Hybrid drive diversity: a candy store for design engineers?

A look at current developments in hybrid drives reveals a fascinating wealth of options. But sometimes, too much choice can be a bad thing. Since you can’t have it all, it’s important to make the right decisions.

Diversity sparks desires and makes orientation more difficult

The electrification of powertrains has made wish lists longer too. Many boxes can be ticked without neglecting the compulsory task of reducing CO2 emissions. Even a 48V mild hybrid adds numerous useful functionalities for drivers. And thanks to increased overall system performance, higher-scale solutions offer more driving enjoyment and thrilling acceleration. Other attractive benefits include emissions-free driving in city centres, and the advantages of four-wheel drive. The only question is which powertrain architecture variant – and which individual modules – will be most successful in different scenarios.

CTI SYMPOSIUM USA – diversity in a nutshell

At the 13th international CTI SYMPOSIUM USA, the full spectrum of hybrid drives is on the agenda. Come and soak up in-depth information on the latest developments, discover innovative strategies and discuss trendsetting developments. In other words: get yourself fit to master diversity.

Electrified powertrain of the future – scalability and individuality are key

Dr Carsten Bünder (Magna, Germany) will show a new and holistic approach in his presentation. His starting point is that people have very specific requirements for their cars that no single powertrain architecture can fulfil. Not today, and not anytime soon. At the same time, vehicle manufacturers have a vital interest in scalable solutions that adapt flexibly to different markets and vehicle classes. Naturally, the brand DNA always needs to reflect in the driving experience.

By displaying different e-drive variants in a single vehicle, Magna’s e2-eDrive technology demonstrator enables developers to experience different systems and compare their respective benefits. Instead of focussing exclusively on efficiency, they are now looking holistically at the requirements for modularity and scalability, taking CO2, performance and driving dynamics into account. Dr Carsten Bünder will illustrate this innovative strategy with practical performance simulations for different scales of drivetrain architectures.

Until now, vehicle performance has mainly been defined by its ‘heart’: the internal combustion engine. In future, electrified powertrains will open up totally new ways of thinking and solution approaches. If OEMs can square the circle by uniting scalability and individuality, they will benefit from a considerable reduction in powertrain complexity. And thanks to intelligent hybrid drive configurations, the world’s motorists can look forward to vehicles that fulfil their personal wishes more than ever in terms of performance and driving dynamics.

Hybrid DCT for mid-engine supercars – from F1 to P2.5

How do you equip tomorrow’s mid-engine sports cars and supercars with a hybrid DCT? That’s the question Howard Marshall (Ricardo, UK) will be answering in his presentation of a new hybrid 8-speed Transverse DCT. The design incorporates Ricardo’s experience with the McLaren F1 transmission, which it has now applied to a modern 8-speed dual-clutch format with a P2.5 hybridization setup.

Mid-engine high performance vehicles call for highly efficient packaging solutions. Ricardo meets these requirements with a new transversal DCT concept. The unit’s dual clutch stays in line with the engine, while the two outputs drive high-speed bevel gear sets that respectively deliver torque to the odd and even plus reverse gear sets on either side of the vehicle. This configuration makes for a very efficient axial packaging: the Ricardo Hybrid Transverse DCT concept is around 37 percent shorter than a conventional transmission.

The e-Machines can be arranged on the odd, even or both banks of the DCT as a P2.5 hybrid architecture. Thanks to the hybrid 8-speed Transverse DCT, hitherto excluded applications can now benefit from a DCT – and the hybrid functionalities of mild-to-full hybrid – too. What’s more, transverse packaging lowers the centre of gravity, which is a key factor for optimal handling in sports and supercars. It also frees up space that can be used for other mechanical components, or to make the passenger space and rear trunk roomier.

Dedicated Hybrid Magnetic Transmission – Power Split on an air cushion

Dr Stuart Calverley (Magnomatics, UK) believes magnetic transmissions are an excellent choice for power split hybrid drives. To back that up, he will present a highly innovative Dedicated Hybrid Magnetic Gearbox that Magnomatics has developed specially for power split applications.

In this MAGSPLIT system, rpm changes and torque transfer are completely electromagnetic, with no need for mechanical components such as cogs or thrust belts. The rotors are held in place by the fact that magnets with the same polarity repel each other; the rotors ‘float’ on air cushions, so no lubrication or maintenance is required. What’s more, magnetic transmissions cannot be damaged by overload. Another key feature is that crankshaft torsional vibration can be completely isolated from the drivetrain. This opens up very interesting new opportunities for design engineers.

