JP2006192317A5 - - Google Patents

Claims (6)

A rotor case provided with a nonmagnetic eccentric weight and an axial gap type magnet having a plurality of magnetic poles, and an eccentric rotor provided with a bearing arranged in the center of the rotor case inside the axial direction gap type magnet When the shaft for supporting the eccentric rotor, a plurality of air-core armature coil for driving the eccentric rotor via the axial air gap, the stator base arranged a drive circuit member to a position not located in the air-core armature coils a stator consisting of, provided with a housing for storing them, flat type brushless vibration motor is magnetic balancing means having an outer diameter which is formed of a magnetic body that becomes the center of rotation concentric configured to the eccentric rotor. 2. The flat brushless vibration motor according to claim 1, wherein at least a part of the magnetic balance means is constituted by the rotor case. The rotor case has a flat portion that receives the magnetic field of the axial gap type magnet, and a flange portion concentric with the rotation center is projected radially outward to obtain a magnetic balance following the flat portion, The flat-type brushless vibration motor according to claim 1, wherein the eccentric weight is disposed on the flange portion by concavity and convexity. In order to obtain a magnetic balance, the eccentric rotor is configured such that each of the eccentric weight and the bearing is pressed by an auxiliary yoke plate configured so that the outer diameter is concentric with the center of rotation, and the housing faces the auxiliary yoke plate. The flat brushless vibration motor according to claim 1, wherein a bulging portion is formed in a ceiling portion of a case constituting a part. The lower part of the case constituting a part of the housing extends as a flange outward in the radial direction, and the flange part is joined to a bracket constituting the other part of the housing. The flat type brushless vibration motor described in the item . The flat brushless vibration motor according to claim 5 is arranged in the center of the speaker housing, and the flat brushless vibration motor is attached to the speaker housing using the flange, and the flat brushless vibration motor One end of a ring-shaped movable voice coil is arranged so as to face the outer circumference in the radial direction through a gap, and a vibration thin plate is arranged with the outer circumference arranged in the speaker housing, and the outer circumference of the movable coil is arranged through the gap An electro-acoustic transducer in which a base portion of a ring-shaped excitation magnet that is exposed is placed on the flange portion, and the flat brushless vibration motor functions as a magnetic path of the excitation magnet .