To mount a roller even in a narrow space, to lighten and miniaturize an entire moving device of a heavy product, and facilitate handling.

A ball bearing 60 of a wave generator 58 is disposed inside the opening end of a thin cup like flexible spline 62 having flexibility having a plurality of teeth in its outer periphery, the tooth part of the outer periphery is deformed into an elliptical shape, tooth parts near both ends of the major axis side of the flexible spline 62 are fitted to a tooth part in the inner periphery of a circular spline 64 having slightly more teeth than that of the flexible spline 62, and a harmonic drive type speed reduction mechanism 33 is constituted. Rotation of the wave generator 58 rotated by a driving source 21 via a first shaft 46A rotates a drive roller 31 with a driving force outputted as a reduction rotation from the circular spline 64.