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The Powertrain as an Intelligent System

The automotive world is changing, and the CTI Symposium is helping to drive the transformation. Where will the boundaries of powertrains lie in future? While powertrains will still be centre stage of the Symposium, the scope will expand. Artificial intelligence will play a growing role, and so will the provision of energy sources.

The 22nd CTI Symposium 2023 in Berlin (5 – 6 December) began with an important announcement, as Prof. Ferit Küçükay handed over his role as chairperson to Prof. Malte Jaensch. Jaensch‘s primary role is Chair of Sustainable Mobile Powertrain at the Technical University of Munich. Professor Küçükay will stay with the Symposium in the role of Founding Chairman. Malte Jaensch justifiably praised his predecessor’s work for CTI as a “lifetime achievement.”

For nearly 25 years, Professor Küçükay shaped the themes of the CTI Symposium, and oversaw a number of paradigm shifts along the way. It all began in late 2000, just after Professor Küçükay became head of the Institute of Automotive Engineering at the TU Braunschweig. One day, he took a call from Sylvia Zenzinger, now the symposium’s conference director. Would he be interested in chairing a new congress on vehicle drives? Küçükay agreed right away.

Since then, both the Symposium’s topics and its tagline have evolved steadily. In 2010, hybrid and electric drives were added to the programme and tagline. Recently, “Automotive Drivetrains, Intelligent, Electrified” has reflected the growing importance of electrification. Today, the CTI Symposium is a major international event, with presentations held exclusively in English.

This December, the Symposium changed its tagline to “Automotive Powertrain Systems”. This reflects two current developments: Firstly, that electrification is now a perfectly normal powertrain topic; secondly, that adopting a system view is crucial when developing vehicle drives.

The BEV for Everybody
As Professor Malte Jaensch specified in his opening speech, we need to consider the powertrain as a system and understand how all the individual components work. That starts with electric motors, gearboxes for elctric drives, inverters and batteries – and extends right up to the overall vehicle and, of course, the consumers’ wishes.

With BEVs, another question is how to make them affordable for everyone. In Berlin, this was the focus of the Executive Discussion “The BEV for Everybody”, with participants Karsten Bennewitz, Volkswagen, Marcus Lott, Opel, Prof. Maximilian Fichtner, Helmholtz Institute Ulm, and David Green from Lynk.

The first question was, “When will BEVs dominate the vehicle market?” Using their voting app, the majority of audience members said it would be when cost parity was achieved with other drive types. In second place came adequate infrastructure, followed by sufficient range and/or faster charging times.

On costs, Bennewitz agreed that we need to approach cost parity, but said Germany already had an adequate charging infrastructure, with high numbers of fast charging stations. He cited fun-to-drive as a further important factor for winning over consumers to BEV. From an OEM perspective, he does not foresee an immediate switch to BEV, saying markets such as India had totally different requirements.

Marcus Lott took a similar view. He said combustion engines are still needed for other markets, but PSA and Opel have started their electric transformation process early on, driven by legislation. If legislation were to develop less stringently in Europe, reverting to conventional drives would not pose a problem. That said, consumers who switch to BEV “never go back”. As for costs, the competition in China is making us “fit and lean”.

David Green, from the Geely subsidiary Lynk, said other forms of ownership were a way to reduce costs. Lynk’s offering includes a subscription model that could be canceled at any time, but also a
rental model that increases vehicle use times, and thus distributes costs more effectively over the life cycle. Unlike Bennewitz, Green thinks charging options could be improved, noting that ‘BEV for Everybody’ would not work if you lived in an apartment in Munich, or any other urban area with poor charging availability.

For Professor Fichtner, a battery expert at the Helmholtz Institute, the main lever for making BEVs affordable is new battery technology. In future, he said, charging times of ten minutes for a range of 700 km would be possible. In addition, cost issues should be bundled with other issues: whereas batteries can be recycled, fossil fuels are “gone” once you burn them.

The discussion may have been a starting point for further questions in the future. One may be: How can we make make used BEVs more attractive, for example through more hardware and software update abilities?

The advent of new battery technologies
But back to batteries for now: Prof. Fichtner examined batteries more closely in his plenary speech, “Recent trends in battery research and development”. Given the growth of e-mobility, he said, Europe would need a production capacity of around 1 TWh in 2030, compared to just 21 kWh in 2020. On the other hand, we need higher numbers of sustainable batteries, and hence new raw materials. On the cathode side, these would lithium iron phosphate (LiFePO4), lithium manganese oxide (LiNi3/4Mn1/4O2) and nickel manganese (LiMnO2), all without cobalt. New anode materials were also expected, such as silicon carbon composites. These would enable 40% more energy content at cell level, putting them on a par with solid-state batteries – a technology he said has had a great future for a long time, but one that might not materialize.

In future, sodium batteries would enable batteries that required no critical raw materials. And generally, lithium, nickel, cobalt, graphite and copper could be replaced by sodium, iron, magnesium, hard carbon and aluminum. Since some new developments would mean reduced energy density, Fichtner advocates close collaboration between chemists and engineers in order to optimize battery weight and packaging at the construction level. He cited CATL‘s cell-to-pack process as an example.

Battery topics were also discussed intensively in the Deep Dive sessions. Presentations by TotalEnergies and Valeo covered cooling aspects, while APL reported on “Mastering Thermal Runaway” and Marelli dealt with wireless battery management systems.

Remarkable progress in e-motors and e-drives
As to future electric drives, Jörg Gindele from Magna Powertrain talked about the companies next gen e-drive portfolio. He said system efficiency of the new development is 93% (motor efficiency 96.3%), namely in WLTC and with additional highway components – so basically, in real life operation.

The high system-level efficiency is due to the significantly expanded sweet spot, Gindele said. This also helped for what Magna calls the ‘complementary operation’ of the front and rear axle drives. Basically, this means the gear ratio of the front primary drive can be made longer, and hence more efficient, while the secondary (rear) drive, which can be activated at will, can be configured for performance.

A few design features: The drive is so compact that it can tilt 90 degrees and be used on either the front or rear axle. To optimize motor costs, the magnets are fixed by mechanical means only, using flaps. The active fluid control system uses a pump actuator taken from transmission technology. Since its direction of rotation is reversible, the oil flow can, for example, be distributed between the motor shaft and the winding heads. An HV Embedding process reduces shift losses, while Optimized Pulse Patterns smooth out the drive’s pulse – and hence vibration – behavior.

Gindele concluded with an outlook for further goals in tomorrow’s drives. These included new magnet-free motor concepts, the elimination of rare earths, GaN architectures for both 800 and 400 V, and further digitalization, for example the Digital Energy Twin, to improve range prediction.

His speech is just one example for the lively development activitiy in the e-drive field. In Berlin, no fewer than three Deep Dive sessions with over 14 presentations were dedicated to e-motors and e-drives. Just a few examples:

Volkswagen presented their new electric MEB platform in detail. Great wall introduced the e-drive architecture of their ORA Lightning Cat. DeepDrive talked about the advantes of the radial-flux electric machines. New e-motor technologies and approaches were presented by ZF, Infimotion, BorgWarner, Dana and Valeo. American Axle discussed solutions for high-speed e-motors, Valeo talked about optimizing e-drive efficiency. AVL List presented their development process for an e-drive system, and Hofer Powertrain several torque vectoring solutions for unique markets.

This short list shows how manifold the e-drive topic is and there is much more to come and discuss on upcoming CTI symposia.

How are OEMs electrifying?
Volkswagen, Mercedes-Benz and Opel gave insights into their plans for further electrification.

In his plenary speech, Thorsten Jablonski showed how the Volkswagen Components Group was transforming itself into an Electric Powertrain Supplier. Until recently, the group and its 69,000 employees manufactured transmissions, combustion engines and more. Today, it’s becoming an electric drive supplier with a holistic perspective that includes e-drives, inverters, batteries and thermal management, as well as their system integration. In future, Jablonski said, the SSP platform (Scalable Systems Platform) would be used in a scalable manner for all Group brands and segments. His comments on scalable battery technology were equally interesting: At its Powerco subsidiary in Salzgitter, Volkswagen is planning different cell chemistries for different vehicle segments: iron phosphate for the entry level, high manganese for the mass market, and increased silicon content as a best-in-class application.

