A slip ring device comprising: - a slip ring shaft; - a first slip ring and a second slip ring, both of which being put from both ends of the slip ring shaft, respectively, the first slip ring being attached by shrink-fitting to a first slip ring attaching portion of the slip ring shaft, and the second slip ring being attached by shrink-fitting to a second slip ring attaching portion of the slip ring shaft; - a first radial lead and a second radial lead, the first radial lead being placed in a first radial lead placing hole and the second radial lead being placed in a second radial lead placing hole; - a first axial lead and a second axial lead, both of which being placed in a hollow hole formed in a central portion of the slip ring shaft, the first axial lead being connected to the first radial lead and the second axial lead being connected to the second radial lead; - a first slip ring lead which is connected to the first slip ring and to the first radial lead; - a second slip ring lead which is connected to the second slip ring and to the second radial lead; characterized in that: - the slip ring shaft is provided separately from a rotor shaft; - it comprises a lead connecting portion which is located between the first slip ring attaching portion and the second slip ring attaching portion in the slip ring shaft and is formed to have a shaft diameter larger than the shaft diameters of the first slip ring attaching portion and the second slip ring attaching portion of the slip ring shaft; - the radial lead placing holes (106, 107) being formed in the lead connecting portion, and - it comprises a coupling which is attached by shrink-fitting to a shaft end portion on the rotor shaft side of the slip ring shaft after the first slip ring has been attached by shrink-fitting. - a slip ring shaft; - a first slip ring and a second slip ring, both of which being put from both ends of the slip ring shaft, respectively, the first slip ring being attached by shrink-fitting to a first slip ring attaching portion of the slip ring shaft, and the second slip ring being attached by shrink-fitting to a second slip ring attaching portion of the slip ring shaft; - a first radial lead and a second radial lead, the first radial lead being placed in a first radial lead placing hole and the second radial lead being placed in a second radial lead placing hole; - a first axial lead and a second axial lead, both of which being placed in a hollow hole formed in a central portion of the slip ring shaft, the first axial lead being connected to the first radial lead and the second axial lead being connected to the second radial lead; - a first slip ring lead which is connected to the first slip ring and to the first radial lead; - a second slip ring lead which is connected to the second slip ring and to the second radial lead; characterized in that: - the slip ring shaft is provided separately from a rotor shaft; - it comprises a lead connecting portion which is located between the first slip ring attaching portion and the second slip ring attaching portion in the slip ring shaft and is formed to have a shaft diameter larger than the shaft diameters of the first slip ring attaching portion and the second slip ring attaching portion of the slip ring shaft; - the radial lead placing holes (106, 107) being formed in the lead connecting portion, and - it comprises a coupling which is attached by shrink-fitting to a shaft end portion on the rotor shaft side of the slip ring shaft after the first slip ring has been attached by shrink-fitting.