Suspensions have not always been the same. Citroën’s late hydropneumatic suspension is an example of that. It died due to costs and scale. But these matters can be overcome if the suspension helps in more aspects than just in ride comfort and safety. What if it helps reduce CO2 emissions? What if it generates energy? This is what Audi is studying with the eROT concept. eROT stands for Electromechanical Rotary Damper. In simple words, it is a damper that is placed horizontally, not vertically, as common dampers are.
Instead of a piston rod, it has a sort of lever that is connected to the wheels, as you can see in the image above. That allows the eROT to generate energy with the movement of the wheels. Besides that, the electric motors make it possible to adjust the ride of the car simply with software changes. There is no dependence between rebound and compression strokes. In other words, the car can face potholes-plenty streets as if you were driving in an autobahn. Since the dampers are placed horizontally, they do not demand strut towers, what saves space in the trunk, be it in the front, as in a Tesla Model S, or in the rear of the car.
The eROT demands a 48 V electrical system to work, with a 0.5 kWh lithium-ion battery, with a peak output of 13 kW. The 48 V electrical system is a long time demand from automakers. We are not sure why they have not been implemented so far, but this is a good theme for an article of its own.