Alex Tylee-Birdsall

Alex Tylee-Birdsall

Continuing just-auto/QUBE's series of interviews with suppliers, we spoke to Alex Tylee-Birdsall, co-founder and director of Drive System Design, about how the transmissions market is undergoing a period of change.

What was the landscape like for transmission engineering, when Drive System Design was founded in 2007?

Manual transmissions were still very popular, dual clutch systems were just reaching the market, and HEVs were still a rare sight. As OEM and Tier 1 customers adopted new technologies, such as electrification, unfamiliar challenges arose. We saw an opportunity to respond to those challenges because our origins in transmission design included maintaining a 'whole system' approach which was effective in providing solutions to issues that had not been encountered before.

What kinds of issues were encountered by electric vehicles back then?

The move to electric vehicles (EVs) highlighted an immediate concern about transmission noise because the absence of an IC engine meant that background cabin noise levels were much lower and occupants became more sensitive to other sources, such as gearing.

We actually took on our first noise reduction programme free of charge as a loss leader to establish our reputation within the EV community. We now have a portfolio of electrified driveline projects, with eight currently underway, so it's clearly still a big challenge for the industry.

Our exposure to EV customers through noise work led to additional design activity, such as park lock design. There are important legislative controls on park lock performance and trade-offs, such as between latching speed threshold and roll-away on a slope.

Were any other external factors driving the engineering direction?

Powertrain efficiency had a big influence on the direction of development within the industry. Our knowhow in efficient hypoid gear design, for example, has stimulated business growth year on year, as customers have sought improved fuel economy. Efficiency modelling and testing of full driveline systems is now a significant part of our business. The 2020 emissions target of 95 g/km of CO2 as a fleet average continues to maintain pressure on manufacturers to improve efficiency throughout the driveline.

There will be more electrification with greater emphasis on integration of e-machines.

DSD also identified the value of using a multi-speed transmission in an EV application, in order to improve e-machine efficiency and the trade-off between range, cost and vehicle performance. We began in the field of transmission design, with ambitions to include control expertise and test facilities. Our subsequent move into e-machine design and development was a strategic decision in recognition of the evolving market.

How are things different today?

Many people thought that there would be a gradual progression through mild hybrids to full hybrids and EVs, giving them time to gain expertise and familiarity with the technologies. In fact, EVs have become established much more quickly, partly through the pace of improvement of battery technology and partly through the adverse publicity surrounding diesels.

What do you expect over the next 10 years?

Manual transmissions do still account for around 50 per cent of all transmissions sold and, in the short term, these can be combined with 48V electrical systems to enable the configuration of a low-cost mild hybrid.

Looking further ahead, there will be much more electrification, with greater emphasis on integration of the e-machines, and a drop in the popularity of IC engines. Previous estimates for the future global EV market were 10 per cent of the total vehicle population by 2025. This now looks as though it could be appreciably higher, up to 30 per cent, if legislation regarding urban air quality forces faster change.

Future EVs are more likely to use multi-speed transmissions than the first generation single-speed units because, although simpler, the single-speed transmissions cannot match the efficiency of the multi-speed systems. Planning the vehicle architecture to accommodate future trends is leading some customers to propose FWD with an IC engine, hybridised by the addition of a RWD EV module. When a point is reached where demand for an IC-engined hybrid falls, they will replace the IC FWD module with a second electric module.

We know of no companies currently working on new DCT technology without electrification.

However, even looking ahead to 2027 there will remain a demand for manuals from customers requiring a car with the lowest possible purchase price. Dual clutch transmissions (DCTs) will remain popular in performance cars but with some form of hybrid architecture. We know of no companies currently working on new DCT technology without electrification.

See also Global light vehicle transmissions and clutches market - forecasts to 2031