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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.

E-X-Drive® combines electrical and mechanical components in a novel configuration that is efficiently packaged, incorporates mechanical regenerative transfer of steering power, range-shift mechanisms, and permanent magnet motor technology. E-X-Drive® 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
  • Silent launch, with ‘on the move’ engine start
  • 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

Hub Drive

Building on our technical expertise across highly integrated electromechanical transmissions, our new electric hub drive is intended to revolutionise the mobility and performance of wheeled military vehicles. As part of an electric propulsion system, in-wheel hub drives replace the main transmission and ‘drop-boxes’, differentials, and drive shafts with compact and extremely high-powered electric motors contained completely within the wheel rim. As part of a series hybrid-electric powertrain, this approach opens up dramatic new design possibilities that increase performance and improve safety and survivability of military vehicles.

QinetiQ offer a family of Hub Drive Units (HDU) providing a compact in-wheel solution that fits within a standard 20” tyre rim delivering more power, torque, and mobility compared with conventional mechanical transmission systems. Our Hub Drive is uniquely packaged containing a permanent magnet motor, 3-stage gearbox, integrated brake, with water based cooling.

The Hub Drive is offered with an accompanying umbilical system and Wheel Station Controller (WSC). Each hub drive is controlled by an individual WSC containing the power inverter, controller, and pneumatics for the gear shift. These are delivered through the custom built armoured umbilical system.

The hub drive system delivers two critical areas of benefits:


  • Provides significant design flexibility for enhanced vehicle chassis, suspension and steering systems
  • High torque from a standstill for excellent acceleration and tractive capability
  • Reduced rotating driveline mass and low centre of gravity
  • Individual wheel station control for superior traction and yaw control, and emergency neutral-axis pivot turns
  • Improved velocity control and downhill decent through regenerative braking


  • Removal of mechanical driveline components leaves a clean floor space and freedom for a purpose designed armour system
  • Ability to keep driving with the loss of one or more hubs
  • A liquid cooling circuit ensures control of hub temperature; external thermal shields blend the hub signature with that of the vehicle tyres
  • Silent driving and stealth operation achieved in pure electric mode utilising battery power

Understand the Hybrid Electric Powertrain system integration

QinetiQ offer customers a complete understanding of the impact integrating a Hybrid Electric Powertrain (HEP) system has on their vehicle including performance and cost through the use of our validated HYSIM® model.

HYSIM® – Capability Overview

QinetiQ offers simulation capabilities in the form of a validated computer model known as ‘HYSIM®’. At its core HYSIM® is a powertrain simulation tool used to assess various technology and configuration options for both conventional and hybrid electric drive systems in the context of wheeled and tracked vehicles. It is ideal for performing iterative concept studies (at a systems level) to quantify the benefits of transitioning to a hybrid electric system (from a conventional one). The model takes into account the major longitudinal forces that affect vehicle propulsion (i.e. aerodynamic drag, rolling resistance and gradient forces), and hence the influence on fuel consumption and acceleration.

HYSIM is capable of predicting vehicle performance and fuel consumption for various powertrain topologies including conventional systems, series HEVs (Hybrid Electric Vehicles), and parallel HEVs. It consists of a powertrain model built in SIMULINK that is linked to an MS-Access database of input, output and sub-model data. The primary components in the model comprise the ‘duty cycle’ definition, engine, generator, battery, transmission, and electric motor.

Key benefits are:

  • Military applications

    HYSIM® is suitable for predicting the response of both military tracked and wheeled vehicles equipped with hybrid drive technology over various terrain and ground composition (excluding sand).
  • Proof of concept

    HYSIM® will demonstrate the feasibility of a hybrid architecture during the early stages of development to deliver a more informed design.
  • Simple user interface

    HYSIM® is designed to be easy to use allowing the user to operate the program via an MS-Access user interface without having to possess any prior knowledge of SIMULINK.
  • Batch testing

    HYSIM® permits the rapid iteration of multiple test cases for situations where the user is required to make direct comparison between a set of options in terms of technology, component sizing or power management strategies.

Integration cost and planning

QinetiQ also provide the service of ‘True Planning’ to customers. This provides a clear insight into the cost of integrating a Hybrid Electric Powertrain to their vehicle, the required work-packages and schedule associated. This can be broken down into the prototype phase, production phase, and through life costing.

The cost analysis for the implementation, development, and through life is conducted through familiarity of market costs and a thorough market analysis to inform the price.

Additionally, a timeline is produced by breaking the project into work-packages illustrating what is required to achieve the final solution.


Q-Shift has developed a high performance low cost gear change technology. It uses simple dog clutch components to pass the driving torque directly from one gear to the next without passing through a neutral state. Its sequential shift event is controlled mechanically via a simple barrel arrangement. Additional patents in the portfolio take this concept further, including a version which seamlessly multiplies the number of ratios.

For further details please download our concept sheet.

Key benefits

  • Rapid seamless up-shifting under full load and seamless down-shifting under engine braking.
  • High efficiency, no de-clutching or loss of torque during shifts.
  • Reduced part count and complexity compared to a manual synchromesh transmission.
  • Smaller, lighter and significantly cheaper than Automatics and Dual Clutch Transmissions.
  • Scalable from 2-15 ratios for light or heavy duty use.

Partnering Opportunity

  • Licensing of the Q-Shift intellectual property
  • Patent acquisition

Want to know more?

Get in touch



Vehicle Drive Technology