FRICTIONAL DRIVE UNIT

To provide a frictional drive unit that can arrange drive rollers with high density and facilitate an attachment operation of the drive rollers, a frictional drive unit includes a pair of drive disks , a plurality of drive rollers rotatably supported by an outer circumferential portion of each drive disk, a pair of actuators configured to independently rotate the pair of drive disks, and an annular main wheel arranged between the pair of drive disks and coming into contact with the drive rollers. Each drive roller includes a roller shaft and a round roller body provided on an intermediate portion of the roller shaft. Each drive disk includes plural pairs of bearing grooves each receiving both ends of the roller shaft of each drive roller. Each bearing grooves open toward the main wheel.