For a century a car’s engine drove its wheels through a gearbox, and the only question was which ratio. A two-motor hybrid throws that assumption out: most of the time the engine never touches the wheels at all. It spins a generator to make electricity, a separate traction motor turns the wheels, and a single lock-up clutch closes only at a steady cruise to let the engine drive directly through one fixed gear. This exhibit is that powertrain with its case cut away — engine on the left, two-motor e-CVT on the right, every gear meshing at its real tooth count.
Switch between the four states and watch the power find a different path each time. In EV the battery feeds the motor and the engine sits dead. In hybrid the engine wakes, spins the generator, and its electricity drives the motor in series — watch the two clutch packs turn at different speeds, proof the engine and wheels are still disconnected. At a steady cruise the clutch locks and the engine drives the wheels through one ratio, its rpm tied to road speed. Lift off and the motor runs backwards as a generator, pouring braking energy back into the battery.
The engine itself is a 2.0-litre Atkinson-cycle four — the same hardware as an ordinary Otto engine, but with the intake valve held open past bottom-dead-centre so the expansion stroke does more work than the compression stroke. Slide the cam-phasing control and watch the effective compression ratio change on the readout. It is the efficiency trick that lets a hybrid sip fuel — and, like every machine in this museum, it runs on simple relationships you can wire up gate by gate in DigiSim’s labs.
Specifications
- Layout
- Two-motor i-MMD e-CVT, 2.0L Atkinson engine
- Modes
- EV · series hybrid · engine direct-drive · regen
- Coupling
- Lock-up clutch — engine to wheels only at cruise
- Simulated
- Gear-train ratios, valve timing, live power-path flow
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