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New Mahle scalable and modular hybrid drive


Mahle Powertrain will showcase its new, fully integrated and modular hybrid drive, which can be tailored to suit a wide range of vehicle applications, at Aachen Colloquium in Germany from October 7-9.

The Mahle Modular Hybrid Powertrain (MMHP) is a fully integrated, plug-in hybrid drive that incorporates a highly efficient 2- or 3-cylinder, turbocharged gasoline engine featuring the latest Mahle technologies. It offers several advantages over established hybrid technologies, including cost-efficiency, compactness and reduced weight.

“The launch of MMHP at the Low Carbon Vehicle Event at Millbrook in the UK and overwhelming subsequent industry interest in the technology at IAA Frankfurt has been hugely encouraging and proves that we have delivered an industry solution at exactly the right time,” says Dr. Martin Berger, Mahle Powertrain’s Engineering Director. “The need for vehicle manufacturers to comply with the EU’s legislative target of fleet average CO2 emissions of 59.4 g/km by 2030 requires dynamic technology development and implementation. Electrification is leading the way as the industry’s chosen technology to achieve this and MMHP could provide a timely head-start for manufacturers on the brink of new vehicle development.”

Further detailed specifications of the Mahle Modular Hybrid Powertrain and the challenges currently facing the automotive industry, will be presented at Aachen by Dr. Mike Bassett, Mahle Powertrain’s chief engineer for research.

“The extreme flexibility of MMHP is enabled by the ability to deliver an optimised power unit whatever the manufacturer requirements,” explains Dr. Bassett. “The key to the concept is that the engine performance and number of transmission ratios can be optimised, using common building blocks, to enable charge sustaining operation for a wide array of vehicles and performance levels. This helps to control costs and avoid unnecessary investment in sub-optimally specified components that jeopardise ultimate efficiency and development times. MMHP offers a perfect blend of efficiency and performance without compromising driving pleasure or vehicle range.”

The performance of the electric powertrain harnessed in MMHP reduces the requirements of the combustion engine, enabling the development of a cost-optimised Dedicated Hybrid Engine (DHE). The engine concept was designed exclusively for hybrid applications and employs port fuel injection (PFI), a single overhead camshaft (SOHC) without variable valve timing control, and simple two-valve per-cylinder technology to optimise costs.

In addition, the engine benefits from the latest innovations made with the passive Mahle Jet Ignition (MJI) system. MJI technical information and details of its development will also be presented in a paper at Aachen, Development of both active and passive pre-chamber jet ignition multi-cylinder demonstrator engines, delivered by Michael Bunce, head of research at Mahle Powertrain, LLC . MJI has been designed to increase ignition energy available in the main combustion chamber through use of a small pre-chamber. This generates hot ignition jets, which result in more efficient, stable combustion within the cylinder, enabling a safe increase in compression ratio and a highly dilute mixture, through the use of air or exhaust gas recirculation, to help reduce fuel consumption. Mahle Powertrain’s testing has shown a 10-20 per cent increase in thermal efficiency with active MJI compared to baseline modern engines.

MMHP, which is suitable for a variety of applications – from B-segment through to large J-segment SUVs – operates a dual-mode hybrid arrangement as it combines the best features of both series and parallel hybrid architectures. It allows for flexible vehicle operation, while providing optimal NVH behaviour. When battery SOC is high, the vehicle can operate as a pure EV, whereas when SOC is low and at slow driving speeds it can switch to series hybrid mode. At higher vehicle speeds, however, the combustion engine can be connected directly to the wheels, in a parallel hybrid arrangement.

The transmission uses entirely customisable ratios to enable the engine to run flexibly at any given vehicle speed. Options for 1-, 2- and 4-speed transmissions are available, depending on application requirements. As a result, the fully integrated, electric traction motor is directly connected to the wheels at all times, facilitating uniform performance and a dynamic driving experience with uninterrupted torque delivery. The motor can also be designed with different power/torque outputs. Coupled with optimised battery sizing, this allows full scalability of the hybrid powertrain for all applications.