Konstantin Neiß, Mercedes-Benz, began his plenary speech by reiterating his company‘s commitment to becoming CO2-neutral by 2039. He said Mercedes was also investing in transforming its Stuttgart plant for more electrification, with a focus on batteries and e-drives. This includes small series production of Li-ion cells, though Mercedes plans to buy in more from various sources. Neiß also mentioned the acquisition of Yasa, which will produce performance electric motors at its Berlin factory. In 2025, Mercedes plans to launch its first ‘electric first’ platform (MMA), for which combustion engines are just one of several options. Neiß then showed a vehicle based on this MMA platform: the Concept CLA Class. He put the powertrain overall efficiency at 93%, with an energy consumption as low as 12 kWh per 100 km. The range would be 750 km (WLTC), and 400 km of range could be ‘refueled’ in 15 minutes. The speaker then touched briefly on the Vision One-Eleven vehicle, which features axial flux machines by Yasa. The advantages of this design: very short, very good continuous performance, and low weight.

In his plenary speech, Marcus Lott, Opel, talked about the “BEV for Everybody” that Opel and its parent company Stellantis are striving for. From 2024, Opel wants to offer at least one BEV in every vehicle series; from 2025 on, every new launch would be a BEV. In future, Opel would have access to four Stellantis platforms with ranges of 500 to 800 km. The group was pursuing a circular strategy for batteries, including a ‘second life’ and materials recycling. Lott noted that Opel has also offered an FCEV transporter – the Vivaro-e Hydrogen – since 2021. The design is interesting: a 45 kW fuel cell stack, and a battery and electric drive with a maximum output of 100 kW each. At 10.5 kWh, the battery is fairly large and provides around 50 km of electric driving; the total range is 400 km. Opel describe this as a “mid-power concept” with an optimal balance of customer benefits. In 2023, Lott said, Europe had over 150 700-bar gas stations; by the end of 2025, that should rise to more than 450. According to the EU AFIR (EU Alternative Fuels Infrastructure Regulation), from 2030 on filling stations of this type will be mandatory every 200 km, plus an additional station at every urban node.

Heavy commercial vehicles have diverse requirements
Requirements in the heavy commercial vehicle segment are different from those for passenger cars, as the Expert Discussion “Who Will Take the Heavy-Duty Vehicle Volume – FCEV, Green ICE or BEV?” confirmed. The participants were Gernot Graf, AVL, Michael Himmen, Hydrogenics, Loek van Seeters, DAF, and Götz von Esebeck, Traton.

Right at the start, audience members were able to cast their app votes in response to the question: “Which drive concept will take the volume in heavy-duty vehicles in the long run?” Multiple answers were permitted. Overall, 47% said BEV, 45% FCEV, 31% H2 combustion, 22% e-fuels, 18% HEV and 14% diesel engines. This showed just how diverse the possible solutions are considered to be.

This diversity was reflected in the views of the discussion participants. Gernot Graf argued in favor of hydrogen for both FCEVs and combustion engines, saying fuel cell had an efficiency of around 50%, a combustion engine slightly more. He said, it all depends on the application: Above a certain performance threshold, you need a combustion engine with its better power-to-weight ratio. Fuel cell are better under partial load, combustion engines at high and full load.

Götz von Esebeck was sure that BEV would dominate in terms of volume. In the transport business, he said, TCO is king, and electricity weill be the cheapest option in future. He even sees opportunities for BEV on long hauls, especially since fast charging were not an issue for the large batteries involved. Of course, the infrastructure would need to be built first.

For Michael Himmen there is no “super answer for all”. Fuel cell would come; there is a “momentum”, he said, as the industry has special requirements in terms of weight and distance. Transporting goods from Poland to Spain, for example, would remain challenging for a long time to come. Markets like India would still need ICEs for many years, due to the lack of infrastructure. Interestingly, Himmen also sees fuel cell mainly for stationary applications. He said Hydrogenics and its parent company Cummins were covering this aspect as well.

In the discussion and the plenary speech he gave earlier, Loek van Seeters spoke in favor of developing all drive options, then seeing which prevailed. After all, new technologies needed a certain ramp-up time. Today we still needed diesel engines; drives that used no fossil fuels would not arrive around 2040 – but DAF is committed to developing them. In his talk, the speaker presented the manufacturer‘s range of drives for commercial vehicles. Besides conventional drives, this includes hybrid drives, purely electric tractors and, as of 2021, a tractor with a hydrogen combustion engine. But in order to achieve the EU goal of reducing CO2 emissions from electrically powered trucks and buses by 45% by 2030, he said a lot more would have to happen. Per year, 42 TWh – the equivalent of 17 million households or 11 nuclear power plants – would have to be upgraded. We also needed 280,000 charging stations and 50,000 public charging stations; the rollout is still progressing far too slowly, he said.

AI – the 5th revolution?
Another topic is currently growing at breakneck speed: artificial intelligence. The catalyst here may have been ChatGPT, the AI tool that is already being used for automated text creation.

In Berlin, Hamidreza Hosseini, CEO of Ecodynamics GmbH, gave a highly anticipated speech entitled: “GenAI, & ChatGPT‘s Impact on Future Automotive Development and Engineering”. Hosseini described and demonstrated how generative AI can also change processes in the automotive industry. GenAI can generate new content by processing patterns drawn from training data; ChatGPT, now familiar to many people, is just one part of it.

Hosseini also pointed out that ethical issues are involved, and that systemic transparency is a prerequisite for using AI tools of this kind. But what stuck most in listeners’ minds was the message that artificial intelligence could change work processes in the automotive industry very quickly. Hosseini spoke of a 5th industrial revolution, adding that others could follow. In 50 to 60 years’ time, the “merging of humans and machines” could be next.

The CTI symposium helps shaping the transition
What were the key learnings from the CTI Symposium Berlin? Summing up, chairperson Prof. Malte Jaensch mentioned several points. Firstly, it’s becoming more and more important to see the powertrain as a system – a development that is reflected in the new symposium tagline “Automotive Powertrain Systems”. Secondly, there is no such thing as “one size fits all”. Instead, we need to strike the optimal balance between sustainability, development, production, cost, efficiency and more besides.

Thirdly, as the conference showed, drive options for heavy-duty vehicles were more varied than for passenger cars. All the same, it was important for passenger car and heavy-duty developers to exchange ideas at the CTI Symposium, and to learn from each other across functional and product boundaries.

In general – and despite the importance of overall systems – powertrains would always be at the heart of the CTI symposium, Jaensch added. That said, there would be changes. The topic of AI in automotive engineering could – and probably will – be accompanied by a growing number of lectures and discussions. Jaensch said we should see this as an opportunity, not a threat.

He also mentioned the topic of “Energy Formability,” which essentially places the system idea in a larger context. Powertrains alone could not be “green”; instead, we must consider drives, mobility and energy together as a whole. This included topics such as bidirectional charging, vehicle-to-x or “second life of batteries”, which could likewise become symposium topics in future.

The next CTI Symposium Berlin is scheduled for 3 – 4 December 2024. The next US symposium takes place much earlier (15 – 16 May 2024, in Novi near Detroit), and we warmly invite you to attend.

“Serial-parallel hybrid designs will become increasingly popular”

At the CTI Symposium USA in May 2024, Aditya Dattawadkar, Schaeffler, presented recent advances in hybrid architectures in his talk “Hybrids are Making a Comeback”. In our interview, we followed up by asking: What will tomorrow’s hybrid drives look like?

Interest in hybrids has been growing again recently in the US, as well as in the UK for example. Why would you say that is?

I think right now, people everywhere are looking for an option that lets them try going electric as they look for better performance or more fuel economy. Because of range and charging network availability, many don’t want to jump straight from an engine-based car to a battery-electric. That’s where hybrids come in. They allow people to try these electric vehicles, let’s say semi-electric vehicles, without jumping straight to BEV. And whether it’s in the US, UK or somewhere else, I think the challenges and anxieties are similar.

Powertrain diversity is generally increasing. How would you differentiate between designs for various vehicle segments – for example B to E and SUVs or pick-up trucks?

