Abstract: A diagnostic system for a lubrication circuit of an internal combustion engine of a vehicle. The system includes a viscometer for detecting the viscosity of a lubricating liquid of the lubrication circuit, a temperature sensor for detecting the temperature of the lubricating liquid, and a control unit to acquire the state of the lubricating liquid, given by the viscosity detected for a given lubricating liquid condition, which includes the lubricating liquid temperature and the date of last replacement of the lubricating liquid, and for a given condition of use of the engine, and to assess the state of the lubricating liquid by comparing the detected viscosity of the lubricating liquid with the viscosity reference values stored in the database in the same or similar condition of lubricating liquid temperature, date of last replacement of the lubricating liquid and use of the engine.

Abstract: A diagnostic system for a lubrication circuit of an internal combustion engine of a vehicle. The system includes a viscometer for detecting the viscosity of a lubricating liquid of the lubrication circuit, a temperature sensor for detecting the temperature of the lubricating liquid, and a control unit to acquire the state of the lubricating liquid, given by the viscosity detected for a given lubricating liquid condition, which includes the lubricating liquid temperature and the date of last replacement of the lubricating liquid, and for a given condition of use of the engine, and to assess the state of the lubricating liquid by comparing the detected viscosity of the lubricating liquid with the viscosity reference values stored in the database in the same or similar condition of lubricating liquid temperature, date of last replacement of the lubricating liquid and use of the engine.

Abstract: A rotary vacuum pump, for instance a vane pump, has at least one circumferential groove (6) between facing side surfaces of the rotor (2) and of the rotor guide (3) for receiving a lubricating and sealing fluid. The circumferential groove (6) is a partial annular groove, which has an angular extension of less than 360° and has at least one interruption enabling creating a hydrodynamic fluid bearing in a region opposite a discharge region of the pump (1; 101; 121; 201), over the whole axial extension of the facing surfaces. A method of lubricating a rotary vacuum pump is also provided.

Abstract: A rotary vacuum pump, for instance a vane pump, has at least one circumferential groove (6) between facing side surfaces of the rotor (2) and of the rotor guide (3) for receiving a lubricating and sealing fluid. The circumferential groove (6) is a partial annular groove, which has an angular extension of less than 360° and has at least one interruption enabling creating a hydrodynamic fluid bearing in a region opposite a discharge region of the pump (1; 101; 121; 201), over the whole axial extension of the facing surfaces. A method of lubricating a rotary vacuum pump is also provided.