Cylinder on demand hydraulic device

A hydraulic device having:

• a plurality of main piston-cylinder arrangements, each of the respective pistons having a fixed stroke length and configured for reciprocation within their respective cylinder;
• a plurality of flow control valves for switching between a lockdown state and an unlocked state of one or more of the plurality of main piston cylinder arrangements during operation of the hydraulic device;
• one or more control valves for directing the plurality of flow control valves between their respective unlock and lock positions;
• and
• a distributor coupled to a main shaft of the hydraulic device, such that the distributor rotates in conjunction with the main shaft, the distributor having a distributor body including a first port configured for fluid communication with an input port and a second port configured for fluid communication with an output port;
• wherein the first port and the second port are fluidly coupled to the input port and the output port external to a shaft body of the main shaft;
• wherein once operated, the one or more control valves switches an operational mode of the plurality of main piston cylinder arrangements from a variable displacement mode to a fixed displacement mode such that in the fixed displacement mode all of the respective pistons are reciprocating.