An apparatus including a piston bore, exhibiting a longitudinal axis, and a piston, including a piston head and a piston shaft. The piston being axially displace-able within the piston bore along the longitudinal axis. The piston bore and a first surface of the piston head form a first working volume and displacement of the piston alters the first working volume. The apparatus also includes a first plurality of injectors coupled to the first working volume and a first common rail. The first plurality of injectors are configured to inject a hydraulic fluid from the common rail into the first working volume. The first common rail is configured to store the hydraulic fluid at an elevated pressure of 1,000 bar or greater. The apparatus includes a flow path between the first working volume and a reservoir for the hydraulic fluid.
Riccardo Meldolesi; Peter Mark Lee