Alternator

An alternator comprising:

• a case;
• a shaft rotatably provided in said case;
• a rotor secured to said shaft;
• a stator secured to said case and provided with a stator coil composed of a stator core around which a lead wire is wound;
• and
• a rectifier electrically collected to said stator coil and which rectifies an alternating current, which is generated in said stator coil, into direct current,
• wherein said rectifier comprises:
• a first circular strip-shaped heat sink which is orthogonalized with said shaft and has a plurality of first diodes secured thereto;
• and
• a second circular strip-shaped heat sink which is provided outside said first heat sink so that it is orthogonalized with said shaft, and has a plurality of second diodes secured thereto;
• at least one of said first diodes or said second diodes being composed of diodes on an inside diameter side and diodes on an outside diameter side that are arranged in a zigzag pattern in a circumferential direction,
• wherein one of said diodes on the inside diameter side and said diodes on the outside diameter side are disposed such that they are partly included in a region of an air detachment portion produced on a peripheral surface by cooling air that collides with the other of said diodes on the inside diameter side and said diodes on the outside diameter side.