Abstract: An intermediate duct (108) is connected between first and second positive displacement machines (104, 106). An inlet duct (107) is connected to the first positive displacement machine (104). An outlet duct (109) is connected to the second positive displacement machine (106). A heater (102) raises the temperature and pressure of a gaseous working fluid in the intermediate duct (108). There is a kinematic connection (111) between the first and second positive displacement machines (104, 106) and the arrangement is such that, in operation, the first positive displacement machine (104) causes the working fluid to flow through the intermediate duct (108) to the second positive displacement machine (106), the heated working fluid drives the second positive displacement machine (106), and the second positive displacement machine (106) drives the first positive displacement machine (104) via the kinematic connection (111). The positive displacement machines include at least one orbiting piston.

Abstract: A rotary displacement machine includes a casing having a circular cylindrical internal surface and a rotor disposed in the chamber mounted to orbit about a chamber axis, with the rotor having a circular cylindrical external surface. A vane member is mounted on the casing and pivotable about a pivot axis parallel to the chamber axis. The vane member has a passage way communicating between the exterior of the casing and the operating chamber. A linkage connects the vane member to the rotor so as to keep a tip face of the vane member in sealing contact with an external surface of the rotor.

Abstract: A casing 1 has a circular cylindrical internal surface 3 delimiting an operating chamber. An orbiting piston 4 in the operating chamber is mounted so as to orbit about a chamber axis which is the axis of the internal surface 3. The orbiting piston 4 has a circular cylindrical external surface 11, a generatrix of the external surface being adjacent to the said internal surface, and a diametrically opposite generatrix being spaced from the said internal surface. A vane member 17 mounted on the casing 1 has a tip face which faces the external surface of the orbiting piston and which has a length substantially equal to that of the orbiting piston 4. A linkage 71 connects the vane membe 17r to the orbiting piston 4 so as to keep the tip face of the vane member adjacent the external surface 11 of the orbiting piston.

Abstract: A stator (1) has a circular cylindrical internal surface (3) delimiting an operating chamber. A rotor (4) is mounted so as to be rotatable about the axis (8) of the internal surface (3) and has a cylindrical external surface (11), with one generatrix (13) adjacent to the internal surface (3), a diametrically opposite generatrix being spaced from the internal surface. A sealing member (17), projecting through a slot in the stator (1) into the operating chamber and being movable substantially radially, has an axial length substantially equal to that of the rotor (4). The sealing member (17) is connected to the rotor (4) by a linkage which causes the radially inner end of the sealing member to closely follow the external surface (3). A shutter disc (6) at one end of the rotor (4) covers a port (14), in particular an inlet port, in the stator (1).