For nearly 125 years, Renault has been constantly seeking to innovate. Its inventions have stood the test of time and are still used even today with many people not even realising it. Direct drive gearbox (1899), replacement of the hand crank with an electric starter (1909), addition of the ‘5th door’ (1961), central opening (1983), hands-free key card (2000). All these and more are Renault designs. The All-new Megane E-TECH Electric – the first of Renault’s Nouvelle Vague – sees Renault still innovating. More than 300 patents have been lodged for the design of the vehicle and its platform, of which we have selected seven to showcase over the summer period. In this fourth article Fabrice Bernardin, Head of the e-technology work unit at Renault’s Engineering Department, tells us more about the All-new Megane E-Tech Electric’s engine and how its performance is enhanced by its innovative oil cooling system that features two patented innovations.
The powertrain of the All-new Megane E-TECH Electric was fully developed by the Alliance. Produced in Japan for Nissan and in France – at the plant in Cléon, to be precise – for Renault, this powertrain provides optimal energy efficiency along with all the pleasure of an electric drive, such as instantaneous acceleration that is both dynamic and linear.
“Electric motors must have an excellent cooling system in order to be efficient. We therefore worked with our colleagues in both Japan and Cléon, France, to develop two patented innovations. The first of those patents covers the oil cooling system for our wound rotor synchronous motor. We fitted injectors in strategic places to splash the electric wound rotor motor while simultaneously cooling both the rotor and the stator. The second patented innovation covers a clever technique that enables us to harness the rotor’s momentum, using a ring gear system to accentuate stator cooling by projecting oil towards the heads.”
What the innovations bring
This innovative new oil cooling system for the wound rotor synchronous motor of the All-new Megane E-TECH Electric offers a number of advantages:
Increased efficiency due to the strategic placement of four injectors to splash the electrical circuit where needed while cooling the electric engine’s rotor (moving component) and stator (fixed component).
A more compact engine whose mass has been reduced by 33 percent compared to the previous generation of electric motors; a gain in mass which contributes to lower energy consumption.
Enhanced driving pleasure with smooth and dynamic acceleration and reversing in all situations, as well as greater engine power over long periods of accelerator operation, even at high speeds on the motorway.
A brand-new process
The new oil cooling system combines simple and efficient technical solutions to keep the engine of the Megane E-TECH Electric at an optimal temperature – namely, the use of oil to splash targeted areas of the engine and an optimised oil cooling circuit.
These patented innovations enabled Renault engineers to design a compact yet ultra-powerful and high performing electric engine for the benefit of the user’s driving pleasure.
