A thermal energy storage system comprising a working fluid to store and transfer thermal energy between a heat source and a thermal load and a vessel to store the working fluid. The vessel has an interior region and a floating separator piston in the interior region to separate a hot portion from a cold portion of the working fluid. There is a first manifold thermally coupled to an output of the heat source and to an input of the thermal load and fluidly coupled to the interior region of the vessel and a second manifold thermally coupled to an input of the heat source and an output of the thermal load and fluidly coupled to the interior region of the vessel. There is a controller configured to maintain the working fluid in a liquid state.

A motor for driving a liquid end of a pump system. The motor having an inner housing having an outer surface, a mechanical actuator disposed in the inner housing, and a water jacket surrounding at least a portion of the outer surface of the inner housing to define a volume between the inner housing and the water jacket. The volume being sized to circulate water within the water jacket so as to transfer heat from the inner housing to the water.

A piston ring configured to be disposed in a floating piston for use in a vessel of a thermal energy storage system to separate a hot working fluid from a cold working fluid, wherein the piston ring comprises of a plurality of arc segments, each arc segment interconnected by a joint.

A hydraulic piston unit including a rotational group for driving or being driven by a driving shaft, and having a tiltable displacement element for adjusting the displacement volume of the rotational group between a minimum or a maximum displacement, wherein, on t valve segment between a kidney-shaped inlet port and a kidney-shaped outlet port at respective dead end positions of reciprocally moveable working pistons first and second control ports are located in fluid connection with cylinder bores in the cylinder block, for controlling the position of the displacement element. The hydraulic piston unit further includes a control valve with a shiftable control valve spool fluidly connected via a high pressure port to a high pressure side of the hydraulic piston unit. The control valve spool is configured to conduct hydraulic fluid from the high pressure side to one of the first or the second control port.

A motor for driving a liquid end of a pump system. The motor having an inner housing having an outer surface, a mechanical actuator disposed in the inner housing, and a water jacket surrounding at least a portion of the outer surface of the inner housing to define a volume between the inner housing and the water jacket. The volume being sized to circulate water within the water jacket so as to transfer heat from the inner housing to the water.

A generator is described comprising in particular a vertical supply column that can be filled with a certain quantity of liquid, an intake valve disposed at a base of the vertical supply column, and a leaktight tank communicating with the vertical supply column via the intake valve, which leaktight tank can be filled with liquid. The generator also comprises an exhaust valve disposed on the leaktight tank and capable of releasing pressure generated in the leaktight tank, and a piston-forming device disposed inside the leaktight tank so as to be immersed in the liquid contained in the leaktight tank. This piston-forming device is capable of being set in reciprocating movement between an upper position and a lower position, the piston-forming device comprising a first, float-forming portion capable of bringing the piston-forming device into the upper position and a second portion forming an output shaft. The generator further comprises a converter device coupled to the output shaft, which converter device is capable of converting the reciprocating movement of the piston-forming device into mechanical or electrical energy. The generator is configured in such a way that, in operation, the leaktight tank is filled with liquid, and in such a way as to repeat a sequence of operating phases in order to induce the reciprocating movement of the piston-forming device.

A generator is described comprising in particular a vertical supply column that can be filled with a certain quantity of liquid, an intake valve disposed at a base of the vertical supply column, and a leaktight tank communicating with the vertical supply column via the intake valve, which leaktight tank can be filled with liquid. The generator also comprises an exhaust valve disposed on the leaktight tank and capable of releasing pressure generated in the leaktight tank, and a piston-forming device disposed inside the leaktight tank so as to be immersed in the liquid contained in the leaktight tank. This piston-forming device is capable of being set in reciprocating movement between an upper position and a lower position, the piston-forming device comprising a first, float-forming portion capable of bringing the piston-forming device into the upper position and a second portion forming an output shaft. The generator further comprises a converter device coupled to the output shaft, which converter device is capable of converting the reciprocating movement of the piston-forming device into mechanical or electrical energy. The generator is configured in such a way that, in operation, the leaktight tank is filled with liquid, and in such a way as to repeat a sequence of operating phases in order to induce the reciprocating movement of the piston-forming device.

A power generating unit including a hydraulic unit; an interface unit connected to the hydraulic unit, the interface unit being connectable to a stationary unit; a power flow shaft connected between the hydraulic unit and the interface unit for supply of a torque load therebetween; and at least one connecting element arranged between the hydraulic unit and the interface unit, the at least one connecting element being controllable between a first state in which a relative rotation between the hydraulic unit and the interface unit is allowed, and a second state in which a relative rotation between the hydraulic unit and the interface unit is prevented.

A hydraulic piston unit including a rotational group for driving or being driven by a driving shaft, and having a tiltable displacement element for adjusting the displacement volume of the rotational group between a minimum or a maximum displacement, wherein, on t valve segment between a kidney-shaped inlet port and a kidney-shaped outlet port at respective dead end positions of reciprocally moveable working pistons first and second control ports are located in fluid connection with cylinder bores in the cylinder block, for controlling the position of the displacement element. The hydraulic piston unit further includes a control valve with a shiftable control valve spool fluidly connected via a high pressure port to a high pressure side of the hydraulic piston unit. The control valve spool is configured to conduct hydraulic fluid from the high pressure side to one of the first or the second control port.

A thermal energy storage system comprising a working fluid to store and transfer thermal energy between a heat source and a thermal load and a vessel to store the working fluid. The vessel has an interior region and a floating separator piston in the interior region to separate a hot portion from a cold portion of the working fluid. There is a first manifold thermally coupled to an output of the heat source and to an input of the thermal load and fluidly coupled to the interior region of the vessel and a second manifold thermally coupled to an input of the heat source and an output of the thermal load and fluidly coupled to the interior region of the vessel. There is a controller configured to maintain the working fluid in a liquid state.