Engine-driven permanent magnetic type welding generator

An engine-driven permanent magnet type welding generator, which comprises:

• a stator including:
• a laminated armature core;
• and
• an armature winding wound around the armature core, a coil end of the armature winding from one side of the armature core being long enough to be cooled by ventilated cooling air;
• a rotor including:
• a field core fixed to an engine rotary shaft and supported by an engine in cantilever fashion so as to be located at a central position of the stator, a thickness of the field core being equivalent to that of the armature core, the field core being formed with a cross sectional area effective for field magnet flux in an outer circumferential portion thereof and with a plurality of axial fan-shaped air passages in an inner circumferential portion thereof;
• a plurality of magnet plates each formed into a substantially square shape and arranged in line on an outer circumferential surface of the field core, the number of the magnet plates being the same as a number of field poles of the field core;
• and
• a plurality of centrifugal fan blades arranged in the vicinity of an outer circumference of and on both side surfaces of the field core, for ventilating cooling air in radial direction of the stator;
• and
• an enclosure including:
• a housing fixed to the engine, the housing having a faucet portion for supporting the stator, and air outlet holes;
• and
• a top cover to be attached to the housing, the top cover having air inlet holes and being formed with a plurality of air passages for introducing cooling air from one side surface of the rotor remote from the engine through the air inlet holes and the fan-shaped air passages formed in the rotor core and the coil end of the armature winding in cooperation with the housing to the air outlet holes.