Abstract: The vacuum pump is subdivided into: a first part (13), consisting of an "actuating module" comprising the electric motor (15) and a support structure (16) containing both the half-couple (37) of the transmission coupling (35, 37), and the channels (53, etc.) and connections for the intake and delivery of the gases, connected to the various external pipes (47, etc.) and emerging at a coupling surface (C--C); and a second functional part (11), constituting a "pump module" and comprising the rotor or rotors (24, 25) with the associated rotating axle (33) complete with half-couple (35), the stators (21) and the delivery valves contained in a housing (27) which contains the special liquid for leaktightness and lubrication, which can be coupled to and uncoupled from the "actuating module" at said coupling surface (C--C), where corresponding connections emerge.

Abstract: A lubrication circuit connected to rotary vacuum pumps is composed of a hydraulic circuit and of the relative pump unit for lubrication and for auxiliary controls, including isolation of the negative pressure space from the pump on the stopping of the latter, with the aid of a closure member (10), for the operation of which use is made of the pressure of the fluid present in the pump discharge space with the aid of a duct (33, 34) between said discharge space and a means (8, 9) operating the closure member (10), which duct is subdivided into two portions between which is disposed a control member (27, 31) the operation of which is dependent on the oil pressure produced by the pump unit and propagated, with complete absence of flow, through a duct (23) so as to reach a control member (27, 31) which supervises the operation of the closure member (10).