Abstract: A dry rotary pump for recirculating an at least partially gaseous composition containing hydrogen. The dry rotary pump comprising a first rotating shaft and a second rotating shaft. The first rotating shaft and the second rotating shaft are driven in rotation by a drive system in a gear chamber. The dry rotary pump comprises a first pair of seals and a second pair of seals, each comprising a first shaft seal and a second shaft seal. The dry rotary pump comprises a pressure equalization chamber in fluid connection with a gap between the first shaft seal and the second shaft seal to regulate pressure in the gap. The gear chamber is in fluid connection with the gap, and the pumping chamber is in fluid connection with the first shaft seal and the first shaft seal by a pulsation attenuation chamber.

Abstract: In a rotating-slide vacuum pump or compressor having a rotor (6) which can rotate in a housing (2) and is driven by a drive shaft, and having slides (8) which can be moved outwards in the circumferential direction herein in slots (7) in the rotor (6) and separate individual feed chambers of a working area (9), which is provided with an intake opening (1) and an outlet opening, from one another, and each assume a maximum outer position adjacent to the housing inner wall, driven by centrifugal force, the arrangement is designed such that a brushless disc-rotor synchronous motor (11, 12) is fitted in the axial direction to the rotor shaft.