The Belgian company Mazaro is developing potentially disruptive transmission technology targeted at the commercial vehicle segment. According to co-founder and director Filip De Mazière, it offers significant energy, emissions, and cost savings in vehicles with a dynamic driving style: fast and slow, loaded and unloaded.
With the introduction of this new approach, two different types of transmissions are being developed. The first is a Reversible Variable Transmission (RVT), offering an overdrive speed ratio of 2.6 between stop and reverse without traction interruption. Initial findings suggest that, in urban buses, this could reduce fuel consumption and emissions by 11-19% compared to an automatic transmission. Its compact form is 25% lighter than most AT (automatic transmission) options, providing an 11% cost saving, eliminating the need for a clutch, torque converter, and gears. The overall efficiency is estimated at 94.9%.
At its core, there is a unique mechanical system based on two sets of wheels rolling on each other. “This pure rolling is entirely different from belt CVTs (continuously variable transmissions),” says De Mazière.
The wheels are made with a specific curve: not circular, but with a patented special shape that eliminates bit slippage, resulting in higher efficiency. As the rolling surfaces come together without slipping, the oil film between the cones remains relatively cool, and viscosity stays high. This separates the steel surfaces from each other, meaning there is never any steel-to-steel contact. The oil, which does not heat up, has an almost unlimited lifespan.
“Maintenance should be completely eliminated,” he promises. “The overall cost is lower because there are fewer components.” This unit is designed for use with an internal combustion engine (ICE), either alone or combined with an electric system in a hybrid configuration.
For fully electric vehicles, Mazaro is working on a Single-Stage Variable Transmission (SVT) which, they claim, is the first CVT capable of handling high torques in heavy-duty vehicles. This unit features one set of wheels, compared to the two found in the RVT, and the overall efficiency is estimated at 97.5%. Initial tests on a 3.5-ton electric truck found that it offered 16% more range and 50% higher top speed.
Both RVT and SVT units are designed to keep the engine in its best efficiency curve all the time, at low or high power, as the vehicle accelerates, goes uphill, or maintains a constant speed.
While the technology has the potential to improve performance in many vehicle segments, those operating with a diversified style stand to benefit the most. This includes urban buses, delivery trucks navigating dense traffic, construction trucks, terminal tractors, agricultural tractors, and electric trucks and buses. A demonstration electric truck with the SVT is currently operating on the road, and three different projects are underway, leading to functional prototypes in 2021. Mass production is planned for early 2023.