If someone buys a smaller vehicle, they will likely lean towards a battery electric vehicle, as long as the price is OK and it has a decent range. People mostly use them for daily commuting or for short-distance travel. But bigger vehicles, like SUVs or pick-up trucks, are generally meant for longer distances – towing boats or trailers, transporting bigger families, and so on. That’s where hybrids are better suited, either as plug-ins or full hybrids. Whether you choose plug-in or full hybrid will depend on efficiency calculations. If you’re constantly driving long distances, a full hybrid might be better than a plug-in because you reduce the amount of energy conversions or carry a smaller size motor. Additionally, the city v/s highway driving can influence these calculations. But if you want to sample the flavor of a battery-electric vehicle, a plug-in hybrid is a good solution.

So far, most hybrid designs in western markets have been add-on P2 designs, not dedicated solutions. Which type would you recommend?

Part of the reason why P2 designs have been popular is because you can fit them in into existing powertrains with less difficulty. You don’t need to change the engine design; you don’t have to change the transmission architecture significantly. Having said that, I think in future, serial-parallel designs will see increased adoption. Then of course a P1/P3 multimode transmission like ours also has great potential in my opinion. We will probably see that each of these solutions has an advantage for a specific application. When hybrids started, they were basically an electric motor that supported the ICE. Now we’re going to see hybrids that are more of an electric vehicle, with an ICE for support. So, it’s going to be a different type of hybrid than what we’ve seen in the past.

Will multimode hybrids and range extenders replace P2 designs, or is there still a place for them?

Serial and multimode hybrids make a lot of sense for people with flexible driving habits. But P2 still makes most sense for people who have consistently longer drives and heavy load requirements, because we don’t want to get into ICE recharging mode regularly. Due to the additional energy conversions, the goal should be to use the feature of recharging battery with ICE in serial hybrids only occasionally when necessary. Based on use cases of individuals every hybrid architecture provides some advantages based on the application.

How close can a PHEV with a suitable drive architecture get to a BEV in terms of efficiency, in electric operation?

I think it’s a little bit unfair to compare the efficiency of PHEVs and BEVs, because the goal of a PHEV is to let you drive electrically for a limited range. PHEVs exist because today’s battery-electric vehicles can’t meet every customer’s needs, especially their long-range needs. A fair question might be whether PHEVs are better than the ICEs we have. I think they are, because you can charge them with an outlet. So, then you have a cleaner source of energy for driving in cities, where you want to focus on limiting emissions due to congestion. One has the ability to use some PHEVs similar to BEVs for limited range.

China announced last year that the ICE would be needed up until 2060. Looking at the US and Europe, what prospects do you see for HEVs and PHEVs?

It’s really hard to predict what kind of drives we will have in 2060. Just ten or fifteen years ago, people were only just starting to talk about battery electric vehicles and plug-in hybrid drives as mainstream vehicles. Now battery-electric vehicles are already at ten percent, or much higher if you include plug-ins and hybrids. I think there is a lot of strong motivation to go to electric drives. In particular, tech innovations in the fields of batteries, charging infrastructure and charging speed could change things quickly. What is more predictable is, say, 10 to 15 years ahead. On that horizon, I expect to see all three options: ICE, hybrids, and battery electric vehicles.

Interview: Gernot Goppelt

Interview “Digital Twin enables a whole new functional level”

At the CTI Symposium Berlin in December 2023, Dr Jörg Gindele, Magna Powertrain, spoke on progress in new electric drives. We interviewed him about new developments in hardware and software, functional integration on a higher software level – and the new possibilities that the ‚Digital Twin‘ opens up.

Dr Gindele, you presented a new generation of electric drives at the CTI Symposium in Berlin. What is new?

We’ve made improvements in many areas. First of all, we increased efficiency further still with an improved electromagnetic design. One particular highlight is that we managed to expand the sweet spot significantly. In this context, I want to mention the cooperation with our JV partner LG Magna, who contributed several improvements here. We also implemented several improvements at the system level, such as improved cooling and reduced ohmic and inductive scattering losses. I’d like to give three more innovations a special mention: active fluid control, which uses a pump actuator to distribute cooling flows flexibly between the motor shaft and the winding heads; HV module embedding, which enables us to design a highly integrated semiconductor package that’s integrated into the inverter; and software-optimized pulse patterns, which further reduce electric motor and inverter losses.

The importance of software-level integration into the overall system is growing. How does the new generation reflect this?

Our main focus is on stronger integration at the system level. Software is the enabler here. For example, our Motion and Energy Control software can control the electric motors and the brakes simultaneously; it integrates their functionalities on a higher level. That benefits driving dynamics considerably and also improves driving safety. Another example is the way the thermal management system interacts with the drive control. This means you can coordinate the energy flows, and use them synergistically. We have developed a new software platform that can regulate the entire energy and power flow in BEVs. Additional new features are available as cloud-based functions. These enable predictive driving functionalities, as well as a row of applications.

You also spoke about ‘complementary electric all-wheel drives’. What does that mean?

It means coordinating the drive units in a 4WD system in such a way that they complement each other in various operating scenarios. This can deliver even higher energy efficiency than a 2WD system. Put simply, you give the primary drive unit a longer gear ratio, which is good for efficiency. The secondary drive unit, which is usually on the rear axle, is mainly for high available torque. In terms of efficiency, you could say the result of this interaction is ‘guilt-free’ performance. With features like its expanded sweet spot, our new-generation drive is designed for just such a system. And thanks to its compact package, it can be used flexibly on either the front or the rear axle.

You could also use a two-speed transmission. What are your thoughts on that?

Multi-speed transmissions can certainly make better use of the efficiency map, and also improve climbing and towing performance. But in many of today’s drive solutions, the extra effort involved outweighs the benefits. That said, they are worth considering in applications like performance vehicles, pickup trucks, or light commercial vehicles. Looking ahead, another interesting aspect is that by teaming up multi-speed transmissions with new types of e-machines, we could potentially make system-level solutions that require no rare earths.

What does the ‘Digital Twin’ do in the new drive generation?

Digitalization plays a key role in lifting drive technology to a new functional level, while also saving time and money during development. The Digital Twin is a precise digital image of the product you are developing. It helps you to reach higher levels of maturity faster, and to avoid many expensive and time-consuming hardware loops. In series applications, a Digital Twin lets you catch quality issues faster and monitor the ‘health’ of your product. But the possibilities go far beyond that. Another example is improved range forecasts, based on the accuracy that a Digital Twin model provides. And that‘s just the beginning – the possibilities seem to be almost infinite.

Interview: Gernot Goppelt

JJE 18,000Nm 2-Speed Electric Beam Axle for Medium Duty Trucks

Ping Yu, CEO, Chief Engineer, Founder, Jing-Jin Electric
Dr. Yang Cao, Transmission Senior Supervisor, Jing-Jin Electric

JJE’s latest innovation, a 2-speed electric beam axle that was unveiled at the 2023 CTI Berlin symposium, has recently completed vehicle testing. The tests were conducted on two trucks at the JJE China test center track and at the JJE North America facility in Farmington Hills, MI. The electric beam axle performs with strong power, uncompromised towing capacity, payload, and gradeability. It features an extremely fast, smooth, and high-quality shift, that makes it feel like a single-speed system. This electric beam axle integrates multiple advanced technologies; such as bi-stable electromagnetic clutches, a bi-directional shifting clutch, a bi-stable eLocker, a linear park lock system, and an active cooling and lubrication system, all of which have now been validated through vehicle testing. The controls for these functions have been integrated into the electric beam’s SiC inverter, as JJE’s “One-Box” control. The entire system has undergone comprehensive validation at JJE’s track- covering straight track, cross twist, cobble stone, potholes and grades.

The 2-speed axle features a high efficiency hair-pin electric motor and a 400kW SiC inverter with a “safe towing” feature. It also includes an electromagnetically shifted 2-speed gearbox with a neutral position that also serves as a disconnect, a bi-stable differential eLocker, and a linear park lock system. The gearbox enables the axle to deliver up to 18,000Nm of wheel-end torque, and maximum vehicle speed exceeding 160km/h. The integrated design of the motor and gearbox reduces the axial length of the system.

