Abstract: In an expansion device for use in a working medium circuit, for performing a process sequence corresponding to that of a Clausius Rankine cycle or an Organic Rankine cycle, a working unit comprising two interleaved scroll elements is provided of which one is stationary whereas the other is supported for orbiting relative to the stationary scroll element so as to form separate expansion regions between the scrolls moving, upon orbiting of the movable scroll, from the center of the interleaved scroll elements circularly outwardly with increasing volumes in which a working medium admitted at the center can expand for driving the movable scroll element.

Abstract: In an air-conditioning system for a motor vehicle having an internal combustion engine with an engine cooling circuit with a heat exchanger for heating and a heat pump with a refrigerant circuit including a heat exchanger for cooling the interior compartment of the motor vehicle, the refrigerant circuit includes also heat exchanges for heating or for cooling the coolant in the engine cooling circuit.

Abstract: In an air-conditioning system for a motor vehicle having an internal combustion engine with an engine cooling circuit with a heat exchanger for heating and a heat pump with a refrigerant circuit including a heat exchanger for cooling the interior compartment of the motor vehicle, the refrigerant circuit includes also heat exchanges for heating or for cooling the coolant in the engine cooling circuit.

Abstract: In an air-conditioning system for a motor vehicle having an integrated heat pump for cooling and heating, in which refrigerant is circulated and which allows heat exchange with the incoming air for the interior compartment of the motor vehicle, the heat transfer is effected either directly, by means of a refrigerant/air heat exchanger through which the air for the interior compartment is conducted, or by means of a secondary refrigerant circuit, which includes two expansion devices and three heat exchangers provided in the refrigerant circuit of the system.

Abstract: In an air-conditioning system for a motor vehicle having an integrated heat pump for cooling and heating, in which refrigerant is circulated and which allows heat exchange with the incoming air for the interior compartment of the motor vehicle, the heat transfer is effected either directly, by means of a refrigerant/air heat exchanger through which the air for the interior compartment is conducted, or by means of a secondary refrigerant circuit, which includes two expansion devices and three heat exchangers provided in the refrigerant circuit of the system.

Abstract: In a piston for a compressor, the piston comprises a stem by which the piston may be guided in the housing in an axially displaceable manner, and a force introducing section where an outer drive force can be introduced into the piston. The piston head, the piston skirt and the force introducing section are successively arranged in the direction of the piston axis. The piston head, the piston skirt and the force introducing section are produced as a single element of graphite or a synthetic material, and the piston skirt comprises a solid strut structure and a guide section, the cross-sectional area of the strut structure being smaller than the surface of the piston head. The piston consists of a non-organic, non-metallic material having an average thermal expansion of less than 7×106/° C. in the temperature range of 0° C. to 200° C.

Abstract: In a needle valve (1) for a high-pressure gas conduit system consisting of two units (2, 3) which are joined and one of which encloses a stepping motor (8) and the other includes gas flow passages and a gas flow control bore (17), a valve needle (10) is supported in the housing unit which includes the stepping motor so as to be movable by the stepping motor and extends into the gas flow control bore (17) in the other housing unit through a guide passage (18) provided with sealing means to prevent gas from flowing to the housing unit including the stepping motor (18). The needle valve is particularly suitable as an expansion valve in an automotive CO2 air conditioning system.