subject: Fan arrangement for a vehicular AC generator [print this page] Fan arrangement for a vehicular AC generatorFan arrangement for a vehicular AC generator
A vehicular AC generator comprising a magnetic pole core secured to a shaft and excited by an excitation coil, the magnetic pole core having opposite end faces, a stationary core surrounding the magnetic pole core and having mounted thereon a stationary coil, and a front and a rear bracket supporting the stationary core and rotatably supporting the shaft through bearings.
Accordingly, one object of the present brushless alternator is to provide a vehicular AC generator free from the above-discussed problems.
Another object of the present invention is to provide a vehicular AC generator in which an overall sound pressure level of the wind noise can be decreased.
Another object of the present invention is to provide a vehicular AC generator in which the sound pressure level of the frequency multiplied by the number of the fan blades and the frequency multiplied by the even number of the inlet openings can be decreased, thereby eliminating annoying noise characteristics.
Still another object of the present invention is to provide a fan arrangement for a brushless ac generator in which the sound pressure level of the frequency of the order of the multiple of the number of the magnetic pole pieces therewithin is decreased.
With the above objects in view, the vehicular AC generators according to the present invention comprises a magnetic pole core secured to a shaft and excited by an excitation coil, a stationary core surrounding said magnetic pole core and having mounted thereon a stationary coil.
The fan arrangement of another aspect of the present AC generator is characterized in that the blade configuration includes a straight blade and a curved blade, that the blades are arranged at different circumferential intervals, and that the inner end of all the blades are disposed at the same distance from the center of rotation.
In this arrangement, the frequencies of wind noise generated by the rotation of the fan is dispersed, and the sound pressure level of various frequencies is supressed so that the overall level can be advantageously reduced.