Fig. 2 JJE Electric Beam at the Rear of a Truck Demonstrator

JJE’s 2-speed electric beam axle delivers high performance and high output speed that can be achieved with little power degradation at high speeds. Its efficiency spans a broad speed range and significantly outperforms single speed axles thanks to the 2-speed gearbox. During vehicle testing, the shift quality was found to be seamless, with upshifts or downshifts achieved in less than 300ms- faster and smoother than any DCT, CVT, or AT.

Electric Motor

JJE’s mature hairpin motor designs cover the performance requirements for a wide range of vehicles. For this electric beam axle system, the electric motor’s peak power reaches 420kW at 650Vdc, with 97.4% maximum efficiency, and over 90% of the efficiency map stays above 88%. The water & oil cooling design allows the electric motor to produce high continuous power.

2-speed Gearbox

The 2-speed gearbox provides high launch torque, high vehicle speed, and high efficiency over a broad duty of conditions and helps contain the motor’s top speed for better reliability and durability. It also broadens the high efficiency operating range, and significantly reduces thermal loading in the system at high speeds. The neutral position is a natural “disconnect.” Combining this rear axle with a neutral position and a constantly powered front eAxle, the vehicle efficiency can be improved.

JJE’s patented DirectFluxTM Bi-stable eLocker enhances the functional safety of the locker and eliminates the constant power consumption. A proven park lock system is implemented on the motor shaft, or the “lowest torque” point of the system. An oil pump provides active oil lubrication, which allows for a low oil level in the gearbox, reduces gear churning loss. All these sub-components have been fully validated on JJE’s test track.

SiC Inverter

The electric beam axle includes an 850V SiC integrated inverter, with functional safety capability up to ASIL-D level. Multiple functions, such as: motor control, differential locker control, 2-speed transmission control, and park lock control are integrated in the inverter, taking advantage of the inverter’s high functional safety control platform as a powerful “One Box” control. With a backup power supply, the inverter enables “safe towing,” a feature highly desired by end users. It is a critical safety redundancy in the event of 12V power supply loss.

DirectFluxTM Bi-stable Electromagnetic Clutch

Patented bi-stable electromagnetic clutch is one of JJE’s most advanced technologies. It is used for gear shifting and locking the differential in the electric beam axle system. This technology has been successfully used as a differential locker in JJE’s 300kW SiC EDM and as a disconnect in JJE’s new AWD EDM.

Fig. 5 Linear Park Lock System

DirectFluxTM electromagnetic clutch takes advantage of its innovative magnetic circuit design. Compared to the more conventional reluctance flux magnetic circuit design, the DirectFluxTM design greatly reduces flux leakage, and therefore, utilizes magnetic flux more effectively to generate force. The conventional reluctance flux design cannot avoid magnetization of parts near flux circuit, or “flux leakage”, which causes less effective utilization of magnetic flux. As a result, DirectFlux acts 2-3 times faster than a reluctance flux design.

The bi-stable clutch is inherently fail-safe as it won’t change state in the event of loss of power. This feature gives the bi-stable clutch a higher safety level than a mono-stable clutch. For the differential locker, it will prevent sudden locker release due to the loss of power or control failures. For the transmission shift, it will prevent unexpected gear shift back to neutral which could lead to the vehicle loss of traction. On energy consumption aspect, the bi-stable clutch’s feature of “zero holding current” eliminates the need for a holding current and, in turn, achieves zero constant power consumption.

In the development stage of the electromagnetic clutch, a software platform based on several simulation tools is built for precise simulation result. This platform covers signal, electric, electromagnetic, and mechanical aspects. It addresses almost every detail, including software control, PCB layout, electromagnetic transient simulations, multi-body dynamic simulations, and strength, providing strong support to the clutch’s development.

Electric beam axles are designed for pickup trucks, light-duty trucks, or medium-duty trucks. The vehicle test of the electric beam further reinforces the advantages of electric beam axle utilization and gains confidence in the roadmap of trucks electrification. JJE takes advantage of its experience, knowledge, and know-how in electric drive, strong R&D capabilities on motor, inverter, transmission and clutches and expertise in system integration, creating a 2-speed electric beam axle for the large medium truck segment.

Fig.6 JJE DirectFluxTM Bi-Stable Electromagnetic Differential Locker

A game changer for e-mobility: glulock® MD

Markus Lock, Head of R&D and Engineering Feintool System Parts Sachsenheim GmbH, Germany

The future of e-mobility lies in more efficient and smaller motors. Rotors and stators — the heart of a motor — play the central role in any motor design. Feintool glulock® MD (Multiple Dots) technology removes longstanding limitations on rotor and stator production, enabling more compact designs to increase the efficiency of electric motors.

E-mobility is clean, quiet and, above all, efficient. No other drive concept has such a high level of efficiency: electric cars transfer around 80 percent of the energy supplied to the road. With hydrogen drivetrain, the efficiency is only around 50 percent, and a combustion engine comes in, at best, near 40 percent. The rest of the energy is lost in the form of waste heat.

Nevertheless, electric motors still need to become more efficient. After the capacity of the battery, the energy efficiency of the motor is the most significant factor in determining the vehicle’s range. Even small increases in efficiency can deliver major improvement in range. “In the next few years, it will be a matter of exploiting those last few percent of efficiency,” says Markus Lock, Head of Engineering at Feintool.

Innovative manufacturing processes are in demand

There is room for improvement in the design of rotor and stator stacks, which together form the heart of any electric motor. In the conventional stamping and stacking process, individual laminations are joined together to form stacks using mechanical connections. However, this has disadvantages, as Markus Lock explains: “Mechanical joints always have some play. The lamellas behave like a spring, leading to a loss of performance. The deformation of the sheet metal, which is necessary for the mechanical connection, also negatively impacts efficiency.”

Joints with adhesive or bonding varnish, on the other hand, have much less of an impact on the electromagnetic properties. Thinner sheets can also be processed using this technology. While stamping stacks reach their limits at 0.3 millimeters, sheets as thin as 0.1 millimeters can be processed with adhesive or bonding. At the same time, the rotor and stator stacks become stronger and more robust. “All of the advantages of bonded design have a positive effect on motor performance,” summarizes Markus Lock.

The more efficient alternative to Backlack: glulock®

To improve electric motor efficiency, the automotive industry has increasingly turned to Backlack — a traditional secondary bonding process. The big disadvantage? It’s expensive. In addition, the process is time-consuming and energy-intense, requiring the baking varnish to be melted in an oven. Finally, electrical steel with a special coating must be used, so the material itself is also expensive.

Feintool has addressed these issues in its patented glulock® process, a more economical alternative with several benefits. As with punch stacking, the stacking process is integrated into the tool, making it very efficient. The material costs are also lower, as conventional electrical steel can be used with glulock® thanks to its application of adhesive to the metal inprocess, unlike the specialized baking varnish required in Backlack. In addition to these savings, there’s no heat required, so it’s also more sustainable. As Lock explains: “We don’t need additional energy for ovens because the glulock® process allows the packs to cure at room temperature.”

Tailor-made solutions for e-mobility

When it comes to precision, glulock® is setting new standards. “We achieve significant improvements in E-lamination stack tolerances in terms of parallelism, shape accuracy, concentricity and length tolerance,” says Lock. These improvements are the result of years of experience with adhesive packaging. The first glulock® series tool for an industrial motor was developed back in 2008. Since then, the technology has been geared towards the requirements of the automotive industry. The glulock® High Temperature (HT) process, launched in 2014, has quickly established itself in the industry. It can withstand temperatures of up to 180°C/356°F and is particularly suitable for high-speed motors.

The latest development in the glulock® process is glulock® MD (Multiple Dots), and it is going to shape the next generation of electric motors. The innovative feature? Adhesive dots are no longer only applied to the yoke, but also to the teeth of the laminations. This achieves almost full-surface bonding, which makes the stacks even stronger. A US car manufacturer is already using the technology, launched in 2022, in series production. Feintool will produce a total of over 800,000 rotorstator sets by 2026. “The first automotive series order underlines the outstanding performance and potential of glulock® MD,” says Lock.

