PROBLEM TO BE SOLVED: To stabilize seedling picking operation and planting operation by a non-constant velocity transmission mechanism disposed in a planting transmission path, and meanwhile to effectively prevent or reduce a torque fluctuation caused by the non-constant velocity transmission mechanism.SOLUTION: A rice transplanter comprises a torque leveling mechanism including: a torque action shaft operably connected to a rotary shaft forming a planting transmission path in which a non-constant velocity transmission mechanism is interposed； and an elastic member operationally engaged with the torque action shaft. The torque action shaft has a shaft body operably connected to the rotary shaft and a crank part eccentrically deviated from the shaft body. The elastic member extends or contracts according to movement in which the crank part eccentrically rotates around the axis of the shaft body in accordance with the rotation of the shaft body around the axis, and thus, torque for leveling a torque fluctuation caused by the non-constant velocity transmission mechanism is applied to the torque action shaft.SELECTED DRAWING: Figure 3【課題】植付伝動経路に不等速伝動機構を備えることによる苗取り動作及び植付動作の安定化を図りつつ、不等速伝動機構に起因するトルク変動を有効に防止乃至は低減する。【解決手段】不等速伝動機構が介挿されてなる植付伝動経路を形成する回転軸に作動連結されたトルク作用軸と前記トルク作用軸に作動的に係合される弾性部材とを含むトルク平準化機構を備える。前記トルク作用軸は、前記回転軸に作動連結された軸本体と前記軸本体から偏心されたクランク部とを有し、前記弾性部材は、前記軸本体の軸線回りの回転に応じて前記クランク部が前記軸本体の軸線回りに偏心回転する動きに応じて伸縮して、前記不等速伝動機構に起因するトルク変動を平準化させるトルクを前記トルク作用軸に付加する。【選択図】図３
