BRUSHLESS FLAT-TYPE VIBRATION MOTOR

摘要

A brushless flat type vibration motor is provided to reduce a cost of parts and to minimize the number of processes by integrally arranging a cogging torque generation unit on an upper case. A lower case(52) has a circular rib on a center. A flexible printed circuit board(56) is mounted on the lower case(52) so that a driving IC(58) and a coil are installed. The driving IC(58) has a hole sensor which detects an electrode and an electrode position of a permanent magnet(88), and a driving driver. The coil(60) rotates the permanent magnet(88) by generating a rotation magnetic field. An upper case(54) is made of a magnetic material to generate a cogging torque. A plurality of incision units forms a non-magnetic part. A rib protruded toward a lower part is formed on a central part of the upper case(54). A bracket(72) of a non-magnetic material is coupled to an upper part of the upper case(54). A lower part of a shaft(62) is installed on a rib of the lower case(52). An upper part of the shaft(62) is installed on the rib of the upper case(54). A washer(64) is installed on the upper part of the rib. A bearing(66) is installed on the upper part of the washer(64). A slide sheet(68) for preventing thermal deformation and abrasion of the rib according to a high speed rotation of the bearing(66) is formed on the upper part of the bearing(66). The rib is formed on a central part of the bearing so that the bearing(66) is inserted into the rib. The permanent magnet(88) having a multi-polarity and a weight(78) are installed on an upper part of a rotator bracket(82). The weight(78) generates an eccentric force on an outer side of the permanent magnet(88).