New possibilities for cooling electric motors

The glulock® MD technology also helps to solve another challenge of an electric drives: cooling. Electric motors overheat quickly, and maximum power can therefore only be delivered for a relatively short time. This becomes apparent, for example, during repeated acceleration or when driving over mountain passes. This problem is now being tackled with a completely new concept. Lock explains, “The trend is to cool electric motors from the inside, not the outside. Cooling is integrated directly into the rotors and stators.”

Integrated cooling allows the heat to be dissipated directly at the source to combat overheating. This increases motor efficiency and enables a more compact design, but requires impermeable stator and rotor stacks. “The automotive industry is currently looking for the optimum sealing method,” says Lock, “The glulock® MD adhesive packaging process is perfect for this.” The well-bonded, tight stack ensures no coolant penetrates the engine compartment. Multiple development projects are underway with manufacturers to use the Feintool glulock® MD process to make integrated motor cooling possible.

More compact design, greater efficiency

glulock® technology is already contributing to more compact and efficient motor designs. In one development project, Feintool convinced a car manufacturer to switch from mechanical joining to glulock®. Lock explains how Feintool worked with the manufacturer to optimize the design, “We were able to save six out of a total of around 200 lamellas. That doesn’t sound like much, but if you extrapolate that across the service life and the high quantities, it’s quite significant.”

The bottom line: glulock® achieves an increase in energy efficiency of up to 10 percent compared to punch stacking — the most common process in the production of rotors and stators. The iron losses caused by the build-up and continuous changes in the magnetic field can even be reduced by up to 30 percent. In this way, the innovative connection technology Feintool offers brings e-mobility closer to its ultimate goal: increased range via more efficient and compact electric motors.

Markus Lock, Head of R&D and Engineering, Feintool System Parts, Sachsenheim GmbH, Germany

About Feintool

Feintool is the international technology and market leader in electrical sheet metal stamping, fine blanking and forming. We produce highquality precision parts in large series from steel. Our customers come from automobile production, are providers of sophisticated industrial applications and operate in the energy sector. The components produced by Feintool significantly complement the megatrends for generating, storing and using green energy.

Our three core technologies are characterized by their costeffectiveness, productivity and consistently high quality. As a technology leader, Feintool is constantly expanding the limits of the production methods used and developing intelligent solutions, innovative tools and state-of-the-art manufacturing processes based on customer needs.

The company, founded in 1959 and headquartered in Switzerland, has 17 production sites in Europe, the USA, China, Japan and, from 2025, in India − with around 3,300 employees and 100 trainees. In 2023, sales amounted to 848 million Swiss francs. Feintool is listed on the stock exchange and is majority owned by the Artemis group of companies. For more information about Feintool please visit: www.feintool.com

The Hybrid was Never Gone

How is the electrification of light vehicles and trucks progressing? As the US CTI Symposium Novi 2024 showed, hybrid drives may be involved for longer than developers expected. Meanwhile, OEMs and suppliers are working tirelessly to make all kinds of electrified drives more efficient – and more sustainable.

The development came as something of a surprise. Just a year or so ago, the broad consensus in the industry was that there is no alternative to purely battery-electric cars (BEVs). Now, many OEMs are moving hybrid drives higher up the agenda again. At the CTI Symposium USA (Novi, MI, May 15-16, 2024), Chair Patrick Lindemann addressed this development right at the start of his introductory speech, saying BEVs were not catching on as quickly as expected, and in some cases registration numbers were falling. For the US market, Lindemann thinks advanced hybrid drives could still play a significant role up until 2040. Hence, hybrids featured more strongly again in this year’s conference program – both in the specialist lectures and in the discussions.

Obviously, that doesn’t mean the overall development strategy is being upended. As always, all sensible drive electrification solutions will continue to be discussed at Novi. This year, examples included: What are the trends in future electric motors, and what role will hydrogen play? To what extent can heavy trucks be electrified? How will battery technology develop further? And how is growing electrification changing vehicle production?

We’ll need hybrids a little longer

But let’s begin with the new trends in hybrid drives. These also featured in the OEM panel discussion with Mike Anderson, GM, Micky Bly, Stellantis, Greg Gardner, Ford, Jonathon Ratliff, Nissan, and Brian Schneidewind, Toyota. All the participants bar one agreed that in 2035, the BEV market share would probably not exceed 50%. The exception was Mike Anderson, who stood by GM’s strategy of being 100% electric by 2035, at least for light vehicles, but added: “We’ll adapt to developments until then where necessary”. Generally speaking, Ford foresees a very ‘blended’ market, with the move to full electrification progressing faster in cars than in SUVs and trucks. Nissan takes a similar view and is sticking with hybrid drives, especially for larger vehicles. Toyota is backing a ‘multiway path platform’, while Stellantis still plans to be fully electric by 2040.

In this context, the new RAM Charger was mentioned in the discussion, which “breaks all the rules” according to RAM. The truck has a purely serial drive, with a Pentastar V6 petrol engine that powers a 130 kW generator. The two electric drive motors produce 250 and 238 kW respectively. Stellantis claims an electric range of 145 miles, and a total range of 690 miles. According to Micky Bly, the group is taking a three-pronged approach: range extender drives, purely electric, but also 48V hybrids.

As for future hybrid architectures, the panel agreed that there would be different approaches, or “the right tool for the job,” as Mike Anderson put it. Greg Gardner thinks multi-speed transmissions for hybrid drives will still be available “for a good while yet.” Micky Bly does not see any convergence in hybrid architectures yet, saying Stellantis was also counting on suppliers to contribute flexible solutions. Toyota is focusing on powersplit for passenger cars, and also more on plug-in hybrids, where only the battery – not the drive itself – is scaled. In general, Toyota is focusing on platforms that work for both BEVs and xHEVs.

There were several specialist lectures on hybrid drives in the Deep Dive sessions. Aditya Dattawadkar, Schaeffler, described recent advances in hybrid architectures in his talk “Hybrids are Making a Comeback”. Sarah Zitouni, Aurobay, asked: “ICE is dead? – The Need for ICE through Hybrid”. Aurobay is a Volvo-Geely joint venture. It became part of Horse Powertrain, a global Geely-Renault joint venture, at the end of May 2024. Its business field covers dedicated combustion engines, hybrid transmissions and batteries. For several years, Geely has been backing series-parallel hybrid drives and combustion engines with a high efficiency of well over 40%.

Brian Schneidewind, Vice President of Powertrain Design, gave a plenary lecture called “A global development approach to Toyota’s 5^th generation hybrid system for Camry”. He explained that while the Camry was essentially the same vehicle in all global markets, Toyota implemented detail solutions differently, taking local supplier structures and their respective capabilities into account. For example, oil pumps were constructed differently in Japan and North America, yet their function was the same. During development, different regions could take the lead: Ann Arbor, Brussels, Shanghai or Toyota City. The basic principle was this: “When a region had a particular technology lead, they took the global development responsibility”.

E-drives to become more efficient and sustainable

However the future looks for hybrid drives – they are part of an electrification process that is progressing overall, and comprises many facets. Of course, all-electric drives were still a dominant topic on the symposium. They were also discussed in the OEM panel mentioned above, including the enduring question of how many gears an electric drive needs. For Brian Schneidewind, Toyota, one is usually enough, with two driven axles plus disconnect as an alternative to two gears. Micky Bly, Jonathon Ratliff, Greg Gardner and Mike Anderson (Stellantis, Nissan, Ford and GM) took the same view.

Another interesting question was whether OEMs prefer to make electric motors in-house, or outsource their production to suppliers. GM wants to manufacture some PMSMs and ASMs in-house, but also involve suppliers. Ford wants to make mass-production motors in-house, but also retain a “good mix” of suppliers. Ratliff said Nissan were also looking at externally excited e-motor designs (like WRSMs and EESMs) being developed by several makers. Toyota prefers PMSMs for in-house production, but is likewise also looking at external alternatives. So the general view was that PMSMs would continue to improve significantly, but that developers were seeking to minimize the use of heavy rare earths (HRE) in magnets – or even do away with magnets entirely.

The impressive progress of electrification technology was also reflected in the high number of Deep Dive sessions on electric drive units, electric motors, batteries, thermal management, development tools, power electronics, electric components and electric motor development tools. On electric drives and electric motors alone, there were over 25 specialist presentations. As usual, these and other presentations are available as downloads for symposium participants.

