| 摘要 |
In an alternator, a pole core has a plurality of claw-pole pieces, and a cooling fan has a plurality of diagonal-flow-type blades and a plurality of centrifugal-flow-type blades. A combination of numbers of the claw-pole pieces and the diagonal-flow-type blades is determined to suppress an interference of wind noises caused by the claw-pole pieces and the diagonal-flow-type blades during operation, such that one of the numbers of the claw-pole pieces and the diagonal-flow-type blades is not divisible by the other and both numbers have no common divisor other than one. Further, a number of the centrifugal-flow-type blades is determined not to be divisible by the numbers of the diagonal-flow-type blades and the claw-pole pieces, and all the three numbers have no common divisor other than one.
|
