Patent ID: 8104557

Claim:
A linear drive travel system comprising: a metal wheel having a drum rotor and a stator arranged inside the metal wheel, wherein the metal wheel has a rotary shaft as an axis of rotation of the metal wheel, the stator has a plurality of rows of electromagnets arranged in the direction of the axis of rotation, each row being formed by a plurality of the electromagnets arranged around the circumference of the rotary shaft, a stator base having the electromagnets attached to an outer periphery thereof and a through hole for passing the rotary shaft therethrough, a plurality of bearings engaged in the through hole of the stator base and a plurality of bearings having an inner ring through which the rotary shaft passes, and a rotary sensor provided between two bearings of the plurality of bearings, the drum rotor has a plurality of arc-shaped rotor rotary cores arranged along the circumference of the rotary shaft, and a slit is provided between the rotor rotary cores.