The piston of the free-piston internal combustion engine pumps hydraulic
fluid into the accumulator. It stores the energy by compressing the gas bladder
inside. The engine will be turned off
automatically when the accumulator is filled – and turned on again
before it becomes empty.
The pressurized fluid drives the wheelmotors, one in each wheel. Their
driving power is continuously variable from zero to maximum speed.
The wheelmotors are reversed during braking and become pumps. They are
powerful enough to stop the car like disk brakes, while recuperating the entire
braking energy. The energy is stored in the accumulator and used again for
driving. The ‘round-trip-efficiency’ during braking is 70% to 85%. The energy is
stored in the accumulator and will be used again to drive the car.
The powertrain computer controls the functioning of the engine and the
wheelmotors. It also manages the state of charge of the accumulators for driving
The wheel is driving the car.
The wheel is driven by the energy from the accumulator.
The engine charges the accumulator with pressurized fluid
The car has four wheels. All wheels have a wheelmotor.