Abstract: A drive arrangement for producing a rotary motion by means of a fluid or eous pressure medium in which a working shaft and an eccentric part within a housing are acted upon by at least one freely deformable expansion cell mounted between the housing and the eccentric part in such a manner that expansion of the collapsible cell exerts a rotational moment on the eccentric part, a force that is directed along the central axis and therefore along the working shaft. The expansion cells are connected with the working medium by suitable control means.