A thermodynamic apparatus having a first fluid flow section comprising: a first shaft portion which defines, and is rotatable about, a first rotational axis; a first axle defining a second rotational axis, the first shaft portion extending through the first axle; a first piston member provided on the first shaft portion, the first piston member extending from the first axle towards a distal end of the first shaft portion; a first rotor carried on the first axle; the first rotor comprising: a first chamber, the first piston member extending across the first chamber; a first housing wall adjacent the first chamber, a first port and second port provided in the first housing wall and each in flow communication with the first chamber; whereby: the first rotor and first axle are rotatable with the first shaft portion around the first rotational axis; and the first rotor is pivotable about the first axle about the second rotational axis to permit the first rotor to pivot relative to the first piston member as the first rotor rotates about the first rotational axis; such that the first fluid flow section is configured for the passage of fluid between the first port and second port via the first chamber; the apparatus further comprising a second fluid flow section, which comprises: a second chamber, a second housing wall adjacent the second chamber, a third port and a fourth port provided in the second housing wall and each in flow communication with the second chamber, such that the second fluid flow section is configured for the passage of fluid between the third port and fourth port via the second chamber; the second port being in fluid communication with the third port via a first heat exchanger, wherein: the second rotational axis is substantially perpendicular to the first rotational axis. a first shaft portion which defines, and is rotatable about, a first rotational axis; a first axle defining a second rotational axis, the first shaft portion extending through the first axle; a first piston member provided on the first shaft portion, the first piston member extending from the first axle towards a distal end of the first shaft portion; a first rotor carried on the first axle; the first rotor comprising: a first chamber, the first piston member extending across the first chamber; a first chamber, the first piston member extending across the first chamber; a first housing wall adjacent the first chamber, a first port and second port provided in the first housing wall and each in flow communication with the first chamber; whereby: the first rotor and first axle are rotatable with the first shaft portion around the first rotational axis; and the first rotor is pivotable about the first axle about the second rotational axis to permit the first rotor to pivot relative to the first piston member as the first rotor rotates about the first rotational axis; the first rotor and first axle are rotatable with the first shaft portion around the first rotational axis; and the first rotor is pivotable about the first axle about the second rotational axis to permit the first rotor to pivot relative to the first piston member as the first rotor rotates about the first rotational axis; such that the first fluid flow section is configured for the passage of fluid between the first port and second port via the first chamber; the apparatus further comprising a second fluid flow section, which comprises: a second chamber, a second housing wall adjacent the second chamber, a third port and a fourth port provided in the second housing wall and each in flow communication with the second chamber, a second chamber, a second housing wall adjacent the second chamber, a third port and a fourth port provided in the second housing wall and each in flow communication with the second chamber, such that the second fluid flow section is configured for the passage of fluid between the third port and fourth port via the second chamber; the second port being in fluid communication with the third port via a first heat exchanger,