Abstract: A vacuum pump unit including a secondary pump sub-assembly (6) rotated by an electric motor M2 and applying suction to a chamber to be evacuated (1), and a primary pump sub-assembly (2) rotated by an electric motor M1 and whose suction is connected to the output of the secondary pump sub-assembly (6), the unit being characterized in that it includes an electronic control circuit (7) for controlling the speed of rotation of the electric motor M1 as a function of to the current I2 drawn by the electric motor M2.

Abstract: The invention relates to a mechanical vacuum pump having a displacement member (2) and a casing (1) which is provided with an inlet channel (3) on the suction side and an outlet channel (4) on the discharge side. A spring-loaded non-return flap valve (5) is incorporated into the outlet channel (4). Upstream of this flap (5), a gas jet pump (7, 8) is installed in the outlet channel (4), the jet direction being parallel to the sealing surface of the non-return flap valve (5).This gas jet pump allows to significantly increase the final vacuum of the mechanical vacuum pump and to improve the cooling of the pump.

Abstract: A molecular high-vacuum pump has a bell-shaped rotor 5 including a shaft supported by roller bearings 12, 13 disposed inside the bell rotor. The stator 1, 6 defines two converging pumping stages, one in cooperation with the inner cylindrical surface 10 of the rotor and the other in cooperation with the outer cylindrical surface 9 of the rotor. The suction inlet 3 is disposed in the apex area 4 of the bell rotor. The discharge outlet 11 of the pump is disposed in the vicinity of the lower rim of the bell, and both pumping stages transfer gases towards this rim. In this way, gases introduced through the inlet 3 into the pump cannot penetrate into the motor space 15 and damage the bearings of the pump.