Abstract: The reciprocating piston machine has a wobble plate gear, in which the pins (2) are connected in articulated manner to the circumference of the wobble plate (3) by in each case one ball end (21), which engages directly or by means of an interposed slip ring (29) with a spherical inner face (30) in a guide (28) directed transversely to the piston axis. As this leads to the avoidance of connecting rods with in each case two ball ends, the machine can be given a more compact construction.

Abstract: The internally axed single-rotation machine has inlet and outlet channels , 6), which extend arcuately round the circular cylindrical housing space (11) enclosing the rotors (1, 2) to such an extent that the tangentially connecting inlet and outlet connections (12, 13) cross and the outlet channel (6) extends over part of the inlet channel (5). In the vicinity of this approach between the outlet and inlet channels (6, 5) there is a flow connection (19), which continues the arcuate shape of the outlet channel (6) to that of the inlet channel (5). The gas pressure in the outlet channel (6) is variable by a control element (20) located in said flow connection (19). The single-rotation machine pressure control is associated with minimum noise generation and minimum flow losses and a particularly compact construction is obtained.

Abstract: In a vehicle air conditioning system CO.sub.2 as the refrigerant is compred by an internally controlled swash plate compressor (1) and circulates in a main circuit (2) having at least two heat exchangers (3, 5). An expansion valve (4) subdivides the main circuit (2) into a high and a low pressure part. The capacity control of the swash plate compressor (1) and therefore the air conditioning system takes place by means of a valve (23), which is located in a partial circuit (22) branched from the main circuit (2) by means of a constant choke (21) and which includes the drive chamber (18) of the swash plate compressor (1), so that in the latter it is possible to modify the pressure for adjusting the stroke length of the compressor piston (7). The branching point for the partial circuit (22) is located on an oil separator (20), which is located in the flow direction behind a first heat exchanger (5), so that the swash plate compressor (1) is cooled and is supplied with returned, cooled oil.

Abstract: The radial cross sections of the three engagement parts of the external rr of an internal axis single-rotation machine are defined by outer and inner circular arcs. The shape of the internal rotor, having two engagement parts, is kinematically precisely adapted to the external rotor. In order that the internal rotor can be easily manufactured with high shape accuracy, that the machine be given a good volumetric efficiency, and that a good seal be obtained between the rotors, even in the case of high rotational speeds, the center of the circle containing the arcs of the inner faces of the engagement parts of the external rotor has a spacing from the rotational axis of the external rotor of at least approximately 9 times the amount of the eccentricity between the two rotors, and the radius of the external rotor inner faces is about to 7 to 7.5 times this eccentricity.

Abstract: For improving the gap sealing between the circumferential surfaces of rot of a rotary piston machine and circular cylindrical inner surfaces (9) of the surrounding casing, rib-like protuberances (11) are displaced from the casing inner surfaces by cold working. On running in the rotary piston machine the external cross-sectional area of the protuberances (11) is removed by wear, so that between the protruberance (11) and the inner surface (9) a minimum sealing gap is obtained without corresponding manufacturing costs being involved in the formation thereof.