Our linear power systems provide class-leading motion control authority and power conversion efficiency for the most demanding power and motion applications. We provide design and development services to help customers incorporate this core technology into their new product developments.

Linear power systems

Libertine makes linear electrical machines that are closely integrated with linear bearings, valves and seals so that the electrical machine mover can also act as a piston to expand, compress or move a working fluid.

These ‘Linear power systems’ are controlled using state-of-the-art servo-drive and motion control technology, and provide the basis for a wide range of power and motion devices.

Free piston innovation

Ideal applications include linear actuators, gas expanders and Free Piston Engines which can all be built around Libertine’s core linear power systems.

The Free Piston Engine concept was first developed in the 1920s and has since been applied in power stations, navy vessels and prototype cars and trains. Free piston innovation has accelerated in the past decade, but the format has not yet been commercialised, largely because of the difficulty of controlling free piston motion.

Motion control

The most important metric for piston motion control is ‘specific force’ – the amount of electrical machine force that can be applied to the moving piston per unit of piston mass.

Libertine’s approach to linear power systems design focuses on specific force. Through the use of highly optimised electrical machine designs, elimination of non-essential mass from the piston and use of advanced engineering materials and manufacturing methods, Libertine’s linear power systems are capable of delivering twice the specific force of many other linear electrical machines and free piston systems.


Inside the Smart Engine


What is a Free Piston Engine?


Linear Power 2015 slides “History, applications, opportunities and challenges”


Future Powertrain 2016 conference poster


Sample product specification – Free piston gas expander


Sample product specification – Dynamic test actuator


Sample product specification – Linear electrical machine