Patent ID: 7224078

Claim:
A vehicle electric rotating machine that is driven by an electric power of a battery to start an engine at the time of start-up of said engine, as well as that is driven by the engine to generate an AC power after said engine has been started, said vehicle electric rotating machine comprising: a power section in which there are provided plural sets of a pair of switching elements connected in series between positive and negative terminals of said battery, and diodes connected in parallel to said switching elements respectively, and in which a connection point of the switching elements connected in series is connected to a stator winding of said vehicle electric rotating machine; and a control circuit section that controls said power section so that an electric power of said battery is supplied to said vehicle electric rotating machine to drive a rotor by ON/OFF control of said switching elements at the time of start-up of said engine, and an AC power, which is generated at said vehicle electric rotating machine, is rectified to a DC power with said switching element and diode group to charge said battery in a normal engine speed region of said engine at the time of power generation; wherein with respect to flow of cooling air made by a centrifugal fan that is fixed to said rotor, there are separately located the control circuit section on the upstream side, and the power section on the downstream side; and the mentioned control circuit section is provided with a through hole so that the mentioned cooling air flows linearly through the mentioned power section.