New opportunities for suppliers

In the Supplier panel discussion on Day Two – “How to deal with the supply chain, sustainability and accessibility requirements and challenges” – supplier representatives shared their views. The participants were Zobeida Gutierrez, Valeo, Dhanashree (Dhana) Kad, ZF, Keiwan Kashi, GKN, and Chandra Krishnamurthy, BorgWarner. Again, there were some fascinating findings. Keiwan Kashi, for example, pointed out that copper supplies were finite, so developers need to reduce the percentage of copper in motors. Ms. Gutierrez said Valeo was working on developing closed material cycles in some fields. Krishnamurthy saw a need to develop modular systems that would enable scaling across hybrid and all-electric drives. Another important statement from Dhana Kad: “We shouldn’t just shift emissions to another sector – we can’t just shift to electric powertrains and think we’re done.”

At the CTI Symposium 2023, Micky Bly had spoken ironically of an electrification ‘bloodbath’ that could engulf many suppliers. In this year’s OEM panel discussion, Patrick Lindemann took up the thought, asking where the opportunities for suppliers lay, from an OEM perspective. For Brian Schneidewind and his fellow participants, the key fields are air conditioning and thermal management. Micky Bly said support was still needed for combustion engines, while Jonathon Ratliff cited battery development and production. Ford sees a need for external manufacturing capacities to cast new materials based on powdered metal, since production is space-intensive. Finally, looking to China, Mike Anderson said: “We need support to reduce the cost of batteries!”

Will BEV prevail in Long Haulage Trucks?

The question of how feasible full electrification is applies even more to heavy-duty trucks than to light vehicles. In a surprising plenary lecture entitled “The future of heavy-duty trucks – is one technology enough to decarbonize haulage?” Andreas Kammel, Traton, said that in long-haul applications, purely electric drives for heavy trucks would prevail more quickly than some people expected. Kammel believes that particularly in long haul scenarios, operators could quickly recoup their battery costs. Megawatt charging (MCS) would reduce charging times, and hence downtime. Particularly on interstates across the USA, an MCS infrastructure could be set up cost effectively. Also, travel times and routes were easy to plan. Given a successful infrastructure rollout, Kammel sees a clear lead for BEV in terms of TCO.

In his lecture “Integrated and modular – ZF’s future commercial powertrains”, Christian Feldhaus, ZF, said global variations in legislation and geopolitical conditions were the push factors, while TCO was the pull factor and infrastructure the enabler. While Feldhaus also sees BEV as the ‘endgame’, he predicts multiple drive options en route, with diesel remaining a player for quite a while. Since customers prefer different solutions, the industry needed a variety of drives, modular and scalable solutions, with flexible production facilities to match.

Challenges and solutions in batteries

On the Supplier panel, Chandra Krishnamurthy coined a memorable phrase, saying: “The devil is sitting on the battery”. There were also two plenary lectures on new battery developments:

Tim de Bastos, LG Energy Solutions, shared his take on current battery developments in his talk entitled “The state of energy solutions”. Firstly, the ‘pain points’ in EV proliferation were costs, infrastructure, range anxiety and the political environment. Hence, the requirements for new battery types were price, safety, fast charging ability and range. An 80% charge should take 10-20 minutes in the premium segment, and 20-30 minutes in the mainstream. With a full charge, range should be 700 or 500-600 km respectively. LG saw lithium-sulfur batteries and solid-state batteries as future technologies. Broadly speaking, Tim de Bastos defined four areas that determine quality: materials (e.g., eliminating cobalt in future), new processes (e.g., solvent-free dry electrodes), cell to pack with pouch cells, and better diagnostics via cloud and big data processes. The speaker then outlined LG’s next steps up to 2030 and beyond. The polymer-based semi-solid-state battery would enter series production by 2027, the lithium-sulfur battery by 2029, and the polymer-based solid-state battery by 2030. Further down the road, the sulfide-based solid-state battery could become reality. This would require no lithium, and would comprise high-nickel cathodes, silicon anodes and a solid electrolyte.

Taylor Hansen spoke on behalf of Webasto, a company many people still associate with roof solutions. But Webasto is also a leading supplier of aircon systems, which spans the arc to battery technology. In her presentation “Traction battery considerations for medium and heavy-duty vehicles”, Hansen covered solutions for commercial vehicles. She began by saying that requirements varied widely across different applications in terms of range, operating behavior, packaging, robustness, thermal management or safety. Sometimes, objectives could conflict – for example service life vs. range, since the latter required a higher discharge capacity (specifically, 90 vs. 80%). Severe-duty applications had their own specific requirements, for example in terms of thermal propagation, salt-water safety or operation in mining. Interestingly, Hansen said cylindrical cells were more powerful, while prismatic cells were more durable and less expensive. On the subject of common battery chemistries, she said LFP (lithium iron phosphate) had several advantages over NMC (nickel manganese cobalt oxide): LFP could endure more charging cycles, was cheaper, and more thermally stable. On the other hand, NMC offered higher energy density and higher efficiency at low temperatures. LTO (lithium titanium oxide) was also an option for severe-duty and marine applications: its discharge capacity and thermal stability were very high, but at around $1000/kWh, it was also very expensive, she said. Taylor Hansen closed by touching on two other important topics. ‘Harmonious’ thermal management could yield up to 30% more range, and batteries should have redundant battery management – primarily to increase safety.

New production concepts for BEVs

The day before the symposium, there was an excursion to Caresoft in Livonia, MI. Here, the company gave fascinating insights into the benchmarking of electric cars from Tesla, Ford, VW, BYD and others. The visit went down well with participants, and may be repeated in future. In his plenary lecture “Global automotive modular evolution for electric vehicles”, Matthew Vachaparampil, Caresoft, addressed one aspect of the topic. Among other things, he compared various methods of bodywork production, including Tesla’s ‘Giga Casting’ and ‘Unboxed Manufacturing’. The speaker showed how these cost $150 to $300 more in materials, but save 30% in work time, meaning they saved money overall. As audience questions revealed, however, conflicting objectives are at work here. For example, fewer body parts could be a disadvantage when repairs are needed.

Abey Abraham from Ducker Carlisle spoke on “The role of aluminium, steel, and other materials in the future of NA automotive mobility”. He began by echoing the view that in 2030, a good 60% of cars will likely still have an ICE on board. Nevertheless, lightweight construction was definitely necessary in order to cut fuel consumption. Aluminum would partly replace steel, but lightweight high-strength steels would also become more important, as would material composites, including in combination with steel. Abraham also predicted more processes like Giga Casting to save work steps and weight, saying that Honda, for example, was also heading in that direction. For batteries, Abraham expects more cell-to-pack designs, despite accessibility issues. He also emphasized the importance of recycling, even with lightweight construction; materials such as carbon fiber were not suitable.

More variety, more female engineers

The foremost insight from this year’s CTI Symposium Novi is probably that hybrid drives will be around for longer than expected. As chair Patrick Lindemann said at the end: “There is no hybrid comeback; hybrids were never gone.” That said, it would be wrong to cast doubt on the industry’s determination to electrify. As the examples and arguments given here show, developers are continuing their quest for new and better solutions in all areas of electrification. The current development could argue in favor of stronger hybrid electrification, and for scaling components like electric motors, power electronics etcetera as part of an overall electrification strategy. We look forward to seeing how this topic evolves – first at the CTI Symposium Germany in Berlin (December 5-7, 2024) – and, of course, next year back in Novi.

Finally, two other highlights at Novi deserve a special mention: The new, dedicated Female Session on May 15 was highly successful, and very well attended. The CTI has entered into a partnership with the AWA Foundation to involve women more closely in the symposium as participants and speakers in an exchange of experiences and experts on the diverse topics of the industry. With more female plenary and specialist speakers this year, and also in the panel discussions, the first fruits are already appearing.

Something else was also new this year: In addition to his summary, chair Patrick Lindemann invited the entire advisory board up on stage to review their impressions, together with the audience. There were driver-friendly drinks all round, and the casual, family-like atmosphere gave birth to several new ideas, such as ​​focusing more on lifecycle assessment (LCA) in future. After all, this will be a key lever for further reducing CO₂ emissions efficiently and credibly – whether from BEV, FCEV or advanced hybrid solutions.

