Multi-temperature double-acting piston

A multi-temperature double-acting piston being able to move in translation in a cold cylinder arranged in a cooled cylinder casing which comprises a heat engine, said piston being directly or indirectly connected by power transmission means housed in a transmission casing to at least one rotary or reciprocating power output shaft while said piston forms a lower variable volume chamber with the cold cylinder and a lower cylinder head which is positioned between said piston and the transmission housing, said piston simultaneously forming an upper variable volume chamber with said cylinder and an upper cylinder head, said chambers containing a working gas, comprising

• a central piston pin which is approximately coaxial with the cold cylinder and that has a first end that forms a lower piston rod which passes right through the lower cylinder head via a lower rod orifice that engages with lower rod sealing means so as to open out into the transmission casing and so as to be connected directly or indirectly to the power transmission means by means of piston fixing means, while the second end of said pin forms a upper piston rod which passes right through the upper cylinder head via an upper rod orifice which engages with upper rod sealing means so as to open out into a piston cooling and lubricating chamber connected to a source of lubricating-cooling fluid, the source of lubricating-cooling fluid introducing a lubricating-cooling fluid into said chamber;
• a peripheral sealing ring the outer diameter of which is substantially smaller than the inner diameter of the cold cylinder, said ring comprising piston sealing means which are in contact with said cylinder to provide sealing therewith;
• a lower radial connecting disk which radially connects the central piston pin with the peripheral sealing ring on the lower variable volume chamber side, and an upper radial connecting disk which radially connects the central piston pin with the peripheral sealing ring on the upper variable volume chamber side, the space left between said disks, the peripheral sealing ring and the central piston pin forming an internal piston volume;
• a lubricating-cooling gallery arranged mainly axially in the central piston pin and in one or more sections, said gallery putting the piston cooling and lubricating chamber into communication with both the internal piston volume, and also said volume with the inside of the transmission casing;
• at least one peripheral ring lubricating orifice which puts the internal piston volume into communication with the outer peripheral face of the peripheral sealing ring, said orifice opening axially from said face between at least two piston sealing means;
• guide means which directly or indirectly bear on or in the vicinity of the power transmission means and/or the cold cylinder and/or the lower cylinder head and/or the upper cylinder head, said means directly or indirectly maintaining the peripheral sealing ring centered in the cold cylinder;
• a lower hot crown interposed between the lower radial connecting disk and the lower variable volume chamber and/or an upper hot crown interposed between the upper radial connecting disk and the upper variable volume chamber;
• crown applying means which directly or indirectly hold the lower hot crown applied against the peripheral sealing ring and/or against the lower radial connecting disk, and/or which directly or indirectly hold the upper hot crown applied against said ring and/or against the upper radial connecting disk, said means leaving said crowns free to expand relative to said ring and/or to said disks;
• crown centering means which locate the lower hot crown and/or the upper hot crown relative to the peripheral sealing ring.