Abstract: The invention relates to an adapter for vacuum pumps, characterized in that it comprises an annular inlet flange (15) intended to be coupled to an outlet orifice of a chamber and an outlet coupling (16) comprising at least two cylindrical outlet through-housings (21) and forming an at least partial pump casing for the case (4) of a respective turbomolecular vacuum pump (3), said turbomolecular vacuum pumps (3) being intended to be received in a respective cylindrical outlet housing (21). The invention also relates to a pumping device, characterized in that it comprises an adapter for vacuum pumps (2) as described hereinabove and at least two turbomolecular vacuum pumps (3) housed at least partially in a respective cylindrical outlet housing (21).

Abstract: The invention relates to an adapter for vacuum pumps, characterized in that it comprises an annular inlet flange (15) intended to be coupled to an outlet orifice of a chamber and an outlet coupling (16) comprising at least two cylindrical outlet through-housings (21) and forming an at least partial pump casing for the case (4) of a respective turbomolecular vacuum pump (3), said turbomolecular vacuum pumps (3) being intended to be received in a respective cylindrical outlet housing (21). The invention also relates to a pumping device, characterized in that it comprises an adapter for vacuum pumps (2) as described hereinabove and at least two turbomolecular vacuum pumps (3) housed at least partially in a respective cylindrical outlet housing (21).

Abstract: A fastener system with a coaxial annular flange (14) having through holes (16), each serving to pass a screw (17) for screwing into an associated tapped hole (16) in the wall (2) of a stationary structure. Each through hole (16) has a circularly cylindrical distal segment (16a) followed by an enlarged proximal segment (16b) adjacent to the wall (2) of the stationary structure, allowing the shank (19) of the screw to bend and enabling a corresponding lateral offset (D). This prevents the screw (17) rupturing under high shear forces due to accidental destruction of a vacuum pump rotor while rotating at full speed.

Abstract: The fastener system of the invention comprises a coaxial annular flange (14) having through holes (16) provided therein, each serving to pass a screw (17) for screwing into an associated tapped hole (16) in the wall (2) of a stationary structure. Each through hole (16) comprises a circularly cylindrical distal segment (16a) followed by an enlarged proximal segment (16b) adjacent to the wall (2) of the stationary structure, and allowing the shank (19) of the screw to bend and enabling a corresponding lateral offset (D). This prevents the screw (17) rupturing under high shear forces due to accidental destruction of a vacuum pump rotor while rotating at full speed.

Abstract: According to the invention, a landing bearing for a vacuum pump comprises a rotor ball race and a coaxial stator ball race with rolling elements placed between them, housed one after another and rolling on respective rolling tracks of the rotor and stator ball races. The rolling elements comprise a succession of rolling elements having outside surfaces made of zirconium dioxide. This reduces the resistance of the landing bearing to acceleration, while nevertheless providing good resistance to chemical attacks from process gases and plasmas.

Abstract: A secondary pump unit comprising a mechanical secondary pump and a cryogenic trap, wherein the cryogenic trap forms a ring surrounding the outside of the mechanical secondary pump at its intake end, and the trap is enclosed in a casing defining, in parallel, the intake opening of the mechanical pump and of the cryogenic trap.