Abstract: The machine comprises first and second screw rotors (1, 2) supported by bearings (47) in a stator casing (3) which is provided with a suction inlet and a delivery outlet, the first rotor is driven by a motor (10) and the second rotor is driven by means of synchronizing gearing (11-12) situated in a first chamber (14) of the casing and located between the motor (10) and one of the ends of the rotors, the gearing (11-12) running in a lubricating fluid (15), the machine is characterized in that the cavity (30) of the casing containing the rotors (1-2) is separated from the first chamber (14) by a first wall (16) having the shafts (8, 13) of the rotors passing therethrough via seals (17-18), in that the shafts of the rotors at the opposite ends of the rotors to the ends having the gearing pass through a second wall (20) via seals (24-25), and in that the casing (3 ) includes, beyond the second wall (20), a second chamber (31) connected to the first chamber (14) by a main pipe (29) provided with pumping means (49)

Abstract: A valve which opens on reduced pressure comprises: a hollow body (1) divided into first and second portions (2 and 3) by an internal partition (4), with the first portion being provided with a first opening (5) for connection to an enclosure to be evacuated and with a second opening (6) for connection to the aspiration side of a vacuum pump; a moving valve plate (7) disposed inside the first portion; a spring (8) urging the valve plate to close the first opening; a rod (10) having one end connected to the valve plate and passing through the internal partition; and a piston (b 11) which is connected to the other end of the rod, and which divides the second portion into a first chamber (13) and a second chamber (14) which are sealed from each other, the first chamber being on the rod side of the piston and being in communication with the outside (19), and the second chamber including an orifice (22) for communication with the outside, which orifice is fitted with closure means (23), the second chamber further i

Abstract: Oil-sealed vane pump has a stator and a rotor assembly housed in an oil-filled tank, said stator comprising an oil injection orifice, a suction port connected to a tank inlet pipe and a discharge port opening into said tank, said discharge port being provided with a check valve, said check valve being mounted in a spot facing in the stator and said tank further comprising a discharge outlet. The stator is provided with at least one slot opening into the spot facing.