Abstract: A rotary piston machine includes a piston arrangement mounted in a gas-tight interior housing, wherein the piston arrangement has at least four individual rotary pistons which are constructed essentially equally and have end faces which are arranged so as to be in alignment with each other. The rotary piston machine further includes sealing assemblies composed of positioning members and sealing rods, wherein a sealing assembly is provided for each gap between adjacent rotary pistons and wherein each sealing assembly includes at least one sealing rod. The center points of circular arcs with two different radii defining the cross-section of each rotary piston are located on the corner points of a rhombus and the center points of the larger circular arcs are located in the corner points with the larger rhombus angles, wherein the larger rhombus angle is greater by 50.degree. to 50.degree. than the smaller rhombus angle.

Abstract: A rotary piston machine includes, arranged inside the gas-tight inner chamber (22) of a housing (24), a piston assembly (20) having at least three separate pistons (26) of identical design in the form of rectilinear prisms having front faces limited by several arcs of a circle (28, 30). The pistons are each fixedly secured to and turn in the same direction (36) as a shaft (34) rotatably mounted in the housing, extending through the geometric central axis and the rotation of which is synchronized by means of a gear, have flushed front faces and laterally limit the inner working space (38) with their curved circumferences, leaving a gap (S) between adjacent rotary pistons (26). Sealing elements (42) mounted in each gap (S) have two parallel sealing bars (44, 46) which have a cross section that is wider than the gap (S) are mutually linked by a connecting piece (48) narrower than the gap (S), and have a length that substantially corresponds to the length of the rotary pistons (26).

Abstract: The invention relates to a stepped-disc pump with at least two mutually engaging rotors rotating at the same speed in opposite directions and constructed from stepped discs arranged in a row on a shaft and each having only one engagement segment, adjacent stepped discs being in each case mutually offset by a defined angle and being constructed and arranged in such a way that, together with the casing, they form closed delivery chambers. The characteristic feature of the invention is that the offset angle .alpha. is equal to the angle .beta. which is obtained by connecting the points of intersection (5.sub.1, 5.sub.2) of the envelope circles of the rotors (2, 3) to the centers (M.sub.1, M.sub.2) thereof, and that the offset angle .alpha. is equal to 360.degree./n, n being an integer greater than 3.