摘要 |
A driving wheel assembly including a driving wheel, a housing, a driving motor, a rotary member with rotation around a rotation shaft of the driving motor, where the rotary member includes a first unit and a second unit disposed at a position opposite to the driving wheel with respect to the rotation shaft of the driving motor, and a compression coil spring disposed between the housing and the second unit to apply pressure to the second unit, where a distance between a contact point where the compression coil spring and the second unit contact and the rotation shaft of the driving motor is shorter than a distance between a rotation shaft of the driving wheel and a rotation shaft of the driving motor. |