Patent ID: 8729761
Filing Date: 2014-05-20
Classification: H02K

Abstract:
1. A motor with an axial air gap, comprising: a base having a shaft-coupling portion integrally extending therefrom and one or more coupling protrusions integrally extending therefrom; a rotor having a body coupled with a permanent magnet and a shaft, wherein the permanent magnet has inner and outer circumferential faces, the inner circumferential face of the permanent magnet is projected onto the base as an inner circle, the outer circumferential face of the permanent magnet is projected onto the base as an outer circle, and the shaft is rotatably coupled with the shaft-coupling portion of the base; and a coil unit mounted on the base and having a base plate and one or more coils formed on the base plate, with the one or more coupling protrusions of the base extending through the base plate, with each of the one or more coils winding around a respective one of the one or more coupling protrusions, and with the base plate extending outwards beyond the one or more coils in a radial direction of the shaft-coupling portion; wherein the permanent magnet and the coil unit face each other in an axial direction of the motor, at least one of the one or more coils has a periphery intersecting with the inner and outer circles of the projection of the permanent magnet, the permanent magnet has a first radial length between the inner circumferential face and the outer circumferential face thereof, at least one of the one or more coils has a second radial length, and the first radial length of the permanent magnet is 10% to 90% of the second radial length of the at least one of the one or more coils.