| 摘要 |
A tubeaxial type electrical cooling fan is constructed with two or more fan struts that extend across the open back of the fan to a circular support ring that supports the shaft of the motor, which in turn supports the fan blades. In such a structure, bending or flexing can occur in the fan struts which generate and transmit structureborne noise. In addition, these types of motors have a higher than desirable external magnetic field and noise may be generated by the bearings in the motor or in the resonance of other structural numbers. A nickel-iron shield is provided that fits over the supporting hub and the radial fan struts. An intermediate sound damping adhesive layer between the struts and the shield provides both a magnetic flux shielding and vibration damping of the structureborne noise.
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