Author: Gernot Goppelt

The Next Evolution in Multi-Functional Shift Systems for EVs

John Jennings, Director of Innovation and eMobility, Amsted Automotive

The demands on Electric Vehicles (EV) powertrain systems continue to escalate to better meet customer needs – specially extended driving range and better overall driving dynamics – and Amsted Automotive is developing solutions to meet those needs. The latest evolution for next-generation EV drivetrain systems are two variations of a multi-functional shift system with integrated one-way-clutch functionality.

The EV market is growing at a fast pace, creating new and unique challenges for our automakers and tier 1 automotive suppliers. Traditional internal combustion engine (ICE) drivetrains and EV drivetrains are not the same. Without the ability to meet the unique requirements of EV powertrain systems, there are missed opportunities for new success within the transportation sector. Electric propulsion is fundamentally different than ICE propulsion, and the ability to accurately control an electric motor allows for a fundamental paradigm shift that allows new transmission and drivetrain designs to be developed.

Multi-Speed EV Drivetrain

The next generation of EV propulsion systems will need to be further optimized for function, efficiency, range and cost as the EV market scales up. This includes the need for new solutions to improve energy efficiency and extend the range of EVs.

The focus on EV propulsion systems optimization is on right-sizing the eMotor, inverter, drivetrain and the system thermal management. There is also a special focus on reducing or eliminating any sources  of mechanical drag and friction elements. Multi-speed drivetrains can provide additional opportunity to optimize EV propulsion systems beyond what can be achieved by right-sizing the individual components and systems alone.

Compared to a direct-drive EV drivetrain, a multi-speed system can increase the low-speed, high-torque capability and also increase the high-speed, low-torque performance and efficiency. Effectively, a multi-speed system enables increased propulsion system perfor- mance without increasing the size of the eMotor and power electronics. This solution also reduces the associated thermal loading. This is especially beneficial for applications with heavy loads and a lot of start-stop usage.

From a vehicle performance perspective, a multi-speed driveline system can help to improve energy efficiency, vehicle range, launch torque, towing capacity, gradeability, highway performance and thermal durability.

To illustrate the benefits of a 2-speed shift system, this figure shows a typical eMotor torque and speed map. Adding a Second gear can increase the low-speed, high-torque capability while also increasing the high-speed, low-torque performance and efficiency

Transition of Transmissions to EV Drivetrains

The overall principle for multi-speed transmissions is the same for ICE and EV drivetrains, which is to optimize propulsion system efficiency, engine or motor efficiency, vehicle range, launch torque, power and overall vehicle performance.

However, in an EV architecture, each axle may have a dedicated eMotor with the possibility of a dedicated multi-shift system. This leads to advantages for the EV architecture. The dedicated power at each axle allows for the torque and speed to be controlled independently between the front and rear axle systems. This enables the possibility of different features at each axle such as percentage torque split between axles, gear ratios and ratio staggering between the front and rear axles. Furthermore, the shift and disconnect functions can be controlled and synchronized using the propulsion motor controls. In the case of AWD systems, one axle can be used to compensate for the other axle during a shift in order to maintain continuous vehicle power and a smooth gear shift feel.

All of this creates opportunities for new and innovative approaches for managing multi-speed shift systems that were not possible without the accuracy and control of electric motor propulsion controls and simply are not possible in an ICE architecture.

Amsted Controllable Clutch Use in a Powershift Application

The Amsted controllable clutch incorporates two proven technologies: a controllable mechanical diode one-way clutch (OWC) in combination with an existing friction clutch.

The unique Amsted OWC enables automatic and seamless gear shifts with no torque interruption in conjunction with a friction clutch pack.The controllable OWC can be quickly engaged for reverse gear or electric regeneration without the possibility of blocked shifts. This core Amsted OWC technology has been used by global automakers in mass-production automatic transmissions, and there have been more than 60 million produced over the past 25 years.

Recently, the Amsted Controllable Clutch technology has been adapted for 2-speed EV applications in both co-axial (planetary) and parallel axis drivetrain architectures. The system incorporates the Amsted Dynamic Controllable Clutch (DCC) with electromagnetic actuation technology and is a bi-stable actuation design that latches in state without a constant power supply. The system shifts ultra-quick – 17 milliseconds – without the possibility of blocked shifts.

The Controllable Clutch system can be integrated into gears or differentials within the EV drivetrain to minimize package space. This system is currently on a production path to enable Powershifting for seamless and efficient electric vehicle performance.

Amsted Electro-Mechanical OWC Shift System (Next-Generation EV Shift System)

The next step of product evolution for the Amsted multi-speed shift systems is an electro-mechanical shift system that eliminates the drag losses associated with wet friction clutches. Leveraging the unique ability of electric motors and the ability to accurately control and manage on-demand torque, Amsted can eliminate the need for wet-friction clutches.

Starting with the Amsted Powershift System, the friction clutch and 2-mode OWC is replaced with one 3-mode (3-position) OWC system. This new multi-speed shift system offers a controllable bi-directional OWC with a forward OWC and a controllable reverse OWC operation. The new 3-position mechanical shifting system is created by combining the elements of a OWC (1st gear) on one gear while utilizing an on-off disconnect (2nd gear) on the other gear. The passive forward OWC and controllable reverse OWC when combined provide 1st gear forward drive, regen, and reverse vehicle functions.

The Amsted Powershift System incorporates a OWC disconnect and a friction clutch pack to provide the advantages of a multi-shift system for EV architectures using
proven, production technologies.

For further functionality, controllable-passive OWC modes can also be incorporated for the 2nd gearset in addition to the 1st gearset utilizing a common electro-mechanical actuator enabling additional vehicle functions that include 2nd gear forward coast. This can provide further shift customization to reduce shift time, improve shift smoothness and eMotor matching utilizing Amsted 4 and 5 mode actuation technology. In this configuration, the OWC and controllable OWC provide the shift transition functions, allowing the electric motor to transition between gear speeds. The OWC function then enables an automatic engagement and disengagement with the appropriately selected gears.

For example, to complete a 1st to 2nd gear upshift, the controllable OWC for reverse is disengaged and the forward OWC is then staged for a gear shift. The shift is accomplished by decelerating the propulsion motor, causing 1st gear to automatically disconnect via the OWC. When the motor speed matches the 2nd gear speed, the second gear OWC will automatically engage and complete the shift. At any point after the second gear is connected, the system is synchronized and the controllable OWC can be engaged for regen braking.

For a 2 nd to 1 st gear downshift, the order of shift sequence is simply reversed.

Advantage of Amsted Electro-Mechanical OWC Multi-Speed Shift Systems

First, we’ll look at the specific advantages compared to traditional Powershift System with friction clutches:

• Friction pack is eliminated
• Reduced weight of system
• Reduced package space
• Eliminated oil circuit and pump for friction pack
• Eliminated actuation system for friction pack
• Improved efficiency – no friction elements
• No wear particle contamination from friction surfaces (supports sustainability).
• Lower cost

Advantages compared to traditional dog clutch technologies:

• Smoother and faster shift times
• Automatic OWC shifting (gear engagement and disengagement)
• Shift times are managed only by the motor and motor controls – no synchronization is required between motor and shift actuation devices
• Simplified system controls
• System can shift when vehicle is stopped
• Improved reliability (no blocked shifts)
• Eliminates shift fork hardware and related package space
• Flexible design applications: can be used in both parallel-axis and co-axial drivetrains
• Options for 3, 4 and 5 mode operations

Who is Amsted Automotive?

In 2021, Amsted Automotive Group brought together Means Industries Inc., Transform Automotive, SMW Manufacturing, and Burgess-Norton Mfg. Co., Inc. to form a new and innovative technology team. The integration provides an expanded global presence with 21 facilities in North America, Europe, and Asia to serve the global automotive, off-highway and mining industries with a robust manufacturing footprint, producing over 100 million components and assemblies annually. The group combines design and engineering expertise, strategically aligned to be a leader in precision products and efficiency solutions for electrified, hybrid and ICE propulsion systems. Amsted Automotive Group plays an integral role in global automatic transmissions designed and manufactured in North America, Europe, and Asia.

