Europe may have long resisted the automatic gearbox, but new environmental and fuel efficiency legislation combined with major advances in electronics and manufacturing techniques are paving the way for a flood of new automated transmission technologies. In this round-up of recent developments, Matthew Beecham talks with executives of BorgWarner , Getrag , LuK, Prodrive , Torotrak, Valeo , Vocis Driveline Controls and ZF.

Automated transmission technologies include high-performance automated manual transmissions (AMTs), dual-clutch transmissions (DCTs), continuously variable transmissions (CVTs) for smaller vehicles and highly innovative new technologies such as Torotrak’s infinitely variable transmission (IVT).

The direct shift gearbox, powershift gearbox, twin-clutch gearbox are just a few of the terms used to describe the dual-clutch gearbox. The gearbox concept combines the advantages of a conventional manual shift with the qualities of a modern automatic transmission. It originated in motor sport and is characterised by having two part gearbox units, which operate the odd and even gears, respectively. It means that when changing gear, the engine torque is transferred continuously from one gear to the other. The result is gentle, jerk-free gear changes with the same relaxed driving style found in an automatic combined with the efficiency of a manual transmission.

DCT is growing in significance due to its combination of refinement, efficiency, low cost and driving satisfaction. The VW Group pioneered DCT and continues to push dual-clutch technology in Europe.  BorgWarner played a key role in the development of VW’s DSG 6-speed automatic gearbox, which combines the smoothness of a state-of-the-art torque converter with the fuel efficiency of a lighter and cheaper to manufacture 6-speed manual. BorgWarner is continuing to push back the technical boundaries of dual-clutch innovations. Its DualTronic® clutch and transmission control technology enables a conventional, manual gearbox to function as a fully automatic transmission while delivering improved fuel efficiency and enjoyable drive experience.

In explaining how BorgWarner is maintaining its technological lead, Bob Blakely, marketing director of BorgWarner Drivetrain Systems , said: “At the heart of BorgWarner’s DualTronic® technologies are two key core competencies in wet (oil bath) friction clutches and electro-hydraulic solenoids, which we continue to evolve and refine to maintain our competitive edge.  Our latest friction materials deliver the industry’s highest ever thermal capacity, enabling operation in low oil flow environments.   Our latest solenoid designs deliver greater precision while reducing control system leakage, thus minimizing energy consumption.”

Meanwhile, a number of other companies are pushing back the technical boundaries of automated transmissions. UK-based Vocis Driveline Controls was formed in 2006 by four engineers and a project manager who left Ricardo to establish their own business specialising in driveline control systems and programme management. All five have hands-on experience of developing transmission control and software systems, specifically the emerging DCT technology. Since then, the company has developed and integrated DCTs and control systems for several European vehicle manufacturers and is also developing a multispeed transmission for electric vehicles.

“Through 2009 we have taken the original concept to a first prototype level after an extensive design analysis and simulation phase,” said Mike Everitt, managing director of Vocis driveline Controls. “Six first phase prototypes are due to start build at the end of this month [February 2010] and will then undergo a series of tests at various venues. The heart of the system is a fusion of several existing technologies in a novel way that will allow a simple control system to provide a very smooth seamless shift. It saves battery energy by optimising the electric motors speed and torque operating points to more closely meet the driving requirements. Electric motors are generally very efficient devices but they are not perfect and can benefit from a multi ratio transmission in the same way an internal combustion engine can. In addition to a predicted like for like range extension of approximately 10% we can also choose to balance other vehicle performance factors such as; operate the vehicle at higher speed (due to its taller second gear ratio), on steeper gradients or with higher payloads (due to its lower first gear ratio), or with a smaller cheaper motor for comparable single speed overall performance.”

With electric vehicles still at an embryonic stage, fuel-efficient transmissions such as DCTs and CVTs are likely to enjoy a greater market share.  Dr Gerhard Wagner, group executive of the ZF’s car driveline technology division and CEO of ZF Getriebe GmbH, told us: “Due to the actual savings in our customer’s operations, we have been observing a continuous increase in highly-efficient automatic transmissions for some years now. In this field, the torque-converter transmission remains the prevailing technology and will also be the main business field for ZF. The dual clutch transmission will primarily be used in Western Europe for sporty vehicles. The advantage of the dual clutch transmission is its high-speed resistance.  A disadvantage is the slightly higher cost compared to torque-converter transmissions. This means that torque-converter transmissions will remain unrivaled in the future as well – also thanks to their weight advantage. We expect the CVT to disappear again from the markets in Europe and North America. The system-related poorer efficiency, limitations when transmitting torques (max. 400 Nm), the maximum transmission ratio range (max. 6.5), and the higher weight reveal the physical limits of this transmission design.”

