Bosch hybrid drives cut CO2

Hybrid drives for automotive applications, combining the internal combustion engine with an electric motor, offer significant potential for reducing both fuel consumption and CO2 emissions. Bosch is currently working on the development of a parallel hybrid system, with modular components which can be customized to meet individual OEM requirements and, due to the make-up of the system can also be combined with different transmission types. Bosch already has its first orders for both gasoline and diesel hybrids.

Diesel hybrids produce 20 percent less CO2 than conventional diesel engines, while the emissions for petrol hybrids are up to 25 percent less than their conventional counterparts. Coupled with technologies such as gasoline direct injection and optimised transmission systems, hybrid systems can offer further improvements to fuel consumption and emissions.

The electric drive of the Bosch parallel hybrid system generates enough power to allow a vehicle to cover short distances using solely electrical power, therefore reducing CO2 emissions completely. It also acts as a powerful boost for the internal combustion engine – a significant benefit for urban driving.

Alongside this parallel system, Bosch is also developing several further hybrid concepts as well as a number of simpler methods to allow notable CO2 reductions such as innovative start-stop techniques and the recovery of braking energy via the alternator.

Bosch predicts that by 2015, the hybrid market will be split 50:50 between parallel hybrid systems, the main focus of Bosch hybrid development, and distributed hybrids. The potential growth markets for hybrid drives include the NAFTA countries – Canada, the United States and Mexico – and Japan, as efforts are made by these countries to further reduce emission levels. Bosch believes that, by 2015, hybrid vehicles will account for nine per cent in Japan and four per cent of production in the NAFTA countries. Forecasts for Europe are comparatively low, with hybrid production accounting for only one per cent.

Over 30 years of expertise in electric drives

Bosch has been working on hybrid technologies for over 30 years and has a wealth of experience at its disposal – including extensive knowledge in battery, electric drive, and brake management as well as engine management and transmission control. In addition, the company already has a wide range of components that can be used in both parallel and distributed hybrid systems, including powerful electric motors, the necessary power electronics, and DC/DC converters. The introduction of hybrid drives will also result in the use of electric auxiliary systems where, again, Bosch already has the appropriate products available, such as electric water pumps. A cooperation agreement with transmission manufacturer Getrag for the development and marketing of parallel hybrid systems in conjunction with dual clutch transmissions and electric final-drive units rounds off the portfolio.

"Our broad-based footing gives us the expertise required for complete system integration of hybrid drives," says Dr. Matthias Küsell, head of the hybrid project program in Bosch's Gasoline Systems division. The "Bosch Hybrid Systems Project Unit" has assumed this task. Midway through 2007, it employed over 250 people involved in hybrid drive development and sales.