Interview: “In E-Mobility, Performance doesn’t have to be Expensive.”

How do you make e-mobility more affordable? At the CTI Symposium Berlin in December 2023, we caught up with Thorsten Jablonski, Head of Development & Product Management Volkswagen Group Components. As he sees it, there are several levers: for example battery technology, electric drives, and leaner processes in development and production.

On the product side, what key levers can make BEVs affordable for people who find them too expensive?

The biggest cost driver for electric cars is still the battery. Fast charging tech costs money, and so does battery capacity. Volkswagen has to focus on customers’ priorities. Is this a second vehicle that you can charge slowly at home, but which has a high range? Or are 200 kilometers of range enough? Another big cost factor is cell chemistry. With electric powertrains, it’s all about simplification. With electric drives, you can dial some of the requirements down a bit, for example how quickly the interior heats up. So it’s simplification and the battery system. For me, those are the two levers for building an electric car in an affordable price range.

What are you doing in the field of batteries?

Volkswagen develops and produces its own battery systems, and also assembles them. It started with the E-Golf and also the systems for the E-Up were produced in-house. The only components which were bought are the battery cells and the modules. In the future, the modules will gradually disappear and the cells will increasingly migrate into the vehicle. Today Volkswagen also develops the battery management software and battery system in-house and assembles them at its own factories, sometimes via third-party manufacturers. But the development is always 100 percent Volkswagen.

Depending on the brand and segment, you might also want to scale the electric drives. How do you reduce variance there?

In electromobility, performance doesn’t have to be expensive. The cost difference between 100 and 400 kW doesn’t have to be that big. The key is a concept for scaling performance neatly, in a modular system. That means all drives can be manufactured on the same production lines. It takes a lot of brainpower to avoid compromising on the costs of drives, which need to be affordable. The modular system achieves best-in-class scores in many areas. All that calls for a lot of discipline, and a great deal of engineering skill. Charging options are the make-or-break factor for BEV acceptance.

What is Volkswagen doing to improve public charging infrastructures?

Within the Group, the Elli brand is responsible specifically for this purpose. With Elli we are offering one of the the largest charging networks in Europe and are giving access to more than 620,000 charging points. And through Electrify America Volkswagen has built up the most powerful open hyper-fast charging network in the United States and Canada. Another factor with range is thermal management.

How can that be made more efficient?

If you look at the total number of hoses in there today, it’s enormous. It`s called the ‘snake pit’. All those connecting hoses will disappear in the future; everything will be combined in a single module. You can even replace hardware with software. That improves your cost efficiency, and also your energy efficiency. But you have to think holistically, throughout the whole electric powertrain. That’s one key reason why we focus on the entire powertrain.

Which areas will Volkswagen withdraw from, in favor of electric drives?

Everything about electric powertrains will be kept, including the chassis that were designed for them. But components that are costly and not sustainable will be skipped. For example, the development and production of shock absorbers. What will remain apart from BEVs? In China, P1/P3-xHEVs are still selling.

Do you see any future in Europe for solutions like these?

Often markets depend on legislation. In China, plug-in hybrids grew their market share from one or two to thirty percent. Some Chinese manufacturers decided to back PHEVs – and then they got subsidized. If Volkswagen starts selling systems like that now in China, I believe that those incentives will soon be scrapped. As for Europe or Germany, if biofuels are not accepted as sustainable and there is no funding, plug-in hybrids will not gain a huge market share. Germany and Europe are concentrating on electric cars now because they want to get one technology established first.

Interview: Gernot Goppelt

eS4500i: Highly Integrated Electric Drive Unit for Multiple Applications

Marco Silvestri, Chief Engineer, Dana Incorporated

Across all our actions, we never lose sight of a guiding vision toward a zeroemissions future. This has powered our first-mover advantage in electrification.

At Dana, we strategically invest in technical competence − designing, engineering, and manufacturing the components of a complete e-Propulsion system in-house. These innovations include efficient EV systems and new electrodynamic products like motors, inverters, controls and software, battery cooling systems, and metallic bipolar plates for fuel cell applications.

The legislation for pollutants and emissions is driving OEMs to design their reduction programs to align with aggressive timelines — accelerating the adoption of electrification. These mandates, coupled with corporate commitments from OEMs, will significantly increase the demand for electrified vehicle architectures, the main components of a Battery Electric Vehicle.

Dana’s solution is the Spicer® Electrified eS4500i e-Drive Unit − a highly versatile 3-in-1 electric drive unit (EDU) that converts the stored electrical energy from the battery into mechanical power to the wheels.

eS4500i Platform

Utilizing competencies from Dana’s global network of technology centers, the highly integrated eS4500i comprises an inverter, motor, one-speed geartrain, open differential, and optional park-lock.

The thinking behind the eS4500i was really to provide more than a single EDU. What was needed was a versatile platform offering multiple ratios and integrated design of motor and gearbox while also taking into consideration efficiency, optimized packaging space, and lower weight.

To cover multiple applications, five different ratios were designed (macrogeometry) with the same center distances, same gear width, and similar envelopes diameters also recombining the same gears to reach five different ratios.

In this way, with a unique design of the housing and bearings, the eS4500i can host five different gear-trains to be able to match different vehicle requirements in terms of maximum torque and speed. From figure 2, it’s appreciable the spread of torque and speed that the system can cover with the five different ratios options. A limitation of around 4,500 Nm (as max nominal output torque value) has been decided for ratio 15.1 and 13.1 because of match with other Dana products but useful in case of demanding vehicle gradeability and high continuous torque.

Highly Integrated Layout

The design of the gearbox and the motor was improved by integrating the components as much as possible to provide a light, compact, and power-dense EDU.

For the eS4500i, it has been decided to have a highly integrated design between the motor and gearbox to save weight and to improve the power density.

Only three housings compose the structure of the EDU and shape two separate environments: a dry one for the motor and a wet one for the oil-lubricated gearbox.

Referring to figure 3, from right to left:

The motor back-case supports the rear motor bearing and becomes the seat for the stator and the internal side of the motor cooling jacket. The helical cooling path is made by die-cast molding for manufacturing efficiency.

A carrier housing supports the front motor bearing and becomes one of two gearbox housings as well as the external side of the motor cooling jacket to complete the sealed channel.

The cover housing enclosures the gearbox components.

One of the main characteristics of the highly integrated layout is the over-hanged pinion gear directly mounted on the head of the rotor shaft. Between the pinion gear and the motor front bearing, there is a parking gear.

The layout is completed by an intermediate shaft and an open differential, both supported by taper roller bearings.

This new layout reduces the interfaces between the gearbox and the motor to achieve a precise axial centering of the gearbox with the output shaft of the motor. This also allowed a significant reduction of components like having only two bearings on the input axis, a reduction of the number of housings and a significant a reduction of fasteners.

The EDU is completed by the inverter that is direct-mounted on top of the motor with the high voltage connections passing through the back housing.

The park-lock adds another degree of flexibility because it can be added or removed on customer request. This park-lock option is already patented and in series production, with a mechanism layout now upgraded with a new smart actuator.

Motor and Inverter

The eS4500i is powered by a propulsion system composed of an asynchronous dry 450V motor and with a Dana 2nd generation directmounted inverter.

The propulsion system is cooled by water-glycol and the theoretical performance curves are shown in fig. 5 at 65°C coolant temperature.

Since this propulsion system is for a medium voltage (450V) application, Dana decided to use the latest IGBT module technology for this inverter over the newer SiC MOSFET technology. This allows the use of our proprietary Reflex gate driver technology to achieve the most cost-effective solution for this voltage range.

Conclusion

As a Tier 1 supplier, Dana offers its new eS4500i EDU, an off-the-shelf solution on the path to electrification, with a compact and light package for a wide range of applications.

The eS4500i is equipped with the well-known Dana differential from a robust off-road heritage, with an optional park lock system.

Dana is offering its all-new configurable off-the-shelf eS4500i EDU to a multitude of segments and applications. This work is the result from the synergy between the different technical centers and other global Dana branches, putting together different competencies. With its power density, reliability, and cost competitiveness, this product will contribute to our customers’ success on the path to electrification.