Dr Peter Bührle LuK GmbH & Co. oHG added: “As a component supplier, it is important to support all technologies that may be needed in future markets. All of the mentioned [DCTs and CVTs] technologies are promising, each of them in the segment where the customer gain the highest benefit of the respective technology. For DCTs and CVTs, the prospects in the near future are excellent indeed. Electric vehicles, combined with fuel stacks or range extenders, may grow in parallel as soon as the economic boundary conditions are attractive enough.”

Germany-based Getrag is  the  largest  independent  passenger  vehicle  transmissions manufacturer  worldwide  employing  12,850  people at  24  locations.  The group develops technical solutions for the automotive industry and possesses a broad product portfolio  of  drivetrain  systems  and  powertrain  components  for  passenger  vehicles,  SUV, motorcycles and light utility vehicles. In terms of the outlook for manual gearboxes, Getrag executives told us: “We expect a main volume growth for manual transmissions in the BRIC [Brazil, Russia, India and China] countries. The manual gearboxes will further play an important role due to lower cost and affordability and will stay at approximately 52% market share until 2015. We expect the portion of front-wheel-drive transmissions to grow caused by downsizing and standardisation. Getrag is matching the market requirements with a wide portfolio of transmission architectures and torque ranges.”

Markus Kneissler of LuK GmbH & Co. oHG, believes that DCTs will appear in all segments of passenger vehicles. He told us: “It looks like the prospects for the near future are best in the mid-class cars with dry DCT. The combination of comfort, performance and best fuel economy seems to be what everybody is looking for.”

Meanwhile, Valeo sees the transmission market as one with strong regional disparities. Valeo executives told us:  “DCT is a fast growing market, mainly in Europe and in China. Through co-operations and alliances, we also see DCT in NAFTA with a significant market share but limited to mid- and low-end segments.  Fuel efficient automatic transmissions will remain the transmission of choice of US OEMs. In Japan, new generations of CVTs will remain the OEM choice, for FWD, whilst 6/7/8 speeds automatic transmission will maintain the market share for RWD applications, DCT are not expected to witness a significant growth in the Japanese domestic market.”

Another company making significant strides in the transmission field is Torotrak, a technology company based in the UK with a clear goal: to bring its revolutionary and patented automatic gearbox technology to the market. According to the company, its Infinitely Variable Transmission (IVT) brings fuel economy gains without performance compromises. In terms of developing markets, James Batchelor, Torotrak’s commercial director, believes that CVTs and IVTs will become more popular. He told us:  “We believe that, on a global basis and over time, environmental pressures and related legislation will mandate the increased use of ‘automatic’ transmissions to take the driver out of the loop so as to ensure optimal fuel economy, irrespective of driving conditions.  This will apply across all vehicle types.  We see this trend extending into developing markets, as well, although the time scale may well be longer than in the more established markets. In Western markets, there is substantial investment in both expertise and manufacturing infrastructure for planetary automatics, which creates a barrier to radical change – for instance, to move into full-toroidal CVTs and IVTs. This is not generally the case in developing markets, however, where vehicle manufacturers and suppliers are interested in taking a leap to the next generation of technology and owning the ability to develop it and sell it on. We believe that as a main drive technology, Torotrak full-toroidal traction drive technology provides an excellent low-cost automatic transmission solution for a light-weight car that needs to maximise both passenger space and fuel economy.”

Meanwhile, Prodrive has built up an enviable reputation as one of the world’s most successful motorsport engineering businesses.  Formed in 1984, it has won international races and rallies across the world, including six World Rally Championship titles; five British Touring Car Championships and three Le Mans GT class wins. While the company is best known for its motorsport achievements, more than half the company’s turnover comes from engineering activity in the mainstream automotive sector. Simon Leleu, Prodrive team leader for transmission and driveline systems, believes that in developing markets there is a latent and growing demand for highly controllable automatics that is currently not being satisfied.  He points out that in commercial vehicles and buses for instance, there are varying levels of driver skill and vehicle operators are attracted to the benefits automatics can bring, in terms of reduced wear and tear on the driveline and improvements in fuel economy.  However, many markets do not have a domestic manufacturer of automatic transmissions, and many vehicle manufacturers do not want the costs associated with either buying in or manufacturing planetary autos.  “As a result AMT is a very good solution,” said Leleu.  “With our technology, existing manual transmission production lines can manufacture a mix of both AMT and manual transmissions, as almost all the manual gearbox components can be carried straight over to the AMT, including the synchromesh. It is also simple to build a number of variants with different ratios, so that the ratio selection compromises that are often part of a diverse model range can be reduced.”

Matthew Beecham