Planetary Gears - Changing Steps into Slopes - Hybrid Awareness

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Planetary Gears – Changing Steps into Slopes

The secret of the Hybrid System is a power split device equipped with a planetary gear. The device enables seamless switching between power from the gas/petrol engine and the electric motor, eliminating jolts and vibrations, almost like climbing a smooth slope.

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Seamlessly Connecting the Gas/petrol Engine and Electric Motor

The Toyota Hybrid System has the unique “power split device” which can seamlessly mix power from the gas/petrol engine and electric motor. In the power split device comprised of a set of planetary gears, the output shaft is connected to the gas/petrol engine, the electricity-generating electric motor/generator (MG1), the motive power electric motor/generator (MG2), and wheels. This mechanism can flexibly receive and combine power from each of these. This simple, highly reliable mechanism also has many functions; such as a step-less speed change function which controls the rpm of the gas/petrol engine and electric motor.

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The Key to Creating a Smooth Ride

The power split device uses planetary gears. This is a set of gears: one large ring gear, a sun gear in its center, and small pinion gear arranges around these, all supported by a planetary carrier.
In the Toyota Hybrid System, the rotating axle of the planetary carrier is connected to the gas/petrol engine, and rotates the ring gear and sun gear via pinion gears. The sun gear’s shaft is connected to the motive power electric motor/generator (MG1), and regenerated by the gas/petrol engine. The rotating axle of the ring gear is connected to the electricity-generating electric motor/generator (MG2), transferring drive force to the wheels.
With these gears constantly in a meshed position, each of their rotation ratios and loads are changed to continually mix and distribute the power. A clutch is not needed, so power is not cut, with the advantage of fewer shocks.