The MAGSPLIT system replaces the planetary transmission and motor/generator in the hybrid drive and offers a continuously variable transmission – all in a simple concentric housing. Other features include engine start, reverse, and a neutral function. The MAGSPLIT system Dr Stuart Calverley will present is structured for C-segment passenger cars, and has already undergone intensive, rigorous testing on a dedicated test bed. Using power flow diagrams and measured data, the speaker will detail the experimentally-verified performance data and discuss in depth the specific control functions that are easy to implement using standard motor controller equipment. Using magnetic force instead of mechanical components certainly sounds tempting. Vehicles with magnetic transmissions could well be rolling down the road in the near future – and according to the grapevine, China could be first.

Forward-looking rear axles: innovative hybrid differential for P3 and P4 applications

So far, rear-wheel drives have taken a back seat in passenger car hybridization. Now Oerlikon Graziano’s new Hybrid Rear Axle Module (H-RAM) proves it’s worth discovering – and exploiting – the specific innovation potential of a rear axle with a differential.

In essence, the H-RAM that Carlo Cavallino (Oerlikon Graziano, Italy) will present is a bevel gear set that drives a conventional differential via the driveshaft. The hybrid functionality for this fully integrated system comes from an electric motor with a hollow rotor that allows one half shaft to pass through it. A two-speed planetary transmission connects the e-motor to the differential housing.

This P3 configuration with a planetary transmission is interesting for two reasons: it is particularly efficient in pure EV mode, and it delivers a very strong e-boost at low speeds. The H-RAM is available with an open differential. Alternatively, it can be modularly extended via mLSD or eLSD (Limited Slip Differential) or a torque vectoring unit.

The H-RAM’s compact size enables OEMs to package a complete hybrid system in the rear axle area without modifications to the standard ICE powertrain. This is a big advantage for vehicle platforms shared by hybrid and non-hybrid models. The H-RAM can also be used as a stand-alone P4 Electric Axle that can add AWD to vehicles via hybridization.

After offering insights into the mechanical transmission details, Carlo Cavallino will demonstrate how the H-RAM performs in terms of packaging, weight and cost comparisons, and will show analysis and simulation results that confirm the improved performance.

5,500 lbs in 4 seconds – performance hybridization for Full Size Pickup Trucks

Drivers love automobiles for the pleasure and prestige they bring. In the United States, the land of opportunity, Full Size Pickup Trucks fulfil those desires in a very special way. Accordingly, Dr Christoph Danzer (IAV, Germany) will use his lecture to address the challenges of applying intelligent hybridization to catapult a 5,500 lb vehicle of this type from 0 – 100 km/h in 4 seconds in the best way possible.

His provocative statement: “Everyone’s talking about emission targets, CO2 legislation and electrical cruising range. But vehicle powertrains are not just there to meet these mainly legislative requirements. Next to fuel consumption, customers are thinking about horsepower, torque, acceleration and comfort too.”

The IAV Powertrain Synthesis is a holistic method for examining variants of conventional, hybridized and electric powertrains. The innovative approach involves systematically computing large parameter and engine map areas for up to several million powertrain configurations. Each individual powertrain configuration is evaluated for performance, cost and fuel economy, based on the descriptions provided by parameters and maps for combustion engines, transmissions, electric motors, power electronics, battery systems and vehicles. Unlike conventional DoE methods, IAV Powertrain Synthesis can evaluate all possible technology combinations. Which configuration yields the best technological compromise for a hybridized Full Size Pickup? Listeners can expect some fascinating answers when Dr Christoph Danzer presents the findings from a systematic optimization of hybrid drives.

CTI SYMPOSIUM USA boosts more than just drivetrains

High-level performance describes the high-calibre program at the 13th CTI SYMPOSIUM USA (13 – 16 May 2019) as well as modern automobiles. Be there when participants discuss tomorrow’s trends in the plenary and the parallel sessions. Extend your horizons in dialogue with attendees from 20 countries. Explore CTI SYMPOSIUM EXPO, the exciting platform for innovation. If you feel like taking it to the limit, hop into a demo vehicle at CTI TEST DRIVE. At the CTI NETWORKING NIGHT, intensive networking is on the menu. Enjoy fine dining and drinks – and share ideas and impressions – with all participants, speakers, exhibitors and sponsors – in the inspiring surroundings of the Henry Ford Museum.


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