Oscillating roller and printing press having a plurality of printing units that have such a roller

A roller (13) of a printing unit of a printing press, which printing unit comprises a roller inking unit, said roller having a roller outer body (14), which is mounted on a roller inner body (16) so as to be movable axially in a reciprocating manner, wherein for the axial movement of the roller outer body (14) in at least a first direction a pneumatic drive is provided, having at least one first chamber (32;

• 33), which is formed in the interior of the roller in the manner of a cylinder/piston system between one or more structural elements (34;
• 36;
• 37) that are fixed to the roller outer body and one or more structural elements (38;
• 39) that are fixed to the roller inner body, and which can be pressurized with compressed air, characterized in that the parts of the structural elements (34;
• 36;
• 37;
• 38;
• 39) delimiting the chamber (32;
• 33) that are movable axially relative to one another form a non-contact seal (41;
• 42;
• 43) between themselves on their mutually facing sides.