Direct current machine with brushes having a protection index greater than or equal to the IP54 index and suitable for being powered by a power supply voltage greater than 72 Vdc, this machine comprising: - a stator equipped: • with permanent magnets (22, 24) or stator windings capable of inducing a magnetic flux, • with a first and a second end flange (18, 20) comprising, respectively, a first and a second hub (26, 28), • with brushes (36, 38), - a wound rotor equipped: • with rotor windings (46, 48), • with a shaft, and • with a collector situated facing the brushes (36, 38) of the stator and on which the brushes (36, 38) rub to power the rotor windings (46, 48), - a first and a second bearing (30, 32) in which respective ends of the shaft are fitted, these first and second bearings (30, 32) being received in, respectively, the first and second hubs (26, 28), characterized in that: - at least the first flange is produced in an electrically insulating material whose electrical resistivity at 20°C is greater than 10 5 Ω•m, and - the rotor also comprises a washer made of electrically insulating material whose electrical resistivity at 20°C is greater than 10 5 Ω•m, fixed with no degree of freedom onto the shaft of the rotor, this washer: • being interposed between the collector and the first bearing, and • comprising a front face turned towards the collector and blades protruding on this front face. - a stator equipped: • with permanent magnets (22, 24) or stator windings capable of inducing a magnetic flux, • with a first and a second end flange (18, 20) comprising, respectively, a first and a second hub (26, 28), • with brushes (36, 38), • with permanent magnets (22, 24) or stator windings capable of inducing a magnetic flux, • with a first and a second end flange (18, 20) comprising, respectively, a first and a second hub (26, 28), • with brushes (36, 38), - a wound rotor equipped: • with rotor windings (46, 48), • with a shaft, and • with a collector situated facing the brushes (36, 38) of the stator and on which the brushes (36, 38) rub to power the rotor windings (46, 48), • with rotor windings (46, 48), • with a shaft, and • with a collector situated facing the brushes (36, 38) of the stator and on which the brushes (36, 38) rub to power the rotor windings (46, 48), - a first and a second bearing (30, 32) in which respective ends of the shaft are fitted, these first and second bearings (30, 32) being received in, respectively, the first and second hubs (26, 28), - at least the first flange is produced in an electrically insulating material whose electrical resistivity at 20°C is greater than 10 5 Ω•m, and - the rotor also comprises a washer made of electrically insulating material whose electrical resistivity at 20°C is greater than 10 5 Ω•m, fixed with no degree of freedom onto the shaft of the rotor, this washer: • being interposed between the collector and the first bearing, and • comprising a front face turned towards the collector and blades protruding on this front face. • being interposed between the collector and the first bearing, and • comprising a front face turned towards the collector and blades protruding on this front face.