Patent ID: 7849832

Claim:
A rotary piston machine, comprising a housing, at least two pistons arranged in said housing and being able to revolve together in said housing about an axis of rotation which is fixed with respect to said housing, a piston cage arranged in said housing, in which said at least two pistons are mounted slidingly, said piston cage revolving together with said at least two pistons about said axis of rotation, said at least two pistons executing mutually opposing reciprocating motions while revolving about said axis of rotation in order to alternately increase and decrease the volume of a working chamber defined by end faces of said at least two pistons which are oriented towards one another, and by said piston cage, said axis of rotation running through said working chamber, said piston cage having a gas exchange opening for the admission and discharge of gas to and from said working chamber, said gas exchange opening being arranged on said axis of rotation, a closing member arranged in said gas exchange opening which is connected to said piston cage in a rotationally fixed manner with respect to said axis of rotation and being axially movable relative to said piston cage in direction of said axis of rotation in order to open and close said gas exchange opening, and a control mechanism for said closing member which derives an axial motion of said closing member from a rotary motion of said closing member about said axis of rotation.