ROTOR ASSEMBLY, ELECTRIC BLOWER INCLUDING ROTOR ASSEMBLY, AND VACUUM CLEANER INCLUDING ROTOR ASSEMBLY

摘要

PROBLEM TO BE SOLVED: To provide a rotor assembly which suppresses the variation of magnetic flux density distribution, an electric blower and a vacuum cleaner which employ the rotor assembly and are easily dynamically balanced.SOLUTION: The rotor assembly comprises: a rotary shaft that is provided in a freely rotatable manner; a centrifugal impeller that is provided at one end of the rotary shaft; a rotor core that is provided at the other end of the rotary shaft; and at least one bearing part that is provided between the centrifugal impeller and the rotor core. The rotor core is characterized in that magnetization is performed during molding while filling a cavity of a metal die which is provided in such a manner that a line connecting a pair of gates becomes parallel to an orientation magnetic field forming a pair of magnetic poles with a mixture of magnetic powder and a resin via the pair of gates in the state where the orientation magnetic field is applied, or the magnetization is performed by applying the orientation magnetic field after molding by filling the cavity of the metal die with the mixture via the pair of gates, such that a weld is formed near a boundary of the magnetic poles.SELECTED DRAWING: Figure 2