Eaton has announced its newest supercharger—TVS2—which improves vehicle manufacturers’ ability to deliver an optimal single boosted application, or to pair this device with other boosting technologies in order to deliver compound boosting solutions for improved engine performance—a combined supercharger-turbocharger system. The announcement came at the 20th Supercharging Conference in Dresden, Germany.
Eaton’s Twin Vortices Series (TVS) is a Roots-type supercharger with four- lobe rotors and high-flow inlet and outlet ports. TVS2 technology builds on Eaton’s supercharger portfolio by delivering significant improvements in efficiency and increased capability, achieved through a rotor design that improves the internal aerodynamics. Key elements of this new design include:
Rotor profile changes to reduce the clearance between the rotors reducing internal leakage;
Modifying the twist of the rotors to shift the peak efficiency to a location that improves overall fuel economy; and
Adding new porting features that eliminate unnecessary compression of air.
Combined, these items deliver 10 to 16% improvement in isentropic efficiency in the targeted operating zones compared to the TVS R410 product. The efficiency improvement also reduces the power required to drive the supercharger resulting in improved fuel economy.
The low-speed airflow has been improved by more than 30% and enables increased torque at low engine speed. This improved flow, along with the supercharger’s benchmark transient response, will deliver smooth and effortless acceleration.
Combining TVS2 with a turbocharger on gasoline engines can yield specific torque output greater than 240 N·m/L (177 lb-ft/L) with power output in excess of 190 hp/L (142 kW/L) while maintaining the driving response of larger displacement engines.
As an example, a 2.0 liter engine equipped with a compound boost system including a TVS2 supercharger could deliver greater than 480 N·m (350 lb-ft) of torque and 380 hp (283 kW). Such an engine could be utilized in larger vehicles because of the excellent transient response and airflow capability of TVS2, Eaton said.
TVS2 is more than 25% lighter compared to the previous generation of product, incorporating many lightweight components and new interface locations resulting in an overall smaller package. With increasing boosting system complexities, mass reduction targets were a key goal of TVS2 development.
A key application target of the TVS2 product is a Super-Turbo system that requires the supercharger to operate in a high pressure environment located after the turbocharger. TVS2 incorporates high pressure seals that can withstand pressurized environments, along with an increased airflow range that provides system level benefits and efficiency optimization. To achieve the higher airflow range, TVS2 incorporates a full ball bearing system that enables temporary speeds up to 30,000 rpm—a 25% increase over current offerings.
The higher speeds and increased boost pressures created noise, vibration and harshness (NVH) challenges, so the TVS2 design includes a new backflow port that reduces noise without impacting airflow or efficiency. A micro-perforated panel technology enables targeted noise treatment, resulting in a decibel level improvement of up to 8 dB at low speeds.
TVS2 is part of the Eaton Vehicle Group’s total engine air management portfolio, which includes several supercharger offerings, engine valves (including standard, exotic materials, and hollow technologies) and advanced valve actuation technologies (cylinder deactivation, variable valve lift, dynamic cylinder deactivation, and decompression engine brake).
Eaton’s hollow valves are used in boosted and/or downsized applications due to their ability to withstand higher temperatures, improve valvetrain dynamics, and reduce system weight by as much 10-15% per valve.