Patent ID: 7011591

Claim:
A belt-drive system driven by an internal combustion engine mounted on an automotive vehicle, the belt-drive system comprising: a driving pulley connected to a crankshaft of the internal combustion engine; a plurality of driven pulleys connected to respective on-board devices; a belt wound around the driving pulley and the plurality of the driven pulleys so that all the driven pulleys are driven by the driving pulley, wherein: the plurality of the driven pulleys include a pulley of an automatic belt-tensioner that controls a belt tension and pulleys of a first generator and a second generator; the first generator is controlled to generate a generation torque that reduces fluctuations in the belt tension by controlling excitation current supplied to a field coil of the first generator; and the second generator is controlled to generate an amount of required electric power by controlling excitation current supplied to a field coil of the second generator.