Hybrid Electric Drive can enhance existing platforms and support future decision making for wheeled platform electrification
We have the technology and expertise to support the integration, demonstration and evaluation of wheeled electric drive technologies. We have developed scalable, compact and efficient military specific Hub Drive Units (HDUs) to Technology Readiness Level (TRL) 5 on two occasions, and are well positioned to support decision making in this space.
Excellent automotive performance is inherent in electric drive systems and while there are different types of hybrid architecture, we see the series-hybrid layout as ideally suited for the military application; this has been validated through studies using our power train modelling tool HYSIM, and subsequent real-world testing in military electric drive programmes.
The electrical power path between the diesel engine and generator allows for increased flexibility in vehicle packaging; this enables a step change in the design boundaries associated with conventional mechanical architectures and has most impact when designing a new platform around the freedoms of a hybrid power train.
In-wheel electric Hub Drives
Hub Drive technology combines electric propulsion with mechanical and regenerative braking in a compact package. Efficiency and size has been the weakness of previous attempts at electric propulsion for wheeled military vehicles where the direct drive of motors to wheels has been used, usually without a range change gearbox which results in over-sized, heavy motors.
As part of an electric tracked vehicle propulsion system, E-X-Drive® offers a lighter, more compact and efficient solution compared with conventional mechanical transmission systems. Combining electrical and mechanical components in a novel configuration that is efficiently packaged, E-X-Drive® incorporates mechanical regenerative transfer of steering power, range-shift mechanisms, and permanent magnet motor technology. It is a demonstrated and low risk solution, with low stress levels in the motors, gears, shafts and bearing components.
Using E-X-Drive® as part of an electric propulsion system offers the opportunity for innovative tracked vehicle configurations founded on a fundamental shift in platform design trade space options. Not only is an E-X-Drive®-based transmission package smaller and lighter than comparable conventional transmissions it also lends itself to novel vehicle layouts to improve survivability, agility, and mission success.
Key performance advantages
- Increased automotive performance and mobility
- Full torque from standstill
- High burst acceleration with Improved fuel efficiency
- Engine downsizing and speed optimisation
- Energy storage to allow load-levelling, regenerative braking, and silent watch capability
- Flexibility in powertrain layout – whether a decentralised system or a consolidated power pack