Sun Gear *6 MG2
        *7 Oil Pump *8 Ring Gear
        *9 Carrier *10 Counter Drive Gear (Compound Gear)
        *11 Final Drive Gear *12 Counter Driven Gear
        *13 Final Driven Gear *14 Differential Gear Unit

    2. Engine Motive Force and MG2 Motive Force Transmission Path


      1. The engine motive force, which is input by the carrier, is output to the ring gear. The motive force of MG2 is output to the ring gear via the motor speed reduction planetary gear unit. The sum of these two motive forces is transmitted by the compound gear in order to drive the wheels.

        A01LPGUE10
        Text in Illustration
        *1 MG1 *2 MG2
        *3 Power Split Planetary Gear Unit *4 Motor Speed Reduction Planetary Gear Unit
        A01LPNB Rotation Direction A01LPNE from Engine
        A01LP95 from MG2 A01LPKC to Wheel

    3. MG2 Motive Force Transmission Path


      1. The motive force of MG2 is transmitted via the sun gear and is output to the ring gear, in order to drive the wheels. The carrier of the motor speed reduction planetary gear unit is fixed. As a result, the motor speed reduction planetary gear unit reduces the speed of MG2, increasing torque, in accordance with a set gear ratio. The rotation directions of forward and reverse becomes the opposite direction.

        A01LPBME06
        Text in Illustration (Driving Forward:)
        *1 MG1 *2 MG2
        *3 Power Split Planetary Gear Unit *4 Motor Speed Reduction Planetary Gear Unit
        A01LPNB Rotation Direction A01LPNE from MG2
        A01LP95 to Wheel - -
        A01LPN7E06
        Text in Illustration (Driving in Reverse:)
        *1 MG1 *2 MG2
        *3 Power Split Planetary Gear Unit *4 Motor Speed Reduction Planetary Gear Unit
        A01LPNB Rotation Direction A01LPNE from MG2
        A01LP95 to Wheel - -

    4. Engine Motive Force Transmission Path


      1. The engine motive force, which is input by the carrier, is output to the sun gear. Thus, motive force is transmitted in order to operate MG1 as a generator.

        A01LP74E07
        Text in Illustration
        *1 MG1 *2 MG2
        *3 Power Split Planetary Gear Unit *4 Motor Speed Reduction Planetary Gear Unit
        A01LPNB Rotation Direction A01LPNE from Engine
        A01LP95 to MG1 - -

    5. MG1 Motive Force Transmission Path


      1. The motive force of MG1 is transmitted via the sun gear and is output to the carrier. Thus, motive force is transmitted in order to start the engine.

        A01LPHSE09
        Text in Illustration
        *1 MG1 *2 MG2
        *3 Power Split Planetary Gear Unit *4 Motor Speed Reduction Planetary Gear Unit
        A01LPNB Rotation Direction A01LPNE from MG1
        A01LP95 to Engine - -