Patent ID: 8174156

Claim:
A rotating electrical machine comprising: a rotor comprising a rotor core and a field winding wound round the rotor core; and a stator comprising a stator core and a stator winding wound round the stator core, the stator being arranged in opposition to the rotor with a predetermined spacing therebetween, and wherein the stator core is formed by punching a split piece, which comprises teeth for insertion of the stator winding thereinto and a core back on an outer periphery thereof, from a magnetic steel sheet, and laminating a plurality of those circular configurations in an axial direction, in which a plurality of the split pieces are arranged in a circle in a circumferential direction, a plurality of cooling ducts for flowing of a cooling medium in a diametrical direction are formed midway of the axial direction of the stator core; the rotating electrical machine further comprising an exhaust section, in which a cooling medium in the machine is caused to flow radially outwardly of the cooling ducts from radially inwardly thereof, and an intake section, in which a cooling medium in the machine is caused to flow radially inwardly of the cooling ducts from radially outwardly thereof in an opposite manner to the exhaust section, wherein magnetic steel sheets different in kind between the exhaust section positioned in the axial central region and exhaust and intake sections other than the exhaust section positioned in the axial central region are laminated in the stator core, and wherein the exhaust section positioned in the axial central region of the stator core is smaller in axial spacing between the cooling ducts than exhaust and intake sections other than the exhaust section positioned in the axial central region.