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 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 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 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 fluid-driven linear motor comprises a cylinder (5), a piston (4) and a piston rod (3) connected to the piston (4), wherein the two sides of the piston (4) in the cylinder (5) are alternatively supplied with fluid from a slide valve arrangement, the slide valve arrangement including a slide (9) accommodated in a chamber and which is shifted between its end positions controlled by a pilot rod (22) coaxially mounted in a through bore (12) in the slide (9). The pilot rod (22) is adapted to alternately set the through bore (12) in fluid connection with the ends of the slide (9) when the piston (4) is located in its end positions. The pilot rod (22.) is provided with an extension rod (204) adapted to slide inside a bore (203) inside said piston (5) and said piston rod (3), so that the stroke length of the linear motor can be extended. Moreover, a pressure chamber (209) is provided at the distal end of the pilot rod (22), said pressure chamber (209) being adapted to hold on the pilot rod (22) with a holding force when in its end positions until mechanical forces from the piston overcome said holding force.

The invention relates mainly to a pumping system (1) which comprises an alternating distribution device comprising at least one shut-off device (7) comprising four mobile shut-off members (70-73) for shutting off first and second inlets (E1, E2; E1a, E2a) and first and second outlets (S1, S2; S1a, S2a) of the pumping system (1) and at least one trigger (8, 9) configured to actuate said shut-off members (70-73) between two positions, respectively a shutting-off position and an open position, which alternating distribution device can be actuated between a first arrangement associated with a first fluid distribution cycle and a second arrangement associated with a second fluid distribution cycle.

A system for cleaning solar panels (photo-electric and/or water heating etc.) is driven by fluid driven motor (water and/or air driven motor) such as a piston motor or a vane motor. Some or all of the outlet water/air from the motor is used for cleaning the panels. The motor preferably also operates a cleaning mechanism, such as a rotating and or linear brush arrangement. The motor, gear system and/or components may be made from plastic. Optionally, a cleaning device travels along the edges of panels, optionally without requiring an additional rail structure. The cleaning device optionally includes a trailing water/air supply hose. In some embodiments, electrical components of the cleaning device are powered by an internal power supply. Control is optionally via an electrically actuated valve, a timer (for example a real time clock), a wireless receiver and/or a controller.

A system for cleaning solar panels (photo-electric and/or water heating etc.) is driven by fluid driven motor (water and/or air driven motor) such as a piston motor or a vane motor. Some or all of the outlet water/air from the motor is used for cleaning the panels. The motor preferably also operates a cleaning mechanism, such as a rotating and or linear brush arrangement. The motor, gear system and/or components may be made from plastic. Optionally, a cleaning device travels along the edges of panels, optionally without requiring an additional rail structure. The cleaning device optionally includes a trailing water/air supply hose. In some embodiments, electrical components of the cleaning device are powered by an internal power supply. Control is optionally via an electrically actuated valve, a timer (for example a real time clock), a wireless receiver and/or a controller.

A fluid-driven linear motor comprises a cylinder, a piston, and a piston rod connected to the piston. Two sides of the piston in the cylinder are alternately supplied with fluid from a slide valve arrangement. The slide valve arrangement includes a slide and a pilot rod adapted to alternately set a through-bore of a slide in fluid connection with the ends of the slide when the piston is located in its end positions. The pilot rod is provided with an extension rod adapted to move inside a bore of the piston and the piston rod, so that the stroke length of the linear motor can be extended. A pressure chamber is provided at the distal end of the pilot rod. The pressure chamber is adapted to hold the pilot rod with a holding force when in its end positions until mechanical forces from the piston overcome said holding force.

A fluid-driven linear motor comprises a cylinder, a piston, and a piston rod connected to the piston. Two sides of the piston in the cylinder are alternately supplied with fluid from a slide valve arrangement. The slide valve arrangement includes a slide and a pilot rod adapted to alternately set a through-bore of a slide in fluid connection with the ends of the slide when the piston is located in its end positions. The pilot rod is provided with an extension rod adapted to move inside a bore of the piston and the piston rod, so that the stroke length of the linear motor can be extended. A pressure chamber is provided at the distal end of the pilot rod. The pressure chamber is adapted to hold the pilot rod with a holding force when in its end positions until mechanical forces from the piston overcome said holding force.