Abstract: The connecting device is interposed between a rotating electric machine and a toothed lubricated device of the speed-reducer or multiplier type, this device comprising an output shaft of the electric machine, a screen, for opposing the propagation, towards the electric machine, of eventual lubricant leak in the vicinity of the shaft of the toothed device, closes, on one side, a cavity at the end of the casing of this toothed device and whereby this cavity presents on its lower portion an outlet hole for discharging the lubricant leaks, and the rotating screen presents a cylindrical projection directed towards the inside of the cavity and disposed so as to deviate towards the discharge hole the lubricant particles escaping from the toothed device. Application to the connection of the electric starter with an aeroplane or helicopter motor.