US Patent 9273947 Sensing magnet apparatus for motor

Disclosed is a sensing magnet apparatus for an motor, the apparatus including a disk-shaped plate centrally inserted by a rotation shaft, a ring-shaped sensing magnet so installed as to surface-contact an upper surface of the plate, formed at a position near to a periphery with a main magnet, and formed at a position near to a through hole with a sub magnet, and a separation inhibition unit physically coupling the plate and the sensing magnet to maintain the coupled state between the plate and the sensing magnet.