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 present invention relates to the field of high rotation speed vacuum pumps, which are fastened to and connected to a structure such as a vacuum enclosure or a pipe to generate a hard vacuum. It consists in an annular fixing flange including holes cooperating with headed bolts to fasten a vacuum pump to a structure. The flange comprises an upper ring and a lower ring cooperating to clamp the end of the pump body between the upper ring and the lower ring, and at least one first cavity in a face of the upper ring that is in a plane perpendicular to that of the face of the upper ring intended to come into contact with the wall of the structure. The invention also consists in a fixing system comprising an annular flange disposed coaxially with the pump body around the inlet orifice of the pump.

Abstract: The present invention relates to the field of high rotation speed vacuum pumps, which are fastened to and connected to a structure such as a vacuum enclosure or a pipe to generate a hard vacuum. It consists in an annular fixing flange including holes cooperating with headed bolts to fasten a vacuum pump to a structure. The flange comprises an upper ring and a lower ring cooperating to clamp the end of the pump body between the upper ring and the lower ring, and at least one first cavity in a face of the upper ring that is in a plane perpendicular to that of the face of the upper ring intended to come into contact with the wall of the structure. The invention also consists in a fixing system comprising an annular flange disposed coaxially with the pump body around the inlet orifice of the pump.

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: There is provided a rotor for a turbo/drag vacuum pump, the rotor comprising an upstream rotor segment of the turbine type made of metal or alloy, and a downstream rotor segment of Holweck type made of composite material. The downstream segment of the rotor has a reinforcing structure made of long fibers that are distributed in a manner that varies as a function of the section under consideration: in the annular connection region connected to the upstream segment of the rotor, the fibers are inclined and/or spaced apart in order to conserve sufficient flexibility for the composite material to enable it to deform so as to track deformation of the metal of the upstream rotor segment while it is in operation; in contrast, the fibers are close together and form turns that touch in the downstream region of the skirt, thereby guaranteeing greater stiffness in order to withstand the mechanical stresses that occur during high-speed rotation of the rotor in operation.

Abstract: The invention provides a rotor for a turbo/drag vacuum pump, the rotor comprising an upstream rotor segment of the turbine type made of metal or alloy, and a downstream rotor segment of Holweck type made of composite material. The downstream segment of the rotor has a reinforcing structure made of long fibers that are distributed in a manner that varies as a function of the section under consideration: in the annular connection region connected to the upstream segment of the rotor, the fibers are inclined and/or spaced apart in order to conserve sufficient flexibility for the composite material to enable it to deform so as to track deformation of the metal of the upstream rotor segment while it is in operation; in contrast, the fibers are close together and form turns that touch in the downstream region of the skirt, thereby guaranteeing greater stiffness in order to withstand the mechanical stresses that occur during high-speed rotation of the rotor in operation.

Abstract: A molecular drag pump including a stator and a rotor supported in the stator using two ball bearings at least one of which presses against at least one bearing surface of the stator serving as an axial abutment for the rotor, wherein the contact between the ball bearing and the bearing surface operates in bending and not in shear.

Abstract: A molecular drag pump comprising a rotor and a stator, the pump being of the type including at least alternating finned stages of the rotor and of the stator, and in which the rotor is bell-shaped, while the stator includes at least one external portion carrying the stator fins and at least one internal portion penetrating into the bell-shaped rotor, said internal portion closing the pump at its delivery end and including a flange-forming external peripheral rim, wherein said external portion of the stator carrying the stator pins is made up of two half-stators that meet in a diametral plane, each half-stator comprising a single piece and being positioned axially by having a bearing surface situated at its end remote from its suction end that hooks into a complementary circular groove of said internal portion of the stator, and wherein the outside diameter of the first finned stage of the rotor at its suction end corresponds, ignoring operating clearance, to the outside diameter of the external portion of the