An engine (5) with a gas supply unit (10) that supplies combustion gas for driving purposes with linear reciprocal movement of a piston (12) is provided. The gas supply unit (10) includes a first combustion chamber (31) provided on a first side of the piston, a first gas outlet (17) that supplies high pressure combustion gas generated in the first combustion chamber for driving purposes, and a second combustion chamber (32) that is provided on a second side on the other side of the piston and generates a second force that moves the piston toward the first side. The engine (5) further includes a piston control unit (60) that controls the position of the piston against a first force of the piston that moves due to combustion in the first combustion chamber and the second force described above.

Linear generator systems are presented herein for interfacing a number of different linear electromagnetic machines (LEMs) for generating collective power outputs. A plurality of LEMs is coaxially arranged in sequence along a longitudinal axis. Each LEM comprises a respective translator, and a respective stator. A pair of gas springs are each respectively arranged outboard of a pair of outboard LEMs in contact with the respective translators of the outboard LEMs. A plurality of reaction sections is arranged between adjacent LEMs of the plurality of LEMs. Each of the plurality of reaction sections is in contact with respective translators of the respective adjacent LEMs.

A linear power generator has a gas pressure cylinder structure which causes reciprocating motion of a piston in an axial direction by supplying a high-pressure gas alternately to a left gas chamber and a right gas chamber of a cylinder which includes an electromotive coil, and alternately applying a gas pressure in the left gas chamber and a gas pressure in the right gas chamber to the piston which includes a permanent magnet in the cylinder, and which induces power generation of the electromotive coil by way of reciprocating motion of the piston which has the permanent magnet in the axial direction. The linear power generator encourages movement of the piston by supplying a first high-pressure gas into the left gas chamber and the right gas chamber, and keeps moving the piston by supplying a second high-pressure gas for supplementing the first high-pressure gas into the left gas chamber and the right gas chamber.

A plunger pump or plunger motor includes a block accommodating a first cylindrical chamber and a plunger movable in this chamber and a drive shaft connected to this plunger, as well as a second cylindrical chamber and a control valve movable in this second cylindrical chamber. Holes O.sub.3 and O.sub.4 can alternately be brought into communication with the connection for the delivery pipe by the plunger and with a connecting hole for a pressure line. The control valve can establish a communication between the hole O.sub.2 and the connecting hole. The drive shaft is connected to a further plunger which is movable in a third cylindrical chamber in which there is a suction hole or delivery hole. The control valve can alternately establish a communication between the suction hole or delivery hole with a connecting hole for a suction pipe and the connecting hole for the pressure line.