Patent ID: 6983729

Claim:
A rotary piston machine, comprising (a) a housing defining a prismatic chamber the cross section of which forms an oval of odd order, which is alternatively composed of circular arcs having a first relatively small radius of curvature and circular arcs having a second, relatively large radius of curvature, said circular arcs changing into each other continuously and differentially, whereby corresponding first and second cylindrical inner wall sections of said chamber are formed, (b) a prismatic rotary piston on which diametrically opposite, cylindrical nappe sections having said first radius of curvature are formed, of which, in each position, a respective one is rotatable in a first one of said cylindrical inner wall sections and the respective other one engages an opposite one of said second inner wall sections, whereby said rotary piston, in each position, subdivides said chamber into two working chambers, the volumes of which, with progressive rotation of the rotary piston are alternatively increased and reduced, said cylindrical nappe sections defining a center plane, in which piston-fixed instantaneous axes of rotation of the rotary piston extending along the cylinder axes of said cylindrical nappe sections are defined, (c) means for cyclically passing working medium into the working chambers and letting it escape therefrom, said rotary piston, in each interval of movement rotating with a first one of said diametrically opposite nappe sections in a first inner wall section about a first associated instantaneous axis of rotation, which extends along the cylinder axis of said first inner wall section, and sliding with the second one of said diametrically opposite nappe sections along the opposite second inner wall section of the chamber into the next following first inner wall section of the chamber and reaching a stop position there; and the instantaneous axis of rotation subsequently jumping, for the next interval of movement, into a changed position defined by said consecutive inner wall section and corresponding to the other piston-fixed axis of rotation, and (d) means for coupling a driving or driven shaft with said the rotary piston, and further comprising (e) fixing means for temporarily fixing said instantaneous axis of rotation for the subsequent interval of movement, when said changed position has been reached.