To convert complete round rotary motion into oscillating rotary motion by a small-sized spindle mechanism and to reduce cost of a device by incorporating a plurality of gears including planetary gears into a driving side and an output side, interposing an oscillating means and supporting a drive shaft and an output shaft at an eccentric position.

A fixed gear 3 is fixed to a fixed plate 4 and a rotary plate 2 is fixed to a driving rotary shaft 1 in which these fixed plate 4 and fixed gear 3 are freely rotatably passed through. By rotating the driving rotary shaft 1 from a driving source, a driving planetary gear 5 supported at an outer peripheral part of the rotary plate 2 is revolved, rotating the gear 5 by engagement with the fixed gear 3. At the same time, an output gear 8 engaged with an output planetary gear 6 is rotated and rotation of the output gear 8 is taken out via an output rotary shaft 9 by rotation of a shaft for planetary gear 7 to which the driving planetary gear 5 and the output planetary gear 6 are fixed. The output rotary shaft 9 is made to perform oscillating motion together with rotary motion because the output rotary shaft 9 is supported at an eccentric position together with the driving rotary shaft 1.