Patent ID: 7180213
Filing Date: 2007-02-20
Classification: H02K

Abstract:
1. A vibration motor, comprising: a stator assembly including a magnet and a substrate; a rotor assembly having an eccentric weight, a commutator, and a coil assembly electrically connected to the commutator; a shaft inserted through the rotor assembly and defining a rotational axis of the rotor assembly; and first and second brushes each having a fixed portion fixed to the substrate of the stator assembly and a contacting portion contacting the commutator to apply electric current to said commutator; wherein the contacting portions of the first and second bushes in a non-operational state of said motor are located at first and second distances, respectively, from a central point where the rotational axis of the rotor assembly meets the commutator, the first and second distances being different from each other, whereby, as said rotor assembly rotates without vibration, the contacting portions of the first and second brushes follow and contact the commutator along different tracks on said commutator.