CENTRIFUGAL FAN

PROBLEM TO BE SOLVED: To increase the amount of blowing air while heightening static pressure and to protect electronic components from heat by suppressing the calorific value of a motor. SOLUTION: This centrifugal fan 1 is provided with an impeller of long cylindrical shape with an outer diameter of 25 mm or less, the motor 3 for rotating the impeller 2; and a housing 4 enclosing the impeller 2. The motor 3 is a three-phase motor and rotates the impeller 2 at 10,000 rpm or around a center shaft 10. Since the motor 3 is the three-phase motor, the utilization efficiency of coils is high, and the calorific value of a stator 38 is reduced. Further, the motor 3 is driven to always carry a current to three coils, which also reduces the calorific value of the stator 38. As a result, the electronic component 391 is protected from heat in the small centrifugal fan 1 rotating at high speed, to prevent a failure and operating abnormality. COPYRIGHT: (C)2006,JPO&NCIPI